JPH11294405A - Automatic selector valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid an effect that a mechanical member is located in an automatic selector valve circuit and to perform switching and control of a hydraulic piston only through pure hydraulic control. SOLUTION: Input ports 11 and 12 are connected to the cylinder chamber 19 of a selector valve body 10 and a selector valve comprises an outside spool 15 and subspools 16 and 16' axially movably fitted in internally of the outside spool 15. The cylinder chamber 19 is connected to output ports 29 and 30 for a hydraulic piston cylinder unit 8, and this constitution executes the right and left stroke of an outer spool 15 through displacement of the subspool 16 when the oil pressure of the output port 29 or 30 reaches the set pressure of a relief valve 3. Through switching of the position, the stroke direction of the piston of the hydraulic cylinder unit 8 is switched, and the switch continuously repeats the right and left strokes of the piston in correspondence to the right and left strokes of the selection valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic switching valve device for reciprocating a piston of a hydraulic piston cylinder unit.

[0002]

2. Description of the Related Art Various automatic switching valve devices for reciprocating a piston of a hydraulic piston cylinder unit are known. However, in these known automatic switching valve devices, the switching control is not limited to the hydraulic device, and a mechanical member such as a pressure sensor is built in a part of the hydraulic device. Therefore, there is a disadvantage that the switching control of the hydraulic device is not smooth and cannot be performed quickly.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to obviate the above-mentioned difficulties and to make it possible to control the switching of the piston of the hydraulic piston cylinder unit smoothly and quickly.

[0004]

This problem is solved in an automatic switching valve device by the invention-specifying matters described in claims 1 to 4. An embodiment of the present invention will now be described in detail with reference to the drawings.

[0005]

1, 2 and 3 show a first embodiment of an automatic switching valve device according to the present invention. In FIG. 1, reference numeral 1 denotes a hydraulic pump, 2 denotes a relief valve, 3 denotes an oil tank, and 4 denotes a switching valve, in particular, a 3-position 4-connection switching valve, and 8 denotes a hydraulic piston cylinder unit. The automatic switching valve device is configured as follows.

The output port of the switching valve 4 is connected to the input port 11 and the input port 12 of the switching valve body 10 via a conduit. Input port 11 and input port 1
Each 2 is connected to a cylinder chamber 19. Ports 10a, 10b, 10c, 10d, and 10 are provided at predetermined intervals on a wall surface surrounding the cylinder chamber 19 of the switching valve body 10.
e and 10f are formed. A hydraulic conduit is connected from the cylinder chamber 19 to the hydraulic piston cylinder unit 8 via two output ports 29, 30. The output port 12 is similarly connected to a cylinder chamber 19 via a check valve A comprising a valve body 13 and a spring 14. An outer spool 15 in which two sub-spools 16 and 16 ′ are fitted movably in the axial direction thereof is disposed in the cylinder chamber 19 so as to be movable in the longitudinal direction of the cylinder chamber 19.
The outer spool 15 has openings 15a and 15b, a throttle hole 15c and an opening 15a 'at symmetrical positions with respect to the center thereof.
15b 'and a throttle hole 15c' are provided. The right sub-spool 16 fitted inside the outer spool 15
The aperture 16a at the left end, the spring chamber 16b communicating with the aperture 16a and in which the spring 17 is mounted, and the aperture 16 at the end.
c and the left side sub-spool 16 'also has a rightmost throttle hole 16'a', a spring chamber 16'b 'communicating with the throttle hole 16'a' and in which a spring 17 'is mounted, and an end portion. A throttle hole 16'c 'is provided. Spring retainers 18 and 18 'are provided at both ends of the outer spool 15 respectively.
5, which closes the spring chambers 16b, 16'b ', this end region of the outer spool 15 being located in the right end chamber 19' and the left end chamber 19 '' of the cylinder chamber 19. The right end chamber 19 'and the left end chamber 19''are respectively provided with a check valve B comprising a valve body 20 and a spring 21 and a valve body 20' and a spring 21 '.
And is connected to a common communication passage 27 through a check valve C composed of

When the outer spool 15 is at the neutral position as shown in FIG. 1, the pressure oil from the hydraulic pump 1 returns to the tank 3 as it is. On the other hand, the input port 11 connected to the output port 29 of the hydraulic piston cylinder unit 8 and the input port 12 connected to the output port 30 are also blocked by the switching valve 4. As shown in FIG. 1, when the switching valve 4 is switched from the neutral position to the left connection position by operating the handle, the hydraulic oil from the hydraulic pump 1 is supplied from the input port 12 to the sub port through the opening 15 a of the outer spool 15. After entering the throttle hole 16a of the spool 16, the outer spool 1
5 through the output port 30 into the piston side chamber of the hydraulic piston cylinder unit 8 through the outlet port 15b, and the piston is moved to the left. At this time, as is evident from FIG. 1, the cross-sectional area of the flow path through which the hydraulic oil can be supplied from the passage 15a of the outer spool 15 through the sub-spool 16 is small, so that a small flow rate flows through the output port 30 and the piston of the hydraulic piston cylinder unit 8 Enter the concubine. In the pressure oil supply state, there is a tendency that the sub-spool 16 is displaced to the right due to a difference between the cross-sectional area of the spring chamber 16b of the right sub-spool 16 and the cross-sectional area of the outside of the right sub-spool 16. If it is necessary to operate the hydraulic piston cylinder unit 8 at a high speed, if the flow rate from the hydraulic pump 1 is increased, the right sub-spool 16 is displaced rightward to compress the spring 17 in the spring chamber 16b and Due to the rightward displacement of the sub spool 16, communication between the throttle hole 16c at the right end of the sub spool 16 and the throttle hole 15c at the right end of the outer spool 15 is interrupted.

When the piston rod receives a large load during the left stroke of the piston of the hydraulic piston cylinder unit 8 or reaches the stroke end of the left stroke of the piston, the hydraulic pressure of the piston side chamber of the hydraulic piston cylinder unit 8 becomes the set pressure of the relief valve 2. Can rise to Hydraulic pressure is relief valve 2
, The hydraulic pressure in the spring chamber 16b of the right sub-spool 16 and the hydraulic pressure on the right side of the sub-spool 16 become equal. As a result, the right side pressure is generated by the force of the spring 17 previously compressed by the right displacement of the sub-spool 16. The force acting on the right side of the sub-spool 16 is larger than the force acting on the left side of the sub-spool 16 by the force of the compression of the spring 17, whereby the right sub-spool 16 In this case, the throttle hole 16c at the right end of the sub spool 16 on the right side communicates with the through hole 15c at the right end of the outer spool 15 so that the pressure oil in the spring chamber 16b is released from the right end chamber 19 at the right end of the cylinder chamber 19. ′, Whereby the outer spool 15 performs a left stroke with the right sub-spool 16. As a result, the opening 15a 'of the outer spool 15
Pressure oil through the sub-spool 16 'on the left
From b ', it enters the output port 29, enters the piston rod side chamber of the hydraulic piston cylinder unit 8, the piston is switched to the right stroke in the middle of the left stroke, and the compression of the hydraulic piston cylinder unit 8 is started. At this time, the oil in the piston side chamber of the hydraulic piston cylinder unit 8 reaches the port 10a of the switching valve body 10 from the output port 30, but since the flow path is closed by the check valve A, the port 10a, the outside of the sub-spool 16 and the port 10b enters the communication passage 27, and enters the input port 11 from the port 10f of the switching valve body 10.
Is returned to the tank 3. This is the return stroke of the piston of the hydraulic piston cylinder unit 8 in the working process, and finally the stroke end of the return stroke of the piston is achieved, and the outer spool 15 reaches the stroke end of the left stroke (FIG. 3). .

After reaching the stroke end of the return stroke (right stroke) of the piston of the hydraulic piston cylinder unit 8, the pressure oil in the piston rod side chamber of the hydraulic piston cylinder unit 8 and communicating with the output port 29 is supplied to the left side. The hydraulic pressure in the spring chamber 16'b 'of the left sub-spool 16' and the right hydraulic pressure of the right end of the left sub-spool 16 'are accumulated in the relief valve 3 in the spring chamber 16'b' of the sub-spool 16 '. The oil pressure rises until it becomes equal to the set oil pressure, and both oil pressures are balanced, but the force for urging the left sub-spool 16 ′ to the right by the force of the compression of the spring 17 ′ is large,
As a result, the rightward displacement of the left sub-spool 16 ', and thus the left-hand throttle hole 16'c' of the sub-spool 16 'and the left-hand throttle hole 15'c' of the outer spool 15, communicate with each other to form the spring chamber 16'b. The pressure oil inside the cylinder spool 19 enters the left end chamber 19 '' of the cylinder chamber 19 via the throttle hole 15'c 'at the left end of the outer spool 15, and as a result, the spring 25 mounted in the left end chamber 19''of the cylinder chamber 19 is formed. The outer spool 15 is moved to the right with the assistance of the force of the compression. At this time, the oil in the right end chamber 19 'of the cylinder chamber 19 opens the check valve B, enters the communication passage 27, and is returned to the tank 3 from the port 10f of the switching valve body 10 via the input port 11. At the end of the right stroke of the outer spool 15, the outer spool 15 occupies the position shown in FIG.

In the state shown in FIG. 2, the hydraulic oil from the hydraulic pump 1 enters the inlet port 15a of the outer spool 15 from the input port 11, further passes through the outlet port 15b via the sub-spool 16, and the output port 30 to the hydraulic piston cylinder unit. 8 enters the piston side chamber. This is the outer spool 1 shown in FIG.
The relationship between the outer spool 15, the sub-spool 16, and the piston of the hydraulic piston cylinder unit 8 is the same as that described above with respect to the relative position between the sub spool 5 and the sub spool 16. In this manner, the right stroke and the left stroke of the outer spool 15 are continuously repeated corresponding to the left stroke and the right stroke of the piston of the hydraulic piston cylinder unit 8. As the pressure oil flow rate increases, the number of cycles of the left stroke and the right stroke increases.

In the position shown in FIG. 3, the hydraulic pump 1
The pressure oil which has flowed out passes through the input port 12, passes through the port 10d of the switching valve body 10, the through port 15a 'of the outer spool 15, the right side of the right end of the left sub spool 16', and further through the through port 15b of the outer spool 15. ′, Enters the output port 29 from the port 10 e, enters the piston rod side chamber of the hydraulic piston cylinder unit 8, and acts on the shortening stroke of the hydraulic piston cylinder unit 8. In the position of FIG.
The oil in the piston side chamber of the hydraulic piston cylinder unit 8 enters the communication passage 27 via the output port 30 and the port 10b, and is similarly returned from the input port 11 to the tank 3 via the port 10e. At the stroke end of the right stroke of the hydraulic piston cylinder unit 8, the outer spool 15 occupies the position shown in FIG.

When the connecting position of the switching valve 4 is first selected by operating the handle of the three-position four-connection switching valve 4 as described above, the left stroke or the right stroke of the piston of the hydraulic piston cylinder unit 8 is performed. The right or left stroke is then carried out, after which this stroke will be repeated automatically and continuously. Represents

FIGS. 4, 5 and 6 show a second embodiment of the automatic switching valve device according to the present invention. The automatic switching valve device according to FIGS. 4, 5 and 6 differs from the automatic switching valve device according to FIGS. 1, 2 and 3 in that the sub-spools are not provided separately on the left and right sides, a sub-spool is provided on the right side, and Is provided with only a needle valve. In FIG.
Is a hydraulic pump, 2 is a relief valve, 3 is an oil tank and 4
Denotes a three-position four-connection switching valve and 8 denotes a hydraulic piston-cylinder unit.

The automatic switching valve device is configured as follows. The output port of the three-position four-connection switching valve 4 is connected to the input port 11 and the input port 12 of the switching valve body 10 via a conduit. The input port 11 and the input port 12 are connected to the cylinder chamber 19, respectively. Cylinder chamber 19
From the hydraulic piston cylinder unit 8 via two output ports 29, 30. The output port 12 is similarly connected to a cylinder chamber 19 via a check valve A comprising a valve body 13 and a spring 14. Cylinder chamber 19
The outer spool 15 in which the sub-spool 16 is movably fitted inside is provided so as to be movable in the longitudinal axis direction of the cylinder chamber 19.

The output port of the three-position / four connection switching valve 4 is connected to the input port 11 and the input port 12 of the valve body 10 via a conduit.
Connected to The input port 11 and the input port 12 are connected to the cylinder chamber 19, respectively. Switching valve body 1
0, the ports 10a, 10b, 10c, 10d, 10
e and 10f are formed. A conduit is connected from the cylinder chamber 19 to the hydraulic piston cylinder unit 8 via two output ports 29, 30. The output port 12 is similarly connected to a cylinder chamber 19 via a check valve A comprising a valve body 13 and a spring 14. An outer spool 15 into which an inner spool 16 is movably fitted is provided in the cylinder chamber 19 so as to be movable in the longitudinal axis direction of the cylinder chamber 19. Outlet 15 for outer spool 15
a, 15b, aperture 15c, port 15d, and port 15
throttle hole 15 on the axis of outer spool 15 connected to d
e, a spring chamber 15f on the axial line and a wide spring chamber 15g at the left end are formed. A throttle hole 16a and a spring chamber 16b are provided on the right side of the sub-spool 16, and a through hole 16d, a hollow chamber 16e and a throttle hole 16f are provided in the center. A spring 17 is mounted in the spring chamber 16b. A throttle hole 15 is provided in the left spring chamber 15f of the outer spool 15.
The needle valve body 22 is mounted with its pointed end facing the e.
And a spring retainer 24 is screwed to the left end of the spring chamber 15f. Outer spool 15
A spring 25 for urging the outer spool 15 to the right is mounted in a spring chamber 15g at the left end of the spring. The right end of the right end chamber 19 'of the cylinder chamber 19 is screwed to the outer spool 15 and provided with a spring retainer 18. The right end chamber 19 'of the cylinder chamber 19 communicates with a communication passage 27 through a check valve B comprising a valve body 20 and a spring 21, and the communication passage 27 is connected to a left end of a similarly configured valve body 20' and spring 21 '. Is connected to the left end chamber 19 '' of the cylinder chamber 19 via a check valve C comprising The communication passage 27 is connected to the port 10 opening to the cylinder chamber 19.
b and 10f, and is connected to the tank 2 from the port 10f via the input port 11.

When the outer spool 15 is at the neutral position as shown in FIG. 4, the pressure oil from the hydraulic pump 1 returns to the tank 3 as it is. On the other hand, the input port 11 connected to the output port 29 of the hydraulic piston cylinder unit 8 and the input port 12 connected to the output port 30 are also blocked by the switching valve 4. As shown in FIG. 4, when the outer spool 15 is switched from the neutral position to the left position by operating the three-position / four-connection switching valve 4, the hydraulic oil from the hydraulic pump 1 flows from the input port 12 to the through port 15a of the outer spool 15. Through the throttle hole 16d of the sub-spool 16, through the outlet port 15b of the outer spool 15, through the output port 30, into the piston side chamber of the hydraulic piston cylinder unit 8, and causes the piston to move to the left. At this time, as is apparent from FIG. 4, the output port 30 from the neutral position through the flow path from the opening 15a of the outer spool 15 to the other opening 15b of the outer spool 15 through the opening 16d of the right sub-spool 16 To the piston side chamber of the hydraulic piston cylinder unit 8 to move the piston to the left. The left stroke of the piston is a working stroke of the hydraulic piston cylinder unit 8, that is, an extension stroke.

When the flow rate of the hydraulic pump 1 increases, pressure oil accumulates in the hollow chamber 16e of the sub-spool 16, thereby displacing the sub-spool 16 to the right, and the spring in the right spring chamber 16b of the sub-spool 16 17 is compressed. When the piston rod receives a large load during the left stroke of the hydraulic piston cylinder unit 8 or when the piston of the hydraulic piston cylinder unit 8 reaches the stroke end of the left stroke, the left stroke of the piston is performed as follows. Or from the stroke end of the left stroke to the right stroke. The hydraulic pressure in the piston-side chamber of the hydraulic piston cylinder unit 8 can increase to the magnitude set by the relief valve 3. This hydraulic pressure acts on the spring chamber 16b of the sub-spool 16 through the passage 15a of the outer spool 15 and the throttle hole 16a of the sub-spool 15, and also acts on the left hollow chamber 16e of the sub-spool 16. At this time, the spring chamber 16b of the sub-spool 16 and the hollow chamber 1
6e increases to the set pressure of the relief valve 3 and the hydraulic pressures acting on both chambers are balanced. The force between the hollow chamber 16e and the spring chamber 16b of the sub-spool 16 The force displaced to the left is superior, whereby the sub-spool 16 is displaced to the left.
As a result, the opening 16d of the hollow chamber 16e of the sub-spool 16
And the throttle hole 15c of the outer spool 15 communicate with each other to form a flow path. This flow path is connected to the communication path 28, so that the pressure oil enters the right end chamber 19 'of the cylinder chamber 19 and moves the outer spool 15 to the left. At the end of the stroke of the left stroke, the outer spool 15 reaches the left end position shown in FIG.
At this time, the oil in the left end chamber 19 '' of the cylinder chamber 19 simultaneously
The check valve C including the valve body 20 'and the spring 21' is opened to enter the communication passage 27, and further, the input port 11 is connected to the port 10f.
Is returned to the tank 3. The piston of the hydraulic piston cylinder unit 8 reaches the rightmost stroke end at the end of its right stroke.

The switching of the piston of the hydraulic piston cylinder unit 8 to the left stroke again from the state shown in FIG. 6 is performed as follows. That is, in the state of FIG. 6, the pressure oil discharged from the hydraulic pump 1
Outer spool 1 through throttle hole 16f of sub-spool 16
From the outside of the valve 5, through the port 10e of the switching valve body 10, the output port 29 enters the piston rod side chamber of the hydraulic piston cylinder unit 8. Thereby, the right stroke of the piston of the hydraulic piston cylinder unit 8 is performed.
During the right stroke of the piston, the pressure oil in the piston side chamber of the hydraulic piston cylinder unit 8 enters the communication path 27 from the output port 30 through the outside of the outer spool 15 and the port 10b of the switching valve body 10, and enters through the port 10f. It is returned from the port 11 to the tank 3. The right stroke of the piston is a return stroke, and does not require high oil pressure as in the working stroke like the left stroke. Therefore, when the set pressure of the needle valve is set to be equal to or less than the set pressure of the relief valve 2, the output port 2
A part of the pressure oil in the cylinder 9 is pushed down from the throttle hole 15 e of the outer spool 15 against the force of the spring 23 to the left to push the needle valve body 22 to the left. Into the left end chamber 19 '', a force is generated to slightly displace the outer spool 15 to the right.
5 from the outside of the sub-spool 16, by narrowing the flow path by the port 10 e of the switching valve body 10 to the output port 2.
The flow rate entering into 9 will be reduced. As a result, relief valve 2
The piston can perform the right stroke at a low pressure equal to or lower than the set pressure, and economic operation can be performed. The pressure oil in the throttle hole 15d of the outer spool 15 is removed from the throttle hole 15e of the outer spool 15.
When the needle valve element 22 is depressed to the left against the force of the spring 23 and pressurized oil flows, the pressurized oil accumulates in the left end chamber 19 '' of the cylinder chamber 19 through the small hole at the center of the spring retainer 24, and With the aid of 25 forces, the outer spool 15 performs a right stroke with the sub-spool 16. At this time, the outer spool 1
5, the right end chamber 1 of the cylinder chamber 19 located at the right end area
The oil in 9 'opens the check valve B, enters the communication passage 27, and is returned to the tank 3 from the port 10f via the input port 11. At the stroke end of the right stroke of the sub-spool 16, the relative positions of the outer spool 15 and the sub-spool 16 are the same as those shown in FIGS. 4 and 5. Thereby, the piston of the hydraulic piston cylinder unit 8 is switched from the stroke end of the right stroke to the left stroke.

When the connection position of the switching valve 4 is first selected by operating the handle of the switching valve 4 as described above,
The left or right stroke of the piston of the hydraulic piston cylinder unit 8 is performed, and the hydraulic piston cylinder unit 8
The left and right strokes of the sub-spool 16 are performed corresponding to the left and right strokes of the piston, and as a result, the reciprocating stroke of the piston of the hydraulic piston cylinder unit 8 and the outer spool of the sub-spool is continuously repeated.

FIG. 7 shows a third embodiment of the automatic switching valve device according to the present invention.
1 shows an embodiment. This automatic switching valve device is formed as an automatic switching pressure increasing valve device. In FIG. 7, 1 is a hydraulic pump, 2 is a relief valve, 3 is an oil tank and 4 is a switching valve,
In particular, the three-position, four-connection switching valve, 8 represents a hydraulic piston-cylinder unit. The automatic switching pressure increasing valve device is configured as follows.

The output port of the switching valve 4 is connected to an input port 41 and an input port 42 of the automatic switching valve body 40 via a conduit. The input port 41 and the input port 42 are connected to the cylinder chamber 49, respectively. The input port 42 is connected to a right end chamber 49 'of the cylinder chamber 49 via a check valve D comprising a valve body 43 and a spring 44, and to the valve body 43''and the spring 4
4 ″ can be connected to the left end chamber 49 ″ of the cylinder chamber 49 via a check valve F, and the valve body 43 ′ and the spring 4
It can be connected to the left part of the cylinder chamber 49 via a check valve E consisting of 4 '. Left and right 2 inside the cylinder chamber 49
An outer spool 45 in which three sub-spools 46 'and 46 are fitted so as to be displaceable in the axial direction is disposed so as to be movable in the axial direction. The outer spool 45 has through holes 45a 'and 45 at symmetrical positions with respect to the center thereof.
b ', a throttle hole 45c', openings 45a and 45b, and a throttle hole 45c. The left sub-spool 46 'has a throttle hole 46'a' at its right end, a spring chamber 46'b 'connected to the throttle hole 46'a', and a throttle hole 46'c 'at the left end of the sub-spool 46'. The sub-spool 46 is provided with a throttle hole 46a at its left end, a spring chamber 46b connected to the throttle hole 46a, and a throttle hole 46c at the left end of the sub-spool 46. Springs 47, 47 'are mounted in the spring chambers 46b and 46'b', and the sub spools 46, 4 '
At the right and left ends of 6 'are spring retainers 48, 48', respectively.
Are screwed together to close the spring chambers 46b and 46'b '. Two output ports 58, 59 are provided in the cylinder chamber 49.
The booster valve main body 60 is provided with two input ports 61 and 62 connected to the output ports 58 and 59, and the input ports 61 and 62 are connected to a booster valve cylinder chamber 69. . The input ports 61 and 62 each have a check valve G and a valve body 6 which are branched and include a valve body 63 and a spring 64.
The right end chamber 69 "" of the pressure-intensifying valve cylinder chamber 69 and the pressure-increasing valve cylinder chamber 69 via a check valve H comprising a 3 'and a spring 64'.
Is connected to the left end chamber 69 ′ ″ ″. Right end room 6
9 '''and the left end chamber 69''''' are respectively connected to booster valve housings 67 and 6 mounted on the booster valve main body 60.
7 '. The pressure-intensifying valve cylinder chamber 69 has a left portion 69 ″ and a right portion 6 symmetrically with respect to the center.
9 '. A pressure-intensifying piston 66 is provided in the pressure-intensifying valve cylinder chamber 69 so as to be movable in the axial direction thereof.
The pressure-intensifying piston 66 integrally includes a left portion 66b and a pressure-increasing piston right portion 66a having a smaller cross-sectional area on the left and right sides. The left part 66b and the right part 66a can enter the '''''' and right end chambers 69 '''' respectively during the left and right strokes of the pressure-intensifying piston 66. Left end room 69 ′ ″ ″ and right end room 6
9 '''is connected to the communication passage 73 via a check valve J comprising a valve body 70' and a spring 71 'and a check valve I comprising a valve body 70 and a spring 71, respectively. The communication passage 73 is connected to the piston side chamber of the hydraulic piston cylinder unit 8 via one output port 74. A conduit 75 is similarly connected to the piston side chamber, and the conduit 75 is connected to the input port 41 via a check valve 77. Further, a conduit 76 is connected to the piston rod side chamber of the hydraulic piston cylinder unit 8, and the conduit 76 is connected to the input port 42.

The automatic switching booster valve operates as follows. The pressure oil discharged from the hydraulic pump 1 is supplied to a three-position four-connection switching valve 4
For example, when the right connection position is selected by operating the handle, the pressure oil enters the cylinder chamber 49 from the input port 41, passes through the opening 46a of the outer spool 45, the left side of the left end of the right sub-spool 46, and the outer spool. 45, through the output port 59 and the input port 62 of the pressure-intensifying valve main body 60, and enters the right-hand portion 69 'of the pressure-intensifying valve cylinder chamber 69. At the same time, the pressure oil opens the check valve G to enter the right end chamber 69 ′ ″ of the pressure-intensifying valve cylinder chamber 69, and further opens the check valve I to communicate with the piston of the hydraulic piston cylinder unit 8 through the communication passage 73 and the output port 74. After entering the side chamber, the extension stroke of the hydraulic piston cylinder unit 8 is performed. At this time, the oil in the left end chamber 69 ′ ″ ″ of the booster valve cylinder chamber 69 is formed by the difference in the cross-sectional area between the central region and the end regions 66 a and 66 b of the booster piston 66. 'And the left end chamber 6 of the booster valve cylinder chamber 69
The hydraulic pressure in the left end chamber 69 ′ ″ ″ is increased at the ratio of the cross-sectional area of 9 ″ ″ ″ and the check valve J set to a pressure higher than the set pressure of the relief valve 2 is opened to open the communication passage 27. And a unit amount of pressurized oil enters the piston side chamber of the hydraulic piston cylinder unit 8 via the output port 74, and causes the piston to perform the extension stroke by the unit stroke. At this time, the oil is returned to the tank 3 via the conduit 76 connected to the piston rod side chamber of the hydraulic piston cylinder unit 8. At this time, since the conduit 75 connected to the piston side chamber of the hydraulic piston cylinder unit 8 is connected to the check valve 77, the conduit 75
The oil cannot flow through. The pressure oil branched from the input port 62 enters the right end chamber 69 ′ ″ of the pressure-intensifying valve cylinder chamber 69 by opening the check valve G, but the check valve I is higher than the set pressure of the relief valve 3. Since the pressure is set, the check valve I does not open.

On the other hand, the pressure oil in the right portion 69 ′ of the pressure-intensifying valve cylinder chamber 69, on which the set pressure of the relief valve 2 is acting, is supplied to the port 40 a of the cylinder chamber 49 of the switching valve body 10 and the throttle hole of the right sub-spool 46. 46a, right sub spool 4
6 and the right sub-spool 46
And the hydraulic pressure in the spring chamber 46b is in equilibrium, and only the force due to the compression of the spring 47 is different, so that the sub-spool 46 is displaced to the left. The right end throttle hole 46c communicates with the right end throttle hole 45c of the outer spool 45, and the port 4
0c, pressure oil enters the right end chamber 49 'of the cylinder chamber 49,
This causes the outer spool 45 to move to the left. At this time, the oil in the left end chamber 49 ″ of the cylinder chamber 49 opens the check valve F, enters the communication passage 56, and passes through the input port 42 to the tank 3.
Returned to. As a result, the pressure oil acting on the input port 41 is supplied to the port 40 d of the switching valve body 40 and the outer spool 4.
5, through the outside of the right sub spool 46, from the port 40e to the output port 58, the booster valve cylinder chamber 69
, And the check valve H is opened to enter the left end chamber 69 ′ ″ of the pressure-intensifying valve cylinder chamber 69. As a result, the booster piston 66 moves the right end chamber of the booster valve cylinder chamber 69 according to the ratio of the cross sectional area of the left portion 69 '' of the booster valve cylinder chamber 69 to the cross sectional area of the right end chamber 69 '''of the booster valve cylinder chamber 69. The oil at 69 '''is pressurized to the set pressure of check valve I. The check valve I is opened by the hydraulic pressure pressurized thereby, and the right end chamber 6 of the booster valve cylinder chamber 69 is opened.
The oil in 9 ′ ″ is increased in pressure and enters the communication passage 73, and a unit amount of hydraulic oil enters the piston side chamber of the hydraulic piston cylinder unit 8 from the output port 74, and is extended to the hydraulic piston cylinder unit 8 in the unit stroke extension stroke. Is performed. At this time, the oil is returned to the tank 3 via the conduit 76 connected to the piston rod side chamber of the hydraulic piston cylinder unit 8. At this time, since the conduit 75 connected to the piston side chamber of the hydraulic piston cylinder unit 8 is connected to the check valve 77, oil cannot flow through the conduit 75.

The right end chamber 69 '''of the pressure-intensifying valve cylinder chamber 69
When the pressure oil is sent to the communication passage 27 by opening the check valve I, the pressure oil in the input port 61, and hence in the output port 58, is supplied to the port 40e of the switching valve body 60 and the communication port 45e of the outer spool 45. , Throttle hole 46 'in left subspool 46'
a ', the left end chamber 49' of the cylinder chamber 49 from the port 40c 'through the left end throttle hole 45f of the outer spool 45 which communicates with the left end throttle hole 46'c' of the sub spool 46 'through the spring chamber 46'b'. ′ And the outer spool 45 is moved to the right with the aid of the force of the spring 55 in the left end chamber 49 ″ of the cylinder chamber 49. At this time, the right end chamber 4 of the cylinder chamber 49
The oil in 9 'is returned to the tank 3 from the input port 42 by opening the check valve D.

As described above, the left and right strokes of the pressure increasing piston 66 are continuously repeated corresponding to the right and left strokes of the outer spool 45. When a large load acts on the piston rod during the upward stroke (extension stroke) of the piston of the hydraulic piston cylinder unit 8 or when the piston reaches the stroke end of the upward stroke, the relief side valve 3 is provided to the piston side chamber of the hydraulic piston cylinder unit 8. It can rise to a pressure above the set pressure and thus to the pressure set by the check valve I or J.
If the hydraulic pressure increases due to a large load acting on the piston rod or the end of the piston at the stroke end of the upward stroke, even if the check valve I or J is open, the right end chamber 69 ′ of the booster valve cylinder chamber 69. '' Or left end room 6
The pressure oil at 9 ′ ″ ″ is equal to the oil pressure of the piston side chamber of the hydraulic piston cylinder unit 8 and the check valve I
Or no pressurized oil can flow through J, so that check valve I or J closes. In this state, the piston of the hydraulic piston cylinder unit 8 stops at the stroke end of the upward stroke or in the middle of the upward stroke. Therefore, unless the operator subsequently switches the switching valve 4 to the left position by operating the handle, the state remains as it is. . When the operator switches the switching valve 4 to the left position by operating the handle, the input port 6 of the pressure-intensifying valve main body 60 passes from the input port 41 via the output port 58 or 59.
The pressure oil communicated with 1 or 62 is returned to the tank 2 via the input port 62, and the piston of the hydraulic piston cylinder unit 8 is returned to the lower stroke end.

According to the present invention, the disadvantages of the prior art can be avoided, the switching control of the piston of the hydraulic piston cylinder unit can be smoothly and quickly repeated, and the reciprocating stroke of the piston can be accelerated. In particular, safety against overload is achieved during operation of a hydraulic piston cylinder unit used as a drive for a crusher or the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an initial state of a first embodiment of an automatic switching valve device according to the present invention.

FIG. 2 is a schematic diagram showing a state of the first embodiment of the automatic switching valve device according to the present invention when the cylinder is extended.

FIG. 3 is a schematic diagram showing a state of the first embodiment of the automatic switching valve device according to the present invention when the cylinder is shortened.

FIG. 4 is a schematic diagram showing an initial state of a second embodiment of the automatic switching valve device according to the present invention.

FIG. 5 is a schematic diagram showing a state of a second embodiment of the automatic switching valve device according to the present invention when the cylinder is extended.

FIG. 6 is a schematic diagram showing a second embodiment of the automatic switching valve device according to the present invention when the cylinder is shortened.

FIG. 7 is a schematic diagram showing an initial state of a cylinder in a third embodiment of the automatic switching valve device according to the present invention.

[Description of sign]

 Reference Signs List 1 hydraulic pump 2 relief valve 3 tank 4 3 position 4 connection switching valve 8 hydraulic piston cylinder unit 10 switching valve body 10a port 10b port 10c port 10d port 10e port 10f port 11 input port 12 input port 13 valve body 14 spring 15 outer spool 15a port 15a 'port 15b spring chamber 15b' spring chamber 15c aperture 15c 'aperture 15d aperture 15e aperture 15f spring chamber 15g spring chamber 16 sub spool 16a right aperture 16b spring chamber 16c aperture 16' left 16'a 'Restriction hole 16'b' Spring chamber 16'c 'Restriction hole 16d Passage 16e Hollow chamber 16f Restriction hole 17 Spring 17' Spring 18 Spring retainer 18 'Spring retainer 19 Cylinder chamber 19' Right end chamber 19 '' Left end chamber 20 Valve 0 'valve body 21 spring 21' spring 22 needle valve body 23 spring 24 spring retainer 25 spring 27 communication path 28 communication path 29 output port 30 output port 40 switching valve body 40a port 40a 'port 40b port 40b' port 40c port 40c ' Port 41 Input port 42 Input port 43 Valve body 43 'Valve body 43' 'Valve body 44 Spring 44' Spring 44 '' Spring 45 Outer spool 45a Opening 45a 'Opening 45b Opening 45b' Opening 45c Restriction hole 45c ' Restriction hole 46 Right sub-spool 46a Restriction hole 46b Spring chamber 46c Restriction hole 46 'Left sub-spool 46'a' Restriction hole 46'b 'Spring chamber 46'c' Restriction hole 47 Spring 47 'Spring 48 Spring retainer 48' Spring retainer 49 Cylinder chamber 49 'Right end chamber 49' 'Left end chamber 56 Communicating passage 58 Output port 59 Output port 60 Booster valve body 61 Input port 62 Input port 63 Valve body 63 'Valve body 64 Spring 64' Spring 66 Booster piston 66a Small diameter portion on right side 66b Small diameter portion on left side 67 Booster valve right side Housing 67 ′ Pressure booster valve left housing 69 Pressure booster valve cylinder chamber 69 ′ Right part 69 ″ Left part 69 ″ Right end chamber 69 ″ ″ Left end chamber 70 Valve body 70 ′ Valve body 71 Spring 71 ′ Spring 73 Communication path 74 Output port 75 Conduit 76 Conduit 77 Check valve

Claims (4)

[Claims] In an automatic switching valve device, an input port (11 and 12) is connected to a cylinder chamber (19) of a switching valve body (10), and a switching valve is provided between an outer spool (15) and an inner side thereof. A sub-spool (16, 16 '; 16) fitted movably in its axial direction, the cylinder chamber (19) being connected to an output port (29, 30) for a hydraulic piston-cylinder unit (8). When the hydraulic pressure at the output port (29 or 30) reaches the set pressure of the relief valve (3), the displacement of the sub spool (16, 16 '; 16) causes the left and right sides of the outer spool (15) to move. When the stroke is performed and its position is switched, the stroke direction of the piston of the hydraulic piston cylinder unit (8) is switched, whereby the hydraulic piston corresponds to the left and right strokes of the switching valve. The automatic switching valve device, characterized in that the piston of the right and left stroke Linda units (8) are repeated continuously. 2. An outer spool (15) having two sub-spools (16, 16 ') arranged symmetrically with respect to the center thereof so as to be movable in its axial direction, and having a spring chamber (16).
b, 16'b ') is provided with a spring (17, 17'), and the pressure oil of the output port (29 or 30) communicates with the spring chamber (16b or 16'b '). Therefore, the left and right strokes of the outer spool (15) can be adjusted so that the sub-spool (16 or 16) increases when the load on the piston increases during the right / left stroke of the hydraulic piston cylinder unit (8) or at the stroke end of the right / left stroke. 2. The automatic switching valve device according to claim 1, wherein the right and left strokes of the hydraulic piston cylinder unit (8) are performed by performing the left and right strokes of the outer spool (15) via the displacement of (1). 3. A sub-spool (16) is provided in the outer spool (15).
6) has one spring chamber (16) mounted with a spring (17).
b) is provided, and the outer spool (15) is provided with a spring chamber (15f) connected to the throttle hole (15e), and the needle valve element (22) and the spring ( 23) is mounted, the needle valve element (22) is urged to close the restriction hole (15e) by the force of the spring (23), and the restriction of the needle valve communicating with the output port (29 or 30). The hole (15e) is connected to the output port (2
9 or 30) Needle valve element (22) by increasing hydraulic pressure
, The stroke of the outer spool (15) is switched from the stroke end of the left stroke to the right stroke, whereby the piston of the hydraulic piston cylinder unit (8) is switched from the right stroke to the left stroke,
On the other hand, when the pressure oil at the output port (30 or 29) communicates with the spring chamber (16b) of the sub-spool (16), the outer spool (1) is displaced via the leftward displacement of the sub-spool (16).
5. The automatic switching valve device according to claim 1, wherein 5) switches the stroke of the hydraulic piston cylinder unit (8) from the left stroke to the right stroke by switching from the stroke end of the right stroke to the left stroke. 4. An automatic switching valve device in which a switching valve is fitted into an outer spool (45) and two sub-spools (46, 46) which are slidably fitted in its axial direction symmetrically with respect to the center thereof. '), And the output ports (58, 59) of the switching valve are connected to the right portion (69') or the left portion (6) of the booster valve cylinder chamber (69) of the booster valve body (60).
9 "), while the booster piston (66)
The smaller left and right portions (66a, 66b) of the cross section of the right side can enter the right end chamber (69 "") and the left end chamber (69 "") of the booster valve cylinder chamber (69), thereby switching. The right and left strokes of the pressure booster piston (66) are performed corresponding to the left and right strokes of the outer spool (45) of the valve, thereby connecting the pressure booster valve body (60) connected to the cylinder chamber of the hydraulic piston cylinder unit (8). The pressure oil that has been alternately increased in pressure by the unit amount is supplied to the passage (73) from the left end chamber (69 "") and the right end chamber (69 "") of the pressure increase valve cylinder chamber (69). The automatic switching valve device according to claim 1, wherein the piston of the hydraulic piston cylinder unit (8) is moved by a unit stroke in the same stroke direction.