JPH05280201A - Mounting device for wall surface working tool - Google Patents

Abstract

(57) [Abstract] [Purpose] For a work machine front attachment, a boom and an arm that rotate up and down are provided, and a wall work tool is attached to the tip of the arm and the work is moved vertically along the wall. This is intended to facilitate driving operation. [Structure] Instead of an arm having a constant effective length, a rear arm and a front arm that is slidable along the longitudinal direction of the arm are used. A telescopic arm capable of adjusting the height is provided, a wall surface working tool is provided at the tip of the front arm, and the telescopic cylinder can be extended and retracted from the driver's seat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic circuit of a work attachment tracking mechanism in a work machine.

[0002]

2. Description of the Related Art FIG. 6 is an overall side view of a work machine 1'with a conventional work attachment 3'mounted on the front part of an upper revolving structure 2 ', and 4 is a boom, 5 is a boom cylinder, and 6 is a boom cylinder. Is a boom foot pin, 7'is an arm, 8 is an arm cylinder, 12 is a scraping tool, and 17 is a side wall. When the scraping tool 12 and the side wall 17 shown in FIG. , The same as shown in FIG.
Reference numeral 3 denotes a roller attached to the tip of the scraping tool 12, and the roller 13 rolls as the scraping tool 12 moves vertically along the side wall 17. Reference numeral 14 denotes a plate, which is a spatula-shaped member for scraping off the deposits adhering to the side wall 17 or the groove 18. Reference numeral 15 is a pin for pivotally supporting the scraping tool 12 with respect to the arm 7 ′ so as to be rotatable in the left-right direction, and 16 is attached between the left and right side surfaces of the scraping tool 12 and the left and right side surfaces of the arm 7 ′ tip. Unless the external force of a predetermined value or more acts on the tool 12 scraped by the spring from the left and right, the tool 12 is held forward. In FIG. 6, the scraping tool 12 attached to the tip of the arm 7'is used to scrape off the deposits adhering to the side wall 17. The side wall 17 has not only an upright plane but also an uneven surface having a groove 18 in the vertical direction as shown in FIG. For example, it is often the case that the inner wall surface of the hold of a large ship for transporting pulverized coal or ore is an uneven upright surface having the groove portion 18. Therefore, during landing and loading of pulverized coal or ore, the material adheres to the groove portion 18 of the inner wall of the hold and remains in a clogged state. Therefore, as shown in FIG. 6, the scraping tool 12 is attached to the work attachment 3 ′ of the working machine 1 ′ so as to be rotatable in the left and right directions to scrape off the adhered matter.

[0003]

In the above-mentioned prior art, the scraping tool 1 raised by the operator of the working machine 1'is raised.
When lowering 2 along the side wall 17, if the boom cylinder 5 is simply contracted, the roller 13 at the tip of the scraping tool 12 follows a trajectory having a radius R centering on the boom foot pin 6 as shown in FIG. Scraping work is not possible.
Therefore, the driver operates an operation lever (not shown) so that the boom cylinder 5 and the arm cylinder 8 are simultaneously operated to move the roller 13 downward along the side wall 17. However, unless the driver is particularly skilled, the finish of this scraping work is not smooth or the wall surface is damaged, which causes many problems. Also, instead of the arm 7'of FIG. 6, even if a telescopic arm is attached and scraping is performed,
Similarly, a very high level of driving skill is required for scraping work, and when this is not obtained, most of the scraping work for adhering substances on the upright wall surface or the inclined wall surface, the worker uses a ladder or scaffolding, Since the spatula plate was manually used, a great deal of time and labor was required. An object of the present invention is to enable all such scraping work to be performed with a mechanical force that is easy to operate.

[0004]

[Means for Solving the Problems] Means for solving the problems described above are as follows. The operation mechanism installed in the operator's cab switches the hydraulic switching valve that operates the work attachment to operate various actuators, and it is effective by operating the telescope cylinder at the tip of the boom as a work attachment. A telescopic arm whose length extends and contracts is attached, and a work tool is attached to the tip of the telescopic arm so that the telescopic arm can be rotated in the left-right direction when an external force of a predetermined value or more acts. B. Inside the operator's cab, there is provided an operating means for the hydraulic switching valve for telescopic arm expansion / contraction operation, and a signal means for issuing a signal only when the operating means is operated to a position other than neutral, that is, when the hydraulic switching valve is switched to normal and reverse directions. C. A low-pressure hydraulic source provided with a low-pressure relief valve is separately provided so that a predetermined low-pressure oil can be constantly supplied. D. A first switching valve that is switched by an external signal is provided in the middle of an oil passage that connects the head-side oil chamber of the telescope cylinder and the hydraulic switching valve. When no signal acts on the switching valve, the hydraulic switching valve is provided. From the low-pressure hydraulic source to the head-side oil chamber of the telescope cylinder, but when a signal acts, only the oil passage connected to the hydraulic switching valve is connected to the head-side oil chamber. I'm going to get to. E. A second switching valve that branches from an oil passage communicating with the rod-side oil chamber of the telescope cylinder and communicates with an oil passage communicating with the head-side oil chamber is provided in the middle of the branch oil passage by an external signal. A branch oil passage that opens the internal oil passage when a signal does not act on the second switching valve and closes the signal when a signal acts, leading to the head-side oil chamber and the rod-side oil chamber of the telescope cylinder. To shut off. F. Furthermore, the above-mentioned signal means, the above-mentioned first switching valve, and the second
Connect to the receiving part of the switching valve.

[0005]

[Operation] a. If the driver operates the operating means in the direction in which the telescopic arm extends when the work tool attached to the tip of the telescopic arm does not contact the side wall, the signal from the signal means is switched at the same time as the hydraulic switching valve is switched. Since it acts on the first and second switching valves to switch the valves, the low-pressure hydraulic pressure source and the branch oil passage are cut off, and the pressure oil from the hydraulic pressure switching valve is sent to the head side oil chamber of the telescope cylinder. The return oil from the rod-side oil chamber returns to the oil tank via the hydraulic pressure switching valve. As a result, the telescopic arm extends, and the work tool attached to the tip of the telescopic arm advances. B. In order to perform the operation opposite to the above item (a), when the driver operates the operation means to the contracting side of the telescopic arm, the hydraulic switching valve is switched in the opposite direction to the above item (a). But,
The signal from the signal means is the first and second signals as in the above item (a).
It acts on the receiving part of the switching valve, and its position function is the same as that of the item a. Therefore, the pressure oil from the hydraulic switching valve is sent to the rod-side oil chamber of the telescope cylinder, and the return oil from the head-side oil chamber returns to the oil tank via the hydraulic switching valve. As a result, the telescopic arm contracts and the work tool at its tip retracts. C. When the work tool attached to the tip of the telescopic arm is brought into contact with the upper side wall and the operator causes the boom cylinder to contract, the telescope cylinder tends to be contracted as the work tool moves downward. At this time, since the operation means for the telescope cylinder is in the neutral position and no signal is emitted from the signal means, the head side oil chamber is provided with the first switching valve and the rod side oil chamber is provided with the first operation valve.
The pressure oil from the low-pressure hydraulic source simultaneously acts via the second switching valve and a limited extension force is generated in this telescope cylinder. Low pressure oil in the side oil chamber goes to the rod side oil chamber,
The excess low-pressure oil flows in through the second switching valve, and the surplus low-pressure oil flows through the first switching valve and flows out to the oil tank via the low-pressure relief valve provided on the low-pressure hydraulic pressure source side.

As a result, the work tool moves downward along the side wall while pressing the side wall with the limited extension force. That is, in order to lower the work tool along the wall surface, it is mainly necessary to operate only the boom cylinder. Next, conversely to the above, contact the work tool below the side wall,
When the driver extends the boom cylinder to move the work tool upward, a signal does not act on the first and second switching valves as described above, and the telescope cylinder has a limited extension. Even if the force is retained and the telescope cylinder extends, the low pressure oil in the rod side oil chamber goes through the second switching valve to the head side oil chamber, and from the low pressure hydraulic source. Low-pressure oil is replenished via the first switching valve. As a result, the work tool moves upward along the side wall while pressing the side wall with the limited extension force. That is, even if the work tool is raised along the wall surface, it is sufficient to operate mainly the boom cylinder.

When the groove on the wall surface and the vertical movement direction of the work tool do not coincide with each other, an external force is applied to the work tool in the horizontal direction. When the external force exceeds a predetermined value, the work tool rotates with respect to the telescopic arm. Since it is mounted like this, there is no useless scraping resistance and smooth work is possible.

[0008]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a work machine 1 having a hydraulic circuit according to the present invention, in which a scraping tool 12 which is one kind of work tool is attached to the tip of a work attachment 3 to scrape off an adhering substance attached to a side wall 17. FIG.
2 is an upper swing body, 4 is a boom, 5 is a boom cylinder, 6
Is a boom foot pin, 7 is a telescopic arm, 8 is an arm cylinder, 9 is a rear arm of the telescopic arm 7, and 10 is a front arm of the telescopic arm 7. The front arm 10 is configured to slide along the rear arm 9 so that it can expand and contract, and there is a telescope cylinder 11 between them, and the telescopic arm 7 expands and contracts when the telescope cylinder 11 expands and contracts.

FIG. 2 shows the scraping tool 12 and the side wall 1 of FIG.
It is the top view which looked at 7 from the arrow A direction. FIG. 3 shows a hydraulic circuit diagram of the present invention. 19 is a foot-operated pedal operated by a driver, 21 is a limit switch for opening and closing electric contacts in association with the movement of the pedal 19 via a pedal-like link 20. is there. Reference numeral 22 is a remote control valve that is interlocked with the operation of the pedal 19, and has pilot valves 23 and 24 therein. Reference numeral 25 is a hydraulic switching valve which is switched by the remote control valve 22 to extend and retract the telescope cylinder 11. Hydraulic pressure switching valves 26, 2
Reference numerals 7 and 28 are for switching operation by various pilot pressures from other remote control valves (not shown) to switch various actuators (a boom cylinder, an arm cylinder, etc., but not shown). Reference numerals 29 and 30 denote left and right pilot oil chambers for the hydraulic pressure switching valve 25 into which the pilot pressure oil sent from the remote control valve 22 flows. 31 is a piston rod of the telescope cylinder 11, 32 is a head side oil chamber, 33 is a rod side oil chamber, 34 and 35 are solenoid valves, 36 is a low pressure relief valve for holding back pressure, and 37, 38 and 39 are relief valves. Four
0 and 41 are check valves, 42 is a main hydraulic pump, 43 is a pilot pump, 44 is a follower pump, 45 is a pump driving prime mover, 46 is an oil tank, 47, 48, 49, 5
0, 51, 52, 53, 54, 55, 56, 57, 5
8, 59, 60, 61 and 62 are oil passages.

The configuration of the present invention is as described above,
Next, details of the operation of the hydraulic circuit will be described. First, the prime mover 45 of the work machine 1 is started, the boom cylinder 5 is extended, and the scraping tool 12 at the tip of the work attachment 3 is raised to a height above the side wall 17. When the scraping tool 12 is not in contact with the side wall 17 and the driver is not operating the foot pedal 19, the remote control valve 22 is in the neutral position as shown in FIG. At that time, since the electrical contacts of the limit switch 21 are open, the solenoid valve 34 is in the a position, the solenoid valve 35 is in the c position, the pilot valves 23 and 24 are not operated, and the hydraulic pressure switching valve 25 is in the neutral position. .. On the other hand, the pressure oil from the trailing pump 44 is supplied to the oil passage 47,
The check valve 40, the oil passages 48, 49, and the solenoid valve 34 are passed through the oil passage 50 to reach the head-side oil chamber 32 of the telescope cylinder 1 through the oil passage 50.
1. It also acts on the rod-side oil chamber 33 via the c position of the solenoid valve 35 and the oil passage 52. Then, since the inner diameter cross-sectional area S1 of the rod-side oil chamber 32 of the telescope cylinder 11 is larger than the inner diameter effective cross-sectional area S2 of the rod-side oil chamber 33, the telescope cylinder 11 extends due to the difference in the operating force,
The oil in the rod-side oil chamber 33 passes through the oil passage 52, the position of the electromagnetic valve 35, the oil passage 51, and joins the oil passage 50. At this time, the pressure oil discharged from the trailing pump 44 passes through the low pressure relief valve 36 for holding the back pressure and the oil passage 53, and the oil tank 46.
Therefore, the pressure acting on the head-side oil chamber 32 and the rod-side oil chamber 33 is limited, and the extension force of the telescope cylinder 11 also becomes a limited predetermined value. Therefore, when the scraping tool 12 is not in contact with the side wall 17 and the remote control valve 22 connected to the pedal 19 is in the neutral position, the scraping tool 12 is moved by the telescope cylinder 11 to the predetermined position. Move forward with the extension force of the value.

Next, when the scraping tool 12 is not in contact with the side wall 17 and the telescopic cylinder is contracting, the scraping tool 12 is removed at a speed faster than that in the above case or with a strong extension force. The hydraulic function when moving forward will be described. As shown in FIG. 4, the driver steps on the front step portion 63 of the pedal 19 to operate the pilot valve 23 of the remote control valve 22. By this operation, the pedal link 20 acts on the limit switch 21 and closes its electrical contact, so that the solenoid valve 34 is set to the position b.
5 is switched to the two position (electric circuit is not shown). From these results, the pressure oil from the pilot pump 43 is
4. Since the pilot pressure reaches the pilot oil chamber 29 from the pilot oil passage 56 via the pilot valve 23, the hydraulic pressure switching valve 25 switches to the E position. Therefore, the oil discharged from the main hydraulic pump 42 is supplied to the oil passages 57, 58 and the hydraulic pressure switching valve 2.
5 E position, oil passage 59, solenoid valve 34 B position, oil passage 50
Through the head side oil chamber 32 of the telescope cylinder 11.
Sent to. As a result, the piston rod 31 moves forward, and the return oil from the rod-side oil chamber 33 passes through the oil passages 52, 60, the E position of the hydraulic pressure switching valve 25, and the oil passages 61, 62.
Return to 6. At this time, the solenoid valve 35 is at the two position and the oil passage 5
0 and 52 are shut off, and no pressure oil flows in or out. The oil discharged from the trailing pump 44 is supplied to the oil passage 47 and the check valve 4.
Although it reaches 0 through the oil passage 48 and reaches the oil passage 49, since the oil passage is blocked at the position b of the solenoid valve 34, it returns to the oil tank 46 through the low pressure relief valve 36 and the oil passage 53. Therefore, when the front stepping portion 63 of the pedal 19 is stepped on, the front arm 10 and the scraping tool 12 move forward.

Next, with the telescopic arm extended, the work machine 1 is moved forward to scrape the roller 13 at the tip of the tool 12 into contact with the upper side wall 17. In this case, as shown in FIG. 1, if the radius connecting the centers of the boom foot pin 6 and the roller 13 is R and the horizontal distance from the boom foot pin 6 to the side wall 17 is l1, the telescope cylinder 1
The stroke S0 of 1 has a length l2 (where l2 = R-l
1) Keep it larger. To perform the scraping work from this state, the boom cylinder 5 is contracted and the boom 4 is rotated downward to lower the roller 13 and the plate 14 at the tip of the scraping tool 12. In that case, since the driver does not operate the pedal 19, the hydraulic circuit diagram showing the hydraulic function at that time is shown in FIG. That is, since the remote control valve 22 is in the neutral position, the hydraulic pressure switching valve 2
5 is a neutral position without switching. Further, since the electrical contacts of the limit switch 21 are still open, the solenoid valve 34 is in the a position and the solenoid valve 35 is in the c position. So
The boom cylinder 5 is contracted and scraped off, and the tool 12 is attached to the side wall 1.
If you lower it while touching 7, front arm 1
The piston rod 31, which is connected to 0, is pushed into the telescope cylinder 11 and tries to contract. That is, the oil in the head side oil chamber 32 of the telescope cylinder 11 is the oil passages 50 and 51, the position of the solenoid valve 35, and the oil passage 52.
Is sent to the rod side oil chamber 33.

Further, the pressure oil discharged from the trailing pump 44 is held at a predetermined pressure by a low pressure relief valve 36 for holding the back pressure, which is the head side oil chamber 32 and the rod side oil chamber 33.
As described above, the telescopic cylinder 11 exerts a limited predetermined extension force, because they act simultaneously.
Therefore, when an external force equal to or larger than the extension force is applied by reducing the boom cylinder, the pressure oil in the head side oil chamber 32 flows out to the oil tank 46 through the rod side oil chamber 33 or the low pressure relief valve 36. Therefore, the telescope cylinder 11 is reduced. Therefore, when the boom cylinder 5 is contracted, the scraping tool 12 can be lowered along the sidewall 17 while being pressed against the sidewall 17 with a predetermined force. If the height of the roller 13 from the floor surface 65 becomes smaller than the height of the boom foot pin 6 and the telescope cylinder 11 is not pushed in even if the boom cylinder 5 is contracted, the telescope shown in FIG. Since the acting force by the pressure of the head side oil chamber 32 in the scope cylinder 11 is larger than the acting force by the pressure of the rod side oil chamber 33, the piston rod 31 starts moving forward, and the scraping tool 12 moves along the side wall 17 as well. To do. Further, when the driver does not operate the pedal 19 and extends the boom cylinder 5 in the opposite direction to the above and raises the boom cylinder 5 upward, the scraping tool 12 is moved to the side wall 17 by an operation similar to the hydraulic function of lowering the boom cylinder 5. It goes up along with.

Next, the hydraulic function when the scraping tool 12 is separated from the side wall 17 and the front arm 10 is retracted will be described. As shown in FIG. 5, the driver depresses the rear stepping portion 64 of the pedal 19 to push the remote control valve 22
The pilot valve 24 is operated. By this operation, the pedal link 20 closes the electric contact of the limit switch 21, the solenoid valve 34 is switched to the b position, and the solenoid valve 35 is switched to the two position. That is, regardless of whether the front step portion 63 of the pedal 19 is stepped on or the rear step portion 64 is stepped on, the electric contact of the limit switch 21 is closed by the pedal link 20, and the solenoid valve 34 is turned to the electromagnetic position. Although the valve 35 is switched to the two position, the operating side of the pilot valve of the remote control valve 22 is different. That is, since the pressure oil from the pilot pump 43 reaches the pilot oil chamber 30 through the oil passage 54, the pilot valve 24, and the pilot oil passage 66, the hydraulic pressure switching valve 25 switches to the F position. Therefore, the oil discharged from the main hydraulic pump 42 is sent to the rod-side oil chamber 33 of the telescope cylinder 11 via the oil passages 57 and 58, the positions of the hydraulic pressure switching valve 25, and the oil passages 60 and 52. As a result, the piston rod 31 retracts, and the return oil from the head side oil chamber 32 receives the oil passage 50, the position of the solenoid valve 34, the oil passage 59,
It returns to the oil tank 46 through the position of the hydraulic pressure switching valve 25 and the oil passages 61 and 62. The oil discharged from the trailing pump 44 passes through the oil passage 47, the check valve 40, and the oil passage 48, and then the oil passage 4 is discharged.
However, since the oil passage is blocked at the position b of the solenoid valve 34, it returns to the oil tank 46 through the low pressure relief valve 36 and the oil passage 53. Therefore, when the rear stepping portion 64 of the pedal 19 is stepped on, the front arm 10 retracts.

As described above, the telescopic arm 7 and the scraping tool 12 are attached to the working machine 1 having the hydraulic circuit according to the present invention, and the tip of the scraping tool 12 is brought into contact with the side wall 17 and moved vertically. In this case, the tip of the scraping tool 12 comes into contact with the side wall 17 with a predetermined pressing force and moves in the vertical direction. Also, telescopic arm 7
While the tool is contracting, scrape off the tool 12 tip to the side wall 17
When the front stepping portion 63 of the foot operation type pedal 19 is stepped on without contacting with, the front arm 10 equipped with the scraping tool 12 rapidly or strongly moves forward, and on the contrary, the rear stepping portion 64 is stepped on. In this case, the front arm 10 equipped with the scraping tool 12 moves backward.

[0016]

As described in the embodiments of the present invention, as a work attachment to be mounted in front of the upper swing body of a work machine, a boom having a base pivotally attached to the upper swing body, and a boom attached to the tip of the boom. It consists of a telescopic arm which has a scraping tool and a scraping tool at its tip. Each of them is vertically rotatable by a horizontal axis and a hydraulic cylinder, and the scraping tool can be rotated left and right by a vertical axis. It is freely pivoted to the telescopic arm. Then, in order to give a tracking function to the arm, a telescopic arm composed of a rear arm and a front arm, which are connected by a telescope cylinder and can slide and expand and contract with each other, is used to extend and retract the telescope cylinder. The front arm and the scraping tool can be moved forward and backward by allowing the seat to be forcibly or automatically operated as required. In other words, a telescopic cylinder that expands and contracts a normal telescopic arm is used as it is as a cylinder for a tracking mechanism, and in the operating circuit of this telescopic cylinder, it corresponds to the operation signal and automatically has a predetermined limited extension force. A circuit is provided so that it will be expanded or contracted when an external force exceeding the expansion force acts in the opposite direction.

On the other hand, in the prior art, the driver simultaneously operates the boom cylinder, the arm cylinder, or the telescope cylinder of the work machine to linearly move the tip of the work tool in the vertical direction. However, since this operation requires excellent skill and labor, the worker usually uses a ladder, a scaffold, or the like to manually scrape off the deposits on the sidewall. Therefore, in the prior art, the operator requires a great deal of time and labor. As described above, in the present invention in which the trailing mechanism hydraulic circuit is provided, in the work of scraping off the deposits on the side wall, the scraping tool is brought into contact with the side wall, and the boom cylinder is simply extended and retracted. .. Therefore, it is not necessary for the driver to be highly skilled, and the work tool at the tip of the work attachment can be reliably moved in the vertical direction easily along the side wall, improving work efficiency and requiring a simple change of the operating circuit. The work cost can be reduced.

[Brief description of drawings]

FIG. 1 is an overall side view of a machine equipped with a tool according to the present invention for scraping off a wall surface.

2 is a plan view of the tool and the wall surface in FIG. 1 viewed from A. FIG.

FIG. 3 is a hydraulic circuit diagram showing an embodiment of the present invention.

FIG. 4 is an explanatory view of the hydraulic circuit operation of FIG.

5 is an explanatory diagram of the hydraulic circuit operation of FIG.

FIG. 6 is an overall side view in which the work machine of the prior art differs in the work of scraping off the adhered matter adhering to the wall surface.

[Explanation of symbols]

 1, 1'Work machine 3, 3'Work attachment 7 Telescopic arm 10 Front arm 12 Scraping tool 22 Remote control valve 23, 24 Pilot valve 25 Hydraulic switching valve 34, 35 Solenoid valve

Claims (1)

[Claims] 1. A boom having a base end pivotally attached to the front of an upper swing body and an arm pivotally attached to the tip of the boom are pivotally supported by horizontal pins, respectively, and are vertically rotated by a hydraulic cylinder. A wall work tool is pivotally attached to the tip of the arm by a vertical pin so as to be rotatable left and right, and the effective length of the arm can be freely extended and contracted by extension and contraction of a telescope cylinder. Equipment for mounting wall work tools.