crane

Abstract

To provide a crane capable of stably preventing falling-back of an undulation body and pushing back the undulation body in an inverting direction during disassembling.SOLUTION: A crane 10 comprises: an upper turning body 12; a boom 16; a boom support 45; and a boom stop 70. The boom support 45 has a boom support lower part 451, a boom support upper part 452, and a boom support spring 453. A forward biasing force is applied to the boom 16 to support the boom 16 from a rear side. The boom stop 70 is provided between a turning boom 120 and the boom 16 and receives a load of the boom 16 so as to restrict falling-back of the boom 16 in a state where the boom 16 is in a standing state and in a state where the length of the boom support spring 453 is a prescribed restricted length between a maximum spring length and a minimum spring length.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a crane. [Background technology]

[0002] Conventionally, a crane has been known that includes a crane body and a boom. The boom is supported by the crane body so that it can be raised and lowered around a horizontal rotation axis. Patent Document 1 discloses a crane that further includes a pair of left and right backstops interposed between the boom and the crane body to prevent the boom from tipping backward. A support member for receiving the backstops is located in the center of the crane body in the fore-and-aft direction.

[0003] In this technology, each backstop has an outer tube, an inner tube inserted into the outer tube, and a contractible spring member interposed between the outer tube and the inner tube. The length of the backstop changes as the spring member expands and contracts. The base end of the backstop is supported by the boom. When the boom is raised relative to the crane body, the tip of the backstop eventually abuts against the support member provided on the crane body, and the spring member contracts. The contraction energy of this spring member has the function of pushing the boom back in an upside-down direction when the crane is disassembled. If the boom is blown backward by strong winds or other factors during crane operation, the backstop's spring member contracts to its minimum dimension, reducing the backstop to its minimum length and supporting the boom from behind to prevent it from tipping over backward (swinging). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-232822 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the wind-receiving surface area of ​​the crane has tended to increase due to factors such as the lengthening of booms and the increase in accessories attached to the crane. In this case, the force required from the backstop to support the crane from behind to prevent it from tilting during normal operation tends to be greater than the force required to push the crane back in the direction of collapse when the crane is disassembled. For this reason, the conventional technology described in Patent Document 1 has the problem of increasing the strength and cost required for the backstop's spring members.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a crane that can reliably prevent a rafter from tipping over due to strong winds during normal operation, even if the wind-receiving area of ​​the rafter increases, without increasing the strength or cost of the members supporting the rafter, and that can push the rafter back in an upside-down direction when the crane is disassembled. [Means for solving the problem]

[0007] A crane according to one embodiment of the present invention comprises a crane body, a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in the hoisting direction around a horizontal rotation center axis, a support member having an outer tube and an inner tube inserted into the outer tube and capable of extending and contracting between a maximum length and a minimum length, and which is interposed between the hoisting body and the crane body when the hoisting body is in an upright position relative to the crane body and supports the hoisting body from behind while applying a forward biasing force to the hoisting body, and a restricting member which is interposed between the crane body and the hoisting body when the hoisting body is in the upright position and the length of the support member is a predetermined restricting length between the maximum length and the minimum length and which receives the load of the hoisting body to prevent the hoisting body from tipping backward.

[0008] According to this configuration, the restricting member can prevent the hoisting structure from tipping backward before the support members retract to their minimum length. This prevents the maximum load of the hoisting structure from being applied to the support members. As a result, even if the wind-receiving area of ​​the hoisting structure increases due to an increase in the length of the hoisting structure or the number of accessories attached to the hoisting structure, it is possible to reliably prevent the hoisting structure from tipping over due to strong winds during normal operation and to push the hoisting structure back in an upright position when the crane is disassembled, without increasing the strength or cost of the support members.

[0009] In the above configuration, it is desirable that the support member further has a spring member that is arranged so as to be interposed between the outer tube and the inner tube and is contractible between a maximum spring length and a minimum spring length, and when the derricking body is in an upright state and the spring member is contracted below the maximum spring length, the support member is interposed between the derricking body and the crane body to support the derricking body from the rear while applying a forward biasing force to the derricking body, and when the derricking body is in the upright state and the length of the spring member is contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is the restricting length, the regulating member is interposed between the crane body and the derricking body to receive the load of the derricking body so as to prevent the derricking body from tipping backward.

[0010] According to this configuration, the restricting member can prevent the hoisting body from tipping backward before the spring members of the support members contract to their minimum length. This prevents the maximum load of the hoisting body from being applied to the support members, including the spring members. As a result, even if the wind-receiving area of ​​the hoisting body increases due to an increase in the length of the hoisting body or an increase in the number of accessories attached to the hoisting body, it is possible to reliably prevent the hoisting body from tipping due to strong winds during normal operation and to push the hoisting body back in an upright position when the crane is disassembled, without increasing the strength or cost of the spring members.

[0011] In the above configuration, it is desirable that the regulating member be arranged so as to be interposed between the crane body and the elevating body, between the support member and the elevating body fulcrum portion when viewed from a direction parallel to the rotation center axis.

[0012] According to this configuration, the regulating member is positioned closer to the fulcrum of the undulating body than the support member, so that the undulating body can be reliably prevented from tipping backward and the maximum load of the undulating body can be more reliably prevented from being applied to the rear support member.

[0013] In the above configuration, the regulating member has a regulating member base end supported on the elevation body and a regulating member tip end opposite the regulating member base end, and is arranged to protrude from the elevation body, and the crane body has a regulating member receiving portion capable of receiving the regulating member tip end, and when the elevation body is in the upright state and the length of the spring member is set to the regulating length, it is desirable that the regulating member receive the load of the elevation body by the regulating member tip end abutting against the regulating member receiving portion.

[0014] According to this configuration, the restricting member receiving portion receives the tip of the restricting member, thereby reliably preventing the undulating body from falling over due to strong winds or the like during normal operation.

[0015] In the above configuration, it is desirable that the crane body has a rotating frame and a support frame that is arranged at the front end of the rotating frame and includes a hoisting body support portion that rotatably supports the hoisting body fulcrum portion, and that the regulating member receiving portion is arranged on the support frame.

[0016] According to this configuration, a restricting member receiving portion is arranged on a support frame having high strength to rotatably support the fulcrum portion of the elevation body, thereby making it possible to more stably prevent the elevation body from falling over due to strong winds during normal operation, etc.

[0017] In the above configuration, the crane may further include a mast having a mast base end rotatably supported on the crane body behind the hoisting body and supporting the hoisting body from behind, the crane body having a swivel frame, the swivel frame having a mast support part rotatably supporting the mast base end, and the regulating member receiving part being arranged on the mast support part.

[0018] According to this configuration, the restricting member receiving portion is arranged on the mast support portion, which has high strength to support the base end of the mast, so that the collapse of the undulating body due to strong winds during normal operation can be prevented more stably.

[0019] In the above configuration, it is desirable that the elevation body be separable into multiple members, have at least an elevation body lower member including the elevation body fulcrum portion, and that the base end of the regulating member be supported by a portion of the elevation body lower member that is closer to the elevation body fulcrum portion than the longitudinal center of the elevation body lower member.

[0020] According to this configuration, interference between the regulating member and other members arranged at the tip side of the lower member of the undulating body is suppressed, and the degree of freedom in the layout of member arrangement in the lower member of the undulating body can be increased. [Effects of the Invention]

[0021] According to the present invention, a crane is provided that can stably prevent the rafter from tipping over due to strong winds during normal operation, even if the wind-receiving area of ​​the rafter increases, without increasing the strength or cost of the members supporting the rafter, and can push the rafter back in an upside-down direction when the crane is disassembled. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view of a crane according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a side view of a lower boom portion, a boom support, and a boom stop when the boom of the crane according to one embodiment of the present invention is in a lowered position. [Figure 3] FIG. 2 is a side view of the crane body and the crane elevation unit according to the embodiment of the present invention. [Figure 4] FIG. 2 is a rear view of the boom support receiver of the crane according to the embodiment of the present invention. [Figure 5] FIG. 10 is a side view of the elevation body and crane body of a crane according to a modified embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a crane 10 (work machine) according to one embodiment of the present invention. Note that, although the directions of "up," "down," "front," and "rear" are shown in each drawing hereinafter, these directions are shown for the convenience of explaining the structure and assembly method of the crane 10 according to this embodiment, and do not limit the direction of movement or the manner of use of the crane according to the present invention.

[0024] The crane 10 comprises an upper rotating body 12 and a lower running body 14 which correspond to the crane body, a cab 15 provided on the upper rotating body 12, a boom 16 which functions as a hoisting body, a lattice mast 17 which is a member for raising and lowering the boom, and a box mast 21. The lower running body 14 is capable of traveling on the ground (a running surface), and the upper rotating body 12 is supported by the lower running body 14 so as to be rotatable about a rotation center axis which extends in the vertical direction.

[0025] The boom 16 has a boom base end 16P (hoisting body base end) supported on the upper rotating body 12 so as to be rotatable in the hoisting direction, and a boom tip end 16Q (hoisting body tip end) located on the opposite side of the boom base end 16P in the longitudinal direction. In this embodiment, a boom foot 16S (hoisting body fulcrum) provided at the boom base end 16P is supported on a boom foot support 12S (FIG. 3) of the upper rotating body 12 so as to be rotatable in the hoisting direction. The boom 16 shown in FIG. 1 is a so-called lattice type and can be separated into multiple members. More specifically, the boom 16 is composed of a lower boom 16A (hoisting body lower member) including the boom foot 16S, one or more (three in the illustrated example) intermediate booms 16B, 16C, and 16D, and an upper boom 16E.

[0026] The lattice mast 17 includes a mast base end 17P and a mast tip end 17Q. The mast base end 17P is attached to the upper rotating body 12 at a position behind the boom 16 so as to be able to rise and fall about a rotation axis parallel to the rotation axis of the boom 16. In other words, the lattice mast 17 can also rotate in the same direction as the boom 16. The mast tip end 17Q is the tip of the lattice mast 17, located on the opposite side of the mast base end 17P in the longitudinal direction. As shown in FIG. 1, a first mast sheave 171 and a second mast sheave 172 are disposed at the mast tip end 17Q of the lattice mast 17. A boom hoist rope 22, described below, is hung around the first mast sheave 171 and the second mast sheave 172. The lattice mast 17 serves as a support for the rotation of the boom 16.

[0027] A pair of left and right backstops 46 are provided on the mast base end 17P side of the lattice mast 17. These backstops 46 come into contact with the upper rotating body 12 when the lattice mast 17 reaches the upright position shown in Figure 1. This contact prevents the lattice mast 17 from being blown backward by strong winds, etc.

[0028] The crane 10 further includes a lower spreader 18, an upper spreader 19, guy lines 20, a boom hoist rope 22, and a boom hoist winch 38.

[0029] The lower spreader 18 has a lower sheave block 181. The lower sheave block 181 has a plurality of sheaves arranged in the width direction (left and right direction). The upper spreader 19 is disposed in front of the lower spreader 18 at a predetermined interval. The upper spreader 19 is connected to the boom tip 16Q via guy lines 20. The upper spreader 19 has an upper sheave block 191. The upper sheave block 191 has a plurality of sheaves arranged in the width direction (left and right direction).

[0030] A pair of guy lines 20 are arranged in the left-right direction perpendicular to the plane of the paper in Figure 1. The rear end of the guy line 20 is connected to the upper spreader 19, and the front end of the guy line 20 is detachably connected to the boom tip 16Q. The guy line 20 includes guy links (metal plates), guy ropes, guy wires (metal wires), etc.

[0031] The boom hoist rope 22 is pulled out from the boom hoist winch 38, and is then hooked around the first mast sheave 171 and the second mast sheave 172 of the mast tip 17Q, and then wound around multiple times between the lower sheave block 181 and the upper sheave block 191. After being hooked around the lower sheave block 181 and the upper sheave block 191, the tip of the boom hoist rope 22 is fixed to the mast tip 17Q of the lattice mast 17.

[0032] The boom hoist winch 38 is disposed on the mast base end 17P side of the lattice mast 17. The boom hoist winch 38 changes the distance between the lower sheave block 181 of the lower spreader 18 and the upper sheave block 191 of the upper spreader 19 by winding in and letting out the boom hoist rope 22, thereby raising or lowering the boom 16 while rotating the boom 16 relative to the lattice mast 17.

[0033] The box mast 21 has a base end and a pivot end (tip end), and is pivotally connected to the upper rotating body 12 behind the lattice mast 17. The box mast 21 has a rectangular shape in cross section. The pivot axis of the box mast 21 is parallel to the pivot axis of the boom 16 and is located at approximately the same position as the pivot axis of the lattice mast 17. In other words, the box mast 21 can also pivot in the same direction as the boom 16 is raised and lowered.

[0034] The crane 10 also includes guy lines 23, a mast hoisting rope 26, and a mast hoisting winch 30. A pair of guy lines 23 are arranged in the left-right direction, perpendicular to the plane of FIG. 1 . The guy lines 23 connect the mast tip 17Q of the lattice mast 17 to the rotating end of the box mast 21. This connection coordinates the rotation of the lattice mast 17 with the rotation of the box mast 21. The mast hoisting rope 26 is reeled in multiple times between a sheave block 24, which is disposed on the upper rotating body 12 and has multiple sheaves arranged in the width direction, and a sheave block 25, which is disposed on the rotating end of the box mast 21 and has multiple sheaves arranged in the width direction.

[0035] The mast hoist winch 30 is located on the base end side of the box mast 21. The mast hoist winch 30 winds in and pays out the mast hoist rope 26. The winding and paying out operation of the mast hoist winch 30 changes the distance between the sheave block 25 at the tip of the box mast 21 and the sheave block 24 at the rear end of the upper rotating body 12, and the box mast 21 and the lattice mast 17 rotate together relative to the upper rotating body 12, causing the lattice mast 17 to rise and fall.

[0036] In addition to the mast hoist winch 30 and boom hoist winch 38 described above, the crane 10 is also equipped with a main hoist winch 34 and an auxiliary hoist winch 36 for hoisting and lowering a load. In the crane 10 according to this embodiment, the main hoist winch 34 and the auxiliary hoist winch 36 are both installed on the lower boom 16A of the boom 16. The winches 34, 36 of the crane 10 may also be mounted on the upper rotating body 12.

[0037] The main winch 34 hoists and lowers a load using a main hoisting rope 51 (FIG. 1). For this main hoisting, a main hoisting guide sheave (not shown) is rotatably mounted at the boom tip 16Q of the boom 16. A main hoisting sheave block, in which multiple main hoisting point sheaves are arranged in the width direction, is also mounted adjacent to the main hoisting guide sheave. A main hook 53 for the load is connected to the main hoisting rope 51 suspended from the main hoisting sheave block. The main hoisting rope 51 pulled out from the main hoisting winch 34 is looped around the main hoisting guide sheaves in order and is stretched between the sheave of the main hoisting sheave block and the sheave of the sheave block mounted on the main hook 53. Therefore, when the main hoisting winch 34 winds or unwinds the main hoisting rope 51, the main hook 53 is hoisted or lowered.

[0038] Similarly, the auxiliary winch 36 hoists and lowers the load using the auxiliary hoisting rope 52. This auxiliary hoisting is provided with a structure (not shown) similar to that of the main hoisting described above. When the auxiliary hoisting winch 36 winds or unwinds the auxiliary hoisting rope 52, an auxiliary hook (not shown) for the load, which is connected to the end of the auxiliary hoisting rope 52, is hoisted or lowered.

[0039] A counterweight 40 for adjusting the balance of the crane 10 is also loaded on the rear of the upper rotating body 12, and a pallet weight 41 is also disposed behind the upper rotating body 12. The pallet weight 41 serves as an SHL (Super Heavy Lifting) weight provided for the crane 10 to lift heavy loads, and has the function of maintaining the balance of the crane 10. The pallet weight 41 is connected to the mast tip 17Q of the lattice mast 17 by a weight line 42.

[0040] Fig. 2 is a side view of the lower boom 16A, boom support 45, and boom stop 70 when the boom 16 of the crane 10 according to this embodiment is in a lowered position. Fig. 3 is a side view of the lower boom 16A (boom 16) and upper rotating body 12 of the crane 10 according to this embodiment. Fig. 4 is a rear view of the boom support receiver 121 of the crane 10 according to this embodiment.

[0041] Referring to Figure 2, when the boom 16 (lower boom 16A) is viewed in a state where it is lowered relative to the upper rotating body 12, the lower boom 16A has a pair of left and right lower frames 160, a pair of left and right first main pipes 161, a pair of left and right second main pipes 162, a pair of left and right first connecting pipes 163, a pair of upper and lower second connecting pipes (not shown), and a plurality of lattice pipes 165.

[0042] The pair of left and right first main pipes 161 and the pair of left and right second main pipes 162 are pipes that define the outer shape of the lower boom 16A, and as shown in FIG. 2 and other figures, they extend from the vicinity of the boom foot 16S toward the tip of the lower boom 16A so that the distance between them increases. The lower frame 160 is a plate-like member that connects the base ends of the first main pipes 161 and the second main pipes 162 to each other on both the left and right sides of the lower boom 16A. The pair of left and right first connecting pipes 163 connect the tips of the first main pipes 161 and the second main pipes 162 to each other, respectively. Note that a pair of upper and lower second connecting pipes (not shown) connect the tips of the pair of left and right first main pipes 161 to each other and the tips of the pair of left and right second main pipes 162 to each other. The plurality of lattice pipes 165 connect the first main pipe 161 and the second main pipe 162, the pair of left and right first main pipes 161, and the pair of left and right second main pipes 162 to each other at a plurality of locations.

[0043] Furthermore, the lower boom 16A has a pair of left and right boom support supports 161S. The pair of left and right boom support supports 161S are arranged on the first main pipe 161 (the back surface of the lower boom 16A) at a position closer to the tip of the boom foot 16S, more specifically, closer to the tip of the center of the lower boom 16A in the longitudinal direction. The boom support supports 161S support a boom support base end 452S of a boom support 45, which will be described later.

[0044] The crane 10 further includes a pair of left and right boom supports 45 (support members) and a pair of left and right boom stops 70 (restraint members). Note that the left and right structures of these members are the same, so the following description will focus on the structure on the right side.

[0045] Boom support 45 is provided on lower boom 16A. Boom support 45 comes into contact with upper rotating body 12 when boom 16 reaches the upright posture (working posture) shown in FIG. 1 relative to upper rotating body 12, thereby being interposed between boom 16 and upper rotating body 12 and supporting boom 16 from the rear. Boom support 45 is also extendable and has the function of pushing boom 16 forward, i.e., in an inverted direction, when crane 10 is disassembled.

[0046] As shown in FIG. 2, the boom support 45 is disposed on the first main pipe 161. The boom support 45 includes a lower boom support 451 (also referred to as an inner cylinder), an upper boom support 452 (also referred to as an outer cylinder), and a boom support spring 453 (spring member). The lower boom support 451 and the upper boom support 452 have a cylindrical structure, and the lower boom support 451 is inserted into the cylindrical interior of the upper boom support 452 so as to be able to expand and contract. The boom support spring 453 is contractibly mounted between flanges F ( FIG. 2 ) provided on the lower boom support 451 and the upper boom support 452, respectively. The boom support spring 453 is disposed between the lower boom support 451 and the upper boom support 452 and can contract between a predetermined maximum spring length (free length) and a minimum spring length. When the boom support spring 453 is at its maximum spring length, the boom support 45 has its maximum length, and when the boom support spring 453 is at its minimum spring length, the boom support 45 has its minimum length.

[0047] Furthermore, the boom support lower part 451 has a boom support abutment part 451S, and the boom support upper part 452 has a boom support base end part 452S. The boom support base end part 452S corresponds to the base end part of the boom support 45, and the boom support abutment part 451S corresponds to the tip end part of the boom support 45 opposite the boom support base end part 452S. A bifurcated protrusion is provided on the boom support abutment part 451S (FIG. 4). The boom support base end part 452S is rotatably supported (attached) to a boom support support part 161S (FIG. 2) that is located closer to the tip end part (boom tip part 16Q) of the lower boom 16A than the boom foot 16S.

[0048] The crane 10 also has a support column 60. The support column 60 is connected to a fixed portion 65 arranged on the first main pipe 161 and to a supported portion 452T arranged on the boom support upper portion 452 by connecting pins (not shown), respectively. As a result, the boom support 45 is placed in an upright position as shown in FIG. 2. When the support column 60 is removed, for example when disassembling the crane 10, the boom support 45 can be lowered to a position closer to the first main pipe 161 than in FIG. 2 and directly above the boom stop 70.

[0049] The boom support 45 as described above is interposed between the boom 16 and the upper rotating body 12 when the boom 16 is in an upright position relative to the upper rotating body 12 and the boom support spring 453 is contracted, and supports the boom 16 from behind while applying a forward biasing force to the boom 16.

[0050] The boom stop 70 is interposed between the upper rotating body 12 and the boom 16 when the boom 16 is in an upright position and the length of the boom support spring 453 of the boom support 45 is contracted to a predetermined length between the maximum spring length and the minimum spring length (when the length of the boom support 45 is a predetermined restricted length between the maximum length and the minimum length), and receives the load (own weight) of the boom 16 to prevent the boom 16 from tipping backward.

[0051] The boom stop 70 is disposed on the first main pipe 161, similar to the boom support 45. Specifically, a boom stop support portion 166 is disposed on the first main pipe 161 near the boom foot 16S. The boom stop 70 extends (protrudes) from the boom stop support portion 166 in substantially the same direction as the boom support 45 in the upright position. The boom stop 70 has a boom stop abutment portion 70S and a boom stop base end portion 70H. The boom stop abutment portion 70S corresponds to the tip end of the boom stop 70. Note that the boom stop abutment portion 70S also has a bifurcated protrusion similar to the boom support abutment portion 451S. The boom stop base end portion 70H is the base end portion of the boom stop 70 opposite the boom stop abutment portion 70S, and is fixed to the boom stop support portion 166.

[0052] 3, the upper rotating body 12 includes a rotating frame 120. The rotating frame 120 is supported so as to be able to rotate on the lower traveling body 14. The rotating frame 120 is a member extending in the front-rear and left-right directions, and is formed, for example, by a frame made of joined steel members.

[0053] The upper rotating body 12 further has a pair of left and right boom foot support portions 12S, a pair of left and right boom support receiving portions 121, a pair of left and right box-shaped support bodies 122, a pair of left and right boom stop receiving portions 123 (regulating member receiving portions), and a pair of left and right mast support portions 124.

[0054] The pair of left and right boom foot supports 12S rotatably support boom feet 16S of the boom 16. Each boom foot support 12S has a pin hole that penetrates in the left-right direction. Similar pin holes are also formed in the boom foot 16S of the boom 16, and with both pin holes aligned, connecting pins (not shown) are inserted into each pin hole in turn, thereby supporting the boom 16 on the upper rotating body 12 so that it can be raised and lowered.

[0055] A pair of left and right boom support receiving portions 121 are fixed to the revolving frame 120 behind the boom foot support portions 12S. Each boom support receiving portion 121 is a U-shaped receiving portion that opens forward and upward. Each boom support receiving portion 121 receives (supports) a boom support abutment portion 451S of the boom support 45. As shown in FIG. 4, the boom support receiving portions 121 are arranged so as to protrude outward from the revolving frame 120 to the left and right. As a result, interference between the boom support 45 and a winch 30 (FIG. 1) or the like arranged in the left and right central portion (center section) of the upper revolving body 12 is prevented.

[0056] A pair of left and right supports 122 are disposed on the revolving frame 120 immediately rearward of the boom foot support 12S. Each support 122 is a box-shaped member having an upper surface, a lower surface opposite the upper surface, right and left sides connecting the upper and lower surfaces, and a front and rear surface. The lower surface and the inner left and right sides of each support 122 are supported by the revolving frame 120. Because the supports 122 have such a box shape, the rigidity and strength of the support 122 can be increased compared to when the support 122 is made of a single plate material. Like the revolving frame 120, the support 122 is also made of steel.

[0057] The pair of left and right boom stop receiving portions 123 are U-shaped receiving portions that are respectively fixed to the upper surface of the support body 122 and open forward and upward. Each boom stop receiving portion 123 has the function of receiving a boom stop abutment portion 70S of the boom stop 70 described below.

[0058] The pair of left and right mast support parts 124 are part of the revolving frame 120 and are arranged above the support body 122. Each mast support part 124 rotatably supports the mast base end part 17P (FIG. 1) of the lattice mast 17. Each mast support part 124 has a pin hole 124H.

[0059] In the state shown in FIG. 2, when the boom 16 is formed by sequentially connecting the intermediate booms 16B, 16C, and 16D to the lower boom 16A and the upper boom 16E (FIG. 1), the lattice mast 17 pulls the boom 16 via the guy lines 20, causing the boom 16 to rise relative to the upper rotating body 12. As shown in FIG. 3, when the angle θ between the center line of the boom 16 and the horizontal line reaches, for example, 85 degrees, the boom support abutment portion 451S of the boom support 45 first abuts against the boom support receiving portion 121, and the boom support spring 453 begins to contract. When the boom support spring 453 contracts to a predetermined length, the boom 16 rises to the angle required for normal operation. At this time, the boom stop abutment portion 70S of the boom stop 70 does not abut against the boom stop receiving portion 123.

[0060] On the other hand, when the boom 16 is blown backward by a strong wind or the like during operation of the crane 10, and the angle θ of the boom 16 reaches, for example, 90 degrees (maximum angle), the boom stop abutment portion 70S of the boom stop 70 abuts against the boom stop receiving portion 123. As a result, the boom stop 70 receives the maximum load (maximum reaction force) of the boom 16 and is interposed between the upper rotating body 12 and the boom 16, preventing the boom 16 from tipping backward.

[0061] At this time, the boom support spring 453 of the boom support 45 has not contracted to its minimum length. In other words, the boom support 45 has not bottomed out. This prevents the large weight (load) of the boom 16 from being applied to the boom support 45 and the boom support receiving portion 121. When the strong wind around the crane 10 subsides, the boom 16 is pushed back by the biasing force of the boom support spring 453, and the boom stop abutment portion 70S moves away from the boom stop receiving portion 123.

[0062] Meanwhile, when the boom hoist winch 38 in Figure 1 pays out the boom hoist rope 22 during disassembly of the crane 10, the boom 16 begins to collapse forward. At this time, the elastic energy of the boom support spring 453 of the boom support 45 is released, and the boom support 45 applies a force pushing the boom 16 forward. As a result, the boom 16, which is a heavy load, can be guided into a collapsed position.

[0063] As described above, in this embodiment, the crane 10 includes the boom support 45 and the boom stop 70. The boom stop 70 prevents the boom 16 from tipping backward before the boom support spring 453 of the boom support 45 retracts to its minimum length. Therefore, the boom support 45, including the boom support spring 453, only needs to generate a force to push back the boom 16 when the crane is disassembled, preventing the maximum load of the boom 16 from being applied to the boom support 45. As a result, even if the wind-receiving area of ​​the boom 16 increases due to an increase in the length of the boom 16 or an increase in the number of accessories attached to the boom 16, the boom 16 can be reliably prevented from tipping over due to strong winds during normal operation and can be pushed back in an inverted direction when the crane is disassembled. Furthermore, the boom support spring 453 of the boom support 45 can be designed based on the pushing back force, thereby reducing its size and cost. As a result, the outer diameter and plate thickness of lower boom support 451 and upper boom support 452 of boom support 45 can be reduced compared to when boom support 45 bears the maximum load of boom 16. Furthermore, when it is necessary to detect the reaction force received by boom support 45 using a load cell (not shown), the capacity of the load cell can also be reduced.

[0064] Furthermore, in this embodiment, the boom stop 70 is disposed between the boom support 45 and the boom foot 16S when viewed in a direction parallel to the rotation center axis, so as to be interposed between the upper rotating body 12 and the boom 16. In this way, the boom stop 70 is disposed at a position closer to the boom foot 16S than the boom support 45, which can reliably prevent the boom 16 from tipping backward and can more reliably prevent the maximum load of the boom 16 from being applied to the rear boom support 45.

[0065] Furthermore, unlike conventional backstops, this embodiment does not use a single component to both prevent the boom 16 from tipping backward and push the boom 16 forward. Therefore, even if the wind-receiving area of ​​the boom 16 increases, there is no need to significantly increase the rigidity and strength of the single component. Furthermore, because the boom supports 45 and the boom stop 70, each having a predetermined size and strength, are dispersedly arranged on the revolving frame 120, the degree of freedom in arranging components on the revolving frame 120 is increased. Furthermore, the structure of the boom support receiver 121 can be simplified compared to a conventional backstop receiver that receives the tip of a backstop. Furthermore, in this embodiment, the boom stop 70 does not need to be rotatably supported by the boom support support portion 161S, and the relative angle of the boom stop 70 with respect to the lower boom 16A may be constant.

[0066] Furthermore, in this embodiment, when the boom 16 is in the upright state and the length of the boom support 45 is set to the regulated length, the boom stop abutment portion 70S abuts against the boom stop receiving portion 123, causing the boom stop 70 to receive the load of the boom 16. In this way, the boom stop receiving portion 123 provided on the upper rotating body 12 receives the boom stop abutment portion 70S, thereby reliably preventing the boom 16 from tipping over due to strong winds or the like during normal operation.

[0067] In particular, in this embodiment, the boom stop receiving portion 123 is arranged on a support body 122 that has high strength to rotatably support the boom foot 16S, which makes it possible to more stably prevent the boom 16 from tipping over due to strong winds during normal operation.

[0068] Furthermore, in this embodiment, the boom stop support portion 166 is disposed on the lower boom 16A closer to the boom foot 16S than the longitudinal center of the lower boom 16A. This prevents interference between the boom stop 70 and other components disposed on the tip side of the lower boom 16A, such as the winches 34 and 36 in FIG. 1. As a result, even when the lower boom 16A supports the boom stop 70, the degree of freedom in the layout of component arrangement on the lower boom 16A can be increased.

[0069] The crane 10 according to one embodiment of the present invention has been described above. However, the present invention is not limited to these embodiments. The following modified embodiments are possible in the present invention.

[0070] (1) The present invention is not limited to the above-described embodiments. Fig. 5 is a side view of the boom 16 and upper rotating body 12 of the crane 10 according to a modified embodiment of the present invention. In the above-described embodiment, the boom stop receiving portion 123 that receives the boom stop 70 is disposed on the support body 122, but the present invention is not limited to this. In the embodiment shown in Fig. 5, the boom stop receiving portion 125 is disposed on the mast support portion 124 provided at the front end of the rotating frame 120.

[0071] On the other hand, the boom stop 80 is supported by a boom stop support portion 167 provided on the lower boom 16A. As the boom 16 is raised, the boom stop abutment portion 80S of the boom stop 80 abuts against the boom stop receiving portion 125 and is received.

[0072] In this modified embodiment, too, the boom stop 80 can prevent the boom 16 from tipping backward before the boom support spring 453 of the boom support 45 retracts to its minimum length. Therefore, the boom support 45 including the boom support spring 453 only needs to generate a force to push back the boom 16 when the crane is disassembled, and the maximum load of the boom 16 is prevented from being applied to the boom support 45. As a result, even if the wind-receiving area of ​​the boom 16 increases due to an increase in the length of the boom 16 or an increase in the number of accessories attached to the boom 16, it is possible to reliably prevent the boom 16 from tipping over due to strong winds during normal operation and to push back the boom 16 in an inverted direction when the crane is disassembled, without increasing the strength or cost of the boom support spring 453.

[0073] In this modified embodiment, the boom stop receiving portion 125 is disposed on the mast support portion 124, which has high strength for supporting the mast base end portion 17P of the lattice mast 17, and therefore it is possible to more reliably prevent the boom 16 from tipping over due to strong winds during normal operation. Furthermore, the length of the boom stop 80 can be made shorter than that of the boom stop 70 described above.

[0074] On the other hand, in the case of the boom stop 70 described above, the abutment portions between the boom stop abutment portion 70S and the boom stop receiving portion 123 are located at the same positions as both ends of the lower boom 16A in the left-right direction, making it easy to arrange the boom stop support portion 166 on the first main pipe 161. In contrast, the boom stop support portion 167 (FIG. 5) that supports the boom stop 80 may be arranged on a second connecting pipe (not shown) that connects the left and right first main pipes 161 (FIG. 2) to each other in the left-right direction. Also, in another embodiment, the crane 10 may include both the boom stop 70 and the boom stop 80 described above in addition to the boom support 45.

[0075] (2) Furthermore, while the above embodiments have been described using the crane 10 shown in FIG. 1 , the present invention is not limited to this and can also be applied to cranes with other structures. That is, a crane to which the present invention is applied may be a general-purpose crane equipped with a gantry instead of the lattice mast, and the hoisting winch may be located on the upper frame (rear side) of the upper rotating body 12. Furthermore, a large crane may have a structure in which the boom is hoisted by hoisting a box mast instead of the SHL structure. In this case, the tip of the box mast and the tip of the boom may be directly connected by a guy link, without the sheave block. Furthermore, both general-purpose cranes and large cranes may have a jib or strut attached to the tip of the boom.

[0076] (3) In the above embodiments, the boom support 45 includes the boom support spring 453, and the length of the boom support 45 changes in response to the contraction of the boom support spring 453. However, the present invention is not limited to this. As an example, the boom support 45 may have a hydraulic cylinder structure and extend and retract under hydraulic pressure. In this case, the lower boom support 451 constitutes the cylinder body of the hydraulic cylinder, and the upper boom support 452 constitutes the cylinder rod of the hydraulic cylinder. The cylinder rod has a piston and divides the cylinder body into a head chamber and a rod chamber. When hydraulic oil is received in the head chamber and discharged from the rod chamber, the cylinder rod extends relative to the cylinder body. When hydraulic oil is received in the rod chamber and discharged from the head chamber, the cylinder rod contracts relative to the cylinder body. In the above configuration, the lower boom support 451 may constitute the cylinder rod of the hydraulic cylinder, and the upper boom support 452 may constitute the cylinder body of the hydraulic cylinder.

[0077] Even with this configuration, the boom stop 70 receives the load of the boom 16 before the boom support 45 is hydraulically retracted to its minimum length (before it bottoms out), thereby preventing a large load from being applied to the boom support 45. This reduces the need to expand the cylinder diameter or rod diameter of the boom support 45, which has a hydraulic cylinder configuration, in order to support a large load. This also reduces the need to install equipment and piping within the hydraulic circuit that can withstand large pressures. [Explanation of symbols]

[0078] 10 Crane 12 Upper rotating body (crane body) 120 Swivel Frame 121 Boom support receiving part 122 Support (support frame) 123, 125 Boom stop receiving portion (receiving portion of restricting member) 124 Mast support 124H Mast Foot Support 12S Boom foot support 16 Boom (elevating body) 160 Lower Frame 161 First Main Pipe 161S Boom support part 162 Second Main Pipe 163 First connecting pipe 165 Lattice Pipe 166 Boom stop support 167 Boom stop support 16A Lower boom (lower member of the boom) 16S Boom foot (elevating body support part) 17 Lattice mast (mast) 17P Mast base end 45 Boom support (support member) 451 Boom support bottom 451S Boom support contact point 452 Boom support upper part 452S Boom support base 452T Supported part 453 Boom support spring 60 pillars 65 Fixed part 70, 80 Boom stop (restricting member) 70H, 80H Boom stop base end (base end of restricting member) 70S, 80S Boom stop contact part (tip of restricting member)

Claims

1. The crane body, a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in a hoisting direction around a horizontal rotation center axis; a support member having an outer tube and an inner tube inserted into the outer tube, which is extendable between a maximum length and a minimum length, and which is interposed between the derricking body and the crane body when the derricking body is in an upright position relative to the crane body, and which applies a forward biasing force to the derricking body while supporting the derricking body from the rear; a restricting member that is interposed between the crane body and the rafter and receives the load of the rafter so as to restrict the rafter from tipping backward when the rafter is in the upright state and the length of the support member is set to a predetermined restricted length between the maximum length and the minimum length; Equipped with The crane body has a support member receiving portion and a regulating member receiving portion, The support member has a support member base end portion rotatably supported on the undulating body and a support member abutment portion opposite to the support member base end portion, a crane in which the regulating member is fixed to the derricking body so that when the derricking body is raised to an angle during normal operation at which the support member abutment portion abuts the support member receiving portion, the regulating member does not abut the regulating member receiving portion, and when the derricking body rotates further rearward from the angle during normal operation, the regulating member abuts the regulating member receiving portion when the length of the support member is set to the specified regulating length.

2. The support member further includes a spring member disposed between the outer tube and the inner tube and capable of contracting between a maximum spring length and a minimum spring length, and when the rafter is in an upright position and the spring member is contracted below the maximum spring length, the support member is disposed between the rafter and the crane body and applies a forward biasing force to the rafter, supporting the rafter from behind; 2. The crane according to claim 1, wherein the regulating member is interposed between the crane body and the rafter and receives the load of the rafter so as to prevent the rafter from tipping backward when the rafter is in the upright state and the length of the spring member has contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is set to the regulating length.

3. 3. The crane according to claim 2, wherein the regulating member is arranged so as to be interposed between the crane body and the boom, between the support member and the boom fulcrum portion when viewed in a direction parallel to the central axis of rotation.

4. A crane body, a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in a hoisting direction around a horizontal rotation center axis; a support member having an outer tube and an inner tube inserted into the outer tube, which is extendable between a maximum length and a minimum length, and which is interposed between the derricking body and the crane body when the derricking body is in an upright position relative to the crane body, and which applies a forward biasing force to the derricking body while supporting the derricking body from the rear; a restricting member that is interposed between the crane body and the rafter and receives the load of the rafter so as to restrict the rafter from tipping backward when the rafter is in the upright state and the length of the support member is set to a predetermined restricted length between the maximum length and the minimum length; Equipped with The support member further includes a spring member disposed between the outer tube and the inner tube and capable of contracting between a maximum spring length and a minimum spring length, and when the rafter is in an upright position and the spring member is contracted below the maximum spring length, the support member is disposed between the rafter and the crane body and applies a forward biasing force to the rafter, supporting the rafter from behind; the regulating member is interposed between the crane body and the hoisting body and receives the load of the hoisting body so as to regulate the hoisting body from tipping backward when the hoisting body is in the upright state and the length of the spring member is contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is set to the regulated length; the regulating member has a regulating member base end supported on the undulating body and a regulating member tip end opposite to the regulating member base end, and is disposed so as to protrude from the undulating body; The crane body has a regulating member receiving portion capable of receiving the tip end of the regulating member, A crane in which, when the elevation body is in the upright position and the length of the spring member is set to the regulated length, the tip of the regulating member abuts against the regulating member receiving portion, thereby causing the regulating member to receive the load of the elevation body.

5. The crane body is A rotating frame; a support frame including a hoist support portion disposed at a front end of the swivel frame and rotatably supporting the hoist support portion; and The crane according to claim 4 , wherein the restricting member receiving portion is disposed on the support frame.

6. The crane further includes a mast having a mast base end portion rotatably supported on the crane body at the rear of the hoisting body, and supporting the hoisting body from the rear, The crane body has a rotating frame, the rotating frame has a mast support portion that rotatably supports the mast base end portion, The crane according to claim 4 , wherein the restricting member receiving portion is disposed on the mast support portion.

7. The undulating body can be separated into a plurality of members, and has at least an undulating body lower member including the undulating body fulcrum portion, A crane according to any one of claims 4 to 6, wherein the base end of the regulating member is supported by a portion of the lower member of the elevation structure that is closer to the elevation structure fulcrum portion than the longitudinal center of the lower member of the elevation structure.

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