JP2022054283A - Construction machine pin coupling device - Google Patents

Abstract

To improve workability when retaining a pin that connects two members.SOLUTION: A connecting pin 17 that pin-connects a lower boom 5 and an upper boom 6 includes a pin body portion 17A that is inserted into a pin insertion hole 5A and a pin insertion hole 6A, a flange portion 17B provided at an end of a pin body portion 17A protruding from an outer surface 5B of the lower boom 5, and a concave groove portion 17C provided on the outer peripheral surface of the pin body portion 17A adjacent to the flange portion 17B. Between the flange portion 17B and the lower boom 5, provided is a stopper 18 that becomes engaged with the concave groove portion 17C so as to be rotatable around the axis of the connecting pin 17 and sandwiched between the peripheral edge portion of the pin insertion hole 5A and the flange portion 17B to retain the connecting pin 17 in the axial direction. The outer surface 5B of the lower boom 5 is provided with a guide member 22 for holding the stopper 18 in a state of being engaged with the concave groove portion 17C.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a pin coupling device for construction machinery, which is suitably used for coupling two members such as a plurality of booms mounted on a hydraulic excavator using a pin.

When dismantling a building with a large ground height, a hydraulic excavator equipped with a multi-boom work device that combines multiple booms is usually used. The multi-boom hydraulic excavator frequently moves between work sites and is frequently transported to the work site by a transport vehicle such as a trailer. In a multi-boom hydraulic excavator, a plurality of booms are connected by a pin. Therefore, for example, when loading on a transport vehicle, the booms are divided by pulling out the pins between the plurality of coupled booms, and when the dismantling work is performed, the plurality of divided booms are connected by using the pins.

In a hydraulic excavator with a multi-boom specification, a hydraulic pin attachment / detachment mechanism has been proposed in order to easily connect and divide a plurality of booms. With this pin attachment / detachment mechanism, two connecting pins can be simultaneously inserted / removed from the pin insertion holes of a plurality of booms using a hydraulic cylinder (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-230113

However, in order to prevent the connecting pin from coming out of the pin insertion hole in the axial direction after pin-coupling between a plurality of booms using a connecting pin, for example, a stopper having a larger diameter than the pin insertion hole, such as a bolt, is used. It must be attached to the end of the connecting pin using fasteners. As described above, in the prior art, there is a problem that a fastener and a tool are required for the work for preventing the connecting pin connecting the plurality of booms from coming off, and a large amount of labor is consumed.

An object of an embodiment of the present invention is to provide a pin coupling device for a construction machine capable of enhancing workability when retaining a pin connecting two members.

In one embodiment of the present invention, in order to pin-connect the first member and the second member constituting the working device of the construction machine, the first pin insertion hole provided in the first member and the second member are provided. In a pin coupling device of a construction machine for disconnecting and retaining a connecting pin to be inserted into a second pin insertion hole, the connecting pin is a pin inserted into the first pin insertion hole and the second pin insertion hole. The main body, the flange provided at the end of the pin main body protruding from the outer surface of the first member in a state of being inserted into the first pin insertion hole and the second pin insertion hole, and the said. A concave groove portion provided on the outer peripheral surface of the pin main body portion adjacent to the flange portion and having an outer diameter smaller than that of the pin main body portion is provided, and the concave groove portion is provided between the flange portion and the first member. The connecting pin is axially pulled out by engaging rotatably with the outer peripheral surface of the connecting pin around the axis center of the connecting pin and being sandwiched between the peripheral edge portion of the first pin insertion hole and the flange portion. A stopper for stopping is provided, and a guide member for holding the stopper in a state of being engaged with the outer peripheral surface of the concave groove portion is provided on the outer surface of the first member.

According to one embodiment of the present invention, a stopper is engaged with the concave groove portion of the connecting pin from the outside in the radial direction, and the stopper is rotated around the axis center of the connecting pin along the guide member. As a result, the stopper is held in a state of being sandwiched between the peripheral edge portion of the first pin insertion hole and the flange portion of the connecting pin without using a fastener or the like, and the connecting pin can be retracted in the axial direction. ..

It is a left side view which shows the hydraulic excavator of the multi-boom specification to which the pin coupling apparatus by embodiment of this invention is applied. It is the left side view which shows the lower boom alone. It is an enlarged view of the hydraulic pin attachment / detachment mechanism mounted on the lower boom as seen from the direction of arrow III-III in FIG. It is an exploded perspective view which shows the pin coupling apparatus by embodiment. It is a left side view which shows the state which the connecting pin was inserted into the pin insertion hole of the lower boom. It is a front view of the state where the connecting pin is inserted into the pin insertion hole of the lower boom as seen from the direction of arrow VI-VI in FIG. It is a left side view which shows the state which the stopper is engaged with the concave groove part of a connecting pin. It is a front view which looked at the state which the stopper was engaged with the concave groove part of the connecting pin from the direction of arrow VIII-VIII in FIG. It is a left side view which shows the state which the stopper is stopped rotating with respect to a guide member. It is a front view which looked at the state which stopped the stopper with respect to a guide member from the direction of arrow XX in FIG. It is a left side view which shows the state which the boom cylinder of a hydraulic excavator is fully extended. It is a left side view showing the positional relationship between the position of the center of gravity of the stopper and the protrusion when the boom cylinder of the hydraulic excavator is fully reduced. It is a left side view showing the positional relationship between the position of the center of gravity of the stopper and the protrusion when the boom cylinder of the hydraulic excavator is fully extended.

Hereinafter, the case where the pin coupling device of the construction machine according to the embodiment of the present invention is applied to a hydraulic excavator having a multi-boom specification will be described as an example, and will be described in detail with reference to FIGS. 1 to 13. In the embodiment, the traveling direction of the hydraulic excavator is defined as the front-rear direction, and the direction orthogonal to the traveling direction of the hydraulic excavator is defined as the left-right direction.

In FIG. 1, the multi-boom hydraulic excavator 1 includes a crawler-type lower traveling body 2 capable of self-propelling in the front-rear direction, an upper turning body 3 mounted on the lower traveling body 2 so as to be able to turn, and an upper turning body. It is configured to include a multi-boom type working device 4 provided on the front side of the 3. The lower traveling body 2 and the upper turning body 3 constitute a vehicle body of the hydraulic excavator 1. The hydraulic excavator 1 travels on the work site by the lower traveling body 2, and moves the work device 4 up and down while turning the upper turning body 3, thereby performing demolition work of a building, excavation work of earth and sand, and the like.

The working device 4 includes a lower boom 5 rotatably attached to the front side of the upper swing body 3, an upper boom 6 pin-coupled to the tip of the lower boom 5, and an arm 7 rotatably attached to the tip of the upper boom 6. And a bucket 8 rotatably attached to the tip of the arm 7. Further, the working device 4 has a boom cylinder 9 for driving the lower boom 5, an arm cylinder 10 for driving the arm 7, and a bucket cylinder 11 for driving the bucket 8.

The hydraulic excavator 1 is transported to the work site in a state of being loaded on a transport vehicle (not shown) such as a trailer. When transporting the hydraulic excavator 1, normally, the vehicle body to which the lower boom 5 is attached and the working device 4 (beyond the upper boom 6) are separately loaded on the transport vehicle in a state where the upper boom 6 is removed from the lower boom 5. Then, at the work site, the upper boom 6 is pin-coupled to the tip of the lower boom 5. Therefore, in the present embodiment, the pin attachment / detachment mechanism 12 shown in FIG. 3 and the pin coupling device 16 shown in FIGS. 4 to 10 are provided on the tip end side of the lower boom 5, and the lower boom 5 and the upper boom 6 are pin-coupled. Workability when doing is improved.

Here, the pin attachment / detachment mechanism 12 attaches / detaches a pair of left and right connecting pins 17 to be described later to the lower boom 5 as the first member mounted on the hydraulic excavator 1 and the upper boom 6 as the second member. .. That is, the pin attachment / detachment mechanism 12 includes left and right connecting pins 17, left and right levers 13, hydraulic cylinders 14, and connecting links 15.

The left and right connecting pins 17 are inserted into the pin insertion hole 5A provided in the lower boom 5 and the pin insertion hole 6A provided in the upper boom 6, thereby pin-coupling the lower boom 5 and the upper boom 6. One end 13A of each of the left and right levers 13 is rotatably attached to the connecting pin 17. The hydraulic cylinder 14 is attached to the other end 13B of the left and right levers 13. Both ends of the connecting link 15 in the length direction are connected to the intermediate portion in the length direction of the left and right levers 13, and the left and right levers 13 are connected to each other.

Therefore, when the hydraulic cylinder 14 is reduced, one ends 13A of the left and right levers 13 move in a direction away from each other with the connection portion with the connecting link 15 as a fulcrum. As a result, the left and right connecting pins 17 are inserted into the pin insertion hole 5A of the lower boom 5 and the pin insertion hole 6A of the upper boom 6, and the lower boom 5 and the upper boom 6 are pin-coupled via the connecting pin 17. On the other hand, when the hydraulic cylinder 14 is extended, one ends 13A of the left and right levers 13 move in a direction approaching each other with the connection portion with the connecting link 15 as a fulcrum. As a result, the left and right connecting pins 17 are separated from the pin insertion holes 6A of the upper boom 6, and the lower boom 5 and the upper boom 6 are separated from each other.

As described above, the workability when the lower boom 5 and the upper boom 6 are connected by the pin attachment / detachment mechanism 12 having the hydraulic cylinder 14 by using the connecting pin 17, and the connecting pin 17 from the pin connecting portion between the lower boom 5 and the upper boom 6 It is possible to improve workability when the lower boom 5 and the upper boom 6 are separated by disengaging the cylinder.

Next, the pin coupling device 16 according to the present embodiment will be described. The pin coupling device 16 couples the lower boom 5 and the upper boom 6 via the connecting pin 17, and holds the connecting pin 17 in a retaining state. The pin coupling device 16 includes left and right connecting pins 17 for rotatably pin-coupling the lower boom 5 as the first member and the upper boom 6 as the second member, a stopper 18, and a guide member 22. ing. Since the pin coupling device 16 including the left and right connecting pins 17 has the same configuration, the pin coupling device 16 including the left connecting pin 17 will be described below.

The connecting pin 17 is formed in a columnar shape as a whole. As shown in FIG. 3, one end 13A of the lever 13 constituting the pin attachment / detachment mechanism 12 is attached to the base end side of the connecting pin 17. The connecting pin 17 has a pin main body portion 17A, a flange portion 17B, and a concave groove portion 17C. The pin body 17A of the connecting pin 17 is inserted into the pin insertion hole 5A of the lower boom 5 as the first pin insertion hole and the pin insertion hole 6A of the upper boom 6 as the second pin insertion hole.

The flange portion 17B is provided at the tip of the connecting pin 17, and the pin body portion 17A is inserted from the pin insertion hole 5A of the lower boom 5 and the pin insertion hole 6A of the upper boom 6 from the outer surface 5B of the lower boom 5. Protrude. The concave groove portion 17C is provided on the outer peripheral surface of the pin main body portion 17A adjacent to the flange portion 17B. The concave groove portion 17C is formed by notching the outer peripheral surface of the pin main body portion 17A over the entire circumference, and the outer diameter dimension of the concave groove portion 17C is smaller than the outer diameter dimension of the pin main body portion 17A. The inner peripheral edge 18A of the stopper 18 engages with the concave groove portion 17C.

The stopper 18 is rotatably engaged with the outer peripheral surface of the concave groove portion 17C provided on the connecting pin 17 about the axial center of the connecting pin 17. As shown in FIGS. 4 and 5, the stopper 18 is formed as a semicircular plate and has a plate thickness that can be engaged with the concave groove portion 17C of the connecting pin 17. The inner peripheral edge 18A of the stopper 18 is formed in a semicircular shape having a diameter equal to the radius from the axial center of the connecting pin 17 to the outer peripheral surface of the concave groove portion 17C.

As shown in FIG. 7, the stopper 18 engages with the concave groove portion 17C of the connecting pin 17 from the outside in the radial direction, and is between the peripheral edge portion of the pin insertion hole 5A of the lower boom 5 and the flange portion 17B of the connecting pin 17. By being sandwiched, the connecting pin 17 is prevented from coming off in the axial direction with respect to the pin insertion hole 5A of the lower boom 5. On the other hand, the outer peripheral edge 18B of the stopper 18 has a diameter dimension equal to that of the inner peripheral surface 22A of the guide member 22. As shown in FIG. 7, the stopper 18 is rotatable about the axis center of the connecting pin 17 in a state where the outer peripheral edge 18B is aligned (contacted) with the inner peripheral surface 22A of the guide member 22. It has become.

A handle 19, a ring pin mounting shaft 20, and a protrusion 21 are provided on the outer surface 18C of the stopper 18 opposite to the lower boom 5. The handle 19 is formed in an inverted U shape using a bar or the like, and both ends of the handle 19 are fixed at equal positions from the center of gravity G (see FIG. 12) of the stopper 18. The handle 19 is for the operator to rotate the stopper 18 around the connecting pin 17 when the connecting pin 17 is attached to and detached from the lower boom 5 and the upper boom 6.

The ring pin mounting shaft 20 is provided at the center of the stopper 18 in the length direction (circumferential direction), and projects from the outer surface 18C of the stopper 18 to the side opposite to the lower boom 5. A pin hole 20A penetrating in the radial direction is formed on the protruding end side of the ring pin mounting shaft 20, and a ring pin 25 described later is inserted into the pin hole 20A.

The protrusion 21 is provided on one end side of the stopper 18 in the length direction. The protrusion 21 is formed of a columnar shaft, and protrudes from the outer surface 18C of the stopper 18 to the side opposite to the lower boom 5 in a state where the stopper 18 is engaged with the concave groove portion 17C of the connecting pin 17. As shown in FIG. 9, when the stopper 18 engaged with the concave groove portion 17C of the connecting pin 17 is rotated around the axis center of the connecting pin 17 along the guide member 22, the protrusion 21 is formed. It abuts on the rotation limiting portion 23 of the guide member 22. This limits the range in which the stopper 18 can rotate.

The guide member 22 is provided on the outer surface 5B so as to surround the pin insertion hole 5A of the lower boom 5. The guide member 22 is formed of a semicircular frame centered on the axis center of the connecting pin 17, and is fixed to the outer surface 5B of the lower boom 5 concentrically with the connecting pin 17 by means such as welding. The inner peripheral surface 22A of the guide member 22 has a diameter dimension equal to that of the outer peripheral edge 18B of the stopper 18. Therefore, as shown in FIG. 7, the stopper 18 is connected in a state where the inner peripheral edge 18A is engaged with the concave groove portion 17C of the connecting pin 17 and the outer peripheral edge 18B is engaged with the inner peripheral surface 22A of the guide member 22. It rotates around the center of the axis of the pin 17 in the direction of arrow A. That is, the guide member 22 holds the stopper 18 in a state of being engaged with the concave groove portion 17C of the connecting pin 17.

The guide member 22 is provided with a rotation limiting portion 23 located at one end in the length direction (circumferential direction) and a pin receiving portion 24 located at the center portion in the length direction. The rotation limiting portion 23 projects radially inward (on the connecting pin 17 side) from one end in the length direction of the guide member 22. A gap 23A through which the stopper 18 can pass is formed between the rotation limiting portion 23 and the outer surface 5B of the lower boom 5. As a result, when the stopper 18 is rotated around the axis of the connecting pin 17 along the guide member 22 in a state where the inner peripheral edge 18A of the stopper 18 is engaged with the concave groove portion 17C of the connecting pin 17, FIG. At the indicated position, the protrusion 21 of the stopper 18 comes into contact with the rotation limiting portion 23. This makes it possible to limit the range in which the stopper 18 rotates.

The pin receiving portion 24 is provided at the central portion of the guide member 22 in the length direction. Two notched grooves 22B are formed in the central portion of the guide member 22 in the length direction from the protruding end toward the outer surface 5B of the lower boom 5, and a pin receiving portion 24 is formed between these two notched grooves 22B. Has been done. A pin hole 24A is formed in the pin receiving portion 24, and as shown in FIG. 9, when the protrusion 21 of the stopper 18 comes into contact with the rotation limiting portion 23, the ring pin mounting shaft attached to the stopper 18 is attached. The pin holes 20A of 20 and the pin holes 24A of the pin receiving portion 24 are arranged concentrically.

The ring pin 25 as a detent member is provided between the ring pin mounting shaft 20 of the stopper 18 and the pin receiving portion 24 of the guide member 22. As shown in FIGS. 4 and 9, the ring pin 25 has a rotation stop pin 25A inserted through the pin hole 20A of the ring pin mounting shaft 20 and the pin hole 24A of the pin receiving portion 24, and both ends of the rotation stop pin 25A. It is composed of a rectangular ring 25B to which the ring 25B is attached. The ring 25B is attached to the detent pin 25A at a position where both ends thereof are separated from each other to generate a twisting force, and the ring 25B is pressed against the outer peripheral surface of the detent pin 25A with an appropriate force by this twisting force.

As shown in FIG. 9, in a state where the protrusion 21 of the stopper 18 is in contact with the rotation limiting portion 23 of the guide member 22, the rotation stop pin 25A of the ring pin 25 is the pin hole 20A of the ring pin mounting shaft 20. And the pin hole 24A of the pin receiving portion 24. At this time, the ring 25B is pressed against the outer peripheral surface of the rotation stopper pin 25A protruding from the pin receiving portion 24 by its own twisting force while being housed in the notch groove 22B of the guide member 22. As a result, the rotation of the stopper 18 about the axis center of the connecting pin 17 is blocked by the ring pin 25, and the stopper 18 is placed at a position where the protrusion 21 abuts on the rotation limiting portion 23 of the guide member 22. Positioned.

Here, the lower boom 5 of the hydraulic excavator 1 has a fully lowered posture (posture of FIG. 1) when the boom cylinder 9 is fully retracted and a raised posture (posture of FIG. 11) when the boom cylinder 9 is fully extended. Rotate between. When the lower boom 5 is in the lowest position, the stopper 18 and the guide member 22 are in the positional relationship shown in FIG. 12, and when the lower boom 5 is in the highest position, the stopper 18 and the guide member 22 are shown in FIG. It becomes a positional relationship. That is, in FIGS. 12 and 13, assuming that the vertical line passing through the axis center of the connecting pin 17 is LL, the center of gravity G of the stopper 18 is always the vertical line LL over the entire movable range of the lower boom 5. It is located behind the plumb bob.

As a result, while the lower boom 5 rotates between the lowest position and the highest position (within the movable range), the stopper 18 has a direction in which the protrusion 21 abuts on the rotation limiting portion 23 of the guide member 22 due to its own weight. Is always urged to. Therefore, even if the ring pin 25 is separated from the ring pin mounting shaft 20 of the stopper 18 and the pin receiving portion 24 of the guide member 22, the stopper 18 abuts the protrusion 21 on the rotation limiting portion 23 due to its own weight. Hold the position where it was made. As a result, the stopper 18 can be reliably prevented from being disconnected from the connecting pin 17.

The pin coupling device 16 according to the present embodiment has the above-described configuration, and the work of coupling the lower boom 5 and the upper boom 6 using the connecting pin 17 will be described below.

First, as shown in FIG. 3, the left and right connecting pins 17 are inserted through the pin insertion hole 5A of the lower boom 5 and the pin insertion hole 6A of the upper boom 6 by using the pin attachment / detachment mechanism 12. As a result, the upper boom 6 is pin-coupled to the tip of the lower boom 5.

Next, the pin coupling device 16 is used to perform an operation of axially disconnecting and retaining the connecting pin 17 with respect to the lower boom 5. First, as shown in FIGS. 5 and 6, the inner peripheral edge 18A of the stopper 18 is engaged with the concave groove portion 17C of the connecting pin 17 protruding from the outer surface 5B of the lower boom 5 from the outside in the radial direction. At this time, as shown in FIGS. 7 and 8, the inner peripheral edge 18A of the stopper 18 abuts on the concave groove portion 17C of the connecting pin 17, and the outer peripheral edge 18B of the stopper 18 abuts on the inner peripheral surface 22A of the guide member 22. As a result, the stopper 18 is held in a state of being engaged with the concave groove portion 17C of the connecting pin 17 by the guide member 22, and is between the peripheral edge portion of the pin insertion hole 5A of the lower boom 5 and the flange portion 17B of the connecting pin 17. It is sandwiched between. As a result, the connecting pin 17 can be prevented from coming off in the axial direction with respect to the pin insertion hole 5A of the lower boom 5.

In this state, the handle 19 provided on the outer surface 18C of the stopper 18 is gripped, and the stopper 18 is rotated in the arrow A direction (clockwise) about the axis center of the connecting pin 17. As a result, as shown in FIGS. 9 and 10, the stopper 18 rotates along the inner peripheral surface 22A of the guide member 22 to the position where the protrusion 21 abuts on the rotation limiting portion 23 of the guide member 22. .. Then, when the protrusion 21 of the stopper 18 comes into contact with the rotation limiting portion 23 of the guide member 22 and the rotation of the stopper 18 is stopped, the pin hole of the ring pin mounting shaft 20 attached to the stopper 18 is stopped. 20A and the pin hole 24A of the pin receiving portion 24 provided in the guide member 22 are arranged concentrically.

In this way, with the protrusion 21 of the stopper 18 in contact with the rotation limiting portion 23 of the guide member 22, the rotation stop pin 25A of the ring pin 25 is pinned to the pin hole 20A of the ring pin mounting shaft 20. It is inserted through the pin hole 24A of the receiving portion 24. At this time, the ring 25B is pressed against the outer peripheral surface of the rotation stopper pin 25A protruding from the pin receiving portion 24 by its own twisting force while being housed in the two notch grooves 22B of the guide member 22. As a result, the rotation of the stopper 18 about the axis center of the connecting pin 17 is blocked by the ring pin 25, and the stopper 18 is placed at a position where the protrusion 21 abuts on the rotation limiting portion 23 of the guide member 22. Can be positioned. As a result, it is possible to prevent the stopper 18 from rotating around the connecting pin 17 due to vibration or the like during operation of the hydraulic excavator 1 and inadvertently disconnecting from the connecting pin 17.

As described above, in the pin coupling device 16 according to the present embodiment, after the lower boom 5 and the upper boom 6 are pin-coupled using the connecting pin 17, the stopper 18 is connected to the peripheral edge of the pin insertion hole 5A of the lower boom 5 and the connecting pin 17. By sandwiching the connecting pin 17 with the flange portion 17B of the lower boom 5, the connecting pin 17 can be prevented from coming off in the axial direction with respect to the pin insertion hole 5A of the lower boom 5. Further, by inserting the ring pin 25 into the pin hole 20A of the ring pin mounting shaft 20 provided in the stopper 18 and the pin hole 24A of the pin receiving portion 24 provided in the guide member 22, the shaft of the connecting pin 17 is inserted. The rotation of the stopper 18 around the center can be prevented, and the connecting pin 17 can be held in the retaining state by the stopper 18.

That is, in the pin coupling device 16 according to the present embodiment, the connecting pin 18 is manually sandwiched between the peripheral edge portion of the pin insertion hole 5A of the lower boom 5 and the flange portion 17B of the connecting pin 17. 17 can be prevented from coming off in the axial direction with respect to the pin insertion hole 5A of the lower boom 5. Therefore, as compared with the conventional technique, for example, by attaching a stopper having a diameter larger than that of the pin insertion hole to the end of the connecting pin by using a fastener, the connecting pin is fastened in the axial direction. Tools and tools can be eliminated, and workability when disconnecting and disconnecting connecting pins can be improved.

Thus, in the present embodiment, in order to pin-connect the lower boom 5 and the upper boom 6, a connecting pin 17 to be inserted into the pin insertion hole 5A provided in the lower boom 5 and the pin insertion hole 6A provided in the upper boom 6 is provided. In the pin coupling device 16, the connecting pin 17 is inserted into the pin main body 17A inserted into the pin insertion hole 5A and the pin insertion hole 6A, and the pin insertion hole 5A and the pin insertion hole 6A. The flange portion 17B provided at the end of the pin body portion 17A protruding from the outer side surface 5B and the flange portion 17B adjacent to the flange portion 17B are provided on the outer peripheral surface of the pin body portion 17A and have an outer diameter smaller than that of the pin body portion 17A. A concave groove portion 17C is provided, and the flange portion 17B and the lower boom 5 are rotatably engaged with the concave groove portion 17C around the axis center of the connecting pin 17, and the peripheral portion and the flange portion of the pin insertion hole 5A are provided. A stopper 18 is provided to retain the connecting pin 17 in the axial direction by being sandwiched between the lower boom 5 and the lower boom 5, and a guide member for holding the stopper 18 in a state of being engaged with the concave groove portion 17C on the outer surface 5B of the lower boom 5. 22 is provided.

According to this configuration, the stopper 18 is held in a state of being engaged with the concave groove portion 17C of the connecting pin 17 by the guide member 22, and the peripheral portion of the pin insertion hole 5A of the lower boom 5 and the flange portion 17B of the connecting pin 17 are held. It is sandwiched between and. As a result, the stopper 18 can be prevented from coming off in the axial direction with respect to the pin insertion hole 5A of the lower boom 5 only by manually engaging the stopper 18 with the concave groove portion 17C of the connecting pin 17, and the connecting pin 17 can be held. It is possible to improve workability when preventing it from coming off.

In the present embodiment, the stopper 18 is provided with a protrusion 21 that protrudes to the opposite side of the lower boom 5 in a state of being engaged with the concave groove portion 17C, and the guide member 22 is brought into contact with the protrusion 21 to cause a stopper. A rotation limiting portion 23 that limits the range in which the 18 rotates about the axis center of the connecting pin 17 is provided. According to this configuration, by limiting the rotation range of the stopper 18 by the rotation limiting portion 23, the stopper 18 can be stopped at an appropriate position with respect to the guide member 22.

In the present embodiment, a ring pin 25 is provided between the stopper 18 and the guide member 22 to prevent the stopper 18 from rotating about the axis center of the connecting pin 17 in a state of being engaged with the concave groove portion 17C. Has been done. According to this configuration, the rotation of the stopper 18 is blocked by the ring pin 25, so that the stopper 18 rotates around the connecting pin 17 due to vibration or the like during operation of the hydraulic excavator 1, and the connecting pin 17 is inadvertently rotated. It is possible to prevent withdrawal from.

In the present embodiment, the stopper 18 is always urged in the direction in which the protrusion 21 abuts on the rotation limiting portion 23 due to its own weight within the movable range of the lower boom 5. According to this configuration, even if the ring pin 25 is separated from the ring pin mounting shaft 20 of the stopper 18 and the pin receiving portion 24 of the guide member 22, the stopper 18 rotates the protrusion 21 by its own weight. Holds the position in contact with 23. As a result, it is possible to reliably prevent the stopper 18 from disconnecting from the connecting pin 17.

In the embodiment, the pin attachment / detachment mechanism 12 provided with the hydraulic cylinder 14 is used to insert the connecting pin 17 into the pin insertion hole 5A of the lower boom 5 and the pin insertion hole 6A of the upper boom 6, and the connecting pin 17 is inserted into the pin insertion hole 6A. An example shows a case where the pin coupling device 16 is used to retain the hydraulic pressure in the axial direction. However, the present invention is not limited to this, for example, the connecting pin 17 is manually inserted into the pin insertion hole 5A of the lower boom 5 and the pin insertion hole 6A of the upper boom 6, and is axially retracted by the pin coupling device 16. May be good.

Further, in the embodiment, the hydraulic excavator 1 provided with the crawler type lower traveling body 2 has been described as an example. However, the present invention is not limited to this, and may be applied to a hydraulic excavator provided with a wheel-type lower traveling body.

5 Lower boom (first member)
5A pin insertion hole (1st pin insertion hole)
6 Upper boom (second member)
6A pin insertion hole (second pin insertion hole)
16 Pin coupling device 17 Connecting pin 17A Pin body 17B flange 17C Concave groove 18 Stopper 21 Protrusion 22 Guide member 23 Rotation limiting part 25 Ring pin (rotation stop member)

Claims (4)

In order to pin-connect the first member and the second member constituting the working device of the construction machine, the first pin insertion hole provided in the first member and the second pin insertion hole provided in the second member. In the pin coupling device of construction machinery that disconnects and disconnects the connecting pin that is inserted into
The connecting pin is the first in a state where the pin main body portion inserted into the first pin insertion hole and the second pin insertion hole, and the first pin insertion hole and the second pin insertion hole are inserted. It has a flange portion provided at the end of the pin body portion protruding from the outer surface of the member, and an outer diameter smaller than the pin body portion provided on the outer peripheral surface of the pin body portion adjacent to the collar portion. Equipped with a concave groove,
The flange portion and the first member are rotatably engaged with the concave groove portion around the axial center of the connecting pin, and the peripheral portion of the first pin insertion hole and the flange portion are engaged with each other. A stopper is provided to hold the connecting pin in the axial direction by being sandwiched between them.
A pin coupling device for a construction machine, characterized in that a guide member for holding the stopper in a state of being engaged with the concave groove portion is provided on the outer surface of the first member. The stopper is provided with a protrusion that protrudes to the side opposite to the first member in a state of being engaged with the concave groove portion.
Claim 1 is characterized in that the guide member is provided with a rotation limiting portion that limits the range in which the stopper rotates about the axial center of the connecting pin by abutting the protrusion. Pin coupling device for construction machinery as described in. A rotation stopper member is provided between the stopper and the guide member to prevent the stopper from rotating about the axis center of the connecting pin in a state of being engaged with the concave groove portion. The pin coupling device for construction machinery according to claim 1. The pin of a construction machine according to claim 2, wherein the stopper is always urged in a direction in which the protrusion is in contact with the rotation limiting portion by its own weight within the movable range of the first member. Coupling device.

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