Construction machinery

Abstract

To fix a weight between left and right crawler frames with a simple operation, while achieving easy movement of workers between left and right crawler units and reduction of the bending moment in left and right directions generated in the left and right crawler frames when a lower traveling body turns.SOLUTION: A right crawler frame front 27a has: a right front mount 30 on which a right end of a front weight 13 can be mounted, which supports the right end of the front weight 13 mounted on the right front mount 30 from below; and a right front restraint section 33 that restrains the movement of the right end of the front weight 13 mounted on the right front mount 30 in a front-rear direction and to the right. A left crawler frame front 19a has: a left front mount 43 on which a left end of the front weight 13 can be mounted, which supports the left end of the front weight 13 mounted on the left front mount 43 from below; and a left front restraint section 44 that restrains the movement of the left end of the front weight 13 mounted on the left front mount 43 in a front-rear direction and to the left.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to construction machinery.

Background Art

[0002] Conventionally, crawler-type construction machines such as crawler cranes and hydraulic excavators are known. The crawler-type construction machine includes a self-propelled crawler-type lower traveling body and an upper revolving body rotatably mounted on the lower traveling body. The crawler-type lower traveling body has a carbody that supports the upper revolving body from below so that the upper revolving body can rotate, and a pair of left and right crawler units that are arranged separately on both the left and right sides of the carbody and are responsible for the traveling of the lower traveling body.

[0003] The pair of left and right crawler units each have a crawler frame connected to the carbody and extending in the front and rear of the carbody. That is, the lower traveling body has a pair of left and right crawler frames that are arranged separately on both the left and right sides of the carbody and are respectively connected to the carbody. In the crawler-type construction machine, in order to improve the stability of the machine body, the lower traveling body has a traveling body weight disposed between the pair of left and right crawler frames. Conventionally, the left end portion of this traveling body weight is disposed close to the left crawler unit, and the right end portion of the traveling body weight is disposed close to the left crawler unit, so that when an operator or the like moves between the left and right crawler units, they can move across the traveling body weight without getting off the ground once, facilitating the movement of the operator or the like between the left and right crawler units.

[0004] Also, when the lower traveling body turns left and right, a bending moment in the left - right direction is generated in the left and right crawler frames. To counter this bending moment by the crawler frame itself, it is necessary to make the rigidity of the crawler frame extremely large. However, by utilizing the traveling body weight, the bending moment in the left - right direction can be reduced, and it is possible to counter the bending moment in the left - right direction generated in the crawler frame during the turning of the lower traveling body without significantly increasing the rigidity of the crawler frame. A technique capable of this is disclosed in Patent Document 1 below.

[0005] Patent Document 1 below discloses a crawler crane in which the lower traveling body has a front car body weight and a rear car body weight as the traveling body weight. The front car body weight is disposed in front of the car body of the lower traveling body between the left and right crawler frames, and the rear car body weight is disposed behind the car body of the lower traveling body between the left and right crawler frames.

[0006] And the front parts of the left and right crawler frames located in front of the front end of the car body are connected to the front car body weight via the left and right front lattice parts at a position in front of the connection point of the crawler frame to the car body. The rear parts of the left and right crawler frames located behind the rear end of the car body are connected to the rear car body weight via the left and right rear lattice parts at a position behind the connection point of the crawler frame to the car body. As a result, the arm lengths of the bending moments in the left-right direction of the front parts of the left and right crawler frames are the lengths from the front ends of those crawler frames to the connection points to the left and right front lattice parts, and the arm lengths of the bending moments in the left-right direction of the rear parts of the left and right crawler frames are the lengths from the rear ends of those crawler frames to the connection points to the left and right rear lattice parts. Therefore, compared with the case where the front parts of the left and right crawler frames are not connected via the front car body weight and the rear parts of the left and right crawler frames are not connected via the rear car body weight, the arm lengths of the bending moments in the left-right direction can be reduced. As a result, the bending moments in the left-right direction generated in the left and right crawler frames during the left-right turn of the lower traveling body can be reduced, and it becomes possible to counter the bending moments in the left-right direction without significantly increasing the rigidity of the crawler frames.

[0007] The connection between the front car body weight and the left and right front lattice parts, and the connection between the rear car body weight and the left and right rear lattice parts are each made by pin connection. Specifically, a through hole penetrating in the front-rear direction is formed in the connection part provided at one end in the left-right direction of each lattice part, and a through hole penetrating in the front-rear direction is also formed in the connection part of the car body weight connected to the connection part of the lattice part. The connection pin is inserted into the through hole of the connection part of the lattice part and the through hole of the connection part of the car body weight, whereby each lattice part and the corresponding car body weight are connected.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] By the way, since the counterweight is large and has a large weight, it has been required to be able to fix the counterweight between the left and right crawler frames with a simpler operation than before. For example, in the configuration of Patent Document 1, when fixing the counterweight between the left and right crawler frames, it is necessary to align the through holes of the coupling part of the lattice part and the through holes of the coupling part of the counterweight while suspending the counterweight with an auxiliary crane or the like, and insert the connecting pins into these through holes.

[0010] An object of the present invention is to provide a construction machine that can fix the weight of the lower traveling body between the left and right crawler frames with a simpler operation while facilitating the movement of workers and the like between the left and right crawler units and reducing the bending moment in the left-right direction generated in the left and right crawler frames when the lower traveling body turns.

Means for Solving the Problems

[0011] The construction machine provided by the present invention includes a self - propelled crawler - type lower traveling body and an upper revolving body rotatably mounted on the lower traveling body. The lower traveling body includes a car body that supports the upper revolving body from below so that the upper revolving body can rotate, a left crawler unit and a right crawler unit that are arranged separately on the left and right sides of the car body and are responsible for the traveling of the car body, and a front weight and a rear weight that are arranged separately in the front and rear of the car body. The right crawler unit has a right crawler frame connected to the right end of the car body and extending in the front - rear direction. The left crawler unit has a left crawler frame connected to the left end of the car body and extending in the front - rear direction. The right crawler frame has a front part of the right crawler frame that protrudes forward of the front end of the car body and a rear part of the right crawler frame that protrudes rearward of the rear end of the car body. The left crawler frame has a front part of the left crawler frame that protrudes forward of the front end of the car body and a rear part of the left crawler frame that protrudes rearward of the rear end of the car body. The front part of the right crawler frame is a right front pedestal on which the right end of the front weight can be placed, and the right front pedestal supports the right end from below in a state where the right end of the front weight is placed thereon, and a right front restraint portion that restrains the movement of the right end of the front weight placed on the right front pedestal in the front - rear direction and to the right. The front part of the left crawler frame is a left front pedestal on which the left end of the front weight can be placed, and the left front pedestal supports the left end from below in a state where the left end of the front weight is placed thereon, and a left front restraint portion that restrains the movement of the left end of the front weight placed on the left front pedestal in the front - rear direction and to the left. The rear part of the right crawler frame is a right rear pedestal on which the right end of the rear weight can be placed, and the right rear pedestal supports the right end from below in a state where the right end of the rear weight is placed thereon, and a right rear restraint portion that restrains the movement of the right end of the rear weight placed on the right rear pedestal in the front - rear direction and to the right.The rear part of the left crawler frame is a left rear pedestal on which the left end of the rear weight can be placed, and which supports the left end of the rear weight from below in a state where the left end of the rear weight is placed thereon, and a left rear restraint portion that restrains the movement of the left end of the rear weight placed on the left rear pedestal in the front-rear direction and to the left. The right front pedestal and the left front pedestal are spaced apart in the left-right direction, the front weight connects the right front pedestal and the left front pedestal, the right rear pedestal and the left rear pedestal are spaced apart in the left-right direction, and the... Rear side weight connects the right Rear pedestal and the left Rear pedestal.

[0012] In this construction machine, by utilizing the large weight of the weights and combining the placement of the weights on the pedestals with the restraint of the weights in the horizontal direction by the restraint portions, the front and rear weights can be fixed between the left and right crawler frames. Therefore, the weights can be fixed between the left and right crawler frames with a simple operation. Specifically, by placing the front weights on the left and right front pedestals and placing the rear weights on the left and right rear pedestals, the large weights of the front and rear weights can be utilized to restrain the up-and-down movement of these weights. And the movement of the front and rear weights in the front-rear direction and the left-right direction, which are directions other than the up-and-down direction, can be achieved by the restraint of the front weights by the right front restraint portion and the left front restraint portion and the restraint of the rear weights by the right rear restraint portion and the left rear restraint portion. Therefore, the front and rear weights can be fixed between the left and right crawler frames with a very simple operation of placing the front weights on the left and right front pedestals and restraining the front weights with the left and right front restraint portions, and placing the rear weights on the left and right rear pedestals and restraining the rear weights with the left and right rear restraint portions.

[0013] In addition, in this construction machine, the front weight and the rear weight fixed between the left and right crawler frames can be used as a scaffold to facilitate the movement of workers and the like between the left and right crawler units. Moreover, the front weight and the rear weight fixed between the left and right crawler frames can counteract the bending moment in the left-right direction generated in the left and right crawler frames during the turning of the lower traveling body, thereby reducing the bending moment in the left-right direction.

[0014] Therefore, in this construction machine, while achieving the facilitation of the movement of workers and the like between the left and right crawler units and the reduction of the bending moment in the left-right direction generated in the left and right crawler frames during the turning of the lower traveling body, the front and rear weights can be fixed between the left and right crawler frames with a simpler operation.

[0015] At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a constrained end portion having a recess opening downward. At least one of the right front restraint portion, the left front restraint portion, the right rear restraint portion, and the left rear restraint portion is a crawler frame restraint portion that restrains the movement of the constrained end portion. The crawler frame restraint portion may be a convex portion that fits into the recess so as to restrain the movement of the constrained end portion in the front-rear direction and outward in the left-right direction.

[0016] According to this configuration, when the constrained end portion is placed on the corresponding one of the right front gantry, the left front gantry, the right rear gantry, and the left rear gantry, the convex portion of the crawler frame restraint portion can be fitted into the recess of the constrained end portion from below to restrain the movement of the constrained end portion in the front-rear direction and outward in the left-right direction. Therefore, the work involved in restraining the constrained end portion can be simplified.

[0017] The crawler frame restraint portion may have an upper surface that is a surface facing upward, and the upper surface may have a front inclined portion that inclines downward as it goes forward from a predetermined position in the front-rear direction of the upper surface, and a rear inclined portion that inclines downward as it goes backward from the predetermined position.

[0018] According to this configuration, even when the recess of the constrained end portion is displaced in the front-rear direction with respect to the crawler frame constraint portion and the front edge or the rear edge of the recess abuts against the upper surface of the crawler frame constraint portion when the constrained end portion is placed on the corresponding one of the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal, the inclination of the front inclined portion and the rear inclined portion of the upper surface of the crawler frame constraint portion can guide the constrained end portion to a position where the recess fits with the crawler frame constraint portion, and the fitting between the recess of the constrained end portion and the crawler frame constraint portion can be performed without any trouble.

[0019] Further, the crawler frame constraint portion may have an upper surface which is a surface facing upward, and the upper surface may have an inner inclined portion which inclines downward as it goes inward in the left-right direction.

[0020] According to this configuration, even when the recess of the constrained end portion is displaced outward in the left-right direction with respect to the crawler frame constraint portion and the inner edge in the left-right direction of the recess abuts against the inner inclined portion of the upper surface of the crawler frame constraint portion when the constrained end portion is placed on the corresponding one of the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal, the inclination of the inner inclined portion can guide the constrained end portion to a position where the recess fits with the crawler frame constraint portion, and the fitting between the recess of the constrained end portion and the crawler frame constraint portion can be performed without any trouble.

[0021] Further, in the configuration in which the upper surface has the front inclined portion and the rear inclined portion, the upper surface may further have an inner inclined portion which is located inward in the left-right direction with respect to the front inclined portion and the rear inclined portion and inclines downward as it goes inward in the left-right direction.

[0022] According to this configuration, when placing the constrained end portion on the corresponding one of the right front pedestal, left front pedestal, right rear pedestal, and left rear pedestal, even if the recess of the constrained end portion is displaced in the front-rear direction with respect to the crawler frame restraint portion, or even if the recess of the constrained end portion is displaced outward in the left-right direction with respect to the crawler frame restraint portion, the inclination of each of the front inclined portion, the rear inclined portion, and the inner inclined portion can guide the constrained end portion to a position where the recess fits with the crawler frame restraint portion, and the fitting between the recess of the constrained end portion and the crawler frame restraint portion can be performed without any trouble.

[0023] At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a constrained end portion having a weight through hole penetrating the end portion vertically. At least one of the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal is a crawler frame pedestal on which the constrained end portion is placed. The crawler frame pedestal has a pedestal through hole penetrating the crawler frame pedestal vertically. At least one of the right front restraint portion, the left front restraint portion, the right rear restraint portion, and the left rear restraint portion is a crawler frame restraint portion that restrains the movement of the constrained end portion. The crawler frame restraint portion is inserted into the pedestal through hole and fixed to the crawler frame pedestal, and is inserted into the weight through Hole It may be a restraint pin that is inserted into the hole to restrain the movement of the constrained end portion in the front-rear direction and the left-right direction.

[0024] In this configuration, the movement of the constrained end portion in the front-rear direction and the movement of the constrained end portion to both the left and right sides can be restrained by the restraint pin, so that the movement of the constrained end portion can be restrained more stably.

[0025] At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a weight body end portion placed on a crawler frame pedestal which is a corresponding pedestal among the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal, and a weight end protrusion protruding downward from the weight body end portion, and is a constrained end portion having the same, and at least one of the right front constraint portion, the left front constraint portion, the right rear constraint portion, and the left rear constraint portion is a crawler frame constraint portion that constrains the movement of the constrained end portion, and the crawler frame constraint portion is provided with an insertion hole into which the weight end protrusion can be inserted from above simultaneously with the placement of the weight body end portion on the crawler frame pedestal, and may have a protrusion coupling portion that couples with the weight end protrusion so as to constrain the movement of the weight end protrusion inserted into the insertion hole in the front-rear direction and the left-right direction.

[0026] According to this configuration, when the weight body end portion is placed on the crawler frame pedestal, the weight end protrusion can be inserted into the insertion hole of the protrusion coupling portion at the same time, and the movement of the weight end protrusion in the front-rear direction and the left-right direction can be constrained, whereby the movement of the constrained end portion in the front-rear direction and the left-right direction can be constrained. For this reason, the work related to the constraint of the constrained end portion can be simplified.

[0027] Preferably, the weight end protrusion has a tapered portion that becomes smaller in diameter toward the tip in the protruding direction of the weight end protrusion from the weight body end portion.

[0028] According to this configuration, even if the weight end protrusion is slightly displaced in the front-rear direction and / or the left-right direction with respect to the insertion hole of the protrusion coupling portion when the weight body end portion is placed on the crawler frame pedestal, since the weight end protrusion has the tapered portion, the weight end protrusion can be inserted into the insertion hole.

[0029] The lower traveling body further includes a front upper weight configured to be loadable on the front weight and a rear upper weight configured to be loadable on the rear weight. The front weight has a front weight right restraint portion that restrains the movement of the right end portion of the front upper weight placed on the front weight in the front-rear direction and to the right, and a front weight left restraint portion that restrains the movement of the left end portion of the front upper weight placed on the front weight in the front-rear direction and to the left. The rear weight may have a rear weight right restraint portion that restrains the movement of the right end portion of the rear upper weight placed on the rear weight in the front-rear direction and to the right, and a rear weight left restraint portion that restrains the movement of the left end portion of the rear upper weight placed on the rear weight in the front-rear direction and to the left.

[0030] According to this configuration, it is possible to adjust the weights of the weights loaded on the left front pedestal and the right front pedestal, and the weights of the weights loaded on the left rear pedestal and the right rear pedestal. Also, even when using a transport vehicle with a relatively low loading capacity when disassembling and transporting the construction machine, it is possible to transport the front weight, the front upper weight, the rear weight, and the rear upper weight. Moreover, the lifting operations of these weights for loading the front weight and the front upper weight on the left front pedestal and the right front pedestal, and the lifting operations of these weights for loading the rear weight and the rear upper weight on the left rear pedestal and the right rear pedestal can be facilitated. Additionally, it is possible to perform these lifting operations with an auxiliary crane having a relatively low lifting capacity. Furthermore, the effect that the fixing of the front upper weight to the front weight and the fixing of the rear upper weight to the rear weight can be performed with simple operations is obtained.

[0031] Specifically, in this configuration, since it is possible to select whether or not to load the front upper weight on top of the front weights loaded on the left front mount and the right front mount, the weight of the weights loaded on the left front mount and the right front mount can be adjusted according to whether or not the front upper weight is loaded on the front weights. Similarly, since it is possible to select whether or not to load the rear upper weight on top of the rear weights loaded on the left rear mount and the right rear mount, the weight of the weights loaded on the left rear mount and the right rear mount can be adjusted according to whether or not the rear upper weight is loaded on the rear weights. Further, in this configuration, when disassembling and transporting the construction machine, the front weight and the front upper weight can be separated and transported separately, and the rear weight and the rear upper weight can be separated and transported separately. The weight of each of the front weight and the front upper weight is smaller than the total weight of the front weight and the front upper weight stacked on each other, and the weight of each of the rear weight and the rear upper weight is smaller than the total weight of the rear weight and the rear upper weight stacked on each other. For this reason, in this configuration, even a transport vehicle with a relatively low loading capacity can transport each of the front weight, the front upper weight, the rear weight, and the rear upper weight. Also, in this configuration, the front weight and the front upper weight can be individually lifted and stacked on the left front mount and the right front mount, and the rear weight and the rear upper weight can be individually lifted and stacked on the left rear mount and the right rear mount. As described above, since the weight of each of the front weight and the front upper weight is smaller than the total weight of the front weight and the front upper weight, and the weight of each of the rear weight and the rear upper weight is smaller than the total weight of the rear weight and the rear upper weight, in this configuration, the individual lifting operations of the front weight and the front upper weight for stacking them on the left front mount and the right front mount, and the individual lifting operations of the rear weight and the rear upper weight for stacking them on the left rear mount and the right rear mount are facilitated, and even an auxiliary crane with a relatively low lifting capacity can perform those lifting operations.In addition, in this configuration, by utilizing the weight of the front upper weight, the front upper weight can be fixed to the front weight by combining the placement of the front upper weight on the front weight and the restraint of the front upper weight in the horizontal direction by the right restraint portion and the left restraint portion of the front weight. Therefore, the front upper weight can be fixed to the front weight with a simple operation. Similarly, by utilizing the weight of the rear upper weight, the rear upper weight can be fixed to the rear weight by combining the placement of the rear upper weight on the rear weight and the restraint of the rear upper weight in the horizontal direction by the right restraint portion and the left restraint portion of the rear weight. Therefore, the rear upper weight can be fixed to the rear weight with a simple operation.

[0032] At least one of the right end portion of the front upper weight, the left end portion of the front upper weight, the right end portion of the rear upper weight, and the left end portion of the rear upper weight is an upper weight constrained end portion having an upper weight recess that opens downward, and at least one of the front weight right restraint portion, the front weight left restraint portion, the rear weight right restraint portion, and the rear weight left restraint portion is a weight restraint portion that restrains the movement of the upper weight constrained end portion. The weight restraint portion may be a convex portion that fits into the upper weight recess so as to restrain the movement of the upper weight constrained end portion in the front-rear direction and outward in the left-right direction.

[0033] According to this configuration, when the upper weight constrained end portion is placed on the corresponding one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight, the convex portion of the weight restraint portion can be fitted into the upper weight recess from below to restrain the movement of the upper weight constrained end portion in the front-rear direction and outward in the left-right direction. Therefore, the work involved in restraining the upper weight constrained end portion can be simplified.

[0034] The weight restraint portion has an upper surface of the weight restraint portion that faces upward. The upper surface of the weight restraint portion may have a front inclined portion of the weight restraint portion that inclines downward as it goes forward from a predetermined position in the front-rear direction of the upper surface of the weight restraint portion, and a rear inclined portion of the weight restraint portion that inclines downward as it goes rearward from the predetermined position.

[0035] According to this configuration, when placing the upper weight constrained end portion on the corresponding one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight, if the upper weight recess is displaced forward with respect to the weight restraint portion and the rear edge of the upper weight recess abuts against the rear inclined portion of the upper surface of the weight restraint portion, the inclined rear inclined portion of the weight restraint portion can guide the upper weight constrained end portion to a position where the upper weight recess fits into the weight restraint portion. Also, if the upper weight recess is displaced rearward with respect to the weight restraint portion and the front edge of the upper weight recess abuts against the front inclined portion of the upper surface of the weight restraint portion, the inclined front inclined portion of the weight restraint portion can guide the upper weight constrained end portion to a position where the upper weight recess fits into the weight restraint portion. Therefore, even when the upper weight recess is displaced in the front-rear direction with respect to the weight restraint portion when placing the upper weight constrained end portion on the corresponding one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight, the fitting between the upper weight recess and the weight restraint portion can be performed without hindrance.

[0036] The weight restraint portion has an upper surface of the weight restraint portion that faces upward. The upper surface of the weight restraint portion may have an inner inclined portion of the weight restraint portion that inclines downward as it goes inward in the left-right direction.

[0037] According to this configuration, when placing the upper weight constrained end portion on the corresponding one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight, even if the upper weight recess is displaced outward in the left-right direction with respect to the weight restraint portion and the inner edge in the left-right direction of the upper weight recess abuts against the inner slope portion of the weight restraint portion on the upper surface of the weight restraint portion, the inclination of the inner slope portion of the weight restraint portion can guide the upper weight constrained end portion to the position where the upper weight recess fits into the weight restraint portion, and the fitting between the upper weight recess and the weight restraint portion can be performed without hindrance.

[0038] Further, in a configuration in which the upper surface of the weight restraint portion has the front slope portion of the weight restraint portion and the rear slope portion of the weight restraint portion, the upper surface of the weight restraint portion may further have an inner slope portion of the weight restraint portion that is located inward in the left-right direction with respect to the front slope portion of the weight restraint portion and the rear slope portion of the weight restraint portion and slopes downward as it goes inward in the left-right direction.

[0039] According to this configuration, when placing the upper weight constrained end portion on the corresponding one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight, even if the upper weight recess is displaced outward in the left-right direction with respect to the weight restraint portion and the inner edge in the left-right direction of the upper weight recess abuts against the inner slope portion of the weight restraint portion on the upper surface of the weight restraint portion, the inclination of the inner slope portion of the weight restraint portion can guide the upper weight constrained end portion to the position where the upper weight recess fits into the weight restraint portion, and the fitting between the upper weight recess and the weight restraint portion can be performed without hindrance.

Effect of the Invention

[0040] According to the present invention, there is provided a construction machine capable of facilitating the movement of an operator or the like between the left and right crawler units and reducing the bending moment in the left-right direction generated in the left and right crawler frames when the lower traveling body turns, while fixing the weight of the lower traveling body between the left and right crawler frames with a simpler operation.

Brief Description of the Drawings

[0041]

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Embodiments for Carrying Out the Invention

[0042] Hereinafter, with reference to FIGS. 1 to 6, the configuration of the crane 1 as a construction machine according to an embodiment of the present invention will be described.

[0043] The crane 1 according to the present embodiment is a so-called crawler crane. As shown in FIG. 1, this crane 1 includes an upper slewing body 2, a lower traveling body 3, a boom 6, and a lifting tackle 7.

[0044] The upper revolving body 2 is mounted on the lower traveling body 3 so as to be rotatable about a vertical axis extending in the vertical direction.

[0045] The lower traveling body 3 is of a crawler type and is configured to be self-propelled on the ground.

[0046] The boom 6 has a base end portion rotatably attached to the upper revolving body 2 about an axis extending in the left-right direction of the upper revolving body 2, and is provided on the upper revolving body 2 so as to be able to rise and fall with the base end portion as a fulcrum. The boom 6 extends from the upper revolving body 2 at an arbitrary elevation angle, and a spreader 7 is suspended from the tip end portion thereof so as to be able to move up and down. A suspended load is suspended from this spreader 7, and in this state, lifting work is performed by the elevation of the boom 6 and the up and down movement of the spreader 7.

[0047] Next, the lower traveling body 3 of the crane 1 according to the present embodiment will be described in more detail.

[0048] As shown in FIG. 2, the lower traveling body 3 includes a car body 10, a left crawler unit 11, a right crawler unit 12, a front counterweight 13, and a rear counterweight 14. Here, the "front side" with respect to the lower traveling body 3 means one side in the traveling direction of the lower traveling body 3 and is the forward side set in advance for the lower traveling body 3, and the "rear side" with respect to the lower traveling body 3 means the opposite side to the front side. Also, the "left side" with respect to the lower traveling body 3 means the left side when the lower traveling body 3 is viewed from the rear side toward the front side, and the "right side" with respect to the lower traveling body 3 means the right side when the lower traveling body 3 is viewed from the rear side toward the front side.

[0049] The car body 10 is located at the center of the lower traveling body 3 and supports the upper revolving body 2 from below so that the upper revolving body 2 (see FIG. 1) can rotate about the vertical axis. The car body 10 includes a car body main body 40, a pair of left attachment portions 41, and a pair of right attachment portions 42.

[0050] The car body main body 40 occupies most of the car body 10 and is the part that supports the upper slewing body 2 from below. The car body main body 40 has a substantially rectangular parallelepiped shape.

[0051] A pair of left attachment parts 41 are parts where a left crawler frame 16 (to be described later) of the left crawler unit 11 is attached. The pair of left attachment parts 41 are divided and arranged at the front end and the rear end of the left end of the car body main body 40, and protrude leftward from the left end of the car body main body 40.

[0052] A pair of right attachment parts 42 are parts where a right crawler frame 24 (to be described later) of the right crawler unit 12 is attached. The pair of right attachment parts 42 are divided and arranged at the front end and the rear end of the right end of the car body main body 40, and protrude rightward from the right end of the car body main body 40.

[0053] The left crawler unit 11 and the right crawler unit 12 are traveling devices responsible for the traveling of the lower traveling body 3. The left crawler unit 11 and the right crawler unit 12 are divided and arranged on the left and right of the car body 10 and are respectively attached to the car body 10.

[0054] Specifically, the left crawler unit 11 includes a left crawler frame 16, a left crawler 17, and a left crawler driving device (not shown in the figure).

[0055] The left crawler frame 16 is a frame that supports the left crawler 17 via a driving wheel, a driven wheel, etc. (not shown in the figure) attached to the left crawler frame 16. The left crawler 17 surrounds the left crawler frame 16 and is driven by the left crawler driving device to rotate circularly to generate a propulsive force for the traveling of the lower traveling body 3. The left crawler frame 16 includes a left crawler frame main body 19, a left front connecting part 20, and a left rear connecting part 21.

[0056] The left crawler frame body 19 is a part that supports the left crawler 17 via the above-described drive wheels, driven wheels, etc., and is detachably connected to a pair of left attachment parts 41 of the car body 10 and extends in the front-rear direction. The left crawler frame body 19 is pin-connected to each of the pair of left attachment parts 41 by a connection pin (not shown).

[0057] The left crawler frame 16 has a left crawler frame front part 19a that protrudes forward of the front end of the car body 10 and a left crawler frame rear part 19b that protrudes rearward of the rear end of the car body 10. The left crawler frame front part 19a is composed of a part of the left crawler frame body 19 that is located in front of the front end of the car body 10 and the left front connection part 20. Further, the left crawler frame rear part 19b is composed of a part of the left crawler frame body 19 that is located behind the rear end of the car body 10 and the left rear connection part 21.

[0058] The left front connection part 20 is a part that is coupled to the left end of the front weight 13. Also, the left rear connection part 21 is a part that is coupled to the left end of the rear weight 14.

[0059] The left front connection part 20 includes a left front pedestal 43 on which the left end of the front weight 13 can be placed and that supports the left end of the front weight 13 from below in a state where the left end of the front weight 13 is placed thereon, and a left front restraint part 44 that restrains the movement of the left end of the front weight 13 placed on the left front pedestal 43 in the front-rear direction and to the left.

[0060] The left rear connection part 21 includes a left rear pedestal 47 on which the left end of the rear weight 14 can be placed and that supports the left end of the rear weight 14 from below in a state where the left end of the rear weight 14 is placed thereon, and a left rear restraint part 48 that restrains the movement of the left end of the rear weight 14 placed on the left rear pedestal 47 in the front-rear direction and to the left.

[0061] The right crawler unit 12 has a right crawler frame 24, a right crawler 25, and a right crawler drive device (not shown).

[0062] The right crawler frame 24 is a frame that supports the right crawler 25 via a driving wheel, a driven wheel, etc. (not shown) attached to the right crawler frame 24. The right crawler 25 surrounds the right crawler frame 24 and is driven by a right crawler drive device to perform a circular movement, thereby generating a propulsive force for the running of the lower traveling body 3. The right crawler frame 24 includes a right crawler frame main body 27, a right front connecting portion 28, and a right rear connecting portion 29.

[0063] The right crawler frame main body 27 is a portion that supports the right crawler 25 via the driving wheel, the driven wheel, etc., and is detachably connected to a pair of right attachment portions 42 of the car body 10 and extends in the front-rear direction. The right crawler frame main body 27 is pin-connected to each of the pair of right attachment portions 42 by a connecting pin (not shown).

[0064] The right crawler frame 24 has a right crawler frame front portion 27a that protrudes forward of the front end of the car body 10 and a right crawler frame rear portion 27b that protrudes rearward of the rear end of the car body 10. The right crawler frame front portion 27a is composed of a portion of the right crawler frame main body 27 that is located forward of the front end of the car body 10 and the right front connecting portion 28. Further, the right crawler frame rear portion 27b is composed of a portion of the right crawler frame main body 27 that is located rearward of the rear end of the car body 10 and the right rear connecting portion 29.

[0065] The right front connecting portion 28 is a portion that is coupled to the right end portion of the front weight 13. Also, the right rear connecting portion 29 is a portion that is coupled to the right end portion of the rear weight 14.

[0066] The right front connecting portion 28 includes a right front pedestal 30 on which the right end portion of the front weight 13 can be placed and that supports the right end portion from below in a state where the right end portion of the front weight 13 is placed thereon, and a right front restraint portion 33 that restrains the movement of the right end portion of the front weight 13 placed on the right front pedestal 30 in the front-rear direction and to the right.

[0067] The right rear connecting portion 29 includes a right rear pedestal 45 on which the right end portion of the rear weight 14 can be placed, and which supports the right end portion of the rear weight 14 from below in a state where the right end portion of the rear weight 14 is placed thereon, and a right rear restraining portion 46 that restrains the movement of the right end portion of the rear weight 14 placed on the right rear pedestal 45 in the front-rear direction and to the right.

[0068] The front weight 13 and the rear weight 14 are weights for improving the stability of the crane 1. The front weight 13 and the rear weight 14 are divided and arranged before and after the car body 10 between the left crawler frame body 19 and the right crawler frame body 27. The left end portion of the front weight 13 is fixed by the left front connecting portion 20, and the right end portion of the front weight 13 is fixed by the right front connecting portion 28. Also, the left end portion of the rear weight 14 is fixed by the left rear connecting portion 21, and the right end portion of the rear weight 14 is fixed by the right rear connecting portion 29.

[0069] The front weight 13 and the rear weight 14 have the same structure and are arranged in opposite front-rear directions with respect to each other. Also, the mounting structure of the left end portion of the front weight 13 with respect to the left front connecting portion 20, the mounting structure of the right end portion of the front weight 13 with respect to the right front connecting portion 28, the mounting structure of the left end portion of the rear weight 14 with respect to the left rear connecting portion 21, and the mounting structure of the right end portion of the rear weight 14 with respect to the right rear connecting portion 29 are the same, and the mounting structure of the left end portion of the front weight 13 with respect to the left front connecting portion 20 and the mounting structure of the right end portion of the front weight 13 with respect to the right front connecting portion 28 are symmetric with respect to the left and right, and the mounting structure of the left end portion of the rear weight 14 with respect to the left rear connecting portion 21 and the mounting structure of the right end portion of the rear weight 14 with respect to the right rear connecting portion 29 are symmetric with respect to the left and right. For this reason, hereinafter, the detailed description will be given by taking, as an example, the mounting structure of the right end portion of the front weight 13 with respect to the right front connecting portion 28 among these mounting structures.

[0070] The right end portion of the front weight 13 has a recess 50 that opens downward on its lower surface and opens rightward on its right side surface. The front weight 13 has a front weight main body 13a that occupies most of the front weight 13, and a right end plate 13b that covers and is fixed to the right end surface of the front weight main body 13a. The right end portion of the front weight 13 is composed of the right end portion of the front weight main body 13a and the right end plate 13b. A rectangular parallelepiped-shaped depression 50a that opens downward on its lower surface and opens rightward on its right end surface is provided at the right end portion of the front weight main body 13a. The right end plate 13b is provided with a notch 50b that penetrates the right end plate 13b in the left-right direction and opens downward and is connected to the depression 50a. The notch 50b and the depression 50a constitute the recess 50. The notch 50b has a mountain shape corresponding to the shape of the front-rear movement restraint portion 37 of the right front restraint portion 33 described later when viewed from the left-right direction. When the front-rear movement restraint portion 37 fits into the notch 50b, the right end portion of the front weight 13 and the right front restraint portion 33 are positioned relative to each other in the front-rear direction.

[0071] As shown in FIG. 5, the right front gantry 30 of the right front connecting portion 28 is fixed to the left side surface of the right crawler frame body 27 so as to protrude leftward from the left side surface of the portion included in the right crawler frame front portion 27a of the right crawler frame body 27. As shown in FIGS. 4 and 6, the right front gantry 30 has a pair of leg portions 31 and a mounting portion 32.

[0072] The pair of leg portions 31 are fixed to the left side surface of the portion included in the right crawler frame front portion 27a of the right crawler frame body 27 and extend further leftward from the left side surface. The pair of leg portions 31 are arranged at intervals in the front-rear direction.

[0073] The mounting portion 32 is a portion on which the right end portion of the front weight 13 is mounted, and is installed on the upper surface near the left end portions of the pair of leg portions 31 and is fixed to the pair of leg portions 31. The mounting portion 32 has a substrate portion 35 and a contact portion 36.

[0074] The substrate portion 35 is flat and is installed on a pair of leg portions 31 in a horizontally arranged state and is fixed to those leg portions 31.

[0075] The contact portion 36 is a portion that contacts the lower surface of the right end portion of the front weight 13 before being placed on the placement portion 32. As shown in FIGS. 5 and 6, the contact portion 36 has an elongated and thin plate shape, is installed on the upper surface of the substrate portion 35 in a posture extending in the front-rear direction, and is fixed to the upper surface of the substrate portion 35. The contact portion 36 is arranged at a position near the center of the substrate portion 35 in the left-right direction.

[0076] The right front restraint portion 33 of the right front connecting portion 28 protrudes upward from the upper surface of the placement portion 32 of the right front pedestal 30 and is a convex portion that fits into the concave portion 50 of the right end portion of the front weight 13 placed on the placement portion 32. By fitting into the concave portion 50, this right front restraint portion 33 restrains the movement of the right end portion of the front weight 13 in the front-rear direction and the movement outward (rightward) in the left-right direction, and at the same time, prevents the movement of the right crawler frame front portion 27a with respect to the front weight 13 inward (leftward) in the left-right direction, and is coupled to the right end portion of the front weight 13. This right front restraint portion 33 is installed on the right end portion of the placement portion 32. The right front restraint portion 33 has a front-rear movement restraint portion 37 and a rightward movement restraint portion 38.

[0077] The front-rear movement restraint portion 37 is a portion that restrains the movement of the right end portion of the front weight 13 in the front-rear direction and fits into the notch portion 50b of the concave portion 50. This front-rear movement restraint portion 37 has a mountain-shaped plate shape and is erected on the upper surface of the placement portion 32 in a posture orthogonal to the left-right direction. The front-rear movement restraint portion 37 is installed along the right end edge of the placement portion 32. In a state where the right front restraint portion 33 is fitted into the concave portion 50 of the front weight 13, the front end of this front-rear movement restraint portion 37 contacts the lower front portion of the inner surface of the concave portion 50, and the rear end of the front-rear movement restraint portion 37 contacts the lower rear portion of the inner surface of the concave portion 50. Thereby, the front-rear movement restraint portion 37 restrains the movement of the right end portion of the front weight 13 in the front-rear direction.

[0078] The rightward movement restraint portion 38 is a portion that restrains the rightward movement of the right end portion of the front weight 13. This rightward movement restraint portion 38 is disposed perpendicular to the front-back movement restraint portion 37, is fixed to the left side surface of the front-back movement restraint portion 37 at the central position of the front-back movement restraint portion 37 in the front-back direction, and is erected on the substrate portion 35 of the mounting portion 32. In a state where the right front restraint portion 33 is fitted into the recess 50 of the front weight 13, the left end portion of the rightward movement restraint portion 38 abuts against the right side surface within the recess 50 at the position of the lower end of the recess 50 of the front weight 13 as shown in FIG. 5, thereby restraining the rightward movement of the right end portion of the front weight 13. Further, the rightward movement restraint portion 38 abuts against the right side surface within the recess 50 from the right side as described above, thereby preventing the leftward movement of the right crawler frame front portion 27a with respect to the front weight 13.

[0079] Further, the right front restraint portion 33 has an upper surface 33a that is a surface facing upward. This upper surface 33a includes the upper surface 37a of the front-back movement restraint portion 37 and the upper surface 38a of the rightward movement restraint portion 38.

[0080] The upper surface 37a of the front-back movement restraint portion 37 has a front inclined portion 37c that inclines downward as it goes forward from the central portion 37b in the front-back direction of the upper surface 37a, and a rear inclined portion 37d that inclines downward as it goes backward from the central portion 37b. The front end of the front inclined portion 37c is located at the front end of the front-back movement restraint portion 37, and the rear end of the rear inclined portion 37d is located at the rear end of the front-back movement restraint portion 37.

[0081] Further, the upper surface 38a of the rightward movement restraint portion 38 is located on the inner side (left side) in the left-right direction with respect to the front inclined portion 37c and the rear inclined portion 37d of the upper surface 37a of the front-back movement restraint portion 37, and has an inner inclined portion 38b that inclines downward as it goes toward the inner side (left side) in the left-right direction. The inner end (left end) in the left-right direction of the inner inclined portion 38b is located at the inner end (left end) in the left-right direction of the rightward movement restraint portion 38, that is, the inner end (left end) in the left-right direction of the right front restraint portion 33.

[0082] The same structure as the right end portion and the right front connecting portion 28 of the front weight 13 as described above is applied to the structure of the left end portion and the left front connecting portion 20 of the front weight 13, the structure of the right end portion and the right rear connecting portion 29 of the rear weight 14, and the structure of the left end portion and the left rear connecting portion 21 of the rear weight 14, respectively.

[0083] That is, the left front connecting portion 20 includes a left front pedestal 43 on which the left end portion of the front weight 13 can be placed, and the left front pedestal 43 supports the left end portion from below in a state where the left end portion of the front weight 13 is placed thereon, and a left front restraint portion 44 provided on the left front pedestal 43 and restraining the movement of the left end portion of the front weight 13 placed thereon in the front-rear direction and to the left. The left front restraint portion 44 is coupled to the left end portion of the front weight 13 so as to prevent the rightward movement of the front portion 19a of the left crawler frame with respect to the front weight 13.

[0084] Further, the left front restraint portion 44 is configured symmetrically with the right front restraint portion 33 in the left-right direction, and has a schematic front-rear movement restraint portion and a schematic leftward movement restraint portion having a configuration in which the front-rear movement restraint portion 37 and the rightward movement restraint portion 38 are reversed left and right. The front-rear movement restraint portion of the left front restraint portion 44 is a portion that restrains the movement of the left end portion of the front weight 13 in the front-rear direction, and the leftward movement restraint portion of the left front restraint portion 44 is a portion that restrains the movement of the left end portion of the front weight 13 to the left.

[0085] Also, the right rear connecting portion 29 includes a right rear pedestal 45 on which the right end portion of the rear weight 14 can be placed, and the right rear pedestal 45 supports the right end portion from below in a state where the right end portion of the rear weight 14 is placed thereon, and a right rear restraint portion 46 provided on the right rear pedestal 45 and restraining the movement of the right end portion of the rear weight 14 placed thereon in the front-rear direction and to the right. The right rear restraint portion 46 is coupled to the right end portion of the rear weight 14 so as to prevent the leftward movement of the rear portion 27b of the right crawler frame with respect to the rear weight 14.

[0086] Further, the right rear restraint portion 46 is configured in the same manner as the right front restraint portion 33, and has a schematic front-rear movement restraint portion similar to the front-rear movement restraint portion 37 and a schematic rightward movement restraint portion similar to the rightward movement restraint portion. The front-rear movement restraint portion of the right rear restraint portion 46 is a portion that restrains the movement of the right end portion of the rear weight 14 in the front-rear direction, and the rightward movement restraint portion of the right rear restraint portion 46 is a portion that restrains the movement of the right end portion of the rear weight 14 to the right.

[0087] Further, the left rear connecting portion 21 is a left rear mount 47 on which the left end portion of the rear weight 14 can be placed, and the left rear mount 47 that supports the left end portion from below in a state where the left end portion of the rear weight 14 is placed thereon, and a left rear restraint portion 48 that is provided on the left rear mount 47 and restrains the movement of the left end portion of the rear weight 14 placed thereon in the front-rear direction and to the left. The left rear restraint portion 48 is coupled to the left end portion of the rear weight 14 so as to prevent the rightward movement of the rear portion of the left crawler frame 19b with respect to the rear weight 14.

[0088] Further, the left rear restraint portion 48 is configured in the same manner as the left front restraint portion 44, and has a schematic front-rear movement restraint portion similar to the front-rear movement restraint portion of the left front restraint portion 44 and a schematic leftward movement restraint portion similar to the leftward movement restraint portion of the left front restraint portion 44. The front-rear movement restraint portion of the left rear restraint portion 48 is a portion that restrains the movement of the left end portion of the rear weight 14 in the front-rear direction, and the leftward movement restraint portion of the left rear restraint portion 48 is a portion that restrains the movement of the left end portion of the rear weight 14 to the left.

[0089] The left end portion of the front weight 13 is configured symmetrically with the right end portion of the front weight 13, and the left end portion of the front weight 13 is constituted by the left end portion of the front weight body 13a and a left end plate (not shown) fixed to the left end surface of the left end portion. The left end portion of the front weight 13 has the same structure as the concave portion 50 of the right end portion of the front weight 13 and a schematic concave portion that is symmetric with the concave portion 50 in the left-right direction, and is connected to the left front connecting portion 20 by inserting the left front restraint portion 44 into the concave portion.

[0090] Also, the right end portion of the rear weight 14 is configured by a right end portion of the rear weight body and a right end plate (not shown) fixed to the right end surface of the right end portion, similar to the right end portion of the front weight 13. The right end portion of the rear weight 14 has a recess (not shown) having a structure similar to the recess 50 of the right end portion of the front weight 13, and is connected to the right rear connecting portion 29 by inserting the right rear restraint portion 46 into the recess.

[0091] Also, the left end portion of the rear weight 14 is configured by a left end portion of the rear weight body and a left end plate (not shown) fixed to the left end surface of the left end portion, similar to the left end portion of the front weight 13. The left end portion of the rear weight 14 has a recess (not shown) having a structure similar to the recess 50 of the right end portion of the front weight 13 and having the recess 50 reversed left and right, and is connected to the left rear connecting portion 21 by inserting the left rear restraint portion 48 into the recess.

[0092] The front weight 13 is sandwiched between the right front restraint portion 33 and the left front restraint portion 44, thereby restricting movement in the left - right direction. Also, the movement in the front - rear direction is restricted by the fitting between the right front restraint portion 33 and the recess 50 at the right end portion of the front weight 13 and the fitting between the left front restraint portion 44 and a recess (not shown) at the left end portion of the front weight 13.

[0093] Also, the rear weight 14 is sandwiched between the right rear restraint portion 46 and the left rear restraint portion 48, thereby restricting movement in the left - right direction. Also, the movement in the front - rear direction is restricted by the fitting between the right rear restraint portion 46 and a recess (not shown) at the right end portion of the rear weight 14 and the fitting between the left rear restraint portion 48 and a recess (not shown) at the left end portion of the rear weight 14.

[0094] (Effect according to this embodiment) In this embodiment, by utilizing the large weights of the front and rear weights 13 and 14, the vertical restraint of the front and rear weights 13 and 14 is omitted, and the front weight 13 can be fixed between the left and right crawler frames 16 and 24 only by combining the placement of the front weight 13 on the right front pedestal 30 and the left front pedestal 43 and the restraint of the front weight 13 in the horizontal direction by the right front restraint portion 33 and the left front restraint portion 44. Also, the rear weight 14 can be fixed between the left and right crawler frames 16 and 24 only by combining the placement of the rear weight 14 on the right rear pedestal 45 and the left rear pedestal 47 and the restraint of the rear weight 14 in the horizontal direction by the right rear restraint portion 46 and the left rear restraint portion 48. Therefore, the front and rear weights 13 and 14 can be fixed between the left and right crawler frames 16 and 24 with a very simple operation.

[0095] Specifically, by simply placing the front weight 13 on the left and right front pedestals 43 and 30 and the rear weight 14 on the left and right rear pedestals 47 and 45, the vertical restraint of these weights 13 and 14 can be omitted by utilizing the large weights of the front and rear weights 13 and 14. And the movement of the front and rear weights 13 and 14 in the front-rear direction and the left-right direction, which are directions other than the vertical direction, can be achieved by the restraint of the front weight 13 by the right front restraint portion 33 and the left front restraint portion 44 and the restraint of the rear weight 14 by the right rear restraint portion 46 and the left rear restraint portion 48. Therefore, the front and rear weights 13 and 14 can be fixed between the left and right crawler frames 16 and 24 with a very simple operation of placing the front weight 13 on the left and right front pedestals 43 and 30 and restraining the front weight 13 with the left and right front restraint portions 44 and 33, and placing the rear weight 14 on the left and right rear pedestals 47 and 45 and restraining the rear weight 14 with the left and right rear restraint portions 48 and 46.

[0096] Further, in the present embodiment, the front weight 13 and the rear weight 14 fixed between the left and right crawler frames 16 and 24 are used as a scaffold, so that an operator or the like can move between the left and right crawler units 11 and 12 through the front weight 13 or the rear weight 14 without getting off onto the ground once from above the left and right crawler units 11 and 12. Therefore, the movement of an operator or the like between the left and right crawler units 11 and 12 can be facilitated.

[0097] Further, in the present embodiment, the front weight 13 and the rear weight 14 fixed between the left and right crawler frames 16 and 24 can counteract the bending load applied to the left and right crawler frames 16 and 24 when the lower traveling body 3 turns left and right. Therefore, the bending moment in the left-right direction generated in the left and right crawler frames 16 and 24 during the turning of the lower traveling body 3 can be reduced.

[0098] Specifically, at the position of the left front connection part 20 which is the connection part of the front crawler frame front part 19a to the front weight 13, it can resist the rightward bending load applied to the front crawler frame front part 19a when the lower traveling body 3 turns. Also, at the position of the right front connection part 28 which is the connection part of the right crawler frame front part 27a to the front weight 13, it can resist the leftward bending load applied to the right crawler frame front part 27a when the lower traveling body 3 turns. That is, in this embodiment, the arm length of the rightward bending moment of the front crawler frame front part 19a is the length from the front end of the front crawler frame front part 19a to the position of the left front connection part 20, and the arm length of the leftward bending moment of the right crawler frame front part 27a is the length from the front end of the right crawler frame front part 27a to the position of the right front connection part 28. For this reason, compared with the case where the front crawler frame front part 19a and the right crawler frame front part 27a are not connected to the front weight 13 respectively, the arm lengths of the bending moments of the front crawler frame front part 19a and the right crawler frame front part 27a can be reduced. As a result, the rightward bending moment generated in the front crawler frame front part 19a and the leftward bending moment generated in the right crawler frame front part 27a when the lower traveling body 3 turns can be reduced. Also, for the same reason, the rightward bending moment generated in the rear crawler frame rear part 19b and the leftward bending moment generated in the right crawler frame rear part 27b when the lower traveling body 3 turns can also be reduced.

[0099] From the above, in this embodiment, while facilitating the movement of workers etc. between the left and right crawler units 11, 12 and reducing the left - right bending moments generated in the left and right crawler frames 16, 24 when the lower traveling body 3 turns, the front and rear weights 13, 14 can be fixed between the left and right crawler frames 16, 24 with a simple operation.

[0100] Furthermore, in the present embodiment, when the left end portion of the front weight 13 is placed on the left front mount 43, at the same time, the convex portion of the left front restraint portion 44 is fitted into the concave portion of the left end portion of the front weight 13 from below, so that the movement of the left end portion of the front weight 13 in the front-rear direction and to the left can be restrained. When the right end portion of the front weight 13 is placed on the right front mount 30, at the same time, the convex portion of the right front restraint portion 33 is fitted into the concave portion 50 of the right end portion of the front weight 13 from below, so that the movement of the right end portion of the front weight 13 in the front-rear direction and to the right can be restrained. Therefore, the work related to restraining both the left and right end portions of the front weight 13 can be simplified.

[0101] Also, in the present embodiment, when the left end portion of the rear weight 14 is placed on the left rear mount 47, at the same time, the convex portion of the left rear restraint portion 48 is fitted into the concave portion of the left end portion of the rear weight 14 from below, so that the movement of the left end portion of the rear weight 14 in the front-rear direction and to the left can be restrained. When the right end portion of the rear weight 14 is placed on the right rear mount 45, at the same time, the convex portion of the right rear restraint portion 46 is fitted into the concave portion of the right end portion of the rear weight 14 from below, so that the movement of the right end portion of the rear weight 14 in the front-rear direction and to the right can be restrained. Therefore, the work related to restraining both the left and right end portions of the rear weight 14 can be simplified.

[0102] Also, in the present embodiment, the upper surface 37a of the front-rear movement restraint portion 37 of the right front restraint portion 33 has a front inclined portion 37c that inclines downward as it goes forward from the central portion 37b, and a rear inclined portion 37d that inclines downward as it goes backward from the central portion 37b. Therefore, when the right end portion of the front weight 13 is placed on the right front mount 30 and the concave portion 50 of the right end portion of the front weight 13 is displaced in the front-rear direction with respect to the right front restraint portion 33 and the front edge or the rear edge of the concave portion 50 abuts against the upper surface 37a of the front-rear movement restraint portion 37, even in such a case, due to the inclination of the front inclined portion 37c and the rear inclined portion 37d of the upper surface 37a, the right end portion of the front weight 13 can be guided to a position where the concave portion 50 fits with the right front restraint portion 33, and the fitting between the concave portion 50 of the right end portion of the front weight 13 and the right front restraint portion 33 can be carried out without hindrance.

[0103] Specifically, when placing the right end portion of the front weight 13 on the right front mount 30, if the recess 50 at the right end portion of the front weight 13 is displaced forward with respect to the right front restraint portion 33 and the rear edge of the recess 50 abuts against the rear inclined portion 37d of the upper surface 37a of the front-rear movement restraint portion 37, then along the inclination of the rear inclined portion 37d, the right end portion of the front weight 13 moves downward while being displaced rearward, and the right end portion of the front weight 13 can be guided to a position where the recess 50 fits with the right front restraint portion 33. Further, when placing the right end portion of the front weight 13 on the right front mount 30, if the recess 50 at the right end portion of the front weight 13 is displaced rearward with respect to the right front restraint portion 33 and the front edge of the recess 50 abuts against the front inclined portion 37c of the upper surface 37a of the front-rear movement restraint portion 37, then along the inclination of the front inclined portion 37c, the right end portion of the front weight 13 moves downward while being displaced forward, and the right end portion of the front weight 13 can be guided to a position where the recess 50 fits with the right front restraint portion 33.

[0104] Also, in the present embodiment, the upper surfaces of the front-rear movement restraint portions of the left front restraint portion 44, the upper surfaces of the front-rear movement restraint portions of the right rear restraint portion 46, and the upper surfaces of the front-rear movement restraint portions of the left rear restraint portion 48 are configured in the same manner as the upper surface 37a of the front-rear movement restraint portion 37 of the right front restraint portion 33. Therefore, similar to the case of the fitting between the recess 50 at the right end portion of the front weight 13 and the right front restraint portion 33, the displacement in the front-rear direction during the fitting between the recess at the left end portion of the front weight 13 and the left front restraint portion 44, the displacement in the front-rear direction during the fitting between the recess at the right end portion of the rear weight 14 and the right rear restraint portion 46, and the displacement in the front-rear direction during the fitting between the recess at the left end portion of the rear weight 14 and the left rear restraint portion 48 can be eliminated respectively, and their fittings can be performed without hindrance.

[0105] Further, in the present embodiment, since the upper surface 38a of the rightward movement restraint portion 38 of the right front restraint portion 33 has an inner inclined portion 38b that inclines downward as it goes toward the inner side (left side) in the left-right direction, when the right end portion of the front weight 13 is placed on the right front mount 30, even if the recess 50 at the right end portion of the front weight 13 is displaced outward (rightward) in the left-right direction with respect to the right front restraint portion 33 and the inner edge (left edge) in the left-right direction of the recess 50 abuts against the inner inclined portion 38b, the inclination of the inner inclined portion 38b can guide the right end portion of the front weight 13 to a position where the recess 50 fits with the right front restraint portion 33, and the fitting between the recess 50 at the right end portion of the front weight 13 and the right front restraint portion 33 can be performed without hindrance.

[0106] Specifically, when the recess 50 at the right end portion of the front weight 13 is displaced outward (rightward) in the left-right direction with respect to the right front restraint portion 33 and the inner edge (left edge) in the left-right direction of the recess 50 abuts against the inner inclined portion 38b, the right end portion of the front weight 13 can be guided to a position where the recess 50 fits with the right front restraint portion 33 by being displaced inward (leftward) in the left-right direction while moving downward along the inclination of the inner inclined portion 38b.

[0107] Further, in the present embodiment, since the upper surface of the leftward movement restraint portion of the left front restraint portion 44 is symmetric with the upper surface of the rightward movement restraint portion 38 of the right front restraint portion 33 in the left-right direction, although it is symmetric with the case of the fitting between the recess 50 at the right end portion of the front weight 13 and the right front restraint portion 33, even when the left end portion of the front weight 13 is displaced outward (leftward) in the left-right direction with respect to the left front restraint portion 44 during the fitting between the recess at the left end portion of the front weight 13 and the left front restraint portion 44, the displacement in the left-right direction can be eliminated by the same action as above, and the fitting between the recess at the left end portion of the front weight 13 and the left front restraint portion 44 can be performed without hindrance.

[0108] Further, the upper surface of the rightward movement restraint portion of the right rear restraint portion 46 is configured in the same manner as the upper surface 38a of the rightward movement restraint portion 38 of the right front restraint portion 33, and the upper surface of the leftward movement restraint portion of the left rear restraint portion 48 is configured in the same manner as the upper surface of the leftward movement restraint portion of the left front restraint portion 44. Therefore, when the right end portion of the rear weight 14 is displaced outward (rightward) in the left-right direction with respect to the right rear restraint portion 46 during the fitting of the recess of the right end portion of the rear weight 14 and the right rear restraint portion 46, or when the left end portion of the rear weight 14 is displaced outward (leftward) in the left-right direction with respect to the left rear restraint portion 48 during the fitting of the recess of the left end portion of the rear weight 14 and the left rear restraint portion 48, similar to the above, the displacement in the left-right direction can be eliminated, and the fitting of the recess of the right end portion of the rear weight 14 and the right rear restraint portion 46 and the fitting of the recess of the left end portion of the rear weight 14 and the left rear restraint portion 48 can be performed without any trouble.

[0109] (Modification example) The construction machine according to the present invention is not necessarily limited to the one having the above-described configuration. For the construction machine according to the present invention, for example, the following configurations can be adopted.

[0110] (1) The recess 50 at the right end portion of the front weight 13 and the recess at the left end portion of the front weight 13 may each penetrate the front weight 13 vertically, and the recess at the right end portion of the rear weight 14 and the recess at the left end portion of the rear weight 14 may each penetrate the rear weight 14 vertically. FIG. 7 is a view of the front weight 13 and the right front connecting portion 28 in a first modification example of the present invention adopting such a configuration as viewed from the right to the left. Further, FIG. 8 is a cross-sectional view at the VIII-VIII position of the right end portion of the front weight 13 and the right front connecting portion 28 shown in FIG. 7. Further, FIG. 9 is a view of the right end portion of the front weight 13 and the right front connecting portion 28 shown in FIG. 7 as viewed from above.

[0111] In this first modification example, the recess 50 at the right end of the front weight 13 opens on the lower surface of the front weight 13 and also opens on the upper surface of the front weight 13 by penetrating the front weight 13 in the vertical direction. Further, this recess 50 also opens on the left side surface of the front weight 13. Also, the right front restraint portion 33 of the right front connecting portion 28 has a vertical dimension larger than the vertical dimension of the right front restraint portion 33 in the above-described embodiment. In a state where the right front restraint portion 33 is fitted into the recess 50 at the right end of the front weight 13, an open space is formed above the right front restraint portion 33. Note that the space above the right front restraint portion 33 does not necessarily have to be open and may be closed.

[0112] Also, in this first modification example, the front-rear movement restraint portion 37 of the right front restraint portion 33 is vertically long as compared with the front-rear movement restraint portion 37 in the above-described embodiment. The front inclined portion 37c of the upper surface 37a of the front-rear movement restraint portion 37 in the first modification example is inclined downward as it curves and heads forward, and the rear inclined portion 37d of the upper surface 37a of the front-rear movement restraint portion 37 in the first modification example is inclined downward as it curves and heads backward. Due to the inclination of the front inclined portion 37c and the rear inclined portion 37d, even if there is a displacement in the front-rear direction when the recess 50 and the right front restraint portion 33 are fitted together, the right end portion of the front weight 13 can be guided to the position where the recess 50 is fitted with the right front restraint portion 33, eliminating the displacement and enabling the fitting of the recess 50 and the right front restraint portion 33 without any trouble. This action is the same as the action due to the inclination of the front inclined portion 37c and the rear inclined portion 37d in the above-described embodiment.

[0113] Also, in this first modified example, the rightward movement restraint portion 38 of the right front restraint portion 33 is vertically long as compared with the rightward movement restraint portion 38 in the above-described embodiment, but has the same function. The upper surface 38a of the rightward movement restraint portion 38 of this first modified example has an inner inclined portion 38b that inclines downward as it goes toward the inner side (left side) in the left-right direction. Even when the recess 50 is displaced outward (rightward) in the left-right direction with respect to the right front restraint portion 33 during the fitting of the recess 50 and the right front restraint portion 33, the inclination of the inner inclined portion 38b allows the right end portion of the front weight 13 to be guided to a position where the recess 50 fits with the right front restraint portion 33. For this reason, the displacement in the left-right direction can be eliminated, and the fitting of the recess 50 and the right front restraint portion 33 can be performed without any trouble. This action is the same as the action by the inclination of the inner inclined portion 38b in the above-described embodiment.

[0114] In the first modified example, the same configuration as the recess 50 and the right front connecting portion 28 at the right end portion of the front weight 13 described above may be applied to the recess and the left front connecting portion 20 at the left end portion of the front weight 13, the recess and the right rear connecting portion 29 at the right end portion of the rear weight 14, and the recess and the left rear connecting portion 21 at the left end portion of the rear weight 14, respectively.

[0115] (2) Further, the right front restraint portion 33 may be a restraint pin that connects the right end portion of the front weight 13 placed on the right front pedestal 30 and the right front pedestal 30 and restrains the movement of the right end portion of the front weight 13 placed on the right front pedestal 30 in the front - rear direction and the left - right direction. Also, the left front restraint portion 44 may be a restraint pin that connects the left end portion of the front weight 13 placed on the left front pedestal 43 and the left front pedestal 43 and restrains the movement of the left end portion of the front weight 13 placed on the left front pedestal 43 in the front - rear direction and the left - right direction. Also, the right rear restraint portion 46 may be a restraint pin that connects the right end portion of the rear weight 14 placed on the right rear pedestal 45 and the right rear pedestal 45 and restrains the movement of the right end portion of the rear weight 14 placed on the right rear pedestal 45 in the front - rear direction and the left - right direction. Also, the left rear restraint portion 48 may be a restraint pin that connects the left end portion of the rear weight 14 placed on the left rear pedestal 47 and the left rear pedestal 47 and restrains the movement of the left end portion of the rear weight 14 placed on the left rear pedestal 47 in the front - rear direction and the left - right direction.

[0116] FIG. 10 is a view of the right end portion of the front weight 13 and the right front connecting portion 28 in the second modification of the present invention where the right front restraint portion 33 is the restraint pin 53, as viewed from above. Also, FIG. 11 is a view of the right end portion of the front weight 13 and the right front connecting portion 28 shown in FIG. 10, as viewed from the front.

[0117] In the second modification, the front weight 13 has a front weight main body 51 and an end attachment portion 52 that protrudes rightward from the lower end of the right end face of the front weight main body 51. The end attachment portion 52 corresponds to the right end portion of the front weight 13 and is an example of the weight end portion in the present invention. The end attachment portion 52 has two weight through - holes 52a that penetrate the end attachment portion 52 vertically. These two weight through - holes 52a are arranged side by side in the front - rear direction.

[0118] The right front pedestal 30 of the right front connecting portion 28 has two pedestal through-holes 35a that penetrate the right front pedestal 30 vertically. The right front pedestal 30 is an example of the crawler frame pedestal in the present invention. The two pedestal through-holes 35a are provided in the substrate portion 35 of the mounting portion 32 of the right front pedestal 30 and penetrate the substrate portion 35 vertically. More specifically, the substrate portion 35 has a portion that overlaps with the end attachment portion 52 when the right end portion of the front weight 13 is placed on the mounting portion 32, and two pedestal through-holes 35a are provided in that portion. The two pedestal through-holes 35a are arranged side by side in the front-rear direction in the region between the pair of leg portions 31.

[0119] The right front restraint portion 33 is composed of two restraint pins 53 that are inserted into the two weight through-holes 52a and the two pedestal through-holes 35a and restrain the movement of the end attachment portion 52 of the right end portion of the front weight 13 placed on the right front pedestal 30 in the front-rear direction and the left-right direction. The two weight through-holes 52a coincide with the two pedestal through-holes 35a in a state where the left end portion of the front weight 13 is placed on the mounting portion 32 of the right front pedestal 30. In that state, the restraint pins 53 are inserted into the corresponding weight through-holes 52a and pedestal through-holes 35a from above. The restraint pins 53 inserted in this way restrain the movement of the right end portion of the front weight 13 placed on the right front pedestal 30 in the front-rear direction and the left-right direction.

[0120] Also, in this second modification, two right front connecting portions 28 are provided at two positions spaced apart in the front-rear direction in the front portion 27a of the right crawler frame, and those right front connecting portions 28 are similarly configured. Also, corresponding to the two right front connecting portions 28, two end attachment portions 52 are provided at two positions spaced apart in the front-rear direction at the right end portion of the front weight 13, and those end attachment portions 52 are similarly configured. And each of the two end attachment portions 52 and the right front pedestal 30 of each of the two right front connecting portions 28 are connected by the restraint pins 53 as described above.

[0121] A structure similar to the connection structure by the restraint pin 53 as described above may be applied to the connection between the left end portion of the front weight 13 and the left front mount 43, the connection between the right end portion of the rear weight 14 and the right rear mount 45, and the connection between the left end portion of the rear weight 14 and the left rear mount 47. Also, the right end portion of the front weight 13 may be connected by a connection structure by a similar restraint pin 53 to three or more right front mounts 30 arranged in the front-rear direction, and the left end portion of the front weight 13 may be connected by a connection structure by a similar restraint pin 53 to three or more left front mounts 43 arranged in the front-rear direction. Further, the right end portion of the rear weight 14 may be connected by a connection structure by a similar restraint pin 53 to three or more right rear mounts 45 arranged in the front-rear direction, and the left end portion of the rear weight 14 may be connected by a connection structure by a similar restraint pin 53 to three or more left rear mounts 47 arranged in the front-rear direction.

[0122] In this second modification example, since the restraint pin 53 can restrain the movement of the right end portion of the front weight 13 in the front-rear direction and also restrain the movement of the right end portion of the front weight 13 to both the left and right sides, the movement of the right end portion of the front weight 13 in the horizontal direction can be restrained more stably. Also, when a similar connection structure by the restraint pin 53 is applied to the connection between the left end portion of the front weight 13 and the left front mount 43, the connection between the right end portion of the rear weight 14 and the right rear mount 45, and the connection between the left end portion of the rear weight 14 and the left rear mount 47, the movement of the left end portion of the front weight 13 in the horizontal direction, the movement of the right end portion of the rear weight 14 in the horizontal direction, and the movement of the left end portion of the rear weight 14 in the horizontal direction can be restrained more stably.

[0123] (3) Further, in the configurations of the above-described embodiment and the first modification, a plurality of right front connection portions 28 arranged in the front-rear direction are provided at the front portion 27a of the right crawler frame, and a plurality of recesses 50 arranged in the front-rear direction are provided at the right end portion of the front weight 13. The right end portion of the front weight 13 may be connected to the front portion 27a of the right crawler frame by fitting the right front restraint portions 33 of the plurality of right front connection portions 28 and the plurality of recesses 50. Similarly, in the configurations of the above-described embodiment and the first modification, the left end portion of the front weight 13 and the front portion 19a of the left crawler frame may be connected at a plurality of locations, the right end portion of the rear weight 14 and the rear portion 27b of the right crawler frame may be connected at a plurality of locations, and the left end portion of the rear weight 14 and the rear portion 19b of the left crawler frame may be connected at a plurality of locations.

[0124] (4) Further, the right front restraint portion 33 of the right front connection portion 28 may be configured to restrain the movement of the right end portion of the front weight 13 in the front-rear direction by sandwiching the right end portion of the front weight 13 from both the front and rear sides. FIG. 12 is a view of the front weight 13 and the right front connection portion 28 in the third modification of the present invention in which such a configuration is adopted, as viewed from the right side toward the left side.

[0125] Specifically, in this third modification, the right front connection portion 28 is composed of a front right front connection portion 28a and a rear right front connection portion 28b that are arranged separately before and after the right end portion of the front weight 13. The front right front connection portion 28a has a front right front restraint portion 33b and a front right front pedestal 30a, and the rear right front connection portion 28b has a rear right front restraint portion 33c and a rear right front pedestal 30b. The right front restraint portion 33 includes the front right front restraint portion 33b that is arranged in front of the right end portion of the front weight 13 and restrains the forward movement of the right end portion of the front weight 13, and the rear right front restraint portion 33c that is arranged behind the right end portion of the front weight 13 and restrains the backward movement of the right end portion of the front weight 13. The right end portion of the front weight 13 is sandwiched from both the front and rear sides by the front right front restraint portion 33b and the rear right front restraint portion 33c, thereby restraining the movement of the right end portion of the front weight 13 in the front-rear direction.

[0126] Also, in this third modification example, the right front mount 30 is disposed in front of the right end portion of the front weight 13 and the front end portion of the right end portion of the front weight 13 is placed thereon, and the front right front mount 30a, and is disposed behind the right end portion of the front weight 13 and the rear end portion of the right end portion of the front weight 13 is placed thereon, the rear right front mount 30b, and is constituted by these front right front mount 30a and the rear right front mount 30b support the right end portion of the front weight 13 from below. The front right front restraint portion 33b is provided so as to protrude upward from the upper surface of the mounting portion 32 of the front right front mount 30a, and the rear right front restraint portion 33c is provided so as to protrude upward from the upper surface of the mounting portion 32 of the rear right front mount 30b.

[0127] Also, in this third modification example, the front lower end portion 13c and the rear lower end portion 13d of the right end portion of the front weight 13 are inclined notches that incline toward the center in the front-rear direction of the right end portion of the front weight 13 as they go downward. Then, with the front end portion of the right end portion of the front weight 13 placed on the mounting portion 32 of the front right front mount 30a and the rear end portion of the right end portion of the front weight 13 placed on the mounting portion 32 of the rear right front mount 30b, the front right front restraint portion 33b abuts against the front lower end portion 13c of the right end portion of the front weight 13 to restrain the forward movement of the right end portion of the front weight 13, and the rear right front restraint portion 33c abuts against the rear lower end portion 13d of the right end portion of the front weight 13 to restrain the backward movement of the right end portion of the front weight 13. The contact surface 33d of the front right front restraint portion 33b that abuts against the front lower end portion 13c of the right end portion of the front weight 13 is a slope along the inclination of the front lower end portion 13c, and the contact surface 33e of the rear right front restraint portion 33c that abuts against the rear lower end portion 13d of the right end portion of the front weight 13 is a slope along the inclination of the rear lower end portion 13d.

[0128] Although not shown, in this third modification example, the left front connecting portion is configured in the same manner as the right front connecting portion 28, and includes a front left front connecting portion and a rear left front connecting portion that are divided and arranged before and after the left end portion of the front weight 13. The front left front connecting portion is configured in the same manner as the front right front connecting portion 28a, and the rear left front connecting portion is configured in the same manner as the rear right front connecting portion 28b. A notch similar to the front lower end portion 13c of the right end portion of the front weight 13 is provided at the front lower end portion of the left end portion of the front weight 13, and a notch similar to the rear lower end portion 13d of the right end portion of the front weight 13 is provided at the rear lower end portion of the left end portion of the front weight 13. The left front restraint portion of the left front connecting portion is configured in the same manner as the front right front restraint portion 33b and is a front left front restraint portion that fits into the notch provided at the front lower end portion of the left end portion of the front weight 13, and is configured in the same manner as the rear right front restraint portion 33c and is a rear left front restraint portion that fits into the notch provided at the rear lower end portion of the left end portion of the front weight 13. The front left front restraint portion and the rear left front restraint portion sandwich the left end portion of the front weight 13 from both the front and rear sides to restrain the movement of the left end portion of the front weight 13 in the front-rear direction.

[0129] Although not shown, a structure similar to the structure that restricts the movement of the right end portion of the front weight 13 in the front-rear direction by sandwiching the right end portion of the front weight 13 from both the front and rear sides by the front right front restraint portion 33b and the rear right front restraint portion 33c as described above may be adopted for the structure for restricting the movement of the front weight 13 in the left-right direction. In this case, specifically, when the front weight 13 is viewed from the front, notches are provided at the lower end portions of the right end portion and the left end portion of the front weight 13 so as to incline toward the inner side (center side) in the left-right direction of the front weight 13 as they go downward. The right front restraint portion has a right side restraint portion that fits into the notch provided at the lower end portion of the right end portion of the front weight 13 and restricts the rightward movement of the right end portion of the front weight 13. The left front restraint portion has a left side restraint portion that fits into the notch provided at the lower end portion of the left end portion of the front weight 13 and restricts the leftward movement of the left end portion of the front weight 13. The left side restraint portion and the right side restraint portion sandwich the front weight 13 from both the left and right sides to restrict the movement of the front weight 13 in the left-right direction.

[0130] A configuration similar to the above configuration may be applied to the connection between the right end portion of the rear weight 14 and the right rear connection portion 29, and the connection between the left end portion of the rear weight 14 and the left rear connection portion 21. That is, the right rear restraint portion of the right rear connection portion 29 is composed of a front right rear restraint portion similar to the front right front restraint portion 33b and a rear right rear restraint portion similar to the rear right front restraint portion 33c, and the front right rear restraint portion and the rear right rear restraint portion sandwich the right end portion of the rear weight 14 from both the front and rear sides to restrain the movement of the right end portion of the rear weight 14 in the front-rear direction. Further, the left rear restraint portion of the left rear connection portion 21 is composed of a front left rear restraint portion similar to the front left front restraint portion and a rear left rear restraint portion similar to the rear left front restraint portion, and the front left rear restraint portion and the rear left rear restraint portion sandwich the left end portion of the rear weight 14 from both the front and rear sides to restrain the movement of the left end portion of the rear weight 14 in the front-rear direction. Further, the right rear restraint portion has a right side restraint portion similar to the right side restraint portion of the right front restraint portion, the left rear restraint portion has a left side restraint portion similar to the left side restraint portion of the left front restraint portion, and the right side restraint portion of the right rear restraint portion and the left side restraint portion of the left rear restraint portion sandwich the rear weight 14 from both the left and right sides to restrain the movement of the rear weight 14 in the left-right direction.

[0131] (5) Further, the construction machine according to the present invention is not necessarily limited to a crawler crane, and may be a hydraulic excavator or other crawler-type construction machines.

[0132] (6) Further, in the construction machine according to the present invention, the front weight is not only placed on the right front mounting table and the left front mounting table, but in addition, it may be fixed to the front part of the right crawler frame and the front part of the left crawler frame. Also, the rear weight is not only placed on the right rear mounting table and the left rear mounting table, but in addition, it may be fixed to the rear part of the right crawler frame and the rear part of the left crawler frame. In this case, for example, a fixing bracket is provided at the right end of the front weight, and a fixing connection part for connecting the fixing bracket to the front part of the right crawler frame is provided separately from the right front connection part. By connecting the fixing bracket and the fixing connection part with a connecting member such as a pin or a bolt, the right end of the front weight may be fixed to the front part of the right crawler frame. As the fixing bracket provided at the right end of the front weight, the same one as the end attachment part 52 in the second modification example may be applied, and as the fixing connection part provided at the front part of the right crawler frame, the same one as the right front connection part 28 in the second modification example may be applied.

[0133] A connection structure similar to the connection structure between the fixing bracket and the fixing connection part as described above may be applied to the fixing of the left end of the front weight to the front part of the left crawler frame, the fixing of the right end of the rear weight to the rear part of the right crawler frame, and the fixing of the left end of the rear weight to the rear part of the left crawler frame, respectively. Also, the fixing connection parts provided at the front part of the right crawler frame, the front part of the left crawler frame, the rear part of the right crawler frame, and the rear part of the left crawler frame may be provided integrally with those provided at the corresponding positions among the right front connection part, the left front connection part, the right rear connection part, and the left rear connection part.

[0134] (7) Also, in the above embodiment, the front weight 13 is configured by the front weight body 13a, the right end plate 13b, and the left end plate (not shown) being coupled to each other. However, the front weight according to the present invention may be integrally formed in a shape similar to the shape of the front weight 13 formed by the front weight body 13a, the right end plate 13b, and the left end plate in the above embodiment. In this case, the recess at the right end of the front weight may be formed at the right end of the integrally formed front weight in a shape similar to the recess 50 formed by the depression 50a formed in the front weight body 13a and the notch 50b formed in the right end plate 13b in the above embodiment. The same applies to the recess at the left end of the front weight. Similarly, the rear weight according to the present invention may be integrally formed, and the respective recesses at the right and left ends of the rear weight may be formed at the right and left ends of the integrally formed rear weight, respectively.

[0135] (8) Also, the contact portion of the mounting portion of each pedestal on which the left and right ends of the front and rear weights according to the present invention are placed is not necessarily limited to an elongated shape as viewed from above like the contact portion 36 of the above embodiment shown in FIG. 6. For example, the contact portion may be elliptical or other shapes as viewed from above. Also, a plurality of circular contact portions may be arranged in a predetermined array or scattered on the substrate portion of the mounting portion as viewed from above.

[0136] (9) Also, in the above embodiment and the modification, in the right front restraint portion 33, the rightward movement restraint portion 38 is formed separately from the forward and backward movement restraint portion 37 and fixed to the forward and backward movement restraint portion 37. However, the rightward movement restraint portion may be integrally formed with the forward and backward movement restraint portion. The same applies to the left front restraint portion, the right rear restraint portion, and the left rear restraint portion.

[0137] (10) Further, the longitudinal width of the rightward movement restraint portion 38 of the right front restraint portion 33 may be set to any width equal to or less than the longitudinal width of the forward and backward movement restraint portion 37. For example, the longitudinal width of the rightward movement restraint portion 38 may be larger than the longitudinal width of the rightward movement restraint portion 38 shown in FIG. 6 of the embodiment, or may be equal to the longitudinal width of the forward and backward movement restraint portion 37. The same applies to the longitudinal width of the leftward movement restraint portion of the right front restraint portion 33, the longitudinal width of the rightward movement restraint portion of the left rear restraint portion 48, and the longitudinal width of the leftward movement restraint portion of the right rear restraint portion 46.

[0138] (11) The upper surface 33a of the right front restraint portion 33 has a front inclined portion 37c and a rear inclined portion 37d, while it does not necessarily have an inner inclined portion 38b. That is, in this case, the upper surface 38a of the rightward movement restraint portion 38, which is a part of the upper surface 33a of the right front restraint portion 33, does not necessarily incline downward as it goes inward in the left-right direction. For example, it may have a shape that extends flat in the horizontal direction or other shapes. Further, the upper surface 33a of the right front restraint portion 33 has an inner inclined portion 38b, while it does not necessarily have a front inclined portion 37c and a rear inclined portion 37d. That is, in this case, the upper surface 37a of the forward and backward movement restraint portion 37, which is a part of the upper surface 33a of the right front restraint portion 33, does not necessarily incline at the front and rear portions from its central portion 37b. For example, it may have a shape that extends flat in the horizontal direction or other shapes. The above also applies to the upper surfaces of the left front restraint portion 44, the right rear restraint portion 46, and the left rear restraint portion 48.

[0139] (12) Further, the crawler frame restraint portion in the present invention may have a protrusion coupling portion provided with an insertion hole into which a weight end protrusion protruding downward from the end of the weight body can be inserted from above, and this protrusion coupling portion is coupled to the weight end protrusion so as to restrain the movement of the weight end protrusion inserted into the insertion hole in the front-rear direction and the left-right direction, thereby restraining the movement of the corresponding weight end in the front-rear direction and the left-right direction. FIGS. 13 to 22 show a configuration according to a fourth modification of the present invention in which such a crawler frame restraint portion is adopted.

[0140] Specifically, as shown in FIGS. 13 and 14, the lower traveling body 3 of the crane 1 according to this fourth modification has a front lower weight 61, a front upper weight 62, a rear lower weight 71, and a rear upper weight 72. The front lower weight 61 is an example of the front weight in the present invention, and the rear lower weight 71 is an example of the rear weight in the present invention.

[0141] As shown in FIG. 19, the front lower weight 61 has a front lower weight body 63, a front weight right end protrusion 64, and a front weight left end protrusion 65.

[0142] The front lower weight body 63 is in the shape of a plate extending in the left-right direction. The right end of the front lower weight body 63 is placed on the right front pedestal 30 of the right crawler frame front portion 27a as shown in FIG. 14. The left end of the front lower weight body 63 is placed on the left front pedestal 43 of the left crawler frame front portion 19a. The right end and the left end of the front lower weight body 63 are examples of the weight body ends in the present invention.

[0143] As shown in Fig. 19, the protrusion 64 at the right end of the front weight projects downward from the lower surface of the right end of the front lower weight body 63. This protrusion 64 at the right end of the front weight is an example of the weight end protrusion in the present invention. The protrusion 64 at the right end of the front weight has a round bar shape. The protrusion 64 at the right end of the front weight has a tapered portion 64a that becomes smaller in diameter toward the tip in the protruding direction of the protrusion 64 at the right end of the front weight from the front lower weight body 63.

[0144] The protrusion 65 at the left end of the front weight projects downward from the lower surface of the left end of the front lower weight body 63. This protrusion 65 at the left end of the front weight is an example of the weight end protrusion in the present invention. The protrusion 65 at the left end of the front weight is arranged at a position symmetric with the protrusion 64 at the right end of the front weight with respect to the center in the left-right direction of the front lower weight body 63. The protrusion 65 at the left end of the front weight has the same shape as the protrusion 64 at the right end of the front weight, and has a tapered portion 65a that becomes smaller in diameter toward the tip in the protruding direction of the protrusion 65 at the left end of the front weight from the front lower weight body 63. The protruding amount of the protrusion 65 at the left end of the front weight from the lower surface of the front lower weight body 63 is equal to the protruding amount of the protrusion 64 at the right end of the front weight from the lower surface of the front lower weight body 63.

[0145] Also, in this fourth modification, the right front gantry 30 of the right crawler frame front portion 27a supports the right end portion of the front lower weight 61 from below with the right end portion of the front lower weight 61 placed thereon. This right front gantry 30 is an example of the crawler frame gantry in the present invention. On the right front gantry 30, the right end portion of the front lower weight body 63 among the right end portions of the front lower weight 61 is placed. As shown in Figs. 15 to 17, the right front gantry 30 has a pair of legs 31 similar to the pair of legs 31 of the right front gantry 30 in the above embodiment, and a right front placement portion 81 installed on the pair of legs 31.

[0146] The right front mounting portion 81 is a portion on which the right end portion of the front lower weight body 63 is mounted, and has a flat plate shape extending in the front-rear direction. This right front mounting portion 81 is installed on the upper surface near the left end portions of the pair of leg portions 31 and is fixed to the pair of leg portions 31.

[0147] Also, in this fourth modification example, the right crawler frame front portion 27a has a right front restraint portion 33 (see FIG. 17) that restrains the movement of the right end portion of the front lower weight 61 mounted on the right front pedestal 30 in the front-rear direction and the left-right direction. This right front restraint portion 33 is an example of the crawler frame restraint portion in the present invention. The right front restraint portion 33 has a right front protrusion coupling portion 82 provided on the right front mounting portion 81 of the right front pedestal 30. This right front protrusion coupling portion 82 is an example of the protrusion coupling portion in the present invention.

[0148] The right front protrusion coupling portion 82 is coupled to the right end protrusion 64 of the front weight so as to restrain the movement of the right end protrusion 64 of the front weight in the front-rear direction and the left-right direction in a state where the right end portion of the front lower weight body 63 is mounted on the right front mounting portion 81 of the right front pedestal 30. The right front protrusion coupling portion 82 is integrally formed with the right front mounting portion 81. That is, the right front protrusion coupling portion 82 is integrally formed with the right front mounting portion 81 and has a flat plate shape. The right front protrusion coupling portion 82 is provided with a right front insertion hole 82a (see FIG. 17) into which the right end protrusion 64 of the front weight can be inserted from above at the same time as the right end portion of the front lower weight body 63 is mounted on the right front mounting portion 81. The right front insertion hole 82a is an example of the insertion hole in the present invention. The right front insertion hole 82a is a circular hole when viewed from above. The right front protrusion coupling portion 82 is coupled to the right end protrusion 64 of the front weight so as to restrain the movement of the right end protrusion 64 of the front weight inserted into the right front insertion hole 82a in the front-rear direction and the left-right direction.

[0149] In addition, in this fourth modification example, the left front pedestal 43 of the front portion 19a of the left crawler frame supports the left end portion of the front lower weight 61 from below with the left end portion of the front lower weight 61 placed thereon. This left front pedestal 43 is an example of the crawler frame pedestal in the present invention. On the left front pedestal 43, the left end portion of the front lower weight main body 63 among the left end portions of the front lower weight 61 is placed. The left front pedestal 43 is configured symmetrically with the right front pedestal 30 in the left-right direction. Specifically, the left front pedestal 43 has a pair of leg portions 83 and a left front placement portion 84 configured symmetrically with the pair of leg portions 31 and the right front placement portion 81 of the right front pedestal 30 in the left-right direction. On the left front placement portion 84, the left end portion of the front lower weight main body 63 is placed.

[0150] The front portion 19a of the left crawler frame has a left front restraint portion 44 (see FIG. 13) that restrains the movement of the left end portion of the front lower weight 61 placed on the left front pedestal 43 in the front-rear direction and the left-right direction. This left front restraint portion 44 is an example of the crawler frame restraint portion in the present invention. The left front restraint portion 44 has a left front protrusion coupling portion 85 provided on the left front placement portion 84 and configured in the same manner as the right front protrusion coupling portion 82. This left front protrusion coupling portion 85 is an example of the protrusion coupling portion in the present invention. The left front protrusion coupling portion 85 is provided with a left front insertion hole 85a configured in the same manner as the right front insertion hole 82a. The left front insertion hole 85a is an example of the insertion hole in the present invention. The left front protrusion coupling portion 85 is coupled to the left end protrusion 65 of the front weight so as to restrain the movement of the left end protrusion 65 of the front weight in the front-rear direction and the left-right direction in a state where the left end portion of the front lower weight main body 63 is placed on the left front placement portion 84.

[0151] In addition, the rear lower weight 71 has a rear lower weight main body 73, a rear weight right end protrusion 74, and a rear weight left end protrusion 75 configured symmetrically with the front lower weight main body 63, the front weight right end protrusion 64, and the front weight left end protrusion 65 in the front-rear direction (see FIG. 13).

[0152] The right rear pedestal 45 of the rear part 27b of the right crawler frame supports the right end portion of the rear lower weight 71 from below with the right end portion of the rear lower weight 71 placed thereon. This right rear pedestal 45 is an example of the crawler frame pedestal in the present invention. On the right rear pedestal 45, the right end portion of the rear lower weight body 73 among the right end portions of the rear lower weight 71 is placed. The right rear pedestal 45 is configured symmetrically with the right front pedestal 30 in the front-rear direction. Specifically, the right rear pedestal 45 has a pair of legs 86 and a right rear placement portion 87 configured symmetrically with the pair of legs 31 and the right front placement portion 81 of the right front pedestal 30 in the front-rear direction. The right rear placement portion 87 is a portion where the right end portion of the rear lower weight body 73 is placed thereon.

[0153] The rear part 27b of the right crawler frame has a right rear restraint portion 46 that restrains the movement of the right end portion of the rear lower weight 71 placed on the right rear pedestal 45 in the front-rear direction and the left-right direction. This right rear restraint portion 46 is an example of the crawler frame restraint portion in the present invention. The right rear restraint portion 46 has a right rear protrusion coupling portion 88 provided on the right rear placement portion 87 and configured in the same manner as the right front protrusion coupling portion 82. This right rear protrusion coupling portion 88 is an example of the protrusion coupling portion in the present invention.

[0154] The right rear protrusion coupling portion 88 is provided with a right rear insertion hole 88a configured in the same manner as the right front insertion hole 82a. The right rear insertion hole 88a is an example of the insertion hole in the present invention. The right rear protrusion coupling portion 88 couples with the right end protrusion 74 of the rear weight so as to restrain the movement of the right end protrusion 74 of the rear weight in the front-rear direction and the left-right direction in a state where the right end portion of the rear lower weight body 73 is placed on the right rear placement portion 87 and is inserted into the right rear insertion hole 88a.

[0155] Further, the left rear pedestal 47 of the rear part 19b of the left crawler frame supports the left end portion of the rear lower weight 71 from below with the left end portion of the rear lower weight 71 placed thereon. This left rear pedestal 47 is an example of the crawler frame pedestal in the present invention. On the left rear pedestal 47, the left end portion of the rear lower weight body 73 among the left end portions of the rear lower weight 71 is placed. The left rear pedestal 47 is configured symmetrically with the left front pedestal 43 in the front-rear direction. Specifically, the left rear pedestal 47 has a pair of leg portions 89 and a left rear mounting portion 90 configured symmetrically with the pair of leg portions 83 and the left front mounting portion 84 of the left front pedestal 43 in the front-rear direction. The left rear mounting portion 90 is a portion on which the left end portion of the rear lower weight body 73 is placed.

[0156] The rear part 19b of the left crawler frame has a left rear restraint portion 48 that restrains the movement of the left end portion of the rear lower weight 71 placed on the left rear pedestal 47 in the front-rear direction and the left-right direction. This left rear restraint portion 48 is an example of the crawler frame restraint portion in the present invention. The left rear restraint portion 48 is provided on the left rear mounting portion 90 and has a left rear protrusion coupling portion 91 configured in the same manner as the right front protrusion coupling portion 82. This left rear protrusion coupling portion 91 is an example of the protrusion coupling portion in the present invention.

[0157] The left rear protrusion coupling portion 91 is provided with a left rear insertion hole 91a configured in the same manner as the right front insertion hole 82a. The left rear insertion hole 91a is an example of the insertion hole in the present invention. The left rear protrusion coupling portion 91 is coupled to the left end protrusion 75 of the rear weight so as to restrain the movement of the left end protrusion 75 of the rear weight in the front-rear direction and the left-right direction in a state where the left end portion of the rear lower weight body 73 is placed on the left rear mounting portion 90 and is inserted into the left rear insertion hole 91a.

[0158] Also, in this fourth modification, a configuration similar to the configuration for restraining the movement of the right end portion of the front weight 13 in the above embodiment is applied to the configuration for restraining the movement of the right end portion of the front upper weight 62, and a configuration similar to the configuration for restraining the movement of the left end portion of the front weight 13 in the above embodiment is applied to the configuration for restraining the movement of the left end portion of the front upper weight 62.

[0159] Specifically, the front upper weight 62 is loaded on the front lower weight 61 so as to cover the front lower weight 61 from the right end portion to the left end portion of the front lower weight 61. The front upper weight 62 is fixed to the front lower weight 61 in a state separable upward from the front lower weight 61. The right end portion of the front upper weight 62 has a front upper weight right recess 92 (see FIG. 15) which is a recess opening downward on its lower surface and opening rightward on its right side surface. The front upper weight right recess 92 is configured in the same manner as the recess 50 at the right end portion of the front weight 13 in the above embodiment.

[0160] Specifically, the front upper weight 62 has a front upper weight main body 62a that occupies most of the front upper weight 62, and a right end plate 62b that covers and is fixed to the right side surface of the front upper weight main body 62a. A recess 92a similar to the recess 50a provided at the right end portion of the front weight 13 in the above embodiment is provided at the right end portion of the front upper weight main body 62a. A notch 92b similar to the notch 50b provided in the right end plate 13b of the front weight 13 in the above embodiment is provided in the right end plate 62b. The front upper weight right recess 92 is formed by the notch 92b and the recess 92a.

[0161] The left end portion of the front upper weight 62 is configured symmetrically with the right end portion of the front upper weight 62. Specifically, the left end portion of the front upper weight 62 has a front upper weight left recess (not shown) which is a recess opening downward on its lower surface and opening leftward on its left side surface. The front upper weight left recess is configured symmetrically with the front upper weight right recess 92.

[0162] The right end portion of the front lower weight 61 has a front weight right restraint portion 94 that restrains the movement of the right end portion of the front upper weight 62 placed thereon in the front-rear direction and to the right. This front weight right restraint portion 94 is installed on the upper surface of the right end portion of the front lower weight body 63 so as to protrude upward from the upper surface of the right end portion of the front lower weight body 63, and is a convex portion that fits into the front upper weight right recess 92 of the right end portion of the front upper weight 62 placed on the right end portion of the front lower weight body 63. This front weight right restraint portion 94 has the same configuration as the right front restraint portion 33 in the above embodiment. That is, the front weight right restraint portion 94 has a front weight right end portion front-rear movement restraint portion 95 and a front weight rightward movement restraint portion 96 configured in the same manner as the front-rear movement restraint portion 37 and the rightward movement restraint portion 38 of the right front restraint portion 33 in the above embodiment.

[0163] The front weight right restraint portion 94 has an upper surface of the front weight right restraint portion 94a that faces upward. This upper surface of the front weight right restraint portion 94a is an example of the upper surface of the weight restraint portion in the present invention. The upper surface of the front weight right restraint portion 94a includes an upper surface of the front weight right end portion front-rear movement restraint portion 95a that faces upward among the front weight right end portion front-rear movement restraint portion 95 and an upper surface of the front weight rightward movement restraint portion 96a that faces upward among the front weight rightward movement restraint portion 96.

[0164] The front weight right end portion front-rear movement restraint portion 95 has the same mountain-shaped plate shape as the front-rear movement restraint portion 37 in the above embodiment, and fits into the notch 92b that constitutes the front upper weight right recess 92 in the same manner as the fitting of the front-rear movement restraint portion 37 to the notch 50b in the above embodiment. In a state where the front weight right restraint portion 94 is fitted into the front upper weight right recess 92, that is, in a state where the front weight right end portion front-rear movement restraint portion 95 is fitted into the notch 92b, the front end of the front weight right end portion front-rear movement restraint portion 95 abuts against the lower front portion of the inner surface of the front upper weight right recess 92, and the rear end of the front weight right end portion front-rear movement restraint portion 95 abuts against the lower rear portion of the inner surface of the front upper weight right recess 92, whereby the front weight right end portion front-rear movement restraint portion 95 restrains the movement of the right end portion of the front upper weight 62 in the front-rear direction.

[0165] The upper surface 95a of the front weight right end portion front-rear movement restraint portion slopes downward as it extends forward from the central portion 95b in the front-rear direction of the upper surface 95a, and has a front inclined portion 95c and a rear inclined portion 95d that slopes downward as it extends rearward from the central portion 95b. The front inclined portion 95c is an example of the front inclined portion of the weight restraint portion in the present invention, and the rear inclined portion 95d is an example of the rear inclined portion of the weight restraint portion in the present invention.

[0166] Also, with the front weight right restraint portion 94 fitted into the front upper weight right concave portion 92, the left end portion of the front weight rightward movement restraint portion 96 abuts against the right inner surface of the front upper weight right concave portion 92 from the right side at the position of the lower end of the front upper weight right concave portion 92. Thereby, the front weight rightward movement restraint portion 96 restrains the rightward movement of the right end portion of the front upper weight 62. The upper surface 96a of the front weight rightward movement restraint portion is located on the inner side (left side) in the left-right direction with respect to the front inclined portion 95c and the rear inclined portion 95d of the upper surface 95a of the front weight right end portion front-rear movement restraint portion 95, and has an inner inclined portion 96b that slopes downward as it extends inward (leftward) in the left-right direction. This inner inclined portion 96b is an example of the inner inclined portion of the weight restraint portion in the present invention.

[0167] Further, the left end portion of the front lower weight 61 has a front weight left restraint portion 97 that restrains the movement of the left end portion of the front upper weight 62 placed thereon in the front-rear direction and to the left. This front weight left restraint portion 97 is installed on the upper surface of the left end portion of the front lower weight body 63 so as to protrude upward from the upper surface of the left end portion of the front lower weight body 63, and is a convex portion that fits into a front upper weight left concave portion (not shown) of the left end portion of the front upper weight 62 placed on the left end portion of the front lower weight body 63. The front weight left restraint portion 97 is configured symmetrically with the front weight right restraint portion 94 in the left-right direction. Specifically, the front weight left restraint portion 97 has a front weight left end portion front-rear movement restraint portion 98 and a front weight leftward movement restraint portion 99 that are configured symmetrically with the front weight right end portion front-rear movement restraint portion 95 and the front weight rightward movement restraint portion 96 in the left-right direction. The front weight left end portion front-rear movement restraint portion 98 is a portion that restrains the movement of the left end portion of the front upper weight 62 in the front-rear direction, and the front weight leftward movement restraint portion 99 is a portion that restrains the movement of the left end portion of the front upper weight 62 to the left.

[0168] The front weight left restraint portion 97 has a front weight left restraint portion upper surface 97a that is a surface facing upward. The front weight left restraint portion upper surface 97a is an example of the weight restraint portion upper surface in the present invention. The front weight left restraint portion upper surface 97a includes a front weight left end portion front-rear movement restraint portion upper surface 98a that is a surface facing upward among the front weight left end portion front-rear movement restraint portion 98, and a front weight leftward movement restraint portion upper surface 99a that is a surface facing upward among the front weight leftward movement restraint portion 99. The front weight left end portion front-rear movement restraint portion upper surface 98a is configured in the same manner as the front weight right end portion front-rear movement restraint portion upper surface 95a. Further, the front weight leftward movement restraint portion upper surface 99a is configured symmetrically with the front weight rightward movement restraint portion upper surface 96a in the left-right direction. That is, the front weight leftward movement restraint portion upper surface 99a has an inner inclined portion 99b that is configured symmetrically with the inner inclined portion 96b of the front weight rightward movement restraint portion upper surface 96a. This inner inclined portion 99b is an example of the weight restraint portion inner inclined portion in the present invention.

[0169] With the left end portion of the front upper weight 62 placed on the left end portion of the front lower weight body 63, the front weight left restraint portion 97 fits into a front upper weight left recess (not shown in detail) at the left end portion of the front upper weight 62, whereby the movement of the left end portion of the front upper weight 62 in the front-rear direction and to the left with respect to the left end portion of the front lower weight 61 is restrained. The fitting structure between the front upper weight left recess and the front weight left restraint portion 97 is symmetric with the fitting structure between the front upper weight right recess 92 and the front weight right restraint portion 94 in the left-right direction.

[0170] Also, the rear upper weight 72 is loaded on the rear lower weight 71 so as to cover the rear lower weight 71 from the right end portion to the left end portion thereof. The rear upper weight 72 is fixed to the rear lower weight 71 in a state where it can be separated upward from the rear lower weight 71. The right end portion of the rear upper weight 72 has a rear upper weight right recess (not shown in detail) which is a recess opening downward on its lower surface and opening rightward on its right side surface. The rear upper weight right recess is configured in the same manner as the front upper weight right recess 92. Further, the left end portion of the rear upper weight 72 has a rear upper weight left recess (not shown in detail) which is a recess opening downward on its lower surface and opening leftward on its left side surface. The rear upper weight left recess is configured symmetrically with the rear upper weight right recess in the left-right direction.

[0171] The right end portion of the rear lower weight 71 has a rear weight right restraint portion 101 that restrains the movement of the right end portion of the rear upper weight 72 placed thereon in the front-rear direction and to the right. This rear weight right restraint portion 101 is installed on the upper surface of the right end portion of the rear lower weight main body 73 so as to protrude upward from the upper surface of the right end portion of the rear lower weight main body 73, and is a convex portion that fits into a rear upper weight right concave portion (not shown in detail) of the right end portion of the rear upper weight 72 placed on the right end portion of the rear lower weight main body 73. This rear weight right restraint portion 101 is configured in the same manner as the front weight right restraint portion 94. That is, the rear weight right restraint portion 101 has a rear weight right end portion front-rear movement restraint portion 102 configured in the same manner as the front weight right end portion front-rear movement restraint portion 95, and a rear weight rightward movement restraint portion 103 configured in the same manner as the front weight rightward movement restraint portion 96. When the rear weight right restraint portion 101 fits into the rear upper weight right concave portion (not shown in detail) of the right end portion of the rear upper weight 72 in a state where the right end portion of the rear upper weight 72 is placed on the right end portion of the rear lower weight main body 73, the movement of the right end portion of the rear upper weight 72 with respect to the right end portion of the rear lower weight 71 in the front-rear direction and to the right is restrained. The fitting structure between the rear upper weight right concave portion and the rear weight right restraint portion 101 is the same as the fitting structure between the front upper weight right concave portion 92 and the front weight right restraint portion 94.

[0172] The left end of the rear lower weight 71 has a rear weight left restraint portion 104 that restrains the movement of the left end of the rear upper weight 72 placed thereon in the front-rear direction and to the left. This rear weight left restraint portion 104 is installed on the upper surface of the left end of the rear lower weight body 73 so as to protrude upward from the upper surface of the left end of the rear lower weight body 73, and is a convex portion that fits into the rear upper weight left concave portion at the left end of the rear upper weight 72 placed on the left end of the rear lower weight body 73. This rear weight left restraint portion 104 is configured in the same manner as the front weight left restraint portion 97 and is configured symmetrically with the rear weight right restraint portion 101 in the left-right direction. This rear weight left restraint portion 104 has a rear weight left end front-rear movement restraint portion 105 configured in the same manner as the front weight left end front-rear movement restraint portion 98, and a rear weight leftward movement restraint portion 106 configured in the same manner as the front weight leftward movement restraint portion 99. When the left end of the rear upper weight 72 is placed on the left end of the rear lower weight body 73 and the rear weight left restraint portion 104 fits into the rear upper weight left concave portion (not shown) at the left end of the rear upper weight 72, the movement of the left end of the rear upper weight 72 with respect to the left end of the rear lower weight 71 in the front-rear direction and to the left is restrained. The fitting structure between the rear upper weight left concave portion and the rear weight left restraint portion 104 is symmetric with the fitting structure between the rear upper weight right concave portion and the rear weight right restraint portion 101 in the left-right direction.

[0173] Also, the front lower weight 61 is configured such that when the front lower weight 61 is placed on the ground, the front lower weight 61 can be placed on the ground with the front lower weight body 63 floating from the ground, and when the front lower weight 61 is loaded on a transport vehicle for transporting the front lower weight 61, the front lower weight 61 can be placed on the loading surface of the transport vehicle with the front lower weight body 63 floating from the loading surface of the transport vehicle.

[0174] Specifically, the front lower weight 61 has a front lower weight right support leg 66 and a front lower weight left support leg 67 that protrude downward from the lower surface of the front lower weight body 63. The protruding amounts of the front lower weight right support leg 66 and the front lower weight left support leg 67 from the lower surface of the front lower weight body 63 are equal to the protruding amounts of the front weight right end protrusion 64 and the front weight left end protrusion 65 from the lower surface of the front lower weight body 63. The front lower weight right support leg 66 and the front lower weight left support leg 67, together with the front weight right end protrusion 64 and the front weight left end protrusion 65, support the front lower weight body 63 in a floating state with respect to the ground or the loading surface of the transport vehicle. In other words, the front weight right end protrusion 64 and the front weight left end protrusion 65 also have the function of support legs that support the front lower weight body 63 in a floating state with respect to the ground or the loading surface. The front lower weight right support leg 66 is located to the right of the center in the left-right direction of the front lower weight body 63 and to the left of the front weight right end protrusion 64, and is located behind the front weight right end protrusion 64. The front lower weight left support leg 67 is located to the left of the center in the left-right direction of the front lower weight body 63 and to the right of the front weight left end protrusion 65, and is located behind the front weight left end protrusion 65. The front lower weight right support leg 66 and the front lower weight left support leg 67 are arranged at positions that are symmetric with respect to each other with respect to the center in the left-right direction of the front lower weight body 63.

[0175] Also, regarding the rear lower weight 71, similar to the front lower weight 61, when the rear lower weight 71 is placed on the ground, the rear lower weight 71 can be placed on the ground with the rear lower weight main body 73 floating above the ground, and when the rear lower weight 71 is loaded onto a transport vehicle for transporting the rear lower weight 71, the rear lower weight 71 can be placed on the loading surface of the transport vehicle with the rear lower weight main body 73 floating above the loading surface of the transport vehicle. Specifically, the rear lower weight 71 is configured symmetrically with the front lower weight 61 in the front-rear direction, and has a rear lower weight right support leg 76 and a rear lower weight left support leg 77 that protrude downward from the lower surface of the rear lower weight main body 73. The rear lower weight right support leg 76 and the rear lower weight left support leg 77 are configured in the same manner as the front lower weight right support leg 66 and the front lower weight left support leg 67. The rear lower weight right support leg 76 and the rear lower weight left support leg 77, together with the rear weight right end protrusion 74 and the rear weight left end protrusion 75, support the rear lower weight main body 73 in a state of floating above the ground or the loading surface of the transport vehicle. In other words, the rear weight right end protrusion 74 and the rear weight left end protrusion 75 also have a function as support legs that support the rear lower weight main body 73 in a state of floating above the ground or the loading surface.

[0176] In this fourth modification example, while placing the right end portion of the front lower weight body 63 on the right front placement portion 81 of the right front pedestal 30, the right front end projection 64 of the front weight is inserted into the right front insertion hole 82a of the right front projection coupling portion 82, thereby restricting the movement of the right front end projection 64 of the front weight in the front-rear direction and the left-right direction. At the same time, while placing the left end portion of the front lower weight body 63 on the left front placement portion 84 of the left front pedestal 43, the left front end projection 65 of the front weight is inserted into the left front insertion hole 85a of the left front projection coupling portion 85, thereby restricting the movement of the left front end projection 65 of the front weight in the front-rear direction and the left-right direction. Then, by restricting the movement of the right front end projection 64 of the front weight, the movement of the right end portion of the front lower weight 61 in the front-rear direction and the left-right direction is restricted, and by restricting the movement of the left front end projection 65 of the front weight, the movement of the left end portion of the front lower weight 61 in the front-rear direction and the left-right direction is restricted. Therefore, in this fourth modification example, the work related to restricting the right end portion and the left end portion of the front lower weight 61 can be simplified.

[0177] Also, in this fourth modification example, while placing the right end portion of the rear lower weight body 73 on the right rear placement portion 87 of the right rear pedestal 45, the right rear end projection 74 of the rear weight is inserted into the right rear insertion hole 88a of the right rear projection coupling portion 88, thereby restricting the movement of the right rear end projection 74 of the rear weight in the front-rear direction and the left-right direction. At the same time, while placing the left end portion of the rear lower weight body 73 on the left rear placement portion 90 of the left rear pedestal 47, the left rear end projection 75 of the rear weight is inserted into the left rear insertion hole 91a of the left rear projection coupling portion 91, thereby restricting the movement of the left rear end projection 75 of the rear weight in the front-rear direction and the left-right direction. Then, by restricting the movement of the right rear end projection 74 of the rear weight, the movement of the right end portion of the rear lower weight 71 in the front-rear direction and the left-right direction is restricted, and by restricting the movement of the left rear end projection 75 of the rear weight, the movement of the left end portion of the rear lower weight 71 in the front-rear direction and the left-right direction is restricted. Therefore, in this fourth modification example, the work related to restricting the right end portion and the left end portion of the rear lower weight 71 can be simplified.

[0178] Also, in this fourth modification example, the front weight right end protrusion 64 has a tapered portion 64a that becomes smaller in diameter toward its tip, and the front weight left end protrusion 65 has a tapered portion 65a that becomes smaller in diameter toward its tip. Further, the rear weight right end protrusion 74 and the rear weight left end protrusion 75 also each have a similar tapered portion. Therefore, when placing the right end of the front lower weight body 63 on the right front mounting portion 81 of the right front pedestal 30, even if the front weight right end protrusion 64 is somewhat misaligned in the front-rear direction and / or the left-right direction with respect to the right front insertion hole 82a, the front weight right end protrusion 64 can be inserted into the right front insertion hole 82a. When placing the left end of the front lower weight body 63 on the left front mounting portion 84 of the left front pedestal 43, even if the front weight left end protrusion 65 is somewhat misaligned in the front-rear direction and / or the left-right direction with respect to the left front insertion hole 85a, the front weight left end protrusion 65 can be inserted into the left front insertion hole 85a. Also, when placing the right end of the rear lower weight body 73 on the right rear mounting portion 87 of the right rear pedestal 45, even if the rear weight right end protrusion 74 is somewhat misaligned in the front-rear direction and / or the left-right direction with respect to the right rear insertion hole 88a, the rear weight right end protrusion 74 can be inserted into the right rear insertion hole 88a. When placing the left end of the rear lower weight body 73 on the left rear mounting portion 90 of the left rear pedestal 47, even if the rear weight left end protrusion 75 is somewhat misaligned in the front-rear direction and / or the left-right direction with respect to the left rear insertion hole 91a, the rear weight left end protrusion 75 can be inserted into the left rear insertion hole 91a.

[0179] Also, in this fourth modification example, since it is possible to select whether to stack the front upper weight 62 on the front lower weight 61 stacked on the left front pedestal 43 and the right front pedestal 30, the weight of the weight stacked on the left front pedestal 43 and the right front pedestal 30 can be adjusted according to whether the front upper weight 62 is stacked on the front lower weight 61 or not. Similarly, since it is possible to select whether to stack the rear upper weight 72 on the rear lower weight 71 stacked on the left rear pedestal 47 and the right rear pedestal 45, the weight of the weight stacked on the left rear pedestal 47 and the right rear pedestal 45 can be adjusted according to whether the rear upper weight 72 is stacked on the rear lower weight 71 or not.

[0180] Also, in this fourth modification example, when disassembling and transporting the crane 1, the front lower weight 61 and the front upper weight 62 can be separated and transported separately, and the rear lower weight 71 and the rear upper weight 72 can be separated and transported separately. The weight of each of the front lower weight 61 and the front upper weight 62 is smaller than the total weight of the front lower weight 61 and the front upper weight 62 in a stacked state, and the weight of each of the rear lower weight 71 and the rear upper weight 72 is smaller than the total weight of the rear lower weight 71 and the rear upper weight 72 in a stacked state. Therefore, in this fourth modification example, even a transport vehicle with a relatively low loading capacity can transport each of the front lower weight 61, the front upper weight 62, the rear lower weight 71, and the rear upper weight 72.

[0181] Also, in this fourth modification example, the front lower weight 61 and the front upper weight 62 can be individually lifted and stacked on the left front pedestal 43 and the right front pedestal 30, and the rear lower weight 71 and the rear upper weight 72 can be individually lifted and stacked on the left rear pedestal 47 and the right rear pedestal 45. As described above, the weight of each of the front lower weight 61 and the front upper weight 62 is smaller than the total weight of the front lower weight 61 and the front upper weight 62, and the weight of each of the rear lower weight 71 and the rear upper weight 72 is smaller than the total weight of the rear lower weight 71 and the rear upper weight 72. Therefore, in this fourth modification example, the individual lifting operations of the front lower weight 61 and the front upper weight 62 for stacking them on the left front pedestal 43 and the right front pedestal 30, and the individual lifting operations of the rear lower weight 71 and the rear upper weight 72 for stacking them on the left rear pedestal 47 and the right rear pedestal 45 are facilitated, and even an auxiliary crane with a relatively low lifting capacity can perform those lifting operations.

[0182] Also, in this fourth modification example, when loading the front upper weight 62 onto the front lower weight 61, by utilizing the weight of the front upper weight 62, the vertical restraint of the front upper weight 62 is omitted. Only the combination of placing the front upper weight 62 on the front lower weight 61 and the horizontal restraint of the front upper weight 62 by the front weight right restraint portion 94 and the front weight left restraint portion 97 can fix the front upper weight 62 to the front lower weight 61. Therefore, the front upper weight 62 can be fixed to the front lower weight 61 with a simple operation. Similarly, when loading the rear upper weight 72 onto the rear lower weight 71, by utilizing the weight of the rear upper weight 72, the vertical restraint of the rear upper weight 72 is omitted. Only the combination of placing the rear upper weight 72 on the rear lower weight 71 and the horizontal restraint of the rear upper weight 72 by the rear weight right restraint portion 101 and the rear weight left restraint portion 104 can fix the rear upper weight 72 to the rear lower weight 71. Therefore, the rear upper weight 72 can be fixed to the rear lower weight 71 with a simple operation.

[0183] Also, in this fourth modification example, the right end portion of the front upper weight 62 has a front upper weight right concave portion 92 that opens downward, and the front weight right restraint portion 94 is a convex portion that fits into the front upper weight right concave portion 92 from below so as to restrain the movement of the right end portion of the front upper weight 62 in the front-rear direction and to the right. Further, the left end portion of the front upper weight 62 has a front upper weight left concave portion (not shown) that opens downward, and the front weight left restraint portion 97 is a convex portion that fits into the front upper weight left concave portion from below so as to restrain the movement of the left end portion of the front upper weight 62 in the front-rear direction and to the left. Therefore, when the right end portion of the front upper weight 62 is placed on the right end portion of the front lower weight 61, at the same time, the front weight right restraint portion 94 is fitted into the front upper weight right concave portion 92 from below to restrain the movement of the right end portion of the front upper weight 62 in the front-rear direction and to the right, and when the left end portion of the front upper weight 62 is placed on the left end portion of the front lower weight 61, at the same time, the front weight left restraint portion 97 is fitted into the front upper weight left concave portion from below to restrain the movement of the left end portion of the front upper weight 62 in the front-rear direction and to the left. For this reason, the work related to restraining the right end portion and the left end portion of the front upper weight 62 can be simplified.

[0184] Also, the right end portion of the rear upper weight 72 has a rear upper weight right concave portion (not shown) that opens downward, and the rear weight right restraint portion 101 is a convex portion that fits into the rear upper weight right concave portion from below so as to restrain the movement of the right end portion of the rear upper weight 72 in the front-rear direction and to the right. Further, the left end portion of the rear upper weight 72 has a rear upper weight left concave portion (not shown) that opens downward, and the rear weight left restraint portion 104 is a convex portion that fits into the rear upper weight left concave portion from below so as to restrain the movement of the left end portion of the rear upper weight 72 in the front-rear direction and to the left. Therefore, similar to the case of the front upper weight 62, the work related to restraining the right end portion and the left end portion of the rear upper weight 72 can be simplified.

[0185] Further, in this fourth modification example, the upper surface 95a of the front weight right end longitudinal movement restraint portion 95 of the front weight right restraint portion 94 has a front inclined portion 95c that inclines downward as it goes forward from the central portion 95b thereof, and a rear inclined portion 95d that inclines downward as it goes backward from the central portion 95b thereof. Therefore, when placing the right end portion of the front upper weight 62 on the right end portion of the front lower weight 61, even if the front upper weight right recess 92 is displaced in the front-rear direction with respect to the front weight right restraint portion 94 and the front edge or the rear edge of the front upper weight right recess 92 abuts on the upper surface 95a of the front weight right end longitudinal movement restraint portion 95, due to the inclination of the front inclined portion 95c and the rear inclined portion 95d of the upper surface 95a, the right end portion of the front upper weight 62 can be guided to a position where the front upper weight right recess 92 fits with the front weight right restraint portion 94, and the fitting between the front upper weight right recess 92 and the front weight right restraint portion 94 can be performed without hindrance.

[0186] Specifically, when placing the right end portion of the front upper weight 62 on the right end portion of the front lower weight 61, if the front upper weight right recess 92 is displaced forward with respect to the front weight right restraint portion 94 and the rear edge of the front upper weight right recess 92 abuts on the rear inclined portion 95d of the upper surface 95a of the front weight right end longitudinal movement restraint portion 95, the right end portion of the front upper weight 62 can be guided to a position where the front upper weight right recess 92 fits with the front weight right restraint portion 94 while moving downward and displacing backward along the inclination of the rear inclined portion 95d. Further, when placing the right end portion of the front upper weight 62 on the right end portion of the front lower weight 61, if the front upper weight right recess 92 is displaced backward with respect to the front weight right restraint portion 94 and the front edge of the front upper weight right recess 92 abuts on the front inclined portion 95c of the upper surface 95a of the front weight right end longitudinal movement restraint portion 95, the right end portion of the front upper weight 62 can be guided to a position where the front upper weight right recess 92 fits with the front weight right restraint portion 94 while moving downward and displacing forward along the inclination of the front inclined portion 95c.

[0187] Also, in this fourth modification example, the upper surfaces of the front weight left end longitudinal movement restraint portions 98 of the front weight left restraint portion 97, the upper surfaces of the rear weight right end longitudinal movement restraint portions 102 of the rear weight right restraint portion 101, and the upper surfaces of the rear weight left end longitudinal movement restraint portions 105 of the rear weight left restraint portion 104 are configured in the same manner as the upper surface 95a of the front weight right end longitudinal movement restraint portion 95 of the front weight right restraint portion 94. Therefore, similar to the case of the fitting between the front upper weight right recess 92 and the front weight right restraint portion 94, the longitudinal displacement in the front-rear direction during the fitting between the front upper weight left recess and the front weight left restraint portion 97, the longitudinal displacement in the front-rear direction during the fitting between the rear upper weight right recess and the rear weight right restraint portion 101, and the longitudinal displacement in the front-rear direction during the fitting between the rear upper weight left recess and the rear weight left restraint portion 104 can be eliminated respectively, and their fitting can be performed without hindrance.

[0188] Also, in this fourth modification example, since the upper surface 96a of the front weight rightward movement restraint portion 96 of the front weight right restraint portion 94 has an inner inclined portion 96b that inclines downward as it goes leftward, when the right end portion of the front upper weight 62 is placed on the right end portion of the front lower weight 61 and the front upper weight right recess 92 and the front weight right restraint portion 94 are fitted, if the front upper weight right recess 92 is longitudinally displaced to the right with respect to the front weight right restraint portion 94 and the left side edge of the front upper weight right recess 92 abuts against the inner inclined portion 96b, the inclination of the inner inclined portion 96b can guide the right end portion of the front upper weight 62 to the position where the front upper weight right recess 92 fits with the front weight right restraint portion 94, and the fitting between the front upper weight right recess 92 and the front weight right restraint portion 94 can be performed without hindrance.

[0189] Specifically, when the front upper weight right recess 92 is displaced to the right with respect to the front weight right restraint portion 94 and the left edge of the right end portion of the front upper weight 62 abuts against the inner inclined portion 96b of the upper surface 96a of the front weight rightward movement restraint portion 96 when placing the right end portion of the front upper weight 62 on the right end portion of the front lower weight 61, the right end portion of the front upper weight 62 can be displaced leftward while being moved downward along the inclination of the inner inclined portion 96b, and the right end portion of the front upper weight 62 can be guided to a position where the front upper weight right recess 92 fits with the front weight right restraint portion 94.

[0190] Further, since the upper surface 99a of the front weight leftward movement restraint portion 99 is symmetrical to the upper surface 96a of the front weight rightward movement restraint portion 96 in the left-right direction, when placing the left end portion of the front upper weight 62 on the left end portion of the front lower weight 61 and fitting the front upper weight left recess and the front weight left restraint portion 97, if the front upper weight left recess is displaced to the left with respect to the front weight left restraint portion 97 and the right edge of the front upper weight left recess abuts against the inner inclined portion 99b of the upper surface 99a of the front weight leftward movement restraint portion 99, the left end portion of the front upper weight 62 can be guided to a position where the front upper weight left recess fits with the front weight left restraint portion 97 by the inclination of the inner inclined portion 99b, and the fitting between the front upper weight left recess and the front weight left restraint portion 97 can be performed without any trouble.

[0191] Also, since the upper surface of the rear weight rightward movement restraint portion 103 of the rear weight right restraint portion 101 is configured in the same manner as the upper surface 96a of the front weight rightward movement restraint portion 96 of the front weight right restraint portion 94, when placing the right end portion of the rear upper weight 72 on the right end portion of the rear lower weight 71 and fitting the rear upper weight right recess and the rear weight right restraint portion 101, if the rear upper weight right recess is displaced to the right with respect to the rear weight right restraint portion 101, the displacement can be eliminated in the same manner as in the case of the fitting between the front upper weight right recess 92 and the front weight right restraint portion 94, and the fitting between the rear upper weight right recess and the rear weight right restraint portion 101 can be performed without any trouble.

[0192] Further, since the upper surface of the left rear weight moving restraint portion 106 of the rear weight left restraint portion 104 is configured in the same manner as the upper surface 99a of the left front weight moving restraint portion 99 of the front weight left restraint portion 97, when the left end portion of the rear upper weight 72 is placed on the left end portion of the rear lower weight 71 and the left concave portion of the rear upper weight and the rear weight left restraint portion 104 are fitted together, if the left concave portion of the rear upper weight is displaced to the left with respect to the rear weight left restraint portion 104, the displacement can be eliminated in the same manner as in the case of the fitting of the left concave portion of the front upper weight and the front weight left restraint portion 97, and the fitting of the left concave portion of the rear upper weight and the rear weight left restraint portion 104 can be performed without any trouble.

[0193] (13) Further, the lower traveling body in the present invention may have two or more stages of front upper weights configured to be loadable on the front weight (front lower weight). Further, the lower traveling body in the present invention may have two or more stages of rear upper weights configured to be loadable on the rear weight (rear lower weight).

[0194] In this case, among the front upper weights with two or more stages, the front upper weights other than the uppermost one have left and right restraint portions similar to the front weight left restraint portion and the front weight right restraint portion of the front weight (front lower weight). Each stage of the front upper weight has a front upper weight left concave portion and a front upper weight right concave portion. The left restraint portion of the lower stage front upper weight fits into the front upper weight left concave portion of the upper stage front upper weight stacked on the lower stage front upper weight, and the right restraint portion of the lower stage front upper weight fits into the front upper weight right concave portion of the upper stage front upper weight stacked on the lower stage front upper weight. As long as the movement of the upper stage front upper weight in the left-right direction and the front-back direction with respect to the lower stage front upper weight is restricted in this way. Similarly, among the rear upper weights with two or more stages, the rear upper weights other than the uppermost one have left and right restraint portions similar to the rear weight left restraint portion and the rear weight right restraint portion of the rear weight (rear lower weight). Each stage of the rear upper weight has a rear upper weight left concave portion and a rear upper weight right concave portion. The left restraint portion of the lower stage rear upper weight fits into the rear upper weight left concave portion of the upper stage rear upper weight stacked on the lower stage rear upper weight, and the right restraint portion of the lower stage rear upper weight fits into the rear upper weight right concave portion of the upper stage rear upper weight stacked on the lower stage rear upper weight. As long as the movement of the upper stage rear upper weight in the left-right direction and the front-back direction with respect to the lower stage rear upper weight is restricted in this way.

[0195] If the total weight of the weights loaded on the left front pedestal and the right front pedestal is the same, the greater the number of steps of the front upper weight, the smaller the weight of each step of the front upper weight and the weight of the front lower weight can be made. Also, if the total weight of the weights loaded on the left rear pedestal and the right rear pedestal is the same, the greater the number of steps of the rear upper weight, the smaller the weight of each step of the rear upper weight and the weight of the rear lower weight can be made. Therefore, according to this configuration, by changing the number of steps of the front upper weight loaded on the front weight (front lower weight), it is possible to more finely adjust the weight of the weights loaded on the left front pedestal and the right front pedestal, and by changing the number of steps of the rear upper weight loaded on the rear weight (rear lower weight), it is possible to more finely adjust the weight of the weights loaded on the left rear pedestal and the right rear pedestal. Also, according to this configuration, when transporting the front lower weight, each step of the front upper weight, the rear lower weight, and each step of the rear upper weight individually, even a transport vehicle with a lower transport capacity can transport those weights. Also, according to this configuration, the individual lifting operations of those weights for loading the front weight and each step of the front upper weight on the left front pedestal and the right front pedestal, and the individual lifting operations of those weights for loading the rear weight and each step of the rear upper weight on the left rear pedestal and the right rear pedestal become easier, and even an auxiliary crane with a lower lifting capacity can perform the lifting operation.

[0196] (14) When viewed from above, the shape of the front upper weight in the present invention may be different from the shape of the front weight (front lower weight) when viewed from above. Also, when viewed from above, the shape of the rear upper weight in the present invention may be different from the shape of the rear weight (rear lower weight) when viewed from above. In this case, the position where the left restraint portion of the front weight is provided in the front weight (front lower weight) is not limited to the left end of the front weight. As long as the left restraint portion of the front weight can be fitted into the left concave portion of the front upper weight at a position corresponding to the left end portion of the front upper weight that varies according to the shape of the front upper weight. The position where the right restraint portion of the front weight is provided in the front weight (front lower weight) is not limited to the right end of the front weight. As long as the right restraint portion of the front weight can be fitted into the right concave portion of the front upper weight at a position corresponding to the right end portion of the front upper weight that varies according to the shape of the front upper weight. Also, the position where the left restraint portion of the rear weight is provided in the rear weight (rear lower weight) is not limited to the left end of the rear weight. As long as the left restraint portion of the rear weight can be fitted into the left concave portion of the rear upper weight at a position corresponding to the left end portion of the rear upper weight that varies according to the shape of the rear upper weight. The position where the right restraint portion of the rear weight is provided in the rear weight (rear lower weight) is not limited to the right end of the rear weight. As long as the right restraint portion of the rear weight can be fitted into the right concave portion of the rear upper weight at a position corresponding to the right end portion of the rear upper weight that varies according to the shape of the rear upper weight.

[0197] For example, when the width of the front upper weight in the left-right direction is smaller than the width of the front weight (front lower weight) in the same direction, the position where the left restraint portion of the front weight is provided may be any position that enters from the left end of the front weight (front lower weight) to the right in accordance with the position of the left concave portion of the front upper weight at the left end of the front upper weight. The position where the right restraint portion of the front weight is provided may be any position that enters from the right end of the front weight (front lower weight) to the left in accordance with the position of the right concave portion of the front upper weight at the right end of the front upper weight. Also, when the width of the rear upper weight in the left-right direction is smaller than the width of the rear weight (rear lower weight) in the same direction, the position where the left restraint portion of the rear weight is provided may be any position that enters from the left end of the rear weight (rear lower weight) to the right in accordance with the position of the left concave portion of the rear upper weight at the left end of the rear upper weight. The position where the right restraint portion of the rear weight is provided may be any position that enters from the right end of the rear weight (rear lower weight) to the left in accordance with the position of the right concave portion of the rear upper weight at the right end of the rear upper weight.

[0198] (15) Further, the front upper weight and the rear upper weight of the lower traveling body in the present invention can be made common with the counterweight mounted on the rear part of the upper revolving body. The shape of the counterweight as viewed from above is different from the shape of each of the front weight (front lower weight) and the rear weight (rear lower weight) as viewed from above. However, the shape of each of the front upper weight and the rear upper weight as viewed from above may be made to coincide with the shape of the counterweight as viewed from above, and the front upper weight and the rear upper weight may be made common with the counterweight. In this case, since the shape of the front upper weight as viewed from above is different from the shape of the front weight (front lower weight) as viewed from above, and the shape of the rear upper weight as viewed from above is different from the shape of the rear weight (rear lower weight) as viewed from above, as described above, in the front weight, the front weight left restraint portion is arranged at a position where it can be fitted into the front upper weight left concave portion at the left end of the front upper weight, and the front weight right restraint portion is arranged at a position where it can be fitted into the front upper weight right concave portion at the right end of the front upper weight. Also, in the rear weight, the rear weight left restraint portion is arranged at a position where it can be fitted into the rear upper weight left concave portion at the left end of the rear upper weight, and the rear weight right restraint portion is arranged at a position where it can be fitted into the rear upper weight right concave portion at the right end of the rear upper weight.

[0199] (16) Further, in the configurations of the above-described embodiment and the first to third modified examples, the front part 27a of the right crawler frame may further have a front weight right end upper movement restraint portion that easily restrains the upward movement of the right end of the front weight 13, and the front part 19a of the left crawler frame may further have a front weight left end upper movement restraint portion that easily restrains the upward movement of the left end of the front weight 13. Also, the rear part 27b of the right crawler frame may further have a rear weight right end upper movement restraint portion that easily restrains the upward movement of the right end of the rear weight 14, and the rear part 19b of the left crawler frame may further have a rear weight left end upper movement restraint portion that easily restrains the upward movement of the left end of the rear weight 14.

[0200] Even with such a configuration, since the upward movement of the front weight 13 is suppressed by the large weight of the front weight 13, the restraint of the right end of the front weight 13 by the front weight right end upward movement restraint portion and the restraint of the left end of the front weight 13 by the front weight left end upward movement restraint portion can be made very simple. Also, since the upward movement of the rear weight 14 is suppressed by the large weight of the rear weight 14, the restraint of the right end of the rear weight 14 by the rear weight right end upward movement restraint portion and the restraint of the left end of the rear weight 14 by the rear weight left end upward movement restraint portion can be made very simple.

[0201] (17) Further, in the configuration of the fourth modification example, the right end of the front lower weight 61 may further have a front upper weight right end upward movement restraint portion that easily restrains the upward movement of the right end of the front upper weight 62, and the left end of the front lower weight 61 may further have a front upper weight left end upward movement restraint portion that easily restrains the upward movement of the left end of the front upper weight 62. Also, the right end of the rear lower weight 71 may further have a rear upper weight right end upward movement restraint portion that easily restrains the upward movement of the right end of the rear upper weight 72, and the left end of the rear lower weight 71 may further have a rear upper weight left end upward movement restraint portion that easily restrains the upward movement of the left end of the rear upper weight 72.

[0202] Even with such a configuration, since the upward movement of the front upper weight 62 is suppressed by the weight of the front upper weight 62, the restraint of the right end of the front upper weight 62 by the front upper weight right end upward movement restraint portion and the restraint of the left end of the front upper weight 62 by the front upper weight left end upward movement restraint portion can be made very simple. Also, since the upward movement of the rear upper weight 72 is suppressed by the weight of the rear upper weight 72, the restraint of the right end of the rear upper weight 72 by the rear upper weight right end upward movement restraint portion and the restraint of the left end of the rear upper weight 72 by the rear upper weight left end upward movement restraint portion can be made very simple.

Explanation of Reference Numerals

[0203] 1 Crane 2 Upper slewing body 3 Lower traveling body 10 Car body 11 Left crawler unit 12 Right crawler unit 13 Front side weight 14 Rear side weight 16 Left crawler frame 19a Front part of left crawler frame 19b Rear part of left crawler frame 20 Left front connecting part 21 Left rear connecting part 24 Right crawler frame 27a Front part of right crawler frame 27b Rear part of right crawler frame 28 Right front connecting part 29 Right rear connecting part 30 Right front pedestal 33 Right front restraint part 43 Left front pedestal 44 Left front restraint part 45 Right rear pedestal 46 Right rear restraint part 47 Left rear pedestal 48 Left rear restraint part 50 Concave part 52a Weight through hole 53 Connecting pin 61 Front lower weight (front side weight) 62 Front upper weight 64 Right end protrusion of front side weight 64a Tapered part 65 Left end protrusion of front side weight 65a Tapered part 71 Rear lower weight (rear side weight) 72 Rear upper weight 74 Right end protrusion of rear side weight 75 Left end protrusion of rear side weight 82 Right front protrusion connecting part 82a Right front insertion hole 85 Left front protrusion connecting part 85a Left front insertion hole 88 Right rear protrusion joint 88a Right rear insertion hole 91 Left rear protrusion joint 91a Left rear insertion hole 92 Front upper weight right recess (upper weight recess) 94 Front weight right restraint 94a Front weight right restraint upper surface (weight restraint upper surface) 95c Front inclined part (weight restraint front inclined part) 95d Rear inclined part (weight restraint rear inclined part) 96b Inner inclined part (weight restraint inner inclined part) 97 Front weight left restraint 101 Rear weight right restraint 104 Rear weight left restraint

Claims

1. A self-propelled crawler-type lower traveling body, and an upper slewing body rotatably mounted on the lower traveling body, and comprising: The lower traveling body includes a car body that supports the upper slewing body from below so that the upper slewing body can rotate, a left crawler unit and a right crawler unit that are arranged separately on the left and right of the car body and are responsible for the traveling of the car body, and a front weight and a rear weight that are arranged separately in the front and rear of the car body. The right crawler unit has a right crawler frame connected to the right end of the car body and extending in the front-rear direction. The left crawler unit has a left crawler frame connected to the left end of the car body and extending in the front-rear direction. The right crawler frame has a front part of the right crawler frame that protrudes forward of the front end of the car body and a rear part of the right crawler frame that protrudes rearward of the rear end of the car body. The left crawler frame has a front part of the left crawler frame that protrudes forward of the front end of the car body and a rear part of the left crawler frame that protrudes rearward of the rear end of the car body. The front part of the right crawler frame is a right front mount on which the right end of the front weight can be placed, and a right front restraint that supports the right end of the front weight from below in a state where the right end of the front weight is placed, and restrains the movement of the right end of the front weight placed on the right front mount in the front-rear direction and to the right. The front part of the left crawler frame is a left front mount on which the left end of the front weight can be placed, and a left front restraint that supports the left end of the front weight from below in a state where the left end of the front weight is placed, and restrains the movement of the left end of the front weight placed on the left front mount in the front-rear direction and to the left. The rear part of the right crawler frame is a right rear mount on which the right end of the rear weight can be placed, and a right rear restraint that supports the right end of the rear weight from below in a state where the right end of the rear weight is placed, and restrains the movement of the right end of the rear weight placed on the right rear mount in the front-rear direction and to the right. The rear part of the left crawler frame is a left rear pedestal on which the left end portion of the rear weight can be placed, and the left rear pedestal supports the left end portion from below in a state where the left end portion of the rear weight is placed thereon, and a left rear restraint portion that restrains the movement of the left end portion of the rear weight placed on the left rear pedestal in the front-rear direction and to the left. The right front pedestal and the left front pedestal are separated in the left-right direction, and the front weight connects the right front pedestal and the left front pedestal. A construction machine in which the right rear pedestal and the left rear pedestal are separated in the left-right direction, and the rear weight connects the right rear pedestal and the left rear pedestal.

2. At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a constrained end portion having a recess that opens downward. At least one of the right front restraint portion, the left front restraint portion, the right rear restraint portion, and the left rear restraint portion is a crawler frame restraint portion that restrains the movement of the constrained end portion, and the crawler frame restraint portion is a convex portion that fits into the recess so as to restrain the movement of the constrained end portion in the front-rear direction and outward in the left-right direction. The construction machine according to claim 1.

3. The crawler frame restraint portion has an upper surface that is a surface facing upward. The upper surface has a front inclined portion that inclines downward as it goes forward from a predetermined position in the front-rear direction of the upper surface, and a rear inclined portion that inclines downward as it goes backward from the predetermined position. The construction machine according to claim 2.

4. The crawler frame restraint portion has an upper surface that is a surface facing upward. The upper surface has an inner inclined portion that inclines downward as it goes inward in the left-right direction. The construction machine according to claim 2.

5. The upper surface further has an inner inclined portion that is located inward in the left-right direction with respect to the front inclined portion and the rear inclined portion and inclines downward as it goes inward in the left-right direction. The construction machine according to claim 3.

6. At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a constrained end portion having a weight through hole that penetrates the end portion vertically. At least one of the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal is a crawler frame pedestal on which the constrained end portion is placed, and the crawler frame pedestal has a pedestal through hole that penetrates the crawler frame pedestal vertically. At least one of the right front restraint portion, the left front restraint portion, the right rear restraint portion, and the left rear restraint portion is a crawler frame restraint portion that restrains the movement of the constrained end portion. The crawler frame restraint portion is inserted into the pedestal through hole and fixed to the crawler frame pedestal, and is inserted into the weight through hole so as to restrain the movement of the constrained end portion in the front-rear direction and the left-right direction. The construction machine according to claim 1, which is a restraint pin.

7. At least one of the right end portion of the front weight, the left end portion of the front weight, the right end portion of the rear weight, and the left end portion of the rear weight is a constrained end portion having a weight body end portion placed on a corresponding pedestal of the crawler frame pedestal among the right front pedestal, the left front pedestal, the right rear pedestal, and the left rear pedestal, and a weight end protrusion protruding downward from the weight body end portion. At least one of the right front restraint portion, the left front restraint portion, the right rear restraint portion, and the left rear restraint portion is a crawler frame restraint portion that restrains the movement of the constrained end portion. The crawler frame restraint portion is provided with an insertion hole into which the weight end protrusion can be inserted from above at the same time as the placement of the weight body end portion on the crawler frame pedestal, and has a protrusion coupling portion that couples with the weight end protrusion so as to restrain the movement of the weight end protrusion inserted into the insertion hole in the front-rear direction and the left-right direction. The construction machine according to claim 1.

8. The construction machine according to claim 7, wherein the weight end protrusion has a tapered portion that becomes smaller in diameter toward the tip in the protruding direction of the weight end protrusion from the weight body end portion.

9. The lower traveling body further includes a front upper weight configured to be loadable on the front weight and a rear upper weight configured to be loadable on the rear weight. The front weight has a front weight right restraint portion that restrains the movement of the right end portion of the front upper weight placed on the front weight in the front-rear direction and to the right, and a front weight left restraint portion that restrains the movement of the left end portion of the front upper weight placed on the front weight in the front-rear direction and to the left. The rear weight has a rear weight right restraint portion that restrains the movement of the right end portion of the rear upper weight placed on the rear weight in the front-rear direction and to the right, and a rear weight left restraint portion that restrains the movement of the left end portion of the rear upper weight placed on the rear weight in the front-rear direction and to the left. The construction machine according to any one of claims 1 to 8.

10. At least one of the right end portion of the front upper weight, the left end portion of the front upper weight, the right end portion of the rear upper weight, and the left end portion of the rear upper weight is an upper weight constrained end portion having an upper weight recess that is a recess opening downward. At least one of the front weight right restraint portion, the front weight left restraint portion, the rear weight right restraint portion, and the rear weight left restraint portion is a weight restraint portion that restrains the movement of the upper weight constrained end portion. The weight restraint portion is a convex portion that fits into the upper weight recess so as to restrain the movement of the upper weight constrained end portion in the front-rear direction and outward in the left-right direction. The construction machine according to claim 9.

11. The weight restraint portion has an upper surface of the weight restraint portion that faces upward. The upper surface of the weight restraint portion has a front inclination portion of the weight restraint portion that inclines downward as it goes forward from a predetermined position in the front-rear direction of the upper surface of the weight restraint portion, and a rear inclination portion of the weight restraint portion that inclines downward as it goes backward from the predetermined position. The construction machine according to claim 10.

12. The weight restraint portion has an upper surface of the weight restraint portion that faces upward. The upper surface of the weight restraint portion has an inner inclination portion of the weight restraint portion that inclines downward as it goes inward in the left-right direction. The construction machine according to claim 10.

13. The upper surface of the weight restraint portion is located on the inner side in the left-right direction with respect to the front inclined portion of the weight restraint portion and the rear inclined portion of the weight restraint portion, and further has a weight restraint inner inclined portion that inclines downward as it goes toward the inner side in the left-right direction, for the construction machine according to claim 11.

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