JP2000136801A - Vibration generating fluid circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To vibrate a bucket cylinder with high frequency other than expanding operation while simple in structure. SOLUTION: When a control valve 34 is switched to an open position D with high pressure fluid fed into a head side chamber 12a of the bucket cylinder 11, the high pressure fluid is alternatively fed into a head chamber 12a and a rod side chamber 12b by a rotary valve 46 and a piston rod 13 starts reciprocating motion on the spot to generate high-frequency vibration. Instead of a specific cylinder installed, the existing bucket cylinder is used to generate the bucket's vibration, so the structure can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration generating fluid circuit which can vibrate a working cylinder in addition to extending and retracting.

[0002]

2. Description of the Related Art In general, civil engineering construction machines, for example, hydraulic excavators, are used for excavating earth and sand, consolidating soil, setting piles, etc. Such operations are performed by working cylinders (booms) of the hydraulic excavator. , Arms, and bucket cylinders) are appropriately operated to scoop the earth and sand by the bucket or to press the ground or a pile. Here, as described above, if the bucket hits a large stone while excavating earth and sand, it is empirical that high frequency vibration is applied to the bucket so that even a large stone can be easily excavated. Is also known to
It is known that these operations can be performed quickly and satisfactorily by applying high-frequency vibrations to the bucket even when consolidating the ground, driving a pile, or shaking off the earth and sand adhering to the bucket.

[0003]

However, conventional working cylinders (boom cylinders, arm cylinders, bucket cylinders) are merely connected to a fluid source and a discharge source via a switching valve. The piston rod of the cylinder only expands and contracts smoothly with a large stroke,
There was a problem that it was not possible to vibrate at high frequencies.

An object of the present invention is to provide a vibration generating fluid circuit which has a simple structure and can vibrate a working cylinder at a high frequency in addition to the expansion and contraction operation.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid source, a discharge source, a supply passage and a discharge passage connecting the fluid source, the discharge source and the switching valve, respectively, a supply passage and a fluid motor. A control valve that is provided in the middle of a high-pressure passage connecting the supply port and controls the supply of high-pressure fluid from the supply passage to the fluid motor by opening and closing; and a pair of first supply and discharge passages connected to the switching valve. A pair of second supply / discharge passages connected to the working cylinder, and a pair of first vibration fluid passages and a pair of second vibration fluid passages respectively connected to the first supply / discharge passage. Receiving the rotational force of the fluid motor, connecting the first and second oscillating fluid passages to each other and the first oscillating fluid passage, and connecting the first and second oscillating fluid passages to each other; A vibration valve alternately switching to a second vibration position; A first supply / discharge passage interposed between the second oscillating fluid passage and the second supply / discharge passage, the second oscillating fluid passage being cut off, and the first and second supply / discharge passages being connected to each other; This is achieved by providing a mode position and a mode valve that can be switched to a second mode position in which the first supply / discharge passage is shut off and the second oscillating fluid passage and the second supply / discharge passage are connected to each other. be able to.

When the working cylinder is extended, the control valve is switched to the closed position to shut off the supply of the high-pressure fluid from the supply passage to the fluid motor, thereby stopping the operation of the fluid motor and the vibration valve. Switching the switching valve to one flow position to connect the supply passage to the first supply / discharge passage, connect the discharge passage to the other first supply / discharge passage, and further switch the mode valve to the first mode. Switch to the first and second position
The supply and discharge passages are connected to each other, and the second oscillating fluid passage is shut off. Thereby, the high-pressure fluid from the fluid source flows into the head side of the working cylinder through the supply passage, the one first supply / discharge passage, and the one second supply / discharge passage, and extends the work cylinder. At this time, the return fluid from the working cylinder is discharged to the discharge source through the other second supply / discharge passage, the other first supply / discharge passage, and the discharge passage. At this time, the high-pressure fluid flowing from one first supply / discharge passage into one first oscillating fluid passage is guided to any one of the second oscillating fluid passages through the oscillating valve. And the high-pressure fluid in the second oscillating fluid passage is not supplied to the working cylinder.

Next, when the extension of the working cylinder is stopped and vibrated on the spot, the control valve is switched from the closed position to the open position, and the mode valve is moved from the first mode position to the second mode position. Switch to. By switching the control valve, high-pressure fluid is supplied from the supply passage to the fluid motor through the high-pressure passage, and the fluid motor rotates. Thereby, the vibration valve receives the rotational force of the fluid motor, and connects the first and second vibration fluid passages to each other and the first vibration position, and the first and second vibration fluid passages to one and the other. In this case, the high pressure fluid is supplied to one of the first oscillating fluid passages from one of the first supply / discharge passages as described above. The high-pressure fluid in the first oscillating fluid passage is alternately and repeatedly guided to one or the other second oscillating fluid passage. At this time, the mode valve is switched to the second mode position as described above, and connects the second oscillating fluid passage and the second supply / discharge passage, so that the mode valve is alternately guided to one or the other second oscillating fluid passage. The high-pressure fluid alternately flows into the second supply / discharge passage and the head side and the rod side of the working cylinder to slightly extend the working cylinder,
Shrink and vibrate the working cylinder at high frequency. At this time, the return fluid flowing out of the working cylinder is discharged to the discharge source through the second pressure supply / discharge passage on the low pressure side, the second and first vibration fluid passages, and the other first supply / discharge passage and discharge passage. At this time, since the first supply / discharge passage is shut off by the mode valve, no high-pressure fluid is supplied to the work cylinder from the first supply / discharge passage, and as a result, the work cylinder extends significantly. It vibrates at high frequency without any change.

Next, when the working cylinder is contracted, the control valve is switched to the closed position, the mode valve is switched to the first mode position, and the switching valve is switched to the other flow position to switch the supply passage and the other passage. The first supply / discharge passage is connected, and the discharge passage is connected to one of the first supply / discharge passages. As a result, the high-pressure fluid from the fluid source flows into the rod side of the working cylinder, and the working cylinder contracts. When the contraction of the working cylinder is stopped and vibrated on the spot, the control valve is switched from the closed position to the open position and the mode valve is switched from the first mode position to the second mode position as described above. Just do it.

As described above, the vibration function can be imparted to the already installed working cylinder, so that there is no need to install a special cylinder for vibration, and the structure of the fluid circuit is simplified. In addition, since the fluid supplied to the fluid motor and the vibration valve is guided from the supply passage and the first supply / discharge passage, it is not necessary to provide a special fluid source for these, and the structure of the fluid circuit is further improved. It's easy.

The return fluid flowing out of the fluid motor can be discharged to a low-pressure passage provided with a control valve or to a first oscillating fluid passage according to the second or third aspect of the present invention. In the case of the third aspect, the high-pressure fluid may be supplied to the discharge port of the fluid motor from the first oscillating fluid passage. In such a case, the fluid motor does not rotate. No vibration occurs.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 11 denotes a bucket cylinder as a working cylinder for operating a bucket of a civil engineering construction machine, for example, a hydraulic shovel, and the bucket cylinder 11 has a cylinder chamber 12 inside. The cylinder chamber 12 is slidably housed in the cylinder chamber 12 and is divided into a head side chamber 12a and a rod side chamber 12b by a piston 14 to which a piston rod 13 is connected.
The base end of the bucket cylinder 11 is connected to the arm of the hydraulic shovel, and the tip of the piston rod 13 of the bucket cylinder 11 is connected to the bucket. As a result, the bucket cylinder 11 expands and contracts, that is, ,
When the piston rod 13 projects or retracts, the bucket swings.

A hydraulic pump 17 as a fluid source and a tank 18 as a discharge source are provided on the turning frame of the hydraulic excavator.
The fluid pump 17 and the tank 18 are connected to the switching valve 19 installed on the cab of the revolving frame via a supply passage 20 and a discharge passage 21, respectively.
Reference numeral 22 denotes a pedal-type control valve installed in the cab, and when the control valve 22 is switched, the high-pressure fluid discharged from the fluid pump 23 is supplied to the pilot passage 24 or
The switching valve 19 is supplied to the switching valve 19 through 25, and switches the switching valve 19 from the neutral position C to the first flow position A or the second flow position B. Reference numeral 26 denotes a tank from which the return fluid from the pilot passages 24 and 25 is discharged.

Reference numeral 31 denotes an internal gear type fluid motor, and a supply port 31a of the fluid motor 31 and the supply passage 20 are connected to a high pressure passage.
The discharge port 31b and the discharge passage 21 are connected via a low-pressure passage 33, respectively. A manual control valve 34 installed in the driver's cab is interposed in the high and low pressure passages 32 and 33. When the control valve 34 is switched to the open position D, the high pressure fluid is supplied from the supply passage 20 to the fluid motor 31. When the return fluid from the fluid motor 31 is discharged to the discharge passage 21 while being switched to the closed position E,
The supply of the high-pressure fluid from the supply passage 20 to the fluid motor 31 is shut off, and the supply and discharge ports 31a, 31
b and the discharge passage 21 are communicated. By opening and closing the control valve 34 in this manner, the supply of the high-pressure fluid from the supply passage 20 to the fluid motor 31 is controlled. Reference numeral 35 denotes a flow control valve (may be a flow control valve) provided in the high pressure passage 32 in the high pressure passage 32, specifically between the control valve 34 and the fluid motor 31.

Reference numerals 38 and 39 denote a pair of first supply / discharge passages connected to the switching valve 19, and reference numerals 40 and 41 denote a pair of second supply / discharge passages connected to the head side chamber 12a and the rod side chamber 12b of the bucket cylinder 11, respectively. It is. 42, 43 are the first supply / discharge passages 3
A pair of first oscillating fluid passages respectively connected to 8, 39;
Reference numerals 4 and 45 denote a pair of second oscillating fluid passages. 46 is the first
A rotary valve as a vibration valve interposed between the oscillating fluid passages 42 and 43 and the second oscillating fluid passages 44 and 45.
Is rotated by receiving the driving force from the fluid motor 31 to connect the first and second oscillating fluid passages 42 and 44 to each other and the first and second oscillating fluid passages 43 and 45 to each other. 1
The vibration position F, one first vibration fluid passage 42, and the other second vibration fluid passage 42
The oscillating fluid passages 45 and the other first oscillating fluid passage 43,
The second vibration position is switched alternately to the second vibration position G where the second vibration fluid passages 44 are connected to each other.

A mode valve 50 is provided between the first supply / discharge passages 38, 39 and the second oscillating fluid passages 44, 45 and the second supply / discharge passages 40, 41. I have. A pilot passage 51 connected to the high-pressure passage 32 between the fluid motor 31 and the control valve 34 is connected to the mode valve 50. When the control valve 34 is switched to the closed position E and the supply of the high-pressure fluid through the pilot passage 51 is stopped, the mode valve 50 is switched to the first mode position H by the urging force of the spring 52. , The second oscillating fluid passage 44,
45, and the first and second supply / discharge passages 38, 40 and 39, 41 are connected, while the control valve 34 is in the open position D.
The high pressure fluid is switched to the high pressure passage 32 and the pilot passage 51
When the pressure is supplied to the mode valve 50, the spring 52 is switched to the second mode position J while compressing the spring 52 by the fluid pressure of the high-pressure fluid, and the first supply / discharge passages 38 and 39 are shut off. The oscillating fluid passage and the second supply / discharge passages 44 and 40 are connected to each other and 45 and 41 are connected to each other. 53 is the mode valve 50
This is a drain passage that guides the drain generated in the low pressure passage 33 through the control valve 34.

2 and 3, reference numeral 57 denotes a block fixed to the outer periphery of the bucket cylinder 11, and this block 57 is a first, second and third block 5 which are integrally connected.
It consists of 4, 55 and 56. And the first block 5
4, the mode valve 50 is stored in the second block 55, the rotary valve 46 is stored in the third block 56, and the flow control valve 35 is stored in the third block 56. The first block 54 is a bucket. The third block 56 is connected to a side surface of the second block 55 while being interposed between the cylinder 11 and the second block 55. The fluid motor 31 is provided in the second block 55
Is fixed to one end face. If the rotary valve 46 and the mode valve 50 are housed in the block 57 fixed to the bucket cylinder 11 as described above, the first oscillating fluid passages 42 and 43 for supplying and discharging fluid to the rotary valve 46 are rotated. Since the first oscillating fluid passages 42 and 43 can be connected to the first supply / discharge passages 38 and 39 passing through the inside of the block 57 very close to the valve 46, the lengths of the first oscillating fluid passages 42 and 43 can be reduced.

Next, the operation of the first embodiment of the present invention will be described. When the bucket cylinder 11 is extended, that is, when the piston rod 13 is projected to excavate earth and sand by the bucket, the control valve 34 is switched to the closed position E,
The switching valve 19 is switched by the control valve 22 to one flow position, here the first flow position A. Here, when the control valve 34 is switched to the closed position E as described above, the supply of the high-pressure fluid from the supply passage 20 to the mode valve 50 through the pilot passage 51 is stopped. The mode is switched to the first mode position H by the force, and the supply of the high-pressure fluid from the supply passage 20 to the fluid motor 31 is shut off, so that the operations of the fluid motor 31 and the rotary valve 46 are stopped. When the switching valve 19 is switched to the first flow position A as described above, the supply passage 20 is connected to one of the first supply / discharge passages 38, and the discharge passage 21 is connected to the other first supply / discharge passage. When the mode valve 50 is switched to the first mode position H, the second oscillating fluid passages 44 and 45 are shut off, and the first and second supply / discharge passages 38 and 40 are connected to each other. , 41 are connected to each other. Thus, the high-pressure fluid discharged from the fluid pump 17 is supplied to the supply passage 20, the first supply / discharge passage 38, and the second supply / discharge passage.
It flows into the head side chamber 12a of the bucket cylinder 11 through 40, and as a result, the piston rod 13 projects, the bucket cylinder 11 extends, and the bucket swings. At this time, the return fluid pushed out from the rod side chamber 12b of the bucket cylinder 11 is supplied to the second supply / discharge passage 41, the first supply / discharge passage 39, and the discharge passage 21.
Through the tank 18. At this time, the first
The high-pressure fluid flowing from the supply / discharge passage 38 into the first oscillating fluid passage 42 is guided to one of the second oscillating fluid passages 44 or 45 through the rotary valve 46, and the second oscillating fluid passages 44 and 45 are The high-pressure fluid in the second oscillating fluid passages 44 and 45 is
Not supplied to 11.

If the bucket collides with a large stone during the excavation work of earth and sand as described above, the bucket cylinder 11
By stopping the elongation of the stone and vibrating the bucket at a high frequency, vibration is imparted to the bucket to facilitate excavation of the stone. In this case, the control valve 34 is switched from the closed position E to the open position D.
Since the high-pressure fluid in 20 is supplied to the mode valve 50 through the high-pressure passage 32 and the pilot passage 51, the mode valve 50 switches from the first mode position H to the second mode position J while compressing the spring 52. When the control valve 34 is switched to the open position D, high-pressure fluid is supplied from the supply passage 20 to the fluid motor 31 through the high-pressure passage 32, and the fluid motor 31 rotates. As a result, the rotary valve 46 alternately switches between the first vibration position F and the second vibration position G by receiving the rotational force of the fluid motor 31. At this time, as described above, the first vibration fluid passage
Since the high-pressure fluid is supplied to 42 from the first supply / discharge passage 38, the high-pressure fluid in the first vibration fluid passage 42 is alternately guided to one or the other second vibration fluid passage 44 or 45. At this time, the mode valve 50 is switched to the second mode position J as described above, and the second oscillating fluid passage and the second supply / discharge passages 44 and 40 are connected to each other and 45 and 41 are connected to each other. The high-pressure fluid alternately guided to the second oscillating fluid passage 44 or 45 is supplied to the second supply / discharge passage 40, 41 and the bucket cylinder.
The bucket cylinder 11 flows into the head-side chamber 12a and the rod-side chamber 12b alternately and slightly expands and contracts (slightly reciprocates the piston 14) at high frequency to vibrate the bucket cylinder 11. At this time, the return fluid flowing out of the bucket cylinder 11 is supplied to the second supply / discharge passage 40 or 4 on the low pressure side.
1, the second oscillating fluid passage 44 or 45, the first oscillating fluid passage 42
Or 43, the water is discharged to the tank 18 through the other first supply / discharge passage 39 and the discharge passage 21. At this time, since the first supply / discharge passages 38, 39 are both shut off by the mode valve 50, the high pressure fluid is not supplied from the first supply / discharge passages 38, 39 to the bucket cylinder 11. As a result, the bucket cylinder 11 vibrates at a high frequency on the spot without greatly extending.

Next, the operation of discharging the earth and sand from the bucket by contracting the bucket cylinder 11 will be briefly described. In this case, the control valve 34 is switched to the closed position E to stop the supply of the high-pressure fluid to the fluid motor 31 and the rotary valve 46, while the switching valve 19 is controlled by the control valve 22 to the other flow position (second flow position). Switching to B), the supply passage 20 and the other first supply / discharge passage 39 are connected, and the discharge passage 21 and one first supply / discharge passage 38 are connected. At this time, the mode valve 50 is switched to the first mode position H by switching the control valve 34, and connects the first and second supply / discharge passages 38, 40 and 39, 41. As a result, the high-pressure fluid from the fluid pump 17
And the bucket cylinder 11 is contracted. At this time, the head side chamber 12 of the bucket cylinder 11
The return fluid pushed out from a is discharged to the tank 18.

Here, since the scooped soil is soft,
In the case of sticking to the bucket, the shrinkage of the bucket cylinder 11 is stopped during the discharge of the earth and sand, and the bucket cylinder 11 is vibrated in place to shake off the earth and sand from the bucket. In this case, the mode valve 50 is switched from the first mode position H to the second mode position J by switching the control valve 34 from the closed position E to the open position D in the same manner as described above. May be alternately supplied to the head side and the rod side chambers 12a, b by the rotary valve 46 to vibrate the bucket cylinder 11.

As described above, since the vibration function can be provided to the existing bucket cylinder 11, there is no need to install a special cylinder for vibration, and the structure of the fluid circuit is simplified. In addition, since the fluid supplied to the fluid motor 31 and the rotary valve 46 is guided from the supply passage 20 and the first supply / discharge passages 38 and 39, it is not necessary to provide a special fluid source for them. The structure of the fluid circuit is further simplified.

FIG. 4 is a diagram showing a second embodiment of the present invention. In this embodiment, the outlet of the fluid motor 31
The low-pressure passage 33 between the control valve 34 and the control valve 34 is eliminated, and the discharge port 31b of the fluid motor 31 and one of the first oscillating fluid passages, in this case, the high pressure when the bucket cylinder 11 contracts, are increased. (1) The oscillating fluid passage 61 is connected by a connection passage 62, and only the flow of fluid from the control valve 34 to the fluid motor 31 is permitted in the high-pressure passage 32 between the control valve 34 and the fluid motor 31 (fluid motor A check valve 63 for preventing fluid flow from 31 to the control valve 34 is interposed. Here, the check valve 63 is housed in the first block 54 beside the mode switching valve 50 as shown in FIG. In such a configuration, the return fluid flowing out of the fluid motor 31 is supplied to the tank through the first oscillating fluid passage 61 and the first supply / discharge passage 60.
When the switching valve 19 is switched to the first flow position A to supply high-pressure fluid to the first supply / discharge passage 60 and the bucket cylinder 11 is contracted, the supply / discharge port of the fluid motor 31 is returned. Since the high-pressure fluid is guided to both 31a and 31b, the fluid motor 31 cannot rotate, and as a result, the bucket cylinder 11 expands or contracts without vibrating. Thus, in this embodiment, the bucket cylinder
It is specialized to apply vibration only when 11 is extended. Other configurations and operations are the same as those of the first embodiment.

FIG. 6 is a diagram showing a third embodiment of the present invention. In this embodiment, the outlet of the fluid motor 31
The low pressure passage 33 between the control valve 31b and the control valve 34 is omitted, and the discharge port 31b of the fluid motor 31 or one of the first oscillating fluid passages, here, the high pressure when the bucket cylinder 11 is extended, is increased. 1 A check valve 66 that connects the oscillating fluid passage 42 with a connection passage 65 and allows only the flow of fluid from the control valve 34 to the fluid motor 31 to the high-pressure passage 32 between the control valve 34 and the fluid motor 31. Is interposed. With this configuration, the return fluid flowing out of the fluid motor 31 is returned to the tank 18 through the first oscillating fluid passage 42 and the first supply / discharge passage 38, but the switching valve 19 is switched to the first flow position A. When the high pressure fluid is supplied to the first supply / discharge passage 38 and the bucket cylinder 11 is extended, the high pressure fluid is guided to both the supply and discharge ports 31a and 31b of the fluid motor 31.
The fluid motor 31 cannot rotate, and as a result, the bucket cylinder 11 expands or contracts without vibrating. As described above, this embodiment is specialized for applying vibration only when the bucket cylinder 11 is contracted. Other configurations and operations are the same as those of the first embodiment.

In the above embodiment, the working cylinder is the bucket cylinder 11, but in the present invention, the boom cylinder, the arm cylinder, the arm cylinder, It may be a plate cylinder. In addition, the vibration generating fluid circuit of the present invention may be applied to, for example, a cylinder device that opens and closes a door of a garbage incinerator, in addition to civil engineering and construction machines, in which case, dust attached to the door is shaken off by vibration. be able to.

[0025]

As described above, according to the present invention, the working cylinder can be vibrated at a high frequency in addition to the expansion and contraction operation while having a simple structure.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the vicinity of a working cylinder, a vibration valve, and a mode valve.

FIG. 3 is a sectional view taken along the line II of FIG. 2;

FIG. 4 is a circuit diagram showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing the vicinity of a mode switching valve.

FIG. 6 is a circuit diagram showing a third embodiment of the present invention.

[Explanation of symbols]

11 working cylinder 17 supply source 18 discharge source 19 switching valve 20 supply passage 21 discharge passage 31 fluid motor 31a supply inlet 31b discharge outlet 32 high pressure passage 33 low pressure passage 34 control valve 38 39, first supply / discharge passage 40, 41 second supply / discharge passage 42, 43 first vibration fluid passage 44, 45 second vibration fluid passage 46 vibration valve 50 mode valve 62 connection passage 63 check Valve F: First vibration position G: Second vibration position H: First mode position J: Second mode position

Claims (3)

[Claims] 1. A fluid source, a discharge source, a supply passage and a discharge passage connecting the fluid source, the discharge source and the switching valve, respectively, and a middle of a high pressure passage connecting the supply passage and a supply port of the fluid motor. A control valve for controlling the supply of the high-pressure fluid from the supply passage to the fluid motor by opening and closing, a pair of first supply / discharge passages connected to the switching valve, and a pair of first supply / discharge passages connected to the working cylinder. A second supply / discharge passage, interposed between a pair of first oscillating fluid passages and a pair of second oscillating fluid passages respectively connected to the first supply / discharge passage, and receiving a rotational force of the fluid motor; A first vibration position connecting one and the other of the first and second vibration fluid passages, and a second vibration position connecting the one and the other of the first and second vibration fluid passages.
A vibration valve that is alternately switched to a vibration position, and is interposed between the first supply / discharge passage, the second vibration fluid passage, and the second supply / discharge passage. Second
Switching between a first mode position in which the supply and discharge passages are connected to each other and a second mode position in which the first supply and discharge passage is shut off and the second oscillating fluid passage and the second supply and discharge passage are connected to each other. A vibration generating fluid circuit, comprising: 2. The vibration generating fluid circuit according to claim 1, wherein said discharge passage is connected to a discharge port of a fluid motor by a low pressure passage, and said control valve is located in the middle of said low pressure passage. 3. A fluid passage from the control valve to the fluid motor in a high pressure passage between the control valve and the fluid motor, wherein the discharge port of the fluid motor and one of the first vibration fluid passages are connected by a connection passage. 2. The vibration generating fluid circuit according to claim 1, further comprising a check valve that allows only the flow of the fluid.