JP2578622Y2 - Directional control valve device with pressure compensating valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional control valve device provided with a pressure compensating valve for use in a pressure oil supply device for supplying pressure oil discharged from one hydraulic pump to a plurality of actuators.

[0002]

2. Description of the Related Art A pressure oil supply device disclosed in Japanese Patent Application Laid-Open No. Sho 60-11706 is known. That is, as shown in FIG. 1, a plurality of pressure compensating valves 3 and 1 are connected to the discharge conduit 2 of the hydraulic pump 1.
3 are connected in parallel, and directional control valves 5 and 15 are provided at outlet pipes 4 and 14 of the pressure compensating valves 3 and 13, respectively, and the output sides of the directional control valves 5 and 15 are connected to actuators 6 and 16, respectively. The pressure oil supply device has a structure in which the pressure compensating valves 3 and 13 are pushed in the opening direction by the pump discharge pressure and the direction control valve outlet pressure, and are pushed in the closing direction by the direction control valve inlet pressure and the highest load pressure. . With this pressure oil supply device, the pump discharge pressure oil can be supplied to each actuator at a predetermined distribution ratio when a plurality of directional control valves 3 and 13 are simultaneously operated.

In such a pressurized oil supply device, a shuttle valve 7 is required to supply a higher load pressure to the pressure compensating valve by comparing the load pressure of the actuator. One less than the number is needed, which increases the cost. In the pressure oil supply device shown in FIG. 1 described above, it is assumed that the two actuators 6 and 16 are operated together and that the load pressure on the actuator 6 side is larger than the load pressure. At this time, the pressure in the conduit 8 is guided to the conduit 9 by the shuttle valve 7 as the maximum load pressure. Next, it is assumed that the load pressure fluctuates and the load pressure on the actuator 16 side becomes larger than the load pressure on the actuator 6 side. At that time, that is, when the shuttle valve 7 is switched, the pressure in the conduit 18 is released by the blowout in the shuttle valve 7 and the pressure in the other conduit 8 is suppressed. Therefore, when the shuttle valve 7 is switched, the actuator 16 transiently descends spontaneously and the actuator 6 is accelerated.

As shown in FIG. 2, a plurality of directional control valves 22 are provided in a discharge path 21 of a hydraulic pump 20, and an inlet of each directional control valve 22 is provided as a pressure oil supply device which can solve this problem. On the other hand, a pressure compensation valve 25 comprising a check valve portion 23 and a pressure reducing valve portion 24 is provided on the side.

[0005]

When the directional control valve 22 and the pressure compensating valve 25 are combined to constitute a pressure oil supply device, the directional control valve 22 and the pressure compensating valve 25 are combined into one valve block at the stage of practical use. The pressure compensating valve 24 is required to be built in
3 and the pressure reducing valve section 24, the number of parts is large, and it is very difficult to incorporate the directional control valve 22 and the pressure compensating valve 25 into one valve block due to port communication and the like.

Accordingly, an object of the present invention is to provide a directional control valve device having a pressure compensating valve which can solve the above-mentioned problems.

[0007]

A spool hole 31, a check valve hole 37, and a pressure reducing hole 38 are formed in the valve block 30, and an input port 44 opened in the spool hole 31 is provided in the valve block 30. .Second load pressure detection ports 45 and 4
6, the first and second actuator ports 34, 35, the first
Tank ports 47 are respectively formed, and the spool holes 3 are formed.
A main spool 49 for connecting / disconnecting each port is inserted into 1 to form a directional control valve 55, and the pump port 39 and the check valve hole 37 opened in the check valve hole 37 are connected to the input port 44 in the valve block 30. An oil passage 56 is formed to communicate with the pump port 39 and the oil passage 56 is inserted into the check valve hole 37 and a spool 60 stopped at the shut-off position is inserted into a check valve portion 63 to form a check valve portion 63. The block 30 has first and second ports 42 and 43 that open to the pressure reducing valve hole 38, and a spool 64 is inserted into the pressure reducing valve hole 38 to form a first pressure chamber 65 and a second pressure chamber 66. And the first pressure chamber 65 is connected to the second load pressure detection port 46.
And the second pressure chamber 66 to the second port 43,
The spool 64 is urged in one direction by a spring 69 to press and hold the spool 60 of the check valve portion 63 at the shut-off position to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion 63 provide pressure compensation. The main spool 4
A directional control valve device including a pressure compensating valve configured to connect the second actuator port to the second load pressure detection port when the first pressure oil supply position is set to 9.

[0008]

[Operation] A directional control valve device provided with a pressure compensating valve is housed in a valve block 30 in which a main spool 49 of a directional control valve 55, a valve 60 of a pressure compensating valve 75, and a spool 64 are accommodated. Return oil from the actuator that has flowed into the actuator can be supplied to the actuator again from the first actuator port 34.

[0009]

EXAMPLE As shown in FIG. 3, the valve block 30 has a substantially rectangular parallelepiped shape, and a spool hole 31 is formed near the upper portion of the valve block 30 so as to open on the left and right side surfaces 32 and 33. Opened first and second actuator ports 34 and 35 are formed in the upper surface 36 so as to be opened. Near the lower portion of the valve block 30, a check valve hole 37 opened in the left side 32 and an opening in the right side 33. A pressure reducing valve hole 38 is formed concentrically, and the check valve hole 37 is formed.
A pump port 39 is formed at the front and rear surfaces 40 and 41 and is formed at the front and rear surfaces 40 and 41.
Ports 42 and 43 are formed so as to open to the front and rear surfaces 40 and 41. When the front and rear surfaces 40 and 41 of the plurality of valve blocks 30 are butt-connected to each other, each pump / first / second port 39,
42 and 43 communicate with each other.

As shown in FIG. 4, the valve block 30 has an input port 44 opened to the spool hole 31, first and second load pressure detection ports 45 and 46, and first and second actuator ports 34 and 35. , A first tank port 47 is formed, and a main spool 49 inserted into the spool hole 31 is formed.
Are formed with first and second small-diameter portions 50 and 51, a communication groove 52 and an intermediate small-diameter portion 53, and the first and second load pressure detection ports 45 and 46 communicate with each other through a port 54. The spool 49 is held at a neutral position A where each port is shut off by a spring. When the spool 49 is slid rightward, the second load pressure detection port 46 and the second actuator port 35 are formed by the intermediate small diameter portion 53 and the first notch 53a. The input port 44 communicates with the second load pressure detection port 46 through the communication groove 52,
In the first small diameter portion 50, the first actuator port 34 is
When the spool 49 is slid to the left, the first small-diameter portion 50 is in contact with the first actuator port 34. The first hydraulic port position B is in communication with the load pressure detection port 45, and the first actuator port 34 and the first tank port 47 are shut off. Port 34 first
The pump port 44 communicates with the first load pressure detection port 45 through the communication groove 52, and the second actuator port 35 communicates with the second small diameter portion 51 and the notch 51 a.
Is the second pressure oil supply position C communicating with the second load pressure detection port 46, and constitutes the direction control valve 55.

The check valve hole 37 opens to the input port 44 through the oil passage 56, and the check valve hole 37 is a valve 6 for disconnecting the pump port 39 from the input port 44.
0 is inserted, and the valve 60 is regulated by a stopper rod 62 provided on a plug 61 so as not to slide leftward from the position shown in the figure, and is held at a shut-off position to constitute a check valve portion 63.

The pressure reducing valve hole 38 communicates with the second load pressure detecting port 46 through a third port 57 and an oil passage 58, and a spool 64 is inserted into the pressure reducing valve hole 38 so that the first pressure chamber 6
5 and a second pressure chamber 66, the first pressure chamber 65 communicates with the third port 57, the second pressure chamber 66 communicates with the second port 43, and is inserted into the blind hole 67 of the spool 64. A spring 69 is provided between the piston 68 and the bottom of the blind hole 67 so that the free piston 68 abuts on the plug 70, and a push rod 71 integrally provided on the spool 64 projects from the through hole 72 to operate the valve 60. The spool 64 has a small hole 73 formed in the spool 64 to communicate the first port 42 with the blind hole 67 to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion 63 and pressure compensating valve 75
Is composed.

Because of this, one valve block 3
The main spool 49 and the check valve portion 6 which become the directional control valve at 0
By providing the valve 60 serving as 3 and the spool 64 serving as the pressure reducing valve section 74, a directional switching valve device having a pressure compensating valve can be provided. Further, when the spool 49 is moved rightward to the first pressure oil supply position B, the pressure oil flowing from the actuator into the second actuator port 35 passes through the notch 53 a and the intermediate small diameter portion 53 and the second load pressure detection port. Since it flows to the first actuator port 34 after flowing into the input port 44 and joining with the pressure oil flowing into the input port 44, it has a regeneration function.

Next, the operation of supplying pressure oil to a pair of actuators will be described using the hydraulic circuit shown in FIG. In addition,
In the hydraulic circuit shown in FIG. 5, the left directional switching valve 55 has no regeneration function, and the second tank port 48 is formed in the valve block 30 as shown by the phantom line in FIG. It communicates with the two tank port 48.

When the direction control valve 55 is in the neutral position A. The oil sucked from the tank 86 by the hydraulic pump 80 is guided to the pressure chamber a in the opening direction of the check valve 63 through the discharge path 81. At this time, since both the pressure chambers 65 and 66 of the pressure reducing valve part 74 are in communication with the tank 86, the pressures in the pressure chambers 65 and 66 are both zero, so that the pressure reducing valve part 74 is pushed by the weak spring 69. Only the rod 71 is in contact with the check valve portion 63. On the other hand, the pump discharge pressure is maintained at a constant pressure difference from the pressure in the load pressure detection path 82 by the spring 87 of the pump adjustment direction control valve 85. Now, assuming that the differential pressure is 20 kg / cm ² , the pressure in the load pressure detecting path 82 is zero, and the pump discharge pressure is 2 kg / cm 2.
The stroke rises to 0 kg / cm ^2, and at the same time, the pump discharge pressure flows into the pressure chamber a of the check valve portion 63 and the stroke until the inlet pressure of the directional control valve 55 (the outlet pressure of the check valve portion 63) becomes equal to the pump discharge pressure. And if equal, the weak spring 6
Receipt by 9 The pressure reducing valve 74 communicates the pump discharge passage 81 with the pressure chamber 66 only at the stroke end, while the check valve 63 communicates the pump discharge passage 81 with the outlet before reaching the stroke end. When the control valve 55 is at the neutral position A, the pump discharge passage 81 and the pressure chamber 66 do not communicate with each other, and the pressure chamber 65
Pressure remains at zero.

Only one of the directional control valves 55 is the first
When making a stroke to the pressure oil supply position B. Now, the left directional control valve 55 is stroked to the first pressure oil supply position B, and the right directional control valve 55 is in the neutral position A. Move the direction control valve 55 to the stroke and
And the first actuator port 34, and at the same time,
The second actuator 35 and the second tank port 48 are connected. At this time, if the pressure (load pressure) in the conduit 89 connecting the first actuator port 34 and the actuator 88 is higher than the pump discharge pressure (20 kg / cm ² ), the check valve 63 receives the pressure in the pressure chamber b. ,
The natural descent of the actuator 88 can be prevented. The pressure of the conduit 89 of the actuator 88, that is, the load pressure, is guided from the first oil passage 53 and the passage 58 to one pressure chamber 65 of the pressure reducing valve 74. Since the pressure in the other pressure chamber 66 is zero, the pressure reducing valve portion 74 strokes to the stroke end in a direction in which the pressure reducing valve portion 74 dissociates from the check valve portion 63, and through the throttle of the pressure reducing valve portion 74, connects to the pump discharge passage 81 and the load. The pressure detection path 82 communicates. When the pressure (load pressure) in the conduit 89 is higher than the pump discharge pressure (= 20 kg / cm ² ), the pressure is closed by the pressure in the pressure chamber b of the check valve section 63, and the pressure is reduced to one of the pressure reducing valve sections 74. Since the pressure chamber 65 is guided to the pressure chamber 65, even if the other pressure chamber 66 and the pump discharge path 81 communicate with each other, the pressure reducing valve section 74 remains in a stroke. on the other hand,
The pressure (load pressure) in the conduit 41 is the pump discharge pressure (= 20k)
g / cm ² ), the load pressure is guided to one pressure chamber 65 of the pressure reducing valve section 74, and the pressure reducing valve section 74 strokes at the pressure of the one pressure chamber 65, but the other pressure chamber 66. When the pressure rises to the pressure in one pressure chamber 65 (that is, the load pressure), it is closed by a weak spring 69 and abuts against the check valve portion 63. In any case, the pressure reducing valve section 7
4 until the pressure in one pressure chamber 65 and the pressure in the other pressure chamber 66 become equal.
When the pressures in the two pressure chambers 65 and 66 become equal, the spring is closed by a weak spring 69 and abuts against the check valve portion 63. As a result, the pressure in the load pressure detecting path 82 becomes equal to the load pressure, and the pump discharge pressure is adjusted by the pump adjusting hole control valve 85 to a certain differential pressure (here, 20 kg / cm ² ).
The pressure is controlled to be higher than the pressure in the load pressure detection path 82 by the amount. Since this pump discharge pressure is guided to the input port 44 via the check valve section 63, that is, between the inlet pressure and the outlet pressure (= load pressure) of the directional control valve 55,
The differential pressure (= 20 kg / cm ² ) is maintained. Therefore, the flow rate supplied to the actuator 88 is controlled only by a change in the opening area of the throttle between the inlet side and the outlet side according to the stroke of the direction control valve 55. When the directional control valve 55 is stroked, the conduit 89 or 90 of the actuator 88 is connected to the second oil passage 53 for introducing load pressure, while the second oil passage 53 is connected to one pressure chamber 65 of the pressure reducing valve part 74. However, since the load pressure in the pressure reducing valve portion 74 is used only as a pilot pressure (set pressure of the pressure reducing valve portion), the pressure is not released, that is, the directional control valve 55 is stroked. At this time, there is no spontaneous drop of the actuator 88 due to the release of the load pressure.

The load pressure detecting path 82 is also connected to the other pressure chamber 66 of the pressure reducing valve portion 74 of the pressure compensating valve 75 provided in the other direction control valve 55. 74 is connected to the tank 86 by the neutral position A of the direction control valve 55, the pressure in the first oil passage 53 for introducing load pressure is zero, and thus the pressure chamber 6
The pressure in the pressure reducing valve portion 74 causes the check valve portion 63
Is biased in the closing direction. On the other hand, since the pump discharge pressure is guided from the pump discharge passage 81 to the pressure chamber a in the direction in which the check valve part 74 is opened, the differential pressure between the pump discharge pressure and the pressure in the load pressure detection passage 82 (= 20kg / cm ² )
The check valve portion 63 and the pressure reducing valve portion 74 are stroked in the opening direction of the check valve portion 63, but the stroke is slightly increased, and the pressure of the input port 44 becomes the differential pressure (= 20 k).
g / cm ² ), the receipt is performed by the weak spring 69, and as a result, the pressure reducing valve portion 74 does not stroke until the stroke end, and does not affect the hydraulic control of the direction control valve 55 at all. .

When any of the direction control valves 55 is to be stroked to the first pressure oil supply position B. When the total flow required for each actuator 88 is less than or equal to the maximum discharge flow of the hydraulic pump 20; Now, it is assumed that both the direction control valves 55 are stroked to the first pressure oil supply position B, and the respective input ports 44, the respective conduits 89, and the respective first hydraulic passages 53 for conducting the load pressure are connected. One of the pressure reducing valves 74 operates until the pressure in the pressure chamber 66 becomes equal to the pressure in the one pressure chamber 65, and the other pressure reducing valve 74 operates to reduce the pressure in the pressure chamber 66 to one of the pressure chambers 65. , Respectively, until they equal the internal pressure. Now, of the load pressures of the two actuators 88, 88, the left actuator 88
Is larger than the load pressure. It is assumed that the load pressure of the left actuator 26 is 100 (kg / cm ² ) and the load pressure of the right actuator 27 is 10 (kg / cm ² ). The load pressure detection path 82 is connected to a tank 86 via a throttle 91.
Before the directional control valve stroke, the pressure in the load pressure detection path 82 is zero. Therefore, each pressure reducing valve portion 74 also strokes by the pressure in the first oil passage 53 for load pressure detection, and the pump discharge pressure communicates with the pressure in the pressure detection conduit 34. When the pressure in the load pressure detecting path 82 rises to the pressure (10 kg / cm ² ) in the conduit 90 of the right actuator 88 on the low pressure side, first, the pressure reducing valve portion 74 of the right pressure compensating valve 75 closes. The pressure reducing valve portion 74 of the left pressure compensating valve 90 remains in the stroke state, and the pressure in the load pressure detecting path 82 is changed to the pump discharge pressure (20 kg / c).
m ² ). At this time, the pressure at the input port 44 of the direction control valve 55 of the left actuator 88 on the high pressure side is 100 (kg / cm ² ), the check valve 63 of the pressure compensating valve 75 is closed, and the pressure reducing valve 74 And has dissociated. On the other hand, the pressure reducing valve portion 74 of the pressure compensating valve 75 is provided with a pressure difference between the two pressure chambers 65 and 66 (20−20).
(10 = 10 kg / cm ² ) to urge the check valve portion 63 in the closing direction. On the other hand, the pressure in the pressure chamber a in the opening direction of the check valve portion 63 (pump discharge pressure) 20 (kg / c)
m ² ), the check valve 63 is opened until the pressure at the input port 44 of the direction control valve 55 reaches 10 (kg / cm ² ), and then the receipt is performed by the weak spring 69. By a pump adjusting direction control valve 85, there differential pressure (20kg / cm ²⁾ amount corresponding, pump discharge pressure from the high pressure pressure (20kg / cm ²⁾ of the load pressure Detchi 82 is controlled (40 kg / cm ² ). Also at this time, the pressure in the load pressure detecting path 82 becomes 40 (kg / cm ² ) with the check valve portion 63 of the high-pressure side pressure compensating valve 75 closed and the pressure reducing valve portion 74 being stroked. The pressure reducing valve portion 74 of the pressure compensating valve 75 of the first embodiment has a pressure difference between the load pressure detecting path 82 and the first oil path 53 for introducing the load pressure (= 30 kg /
cm ² ), the check valve portion 63 is urged in the closing direction, and as a result, the pressure at the input port 44 of the directional control valve 55 becomes 10
kg / cm ² . In this way, the pressure in the load pressure detection path 82 and the pump discharge pressure continue to rise, and eventually when the pump discharge pressure becomes equal to the load pressure (100 kg / cm ² ) of the high-pressure side actuator 88, the high-pressure side pressure compensation The pressures in the two pressure chambers 65 and 66 of the pressure reducing valve portion 63 of the valve 75 are both 100 kg / cm ² ,
9 closes and abuts against the check valve portion 63. At this time, the load valve section 74 of the low-pressure side pressure compensating valve 75 is connected to the pressure difference (1) between the load pressure detecting path 82 and the first oil path 53 for introducing the load pressure.
00-10 = 90 kg / cm ² ) to urge the check valve portion 63 in the closing direction. As a result, the low-pressure side directional control valve 5
The pressure at the input port 44 of No. 5 remains at 10 kg / cm ² . Again, the pump discharge pressure is controlled to 120 (kg / cm ² ) by the pump adjustment direction control valve 85. At this time, the pressure reducing valve portion 63 of the high-pressure side pressure compensating valve 75 is merely in contact with the check valve portion 63 by the weak spring 69, and the pressure difference between the two pressure chambers a and b of the check valve portion 63 is Here, the check valve section 63 is opened for the first time, and the pump discharge pressure (120 kg / cm ² ) is guided to the input port 44 of the direction control valve 55. On the other hand, the pressure reducing valve portion 74 of the pressure compensating valve 75 on the low pressure side closes the check valve portion 63 by the pressure difference (= 90 kg / cm ² ) in the load pressure detecting path 82 and the first oil passage 53 for introducing the load pressure. Direction, but the pressure in the pressure chamber a in the opening direction of the check valve portion 63 becomes 120
(Kg / cm ² ), the pressure at the input port 44 of the directional control valve 55 becomes 30 (kg / cm ² ) (120-9).
0), the check valve 63 and the pressure reducing valve 74
Pressure balance. That is, the check valve section 63 and the pressure reducing valve section 74 slightly stroke, and the check valve section 6
3. In 120 kg / cm ² to 30 kg / cm ²
It is in a state where it is squeezed so as to become. For the first time, this hydraulic control system is balanced, the pressure at the input port 44 of the directional control valve 55 on the high pressure side is 120 kg / cm ² , and the pressure at the input port 44 of the directional control valve 55 on the low pressure side is 30 kg / cm 2.
² , that is, the difference between the inlet pressure and the outlet pressure (load pressure) of the two directional control valves 55, 55 is 20 kg / cm
² , the two directional control valves 55, 55
Are actuators 88,
It becomes possible to control the flow rate supplied to 88.

When the sum of the flow rates required for the actuators 88 is greater than the maximum discharge flow rate of the hydraulic pump 80. Now, the load pressure and required flow rate of the actuators 88, 88 are set to 100 kg / cm ² ,
501 / min, right actuator 88 is 10kg
/ Cm ² and 501 / min. When the maximum discharge flow rate of the hydraulic pump 80 is 1001 / min or more, as described above, the difference between the inlet pressure and the outlet pressure of the directional control valves 55, 55 is kept constant (= 20 kg / cm ² ). Thus, the flow rate can be controlled, and the flow rate can be distributed every 501 / min. Next, it is assumed that the maximum discharge amount of the hydraulic pump 80 becomes 701 / min. Two directional control valves 5
The inlet pressure of 5,55 is 120 kg / cm ² , 3 as described above.
Since the pressure is 0 kg / cm ² , the flow rate to the high-pressure side directional control valve 55 is reduced from 501 / min to 201 / min. The flow rate to the low pressure side directional control valve 55 remains at 501 / min. If the strokes (opening areas) of the two directional control valves 55 are not changed, the differential pressure between the inlet pressure and the outlet pressure of the high-pressure side directional control valve 55 is reduced by 20 k by the reduced flow rate.
g / cm ² . Now, the differential pressure is 14kg / c
m ² , ie, the inlet pressure is from 120 kg / cm ² to 1
Assume that the pressure has dropped to 14 (100 + 14) kg / cm ² .
At this time, the two pressure chambers 6 of the pressure reducing valve portion 74 of the pressure compensating valve 75
Since the pressures 5 and 66 remain at 100 kg / cm ² , the pressure-reducing valve portion 74 is only in contact with the check valve portion 63 by the weak spring 69, and the check valve portion 6
3. The pressure in the pressure chamber b in the closing direction is 120 kg / cm.
If the pressure is reduced from ² to 114 kg / cm ² , the pressure in the pressure chamber a in the opening direction of the check valve 63, that is, the pump discharge pressure is 120 kg / cm ² , while the check valve 63 is open (stroke end). To 114 kg / cm ²
To decrease. At this time (when the pump discharge flow rate is insufficient), the pump discharge pressure is not controlled by the pump adjusting direction control valve 85. On the other hand, the pressure reducing valve portion 7 of the pressure compensating valve 75 on the low pressure side
4, two pressure chambers 65 and 66 are 100 kg / cm ² ,
10 kg / cm ² , the differential pressure is 90 kg / cm ²
To continue to bias the check valve 63 in the closing direction. On the other hand, the pressure in the pressure chamber a in the opening direction of the check valve portion 63,
That is, since the pump discharge pressure has been reduced to 114 kg / cm ² , the check valve 63 and the pressure reducing valve are maintained in a state where the pressure in the pressure chamber b in the closing direction of the check valve 63 is reduced from 30 kg / cm ² to 24 kg / cm ^2. Section 74 is pressure balanced. Therefore, the differential pressure between the inlet pressure and the outlet pressure of the directional control valve 55 on the low pressure side is 20 kg / cm ² to 14 kg / cm ^2.
2 (24-10). Due to the decrease in the differential pressure of the directional control valve 55, the supply flow rate to the actuator 88 on the low pressure side decreases from 501 / min, and the supply flow rate to the actuator 88 on the high pressure side increases accordingly from 201 / min. That is, the differential pressure between the inlet pressure and the outlet pressure of the directional control valves 55 and 55 is equal, and the two actuators 8
The hydraulic control system is balanced in a state where the supply amounts to 8, 88 are both distributed at 351 / min.

When three or more actuators are loaded by one hydraulic pump 80. Even when there are three or more actuators, the same check valve portion 63 and pressure reducing valve portion 74 are provided between the directional control valve and the hydraulic pump.
The pressure compensating valve 75 provided with the pressure reducing valve is provided, and the pressure difference in the closing direction of each pressure reducing valve portion is merely communicated by the load pressure detecting path 82. Even when the number of actuators is three or more, the operation based on the above-described operation principle can be performed. Is achieved. Although the hydraulic pump 80 is a variable displacement type in the above embodiment, the hydraulic pump 80 may be a fixed displacement type. In this case, an unload valve may be provided in the pump discharge path 81 of the hydraulic pump 80.

[0021]

The main spool 4 is mounted on one valve block 30.
9, since the direction control valve 55, the check valve section 63 and the pressure reducing valve section 74 can be incorporated by providing the valve 60 and the spool 64,
A directional control valve device having a pressure compensating valve can be provided. When the main spool 49 is switched so that the input port 44 communicates with the first actuator port 34, the second actuator port 35 communicates with the first actuator port 34. It becomes a directional control valve device.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional pressure oil supply device.

FIG. 2 is a circuit diagram of a conventional pressure oil supply device.

FIG. 3 is a perspective view of a valve block showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a state where the main spool and the spool are incorporated in the valve block.

FIG. 5 is a hydraulic circuit diagram for supplying pressure oil to a plurality of actuators.

[Explanation of symbols]

30 ... valve block, 31 ... spool hole, 34 ... first actuator port, 35 ... second actuator port,
37 ... check valve hole, 38 ... pressure reducing valve hole, 39 ... pump port, 42 ... first port, 43 ... second port, 44
... input port, 45 ... first load pressure detection port, 46 ... second load pressure detection port, 47 ... first tank port, 48 ...
Second tank port, 49 Main spool, 53 First oil passage, 56 Oil hole, 58 Oil hole, 60 Valve, 63 Check valve, 64 Spool, 65 First pressure chamber, 66 Second pressure chamber 69 69 Spring 74 Pressure reducing valve 75 Pressure compensating valve 80 Hydraulic pump 81 Pump discharge path 82
Load pressure detection path.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F15B 11/00-11/16

Claims (2)

(57) [Scope of request for utility model registration] 1. A valve block 30 has a spool hole 31, a check valve hole 37, and a pressure reducing valve hole 38, and the valve block 30 has an input port 4 opened to the spool hole 31.
4. A main spool for forming first and second load pressure detecting ports 45 and 46, first and second actuator ports 34 and 35, and a first tank port 47, respectively, and communicating and blocking each port with the spool hole 31. 49 is inserted into the directional control valve 55, and the valve block 30 is formed with a pump port 39 opened to the check valve hole 37 and an oil passage 56 communicating the check valve hole 37 to the input port 44. The pump port 39 and the oil passage 56 are communicated / blocked with the valve hole 37, and a spool 60 stopped at the blocking position is inserted into the check valve portion 63 to open the valve block 30 with the pressure reducing valve hole 38. First
The second ports 42 and 43 are formed, and the pressure reducing valve holes 38 are formed.
A first pressure chamber 65 and a second pressure chamber 66 are formed by inserting a spool 64 into the first pressure chamber 65, the first pressure chamber 65 is communicated with the second load pressure detection port 46, and the second pressure chamber 66 is connected to the second port 43. , The spool 64 is urged in one direction by a spring 69 to press and hold the spool 60 of the check valve portion 63 at the shut-off position to form a pressure reducing valve portion 74. The pressure reducing valve portion 74 and the check valve portion At 63, the pressure compensating valve 75 is used.
When the pressure oil supply position is established, the input port 44 communicates with the first actuator port 34 and the second actuator port 35 communicates with the tank port.
Is moved from the neutral position to the other position to set the second pressure oil supply position, the input port 44 communicates with the second actuator port 35, and the first actuator port 34 communicates with the tank port. Directional control valve device provided. 2. A first small-diameter portion 50 for connecting and disconnecting a first tank port 47, a first actuator port 34, and a first load pressure detection port 45 to and from a main spool 49, a second load pressure detection port 46, and a second Connect actuator port 35
An intermediate small-diameter portion 53 and a notch portion 53a and a second small-diameter portion 51 and a notch portion 51a to be cut off are formed.
A directional control valve device comprising a pressure compensating valve according to claim 1, wherein a communication groove (52) selectively communicating with one of the first and second load pressure detecting ports (45, 46) is formed.