阅读说明：本技术 流体压控制装置 (Fluid pressure control device ) 是由 松崎敬一 福田俊介 于 2019-02-27 设计创作，主要内容包括：流体压控制装置包括：第1切换阀(51),其设在第1主通路(41)中的第1行驶用控制阀(11)的下游,具有开放位置(51A)和优先位置(51B)；第2切换阀(52),其设在第2主通路(42)中的第2行驶用控制阀(21)的下游,具有开放位置(52A)和优先位置(52B)；以及合流通路(45),其将第1主通路(41)中的第1切换阀(51)的下游和第2主通路(42)中的第2切换阀(52)的下游连接在一起,在不对第1作业用控制阀(12～14)及第2作业用控制阀(22～24)进行操作并且对第1行驶用控制阀(11)进行操作的状态下,第1切换阀(51)成为第1优先位置(51B),在不对第1作业用控制阀(12～14)及第2作业用控制阀(22～24)进行操作并且对第2行驶用控制阀(21)进行操作的状态下,第2切换阀(52)成为第1优先位置(52B)。(The fluid pressure control device includes: a 1 st switching valve (51) which is provided downstream of the 1 st travel control valve (11) in the 1 st main passage (41) and has an open position (51A) and a priority position (51B); a 2 nd switching valve (52) that is provided downstream of the 2 nd travel control valve (21) in the 2 nd main passage (42), and that has an open position (52A) and a priority position (52B); and a merging passage (45) that connects the downstream of the 1 st switching valve (51) in the 1 st main passage (41) and the downstream of the 2 nd switching valve (52) in the 2 nd main passage (42), wherein the 1 st switching valve (51) is set to the 1 st priority position (51B) in a state where the 1 st traveling control valve (11) is operated without operating the 1 st working control valves (12 to 14) and the 2 nd working control valves (22 to 24), and the 2 nd switching valve (52) is set to the 1 st priority position (52B) in a state where the 2 nd traveling control valve (21) is operated without operating the 1 st working control valves (12 to 14) and the 2 nd working control valves (22 to 24).)

1. A fluid pressure control device, wherein,

the fluid pressure control device includes:

a 1 st main passage to which a working fluid is supplied from a 1 st pump port;

a 2 nd main passage for supplying the working fluid from the 2 nd pump port to the 2 nd main passage;

a plurality of 1 st work control valves for a work machine, which are connected in parallel to the 1 st main passage;

a plurality of 2 nd work control valves for a work machine, which are connected in parallel to the 2 nd main passage;

a 1 st travel control valve for a travel device, which is connected to the 1 st main passage upstream of the 1 st work control valve and in parallel with the 1 st work control valve;

a 2 nd travel control valve for a travel device, which is connected to the 2 nd main passage upstream of the 2 nd work control valve and in parallel with the 2 nd work control valve;

a 1 st switching valve provided in the 1 st main passage downstream of a connection portion of the 1 st traveling control valve, and having an open position at which the 1 st main passage is opened and a 1 st priority position at which the working fluid from the 1 st pump port is preferentially guided to the 1 st traveling control valve;

a 2 nd switching valve provided in the 2 nd main passage downstream of a connection portion of the 2 nd traveling control valve, and having an open position at which the 2 nd main passage is opened and a 1 st priority position at which the working fluid from the 2 nd pump port is preferentially guided to the 2 nd traveling control valve; and

a merging passage that connects the downstream of the 1 st switching valve in the 1 st main passage and the downstream of the 2 nd switching valve in the 2 nd main passage together,

the 1 st switching valve is set to the 1 st priority position in a state where the 1 st work control valve and the 2 nd work control valve are not operated and the 1 st travel control valve is operated,

the 2 nd switching valve is set to the 1 st priority position in a state where the 1 st work control valve and the 2 nd work control valve are not operated and the 2 nd travel control valve is operated.

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

the 1 st switching valve and the 2 nd switching valve are in the open position in a state where at least one of the 1 st work control valve and the 2 nd work control valve is operated.

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

at least one of the 1 st work control valve is a priority control valve provided upstream of the 1 st switching valve in parallel with the 1 st travel control valve,

the 1 st switching valve is set to the 1 st priority position in a state where the 1 st travel control valve and the 2 nd travel control valve are not operated and the priority control valve is operated.

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

at least one of the 1 st work control valve is a priority control valve provided upstream of the 1 st switching valve in parallel with the 1 st travel control valve,

the 1 st switching valve further has a 2 nd priority position for directing the working fluid from the 1 st pump port to the priority control valve in preference to the other 1 st working control valve,

the 1 st switching valve is set to the 2 nd priority position in a state where the 1 st travel control valve and the 2 nd travel control valve are not operated and the priority control valve is operated.

5. The fluid pressure control device according to claim 3 or 4,

the 1 st switching valve is set to the open position in a state where the 1 st travel control valve and the priority control valve are operated.

6. The fluid pressure control device according to claim 4,

the 1 st switching valve blocks the flow of the working fluid at the 1 st priority position and has a throttle portion that applies resistance to the flow of the working fluid at the 2 nd priority position.

Technical Field

The present invention relates to a fluid pressure control device.

Background

JP 2006-83696A discloses a hydraulic device as follows: in a traveling state in which a control valve for a traveling device is operated, a flow path switching valve is switched to an independent position, and pressure oil from a 1 st pump port and a 2 nd pump port of a pump is supplied to control valves for left and right traveling independently of each other.

Disclosure of Invention

In the hydraulic apparatus described in JP 2006-83696A, when one of the control valves for left and right traveling is operated, the flow path switching valve is switched to the independent position. Therefore, even when only one of the left and right travel control valves is operated to drive only a single travel device, the flow path switching valve is switched to the independent position. Therefore, in this state, the pressure oil at the pump port supplied to the control valve for traveling that is not operated cannot be effectively used, and as a result, the workability is reduced.

The invention aims to provide a fluid pressure control device with excellent operability.

According to one aspect of the present invention, there is provided a fluid pressure control device, comprising: a 1 st switching valve provided in the 1 st main passage at a position downstream of a connection portion of the 1 st traveling control valve, and having an open position at which the 1 st main passage is opened and a 1 st priority position at which the working fluid from the 1 st pump port is preferentially guided to the 1 st traveling control valve; a 2 nd switching valve provided in the 2 nd main passage at a position downstream of the connection portion of the 2 nd traveling control valve, and having an open position at which the 2 nd main passage is opened and a 1 st priority position at which the working fluid from the 2 nd pump port is preferentially guided to the 2 nd traveling control valve; and a merging passage connecting a downstream of the 1 st switching valve in the 1 st main passage and a downstream of the 2 nd switching valve in the 2 nd main passage, wherein the 1 st switching valve is set to the 1 st priority position in a state where the 1 st work control valve and the 2 nd work control valve are not operated and the 1 st travel control valve is operated, and the 2 nd switching valve is set to the 1 st priority position in a state where the 1 st work control valve and the 2 nd work control valve are not operated and the 2 nd travel control valve is operated.

Drawings

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

Fig. 2 is a circuit diagram of a fluid pressure control device according to a modification of embodiment 1 of the present invention.

Fig. 3 is a circuit diagram of a fluid pressure control device according to a modification of embodiment 1 of the present invention.

Fig. 4 is a circuit diagram of a fluid pressure control device according to embodiment 2 of the present invention.

Fig. 5 is a circuit diagram of a fluid pressure control device according to a modification example of embodiment 2 of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

< embodiment 1 >

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

The fluid pressure control device 100 is used to control the operation of hydraulic working equipment such as a hydraulic excavator. In the present embodiment, a case of controlling the operation of the hydraulic excavator will be described.

The hydraulic excavator includes a plurality of actuators, a left travel motor 1 for driving a left travel device, a boom cylinder 2 for driving a boom, a bucket cylinder 3 for driving a bucket, a blade cylinder 4 for driving a blade (blade), a right travel motor 5 for driving a right travel device, an arm cylinder 6 for driving an arm, a swing motor 7 for driving a swing, and a boom swing cylinder 8 for driving a boom swing (swing). Hereinafter, the motor and the cylinder are also referred to as a hydraulic actuator.

The fluid pressure control device 100 includes an engine (not shown) as a power source, a main pump 31 as a fluid pressure supply source driven by the engine, and a pilot pump 32 as a pilot pressure supply source driven by the engine.

The main pump 31 is a split hydraulic pump having two pump ports, a 1 st pump port 31a and a 2 nd pump port 31 b.

The fluid pressure control device 100 further includes a 1 st main passage 41 to which the working fluid (working oil) is supplied from the 1 st pump port 31a, a 2 nd main passage 42 to which the working oil is supplied from the 2 nd pump port 31b, a 1 st circuit system 10 for controlling the supply of the working oil from the 1 st main passage 41 to the hydraulic actuators 1 to 4, and a 2 nd circuit system 20 for controlling the supply of the working oil from the 2 nd main passage 42 to the hydraulic actuators 5 to 8.

The 1 st circuit system 10 includes a 1 st travel control valve 11 for controlling supply of the hydraulic oil to the left travel motor 1, a boom control valve 12 for controlling supply of the hydraulic oil to the boom cylinder 2, a bucket control valve 13 for controlling supply of the hydraulic oil to the bucket cylinder 3, and a blade control valve 14 for controlling supply of the hydraulic oil to the blade cylinder 4. The 1 st travel control valve 11, the boom control valve 12, the bucket control valve 13, and the blade control valve 14 are connected to the 1 st main passage 41 in parallel in this order. Hereinafter, the boom control valve 12, the bucket control valve 13, and the blade control valve 14 will also be referred to as the 1 st work control valve.

The 2 nd circuit system 20 includes a 2 nd travel control valve 21 for controlling the supply of the hydraulic oil to the right travel motor 5, an arm control valve 22 for controlling the supply of the hydraulic oil to the arm cylinder 6, a swing control valve 23 for controlling the supply of the hydraulic oil to the swing motor 7, and a boom swing control valve 24 for controlling the supply of the hydraulic oil to the boom swing cylinder 8. The 2 nd travel control valve 21, the arm control valve 22, the swing control valve 23, and the boom swing control valve 24 are connected to the 2 nd main passage 42 in parallel in this order. Hereinafter, the arm control valve 22, the swing control valve 23, and the boom swing control valve 24 will also be referred to as "2 nd work control valves".

The 1 st travel control valve 11 switches its position in accordance with the pilot pressure that is guided from the pilot pump 32 to the pilot chambers 11a and 11b via the pilot control valve 33a as the operator of the hydraulic excavator manually operates the operation lever 9 a. Specifically, when the pilot pressure is introduced into the pilot chamber 11A, the 1 st travel control valve 11 is switched to the forward position 11A, the left travel motor 1 rotates forward, and the left travel device is driven to travel forward. When the pilot pressure is introduced into the pilot chamber 11B, the 1 st travel control valve 11 is switched to the reverse position 11B, the left travel motor 1 is reversely rotated, and the left travel device is driven to be reversed. When the pilot pressure is not led to the pilot chambers 11a and 11b, the 1 st travel control valve 11 is switched to the neutral position 11C, the left travel motor 1 is stopped, and the left travel device is stopped.

Similarly, the 2 nd travel control valve 21 switches its position (forward position 21A, reverse position 21B, neutral position 21C) in accordance with the pilot pressure that is guided from the pilot pump 32 to the pilot chambers 21A, 21B via the pilot control valve 33B as the operator of the hydraulic excavator manually operates the operation lever 9B.

The boom control valve 12 switches its position according to a pilot pressure that is introduced from the pilot pump 32 to the pilot chambers 12a and 12b via the pilot control valve as the operator of the hydraulic excavator manually operates the operation lever. Specifically, when the pilot pressure is introduced into the pilot chamber 12A, the boom control valve 12 is switched to the contraction position 12A, and the boom cylinder 2 performs a contraction operation. When the pilot pressure is introduced into the pilot chamber 12B, the boom control valve 12 is switched to the extension position 12B, and the boom cylinder 2 performs the extension operation. When the pilot pressure is not guided to the pilot chambers 12a and 12b, the boom control valve 12 is switched to the neutral position 12C, and the expansion and contraction operation of the boom cylinder 2 is stopped. The other 1 st work control valves 13, 14 and 2 nd work control valves 22 to 24 except the boom control valve 12 have the same configuration as the boom control valve 12, and therefore, description thereof is omitted. Hereinafter, the position at which the hydraulic actuator is operated in addition to the neutral position is also referred to as an operation position in each of the control valves 11 to 14, 21 to 24.

A 1 st switching valve 51 is provided in the 1 st main passage 41 downstream of the connection portion 43 with the 1 st travel control valve 11. Similarly, a 2 nd switching valve 52 is provided in the 2 nd main passage 42 at a position downstream of the connection portion 44 to the 2 nd travel control valve 21. The downstream of the 1 st switching valve 51 in the 1 st main passage 41 and the downstream of the 2 nd switching valve 52 in the 2 nd main passage 42 are connected together by the merging passage 45. In this way, the 1 st main passage 41 and the 2 nd main passage 42 are merged by the merging passage 45.

The 1 st switching valve 51 has an open position 51A at which the 1 st main passage 41 is opened and a priority position 51B as a 1 st priority position at which the hydraulic oil from the 1 st pump port 31A is preferentially guided to the 1 st travel control valve 11. The 1 st switching valve 51 is switched to the open position 51A or the priority position 51B in accordance with the balance between the pilot pressure introduced into the pilot chambers 51A and 51B and the biasing force of the spring 53. At the open position 51A, the working oil supplied from the 1 st pump port 31A to the 1 st main passage 41 is supplied to the 1 st travel control valve 11 and also to the 1 st work control valves 12 to 14. At the same time, the mixed gas is also supplied to the 2 nd main passage 42 via the merging passage 45. On the other hand, at the priority position 51B, since the flow of the hydraulic oil in the 1 st main passage 41 is blocked, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is preferentially supplied to the 1 st traveling control valve 11, not to the 1 st working control valves 12 to 14.

Similarly, the 2 nd switching valve 52 has an open position 52A at which the 2 nd main passage 42 is opened and a priority position 52B as a 1 st priority position at which the hydraulic oil from the 2 nd pump port 31B is preferentially led to the 2 nd traveling control valve 21. The 2 nd switching valve 52 is switched to the open position 52A or the priority position 52B in accordance with the balance between the pilot pressure introduced into the pilot chambers 52A and 52B and the biasing force of the spring 54. At the open position 52A, the working oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 is supplied to the 2 nd travel control valve 21 and also to the 2 nd work control valves 22 to 24. At the same time, the mixed gas is also supplied to the 1 st main passage 41 through the merging passage 45. On the other hand, at the priority position 52B, since the flow of the hydraulic oil in the 2 nd main passage 42 is blocked, the hydraulic oil supplied from the 2 nd pump port 31B to the 2 nd main passage 42 is not supplied to the 2 nd work control valves 22 to 24, but is preferentially supplied to the 2 nd travel control valve 21.

The pilot pump 32 is connected with a 1 st detection passage 60 for detecting operations of the 1 st work control valves 12 to 14 and operations of the 2 nd work control valves 22 to 24. The 1 st detection passage 60 is connected to the tank passage 63 via the blade control valve 14, the bucket control valve 13, the boom control valve 12, the arm control valve 22, the swing control valve 23, and the boom swing control valve 24 in this order. A 1 st detection pressure derivation passage 62 branched from the upstream side of the blade control valve 14 located most upstream is connected to the 1 st detection passage 60. The 1 st detection pressure lead-out passage 62 is connected to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52.

When all of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and are in the neutral position, the 1 st detection passage 60 communicates with the tank passage 63, and therefore the pilot pressure is not led to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52. On the other hand, in a state where at least one of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 is operated, since the communication between the 1 st detection passage 60 and the tank passage 63 is blocked, the pilot pressure is led to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52 via the 1 st detection pressure lead-out passage 62.

The pilot chamber 51b of the 1 st switching valve 51 is connected to the pilot chambers 11a and 11b of the 1 st travel control valve 11 via the high-pressure selector valve 64. Therefore, the high pilot pressure in pilot chamber 11a and pilot chamber 11b is led to pilot chamber 51b of first switching valve 51. In this way, when the 1 st traveling control valve 11 is operated, the pilot pressure for operating the 1 st traveling control valve 11 is introduced into the pilot chamber 51b of the 1 st switching valve 51.

Similarly, the pilot chamber 52b of the 2 nd switching valve 52 is connected to the pilot chambers 21a and 21b of the 2 nd travel control valve 21 via the high-pressure selector valve 65, and when the 2 nd travel control valve 21 is operated, the pilot pressure for operating the 2 nd travel control valve 21 is introduced into the pilot chamber 52 b.

In the 1 st main passage 41, a 1 st unload passage 66 branches from the upstream side of the 1 st switching valve 51 and is connected to the 1 st main passage 41, and a 1 st unload valve 67 is provided in the 1 st unload passage 66. The 1 st unloading valve 67 has a blocking position 67A that blocks the 1 st unloading passage 66 and an unloading position 67B that discharges a part of the working oil supplied from the 1 st pump port 31a to the 1 st main passage 41 to the working fluid tank passage 63. When the pilot pressure is led to the pilot chamber 67A, the 1 st unloading valve 67 is switched to the blocking position 67A, and when the pilot pressure is not led to the pilot chamber 67A, the 1 st unloading valve 67 is switched to the unloading position 67B by the pressure upstream of the 1 st unloading valve 67. Pilot chamber 67a is connected to pilot passage 1, and pilot passages 1, 56 are connected to control valves 11 to 14, respectively. In a state where at least one of the control valves 11 to 14 is operated to be in the operating position, the hydraulic oil discharged from the main pump 31 is guided to the 1 st pilot passage 56 through the control valves 11 to 14 in the operating position.

Similarly, in the 2 nd main passage 42, a 2 nd unload passage 68 branches from the upstream side of the 2 nd switching valve 52 and is connected to the 2 nd main passage 42, and a 2 nd unload valve 69 is provided in the 2 nd unload passage 68. The 2 nd unload valve 69 has a blocking position 69A at which the 2 nd unload passage 68 is blocked and an unload position 69B at which a part of the working oil supplied from the 2 nd pump port 31B to the 2 nd main passage 42 is discharged to the working fluid tank passage 63. When the pilot pressure is introduced into the pilot chamber 69A, the 2 nd unloading valve 69 is switched to the blocking position 69A, and when the pilot pressure is not introduced into the pilot chamber 69A, the 2 nd unloading valve 69 is switched to the unloading position 69B by the pressure upstream of the 2 nd unloading valve 69. Pilot chamber 69a is connected to pilot passage 2, and pilot passages 2, 57 are connected to control valves 21 to 24, respectively. In a state where at least one of the control valves 21 to 24 is operated to be in the operating position, the hydraulic oil discharged from the main pump 31 is guided to the 2 nd pilot passage 57 through the control valves 21 to 24 in the operating position.

Pilot passage 1 and pilot passage 2 57 are switched between merging and blocking each other by a merging valve 58. The merge valve 58 is switched to the merge position 58A or the block position 58B in accordance with the balance between the pilot pressure introduced into the pilot chambers 58A, 58B and the force of the spring 55.

Here, the 2 nd detection passage 77 for detecting the operation of the 1 st travel control valve 11 and the operation of the 2 nd travel control valve 21 is connected to the pilot pump 32. The 2 nd detection passage 77 is connected to the working fluid tank passage 63 via the 2 nd travel control valve 21 and the 1 st travel control valve 11 in this order. A 2 nd detection pressure lead-out passage 78 branched from the upstream of the 2 nd travel control valve 21 located at the most upstream is connected to the 2 nd detection passage 77. The pilot chamber 58a of the flow merging valve 58 is connected to the 1 st detection pressure lead-out passage 62, and the pilot chamber 58b is connected to the 2 nd detection pressure lead-out passage 78.

As described above, when all of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and are in the neutral position, the 1 st detection passage 60 communicates with the tank passage 63, and therefore the pilot pressure is not guided to the pilot chamber 58a of the confluence valve 58. On the other hand, in a state where at least one of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 is operated, since the communication between the 1 st detection passage 60 and the working fluid tank passage 63 is blocked, the pilot pressure is guided to the pilot chamber 58a of the confluence valve 58 through the 1 st detection pressure leading-out passage 62.

Further, when both the 1 st travel control valve 11 and the 2 nd travel control valve 21 are not operated but are placed in the neutral position, the 2 nd detection passage 77 communicates with the tank passage 63, and therefore the pilot pressure is not led to the pilot chamber 58b of the confluence valve 58. On the other hand, in a state where at least one of the 1 st travel control valve 11 and the 2 nd travel control valve 21 is operated, since the communication between the 2 nd detection passage 77 and the tank passage 63 is blocked, the pilot pressure is guided to the pilot chamber 58b of the merging valve 58 via the 2 nd detection pressure lead-out passage 78.

When the pilot pressure is guided to both the pilot chamber 58A and the pilot chamber 58b of the confluence valve 58, the confluence valve 58 is switched to the confluence position 58A by the biasing force of the spring 55.

Next, the operation of the fluid pressure control device 100 will be described.

In a state where all of the control valves 11 to 14 and 21 to 24 are not operated and are in the neutral position, the 1 st switching valve 51 is in the open position 51A by the biasing force of the spring 53, and the 2 nd switching valve 52 is in the open position 52A by the biasing force of the spring 54. In this state, the pilot chamber 67a communicates with the tank passage 63 via the 1 st pilot passage 56, and therefore the 1 st unloading valve 67 is at the unloading position 67B by the pressure upstream of the 1 st unloading valve 67. Similarly, the 2 nd unload valve 69 is also in the unload position 69B. Therefore, a part of the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is discharged to the tank passage 63 via the 1 st unloading valve 67, and a part of the hydraulic oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 is discharged to the tank passage 63 via the 2 nd unloading valve 69.

In a state where at least one of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 is operated to be in the operation position and the 1 st travel control valve 11 and the 2 nd travel control valve 21 are operated to be in the operation position, the pilot pressure is guided to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52 via the 1 st detection pressure derivation passage 62, the pilot pressure for operating the 1 st travel control valve 11 is guided to the pilot chamber 51b of the 1 st switching valve 51, and the pilot pressure for operating the 2 nd travel control valve 21 is guided to the pilot chamber 52b of the 2 nd switching valve 52. Here, the pilot pressure led through the 1 st detection pressure lead-out passage 62 is larger than the pilot pressure for operating the 1 st travel control valve 11 and the pilot pressure for operating the 2 nd travel control valve 21. Therefore, the 1 st switching valve 51 is at the open position 51A, and the 2 nd switching valve 52 is at the open position 52A. In this state, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 and the hydraulic oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 are merged via the merging passage 45. Therefore, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b can be supplied to the hydraulic actuators 1 to 8 by being merged.

In this state, the pilot pressure is introduced into both the pilot chamber 58A and the pilot chamber 58b with respect to the confluence valve 58, but the confluence valve 58 is switched to the confluence position 58A by the biasing force of the spring 55. Therefore, the 1 st unloading valve 67 is at the blocking position 67A by the pilot pressure guided to the 1 st pilot passage 56 via the operated control valve of the control valves 11 to 14, 21 to 24. Similarly, the 2 nd unloading valve 69 is also at the blocking position 69A.

As described above, since the pilot pressure led through the 1 st detection pressure lead-out passage 62 is higher than the pilot pressure for operating the 1 st travel control valve 11 and the pilot pressure for operating the 2 nd travel control valve 21, the 1 st switching valve 51 is set to the open position 51A and the 2 nd switching valve 52 is set to the open position 52A regardless of whether or not the 1 st travel control valve 11 and the 2 nd travel control valve 21 are operated in a state where at least one of the 1 st work control valve 12 to 14 and the 2 nd work control valve 22 to 24 is operated to be set to the operation position.

In a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated to be in the neutral position and the 1 st travel control valve 11 is operated to be in the operation position, the pilot pressure for operating the 1 st travel control valve 11 is not led to the pilot chamber 51a but led to the pilot chamber 51B, so that the 1 st switching valve 51 becomes the priority position 51B against the biasing force of the spring 53. Similarly, in a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated to be in the neutral position and the 2 nd travel control valve 21 is operated to be in the operation position, the pilot pressure for operating the 2 nd travel control valve 21 is not led to the pilot chamber 52a but led to the pilot chamber 52B, so the 2 nd switching valve 52 becomes the priority position 52B against the biasing force of the spring 54. In this state, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is supplied only to the 1 st traveling control valve 11, and the hydraulic oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 is supplied only to the 2 nd traveling control valve 21. In this way, in a state where only the left and right traveling devices are driven, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b are supplied to the left traveling motor 1 and the right traveling motor 5, respectively, independently of each other, and therefore, the traveling performance in turning or straight traveling can be improved.

In this state, the pilot pressure is introduced into the pilot chamber 58B, so that the merge valve 58 is at the blocking position 58B. Therefore, when the 1 st traveling control valve 11 is operated, the 1 st unloading valve 67 is at the blocking position 67A by the pilot pressure guided to the pilot chamber 67A via the 1 st traveling control valve 11. On the other hand, when the 2 nd traveling control valve 21 is operated, the 2 nd unloading valve 69 becomes the blocking position 69A by the action of the pilot pressure guided to the pilot chamber 69A via the 2 nd traveling control valve 21. In this way, the 1 st unloading valve 67 is independently controlled in accordance with the operation of the 1 st traveling control valve 11, and the 2 nd unloading valve 69 is independently controlled in accordance with the operation of the 2 nd traveling control valve 21.

In the fluid pressure control device 100, the working oil discharged from the 1 st pump port 31a and the working oil discharged from the 2 nd pump port 31b are merged and separated by the two valves, i.e., the 1 st switching valve 51 and the 2 nd switching valve 52. Then, the 1 st switching valve 51 is switched to the priority position 51B on the condition that the 1 st travel control valve 11 is operated, and the 2 nd switching valve 52 is switched to the priority position 52B on the condition that the 2 nd travel control valve 21 is operated. Therefore, for example, when the hydraulic excavator is to turn to the right side without driving the front working device such as a boom, an arm, or a bucket, only the left travel device is driven and the right travel device is not driven, and therefore the 1 st switching valve 51 becomes the priority position 51B and the 2 nd switching valve 52 becomes the open position 52A. In this state, the hydraulic oil discharged from the 1 st pump port 31a is independently supplied to the left travel motor 1 via the 1 st travel control valve 11 to stabilize the driving of the left travel motor 1, while the hydraulic oil discharged from the 2 nd pump port 31b is supplied to the 2 nd travel control valve 21 and is supplied to the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 via the 2 nd switching valve 52 and the merging passage 45. In this way, since the hydraulic oil discharged from the 2 nd pump port 31b is in a state in which it can be supplied to each hydraulic actuator such as the boom cylinder 2, the bucket cylinder 3, and the arm cylinder 6, it is possible to drive the front working device such as the boom, the arm, and the bucket with good responsiveness when driving it.

When the 1 st switching valve 51 is switched to the priority position 51B and the 2 nd switching valve 52 is switched to the priority position 52B when one of the left and right traveling devices is driven without driving the front working device such as a boom, an arm, and a bucket, the hydraulic oil discharged from the 1 st pump port 31a and the 2 nd pump port 31B is not allowed to be supplied to the hydraulic actuators such as the boom cylinder 2, the bucket cylinder 3, and the arm cylinder 6. Therefore, when the front work implement such as a boom, an arm, or a bucket is driven from this state, the driving of the front work implement is delayed by the time required for switching the 1 st switching valve 51 from the priority position 51B to the open position 51A and switching the 2 nd switching valve 52 from the priority position 52B to the open position 52A.

According to embodiment 1 above, the following operational effects are exhibited.

The working oil discharged from the 1 st pump port 31a and the working oil discharged from the 2 nd pump port 31B are merged and separated by the 1 st switching valve 51 and the 2 nd switching valve 52, and the 1 st switching valve 51 is switched to the priority position 51B on the basis of the operation of the 1 st traveling control valve 11, and the 2 nd switching valve 52 is switched to the priority position 52B on the basis of the operation of the 2 nd traveling control valve 21. Therefore, in a state where only one of the 1 st travel control valve 11 and the 2 nd travel control valve 21 is operated, the switching valve corresponding to the operated travel control valve is set to the priority position, and the switching valve corresponding to the travel control valve that is not operated is set to the open position. Therefore, the hydraulic oil from the pump port supplied to the travel control valve that is not operated is supplied to the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 via the switching valve and the merging passage 45. Therefore, when the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are operated, the front work device such as a boom, an arm, and a bucket can be driven with good responsiveness.

Next, a modification of embodiment 1 will be described.

(1) In the above-described embodiment 1, the configuration in which the 1 st switching valve 51 blocks the flow of the hydraulic oil in the 1 st main passage 41 at the priority position 51B and the 2 nd switching valve 52 blocks the flow of the hydraulic oil in the 2 nd main passage 42 at the priority position 52B is described. Instead, as shown in fig. 2, the 1 st switching valve 51 may not completely block the flow of the hydraulic oil in the 1 st main passage 41 at the priority position 51B, and the 2 nd switching valve 52 may not completely block the flow of the hydraulic oil in the 2 nd main passage 42 at the priority position 52B, and may be configured to apply resistance to the flow of the hydraulic oil. Specifically, the 1 st switching valve 51 has a throttle portion 70a for restricting the flow of the hydraulic oil at the priority position 51B, and the 2 nd switching valve 52 has a throttle portion 70B for restricting the flow of the hydraulic oil at the priority position 52B. In this modification, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is preferentially supplied to the 1 st travel control valve 11 at the priority position 51B. Similarly, at the priority position 52B, the hydraulic oil supplied from the 2 nd pump port 31B to the 2 nd main passage 42 is preferentially supplied to the 2 nd travel control valve 21.

When the 1 st switching valve 51 is in the priority position 51B and the 2 nd switching valve 52 is in the priority position 52B, basically, the working oil discharged from the 1 st pump port 31a is supplied to the 1 st traveling control valve 11, and the working oil discharged from the 2 nd pump port 31B is supplied to the 2 nd traveling control valve 21. However, when a pressure difference between the pressure of the hydraulic oil discharged from the 1 st pump port 31a and the pressure of the hydraulic oil discharged from the 2 nd pump port 31b occurs due to a difference between the load of the left travel motor 1 and the load of the right travel motor 5, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b flow into and out of each other through the throttle portions 70a and 70b and the merging passage 45. Therefore, the pressure difference between the pressure of the hydraulic oil discharged from the 1 st pump port 31a and the pressure of the hydraulic oil discharged from the 2 nd pump port 31b is absorbed, and therefore the straightness of the traveling apparatus can be improved.

(2) As shown in fig. 3, the 1 st switching valve 51 includes a check valve 71a at the priority position 51B for blocking the flow of the hydraulic oil from the 1 st traveling control valve 11 side to the 1 st working control valves 12 to 14 side and allowing the flow in the opposite direction. Similarly, the 2 nd switching valve 52 has a check valve 71B at the priority position 52B for blocking the flow of the working oil from the 2 nd traveling control valve 21 side to the 2 nd work control valves 22 to 24 side and allowing the flow in the opposite direction.

In this modification, since the flow of the hydraulic oil to the 1 st working control valve 12 to 14 side is blocked by the check valve 71a at the priority position 51B, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is preferentially supplied to the 1 st working control valve 12 to 14, but not supplied to the 1 st traveling control valve 11. Similarly, since the flow of the hydraulic oil to the 2 nd work control valves 22 to 24 side is blocked by the check valve 71B at the priority position 52B, the hydraulic oil supplied from the 2 nd pump port 31B to the 2 nd main passage 42 is not supplied to the 2 nd work control valves 22 to 24, but is preferentially supplied to the 2 nd travel control valve 21. Therefore, in the present modification, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b are supplied to the left travel motor 1 and the right travel motor 5, respectively, independently of each other, in a state where only the left and right travel devices are driven.

Further, for example, when the hydraulic excavator is steered to the right side without driving the front working device such as a boom, an arm, or a bucket, since only the left traveling device is driven and the right traveling device is not driven, the 1 st switching valve 51 becomes the priority position 51B, and the 2 nd switching valve 52 becomes the open position 52A. In this state, the hydraulic oil discharged from the 1 st pump port 31a is supplied to the left travel motor 1 via the 1 st travel control valve 11. The hydraulic oil discharged from the 2 nd pump port 31b is also supplied from the 2 nd switching valve 52, the merging passage 45, and the check valve 71a of the 1 st switching valve 51 to the left travel motor 1 via the 1 st travel control valve 11. Therefore, when the hydraulic excavator turns, the working oil can be supplied to the left travel motor 1 from both the 1 st pump port 31a and the 2 nd pump port 31b, and therefore the left travel device can be stably driven.

(3) The throttle portions 70a and 70b shown in fig. 2 and the check valves 71a and 71b shown in fig. 3 may be provided in series. That is, the following structure is also possible: the 1 st switching valve 51 has a throttle portion 70a and a check valve 71a provided in series with the throttle portion 70a at the priority position 51B, and the 2 nd switching valve 52 has a throttle portion 70B and a check valve 71B provided in series with the throttle portion 70B at the priority position 52B.

(4) In the above-described embodiment 1, a mode in which the main pump 31 is a split hydraulic pump having two pump ports 31a and 31b is described. However, instead of this, a structure is also possible: two main pumps are provided, and hydraulic oil is supplied from pump ports of the two main pumps to the 1 st main passage 41 and the 2 nd main passage 42, respectively.

< embodiment 2 >

Next, a fluid pressure control device 200 according to embodiment 2 of the present invention will be described with reference to fig. 4. Hereinafter, points different from the fluid pressure control device 100 according to embodiment 1 will be described, and in the drawings, the same components as those of the fluid pressure control device 100 are denoted by the same reference numerals, and description thereof will be omitted.

In the fluid pressure control device 100 according to embodiment 1 described above, only the 1 st traveling control valve 11 among the control valves 11 to 14 connected in parallel to the 1 st main passage 41 is provided upstream of the 1 st switching valve 51. In contrast, in the fluid pressure control device 200, the 1 st traveling control valve 11 and the boom control valve 12 among the control valves 11 to 14 connected in parallel to the 1 st main passage 41 are provided upstream of the 1 st switching valve 51. That is, the boom control valve 12 is connected to the 1 st main passage 41 upstream of the 1 st switching valve 51 in parallel with the 1 st travel control valve 11. The following description is made in detail.

A branch detection passage 61 branching from the upstream side of the blade control valve 14 located at the most upstream side is connected to the 1 st detection passage 60. The branch detection passage 61 is connected to the working fluid tank passage 63 via the 1 st travel control valve 11 and the 2 nd travel control valve 21 in this order. In a state where at least one of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 is operated and at least one of the 1 st travel control valve 11 and the 2 nd travel control valve 21 is operated, the pilot pressure is guided to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52 via the 1 st detection pressure derivation passage 62.

The pilot chamber 51b of the 1 st switching valve 51 is connected to the pilot chambers 11a and 11b of the 1 st travel control valve 11 via a high-pressure selector valve 64, and is connected to the pilot chambers 12a and 12b of the boom control valve 12 via a high-pressure selector valve 75. Therefore, the high pilot pressures in the pilot chamber 11a and the pilot chamber 11b of the 1 st traveling control valve 11 and the high pilot pressures in the pilot chambers 12a and 12b of the boom control valve 12 are led to the pilot chamber 51b of the 1 st switching valve 51. In this way, when the 1 st travel control valve 11 is operated, the pilot pressure for operating the 1 st travel control valve 11 is introduced into the pilot chamber 51b of the 1 st switching valve 51, and when the boom control valve 12 is operated, the pilot pressure for operating the boom control valve 12 is introduced into the pilot chamber 51b of the 1 st switching valve 51.

Next, the operation of the fluid pressure control device 200 will be described.

In a state where at least one of the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 is operated to be in the operation position and at least one of the 1 st travel control valve 11 and the 2 nd travel control valve 21 is operated to be in the operation position, the pilot pressure for operating the 1 st travel control valve 11 is guided to the pilot chamber 51a of the 1 st switching valve 51 and the pilot chamber 52a of the 2 nd switching valve 52 via the 1 st detection pressure derivation passage 62, the pilot pressure for operating the 1 st travel control valve 11 is guided to the pilot chamber 51b of the 1 st switching valve 51, and the pilot pressure for operating the 2 nd travel control valve 21 is guided to the pilot chamber 52b of the 2 nd switching valve 52. Here, the pilot pressure led through the 1 st detection pressure lead-out passage 62 is larger than the pilot pressure for operating the 1 st travel control valve 11 and the pilot pressure for operating the 2 nd travel control valve 21. Therefore, the 1 st switching valve 51 is at the open position 51A, and the 2 nd switching valve 52 is at the open position 52A. In this state, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 and the hydraulic oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 are merged via the merging passage 45. Therefore, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b are merged and can be supplied to the hydraulic actuators 1 to 8.

In a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and are in the neutral position and the 1 st travel control valve 11 is operated and is in the operation position, the pilot pressure for operating the 1 st travel control valve 11 is not led to the pilot chamber 51a but led to the pilot chamber 51B, so the 1 st switching valve 51 becomes the priority position 51B against the biasing force of the spring 53. Similarly, in a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and are in the neutral position and the 2 nd travel control valve 21 is operated and is in the operation position, the pilot pressure for operating the 2 nd travel control valve 21 is not led to the pilot chamber 52a but led to the pilot chamber 52B, so the 2 nd switching valve 52 is set to the priority position 52B against the biasing force of the spring 54. In this way, in a state where only the left and right traveling devices are driven, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b are supplied to the left traveling motor 1 and the right traveling motor 5 independently of each other.

In a state where the 1 st traveling control valve 11 and the 2 nd traveling control valve 21 are not operated and are in the neutral position and the boom control valve 12 is operated and is in the operation position, the pilot pressure for operating the boom control valve 12 is not led to the pilot chamber 51a but led to the pilot chamber 51B, so that the 1 st switching valve 51 becomes the priority position 51B against the biasing force of the spring 53. On the other hand, since the pilot pressure is not led to the pilot chambers 52A and 52b, the 2 nd switching valve 52 is at the open position 52A. In this state, the hydraulic oil supplied from the 1 st pump port 31a to the 1 st main passage 41 is supplied only to the boom cylinder 2, and the hydraulic oil supplied from the 2 nd pump port 31b to the 2 nd main passage 42 is supplied to the hydraulic actuators such as the bucket cylinder 3 and the arm cylinder 6 via the 2 nd switching valve 52 and the merging passage 45. Therefore, when the front working devices such as the boom, the arm, and the bucket are simultaneously driven without driving the left and right traveling devices, the hydraulic oil discharged from the 1 st pump port 31a is preferentially guided to the boom cylinder 2. Therefore, the boom that requires the most driving force in the front working device can be stably driven. In this way, the 1 st switching valve 51 also has a function as a boom priority valve that preferentially guides the hydraulic oil to the boom cylinder 2.

In a state where the 1 st travel control valve 11 and the boom control valve 12 are operated to be at the operation positions, the pilot pressure is guided to the pilot chamber 51a of the 1 st switching valve 51 via the 1 st detection pressure derivation passage 62, and the pilot pressure for operating the 1 st travel control valve 11 and the pilot pressure for operating the boom control valve 12 are guided to the pilot chamber 51b of the 1 st switching valve 51. Here, the pilot pressure led through the 1 st detection pressure derivation passage 62 is larger than the pilot pressure for operating the 1 st travel control valve 11 and the pilot pressure for operating the boom control valve 12. Therefore, the 1 st switching valve 51 is at the open position 51A. On the other hand, in a state where the 1 st travel control valve 11 and the boom control valve 12 are operated to be in the operation positions, the 2 nd switching valve 52 is also brought into the open position 52A by the pilot pressure guided to the pilot chamber 52A via the 1 st detection pressure lead-out passage 62. In this way, in a state where the 1 st traveling control valve 11 and the boom control valve 12 are operated, the hydraulic oil discharged from the 1 st pump port 31a and the hydraulic oil discharged from the 2 nd pump port 31b merge. Therefore, even when the boom that requires the most driving force in the front working device is driven while the left and right traveling devices are driven, the traveling devices can be stably driven.

According to embodiment 2 above, the following operational effects are exhibited.

In the fluid pressure control apparatus 200, the boom control valve 12 is provided upstream of the 1 st switching valve 51, and in a state where the 1 st traveling control valve 11 and the 2 nd traveling control valve 21 are not operated and are set to the neutral positions and the boom control valve 12 is operated and set to the operation positions, the 1 st switching valve 51 is set to the priority position 51B, and the hydraulic oil discharged from the 1 st pump port 31a is preferentially guided to the boom cylinder 2. Therefore, when the front working devices such as the boom, the arm, and the bucket are simultaneously driven without driving the left and right traveling devices, the boom cylinder 2 can be stably operated.

Next, a modification of embodiment 2 will be described.

(1) In the above-described embodiment 2, the description has been given of a configuration in which the boom control valve 12 is provided upstream of the 1 st switching valve 51, and the hydraulic oil discharged from the 1 st pump port 31a is preferentially supplied to the boom control valve 12. That is, the description has been given of the case where the boom control valve 12 is a priority control valve. However, the priority control valve is not limited to the boom control valve 12, and at least one of the 1 st work control valves 12 to 14 may be selected, and the control valve to which the hydraulic oil is supplied preferentially may be selected.

(2) Similarly to fig. 2, the 1 st switching valve 51 and the 2 nd switching valve 52 may be configured to apply resistance to the flow of the hydraulic oil without completely blocking the flow of the hydraulic oil in the 1 st main passage 41 and the flow of the hydraulic oil in the 2 nd main passage 42 at the priority positions 51B and 52B.

(3) The 1 st switching valve 51 may have a check valve at the priority position 51B to block the flow of the hydraulic oil from the 1 st traveling control valve 11 side to the 1 st working control valves 12 to 14 side and to allow the flow in the opposite direction, as in fig. 3. Similarly, the 2 nd switching valve 52 may be configured to have a check valve at the priority position 52B to block the flow of the hydraulic oil from the 2 nd traveling control valve 21 side to the 2 nd work control valves 22 to 24 side and to allow the flow in the opposite direction.

(4) In the above-described embodiment 2, a description has been given of a configuration in which the 1 st switching valve 51 has two switching positions, that is, the open position 51A and the priority position 51B. Alternatively, as shown in fig. 5, the 1 st switching valve 51 may have a configuration having a 2 nd priority position 51C in addition to the open position 51A and the priority position 51B. Hereinafter, the priority position 51B is referred to as the 1 st priority position 51B.

The 1 st priority position 51B blocks the flow of the working oil in the 1 st main passage 41. The 2 nd priority position 51C applies resistance to the flow of the hydraulic oil in the 1 st main passage 41. That is, the 1 st switching valve 51 has a throttle portion 80 for restricting the flow of the working oil at the 2 nd priority position 51C.

In the present modification, in a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and are in the neutral position and the 1 st travel control valve 11 is operated and is in the operation position, the pilot pressure for operating the 1 st travel control valve 11 is not led to the pilot chamber 51a but led to the pilot chamber 51B, so the 1 st switching valve 51 becomes the 1 st priority position 51B against the biasing force of the spring 53.

In a state where the 1 st traveling control valve 11 and the 2 nd traveling control valve 21 are not operated and are in the neutral position and the boom control valve 12 is operated and is in the operation position, the pilot pressure for operating the boom control valve 12 is not led to the pilot chamber 51a but led to the pilot chamber 51b, so that the 1 st switching valve 51 becomes the 2 nd priority position 51C against the biasing force of the spring 53. Since the pilot pressure for operating the boom control valve 12 is smaller than the pilot pressure for operating the 1 st travel control valve 11, the 1 st switching valve 51 is at the 2 nd priority position 51C, which is the intermediate position. In this state, the 1 st switching valve 51 directs the hydraulic oil discharged from the 1 st pump port 31a to the boom control valve 12 located upstream of the throttle portion 80 in preference to the other control valves.

Hereinafter, the structure, operation and effects of the embodiments of the present invention will be described in summary.

The fluid pressure control device 100 includes: a 1 st main passage 41 for supplying the working fluid from the 1 st pump port 31a to the 1 st main passage 41; a 2 nd main passage 42 for supplying the working fluid from the 2 nd pump port 31b to the 2 nd main passage 42; a plurality of 1 st work control valves 12 to 14 for the working device, which are connected in parallel to the 1 st main passage 41; a plurality of 2 nd work control valves 22 to 24 for the work equipment, which are connected in parallel to the 2 nd main passage 42; a 1 st traveling control valve 11 for the traveling device, which is connected to the 1 st main passage 41 in parallel with the 1 st working control valves 12 to 14 and is connected upstream of the 1 st working control valves 12 to 14; a 2 nd travel control valve 21 for the travel device, which is connected to the 2 nd main passage 42 in parallel with the 2 nd work control valves 22 to 24 and is connected upstream of the 2 nd work control valves 22 to 24; a 1 st switching valve 51 provided downstream of the connection portion 43 of the 1 st traveling control valve 11 in the 1 st main passage 41, and having an open position 51A at which the 1 st main passage 41 is opened and a 1 st priority position 51B at which the working fluid from the 1 st pump port 31A is preferentially led to the 1 st traveling control valve 11; a 2 nd switching valve 52 provided downstream of the connection portion 44 of the 2 nd traveling control valve 21 in the 2 nd main passage 42, and having an open position 52A at which the 2 nd main passage 42 is opened and a 1 st priority position 52B at which the working fluid from the 2 nd pump port 31B is preferentially led to the 2 nd traveling control valve 21; and a merging passage 45 that connects the downstream of the 1 st switching valve 51 in the 1 st main passage 41 and the downstream of the 2 nd switching valve 52 in the 2 nd main passage 42, wherein the 1 st switching valve 51 is set to the 1 st priority position 51B in a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and the 1 st travel control valve 11 is operated, and the 2 nd switching valve 52 is set to the 1 st priority position 52B in a state where the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are not operated and the 2 nd travel control valve 21 is operated.

In this configuration, the working fluid discharged from the 1 st pump port 31a and the working fluid discharged from the 2 nd pump port 31B are merged and separated by the 1 st switching valve 51 and the 2 nd switching valve 52, the 1 st switching valve 51 is switched to the 1 st priority position 51B on the condition that the 1 st traveling control valve 11 is operated, and the 2 nd switching valve 52 is switched to the 1 st priority position 52B on the condition that the 2 nd traveling control valve 21 is operated. Therefore, in a state where only one of the 1 st travel control valve 11 and the 2 nd travel control valve 21 is operated, the switching valve corresponding to the operated travel control valve is set to the 1 st priority position, and the switching valve corresponding to the travel control valve that is not operated is set to the open position. Therefore, the working fluid from the pump port supplied to the travel control valve that is not operated is supplied to the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 via the switching valve and the merging passage 45. Therefore, when the 1 st work control valves 12 to 14 and the 2 nd work control valves 22 to 24 are operated, the work devices can be driven with good responsiveness. Therefore, a fluid pressure control device having excellent workability can be provided.

In addition, the 1 st switching valve 51 and the 2 nd switching valve 52 are in the open position 51A in a state where at least one of the plurality of 1 st work control valves 12 to 14 and the plurality of 2 nd work control valves 22 to 24 is operated.

In this configuration, the working fluid discharged from the 1 st pump port 31a and the working fluid discharged from the 2 nd pump port 31b can be supplied to the control valves 11 to 14, 21 to 24 by being merged.

At least one of the 1 st work control valves 12 to 14 is a priority control valve provided upstream of the 1 st switching valve 51 in parallel with the 1 st travel control valve 11, and the 1 st switching valve 51 is set to the 1 st priority position 51B in a state where the 1 st travel control valve 11 and the 2 nd travel control valve 21 are not operated and the priority control valve is operated.

At least one of the plurality of 1 st working control valves 12 to 14 is a priority control valve provided upstream of the 1 st switching valve 51 in parallel with the 1 st traveling control valve 11, the 1 st switching valve 51 further has a 2 nd priority position 51C for guiding the working fluid from the 1 st pump port 31a to the priority control valve in preference to the other 1 st working control valve, and the 1 st switching valve 51 is set to the 2 nd priority position 51C in a state where the 1 st traveling control valve 11 and the 2 nd traveling control valve 21 are not operated and the priority control valve is operated.

In this configuration, the 1 st switching valve 51 also has a function of preferentially guiding the working fluid to the priority control valve.

In a state where the 1 st travel control valve 11 and the priority control valve are operated, the 1 st switching valve 51 is in the open position 51A.

In this configuration, even when the working device is driven while the traveling device is driven, the traveling device can be stably driven.

Further, the 1 st switching valve 51 has a throttling portion 70a for applying resistance to the flow of the working fluid at the 1 st priority position 51B, and the 2 nd switching valve 52 has a throttling portion 70B for applying resistance to the flow of the working fluid at the 1 st priority position 52B.

In this configuration, when the working fluid discharged from the 1 st pump port 31a and the working fluid discharged from the 2 nd pump port 31b are supplied to the 1 st travel control valve 11 and the 2 nd travel control valve 21 independently of each other, the working fluid discharged from the 1 st pump port 31a and the working fluid discharged from the 2 nd pump port 31b flow toward each other via the throttle portions 70a and 70b and the merging passage 45. Therefore, the pressure difference between the pressure of the working fluid discharged from the 1 st pump port 31a and the pressure of the working fluid discharged from the 2 nd pump port 31b is absorbed, and therefore the straightness of the traveling apparatus can be improved.

The 1 st switching valve 51 has a check valve 71a at the 1 st priority position 51B for blocking the flow of the working fluid from the 1 st travel control valve 11 side to the 1 st work control valves 12 to 14 side and allowing the flow in the reverse direction, and the 2 nd switching valve 52 has a check valve 71B at the 1 st priority position 52B for blocking the flow of the working fluid from the 2 nd travel control valve 21 side to the 2 nd work control valves 22 to 24 side and allowing the flow in the reverse direction.

In this invention, in a state where the 1 st switching valve 51 is at the 1 st priority position 51B and the 2 nd switching valve 52 is at the open position 52A, the working fluid discharged from the 1 st pump port 31a is supplied to the 1 st travel control valve 11, and the working fluid discharged from the 2 nd pump port 31B is also supplied to the 1 st travel control valve 11 via the 2 nd switching valve 52, the merging passage 45, and the check valve 71a of the 1 st switching valve 51. Therefore, the driving of the traveling device by the 1 st traveling control valve 11 can be stabilized.

Further, in the present invention, the 1 st switching valve 51 blocks the flow of the working fluid at the 1 st priority position 51B and has a throttle portion that applies resistance to the flow of the working fluid at the 2 nd priority position 51C.

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

The present application claims priority based on Japanese patent application 2018-87396 filed on the Japanese patent office on 2018, 4, 27, and the entire contents of the application are incorporated in the present specification by reference.