JPH0348361B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for switching between the inflow path and the first load path, between the inflow path and the second load path, between the outflow path and the first load path, and between the outflow path and the first load path, by operating a pilot switching valve. The present invention relates to a fluid control valve that disconnects communication between two load paths and operates a fluid actuator connected to both load paths using pressure fluid from a pressure source such as a fluid pump connected to an inflow path.

As one of this type of fluid control valve, a first valve that cuts off communication between an inflow path 1 and a first load path 2, as shown in FIG. A poppet valve body 3, a second poppet valve body 5 for communicating and blocking communication between the inflow path 1 and the second load path 4, a third poppet valve body 7 for communicating and disconnecting between the outflow path 6 and the first load path 2, and an outflow path. 6 and the second load path 4, each pilot chamber 9 is formed at the back of each poppet valve body 3, 5, 7, 8 by a pilot switching valve V1. 10,11,1
2, between the inflow path 1 and the first load path 2, between the inflow path 1 and the second load path 4, and the outflow path 6.
and the first load path 2, and between the outflow path 6 and the second load path 4.
Pressure fluid is introduced into the respective pilot chambers 9, 12 of the first poppet valve body 3 and the fourth poppet valve body 8 through the first pilot passage 13, and
By discharging the fluid in each of the pilot chambers 10 and 11 of the poppet valve body 5 and the third poppet valve body 7 through the second pilot passage 14, the fluid between the inflow passage 1 and the second load passage 4 and between the outflow passage 6 and the first load is discharged. The passage 2 is communicated with the inflow passage 1 and the first load passage 2, and the outflow passage 6 and the second load passage 4 are disconnected. 10, 11 through the second pilot passage 14, and the fluid in each pilot chamber 9, 12 of the first poppet valve body 3 and the fourth poppet valve body 8 is discharged through the first pilot passage 13. between the inflow path 1 and the first load path 2 and the outflow path 6
and the second load path 6, and the inflow path 1
and the second load path 4 and between the outflow path 6 and the first load path 2; and the first pilot path 1.
3 or a relief valve 1 and an on-off valve 16 operated by fluid applied through the second pilot passage 14.
A fluid control valve with an unload valve 18 controlled by 7 is proposed.

In such a fluid control valve, since the poppet valve bodies 3, 5, 7, and 8 are employed in the switching valve 15, there is little leakage when the valve bodies are shut off.
By introducing and discharging pressure fluid into each pilot chamber 9, 10, 11, 12 formed at the back of each poppet valve body 3, 5, 7, 8,
Since switching between 4 and 6 is performed, the operational response is good. Since the unload valve 18 is controlled by the on-off valve 16 and the relief valve 17, which are operated by the fluid applied through the first pilot passage 13 or the second pilot passage 14, the pressure rise and fall of the inflow passage 1 can be appropriately controlled. can get. However, when the on-off valve 16 is operated, the unload valve 18 will not operate unless the pressure in the inflow passage 1 rises to the pressure specified by the relief valve 17, and each poppet valve The inlet passage 1 is closed by the restriction at the valve parts 3 and 5.
A differential pressure is generated between the load paths 2 and 4, and the pressure in the inflow path 1, that is, the discharge pressure of the fluid pump P connected to the inflow path 1, is increased at the actuator (fluid cylinder) C connected to each load path 2, 4. The pressure may exceed the required pressure, and energy loss (unnecessary high-load operation of the fluid pump P) due to this is unavoidable.

The present invention has been made in view of this problem, and its purpose is to eliminate the above-mentioned energy loss without sacrificing the advantages of the conventional device.

In order to achieve such an object, the present invention provides the fluid control valve with a first poppet valve body that disconnects communication between the inflow path and the first load path, and a second poppet valve body that disconnects communication between the inflow path and the second load path. It has a poppet valve body, a third poppet valve body that disconnects communication between the outflow path and the first load path, and a fourth poppet valve body that disconnects communication between the outflow path and the second load path,
By guiding pressure fluid to each pilot chamber formed at the back of each poppet valve body by a pilot switching valve, a pressure fluid is established between the inflow path and the first load path, between the inflow path and the second load path, and between the outflow path and the first load path. The load path and the outflow path and the second load path are cut off, pressure fluid is introduced into each pilot chamber of the first poppet valve element and the fourth poppet valve element through the first pilot path, and the pressure fluid is introduced into the pilot chamber of the first poppet valve element and the fourth poppet valve element. By discharging the fluid in each pilot chamber of the body and the third poppet valve body through the second pilot passage, communication is established between the inflow passage and the second load passage, and between the outflow passage and the first load passage, and also between the inflow passage and the second load passage. the first load passage and the outflow passage and the second load passage, and introducing pressure fluid into each pilot chamber of the second poppet valve body and the third poppet valve body through the second pilot passage, and By discharging the fluid in each pilot chamber of the valve body and the fourth poppet valve body through the first pilot passage, communication is established between the inflow passage and the first load passage, and between the outflow passage and the second load passage, and also between the inflow passage and the second load passage. A first switching valve that shuts off between the second load path and between the outflow path and the first load path, and a valve body that controls communication between the inflow path and the outflow path, and a fluid formed at the back of the valve body. a pressure control valve that controls the pressure in the inflow passage by fluid pressure applied to the chamber; and the fluid chamber of the pressure control valve is connected to the discharge passage;
a valve body that selectively communicates with the load path or the second load path, which communicates the fluid chamber with the discharge path when pressure fluid is supplied through the first pilot path and the second pilot path; a second switch which communicates the fluid chamber with the second load path when pressure fluid is supplied through the first pilot path, and communicates the fluid chamber with the first load path when pressure fluid is supplied through the second pilot path; a pilot relief valve that sets the maximum pressure applied to the fluid chamber of the pressure control valve; and a throttle that restricts the flow of pressure fluid into the fluid chamber when the pilot relief valve operates for relief. . Note that the first switching valve has the same configuration as the switching valve 15 of the conventional device.

Accordingly, in the present invention, since the poppet valve element is employed in the first switching valve, there is little leakage when the valve element shuts off. By introducing and discharging pressure fluid into each pilot chamber formed at the back of each poppet valve body, the inflow path, first load path, second load path, and outflow path are switched.
Good operational response. 1st pilot path or 2nd pilot path
Since the pressure control valve is controlled by the second switching valve operated by the fluid applied through the pilot passage, the pressure rise and fall of the inflow passage can be accurately achieved.
Of course, when all the poppet valve bodies are closed, the fluid chamber of the pressure control valve is communicated with the outflow path by the second switching valve, and the pressure in the inflow path becomes extremely low. When the value is low and the inflow path and the first or second load path are in communication, the fluid chamber of the pressure control valve is communicated with the first or second load path, and the pressure in the inflow path becomes the first or second load path. Since the required pressure is maintained in the second load path, the pressure in the inflow path does not always exceed the required pressure. Moreover, when the fluid chamber of the pressure control valve is communicated with the first or second load path and the pressure in the inflow path is set to the required pressure in the first or second load path, the pressure in the fluid chamber is When the set pressure of the pilot relief valve is reached, the pilot relief valve operates to quickly and accurately release the pressure fluid in the fluid chamber to the discharge path under the action of the throttle, and the pressure control valve quickly opens to prevent inflow. The pressure fluid in the passage is accurately bled to the outflow passage, and the pressure in the inflow passage does not exceed the pressure set by the pilot relief valve. Therefore, unnecessary high-load operation of the fluid pump can be avoided, and unnecessary energy loss can be eliminated.

An embodiment of the present invention will be described below based on the drawings. The fluid control valve according to the present invention shown in FIG. 2 is composed of a pilot switching valve V1, a first switching valve V2, a pressure control valve V3, and a second switching valve V4. The pilot switching valve V1 is connected to the pilot path 20.
This is an electromagnetic switching valve that communicates the pilot passage 21 and/or 22 with the pilot passage 20 as shown in the figure.
The pilot passage 20 may be made to communicate with the right pilot passage 21 and the left pilot passage 22 may be made to communicate with the discharge passage 23, or the pilot passage 20 may be made to communicate with the left pilot passage 21. 22 and the pilot path 2 on the right
1 can be communicated with the discharge path 23. Note that the discharge path 23 is connected to the tank T.

The operation of the first switching valve V2 is controlled by the pilot switching valve V1, and the main body 24 includes pilot passages 20, 21, 22, a discharge passage 23, an inflow passage 25, a first load passage 26, and a first switching valve V2. 2 load passage 27 and an outflow passage 28 are provided, and four different diameter holes 2 are provided.
9, 30, 31, 32 are valve seats 33, 3 on the stepped portions with different diameters.
4, 35, and 36, and poppet valve bodies 37, 38, 39, and 40 are slidably inserted into the holes 29, 30, 31, and 32 of different diameters, respectively. The inflow path 25 has different diameter holes 29 and 30.
It communicates directly with the small diameter hole of , and also communicates with the pilot passage 20 via a check valve 41, and is connected to the fluid pump P. The first load path 26 directly communicates with the large diameter hole of the different diameter hole 29 and the small diameter hole of the different diameter hole 31, and also communicates with the pilot path 20 via the check valve 42, and is connected to the cylinder as a fluid actuator. It is connected to one chamber of C. The second load path 27 includes a large diameter hole of the different diameter hole 30 and a different diameter hole 3.
The check valve 43 directly communicates with the small diameter hole of No.2.
It communicates with the pilot passage 20 via the cylinder C, and is connected to the other chamber of the cylinder C. Outflow channel 28
is in direct communication with the large diameter holes of the different diameter holes 31 and 32, and is connected to the tank T. Each poppet valve body 37, 38, 39, 40 has a valve seat 33, 34, 3
5, 36, and has pilot chambers 44, 45, 46, 47 formed in the back. Pilot chambers 44 and 47 communicate with pilot passage 21, and pilot chambers 45 and 46 communicate with pilot passage 22.

The pressure control valve V3 controls the pressure within the inflow passage 25, and as shown in FIG.
Inflow path 25, first load path 26, second load path 27,
An outflow passage 28 is provided, as well as an inner hole 49 having a large diameter in the middle, and a spool valve 50 is slidably inserted into the inner hole 49.
The inlet passage 25 communicates with a small diameter hole of the inner hole 49, and the outlet passage 28 communicates with a large diameter hole of the inner hole 49. The first load path 26 and the second load path 27 are branch paths 51 and 52.
Fixed throttles 53 and 54 are provided in each branch path 51 and 52, respectively. Spool valve 50
, which controls communication between the inflow passage 25 and the outflow passage 28, is biased toward the small diameter hole of the inner hole 49 by a spring 55, and forms a fluid chamber 56 at the back.

The operation of the second switching valve V4 is controlled by pressure fluid supplied through the pilot passages 21 and 22 to control the operation of the pressure control valve V3, and as shown in FIG. 57 includes pilot passages 21 and 22, a discharge passage 23, and a first load passage 26.
The branch path 51 of the second load path 27, the branch path 52 of the second load path 27, and the passages 58, 59, 6 communicating with the fluid chamber 56, respectively.
0, 61, 62, and 63 are provided, and an inner hole 64 through which the passages 58 to 63 are opened is provided, and a spool valve 65 is slidably inserted into the inner hole 64. The inner hole 64 has a passage 6 in the middle part.
Annular grooves 66, 6 with openings 0, 61, 62, 63
7, 68, and 69, both ends are formed with a large diameter, and both ends are closed by plugs 70, 71. The spool valve 65 has a communication hole 7 in the middle part.
2 and are centered by a pair of springs 73 and 74 as shown in the figure, forming fluid chambers 75 and 76 with passages 58 and 59 opening at both ends. Further, the second switching valve V4 includes a spool valve 6.
5 cuts off the communication between the annular grooves 66 and 67,
Annular groove 67 or fluid chamber 56 of pressure control valve V3
A pilot relief valve (hereinafter simply referred to as a relief valve) 77 is installed in parallel to set the maximum pressure applied to the valve.

In the fluid control valve configured as above,
As shown in Fig. 2, when the pilot switching valve V1 is in the neutral position, the pilot passage 20 is connected to both pilot passages 2 and 2.
1 and 22, the pressure fluid from the fluid pump P passes through the inlet passage 25, the check valve 41, and the pilot passages 20, 21, and 22 to the pilot chambers 44,
45, 46, 47, and the poppet valve body 3
7, 38, 39, and 40 are between the inflow path 25 and the first load path 26, between the inflow path 25 and the second load path 27, between the first load path 26 and the outflow path 28, and between the second load path 27 and the outflow path 28. The piston of cylinder C is stopped because the gap is completely blocked. At this time, the pilot passage 2 is also connected to the fluid chambers 75 and 76 of the second switching valve V4.
Since pressure fluid is introduced through 1 and 22, the spool valve 65 has springs 73 and 22, as shown in FIG.
74 in the position shown, and the pressure control valve V3
The fluid chamber 56 includes a passage 63, an annular groove 67, and an inner hole 6.
4. The tank T is communicated through the annular groove 66 and the discharge passage 23. Therefore, at this time, the inflow path 25
When the internal pressure exceeds the force of the spring 55, the spool valve 65 slides the full stroke, and the inlet passage 25
The entire pressure fluid discharged into the chamber is bled to the outflow path 28, and the fluid pump P is unloaded.

When the pilot switching valve V1 is switched to the right position in this state, the pilot passage 21 is communicated with the discharge passage 23, and the pilot chambers 44, 47 and the fluid chamber 75 are communicated with the tank T. Therefore, in the first switching valve V2, the poppet valve body 37 can be pushed open by the pressure inside the inflow passage 25, and
The poppet valve body 40 can now be pushed open by the pressure in the second load path 27, and in the second switching valve V4, the spool valve 65 is connected to the fluid chamber 75,
76 slides against the spring 73, the annular grooves 66 and 67 are cut off, and the annular grooves 67 and 68 are communicated through the communication hole 72.
The pressure in the first load path 26 is applied to the fluid chamber 56 and the spool valve 50 slides downward in FIG. It is assumed that the pressure corresponds to the sum of
Therefore, at this time, the pressure fluid in the inlet passage 25 whose pressure corresponds to the sum of the force of the spring 55 and the pressure in the first load passage 26 is supplied to one chamber of the cylinder C through the first load passage 26. At the same time, the fluid discharged from the other chamber of the cylinder C through the second load path 27 is returned to the tank T through the outflow path 28, and the piston of the cylinder C moves to the right. During this time, the pressure inside the inflow channel 25 is reduced by the spring 5.
Since the pressure corresponds to the sum of the force of 5 and the pressure in the first load path 26, unnecessary high-load operation of the fluid pump P can be avoided, and there is no unnecessary energy loss.
Further, during the above operation, when the pressure in the first load path 26 increases and reaches the pressure set by the relief valve 77, the relief valve 77 operates and the fixed throttle 53
The pressure fluid in the fluid chamber 56 is transferred to the tank T under the action of
spool valve 5 for quick and accurate discharge.
0 quickly slides upward (in the opening direction) as shown in FIG.
The pressure will not exceed the pressure set in step 7. Therefore, this also avoids unnecessary high-load operation of the fluid pump P, and no unnecessary energy loss occurs.

Next, when the pilot switching valve V1 is returned to the neutral position, the pilot path 21 changes to the pilot path 2.
0, and pressure fluid is introduced into the pilot chambers 44, 47 and the fluid chamber 75. Therefore, in the first switching valve V2, the poppet valve bodies 37 and 40 are seated on the valve seats 33 and 36 to shut off between the inflow path 25 and the first load path 26 and between the second load path 27 and the outflow path 28. However, in the second switching valve V4, the fluid chamber 7
5 and 76 become the same pressure, the spool valve 65 returns to the illustrated state, and the fluid chamber 56 of the pressure control valve V3 communicates with the tank T. Therefore, the fluid pump P is unloaded again.

On the other hand, when the pilot switching valve V1 is switched to the left position, the pilot passage 22 communicates with the discharge passage 23,
Pilot chambers 45, 46 and fluid chamber 76 communicate with tank T. Therefore, in the first switching valve V2, the poppet valve body 38 can be pushed open by the pressure in the inflow passage 25, and the poppet valve body 39 can be pushed open by the pressure in the first load passage 26. It can be pushed open, and the second switching valve V4
In this case, the spool valve 65 is connected to the fluid chambers 75 and 76.
slides against the spring 74 due to the pressure difference,
The annular grooves 66 and 69 are cut off, and the annular grooves 67 and 68 are communicated through the inner hole 64, and the pressure in the second load path 27 is applied to the fluid chamber 56, causing the spool valve 50 to move downward in the third figure. Slide into the inflow channel 2
The pressure inside the spring 55 and the second load path 2
The pressure corresponds to the sum of the pressures within 7. Therefore, at this time, the pressure fluid in the inlet passage 25 whose pressure corresponds to the sum of the force of the spring 55 and the pressure in the second load passage 27 is supplied to the other chamber of the cylinder C through the second load passage 27. At the same time, the fluid discharged from one chamber of the cylinder C through the first load path 26 is returned to the tank T through the outflow path 28, and the piston of the cylinder C moves to the left. During this time, the pressure in the inflow path 25 is set to a pressure corresponding to the sum of the force of the spring 55 and the pressure in the second load path 27, so unnecessary high-load operation of the fluid pump P is avoided and unnecessary energy is saved. There is no loss. Further, during the above operation, when the pressure in the second load path 27 increases and reaches the pressure set by the relief valve 77, the pressure fluid in the fluid chamber 56 is is discharged into the tank T quickly and accurately, the spool valve 50 quickly slides upward (in the opening direction) as shown in FIG. The pressure in the inflow path 25 does not exceed the pressure set by the relief valve 77. Therefore, this also avoids unnecessary high-load operation of the fluid pump P, and no unnecessary energy loss occurs.

Next, when the pilot switching valve V1 is returned to the neutral position, the pilot path 22 changes to the pilot path 2.
0, and pressure fluid is introduced into the pilot chambers 45, 46 and the fluid chamber 76. Therefore, in the first switching valve V2, the poppet valve bodies 38 and 39 are seated on the valve seats 34 and 35 to block the inflow path 25 and the second load path 27 and between the first load path 26 and the outflow path 28. However, in the second switching valve V4, the fluid chamber 7
5 and 76 become the same pressure, the spool valve 65 returns to the illustrated state, and the fluid chamber 56 of the pressure control valve V3 communicates with the tank T. Therefore, the fluid pump P is unloaded again.

During the series of operations described above, the load path 26,
Even if an overload pressure occurs in the valve 27, the overload pressure is applied to the check valves 42, 43 and the pilot passages 20, 21, 2.
2 through the pilot chamber 44, 45, 46, 47
poppet valve bodies 37, 38, 3.
Error movement of the cylinder C due to the unseated operation of the cylinders 9 and 40 is prevented.

In the above embodiment, a single relief valve 7
7, each load path 2 when cylinder C is activated.
Although the maximum pressure of 6 and 27 was set, each load path 2
If it is necessary to set the maximum pressures of 6 and 27 separately, as shown in Figures 4 and 5,
It is also possible to install two relief valves 78 and 79 in parallel to the second switching valve V4. The relief valve 78 is a relief valve that sets the maximum pressure of the first load path 26, and the relief valve 79 is a relief valve that sets the maximum pressure of the second load path 27. The rest of the structure of the fluid control valve shown in FIGS. 4 and 5 is the same as that of the above embodiment, and the operation is also substantially the same as that of the above embodiment, so the same reference numerals will be used for explanation.

In addition, in each of the above embodiments, the poppet valve body 3
If the sliding amount of the poppet valve bodies 39 and 38 is configured to be adjustable using adjustment screws, the operating speed of the fluid actuator can be adjusted by restricting the flow rate on the inlet side of the fluid actuator, and the poppet valve body 39,
If the sliding amount of 40 is configured to be adjustable using an adjustment screw, the operating speed of the fluid actuator can be adjusted by restricting the flow rate on the outlet side of the fluid actuator.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a part of a conventional fluid control valve with symbols, FIG. 2 is a sectional view of an embodiment of a fluid control valve according to the present invention, a part of which is shown with symbols. The figure is a cross-sectional view of a portion of the fluid control valve according to the present invention surrounded by imaginary lines in Figure 2, and Figure 4 shows another embodiment of the fluid control valve according to the present invention, part of which is shown by symbols. FIG. 5 is a sectional view of a portion of the fluid control valve according to the present invention surrounded by an imaginary line in FIG. 4. Explanation of symbols V1...Pilot switching valve, V2
...First switching valve, V3...Pressure control valve, V4...
Second switching valve, 21... (first) pilot path, 2
2... (second) pilot path, 23... discharge path,
25... Inflow path, 26... First load path, 27...
Second load path, 28... Outflow path, 37... (first)
Poppet valve body, 38... (second) poppet valve body,
39... (third) poppet valve body, 40... (fourth) poppet valve body, 50... spool valve (valve body of pressure control valve), 53, 54... throttle, 56... fluid chamber, 65 ...Spool valve (valve body of second switching valve),
77...Pilot relief valve.

Claims (1)

[Claims] 1. A first poppet valve body that disconnects communication between the inflow path and the first load path, a second poppet valve body that disconnects communication between the inflow path and the second load path, and an outflow path and the first load path. a third poppet valve body that cuts off communication between the outflow passage and the second poppet valve;
It has a fourth poppet valve body that disconnects communication between the load passages, and a pilot switching valve guides pressure fluid to each pilot chamber formed at the back of each of the poppet valve bodies, thereby controlling the inflow passage and the first load passage. between the inflow passage and the second load passage, between the outflow passage and the first load passage, and between the outflow passage and the second load passage, and in each pilot chamber of the first poppet valve body and the fourth poppet valve body. By introducing pressure fluid through the first pilot passage and discharging the fluid in each pilot chamber of the second poppet valve element and the third poppet valve element through the second pilot passage, the fluid between the inflow passage and the second load passage and the outflow is established. The passageway and the first load passage are communicated with each other, and the inflow passage and the first load passage are isolated from each other, and the outflow passage and the second load passage are isolated from each other. By introducing pressure fluid through the second pilot passage and discharging the fluid in each pilot chamber of the first poppet valve element and the fourth poppet valve element through the first pilot passage, the flow between the inflow passage and the first load passage and a first switching valve that communicates between the outflow path and a second load path and blocks off between the inflow path and the second load path and between the outflow path and the first load path; and controlling communication between the inflow path and the outflow path. a pressure control valve that controls the pressure in the inflow path by fluid pressure applied in a fluid chamber formed at the back of the valve body; , said first
a valve body that selectively communicates with the load path or the second load path, which communicates the fluid chamber with the discharge path when pressure fluid is supplied through the first pilot path and the second pilot path; a second switch which communicates the fluid chamber with the second load path when pressure fluid is supplied through the first pilot path, and communicates the fluid chamber with the first load path when pressure fluid is supplied through the second pilot path; A fluid comprising: a valve; a pilot relief valve that sets a maximum pressure applied to the fluid chamber of the pressure control valve; and a throttle that restricts the flow of pressure fluid into the fluid chamber when the pilot relief valve operates for relief. control valve.