JPH0710053U - Bucket desorption device - Google Patents

Abstract

(57) [Abstract] [Purpose] In the prior art, since the pins are pivotally mounted between the tip of the arm and the bucket link and the bracket of the bucket, the driver takes a lot of labor and time to remove the pins. I took it off and replaced the bucket. The present invention provides a bucket attachment / detachment device that can automatically perform a bucket replacement operation. [Structure] In the bucket attaching / detaching device of the present invention, the pipes leading to the spring chamber and the piston pin oil chamber inside the arm tip boss and the bucket link tip boss, respectively, and the pipeline passing through the hydraulic pump and the oil tank are The first, second and third electromagnetic switching valves are provided so that the piston pin can be pulled in or projected by operating the switch. After the bucket is attached to the tip of the work attachment, all the electromagnetic switching valves are switched to the tank communication oil passage position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to a control circuit of a bucket attachment / detachment device equipped on a construction machine such as a hydraulic excavator.

FIG. 7 is a side view of a hydraulic excavator. In the figure, 1 is a work attachment mounted on the front portion of a hydraulic excavator, 2 is a boom of the work attachment 1, 3 is an arm, 4 is a bucket, 5 is a bucket link, 6 is an idler link, 7 is a bucket 4 Brackets, which are erected on the rear surface of, and 8 and 9 are connecting pins. FIG. 8 is a sectional view taken along the line AA of FIG. 7. In the figure, 10 is an arm tip boss of the arm 3, 11 is a bucket link tip boss of the bucket link 5, 12 is a pin hole for mounting the arm tip portion of the bracket 7, 13 is a bucket link tip portion The pin holes 14 and 15 are locking portions when the pins 8 and 9 are pivotally attached.

As shown in FIGS. 7 and 8, in the bucket attaching / detaching device of the prior art, a bracket 7 is erected on the back surface of the bucket 4 and the bracket 7 has an arm tip attaching pin hole 12 and a bucket link tip. The mounting pin holes 13 are opened in parallel with each other so that the tip of the arm 3 and the tip of the bucket link 5 of the work attachment 1 and the bracket 7 of the bucket 4 are attached and detached via the pins 8 and 9. ing.

[0004]

[Problems to be solved by the device]

 For hydraulic excavators, buckets are frequently replaced depending on the type of work, work content, or work status. In the prior art shown in FIGS. 7 and 8, since the pins are pivotally attached to the tips of the arm and the bucket link and the bracket of the bucket, respectively, the driver or the operator removes the pin to remove the bucket. It was changing. For this reason, it takes a lot of labor and time to replace the bucket, and the work efficiency is lowered. In view of this, various bucket attaching / detaching devices that allow easy and quick operation of bucket replacement have been taken into consideration, but an object of the present invention is to provide a control circuit for the bucket attaching / detaching device.

[0005]

[Means for Solving the Problems]

 In the bucket attaching / detaching device of the present invention, the arm tip mounting pin hole and the bucket link tip mounting pin hole are opened parallel to each other in the bracket on the back surface of the bucket, and the arm tip portion and the bucket link tip portion are respectively bossed. A piston pin that is separated into the left and right and is movable in the axial direction of the boss is provided inside, and springs are arranged in the spring chambers between the left and right piston pins to urge the piston pins outward respectively. In the bucket attaching / detaching device, which supplies pressure oil to the spring chamber and the piston pin oil chamber to attach / detach the arm tip and bucket link tip of the work attachment to the bucket bracket. The hydraulic fluid pump is connected to the pipeline communicating with the pin oil chamber via the first electromagnetic switching valve, and the first electromagnetic switching valve is disconnected. It is sometimes set to switch to the tank communication oil passage position, and to switch to the opening oil passage position when energized. Also, the pipe communicating with the spring chamber inside the arm tip boss and the hydraulic pump are connected via the second electrification switching valve. Of the bucket link tip boss and the hydraulic pump and the hydraulic pump are communicated with each other through the third electromagnetic switching valve, and the second and third electromagnetic switching valves are de-energized. Sometimes it is set to open oil passage position, and when energized, it is set to switch to tank communication oil passage position, and when the insertion state of the piston pin into the bucket is maintained, the first electromagnetic switching valve is de-energized and the second and third By turning on the electromagnetic switching valve, the spring chamber and the piston pin oil chamber are all connected to the oil tank.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing a cross section of a bucket attaching / detaching device of the present invention and a hydraulic circuit for operating the bucket attaching / detaching device. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. 16 is a boss portion for an arm tip attaching pin hole 12 that is fixedly provided on the inner surface side of the bracket 7 of the bucket 4 that is opposed, 17 is a boss portion for a bucket link tip attaching pin hole 13, and 18 is a boss portion. An arm tip boss, 19 is a bucket link tip boss, 20 is a piston pin fitted at both left and right ends of the arm tip boss 18 and the bucket link tip boss 19, 21 is a bush, 22 is a seal member, and 23 is O. A ring, 24 is a seal member fitted around the outer periphery of the base of the piston pin 20, 25 and 25 'are spring chambers inside the bosses 18 and 19, respectively, 26 is a spring, and 27 and 27' are for piston pins, respectively. An oil chamber 28 is a stopper portion of the piston pin 20, and 29L and 29R are open holes in the arm tip boss 18 and communicate with the left and right piston pin oil chambers 27. , 30L and 30R are hydraulic ports that are opened in the bucket link tip boss 19 and communicate with the left and right piston pin oil chambers 27 ', and 31 and 31' are spring chambers 25 and 25 'of the bosses 18 and 19, respectively. For hydraulic pressure, 32 for the frame, 33L and 33R for the left and right plates of the frame 32, 34 for the central connecting plate, 35, 36, 37 for the first, second, and third electromagnetic switching valves, respectively. 38, 39 and 40 are solenoids of the electromagnetic switching valves 35, 36 and 37, 41 is a hydraulic power source, and 42 is an oil tank. Since the bucket 4 is used by exchanging and exchanging for excavation work and loading work, the inner diameters of the arm tip end attachment pin hole 12 and the bucket link tip end attachment pin hole 13 are set to the same size φd. Therefore, the diameter of the piston pin 20 is set to be the same size as the inner diameter φd of both the pin holes 12 and 13 (to be exact, slightly smaller), and the both bosses 18 and 19 are connected by the frame 32. The distance between the axes of the bosses 18 and 19 is set to be the same as the distance between the centers of the pin holes 12 and 13 of the bucket 4 (dimension p shown in FIG. 1). 2 and 3 are views showing respective working examples of the bucket attaching / detaching device in FIG.

FIG. 4 is an electric circuit diagram for switching the electromagnetic switching valves (35, 36, 37) in FIG. In the figure, 43 is a changeover switch, 44 is a power supply, 45, ..., 51 are diodes, and 52 is a fuse. FIG. 5 is a plan view showing the bucket attaching / detaching device of the present invention. In the figure, 53L and 53R are positioning guide plates fixed to the outer surfaces of the left and right plates 33L and 33R of the frame 32, respectively. FIG. 6 is a side view of the main part viewed from B of FIG. In the figure, 54L and 54R (not shown because 54R is on the opposite side) are guide surfaces of the positioning guide plates 53L and 53R, respectively.

Next, the structure of the bucket attaching / detaching device of the present invention will be described with reference to FIGS. In the present invention, the pipe lines 55 leading to the left and right piston pin oil chambers 27 inside the arm tip boss (18) and the left and right piston pin oil chambers 27 'inside the bucket link tip boss (19). (Shown in FIGS. 1, 2 and 3) and the hydraulic pump 41 are communicated with each other via the first electromagnetic switching valve 35, and the first electromagnetic switching valve 35 is connected to the tank communication oil passage when not energized. The position (a) is set so as to be switched to the open oil passage position (c) when energized, and the pipe 56 that communicates with the spring chamber 25 inside the arm tip boss (18) and the hydraulic pump 41 are connected to each other. The second electromagnetic switching valve 36 and the third electromagnetic switching valve 36 communicate with each other via the hydraulic pump 41, which communicates with each other through the electromagnetic switching valve 36 and also with the pipe 57 communicating with the spring chamber 25 ′ inside the bucket link tip boss (19). The electromagnetic switching valve 37 of each is opened in the oil passage when not energized. Positions (c) and (e) are set to switch to the tank communication oil passage positions (d) and (d) respectively when energized, and when the piston pin 20, 20 'is held in the inserted state with respect to the bucket 4. By deenergizing the first electrification switching valve 35 and energizing the second solenoid switching valve 36 and the third solenoid switching valve 37, the spring chambers 25, 25 ′ and the piston pin oil chambers All of 27 and 27 'are configured to communicate with the oil tank 41.

Next, the operation of the bucket attaching / detaching device of the present invention will be described. First, when the bucket 4 attached to the tip of the work attachment is removed, the changeover switch 43 (shown in FIG. 4) is operated to the pin removal position a. The current from the power source 44 passes through the a position terminal of the changeover switch 43 and the diodes 45, 47 and 48, so that all the solenoids 38, 39 and 40 are energized. Therefore, as shown in FIG. 1, the first electromagnetic switching valve 35 is switched to the open oil passage position B, and the second electromagnetic switching valve 36 and the third electromagnetic switching valve 37 are switched to the tank communication oil passage positions D and F, respectively. Replace The spring chamber 25 inside the arm tip boss (18) and the spring chamber 25 'inside the bucket link tip boss (19) pass through the tank switching oil passage positions d and f of the electromagnetic switching valves 36 and 37, respectively. Connect to 2. The pressure oil from the hydraulic pressure source 41 passes through the opening oil passage position b of the electromagnetic switching valve 35 and the passage 55, one passage through the passages 58, 59L, 59R and the ports 29L, 29R, and the left and right piston pin oil chambers 27, The oil is sent to 27, and is branched at the pipe 55, and the other is sent to the left and right piston pin oil chambers 27 and 27 'through the pipes 60, 61L and 61R and the ports 30L and 30R. As a result, all the piston pins 20 are pulled inward against the spring force of the spring 26. Further, since the tip ends of all the piston pins 20 are retracted inward from the left and right outer side surfaces of the frame body 32, the bucket 4 can be removed from the tip end portion of the work attachment.

Next, the case where the detached bucket 4 is attached to the tip of the work attachment will be described. The driver operates the work attachment of the hydraulic excavator to insert the outer surface side of the frame body 32 into the inner surface sides of the opposing boss portions 16 and 17 of the bracket 7 of the bucket 4. At the same time, the guide surfaces 54L and 54R (shown in FIG. 6) of the positioning guide plates 53L and 53R fixed to the left and right of the frame 32 come into contact with the upper outer peripheral surfaces of the boss portions 16 and 17 of the bucket 4 bracket 7. . When operated in this state, the shaft centers of the piston pins 20 of both bosses 18 and 19 and the hole centers of both pin holes 12 and 13 of the bracket 7 of the bucket 4 can be aligned. In this state, the changeover switch 43 shown in FIG. 4 is operated to the arm side pin insertion position b. While the solenoids 38 and 40 are energized, the solenoid 39 is de-energized. In this case, as shown in FIG. 2, the electromagnetic switching valves 35 and 37 remain in the low position and the F position, respectively, but the electromagnetic switching valve 36 switches to the open oil passage position C. The spring chamber 25 ′ inside the bucket link tip boss (19) communicates with the oil tank 42 via the position of the electromagnetic switching valve 37, and the piston pin oil chamber 27 ′ passes through the position of the electromagnetic switching valve 35. The piston pin 20 inside the bucket link tip boss (19) remains in the retracted state. On the other hand, the oil pressure from the hydraulic pressure source 41 acts on the piston pin oil chamber 27 inside the arm tip boss (18) via the position b of the electromagnetic switching valve 35. The same hydraulic pressure acts on the spring chamber 25 through the position C of the electromagnetic switching valve 36, the conduit 56, and the port 31. Therefore, the piston pin 20 inside the arm tip boss (18) is caused to project outward due to the pressure due to the difference in piston pin pressure receiving area and the spring force of the spring 26. Then, the protruding tip side of the piston pin 20 can be fitted into the pin hole 12 of the bucket 4.

At the stage where the piston pin 20 on the arm tip boss (18) side is fitted into the pin hole 12 of the bucket 4 as described above, the changeover switch 43 shown in FIG. Operate to C. Since no conduction circuit is connected to the C position terminal, all the solenoids 38, 39 and 40 are de-energized. Therefore, the switching positions of the electromagnetic switching valves 35, 36, and 37 are the a position, the c position, and the e position, respectively, as shown in FIG. In this case, all the piston pin oil chambers 27, 27 'communicate with the oil tank 42 via the position of the electromagnetic switching valve 35, but the spring chamber 25 inside the arm tip boss (18) is electromagnetically switched. Since the hydraulic pressure from the hydraulic pressure source 41 is acting via the c position of the valve 36, the piston pin 20 on the arm tip boss (18) side is still in the pin hole 12 of the bucket 4. . At the same time, the pressure oil from the hydraulic pressure source 41 acts on the spring chamber 25 'through the position E of the electromagnetic switching valve 37, the conduit 57, and the port 31'. Therefore, the piston pin 20 inside the bucket link tip boss (19) operates to project outward, and the tip side can be fitted into the pin hole 13 of the bucket 4. Thereby, the bucket 4 can be attached to the work attachment.

When the bucket 4 is attached to the work attachment as described above, the changeover switch 43 shown in FIG. 4 is operated to the bucket use position d. The solenoid 38 remains de-energized, while the solenoids 39 and 40 are energized. That is, all the electromagnetic switching valves 35, 36 and 37 are switched to the tank communication oil passage positions a, d and f, respectively. As a result, the oil pressure from the oil pressure source 41 does not act on the inside of the arm tip boss (18) and the inside of the bucket link tip boss (19). Therefore, even when excavating with the bucket 4, the piston pin oil chambers 27, 27 ′ are provided. No oil leaks from the spring chambers 25, 25 '. In this case, it is the spring force of the spring 26 that holds all the piston pins 20 in the protruding state.

[0013]

EFFECTS OF THE INVENTION In the bucket attaching / detaching device of the present invention, the pipes leading to the spring chamber and the piston pin oil chamber inside the arm tip boss and the bucket link tip boss, respectively, and the pipeline passing through the hydraulic pump and the oil tank are provided. The first, second, and third electromagnetic switching valves are provided so that the piston pin can be pulled in or projected by a switch operation. After the bucket was attached to the tip of the work attachment, all of the above electromagnetic switching valves were switched to the tank communication oil passage position. As a result, after the bucket is attached to the tip of the work attachment, the hydraulic pressure from the hydraulic source does not act inside the arm tip boss and the bucket link tip boss, so when using the bucket, oil leaks from the piston pin oil chamber and spring chamber. It won't happen. That is, in the bucket attaching / detaching device of the present invention, the protruding state of the piston pin is maintained by the spring force of the spring, and the oil leakage from the oil chamber for the piston pin and the spring chamber is prevented. The maintenance property can be improved.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a bucket attaching / detaching device of the present invention and a hydraulic circuit for operating the bucket attaching / detaching device.

FIG. 2 is a diagram showing an operation example of the bucket attaching / detaching device in FIG.

FIG. 3 is a diagram showing an operation example of the bucket attaching / detaching device in FIG.

4 is an electric circuit diagram for switching the solenoid operated directional control valve in FIG.

FIG. 5 is a plan view showing a bucket attaching / detaching device of the present invention.

FIG. 6 is a side view of a main part as seen from B of FIG.

FIG. 7 is a side view of the hydraulic excavator.

8 is a cross-sectional view showing a conventional technique seen from AA in FIG.

[Explanation of symbols]

 4 Bucket 7 Bracket 10,18 Arm tip boss 11,19 Bucket link tip boss 12,13 Pin hole 20 Piston pin 25,25 'Spring chamber 26 Spring 27,27' Piston pin oil chamber 32 Frame body 35,36,37 Electromagnetic changeover valve 38, 39, 40 Solenoid 41 Oil pressure source 42 Oil tank 43 Changeover switch

Claims (1)

[Scope of utility model registration request] 1. An arm tip mounting pin hole and a bucket link tip mounting pin hole are formed in the bracket on the back surface of the bucket in parallel to each other, and the arm tip and the bucket link tip are respectively left and right inside the boss. And a piston pin that is movable in the axial direction of the boss is provided, and springs are arranged in the spring chambers between the left and right piston pins to urge the piston pins to the outside. In a bucket attachment / detachment device that supplies pressure oil to the pin oil chamber to attach and detach the arm tip and bucket link tip of the work attachment and the bracket of the bucket, all piston pin oil chambers A hydraulic fluid pump communicates with a pipeline communicating with the hydraulic pump via a first electromagnetic switching valve, and the first electromagnetic switching valve is connected to the tank communication oil passage position when not energized. Is set to switch to the open oil passage position when energized, and the pipeline communicating with the spring chamber inside the arm tip boss is communicated with the hydraulic pump via the second electromagnetic switching valve, and the bucket link A hydraulic fluid pump is connected to a pipeline communicating with a spring chamber inside the tip boss via a third electromagnetic switching valve, and the second and third electromagnetic switching valves are energized to an open oil passage position when not energized. Sometimes it is set to switch to the tank communication oil passage position, and the first electromagnetic switching valve is de-energized when the piston pin is kept fitted in the bucket.
A bucket attaching / detaching device characterized in that the spring chamber and the piston pin oil chamber are all communicated with the oil tank by energizing the second and third electromagnetic switching valves.