JP2009208865A - Counterweight attachment/detachment structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a counterweight attachment/detachment structure easily attaching a weight lifter moving up and down a counterweight to the rear portion of an upper turning body. <P>SOLUTION: This structure includes: a first supporting portion 105 extending rearward of the upper turning body 102; a second supporting portion 121 provided to the rear portion of the upper turning body 102; and the weight lifter 1 liftably moving the counterweight 108 by advancing/retreating piston rods 12 connected to the counterweight 108 to/from hydraulic cylinders 11 with a body portion 13 attached to the second supporting portion 121. The first supporting portion 105 is provided with portions to be connected 154 attached with the piston rods 12 advanced vertically upward. The second supporting portion 121 is attached with the body portion 13 by vertically moving the body portion 13 of the weight lifter 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a counterweight attaching / detaching structure in a construction machine such as a crane or a hydraulic excavator.

  Conventionally, the thing of patent document 1 is known as a counterweight attachment-detachment structure in construction machines, such as a crane and a hydraulic shovel. The counterweight self-removing device described in Patent Document 1 includes a box-shaped bracket attached to the rear part of the upper swing body, a link member that can be moved up and down provided on the bracket, and the link member fixed to the bracket. And a hydraulic cylinder for moving up and down. A counterweight connecting portion for connecting a suspension portion of the counterweight is provided at the lower end portion of the link member. After this counterweight self-removing / attaching device is attached to the rear part of the upper swing body, the counterweight can be connected to the counterweight connection part of the link member, and the counterweight can be pulled up and fixed to the bracket.

JP 2004-67298 A

Here, in the counterweight attaching / detaching structure described in Patent Document 1, when the counterweight self-attaching / detaching device as the weight lifting device is attached to the rear part of the upper swing body, the lifting cylinder is extended to the maximum. One end of the rope is connected to the connecting tool, and the rope is looped around a sheave provided on the gantry, and the other end is connected to the upper end of the bracket. In this state, after the lifting cylinder is reduced, the gantry is slightly raised, the counterweight self-removing device is pulled toward the upper swing body, the lifting cylinder is slightly extended, and the bracket mounting shaft is hooked on the receiving portion.
As described above, in the counterweight attaching / detaching structure described in Patent Document 1, it is necessary to raise the gantry slightly to lift the counterweight self-attaching / detaching device and draw it toward the upper swinging body. In this case, since an operation for raising the gantry by a predetermined amount is required, the work becomes complicated and the work efficiency may be deteriorated.

  In view of the above circumstances, an object of the present invention is to provide a counterweight attaching / detaching structure capable of easily attaching a weight lifting device capable of lifting a counterweight to a rear portion of an upper swing body.

Means and effects for solving the problems

  The present invention relates to a counterweight attaching / detaching structure in a construction machine such as a crane or a hydraulic excavator. The counterweight attaching / detaching structure according to the present invention has the following features in order to achieve the above object. That is, the counterweight attachment / detachment structure of the present invention includes the following features alone or in combination.

  In order to achieve the above object, a first feature of the counterweight attachment / detachment structure according to the present invention is a counterweight attachment / detachment structure for attaching / detaching a counterweight to / from an upper swing body of a construction machine, wherein the upper swing body A first support portion that is provided on the upper swing body and that can extend rearward of the upper swing body, and is positioned below the first support portion that extends rearward of the upper swing body. A second support portion provided at a rear portion; a hydraulic cylinder; a piston rod protruding from the hydraulic cylinder; and a main body portion to which the hydraulic cylinder is fixed; and the main body portion is attached to the second support portion. In this state, the piston rod connected to the counterweight is moved up and down with respect to the hydraulic cylinder so that the counterweight can be moved up and down. A connecting portion provided on the piston rod in a state where the piston rod of the weight lifting device placed at a predetermined position is advanced vertically upward. The second support portion can be attached to the second support portion by moving the body portion of the weight lifting device placed at the predetermined position in the vertical direction. That is.

According to this structure, a weight raising / lowering apparatus can be attached to the rear part of an upper turning body as follows. First, the 1st support part provided in the upper turning body is extended to the back of the upper turning body. And a weight raising / lowering apparatus is mounted in the predetermined position on the ground, for example, a piston rod is advanced vertically upwards, and the connection part provided in the piston rod is attached to the to-be-connected part of a 1st support part. In this state, by retracting the piston rod toward the hydraulic cylinder fixed to the main body, the main body and the hydraulic cylinder can be drawn toward the first support portion, that is, moved vertically upward from the ground. . And the said main-body part can be attached to a 2nd support part by moving a main-body part vertically upwards to predetermined | prescribed height.
In this way, the weight lifting device can be moved to the mounting position only by operating the hydraulic cylinder, so that the mounting operation can be easily performed without complicating the operation.

  A second feature of the counterweight attachment / detachment structure according to the present invention is that the construction machine is a crane in which a gantry is provided on the upper swing body, and the gantry extends rearward of the upper swing body. The first support part is configured by the gantry.

  According to this structure, since the gantry with which a crane is provided can be used as a 1st support part, it is not necessary to provide a part equivalent to a 1st support part in a crane separately, and manufacturing cost can be reduced and it is economical. . In addition, the gantry only needs to be additionally provided with a connected portion for attaching the connecting portion of the piston rod of the weight lifting device, so that it can be realized at a low cost without excessively increasing the weight. it can.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing a crawler crane 100 provided with a part of a counterweight attaching / detaching structure according to an embodiment of the present invention. FIG. 1 shows a state in which the counterweight 108 is placed at a predetermined position by the crawler crane 100.

  As shown in FIG. 1, the crawler crane 100 includes a lower traveling body 101 made of a crawler, and an upper revolving body 102 that is mounted on the lower traveling body 101 so as to be rotatable about a vertical axis via a revolving bearing. A cab 103 serving as a driver's cab at the time of traveling and a cockpit at the time of crane work provided on the upper swing body 102, a boom 104 attached to the upper swing body 102 with a boom foot pin as a base end, A gantry 105 provided on the upper swing body 102 and a hook 106 suspended from a sheave 141 provided at the tip of the boom 104 are provided. In addition, the side in which the cab 103 and the boom 104 in the upper swing body 102 are provided will be described as the front portion of the upper swing body 102, and the opposite side will be described as the rear portion of the upper swing body 102. In addition, a description will be given assuming that the direction perpendicular to the front-rear direction in the horizontal plane is the left-right direction.

  A bracket 121 is provided on the upper swing body 102 so as to extend rearward from the rear end portion of the upper swing body 102. The bracket 121 includes a pair of left and right plate-like members 121S. The plate-like member 121S has an engaging portion 121a formed in a concave shape toward the ground side, and an attachment hole 121b penetrating the plate-like member 121S.

  The gantry 105 has a first beam member 151 that is pivotally supported at one end at a substantially central portion in the front-rear direction of the upper swing body 102 and a bracket 121 that extends rearward from the rear end portion of the upper swing body 102. And a second beam member 152 having one end rotatably connected thereto. The first beam member 151 and the second beam member 152 are pivotally connected at their respective ends, so that the position is fixed with respect to the upper swing body 102.

  The second beam member 152 of the gantry 105 is configured by connecting a first link member 152 a connected to the first beam member 151 and a second link member 152 b connected to the bracket 121. As described later, the gantry 105 can be folded by bending the second beam member 152 at the link portion between the first link member 152a and the second link member 152b. In the state shown in FIG. 1, the second beam member 152 of the gantry 105 is fixed so as to be in a straight state, that is, not bent at the link portion between the first link member 152a and the second link member 152b. ing.

  An upper spreader 142 is provided at the tip of the boom 104, and a lower spreader 153 is provided at the tip of the first beam member 151 of the gantry 105. A boom hoisting wire rope 107 is hung between the upper spreader 142 and the lower spreader 153. One end of the boom hoisting wire rope 107 is connected to a boom hoisting drum (not shown) provided on the upper swing body 102. Accordingly, the hoisting angle of the boom 104 can be adjusted by operating the boom hoisting drum and adjusting the distance between the upper spreader 142 and the lower spreader 153.

  When the counterweight 108 is attached to the rear portion of the upper swing body 102, first, the counterweight 108 is placed at a predetermined position by the crawler crane 100 as shown in FIG. In FIG. 1, the counter weight 108 is indicated by a solid line only for the base counter weight 181 located at the lowermost stage, and the weight member 182 appropriately stacked on the base counter weight 181 is indicated by a two-dot chain line.

  Next, as shown in FIG. 2, the weight lifting device 1 that is a part of the counterweight attaching / detaching structure according to the embodiment of the present invention is placed on the base counterweight 181 by the crawler crane 100. Here, the weight lifting device 1 is a device that is attached to the rear portion of the upper swing body 102 and that can lift and lower the base counterweight 181 and the weight member 182 stacked on the base counterweight 181. The weight raising / lowering device 1 mainly includes a hydraulic cylinder 11, a piston rod 12 protruding from the hydraulic cylinder 11, and a main body 13 to which the hydraulic cylinder 11 is fixed. Details will be described later.

  After the weight lifting device 1 is placed on the base counterweight 181, as shown in FIG. 3, the upper swing body 102 is turned 180 °, and the bracket 121 located at the rear of the upper swing body 102 is attached to the weight lift device 1. On the other hand, the crawler crane 100 is moved so as to be arranged at a predetermined position in the front-rear direction. The weight elevating device 1 is arranged in advance so that the bracket 121 is arranged at a predetermined position with respect to the weight elevating device 1 only by turning the upper revolving body 102 without operating the lower traveling body 101. , Work can be done more efficiently.

  Then, as shown in FIG. 3, the gantry 105 is folded so that the first beam member 151 extends substantially horizontally toward the rear of the upper swing body 102. That is, the gantry 105 is folded by bending the second beam member 152 at the link portion between the first link member 152a and the second link member 152b.

  The hydraulic cylinder 11 is connected to a pipe 122 extending from a hydraulic pressure supply means (not shown) such as a hydraulic pump provided on the upper swing body 102. In addition, the said piping 122 is comprised freely, for example. Thus, the hydraulic cylinder 11 can be moved up and down with respect to the upper swing body 102 in a state where the hydraulic cylinder 11 and the upper swing body 102 are connected via the pipe 122.

FIG. 4 is an enlarged view of the vicinity of the weight lifting apparatus 1 in FIG.
As shown in FIG. 4, the weight lifting apparatus 1 mainly includes a hydraulic cylinder 11, a piston rod 12 protruding from the hydraulic cylinder 11, and a main body 13 to which the hydraulic cylinder 11 is fixed.

A rod tip member 14 is provided at the tip of the piston rod 12 so as to spread forward and backward toward the hydraulic cylinder 11 side.
A connecting member 15 (connecting portion) for connecting to the gantry 105 is provided at the upper end portion of the rod tip member 14. In the first beam member 151 of the gantry 105 in the state shown in FIG. 4, the connection member 15 is configured to be connectable to a rod fixing bracket 154 provided so as to protrude upward.

  Moreover, the weight raising / lowering link member 16 is provided in the both ends of the rod front-end | tip member 14 via the connection pin 16a. The weight raising / lowering link member 16 is formed with a long hole extending parallel to the longitudinal direction of the weight raising / lowering link member 16. The weight raising / lowering link member 16 is attached to the rod tip member 14 by inserting the connecting pin 16 a into the elongated hole and the attachment holes at both ends of the rod tip member 14. Therefore, the weight lifting link member 16 can move in parallel to the longitudinal direction of the elongated hole with respect to the rod tip member 14.

5 is a cross-sectional view taken along the line XX showing a part of the weight lifting device 1 and the gantry 105 in FIG.
As shown in FIG. 5, the main body 13 includes a pair of left and right side plate portions 13S and 13S and a connection plate portion 13T that connects the pair of side plate portions 13S and 13S at the upper end. ing. A pair of hydraulic cylinder 11, piston rod 12, rod tip member 14, connection member 15, and weight lifting link member 16 (not shown in FIG. 5) are attached to the main body 13 symmetrically. .

  The connection member 15 is provided with a first connection portion 17 provided so as to protrude upward at the upper end of the rod tip member 14, and one end rotatably provided to the first connection portion 17 via a pin 17 a. It has the 2nd connection part 18, and the 3rd connection part 19 provided so that an end can be freely rotated with respect to the said 2nd connection part 18 via the pin 18a. The second connection portion 18 and the third connection portion 19 are attached to the first connection portion 17 and the second connection portion 18 so as to be rotatable around an axis extending in parallel with the front-rear direction of the upper swing body 102, respectively. It has been.

  Each of the second connection portion 18 and the third connection portion 19 is formed with three through holes a, b, and c arranged at equal intervals, with the through hole b through which the pin 18a passes as a central through hole. ing. Therefore, the third connection portion 19 is formed by connecting the second connection portion 18 and the third connection portion 19 by passing the other pins through the other through holes a and c other than the through hole b through which the pin 18a passes. Can be fixed so as not to rotate with respect to the second connecting portion 18.

  Further, two through holes 19a and 19b are formed side by side at the end of the third connecting portion 19 opposite to the end where the through holes a, b and c are formed. The through holes 19 a and 19 b are formed at the same interval as the interval between the two through holes 154 a and 154 b formed in the rod fixing bracket 154.

Next, a process of attaching the weight lifting device 1 to the upper swing body 102 will be described.
FIG. 6 shows a state in which the piston rod 12 of the weight lifting device 1 is advanced upward from the state shown in FIG. 7 is a YY cross-sectional arrow view showing a part of the weight lifting device 1 and the gantry 105 in FIG.

  After the crawler crane 100 and the weight lifting device 1 are arranged at predetermined positions (see FIG. 4), first, the piston rod 12 of the weight lifting device 1 is advanced upward from the hydraulic cylinder 11 as shown in FIGS. .

  The predetermined position means that the rod fixing bracket 154 in the gantry 105 extending rearward of the upper swing body 102 and the connection member 15 in the weight lifting device 1 are disposed at the same position in the front-rear direction of the upper swing body 102. In addition, it refers to the position of the crawler crane 100 and the weight lifting device 1 such that the center of the gantry 105 and the center of the weight lifting device 1 are disposed at the same position in the left-right direction of the upper swing body 102.

  Next, as shown in FIG. 7, the piston rod 12 is advanced to a position where the lower end portion of the third connecting portion 19 of the connecting member 15 is substantially the same height as the upper surface of the first beam member 151. The second connecting portion 18 is directed to the opposite side to the first beam member 151 and extends substantially horizontally. The third connecting portion 19 is suspended from the second connecting portion 18 by its own weight with the through holes 19a and 19b facing downward.

  Next, as shown in FIG. 8, the second connecting portion 18 and the third connecting portion 19 are rotated to the first beam member 151 side. In a state where the second connection portion 18 is rotated to a position facing substantially the horizontal direction, the third connection portion 19 is suspended by its own weight with the through holes 19a and 19b facing downward. Thus, the through holes 19a and 19b of the third connecting portion 19 are arranged so as to be coaxial with the through holes 154a and 154b of the rod fixing bracket 154, respectively.

  Then, two pins are inserted so as to pass through the through holes 19a and 19b of the third connecting portion 19 and the through holes 154a and 154b of the rod fixing bracket 154, respectively, and the third connecting portion 19 and the rod fixing are inserted. The bracket 154 is fixed.

  Next, hydraulic pressure is supplied to the hydraulic cylinder 11 so that the piston rod 12 retracts (withdraws) into the hydraulic cylinder 11. Since the piston rod 12 is fixed with respect to the first beam member 151, the hydraulic cylinder 11 and the main body 13 are moved vertically as shown in FIG. Can be pulled up.

FIG. 10A is an enlarged schematic view of a connecting portion between the main body 13 and the bracket 121 in FIG. Moreover, FIG.10 (b) is a ZZ cross-sectional arrow view in Fig.10 (a).
As shown in FIGS. 10 (a) and 10 (b), the side plate 13S of the main body 13 has a pair of side plates s1 and s2 provided in parallel at a predetermined interval. The pair of side plates s1 and s2 are respectively formed with first mounting holes 13a that pass through coaxially. The pair of side plates s1 and s2 are formed with second mounting holes 13b that pass through coaxially at positions below the first mounting holes 13a. Further, circular plate-like members s3 and s4 surrounding the first mounting hole 13a are welded to the mutually facing surfaces of the pair of side plates s1 and s2, respectively. Further, a reinforcing plate member 121T is welded to the side surface of the plate member 121S forming the bracket 121 in the vicinity of the engaging portion 121a.

  In the side surface plate portion 13S of the main body portion 13, the distance between the opposing surfaces of the pair of circular plate-like members s3 and s4 is larger than the thickness of the plate-like member 121S forming the bracket 121 and the reinforcing plate-like member 121T being laminated. It is configured to be wide. Therefore, the weight elevating device 1 is lifted vertically upward so that the plate-like member 121S passes between the side plate s1 and the side plate s2, so that the weight can be appropriately reached without causing the main body 13 and the bracket 121 to interfere with each other. The lifting device 1 can be pulled up.

The first connecting pin 20a and the second connecting pin 20b are inserted as follows.
The main body part 13 is pulled up until the position of the first mounting hole 13a of the main body part 13 is higher than the engaging part 121a of the bracket 121 (a position higher than the position shown in FIGS. 9 and 10). In this state, first, the first connecting pin 20a is inserted into the first mounting hole 13a of the main body 13.

  The main body 13 moves downward by its own weight by stopping the supply of the hydraulic pressure that acts to pull the piston rod 12 into the hydraulic cylinder 11 and allowing the piston rod 12 to move in the advance direction. And the 1st connection pin 20a contact | abuts to the engaging part 121a of the bracket 121 because the main-body part 13 moves below. Thereby, the load of the hydraulic cylinder 11 and the main body 13 is supported by the engaging portion 121a of the bracket 121 via the first connecting pin 20a (supported at the positions shown in FIGS. 9 and 10). In this state, the second mounting hole 13b of the main body 13 and the mounting hole 121b of the bracket 121 are substantially coaxial. Then, the second connection pin 20 b is inserted into the second mounting hole 13 b of the main body 13 and the mounting hole 121 b of the bracket 121. Thereby, the position of the main-body part 13 is fixed with respect to the bracket 121 by the 1st connection pin 20a and the 2nd connection pin 20b.

  As described above, since the circular plate-like members s3 and s4 surrounding the first mounting hole 13a are fixed to the side plates s1 and s2, respectively, the side plates s1 and s2 in the vicinity of the first mounting hole 13a are fixed. Can be prevented from being deformed. Further, since the reinforcing plate member 121T is fixed to the plate member 121S forming the bracket 121, the deformation of the plate member 121S in the vicinity of the engaging portion 121a can be prevented.

  Further, as shown in FIG. 9, the position of the piston rod 12 is adjusted with the first connecting pin 20 a and the second connecting pin 20 b supported by the hydraulic cylinder 11 and the main body 13 with respect to the bracket 121. Thus, the force acting on the pin connecting the connecting member 15 and the rod fixing bracket 154 is released. Thereby, the pin inserted into the connecting member 15 and the rod fixing bracket 154 can be easily removed, and the connection between the connecting member 15 and the rod fixing bracket 154 can be released. Thereafter, as shown in FIG. 11, the gantry 105 can be raised and returned to a state in which the boom 104 can be raised and lowered.

  Next, a process of attaching the counterweight 108 to the upper swing body 102 will be described. In the present embodiment, the counterweight 108 is attached to the upper swing body 102 via the main body 13 of the weight lifting device 1.

  First, as shown in FIG. 12, the connection fitting 183 is connected to the hanging portion 181 a that protrudes upward from the base counterweight 181. Further, the upper end portion of the auxiliary link member 21 is connected to the lower end portion of the weight lifting link member 16. The auxiliary link member 21 is connected to the weight lifting link member 16 by inserting a pin into a through hole formed in the upper end portion and a long hole of the weight lifting link member 16. Then, a pin is inserted into the through hole formed in the lower end portion of the auxiliary link member 21 and the through hole formed in the upper end portion of the connection fitting 183 to connect the auxiliary link member 21 and the connection fitting 183. .

  After connecting the suspension portion 181a of the base counterweight 181 and the weight lifting link member 16 via the auxiliary link member 21 and the connecting fitting 183, the piston rod 12 is moved upward from the hydraulic cylinder 11 as shown in FIG. The counterweight 108 is pulled up. The counterweight 108 is pulled up to a position where the base counterweight 181 contacts the lower end of the main body 13 in the weight lifting device 1.

  Then, the fixing pin 22 is inserted into the mounting hole 181c formed in the mounting plate 181b provided so as to protrude upward from the base counterweight 181 and the mounting hole 13c formed in the side surface plate portion 13S of the main body portion 13. The base counterweight 181 is fixed to the weight lifting device 1. Thereby, the counterweight 108 is fixed to the upper swing body 102.

  When removing the counterweight 108, the counterweight 108 can be lowered to the ground by removing the fixing pin 22 and retracting the piston rod 12 into the hydraulic cylinder 11 from the state shown in FIG.

  Moreover, after removing the counterweight 108, the weight lifting apparatus 1 can be removed from the upper swing body 102 by performing the removal process in the reverse order of the process of attaching the weight lifting apparatus 1 to the upper swing body 102 described above. it can.

  As described above, the counterweight attachment / detachment structure according to the present embodiment is a counterweight attachment / detachment structure for attaching / detaching the counterweight 108 to / from the upper swing body 102 of the crawler crane 100, and is provided on the upper swing body 102. And a bracket 121 provided at the rear of the upper swing body 102 so as to be positioned below the gantry 105 extending rearward of the upper swing body 102. And a piston rod 12 projecting from the hydraulic cylinder 11 and a main body 13 to which the hydraulic cylinder 11 is fixed, and connected to the counterweight 108 with the main body 13 attached to the bracket 121. Counterweight by moving the piston rod 12 back and forth with respect to the hydraulic cylinder 11 And a, a weight lifting device 1 capable of causing the 08 up and down movement. The gantry 105 has a rod fixing bracket to which the connecting member 15 provided on the piston rod 12 can be attached in a state where the piston rod 12 of the weight lifting device 1 placed at a predetermined position is advanced vertically upward. 154 is provided, and the bracket 121 can attach the main body 13 by moving the main body 13 of the weight lifting device 1 placed at the predetermined position in the vertical direction.

  According to this structure, the weight raising / lowering apparatus 1 can be attached to the rear part of the upper turning body 102 as follows. First, the gantry 105 provided on the upper swing body 102 is extended to the rear of the upper swing body 102. Then, the weight lifting device 1 is placed at a predetermined position, the piston rod 12 is advanced vertically upward, and the connecting member 15 provided on the piston rod 12 is attached to the rod fixing bracket 154 of the gantry 105. In this state, by retracting the piston rod 12 toward the hydraulic cylinder 11 fixed to the main body 13, the main body 13 and the hydraulic cylinder 11 are drawn toward the gantry 105, that is, moved vertically upward from the ground. Can do. Then, the main body 13 can be attached to the bracket 121 by moving the main body 13 vertically upward to a predetermined height.

  As described above, the weight lifting device 1 can be pulled up and attached to the rear portion of the upper swing body 102 only by the power of the hydraulic cylinder 11 in the weight lifting device 1, so that a separate power source is not required. Cost reduction can be achieved. Further, since the weight lifting device 1 can be moved to the attachment position only by operating the hydraulic cylinder 11, the operation is not complicated and the attachment operation can be performed easily.

  Further, since the weight lifting device 1 can be pulled up and attached to the rear part of the upper swing body 102 only by the power of the hydraulic cylinder 11 in the weight lifting device 1, a power source for lifting the weight lifting device 1 separately. Is unnecessary. Thereby, the counterweight attaching / detaching structure can be realized at low cost.

  Further, in the crawler crane 100 according to the present embodiment, the gantry 105 is configured to be able to rise and fall so as to extend rearward of the upper swing body 102, and the rod fixing bracket 154 is provided on the gantry 105.

  According to this configuration, since the gantry 105 included in the crawler crane 100 can be used as a support portion for moving the weight lifting device 1 up and down, it is not necessary to separately provide a portion corresponding to this in the crawler crane 100, and the manufacturing cost can be reduced. It can be reduced and it is economical.

  Further, in the conventional configuration, for example, it is necessary to install a sheave for hanging a rope for lifting the counterweight self-removing device on the gantry, which causes problems such as an increase in cost and an increase in gantry weight. . In this respect, in the present embodiment, the gantry 105 only needs to be additionally provided with a rod fixing bracket 154 for attaching the connecting member 15 of the piston rod 12 of the weight lifting apparatus 1. It can be realized at a low cost without increasing.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the following modifications can be made.

  In the present embodiment, the configuration in which the gantry 105 is provided with the rod fixing bracket 154 as the connected portion has been described, but the present invention is not limited to this. For example, a second bracket that protrudes rearward from the rear end of the upper swing body 102 is provided above the bracket 121 at the rear of the upper swing body 102, and a connected portion is formed on the second bracket. May be. In this case, the step of setting the gantry 105 to the rearward position can be omitted. Moreover, if it is the structure which has the said 2nd bracket, it can apply also to the construction machine which does not have the gantry 105.

It is a schematic diagram which shows the crawler crane provided with a part of counterweight attachment / detachment structure which concerns on embodiment of this invention, and the counterweight mounted in the predetermined position. It is a schematic diagram which shows the state which mounted the weight raising / lowering apparatus which is a part of counterweight attachment / detachment structure which concerns on embodiment of this invention. It is a schematic diagram which shows the state by which the bracket located in the rear part of an upper turning body is arrange | positioned with respect to the weight raising / lowering apparatus. It is an enlarged view of the vicinity part of the weight raising / lowering apparatus in FIG. FIG. 5 is an XX cross-sectional arrow view showing a part of the weight lifting device 1 and the gantry 105 in FIG. 4. It is a schematic diagram which shows the state which advanced the piston rod upward from the state shown in FIG. FIG. 7 is a YY cross-sectional arrow view showing a part of the weight lifting device 1 and the gantry 105 in FIG. 6. It is a schematic diagram which shows the state which fixed the piston rod and the gantry. It is a schematic diagram which shows the state which pulled up the hydraulic cylinder and the main-body part vertically upward. It is the expansion schematic diagram of the connection part of the main-body part in FIG. 9, and a bracket, and the ZZ cross-sectional arrow view. It is a schematic diagram which shows the state which stood up the gantry. It is a schematic diagram which shows the state which linked the weight raising / lowering link member and the base counterweight. It is a schematic diagram which shows the state which attached the counterweight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Weight raising / lowering apparatus 11 Hydraulic cylinder 12 Piston rod 13 Main-body part 15 Connection member (connection part)
100 crawler crane (construction machine)
102 Upper swing body 108 Counterweight 105 Gantry (first support part)
121 Bracket (second support part)
154 Rod fixing bracket (connected part)

Claims (2)

A counterweight attaching / detaching structure for attaching / detaching the counterweight to / from the upper swing body of the construction machine,
A first support that is provided on the upper swing body and that can extend rearward of the upper swing body;
A second support portion provided at a rear portion of the upper swing body so as to be positioned below the first support portion extending rearward of the upper swing body;
The piston having a hydraulic cylinder, a piston rod protruding from the hydraulic cylinder, and a main body portion to which the hydraulic cylinder is fixed, and connected to the counterweight in a state where the main body portion is attached to the second support portion A weight lifting device capable of moving the counterweight up and down by moving a rod back and forth with respect to the hydraulic cylinder;
With
The first support portion has a connected portion to which a connecting portion provided on the piston rod can be attached in a state where the piston rod of the weight lifting device placed at a predetermined position is advanced vertically upward. Provided,
The counterweight attaching / detaching structure characterized in that the second support part can attach the main body part by moving the main body part of the weight lifting device placed at the predetermined position in the vertical direction. The construction machine is a crane in which a gantry is provided on the upper swing body,
The gantry is configured to be able to undulate so as to extend to the rear of the upper swing body,
The counterweight attaching / detaching structure according to claim 1, wherein the first support portion is configured by the gantry.

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