JP2002371589A - Connection pin connecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent replacement operation from taking a time during working and also prevent an drop out prevention pin from being fallen out during operation. SOLUTION: A ring groove 17b is provided in the outer peripheral surface of a fixed boss member 17 fitted to one bracket 14, and the drop out prevention pin 20 is inserted into a pair of through-holes 17c and 17d provided in the fixed boss member 17 and a through-hole 16a provided in a connection pin 16. To prevent the drop out pin 20 from being dropped out, an elastic ring 20 with overlapped part is fitted into the ring groove 17b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for rotatably connecting a pair of brackets and a member to be connected disposed between the brackets, and which is suitable for use in a construction machine such as a hydraulic shovel. The present invention relates to a pin coupling device.

[0002]

2. Description of the Related Art Conventionally, for example, in a joint of a boom, an arm, and a bucket of a hydraulic shovel, a structure has been adopted in which two members are rotatably connected by a connecting pin, and connected by a connecting pin connecting device. The pin is connected to each member so that the connecting pin does not come off.

[0003] Among the conventional connecting pin connecting devices, the most commonly used system is a fastening system using bolts and nuts. FIG. 5A shows an example of the bolt and nut fastening system. In the connecting pin connecting device 50 shown in this example, a collar (boss member) 52 is fixed to the outer surface of the bracket 51, and the connecting pin 54 is inserted into the connecting pin insertion hole 53 of the bracket 51. A bolt 58 is inserted into the holes 55 and 56 provided in the collar 52 and the hole 57 provided in the connection pin 54, and a nut (double nut) 59 is screwed into the bolt 58 to prevent the rotation of the connection pin 54. And the retaining is done.

Another conventional example is disclosed in Japanese Utility Model Laid-Open No. 4-26250.
There is a fastening method using a locking pin (retaining pin) disclosed in Japanese Patent Publication No. As shown in FIG. 5 (b), the connecting pin coupling device 60 disclosed in this publication
A detent collar (boss member) 62 is fixed to the outer surface of the bracket, and the connecting pin 6 is inserted into the connecting pin insertion hole 63 of the bracket 61.
4 is inserted. The holes 65 and 66 provided in the detent collar 62 and the connecting pins 6
A locking pin 69 with an elastic ring 68 is inserted into a hole 67 provided in the bracket 4, and the elastic ring 68 is brought into contact with the outer end surface of the bracket 61 beyond the center of the locking pin 69.

As another example of the locking pin fastening system,
There is one disclosed in Japanese Utility Model Laid-Open No. 7-41031.
The connecting pin coupling device 70 disclosed in this publication has a structure shown in FIG.
As shown in (c), a ring groove 73 is provided in a fixed ring (boss member) 72 provided in the bracket 71, and a connection pin 75 is inserted into a connection pin insertion hole 74 of the bracket 71, and A locking pin (retaining pin) 76 is inserted into the hole provided in the ring groove 73 and the hole provided in the connecting pin 75
After the locking pin 76 is inserted, a retaining ring 78 having an inclined slit 77 that can be reduced in diameter and expanded is fitted into the ring groove 73.

[0006]

However, FIG.
In the bolt / nut fastening method shown in FIG. 5A, the head or the end of the screw portion of the bolt 58 is often damaged by earth and sand wear or rust, so that a tool is not applied to the bolt head when attaching / detaching the working machine. There is a possibility that a malfunction such as missing or a failure to rotate the nut 59 may occur. In addition, there is also a problem that the work itself is difficult because the work needs to be carried by holding two tools in order to perform the attaching / detaching work.

On the other hand, the locking pin fastening method shown in FIG. 5B can solve the above-mentioned problem of the bolt / nut fastening method, but the elastic ring 68 is locked by vibration during operation. There is a problem that the pin 69 is easily detached beyond the center of the pin 69, and as a result, the locking pin 69 falls off and the connecting pin 64 comes off from the bracket 61.

In the fastening system shown in FIG. 5 (c) using the locking pin and the retaining ring, the weight of the locking pin 76 also causes the force to open the inclined slit 77 of the retaining ring 78 due to the vibration during operation. And this locking pin 7
6 falls off and the connecting pin 75 comes off the bracket 71.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and there is no need for troublesome replacement work, and the retaining pins do not fall off during operation, and sufficient connection is achieved. It is an object of the present invention to provide a connecting pin coupling device capable of maintaining its function.

[0010]

In order to achieve the above object, a connecting pin connecting device according to the present invention comprises a pair of brackets and a member to be connected disposed between the brackets, the bracket and the connecting member. In a connecting pin connecting device rotatably connected by a connecting pin inserted into a connected member, (a) provided on at least one bracket, the connecting pin is inserted, and a ring groove is provided on an outer peripheral surface. A fixed boss member having a pair of through holes formed at positions opposed to each other in the radial direction of the ring groove; (b) inserted through the pair of through holes of the fixed boss member and the through hole provided in the connection pin; And (c) an elastic ring having an overlapping portion fitted into the ring groove to prevent the retaining pin from coming off. And it is characterized in Rukoto.

According to the present invention, since the elastic ring to be fitted into the ring groove of the fixed boss member has an overlapping portion, and the cut ends at both ends of the elastic ring are completely closed during operation, the work can be performed, Even if the retaining pin dances in the through hole of the connecting pin due to the vibration during the excavation work by the machine, and the axial force of the retaining pin generates a force in the elastic ring in the radially expanding direction, the retaining pin does not move. Dropping can be reliably prevented. In addition, when attaching and detaching a member to be connected such as a bucket, for example, the operation of mounting the elastic ring in the ring groove can be easily performed with the same pushing force as in the related art. According to the connecting pin connecting device, even if the connecting portion is exposed to earth and sand or crushed stone during operation of the work machine,
Since there is no screw portion as in the bolt and nut fastening method, there is no need to take time for the attaching and detaching work when replacing the connected member. In addition, since there is no wear or dropout of the component parts, the component parts can be reused when attaching and detaching the connected member.

In the present invention, it is preferable that a chamfer is provided at an outer peripheral corner of the fixed boss member. This makes it easier to insert the elastic ring into the ring groove.

Preferably, a cushion material is provided at an end of the retaining pin. In this way, rotation of the elastic ring and flapping of the retaining pin during operation can be minimized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a connecting pin connecting device according to the present invention will be described with reference to the drawings.

FIG. 1 is a side view of a hydraulic excavator according to one embodiment of the present invention, and FIG. 2 is a partial external view (a) and a cross-sectional view (a) of a connecting pin coupling device according to this embodiment. FIG. 3B is a sectional view taken along line AA of FIG.
And a perspective view (b) showing an elastic ring attached state.

The hydraulic excavator 1 according to the present embodiment includes an upper revolving unit 4 above a lower traveling unit 2 via a swing circle 3.
Is mounted on the upper revolving superstructure 4 in a cab 5
And a work machine 6 are provided. The working machine 6 includes a boom 7, an arm 8, and a bucket 9,
The boom 7 is connected to the upper revolving unit 4 with the boom cylinder 1
The arm 8 is arranged at the tip of the boom 7 and is swingable by an arm cylinder 11, and the bucket 9 is arranged at the tip of the arm 8 and is swingable by a bucket cylinder 12. It has been.

The boom 7, the arm 8, the bucket 9, and each of the cylinders 10, 11, 12 are connected to each other by a connecting pin connecting device 13. In FIG. 1, a connecting pin connecting device for connecting the boom 7 and the boom cylinder 10 to the upper swing body 4 is not shown. Hereinafter, the detailed structure of the connecting pin connecting device 13 for connecting the bucket 9 to the distal end of the arm 8 will be described, but the other connecting pin connecting devices 13 have substantially the same structure.

As shown in FIGS. 2 and 3, the connecting pin connecting device 13 includes a bracket 14 of the bucket 9 and an arm 8 as a member to be connected (a member to be connected) disposed between the brackets 14. The boss 15 is rotatably connected to each other by a connecting pin 16 inserted between them.

An annular fixed boss member 17 is fixed outside the one bracket 14 by welding. The fixed boss member 17 has a connecting pin 16 at the center.
A connecting pin insertion hole 17a is formed for inserting a through hole. The connection pin insertion hole 17a is
The connection pin 16 is inserted through the connection pin insertion hole 17a and the through holes 14a, 15a so as to communicate with the through hole 14a formed in the boss portion 15 and the through hole 15a formed in the boss portion 15. Fixed boss member 17,
The bracket 14 and the boss 15 are connected to each other. A bush 18 is inserted on the inner peripheral surface of the boss 15 and seals 19 are inserted on both ends of the inner peripheral surface.

The fixed boss member 17 has a ring groove 17b formed on the outer peripheral surface thereof, and a pair of through holes 17c and 17d are formed at radially opposite positions of the ring groove 17b. Also, a through hole 16a is formed in the connection pin 16 so as to correspond to the through holes 17c and 17d. Thus, the retaining pin 20 is inserted into the pair of through holes 17c and 17d formed in the ring groove 17b and the through hole 16a formed in the connecting pin 16,
As a result, the connection pin 16 is prevented from coming off and rotating from the bracket 14.

When the retaining pin 20 is inserted into the through holes 17c, 17d, 16a, the ring groove 17b is formed to prevent the retaining pin 20 from coming out.
The elastic ring 21 is fitted from the end of the connecting pin 16. In order to facilitate the fitting of the elastic ring 21, a chamfered portion 17e is provided at the outer peripheral corner of the fixed boss member 17.

The elastic ring 21 is formed in a ring shape from a long and thin plate spring material, and as shown in FIG. 3, the cut ends at both ends are formed to overlap each other. . Here, the range of the overlapping portion (overlap portion) R is in the range of 5 ° to 90 °, preferably 15 ° to 90 ° in central angle when the elastic ring 21 is attached.
It is preferable to set the range to 30 °. This elastic ring 21
At the time of mounting, it is expanded to a diameter larger than the outer diameter of the fixed boss member 17 and inserted into the fixed boss member 17 from the end side of the connection pin 16,
The retaining pin 20 is inserted into the ring groove 17b so as to cover both end faces. On the other hand, when the bucket 9 is attached or detached, one end of the elastic ring 21 fitted in the ring groove 17b is pushed open by a tool such as a flathead screwdriver, and the elastic ring 21 is pulled out from the ring groove 17b. After the elastic ring 21 is pulled out, the retaining pin 20 is pulled out, and then the connecting pin 16 connecting the bucket 9 is pulled out.

According to the connecting pin connecting device 13 of the present embodiment, since the cut ends at both ends of the elastic ring 21 are completely closed, the retaining pin 20 is connected to the connecting pin 16 by mechanical vibration during operation of the hydraulic excavator 1. Even when dancing in the through hole 16a and the axial force of the retaining pin 20 causes a force in the radially expanding direction on the elastic ring 21, this force is suppressed by the elastic ring 21 and the retaining pin 20 falls off. Can be reliably prevented. Further, in the present embodiment, when the elastic ring 21 is inserted into the ring groove 17b, the diameter of the elastic ring 21 may be increased by an amount exceeding the large diameter portion of the fixed boss member 17, so that FIG. ) Can be inserted with the same spreading force as in the conventional device shown in FIG. In order to confirm the effect of the connecting pin coupling device 13 of the present embodiment, the load when the retaining pin 20 comes out, in other words, the opening amount of the cutout of the elastic ring 21 is the same size as the diameter of the retaining pin 20. Was measured, the load was about 1.5 times that of the conventional example (FIG. 5C).
It turns out that a double load is required.

FIG. 4A shows another embodiment of the elastic ring. Elastic ring 21A according to this embodiment
Here, the cushion member 22 is attached to the inner peripheral surface of the ring main body 21a. In this way, the retaining pin 2 during operation is
Since the vibration in the axial direction of 0 can be absorbed, the noise of the portion during the excavation work can be suppressed.

FIG. 4B shows another embodiment of the retaining pin. In the retaining pin 20A according to this embodiment, cushion members 23 are attached to both ends of the pin main body 20a. With such a configuration, it is possible to prevent noise during operation, similarly to the embodiment shown in FIG.

In the above embodiment, the excavator has been described as an example. However, the present invention is not limited to the excavator but can be applied to various other mechanical devices.

[Brief description of the drawings]

FIG. 1 is a side view of a hydraulic shovel according to an embodiment of the present invention.

FIGS. 2A and 2B are a partial external view (a) and a cross-sectional view (b) of the connecting pin coupling device of the present embodiment.

FIGS. 3A and 3B are a sectional view taken along line AA of FIG. 2B and a perspective view showing an elastic ring attached state.

FIG. 4 is another embodiment (a) of the elastic ring and another embodiment (b) of the retaining pin.

5 (a), 5 (b) and 5 (c) are views showing a conventional connecting pin coupling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 7 Boom 8 Arm 9 Bucket 13 Connection pin coupling device 14 Bracket 14a, 15a Through hole 15 Boss 16 Connection pin 16a Through hole 17 Fixed boss member 17a Connection pin insertion hole 17b Ring groove 17c, 17d Through hole 17e Beveled portion 20, 20A Retaining pin 21, 21A Elastic ring 22, 23 Cushion material R Overlapping part

Claims (3)

[Claims] 1. A connecting pin connecting device for rotatably connecting a pair of brackets and a connected member disposed between the brackets by a connecting pin inserted through the bracket and the connected member, wherein (a) A fixed boss member provided on at least one of the brackets, through which the connection pin is inserted, and having a ring groove on the outer peripheral surface, and a pair of through holes formed at positions opposed to each other in a radial direction of the ring groove; b) a retaining pin inserted through the pair of through holes of the fixed boss member and a through hole provided in the connecting pin; and (c) fitted into the ring groove to prevent the retaining pin from coming off. A connecting pin coupling device, comprising: an elastic ring having an overlapping portion to be joined. 2. The connecting pin coupling device according to claim 1, wherein a chamfered portion is provided at an outer peripheral corner of the fixed boss member. 3. The connecting pin coupling device according to claim 1, wherein a cushion material is provided at an end of the retaining pin.