Counterweight movement device

Abstract

A movement device (1) for a counterweight (10), wherein the movement device (1) moves the counterweight (10) between a mounting position on a machine frame (7) and the ground (G), wherein the movement device (1) comprises: an attachment element (20) which is fixed to the machine frame (7); a support element (40) which is fixed to the machine frame (7) and has a support surface (40Aa) on which the counterweight (10) is placed in its attached state; a linkage mechanism (30) mounted on the attachment element (20) and adapted to move the counterweight (10), the linkage mechanism (30) comprising: an arm element (34), one end (34a) of which is axially supported by the attachment element (34) and the other end (34b) of which is axially supported at the top in a recess (12) in the front surface (10a) of the counterweight (10); and a rotary cylinder (35), one end (35a) of which is axially supported by the attachment element (20) and the other end (35b) of which is axially supported at the top of the recess (12), the rotary cylinder (35) being designed to be extendable and retractable and to rotate the arm element (34) about one end (34a) of the arm element (34); and a contact surface (15c) of the support surface (40a) on one side of the counterweight (10), which in the attached state is in contact with the support surface (40a), which is formed in a shape based on an arcuate guide path (L, L') which is described during the movement of the counterweight (10), wherein the contact surface (15c) is formed in a shape which is the same as the shape of the support surface (40a) and in the attached state is in surface contact with the support surface (40a).

Description

[Technical field]

[0001] The present invention relates to a moving device for a counterweight mounted on a construction machine such as a hydraulic excavator or a crane truck. [State of the art]

[0002] A counterweight is mounted on a construction machine such as a hydraulic excavator or a crane truck to prevent tipping and suppress vibration of the machine body during operation, to improve static stability under heavy loads, and so on. The counterweight is attached to and detached from the machine body, for example, during transportation of the construction machine or when changing a work tool attached to the machine body. To facilitate the attachment and removal of the counterweight, the construction machine may be provided with a moving device that moves (raises and lowers) the counterweight between the ground and the height (an attachment position) of the machine body.

[0003] As a counterweight moving device, a moving device with a lifting and lowering mechanism (a linkage mechanism) including an arm member and a cylinder for lifting and lowering is known. For example, a device in Patent Literature 1 includes a rotating arm (an arm member) whose one end is pivotally connected to the rear side of a bogie (a machine frame), and a lifting and lowering cylinder that rotates the rotating arm in the vertical direction. For lifting and lowering, the device extends and retracts the cylinder to thereby rotate the rotating arm and move a counterweight suspended from the other end of the rotating arm in an arc shape.

[0004] Furthermore, the counterweight configured for detachable attachment is attached (fixed) to the machine body by tightening a bolt on a mounting surface (e.g., a support plate according to Patent Literature 1) extending vertically from the rear portion of the machine frame and horizontally from the rear portion to the front portion of the machine body. When the counterweight is supported only by the bolt extending horizontally, the total load of the counterweight acts on the bolt in the shear direction. Therefore, there are concerns about strength.As a countermeasure, a structure has been proposed in which a part is provided on the machine frame side to support the counterweight attached to the machine frame from below, and further the load of the counterweight is supported by a portion other than the bolt (see, for example, Patent Literatures 2 and 3). [Patent literature] [PTL 1] JP H07 - 268 908 A [PTL 2] JP H08 - 319 637 A [PTL 3] JP 2012 - 57 299 A [Technical task]

[0005] In the case of a moving device having a support portion that supports a counterweight from below, as in Patent Literature 2 and 3 mentioned above, a component is required to prevent mutual interference between the counterweight and the support portion during counterweight installation and removal. In Patent Literature 2, for example, a third pin serving as a counterweight suspension position is arranged farther in the machine body forward direction than a first pin and a second pin, respectively, at rotation centers of a hydraulic cylinder and a linkage (an arm member) so that it and a vehicle body frame (the support portion) do not interfere with each other. In Patent Literature 3, in addition to the above-mentioned raising and lowering mechanism, a raising and lowering cylinder is provided that raises the counterweight with respect to a rotatable-type support member (arm member).That is, in a device of Patent Literature 3, two cylinders, that is, the cylinder for rotating the arm member and the lifting and lowering cylinder for lifting the counterweight, are used to avoid them and the saddle bearing (the support portion) of the counterweight from interfering with each other.

[0006] However, in the device of Patent Literature 2, the rotation centers of the hydraulic cylinder and linkage must be located further in the rearward direction of the machine body than the suspension position of the counterweight. Therefore, it is necessary to ensure a large space in the counterweight. A large amount of space is also required on the vehicle body frame. Since the device of Patent Literature 3 uses two hydraulic cylinders, the number of components increases, increasing the cost and making the structure more complicated.

[0007] The present invention has been made in view of such problems. It relates to a counterweight moving device. It has an object to place the counterweight in the attached state on a support surface on the machine frame and to move the counterweight, while avoiding mutual interference between the counterweight and the support surface with a simple structure. It should be noted that the present invention is not limited to this object. Another object of the present invention can be considered to achieve an effect and effects resulting from embodiments described as embodiments of the invention explained below, that is, an effect and effects not achieved by the prior art.

[0008] From US 8 434 787 B2, an attachment and removal system for a counterweight is known, which can be coupled to a work machine such as a hydraulic excavator.

[0009] The object is achieved by a movement device having the features of patent claim 1 as described below: (1) A moving device for a counterweight, said moving device moving the counterweight between an attachment position on a machine frame and the ground, said moving device comprising: an attachment member fixed to the machine frame; a support member fixed to the machine frame and having a support surface on which the counterweight is placed in its attached state; and a linkage mechanism attached to the attachment member and configured to move the counterweight.

[0010] The linkage mechanism includes an arm member, one end of which is axially supported by the attachment member and the other end of which is axially supported at the top in a recess in the front surface of the counterweight. The linkage mechanism includes a rotary cylinder, one end of which is axially supported by the attachment member and the other end of which is axially supported at the top in the recess. The rotary cylinder is provided in such a way that it is extendable and retractable and rotates the arm member about one end of the arm member. Furthermore, on a side of the counterweight that is in contact with the support surfaces in the attached state, a contact surface is formed in a shape based on an arcuate guide path that is described during the movement of the counterweight.

[0011] The contact surface is formed in a shape that is identical to the shape of the support surface and, when attached, is in surface contact with the support surface.

[0012] Advantageous embodiments are the subject of the dependent claims as described below:(2) Preferably, the support surface is an inclined surface obtained by linear approximation of the path.

[0013] (3) Alternatively, the support surface is preferably a curved surface extending along the track.

[0014] (4) Preferably, the support surface has a shape based on a trajectory at the time during which an edge portion on the contact surface on a side opposite to a moving direction of the counterweight moves between a position in the attached state and a position in which the edge portion overlaps in a vertical direction an edge portion on the support surface on a side of the moving direction.

[0015] (5) Preferably, the support element is designed to be removable from the machine frame.

[0016] (6) Preferably, the moving device includes an adjustment mechanism for adjusting the upper and lower positions of the counterweight when mounting the counterweight. That is, the adjustment mechanism adjusts the mounting position of the counterweight in the vertical direction.

[0017] (7) Preferably, the linkage mechanism is disposed substantially at the center in the left-to-right direction of the machine frame. In this case, a pair of support members are preferably provided arranged to the left and right of the linkage mechanism. Note that "substantially at the center in the left-to-right direction" does not necessarily mean the exact center position in the left-to-right direction, but means that a certain error tolerance is allowed. That is, the linkage mechanism may be disposed at a position slightly offset in the left-to-right direction from the center position of the machine frame in the left-to-right direction. [Advantageous effects of the invention]

[0018] In the disclosed counterweight moving device, the support surface that supports the counterweight from below is formed in a shape based on the arcuate guideway that defines the contact surface. Consequently, even though the linkage mechanism has a simple structure, providing a rotary cylinder that rotates the arm member, it is possible to move (raise and lower) the counterweight while avoiding mutual interference between the contact surface of the counterweight and the support surface on the machine frame side. It should be noted that by simplifying the structure, it is possible to reduce manufacturing costs and product costs.

[0019] In the disclosed counterweight moving device, the counterweight is placed on the support surface in its mounted state. Therefore, it is also possible to support the load of the counterweight with the support surface. This makes it possible to reduce the load acting on the bolts for fixing the counterweight. [Short description of the drawing] Fig. 1 is a perspective view showing a construction machine to which a counterweight moving device according to an embodiment is applied. Fig. 2 is a sectional view (according to section line AA in Fig. 3) for explaining a linkage mechanism of the moving device according to the embodiment. Fig. 3 is a longitudinal section view (according to section line BB in Fig. 2) to explain a path during the movement of the counterweight by the moving device according to the embodiment. Fig. Fig. 4 is a diagram for explaining a support surface of the moving device according to the embodiment, wherein (a) is an enlarged sectional view (corresponding to the section line CC in Fig. 2), (b) is a perspective view of a support block, and (c) is a side view showing a fixed state of the support block. Fig. Fig. 5 is a diagram for explaining an adjusting mechanism of the movement device according to the embodiment, wherein (a) is a longitudinal sectional view (corresponding to the section line DD in Fig. 2) of the adjustment mechanism and the peripheral portion thereof, and (b) is a perspective view showing an adjusting body and a nut. Fig. 6 is a side view showing a fixed state of a support block according to a modification. Fig. 7 is a perspective view showing an adjusting body and a screw according to the modification. [Description of embodiments]

[0020] With reference to the drawings, a counterweight moving device according to an embodiment will be explained. The embodiment explained below is for illustrative purposes only and should not be construed as excluding various modifications and applications of techniques not clearly indicated herein. Forms of this embodiment can be modified in various ways and implemented within a range without departing from the gist of the forms, and can be selected according to need or combined as applicable. [1. Design]

[0021] In Fig. 1 shows a construction machine (a work machine) equipped with a counterweight moving device of this embodiment. In this embodiment, a hydraulic excavator 9 is illustrated as the construction machine. In the following explanation, the traveling direction of the hydraulic excavator 9 is set as the forward direction, and the opposite direction is set as the reverse direction. Left and right are set based on the forward direction. The direction of gravity is set as the downward direction (downward), and the opposite direction is set as the upward direction (upward). In the explanation of devices and components mounted on a machine body, the vertical direction, the left-to-right direction, and the front-to-rear direction are set based on the state in which the devices and components are mounted on the machine body.

[0022] The hydraulic excavator 9 includes a crawler-type lower traveling body 2 and an upper slewing body 3 provided so as to be capable of rotating above the traveling body 2. In the upper slewing body 3, a work machine 4 that performs various works and a cab 5 from which vehicle operation is performed by the operator are mounted in the front part of the upper slewing body 3. Drive units such as a prime mover, a hydraulic pump, a fuel tank, a hydraulic oil tank, and the like (all not shown in the figure) are mounted in the rear part of the upper slewing body 3. Further, a counterweight 10 is mounted in the rearmost part of the upper slewing body 3. Regarding the work machine 4, it is noted that various attachments 6, such as a loader bucket and a hydraulic hammer, are mounted on the front part of the work machine 4.

[0023] The upper slewing body 3 includes a machine frame 7 forming the bottom surface of the upper slewing body 3. The machine frame 7 is a frame member of the hydraulic excavator 9 and is formed by a bottom plate, a side plate, a reinforced plate, and the like, which have high strength. The work implement 4, the cab 5, the power units, and the like are mounted at a predetermined position on the machine frame 7. The machine frame 7 includes a fixed portion 7A extending in the left-right direction and in the vertical direction substantially at the center of the left-right direction of the rear portion of the machine frame 7, and two protrusion portions 7B projecting in the lower part of the rear surface of the fixed portion 7A in the machine body rearward direction. The fixed portion 7A is a part to which the counterweight 10 is fixed.The fixed portion 7A is arranged such that its lower edge portion protrudes downward no further than the bottom of the machine frame 7. The protrusion portions 7B are members serving as support portions that support the counterweight 10 from below. The two protrusion portions 7B are spaced apart from each other in the left-right direction and arranged to be symmetrical with respect to the center line of the left-right direction.

[0024] The counterweight 10 is a heavy load that ensures the weight distribution of the machine body during work. The counterweight 10 can be attached to and detached from the hydraulic excavator 9 of this embodiment. That is, in the hydraulic excavator 9, the counterweight 10 placed on the ground G can be lifted and attached to the machine frame 7. The counterweight 10 attached to the machine frame 7 can be uncoupled and lowered to the ground G. In the hydraulic excavator 9, a moving device 1 is provided that moves (raises and lowers) the counterweight 10 in the vertical direction when attaching and detaching it.

[0025] Note that the counterweight 10 has two locking portions 11 projecting upward on its upper surface. The two locking portions 11 are spaced apart from each other in the left-right direction in a state where the counterweight 10 is mounted on the machine frame 7, and are arranged to be symmetrical with respect to the center line of the left-right direction. The locking portions 11 are members formed in a flat shape. Holes for receiving hooks are drilled centrally in the locking portions 11. The hooks are locked in the locking portions 11 when the counterweight 10 is lifted from the ground G by a hoist (a crane) not shown.

[0026] In the following, the structure of the counterweight 10, which is attached to and detached from the machine frame 7, is explained in detail and the structure of the moving device 1 is described with reference to Fig. 2 to 5 are explained in detail.

[0027] Fig. 2 is a sectional view (according to section line AA in Fig. 3) a front surface 10a of the counterweight 10, as viewed from the forward direction of the machine body. Note that the front surface 10a of the weight is a surface facing the forward direction of the machine body when the counterweight 10 is attached. Fig. 3 is a longitudinal section view (according to section line BB in Fig. 2) of the machine body rear part of the hydraulic excavator 9. The state in which the counterweight 10 is lowered to the ground G is shown in Fig. 3 is indicated by a solid line. The attached state of counterweight 10 is indicated by a dash-dot-dot line.

[0028] As in Fig. 2 and Fig. 3, the counterweight 10 of this embodiment includes a recess 12 formed vertically substantially at the center of the left-to-right direction of the front surface 10a of the weight, and a step portion 13 projecting in the left-to-right direction at a lower part of the front surface 10a of the weight. The recess 12 is a space in which a linkage mechanism 30, explained below, of the moving device 1 is housed. The recess 12 is open in the forward direction of the machine body. Note that the recess 12 is closed at the top by a flat section 16 provided so as to be removable by loosening a screw (not shown). However, the recess 12 is open at the bottom.

[0029] The recess 12 has a step surface 12a extending in the horizontal direction at an intermediate part in the vertical direction. The recess 12 is formed such that a length in the left-to-right direction above the step surface 12a is greater than a length in the left-to-right direction below the step surface 12a. The recess 12 is formed in a T-shape in the front view. On the step surface 12a, flat suspension plates 14 are formed upright along two edges on the central side of the step surface 12a in the left-to-right direction. Holes 14h are drilled in upper parts of the suspension plates 14, through which pins 37, which will be explained below, are inserted and in which adjusting bodies 51, which will be explained below, are arranged.

[0030] The step portion 13 is a part that protrudes from the front surface 10a of the weight in the machine body forward direction and is formed in a rectangular shape in side view. On the front surface 13a of the step portion 13 (in the lower part of the front surface 10a of the weight), two hollow portions 15 that are open in the forward and downward directions of the machine body are arranged at a distance from each other in the left-to-right direction and formed to be symmetrical with respect to the center line of the left-to-right direction. The hollow portions 15 constitute spaces in which the projection portions 7B provided on the machine frame 7 are received. In the attached state of the counterweight 10, top surfaces 15a of the hollow portions 15 and a member on the machine frame 7 side are in contact with each other.The hollow portions 15 of this embodiment include protruding portions 15b projecting downward in the front portions of the upper surfaces 15a. The bottom surfaces of the protruding portions 15b (the front portions of the upper surfaces 15a) contact the member on the machine frame 7 side (in this embodiment, contact surfaces 40a of the support blocks 40a, explained below). In the following explanation, the surfaces in contact with the machine frame 7 side on the upper surfaces 15a of the hollow portions 15 are referred to as contact surfaces 15c.

[0031] The moving device 1 includes an attachment member 20 fixed to the fixed portion 7A of the machine frame 7, the linkage mechanism 30 for moving the counterweight 10, the support blocks 40 (support members) fixed to the overhang portion 7B of the machine frame 7, and an adjustment mechanism 50 for adjusting a position (an attachment position) in the vertical direction when attaching the counterweight 10. The attachment member 20 and the linkage mechanism 30 are arranged substantially at the center of the left-to-right direction of the machine frame 7. The support blocks 40 are arranged on the left and right sides of the attachment member 20 and the linkage mechanism 30, respectively. Note that "substantially the center of the left-to-right direction" does not necessarily mean the exact center position in the left-to-right direction, but means that a certain error tolerance is allowed.That is, the attachment member 20 and the linkage mechanism 30 may be arranged at positions slightly offset to the left or right from the center position, with respect to the left-right direction, of the machine frame 7.

[0032] As in Fig. 2 and Fig. 3, the attachment member 20 includes a base material 21 disposed along the rear surface of the fixed portion 7A, and a pair of bearing brackets 22 standing upright in a vertical direction with respect to the base material 21. In the attachment member 20, the base material 21 is screw-fixed substantially at the center of the left-to-right direction of the fixed portion 7A, thereby extending the bearing bracket 22 from the base material 21 in the machine body rearward direction. Shaft holes are formed in the upper and lower portions of the pair of bearing brackets 22, respectively. The shaft holes in the upper portions are located further forward in the machine body than the shaft holes in the lower portions. A first base shaft 31, explained below, is inserted through the shaft holes in the upper portions. A second base shaft 32, explained below, is inserted through the shaft holes in the lower portions.

[0033] The linkage mechanism 30 includes a pair of arm members 34 and a rotating cylinder 35 that rotates the counterweight 10, wherein the first base shaft 31 and the second base shaft 32 serve as rotation centers of the arm member 34 and the rotating cylinder 35, and a support shaft 33 serves as a suspension position when the counterweight 10 is lifted.

[0034] The arm member 34 is a flat, thin plate member having a longitudinal direction. The two arm members 34 are spaced apart from each other in the left-to-right direction in a position where a normal direction is the left-to-right direction, and are arranged such that they are symmetrical with respect to the center line of the left-to-right direction.

[0035] One end 34a in the longitudinal direction of the arm member 34 is axially supported by the attachment member 20. The other end 34b in the longitudinal direction of the arm member 34 is axially supported at the top of the recess 12 of the counterweight 10. The other end 34b rotates around the one end 34a. In the following explanation, one end 34a of the arm member 34 is referred to as the proximal arm end 34a, and the other end 34b is referred to as the distal arm end 34b. A hole is drilled in the proximal arm end 34a, through which the first base shaft 31 is inserted. A hole is drilled in the distal arm end 34b, through which the support shaft 33 is inserted. The arm member 34 is rotatably supported by the first base shaft 31 and the support shaft 33, which are respectively inserted through the holes drilled in both ends.

[0036] Specifically, the proximal arm ends 34a of the pair of arm members 34 are arranged to overlap, in the left-to-right direction, the shaft holes drilled into the upper parts of the pair of bearing brackets 22. Two first base shafts 31 are respectively inserted through the hole of the proximal arm end 34a and the shaft hole of the bearing bracket 22, thereby providing the arm member 34 so as to be rotatable (hinged) with respect to the bearing bracket 22.

[0037] On the other hand, a support shaft 33 extending upward in the left-right direction into the recess 12 is inserted through the distal arm ends 34b of the pair of arm members 34.

[0038] Both ends of the support shaft 33 are rotatably supported with respect to the suspension plates 14 via a pair of coupling devices 36 and a pair of pins 37 provided on the step surface 12a of the recess 12. The support shaft 33 is fixed to an upper part of the coupling device 36. The pin 37 inserted through the hole 14h of the suspension plate 14 passes through a lower part of the coupling device 36 and is pivotally connected thereto. Thus, the arm member 34 is rotatably provided with respect to the suspension plate 14. Note that a projection 36a is provided at the lower end of the coupling device 36, which regulates the movement of the coupling device 36 in the left-to-right direction with respect to the suspension plate 14.

[0039] The rotary cylinder 35 is an actuator for rotating the arm member 34. A piston, provided at one end of a rod 35D, is slidably fitted inside a tube 35C. The other end of the rod 35D protrudes from the tube 35C. The rotary cylinder 35 is, for example, a hydraulic cylinder actuated by the hydraulic pressure from a hydraulic pump applied to the upper rotary body 3. The rotary cylinder 35 is provided in such a way that it can be extended and retracted. The rotary cylinder 35 is arranged substantially at the center of the left-to-right direction of the machine body and is located between the two arm members 34.

[0040] One end 35a of the rotary cylinder 35 is axially supported by the attachment 20. The other end 35b of the rotary cylinder 35 is axially supported at the top of the recess 12 of the counterweight 10. The other end side 35b rotates around the one end 35a. In the following explanation, the one end 35a of the rotary cylinder 35 is referred to as the proximal cylinder end 35a. The other end 35b of the rotary cylinder 35 is referred to as the distal cylinder end 35b. The proximal cylinder end 35a is an end portion on a side opposite the rod 35D of the tube 35C. The distal cylinder end 35b is the distal end of the rod 35D.

[0041] A second base shaft 32 is inserted through the proximal cylinder end 35a. Both ends of the second base shaft 32 are respectively inserted through the shaft holes in the lower parts of the pair of bearing brackets 22. Thus, the rotary cylinder 35 is provided rotatably with respect to the bearing bracket 22 (hingably connected thereto). On the other hand, the support shaft 33 is inserted through the distal cylinder end 35b. That is, the distal cylinder end 35b is inserted through substantially the center in the left-to-right direction of the support shaft 33. The distal arm ends 34b are inserted through both sides of the support shaft 33. Further, the coupling devices 36 are fixed on both sides of the support shaft 33. Thus, the other cylinder end 35b of the rotary cylinder 35 is provided rotatably with respect to the suspension plate 14.

[0042] As in Fig. 3, the counterweight 10 moves between the ground G and the attachment position on the machine frame 7 through the linkage mechanism 30 configured as described above. Specifically, as indicated by a solid line in the figure, the pair of coupling devices 36 are respectively connected by the pins 37 to the pair of suspension plates 14 of the counterweight 10 placed on the ground G. The rotary cylinder 35 is actuated and extended to rotate the arm member 34 about the proximal arm end 34a such that the distal arm end 34 moves upward. Consequently, the counterweight 10 is lifted. As indicated by a dash-dot-dot line in the figure, the counterweight 10 moves to the attachment position where it is attached to the machine frame 7.

[0043] It should be noted that when the counterweight 10 attached to the machine frame 7 is uncoupled and lowered to the floor G, an operation opposite to that when the counterweight 10 is raised occurs. That is, the rotary cylinder 35 is actuated and retracted to rotate the arm member 34 about the proximal arm end 34a so that the distal arm end 34 moves downward. The trajectory L that the distal arm end 34b describes during such movement of the counterweight 10 is indicated by a chain line. The trajectory L is formed in an arc shape whose center (point P in the figure) lies on the center line of the first base shaft 31 supporting the proximal arm end 34a, and has the distance (straight line) from the center line (from point P) to a center line (point M in the figure) of the support shaft 33 as its radius. The counterweight 10 moves along the path L.

[0044] As in Fig. 3 and Fig. 4 (a) to (c), the support block 40 is a member that supports the counterweight 10 from below in the attached state in which it is attached to the machine frame 7. It should be noted that Fig. 4(a) a longitudinal sectional view (corresponding to section line CC in Fig. 2) showing a state in which the counterweight 10 is supported by the projection portion 7B and the support block 40. Fig. 4(b) is a perspective view of the support block 40. Fig. 4(c) is a side view showing a fixed state of the support block 40.

[0045] The support block 40 is formed in a shape obtained by obliquely cutting off an edge extending in the longitudinal direction of a cuboid block. The support block 40 is fixed to the machine frame 7 in a position where a flat inclined surface is formed by the cutting surface in the upward and backward directions (the normal of the inclined surface extends obliquely backward upward). That is, the inclined surface extends obliquely downward in the machine body backward direction. The inclined surface is a surface that contacts the counterweight 10 and supports the counterweight 10 from below. In the following explanation, the inclined surface is referred to as a support surface 40a. The support surface 40a is in contact with the contact surface 15c provided on the underside of the protruding portion 15b of the counterweight 10.

[0046] In Fig. 4 (a), the trajectory described by the leading edge portion of the contact surface 15c during the movement of the counterweight 10 is indicated by a dash-dot line L'. The trajectory L' coincides with the trajectory obtained by shifting the trajectory L described by the distal arm end 34 such that the point M comes to lie at a position (a point E) at which, in the attached state of the counterweight 10, the leading edge portion of the contact surface 15c and the support block 40 are in contact with each other. That is, the trajectory L' is the same arc with a radius corresponding to the radius of the Fig. 3 shown path L is equal.

[0047] The support surface 40a of the support block 40 is formed in a shape based on the arcuate path L' described by the leading edge portion of the contact surface 15c. That is, the support surface 40a is formed in a shape that is close to the shape of the path L' and does not interfere with the path L'. The support surface 40a of this embodiment is provided as a flat, inclined surface obtained by linearly approximating the path L'. As a method for linearly approximating the path L', for example, as shown in Fig. As shown in Fig. 4 (a), there is a method of linearly approximating the trajectory L' by a straight line connecting the point E where the support block 40 and the leading edge portion of the contact surface 15c of the counterweight 10 are in contact with each other, and a point F where the trailing edge portion of the support block 40 and the trajectory L' overlap in the vertical direction. The support surface 40a is provided as an inclined surface having at least an inclination greater than an inclination with respect to the horizontal direction of the straight line connecting the point E and the point F.

[0048] The support surface 40a of this embodiment is formed in a shape based on the trajectory L' at the time the leading edge portion of the contact surface 15c moves between the position in the attached state of the counterweight 10 (i.e., point E) and the position where the trajectory L' overlaps the trailing edge portion of the support surface 40a (the edge portion on the moving direction side of the counterweight 10) in the vertical direction (i.e., point F). That is, the support surface 40a is formed based on the trajectory L' at the time when, on the trajectory L', an edge portion on the contact surface 15c on a side opposite to the moving direction of the counterweight 10 moves between point E and point F.As a result, since the support surface 40a is formed in the shape based on the path L', the contact surface 15c and the support surface 40a do not intersect (disturb) each other during the movement of the counterweight 10. Note that since the path L and the path L' represent the same arc as explained above, the support surface 40a is also considered to have a shape based on the path L.

[0049] The support block 40 is placed on top of the projection section 7B and fixed to the projection section 7B by a screw connection. As shown in Fig. As shown in Figure 4(b), two cylindrical channel portions 41 are formed in the support surface 40a, which are spaced apart from each other. The cylindrical channel portion 41 is formed in a circular shape in plan view. As shown in Fig. As shown in Figure 4(c), the cylindrical channel portion 41 is formed with a depth that prevents the head of the bolt 42 from projecting from the support surface 40a, and is formed such that its bottom surface extends horizontally. The bottom surface of the cylindrical channel portion 41 serves as a support surface for the bolt 42. A through hole is formed downward in the bottom surface. A threaded hole is formed in the projection portion 7B. The bolt 42 inserted through the hole portion of the support block 40 is fastened in the threaded hole of the projection portion 7B. Thus, the support block 40 is fixed to the projection portion 7B.

[0050] Note that the support block 40 can be detached from the projection portion 7B by removing the bolt 42. That is, the support block 40 is designed to be detachable from the machine frame 7.

[0051] On the other hand, the contact surface 15c of the counterweight 10 is formed in a shape identical to the shape of the support surface 40a. That is, the contact surface 15c is provided as a flat, inclined surface having an inclination equal to the inclination of the support surface 40a. Consequently, in the mounted state of the counterweight 10, the contact surface 15c and the support surface 40a are in planar contact with each other.

[0052] When the counterweight 10 is moved to the mounting position (position according to the dash-dot-dot line in Fig. 3) is lifted, in which the counterweight 10 is attached to the machine frame 7, as explained above, the upper surface 15a of the hollow portion 15 is located above the protruding portion 7B of the machine frame 7. The contact surface 15c of the hollow portion 15 is in surface contact with the bearing surface 40a of the support block 40 fixed to the protruding portion 7B. The counterweight 10 is supported by the support block 40 and the protruding portion 7B.

[0053] Depending on the play, dimensional accuracy, or the like of the linkage mechanism 30, a delicate position adjustment in the vertical direction is sometimes required in the attached state of the counterweight 10. Therefore, the movement device 1 of this embodiment includes the adjustment mechanism 50 for adjusting the upper and lower positions when attaching the counterweight 10. The adjustment mechanism 50 of this embodiment, as shown in Fig. 5(a) and (b), comprises a threaded hole 14k formed in the suspension plate 14, an adjusting body 51 on which a threaded portion 52 is integrally provided, and a nut 53 that can be screwed to the threaded portion 52. It should be noted that Fig. 5(a) a longitudinal sectional view (corresponding to section line DD in Fig. 2) to explain the adjustment mechanism 50. Fig. Fig. 5(b) is a perspective view showing the structure of the adjustment mechanism 50.

[0054] As explained above, the suspension plate 14 has the hole 14h drilled in the upper part. Viewed from the side, the hole portion 14h is formed in a shape obtained by combining a rectangular hole with an elongated hole located below. The threaded hole 14k is a hole portion from the top surface of the suspension plate 14 to the hole 14h, into which a thread is cut. The adjusting body 51 has a curved surface portion 51a machined in an arc shape on the underside of a cuboid block, and has a vertically projecting threaded portion 52 on a surface (the top surface) opposite the curved surface portion 51a.

[0055] The adjusting body 51 is arranged in a rectangular section of the hole portion 14h of the suspension plate 14. The threaded portion 52 is screwed into the threaded hole 14k from the hole portion 14h side. The nut 53 is screwed to the threaded portion 52 protruding from the top of the suspension plate 14. The peripheral surface of the pin 37 is in contact with the curved surface portion 51a of the adjusting body 51. Accordingly, the upper and lower positions of the pin 37 are adjusted by rotating the adjusting body 51 and adjusting a screw-in length of the threaded portion 52 with respect to the threaded hole 14k of the suspension plate 14. The pin 37 is inserted through the lower part of the coupling device 36. Therefore, when the upper and lower positions of the pin 37 are adjusted, the upper and lower positions of the coupling device 36, that is, the upper and lower positions of the support shaft 33, are adjusted.Consequently, since the suspension position of the counterweight 10 is set in the vertical direction, the contact surface 15c and the support surface 40a are securely in surface contact with each other.

[0056] Note that when a plurality of bolts (not shown in the figure) are inserted from the rear side of the counterweight 10 toward the machine frame 7 in a state where the counterweight 10 is raised to the mounting position, the counterweight 10 is fixed (fixed) to the machine frame 7. When the counterweight 10 is lowered to the ground G, the above-mentioned operation is performed after loosening the bolts. [2. Impact and effects]

[0057] In the above-described moving device 1, the support surface 40a supporting the counterweight 10 from below is formed in the shape based on the arcuate trajectory L' described by the leading edge portion of the contact surface 15c. Consequently, with the linkage mechanism 30 having the simple structure in which a rotary cylinder 35 is provided that rotates the arm member 34, it is possible to move the counterweight 10 while avoiding mutual interference between the contact surface 15c of the counterweight 10 and the support surface 40a on the machine frame 7 side. It should be noted that by simplifying the structure, it is possible to reduce manufacturing costs and product costs.

[0058] In the above-described movement device 1, the counterweight 10 is placed on the support surface 40a in its mounted state. Therefore, the load of the counterweight 10 can be additionally supported by the support surface 40a. It is possible to reduce the load acting on the bolts for fixing the counterweight 10.

[0059] It should be noted that, in the above-described moving device 1, the shape of the support surface 40a supporting the counterweight 10 is designed to avoid mutual interference between the counterweight 10 and the support surface 40a. Therefore, unlike, for example, Patent Literature 2 described above, it is unnecessary to arrange the centers of the first base shaft 31 and the second base shaft 32 further in the machine body rearward direction than the center of the support shaft 33 in order to avoid interference during the movement of the counterweight 10. Therefore, in the above-described moving device 1, it is not necessary to enlarge the recess 12 of the counterweight 10. It is not necessary to provide a wide space in the rear portion of the machine frame 7 in order to avoid interference during the movement.This means that with the above-described movement device 1, it is possible to achieve space savings. It is possible to increase the design freedom of the upper rotating body 3.

[0060] In the above-described movement device 1, the contact surface 15c provided in the counterweight 10 is formed in a shape identical to the shape of the support surface 40a. When the counterweight 10 is mounted, the contact surface 15c is in surface contact with the support surface 40a. Consequently, the load of the counterweight 10 is not concentrated on a portion of the support surface 40a. With the support surface 40a, it is possible to stably support the counterweight 10.

[0061] In the above-described moving device 1, the support surface 40a is provided as the inclined surface obtained by linearly approximating the trajectory L'. Therefore, it is possible to simplify the structure of the moving device 1. Furthermore, it is possible to easily perform machining of the support surface 40a.

[0062] The support surface 40a of this embodiment is formed in the shape based on the trajectory L' at the time the leading edge portion of the contact surface 15c moves between the position in the mounted state of the counterweight 10 (i.e., point E) and the position where the leading edge portion overlaps the trailing edge portion of the support surface 40a in the vertical direction (i.e., point F). Consequently, it is possible to further prevent mutual interference between the contact surface 15c and the support surface 40a during the movement of the counterweight 10. Since the inclination angle of the support surface 40a with respect to the horizontal direction decreases, it is possible to support the counterweight 10 more stably.

[0063] In the above-described moving device 1, the support block 40, including the support surface 40a, is provided on the overhang portion 7B of the machine frame 7 in such a way that it can be detachably attached. Consequently, regardless of the attached state of the moving device 1, it is possible to achieve widespread use of the configuration of the machine frame 7.

[0064] That is, it is also possible to apply the moving device 1 of this embodiment to the existing machine frame 7.

[0065] The above-described movement device 1 includes the adjustment mechanism 50 for adjusting the upper and lower positions when attaching the counterweight 10. Therefore, even if there is play, a dimensional error, or the like in the linkage mechanism 30, it is possible to firmly bring the counterweight 10 into contact with the support surface 40a. With the support surface 40a, it is possible to securely support the counterweight 10.

[0066] In the above-described moving device 1, the linkage mechanism 30 is arranged substantially at the center of the left-to-right direction of the machine frame 7. The support blocks 40 are arranged on the left and right sides of the linkage mechanism 30, respectively. Consequently, it is possible to move the counterweight 10 with good balance. It is possible to stably support the counterweight 10. [3. Miscellaneous]

[0067] The embodiment of the present invention has been explained above. However, the present invention is not limited to the above-described embodiment and can be modified in various ways within a range that does not depart from the spirit of the present invention.

[0068] The configuration of the support surface 40a explained above is an example and is not limited thereto. For example, as shown in Fig. 6, a support surface 40a' may be a curved surface extending along the path L'. With such a configuration, it is possible to more securely support the counterweight 10 while avoiding mutual interference between the contact surface 15c and the support surface 40a' during the movement of the counterweight 10. Note that the support surface 40a may be provided integrally with the machine frame 7. That is, the support block 40 may be provided, for example, using the upper surface of the protruding portion 7B as a support surface rather than as a separate body. In this case, the protruding portion 7B serves as a support member.

[0069] The shape of the counterweight 10 is not limited to the one explained above. For example, the counterweight 10 may not include the step portion 13. The front surface 10a of the weight may be a surface extending in the vertical direction. Optionally, the contact surface 15c in contact with the support surface 40a may not be provided as part of the top surface 15a of the hollow portion 15 explained above. For example, when the position of the support member is such that it extends along the lower end surface of the machine frame 7, the contact surface may be formed by cutting out the lower end portion of the front surface 10a of the weight. Alternatively, when the support member projects downward further than the lower end surface of the machine frame 7, the contact surface may be provided on the lower end surface of the weight 10.It should be noted that the contact surface 15c does not have to be formed in a shape identical to the shape of the support surface 40a. For example, the contact surface and the support surface 40a may be planes with the same inclination and formed to have different plane sizes. When the support surface 40' is the curved surface as shown in FIG. Fig. 6, the contact surface may be a curved surface having a radius equal to the radius of the support surface 40' and may be convex upwards.

[0070] The configuration of the adjustment mechanism 50 explained above is an example and is not limited thereto. For example, as shown in Fig. 7, an adjustment mechanism may comprise an adjusting body 54, wherein in addition to the threaded hole 14k formed in the suspension plate 14, Fig.5(a), a threaded hole 54h is formed, and a screw 55 can be screwed into the two threaded holes 14k and 54h. The adjusting body 54 is arranged in a rectangular portion of the hole portion 14h of the suspension plate 14. On the other hand, the screw 55 is screwed into the threaded holes 14k and 54h from above with respect to the suspension plate 14. The peripheral surface of the pin 37 is in contact with a curved surface portion 54a of the adjusting body 54.

[0071] With such an adjustment mechanism, the upper and lower positions of the pin 37 are adjusted by rotating the screw 55 and adjusting a screwing length of the screw 55 with respect to the threaded hole 54h of the adjusting body 54. Accordingly, even with such an adjustment mechanism, it is possible to achieve effects similar to those explained above. Note that the position at which the adjustment mechanism 50 is provided is not limited to the above-mentioned position. The adjustment mechanism 50 only needs to be provided at a position where, at the time the counterweight 10 is mounted, the positional relationship in the vertical direction between the counterweight 10 and the machine frame 7 or the support surface 40a can be changed (adjusted).

[0072] The moving device 1 that moves the counterweight 10 of the hydraulic excavator 9 has been illustrated in the above-described embodiment. However, a construction machine equipped with the moving device 1 is not limited to the hydraulic excavator 9. The moving device 1 can be applied to various construction machines. [List of reference symbols] 1 movement device 7 Machine frame 10 Counterweight 10a Front surface of the weight (front surface) 12 recess 15c contact surface 16 flat profile 20 add-on element 30 Linkage mechanism 34 Arm element 34a proximal arm end (one end) 34b distal arm end (the other end) 35 rotary cylinders 35a proximal cylinder end (one end) 35b distal cylinder end (the other end) 40 Support block (support element) 40a support surface 50 adjustment mechanism G Floor L, L' Bahn

Claims

[1] Moving device (1) for a counterweight (10), wherein the moving device (1) moves the counterweight (10) between a mounting position on a machine frame (7) and the ground (G), wherein the moving device (1) comprises: an attachment element (20) which is fixed to the machine frame (7); a support element (40) which is fixed to the machine frame (7) and has a support surface (40Aa) on which the counterweight (10) is placed in its attached state; a linkage mechanism (30) mounted on the attachment element (20) and adapted to move the counterweight (10), the linkage mechanism (30) comprising: an arm element (34), one end (34a) of which is axially supported by the attachment element (34) and the other end (34b) of which is axially supported at the top in a recess (12) in the front surface (10a) of the counterweight (10); and a rotary cylinder (35), one end (35a) of which is axially supported by the attachment element (20) and the other end (35b) of which is axially supported at the top of the recess (12), the rotary cylinder (35) being designed to be extendable and retractable and to rotate the arm element (34) about one end (34a) of the arm element (34); and a contact surface (15c) of the support surface (40a) on one side of the counterweight (10), which in the attached state is in contact with the support surface (40a), which is formed in a shape based on an arcuate guide path (L, L') which is described during the movement of the counterweight (10), wherein the contact surface (15c) is formed in a shape which is the same as the shape of the support surface (40a) and in the attached state is in surface contact with the support surface (40a). [2] A moving device (1) for a counterweight (10) according to claim 1, wherein the support surface (40a) is an inclined surface obtained by linear approximation of the trajectory (L, L'). [3] A moving device (1) for a counterweight (10) according to claim 1, wherein the support surface (40a) is a curved surface extending along the path (L, L'). [4] A moving device (1) for a counterweight (10) according to any one of claims 1 to 3, wherein the support surface (40a) has a shape based on a trajectory (L, L') at the time during which an edge portion on the contact surface (15c) on a side opposite to a moving direction of the counterweight (10) moves between a position in the attached state and a position in which the edge portion overlaps in a vertical direction an edge portion on the support surface (40a) on a side of the moving direction. [5] Moving device (1) for a counterweight (10) according to one of claims 1 to 4, wherein the support element (40) is adapted to be removable from the machine frame (7). [6] A moving device (1) for a counterweight (10) according to any one of claims 1 to 5, further comprising an adjusting mechanism (50) for adjusting the upper and lower positions of the counterweight (10) when attaching the counterweight (10). [7] A moving device (1) for a counterweight (10) according to any one of claims 1 to 6, wherein the linkage mechanism (30) is arranged substantially at the center of the left-to-right direction of the machine frame (7), and a pair of support members (40) are provided which are arranged to the left and right of the linkage mechanism (30).

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