JP5861682B2 - Boom footpin attaching / detaching device for crawler crane - Google Patents

Description

The present invention relates to a boom foot pin attachment and detachment apparatus installed in the crawler crane.

Generally, Oite crawler cranes, when the upper swing structure attaching the base end portion, i.e. the boom foot boom, respectively to form a bifurcated connection portion on one of the left and right two positions of the upper rotating body and the boom foot In addition, a plate-like coupling portion to be inserted into the bifurcated coupling portion is formed at the other two left and right locations, and a pin hole is provided in each coupling portion, and a pin hole of the bifurcated coupling portion is provided at the two left and right locations, respectively. In this state, the boom foot is detachably coupled to the upper swing body by inserting the boom foot pin into both the pin holes in a state where the pin holes of the plate-like coupling portion are aligned. In particular, a large crawler crane is equipped with a boom foot pin attaching / detaching device that automatically inserts and pulls out the boom foot pin because the boom foot pin is large and heavy.

And as this kind of boom foot pin attaching / detaching device, for example, as disclosed in Patent Document 1, a base end flange is attached to an inner piece of the bifurcated coupling portion by a bolt, and the boom foot pin is attached to a pin hole. A cylinder bracket (referred to as a “cover member” in Patent Document 1) that is movably held between an insertion position inserted into the pin hole and a drawing position pulled out from the pin hole, and a cylinder tube is attached to the tip of the cylinder bracket; A hydraulic cylinder having a piston rod tip connected to the boom foot pin is known, and the boom foot pin is automatically inserted and pulled out by the expansion and contraction of the hydraulic cylinder. This boom foot pin attaching / detaching device is provided as a pair of left and right, and the hydraulic cylinders of the left and right attaching / detaching devices are close to each other in the vicinity of the center line of the upper swing body. Further, when disassembling and transporting the crawler crane , the left and right boom foot pin attaching / detaching devices may be detached from the bifurcated joint portion and transported individually in order to keep the mass limit.

JP 2000-21118A

  However, when such a boom foot pin attaching / detaching device is detached from the bifurcated joint and transported individually, there are the following problems when the boom foot pin attaching / detaching device is attached at the work site of the transport destination.

  In other words, the boom footpin attaching / detaching device is usually attached by lifting the boom footpin attaching / detaching device with an auxiliary crane, but the boom footpin side and the cylinder side of the boom footpin attaching / detaching device have the same mass. Therefore, in order to hang horizontally so that the boom foot pin can easily enter the pin hole of the bifurcated coupling part on the mounting side, it is necessary to attach a hanging ring at a position that matches the center of gravity, and the work is not easy Absent.

  In order to attach the boom foot pin attaching / detaching device, it is usual to provide a guide member so that the boom foot pin in the pull-out position on the cylinder bracket side coincides with the pin hole of the bifurcated coupling portion on the attachment side. However, since the thrust of the hydraulic cylinder acts on this guide member, it is necessary to fix the guide member to the bifurcated coupling portion with a strength that overcomes this thrust. However, if the guide member and the fixed component become heavy in order to increase their strength, the effect of reducing the mass by separating and transporting the attachment / detachment device will be reduced. In addition, since the number of parts increases, there is a problem that the cost increases.

The present invention has been made in view of the above point, and the problem is that the hydraulic cylinders of the conventional boom foot pin attaching / detaching device provided in a pair of left and right are close to each other in the vicinity of the center line of the upper swing body. Focusing on the matching, the left and right hydraulic cylinders are integrated with each other, and the function as a guide member for aligning the boom foot pin itself at the withdrawal position with the pin hole of the bifurcated coupling portion on the mounting side This makes it possible to suspend the attachment / detachment device relatively easily when lifting the boom footpin attachment / detachment device with an auxiliary crane, and to reduce the number of parts and reduce the mass, while connecting the boom footpin to the fork. the alignment between the pin holes of the parts can be easily performed, crawler cranes obtaining aims to enable practical shortened and the cost of cost reduction of working time There is provided cents Mufuttopin attachment apparatus.

In order to solve the above-described problem, the invention according to claim 1 is a boom foot pin attaching / detaching device for a crawler crane , in which a bifurcated coupling portion is formed at each of two left and right portions of the upper swing body and the boom foot. In addition, a flat plate-like connecting portion to be inserted into the bifurcated joint portion is formed at the other two left and right locations, and a pin hole is provided in each of the joint portions. It is assumed that the boom foot is detachably coupled to the upper swing body by inserting the boom foot pin into both pin holes in a state where the pin hole of the coupling portion and the pin hole of the flat plate-like coupling portion are aligned. A pair of left and right hydraulic cylinders for inserting the boom foot pin into and out of the pin hole, a cylinder holder for integrally holding the pair of left and right hydraulic cylinders, and the bifurcated coupling The cylinder holder is detachable from the upper swing body, and the boom foot pin penetrates the inner piece of each part along the lower edge of the pin hole. The left and right side plates are provided with through-holes, and the boom foot pin is set to the drawer position of the boom foot pin when the tip of the boom foot pin protrudes outside by a predetermined dimension from the through-hole of the side plate. The boom foot pins are placed on the pin receivers at two positions on the left and right sides so as to be positioned.

In this arrangement, the boom foot pin attachment and detachment apparatus, a pair of left and right hydraulic cylinders for being made by integrally holding the left and right symmetrical manner constituted by a cylinder holding member, the mounting work of the boom foot pin attachment and detachment apparatus When the boom footpin attaching / detaching device is lifted by the auxiliary crane, the boom footpin attaching / detaching device can be relatively easily suspended horizontally, thereby facilitating and speeding up the attaching operation.

  In addition, the cylinder holder of the boom foot pin attaching / detaching apparatus has left and right side plates provided with through holes through which the boom foot pins pass, and a state in which the tip of the boom foot pins protrudes by a predetermined dimension from the through holes of the side plates. The left and right lengths are set so that the boom foot pin is pulled out, and the boom foot pin at this pulling position is attached to the inner piece of the bifurcated joint that is the mounting side in two places on the left and right Since the boom foot pin is positioned so as to coincide with the pin hole of the bifurcated coupling portion when it is placed on the receiver, the mounting operation can be facilitated and speeded up. Further, since a conventional guide member is not required, the number of parts can be reduced accordingly.

  Further, after the positioning is performed, when the boom foot pin is inserted into the pin hole of one bifurcated coupling portion from the pulled-out position by the extension operation of one of the left and right hydraulic cylinders of the boom foot pin attaching / detaching device, Since the thrust of the cylinder is transmitted to and supported by the other bifurcated joint through the cylinder holder, the other hydraulic cylinder, and the boom foot pin, the pin receiver and its fixed parts like conventional guide members and their fixed parts It is not necessary to increase the strength of the so much.

The invention according to claim 2 is the boom foot pin attaching / detaching device for a crawler crane according to claim 1, wherein the pair of left and right hydraulic cylinders are independently inserted into the both pin holes, respectively. The structure is provided so as to be moved between the drawing positions pulled out from both the pin holes.
According to a third aspect of the present invention, in the boom foot pin attaching / detaching device for a crawler crane according to the first or second aspect, the pin receiver has an arc-shaped cutout portion along a lower edge of the pin hole. It consists of a flat plate. In this configuration, the pin receiving consists one flat, it is possible to reduce the component cost and processing cost.
Furthermore, the invention according to claim 4 is the boom foot pin attaching / detaching device for a crawler crane according to any one of claims 1 to 3, wherein the cylinder holding body includes the two bifurcated joint portions at the left and right sides. A rectangular plate-like bottom plate extending in the left-right direction straddling between the inner pieces, and a reverse channel-shaped partition plate fixed to form a double bottom together with the bottom plate on the bottom plate, the partition Guide grooves extending in the left-right direction are provided on the left and right sides of the plate. In addition, a ring-shaped member having the same outer diameter as that of the boom foot pin is fixed to the end surface of each boom foot pin on the hydraulic cylinder connecting side, and the ring-shaped member is slidably fitted into the guide groove. It is configured to attach a mating fitting.

As described above, according to the boom foot pin attachment and detachment apparatus of the crawler crane of the present invention, compared for unloading device is in universal structure left pair, when lifting the detachable device by the auxiliary crane mounting operation of the detachable device Therefore, the attachment / detachment device can be easily hung horizontally, and the attachment work can be facilitated and speeded up. In addition, when the boom foot pins in the pulled out position protruding from the through holes of the left and right side plates of the cylinder holder are placed on the pin holders attached to the inner pieces of the bifurcated joints at the two left and right positions, the boom foot pins are bifurcated. Since the positioning is performed so as to match the pin hole of the connecting portion, the mounting operation can be facilitated and speeded up, and the working time can be shortened.

  Also, when the boom foot pin is inserted into the pin hole of one bifurcated coupling portion from the pull-out position by either the left or right hydraulic cylinder of the attachment / detachment device, the thrust of this hydraulic cylinder is applied to the cylinder holder, the other hydraulic cylinder and the boom. Because it is transmitted to and supported by the other bifurcated joint through the foot pin, there is no need to increase the strength of the pin holder and its fixing parts so much that the weight is reduced in combination with the fact that a conventional guide member is not required. In addition, it is possible to reduce the number of parts and to contribute to a reduction in cost.

In particular, in the invention according to claim 3, since the pin receiving is formed of one flat plate, it can be cheaper component cost and processing cost, can be further contributing to cost reduction of the cost.

FIG. 1 is a side view of a crawler crane according to a first embodiment of the present invention. FIG. 2 is a plan view of the crawler crane in the vicinity of the boom foot pin attaching / detaching device attachment. FIG. 3 is also a front view. 4 is a cross-sectional view taken along line XX of FIG. FIG. 5 is a perspective view showing a state in which the boom foot pin attaching / detaching apparatus is separated and transported. 6 is an enlarged cross-sectional view taken along line YY of FIG. 7 is an enlarged cross-sectional view taken along the line ZZ in FIG. FIG. 8 is an enlarged cross-sectional view taken along line EE in FIG. FIG. 9 is a plan view in which a part of the crawler crane in the vicinity of the boom foot pin attaching / detaching device attachment is cut open. FIG. 10 is a front view in which a part is similarly cut. FIG. 11 is an enlarged cross-sectional view taken along line FF in FIG. 12 is an enlarged cross-sectional view taken along line GG in FIG. 13 is an enlarged cross-sectional view taken along line HH in FIG. FIG. 14 is an enlarged cross-sectional view taken along the line II of FIG.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments that are modes for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a crawler crane as a construction machine equipped with a boom foot pin attaching / detaching device according to a first embodiment of the present invention, wherein 1 is a crawler type lower traveling body, and 2 is a lower traveling body 1 The upper turning body 2 has a turning frame 3 as a base, and a base end of a boom 4 as a work attachment is provided at the front portion of the turning frame 3. Is attached in a undulating manner, and a gantry 5 and a counterweight 6 are attached to the rear portion of the swivel frame 3.

  One end of a boom guy line 7 is fixed to the tip of the boom 4, and an upper spreader 8 is provided at the other end of the boom guy line 7. A boom hoisting rope 10 is wound around the upper spreader 8 and a lower spreader 9 attached to the top of the gantry 5. One end of the boom hoisting rope 10 is fixed to the gantry 5, and the other end is The boom swing drum 11 provided at the rear of the upper swing body 2 (specifically, the swing frame 3) is wound around. Then, by extending or winding the boom hoisting rope 10 by the boom hoisting drum 11, the distance between the lower spreader 9 and the upper spreader 8 is changed short or long to raise and lower the boom 4.

  A boom point sheave 12, an idler sheave 13, and an auxiliary sheave 14 are rotatably provided at the tip of the boom 4. A main hook 15 is supported and suspended from the boom point sheave 12 by a main hoisting rope 16, and an auxiliary hook 17 is supported and suspended from the auxiliary sheave 14 by an auxiliary hoisting rope 18. One end of the main hoisting rope 16 is fixed to the tip of the boom 4, while the other end of the main hoisting rope 16 is passed through the boom point sheave 12 through the idler sheave 13 to the main swing body 2. The main hook 15 is wound up or down by the main winding drum 19 via the main winding upper rope 16. One end of the auxiliary winding upper rope 18 is coupled to the auxiliary hook 17, while the other end of the auxiliary winding upper rope 18 passes from the auxiliary sheave 14 through the idler sheave 13 to the auxiliary revolving body 2. The auxiliary hook 17 is wound up or down by the auxiliary winding drum 20 via the auxiliary winding upper rope 18.

  The base end of the boom 4, that is, the boom foot 4a, is attached to the front part of the revolving frame 3 of the upper revolving structure 2 as shown in FIGS. That is, bifurcated coupling portions 21 and 21 are formed at two positions on the left and right of the front portion of the revolving frame 3 of the upper swing structure 2, respectively, while the bifurcated coupling portions 21 are disposed on the left and right sides of the boom foot 4 a, respectively. A plate-like coupling portion (not shown) is formed between the inner and outer pieces 21a and 21b. Each coupling portion 21 is provided with a pin hole 23 (only the pin hole of the bifurcated coupling portion 21 is shown). The boom foot 4a is inserted into the two pin holes 23 with the pin holes 23 of the bifurcated coupling portion 21 and the pin holes of the flat plate coupling portion positioned at the left and right positions, respectively. The revolving frame 3 of the revolving body 2 is detachably coupled to the front portion of the revolving frame 2, and a boom footpin attaching / detaching device 30 according to the first embodiment of the present invention is equipped to automatically perform this coupling. ing.

  The boom foot pin attaching / detaching device 30 integrally forms a pair of left and right hydraulic cylinders 31, 31 for inserting and pulling the boom foot pin 24 into and out of the pin hole 23, and the pair of left and right hydraulic cylinders 31, 31. The cylinder holding body 32 to hold | maintain, and the left-right two pin receptacles 33 and 33 each attached to the inner piece 21a of each said bifurcated coupling part 21 along the lower edge of the pin hole 23 are provided.

The cylinder holder 32 includes a rectangular flat plate bottom plate 32a extending substantially in the horizontal direction between the inner pieces 21a and 21a of the two left and right bifurcated coupling portions 21 and 21 at the front portion of the revolving frame 3, and the bottom plate. 32 and the partition plate 32b of the fixed reverse channel-shaped so as to constitute a double bottom on a with the bottom plate 32 a, a central support frame 32c which is fixed to the lateral center portion of the partition plate 32b, the partition plate 32b The two left and right end support frames 32d and 32d fixed to the left and right end portions, the side end face of the bottom plate 32a, the side end face of the partition plate 32b, and the side end face of the end support frame 32c are in contact with each other vertically. Two rectangular flat side plates 32e and 32e fixed in a state, and a top plate 32f made of a thin plate fixed to the upper surface portion of the center support frame 32c and the upper surface portion of each end support frame 32d. That. Guide grooves 34 extending in the left-right direction are provided in the left and right side portions of the partition plate 32b, and through holes 35 through which the boom foot pins 24 pass are formed in portions above the partition plate 32b of the side plates 32e. Is provided.

  The pair of left and right hydraulic cylinders 31, 31 are bolted to a support plate 32g provided on a central support frame 32c of the cylinder holder 32 in a state where the head side end surfaces of the cylinder tubes 31a, 31a face each other. The distal ends of the piston rods 31c that are fixed and connected to the pistons 31b of the hydraulic cylinders 31 are connected to the corresponding boom foot pins 24, respectively. The boom foot pin 24 moves between the insertion position where the boom foot pin 24 is inserted into the pin hole 23 and the extraction position where the boom foot pin 24 is pulled out from the pin hole 23 by the expansion / contraction operation of each hydraulic cylinder 31. As shown in FIG. 4, the boom foot pin 24 is set in a state or position in which the tip of the boom foot pin 24 protrudes from the through hole 35 of the side plate 32 e of the cylinder holder 32 by a predetermined dimension, like the left boom foot pin 24 from the front. .

  A ring-shaped member 36 having the same outer diameter as that of the boom foot pin 24 is fixed to the end surface of the boom foot pin 24 on the piston rod connecting side by bolting. A fitting 37 made of a horizontal roller that is slidably fitted in the guide groove 34 of the plate 32b is attached. Therefore, the boom foot pin 23 is moved between the insertion position and the drawing position by the expansion / contraction operation of each hydraulic cylinder 31. When moving between them, rotation of the boom foot pin 23 around the axis is prevented.

  As shown in FIG. 8, each of the pin receivers 33 is a flat plate in which an arc-shaped first cutout portion 38 is formed along the lower edge of the pin hole 23 of the inner piece 21 a of the bifurcated coupling portion 21. A second notch 39 for avoiding interference with the fitting 37 is formed at the center of the first notch 38 of the pin receiver 33. The boom foot pin attaching / detaching device 30 is positioned when the boom foot pin 24 in the pull-out position is placed on the pin receiver 33 at the two left and right positions.

  2, 3, 5, and 6, reference numeral 41 denotes an upper ladder fixed to the central support frame 32 c of the cylinder holder 32 of the boom foot pin attaching / detaching device 30 via a beam 42, and 43 denotes the upper ladder. The lower ladder 41 is detachably locked to the upper ladder 41. The lower ladder 43 and the upper ladder 41 are used to allow an operator or the like to climb on the upper swing body 2 from the ground. When the crawler crane is disassembled and transported, the lower ladder 43 is fixed on the top plate 32f of the cylinder holder 32 of the boom foot pin attaching / detaching device 30 in a state of being laid down as shown in FIG. In FIG. 3, 44 is a leaving winch.

  2 to 8, 46 is inserted from the insertion port 47 provided in the upper surface portion of the end support frame 32 d of the cylinder holder 32 when the boom foot pin 24 is in the insertion position, and the boom foot pin 24 is removed. The retaining pin 46 is configured to be inserted into a temporary storage port 48 provided in the top plate 32f of the cylinder holder 32 when the boom foot pin 24 is in the pulled-out position. . A suspension ring 49 is provided adjacent to the insertion port 47 on the upper surface of the end support frame 32 d of the cylinder holder 32.

Next, the function and effect will be described in the first embodiment, the boom foot pin attachment and detachment apparatus 30, a pair of left and right hydraulic cylinders 31, 31 in the cylinder holding member 32 will be integrally held, the right and left symmetrical Therefore, when the boom footpin attaching / detaching device 30 is lifted by the auxiliary crane in the attaching operation of the boom footpin attaching / detaching device 30, the upper surface portions of the end support frames 32d, 32d at the left and right ends of the cylinder holder 32 are provided. The boom footpin attaching / detaching device 30 can be suspended relatively easily and horizontally by connecting both ends of the suspension rope to the two left and right suspension rings 49, 49 provided respectively on the left and right sides, and lifting an intermediate portion of the suspension rope with an auxiliary crane. It is possible to facilitate and speed up the installation work.

  Moreover, the cylinder holding body 32 of the boom foot pin attaching / detaching device 30 has two left and right side plates 32e and 32e each provided with a through hole 35 through which the boom foot pin 24 passes, and from the through hole 35 of each side plate 32e. The length in the left-right direction is set so that the boom foot pin 24 is extended to a position where the tip of the boom foot pin 24 protrudes by a predetermined dimension. Since the boom foot pin 24 is positioned so as to coincide with the pin hole 23 of the bifurcated coupling portion 21 when placed on the pin receiver 33 attached to the inner piece 21a of the bifurcated coupling portion 21 on the attachment side, the installation work Easier and faster. In addition, since a conventional guide member is not required, the number of parts can be reduced correspondingly, which can contribute to a reduction in cost.

  Further, after performing the above positioning, the boom foot pin 24 is moved by extending the hydraulic cylinder 31 on the right side when viewed from the front as shown in FIGS. Since the thrust of the hydraulic cylinder 31 is transmitted to and supported by the left bifurcated coupling portion 21 via the cylinder holder 32 when inserted into the pin hole 23 of the right bifurcated coupling portion 21 from the drawing position, It is not necessary to increase the strength of the pin receiver 33 or its fixed part as much as the guide member or its fixed part. As a result, coupled with the fact that a conventional guide member is not required, the mass can be reduced and the number of parts can be reduced, which can further contribute to cost reduction.

In particular, in the case of the first embodiment, the pin receiver 33 is composed of one flat plate in which an arc-shaped cutout portion 38 is formed along the lower edge of the pin hole 23. It can be cheaper, but advantageous in achieving implemented.

  9 to 14 show an attached state of the boom foot pin attaching / detaching device 50 according to the second embodiment of the present invention. This boom foot pin attaching / detaching device 50 is a pair of left and right hydraulic cylinders 51 for inserting and withdrawing the boom foot pin 24 into and from the pin hole 23 as in the case of the boom foot pin attaching / detaching device 30 according to the first embodiment. , 51, a cylinder holder 52 that integrally holds the pair of left and right hydraulic cylinders 51, 51, and an inner piece 21 a of each bifurcated joint 21 along the lower edge of the pin hole 23. Two left and right pin receivers 53 and 53 are provided.

  The cylinder holding body 52 includes two left and right rectangular flat plate side plates 52a and 52a each provided with a through hole 54 through which the boom foot pin 24 passes, and the left and right two side plates 52a and 52a at the four corners in the left and right direction. Of the four tubular frames 52b, 52b,..., Which are arranged across the two and connected to the side plates 52a using bolts 55 or the like, and the four frame members 52b, 52b,. Among them, the upper two frame members or the lower two frame members 52b, 52b are provided with a plurality of connecting bars 52c,. Among the plurality of connecting bars 52c for connecting the lower two frame members 52b, 52b,..., The connecting bar 52c closest to each side plate 52a is provided with a bifurcated connecting portion 57 having a pin hole 56. It has been.

  The pair of left and right hydraulic cylinders 51, 51 are arranged in a state in which the head side end surfaces of the cylinder tubes 51a, 51a face each other, and a rectangular saddle member is disposed on the outer periphery of the intermediate portion of each cylinder tube 51a. 58 is fixed, and the flange member 58 and the side plate 52a on the corresponding side of the cylinder holding body 52 are connected to each other at the four corners of the flange member 58 with rod members 59 interposed therebetween. In addition, the tip of the piston rod 51c connected to the piston 51b of each hydraulic cylinder 51 is connected to the corresponding boom foot pin 24, respectively. The boom foot pin 24 is moved between the insertion position where the boom foot pin 24 is inserted into the pin hole 23 and the extraction position where the boom foot pin 24 is pulled out from the pin hole 23 by the expansion and contraction operation of each hydraulic cylinder 51. 10 and the boom foot pin 24 on the left side when viewed from the front in FIG. 10, the tip of the boom foot pin 24 is set to a state or position protruding outward by a predetermined dimension from the through hole 54 of the side plate 52a of the cylinder holder 52. .

  As shown in FIG. 13, each of the pin receivers 53 is a flat plate having an arc-shaped cutout portion 61 formed at the upper portion along the lower edge of the pin hole 23 of the inner piece 21 a of the bifurcated coupling portion 21. A flat plate-like coupling portion 62 that is inserted into the bifurcated coupling portion 57 of the coupling bar 52c is provided at the lower portion of the pin receiver 53, and a pin hole 63 is provided in the coupling portion 62. The boom foot pin attaching / detaching device 50 is positioned when the boom foot pin 24 in the pulled-out position is placed on the pin receiver 53 at two locations on the left and right sides. The flat joint 62 is inserted into the joint 57, and the pin holes 56, 63 of the joints 57, 62 are aligned. By inserting the pin 64 into the pin holes 56, 63, the boom foot pin is attached / detached. The device 50 is fixed in the positioning state.

9, 10, and 12, reference numeral 71 denotes a ring-shaped member fixed to the piston rod connecting side end face of the boom foot pin 24 by bolting. The outer diameter of the ring-shaped member 71 is the boom foot. The outer diameter of the pin 24 is set substantially the same. Reference numeral 72 denotes a retaining pin for fixing the boom foot pin 24 to the cylinder holder 52.

  In the second embodiment, it is needless to say that the same operational effects as those in the first embodiment can be obtained.

  In addition, this invention is not limited to the said 1st and 2nd embodiment, Other various forms are included. For example, in each of the above-described embodiments, as the pin receivers 33 and 53 attached to the inner piece 21a of the bifurcated coupling portion 21 along the lower edge of the pin hole 23, both arc shapes along the lower edge of the pin hole 23. However, the present invention is not limited to this, and the present invention is not limited to this, and may be configured by using two members each having a plane in contact with the lower edge of the pin hole 23. Good.

  Moreover, in each said embodiment, the bifurcated coupling part 21 is each formed in two right and left places of the front part of the turning frame 3 of the upper revolving structure 2, and this bifurcated coupling part 21 is respectively provided in two right and left parts of the boom foot 4a. Although the case where it applied to the crawler crane in which the flat joint part inserted in is described was described, this invention is bifurcated at two right and left places of a boom foot like patent document 1 illustrated as a prior art document, respectively. A crawler crane in which a connecting portion is formed and a flat plate-like connecting portion to be inserted into the bifurcated connecting portion at each of the left and right positions of the front part of the swing frame of the upper swing structure, or a construction machine other than the crawler crane is also provided. Needless to say, the same applies.

2 Upper swing body 4 Boom 4a Boom foot 21 Forked joint 23 Pin hole 24 Boom foot pin 30, 50 Boom foot pin attaching / detaching device 31, 51 Hydraulic cylinder 32, 52 Cylinder holder
32a Bottom plate
32b Partition plate 32e, 52a Side plate 33, 53 Pin holder
34 Guide groove 35, 54 Through hole
36 Ring-shaped member
37 Mating element 38 First notch 61 Notch

Claims (4)

A bifurcated coupling portion is formed at each of the left and right two locations of either the upper swing body and the boom foot, and a flat plate-shaped coupling portion that is inserted into the bifurcated coupling portion is formed at the other two left and right locations, respectively. In addition, a pin hole is provided in each of the coupling parts, and the boom foot is placed in both the pin holes in a state where the pin hole of the bifurcated coupling part and the pin hole of the plate-like coupling part are aligned at the left and right positions, respectively. A boom foot pin attaching / detaching device for a crawler crane that removably couples a boom foot to an upper swing body by inserting a pin,
A pair of left and right hydraulic cylinders for inserting and withdrawing the boom foot pins into and out of the pin holes;
A cylinder holder that integrally holds the pair of left and right hydraulic cylinders;
A pin receiver attached to the inner piece of each bifurcated coupling portion along the lower edge of the pin hole,
The cylinder holding body is detachable from the upper swing body, and has left and right side plates provided with through holes through which the boom foot pins pass, and the tip of the boom foot pins is outside the through holes of the side plates. Is set so that the boom foot pin is pulled out to a position where it protrudes by a predetermined dimension, and the boom foot pin at this pulled-out position is placed on the pin receiver at two positions on the left and right sides for positioning. A boom foot pin attaching / detaching device for a crawler crane , characterized in that it is provided. The pair of left and right hydraulic cylinders are provided so as to independently move a boom foot pin between an insertion position where the boom foot pin is inserted into both the pin holes and a drawing position where the boom foot pins are pulled out from the both pin holes. The boom foot pin attaching / detaching device for a crawler crane according to claim 1. The boom foot pin attaching / detaching device for a crawler crane according to claim 1, wherein the pin receiver is formed of a flat plate in which an arc-shaped cutout portion is formed along a lower edge of the pin hole. The cylinder holder is fixed so as to form a double bottom with the bottom plate on the bottom plate and a rectangular flat plate extending in the left-right direction across the inner pieces of the bifurcated joints at the two left and right positions. A reverse channel-shaped partition plate, and left and right side portions of the partition plate are provided with guide grooves extending in the left-right direction,
  A ring-shaped member having the same outer diameter as that of the boom foot pin is fixed to the end surface of the boom foot pin on the hydraulic cylinder connecting side, and the ring-shaped member is slidably fitted into the guide groove. The boom footpin attaching / detaching device for a crawler crane according to any one of claims 1 to 3, wherein a fitting is attached.