Assembly method for cranes and counterweights

Abstract

This invention provides a crane and counterweight assembly method that simplifies the management of fixing bolts during counterweight replacement work. [Solution] A crane (10) capable of loading multiple counterweights (111) is characterized by comprising fixing bolts (115) that penetrate the multiple counterweights (111) in the stacking direction and fix the multiple counterweights (111) to the crane body (100), and an adapter (130) positioned between the surface of the counterweights (1111) and the fixing bolts (115).

Description

Technical Field

[0001] The present invention relates to a crane capable of loading a plurality of stages of counterweights and a method for assembling the counterweights fixed to such a crane.

Background Art

[0002] As a background art in this technical field, for example, Patent Document 1 describes a configuration in which a counterweight can be loaded by fixing a counterweight to a revolving body with a fixing bolt.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, every time the number of stages of the loaded counterweight is changed, it is necessary to prepare a fixing bolt having a length suitable therefor, and thus there is a problem that the management of the fixing bolts is complicated.

[0005] The present invention has been made in view of the above-described actual situation, and its main object is to provide a crane and a method for assembling counterweights in which the management of fixing bolts is easier in the counterweight replacement work.

Means for Solving the Problems

[0006] To achieve the above objective, a representative example of the present invention is a crane capable of loading multiple counterweights, characterized by comprising fixing bolts that penetrate the multiple counterweights in the stacking direction and fix the multiple counterweights to the crane body, and an adapter disposed between the surface of the counterweight at one end in the stacking direction and the fixing bolt.

[0007] According to the present invention, the camera mounting position can be suitably adjusted to a reference height in response to changes in the number of counterweight stages. Other problems, configurations, and effects will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of a crane according to an embodiment of the present invention. [Figure 2] This is a perspective view of the rotating body and the counterweight loaded onto it. [Figure 3] Figure 2 shows a cross-sectional view of the main parts of the rotating body and the counterweight loaded onto the rotating body, along the line III-III. [Figure 4] These are schematic diagrams showing the counterweight loading state from a side view, illustrating the maximum loading state (A), the state with one less load than the maximum loading state (B), and the state with two less loads than the maximum loading state (C). [Figure 5] This is a perspective view of the fixing bolt and adapter. [Figure 6] This is a perspective view of the top counterweight and fixing bolts. [Figure 7] These are a plan view (A) and a side view of the area around the reaction force receiving section. [Figure 8] This is a side view showing the loading state of the counterweight according to Modification 1, and shows the maximum loading state (A), the state with one less load than the maximum loading state (B), the state with two less loads than the maximum loading state (C), the state with three less loads than the maximum loading state (D), the state with four less loads than the maximum loading state (E), and the state with five less loads than the maximum loading state (F). [Figure 9] This is a side view of the crane with the fixing bolts according to modified example 2 housed inside. [Figure 10] This is a schematic diagram showing a side view of the counterweight with the fixing bolts according to Modification 3 housed inside. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] [Crane 10] Figure 1 is a side view of a crane 10 according to an embodiment of the present invention. As shown in Figure 1, the crane 10 has a crane body 100 consisting of a traveling body 101, a slewing body 103 rotatably mounted on the traveling body 101 via a slewing wheel 102, and a boom 104 rotatably supported on the slewing body 103. The traveling body 101 has a track frame 101a and a crawler 101b attached to the track frame 101a.

[0011] The slewing body 103 is equipped with a cab 109 and houses the engine 107, which is the prime mover, as well as the winch device consisting of a hoisting drum 105 and a boom luffing drum 106. A counterweight 111 is mounted at the rear end of the slewing body 103 to maintain balance with the weight of the lifted load. The counterweight 111 is configured in multiple layers so that the total weight can be changed according to the weight of the lifted load.

[0012] A hoisting rope 105a is wound around the hoisting drum 105, and the hoisting rope 105a is wound in or unwound by the drive of the hoisting drum 105, causing the hook 110 to rise and fall. One end of a pendant rope 106b is connected to the tip of the boom 104, and the other end of the pendant rope 106b is connected to the luffing rope 106a via a bridle 106c. The luffing rope 106a is wrapped around multiple times between the bridle 106c and the hanger at the top of the gantry 106d, and is wound in or unwound by the drive of the boom luffing drum 106, causing the boom 104 to luff.

[0013] The slewing body 103 is slewing-driven by a slewing hydraulic motor 151 via a slewing ring 102, the hoisting drum 105 is driven by a hoisting hydraulic motor 152, and the boom luffing drum 106 is driven by a boom luffing hydraulic motor 153.

[0014] [Multi-stage counterweight 111] FIG. 2 and FIG. 3 are perspective views and cross-sectional views of main parts of the slewing body 103 and the counterweight 111 loaded on the slewing body 103. In FIGS. 2 and 3, only the frame of the slewing body 103 is shown, and the cab 109, the engine 107, the hoisting drum 105, the boom luffing drum 106, etc. are omitted. The crane 10 can load a multi-stage counterweight 111.

[0015] In this specification, on the premise of the posture in which the cab 109 faces the traveling direction of the traveling body 101 (the posture in FIG. 1), the direction parallel to the rotation axis direction of the slewing body 103 is defined as the "vertical direction", the traveling direction of the traveling body 101 orthogonal to the vertical direction is defined as the "front-rear direction", and the direction orthogonal to the vertical direction and the front-rear direction (the direction orthogonal to the paper surface in FIG. 1) is defined as the left-right direction.

[0016] As shown in FIG. 2, in this embodiment, the stacking direction of the multi-stage counterweight 111 is the vertical direction. Among the multi-stage counterweights 111, the lowermost counterweight 111L is fixed to the slewing body 103.

[0017] As shown in FIG. 3, the counterweight 111L has a protruding portion 111LA provided on the front end side, a support pin 111LB positioned above the protruding portion 111LA and protruding in the left-right direction, and an insertion hole (not shown) positioned between the protruding portion 111LA and the support pin 111LB. The swivel body 103 has a bolt 103A fastened to the rear end portion, a pin receiving portion 103B positioned above the bolt 103A, and an insertion hole 103C. The insertion hole 103C is formed in alignment with the insertion hole of the counterweight 111L. The pin receiving portion 103B is a notch that supports the support pin 111LB from below. The counterweight 111L is fixed to the swivel body 103 by abutting the protruding portion 111A against the bolt 103A, engaging the support pin 111LB with the pin receiving portion 103B, and inserting a mounting pin 112 through the insertion hole 103C. In the present embodiment, the maximum loading state of the counterweight 111 in the crane 10 is four steps. The plurality of steps of counterweights 111 are fastened using fixing bolts 115.

[0018] FIG. 4 is a schematic view showing the loading state of the counterweight 111 in the crane 10. FIG. 4(A) shows the maximum loading state of the counterweight 111, FIG. 4(B) shows the state where the loading is reduced by one step from the maximum loading state, and FIG. 4(C) shows the state where the loading is reduced by two steps from the maximum loading state. In FIG. 4, the illustration of the crane body 100 is omitted. Also, in FIG. 4, H1 to H3 and HL indicate the heights of the counterweight 1111 at the uppermost stage (one end in the stacking direction), the counterweight 1112 at the second stage from the uppermost stage, the counterweight 1113 at the third stage from the uppermost stage, and the counterweight 111L at the lowermost stage, respectively. In the present embodiment, the height H2 of the counterweight 1112 and the height H3 of the counterweight 1113 are the same.

[0019] Each of the counterweights 1111 to 1113 is provided with a reaction force receiving portion 121, a recess 122, and a through hole 123. The reaction force receiving portion 121 is located on the upper surface (front) of the counterweights 1111 to 1113. The recess 122 is located on the bottom surface of the counterweights 1111 to 1113 and is positioned at the same location as the reaction force receiving portion 121 in the front-to-back and left-to-right directions, and is recessed in the vertical direction. The through hole 123 extends from the reaction force receiving portion 121 through the recess 122 and is located along the vertical direction.

[0020] Furthermore, the counterweight 111L has recesses 124 and through holes 125 at the same positions in the front-to-back and left-to-right directions as the recesses 122 and through holes 123 of the counterweights 1111-1113. As a result, when the counterweights 1111-1113 and counterweight 111L are stacked, the reaction force receiving portion 121 is located inside the recess 122 located in the upper layer, and the through holes 123, recesses 122, through holes 125, and recess 124 are positioned in communication with each other. Also, in Figure 4, D indicates the depth of the recess 124 in the vertical direction.

[0021] As shown in Figure 4(A), in the maximum load state, the counterweights 1111 to 1113 and the counterweight 111L are stacked, so the height in the stacking direction of the multiple layers of counterweights 111 is H1 + H2 + H3 + HL. The counterweights 111 in the maximum load state are fastened using fixing bolts 115 and nuts 119.

[0022] As shown in Figure 4(B), in the state with one less layer than the maximum load, the counterweights 1112 and 1113 and the counterweight 111L are stacked, so the height in the stacking direction of the multiple layers of counterweights 111 is H2 + H3 + HL. The counterweights 111 in the state with one less layer than the maximum load are fastened using fixing bolts 115, nuts 119, and adapters 130A.

[0023] As shown in Figure 4(C), in the state where the load has been reduced by two levels from the maximum load state, the counterweights 1113 and 111L are stacked, so the height in the stacking direction of the multiple counterweights 111 is H3 + HL. The counterweights 111 in the state where the load has been reduced by two levels from the maximum load state are fastened using fixing bolts 115, nuts 119, adapters 130A and 130B.

[0024] [Fixing bolt 115] As shown in Figure 5, the fixing bolt 115 consists of a head 116, a shaft 117, and a male threaded portion 118. The shaft 117 is inserted into the through hole 123, the recess 122, and the through hole 125, and has a length L1 that penetrates the counterweights 1111-1113 and counterweight 111L in the maximum load state. In other words, the length L1 of the shaft 117 is matched to H1 + H2 + H3 + HL - D (the height of the counterweight 111 in the maximum load state minus the depth of the recess 124).

[0025] The head 116 is located at the upper end of the shaft 117. The head 116 has a flange portion 116A and a knob portion 116B. The flange portion 116A is formed in the shape of a rectangular plate and is connected to the upper end of the shaft 117. The knob portion 116B is centered on the flange portion 116A and extends in a direction perpendicular to the shaft 117. Through holes 116C and 116D are formed in the flange portion 116A. The through holes 116C and 116D penetrate the flange portion 116A in the vertical direction. The through holes 116C and 116D are arranged symmetrically with the knob portion 116B in between. The male threaded portion 118 is located at the lower end of the shaft 117. The male threaded portion 118 is screwed into the female thread (not shown) formed on the nut 119.

[0026] The adapter 130A consists of a cylindrical portion 131 and a pair of flange portions 132 and 133 positioned at both ends of the cylindrical portion 131 in the axial direction. The adapter 130A has a through hole 134 that penetrates the flange portion 132, the cylindrical portion 131, and the flange portion 133. The shaft portion 117 of the fixing bolt 115 is inserted into the through hole 134. The length L2 of the adapter 130A is at least greater than the thickness of the head 116 of the fixing bolt 115. Specifically, the length L2 of the adapter 130A corresponds to the height H1 of the uppermost counterweight 1112 (height of one stage). Note that the adapter 130A may be divided into multiple members, and the entire assembly may be greater than the thickness of the head 116 of the fixing bolt 115.

[0027] The pair of flange portions 132 and 133 are formed in the same rectangular plate shape as the flange portion 116A of the fixing bolt 115. The flange portion 132 has female screw holes 132A and 132B formed therein. The female screw holes 132A and 132B penetrate the flange portion 132 in the vertical direction. When the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 134, the female screw holes 132A and 132B are positioned to match the through holes 116C and 116D of the flange portion 116A.

[0028] The screw 135 is inserted through the through holes 116C and 116D of the flange portion 116A and screwed into the female screw holes 132A and 132B of the flange portion 132. This fastens (connects) the flange portion 116A (head 116) and the flange portion 132.

[0029] The flange portion 133 has through holes 133A and 133B formed therein. The through holes 133A and 133B penetrate the flange portion 133 in the vertical direction. The through holes 133A and 133B are positioned to correspond to the female screw holes 132A and 132B of the flange portion 132.

[0030] Adapter 130B has the same configuration as adapter 130A except for the length of the cylindrical portion 131, so its description is omitted. The shaft portion 117 of the fixing bolt 115 is inserted into the through hole 134 of adapter 130B, just as in adapter 130A. The length L3 of adapter 130B (see Figure 4(C)) corresponds to the height H2 of the second counterweight 1112 from the top (the height of one stage).

[0031] As described above, the flange portion 133 has through holes 133A and 133B that correspond to the female screw holes 132A and 132B of the flange portion 132. A screw 136 (see Figure 4(C)) passes through the through holes 133A and 133B of the flange portion 133 of the adapter 130A and screws into the female screw holes 132A and 132B of the flange portion 132 of the adapter 130B. The same screw 136 as screw 135 is used. In this way, the flange portion 133 of the adapter 130A and the flange portion 132 of the adapter 130B are fastened (connected).

[0032] [Reaction force receiving part 121] As shown in Figure 6, the reaction force receiving portion 121 is provided on the upper surface of the counterweight 1111, in a position surrounding the through hole 123 (see Figures 7(A) and 7(B)). In other words, when the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, the recess 122, and the through hole 125, the reaction force receiving portion 121 is positioned around the head 116 of the fixing bolt 115. Note that the reaction force receiving portion 121 has the same configuration as the counterweight 1111 in the counterweights 1112 and 1113, and therefore no further explanation is provided.

[0033] The reaction force receiving section 121 is arranged around the through hole 123 and consists of side walls 121A to 121C that protrude from the upper surface of the counterweight 1111. Side walls 121A and 121B are parallel to each other and extend in the front-rear direction. Side wall 121C extends in the left-right direction perpendicular to side walls 121A and 121B. Side walls 121A and 121B are spaced to match one side of the flange portion 116A of the fixing bolt 115. Therefore, when the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, recess 122, and through hole 125, it comes into contact with the side surface of the flange portion 116A (head 116). As a result, when the female thread of the nut 119 is screwed onto the male threaded portion 118 of the fixing bolt 115, the reaction force receiving portion 121 receives the reaction force that would cause the fixing bolt 115 to rotate around its axis, thereby restricting the rotation of the fixing bolt 115.

[0034] [Assembly method for multi-stage counterweight 111] First, in the maximum load state, counterweights 1111-1113 and counterweight 111L are stacked. At this time, they are positioned so that the through hole 123, recess 122, through hole 125, and recess 124 are in communication with each other. The worker inserts the shaft portion 117 of the fixing bolt 115 into the through hole 123, recess 122, and through hole 125. At this time, the worker grasps the grip portion 116B and aligns the flange portion 116A (head 116) of the fixing bolt 115 with the position of the reaction force receiving portion 121.

[0035] The length L1 of the shaft portion 117 of the fixing bolt is matched to the height of the counterweight 111 in its maximum load state minus the depth of the recess 124. Therefore, when the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, recess 122, and through hole 125, the head 116 of the fixing bolt 115 is positioned inside the reaction force receiving portion 121 (between the side wall 121A and the side wall 121B), and the male threaded portion 118 protrudes into the recess 124 of the lowest counterweight 111L. In other words, the shaft portion 117 of the fixing bolt 115 penetrates the counterweight 111 in its maximum load state in the stacking direction.

[0036] Next, the worker performs the step of fixing the counterweight 111 in its maximum load state to the slewing body 103 (crane body 100) using fixing bolts 115 and nuts 119. Specifically, the worker screws the female thread of the nut 119 onto the male thread 118. As described above, the reaction force receiving part 121 receives the reaction force that would cause the fixing bolt 115 to rotate, thus restricting the rotation of the fixing bolt 115 and allowing the male thread 118 and the nut 119 to be fastened together. The counterweight 111 in its maximum load state is then fastened by the fixing bolts 115 and nuts 119. As described above, since the lowest counterweight 111L is fixed to the slewing body 103, the fixing bolts 115 and nuts 119 can fix the counterweight 111 in its maximum load state to the slewing body 103 (crane body 100).

[0037] Furthermore, to reduce the load by one level from the maximum load state, first, the fastening of the fixing bolt 115 and nut 119 is released, and the shaft portion 117 of the fixing bolt 115 is removed from the through hole 123, recess 122, and through hole 125. Then, the uppermost counterweight 1111, which is the target of the reduction in load, is removed. As a result, the counterweights 1112, 1113 and counterweight 111L are stacked (reduced load state).

[0038] Next, the worker connects the fixing bolt 115 and the adapter 130A. More specifically, the worker inserts the screw 135 through the through holes 116C and 116D of the flange portion 116A and screws the screw 135 into the female screw holes 132A and 132B of the flange portion 132. This fastens the flange portion 116A (head 116) and the flange portion 132 together.

[0039] Next, the worker places the adapter 130A between the upper surface (surface) of the counterweight 1112 and the head 116 of the fixing bolt 115. More specifically, with the fixing bolt 115 and the adapter 130A integrated as described above, the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, the recess 122, and the through hole 125. At this time, the worker grasps the grip portion 116B and aligns the flange portion 133 of the adapter 130A with the position of the reaction force receiving portion 121. As described above, since the flange portion 133 has the same outer shape as the flange portion 116A of the fixing bolt 115, the flange portion 133 is housed inside the reaction force receiving portion 121.

[0040] The length L1 of the shaft portion 117 of the fixing bolt 115 is matched to the height of the counterweight 111 in the maximum load state minus the depth D of the recess 124. However, the adapter 130A compensates for the height H1 that is lost when the top counterweight 1111 is removed. Therefore, when the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, recess 122, and through hole 125, the flange portion 133 of the adapter 130A is positioned inside the reaction force receiving portion 121, and the male threaded portion 118 protrudes into the recess 124 of the bottom counterweight 111L. In other words, the shaft portion 117 of the fixing bolt 115 penetrates the counterweight 111 in the stacking direction, even when it is one level lower than the maximum load state.

[0041] The worker performs the process of fixing the counterweight 111, which is in a reduced position from the maximum load state, to the slewing body 103 (crane body 100) using a fixing bolt 115, a nut 119, and an adapter 130A. Specifically, the worker screws the female thread of the nut 119 onto the male thread 118. Then, because the reaction force receiving part 121 receives the reaction force from the flange part 133, the rotation of the fixing bolt 115 is restricted, and the male thread 118 and the nut 119 can be fastened together. The counterweight 111, which is in a reduced position from the maximum load state, is then fastened using the fixing bolt 115, the nut 119, and the adapter 130A. In this way, the fixing bolt 115, the nut 119, and the adapter 130A can fix the counterweight 111, which is in a reduced position from the maximum load state, to the slewing body 103 (crane body 100).

[0042] Furthermore, to reduce the load by two levels from the maximum load state, first, the fastening of the fixing bolt 115 and nut 119 is released, and the shaft portion 117 of the fixing bolt 115 is removed from the through hole 123, recess 122, and through hole 125. Then, the process of removing the uppermost counterweight 1111 and the second-to-last counterweight 1112, which are the targets of the reduction in load, is performed. As a result, the counterweights 1113 and 111L are stacked (reduced load state).

[0043] Next, the worker connects the fixing bolt 115 and the adapter 130A. More specifically, the worker inserts the screw 135 through the through holes 116C and 116D of the flange portion 116A, and screws the screw 135 into the female screw holes 132A and 132B of the flange portion 132. This fastens the flange portion 116A (head 116) and the flange portion 132 of the adapter 130A.

[0044] Furthermore, the worker performs the process of connecting adapter 130A and adapter 130B. More specifically, the worker screws a screw 136 through the through holes 133A and 133B of the flange portion 133 of adapter 130A into the female screw holes 132A and 132B of the flange portion 132 of adapter 130B. This fastens the flange portion 133 of adapter 130A and the flange portion 132 of adapter 130B.

[0045] Next, the worker places adapters 130A and 130B between the upper surface (surface) of the counterweight 1113 and the head 116 of the fixing bolt 115. More specifically, as described above, with the fixing bolt 115, adapter 130A, and adapter 130B integrated, the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, recess 122, and through hole 125. At this time, the worker grasps the grip portion 116B and aligns the flange portion 133 of the adapter 130B with the position of the reaction force receiving portion 121. The flange portion 133 is housed inside the reaction force receiving portion 121.

[0046] The length L1 of the shaft portion 117 of the fixing bolt 115 is matched to the height of the counterweight 111 in the maximum load state minus the depth of the recess 124. However, the adapter 130A compensates for the height lost when the top counterweight 1111 is removed, and the adapter 130B compensates for the height lost when the second-to-last counterweight 1112 is removed. Therefore, when the shaft portion 117 of the fixing bolt 115 is inserted into the through hole 123, recess 122, and through hole 125, the flange portion 133 of the adapter 130B is positioned inside the reaction force receiving portion 121, and the male threaded portion 118 protrudes into the recess 124 of the bottom counterweight 111L. In other words, the shaft portion 117 of the fixing bolt 115 penetrates the counterweight 111 in the stacking direction, even though it is two levels lower than the maximum load state.

[0047] The worker performs the process of fixing the counterweight 111, which is two levels lower than the maximum load, to the slewing body 103 (crane body 100) using fixing bolts 115, nuts 119, adapters 130A and 130B. Specifically, the worker screws the female thread of the nut 119 onto the male thread portion 118.

[0048] The reaction force receiving portion 121 receives the reaction force from the flange portion 133, thereby restricting the rotation of the fixing bolt 115 and allowing the male threaded portion 118 and the nut 119 to be fastened together. The counterweight 111, which is two stages reduced from the maximum load state, is fastened by the fixing bolt 115, nut 119, adapter 130A, and adapter 130B. In this way, the fixing bolt 115, nut 119, adapter 130A, and adapter 130B can fix the counterweight 111, which is two stages reduced from the maximum load state, to the slewing body 103 (crane body 100).

[0049] As described above, this embodiment provides the following advantages. Since the adapter 130A is positioned between the upper surface (surface) of the counterweight 1112 and the fixing bolt 115, when the number of counterweights 111 is reduced from multiple stages, the reduced counterweight 111 can be fixed to the crane body 100 using the same fixing bolt 115 that was used to fix the multiple counterweights 111 before the reduction. Therefore, in this embodiment, it is not necessary to prepare fixing bolts 115 according to the number of stages of the counterweight 111 each time, as in the conventional method. In other words, the management of fixing bolts 115 can be made easier during the replacement of the counterweight 111.

[0050] Furthermore, the nut 119 that screws onto the fixing bolt 115 is screwed onto the fixing bolt at the lower end (other end) in the stacking direction, and the adapter 130A is positioned between the upper surface of the counterweight 1112 located at the upper end (one end) in the stacking direction and the head 116 of the fixing bolt 115. Therefore, the same fixing bolt 115 used to fix the multiple counterweights 111 before the reduction in stages can be used as is and combined with the adapter 130A to fix the reduced-stage counterweight 111 to the crane body 100. Thus, the management of the fixing bolt 115 can be made easier during the counterweight replacement work.

[0051] Furthermore, by inserting the shaft portion 117 of the fixing bolt 115 into the through hole 134 of the adapter 130A, and connecting one flange portion 132 to the head portion 116 of the fixing bolt 115, the other flange portion 133 can be brought into contact with the reaction force receiving portion 121 provided on the counterweight 1112. As a result, with the fixing bolt 115 and the adapter 130A integrated, it is possible to pass multiple stages of counterweights 111 through in the stacking direction, making replacement work easy.

[0052] Since an adapter 130A is used that corresponds to the height of one stage of the counterweight 1111, the adapter 130A can compensate for the height lost when the counterweight 1111 is removed. Therefore, the counterweight 111 with one stage removed can be fixed to the crane body 100 using the same fixing bolts 115 that were used to fix the multi-stage counterweight 111 before the reduction in stage. This makes it easier to manage the fixing bolts 115 during counterweight replacement work.

[0053] Furthermore, the reduced-stage counterweight 111 can be easily fixed to the crane body 100 by the steps of removing the counterweight 1111 to be reduced, connecting the fixing bolt 115 and the adapter 130A, positioning the adapter 130A between the top surface of the reduced-stage counterweight 1112 and the head 116 of the fixing bolt 115, and fixing the counterweight 111 to the crane body 100 with the fixing bolt 115 and the adapter 130A. Therefore, the same fixing bolt 115 used to fix the multiple stages of the counterweight 111 before reduction can be used, making the management of the fixing bolt 115 easier.

[0054] [Example 1] In the above embodiment, the maximum number of counterweights 111 that can be stacked is four, and a common fixing bolt 115 is used to fix multiple counterweights 111 to the crane body 100. When the stack is reduced by one level from the maximum load, the adapter 130A is used, and when the stack is reduced by two levels from the maximum load, the adapters 130A and 130B are used to fix multiple counterweights 111 to the crane body 100. However, the present invention is not limited to this, and as shown in Modification 1, a configuration may be provided in which multiple fixing bolts 115A to 115C of different lengths are used to fix multiple counterweights 111 to the crane body 100 together with a common adapter 130.

[0055] In this modified example 1, the maximum number of stacked counterweights 111 is seven. Furthermore, 1111 to 1116 represent the top counterweight to the sixth counterweight from the top, and 111L represents the bottom counterweight. Counterweights 1111 to 1116 have the same configuration as counterweight 1111 in the above embodiment, and counterweight 111L has the same configuration as counterweight 111L in the above embodiment.

[0056] Furthermore, the configuration of the crane body 100 and the configuration for fixing the lowest counterweight 111L to the crane body 100 are the same as in the upper embodiment. In this modified example 1, the vertical direction is the stacking direction of the multiple counterweights 111.

[0057] Figure 8(A) shows the counterweight 111 in its maximum load state, Figure 8(B) shows it with one load removed from the maximum load state, Figure 8(C) shows it with two loads removed from the maximum load state, Figure 8(D) shows it with three loads removed from the maximum load state, Figure 8(E) shows it with four loads removed from the maximum load state, and Figure 8(F) shows it with five loads removed from the maximum load state. Note that the crane body 100 is not shown in Figure 8. In this modified example 1, the counterweights 1111 to 1116 and 111L all have the same height H, and the length of the adapter 130 corresponds to the height H of the counterweights 1111 to 1116 and 111L (height of one load). The configuration of the fixing bolts 115A to 115C is the same as the fixing bolts 115 in the above embodiment, except for the length of the shaft portion 117, so the explanation is omitted.

[0058] As shown in Figure 8(A), in the maximum load state, the counterweights 1111 to 1116 and the counterweight 111L are stacked, so the height in the stacking direction of the multiple layers of counterweights 111 is 7H. The counterweights 111 in the maximum load state are fastened using fixing bolts 115A and nuts 119.

[0059] The shaft portion 117 of the fixing bolt 115A is inserted into the through hole 123, the recess 122, and the through hole 125, and has a length that penetrates the counterweights 1111-1116 and counterweight 111L in the maximum load state. The length of the shaft portion 117 of the fixing bolt 115A is matched to 7H-D (the dimension obtained by subtracting the depth of the recess 124 from the height of the counterweight 111 in the maximum load state).

[0060] As shown in Figure 8(B), in the state with one less layer than the maximum load, the counterweights 1112-1116 and counterweight 111L are stacked, so the height in the stacking direction of the multiple layers of counterweights 111 is 6H. The counterweights 111 in the state with one less layer than the maximum load are fastened using fixing bolts 115A, nuts 119, and adapters 130.

[0061] The worker performs the process of connecting the fixing bolt 115A and the adapter 130, similar to the embodiment described above. More specifically, the flange portion 116A (head 116) of the fixing bolt 115A is fastened to the flange portion 132 of the adapter 130. Next, the worker performs the process of positioning the adapter 130 between the upper surface (surface) of the counterweight 1112 at one end in the stacking direction and the head 116 of the fixing bolt 115.

[0062] The length of the shaft portion 117 of the fixing bolt 115A is matched to the dimension obtained by subtracting the depth of the recess 124 from the height of the counterweight 111 in the maximum load state. However, since the adapter 130 compensates for the height H obtained by removing the top counterweight 1111, when the shaft portion 117 of the fixing bolt 115A is inserted into the through hole 123, recess 122, and through hole 125, the shaft portion 117 of the fixing bolt 115A penetrates the counterweight 111 in the stacking direction, which is one level lower than the maximum load state.

[0063] The operator can fix the counterweight 111, which is one level lower than the maximum load, to the slewing body 103 (crane body 100) using the fixing bolt 115A, nut 119, and adapter 130 in the same process as in the above embodiment.

[0064] As shown in Figure 8(C), in the state where the load has been reduced by two levels from the maximum load state, the counterweights 1113 to 1116 and the counterweight 111L are stacked, so the height in the stacking direction of the multiple counterweights 111 is 5H. The counterweights 111 in the state where the load has been reduced by two levels from the maximum load state are fastened using fixing bolts 115B and nuts 119.

[0065] The shaft portion 117 of the fixing bolt 115B is inserted into the through hole 123, the recess 122, and the through hole 125, and has a length that penetrates the counterweights 1113-1116 and counterweight 111L in a state where the load has been reduced by two stages from the maximum load state. The length of the shaft portion 117 of the fixing bolt 115B is matched to 5H-D (the dimension obtained by subtracting the depth of the recess 124 from the height of the counterweight 111 in a state where the load has been reduced by two stages from the maximum load state). In other words, the length of the shaft portion 117 of the fixing bolt 115B is shorter than the length of the shaft portion 117 of the fixing bolt 115A by 2H, which is the height of the two stages of the counterweights 1111 and 1112.

[0066] As shown in Figure 8(D), in the state where the load has been reduced by three levels from the maximum load state, the counterweights 1114-1116 and the counterweight 111L are stacked, so the height in the stacking direction of the multiple counterweights 111 is 4H. The counterweights 111 in the state where the load has been reduced by three levels from the maximum load state are fastened using fixing bolts 115B, nuts 119, and adapters 130.

[0067] The worker performs the step of connecting the fixing bolt 115B and the adapter 130, similar to the embodiment described above. Next, the worker performs the step of positioning the adapter 130 between the upper surface (surface) of the counterweight 1114 at one end in the stacking direction and the head 116 of the fixing bolt 115. The length of the shaft portion 117 of the fixing bolt 115B is matched to the dimension obtained by subtracting the depth of the recess 124 from the height of the counterweight 111 in the state where three levels have been removed from the maximum stacking state. However, since the adapter 130 compensates for the height H obtained by removing the third counterweight 1113 from the top, the shaft portion 117 of the fixing bolt 115B penetrates the counterweight 111 in the stacking direction in the state where three levels have been removed from the maximum stacking state.

[0068] The operator can fix the counterweight 111, which is in a state reduced by three stages from the maximum load state, to the slewing body 103 using the fixing bolt 115B, nut 119, and adapter 130 in the same process as in the above embodiment.

[0069] As shown in Figure 8(E), in the state where the load has been reduced by four levels from the maximum load state, the counterweights 1115, 1116 and counterweight 111L are stacked, so the height in the stacking direction of the multiple layers of counterweights 111 is 3H. Therefore, the length of the shaft portion 117 of the fixing bolt 115C used to fix them is 3H-D, which is 2H shorter than the length of the shaft portion 117 of the fixing bolt 115B, by the height of two layers of counterweights 1113 and 1114. The counterweights 111 in the state where the load has been reduced by four levels from the maximum load state are fastened using fixing bolts 115C and nuts 119.

[0070] As shown in Figure 8(F), in the state where the load has been reduced by five levels from the maximum load state, the counterweights 1116 and 111L are stacked, so the height in the stacking direction of the multiple counterweights 111 is 2H. The counterweights 111 in the state where the load has been reduced by five levels from the maximum load state are fastened using fixing bolts 115C, nuts 119, and adapters 130.

[0071] The worker connects the fixing bolt 115C and the adapter 130, as in the above embodiment. Next, the worker positions the adapter 130 between the upper surface (surface) of the counterweight 1114 at one end in the stacking direction and the head 116 of the fixing bolt 115. Since the adapter 130 compensates for the height H of the fifth counterweight 1113 removed from the top, the shaft portion 117 of the fixing bolt 115C penetrates the counterweight 111, which is in a state where five levels have been removed from the maximum load, in the stacking direction. The worker can then fix the counterweight 111, which is in a state where five levels have been removed from the maximum load, to the swivel body 103 using the fixing bolt 115C, nut 119, and adapter 130, in the same manner as in the above embodiment.

[0072] As explained above, in this modified example 1, multiple fixing bolts 115A to 115C of different lengths are provided, and together with a common adapter 130, multiple counterweights 111 are fixed to the crane body 100. Therefore, it is not necessary to prepare fixing bolts of a suitable length for all stages (from one to seven stages), and multiple counterweights 111 can be fixed to the crane body 100 with fewer fixing bolts 115A to 115C and a common adapter 130. Thus, the management of the fixing bolts 115 can be made easier during the counterweight replacement work.

[0073] [Differentiation 2] The crane according to Modification 2, like Modification 1 described above, is equipped with multiple fixing bolts and has a configuration in which multiple counterweights 111 are fixed to the crane body 100 together with a common adapter 130. As shown in Figure 9, the crane body 100 has storage sections 141 and 142 for accommodating spare fixing bolts that are not being used among the multiple fixing bolts. In the example shown in Figure 9, the crane body 100 has the traveling body 101 removed, the boom 104 folded, and has been transported on the vehicle 140.

[0074] In this modified example 2, a storage section 141 is provided inside the frame 104A that constitutes the boom 104. Alternatively, a storage section 142 is provided on the bottom surface of the frame of the slewing body 103. In the example shown in Figure 9, unused spare fixing bolts 115B and 115C are stored in the storage sections 141 and 142. By providing a storage section for spare fixing bolts in the crane body 100 in this way, the management of the fixing bolts 115 can be made easier during the counterweight replacement work. Note that adapters 130 may also be stored in the storage sections 141 and 142.

[0075] [Difference 3] The crane according to Modification 3, like Modification 1 described above, is equipped with multiple fixing bolts and has a configuration in which multiple counterweights 111 are fixed to the crane body 100 together with a common adapter 130. As shown in Figure 10, the uppermost counterweight 1111 has a housing section 143 for accommodating spare fixing bolts that are not being used among the multiple fixing bolts.

[0076] In the example shown in Figure 10, a handrail 144 is erected along the outer circumference of the upper surface of the counterweight 1112, and this handrail 144 is used as a storage section 143. Unused spare fixing bolts 115B and 115C are stored in the storage section 143. By providing a storage section 143 for storing spare fixing bolts in this way, the management of the fixing bolts 115 can be made easier during the replacement of the counterweight. Note that an adapter 130 may also be stored in the storage section 143.

[0077] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. All technical matters included in the technical concept described in the claims are subject to the present invention. The embodiments described above are preferred examples, but those skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed herein, and these are included in the technical scope described in the appended claims.

[0078] In the above embodiment, adapters 130A and 130B are placed between the head 116 of the fixing bolt 115 and the upper surface of the counterweight 111. However, the adapter may be placed on the opposite side of the fixing bolt 115 from the head 116, for example, between the nut 119 and the bottom surface of the counterweight 111. Also, in the above embodiment, the head 116 of the fixing bolt 115 is located on the upper end side, and the nut 119 that screws into the fixing bolt 115 is located on the lower end side of the fixing bolt 115. However, the adapter may be located on the lower end side of the fixing bolt 115 and the nut 119 is located on the upper end side of the fixing bolt 115. Furthermore, in the above embodiment, the stacking direction of the multiple counterweights 111 is vertical. However, the stacking direction of the counterweights 111 may be horizontal (including front-to-back and left-to-right directions) perpendicular to the vertical direction.

[0079] Furthermore, in the above embodiment, the flange portion 116A of the fixing bolt 115 is formed in a square shape, but the shape of the flange portion 116A is not limited to this, and any shape that can receive a reaction force (restrict rotation) by the reaction force receiving portion 121 is acceptable. For example, it may be a polygon other than a square, or it may be gear-shaped.

[0080] Furthermore, while the above embodiment illustrates a crawler crane as an example of a crane, the present invention is not limited to any crane capable of carrying multiple counterweights. For example, in addition to other mobile cranes such as wheel cranes, truck cranes, rough terrain cranes, and all-terrain cranes, the invention is applicable to any crane, including tower cranes, overhead cranes, jib cranes, retractable cranes, stacker cranes, gantry cranes, unloaders, and foundation machinery such as earth drills. [Explanation of Symbols]

[0081] 10 Cranes 100 Crane body 101 Running body 103 Rotating body 104 Boom 111, 1111, 1112, 1113, 1114, 1115, 1116, 111L Counterweight 115 Fixing bolts 116 Head 116A Flange section 117 Shaft 118 Male threaded section 119 Nut 121 Reaction force receiving section 131 Cylinder part 132, 133 Flange section 141, 142, 143 Storage Units

Claims

1. In a crane capable of loading multiple counterweights, Fixing bolts that penetrate the multiple counterweights in the stacking direction and fix the multiple counterweights to the crane body, A crane characterized by comprising an adapter disposed between the surface of the counterweight and the fixing bolt.

2. In the crane according to claim 1, The aforementioned fixing bolt is equipped with a nut that is screwed into it, The fixing bolt has a head located on one end side in the stacking direction, The nut is screwed into the fixing bolt at the other end in the stacking direction. The adapter is positioned between the surface of the counterweight located at one end in the stacking direction and the head, A crane characterized by the following features.

3. In the crane according to claim 2, The aforementioned adapter is The through hole into which the shaft portion of the aforementioned fixing bolt is inserted, It has a pair of flange portions positioned at both ends in the axial direction, One of the flange portions is connected to the head portion, The other end of the flange portion abuts against the reaction force receiving portion provided on the counterweight. A crane characterized by the following features.

4. In the crane according to claim 1, The adapter corresponds to the height of one stage of the counterweight, A crane characterized by the following features.

5. In the crane according to claim 1, The device is equipped with multiple fixing bolts of different lengths, The aforementioned multiple fixing bolts, together with the common adapter, secure the multiple counterweights to the crane body. A crane characterized by the following features.

6. In the crane according to claim 1, The aforementioned fixing bolts are provided in multiple locations. The crane body has a housing section for accommodating spare fixing bolts that are not in use among the plurality of fixing bolts. A crane characterized by the following features.

7. A method for assembling a counterweight in a crane capable of loading multiple counterweights, wherein the counterweight is fixed to the crane body in a state where it has been reduced in number from the multiple counterweights, Fixing bolts that penetrate the multiple counterweights in the stacking direction and fix the multiple counterweights to the crane body, The adapter connected to the aforementioned fixing bolt, A method for assembling a counterweight using the following: A step of removing the counterweight that is subject to the reduction in stage, The process of connecting the fixing bolt and the adapter, The steps include: positioning the adapter between the surface of the counterweight in the reduced-stage state and the fixing bolt; The process includes fixing the reduced-stage counterweight to the crane body using the fixing bolt and the adapter, A method for assembling a counterweight characterized by the following features.

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