WO2020105230A1

WO2020105230A1 - Fluid pressure control device

Info

Publication number: WO2020105230A1
Application number: PCT/JP2019/030975
Authority: WO
Inventors: 俊行木谷; 説与吉田
Original assignee: Ｋｙｂ株式会社
Priority date: 2018-11-20
Filing date: 2019-08-06
Publication date: 2020-05-28
Also published as: CN111556929B; KR20200061372A; KR102503136B1; JP7121641B2; EP3686440B1; CN111556929A; EP3686440A1; JP2020085077A; EP3686440A4

Abstract

A main circuit system (HC1) in a fluid pressure control device (100) has: a neutral cut-off valve (110) that connects or shuts off a first neutral passage (11) and a tank (T); a first external output passage (14) that connects downstream from first control valves (12) in the first neutral passage (11) and upstream from the neutral cut-off valve (110) and can supply hydraulic fluid to outside; and a second external output passage (15) that can supply, to outside, the hydraulic fluid that has been supplied via the neutral cut-off valve (110). The neutral cut-off valve (110) is switched between: a first position (P1) that permits hydraulic fluid to be guided into the tank (T); a second position (P2) that prohibits the supply of hydraulic fluid to outside via the second external output passage (15); and a third position (P3) that permits supply of the hydraulic fluid to outside via the second external output passage (15).

Description

Fluid pressure controller

The present invention relates to a fluid pressure control device.

JP2016-204826A has a fluid pressure control including a first circuit system having a plurality of control valves connected to a first pump and a second circuit system having a plurality of control valves connected to a second pump. The device is described. In the fluid pressure control device described in JP2016-204826A, the neutral cut valve that connects or disconnects the connection between the first neutral passage and the tank, and the neutral cut valve that communicates with the upstream of the neutral cut valve, An external output passage that can be supplied to the outside is provided, and the working fluid can be taken out from the first circuit system through the external output passage.

In this way, the fluid pressure control device described in JP2016-204826A can take out the working fluid to a circuit system different from the first circuit system through the external output passage. However, the first circuit system is provided with only one external output passage. Therefore, in the fluid pressure control device described in JP2016-204826A, it is not possible to add a circuit system different from the circuit system connected to the external output passage to connect to the first circuit system. There was a problem that the degree of freedom of expansion was low.

An object of the present invention is to provide a fluid pressure control device having a high degree of freedom in adding a circuit system.

According to an aspect of the present invention, there is provided a fluid pressure control device for controlling an actuator driven by a working fluid discharged from a pump, the main circuit system having a main control valve connected to the pump and controlling a main actuator. The main circuit system is provided in the main neutral passage for returning the working fluid of the pump to the tank when the main control valve is in the neutral position, and is provided downstream of the main control valve in the main neutral passage, A neutral cut valve that connects or disconnects the main neutral passage and the tank, and a downstream of the main control valve in the main neutral passage that is in communication with an upstream of the neutral cut valve, and is discharged from the pump. A first external output passage capable of supplying the working fluid to the outside, and a second external output passage capable of supplying the working fluid discharged from the pump and guided through the neutral cut valve to the outside. The cut valve has a first position allowing the working fluid discharged from the pump to be guided to the tank, and a working fluid discharged from the pump being supplied to the outside through the second external output passage. A second position that prohibits and prevents the working fluid discharged from the pump from being guided to the tank; and the working fluid discharged from the pump is supplied to the outside through the second external output passage. And a third position that allows the working fluid discharged from the pump to be prevented from being guided to the tank.

FIG. 1 is a circuit diagram showing a fluid pressure control device according to a first embodiment of the present invention. FIG. 2 is a simplified perspective view of the main valve block and the sub valve block. FIG. 3 is a circuit diagram showing a fluid pressure control device according to the second embodiment of the present invention.

<First Embodiment>
A fluid pressure control device 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The fluid pressure control device 100 is used for a working machine such as a power shovel, for example. Here, the case where the working machine is a power shovel will be described, but the fluid pressure control device 100 is also applicable to other working machines such as a wheel loader. Further, in the fluid pressure control device 100, working oil is used as the working fluid, but other fluid such as working water may be used as the working fluid.

Although not shown, the power shovel includes a crawler-type traveling unit, a revolving unit that is rotatably provided above the traveling unit, and an excavation unit provided in the revolving unit. The traveling unit has a pair of left and right crawlers. The power shovel runs by driving the pair of left and right crawlers of the running unit. The excavation unit includes a boom rotatably attached to the swivel unit, an arm rotatably attached to the boom, and a bucket rotatably attached to the arm.

As shown in FIG. 1, a power shovel includes an engine (not shown), a first pump 10 and a second pump 20 which are driven by the engine and discharge hydraulic oil, and a first pump 10 and a second pump 20. A fluid pressure control device 100 that controls an actuator for driving a traveling portion, a turning portion, an excavation portion, and the like by the hydraulic oil discharged from the pump 20, and a tank T in which the hydraulic oil flows back from the fluid pressure control device 100. Equipped with.

The fluid pressure control device 100 controls a plurality of actuators driven by the hydraulic oil discharged from the first pump 10 and the second pump 20. Examples of the plurality of actuators include

hydraulic motors

7A and 8A for driving the traveling unit, hydraulic motors for driving the swing unit (not shown), hydraulic cylinders for driving the boom (not shown), hydraulic cylinders for driving the arm (not shown). (Shown), a hydraulic cylinder 7B for driving a bucket, a hydraulic cylinder 8B for driving a preliminary attachment, a hydraulic cylinder 9A for driving an additional attachment, and the like.

Note that the preliminary attachment and the additional attachment include, for example, a breaker and a crusher that are attached instead of the bucket, an offset device that slides the boom left and right, and a dozer blade that is attached to the revolving part.

The fluid pressure control device 100 is connected to the first pump 10 and is supplied with hydraulic oil from the first pump 10. The first circuit system HC1 is connected to the second pump 20 and is supplied with hydraulic oil from the second pump 20. A second circuit system HC2 and a third circuit system HC3 connected to the first circuit system HC1 and supplied with hydraulic oil from the first pump 10 through a neutral cut valve 110 described later are provided. As will be described later, by switching the straight travel control valve 6, the hydraulic oil discharged from the first pump 10 is also supplied to the second circuit system HC2 and discharged from the second pump 20. Oil is also supplied to the first circuit system HC1 and the third circuit system HC3.

As shown in FIGS. 1 and 2, a fluid pressure control device 100 includes a main valve block 101 having a first circuit system HC1 and a second circuit system HC2 as a main circuit system, and a third circuit system as a sub circuit system. And a sub-valve block 103 having HC3. As shown in FIG. 2, the sub valve block 103 can be attached to the main valve block 101 using a plurality of bolts 105. The main valve block 101 may be formed by stacking and fastening a plurality of valve blocks, or may be formed by one valve block.

The main valve block 101 is formed with a bolt mounting hole 115 that is open to the outer surface and into which the bolt 105 is mounted. The sub valve block 103 is placed on the upper surface of the main valve block 101, the shaft portion of the bolt 105 is passed through the bolt insertion hole 135 of the sub valve block 103, and the tip end portion of the shaft portion of the bolt 105 is screwed into the bolt mounting hole 115. By doing so, the sub valve block 103 is fixed to the main valve block 101.

The sub-valve block 103 is provided to control the hydraulic cylinder 9A for driving the additional attachment. Conventionally, in order to control the hydraulic cylinder 9A for driving the additional attachment, the sub valve block 103 is placed separately from the main valve block 101, and the third circuit system HC3 is placed separately from the first pump 10 and the second pump 20. Had to be connected to the new hydraulic pump.

On the other hand, in the present embodiment, since the sub valve block 103 can be mounted on the main valve block 101, the installation area of the fluid pressure control device 100 can be reduced. Moreover, since it is not necessary to provide a pipe between the main valve block 101 and the sub valve block 103, the installation space of the fluid pressure control device 100 can be reduced. Further, as will be described later, since the hydraulic oil of the first pump 10 is supplied to the sub valve block 103 through the main valve block 101, it is not necessary to connect a new hydraulic pump to the sub valve block 103. That is, according to the present embodiment, it is possible to reduce the number of parts and cost as compared with the case where the sub valve block 103 to which a new hydraulic pump is connected is provided separately from the main valve block 101.

As shown in FIG. 1, the first circuit system HC1 is connected in series to the first neutral passage 11 and a first neutral passage 11 as a main neutral passage for guiding the hydraulic oil discharged from the first pump 10 to the tank T. First control valve 12 as a plurality of main control valves, a first parallel passage 13 branching from a first neutral passage 11 upstream of a straight traveling control valve 6 described later, and a discharge passage connected to the tank T. 19, and. The plurality of first control valves 12 are connected in series by the first neutral passage 11 and connected in parallel by the first parallel passage 13.

The first control valve 12 that is the main control valve that controls the actuator provided in the first circuit system HC1 includes the first traveling control valve 12A, the bucket control valve 12B, the boom first speed control valve 12C, and the arm 2. A speed control valve 12D is included. The hydraulic fluid discharged from the first pump 10 is sequentially introduced from the upstream side to the first travel control valve 12A, the bucket control valve 12B, the boom first speed control valve 12C, and the arm second speed control valve 12D. ..

The first travel control valve 12A controls the supply / discharge of hydraulic oil to / from a hydraulic motor 7A for driving the travel section provided on the left side of the vehicle body of the power shovel. The bucket control valve 12B controls the supply / discharge of hydraulic oil to / from the hydraulic cylinder 7B for driving the bucket. The boom first speed control valve 12C controls supply and discharge of hydraulic oil to and from a hydraulic cylinder (not shown) for driving the boom. The arm 2nd speed control valve 12D controls supply and discharge of hydraulic oil to and from a hydraulic cylinder (not shown) for driving the arm. The main actuators (hydraulic motor 7A, hydraulic cylinder 7B, etc.) controlled by the first control valve 12 are also collectively referred to as the first actuator 7.

As described above, the first circuit system HC1 includes the plurality of first control valves 12 that are connected to the first pump 10 and control the plurality of first actuators 7. The discharge passage 19 guides the hydraulic oil discharged from the first actuator 7 through the first control valve 12 to the tank T.

In the first circuit system HC1, when the straight travel control valve 6 described later is in the normal position (A) and the neutral cut valve 110 described later is in the first position (P1), all the first When the control valve 12 is in the neutral position, the hydraulic oil discharged from the first pump 10 is returned to the tank T through the first neutral passage 11. On the other hand, when at least one of the plurality of first control valves 12 is in the drive position, the communication between the first pump 10 and the tank T in the first neutral passage 11 is cut off.

In the first circuit system HC1, even when any of the first control valves 12A to 12C is switched to the drive position and the communication between the first pump 10 and the tank T in the first neutral passage 11 is cut off, The hydraulic oil discharged from one pump 10 can be supplied to each of the first control valves 12B to 12D through the first parallel passage 13.

The first circuit system HC1 is provided downstream of all the first control valves 12 in the first neutral passage 11 (that is, downstream of the arm 2nd speed control valve 12D) and connects the first neutral passage 11 with the tank T. The neutral cut valve 110 that shuts off and the downstream of all the first control valves 12 in the first neutral passage 11 (that is, the downstream of the arm second speed control valve 12D) and the upstream of the neutral cut valve 110 are communicated. , A first external output passage 14 capable of supplying hydraulic oil discharged from the first pump 10 to the outside, and a second external output passage 14 capable of supplying hydraulic oil discharged from the first pump 10 and guided through the neutral cut valve 110 to the outside. The external output passage 15 is further provided.

The first external output passage 14 is connected to the first external output port 14o opening on the outer surface of the main valve block 101. The second external output passage 15 is connected to the second external output port 15o opening on the outer surface of the main valve block 101. The first parallel passage 13 is connected to the output port 13o opening on the outer surface of the main valve block 101.

The first circuit system HC1 further includes

branch passages

191 and 192 that branch from the discharge passage 19 that guides the hydraulic oil to the tank T. The

branch passages

191 and 192 are respectively connected to

introduction ports

191i and 192i that open to the outer surface of the main valve block 101.

The neutral cut valve 110 has a first position (P1), a second position (P2), and a third position (P3) according to the pilot pressure supplied to the first pilot pressure chamber 116a and the second pilot pressure chamber 116b. It is a pilot type switching valve in which the spool is switched between. The pilot pressure acting on the first pilot pressure chamber 116a and the second pilot pressure chamber 116b may be, for example, in the operating state of the power shovel, the operating position of a dedicated operating member (not shown) for operating the neutral cut valve 110, or the like. It is controlled based on.

The neutral cut valve 110 is held in the first position (P1) by the biasing force of the centering spring 117 when the pilot pressure does not act on each of the first pilot pressure chamber 116a and the second pilot pressure chamber 116b.

The neutral cut valve 110 includes a first inlet port 111 and a second inlet port 112 that communicate with the second neutral speed control valve 12D in the first neutral passage 11, a tank port 119 that communicates with the discharge passage 19, and a second And an outlet port 113 communicating with the external output passage 15.

When the neutral cut valve 110 is in the first position (P1), the first inlet port 111 and the tank port 119 are in communication with each other, and the second inlet port 112 and the outlet port 113 are in communication with each other. Since the first inlet port 111 and the tank port 119 communicate with each other, the hydraulic oil guided to the first neutral passage 11 is guided to the discharge passage 19 through the neutral cut valve 110.

That is, when the neutral cut valve 110 is in the first position (P1), the hydraulic oil discharged from the first pump 10 is prohibited from being supplied to the outside of the main valve block 101 through the second external output passage 15. Also, the hydraulic oil discharged from the first pump 10 is allowed to be guided to the tank T through the discharge passage 19.

When the neutral cut valve 110 is in the second position (P2), the communication between the first inlet port 111 and the tank port 119 is blocked, and the communication between the second inlet port 112 and the outlet port 113 is blocked.

That is, when the neutral cut valve 110 is in the second position (P2), the hydraulic oil discharged from the first pump 10 is prohibited from being supplied to the outside of the main valve block 101 through the second external output passage 15. In addition, the hydraulic oil discharged from the first pump 10 is prohibited from being guided to the tank T through the discharge passage 19.

When the neutral cut valve 110 is in the third position (P3), the communication between the first inlet port 111 and the tank port 119 is cut off, and the second inlet port 112 and the outlet port 113 communicate with each other. Since the second inlet port 112 and the outlet port 113 are in communication with each other, the hydraulic oil introduced into the first neutral passage 11 is introduced into the second external output passage 15 through the neutral cut valve 110.

That is, the neutral cut valve 110 allows the hydraulic oil discharged from the first pump 10 to be supplied to the outside of the main valve block 101 through the second external output passage 15 when in the third position (P3). In addition, the hydraulic oil discharged from the first pump 10 is prohibited from being guided to the tank T through the discharge passage 19.

In this way, the first position (P1) is a position where the first neutral passage 11 and the tank T communicate with each other, and the second position (P2) and the third position (P3) are the first neutral passage 11 and the tank T. It is a position that cuts off communication. Further, the third position (P3) is a position where the first neutral passage 11 and the third neutral passage 31 of the third circuit system HC3 described later communicate with each other, and the first position (P1) and the second position (P2). Is a position that blocks communication between the first neutral passage 11 and the third neutral passage 31.

In the present embodiment, the sub-valve block 103 is attached to the main valve block 101 so that the hydraulic oil discharged from the first pump 10 can be supplied to the third circuit system HC3 through the first circuit system HC1. .. When the sub valve block 103 is not attached, the ports (13o, 15o, 191i, 192i) opening to the outer surface of the main valve block 101 are closed by plugs. When the sub valve block 103 is attached, the ports (13o, 15o, 191i, 192i) opening on the outer surface of the main valve block 101 are connected to the ports (33i, 31i, 38o, 39o) opening on the outer surface of the sub valve block 103. ) Is connected to.

The third circuit system HC3 is connected to the third neutral passage 31 and a third neutral passage 31 that guides the hydraulic oil introduced through the neutral cut valve 110 and the second external output passage 15 of the first circuit system HC1 to the tank T. A third control valve 32 as a sub-control valve for controlling the third actuator 9 as an actuator, and a third parallel passage for guiding hydraulic oil introduced through the first parallel passage 13 of the first circuit system HC1 to the third control valve 32. 33, and

exhaust passages

38, 39 communicating with the exhaust passage 19 of the first circuit system HC1. The third neutral passage 31 is connected to the second external output passage 15 of the first circuit system HC1 and functions as a second external input passage through which hydraulic oil is guided through the first circuit system HC1.

In the circuit system in which the third circuit system HC3 is connected to the first circuit system HC1, the first neutral passage 11, the second external output passage 15, and the third neutral passage 31 are discharged from the first pump 10. It functions as a neutral passage for returning the hydraulic oil to the tank T. That is, in the circuit system in which the third circuit system HC3 is connected to the first circuit system HC1, the plurality of first control valves 12 and the third control valves 32 include the first neutral passage 11 as the neutral passage and the second external passage. The output passage 15 and the third neutral passage 31 are connected in series, and the first parallel passage 13 and the third parallel passage 33 are connected in parallel.

The third control valve 32 controls the supply / discharge of hydraulic oil to / from the hydraulic cylinder 9A as the third actuator 9 that drives the additional attachment according to the pilot pressure acting on the pilot pressure chamber. As described above, the third circuit system HC3 includes the third control valve 32 that controls the third actuator 9 by the hydraulic oil discharged from the first pump 10 and supplied through the main valve block 101. The third control valve 32 communicates the third neutral passage 31 and the discharge passage 39 when in the neutral position, and is an open center type control valve that guides the hydraulic oil guided to the third neutral passage 31 to the tank T. Is.

The third neutral passage 31 is connected to an external input port 31i opening on the outer surface of the sub valve block 103. The external input port 31i of the sub valve block 103 is connected to the second external output port 15o of the main valve block 101.

The third parallel passage 33 is connected to the input port 33i opened on the outer surface of the sub valve block 103. The input port 33i of the sub valve block 103 is connected to the output port 13o of the main valve block 101.

The discharge passage 38 through which the hydraulic oil is guided from the hydraulic cylinder 9A through the third control valve 32 is connected to the outlet port 38o opening to the outer surface of the sub valve block 103. The outlet port 38o of the sub valve block 103 is connected to the inlet port 191i of the main valve block 101.

The discharge passage 39 through which the hydraulic oil is guided from the third neutral passage 31 through the third control valve 32 is connected to the outlet port 39o that opens to the outer surface of the sub valve block 103. The outlet port 39o of the sub valve block 103 is connected to the inlet port 192i of the main valve block 101.

In the third circuit system HC3, when the third control valve 32 is in the neutral position, the hydraulic oil supplied from the first circuit system HC1 is returned to the tank T through the third neutral passage 31 and the discharge passage 39.

The second circuit system HC2 includes a second neutral passage 21 as a main neutral passage for guiding the hydraulic oil discharged from the second pump 20 to the tank T, and a plurality of main control valves connected in series to the second neutral passage 21. A second control valve 22, a second parallel passage 23 branched from the second neutral passage 21 upstream of the second control valve 22, and a discharge passage 19 connected to the tank T. The plurality of second control valves 22 are connected in series by the second neutral passage 21 and connected in parallel by the second parallel passage 23.

The second control valve 22, which is the main control valve that controls the actuator provided in the second circuit system HC2, includes the second traveling control valve 22A, the standby control valve 22B, the turning control valve 22C, and the boom second speed control. A valve 22D and an arm 1st speed control valve 22E are included. The hydraulic fluid discharged from the second pump 20 is, in order from the upstream side, the second traveling control valve 22A, the standby control valve 22B, the swing control valve 22C, the boom second speed control valve 22D, and the arm first speed. It is led to the control valve 22E.

The second traveling control valve 22A controls the supply / discharge of hydraulic oil to / from the hydraulic motor 8A for driving the traveling portion which is provided on the right side of the vehicle body of the power shovel. The spare control valve 22B controls the supply / discharge of hydraulic oil to / from the hydraulic cylinder 8B for driving the spare attachment. The turning control valve 22C controls the supply and discharge of hydraulic oil to and from a hydraulic motor (not shown) for driving the turning portion. The boom second speed control valve 22D controls supply and discharge of hydraulic oil to and from a hydraulic cylinder (not shown) for driving the boom. The arm 1st speed control valve 22E controls the supply / discharge of hydraulic oil to / from a hydraulic cylinder (not shown) for driving the arm. The main actuators (hydraulic motor 8A, hydraulic cylinder 8B, etc.) controlled by the second control valve 22 are collectively referred to as the second actuator 8.

As described above, the second circuit system HC2 has the plurality of second control valves 22 which are connected to the second pump 20 and control the plurality of second actuators 8. The discharge passage 19 guides the hydraulic oil discharged from the second actuator 8 through the second control valve 22 to the tank T. The discharge passage 19 is commonly used as a passage for guiding the hydraulic oil of the first circuit system HC1 and the second circuit system HC2 to the tank T.

In the second circuit system HC2, when all the second control valves 22 are in the neutral position, the hydraulic oil discharged from the second pump 20 is returned to the tank T through the second neutral passage 21. On the other hand, when at least one of the plurality of second control valves 22 is in the drive position, the communication between the second pump 20 and the tank T in the second neutral passage 21 is cut off.

In the second circuit system HC2, even when any of the second control valves 22A to 22D is switched to the driving position and the communication between the second pump 20 and the tank T in the second neutral passage 21 is cut off, The hydraulic oil discharged from the two pumps 20 can be supplied to the respective second control valves 22B to 22E through the second parallel passage 23.

The second circuit system HC2 has a first external input passage 24 that guides hydraulic oil supplied from the outside to a predetermined second control valve 22 (in the present embodiment, the standby control valve 22B). The first external input passage 24 is connected to the first external input port 24i opening on the outer surface of the main valve block 101.

The first circuit system HC1 further includes a straight traveling control valve 6 connected downstream of a branch point of the first neutral passage 11 with the first parallel passage 13 and upstream of the first traveling control valve 12A. The second parallel passage 23 is connected to the straight travel control valve 6. The second parallel passage 23 connects the second parallel upstream passage 23a connecting the second pump 20 and the traveling straight traveling control valve 6, and the second parallel upstream passage 23a connecting the traveling straight traveling control valve 6 and the second control valves 22B to 22E. 2 parallel downstream passages 23b.

The straight travel control valve 6 can be switched between two positions, a normal position (A) shown on the right side of FIG. 1 and a straight travel position (B) shown on the left side of FIG. The straight traveling control valve 6 is switched to the straight traveling position B when hydraulic oil is supplied to the pilot pressure chamber 6a. When the pilot pressure is not acting on the pilot pressure chamber 6a, the straight traveling control valve 6 is held at the normal position A by the urging force of the return spring 6c.

At the normal position (A), the second parallel upstream passage 23a of the second parallel passage 23 is connected to the second parallel downstream passage 23b of the second parallel passage 23, and the second parallel upstream passage 23a is located downstream of the straight travel control valve 6. One neutral passage 11 is connected to the first pump 10. As a result, the hydraulic oil discharged from the first pump 10 is guided to each first control valve 12 through the first neutral passage 11 and the first parallel passage 13. Further, the hydraulic oil discharged from the second pump 20 is guided to each second control valve 22 through the second neutral passage 21 and the second parallel passage 23.

In addition, when the neutral cut valve 110 is in the third position (P3), the hydraulic oil discharged from the first pump 10 includes the first neutral passage 11, the neutral cut valve 110, the second external output passage 15, and the third external passage 15. It is also guided to the third control valve 32 through the neutral passage 31. Further, the hydraulic oil discharged from the first pump 10 is also guided to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33.

In the straight traveling position (B), the second parallel upstream passage 23a of the second parallel passage 23 is connected to the first neutral passage 11 downstream of the straight traveling control valve 6, and the second parallel downstream passage 23b is formed. It is connected to the first pump 10. As a result, the hydraulic fluid discharged from the first pump 10 is guided to the first control valves 12B to 12D through the first parallel passage 13 and the second control is performed through the second parallel downstream passage 23b of the second parallel passage 23. It is led to the valves 22B to 22E. Further, the hydraulic oil discharged from the second pump 20 is guided to the first control valve 12A through the first neutral passage 11 downstream of the straight travel control valve 6 and also through the second neutral passage 21 to the second control valve 22A. Be led to.

In addition, when the neutral cut valve 110 is in the third position (P3), the hydraulic oil discharged from the first pump 10 is also introduced to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33. Get burned. The hydraulic oil discharged from the second pump 20 is also guided to the third control valve 32 through the first neutral passage 11, the neutral cut valve 110, the second external output passage 15 and the third neutral passage 31.

When the power shovel is traveling without driving the excavation part, the pilot pressure chamber 6a has a tank pressure, and the traveling straight traveling control valve 6 is maintained at the normal position (A). Therefore, when operating only the

hydraulic motors

7A and 8A for driving the traveling portion, the hydraulic fluid discharged from the first pump 10 is supplied to the first traveling control valve 12A and the second traveling control valve 22A is supplied. Is supplied with hydraulic oil discharged from the second pump 20.

On the other hand, if the actuator of the excavation unit is driven while the

hydraulic motors

7A and 8A for driving the traveling unit are driven, pilot pressure acts on the pilot pressure chamber 6a, and the traveling straight traveling control valve 6 moves to the traveling straight traveling position ( B). That is, when the

hydraulic motors

7A, 8A for driving the traveling unit and the actuators other than the

hydraulic motors

7A, 8A are simultaneously operated, the first traveling control valve 12A and the second traveling control valve 22A are connected to the second pump 20 from the second pump 20. The discharged hydraulic oil is supplied. The hydraulic oil discharged from the first pump 10 is supplied to the other first control valves 12B to 12D, the other second control valves 22B to 22E, and the third control valve 32. As a result, the traveling circuit and the circuits other than the traveling circuit are independent of each other, so that the traveling straightness of the vehicle body is ensured.

Next, the operation of the neutral cut valve 110 will be described.

The neutral cut valve 110 is in a state where the first pilot pressure chamber 116a and the second pilot pressure chamber 116b are respectively connected to the tank T, and the hydraulic oil is not supplied into the first pilot pressure chamber 116a and the second pilot pressure chamber 116b. Then, the spool is located at the first position (P1). In this state, the first inlet port 111 and the tank port 119 communicate with each other, and the communication between the second inlet port 112 and the outlet port 113 is blocked.

Therefore, the hydraulic oil that has flowed into the first inlet port 111 through the first neutral passage 11 is discharged to the tank T through the tank port 119.

When hydraulic oil is supplied to the first pilot pressure chamber 116a from this state, the spool moves against the biasing force of the centering spring 117 by the pressure of the hydraulic oil supplied to the first pilot pressure chamber 116a, Switch to position 2 (P2). As a result, the communication between the first inlet port 111 and the tank port 119 is blocked. In addition, the cutoff of the communication between the second inlet port 112 and the outlet port 113 is maintained.

The first external output port 14o is always in communication with the first neutral passage 11 regardless of the position of the neutral cut valve 110. However, when the neutral cut valve 110 is located at the first position (P1), the first neutral passage 11 and the tank T communicate with each other as described above, so that the first external output port 14o also communicates with the tank T. As a result, the hydraulic oil discharged by the first pump 10 is returned to the tank T without being supplied to the outside through the first external output port 14o.

On the other hand, when the neutral cut valve 110 is in the second position (P2), the communication between the first neutral passage 11 and the tank T is blocked as described above. Therefore, the hydraulic fluid that has flowed into the first neutral passage 11 downstream of the arm second speed control valve 12D and upstream of the neutral cut valve 110 passes through the first external output passage 14 so that the entire amount of the hydraulic oil is stored in the main valve block 101. It is supplied to the outside.

As described above, in the fluid pressure control device 100, by switching the neutral cut valve 110 to the second position (P2), the hydraulic oil supplied from the first pump 10 to the first circuit system HC1 is supplied to the first external output port 14o. Can be supplied to the outside through.

Therefore, in the fluid pressure control device 100, for example, the hydraulic oil supplied from the first pump 10 to the first circuit system HC1 is used to drive a newly added actuator (not shown) through the first external output port 14o. It is also possible to use the same for a circuit for driving any one of the first actuator 7, the second actuator 8 and the third actuator 9.

Here, for example, a case will be described in which the hydraulic fluid supplied to the outside through the first external output port 14o is joined to the flow path of the hydraulic cylinder 8B for driving the preliminary attachment.

The first external output port 14o and the first external input port 24i are connected outside the main valve block 101 by an external pipe 30. That is, the first external output passage 14 is connected to the first external input passage 24 via the external pipe 30.

In this state, hydraulic oil is supplied to the pilot pressure chamber of the standby control valve 22B that controls the supply and discharge of hydraulic oil to and from the hydraulic cylinder 8B and the first pilot pressure chamber 116a of the neutral cut valve 110. As a result, when the spare control valve 22B is operated, the spare control valve 22B receives, in addition to the hydraulic oil discharged from the second pump 20, the hydraulic oil discharged from the first pump 10 as a first external output. It is supplied through the passage 14, the external pipe 30, and the first external input passage 24.

That is, in the present embodiment, the hydraulic oil discharged from the first pump 10 is guided to the outside through the first external output passage 14 of the first circuit system HC1, and through the first external input passage 24 of the second circuit system HC2. It is introduced upstream of the standby control valve 22B and joins the hydraulic oil discharged from the second pump 20.

The neutral cut valve 110 may be configured to connect or disconnect the first neutral passage 11 and the tank T according to the pilot pressure Pp that controls the standby control valve 22B. In this case, the spool of the neutral cut valve 110 is maintained at the first position (P1) when the pilot pressure Pp is low, and the spool of the neutral cut valve 110 is moved to the second position (P2) when the pilot pressure Pp is high. The spring load of the centering spring 117 may be set so as to switch.

According to this configuration, when the operation amount of the spare control valve 22B is small, the hydraulic cylinder 8B is driven only by the hydraulic oil discharged from the second pump 20. When the operation amount of the spare control valve 22B is large, the hydraulic cylinder 8B is driven by the hydraulic oil discharged from the first pump 10 in addition to the hydraulic oil discharged from the second pump 20.

Therefore, by increasing the operation amount of the spare control valve 22B, the flow rate of hydraulic oil to the spare control valve 22B can be increased and the operation of the hydraulic cylinder 8B controlled by the spare control valve 22B can be accelerated. it can.

Although not shown, in the case where hydraulic oil is supplied to the circuit system for driving the newly added actuator through the first external output passage 14, the neutral cut valve 110 is set when driving the added actuator. It suffices to switch to the second position (P2).

On the other hand, when hydraulic oil is supplied to the second pilot pressure chamber 116b of the neutral cut valve 110, the spool moves against the biasing force of the centering spring 117 due to the pressure of the hydraulic oil supplied to the second pilot pressure chamber 116b. Then, it switches to the third position (P3). As a result, the second inlet port 112 and the outlet port 113 are communicated with each other, and the communication between the first inlet port 111 and the tank port 119 is blocked.

In the state where the neutral cut valve 110 is located at the third position (P3), the third neutral passage 31 of the third circuit system HC3 communicates with the first neutral passage 11 of the first circuit system HC1. The third parallel passage 33 of the third circuit system HC3 always communicates with the first parallel passage 13 of the first circuit system HC1.

Therefore, in the state in which the neutral cut valve 110 is located at the third position (P3), the plurality of first control valves 12 and the third control valves 32 have the first neutral passage 11 and the second external output passage 15 as the neutral passages. And the third neutral passage 31 are connected in series, and the first parallel passage 13 and the third parallel passage 33 are connected in parallel.

Therefore, in the state where the neutral cut valve 110 is located at the third position (P3), any or all of the first control valves 12A to 12D are switched to the drive position and the first pump 10 in the first neutral passage 11 is switched. Even when the communication between the tank T and the tank T is cut off, the hydraulic oil discharged from the first pump 10 can be supplied to the third control valve 32 through the first parallel passage 13 and the third parallel passage 33.

Therefore, by attaching the sub valve block 103 to the main valve block 101, the third actuator 9 that can be driven in the same manner as the first actuator 7 can be easily performed by the hydraulic oil discharged from the first pump 10 or the second pump 20. Can be expanded.

According to the above-described embodiment, the following operational effects are achieved.

By switching the neutral cut valve 110 to the second position (P2), the hydraulic oil discharged from the first pump 10 can be supplied to the outside of the main valve block 101 through the first external output passage 14. Further, by switching the neutral cut valve 110 to the third position (P3), the hydraulic oil discharged from the first pump 10 can be supplied to the outside of the main valve block 101 through the second external output passage 15. ..

Since the hydraulic oil supplied from the first pump 10 to the first circuit system HC1 can be supplied to the outside not only through the first external output passage 14 but also through the second external output passage 15, the degree of freedom in the expansion of the circuit system can be increased. It is possible to provide the fluid pressure control device 100 having a high temperature.

<Second Embodiment>
A fluid pressure control device 200 according to a second embodiment of the present invention will be described with reference to FIG. In the following, the points different from the first embodiment will be mainly described, and in the drawings, the same or corresponding configurations as the configurations described in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted. .

In the first embodiment, the example in which the third circuit system HC3 has the open center type third control valve 32 has been described. On the other hand, in the second embodiment, the third circuit system HC32 has a closed center type third control valve 232.

In the second embodiment, the configurations of the first circuit system HC1 and the second circuit system HC2 are the same as those of the first embodiment, but the configuration of the third circuit system HC32 is different from that of the first embodiment. That is, in the second embodiment, the configuration of the main valve block 101 is the same as that of the first embodiment, but the configuration of the sub valve block 203 is different from that of the first embodiment.

The sub-valve block 203 including the third circuit system HC32 includes an inlet block B30 that takes in hydraulic oil from the first circuit system HC1 and valve blocks B31 and B32 that control the third actuator 9 for driving the additional attachment. .. The inlet block B30 is also an outlet block for discharging the hydraulic oil to the tank T. Since the valve block B31 and the valve block B32 have the same configuration, the illustration of the valve block B32 is partially omitted. Also, the number of valve blocks can be arbitrarily changed depending on the number of actuators to be added.

The third circuit system HC32 is a plurality of third control valves 232 for controlling the plurality of third actuators 9 and a supply passage serving as a second external input passage connected to the second external output passage 15 of the first circuit system HC1. 231, a tank passage 239 connected to the tank T, and a load pressure passage 241 to which the highest load pressure of the plurality of third actuators 9 is introduced. The supply passage 231 guides the hydraulic oil discharged from the first pump 210 and supplied to the third control valve 232 through the first neutral passage 11, the neutral cut valve 110 and the second external output passage 15. The third control valve 232 controls the third actuator 9 with the hydraulic oil discharged from the first pump 210 and supplied to the supply passage 231 through the main valve block 101.

The inlet block B30 is provided with a discharge pressure output port 231p connected to the supply passage 231 and a load pressure output port 241p connected to the load pressure passage 241. Further, the inlet block B30 is provided with a relief valve 261 connected to the supply passage 231. The relief valve 261 has a maximum pressure of a circuit formed by connecting the first circuit system HC1 of the main valve block 101 to the third circuit system HC3 of the sub valve block 203 when the neutral cut valve 110 is in the third position (P3). Stipulate.

Each of the valve blocks B31 and B32 has a third control valve 232 connected to the supply passage 231, and a pressure compensation valve 234 provided between the third control valve 232 and the third actuator 9.

In the present embodiment, an after-orifice type load sensing system in which a pressure compensation valve 234 is provided downstream of the meter-in throttle portion of each third control valve 232 is adopted. In such a load sensing system, when a plurality of third actuators 9 are simultaneously operated, the pressure compensation valve 234 functions as a load adjustment between the third actuators 9.

The pressure compensation valve 234 is provided with the pressure downstream of the meter-in throttle portion provided in the third control valve 232 and the highest load pressure among the load pressures of the plurality of third actuators 9. The pressure compensating valve 234 compensates for the pressure downstream of the meter-in throttle unit to be a pressure higher than the maximum load pressure of the third actuator 9 by a predetermined value.

Therefore, in the present embodiment, when the plurality of third control valves 232 are simultaneously driven, regardless of the load pressure of the third actuator 9, the pressure oil having a flow rate according to the operation amount of the spool of the third control valve 232 is used. Can be supplied.

The first pump 210 and the second pump 220 are variable displacement type piston pumps, and the discharge capacity changes when the inclination of the swash plate is changed by a regulator (not shown). The discharge capacities of the first pump 210 and the second pump 220 are so-called load so that the differential pressure between the pump discharge pressure guided to a regulator (not shown) and the maximum load pressure of the third actuator 9 becomes a predetermined value. It is controlled by sensing control.

The maximum load pressure of the third actuator 9 is guided from the load pressure output port 241p to the regulators (not shown) of the first pump 210 and the second pump 220 through piping and the like. Further, the pump discharge pressure is introduced from the discharge pressure output port 231p to a regulator (not shown) of the first pump 210 and the second pump 220 through a pipe or the like.

In the second embodiment, the output port 13o and the

introduction ports

191i and 192i that are not used in the main valve block 101 are closed by the sub valve block 203. Since the unused ports (13o, 191i, 192i) are closed by the sub valve block 203, it is not necessary to separately provide a closing member such as a plug, and the number of parts can be reduced.

According to the second embodiment as described above, it is possible to obtain the same effect as that of the first embodiment.

As described above, the main valve block 101 according to the second embodiment is similar to that of the first embodiment. Therefore, the main valve block 101 can be used regardless of whether the

third control valves

32, 232 of the sub valve blocks 103, 203 are open center type (see FIG. 1) or closed center type (see FIG. 3). Is. That is, by providing the neutral cut valve 110 and the predetermined ports (15o, 13o, 191i, 192i), it is possible to provide the main valve block 101 with high versatility.

The following modified examples are also within the scope of the present invention, and the configurations shown in the modified examples may be combined with the configurations described in the above-described embodiments, or the configurations described in the above-described different embodiments may be combined, It is also possible to combine the configurations described in the modified examples.

<Modification 1>
In the above embodiment, an example in which a plurality of first actuators 7 and a plurality of first control valves 12 are provided has been described, but the present invention is not limited to this. At least one each of the first actuator 7 and the first control valve 12 may be provided. In the above embodiment, an example in which a plurality of second actuators 8 and a plurality of second control valves 22 are provided has been described, but the present invention is not limited to this. At least one second actuator 8 and at least one second control valve 22 may be provided.

<Modification 2>
In the above embodiment, an example in which the neutral cut valve 110 is provided in the first neutral passage 11 of the first circuit system HC1 has been described, but the present invention is not limited to this. Instead of the neutral cut valve 110 provided in the first neutral passage 11, or in addition to the neutral cut valve 110 provided in the first neutral passage 11, the second neutral passage 21 has the same function as the neutral cut valve 110. A neutral cut valve may be provided.

That is, the second circuit system HC2 is provided with first and second external output passages similar to the first external output passage 14 and the second external output passage 15 of the first circuit system HC1 described in the above embodiment, and A sub valve block similar to the sub valve block 103 described in the embodiment may be attached to the main valve block 101, and the circuit system of the sub valve block may be connected to the second circuit system HC2. Further, the second circuit system HC2 is provided with a first external output passage similar to the first external output passage 14 described in the above embodiment, and the first circuit input HC1 is provided with the first external input passage described in the above embodiment. A first external input passage similar to the passage 24 may be provided and both may be connected by an external pipe. In this case, the neutral cut valve provided in the second circuit system HC2 is used to combine the hydraulic oil of the second circuit system HC2 with the first circuit system HC1 to accelerate the operation of the first actuator 7. You can

The configuration, operation, and effect of the embodiment of the present invention configured as above will be collectively described.

The fluid

pressure control devices

100 and 200 are fluid pressure control devices that control an actuator driven by the working fluid discharged from the pumps (first pumps 10, 210, second pumps 20, 220). It has a main control valve (first control valve 12, second control valve 22) which is connected to the

first pump

10, 210 and the second pump 20, 220) and controls the main actuator (first actuator 7, second actuator 8). A main circuit system (first circuit system HC1, second circuit system HC2) is provided, and the main circuit system (first circuit system HC1, second circuit system HC2) is a main control valve (first control valve 12, second control system). Main neutral passage (first neutral passage 11, second neutral passage 21) for returning the working fluid of the pump (

first pump

10, 210, second pump 20, 220) to the tank T when the valve 22) is in the neutral position. ) And a main neutral passage (first neutral passage 11, second neutral passage 21) downstream of the main control valve (first control valve 12, second control valve 22), and the main neutral passage (first neutral passage). 11, the second neutral passage 21) and the neutral cut valve 110 for connecting or disconnecting the tank T, and the main control valve (first control valve 12, first control valve 12,) in the main neutral passage (first neutral passage 11, second neutral passage 21). The working fluid discharged from the pumps (the first pumps 10, 210, the second pumps 20, 220) communicating with the downstream of the second control valve 22) and the upstream of the neutral cut valve 110 is supplied to the outside. A possible first external output passage 14 and a second external output passage capable of supplying the working fluid discharged from the pumps (first pumps 10, 210, second pumps 20, 220) and guided through the neutral cut valve 110 to the outside. 15, and the neutral cut valve 110 allows the working fluid discharged from the pumps (first pumps 10, 210, second pumps 20, 220) to be guided to the tank T at the first position (P1). ) And the working fluid discharged from the pump (

first pump

10, 210, second pump 20, 220) are prohibited from being supplied to the outside through the second external output passage 15, and the pump (

first pump

10, 210, the second pump 20, 220) and a second position (P2) that prohibits the working fluid discharged from the tank T from being guided to the tank T, and the pump (

first pump

10, 210,

second pump

20, 220). ) Is allowed to be supplied to the outside through the second external output passage 15, and the working fluid discharged from the pumps (the first pumps 10, 210 and the second pumps 20, 220) is Ta It is switched between a third position (P3) which prohibits being guided to the link T and a third position (P3).

In this configuration, the working fluid supplied from the pump (

first pump

10, 210, second pump 20, 220) to the main circuit system (first circuit system HC1, second circuit system HC2) is supplied to the first external output passage 14 In addition, it can be supplied to the outside through the second external output passage 15. Accordingly, it is possible to provide the fluid

pressure control devices

100 and 200 which have a high degree of freedom in adding a circuit system.

The fluid

pressure control devices

100, 200 have a first circuit system HC1 and a second circuit system HC2 as a main circuit system, and one of the first circuit system HC1 and the second circuit system HC2 has a neutral cut valve 110 and a second circuit system HC2. The first external output passage 14 is provided, and the first external input passage 24 to which the first external output passage 14 is connected via the external pipe 30 is provided to the other of the first circuit system HC1 and the second circuit system HC2.

In this configuration, since the working fluid can be supplied from one of the first circuit system HC1 and the second circuit system HC2 to the other via the external pipe 30, the other of the first circuit system HC1 and the second circuit system HC2 is supplied. The operation of the provided actuators (first actuator 7, second actuator 8) can be accelerated.

The fluid

pressure control devices

100, 200 are composed of a main valve block 101 having a main circuit system (first circuit system HC1 and second circuit system HC2) and pumps (first pumps 10, 210, second pumps 20, 220). A sub circuit system (third circuit system HC3, which has a sub control valve (third control valve 32, 232) that controls the sub actuator (third actuator 9) by the working fluid discharged and supplied through the main valve block 101. HC32) and

sub-valve blocks

103 and 203 having a sub-circuit system (third circuit system HC3, HC32), and the sub-circuit system (third circuit system HC3, HC32) is the second external output passage 15 The sub-valve blocks 103 and 203 can be attached to the main valve block 101 by having a second external input passage (third neutral passage 31 and supply passage 231) connected to the main valve block 101.

In this configuration, since the sub valve blocks 103 and 203 can be attached to the main valve block 101, compared with the case where the sub valve blocks 103 and 203 are provided separately from the main valve block 101, the fluid

pressure control devices

100 and 200 are provided. The installation area can be reduced. Furthermore, since it is not necessary to provide piping between the main valve block 101 and the sub valve blocks 103 and 203, the installation space for the fluid

pressure control devices

100 and 200 can be reduced.

Although the embodiment of the present invention has been described above, the above embodiment merely shows a part of the application example of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

The present application claims priority based on Japanese Patent Application No. 2018-217345 filed with the Japan Patent Office on November 20, 2018, the entire contents of which are incorporated herein by reference.

Claims

A fluid pressure control device for controlling an actuator driven by a working fluid discharged from a pump,
A main circuit system having a main control valve connected to the pump and controlling a main actuator;
The main circuit system is
A main neutral passage for returning the working fluid of the pump to the tank when the main control valve is in the neutral position;
A neutral cut valve that is provided downstream of the main control valve in the main neutral passage and connects or disconnects the main neutral passage and the tank.
A first external output passage that is downstream of the main control valve in the main neutral passage and communicates with an upstream of the neutral cut valve, and that can supply the working fluid discharged from the pump to the outside;
A second external output passage capable of supplying the working fluid discharged from the pump and guided through the neutral cut valve to the outside,
The neutral cut valve is
A first position that allows the working fluid discharged from the pump to be guided to the tank;
A second position that prohibits the working fluid discharged from the pump from being supplied to the outside through the second external output passage, and prohibits the working fluid discharged from the pump from being guided to the tank; ,
A third position that allows the working fluid discharged from the pump to be supplied to the outside through the second external output passage, and prohibits the working fluid discharged from the pump from being guided to the tank; Switched between,
Fluid pressure control device.
The fluid pressure control device according to claim 1, wherein
A first circuit system and a second circuit system as the main circuit system,
The neutral cut valve and the first external output passage are provided in one of the first circuit system and the second circuit system,
A first external input passage connected to the first external output passage via an external pipe is provided on the other of the first circuit system and the second circuit system.
Fluid pressure control device.
The fluid pressure control device according to claim 1 or 2, wherein
A main valve block having the main circuit system;
A sub-circuit system having a sub-control valve for controlling the sub-actuator by the working fluid discharged from the pump and supplied through the main valve block,
Further comprising a sub valve block having the sub circuit system,
The sub-circuit system has a second external input passage connected to the second external output passage,
The sub valve block is attachable to the main valve block,
Fluid pressure control device.