JPH0250322B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a pressure compensation control valve,
In particular, it relates to a control valve bank having a work section with pressure-compensated control valves and a pressure-compensated inlet section.

PRIOR ART AND ITS PROBLEMS Control valves for use in mobile equipment, such as bucket hoes, high lifts and the like, are already known and have been in use for some time. Also, in recent years,
There has been an increasing demand for high pressure control valves that provide smooth proportional flow control over a wide operating pressure range. The flow control function further requires simultaneous operation of two or more hydraulic motors or hydraulic cylinders from one pump by one valve combination. While it may seem simple to divide the available pump power between two or more motors or cylinders, dividing the output flow appropriately is in practice extremely difficult and requires special operator requirements. 0.8mm to obtain a capacity that is neither too large nor too small for the desired work.
Very accurate and fine valve spool adjustment of diameters close to or smaller than 200 mm was required.

[Problems to be solved by the invention] The control valve combination of the above type is disclosed, for example, in
-Described in No. 16527. According to the device,
When dividing the input fluid from the pump to control multiple hydraulic motors or hydraulic cylinders, the high pressure side is A check valve is provided to prevent backflow from flowing to the low pressure side or the inlet side, and the flow rate is maintained by keeping the pressure difference between the upstream and downstream sides of the check valve constant regardless of the operating pressure. Compensation means for constant control are provided. However, this pressure difference is constant and cannot be changed. It is desirable to have proportional flow rate control that not only guarantees a constant flow rate over a wide range of operating pressures, but also allows this constant flow rate to be set in proportion to the displacement of the valve spool position.

The present invention provides two or more valve work sections and inlets that operate in conjunction to provide smooth proportional flow control over a wide operating pressure band and to provide flow regulating action for two or more fluid actuated devices simultaneously. It is an object of the present invention to provide a multi-section control valve combination having a section.

[Technical Means for Solving the Problems] To briefly describe the invention with reference to the symbols of the embodiments described in detail below, the invention comprises: an inlet section connected to a single fluid pressure source; a multi-section control valve combination comprising two or more work sections connected and each connected to two or more fluid actuators, each work section having a pressure fluid inlet port 11; Entrance chamber 1 separated from the port
2, an action surface provided between the inlet port 11 and the inlet chamber 12 and on which the pressure fluid of the inlet port 11 acts in the opening direction, and a flow rate adjustment chamber 1 described later.
A check valve 29 having a compensating function and having working surfaces on which pressures 3 and 14 act in the closing direction, and a biasing means 30 acting on the check valve 29 in the closing direction.
and a first and second outlet port 19, 20 connected to an associated fluid actuating device, and each outlet port 1
9, 20 and connected to both sides of the entrance chamber 12, and a first and second work chamber 17, 18 connected to both sides of the entrance chamber 12, and a side of each work chamber 17, 18 opposite to the side where the entrance chamber 12 is arranged. First and second discharge chambers 21 and 22 provided on the sides, the inlet chamber 12 and the first and second discharge chambers
A pair of flow rate adjustment chambers 13 and 14 provided on both sides of the entrance chamber 12 between the work chambers 17 and 18;
One of the flow rate adjustment chambers 13 and 14 is connected to the check valve 29.
Differential pressure adjustment passage 3 connected to the working surface in the valve closing direction of
7 and 38, a main hole 23 extending through all said chambers, movable in said main hole 23 from a neutral position to variable first and second working positions on either side thereof;
said inlet port 1 in first and second working positions;
1 to the inlet chamber 12, then through one of the flow rate adjustment chambers 13, 14 corresponding to the position, and into one of the outlet ports 19, 20; Room 13,
signal passages 31, 32 and 33 or 75 connecting 14 with each other and connecting the inlet chamber 12 in the first and second working positions to one of the flow regulating chambers 13, 14 corresponding to the working position; a flow adjustment passage 24d formed in the spool valve member 24 to allow the spool valve member 24 to have a variable flow cross section in response to the variable work position; and the inlet section has an inlet port 51 connected to a fluid pressure source. an outlet port 53 connected to the inlet port 51 and the inlet port 11 of the work section, an outlet chamber 52, and a discharge chamber 57;
A separate bypass chamber 54 connected to the discharge chamber 57
a signal chamber 55 provided between the discharge chamber 57 and the bypass chamber 54; a hole 60 passing through all the chambers of the inlet section; a valve spool 61 movable between a blocked position in which it does not communicate with the discharge chamber 57 and a bypass position in which fluid is bypassed from the inlet port 51 through the bypass chamber 54 to the discharge chamber 57; Biasing means 65, 67 for resisting movement into the bypass position
and a passage 44 connecting the signal chamber 55 of the entrance section and the flow rate adjustment chambers 13, 14 of the work section.
and 49, and the signal chamber 5 is connected to the valve spool 61.
5 in the blocking direction, and means for applying the pressure in the inlet port 51 in the direction of the bypass position of the valve spool 61, thereby controlling the fluid pressure in the inlet port 51 of the inlet section and the flow regulating chamber 13. , 14 due to the differential pressure of the fluid,
A control valve combination adapted to move the valve spool 61 of the inlet section between the shutoff position and the bypass position.

A feature of the present invention is that the inlet port 11 of the check valve 29
A pressure differential returns the pressure in the inlet chamber 12 of each work section to the check valve so that a constant pressure difference is applied between the working surface in the opening direction leading to the flow control chambers 13 and the working surface in the closing direction leading to the flow regulating chambers 13 and 14. Adjustment passage 3
7 and 38, the spool valve member 24 is also provided with a flow rate adjustment passage 24d having a variable passage cross-sectional area depending on the setting position thereof. Since the flow rate is determined by the cross-sectional area of the flow path and the differential pressure,
This allows different constant flow rates to be set depending on the position of the spool valve member 24 in accordance with the fluid actuated device to be connected.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, and in particular to FIG. 1, there is illustrated a work section of a control valve in accordance with the present invention. The work section includes a housing 10 having a pair of inlet ports 11 and an inlet chamber 1.
2. A pair of flow rate adjustment chambers 13, 14 provided on both sides of the inlet chamber, a pair of work chambers 17, 18 having outlet ports 19, 20 provided on both sides of the flow rate adjustment chambers 13, 14; A pair of discharge chambers 21 and 22 are formed on both sides of the work chambers 17 and 18. All chambers 12-1 pass through the housing 10.
4, 17, 18, 21 and 22 are provided. A spool valve member 24 extends through the main bore 23 and has opposite ends connected to the housing 10.
stands out from A conventional centering mechanism 25 is provided at one end 24a. The other end is provided with an eye 26 for a manual control lever (not shown) of conventional design. The inlet port 11 communicates with an annular chamber 27 that communicates with an elongated hole 28 extending perpendicular to the axis of the main hole 23 but spaced therefrom. A check valve 29 having a compensation function is provided in the hole 28. Check valve 29
is normally biased to the closed position by a spring 30. The two flow chambers 13 and 14 are communicated by an axial passage 31 extending through a portion of the spool valve member 24 and lateral passages 32 and 33 extending into the interior of the spool valve member 24. A flow rate adjustment chamber 24c is formed around the spool valve member 24 and is aligned with the flow rate adjustment chambers 13 and 14 at a neutral position, and these flow rate adjustment grooves are surrounded by a flow rate adjustment path (slot) 2.
4d, and forms a flow path with a variable cross section between the inlet chamber and the flow rate adjustment chambers 13, 14 depending on the amount of movement of the spool valve member 24 to the right or left. Bifurcated heart-shaped passages 34, 35 from the entrance chamber 12 to the annular chamber 36
It extends to. The annular chamber 36 is spaced apart from the annular chamber 27, intersects the bore 28, and surrounds the check valve 29. As mentioned above, one end 2 of the check valve 29
9a is biased towards the end of the hole 28 by a spring 30. The other end of the check valve 29 is hollow,
It has an axial hole 29b. The axial bore 29b carries a spring 30 and opens into a passage 37 provided at the end of the passage 38. The passage 38 is the passage 3
7 is connected to the flow rate adjustment chamber 13. The check valve 29 is provided with an external annular groove 39 in its middle portion. A passageway 40 passes through the main body of the check valve 29 and extends from the annular groove 39 to the end 29a of the check valve 29, providing constant communication between the upper hole 28a of the check valve 29 and the annular chamber 27. The spool valve member 24 is provided with transverse passages 41 and 42 spaced apart from each other. Transverse passages 41 and 42 intersect axial passage 43 and communicate flow control chamber 13 with discharge port 21 when spool valve member 24 is in the neutral position. In other positions, this communication does not occur and is interrupted by the surface of the housing. The flow rate adjustment chamber 13 is connected to the signal passage 4
It is connected to 4. The signal passage 44 has valve seats 45 and 46 at each end (FIG. 3) and a movable valve seat, such as a ball, which can move from one seat to the other in response to the flow of pressure fluid. Check member 4
7 is installed inside. An intermediately located outlet port 48 communicates with a bypass passage 49 that is configured to communicate with a similar passage 44 of an adjacently connected housing 10 via a similar valve seat 45. .

This bypass passage 49 is for transmitting the pressure signal of the work section to the inlet section so that when at least one work section is activated, a high pressure signal is passed back to the inlet section and the inlet section is operated, as described below. When all work sections are inactive, a low pressure signal is returned to bypass the inlet section.

In the present invention, an inlet section is provided having a housing 50 as shown in FIGS. 4-5.
The housing 50 is formed with an inlet port 51 connected to an outlet chamber 52 and an outlet port 53 connected to the same outlet chamber. A bypass chamber 54 is spaced apart from the outlet chamber 52 . A signal chamber 55 is provided on the side of the bypass chamber 54 opposite to the side on which the outlet chamber 52 is disposed. A pair of discharge chambers 56 and 57 are arranged on either side of all said chambers and a passage 58
connected by. The passageway 58 also intersects the bypass chamber 54. The signal chamber 55 has a signal port 59 that communicates with the passageway 49 of the work section housing 10. Holes 60 are formed in the longitudinal direction of the housing 50 through all chambers 52, 54, 55, 56 and 57.
A valve spool 61 having axial holes 62 and 63 at both ends and an annular groove 64 in the center is disposed in the middle of the hole 60. A transverse passage 62a passing through the wall of the valve spool 61 communicates the outlet chamber 52 with the axial hole 62. A piston 65 is movably mounted at the end of the bore 60 adjacent the axial bore 63 . The piston 65 also has an adjacent axial hole 63.
An axial bore 66 is formed that opens at the end of the axial bore 63 and a spring 67 is disposed in the axial bore 63 to urge the piston 65 and the valve spool 61 apart from each other. The axial bore 66 terminates just short of the end of the piston 65 and forms a head 65a. An opening 65b is bored through the head 65a to the end of the hole 60. The piston 65 has a shoulder 68 which limits its movement towards the signal chamber 55 and prevents it from closing. Valve spool 61
is a horizontal passage 63a that penetrates the wall and reaches the axial hole 63.
Equipped with. The lateral passage 63a is normally closed by the wall of the hole 60, but when the valve spool 61 moves to the right against the spring 67, the lateral passage 63a opens into the signal chamber 55.

In operation, the housing 50 of the inlet section
is assembled with one or more work section housing 10 and outlet section housing 70 as illustrated in FIG. When so assembled, the outlet port 53 of the inlet section housing 50 is aligned with the inlet port 11 of the work section housing 10 such that fluid entering the inlet port 51 is directed to the outlet chamber 52.
through the outlet port 53 and into the work section inlet port 11, the annular chamber 27 and the passageway 40, and the non-return valve spool 29, which also serves as a compensator.
As seen in Figure 2, move it downward. That is, fluid in the annular chamber 27 flows into the chamber 28a via the passageway 40 and exerts pressure on the end of the check valve 29, causing the check valve 29 to actuate downwardly against the spring 30. As a result, the annular groove 39 communicates with the passages 34 and 35, and the fluid is divided into the passages 34 and 35 and flows into the inlet chamber 12. It also flows into the inlet port 11 of the next adjacent housing 10 at the same time. When the spool valve member 24 is moved to the working position, for example to the right in FIG. Control room 1
4, and then flows into the work chamber 1 through the right slot of the left and right slots 24f of the annular groove 24e.
Leading to 8. The fluid then flows through the outlet port 20 to the driven motor. At the same time, a portion of the fluid flows into the flow regulating chamber 13 via passages 31 , 32 and 33 and then through differential pressure regulating passage 38 to differential pressure regulating passage 37 . Fluid acts on the bottom end of check valve 29 in a direction opposite to the input pressure in chamber 28a. Further, the fluid in the flow rate adjustment chamber 13 is
It also works on 4. A flow rate adjustment path 24g and a groove 24h at the other end of the spool valve member 24 direct fluid from the motor (not shown) to the outlet port 19 and the work chamber 17.
The water is then refluxed to the discharge chamber 21. Signal passage 44
The entering inlet fluid causes the ball check valve 47 to move to the left as viewed in FIGS. Port 59 and signal room 55
flow into. At the inlet section, fluid pressurizes axial bores 63 and 66 and then flows through opening 65b, forcing piston 65 to the left as viewed in FIG.
Hold the fluid bypass chamber 5 in the position shown in the figure.
4 to prevent detour flow through.

As understood above, the spool valve member 2
4 moves to the right, the flow adjustment groove 24c connects the inlet chamber 12 to the flow adjustment chamber 14, and the annular groove 24c also connects the inlet chamber 12 to the flow adjustment chamber 14.
e connects the work chamber 18 and the flow regulating chamber 14 to create a maximum flow, thus creating a maximum flow at the outlet port 20. Depending on the length and size of the flow rate adjustment passage 24d open to the inlet chamber 12, the check valve 29 which also has a compensating action is operated to maintain the pressure difference between the end chamber 28a and the differential pressure adjustment passage 37 at a constant predetermined value. allows a proportional flow input variation depending on the position of the spool valve member 24 to control exit to the outlet port.
In the neutral position, the flow rate adjustment chamber 13 connects to the discharge chamber 21 via the transverse passages 41 and 42 and the axial passage 43.
The fluid is allowed to escape. The escape passage closes off the lateral passage 41 or 42 by slight movement of the spool valve member 24 to the right or left;
Therefore, the arrangement is such that fluid escape from the flow rate adjustment chamber 13 to the discharge chamber 21 is completed. If the spool valve member 24 of the housing 10 of the other work section of the valve assembly is operated to supply another motor operating at a lower pressure, the high pressure check valve 29 of interest is It closes and acts as a check valve to prevent backflow from the outlet port. Simply put, check valve 29 is a check valve that closes under the pressure of spring 30 when the pressure in inlet chamber 12 is greater than the pressure in inlet port 11 .

When the pressure in the flow rate regulating chamber 13 falls below the pressure in the inlet chamber 12, the check valve 29 with a compensating action causes the pressure in the differential pressure regulating channel 37 to decrease and therefore the end chamber 28
It is moved downward as seen in FIG. 1 by the pressure at point a.

Similarly, if the pressure in the flow regulating chamber 13 of any work section drops below the pressure of any other work section in the system, the ball-shaped check valve 47
is moved to the right as viewed in FIGS. 3 and 5, causing fluid to flow from signal passageway 44 through outlet port 48 and bypass passageway 49 to signal chamber 55 of the input section. When the pressure in the flow rate adjustment passages 32 of all the valves constituting the valve assembly decreases below the input pressure, the pressure in the signal chamber 55 decreases, and the valve spool 6
1 moves to the right in FIG. 4 and directs the input fluid from the outlet chamber 52, around the annular groove 64, through the hole 60 to the bypass chamber 54, and from there to the discharge chamber 5.
7 and let it flow.

FIG. 8 shows the condition when the spool valve member 24 is driven to the left working position, the operation of which is clear from the above description.

FIG. 6 shows that a central passage 75 is formed in the body of the control valve to connect chambers 13' and 14' in place of the axial passage 31 and lateral passage 32 provided in spool valve member 24 of FIG. A valve is shown whose construction is the same as that shown in FIGS. Identical parts are indicated by the same numbers with a ``''' appended. The operation of the second embodiment is identical to the first embodiment of FIGS. 1-5, except for the passageway 75.

FIG. 7 shows a passage 76 instead of the passage of FIG.
A second embodiment of the check valve is illustrated in which 77 and 77 are passages from the signal passage 44'' to the signal passage 44'' of the next work section. Other same parts have the same number with "''" added.

[Effects of the Invention] According to the present invention, when controlling a plurality of hydraulic motors or hydraulic cylinders by dividing the input fluid from a pump, the pressure difference between the upstream side and the downstream side of the check valve is reduced as in the conventional case. By keeping constant regardless of the operating pressure, it is possible not only to control the flow rate to be constant, but also to be able to set this constant flow rate in proportion to the displacement of the valve spool position.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a control valve section according to the invention. FIG. 2 is a sectional view taken along the line - in FIG. 1. FIG. 3 is a schematic sectional view taken along the line - in FIG. 1. FIG. 4 is a longitudinal sectional view of the inlet section according to the invention. FIG. 5 is a cross-sectional view of a control valve combination according to the invention with an inlet section and an outlet section according to the invention. FIG. 6 is a longitudinal sectional view of a second embodiment of a control actuated valve section according to the invention. 7th
The figure is a schematic sectional view of a second embodiment of a logical check valve arrangement of a control actuated valve section according to the invention. FIG. 8 shows the embodiment of FIG. 1 with the valve member moved to the left. 10: Work section housing, 11: Inlet port, 12: Inlet chamber, 13, 14: Flow rate adjustment chamber, 17, 18: Work chamber, 21, 22: Discharge chamber (discharge port), 23: Main hole, 24: Spool (valve member), 29: Check valve/compensation valve spool, 31,
43: Axial passage of spool, 32, 33, 4
1, 42: Lateral passage of spool, 34, 35:
Heart-shaped passage, 44: Fluid operated valve passage, 46: Signal port, 47: Stop, 48: Outlet port, 4
9: bypass passage, 50: inlet section housing, 51: inlet port, 52: outlet chamber, 53:
Exit port, 54: bypass room, 55: signal room,
56, 57: Discharge chamber, 59: Signal port, 61:
Valve spool, 65: piston, 70: outlet section.

Claims (1)

Claims: 1. Multiple work sections comprising an inlet section connected to a single fluid pressure source and two or more work sections connected to the inlet section and each connected to two or more fluid actuated devices. a section control valve combination, each work section having a pressure fluid inlet port 11, an inlet chamber 12 spaced from the inlet port 11, and an inlet port 11 and the inlet chamber 12;
and a non-return check having a compensating function and having a working surface on which the pressure fluid of the inlet port 11 acts in the opening direction and a working surface on which the pressure of the flow rate adjustment chambers 13 and 14 described later acts in the closing direction. a valve 29 and biasing means 3 acting on the check valve 29 in the closing direction;
0, first and second outlet ports 19, 20 connected to associated fluid actuating devices, and first and second outlet ports 19, 20 connected to the respective outlet ports 19, 20 and connected to opposite sides of said inlet chamber 12. Work rooms 17 and 18,
First and second work chambers 17 and 18 are provided on the side opposite to the side where the entrance chamber 12 is arranged.
The inlet chamber 12 is located between the discharge chambers 21 and 22 and the inlet chamber 12 and the first and second work chambers 17 and 18.
A pair of flow rate adjustment chambers 13 and 14 provided on both sides of the
, pressure adjustment passages 37 and 38 that connect one of the flow rate adjustment chambers 13 and 14 to the operating surface of the check valve 29 in the valve closing direction, and a main hole 23 that extends through all the chambers. , is movable in said main hole 23 from a neutral position to variable first and second working positions on either side thereof, and in said first and second working positions from said inlet port 11 to said inlet chamber 12 and then to said position. a spool valve member 24 configured to flow into one of the outlet ports 19, 20 through a corresponding one of the flow rate adjustment chambers 13, 14;
Signal paths 31, 3 connecting 3, 14 to each other
2 and 33 or 75, formed in the spool valve member 24 to connect the inlet chamber 12 to one of the flow rate adjustment chambers 13, 14 corresponding to the working position in the first and second working positions. a flow rate adjustment passage 24d having a variable flow cross-section in accordance with the variable work position; the inlet section includes an inlet port 51 connected to a fluid pressure source; an outlet port 53 and an outlet chamber 52 connected to the inlet port 11; and a discharge chamber 57;
A separate bypass chamber 54 connected to the discharge chamber 57
a signal chamber 55 provided between the discharge chamber 57 and the bypass chamber 54; a hole 60 passing through all the chambers of the inlet section; a valve spool 61 movable between a blocked position in which it does not communicate with the discharge chamber 57 and a bypass position in which fluid is bypassed from the inlet port 51 through the bypass chamber 54 to the discharge chamber 57; Biasing means 65, 67 for resisting movement into the bypass position
and a passage 44 connecting the signal chamber 55 of the entrance section and the flow rate adjustment chambers 13, 14 of the work section.
and 49, and the signal chamber 5 is connected to the valve spool 61.
5 in the blocking direction, and means for applying the pressure in the inlet port 51 to the valve spool 61 in the direction of the bypass position, thereby controlling the fluid pressure in the inlet port 51 of the inlet section and the flow regulating chamber 13 , 14 due to the differential pressure of the fluid,
A control valve combination adapted to move said valve spool 61 of the inlet section between said shutoff position and a bypass position.