阅读说明：本技术 流体压控制装置 (Fluid pressure control device ) 是由 木谷俊行 吉田说与 于 2019-08-06 设计创作，主要内容包括：流体压控制装置(100)的主回路系统(HC1)具有：中立切换阀(110),其用于将第1中立通路(11)和工作流体箱(T)连通或者阻断；第1外部输出通路(14),其与第1中立通路(11)中的第1控制阀(12)的下游且是中立切换阀(110)的上游连通,能够将工作流体向外部供给；以及第2外部输出通路(15),其能够将经由中立切换阀(110)供给的工作流体向外部供给,中立切换阀(110)能够在容许工作流体向工作流体箱(T)引导的第1位置(P1)、禁止工作流体经由第2外部输出通路(15)向外部供给的第2位置(P2)以及容许工作流体经由第2外部输出通路(15)向外部供给的第3位置(P3)之间切换。(A main circuit system (HC1) of a fluid pressure control device (100) is provided with: a neutral switching valve (110) for connecting or blocking the 1 st neutral passage (11) and the working fluid tank (T); a 1 st external output passage (14) which communicates with the 1 st neutral passage (11) downstream of the 1 st control valve (12) and upstream of the neutral switching valve (110) and which is capable of supplying the working fluid to the outside; and a 2 nd external output passage (15) capable of supplying the working fluid supplied through the neutral switching valve (110) to the outside, wherein the neutral switching valve (110) is capable of switching between a 1 st position (P1) allowing the working fluid to be introduced into the working fluid tank (T), a 2 nd position (P2) prohibiting the working fluid from being supplied to the outside through the 2 nd external output passage (15), and a 3 rd position (P3) allowing the working fluid to be supplied to the outside through the 2 nd external output passage (15).)

1. A fluid pressure control device for controlling an actuator driven by a working fluid discharged from a pump,

the fluid pressure control device is provided with a main circuit system which is connected with the pump and is provided with a main control valve for controlling a main actuator,

the main circuit system includes:

a main neutral passage that returns the working fluid of the pump to a working fluid tank when the main control valve is at a neutral position;

a neutral switching valve provided downstream of the main control valve in the main neutral passage and configured to connect or block the main neutral passage and the working fluid tank;

a 1 st external output passage which communicates with the main control valve downstream of the main neutral passage and upstream of the neutral switching valve and which is capable of supplying the working fluid discharged from the pump to the outside; and

a 2 nd external output passage capable of supplying the working fluid discharged from the pump and guided through the neutral switching valve to the outside,

the neutral switching valve is capable of switching among a 1 st position, a 2 nd position and a 3 rd position,

at the 1 st position, the working fluid discharged from the pump is allowed to be guided to the working fluid tank,

at the 2 nd position, the supply of the working fluid discharged from the pump to the outside via the 2 nd external output passage is prohibited, and the guide of the working fluid discharged from the pump to the working fluid tank is prohibited,

at the 3 rd position, the supply of the working fluid discharged from the pump to the outside via the 2 nd external output passage is permitted, and the guide of the working fluid discharged from the pump to the working fluid tank is prohibited.

2. The fluid pressure control device according to claim 1,

the fluid pressure control device has a 1 st loop system and a 2 nd loop system as the main loop system,

the neutral switching valve and the 1 st external output passage are provided in one of the 1 st loop system and the 2 nd loop system,

the other of the 1 st loop system and the 2 nd loop system is provided with a 1 st external input passage connected to the 1 st external output passage through an external pipe.

3. The fluid pressure control device according to claim 1 or 2,

the fluid pressure control device further includes:

a main valve block having the main circuit system;

a sub-circuit system including a sub-control valve for controlling a sub-actuator by a working fluid discharged from the pump and supplied through the main valve block; and

an auxiliary valve block having the auxiliary circuit system,

the sub circuit system has a 2 nd external input path connected to the 2 nd external output path,

the sub valve block can be mounted to the main valve block.

Technical Field

The present invention relates to a fluid pressure control device.

Background

JP 2016-204826 a describes a fluid pressure control device including a 1 st circuit system having a plurality of control valves connected to a 1 st pump and a 2 nd circuit system having a plurality of control valves connected to a 2 nd pump. The fluid pressure control device described in JP 2016-204826 a is provided with a neutral switching valve that communicates or blocks the connection between the 1 st neutral passage and the working fluid tank, and an external output passage that communicates with the upstream side of the neutral switching valve and can supply the working fluid discharged from the 1 st pump to the outside, and the working fluid can be taken out from the 1 st circuit system to the outside via the external output passage.

Disclosure of Invention

Thus, the fluid pressure control device described in JP 2016-204826 a can take out the working fluid to a circuit system other than the 1 st circuit system via the external output passage. However, only one external output path is provided in the 1 st loop system. Therefore, in the fluid pressure control device described in JP 2016-204826 a, it is not possible to add another circuit system to the circuit system connected to the external output passage and connect the circuit system to the 1 st circuit system, and there is a problem that the degree of freedom in addition to the circuit system is low.

The invention aims to provide a fluid pressure control device with high extension freedom of a loop system.

According to one aspect of the present invention, a fluid pressure control device for controlling an actuator driven by a working fluid discharged from a pump includes a main circuit system connected to the pump and including a main control valve for controlling a main actuator, the main circuit system including: a main neutral passage that returns the working fluid of the pump to a working fluid tank when the main control valve is at a neutral position; a neutral switching valve provided downstream of the main control valve in the main neutral passage and configured to connect or block the main neutral passage and the working fluid tank; a 1 st external output passage which communicates with the main control valve downstream of the main neutral passage and upstream of the neutral switching valve and which is capable of supplying the working fluid discharged from the pump to the outside; and a 2 nd external output passage capable of supplying the working fluid discharged from the pump and guided through the neutral switching valve to the outside, wherein the neutral switching valve is switchable among a 1 st position, a 2 nd position, and a 3 rd position, wherein the 1 st position allows the working fluid discharged from the pump to be guided to the working fluid tank, the 2 nd position prohibits the working fluid discharged from the pump from being supplied to the outside through the 2 nd external output passage and prohibits the working fluid discharged from the pump from being guided to the working fluid tank, and the 3 rd position allows the working fluid discharged from the pump to be supplied to the outside through the 2 nd external output passage and prohibits the working fluid discharged from the pump from being guided to the working fluid tank.

Drawings

Fig. 1 is a circuit diagram showing a fluid pressure control device according to embodiment 1 of the present invention.

Fig. 2 is a schematic 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 embodiment 2 of the present invention.

Detailed Description

< embodiment 1 >

A fluid pressure control device 100 according to embodiment 1 of the present invention will be described with reference to fig. 1 and 2.

The fluid pressure control device 100 is applicable to a working machine such as a power shovel, for example. Here, although the case where the work machine is a power shovel is described, the fluid pressure control device 100 may be applied to other work machines such as a wheel loader. In addition, although the hydraulic oil is used as the working fluid in the fluid pressure control device 100, another 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 provided rotatably above the traveling unit, and an excavating unit provided in the revolving unit. The traveling unit has a pair of left and right crawler belts. The power shovel travels by driving a pair of left and right crawler belts of the traveling unit. The excavating part includes a boom rotatably attached to the swing part, an arm rotatably attached to the boom, and a bucket rotatably attached to the arm.

As shown in fig. 1, the power shovel includes an engine (not shown), a 1 st pump 10 and a 2 nd pump 20 as fluid pressure pumps that are driven by the engine to discharge hydraulic oil, a fluid pressure control device 100 that controls actuators for driving a traveling unit, a revolving unit, an excavating unit, and the like, by the hydraulic oil discharged from the 1 st pump 10 and the 2 nd pump 20, and a hydraulic fluid tank T through which the hydraulic oil is returned from the fluid pressure control device 100.

The fluid pressure control device 100 is used to control a plurality of actuators driven by the hydraulic oil discharged from the 1 st pump 10 and the 2 nd pump 20. Examples of the plurality of actuators include hydraulic motors 7A and 8A for driving the traveling part, a hydraulic motor (not shown) for driving the turning part, a hydraulic cylinder (not shown) for driving the boom, a hydraulic cylinder (not shown) for driving the arm, a hydraulic cylinder 7B for driving the bucket, a hydraulic cylinder 8B for driving the auxiliary equipment, and a hydraulic cylinder 9A for driving the additional equipment.

Examples of the spare parts and additional parts include a crusher and a crusher attached in place of the bucket, a shifting device for sliding the boom left and right, and a blade of a bulldozer attached to the swing portion.

The fluid pressure control device 100 includes a 1 st circuit system HC1 connected to the 1 st pump 10 and supplied with hydraulic oil from the 1 st pump 10, a 2 nd circuit system HC2 connected to the 2 nd pump 20 and supplied with hydraulic oil from the 2 nd pump 20, and a 3 rd circuit system HC3 connected to the 1 st circuit system HC1 and supplied with hydraulic oil from the 1 st pump 10 via a neutral switching valve 110 described later. As will be described later, by switching the straight travel control valve 6, the hydraulic oil discharged from the 1 st pump 10 is also supplied to the 2 nd circuit system HC2, and the hydraulic oil discharged from the 2 nd pump 20 is also supplied to the 1 st circuit system HC1 and the 3 rd circuit system HC 3.

As shown in fig. 1 and 2, the fluid pressure control device 100 includes a main valve block 101 having a 1 st circuit system HC1 and a 2 nd circuit system HC2, which are main circuit systems, and a sub valve block 103 having a 3 rd circuit system HC3, which is a sub circuit system. As shown in fig. 2, the sub valve block 103 can be attached to the main valve block 101 using a plurality of screws 105. The main valve block 101 may be formed by stacking and connecting a plurality of valve blocks, or may be formed by 1 valve block.

A screw mounting hole 115, which is opened to the outer surface thereof and to which the screw 105 is mounted, is formed in the main valve block 101. The sub-valve block 103 is placed on the upper surface of the main valve block 101, the stem of the screw 105 is inserted into the screw insertion hole 135 of the sub-valve block 103, and the tip of the stem of the screw 105 is screwed into the screw attachment hole 115, thereby fixing the sub-valve block 103 to the main valve block 101.

The sub valve block 103 is provided to control the hydraulic cylinder 9A for driving the additional components. Conventionally, in order to control the hydraulic cylinder 9A for driving the additional components, it is necessary to separately provide the sub-valve block 103 separately from the main valve block 101 and connect the 3 rd circuit system HC3 to a new hydraulic pump other than the 1 st pump 10 and the 2 nd pump 20.

In contrast, in the present embodiment, since the sub valve block 103 can be attached to the main valve block 101, the installation area of the fluid pressure control device 100 can be reduced. Further, 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 made small. As described later, since the hydraulic oil of the 1 st 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, the number of parts and cost can be reduced compared to the case where the sub valve block 103 to which a new hydraulic pump is connected is separately provided from the main valve block 101.

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

The 1 st control valve 12, which is a main control valve that controls the actuator provided in the 1 st circuit system HC1, includes a 1 st travel control valve 12A, a bucket control valve 12B, a boom first-speed control valve 12C, and an arm second-speed control valve 12D. The hydraulic oil discharged from the 1 st pump 10 is guided to the 1 st travel control valve 12A, the bucket control valve 12B, the boom first-speed control valve 12C, and the arm second-speed control valve 12D in this order from the upstream side.

The 1 st travel control valve 12A is used to control supply and discharge of hydraulic oil to and from a hydraulic motor 7A for driving a traveling unit provided on the left side of the vehicle body of the power shovel. The bucket control valve 12B is used to control supply and discharge of hydraulic oil to and from the bucket driving hydraulic cylinder 7B. The boom first-stage control valve 12C is used to control supply and discharge of hydraulic oil to and from a hydraulic cylinder (not shown) for driving a boom. The arm second-stage 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 (the hydraulic motor 7A, the hydraulic cylinder 7B, and the like) controlled by the 1 st control valve 12 are also collectively referred to as the 1 st actuator 7.

Thus, the 1 st circuit system HC1 has a plurality of 1 st control valves 12 connected to the 1 st pump 10 and for controlling a plurality of 1 st actuators 7. The discharge passage 19 is used to guide the working oil discharged from the 1 st actuator 7 via the 1 st control valve 12 to the working fluid tank T.

In the 1 st circuit system HC1, when the straight traveling control valve 6 described later is in the normal position (a) and the neutral switching valve 110 described later is in the 1 st position (P1), and when all of the 1 st control valves 12 are in the neutral position, the hydraulic oil discharged from the 1 st pump 10 flows back to the hydraulic tank T through the 1 st neutral passage 11. In contrast, when at least one of the 1 st control valves 12 is in the drive position, the 1 st pump 10 and the working fluid tank T are blocked from communicating with the 1 st neutral passage 11.

In the 1 st circuit system HC1, even when any one of the 1 st control valve 12A to the 1 st control valve 12C is switched to the drive position and communication between the 1 st pump 10 and the working fluid tank T in the 1 st neutral passage 11 is blocked, the working oil discharged from the 1 st pump 10 can be supplied to the 1 st control valve 12B to the 1 st control valve 12D via the 1 st parallel passage 13.

The 1 st circuit system HC1 further includes a neutral switching valve 110 provided downstream of all the 1 st control valves 12 in the 1 st neutral passage 11 (i.e., downstream of the arm second-stage control valve 12D) and communicating or blocking the 1 st neutral passage 11 and the working fluid tank T, a 1 st external output passage 14 communicating with all the 1 st control valves 12 in the 1 st neutral passage 11 (i.e., downstream of the arm second-stage control valve 12D) and upstream of the neutral switching valve 110 and capable of supplying the working fluid discharged from the 1 st pump 10 to the outside, and a 2 nd external output passage 15 capable of supplying the working fluid discharged from the 1 st pump 10 and guided through the neutral switching valve 110 to the outside.

The 1 st external output passage 14 is connected to a 1 st external output port 14o that opens at the outer surface of the master valve block 101. The 2 nd external output passage 15 is connected to a 2 nd external output port 15o that opens at the outer surface of the master valve block 101. The 1 st parallel passage 13 is connected to an output port 13o that opens at the outer surface of the master valve block 101.

The 1 st circuit system HC1 further includes branch passages 191 and 192 that branch from the discharge passage 19 for guiding the working oil to the working fluid tank T. The branch passage 191 is connected to an inlet port 191i that opens to the outer surface of the master valve block 101, and the branch passage 192 is connected to an inlet port 192i that opens to the outer surface of the master valve block 101.

The neutral switching valve 110 is a pilot switching valve that switches the spool between the 1 st position (P1), the 2 nd position (P2), and the 3 rd position (P3) in accordance with the pilot pressures supplied to the 1 st pilot pressure chamber 116a and the 2 nd pilot pressure chamber 116 b. The pilot pressures acting on 1 st pilot pressure chamber 116a and 2 nd pilot pressure chamber 116b are controlled in accordance with, for example, an operating state of the power shovel, an operating position of a dedicated operating member (not shown) for operating neutral switching valve 110, and the like.

When no pilot pressure acts on both of 1 st pilot pressure chamber 116a and 2 nd pilot pressure chamber 116b, neutral switching valve 110 is held at the 1 st position (P1) by the biasing force of centering spring 117.

The neutral switching valve 110 has a 1 st inlet port 111 and a 2 nd inlet port 112 that communicate with the downstream side of the arm second-speed control valve 12D in the 1 st neutral passage 11, a tank port 119 that communicates with the discharge passage 19, and an outlet port 113 that communicates with the 2 nd external output passage 15.

When the neutral switching valve 110 is in the 1 st position (P1), the 1 st inlet port 111 and the tank port 119 are communicated, and the 2 nd inlet port 112 and the outlet port 113 are blocked from communicating. Since the 1 st inlet port 111 and the tank port 119 communicate with each other, the hydraulic oil introduced into the 1 st neutral passage 11 is introduced into the discharge passage 19 via the neutral switching valve 110.

That is, when the neutral switching valve 110 is in the 1 st position (P1), the supply of the hydraulic oil discharged from the 1 st pump 10 to the outside of the main valve block 101 through the 2 nd external output passage 15 is prohibited, and the introduction of the hydraulic oil discharged from the 1 st pump 10 to the hydraulic fluid tank T through the discharge passage 19 is permitted.

With the neutral switching valve 110 in the 2 nd position (P2), communication between the 1 st inlet port 111 and the working fluid tank port 119 is blocked, and communication between the 2 nd inlet port 112 and the outlet port 113 is blocked.

That is, when the neutral switching valve 110 is in the 2 nd position (P2), the supply of the hydraulic oil discharged from the 1 st pump 10 to the outside of the main valve block 101 through the 2 nd external output passage 15 is prohibited, and the introduction of the hydraulic oil discharged from the 1 st pump 10 to the hydraulic fluid tank T through the discharge passage 19 is prohibited.

When the neutral switching valve 110 is in the 3 rd position (P3), the 1 st inlet port 111 and the tank port 119 are blocked from communicating with each other, and the 2 nd inlet port 112 and the outlet port 113 are communicated with each other. Since the 2 nd inlet port 112 and the outlet port 113 communicate with each other, the hydraulic oil introduced into the 1 st neutral passage 11 is introduced into the 2 nd external output passage 15 via the neutral switching valve 110.

That is, when the neutral switching valve 110 is in the 3 rd position (P3), the supply of the hydraulic oil discharged from the 1 st pump 10 to the outside of the main valve block 101 through the 2 nd external output passage 15 is permitted, and the introduction of the hydraulic oil discharged from the 1 st pump 10 to the hydraulic fluid tank T through the discharge passage 19 is prohibited.

As described above, the 1 st position (P1) is a position where the 1 st neutral passage 11 and the working fluid tank T are communicated, and the 2 nd position (P2) and the 3 rd position (P3) are positions where the communication between the 1 st neutral passage 11 and the working fluid tank T is blocked. The 3 rd position (P3) is a position where the 1 st neutral passage 11 communicates with the 3 rd neutral passage 31 of the 3 rd circuit system HC3 described later, and the 1 st position (P1) and the 2 nd position (P2) are positions where the communication between the 1 st neutral passage 11 and the 3 rd neutral passage 31 is blocked.

In the present embodiment, the sub valve block 103 is attached to the main valve block 101, and thus the hydraulic oil discharged from the 1 st pump 10 can be supplied to the 3 rd circuit system HC3 via the 1 st circuit system HC 1. When the sub-valve block 103 is not mounted, the ports (13o, 15o, 191i, 192i) that open 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) that open to the outer surface of the main valve block 101 are connected to the ports (33i, 31i, 38o, 39o) that open to the outer surface of the sub valve block 103.

The 3 rd circuit system HC3 includes a 3 rd neutral passage 31 for guiding the hydraulic oil guided through the neutral switching valve 110 of the 1 st circuit system HC1 and the 2 nd external output passage 15 to the hydraulic tank T, a 3 rd control valve 32 as a sub control valve connected to the 3 rd neutral passage 31 for controlling the 3 rd actuator 9 as a sub actuator, a 3 rd parallel passage 33 for guiding the hydraulic oil guided through the 1 st parallel passage 13 of the 1 st circuit system HC1 to the 3 rd control valve 32, and discharge passages 38, 39 communicating with the discharge passage 19 of the 1 st circuit system HC 1. The 3 rd neutral passage 31 is connected to the 2 nd external output passage 15 of the 1 st circuit system HC1, and functions as a 2 nd external input passage for guiding the hydraulic oil through the 1 st circuit system HC 1.

In the circuit system in which the 3 rd circuit system HC3 is connected to the 1 st circuit system HC1, the 1 st neutral passage 11, the 2 nd external output passage 15, and the 3 rd neutral passage 31 function as a neutral passage for returning the hydraulic oil discharged from the 1 st pump 10 to the hydraulic fluid tank T. That is, in the circuit system in which the 3 rd circuit system HC3 is connected to the 1 st circuit system HC1, the 1 st control valve 12 and the 3 rd control valve 32 are connected in series by the 1 st neutral passage 11, the 2 nd external output passage 15, and the 3 rd neutral passage 31, which are neutral passages, and are connected in parallel by the 1 st parallel passage 13 and the 3 rd parallel passage 33.

The 3 rd control valve 32 controls supply and discharge of the hydraulic oil to and from the hydraulic cylinder 9A as the 3 rd actuator 9 for driving the additional component in accordance with the pilot pressure acting on the pilot pressure chamber. In this way, the 3 rd circuit system HC3 has the 3 rd control valve 32 that controls the 3 rd actuator 9 by the hydraulic oil discharged from the 1 st pump 10 and supplied via the main valve block 101. The 3 rd control valve 32 is a neutral fully-opened control valve that communicates the 3 rd neutral passage 31 with the discharge passage 39 when in the neutral position, and guides the hydraulic oil guided to the 3 rd neutral passage 31 to the hydraulic fluid tank T.

The 3 rd neutral passage 31 is connected to an external input port 31i that opens at the outer surface of the sub valve block 103. The external input port 31i of the sub valve block 103 is connected to the 2 nd external output port 15o of the main valve block 101.

The 3 rd parallel passage 33 is connected to an input port 33i that opens at 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.

A discharge passage 38 through which the hydraulic oil is led from the hydraulic cylinder 9A via the 3 rd control valve 32 is connected to an outlet port 38o that opens on 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.

A discharge passage 39 that leads the working oil from the 3 rd neutral passage 31 via the 3 rd control valve 32 is connected to a lead-out port 39o that opens on 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 3 rd circuit system HC3, when the 3 rd control valve 32 is in the neutral position, the working oil supplied from the 1 st circuit system HC1 is returned to the working fluid tank T via the 3 rd neutral passage 31 and the discharge passage 39.

The 2 nd circuit system HC2 includes a 2 nd neutral passage 21 serving as a main neutral passage for guiding the hydraulic oil discharged from the 2 nd pump 20 to the hydraulic tank T, a plurality of 2 nd control valves 22 serving as main control valves connected in series to the 2 nd neutral passage 21, a 2 nd parallel passage 23 branching from the 2 nd control valve 22 in the 2 nd neutral passage 21 upstream, and a discharge passage 19 connected to the hydraulic tank T. The plurality of 2 nd control valves 22 are connected in series by the 2 nd neutral passage 21 and connected in parallel by the 2 nd parallel passage 23.

The 2 nd control valve 22, which is a main control valve that controls the actuator provided in the 2 nd circuit system HC2, includes a 2 nd travel control valve 22A, a preliminary backup control valve 22B, a turning control valve 22C, a boom second-stage control valve 22D, and an arm first-stage control valve 22E. The hydraulic oil discharged from the 2 nd pump 20 is guided from the upstream side to the 2 nd traveling control valve 22A, the preliminary control valve 22B, the turning control valve 22C, the boom second-stage control valve 22D, and the arm first-stage control valve 22E in this order.

The 2 nd travel control valve 22A is used to control supply and discharge of hydraulic oil to and from the hydraulic motor 8A for driving the traveling unit provided on the right side of the vehicle body of the power shovel. The reserve control valve 22B is used to control supply and discharge of the hydraulic oil to and from the hydraulic cylinder 8B for driving the reserve components. The turning control valve 22C controls supply and discharge of the hydraulic oil to and from a hydraulic motor (not shown) for driving the turning part. The boom second-stage control valve 22D controls supply and discharge of hydraulic oil to and from a boom-driving hydraulic cylinder (not shown). The arm first-stage control valve 22E is used to control supply and discharge of hydraulic oil to and from a hydraulic cylinder (not shown) for driving the arm. The main actuators (the hydraulic motor 8A, the hydraulic cylinder 8B, and the like) controlled by the 2 nd control valve 22 are also collectively referred to as the 2 nd actuator 8.

As such, the 2 nd circuit system HC2 has a plurality of 2 nd control valves 22 connected to the 2 nd pump 20 and used to control a plurality of 2 nd actuators 8. The discharge passage 19 is used to guide the working oil discharged from the 2 nd actuator 8 via the 2 nd control valve 22 to the working fluid tank T. The discharge passage 19 is shared as a passage for guiding the hydraulic oil of the 1 st circuit system HC1 and the 2 nd circuit system HC2 to the hydraulic tank T.

In the 2 nd circuit system HC2, when all the 2 nd control valves 22 are in the neutral position, the working oil discharged from the 2 nd pump 20 flows back to the working fluid tank T via the 2 nd neutral passage 21. In contrast, when at least one of the plurality of 2 nd control valves 22 is in the drive position, the communication between the 2 nd pump 20 and the working fluid tank T in the 2 nd neutral passage 21 is blocked.

In the 2 nd circuit system HC2, even when any one of the 2 nd control valve 22A to the 2 nd control valve 22D is switched to the drive position and the communication between the 2 nd pump 20 and the working fluid tank T in the 2 nd neutral passage 21 is blocked, the working oil discharged from the 2 nd pump 20 can be supplied to the 2 nd control valve 22B to the 2 nd control valve 22E through the 2 nd parallel passage 23.

The 2 nd circuit system HC2 has the 1 st external input passage 24 for introducing the working oil supplied from the outside to the upstream side of a predetermined 2 nd control valve 22 (the preliminary backup control valve 22B in the present embodiment). The 1 st external input passage 24 is connected to a 1 st external input port 24i that opens to the outer surface of the master valve block 101.

The 1 st circuit system HC1 further includes a straight traveling control valve 6 connected downstream of the branch point of the 1 st parallel passage 13 in the 1 st neutral passage 11 and upstream of the 1 st traveling control valve 12A. The 2 nd parallel passage 23 is connected to the straight travel control valve 6. The 2 nd parallel passage 23 includes a 2 nd parallel upstream passage 23a connecting the 2 nd pump 20 and the straight traveling control valve 6, and a 2 nd parallel downstream passage 23B connecting the straight traveling control valve 6 and the 2 nd to 2 nd control valves 22B to 22E.

The straight travel control valve 6 can be switched to two positions, i.e., 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. 1. When the hydraulic oil is supplied to the pilot pressure chamber 6a, the straight travel control valve 6 is switched to the straight travel position B. When the pilot pressure is not applied to the pilot pressure chamber 6a, the straight traveling control valve 6 is held at the normal position a by the biasing force of the return spring 6 c.

In the normal position (a), the 2 nd parallel upstream side passage 23a of the 2 nd parallel passage 23 is connected to the 2 nd parallel downstream side passage 23b of the 2 nd parallel passage 23, and the 1 st pump 10 is connected to the 1 st neutral passage 11 downstream of the straight traveling control valve 6. Thus, the hydraulic oil discharged from the 1 st pump 10 is guided to the 1 st control valve 12 through the 1 st neutral passage 11 and the 1 st parallel passage 13. The hydraulic oil discharged from the 2 nd pump 20 is guided to the 2 nd control valves 22 through the 2 nd neutral passage 21 and the 2 nd parallel passage 23.

In addition, in the state where the neutral switching valve 110 is in the 3 rd position (P3), the hydraulic oil discharged from the 1 st pump 10 is also guided to the 3 rd control valve 32 via the 1 st neutral passage 11, the neutral switching valve 110, the 2 nd external output passage 15, and the 3 rd neutral passage 31. The hydraulic oil discharged from the 1 st pump 10 is also guided to the 3 rd control valve 32 through the 1 st parallel passage 13 and the 3 rd parallel passage 33.

In the straight position (B), the 2 nd parallel upstream side passage 23a of the 2 nd parallel passage 23 is connected to the 1 st neutral passage 11 downstream of the straight travel control valve 6, and the 2 nd parallel downstream side passage 23B is connected to the 1 st pump 10. Thus, the hydraulic oil discharged from the 1 st pump 10 is guided to the 1 st to 1 st control valves 12B to 12D via the 1 st parallel passage 13, and is guided to the 2 nd to 2 nd control valves 22B to 22E via the 2 nd parallel downstream passage 23B of the 2 nd parallel passage 23. The hydraulic oil discharged from the 2 nd pump 20 is guided to the 1 st control valve 12A via the downstream side of the straight traveling control valve 6 in the 1 st neutral passage 11, and is guided to the 2 nd control valve 22A via the 2 nd neutral passage 21.

In addition, in the state where the neutral switching valve 110 is at the 3 rd position (P3), the hydraulic oil discharged from the 1 st pump 10 is also guided to the 3 rd control valve 32 via the 1 st parallel passage 13 and the 3 rd parallel passage 33. The hydraulic oil discharged from the 2 nd pump 20 is also guided to the 3 rd control valve 32 through the 1 st neutral passage 11, the neutral switching valve 110, the 2 nd external output passage 15, and the 3 rd neutral passage 31.

When the power shovel travels without driving the digging portion, the pilot pressure chamber 6a becomes the tank pressure, and the straight travel control valve 6 is maintained at the normal position (a). Therefore, when only the hydraulic motors 7A and 8A for driving the traveling unit are operated, the hydraulic oil discharged from the 1 st pump 10 is supplied to the 1 st traveling control valve 12A, and the hydraulic oil discharged from the 2 nd pump 20 is supplied to the 2 nd traveling control valve 22A.

On the other hand, when the hydraulic motors 7A and 8A for driving the traveling portion are driven, the pilot pressure acts on the pilot pressure chamber 6a and the straight travel control valve 6 is switched to the straight travel position (B) when the actuator of the excavation portion is driven. That is, when the hydraulic motors 7A and 8A for driving the traveling unit and the actuators other than the hydraulic motors 7A and 8A are simultaneously operated, the hydraulic oil discharged from the 2 nd pump 20 is supplied to the 1 st traveling control valve 12A and the 2 nd traveling control valve 22A. The working oil discharged from the 1 st pump 10 is supplied to the other 1 st to 1 st control valves 12B to 12D, the other 2 nd to 2 nd control valves 22B to 22E, and the 3 rd control valve 32. Thus, the circuit for traveling is independent from the circuits other than the circuit for traveling, and the straight traveling property of the vehicle body is ensured.

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

In a state where 1 st pilot pressure chamber 116a and 2 nd pilot pressure chamber 116b are connected to working fluid tank T and working oil is not supplied into 1 st pilot pressure chamber 116a and 2 nd pilot pressure chamber 116b, the spool of neutral switching valve 110 is located at the 1 st position (P1). In this state, the 1 st inlet port 111 and the working fluid tank port 119 communicate, and the 2 nd inlet port 112 and the outlet port 113 are blocked from communicating.

Therefore, the hydraulic oil that has flowed into the 1 st inlet port 111 through the 1 st neutral passage 11 is discharged to the hydraulic tank T through the hydraulic tank port 119.

When the working oil is supplied to the 1 st pilot pressure chamber 116a from this state, the spool moves against the biasing force of the centering spring 117 by the pressure of the working oil supplied to the 1 st pilot pressure chamber 116a, and switches to the 2 nd position (P2). Thereby, the 1 st inlet port 111 and the working fluid tank port 119 are blocked from communicating with each other. In addition, the blocking of the communication of the 2 nd inlet port 112 and the outlet port 113 is maintained.

The 1 st external output port 14o always communicates with the 1 st neutral passage 11 regardless of the position of the neutral switching valve 110. However, in the state where the neutral switching valve 110 is located at the 1 st position (P1), the 1 st neutral passage 11 and the working fluid tank T communicate with each other as described above, and therefore the 1 st external output port 14o also communicates with the working fluid tank T. Accordingly, the working oil discharged from the 1 st pump 10 is not supplied to the outside through the 1 st external output port 14o but flows back to the working fluid tank T.

In contrast, in the state where the neutral switching valve 110 is located at the 2 nd position (P2), the communication between the 1 st neutral passage 11 and the working fluid tank T is blocked as described above. Therefore, the entire amount of the hydraulic oil flowing into the 1 st neutral passage 11 downstream of the arm second-speed control valve 12D and upstream of the neutral switching valve 110 is supplied to the outside of the main valve block 101 through the 1 st external output passage 14.

In this way, in the fluid pressure control device 100, the working oil supplied from the 1 st pump 10 to the 1 st circuit system HC1 can be supplied to the outside through the 1 st external output port 14o by switching the neutral switching valve 110 to the 2 nd position (P2).

Therefore, in the fluid pressure control device 100, for example, the hydraulic oil supplied from the 1 st pump 10 to the 1 st circuit system HC1 can be applied to drive a newly added actuator (not shown) via the 1 st external output port 14o, or can be merged with a circuit that drives any of the 1 st actuator 7, the 2 nd actuator 8, and the 3 rd actuator 9 via the 1 st external output port 14 o.

Here, for example, a case will be described in which the hydraulic oil supplied to the outside via the 1 st external output port 14o is merged with the flow path of the hydraulic cylinder 8B for driving the auxiliary equipment.

The 1 st external output port 14o and the 1 st external input port 24i are connected to the outside of the master valve block 101 by an external pipe 30. That is, the 1 st external output passage 14 is connected to the 1 st external input passage 24 via the external pipe 30.

In this state, hydraulic oil is supplied to the pilot pressure chamber of the preliminary control valve 22B for controlling supply and discharge of hydraulic oil to and from the hydraulic cylinder 8B and the 1 st pilot pressure chamber 116a of the neutral switching valve 110. Thus, when the backup control valve 22B is operated, the hydraulic oil discharged from the 2 nd pump 20 is supplied to the backup control valve 22B, and the hydraulic oil discharged from the 1 st pump 10 is also supplied to the backup control valve 22B via the 1 st external output passage 14, the external pipe 30, and the 1 st external input passage 24.

That is, in the present embodiment, the hydraulic oil discharged from the 1 st pump 10 is guided to the outside via the 1 st external output passage 14 of the 1 st circuit system HC1, and is guided to the upstream of the backup control valve 22B via the 1 st external input passage 24 of the 2 nd circuit system HC2, and is merged with the hydraulic oil discharged from the 2 nd pump 20.

The neutral switching valve 110 may be configured to communicate or block the 1 st neutral passage 11 with or from the tank T in accordance with the pilot pressure Pp for controlling the preliminary control valve 22B. In this case, the spring load of the centering spring 117 may be set so that the spool of the neutral switching valve 110 is maintained at the 1 st position (P1) in a state where the pilot pressure Pp is low, and the spool of the neutral switching valve 110 is switched to the 2 nd position (P2) in a state where the pilot pressure Pp is high.

With this configuration, when the operation amount of the preliminary control valve 22B is small, the hydraulic cylinder 8B is driven only by the hydraulic oil discharged from the 2 nd pump 20. When the operation amount of the backup control valve 22B is large, the hydraulic cylinder 8B is driven by the hydraulic oil discharged from the 1 st pump 10 in addition to the hydraulic oil discharged from the 2 nd pump 20.

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

In addition, although not shown, when the hydraulic oil is supplied to the circuit system for driving the newly added actuator via the 1 st external output passage 14, the neutral switching valve 110 may be switched to the 2 nd position (P2) when the added actuator is driven.

On the other hand, when the hydraulic oil is supplied to the 2 nd pilot pressure chamber 116b of the neutral switching valve 110, the spool moves against the biasing force of the centering spring 117 by the pressure of the hydraulic oil supplied to the 2 nd pilot pressure chamber 116b, and is switched to the 3 rd position (P3). Thereby, the 2 nd inlet port 112 and the outlet port 113 are communicated, and the 1 st inlet port 111 and the working fluid tank port 119 are blocked from communicating.

In a state where the neutral switching valve 110 is located at the 3 rd position (P3), the 3 rd neutral passage 31 of the 3 rd circuit system HC3 communicates with the 1 st neutral passage 11 of the 1 st circuit system HC 1. In addition, the 3 rd parallel passage 33 of the 3 rd circuit system HC3 always communicates with the 1 st parallel passage 13 of the 1 st circuit system HC 1.

Therefore, in the state where the neutral switching valve 110 is located at the 3 rd position (P3), the plurality of 1 st control valve 12 and the 3 rd control valve 32 are connected in series by the 1 st neutral passage 11, the 2 nd external output passage 15, and the 3 rd neutral passage 31, which are neutral passages, and are connected in parallel by the 1 st parallel passage 13 and the 3 rd parallel passage 33.

Therefore, in the state where the neutral switching valve 110 is located at the 3 rd position (P3), even when any or all of the 1 st control valve 12A to the 1 st control valve 12D are switched to the drive position and the communication between the 1 st pump 10 and the working fluid tank T in the 1 st neutral passage 11 is blocked, the working oil discharged from the 1 st pump 10 can be supplied to the 3 rd control valve 32 via the 1 st parallel passage 13 and the 3 rd parallel passage 33.

Therefore, by attaching the sub valve block 103 to the main valve block 101, it is possible to easily add the 3 rd actuator 9 that can be driven by the hydraulic oil discharged from the 1 st pump 10 or the 2 nd pump 20, similarly to the 1 st actuator 7.

According to the above embodiment, the following operational effects are exhibited.

By switching the neutral switching valve 110 to the 2 nd position (P2), the hydraulic oil discharged from the 1 st pump 10 can be supplied to the outside of the main valve block 101 through the 1 st external output passage 14. Further, by switching the neutral switching valve 110 to the 3 rd position (P3), the hydraulic oil discharged from the 1 st pump 10 can be supplied to the outside of the main valve block 101 through the 2 nd external output passage 15.

Since the hydraulic oil supplied from the 1 st pump 10 to the 1 st circuit system HC1 can be supplied to the outside not only via the 1 st external output passage 14 but also via the 2 nd external output passage 15, it is possible to provide the fluid pressure control device 100 having a high degree of freedom in addition to the circuit system.

< embodiment 2 >

A fluid pressure control device 200 according to embodiment 2 of the present invention will be described with reference to fig. 3. Hereinafter, differences from embodiment 1 will be mainly described, and in the drawings, the same reference numerals are given to the same or corresponding structures as those described in embodiment 1, and description thereof will be omitted.

In embodiment 1, an example in which the 3 rd circuit system HC3 has the 3 rd control valve 32 of the neutral full open type is described. In contrast, in embodiment 2, the 3 rd circuit system HC32 has the 3 rd control valve 232 of the neutral fully-closed type.

In embodiment 2, the configurations of the 1 st circuit system HC1 and the 2 nd circuit system HC2 are the same as those in embodiment 1, but the configuration of the 3 rd circuit system HC32 is different from that in embodiment 1. That is, in embodiment 2, the structure of the main valve block 101 is the same as that in embodiment 1, but the structure of the sub valve block 203 is different from that in embodiment 1.

The sub valve block 203 having the 3 rd circuit system HC32 includes an oil feed block B30 for receiving working oil from the 1 st circuit system HC1 and valve blocks B31, B32 for controlling the 3 rd actuator 9 for driving the additional accessories. The oil inlet block B30 is also an oil outlet block for discharging the working oil to the working fluid tank T. Since the valve block B31 and the valve block B32 have the same structure, illustration of the valve block B32 is partially omitted. The number of valve blocks can be arbitrarily changed according to the number of additional actuators.

The 3 rd circuit system HC32 includes a plurality of 3 rd control valves 232 for controlling a plurality of 3 rd actuators 9, a supply passage 231 as a 2 nd external input passage connected to the 2 nd external output passage 15 of the 1 st circuit system HC1, a working fluid tank passage 239 connected to the working fluid tank T, and a load pressure passage 241 guiding the highest load pressure among the load pressures of the plurality of 3 rd actuators 9. The supply passage 231 is used to guide the hydraulic oil discharged from the 1 st pump 210 and supplied through the 1 st neutral passage 11, the neutral switching valve 110, and the 2 nd external output passage 15 to the 3 rd control valve 232. The 3 rd control valve 232 controls the 3 rd actuator 9 by the working oil discharged from the 1 st pump 210 and supplied to the supply passage 231 via the main valve block 101.

The oil 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, a relief valve 261 connected to the supply passage 231 is provided in the oil inlet block B30. When the neutral switching valve 110 is in the 3 rd position (P3), the relief valve 261 restricts the maximum pressure of the circuit in which the 3 rd circuit system HC3 of the sub valve block 203 is connected to the 1 st circuit system HC1 of the main valve block 101.

Each of the valve blocks B31, B32 has the 3 rd control valve 232 connected to the supply passage 231 and a pressure compensating valve 234 provided between the 3 rd control valve 232 and the 3 rd actuator 9.

In the present embodiment, a post-throttle type load sensing system in which a pressure compensating valve 234 is provided downstream of the meter-in portion of each 3 rd control valve 232 is used. In such a load sensing system, when the 3 rd actuators 9 are simultaneously operated, the pressure compensating valve 234 functions to adjust the load between the 3 rd actuators 9.

The highest load pressure among the pressure provided downstream of the oil intake throttle portion of the 3 rd control valve 232 and the load pressures of the plurality of 3 rd actuators 9 is applied to the pressure compensation valve 234. The pressure compensating valve 234 compensates so that the pressure downstream of the meter-in portion becomes a pressure higher than the highest load pressure of the 3 rd actuator 9 by a predetermined value.

Therefore, in the present embodiment, when the plurality of 3 rd control valves 232 are driven simultaneously, the pressure oil can be supplied at a flow rate according to the operation amount of the spool of the 3 rd control valve 232 regardless of the magnitude of the load pressure of the 3 rd actuator 9.

The 1 st pump 210 and the 2 nd pump 220 are variable displacement piston pumps, and the discharge capacity is changed by changing the inclination of a swash plate by a regulator (not shown). The discharge capacities of the 1 st pump 210 and the 2 nd pump 220 are controlled by so-called load sensing control so that the pressure difference between the pump discharge pressure led to a regulator (not shown) and the maximum load pressure of the 3 rd actuator 9 becomes a predetermined value.

The highest load pressure of the 3 rd actuator 9 is led from the load pressure output port 241p to the regulators (not shown) of the 1 st pump 210 and the 2 nd pump 220 via piping and the like. The pump discharge pressure is led from the discharge pressure output port 231p to the regulators (not shown) of the 1 st pump 210 and the 2 nd pump 220 via a pipe or the like.

In embodiment 2, the sub-valve block 203 closes the output port 13o and the inlet ports 191i and 192i that are not used in the main valve block 101. Since the unused ports (13o, 191i, 192i) are closed by the sub valve block 203, it is not necessary to provide a closing member such as a plug separately, and the number of parts can be reduced.

According to embodiment 2, the same operational effects as those of embodiment 1 can be obtained.

As described above, the main valve block 101 according to embodiment 2 is the same as that according to embodiment 1. Therefore, the main valve block 101 can be applied to the 3 rd control valve 32 of the sub valve block 103 and the 3 rd control valve 232 of the sub valve block 203 regardless of the neutral full open type (see fig. 1) or the neutral full close type (see fig. 3). That is, the neutral switching valve 110 described above is provided, and the master valve block 101 having high versatility can be provided by providing predetermined ports (15o, 13o, 191i, 192 i).

The following modifications are also within the scope of the present invention, and configurations shown in the modifications and those described in the above embodiments may be combined, or configurations described in the above different embodiments may be combined, or configurations described in the following different modifications may be combined.

< modification 1 >

In the above embodiment, the example in which the 1 st actuator 7 and the 1 st control valve 12 are provided in plural numbers has been described, but the present invention is not limited to this. It suffices that the 1 st actuator 7 and the 1 st control valve 12 are provided with at least 1, respectively. In the above embodiment, the example in which the 2 nd actuator 8 and the 2 nd control valve 22 are provided in plural numbers has been described, but the present invention is not limited to this. It suffices that at least 1 of the 2 nd actuator 8 and the 2 nd control valve 22 is provided, respectively.

< modification 2 >

In the above embodiment, the example in which the neutral switching valve 110 is provided in the 1 st neutral passage 11 of the 1 st circuit system HC1 has been described, but the present invention is not limited to this. Instead of the neutral switching valve 110 provided in the 1 st neutral passage 11, a neutral switching valve having the same function as the neutral switching valve 110 may be provided in the 2 nd neutral passage 21, or a neutral switching valve having the same function as the neutral switching valve 110 may be provided in the 2 nd neutral passage 21 in addition to the neutral switching valve 110 provided in the 1 st neutral passage 11.

That is, the 1 st external output passage, which is the same as the 1 st external output passage 14 of the 1 st circuit system HC1 described in the above embodiment, and the 2 nd external output passage, which is the same as the 2 nd external output passage 15 of the 1 st circuit system HC1 described in the above embodiment, may be provided in the 2 nd circuit system HC2, the sub valve block, which is the same as the sub valve block 103 described in the above embodiment, may be attached to the main valve block 101, and the circuit system of the sub valve block may be connected to the 2 nd circuit system HC 2. Further, a 1 st external output passage similar to the 1 st external output passage 14 described in the above embodiment may be provided in the 2 nd circuit system HC2, a 1 st external input passage similar to the 1 st external input passage 24 described in the above embodiment may be provided in the 1 st circuit system HC1, and both may be connected by an external pipe. In this case, the speed of the operation of the 1 st actuator 7 can be increased by merging the hydraulic oil of the 2 nd circuit system HC2 with the 1 st circuit system HC1 using the neutral switching valve provided in the 2 nd circuit system HC 2.

The structure, operation, and effects of the embodiments of the present invention configured as described above will be described in summary.

The fluid pressure control devices 100 and 200 are used for controlling actuators driven by working fluid discharged from pumps (1 st pumps 10 and 210 and 2 nd pumps 20 and 220), and include a main circuit system (1 st circuit system HC1 and 2 nd circuit system HC2) connected to the pumps (1 st pumps 10 and 210 and 2 nd pumps 20 and 220) and including main control valves (1 st control valve 12 and 2 nd control valve 22) for controlling main actuators (1 st actuator 7 and 2 nd actuator 8), and the main circuit system (1 st circuit system HC1 and 2 nd circuit system HC2) includes: main neutral passages (1 st neutral passage 11, 2 nd neutral passage 21) for returning the working fluid of the pumps (1 st pump 10, 210, 2 nd pump 20, 220) to the working fluid tank T when the main control valves (1 st control valve 12, 2 nd control valve 22) are at the neutral position; a neutral switching valve 110 provided downstream of the main control valves (1 st control valve 12, 2 nd control valve 22) in the main neutral passages (1 st neutral passage 11, 2 nd neutral passage 21) and configured to connect or block the main neutral passages (1 st neutral passage 11, 2 nd neutral passage 21) and the working fluid tank T; a 1 st external output passage 14 which communicates with the main control valves (the 1 st control valve 12, the 2 nd control valve 22) in the main neutral passages (the 1 st neutral passage 11, the 2 nd neutral passage 21) at a position downstream of the neutral switching valve 110 and upstream of the neutral switching valve 110 and which is capable of supplying the working fluid discharged from the pumps (the 1 st pump 10, 210, the 2 nd pump 20, 220) to the outside; and a 2 nd external output passage 15 which is capable of supplying the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) and guided through the neutral switching valve 110 to the outside, the neutral switching valve 110 being switchable among a 1 st position (P1), a 2 nd position (P2), and a 3 rd position (P3), the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) being allowed to be guided to the working fluid tank T at the 1 st position (P1), the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) being prohibited from being supplied to the outside through the 2 nd external output passage 15 at the 2 nd position (P2), and the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) being prohibited from being guided to the working fluid tank T; in the 3 rd position (P3), the supply of the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) to the outside via the 2 nd external output passage 15 is permitted, and the introduction of the working fluid discharged from the pumps (1 st pump 10, 210, 2 nd pump 20, 220) to the working fluid tank T is prohibited.

In this configuration, the working fluid supplied from the pumps (the 1 st pumps 10, 210, the 2 nd pumps 20, 220) to the main circuit system (the 1 st circuit system HC1, the 2 nd circuit system HC2) can be supplied to the outside not only through the 1 st external output passage 14 but also through the 2 nd external output passage 15. This makes it possible to provide the fluid pressure control devices 100 and 200 with a high degree of freedom in addition to the circuit system.

The fluid pressure control devices 100 and 200 include a 1 st circuit system HC1 and a 2 nd circuit system HC2 as main circuit systems, a neutral switching valve 110 and a 1 st external output passage 14 are provided in one of the 1 st circuit system HC1 and the 2 nd circuit system HC2, and a 1 st external input passage 24 connected to the 1 st external output passage 14 via an external pipe 30 is provided in the other of the 1 st circuit system HC1 and the 2 nd circuit system HC 2.

In this configuration, since the working fluid can be supplied from one of the 1 st circuit system HC1 and the 2 nd circuit system HC2 to the other via the external pipe 30, the operation of the actuators (the 1 st actuator 7 and the 2 nd actuator 8) provided in the other of the 1 st circuit system HC1 and the 2 nd circuit system HC2 can be increased in speed.

The fluid pressure control device 100, 200 further includes: a main valve block 101 having a main circuit system (1 st circuit system HC1 and 2 nd circuit system HC 2); a sub-circuit system (3 rd circuit system HC3, HC32) including sub-control valves (3 rd control valves 32, 232) for controlling a sub-actuator (3 rd actuator 9) by working fluid discharged from pumps (1 st pumps 10, 210, 2 nd pumps 20, 220) and supplied via a main valve block 101; and sub valve blocks 103 and 203 each having a sub circuit system (3 rd circuit system HC3 and HC32), the sub circuit system (3 rd circuit system HC3 and HC32) having a 2 nd external input passage (3 rd neutral passage 31 and supply passage 231) connected to the 2 nd external output passage 15, and the sub valve blocks 103 and 203 being attachable 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, the installation area of the fluid pressure control devices 100 and 200 can be reduced as compared with a case where the sub valve blocks 103 and 203 are separately provided independently of the main valve block 101. Further, since it is not necessary to provide a pipe between the main valve block 101 and the sub valve blocks 103 and 203, the installation space of the fluid pressure control devices 100 and 200 can be reduced.

While the embodiments of the present invention have been described above, the above embodiments are merely examples of applications of the present invention, and the scope of the present invention is not limited to the specific configurations of the above embodiments.

The present application claims priority from Japanese patent application 2018-217345 filed on the franchise of the country on the basis of the year 2018, 11 and 20, and the entire contents of the application are incorporated herein by reference.