JPH036363B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stack type fluid control device comprising a switching valve, a throttle valve, and a pressure compensation valve, and in which these valves are stacked.

Specifically, the actuator is equipped with a switching valve, a throttle valve having a throttle control section, and a pressure compensation valve that controls the differential pressure across the throttle control section to a constant value, and the actuator is always operated at a set speed regardless of changes in load. This invention relates to an efficient fluid control device.

Conventionally, a stack-type fluid control device including the above-mentioned valves and stacking these valves has been developed, for example, by
This is already known as shown in Publication No. 10751.

As shown in FIG. 10, this fluid control device is a stack of two throttle valves A and B with a direction switching function and one pressure compensating valve C, and a slide valve D in the throttle valves A and B. , D allows the pump passage P to communicate with one of the load passages E and F, and between the lands of the slide valves D and D and the valve bodies of the throttle valves A and B, Throttle control units G and H are formed respectively, and a flow rate corresponding to the opening degree of these throttle control units G and H can be obtained. side, that is, the load side, is communicated with the piston chamber K of the piston J in the pressure compensation valve C, and the other side chamber L of the piston J is communicated with the pump passage P through the perforation M of the piston L, On one end side of the piston J, that is, on the side of the piston chamber K, there is a load pressure corresponding to the load acting on an actuator (not shown) connected to the load passages E and F, and a spring installed in the piston chamber K. A force added to the force of N acts on the other end, and the discharge pressure of the pump acts on the other end.

Therefore, according to the fluid control device configured as described above, by setting the valve openings of the throttle control units G and H to the desired openings, a flow rate corresponding to the valve openings can be supplied to the actuator. , due to the function of the pressure compensation valve C, the throttle control section G or H
The differential pressure before and after the pressure compensating valve C can be maintained at a differential pressure corresponding to the spring N, and even if the load acting on the actuator changes, the pressure compensating valve C
Due to the pressure compensation, the differential pressure before and after the throttle control part G or H can be kept constant, and the flow rate supplied to the actuator can be kept constant, and according to the adjustment of the valve opening of the throttle control part G or H. Therefore, the operating speed of the actuator can be controlled proportionally.

Incidentally, in the conventional device described above, the throttle control units G and H of the throttle valves A and B are provided on the supply side of the actuator, that is, on the load passages E and F, and meter-in control is performed. In the end, meter-out control is necessary.

This meter-out control includes the aperture control section G,
H is the return side of the actuator, that is, the tank passage.
This can be done by installing it on the T ₁ and T ₂ sides, but the first
As mentioned above, the conventional device shown in FIG _. Since _T2 are arranged in series, even if the throttle valves G, H and pressure compensation valve C are rearranged, it is not possible to change to meter-out control.

Therefore, in this conventional device, in order to change from meter-in control to meter-out control, it is necessary to replace the throttle valves A and B. As a result, the throttle valves for meter-in control and the throttle valve for meter-out control must be replaced. It became necessary to separately prepare a throttle valve for each, which caused a problem of being uneconomical.

An object of the present invention is to make it possible to change the stacking position of the throttle valve and the pressure compensation valve with respect to the switching valve, and to make the stacking direction reversible, so that meter-in control and meter-out control can be achieved by changing the stacking position and stacking direction. The main advantage is that it can be easily changed to any control method.

Further, the configuration of the present invention includes a switching valve and a throttle valve having a throttle control section, a primary side chamber, and a secondary side chamber,
A fluid control device is provided with a pressure compensating valve that maintains a differential pressure across the throttle control section, and has valve bodies of these valves stacked one on top of the other, a first port and a second port provided in the valve body of the switching valve. The first and second ports of the switching valve are arranged symmetrically about the straight line connecting the pair of load ports, and the valve bodies of the throttle valve and pressure compensation valve stacked on the switching valve have first and second ports of the switching valve. First and second connection ports are respectively provided at the same position as the second port, and a first pilot passage communicating with the secondary side of the throttle control section is provided in the valve body of the throttle valve.
Further, a second pilot passage communicating with the secondary side chamber is provided in the valve body of the pressure compensation valve, and these pilot passages are opened on the straight line,
The stacking positions of the throttle valve and pressure compensation valve relative to the switching valve can be changed, and the stacking direction is reversible, so that meter-in control and meter-out control can be easily changed.

Next, an embodiment of the fluid control device of the present invention will be described based on FIGS. 1 to 7.

The fluid control device of the present invention includes a switching valve 1, a throttle valve 2 having a throttle control section 28, and a pressure compensation valve 3 for controlling the differential pressure across the throttle control section 28 to a constant level, as shown in the drawings. The switching valve 1 is a four-way switching valve having a pair of solenoids 10a and 10b.

That is, as shown in FIG. 3, the valve body 11 has four ports: a first port 12, a second port 13, and a pair of load ports 14 and 15, which communicate with a pump passage 4 and a tank passage 5, which will be described later. and among these ports, the first port 12 and the second port 13 are provided so as to be symmetrical about the straight line X connecting the load ports 14 and 15,
A switching spool 16 having two lands is freely movable inside the valve body 11, and springs 17 and 18 are provided at both ends of the spool 16, so that the solenoid 10 is of a spring center type.
The first port 12 communicating with the pump passage 4 is communicated with one of the load ports 14 and 15 by the movement of the spool 16 by the operation of the pumps a and 10b,
The other of the load ports 14 and 15 is communicated with the second port 13 which communicates with the tank passage 5 to perform direction control.

Further, the throttle valve 2 has a proportional solenoid 20 that outputs a force proportional to the input current, and when the solenoid 20 operates, the throttle valve 2 is a proportional flow control valve that controls the flow rate by adjusting the valve opening of the throttle control section 28. is used.

The valve body 21 of the throttle valve 2 has each port 1 provided in the valve body 11 of the switching valve 1 as shown in FIG.
1st and 2nd matching 2, 13, 14, 15
Connection ports 22 and 23 and load ports 24 and 25 are provided, and the valve body 21 also has a spool 2 that is operated by the operation of the proportional solenoid 20.
6 is freely movable internally, and the spool 26
On the opposite side of the solenoid 20 is a spring 27.
The throttle control portion 28 is provided between the land of the spool 26 and the corner portion of the valve body 21 forming the first port 22.
It consists of

The valve body 21 has a first pilot passage 29 that communicates with the secondary side of the throttle control section 28.
The pilot passage 29 is opened on a straight line X connecting the load ports 24 and 25 (this straight line X is also a straight line connecting the load ports 14 and 15 in the switching valve 1).

The proportional solenoid 20 is connected to its armature with a position detector 20a consisting of a differential transformer for position detection, and the spool 26
Position feedback control is performed to make flow rate control more accurate.

Further, the pressure compensating valve 3 is of a pressure reducing type, and the valve body 31 includes each valve body 1 of the switching valve 1 and the throttle valve 2, as shown in FIG.
Each port 12-15 and 22- provided in 1, 21
25, first and second connection ports 32,
33 and load ports 34 and 35. Also, a plunger 36 is movably installed inside the valve body 31, and an inner wall formed inside the plunger 36 is provided at one end side of the plunger 36. A primary side chamber 30a is formed which communicates with the pump passage 4 via a passage 36a, and the discharge pressure of the pump is applied to one end of the plunger 36, and a spring 37 is installed inside the other end of the plunger 36. A second pilot passage 3 forms a secondary chamber 30b and communicates with the secondary chamber 30b.
9 is provided, and this pilot passage 39 is connected to a straight line X connecting the load ports 34 and 35 (this straight line
It is also a straight line connecting the load ports 14 and 15 in the switching valve 1 and the load ports 24 and 25 in the throttle valve 2. ), so that it can communicate with the first pilot passage 29, and the other end of the plunger 36 is connected to the actuator 50 through the first and second pilot passages 29, 39. This is done so that the pressure corresponding to the applied load and the force of the spring 37 are applied.

Further, between the land of the plunger 36 and the corner of the valve body 31, the spring 37 acts to set the valve to the normally open position, and the opening degree changes depending on the corresponding pressure of the load acting on the actuator 50. A pressure control section 38 is provided to control the pressure.

Therefore, the throttle control section 28 in the throttle valve 2
If the pressure on the primary side, that is, the sum of the discharge pressure of the pump and the resistance pressure of the throttle control section 28, overcomes the sum of the corresponding pressure of the load and the force of the spring 37, then the pressure control section 38 closes, the reduced pressure increases, and the differential pressure across the throttle control section 28 corresponds to the force of the spring 37.
The pressure is maintained at the pressure set in step 7.

The switching valve 1, throttle valve 2, and pressure compensation valve 3 configured as described above are stacked as shown in FIGS. 1 and 6, and each of the valves 1, 2,
The first port 12 and first connection ports 22, 32 provided in the valve bodies 11, 21, 31 of No. 3, and the second port 13 and second connection ports 23, 33 are connected to the load ports 14, 15, 24, 25, and 34,3
arranged symmetrically around the straight line X connecting 5, and
Since the first and second pilot passages 29 and 39 provided in the throttle valve 2 and the pressure compensation valve 3 are opened on the straight line X, the throttle valve 2 and the pressure compensation valve 3 are connected to the switching valve 1. However, the stacking position can be changed and the stacking direction can be reversed. By stacking the layers as shown in Figure 1, meter-in control can be achieved, and by stacking the layers as shown in Figure 6, meter-out control can be achieved. becomes possible.

The one shown in FIG. 1 is a stacked structure in which a switching valve 1 and a pressure compensating valve 3 are interposed and a throttle valve 2 is interposed in a sandwich-like manner.
The first connection ports 22 and 32 of the throttle valve 2 and the pressure compensation valve 3 communicate with each other, and the second port 13
The second connection ports 23, 33 communicate with each other, and the load ports 14, 15, 2 of each valve 1, 2, 3 communicate with each other.
4, 25 and 34, 35 are in communication with each other, and the first and second pilot passages 29, 39 are in communication with each other.

Then, in this stacked state, the pump passage 4 is connected to the first connection port 32 of the pressure compensation valve 3, and the second
The tank passage 5 is connected to the connection port 33, and the actuator 50 is connected to the load ports 34, 35 through the load passages 6, 7, respectively. As shown in the figure, meter-in control is used.

Next, the operation of the meter-in control shown in FIGS. 1 and 2 will be explained.

The state shown in FIGS. 1 and 2 is a neutral state, and from this state, the solenoid of the switching valve 1
0a and 10b to perform direction control, and at the same time operate the proportional solenoid 20 of the throttle valve 2.
When the spool 26 is moved to the left, the throttle control section 28 opens at a predetermined opening degree, allowing fluid introduced from the pump passage 4 through the first connection port 32 of the pressure compensation valve 3 to flow. Aperture control section 28
The flow rate according to the opening degree of the load ports 14, 2
4, 34 or 15, 25, 35 to the actuator 50 via the load passage 6 or 7.

At this time, since the secondary side of the throttle control section 28 communicates with the secondary side chamber 30b of the pressure compensation valve 3 via the first and second pilot passages 29 and 39, the pressure compensation valve 3 A pressure corresponding to the load acts on the plunger 36, and due to the action of the pressure compensating valve 3, the throttle control section 2
The differential pressure before and after 8 is kept constant.

Therefore, even if the load acting on the actuator 50 changes, the differential pressure across the throttle control section 28 is kept constant by the pressure compensation of the pressure compensation valve 3, and the opening degree of the throttle control section 28 is kept constant. The flow rate set accordingly can be kept constant, and the actuator 50 can be operated at a desired speed regardless of changes in load.

Furthermore, in the configuration shown in FIG. 6, the stacking positions of the throttle valve 2 and the pressure compensation valve 3 are changed from those shown in FIG. The throttle valve 2 and the pressure compensating valve 3 are stacked in a sandwich-like manner between the throttle valve 2 and the pressure compensating valve 3, and the stacking direction of the throttle valve 2 and the pressure compensating valve 3 is reversed.

In this state, the first port 12 of the switching valve 1 is connected to the second connecting ports 33 and 23 of the pressure compensating valve 3 and the throttle valve 2, and the second port 13 of the switching valve 1 is connected to the first port 12 of the switching valve 1. , the pressure compensation valve 3 and the throttle valve 2
The first connection ports 32 and 22 will communicate with each other.

In addition, load ports 14, 15, 24, 25 and 3
4, 35 and the first and second bypass passages 29, 3
9 are in communication with each other as in FIG.

In this stacked state, the pump passage 4 is connected to the second connection port 23 of the throttle valve 2, the tank passage 5 is connected to the first connection port 22, and the load ports 24 and 25 are connected as shown in FIG. By connecting the load passages 6 and 7 and stacking them as shown in FIG. 6, meter-out control is achieved as shown in FIG. 7.

In this case, as in FIG. 1, the aperture control section 28
The differential pressure before and after can be kept constant, and the actuator 50 can always be operated at the set speed regardless of changes in load.

In the embodiment described above, the spool 26 of the throttle valve 2 is of a two-land type, and one throttle control section 28 is formed between one land and the corner portion of the valve body 21. As shown in FIG. 8, three lands may be formed, and two first and second throttle control portions 28a and 28b may be formed between the two lands and the corner portion of the valve body 21.

In this case, the first pilot passage 29 provided in the valve body 21 is communicated with the secondary side of one of the first throttle control sections 28a, and the first throttle control section 28a with which the first pilot passage 29 is communicated is connected to the secondary side of the first throttle control section 28a.
is set so that its opening is always larger than the opening of the second aperture control section 28b.

Therefore, as in FIG. 1, when meter-in control is used, the second port 33 side communicating with the tank passage 5 is also throttled by the second throttle control section 28b.
Meter-out control can also be used, and even if the actuator 50 is a cylinder, it is possible to prevent the piston from running ahead.

In the embodiment shown in FIGS. 1 to 7, the load port 2 is also connected to the throttle valve 2 and the pressure compensation valve 3.
4, 25, 34, and 35 are provided, but they may not be provided as shown in FIG. Further, the aperture control section 2
8, 28a, 28b, an annular groove 26a is formed in the land of the spool 26 as shown in FIG.
It is preferable that the land forming the annular groove 26a is provided with a through hole 26b penetrating in the radial direction to form an axial thrust compensating type.

As described above, the present invention allows the first port 12 and the second port 13 provided in the valve body 11 of the switching valve 1 to
The valve bodies 21 and 31 of the throttle valve 2 and pressure compensation valve 3, which are arranged symmetrically about a straight line X connecting the pair of load ports 14 and 15 and stacked on the switching valve 1, include the switching valve 1 first and second ports 12,1
At the same position as 3, there is a throttle valve 2 having a switching valve 1 and a throttle control section 28, and a primary chamber 30a and a secondary chamber 30.
b, and includes a pressure compensation valve 3 that keeps the differential pressure across the throttle control section 28 constant, and each of these valves 1,
A fluid control device comprising two and three valve bodies 11, 21, and 31 stacked, the valve body 1 of the switching valve 1
The throttle valve 2 has a first port 12 and a second port 13 provided in the switching valve 1 arranged symmetrically about a straight line X connecting the pair of load ports 14 and 15, and is stacked on the switching valve 1. and the valve body 2 of the pressure compensation valve 3
1 and 31 have first and second ports 12 and 13, respectively, at the same positions as the first and second ports 12 and 13 of the switching valve 1.
Connection ports 22 , 23 and 32 , 33 are provided, and a first pilot passage 29 communicating with the secondary side of the throttle control section 28 is provided in the valve body 21 of the throttle valve 2 . Valve body 31
A second pilot passage 39 communicating with the secondary side chamber 30b is provided, and these pilot passages 2
9, 39 are opened on the straight line Meter-in control and meter-out control can be easily changed by simply changing the stacking position of the valve 2 and pressure compensation valve 3 and reversing the stacking direction.

Therefore, since the throttle valve 2 can be shared, mass production is possible, costs can be reduced, parts management is also simplified, and the entire system is economical.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the device of the present invention.
A schematic cross-sectional view in the case of meter-in control, Fig. 2 is a schematic diagram represented by symbols, Figs. 3 to 5 are end views of only the valve bodies of the switching valve, throttle valve, and pressure compensation valve, and Fig. 6 7 is a schematic sectional view in the case of meter-out control, FIG. 7 is a schematic diagram represented by symbols, FIG. 8 is a schematic sectional view showing another embodiment, and FIG. 9 is a schematic sectional view showing another embodiment.
The figure is an enlarged sectional view of only the main parts showing another embodiment of the diaphragm control section, and FIG. 10 is a sectional view showing the prior art. 1... Switching valve, 2... Throttle valve, 3... Pressure compensation valve, 11, 21, 31... Valve body, 12... First
Port, 13...Second port, 14, 15, 2
4, 25, 34, 35...Load port, 22, 3
2...First connection port, 23, 33...Second connection port, 28...Aperture control section, 29...First pilot passage, 30b...Secondary side chamber, 39...Second
Pilot passage.

Claims (1)

[Claims] 1 Throttle valve 2 having a switching valve 1 and a throttle control section 28
and has a primary side chamber 30a and a secondary side chamber 30b,
A fluid control device comprising a pressure compensating valve 3 that keeps the differential pressure across the throttle control section 28 constant, and in which the valve bodies 11, 21, and 31 of each of the valves 1, 2, and 3 are stacked, The first valve provided in the valve body 11 of the valve 1
The port 12 and the second port 13 are arranged symmetrically about a straight line X connecting the pair of load ports 14 and 15, and the throttle valve 2 and the pressure compensation valve 3 are stacked on the switching valve 1. The valve bodies 21 and 31 have first and second connection ports 22 and 22, respectively, at the same positions as the first and second ports 12 and 13 of the switching valve 1.
23, 32, and 33, a first pilot passage 29 communicating with the secondary side of the throttle control section 28 is provided in the valve body 21 of the throttle valve 2, and a first pilot passage 29 is provided in the valve body 31 of the pressure compensation valve 3. , the secondary side chamber 3
A second pilot passage 39 communicating with 0b is provided, and these pilot passages 29, 39 are opened on the straight line A fluid control device characterized in that the stacking direction is reversible.