Auxiliary device for expanding and contracting lower traveling body and method for expanding and contracting width of lower traveling body

Abstract

To expand or contract the width dimension of a lower traveling body by simple work, regardless of the type or condition of the ground.SOLUTION: An expansion / contraction auxiliary device 21 comprises a bracket member 22 in which a first attachment part 24 and a second attachment part 25 are detachably attached to an outer circumferential side of a crawler track 11, a sliding member 30 attached to the side opposite to the first attachment part 24 and the second attachment part 25 of the bracket member 22 so as to be slidable in the left and right direction. Therefore, the bracket member 22 of the expansion / contraction auxiliary device 21 is attached to a position where it is not in contact with the ground G of the crawler track 11. The expansion / contraction auxiliary device 21 is moved around together with the crawler track 11 to bring the sliding member 30 of the expansion / contraction auxiliary device 21 into contact with the ground G, and the side frame 6 is moved in the left-right direction together with the crawler track 11 and the like. Next, the expansion / contraction auxiliary device 21 is moved around together with the crawler track 11 to place the expansion / contraction auxiliary device 21 at a position away from the ground G, and the bracket member 22 is removed from the crawler track 11.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an expansion and contraction assisting device for an undercarriage used when expanding or contracting the width dimension of the undercarriage of a construction machine, and a method for expanding and contracting the width of the undercarriage.

Background Art

[0002] A hydraulic excavator, which is a representative example of a construction machine, includes a self-propelled undercarriage, an upper revolving body rotatably provided on the undercarriage, and a working device rotatably provided at the front of the upper revolving body.

[0003] The undercarriage includes a center frame located at the center, side frames attached to both left and right sides of the center frame in a state of extending in the front-rear direction, a drive wheel provided at one end in the length direction of the side frame, a trailing wheel provided at the other end in the length direction of the side frame, and a crawler belt wound across the drive wheel and the trailing wheel.

[0004] Some hydraulic excavators can reduce the width dimension of the undercarriage to a dimension that fits within the transport limit width during transportation and expand it to a width dimension that enhances the stability of the undercarriage during work. In this case, the side frames are movable in the left-right direction with respect to the center frame (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the hydraulic excavator of Patent Document 1 expands and contracts the width dimension of the lower traveling body, the ground can be various, such as gravel, sand, concrete, asphalt, etc. Here, depending on the type and condition of the ground, the frictional force generated between the crawler of the lower traveling body and the ground may increase. Even in such a case, it is necessary to use a large hydraulic cylinder as a power source so that the side frame can move in the left-right direction with respect to the center frame. This leads to an increase in the size and weight of the lower traveling body.

[0007] Moreover, it is conceivable that the frictional force generated between the crawler and the ground is large and the side frame cannot move in the left-right direction. In this case, the side frame must be moved in the left-right direction while the hydraulic excavator is lifted by a large hydraulic crane. Therefore, there is a problem that a hydraulic crane must be prepared and wires or the like must be hung, which requires a lot of time and labor.

[0008] The present invention has been made in view of the problems of the above-described prior art, and an object of the present invention is to provide a telescopic auxiliary device for a lower traveling body and a method for expanding and contracting the width of a lower traveling body, which can expand and contract the width dimension of the lower traveling body by simple operations regardless of the type and condition of the ground.

Means for Solving the Problems

[0009] The telescopic auxiliary device for a lower traveling body of the present invention is a telescopic auxiliary device for a lower traveling body used when expanding and contracting the width dimension of a lower traveling body of a construction machine. The lower traveling body includes a center frame located at the center, side frames attached to both the left and right sides of the center frame in a state of extending in the front-rear direction and being movable in the left-right direction with respect to the center frame, a drive wheel provided at one end in the length direction of the side frame, a idler wheel provided at the other end in the length direction of the side frame, and a crawler wound around the drive wheel and the idler wheel. The telescopic auxiliary device includes a bracket member having an attachment portion detachably attached to the outer peripheral side of the crawler, and a sliding member slidably attached in the left-right direction on the side opposite to the attachment portion of the bracket member.

[0010] The method for expanding and contracting the width of the lower traveling body of the present invention is a method for expanding and contracting the width of the lower traveling body using an expansion and contraction assisting device. The lower traveling body includes a center frame located at the center, side frames attached to both left and right sides of the center frame in a state of extending in the front-rear direction and being movable in the left-right direction with respect to the center frame, drive wheels provided at one end in the length direction of the side frames, idler wheels provided at the other end in the length direction of the side frames, and a crawler belt wound around the drive wheels and the idler wheels. The expansion and contraction assisting device includes a bracket member having an attachment portion detachably attached to the outer peripheral side of the crawler belt, and a sliding member slidably attached in the left-right direction to the side opposite to the attachment portion of the bracket member. The attachment portion of the bracket member of the expansion and contraction assisting device is attached to a position on the outer peripheral side of the crawler belt that does not contact the ground, the expansion and contraction assisting device is rotated together with the crawler belt so that the sliding member of the expansion and contraction assisting device is disposed between the crawler belt and the ground and grounded, the side frame is moved in the left-right direction together with the drive wheels, the idler wheels, and the crawler belt, the expansion and contraction assisting device is rotated together with the crawler belt so that the sliding member of the expansion and contraction assisting device is disposed at a position away from the ground, and the attachment portion of the bracket member is removed from the crawler belt.

Effect of the Invention

[0011] According to the present invention, the width dimension of the lower traveling body can be easily expanded and contracted with a simple operation regardless of the type and condition of the ground.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

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Figure 4

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Figure 8

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Figure 11

Figure 12

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Figure 17

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Figure 21

Figure 22

Figure 23

Mode for Carrying Out the Invention

[0013] Hereinafter, taking as an example the case where the expansion and contraction assisting device according to the embodiment of the present invention is used to expand and contract the width dimension of the lower traveling body of a hydraulic excavator, which is a representative example of a construction machine, it will be described in detail with reference to the accompanying drawings.

[0014] FIGS. 1 to 15 show the first embodiment of the present invention. First, the hydraulic excavator 1 to which the width expansion and contraction method using the expansion and contraction assisting device 21 according to the present embodiment is applied will be described. In FIG. 1, the hydraulic excavator 1 includes a lower traveling body 4 described later, an upper revolving body 2 rotatably provided on the lower traveling body 4, and a working device 3 rotatably provided at the front part of the upper revolving body 2 for performing earth and sand excavation work and the like. The hydraulic excavator 1 of the present embodiment is, for example, a large model having the maximum dimension within the width limit when the width dimension of the upper revolving body 2 is loaded on a trailer for transportation.

[0015] Next, the configuration of the lower traveling body 4 of the hydraulic excavator 1 will be described in detail. Note that the front-rear direction as viewed from the operator on the upper revolving body 2 changes depending on the turning position of the upper revolving body 2. However, in the present embodiment, the side where the idler wheel 8 is provided is defined as the front side, and the side where the drive wheel 7 is provided is defined as the rear side, and the configuration and width expansion and contraction operation (method) of the lower traveling body 4 will be described.

[0016] The lower traveling body 4 has a width dimension larger than the width dimension of the upper slewing body 2 so that it can stably support the upper slewing body 2 and the working device 3 during traveling and working. However, when the width dimension of the lower traveling body 4 is formed larger than the width dimension of the upper slewing body 2, the width dimension of the lower traveling body 4 exceeds the restricted width during transportation. Therefore, the lower traveling body 4 is configured to be able to move the attachment positions of the side frames 6 with respect to the center frame 5 described later in the width direction. Specifically, by arranging the left and right side frames 6 close to each other, the width dimension of the lower traveling body 4 is reduced and configured to be within the restricted width during transportation.

[0017] The lower traveling body 4 is for traveling on rough ground, muddy ground, etc. As shown in FIGS. 2 to 6, the lower traveling body 4 includes a center frame 5, left and right side frames 6, drive wheels 7, idler wheels 8, and crawler belts 11, which will be described later.

[0018] The center frame 5 is provided at the center of the lower traveling body 4. The center frame 5 is integrally formed as a substantially H-shaped can body structure by welding a plurality of steel plates. The upper slewing body 2 is rotatably attached to the upper side of the center frame 5. The center frame 5 has a front leg 5A extending in the left-right direction and located on the front side, and a rear leg 5B extending in the left-right direction and located on the rear side. The front leg 5A and the rear leg 5B have flange portions facing the upper surfaces of the side frames 6, and these flange portions are attached to the upper surfaces of the side frames 6 using a plurality of bolts.

[0019] The side frame 6 is attached to both the left and right sides of the center frame 5 in a state of extending in the front-rear direction. The side frames 6 are arranged symmetrically with respect to both the left and right sides of the center frame 5. The side frame 6 is formed as a rectangular tube body extending in the front-rear direction. Thereby, the upper surface of the side frame 6 is brought into contact with the flange portions of the front leg 5A and the rear leg 5B of the center frame 5, and a plurality of bolts inserted through the flange portions are fastened to the side frame 6. Thereby, the side frame 6 can be attached to the front leg 5A and the rear leg 5B of the center frame 5.

[0020] Even when the side frame 6 is displaced in the left-right direction with respect to the front leg 5A and the rear leg 5B, the bolts can be fastened. Therefore, the side frame 6 is movable to the outside or inside in the left-right direction with respect to the center frame 5. That is, as shown in FIG. 6, when the side frames 6 are arranged on the inner side in the left-right direction, the left and right side frames 6 can be brought closer to each other to reduce the width dimension of the lower traveling body 4. On the other hand, when the side frames 6 are arranged on the outer side in the left-right direction, the interval between the left and right side frames 6 can be widened to increase the width dimension of the lower traveling body 4.

[0021] The drive wheel 7 is provided at the rear end, which is one end in the length direction of the side frame 6. The drive wheel 7 is rotationally driven using a hydraulic motor as a power source. Further, the idler wheel 8 is provided at the front end, which is the other end in the length direction of the side frame 6.

[0022] A plurality of, for example, three upper rollers 9 are provided at intervals in the front-rear direction on the upper side of the side frame 6. The upper rollers 9 guide the crawler belt 11 in the front-rear direction above the side frame 6. Also, a plurality of, for example, eight lower rollers 10 are provided at intervals in the front-rear direction on the lower side of the side frame 6. The lower rollers 10 guide the crawler belt 11 in the front-rear direction below the side frame 6.

[0023] The crawler 11 is wound around the drive wheel 7 and the idler wheel 8. The crawler 11 is composed of a plurality of track links 12 (shown in a belt shape in the connected state) connected in a ring shape, and shoes 13 attached to the outer peripheral side of the track links 12. The crawler 11 performs a circumferential movement between the drive wheel 7 and the idler wheel 8 when the drive wheel 7 is rotationally driven.

[0024] As shown in FIGS. 2 to 6, a plurality of shoes 13 are continuously attached to the outer peripheral side of the track links 12 in the circumferential direction. As shown in FIGS. 9 to 12, the shoe 13 is formed as a plate-like body made of metal. The shoe 13 includes a shoe body 13A formed of a rectangular metal plate having a length dimension (width dimension) in the width direction (left-right direction) larger than the length dimension in the front-rear direction, and a plurality of, for example, three ground engaging members 13B, 13C, 13D protruding from the outer surface on the grounding side (the side in contact with the ground G) on the outer peripheral side of the crawler 11, and is formed as a grouser shoe.

[0025] The ground engaging members 13B, 13C, 13D extend in the left-right direction and protrude outward from the outer surface to the side opposite to the track links 12. Since the ground engaging members 13B, 13C, 13D extend and protrude in the left-right direction orthogonal to the circumferential direction of the crawler 11, the crawler 11 can grip the ground G in the circumferential direction even on rough ground and can move forward and backward without idling.

[0026] Next, the expansion and contraction assisting device 21 for the lower traveling body 4 according to the first embodiment of the present invention will be described in detail with reference to FIGS. 2 to 15.

[0027] In FIGS. 2 to 6, the expansion and contraction assisting device 21 for the lower traveling body 4 is an auxiliary tool used when expanding the width dimension of the lower traveling body 4 of the hydraulic excavator 1 to the working width dimension and reducing it to the transport width dimension. The expansion and contraction assisting device 21 includes a bracket member 22 and a sliding member 30.

[0028] As shown in FIGS. 9 to 12, the bracket member 22 is detachably attached to the outer peripheral side of the shoe 13 that constitutes the crawler 11 at the first attachment portion 24 and the second attachment portion 25 described later. The bracket member 22 includes a guide portion 23, a first attachment portion 24, and a second attachment portion 25.

[0029] As shown in FIGS. 11 to 14, the guide portion 23 is formed in a gutter shape by a sliding plate 23A made of a rectangular flat plate extending in the left-right direction, a front clamping plate 23B bent from the front edge of the sliding plate 23A and extending obliquely downward, and a rear clamping plate 23C bent from the rear edge of the sliding plate 23A and extending obliquely downward. The inner surface 23A1 of the sliding plate 23A on the side of the front clamping plate 23B and the rear clamping plate 23C serves as a sliding surface with which the sliding member 30 abuts. Further, the outer surface 23A2 of the sliding plate 23A on the side opposite to the inner surface 23A1 faces the crawler 11 (shoe 13), and the first attachment portion 24, the second attachment portion 25, and the circumferential fixing portion 29 are attached thereto. The width dimension (length dimension in the left-right direction) of the guide portion 23 is set to a value larger than the width dimension of the shoe 13.

[0030] As shown in FIG. 14, a plurality of rectangular engaging claws 23D, for example, two are provided at intervals in the width direction of the guide portion 23, on the tip side of the front clamping plate 23B and the tip side of the rear clamping plate 23C. The engaging claws 23D can engage with the ridge 30D of the sliding member 30 described later from below by protruding inward so as to face each other. Thereby, the engaging claws 23D can allow the sliding member 30 to move in the width direction while holding the sliding member 30 in the thickness direction. The engaging claws 23D are fixed to the front clamping plate 23B and the rear clamping plate 23C using welding means or the like.

[0031] The first attachment part 24 as the left and right fixing part is located at one end in the length direction of the guide part 23 and is attached to the outer surface 23A2 of the sliding plate 23A. As shown in Fig. 13, the first attachment part 24 is made of a rectangular thick plate, and the base end edge is fixed to the outer surface 23A2 of the sliding plate 23A by welding means or the like. Further, at the tip side of the first attachment part 24, two latching pins 24A protrude in the thickness direction of the first attachment part 24. As shown in Fig. 12, the height dimension of the latching pin 24A from the outer surface 23A2 of the sliding plate 23A is set to a value larger than the thickness dimension of the shoe 13 by a predetermined dimension (for example, 1 mm to 20 mm).

[0032] Thereby, the first attachment part 24 can restrict the movement of the bracket member 22 to the other side in the width direction of the shoe body 13A by contacting one end in the width direction of the shoe body 13A. At this time, a load as large as the frictional resistance acting between the guide part 23 and the sliding member 30 when the side frame 6 is expanded and contracted acts on the first attachment part 24. Therefore, the first attachment part 24 is formed of a thick plate so as to be able to withstand this load.

[0033] Further, as shown in Fig. 9, in a state where the shoe body 13A is in contact with the first attachment part 24, one end in the width direction of the shoe body 13A is sandwiched between the sliding plate 23A and the latching pin 24A. Thereby, the first attachment part 24 can fix (latch) one end of the shoe body 13A to the bracket member 22 side. Although two latching pins 24A are provided on the first attachment part 24, only one latching pin may be provided, or a configuration in which a plate material or an angle material is fixed horizontally or the tip of the first attachment part 24 is bent may be adopted.

[0034] The second attachment part 25 as the left and right fixing part is located at the other end in the length direction of the guide part 23 and is attached to the outer surface 23A2 of the sliding plate 23A. The second attachment part 25 includes a fixing plate 26 attached to the sliding plate 23A and a detachable plate 27 detachably attached to the fixing plate 26.

[0035] The fixing plate 26 is made of a rectangular thick plate, and the base end edge is fixed to the outer surface 23A2 of the sliding plate 23A by welding means or the like. Further, two bolt insertion holes 26A are provided in the fixing plate 26 so as to penetrate in the thickness direction of the fixing plate 26.

[0036] The detachable plate 27 is made of a rectangular thick plate, and two screw holes 27A are provided on the base end side corresponding to the bolt insertion holes 26A. Further, two latching pins 27B are provided on the tip end side of the detachable plate 27 so as to protrude in the thickness direction of the detachable plate 27. As shown in FIG. 11, the detachable plate 27 is disposed on one side of the fixing plate 26, and a bolt 28 inserted through the bolt insertion hole 26A is screwed into the screw hole 27A of the detachable plate 27 to attach the detachable plate 27 to the fixing plate 26. In this state, the height dimension of the latching pin 27B from the outer surface 23A2 of the sliding plate 23A2 is set to a value larger than the thickness dimension of the shoe 13 by a predetermined dimension (for example, 1 mm to 20 mm).

[0037] Further, in a state where the detachable plate 27 is attached to the fixing plate 26, the distance dimension (spacing dimension) between the detachable plate 27 and the first attachment portion 24 is set to a value larger than the width dimension of the shoe 13 by a predetermined dimension (for example, 1 mm to 20 mm).

[0038] After hooking the latching pin 24A of the first attachment portion 24 on one end portion in the width direction of the shoe 13, the first attachment portion 24 and the second attachment portion 25 configured as described above bring the outer surface 23A2 of the sliding plate 23A into contact with the tips of the respective groovers 13B to 13C of the shoe 13. Next, the detachable plate 27 is inserted between the other end portion of the shoe 13 and the fixing plate 26 of the second attachment portion 25, and the latching pin 27B is pressed against the shoe body 13A. In this state, a bolt 28 inserted through the bolt insertion hole 26A is screwed into the screw hole 27A of the detachable plate 27 to attach the detachable plate 27 to the fixing plate 26. In this case, by sandwiching the shoe 13 between the first attachment portion 24 and the second attachment portion 25, the bracket member 22 is fixed in the left - right direction with respect to the crawler belt 11. Thereby, the first attachment portion 24 and the second attachment portion 25 constitute left - right fixing portions for fixing the bracket member 22 in the left - right direction with respect to the crawler belt 11.

[0039] As shown in FIGS. 12 and 13, the circumferential fixing portion 29 is located on the end side in the left-right direction of the guide portion 23 and is attached to the outer surface 23A2 of the sliding plate 23A. The circumferential fixing portion 29 is provided at two positions, namely, the inner position in the left-right direction of the first attachment portion 24 and the inner position in the left-right direction of the fixing plate 26 of the second attachment portion 25. The circumferential fixing portion 29 is formed of a plate body having a shape (rectangular shape or trapezoidal shape) that fits between the groovers 13B and 13C of the shoe 13 and is fixed to the outer surface 23A2 of the sliding plate 23A by welding means. Thereby, the circumferential fixing portion 29 can fix the bracket member 22 in the circumferential direction of the crawler 11 that intersects the width direction with respect to the crawler 11 by engaging between the groovers 13B and 13C.

[0040] Furthermore, the circumferential fixing portion 29 is arranged offset to one side in the circumferential direction of the crawler 11 in the sliding plate 23A of the guide portion 23. Thereby, in a state where the circumferential fixing portion 29 is accommodated between the groovers 13B and 13C, all the groovers 13B to 13D can be brought into contact with the outer surface 23A2 of the sliding plate 23A.

[0041] The sliding member 30 is attached to the side opposite to the attachment portions 24 and 25 of the bracket member 22 (the side that can contact the ground G). The sliding member 30 is attached to be slidable in the left-right direction with respect to the guide portion 23. The sliding member 30 is formed of a self-lubricating material, for example, a resin material having self-lubricating properties such as PA, POM, PEEK, a metal material such as copper or a copper alloy, or a composite material containing a lubricant.

[0042] The sliding member 30 is formed as a thick plate body having a rectangular cross section and extending in the left - right direction. The sliding member 30 includes a sliding surface 30A that contacts the sliding plate 23A (inner surface 23A1) of the guide portion 23, a grounding surface 30B that contacts the ground G, and front and rear side surfaces 30C between the sliding surface 30A and the grounding surface 30B. On the front and rear side surfaces 30C, ridges 30D are provided extending in the left - right direction at positions close to the sliding surface 30A. By engaging the engaging claws 23D of the guide portion 23 on the grounding surface 30B side of the ridges 30D, the sliding member 30 is held movably in the left - right direction with respect to the guide portion 23. Also, the sliding member 30 can be inserted into the guide portion 23 from the left - right direction so that the ridges 30D engage with the engaging claws 23D, and can also be pulled out.

[0043] The length dimension L1 of the sliding member 30 in the left - right direction is formed to be longer than the length dimension L2 of the bracket member 22 (guide portion 23) in the left - right direction (L1 > L2). Specifically, the length dimension L1 of the sliding member 30 is set to a dimension obtained by adding the length dimension L2 of the guide portion 23 and the moving distance (moving dimension) of the side frame 6 with respect to the center frame 5, or a dimension close to this dimension. Thereby, the sliding member 30 can contact the entire surface of the sliding plate 23A of the guide portion 23 in either the state where the side frame 6 is arranged at the outermost side (the state in FIG. 5) or the state where it is arranged at the innermost side (the state in FIG. 6), and can receive the load over a wide area. That is, the frictional resistance per unit area between the sliding surface 30A of the sliding member 30 and the sliding plate 23A of the guide portion 23 can be reduced.

[0044] The expansion - contraction assisting device 21 according to the present embodiment has the configuration as described above. Next, a method for expanding and contracting the width of the lower traveling body 4 using this expansion - contraction assisting device 21 will be described.

[0045] First, for the purpose of shifting the hydraulic excavator 1 from the working mode to the transportation mode, a width - reducing operation for reducing the width dimension of the lower traveling body 4 will be described. The specific operation is an operation of moving the side frames 6 inward in the left - right direction, that is, approaching the left and right side frames 6.

[0046] In the width reduction operation, the hydraulic excavator 1 is placed at a location where it can travel and the crawler 11 can make about a half turn.

[0047] First, the expansion / contraction auxiliary device 21 is attached to the crawler 11. In the attachment process of this expansion / contraction auxiliary device 21, the first attachment part 24 and the second attachment part 25 of the bracket member 22 of the expansion / contraction auxiliary device 21 are attached to positions on the outer peripheral side of the crawler 11 that do not contact the ground G. For example, as shown in FIG. 2, two expansion / contraction auxiliary devices 21 are attached to the crawler 11 located above the side frame 6 at a predetermined interval in the circumferential direction (front-rear direction). Note that three or more expansion / contraction auxiliary devices 21 can also be attached.

[0048] The attachment work in the attachment process of the expansion / contraction auxiliary device 21 will be described in detail. The bracket member 22 to which the sliding member 30 is not attached is placed on the crawler 11, the latching pin 24A of the first attachment part 24 is hooked on one end (inner end) in the width direction of the shoe 13, and the outer surface 23A2 of the sliding plate 23A of the guide part 23 constituting the bracket member 22 is brought into contact with (placed on) the tips of the respective grouser 13B to 13C of the shoe 13.

[0049] Next, a detachable plate 27 is inserted between the other end (outer end) of the shoe 13 and the fixing plate 26 of the second attachment part 25, and the latching pin 27B is pressed against the shoe body 13A from below. In this state, a bolt 28 inserted through the bolt insertion hole 26A is screwed into the screw hole 27A of the detachable plate 27, and the detachable plate 27 is attached to the fixing plate 26, thereby attaching the bracket member 22 to the crawler 11.

[0050] After attaching the bracket member 22 to the crawler 11, the sliding member 30 is inserted into the guide part 23 from the outside in the left-right direction so that the protrusion 30D engages with the engaging claw 23D of the guide part 23. In this case, the sliding member 30 is arranged so as to protrude inward in the left-right direction from the bracket member 22 in order to move the side frame 6 (crawler 11) inward in the left-right direction. The same operation is performed at a position separated in the circumferential direction of the crawler 11, and two expansion / contraction auxiliary devices 21 are attached to the crawler 11.

[0051] In this way, by separately attaching the expansion and contraction auxiliary device 21 to the bracket member 22 and the sliding member 30, the weight of the parts to be handled can be reduced, and the work can be easily carried out by one person or a small number of people.

[0052] When two expansion and contraction auxiliary devices 21 are attached to the crawler 11, the process proceeds to the circumferential movement process of the expansion and contraction auxiliary device 21. As shown in FIG. 3, in the circumferential movement process, the lower traveling body 4 is advanced (or retracted), and the expansion and contraction auxiliary device 21 is moved in a circular motion together with the crawler 11. As shown in FIG. 4, by rotating the crawler 11 about a half turn, the sliding member 30 of the expansion and contraction auxiliary device 21 is disposed between the crawler 11 and the ground G to ground the sliding member 30.

[0053] As shown in FIG. 5, when the sliding member 30 of the expansion and contraction auxiliary device 21 is grounded, the left and right movement process of the side frame 6 is performed. In the left and right movement process, the bolts fixing the front legs 5A and the rear legs 5B of the center frame 5 to the side frame 6 are removed, and as shown in FIG. 6, the side frame 6 is driven together with the drive wheel 7, the idler wheel 8, and the crawler 11 to move inward in the left and right direction using a hydraulic cylinder or the like as a power source. At this time, the expansion and contraction auxiliary device 21 can slide the guide portion 23 (sliding plate 23A) of the bracket member 22 above the grounded sliding member 30. Thereby, regardless of the state of the ground G, the crawler 11 (side frame 6) can be moved in the left and right direction on the ground G.

[0054] In the next re-circumferential movement process of the expansion and contraction auxiliary device 21, as shown in FIG. 2, the expansion and contraction auxiliary device 21 is moved in a circular motion about a half turn together with the crawler 11, and the sliding member 30 of the expansion and contraction auxiliary device 21 is disposed at a position away from the ground G. Further, in the removal process of the expansion and contraction auxiliary device 21, the first attachment portion 24 and the second attachment portion 25 of the bracket member 22 are removed from the crawler 11 in a procedure reverse to the above-described attachment process.

[0055] Thereby, the hydraulic excavator 1 has a dimension that fits within the transport limit width including the lower traveling body 4, and thus can be mounted on a trailer and transported.

[0056] Thus, according to the first embodiment, the expansion and contraction assisting device 21 includes a bracket member 22 to which the first attachment portion 24 and the second attachment portion 25 are detachably attached to the outer peripheral side of the crawler belt 11, and a sliding member 30 slidably attached in the left - right direction on the side opposite to the first attachment portion 24 and the second attachment portion 25 of the bracket member 22.

[0057] Therefore, attach the first attachment portion 24 and the second attachment portion 25 of the bracket member 22 of the expansion and contraction assisting device 21 to a position on the outer peripheral side of the crawler belt 11 that does not contact the ground G, rotate and move the expansion and contraction assisting device 21 together with the crawler belt 11, and dispose and ground the sliding member 30 of the expansion and contraction assisting device 21 between the crawler belt 11 and the ground G, and move the side frame 6 in the left - right direction together with the drive wheel 7, the idler wheel 8, and the crawler belt 11. Next, rotate and move the expansion and contraction assisting device 21 together with the crawler belt 11 to dispose the sliding member 30 of the expansion and contraction assisting device 21 at a position away from the ground G, and remove the first attachment portion 24 and the second attachment portion 25 of the bracket member 22 from the crawler belt 11.

[0058] Thereby, even when the frictional force generated between the crawler belt 11 and the ground G increases, the sliding member 30 having self - lubricity can slide with a small frictional resistance against the guide portion 23 of the bracket member 22. Therefore, it is not necessary to use a large - sized hydraulic cylinder as a power source, and the enlargement and weight increase of the lower traveling body 4 can be suppressed. Moreover, it is not necessary to move the side frame in the left - right direction with the hydraulic excavator suspended by a large - sized hydraulic crane. As a result, the width dimension of the lower traveling body 4 can be enlarged and reduced by a simple operation regardless of the type and state of the ground G.

[0059] The sliding member 30 is formed such that the length dimension L1 in the left - right direction is longer than the length dimension L2 in the left - right direction of the bracket member 22. Thereby, when sliding the guide portion 23 of the bracket member 22 on the sliding member 30, the area of the contact portion can be increased, so that the frictional resistance per unit area can be reduced and the slidability can be enhanced.

[0060] The bracket member 22 includes a first attachment portion 24 and a second attachment portion 25 as left - right fixing portions for fixing the bracket member 22 to the crawler 11 in the left - right direction. Thereby, when the side frame 6 is moved in the left - right direction together with the crawler 11 and the like, it is possible to prevent the bracket member 22 from shifting with respect to the crawler 11, and the reliability of the expansion - contraction assisting device 21 can be improved.

[0061] The bracket member 22 includes a circumferential fixing portion 29 for fixing the bracket member 22 to the crawler 11 in the circumferential direction. Thereby, when the crawler 11 is rotated with the expansion - contraction assisting device 21 attached to the crawler 11, it is possible to prevent the bracket member 22 from shifting with respect to the crawler 11, and the reliability of the expansion - contraction assisting device 21 can be improved.

[0062] Next, FIGS. 16 to 22 show a second embodiment of the present invention. The feature of this embodiment is that the sliding member is formed of a metal material. In the second embodiment, components having the same shape and function as those in the first embodiment described above are given the same names, and detailed descriptions of their shapes and functions are omitted. Also, components related to the hydraulic excavator 1 are given the same reference numerals.

[0063] In FIGS. 16 and 17, the expansion - contraction assisting device 31 for the lower traveling body 4 according to the second embodiment is an auxiliary tool used when expanding the width dimension of the lower traveling body 4 of the hydraulic excavator 1 to the working width dimension and reducing it to the transport width dimension, similar to the expansion - contraction assisting device 21 according to the first embodiment described above. The expansion - contraction assisting device 31 includes a bracket member 32 and a sliding member 41.

[0064] The bracket member 32 has a first attachment portion 34 and a second attachment portion 35, which are detachably attached to the outer peripheral side of the shoe 13. The bracket member 32 includes a guide portion 33, a first attachment portion 34, a second attachment portion 35, and a sliding block 40.

[0065] As shown in FIGS. 18 and 19, the guide portion 33 is formed in a gutter shape having a front clamping plate 33B and a rear clamping plate 33C at the front and rear edges of the sliding plate 33A. A sliding block 40 (described later) is attached to the inner surface 33A1 of the sliding plate 33A. A first attachment portion 34, a second attachment portion 35, and a circumferential fixing portion 39 are attached to the outer surface 33A2 of the sliding plate 33A.

[0066] As shown in FIGS. 21 and 22, engaging claws 33D made of a long rectangular plate body are provided at the tip portions of the front clamping plate 33B and the rear clamping plate 33C. By protruding inward so as to face each other, the engaging claws 33D can engage with the edge of the flat plate portion 41A of a sliding member 41 (described later) from below. Thereby, while holding the sliding member 41 in the thickness direction, the engaging claws 33D can permit the sliding member 41 to move in the width direction.

[0067] The first attachment portion 34 as a left - right fixing portion is located at one end in the length direction of the guide portion 33 and is attached to the outer surface 33A2 of the sliding plate 33A. As shown in FIG. 13, two latching pins 34A are provided on the first attachment portion 34. Thereby, by abutting against one end in the width direction of the shoe body 13A, the first attachment portion 34 can restrict the movement of the bracket member 32 to the other side in the width direction of the shoe body 13A.

[0068] The second attachment portion 35 as a left - right fixing portion is located at the other end in the length direction of the guide portion 33 and is attached to the outer surface 33A2 of the sliding plate 33A. The second attachment portion 35 includes a fixing plate 36 and a detachable plate 37.

[0069] The fixed plate 36 is fixed to the outer surface 33A2 of the sliding plate 33A and has two bolt insertion holes 36A penetrating in the thickness direction. Further, the detachable plate 37 is provided with two screw holes 37A corresponding to the bolt insertion holes 36A of the fixed plate 36. Two latching pins 37B protrude in the thickness direction of this detachable plate 37. The second attachment portion 35 arranges the detachable plate 37 on one side of the fixed plate 36, screws the bolt 38 inserted through the bolt insertion hole 36A into the screw hole 37A of the detachable plate 37, and attaches the detachable plate 37 to the fixed plate 36.

[0070] After hooking the latching pin 34A of the first attachment portion 34 on one end portion in the width direction of the shoe 13, the first attachment portion 34 and the second attachment portion 35 bring the outer surface 33A2 of the sliding plate 33A into contact with the tips of the respective groovers 13B to 13C of the shoe 13. Next, the detachable plate 37 is inserted between the other end portion of the shoe 13 and the fixed plate 36 of the second attachment portion 35, and the latching pin 37B is pressed against the shoe body 13A. In this state, the bolt 38 inserted through the bolt insertion hole 36A is screwed into the screw hole 37A of the detachable plate 37, and the detachable plate 37 is attached to the fixed plate 36. Thereby, the first attachment portion 34 and the second attachment portion 35 constitute left and right fixing portions that fix the bracket member 32 in the left - right direction with respect to the crawler 11.

[0071] As shown in FIG. 22, the circumferential fixing portion 39 is attached to the outer surface 33A2 of the sliding plate 33A. The circumferential fixing portion 39 can fix the bracket member 32 in the circumferential direction of the crawler 11 by engaging between the groover 13B and the groover 13C.

[0072] The sliding block 40 is provided on the inner surface 33A1 of the sliding plate 33A that constitutes the guide portion 33 of the bracket member 32. The sliding block 40 is formed of a self-lubricating material, for example, a resin material having self-lubricity such as PA, POM, PEEK, a metal material such as copper or a copper alloy, or a composite material containing a lubricant. As shown in FIG. 19, the sliding block 40 is formed of a prism extending in the left-right direction, and two are provided side by side in the front-rear direction (circumferential direction). Note that the sliding block 40 may be configured to be provided on the sliding member 41 described later. However, when the sliding block 40 is provided on the bracket member 32, it can be formed shorter than when it is provided on the sliding member 41.

[0073] The sliding member 41 is attached to the side opposite to the attachment portions 34 and 35 of the bracket member 32 (the side that can contact the ground G). The sliding member 41 is attached to be slidable in the left-right direction with respect to the guide portion 33 (sliding block 40). The sliding member 41 is formed of a rectangular metal plate slidable with the sliding block 40, and includes a flat plate portion 41A whose front and rear edges are engaged with the engaging claws 33D of the guide portion 33, and a strength portion 41B provided on the surface of the flat plate portion 41A opposite to the sliding block 40. The strength portion 41B is formed of a C-shaped channel steel and is welded to the flat plate portion 41A to enhance the strength of the sliding member 41. Thereby, the sliding member 41 is formed as a metal structure having strength.

[0074] When the engaging claws 33D of the guide portion 33 are engaged with the front and rear edges of the flat plate portion 41A, the sliding member 41 is held so as to be movable in the left-right direction with respect to the guide portion 33. Also, the sliding member 41 can be inserted into the guide portion 33 from the left-right direction so that the flat plate portion 41A is engaged with the engaging claws 33D, and can also be pulled out. Further, the length dimension of the sliding member 41 in the left-right direction is formed to be longer by the movement distance of the side frame 6 than the length dimension of the bracket member 32 (guide portion 33) in the left-right direction.

[0075] Thus, also in the second embodiment configured as described above, substantially the same operations and effects as those of the first embodiment described above can be obtained. In particular, in the second embodiment, since the sliding member 41 is formed as a high-strength metal structure, the sliding member 41 can be surely pressed (braced) even in a place with many irregularities due to rocks or the like, and the width expansion and contraction operation of the lower traveling body 4 can be stably performed.

[0076] In the first embodiment, the case where the sliding member 30 is formed of a resin material having self-lubricity such as PA, POM, PEEK, a metal material such as copper or a copper alloy, or a composite material containing a lubricant has been described as an example. However, the present invention is not limited to this. For example, when the strength is low because the sliding member is formed of a resin material, a metal reinforcing plate 52 may be provided on the ground contact surface 51B of the sliding member 51 in contact with the ground G as in the modified example of FIG. 23. Thereby, the sliding member 51 can be surely pressed even in a place with many irregularities due to rocks or the like.

[0077] In the method for expanding and contracting the width of the lower traveling body 4 according to the first embodiment, the case where the sliding member 30 is attached to the bracket member 22 after the bracket member 22 is attached to the crawler belt 11 is illustrated. However, the present invention is not limited to this, and a configuration may be adopted in which a width expansion and contraction assisting device 21 in which the sliding member 30 is attached to the bracket member 22 in advance is attached to the crawler belt 11. The removal case may be the same.

[0078] In each embodiment, the width expansion and contraction assisting device 21 for the lower traveling body 4 used when expanding and contracting the width dimension of the lower traveling body 4 of the hydraulic excavator 1 has been described as an example. However, the present invention is not limited to this. For example, the width expansion and contraction assisting device 21 can also be used when expanding and contracting the width dimension of the lower traveling body 4 of other construction machines such as a hydraulic crane.

Explanation of Reference Numerals

[0079] 1 Hydraulic excavator (construction machine) 4 Lower traveling body 5 Center frame 6 Side frame 7 Driving wheel 8 Traveling wheel 11 Crawler belt 13 Shoe 21, 31 Telescoping auxiliary device 22, 32 Bracket member 24, 34 First mounting part (left - right fixing part) 25, 35 Second mounting part (left - right fixing part) 29, 39 Circumferential fixing part 30, 41, 51 Sliding member 52 Reinforcing plate G Ground L1 Length dimension of the sliding member L2 Length dimension of the bracket member

Claims

1. A telescoping auxiliary device for a lower traveling body used when expanding or contracting the width dimension of a lower traveling body of a construction machine, wherein the lower traveling body includes: a center frame located at the center; side frames attached to both left and right sides of the center frame in a state of extending in the front-rear direction and being movable in the left-right direction with respect to the center frame; a drive wheel provided at one end in the length direction of the side frame; a idler wheel provided at the other end in the length direction of the side frame; and a crawler belt wound around the drive wheel and the idler wheel, and the telescoping auxiliary device includes: a bracket member having an attachment portion detachably attached to the outer peripheral side of the crawler belt; and a sliding member slidably attached in the left-right direction on the side opposite to the attachment portion of the bracket member, characterized in that it is a telescoping auxiliary device for a lower traveling body.

2. In the telescoping auxiliary device for a lower traveling body according to Claim 1, the sliding member is characterized in that its length dimension in the left-right direction is formed longer than the length dimension in the left-right direction of the bracket member.

3. In the telescoping auxiliary device for a lower traveling body according to Claim 1, the bracket member is characterized in that it includes a left-right fixing portion for fixing the bracket member in the left-right direction with respect to the crawler belt.

4. In the telescoping auxiliary device for a lower traveling body according to Claim 1, the bracket member is characterized in that it includes a circumferential fixing portion for fixing the bracket member in the circumferential direction with respect to the crawler belt.

5. In the telescoping auxiliary device for a lower traveling body according to Claim 1, the sliding member is characterized in that it includes a reinforcing plate at a position in contact with the ground.

6. A method for expanding and contracting the width of a lower traveling body using a telescoping auxiliary device, wherein the lower traveling body includes: a center frame located at the center; side frames attached to both left and right sides of the center frame in a state of extending in the front-rear direction and being movable in the left-right direction with respect to the center frame; a drive wheel provided at one end in the length direction of the side frame; a idler wheel provided at the other end in the length direction of the side frame; and a crawler belt wound around the drive wheel and the idler wheel, and the telescoping auxiliary device includes: a bracket member having an attachment portion detachably attached to the outer peripheral side of the crawler belt; and a sliding member slidably attached in the left-right direction on the side opposite to the attachment portion of the bracket member, ​ A sliding member slidably mounted in the left-right direction on the side opposite to the mounting portion of the bracket member; is provided with; mount the mounting portion of the bracket member of the expansion and contraction assisting device at a position on the outer peripheral side of the crawler belt that does not contact the ground; rotate the expansion and contraction assisting device together with the crawler belt to dispose the sliding member of the expansion and contraction assisting device between the crawler belt and the ground and bring it into contact with the ground; move the side frame in the left-right direction together with the drive wheel, the idler wheel, and the crawler belt; rotate the expansion and contraction assisting device together with the crawler belt to dispose the sliding member of the expansion and contraction assisting device at a position away from the ground; A method for expanding and contracting the width of a lower traveling body, characterized by removing the mounting portion of the bracket member from the crawler belt.

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