CN111556929B - Fluid pressure control device - Google Patents

Abstract

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).

Description

Fluid pressure control device

technical field

The present invention relates to a fluid pressure control device.

Background technique

Japanese JP2016-204826A describes a fluid pressure control device including a first circuit system including a plurality of control valves connected to a first pump, and a second circuit system including a plurality of control valves connected to the second pump. In the fluid pressure control device described in Japanese JP2016-204826A, a neutral switching valve for communicating or blocking the connection between the first neutral passage and the working fluid tank, and the upstream communication with the neutral switching valve are provided, and the first pump can be switched from The external output passage for supplying the ejected working fluid to the outside can take out the working fluid from the first circuit system to the outside through the external output passage.

SUMMARY OF THE INVENTION

In this way, the fluid pressure control device described in Japanese JP2016-204826A can take out the working fluid to a circuit system other than the first circuit system via the external output passage. However, only one external output path is provided in the first loop system. Therefore, in the fluid pressure control device described in Japanese JP2016-204826A, it is not possible to add another circuit system to the circuit system connected to the external output passage and connect it to the first circuit system, and there is a low degree of freedom in adding circuit systems. such a problem.

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

According to one aspect of the present invention, there is provided a fluid pressure control device for controlling an actuator driven by a working fluid ejected from a pump, wherein the fluid pressure control device includes a main circuit system, the main circuit The system is connected to the pump, has a main control valve for controlling the main actuator, and the main circuit system has a main neutral passage that, when the main control valve is in the neutral position, causes all The working fluid of the pump is returned to the working fluid tank; a neutral switching valve, which is arranged downstream of the main control valve in the main neutral passage, is used to communicate or block the main neutral passage and the working fluid tank. a first external output passage, which communicates with the downstream of the main control valve and the upstream of the neutral switching valve in the main neutral passage, and can supply the working fluid discharged from the pump to the outside; and a second external output passage capable of supplying to the outside the working fluid discharged from the pump and guided through the neutral switching valve, which can be set in a first position, a second position, and a third position In the first position, the working fluid ejected from the pump is allowed to be guided to the working fluid tank, and in the second position, the working fluid ejected from the pump is prohibited from passing through any The second external output passage is supplied to the outside, and the working fluid discharged from the pump is prohibited from being guided to the working fluid tank, and at the third position, the working fluid discharged from the pump is allowed to pass through the The second external output passage is supplied to the outside and inhibits the introduction of the working fluid discharged from the pump to the working fluid tank.

Description of drawings

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 schematic perspective view of the main valve block and the sub-valve block.

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

Detailed ways

<First Embodiment>

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

The fluid pressure control device 100 can be applied to a work machine such as a power excavator, for example. Here, the case where the work machine is a power excavator will be described, but the fluid pressure control device 100 may be applied to other work machines such as a wheel loader. In addition, in the fluid pressure control device 100, hydraulic oil is used as the working fluid, but other fluids such as working water may be used as the working fluid.

Although not shown in the figure, the power excavator includes a crawler-type traveling portion, a turning portion rotatably provided on the upper portion of the traveling portion, and an excavating portion provided on the turning portion. The traveling portion has a pair of left and right crawler belts. The power excavator travels by driving a pair of left and right crawler belts of the travel unit. The excavation portion includes a boom rotatably attached to the swing portion, an arm rotatably attached to the boom, and a bucket rotatably attached to the arm.

As shown in FIG. 1 , the power excavator includes an engine (not shown), a first pump 10 and a second pump 20 as fluid pressure pumps that are driven by the engine to discharge hydraulic oil, and a first pump 10 and a second pump 20 that are driven by the engine to discharge hydraulic oil. The fluid pressure control device 100 for controlling the actuators for driving the traveling part, the turning part, the excavation part, etc. with the hydraulic oil discharged from the pump 20 , and the hydraulic fluid for returning the hydraulic oil from the fluid pressure control device 100 Box T.

The fluid pressure control device 100 controls a plurality of actuators driven by hydraulic fluid 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 part, hydraulic motors (not shown) for driving the turning parts, hydraulic cylinders (not shown) for driving the boom, and driving the arm. The hydraulic cylinder (not shown), the hydraulic cylinder 7B for bucket drive, the hydraulic cylinder 8B for spare parts drive, the hydraulic cylinder 9A for additional parts drive, etc.

In addition, spare parts and additional parts include, for example, a crusher and a pulverizer installed instead of a bucket, a deflection device for sliding the boom to the left and right, and a bulldozer blade attached to the turning part.

The fluid pressure control device 100 includes a first circuit system HC1 connected to the first pump 10 and supplying hydraulic oil from the first pump 10, a second circuit system HC2 connected to the second pump 20 and supplying hydraulic oil from the second pump 20, And the 3rd circuit system HC3 which is connected to the 1st circuit system HC1, and supplies hydraulic oil from the 1st pump 10 via the neutral switching valve 110 mentioned later. In addition, 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 the hydraulic oil discharged from the second pump 20 is also supplied to the second circuit system HC2. The first circuit system HC1 and the third circuit system HC3 are supplied.

As shown in FIGS. 1 and 2 , the fluid pressure control device 100 includes a main valve block 101 including a first circuit system HC1 and a second circuit system HC2 as main circuit systems, and a sub-valve including a third circuit system HC3 as a sub-circuit system Block 103. 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 . In addition, the main valve block 101 may be formed by laminating and connecting a plurality of valve blocks, or may be formed of a single valve block.

The main valve block 101 is formed with a screw mounting hole 115 which is opened on the outer surface and into which the screw 105 is mounted. The sub valve block 103 is placed on the upper surface of the main valve block 101, the rod portion of the screw 105 is inserted into the screw penetration hole 135 of the sub valve block 103, and the distal end portion of the rod portion of the screw 105 is screwed into the screw mounting hole 115. Thus, the auxiliary 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 an additional accessory. Conventionally, in order to control the hydraulic cylinder 9A for driving an additional accessory, it is necessary to provide a sub-valve block 103 separately from the main valve block 101, and to connect the third circuit system HC3 to a new one other than the first pump 10 and the second pump 20. hydraulic pump.

On the other hand, 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. In addition, since it is not necessary to provide piping 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. In addition, since the hydraulic oil of the first pump 10 is supplied to the sub-valve block 103 via the main valve block 101 as will be described later, it is not necessary to connect a new hydraulic pump to the sub-valve block 103 . That is, according to this embodiment, 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, the number of parts and the cost can be reduced.

As shown in FIG. 1 , the first circuit system HC1 includes a first neutral passage 11 that is a main neutral passage for guiding the hydraulic fluid discharged from the first pump 10 to the working fluid tank T, and is connected in series to the first neutral passage A first control valve 12 which is a plurality of main control valves of 11 , a first parallel passage 13 branched from the upstream of a straight-running control valve 6 described later in the first neutral passage 11 , and a discharge passage connected to the working fluid tank T 19. 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, which is the main control valve for controlling the actuator provided in the first circuit system HC1, includes a first travel control valve 12A, a bucket control valve 12B, a boom first speed control valve 12C, and a bucket control valve 12C. Control valve 12D for lever second gear. The hydraulic oil discharged from the first pump 10 is guided from the upstream side to the first travel control valve 12A, bucket control valve 12B, boom first speed control valve 12C, and arm second speed control valve 12D in this order.

The first travel control valve 12A is used to control supply and discharge of hydraulic oil to a hydraulic motor 7A for driving a travel portion provided on the left side of the body of the power excavator. The bucket control valve 12B is used to control the supply and discharge of hydraulic oil to the hydraulic cylinder 7B for bucket drive. The boom first speed control valve 12C is used to control the supply and discharge of hydraulic oil to a hydraulic cylinder (not shown) for driving the boom. The arm second-speed control valve 12D is used to control the supply and discharge of hydraulic oil to a hydraulic cylinder (not shown) for arm drive. In addition, the main actuators (the hydraulic motor 7A, the hydraulic cylinder 7B, etc.) controlled by the first control valve 12 are collectively referred to as the first actuator 7 .

In this way, the first circuit system HC1 includes the plurality of first control valves 12 that are connected to the first pump 10 and that control the plurality of first actuators 7 . The discharge passage 19 is used to guide the hydraulic fluid discharged from the first actuator 7 via the first control valve 12 to the hydraulic fluid tank T. As shown in FIG.

In the first circuit system HC1, when the straight-running control valve 6 described later is at the normal position (A) and the neutral switching valve 110 described later is at the first position (P1), all the first control valves 12 In the neutral position, the hydraulic fluid discharged from the first pump 10 is returned to the hydraulic fluid tank T via the first neutral passage 11 . On the other hand, when at least one of the plurality of first control valves 12 is in the driving position, the communication between the first pump 10 and the working fluid tank T in the first neutral passage 11 is blocked.

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

The first circuit system HC1 further includes downstream of all the first control valves 12 provided in the first neutral passage 11 (ie, downstream of the arm 2nd speed control valve 12D), and serves to connect the first neutral passage 11 and the working fluid tank The neutral switching valve 110 that T communicates or is blocked communicates with the downstream of all the first control valves 12 in the first neutral passage 11 (ie, downstream of the arm second-speed control valve 12D) and upstream of the neutral switching valve 110 In addition, a first external output passage 14 capable of supplying the hydraulic oil discharged from the first pump 10 to the outside, and a first external output passage 14 capable of supplying the hydraulic oil discharged from the first pump 10 and guided through the neutral switching valve 110 to the outside. 2 External output path 15.

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

The first circuit system HC1 further includes branch passages 191 and 192 branched from the discharge passage 19 for guiding the hydraulic fluid to the hydraulic fluid tank T. The branch passage 191 is connected to the introduction port 191 i opened on the outer surface of the main valve block 101 , and the branch passage 192 is connected to the introduction port 192 i opened on the outer surface of the main valve block 101 .

In the neutral switching valve 110, the valve body is set to the first position (P1), the second position (P2), and the third position (P3) according to the pilot pressure supplied to the first pilot pressure chamber 116a and the second pilot pressure chamber 116b. A pilot-operated switching valve that switches between. The pilot pressure acting on the first pilot pressure chamber 116a and the second pilot pressure chamber 116b is controlled according to, for example, the operating state of the power excavator, the operation position of a dedicated operation member (not shown) for operating the neutral switching valve 110, and the like. .

When no pilot pressure is applied to the first pilot pressure chamber 116a and the second pilot pressure chamber 116b, the neutral switching valve 110 is held at the first position ( P1 ) by the biasing force of the centering spring 117 .

The neutral switching valve 110 has a first inlet port 111 and a second inlet port 112 communicating with the downstream of the arm 2nd speed control valve 12D in the first neutral passage 11 , a working fluid tank port 119 communicating with the discharge passage 19 , and The outlet port 113 communicated with the second external output passage 15 .

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

That is, when the neutral switching 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 via the second external output passage 15 , and is allowed to be supplied from the main valve block 101 . The hydraulic oil discharged from the first pump 10 is guided to the hydraulic fluid tank T through the discharge passage 19 .

When the neutral switching valve 110 is in the second position ( P2 ), the communication between the first inlet port 111 and the working fluid 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 switching valve 110 is in the second position (P2), the supply of the hydraulic oil discharged from the first pump 10 to the outside of the main valve block 101 via the second external output passage 15 is prohibited, and the supply of hydraulic oil from the first pump 10 to the outside of the main valve block 101 is prohibited. The hydraulic oil discharged from the first pump 10 is guided to the hydraulic fluid tank T through the discharge passage 19 .

When the neutral switching valve 110 is in the third position ( P3 ), the communication between the first inlet port 111 and the working fluid tank port 119 is blocked, 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 communicate with each other, the hydraulic oil guided to the first neutral passage 11 is guided to the second external output passage 15 via the neutral switching valve 110 .

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

In this way, the first position ( P1 ) is a position connecting the first neutral passage 11 and the working fluid tank T, and the second position ( P2 ) and the third position ( P3 ) are the positions connecting the first neutral passage 11 and the working fluid tank T The location where the connection is blocked. In addition, the third position (P3) is a position connecting the first neutral passage 11 and the third neutral passage 31 of the third circuit system HC3 to be described later, and the first position (P1) and the second position (P2) are the 1. The position where the communication between the neutral passage 11 and the third neutral passage 31 is blocked.

In the present embodiment, by attaching the sub-valve block 103 to the main valve block 101, the hydraulic fluid discharged from the first pump 10 can also be supplied to the third circuit system HC3 via the first circuit system HC1. When the sub valve block 103 is not attached, each port (13o, 15o, 191i, 192i) opened on the outer surface of the main valve block 101 is closed by a plug. When the sub-valve block 103 is attached, the ports ( 13o , 15o , 191i , 192i ) opened on the outer surface of the main valve block 101 are connected to the ports ( 33i , 31i ) opened on the outer surface of the sub-valve block 103 , 38o, 39o).

The third circuit system HC3 includes a third neutral passage 31 for guiding the hydraulic oil guided through the neutral switching valve 110 and the second external output passage 15 of the first circuit system HC1 to the working fluid tank T, and is connected to the third neutral Passage 31 and a third control valve 32 serving as a sub-control valve for controlling the third actuator 9 as a sub-actuator, and for guiding the operation of the first parallel passage 13 via the first circuit system HC1 The third parallel passage 33 for guiding the oil to the third control valve 32, and the discharge passages 38 and 39 communicating with the discharge 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 that guides hydraulic oil through the first circuit system HC1.

In addition, 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 serve as the The discharged hydraulic oil functions as a neutral passage in which the hydraulic fluid returns to the working fluid 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 are used as the first neutral passage 11, The second external output path 15 and the third neutral path 31 are connected in series, and are connected in parallel by the first parallel path 13 and the third parallel path 33 .

The third control valve 32 controls the supply and discharge of hydraulic oil to and from the hydraulic cylinder 9A, which is the third actuator 9 , for driving the additional accessory, in accordance with the pilot pressure acting on the pilot pressure chamber. In this way, the third circuit system HC3 includes the third control valve 32 for controlling the third actuator 9 by the hydraulic oil discharged from the first pump 10 and supplied through the main valve block 101 . In addition, the third control valve 32 is a neutral fully open type control valve that communicates the third neutral passage 31 and the discharge passage 39 when in the neutral position, and guides the hydraulic oil guided to the third neutral passage 31 to the hydraulic fluid tank T .

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

A discharge passage 38 through which hydraulic oil is guided from the hydraulic cylinder 9A via the third control valve 32 is connected to a lead-out port 38 o opened 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 guides hydraulic oil from the third neutral passage 31 via the third control valve 32 is connected to a lead-out port 39 o opened 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 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 hydraulic fluid tank T via the third neutral passage 31 and the discharge passage 39 .

The second circuit system HC2 includes a second neutral passage 21 that is a main neutral passage for guiding the hydraulic fluid discharged from the second pump 20 to the working fluid tank T, and a plurality of main controls connected in series to the second neutral passage 21 Valves are the second control valve 22 , the second parallel passage 23 branched from the upstream of the second control valve 22 in the second neutral passage 21 , and the discharge passage 19 connected to the working fluid 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 for controlling the actuator provided in the second circuit system HC2, includes a second travel control valve 22A, a backup control valve 22B, a swing control valve 22C, and a second boom control valve. Control valve 22D and control valve 22E for arm 1st gear. The hydraulic oil discharged from the second pump 20 is directed from the upstream side to the second travel control valve 22A, the backup control valve 22B, the swing control valve 22C, the boom second speed control valve 22D, and the arm first speed control valve in this order. Valve 22E leads.

The second travel control valve 22A is used to control the supply and discharge of hydraulic oil to the hydraulic motor 8A for driving the travel portion provided on the right side of the body of the power excavator. The backup control valve 22B is used to control the supply and discharge of hydraulic oil to the hydraulic cylinder 8B for driving the backup. The turning control valve 22C is used to control supply and discharge of hydraulic oil to a hydraulic motor (not shown) for driving the turning unit. The boom second speed control valve 22D controls the supply and discharge of hydraulic oil to a hydraulic cylinder (not shown) for driving the boom. The arm first-speed control valve 22E is used to control the supply and discharge of hydraulic oil to a hydraulic cylinder (not shown) for arm drive. In addition, the main actuators (the hydraulic motor 8A, the hydraulic cylinder 8B, etc.) controlled by the second control valve 22 are also collectively referred to as the second actuator 8 .

In this way, the second circuit system HC2 includes the plurality of second control valves 22 that are connected to the second pump 20 and that control the plurality of second actuators 8 . The discharge passage 19 is used to guide the hydraulic fluid discharged from the second actuator 8 via the second control valve 22 to the hydraulic fluid tank T. As shown in FIG. In addition, the discharge passage 19 is shared as a passage for guiding the hydraulic fluid of the first circuit system HC1 and the second circuit system HC2 to the hydraulic fluid tank T. As shown in FIG.

In the second circuit system HC2 , when all the second control valves 22 are in the neutral position, the hydraulic fluid discharged from the second pump 20 is returned to the hydraulic fluid 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 driving position, the communication between the second pump 20 and the working fluid tank T in the second neutral passage 21 is blocked.

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

The second circuit system HC2 has a first external input passage 24 for guiding the hydraulic oil supplied from the outside to the upstream of a predetermined second control valve 22 (preparatory control valve 22B in this embodiment). The first external input passage 24 is connected to the first external input port 24i opened on the outer surface of the main valve block 101 .

The first circuit system HC1 further includes the straight travel control valve 6 connected downstream of the branch point of the first parallel passage 13 in the first neutral passage 11 and upstream of the first travel control valve 12A. The second parallel passage 23 is connected to the straight-run control valve 6 . The second parallel passage 23 has a second parallel upstream passage 23a that connects the second pump 20 and the straight-running control valve 6, and a second parallel-upstream passage 23a that connects the straight-running control valve 6 and the second control valve 22B to the second control valve 22E. 2 parallel downstream side passages 23b.

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

In 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 straight-running control valve 6 in the first neutral passage 11 is connected to the The downstream is connected to the first pump 10 . Thereby, the hydraulic oil discharged from the first pump 10 is guided to each of the first control valves 12 via the first neutral passage 11 and the first parallel passage 13 . In addition, the hydraulic oil discharged from the second pump 20 is guided to each of the second control valves 22 via the second neutral passage 21 and the second parallel passage 23 .

In addition, when the neutral switching valve 110 is in the third position (P3), the hydraulic fluid discharged from the first pump 10 also passes through the first neutral passage 11, the neutral switching valve 110, the second external output passage 15, and the first neutral passage 110. The 3rd neutral passage 31 leads to the 3rd control valve 32. In addition, the hydraulic fluid discharged from the first pump 10 is also guided to the third control valve 32 via the first parallel passage 13 and the third parallel passage 33 .

In the straight travel position (B), the second parallel upstream passage 23a of the second parallel passage 23 is connected downstream of the straight travel control valve 6 in the first neutral passage 11, and the second parallel downstream passage 23b is connected to the first pump 10. Thereby, the hydraulic oil discharged from the first pump 10 is guided to the first control valve 12B to the first control valve 12D via the first parallel passage 13 , and is directed to the first control valve 12B to the first control valve 12D via the second parallel downstream passage 23 b of the second parallel passage 23 . The second control valve 22B to the second control valve 22E are guided. The hydraulic fluid discharged from the second pump 20 is guided to the first control valve 12A via the downstream of the straight-running control valve 6 in the first neutral passage 11 , and is guided to the second control valve 22A via the second neutral passage 21 .

Also, when the neutral switching valve 110 is at the third position ( P3 ), the hydraulic oil discharged from the first pump 10 is guided to the third control valve 32 via the first parallel passage 13 and the third parallel passage 33 . In addition, the hydraulic fluid discharged from the second pump 20 is also guided to the third control valve 32 via the first neutral passage 11 , the neutral switching valve 110 , the second external output passage 15 , and the third neutral passage 31 .

When the power shovel travels in a state in which the excavation part is not driven, the pilot pressure chamber 6a becomes the working fluid 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 portion are operated, the hydraulic oil discharged from the first pump 10 is supplied to the first traveling control valve 12A, and the hydraulic oil discharged from the first pump 10 is supplied to the second traveling control valve 22A. 2. Hydraulic oil from the pump 20.

On the other hand, when the hydraulic motors 7A and 8A for driving the traveling portion are driven, when the actuator of the excavating portion is 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). That is, when the hydraulic motors 7A, 8A for driving the traveling part 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 controlled The hydraulic oil discharged from the second pump 20 is supplied. Further, the hydraulic oil discharged from the first pump 10 is supplied to the other first control valve 12B to the first control valve 12D, the other second control valve 22B to the second control valve 22E, and the third control valve 32 . Thereby, the circuit for running is independent of the circuits other than the running circuit, so that the straightness of the vehicle body is ensured.

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

When the first pilot pressure chamber 116a and the second pilot pressure chamber 116b are connected to the working fluid tank T, respectively, and the working oil is not supplied to the first pilot pressure chamber 116a and the second pilot pressure chamber 116b, the neutral switching valve 110 has a The spool is in the 1st position (P1). In this state, the first inlet port 111 and the working fluid 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 working fluid tank T through the working fluid tank port 119 .

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

The first external output port 14o always communicates with the first neutral passage 11 regardless of the position of the neutral switching valve 110 . However, when the neutral switching valve 110 is at the first position ( P1 ), the first neutral passage 11 communicates with the working fluid tank T as described above, so the first external output port 14o also communicates with the working fluid tank T. Thereby, the hydraulic fluid discharged from the first pump 10 is not supplied to the outside through the first external output port 14o, but is returned to the hydraulic fluid tank T.

On the other hand, when the neutral switching valve 110 is located at the second position ( P2 ), as described above, the communication between the first neutral passage 11 and the working fluid tank T is blocked. Therefore, the entire amount of hydraulic oil flowing into the first 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 via the first external output passage 14 . .

In this way, in the fluid pressure control device 100, by switching the neutral switching valve 110 to the second position (P2), the hydraulic oil supplied from the first pump 10 to the first circuit system HC1 can be sent to the first external output port 14o to the first circuit system HC1 via the first external output port 14o. external supply.

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 can be applied to a newly added actuator (not shown) via the first external output port 14o. It is driven, or it merges with a circuit that drives any one of the first actuator 7 , the second actuator 8 , and the third actuator 9 via the first external output port 14o.

Here, for example, a case where the hydraulic oil supplied to the outside via the first external output port 14o and the flow path of the hydraulic cylinder 8B for driving the spare parts is merged will be described.

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

In this state, hydraulic oil is supplied to the pilot pressure chamber of the backup control valve 22B and the first pilot pressure chamber 116a of the neutral switching valve 110 for controlling the supply and discharge of hydraulic oil to and from the hydraulic cylinder 8B. As a result, when the preliminary control valve 22B is operated, the hydraulic oil discharged from the first pump 10 is also supplied through the first pump 10 in addition to the supply of the hydraulic oil discharged from the second pump 20 to the preliminary control valve 22B. The external output passage 14 , the external piping 30 , and the first external input passage 24 are supplied to the backup control valve 22B.

That is, in the present embodiment, the hydraulic fluid 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 is also guided to the outside through the first external input passage of the second circuit system HC2 24 is guided upstream of the backup control valve 22B, and merges with the hydraulic oil discharged from the second pump 20 .

In addition, the neutral switching valve 110 may be configured to communicate or block the first neutral passage 11 and the working fluid tank T according to the pilot pressure Pp of the control preliminary control valve 22B. In this case, the spring load of the centering spring 117 is set so that the spool of the neutral switching valve 110 is maintained at the first position (P1) in a state where the pilot pressure Pp is low, and in a state where the pilot pressure Pp is high It is sufficient to switch the valve body of the neutral switching valve 110 to the second position (P2).

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 second pump 20 . Further, when the operation amount of the preliminary 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 backup control valve 22B, the flow rate of hydraulic oil to the backup control valve 22B can be increased, and the operation of the hydraulic cylinder 8B controlled by the backup control valve 22B can be accelerated.

In addition, although not shown, in the case of supplying hydraulic oil to the circuit system for driving the newly added actuator through the first external output passage 14, it is neutral when driving the additional actuator. The switching valve 110 may be switched to the second position (P2).

On the other hand, when hydraulic oil is supplied to the second pilot pressure chamber 116b of the neutral switching valve 110, the valve body overcomes the biasing force of the centering spring 117 by the pressure of the hydraulic oil supplied to the second pilot pressure chamber 116b. Move and switch to the 3rd position (P3). Thereby, the second inlet port 112 and the outlet port 113 communicate with each other, and the communication between the first inlet port 111 and the working fluid tank port 119 is blocked.

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

Therefore, when the neutral switching valve 110 is in the third position ( P3 ), the plurality of first control valves 12 and the third control valves 32 are used as the first neutral passage 11 , the second external output passage 15 , and the first neutral passage 15 as the neutral passage. The three neutral passages 31 are connected in series, and are connected in parallel by the first parallel passage 13 and the third parallel passage 33 .

Therefore, even if any one or all of the first control valve 12A to the first control valve 12D are switched to the driving position in the state where the neutral switching valve 110 is at the third position ( P3 ), the first pump 10 and the Even when the communication of the fluid tank T in the first neutral passage 11 is blocked, the hydraulic oil discharged from the first pump 10 can be directed to the third control valve 32 via the first parallel passage 13 and the third parallel passage 33 . supply.

Therefore, by attaching the sub-valve block 103 to the main valve block 101 , it is possible to easily add a third one that can be driven by the hydraulic fluid discharged from the first pump 10 or the second pump 20 like the first actuator 7 . Actuator 9.

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

By switching the neutral switching 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 via the first external output passage 14 . Further, by switching the neutral switching 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 via 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 through not only the first external output passage 14 but also the second external output passage 15 , it is possible to provide a circuit system with a relatively high degree of freedom of expansion. High fluid pressure control device 100.

<Second Embodiment>

A fluid pressure control device 200 according to a second embodiment of the present invention will be described with reference to FIG. 3 . Hereinafter, the difference from the above-described first embodiment will be mainly described, and in the drawings, the same or equivalent structures as those described in the above-described first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

In the first embodiment, an example in which the third circuit system HC3 includes the neutral fully open third control valve 32 has been described. On the other hand, in the second embodiment, the third circuit system HC32 includes the neutral fully closed 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 above-described first embodiment, but the configuration of the third circuit system HC32 is different from that of the above-described 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 described above, but the configuration of the sub valve block 203 is different from that of the first embodiment described above.

The sub valve block 203 having the third circuit system HC32 includes an oil intake block B30 for receiving hydraulic oil from the first circuit system HC1 and a valve block for controlling the third actuator 9 for driving additional accessories B31, B32. The oil inlet block B30 is also an oil outlet block for discharging the working oil to the working fluid tank T. In addition, since the valve block B31 and the valve block B32 have the same structure, the illustration of the valve block B32 is partially omitted. In addition, the number of valve blocks can be arbitrarily changed according to the number of additional actuators.

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

The intake 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 . In addition, a relief valve 261 connected to the supply passage 231 is provided in the oil intake block B30. When the neutral switching valve 110 is in the third position ( P3 ), the relief valve 261 limits the maximum pressure of the circuit connecting the third circuit system HC3 of the sub valve block 203 to the first circuit system HC1 of the main valve block 101 .

Each of the valve blocks B31 and B32 includes 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, a rear throttle type load sensing system in which the pressure compensation valve 234 is provided downstream of the throttle portion of each third control valve 232 is employed. In such a load sensing system, for each third actuator 9 , when a plurality of third actuators 9 are simultaneously operated, the pressure compensation valve 234 functions to adjust the load between the respective third actuators 9 .

The pressure compensation valve 234 is applied with the highest load pressure among the pressure provided downstream of the intake throttle portion of the third control valve 232 and the load pressures of the plurality of third actuators 9 . The pressure compensation valve 234 compensates so that the pressure downstream of the throttle portion becomes 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 driven at the same time, regardless of the magnitude of the load pressure of the third actuator 9, it is possible to supply a supply corresponding to the operation amount of the valve body of the third control valve 232 flow of pressure oil.

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

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 via piping or the like. In addition, the pump discharge pressure is guided from the discharge pressure output port 231p to the regulators (not shown) of the first pump 210 and the second pump 220 via piping or the like.

In addition, in the second embodiment, the output port 13 o and the introduction ports 191 i and 192 i which 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 sealing member such as a plug, and the number of parts can be reduced.

According to the second embodiment, the same effects as those of the first embodiment can be obtained.

As described above, the main valve block 101 of the second embodiment is the same as that of the first embodiment. Therefore, for the third control valve 32 of the sub-valve block 103 and the third control valve 232 of the sub-valve block 203, both the neutral fully open type (refer to FIG. 1 ) and the neutral fully closed type (refer to FIG. 3 ) In either case, the main valve block 101 can cope with it. That is, by providing the above-described neutral switching valve 110 and providing predetermined ports (15o, 13o, 191i, 192i), the main valve block 101 with high versatility can be provided.

The following modifications are also within the scope of the present invention, and the configurations shown in the modifications may be combined with the configurations described in the above-described embodiments, or the configurations described in the different embodiments may be combined with each other, or The structures described in the following different modification examples are combined with each other.

<Variation 1>

In the above-described embodiment, the example in which the first actuator 7 and the first control valve 12 are provided in plural is described, but the present invention is not limited to this. At least one of each of the first actuator 7 and the first control valve 12 may be provided. In the above-described embodiment, the example in which the second actuator 8 and the second control valve 22 are provided in plural is described, but the present invention is not limited to this. At least one of each of the second actuator 8 and the second control valve 22 may be provided.

<Variation 2>

In the above-described embodiment, the example in which the neutral switching 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 switching valve 110 provided in the first neutral passage 11, a neutral switching valve having the same function as the neutral switching valve 110 may be provided in the second neutral passage 21, or in addition to the neutral switching valve provided in the first neutral passage 11 A neutral switching valve having the same function as the neutral switching valve 110 is provided in the second neutral passage 21 in addition to 110 .

That is, the second circuit system HC2 may be provided with the same first external output path 14 as the first external output path 14 of the first circuit system HC1 described in the above-mentioned embodiment, and the same as the first external output path 14 described in the above-mentioned embodiment. For the second external output passage that is the same as the second external output passage 15 of the first circuit system HC1, the main valve block 101 is mounted with the same sub valve block as the sub valve block 103 described in the above embodiment, and the sub valve block is The circuit system is connected to the second circuit system HC2. In addition, the same first external output path as the first external output path 14 described in the above embodiment may be provided in the second circuit system HC2, and the same as the first external output path 14 described in the above embodiment may be provided in the first circuit system HC1. The first external input path 24 is the same as the first external input path, and the two are connected by external piping. In this case, the operation of the first actuator 7 can be accelerated by combining the hydraulic oil of the second circuit system HC2 with the first circuit system HC1 using the neutral switching valve provided in the second circuit system HC2.

The structure, action, and effect of the embodiment of the present invention configured as described above will be summarized.

The fluid pressure control devices 100 and 200 are for controlling actuators driven by the working fluid discharged from the pumps (the first pumps 10 and 210 and the second pumps 20 and 220 ), and the fluid pressure control devices include a main A circuit system (1st circuit system HC1, 2nd circuit system HC2), the main circuit system (1st circuit system HC1, 2nd circuit system HC2) is connected to pumps (1st pump 10, 210, 2nd pump 20, 220) ) and a main control valve (the first control valve 12, the second control valve 22) for controlling the main actuators (the first actuator 7, the second actuator 8), the main circuit system (the first circuit The system HC1 and the second circuit system HC2) have the main neutral passage (the first neutral passage 11 and the second neutral passage 21 ), and when the main control valve (the first control valve 12 and the second control valve 22 ) is in the neutral position Next, the main neutral passage (first neutral passage 11, second neutral passage 21) makes the working fluid of the pumps (first pumps 10, 210, second pumps 20, 220) return to the working fluid tank T; neutral switching valve 110 , which is provided downstream of the main control valve (the first control valve 12, the second control valve 22) in the main neutral passage (the first neutral passage 11, the second neutral passage 21), and is used to connect the main neutral passage (the first The neutral passage 11, the second neutral passage 21) communicate with or block the working fluid tank T; the first external output passage 14 is connected to the main control valve in the main neutral passage (the first neutral passage 11, the second neutral passage 21) The downstream of the (first control valve 12, the second control valve 22) and the upstream of the neutral switching valve 110 communicate with each other, and the working fluid discharged from the pumps (the first pump 10, 210, the second pump 20, 220) can be sent to the external supply; and a second external output passage 15 capable of supplying the working fluid discharged from the pumps (first pumps 10, 210, second pumps 20, 220) and guided through the neutral switching valve 110 to the outside, neutral switching The valve 110 can be switched between the first position (P1), the second position (P2), and the third position (P3). 2. The working fluid discharged from the pumps 20, 220) is guided to the working fluid tank T, and the operation of the discharge from the pumps (the first pumps 10, 210, and the second pumps 20, 220) is prohibited at the second position (P2) described above. The fluid is supplied to the outside through the second external output passage 15, and the working fluid ejected from the pumps (the first pumps 10, 210, and the second pumps 20, 220) is prohibited from being guided to the working fluid tank T; at the third position ( P3) allows the working fluid discharged from the pumps (first pumps 10, 210, 20, 220) to be supplied to the outside via the second external output passage 15, and prohibits the supply of working fluids from the pumps (first pumps 10, 210, 20, 220) 2. The working fluid ejected from the pumps 20, 220) is guided to the working fluid tank T.

In this configuration, the working fluid that can be supplied from the pumps (first pumps 10, 210, second pumps 20, 220) to the main circuit system (first circuit system HC1, second circuit system HC2) not only passes through the first external The output path 14 is also supplied to the outside via the second external output path 15 . Thereby, the fluid pressure control apparatuses 100 and 200 with a high degree of freedom of adding a circuit system can be provided.

The fluid pressure control devices 100 and 200 include a first circuit system HC1 and a second circuit system HC2 as main circuit systems, and a neutral switching valve 110 and a first circuit system HC2 are provided in one of the first circuit system HC1 and the second circuit system HC2 The external output path 14 is provided with the first external input path 24 connected to the first external output path 14 via the external piping 30 in 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 through the external piping 30, the first circuit system HC1 and the second circuit system can be provided in the first circuit system HC1 and the second circuit system. The operation of the other actuator (the first actuator 7 and the second actuator 8 ) in HC2 is accelerated.

The fluid pressure control devices 100 and 200 further include: a main valve block 101 having a main circuit system (a first circuit system HC1 and a second circuit system HC2); and a sub circuit system (third circuit systems HC3 and HC32) having a A sub-control valve that controls the sub-actuator (third actuator 9 ) by the working fluid discharged from the pumps (the first pump 10 , 210 , the second pump 20 , 220 ) and supplied via the main valve block 101 (third control valves 32, 232); and sub-valve blocks 103, 203 having sub-circuit systems (third circuit systems HC3, HC32), and sub-circuit systems (third circuit systems HC3, HC32) The second external input passage (the third neutral passage 31 and the supply passage 231 ) of the external output passage 15 and the sub valve blocks 103 and 203 can be attached 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 size of the fluid pressure control device can be reduced compared to the case where the sub-valve blocks 103 and 203 are provided separately from the main valve block 101 . 100, 200 setting area. 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 of the fluid pressure control devices 100 and 200 can be reduced.

The embodiments of the present invention have been described above, but the above-described embodiments merely show some application examples of the present invention, and are not intended to limit the scope of the present invention to the specific configurations of the above-described embodiments.

This application claims priority based on Japanese Patent Application No. 2018-217345 for which it applied to the Japan Patent Office on November 20, 2018, and the entire contents of this application are incorporated herein by reference.

Claims (3)

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 neutral passage downstream of the main control valve and upstream of the neutral switching valve and which is capable of supplying the working fluid discharged from the pump and flowing through the main neutral passage to the outside; and

a 2 nd external output passage capable of supplying the working fluid discharged from the pump, flowing through the main neutral passage 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,

in the 1 st position, the working fluid discharged from the pump and flowing through the main neutral passage is allowed to be introduced into the working fluid tank,

in the 2 nd position, the supply of the working fluid discharged from the pump and flowing through the main neutral passage to the outside via the 2 nd external output passage is prohibited, and the introduction of the working fluid discharged from the pump and flowing through the main neutral passage to the working fluid tank is prohibited,

in the 3 rd position, the supply of the working fluid discharged from the pump and flowing through the main neutral passage to the outside through the 2 nd external output passage is permitted, and the introduction of the working fluid discharged from the pump and flowing through the main neutral passage to the working fluid tank is prohibited.

2. The fluid pressure control device of 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.

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