JP2008133690A - Attaching-detaching device of joint part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an attaching-detaching device of a joint part for reducing the number of part items, and easily installing a hydraulic cylinder, by enhancing installation strength to a boss of the hydraulic cylinder for protruding and retreating a joint part attaching-detaching pin from the boss. <P>SOLUTION: This attaching-detaching device has cylindrical two pins 4 built in the boss 12 fixed to one connecting part for constituting the joint part so as to be retractable from both ends and detachably fitted to the boss 12 of the other connecting part, and has a both-rod-shaped hydraulic cylinder 16 arranged in the boss 12, and connects a piston rod 39 of the hydraulic cylinder 16 to the pins 4, and has a manifold 17 fitted to an opening part 18 arranged on a side surface of the boss and fixedly installed in the boss 12 by a bolt. The hydraulic cylinder 16 is fixed to the boss 12 by fitting a tube 27 of the hydraulic cylinder 16 and the manifold 17 in a recess-projection engagement. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for detachably pin-jointing a joint portion of a multi-joint front by a hydraulic cylinder in a working machine such as a hydraulic excavator.

  In a working machine such as a hydraulic excavator, a structure in which joint portions are detachably connected for disassembly and transportation or for exchanging a work tool such as a bucket is employed. In order to efficiently perform the coupling and disassembly by this pin, a hydraulic cylinder is accommodated in a boss provided on one coupling part (bracket) constituting the joint part, and the other coupling is made by projecting and retracting the pin from both ends by the hydraulic cylinder. Connect to and disconnect from the boss of the bracket (bracket).

  In a conventional joint part attaching / detaching device, as described in Patent Document 1, the joint part attaching / detaching pin is formed in a cylindrical shape, and this joint part attaching / detaching pin is built in a boss so as to project and retract. The hydraulic cylinder tube is fixed to the boss with a fixing pin. In Patent Document 2, a piston is accommodated in a cylindrical pin for attaching and detaching a joint part, which is incorporated in a boss so as to be able to project and retract, and the cylindrical pin for attaching and detaching a joint part is also used as a cylinder and is accommodated in the cylindrical pin. The left and right pistons are connected by a common piston rod, and the central portion of the piston rod is fixed to the boss by a fixing pin.

  Moreover, in patent document 1, in the connection state of the joint part which protruded the pin for joint part attachment / detachment from the boss | hub, and fitted to the boss | hub of the other connection part, it is a radius from the other connection part to the pin for joint part attachment / detachment. To prevent the load applied in the direction from acting as a bending force on the piston rod of the hydraulic cylinder, a retaining ring is provided in the annular groove provided on the inner peripheral surface of the joint attaching / detaching pin and the annular groove provided on the outer periphery of the piston rod. When the retaining ring is attached by pressing the retaining ring with the tip of the bolt screwed in from the outer end of the joint attaching / detaching pin, and an external force is applied to the joint attaching / detaching pin. The retaining ring prevents the external force from being transmitted to the piston rod.

Japanese Patent No. 3747178 JP 2003-160949 A

  As described in Patent Documents 1 and 2, in the structure in which the central part of the tube of the hydraulic cylinder or the piston rod is fixed to the boss by a fixing pin, the axial direction of the joint attaching / detaching pin is in the connected state of the joint part. When this force is applied, the force in the axial direction must be received by the fixing pin, which may cause insufficient strength. Further, it is necessary to provide a plurality of fixing pins for fixing the tube or piston rod of the hydraulic cylinder, and there is a problem that the number of parts increases. Furthermore, there is a problem in that it takes time to connect the oil passage between the tube or piston rod of the hydraulic cylinder and the manifold for connecting to the external pipe, and the number of manufacturing steps is large.

  In addition, as described in Patent Document 1, the structure in which the retaining ring is positioned by a bolt from the outside complicates the structure, and the tip of the bolt is not visible from the outside, which makes maintenance difficult.

  Also, the pin stopper is bolted to the bracket so that the joint attachment / detachment pin does not come out unexpectedly, and the joint attachment / detachment pin is fixed to the pin stopper with the bolt. When the outer end surface of the pin for attaching / detaching the part is in a position where it is recessed from the outer surface of the bracket, when the bolt inserted through the hole of the pin stopper is screwed into the screw hole provided in the pin for attaching / detaching the joint, The bolt for attaching / detaching the joint portion is pulled outward by the bolt, and there is a risk that the hydraulic cylinder that projects and retracts the pin for attaching / detaching the joint portion may be damaged.

  In view of the above problems, the present invention increases the mounting strength of a hydraulic cylinder for projecting and retracting a pin for attaching and detaching a joint from the boss, reduces the number of parts, and facilitates mounting of the hydraulic cylinder. It is an object of the present invention to provide a joint part attaching / detaching device.

  Further, the present invention has a pin stopper for preventing the pin for joint attachment / detachment from coming out unexpectedly, and when the pin stopper is attached with a bolt, a tensile force acts on the hydraulic cylinder to cause damage. Another object of the present invention is to provide a joint attachment / detachment device that is configured so that there is no such a problem.

  In addition, the present invention provides a joint attachment / detachment device having a structure that can prevent the external force from acting on the piston rod when a radial external force is applied to the joint attachment / detachment pin. For other purposes.

The joint part attaching / detaching device according to claim 1 is a joint part attaching / detaching device for connecting the corresponding connecting parts of the front joint part of the work implement detachably with pins.
A boss fixed to one connecting portion constituting the joint portion;
Two cylindrical pins that are built into the boss so as to protrude and retract from both ends and are detachably fitted to the boss of the other connecting portion;
A tube that is provided in a boss fixed to the one connecting portion and on which the two cylindrical pins are slidably fitted;
The tube, two pistons provided in the tube, and two piston rods each having one end connected to each piston and the other end projecting from end plates at both ends of the tube. A double rod type hydraulic cylinder connected to the vicinity of the outer end of the pin;
The hydraulic oil is supplied to a bottom chamber formed between the two pistons and a rod chamber formed between the end plates at both ends of the tube and the piston, which are formed in the thick part of the tube. Oil passage,
A manifold fitted with an opening provided on a side surface of the boss and fixed to the boss with a bolt and having an oil passage communicating with the oil passage;
And a tube mounting portion that protrudes from the outer surface of the tube, is concavo-convexly fitted to the manifold, and is fixed to the manifold by a bolt.

The joint part attaching / detaching device according to claim 2 is the joint part attaching / detaching device according to claim 1,
The one connecting portion includes a pair of brackets on each of the left and right sides of the boss,
The bracket of the other connecting portion is fitted between each pair of brackets, and the pin is inserted into and removed from a boss provided on the bracket,
Of the pair of brackets, provided with a pin stopper to be fixed to the outer bracket with a bolt,
The pin stopper has a protrusion having a bolt insertion hole for inserting the pin stopper into the pin hole of the outer bracket to contact the outer end surface of the pin and fixing the pin,
The protruding width of the protruding portion is set to a width equal to or greater than a maximum manufacturing tolerance between the outer end surface of the pin and the outer surface of the outer bracket when the pin is extended to the maximum outside.

The joint attachment / detachment device according to claim 3 is the joint attachment / detachment device according to claim 1 or 2.
In the connecting portion of the pin with the piston rod, an annular portion formed inwardly projecting on the inner peripheral surface of the pin,
A piston rod ring located on the inner side of the annular portion, the coupling portion of the piston rod connected to the pin includes a fitting portion fitted with a gap between the inner peripheral surface of the annular portion. The piston rod and the pin are connected to each other by sandwiching the annular portion between the portion and a receiver bolted to the fitting portion of the piston rod.

  According to the first aspect of the present invention, the mounting portion of the hydraulic cylinder is mounted by being concavo-convexly fitted to the manifold fitted and fixed to the opening of the boss, so that the manifold can have the function of a fixing pin. This increases the mounting strength of the hydraulic cylinder. Further, since the fixing pin is not necessary, the number of parts can be reduced. Further, since the oil passage is automatically connected by fitting the manifold and the mounting portion of the hydraulic cylinder, assembly is facilitated.

  According to the second aspect of the present invention, the pin stopper is provided with the protruding portion, and the protruding portion is bolted to the pin stopper and fixed to the bracket in a state where the protruding portion is always in contact with the outer end surface of the cylindrical pin. Therefore, when attaching the pin stopper with the bolt, the pulling force does not act on the cylindrical pin, and the hydraulic cylinder is not damaged. Further, it is possible to prevent the hydraulic cylinder from being damaged due to forgetting or losing the shim, such as when using a shim instead of the protruding portion. Further, by adjusting the size of the protruding portion to the pin hole, it is easy to center when tightening the bolt, and the pin stopper can be easily attached.

  According to the invention of claim 3, the connecting portion of the piston rod with the pin for attaching / detaching the joint portion has a gap between the inner peripheral surface of the annular portion formed on the inner peripheral surface of the pin for attaching / detaching the joint portion. Therefore, the force acting in the radial direction on the joint attaching / detaching pin is prevented or reduced from acting on the piston rod. Further, since the annular portion is sandwiched between the ring fixed to the piston rod and the receiving member, the thrust of the piston rod can be reliably transmitted to the pin for attaching and detaching the joint portion. Moreover, since this connection part is visible from the outside, maintenance is easy. Further, the structure is simpler than the structure in which the retaining ring is fixed by a bolt that is screwed to the pin for attaching and detaching the joint portion.

  FIG. 1 is a side view showing a hydraulic excavator which is an example of a working machine to which the joint attaching / detaching device of the present invention is applied. In this hydraulic excavator, a boom 3 is attached to an upper swing body 2 installed on a lower traveling body 1 so that it can be raised and lowered by a boom cylinder 3a around a pin 4, and an arm around a pin 6 is attached to the tip of the boom 3 by an arm cylinder 5a. 5 is rotatably attached, and the bucket 10 is rotatably attached to the tip of the arm 5 around the pin 9 by a bucket cylinder 10a.

  FIG. 2 is a rear view showing an attaching / detaching device using a pin 4 for detachably attaching the boom 3 to the upper swing body 2. Reference numeral 3b denotes a boom foot configured as a connecting portion of the boom 3 with respect to the upper swing body 2, and reference numerals 11a and 11b and reference numerals 11c and 11d denote a pair of brackets, which constitute a connecting portion for the boom 3. Reference numeral 12 denotes a boss fixed by welding or a bolt 13 between the inner brackets 11a and 11c facing each other.

  FIG. 3 is a cross-sectional view showing the attachment / detachment device of this embodiment with the illustration of the boom 3 and the outer brackets 11b and 11d of FIG. 2 omitted, and the pins 4 being contracted. As shown in FIGS. 2 and 3, the pin 4 has a cylindrical shape and is built into the boss 12 so as to protrude and retract from both ends thereof. In this embodiment, the pin 4 is fitted from the boss 12 and the brackets 11a and 11c so as to protrude and retract, and is built in. The brackets 11a to 11d have pin holes 15 formed of bushes 14 for fitting the pins 4 (see FIG. 7).

  Reference numeral 16 denotes a hydraulic cylinder built in and fixed in the boss 12 for projecting and retracting the pin 4. A manifold 17 connects an external pipe (not shown) for supplying hydraulic oil to the hydraulic cylinder 16. The manifold 17 includes a fitting portion 19 that fits into an opening 18 provided in the boss 12, and a flange portion 20 that is provided outside the fitting portion 19. The manifold 17 is provided with oil passages 21 and 22 in the radial direction of the boss 12, and a pipe joint 23 is attached to the outer ends of the oil passages 21 and 22. In the manifold 17, the fitting portion 19 is fitted into the opening 18 provided in the boss 12, and the flange portion 20 is fitted into the concave portion 24 provided on the side surface of the boss 12, and is fixed to the boss 12 by the bolt 25. That is, the manifold 17 is fixed to the boss 12 by screwing the bolt 25 into the screw hole 26 provided in the boss 12 through the bolt insertion hole provided in the flange portion 20 and fastening.

  On the other hand, in the hydraulic cylinder 16, a large-diameter portion 29 is formed in the central portion in the axial direction of the tube 27, and an attachment portion 30 for fixing to the manifold 17 is formed in the large-diameter portion 29. In this example, the mounting portion 30 is formed as a concave portion for fitting the fitting portion 19 of the manifold 17. Instead, a convex portion is formed on the mounting portion 30, and the convex portion is formed on the fitting portion 19 of the manifold 17. You may form the recessed part fitted to a part. The tube 27 is fixed to the manifold 17 by fitting the recessed portion of the mounting portion 30 of the tube 27 into the fitting portion 19 of the manifold 17 and passing the bolt 31 through the bolt insertion hole 32 provided in the manifold 17 to the mounting portion 30. It is carried out by screwing into the provided screw hole 33 and fastening. In this state where the tube 27 is fixed to the manifold 17, the oil passages 34 and 35 provided in the radial direction in the tube 27 communicate with the oil passages 21 and 22 of the manifold 17, respectively.

  The hydraulic cylinder 16 is a double rod type hydraulic cylinder in which two pistons 37 are built in, and piston rods 39 each having an inner end coupled to each piston 37 project from both ends of the tube 27. Reference numeral 40 denotes an end plate fixed by bolts 38 at both ends of the tube 27. A rod chamber 41 is formed between the end plate 40 and the piston 37, and a bottom chamber 42 is provided between the two pistons 37, 37. Is formed. The inner end of one oil passage 34 provided in the tube 27 in the radial direction communicates with the bottom chamber 42. The other oil passage 35 includes an oil passage 43 provided in the axial direction in the thick portion of the tube 27 and an oil passage 44 provided in the radial direction so as to communicate with the oil passage 43 (see FIG. 7). Communicate with.

  As shown in FIGS. 7 and 8, the outer end of the pin 4 is connected to the tip of the piston rod 39 with the following structure. That is, an annular portion 45 formed inwardly projecting on the inner peripheral surface of the pin 4 is provided at the connecting portion of the pin 4 with the piston rod 39. On the other hand, the connecting portion 46 of the piston rod 39 with the pin 4 includes a fitting portion 47 fitted with a gap g between the inner peripheral surface of the annular portion 45 and is more axial than the annular portion 45. The annular portion 45 is sandwiched between a ring portion 48 provided integrally with the piston rod 39 on the inner side of the piston rod 39 and a disc-shaped receiving member 50 fixed to the piston rod 39 with bolts 49 on the outer side in the axial direction of the annular portion 45. Then, the piston rod 39 and the pin 4 are connected. With this structure, even if a radial force is applied to the pin 4, the pin 4 can move in the radial direction relative to the piston rod 39, and no bending force is applied to the piston rod 39.

  In FIG. 7, reference numeral 51 denotes a hydraulic cylinder 16 that restricts the movement (retraction) of the pin 4 by the force generated in the axial direction of the pin 4 when the excavator is turned (stopped), and the pin 4 is moved away from the boom foot 3b. It is a pin stopper that prevents it from coming out. As shown in FIG. 9, the pin stopper 51 has a projecting portion 52 on a surface facing the outer end surface of the pin 4 and a mounting bolt insertion hole 53. The pin stopper 51 is provided in the pin 4 by inserting the protruding portion 52 into the pin hole 15 of the outer brackets 11 b and 11 d to contact the outer end surface of the pin 4 and inserting the bolt 54 through the bolt insertion hole 53. The pin 4 is fixed by screwing into the screw hole 55 and fastening.

  A receiving seat 56 is welded to the outer surfaces of the brackets 11b and 11d, and a screw hole 57 is provided in the receiving seat 56. Reference numeral 59 denotes a pressing plate for pressing the pin stopper 51. Two pressing plates 59 are applied to the pin stopper 51, and bolts 61 are inserted into two bolt insertion holes 60 provided in each pressing plate 59. By screwing into the screw hole 57 and fastening, the pin stopper 51 is detached from the brackets 11b and 11d, and the pin 4 comes out from the state between the brackets 11a and 11b and 11c and 11d to the outside or inside in the axial direction. To prevent.

  Here, the protrusion width t (see FIG. 9) of the protrusion 52 of the pin stopper 51 is unavoidable in manufacturing the width T (see FIG. 7) between the outer end of the pin 4 and the outer surfaces of the brackets 11b and 11d. Set the maximum tolerance T0 or more (t ≧ T0).

  In this joint portion attaching / detaching device, the fitting portion 19 of the manifold 17 is fitted to the opening portion 18 of the boss 12 and fixed by the bolt 25, and the fitting portion 19 of the manifold 17 is unevenly formed on the attaching portion 30 of the tube 27. The tube 27 is fixed to the manifold 17 with the bolt 31.

  As described above, in the present embodiment, the attachment portion 30 of the hydraulic cylinder 16 is attached to the manifold 17 which is fitted and fixed to the opening 18 of the boss 12 so as to be attached to the manifold 17. Therefore, the mounting strength of the hydraulic cylinder 16 is greater than that of the fixing pin. Further, since no fixing pin is required, the number of parts can be reduced. Further, since the oil passages 21 and 34, 22 and 35 automatically communicate with each other by fitting the manifold 17 and the mounting portion 30 of the hydraulic cylinder 16, assembly is facilitated.

  In this embodiment, when the boom foot 3b of the boom 3 is connected to the brackets 11a to 11d and the boom 3 is attached, the connecting operation is performed according to the following procedure. The left and right boom foot 3b is inserted between the brackets 11a and 11b and 11c and 11d, respectively, to align the pin holes 15 of these brackets with the pin holes 15 of the boom foot 3b. Then, the hydraulic cylinder 16 is extended to move the pin 4 outward in the axial direction, and the pin 4 is inserted into the pin hole 15 of the boom foot 3 and the pin holes 15 of the brackets 11b and 11d. Then, the protruding portion 52 of the pin stopper 51 is inserted into the pin hole 15 of the brackets 11b and 11d, and the bolt 54 is inserted into the bolt insertion hole 53 of the pin stopper 51 and screwed into the screw hole 55 provided in the pin 4 and fastened. By doing so, the pin stopper 51 is fixed to the pin 4. After that, the pressing plate 59 is applied to the pin stopper 51, the bolt 61 is inserted into the bolt insertion hole 60 of the pressing plate 59, and is screwed into the screw hole 57 of the receiving seat 56 welded to the brackets 11b and 11d. The pin stopper 51 is pressed by the pressing plate 59 and fixed to the brackets 11b and 11d.

  Here, as described with reference to FIGS. 7 and 9, the protrusion width t of the protrusion 52 of the pin stopper 51 is set to be equal to or greater than the maximum manufacturing tolerance T0 between the outer end surface of the pin 4 and the outer surfaces of the brackets 11b and 11d (t Since ≧ T0), the pin stopper 51 is fixed to the pin 4 and the brackets 11b and 11d with bolts 54 and 61 in a state where the protruding portion 52 of the pin stopper 51 is in contact with the outer end surface of the pin 4.

  Conventionally, when a gap T is generated between the pin 4 and the brackets 11b and 11d as shown in FIG. 11, when the pin stopper 51 is fixed to the pin 4 by the bolt 54, the bolt T is fastened by the presence of the gap T. There is a possibility that the force acts as a tension on the pin 4 and damages the hydraulic cylinder 16, but in the present embodiment, the pin stopper 51 is connected to the pin 4 and the brackets 11b and 11d with the relationship of t ≧ T0. Therefore, when the pin stopper 51 is attached by the bolt 54, a clearance T1 is formed, so that no pulling force acts on the pin 4 and the hydraulic cylinder 16 is not damaged. Further, it is possible to prevent the hydraulic cylinder 16 from being damaged due to forgetting or losing the shim, such as when using a shim instead of the protruding portion 52. Further, by adjusting the size of the projecting portion 52 to the pin hole, the centering is easy when the bolt is tightened, and the pin stopper 51 is easily attached.

  In the present embodiment, as shown in FIGS. 7 and 8, a gap g is formed between the inner peripheral surface of the annular portion 45 provided on the pin 4 and the outer peripheral surface of the fitting portion 47 of the piston rod 39. Since the pin 4 and the piston rod 39 are connected to each other, there is a manufacturing axial misalignment between the pin holes 15 of the brackets 11a and 11b, 11c and 11d, or due to the action of an external force. Even if the axial center of the piston rod 39 is displaced, the bending force of the pin 4 does not act on the piston rod 39, preventing the hydraulic cylinder 16 from being damaged and allowing the hydraulic cylinder 16 to smoothly extend and contract. Thus, the smooth attaching / detaching operation of the pin 4 is ensured.

  Further, since the annular portion 45 is sandwiched between the ring portion 48 that is the convex portion of the piston rod 39 and the receiving member 50, the thrust of the piston rod 39 can be reliably transmitted to the pin 4. Further, the pin stopper 51 is detachable, and if the pin stopper 51 is removed, the connecting portion 46 can be seen from the outside, so that maintenance is easy. Further, the structure is simple compared to the structure in which the retaining ring is fixed by a bolt that is screwed onto the pin 4.

  12 and 13 show another embodiment of the present invention, which shows a detachable structure of the pin 9 for attaching the bucket 10 shown in FIG. In FIG. 13, the right pin 9 shows a state of being immersed in the boss 12, and the left side shows a state in which the pin 9 protrudes, but actually the left and right pins 9 protrude and contract at the same time. In FIGS. 12 and 13, reference numeral 62 denotes a bracket provided on the back surface of the bucket 10 on the attachment side to the arm 5, and these brackets 62 are formed from two parallel plates welded to the attachment portion with respect to the arm 5 of the bucket 10. Become. 63 is a boss welded to each bracket 62. The structure of the pin 9 is the same as that of the pin 4 of the above embodiment, and the structure for attaching the hydraulic cylinder 16 to the manifold 17, the structure for attaching the manifold 17 to the boss 12, and the structure of the connecting portion 46 for the pin 9 of the piston rod 39. Is the same as in the previous embodiment. This embodiment differs from the previous embodiment in that the pin 9 is cantilevered when the pin 9 is inserted into the pin hole 64 of the boss 63 provided in the bracket 62 as shown on the left side of FIG. This is a point supported by the boss 12.

  In such a support structure of the pin 9, the external force acting on the bracket 61 from the bucket 10 makes it easy for the pin 9 to be inclined in the radial direction with respect to the piston rod 39. In this case, FIG. The structure of the connecting portion 46 shown, that is, the structure in which the gap g is formed between the annular portion 45 and the fitting portion 47 prevents damage to the hydraulic cylinder 16 described above, guarantees the attaching / detaching operation of the pin 9, and maintenance. The effect of facilitating inspection can be obtained. Further, the above-described effect can be obtained by the mounting structure by fitting the concave and convex portions of the mounting portion 30 of the hydraulic cylinder 16 to the manifold 17.

It is a side view which shows the hydraulic shovel which is an example of the working machine to which the attachment / detachment apparatus of the joint part by this invention is applied. FIG. 2 is a rear view showing an embodiment of the joint attaching / detaching device according to the present invention by taking as an example a connecting portion for an upper swing body of a boom foot portion of the excavator of FIG. 1. It is sectional drawing which shows the attachment / detachment apparatus of FIG. 2 in the immersion state of a pin. FIG. 4 is a partially enlarged view of FIG. 3. FIG. 5 is a plan view of FIG. 4. It is EE sectional drawing of FIG. It is sectional drawing which shows the attachment / detachment apparatus of the joint part of FIG. 2 in the protrusion state of a pin. It is the elements on larger scale of FIG. (A) is a perspective view of the pin stopper of this Embodiment, (B) is the side view. FIG. 10 is an end view of FIG. 9. It is sectional drawing which shows the attachment structure of the conventional pin stopper. It is a top view of the bucket of FIG. It is sectional drawing which shows the attachment / detachment apparatus of other embodiment of this invention with respect to the arm of the bucket of FIG.

Explanation of symbols

1: Lower traveling body, 2: Upper rotating body, 3: Boom, 3a: Boom cylinder, 3b: Boom foot, 4: Pin, 5: Arm, 5a: Arm cylinder, 6: Pin, 7: Arm, 9: Pin, 10: bucket, 10a: bucket cylinder, 11a, 11b, 11c, 11d: bracket, 12: boss, 13: boss, 14: bush, 15: pin hole, 16: hydraulic cylinder, 17: manifold, 18: opening, 19: fitting part, 20: collar part, 21, 22: oil passage, 23: joint, 24: recessed part, 25: bolt, 26: screw hole, 27: tube, 29: large diameter part, 30: mounting part, 31: Bolt, 32: Bolt insertion hole, 33: Screw hole, 34, 35: Oil passage, 37: Piston, 38: Bolt, 39: Piston rod, 40: End plate, 41: Rod chamber, 42: Bottom chamber, 43, 4 : Oil passage, 45: annular part, 46: coupling part, 47: fitting part, 48: ring part, 49: bolt, 50: receiving tool, 51: pin stopper, 52: protruding part, 53: bolt insertion hole, 54: Bolt, 55: Screw hole, 56: Seat, 57: Screw hole, 59: Holding plate, 60: Bolt insertion hole, 61: Bolt, 62: Boss, 63: Pin hole

Claims (3)

In the attachment / detachment device for the joint part that removably connects the corresponding connection parts of the front joint part of the work machine with pins,
A boss fixed to one connecting portion constituting the joint portion;
Two cylindrical pins that are built into the boss so as to protrude and retract from both ends and are detachably fitted to the boss of the other connecting portion;
A tube that is provided in a boss fixed to the one connecting portion and on which the two cylindrical pins are slidably fitted;
The tube, two pistons provided in the tube, and two piston rods each having one end connected to each piston and the other end projecting from end plates at both ends of the tube. A double rod type hydraulic cylinder connected to the vicinity of the outer end of the pin;
The hydraulic oil is supplied to a bottom chamber formed between the two pistons and a rod chamber formed between the end plates at both ends of the tube and the piston, which are formed in the thick part of the tube. Oil passage,
A manifold fitted with an opening provided on a side surface of the boss and fixed to the boss with a bolt and having an oil passage communicating with the oil passage;
A joint attaching / detaching device comprising: a tube attaching portion that protrudes from an outer surface of the tube, is concavo-convexly fitted to the manifold, and is fixed to the manifold by a bolt. The joint part attaching / detaching device according to claim 1,
The one connecting portion includes a pair of brackets on each of the left and right sides of the boss,
The bracket of the other connecting portion is fitted between each pair of brackets, and the pin is inserted into and removed from a boss provided on the bracket,
Of the pair of brackets, provided with a pin stopper to be fixed to the outer bracket with a bolt,
The pin stopper has a protrusion having a bolt insertion hole for inserting the pin stopper into the pin hole of the outer bracket to contact the outer end surface of the pin and fixing the pin,
The protrusion width of the protrusion is set to a width equal to or greater than the maximum manufacturing tolerance between the outer end surface of the pin and the outer surface of the outer bracket when the pin is extended to the maximum outside. Detachable device. In the joint part attachment / detachment device according to claim 1 or 2,
In the connecting portion of the pin with the piston rod, an annular portion formed inwardly projecting on the inner peripheral surface of the pin,
A piston rod ring located on the inner side of the annular portion, the coupling portion of the piston rod connected to the pin includes a fitting portion fitted with a gap between the inner peripheral surface of the annular portion. The joint part attaching / detaching device characterized in that the piston rod and the pin are connected by sandwiching the annular part between the part and a receiving member bolted to the fitting part of the piston rod.

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