Working device for construction machine

Abstract

A gripping tool (20) for gripping an object between the gripping tool (20) and a bucket (16) is provided with a pin holding member (38) for holding a fixing pin (32) removed from having been inserted between an arm (14) and the gripping tool (20). Therefore, since the pin holding member (38) is provided to the gripping tool (20) close to the attachment position of the fixing pin (32) inserted between the arm (14) and the gripping tool (20), a worker can easily transport the fixing pin (32) to the pin holding member (38).

Description

Construction machinery work equipment

[0001] The present disclosure relates to a working device for construction machinery that is equipped on construction machinery such as a hydraulic excavator and is suitable for use in earth excavation work, building demolition work, and the like.

[0002] Generally, a hydraulic excavator, which is a typical example of a construction machine, is composed of a self-propelled lower running body, an upper rotating body that is rotatably mounted on the lower running body, and a working device that is rotatably mounted on the front side of the upper rotating body.

[0003] The working device is configured to include a boom that is rotatably mounted on the front side of a rotating frame that serves as the base of the upper rotating body in the up-down direction of the upper rotating body or the front-to-back direction of the upper rotating body, with one end as a fulcrum, and is actuated by a boom cylinder, an arm that is rotatably mounted on the other end of the boom in the up-down direction of the upper rotating body or the front-to-back direction of the upper rotating body, with one end as a fulcrum, and is actuated by an arm cylinder, and a bucket that is rotatably mounted on the other end of the arm in the up-down direction of the upper rotating body or the front-to-back direction of the upper rotating body, and is actuated by a bucket cylinder. The construction machine can perform work such as excavating earth and sand by rotating the boom, arm, and bucket while rotating the upper rotating body.

[0004] Some work devices are equipped with a gripper. The base end of this gripper is attached to the other end of the arm so as to be rotatable in the up-down direction of the upper rotating body or the front-to-rear direction of the upper rotating body. This allows the gripper to grip an object between the bucket and the gripper. The work device equipped with the gripper can perform work such as building demolition by gripping an object between the bucket and the gripper by rotating the bucket with the bucket cylinder and the gripper with the gripper cylinder.

[0005] When performing excavation work or the like using a bucket, a work device equipped with a gripper gets in the way, so the gripper is rotated toward the arm and folded along the arm (hereinafter, this position is referred to as the storage position).The work device is further provided with a fixing pin that is inserted between the arm and the gripper to prevent the gripper from rotating so that the gripper in the storage position does not inadvertently move toward the bucket (Patent Document 1).

[0006] Registered Utility Model No. 3059645

[0007] When performing work using the gripping tool, the fixing pin is removed from the arm and gripping tool to release the gripping tool. The removed fixing pin must be stored in a storage box or the like of the upper rotating body to prevent it from being lost.

[0008] However, the storage box of the upper rotating body is located away from the gripping tool. Furthermore, the fixing pin is made of metal and is heavy. Therefore, when storing the removed fixing pin in the storage box of the upper rotating body, it requires effort to transport the fixing pin from the gripping tool to the upper rotating body. Furthermore, there is a risk that the fixing pin will be dropped during transportation, damaging the fixing pin or surrounding components along the way.

[0009] An object of one embodiment of the present invention is to provide a working device for a construction machine that can improve the workability when attaching and detaching a fixing pin.

[0010] One embodiment of the present invention is a work device for a construction machine comprising: an arm rotatably attached to the vehicle body with one end as a fulcrum; a bucket rotatably attached to the other end of the arm; a gripping device whose base end is rotatably attached to the other end of the arm and which grips an object between the arm and the bucket; and a fixing pin that is inserted between the arm and the gripping device and prevents the gripping device from rotating, wherein the gripping device is provided with a pin holding member for holding the fixing pin when it is removed from its inserted state between the arm and the gripping device.

[0011] According to one embodiment of the present invention, the workability when attaching and detaching the fixing pin can be improved.

[0012] 8 is a left side view showing a hydraulic excavator equipped with a working device according to an embodiment of the present invention. FIG. 9 is a left side view showing the working device in a position when attaching or detaching a fixing pin. FIG. 10 is a perspective view showing a state in which a gripping tool is fixed to an arm by a fixing pin. FIG. 11 is a plan view showing the arm, gripping tool, and fixing pin of FIG. 3. FIG. 12 is a perspective view showing the arm and pin bracket. FIG. 13 is a bottom view showing the arm and pin bracket from below. FIG. 14 is a left side view showing a gripping tool. FIG. 15 is a cross-sectional view showing the gripping tool, fixing pin, and pin holding member, taken from the direction of arrows VIII-VIII in FIG. 9. FIG. 16 is a plan view showing the gripping tool, fixing pin, and pin holding member. FIG. 17 is a perspective view showing the gripping tool and pin holding member with the left side plate omitted. FIG. 18 is an explanatory diagram of an operation showing a state in which the pin body of the fixing pin is inserted into the holding insertion hole of the first fixing part. FIG. 19 is an explanatory diagram of an operation showing a state in which the anti-detachment pin of the fixing pin is engaged with the entrance groove portion of the engagement groove. FIG. 19 is an explanatory diagram of an operation showing a state in which the anti-detachment pin is engaged with the anti-detachment groove portion of the engagement groove, and a anti-detachment bolt is inserted across the bolt insertion hole and the bolt hole portion. 10 is an explanatory view showing the state in which the retaining pin is engaged with the fall-off prevention groove portion of the engagement groove with the left side plate omitted; FIG.

[0013] An embodiment of a working device for a construction machine according to the present invention will be described below with reference to Figures 1 to 14, taking as an example a working device equipped on a hydraulic excavator, which is a representative example of a construction machine. In this embodiment, regardless of the rotation position of the upper rotating body, the side on which the working device is located will be referred to as the front side, the side on which the counterweight is located will be referred to as the rear side, the side on which the cab is located will be referred to as the left side, and the side opposite the cab will be referred to as the right side. Furthermore, the rotation directions of the boom, arm, bucket, gripper, etc. that make up the working device will be described as the up-down direction and the fore-and-aft direction relative to the upper rotating body as the vehicle body.

[0014] In Figure 1, the hydraulic excavator 1 is configured to include a self-propelled crawler-type lower traveling body 2 and an upper rotating body 3 that is rotatably mounted on the lower traveling body 2. A working device 11, which will be described later, is rotatably provided on the front side of the upper rotating body 3. The hydraulic excavator 1 can perform work such as excavating earth and sand and demolishing buildings using this working device 11. The lower traveling body 2 and the upper rotating body 3 constitute a vehicle body of the present invention.

[0015] The upper rotating body 3 is composed of a rotating frame 4 that forms a support structure, a cab 5 mounted on the front left side of the rotating frame 4, a counterweight 6 that is arranged on the rear end side of the rotating frame 4 and balances the weight with the working device 11, and an exterior cover 7 that is provided on the rotating frame 4 and covers the engine, hydraulic pump, control valve device, etc. (none of which are shown).

[0016] Next, the working device 11 rotatably provided on the upper rotating body 3 of the hydraulic excavator 1 will be described in detail.

[0017] The working device 11 is provided on the front side of the rotating frame 4. The working device 11 includes a boom 12, an arm 14, a bucket 16, a gripping tool 20, a locking device 28, and a pin holding member 38. The working device 11 is used for excavating earth and sand, demolishing buildings, and the like.

[0018] The boom 12 is provided on the front side of the upper rotating body 3 so as to be rotatable in the up-down direction and the front-rear direction. The boom 12 is made of a rectangular cylindrical body bent into an L shape, and one end is rotatably attached to the rotating frame 4. The other end of the boom 12 forms an arm connecting portion 12A to which a boom connecting boss portion 14D of the arm 14, which will be described later, is rotatably connected.

[0019] Boom cylinder bosses 12B are provided on the left and right sides of the boom 12 at longitudinally intermediate positions. The protruding ends of the rods of boom cylinders 13, which will be described later, are attached to these boom cylinder bosses 12B. Additionally, arm cylinder brackets 12C are provided on the top surface of the boom 12 at longitudinally intermediate positions. The bottom side of the tube of arm cylinder 15, which will be described later, is attached to these arm cylinder brackets 12C.

[0020] Two boom cylinders 13 are provided at positions sandwiching the boom 12 (only the one on the left is shown). These two boom cylinders 13 are provided between the revolving frame 4 and the boom 12 and rotate the boom 12 up and down and back and forth. The bottom side of the tube of the boom cylinder 13 is attached to the revolving frame 4. The protruding end of the rod of the boom cylinder 13 is attached to the boom cylinder boss portion 12B of the boom 12.

[0021] 1 and 2, the arm 14 is provided so as to be rotatable with respect to the upper rotating body 3, with one end serving as a fulcrum. Specifically, one end of the arm 14 is attached to the other end of the boom 12 so as to be rotatable in the up-down direction and the front-to-rear direction. The arm 14 is formed as a rectangular tube that tapers from one end to the other. Specifically, when the arm 14 is extended forward, it includes an upper plate 14A and a lower plate 14B that face each other with a gap between them in the up-down direction, and left and right side plates 14C that face each other and sandwich the upper plate 14A and the lower plate 14B in the left-to-right direction.

[0022] A boom connecting boss 14D is provided on one end of the arm 14. This boom connecting boss 14D is rotatably connected to the arm connecting portion 12A of the boom 12. Meanwhile, a bucket connecting boss 14E made of a cylindrical body extending in the left-right direction is provided on the other end of the arm 14 (see FIGS. 3 and 5).

[0023] An arm cylinder bracket 14F is provided at one end of the arm 14. A bucket cylinder bracket 14G is provided at one end of the upper plate 14A. A gripper cylinder bracket 14H is provided at the middle of the lower plate 14B in the longitudinal direction.

[0024] The protruding end of the rod of the arm cylinder 15 is attached to the arm cylinder bracket 14F. The bottom side of the tube of the bucket cylinder 19 is attached to the bucket cylinder bracket 14G. The bottom side of the tube of the gripper cylinder 27 is attached to the gripper cylinder bracket 14H.

[0025] Furthermore, as shown in Figure 5, the arm 14 is provided with a mounting base 14J located on the other end side of the lower plate 14B. A pin bracket 29 (described below) is attached to the mounting base 14J. Specifically, the mounting base 14J has a plurality of screw holes (not shown) with their axes aligned in the thickness direction. This allows the pin bracket 29 to be detachably attached to the mounting base 14J using a plurality of bolts 30.

[0026] The arm cylinder 15 is provided between the boom 12 and the arm 14 and rotates the arm 14 up and down and back and forth. The bottom side of the tube of the arm cylinder 15 is attached to an arm cylinder bracket 12C of the boom 12. The protruding end of the rod of the arm cylinder 15 is attached to an arm cylinder bracket 14F of the arm 14.

[0027] The bucket 16 is attached to a bucket connecting boss 14E located at the other end of the arm 14 so as to be rotatable in the vertical and longitudinal directions. The bucket 16 includes a container-shaped bucket body 16A that scoops up and stores earth and sand through an opening, a pair of mounting plates 16B (only the left side is shown) that are erected at one end of the bucket body 16A with a gap between them in the lateral direction, and a plurality of excavation claws 16C (only one is shown) that are provided at the other end of the bucket body 16A.

[0028] The pair of mounting plates 16B extend from the bottom side of the bucket body 16A toward the opening side. One ends of the mounting plates 16B are disposed across a bucket connecting boss portion 14E of the arm 14. One ends of the pair of mounting plates 16B are rotatably attached to the bucket connecting boss portion 14E using bucket pins 17 (described below). In addition, bucket links 18 (described below) are rotatably attached to the other ends of the pair of mounting plates 16B.

[0029] The bucket pin 17 attaches the bucket 16 to the other end of the arm 14 so that the bucket 16 can rotate up and down and back and forth. When the bucket pin 17 is inserted into the bucket connecting boss 14E, a protruding portion that protrudes from the bucket connecting boss 14E is connected to one end of a pair of mounting plates 16B. Both ends of the bucket pin 17 extend beyond the pair of mounting plates 16B. Both ends of the extended bucket pin 17 are inserted into bucket pin holes 21A in a left side plate 21 and bucket pin holes 22A in a right side plate 22 of a gripping tool 20, which will be described later.

[0030] The bucket link 18 is provided to connect the arm 14, the bucket 16, and a bucket cylinder 19 (described later). The bucket link 18 converts the extension and contraction movement of the bucket cylinder 19 into a large rotation movement of the bucket 16.

[0031] The bucket cylinder 19 is provided between the arm 14 and the bucket link 18. The bucket cylinder 19 rotates the bucket 16 in the up-down direction and the front-rear direction via the bucket link 18. The bottom side of the tube of the bucket cylinder 19 is attached to a bucket cylinder bracket 14G of the arm 14. The protruding end of the rod of the bucket cylinder 19 is attached to the bucket link 18.

[0032] The gripper 20 is provided at the other end of the arm 14. The base end of the gripper 20 is attached to the other end of the arm 14 so as to be rotatable in the up-down direction and the front-back direction. The gripper 20 is also attached so as to be rotatable coaxially with the bucket 16. This allows the gripper 20 to grip an object between itself and the bucket 16.

[0033] The gripper 20 rotates about the bucket pin 17 between the arm 14 and the bucket 16, i.e., between a position facing the lower plate 14B of the arm 14 (the position shown in Figures 1 and 2, etc.) and a position facing the opening side of the bucket 16. As shown in Figures 7 to 9, the gripper 20 is configured to include a left side plate 21, a right side plate 22, a bottom plate 23, gripping claws 25, and a common bracket 26, which will be described later.

[0034] The left side plate 21 and the right side plate 22 constitute a pair of side plates facing each other in the left-right direction, with a bottom plate 23 (described later) sandwiched between them. The left side plate 21 is formed as an elongated plate having a predetermined width in the rotation direction. The left side plate 21 has a bucket pin hole 21A at its base end. An end of a bucket pin 17 is rotatably inserted into this bucket pin hole 21A. Meanwhile, a gripping claw 25 is attached to the tip of the left side plate 21.

[0035] Furthermore, a bottom plate 23 is attached to the left side plate 21 at the edge opposite the arm 14 when the gripper 20 is rotated toward the arm 14 (i.e., the storage position where the gripper 20 is closest to the arm 14). That is, the left side plate 21 forms a protective wall that rises from the bottom plate 23 toward the arm 14. The left side plate 21 as this protective wall can cover and protect the left side of the pin holding member 38 provided on the bottom plate 23. Furthermore, a gripper-side pin hole 31 of a locking device 28 (described later) is provided in the middle of the longitudinal direction of the left side plate 21, penetrating in the left-right direction (plate thickness direction).

[0036] As shown in FIG. 8 , the right side plate 22 is formed similarly to the left side plate 21. That is, the right side plate 22 is formed as an elongated plate having a predetermined width in the rotation direction. A bucket pin hole 22A is formed at the base end of the right side plate 22. Meanwhile, a gripping claw 25 is attached to the tip of the right side plate 22. Furthermore, a bottom plate 23 is attached to the edge of the right side plate 22 opposite the arm 14 when the gripper 20 is in the retracted position. This allows the right side plate 22 to function as a protective wall extending from the bottom plate 23 toward the arm 14 to protect the right side of the pin holding member 38. Furthermore, as shown in FIG. 3 , a gripper-side pin hole 31 of a locking device 28 (described later) is formed in the middle of the right side plate 22 in the longitudinal direction, penetrating in the left-right direction (plate thickness direction).

[0037] The bottom plate 23 faces the arm 14 when the gripper 20 is rotated toward the arm 14. The bottom plate 23 connects the pair of left and right plates 21 and 22. The bottom plate 23 is formed of a rectangular plate. The left edge of the bottom plate 23 is attached to the edge of the left plate 21 opposite the arm 14, and the right edge is attached to the edge of the right plate 22 opposite the arm 14. As a result, the bottom plate 23 cooperates with the left and right plates 21 and 22 to form a wide U-shape. In addition, a pin holding member 38 (described below) is provided on the opposing surface 23A of the bottom plate 23, which faces the lower plate 14B of the arm 14 at a recessed inner position.

[0038] The reinforcing plate 24 extends obliquely from the base end of the bottom plate 23 toward the bucket pin holes 21A, 22A. The reinforcing plate 24 also extends in the left-right direction and is attached to the left plate 21 and the right plate 22. This allows the reinforcing plate 24 to increase the strength of the gripper 20.

[0039] The gripping claws 25 are provided on the tips of the left side plate 21, the right side plate 22, and the bottom plate 23. As shown in Fig. 9, the gripping claws 25 are composed of a mounting plate 25A that is a rectangular plate extending in the left-right direction and attached to the tips of the left side plate 21, the right side plate 22, and the bottom plate 23, two long claws 25B extending from both left-right ends of the mounting plate 25A, two short claws 25C extending from the mounting plate 25A and positioned between the two long claws 25B, and reinforcing plates 25D and 25E provided between the long claws 25B and the short claws 25C.

[0040] The common bracket 26 is formed of two plates facing each other with a gap in the left-right direction. The common bracket 26 is provided across the opposing surface 23A of the bottom plate 23 and the reinforcing plate 24. A gripper cylinder mounting hole 26A is formed in the common bracket 26 at a position close to the bottom plate 23. As shown in Fig. 3, the protruding end of the rod of the gripper cylinder 27 is attached to the gripper cylinder mounting hole 26A. Furthermore, as shown in Fig. 8, the common bracket 26 is provided with a gripper side pin hole 31 (described later) at a position away from the bottom plate 23.

[0041] As shown in Figure 2, the gripping tool cylinder 27 is provided between the arm 14 and the gripping tool 20. The gripping tool cylinder 27 rotates the gripping tool 20 in the up-down direction and the front-rear direction. The bottom side of the tube of the gripping tool cylinder 27 is attached to the gripping tool cylinder bracket 14H of the arm 14. The protruding end of the rod of the gripping tool cylinder 27 is attached to the gripping tool cylinder attachment hole 26A of the common bracket 26 of the gripping tool 20.

[0042] The locking device 28 fixes (locks) the gripping tool 20 in the stored position (hereinafter referred to as the stored position) when the gripping tool 20 is rotated toward the arm 14 and the gripping tool 20 is closest to the arm 14. The locking device 28 is provided between the arm 14 and the gripping tool 20. That is, the locking device 28 is composed of a pin bracket 29, a gripping tool pin hole 31, a fixing pin 32, and a retaining bolt 36.

[0043] The pin bracket 29 is provided on the side of the arm 14 facing the gripping tool 20. More specifically, the pin bracket 29 is attached to the other end of the lower plate 14B, i.e., the mounting base 14J. The pin bracket 29 is composed of a rectangular base plate 29A facing the mounting base 14J, a pair of plate members 29B extending downward from the base plate 29A with a gap between them in the left-right direction, and arm-side pin holes 29C passing through the pair of plate members 29B in the left-right direction. The base plate 29A of the pin bracket 29 is attached to the mounting base 14J using multiple bolts 30. This allows the pin bracket 29 to be removed when the gripping tool 20 is removed and the pin bracket 29 is no longer needed.

[0044] The gripper-side pin hole 31 is formed coaxially in the left-right direction on each of the left side plate 21, right side plate 22, and common bracket 26 that constitute the gripper 20. The gripper-side pin hole 31 is formed at a position that is coaxial with the arm-side pin hole 29C of the pin bracket 29 when the gripper 20 is rotated toward the arm 14. Specifically, the gripper-side pin hole 31 is formed at a position that is coaxial with the arm-side pin hole 29C of the pin bracket 29 when the gripper 20 is disposed in the storage position (the position shown in FIGS. 1 and 2 ) closest to the arm 14.

[0045] The fixing pin 32 is inserted between the arm 14 and the gripping tool 20 to prevent the gripping tool 20 from rotating. Specifically, the fixing pin 32 is inserted between the gripping tool pin hole 31 and the arm pin hole 29C of the pin bracket 29, which are coaxially arranged when the gripping tool 20 is in the storage position. The fixing pin 32 can be removed from the state where it is inserted between the arm 14 and the gripping tool 20 by pulling it out to the left, which is one side of the upper rotating body 3 in the left-right direction. In other words, since the fixing pin 32 is pulled out toward the left side of the working device 11, when removing the fixing pin 32, an operator stands on the left side of the arm 14 and the gripping tool 20 to perform the work. The fixing pin 32 includes a pin body 33, a retaining pin 34, a bolt insertion hole 35, and a retaining bolt 36, which will be described later.

[0046] The pin body 33 is inserted through the gripper-side pin hole 31 provided in the left side plate 21, right side plate 22, and common bracket 26 of the gripper 20, and through the arm-side pin hole 29C of the pin bracket 29. The pin body 33 is formed, for example, as a cylindrical body having a length equal to the distance between the left side plate 21 and the right side plate 22. A retaining pin 34 is attached to one end of the pin body 33. Meanwhile, a chamfered portion 33A is provided at the other end of the pin body 33. As a result, the pin body 33, which is tapered by the chamfered portion 33A, can be easily inserted into the gripper-side pin hole 31, the arm-side pin hole 29C, and a holding insertion hole 39A of the first fixing portion 39, which will be described later.

[0047] The retaining pin 34 is provided at one end of the pin body 33 and extends perpendicular to the axis O-O of the pin body 33. The retaining pin 34 is formed as a cylindrical body that is thinner than the pin body 33 and longer in diameter than the pin body 33. As a result, both ends of the retaining pin 34 form a pair of protruding ends 34A that protrude radially outward from the outer circumferential surface of the pin body 33. When the pin body 33 is inserted through the gripper-side pin hole 31 and the arm-side pin hole 29C, the pair of protruding ends 34A abut against either one of the pair of left side plate 21 and right side plate 22, which is provided with the gripper-side pin hole 31. In other words, when the pin body 33 is inserted through the gripper-side pin hole 31 and the arm-side pin hole 29C, the pair of protruding ends 34A abut against the outer surface of the left side plate 21. Furthermore, when the fixing pin 32 is held by the pin holding member 38, the pair of protruding ends 34A can engage with an engaging groove 41, which will be described later.

[0048] The bolt insertion hole 35 is provided at one end side of the pin body 33, penetrating the pin body 33 in the radial direction. More specifically, the bolt insertion hole 35 is inserted through the pin body 33 from the gripper-side pin hole 31 to the arm-side pin hole 29C, and is positioned between the left side plate 21 and the pin bracket 29 when the protruding end 34A of the retaining pin 34 faces the outer surface of the left side plate 21. In other words, as shown in FIG. 4 , the bolt insertion hole 35 is positioned so that the left side plate 21 is sandwiched between the bolt insertion hole 35 and the protruding end 34A.

[0049] The retaining bolt 36 is inserted into the bolt insertion hole 35 located between the left side plate 21 and the pin bracket 29. This allows the retaining bolt 36 to sandwich the left side plate 21 between itself and the retaining pin 34. The retaining bolt 36 has the pin body 33 inserted through the gripper-side pin hole 31 and the arm-side pin hole 29C, and is inserted into the bolt insertion hole 35 with the protruding end 34A of the retaining pin 34 facing the outer surface of the left side plate 21. A nut 37 is then threaded onto the tip of the retaining bolt 36. This prevents the retaining bolt 36 from being attached to the pin body 33. The retaining bolt 36 is attached to the pin body 33, and faces the inner surface of the left side plate 21 to prevent the pin body 33 from coming out (see FIG. 4 ).

[0050] When the fixing pin 32 is held by the pin holding member 38, the retaining bolt 36 is inserted into the coaxially arranged bolt hole portion 42 and bolt insertion hole 35, and the nut 37 is screwed onto the tip of the retaining bolt 36. In this way, the retaining bolt 36 securely holds the fixing pin 32 to the pin holding member 38.

[0051] Next, the configuration of the pin holding member 38, which is a characteristic feature of this embodiment, and the structure for holding the fixing pin 32 by the pin holding member 38 will be described with reference to FIGS. 8 to 14. FIG.

[0052] 8 to 10 , the pin holding member 38 is provided on the gripping tool 20 and is located between the left side plate 21 and the right side plate 22. The pin holding member 38 holds the fixing pin 32 that has been removed from the state in which it was inserted between the arm 14 and the gripping tool 20 in order to operate the gripping tool 20. The pin holding member 38 is positioned so that it faces the arm 14 when the gripping tool 20 is rotated toward the arm 14. Furthermore, the pin holding member 38 is positioned so that it is sandwiched between the lower plate 14B of the arm 14 and the bottom plate 23 of the gripping tool 20 when the gripping tool 20 is rotated toward the arm 14.

[0053] Specifically, the pin holding member 38 is positioned on the opposing surface 23A of the bottom plate 23 that faces the lower plate 14B of the arm 14 when the gripping tool 20 is positioned in the storage position closest to the arm 14 (the position shown in Figures 1 and 2).

[0054] Therefore, the left and right plates 21 and 22 that rise from the bottom plate 23 act as protective walls to cover the pin holding member 38, and the lower plate 14B of the arm 14 acts as a lid to cover the pin holding member 38. As a result, the left and right plates 21 and 22 can protect the pin holding member 38 and the fixing pins 32 held by the pin holding member 38 from stones, concrete pieces, obstacles, and the like.

[0055] 9, the pin holding member 38 is disposed at a position shifted to the left side, which is the direction in which the fixed pin 32 is pulled out. In other words, the pin holding member 38 is disposed between the left side plate 21 and the common bracket 26. Furthermore, the pin holding member 38 holds the fixed pin 32 so that the axis O-O of the fixed pin 32 is aligned with the longitudinal direction of the gripping tool 20. That is, the first fixing portion 39 of the pin holding member 38 is disposed on the base end side of the gripping tool 20, and the second fixing portion 40 is disposed on the tip end side of the gripping tool 20.

[0056] Therefore, when attaching or detaching the fixing pin 32 to or from the pin holding member 38, an operator standing on the left side of the gripping tool 20 can hold the other end of the pin body 33 with his left hand and one end with his right hand. This allows the operator to stably hold the fixing pin 32 with both hands, improving workability.

[0057] The pin holding member 38 is configured to include a first fixing portion 39, a second fixing portion 40, an engagement groove 41, and a bolt hole portion 42, which will be described later.

[0058] The first fixing portion 39 is disposed toward the left side of the bottom plate 23 (opposing surface 23A). As shown in FIG. 10 , the first fixing portion 39 is formed as a plate with a circular retaining insertion hole 39A. The first fixing portion 39 extends in the left-right direction and is erected on the opposing surface 23A of the bottom plate 23 so that the axis (drilling direction) of the retaining insertion hole 39A coincides with the longitudinal direction of the gripper 20. The other end of the pin body 33 is inserted into the retaining insertion hole 39A. In this case, the inner diameter of the retaining insertion hole 39A is larger than the diameter of the pin body 33. As a result, even when the other end of the pin body 33 is inserted into the retaining insertion hole 39A, the anti-detachment pin 34 can be inserted and removed from the engagement groove 41 (described below) by moving one end of the pin body 33.

[0059] The second fixing portion 40 is disposed at a position spaced apart from the first fixing portion 39 in the axial direction (direction of extension of the axis) of the holding insertion hole 39A. Specifically, the second fixing portion 40 is located on the tip side of the bottom plate 23 (opposing surface 23A) and disposed toward the left side of the bottom plate 23. The second fixing portions 40 form a pair facing each other so as to sandwich the pin body 33 inserted into the holding insertion hole 39A in the radial direction.

[0060] The pair of second fixing portions 40 are made of rectangular plates extending in the longitudinal direction of the gripping tool 20, and are arranged parallel to each other so as to face each other in the left-right direction with a gap between them that is greater than the diameter of the pin body 33. One long side of each of the pair of second fixing portions 40 is attached to the opposing surface 23A of the bottom plate 23. The pair of second fixing portions 40 includes an engagement groove 41 and a bolt hole 42.

[0061] The engagement grooves 41 are formed in the pair of second fixing parts 40. The engagement grooves 41 are engaged with the retaining pins 34 and are formed to penetrate the second fixing parts 40 in the thickness direction (left-right direction). The engagement grooves 41 are located on the tip side of the gripping tool 20 in the second fixing parts 40.

[0062] The engagement groove 41 is formed to include an inlet groove 41A extending from an edge (the other long side) of the second fixing portion 40 opposite the bottom plate 23 toward the bottom plate 23, a retaining groove 41B bending from the back of the inlet groove 41A in the axial direction of the holding insertion hole 39A and extending to the opposite side of the first fixing portion 39 (the tip side of the gripper 20), and a fall-off prevention groove 41C bending from the back of the inlet groove 41A in the axial direction of the holding insertion hole 39A and extending to the first fixing portion 39 side (the opposite side to the fall-off prevention groove 41B). The engagement groove 41 is formed in an inverted T shape by the inlet groove 41A, the fall-off prevention groove 41B, and the fall-off prevention groove 41C.

[0063] The entrance groove 41A serves as an entrance portion through which the retaining pin 34 of the fixing pin 32 engages with the engagement groove 41. The retaining pin 34 reaches the deepest portion of the entrance groove 41A and moves together with the pin body 33 toward the tip end of the gripping tool 20, thereby engaging with the retaining groove 41B. The retaining pin 34, which has engaged with the entrance groove 41A, moves together with the pin body 33 toward the base end of the gripping tool 20, thereby passing through the entrance groove 41A and engaging with the fall-off prevention groove 41C.

[0064] The bolt holes 42 are provided in the pair of second fixing parts 40. The retaining bolts 36 are inserted into the bolt holes 42, which are formed by penetrating the second fixing parts 40 in the thickness direction (left-right direction). The bolt holes 42 are located on the base end side of the second fixing parts 40, opposite the engagement grooves 41, of the second fixing parts 40.

[0065] The bolt hole portion 42 is disposed in a position where it is coaxial with the bolt insertion hole 35 of the fixing pin 32 (a position communicating with the bolt insertion hole 35) when the retaining pin 34 engages with the retaining groove portion 41B of the engagement groove 41. The retaining bolt 36 is inserted into the bolt hole portion 42 so as to be coaxial with the bolt insertion hole 35. A nut 37 is screwed onto the tip of the retaining bolt 36 inserted into the bolt hole portion 42 and the bolt insertion hole 35.

[0066] The working device 11 of the hydraulic excavator 1 according to this embodiment has the configuration as described above. When this working device 11 is used to perform building demolition work, the bucket cylinder 19 is extended and retracted to rotate the bucket 16, and the gripping tool cylinder 27 is extended and retracted to rotate the gripping tool 20. This allows the bucket 16 and the gripping tool 20 to clamp and demolish an object to be demolition, or to grip the dismantled object and transport it to a desired disposal site.

[0067] On the other hand, when performing work such as excavating earth and sand using the bucket 16, the gripper 20 gets in the way. In this case, as shown in Figure 1, the gripper 20 is rotated toward the arm 14 and placed in a storage position closest to the arm 14. Furthermore, to prevent the gripper 20 placed in the storage position from accidentally moving toward the bucket 16, the gripper 20 is fixed in the storage position using a locking device 28.

[0068] Next, we will describe the operations for fixing the gripping tool 20 to the arm 14 side using the locking device 28 and for releasing the gripping tool 20 from the locking device 28. When performing these operations, the boom 12 is tilted forward and the arm 14 is extended forward (the position shown in FIG. 2) so that operations can be performed from the ground.

[0069] First, when using the locking device 28 to fix the gripping tool 20 to the arm 14 side, the gripping tool 20 is rotated toward the arm 14 side, and the gripping tool-side pin hole 31 of the gripping tool 20 and the arm-side pin hole 29C of the pin bracket 29 are aligned coaxially. In this state, the worker inserts the pin body 33 of the fixing pin 32 from the left side of the gripping tool 20 (the side of the left side plate 21) into the gripping tool-side pin hole 31 and the arm-side pin hole 29C. As a result, the gripping tool 20 is prevented from rotating by the fixing pin 32, and is fixed in the storage position on the arm 14 side.

[0070] Furthermore, when the fixing pin 32 is inserted to a predetermined position into the gripper-side pin hole 31 and the arm-side pin hole 29C, the bolt insertion hole 35 is positioned to the right, beyond the left side plate 21. Once the bolt insertion hole 35 is positioned in this position, the worker inserts the anti-pullout bolt 36 into the bolt insertion hole 35, causing its tip to protrude, and screws the nut 37 onto the protruding end. In this way, the fixing pin 32 can be prevented from coming out by the anti-pullout bolt 36, and the anti-pullout bolt 36 can be prevented from coming out by the nut 37.

[0071] On the other hand, when releasing the fixation of the gripping tool 20 by the locking device 28, the fixation pin 32 can be pulled out to the left side of the gripping tool 20 and removed by performing the procedure in reverse to the fixation procedure of the gripping tool 20 described above.

[0072] Next, a procedure for holding the fixing pin 32 removed from the gripping tool 20 in the pin holding member 38 will be described.

[0073] After removing the fixing pin 32 from the gripping tool 20, the worker carries the fixing pin 32 to the pin holding member 38. In this case, the pin holding member 38 is provided on the bottom plate 23 of the gripping tool 20. Moreover, the pin holding member 38 is positioned toward the left side, which is the direction in which the fixing pin 32 is pulled out. Therefore, the distance from the gripping tool pin hole 31 to the pin holding member 38 is short, and the pin holding member 38 is easily reachable. This allows the worker to easily carry the fixing pin 32 to the pin holding member 38.

[0074] After transporting the fixing pin 32 to the pin holding member 38, the worker inserts the other end of the pin body 33 into the holding insertion hole 39A of the first fixing part 39, as shown by arrow A in Figure 11. At this time, because the other end of the pin body 33 has a chamfered portion 33A, the pin body 33 can be easily inserted into the holding insertion hole 39A.

[0075] After inserting the pin body 33 into the retaining insertion hole 39A of the first fixing portion 39, the operator moves the protruding end portion 34A of the anti-pullout pin 34 toward the entrance groove portion 41A of the engagement groove 41 provided in the pair of second fixing portions 40, as shown by arrow B in Figure 11.

[0076] 12, once the protruding end 34A of the retaining pin 34 has been engaged all the way into the entrance groove 41A of the engagement groove 41, the retaining pin 34 is moved in the direction of arrow C together with the pin body 33. As shown in FIG. 13, once the protruding end 34A of the retaining pin 34 has been engaged with the retaining groove 41B of the engagement groove 41, the retaining bolt 36 is inserted into the bolt hole 42 and the bolt insertion hole 35 of the fixing pin 32, and a nut 37 is screwed onto the tip of the protruding retaining bolt 36. This allows the fixing pin 32, which has been removed from the gripping tool 20, to be held in the pin holding member 38.

[0077] Next, a case will be described in which the retaining bolt 36 falls off while the fixing pin 32 is held by the pin holding member 38. When the tip of the gripping tool 20 is lower than the base end, the protruding end 34A of the retaining pin 34 engages with the retaining groove portion 41B of the engagement groove 41, so the retained state of the fixing pin 32 can be maintained. On the other hand, as shown in Figure 14, when the tip of the gripping tool 20 is higher than the base end, gravity moves the fixing pin 32 in the direction of arrow D, and the protruding end 34A of the retaining pin 34 passes through the entrance groove portion 41A and engages with the fall-prevention groove portion 41C. This allows the retained state of the fixing pin 32 to be maintained.

[0078] Thus, according to this embodiment, the gripper 20 that grips an object between it and the bucket 16 is provided with a pin holding member 38 for holding the fixing pin 32 that has been removed from the state in which it was inserted between the arm 14 and the gripper 20. Therefore, the pin holding member 38 is provided on the gripper 20 close to the attachment position of the fixing pin 32 that was inserted between the arm 14 and the gripper 20.

[0079] As a result, even if the removed fixing pin 32 is a heavy metal object, the worker can easily transport the fixing pin 32 to the pin holding member 38. As a result, the workability when attaching and detaching the fixing pin 32 can be improved, and the fixing pin 32 can be prevented from falling, improving the durability of the fixing pin 32 and surrounding components that may be positioned during transportation.

[0080] The gripping tool 20 rotates between the arm 14 and the bucket 16, and the pin holding member 38 is disposed in a position facing the arm 14 when the gripping tool 20 is rotated toward the arm 14. This allows the pin holding member 38 and the fixing pin 32 to be disposed between the gripping tool 20 and the arm 14, thereby protecting the pin holding member 38 and the fixing pin 32 from stones, concrete pieces, obstacles, and the like. Furthermore, the pin holding member 38 disposed in a position facing the arm 14 is close to the attachment position of the fixing pin 32, making it even easier to hold the fixing pin 32.

[0081] The fixing pin 32 can be removed from its inserted state between the arm 14 and the gripping tool 20 by pulling it out to the left, and the pin holding member 38 is positioned toward the left side, which is the pulling direction of the fixing pin 32. Therefore, following the operation of pulling out the fixing pin 32, the operation of attaching the fixing pin 32 to the pin holding member 38 can be performed. In addition, the pin holding member 38 can be positioned in a position close to and easily reachable by a worker working while standing on the left side of the gripping tool 20. This allows the worker to easily perform operations such as attaching and detaching the fixing pin 32 and transporting the device.

[0082] The gripping tool 20 includes a bottom plate 23 that faces the arm 14 when the gripping tool 20 is rotated toward the arm 14, and a pair of left and right plates 21, 22 that face each other across the bottom plate 23. The pin holding member 38 is disposed between the pair of left and right plates 21, 22. Therefore, the left and right plates 21, 22 can act as a protective wall to cover the pin holding member 38, and can protect the pin holding member 38 and the fixing pins 32 held by the pin holding member 38 from stones, concrete pieces, obstacles, and the like.

[0083] The pin holding member 38 is disposed in a position sandwiched between the arm 14 and the bottom plate 23 when the gripping tool 20 is rotated toward the arm 14. This allows the pin holding member 38 and the fixing pin 32 to be disposed in the narrow space sandwiched between the arm 14 and the bottom plate 23, thereby protecting the pin holding member 38 and the fixing pin 32 from stones, concrete pieces, obstacles, etc. Furthermore, even if the fixing pin 32 falls during the operation of holding it, the bottom plate 23 can catch the fallen fixing pin 32.

[0084] The pin holding member 38 holds the fixed pin 32 so that the axis O-O of the fixed pin 32 is aligned with the longitudinal direction of the gripping tool 20. Therefore, when attaching or detaching the fixed pin 32 to or from the pin holding member 38, the worker can hold both longitudinal ends of the fixed pin 32 with both hands. This allows the worker to hold the fixed pin 32 stably, improving workability.

[0085] A pin bracket 29 is provided on the arm 14 on the side facing the gripping tool 20, and an arm-side pin hole 29C is formed in the pin bracket 29. A gripping tool-side pin hole 31 is formed in the left side plate 21 of the gripping tool 20, which is coaxial with the arm-side pin hole 29C when the gripping tool 20 is rotated toward the arm 14. The fixing pin 32 is made up of a pin body 33 provided with a bolt insertion hole 35 passing through in the radial direction, and a retaining pin 34 provided on one side of the pin body 33 so as to extend perpendicular to the axis O-O of the pin body 33. and a retaining bolt 36 inserted into the bolt insertion hole 35. When the fixing pin 32 is inserted across the arm 14 and the gripping tool 20, the pin body 33 is inserted across the coaxially arranged gripping tool side pin hole 31 and arm side pin hole 29C, the retaining pin 34 abuts against the outer surface of the left side plate 21, the bolt insertion hole 35 is located between the left side plate 21 and the pin bracket 29, and the retaining bolt 36 is inserted into the bolt insertion hole 35 located between the left side plate 21 and the pin bracket 29.

[0086] Therefore, when using the fixing pin 32 to fix the gripper 20 to the arm 14 side, the gripper 20 is rotated toward the arm 14 side, and the gripper-side pin hole 31 of the gripper 20 and the arm-side pin hole 29C of the pin bracket 29 are aligned coaxially. In this state, the pin body 33 of the fixing pin 32 is inserted from the left side of the gripper 20 across the gripper-side pin hole 31 and the arm-side pin hole 29C. This allows the fixing pin 32 to prevent the gripper 20 from rotating and fix the gripper 20 to the storage position on the arm 14 side.

[0087] Furthermore, when the fixing pin 32 is inserted into the gripper-side pin hole 31 to a predetermined position, the bolt insertion hole 35 passes over the left side plate 21 and is positioned between the left side plate 21 and the pin bracket 29. A retaining bolt 36 is inserted into this bolt insertion hole 35, and a nut 37 is screwed onto the protruding end of the retaining bolt 36. This makes it possible for the retaining bolt 36 to prevent the fixing pin 32 from coming out, and for the nut 37 to prevent the retaining bolt 36 from coming out.

[0088] On the other hand, when releasing the fixation of the gripping tool 20 by the fixing pin 32, the fixation pin 32 can be pulled out to the left side of the gripping tool 20 and removed by performing the procedure in reverse to the above-mentioned fixing procedure of the gripping tool 20.

[0089] The pin retaining member 38 comprises a first fixing portion 39 having a retaining insertion hole 39A into which the other side of the pin body 33 is inserted, and a pair of second fixing portions 40 which are arranged at a position away from the first fixing portion 39 in the axial direction of the retaining insertion hole 39A and face each other so as to sandwich the pin body 33 radially, and the pair of second fixing portions 40 have engagement grooves 41 formed therein into which the anti-pullout pin 34 engages.

[0090] As a result, the worker inserts the other side of the pin body 33 into the holding insertion hole 39A of the first fixing part 39 and engages the protruding end 34A of the anti-pullout pin 34 with the engaging groove 41 provided in the pair of second fixing parts 40. In this way, the fixing pin 32 removed from the gripping tool 20 can be held by the pin holding member 38.

[0091] The arm 14 and the gripping device 20 can rotate in the vertical direction of the upper rotating body 3 or in the longitudinal direction of the upper rotating body 3, and a pair of second fixing portions 40 are attached to the bottom plate 23, and the engagement groove 41 is formed to include an inlet groove portion 41A extending from the edge opposite the bottom plate 23 toward the bottom plate 23, and a pull-out prevention groove portion 41B bending from the back of the inlet groove portion 41A in the axial direction of the retaining insertion hole 39A and extending opposite the first fixing portion 39, and the pair of second fixing portions 40 are formed with bolt hole portions 42 which become coaxial with the bolt insertion hole 35 of the fixing pin 32 when the pull-out prevention pin 34 engages with the pull-out prevention groove portion 41B, and into which the pull-out prevention bolt 36 is inserted.

[0092] Therefore, the retaining pin 34 engages deep into the entrance groove portion 41A of the engagement groove 41, and at this position, the retaining pin 34 moves together with the pin body 33 toward the opposite side from the first fixing portion 39, thereby allowing the retaining pin 34 to engage with the retaining groove portion 41B of the engagement groove 41. Furthermore, the retaining bolt 36 is inserted through the bolt hole portion 42 and the bolt insertion hole 35 of the fixing pin 32. This allows the fixing pin 32 to be held in a retained state by the pin holding member 38.

[0093] The engagement groove 41 is formed with a fall-off prevention groove 41C that bends from the deepest part of the inlet groove 41A in the axial direction of the holding insertion hole 39A and extends toward the first fixing part 39. As a result, even if the retaining bolt 36 of the fixing pin 32 falls off, the retaining pin 34 passes through the inlet groove 41A and engages with the fall-off prevention groove 41C, so that the retaining state of the fixing pin 32 can be maintained.

[0094] Furthermore, the pin bracket 29 is attached to the arm 14 using a bolt 30. This allows the pin bracket 29 to be removed when the gripping tool 20 is removed and the pin bracket 29 is no longer needed.

[0095] In the embodiment, the direction in which the fixing pin 32 is pulled out is the left side, and the pin holding member 38 is disposed toward the left side of the gripping tool 20. However, the present invention is not limited to this, and the fixing pin may be pulled out toward the right side, and the pin holding member may be disposed toward the right side of the gripping tool.

[0096] In the embodiment, the engagement groove 41 is formed in an inverted T-shape by the inlet groove 41A, the retaining groove 41B, and the fall-off prevention groove 41C. However, the present invention is not limited to this. For example, the fall-off prevention groove may be omitted, and the inlet groove and the retaining groove may be formed in an L-shape. Furthermore, the engagement groove may be omitted, and the fixing pin may be held in the pin holding member by the retaining bolt alone.

[0097] Furthermore, in the above-described embodiment, a hydraulic excavator 1 equipped with a crawler-type undercarriage 2 is used as an example of a construction machine, but the present invention is not limited to this and can also be applied to, for example, a working device of a wheeled excavator equipped with a wheeled undercarriage.

[0098] DESCRIPTION OF SYMBOLS 1 Hydraulic excavator (construction machine) 2 Lower traveling body (vehicle body) 3 Upper rotating body (vehicle body) 11 Work device 14 Arm 16 Bucket 20 Gripper 21 Left side plate (side plate) 22 Right side plate (side plate) 23 Bottom plate 29 Pin bracket 29C Arm side pin hole 30 Bolt 31 Gripper side pin hole 32 Fixing pin 33 Pin body 34 Anti-withdrawal pin 35 Bolt insertion hole 36 Anti-withdrawal bolt 38 Pin holding member 39 First fixing portion 39A Holding insertion hole 40 Second fixing portion 41 Engagement groove 41A Entrance groove portion 41B Anti-withdrawal groove portion 41C Fall-off prevention groove portion 42 Bolt hole portion O-O Axis

Claims

1. A working device for a construction machine comprising: an arm rotatably attached to the vehicle body with one end as a fulcrum; a bucket rotatably attached to the other end of the arm; a gripping device whose base end is rotatably attached to the other end of the arm and which grips an object between the arm and the bucket; and a fixing pin that is inserted between the arm and the gripping device to prevent the gripping device from rotating, wherein the gripping device is provided with a pin holding member for holding the fixing pin when it is removed from its inserted state between the arm and the gripping device.

2. A working device for a construction machine as described in claim 1, characterized in that the gripping tool rotates between the arm and the bucket, and the pin holding member is positioned so as to face the arm when the gripping tool is rotated towards the arm.

3. A working device for a construction machine as described in claim 1, wherein the fixing pin can be removed from its inserted state between the arm and the gripping device by being pulled out, and the pin holding member is positioned in a position close to the direction in which the fixing pin is pulled out.

4. A working device for a construction machine as described in claim 2, wherein the gripping device comprises a bottom plate that faces the arm when the gripping device is rotated toward the arm, and a pair of side plates that face each other across the bottom plate, and the pin holding member is positioned between the pair of side plates.

5. A working device for a construction machine as described in claim 4, characterized in that the pin holding member is positioned in a position sandwiched between the arm and the bottom plate when the gripping tool is rotated toward the arm.

6. A working device for a construction machine according to claim 2, characterized in that the pin holding member holds the fixing pin so that the axis of the fixing pin is aligned with the longitudinal direction of the gripping tool.

7. A working device for a construction machine as set forth in claim 4, wherein the arm is provided with a pin bracket on the side facing the gripping tool, and an arm-side pin hole is formed in the pin bracket, and a gripping tool-side pin hole is formed in at least one of the pair of side plates of the gripping tool so as to be coaxial with the arm-side pin hole when the gripping tool is rotated towards the arm, and the fixing pin has: a pin body with a bolt insertion hole passing therethrough in the radial direction; a stop pin provided on one side of the pin body and extending perpendicular to the axis of the pin body; and a stop bolt inserted in the bolt insertion hole, and when the fixing pin is inserted between the arm and the gripping tool, the pin body is inserted between the gripping tool-side pin hole and the arm-side pin hole which are arranged coaxially, and the stop pin abuts against the outer surface of one of the pair of side plates on which the gripping tool-side pin hole is formed, a work device for a construction machine, characterized in that the bolt insertion hole is located between the pin bracket and one of the pair of side plates on which the gripping tool side pin hole is provided, and the anti-pullout bolt is inserted into the bolt insertion hole located between the pin bracket and one of the pair of side plates on which the gripping tool side pin hole is provided.

8. A working device for a construction machine as described in claim 7, wherein the pin holding member comprises a first fixing portion having a holding insertion hole into which the other side of the pin body is inserted, and a pair of second fixing portions which are positioned away from the first fixing portion in the axial direction of the holding insertion hole and which face each other so as to sandwich the pin body in the radial direction, and wherein an engagement groove into which the anti-pullout pin engages is formed in the pair of second fixing portions.

9. A working device for a construction machine as described in claim 8, wherein the arm and the gripping device are rotatable in the vertical direction of the vehicle body or the longitudinal direction of the vehicle body, the pair of second fixing parts are attached to the bottom plate, the engagement groove is formed to include an inlet groove part extending from the edge opposite the bottom plate towards the bottom plate, and a pull-out prevention groove part bending from the inner part of the inlet groove part in the axial direction of the retaining insertion hole and extending to the opposite side of the first fixing part, and the pair of second fixing parts are formed with bolt hole parts which become coaxial with the bolt insertion hole of the fixing pin when the pull-out prevention pin engages with the pull-out prevention groove part, and into which the pull-out prevention bolt is inserted.

10. A working device for a construction machine as described in claim 9, characterized in that the engagement groove is formed with a fall-off prevention groove portion that bends from the deepest part of the inlet groove portion in the axial direction of the retaining insertion hole and extends toward the first fixed portion.

11. A working device for a construction machine according to claim 7, wherein the pin bracket is attached to the arm using a bolt.

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