Fluid pressure control device

Abstract

A fluid pressure control device (100) is provided with: a main valve block (1); a sub-valve block (50) attached to a main valve block (1), the main valve block (1) having: an actuator passage (21) through which a working fluid supplied to and discharged from the actuator flows; a main spool valve (2) that switches the supply / discharge direction of the working fluid supplied to the actuator via an actuator passage (21) and discharged from the actuator; and a first pressure detection passage (41) that communicates with the actuator passage (21), and the sub-valve block (50) has: a second pressure detection passage (51) that communicates with the first pressure detection passage (41); and a pressure detection port (52) that communicates with the second pressure detection passage (51) and to which a pressure detector (60) is attached.

Description

Technical Field

[0001] The invention relates to a fluid pressure control device. Background Art

[0002] Japanese Patent Publication No. JP2003-202003A discloses a switching valve device for supplying and discharging pressure oil to a boom cylinder. In the switching valve device, a supply and discharge passage is formed on a block-shaped body, and pressure oil from a pump is supplied and discharged to the cylinder via the supply and discharge passage. A slide valve is provided on the body, and the slide valve moves axially by pilot pressure, thereby switching the supply and discharge direction of the pressure oil relative to the cylinder. In addition, a relief valve is provided on the supply and discharge passage. Summary of the invention

[0003] In the switching valve device described in Japanese Patent Laid-Open JP2003-202003A, in order to control the operation of the cylinder, a step of detecting the pressure of the working fluid supplied and discharged to the cylinder is generally implemented. In order to detect the pressure of the working fluid, it is conceivable to guide the working fluid from the supply and discharge passage to the port for pressure detection, and install a sensor or the like on the port. However, in the switching valve device described in Japanese Patent Laid-Open JP2003-202003A, an overflow valve is provided near the supply and discharge passage, so there is no space sufficient to form a port for pressure detection on the main body. Therefore, when it is desired to ensure space for forming a port for pressure detection on the main body, the main body becomes larger, and as a result, the switching valve device is enlarged as a whole.

[0004] An object of the present invention is to detect the pressure of a working fluid supplied and discharged to an actuator in a fluid pressure control device while suppressing an increase in the size of a main valve block.

[0005] According to one embodiment of the present invention, a fluid pressure control device controls an actuator driven by a working fluid ejected from a pump, wherein the device comprises: a main valve block; a sub-valve block installed on the main valve block, the main valve block having: an actuator passage for the flow of working fluid supplied to and discharged from the actuator; a valve body for switching the supply and discharge direction of the working fluid supplied to and discharged from the actuator via the actuator passage; a first pressure detection passage connected to the actuator passage, the sub-valve block having: a second pressure detection passage connected to the first pressure detection passage; a pressure detection port connected to the second pressure detection passage and for installing a pressure detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a cross-sectional view showing a fluid pressure control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0007] A fluid pressure control device 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0008] The fluid pressure control device 100 is a device that controls an actuator (not shown) driven by a working fluid ejected from a pump (not shown), and is mounted on, for example, a construction machine, agricultural machine, industrial machine, or other working machine. Hereinafter, a case will be described in which the fluid pressure control device 100 is mounted on a hydraulic excavator and used to control the operation of an actuator such as a hydraulic cylinder for driving a hydraulic motor for traveling, a boom, an arm, a bucket, or the like. In addition, although an example of using working oil as a working fluid for driving an actuator of a hydraulic excavator is described, other fluids such as working water may be used as the working fluid.

[0009] The fluid pressure control device 100 includes a main valve block 1 and a sub-valve block 50 attached to the main valve block 1 .

[0010] The main valve block 1 comprises: a main slide valve 2 as a valve body, which switches the supply and discharge direction of the working oil; an auxiliary slide valve 3, which moves in a direction orthogonal to the axial direction of the main slide valve 2; a main receiving hole 6, which receives the main slide valve 2 so as to slide freely; and an auxiliary receiving hole 7, which receives the auxiliary slide valve 3 so as to slide freely.

[0011] The main receiving hole 6 is formed to penetrate the main valve block 1. Pilot pressure chambers 10 are respectively provided at the two openings of the main receiving hole 6 in the main valve block 1. In the fluid pressure control device 100, the pilot pressure is guided to the pilot pressure chamber 10 by the operation of a rod not shown in the figure, and the main slide valve 2 moves in the axial direction by the pilot pressure, thereby switching the supply and discharge direction of the working oil relative to the actuator. A spring not shown in the figure is provided on the pilot pressure chamber 10, and the main slide valve 2 is urged toward the neutral position by the spring. The auxiliary receiving hole 7 is connected to the main receiving hole 6 and is formed to extend in a direction orthogonal to the main receiving hole 6. The auxiliary slide valve 3 switches the connection between the supply port 20 and the outlet passage 22 described later.

[0012] The main valve block 1 has a supply port 20 to which the working oil ejected from the pump is supplied, an actuator passage 21 for the flow of the working oil supplied to the actuator and discharged from the actuator, a derivation passage 22 for guiding the working oil supplied from the supply port 20 to the actuator passage 21, and a discharge passage 23 connected to a fluid tank (not shown). In the present embodiment, the supply port 20, the actuator passage 21, and the derivation passage 22 are formed in a pair with the auxiliary accommodation hole 7 sandwiched therebetween, and are connected to the main accommodation hole 6, respectively. In addition, the derivation passage 22 is also connected to the auxiliary accommodation hole 7.

[0013] The passage formed in the main valve block 1 is arranged approximately bilaterally symmetrically with respect to the auxiliary receiving hole 7. Figure 1 The components on the right side of the auxiliary receiving hole 7 are called the first supply port 20a, the first actuator passage 21a, and the first outlet passage 22a, and Figure 1 The components on the left side of the auxiliary housing hole 7 are referred to as a second supply port 20 b , a second actuator passage 21 b , and a second outlet passage 22 b .

[0014] The supply port 20 is connected to a pump, and the working oil is supplied from the pump to the supply port 20. The actuator passage 21 is connected to a pipe (not shown) of the actuator, and the working oil is supplied and discharged to the actuator via the actuator passage 21. The discharge passage 23 can communicate with the actuator passage 21, and guides the working oil discharged from the actuator to the fluid tank via the actuator passage 21. The discharge passage 23 is provided on the opposite side of the actuator passage 21 across the main slide valve 2.

[0015] The main spool valve 2 is a valve body formed in a manner to control the communication between the supply port 20 and the auxiliary housing hole 7, the communication between the outlet passage 22 and the actuator passage 21, and the communication between the actuator passage 21 and the discharge passage 23. Specifically, Figure 1 As shown, in a state where the pilot pressure is not introduced to any of the pilot pressure chambers 10, the communication between the supply port 20 and the auxiliary receiving hole 7, the communication between the outlet passage 22 and the actuator passage 21, and the communication between the actuator passage 21 and the discharge passage 23 are completely cut off by the main spool valve 2. Figure 1 In the state shown, the communication between the supply port 20 and the outlet passage 22 is also blocked by the secondary spool valve 3 .

[0016] In contrast, when the pilot pressure is directed to Figure 1 The pilot pressure chamber 10 on the left side of the main slide valve 2 Figure 1 When sliding to the right from the state shown, the first supply port 20a is connected to the auxiliary receiving hole 7, and the second outlet passage 22b is connected to the second actuator passage 21b. In addition, the auxiliary slide valve 3 is opened by the pressure of the working oil guided from the first supply port 20a to the auxiliary receiving hole 7, and the working oil is guided from the first supply port 20a to the second outlet passage 22b. As a result, the working oil from the first supply port 20a is supplied to the actuator via the auxiliary receiving hole 7, the second outlet passage 22b, and the second actuator passage 21b. On the other hand, the first actuator passage 21a is connected to the discharge passage 23, whereby the working oil is discharged to the fluid box via the first actuator passage 21a and the discharge passage 23.

[0017] In addition, when the pilot pressure is directed to Figure 1The pilot pressure chamber 10 on the right side of the main slide valve 2 Figure 1 When sliding to the left from the state shown, the second supply port 20b is connected to the auxiliary receiving hole 7, and the first outlet passage 22a is connected to the first actuator passage 21b. In addition, the auxiliary slide valve 3 is opened by the pressure of the working oil guided from the second supply port 20b to the auxiliary receiving hole 7, and the working oil is guided from the second supply port 20b to the first outlet passage 22a. As a result, the working oil from the second supply port 20b is supplied to the actuator via the auxiliary receiving hole 7, the first outlet passage 22a, and the first actuator passage 21a. On the other hand, the second actuator passage 21b is connected to the discharge passage 23, whereby the working oil is discharged to the fluid box via the second actuator passage 21b and the discharge passage 23. In this way, the main slide valve 2 switches the supply and discharge direction of the working oil supplied and discharged to the actuator via the actuator passage 21.

[0018] In addition, the main valve block 1 includes a relief passage 31 that connects the discharge passage 23 and the actuator passage 21 , a relief valve 30 provided in the relief passage 31 , and a first pressure detection passage 41 that connects to the actuator passage 21 .

[0019] When the pressure in the actuator passage 21 exceeds the preset relief pressure of the relief valve 30, the relief valve 30 opens, and the high-pressure hydraulic oil is discharged from the actuator passage 21 to the discharge passage 23 via the relief passage 31. This prevents the actuator passage 21 and the actuator from becoming high pressure and causing damage to the fluid pressure control device 100 and the actuator.

[0020] The first pressure detection passage 41 is a through hole formed to extend linearly in a manner that one end opens on the outer surface of the main valve block 1 and the other end opens in the actuator passage 21, and communicates the actuator passage 21 with the outside of the main valve block 1. Specifically, the first pressure detection passage 41 is formed between the outer surface 1a of the main valve block 1 where the actuator passage 21 opens, the relief passage 31, and the relief valve 30. The function of the first pressure detection passage 41 will be described later together with the description of the sub-valve block 50.

[0021] Next, the structure of the sub-valve block 50 will be described in detail.

[0022] The auxiliary valve block 50 is mounted to the opening of the first pressure detection passage 41 in the main valve block 1 by fixing members such as bolts (not shown). In the present embodiment, the auxiliary valve block 50 is mounted to each of the openings of the two first pressure detection passages 41 that communicate with the actuator passages 21a and 21b. The auxiliary valve block 50 has a second pressure detection passage 51 that communicates with the first pressure detection passage 41, and a pressure detection port 52 that communicates with the second pressure detection passage 51 and is provided with a pressure sensor 60 as a pressure detector.

[0023] The second pressure detection passage 51 extends coaxially with the first pressure detection passage 41 and is formed to have substantially the same diameter as the first pressure detection passage 41. The pressure detection port 52 is formed to extend in a direction orthogonal to the second pressure detection passage 51. The pressure detection port 52 is formed to have a larger diameter than the first pressure detection passage 41 and the second pressure detection passage 51.

[0024] The working oil in the actuator passage 21 is guided to the pressure sensor 60 through the first pressure detection passage 41, the second pressure detection passage 51, and the pressure detection port 52. Therefore, the pressure of the working oil supplied to the actuator can be detected by the pressure sensor 60. By this, for example, the pressure of the working oil supplied to the actuator is detected by the pressure sensor 60, and when the detected pressure is lower than a preset value, the operation of the actuator can be controlled by increasing the discharge pressure of the pump. In addition, the pressure detection port 52 is not limited to a structure formed in a manner extending in a direction orthogonal to the second pressure detection passage 51. For example, it can be a structure formed in a manner extending coaxially with the second pressure detection passage 51, or a structure extending in parallel with the second pressure detection passage 51, and the axis of the second pressure detection passage 51 and the axis of the pressure detection port 52 are offset.

[0025] As described above, when the relief valve 30 is provided near the actuator passage 21, it is difficult to ensure sufficient space for forming a relatively large diameter pressure detection port 52 on the main valve block 1. When it is assumed that space is to be ensured for forming the pressure detection port 52 on the main valve block 1, the main valve block 1 becomes larger. As a result, there is a possibility that the entire fluid pressure control device 100 will be enlarged.

[0026] In contrast, in the fluid pressure control device 100 of the present embodiment, as described above, the pressure detection port 52 is formed on the sub-valve block 50 mounted on the main valve block 1, and the pressure sensor 60 is mounted. As a result, the pressure detection port 52 of a relatively large diameter is not formed on the main valve block 1, and only the first pressure detection passage 41 of a smaller diameter than the pressure detection port 52 is formed. Therefore, even if there is no space for forming the pressure detection port 52 on the main valve block 1, the pressure of the working oil supplied and discharged to the actuator can be detected by the pressure sensor 60 without increasing the size of the main valve block 1. In addition, even for an existing valve block, the sub-valve block 50 and the pressure sensor 60 can be mounted by processing the first pressure detection passage 41, thereby detecting the pressure of the working oil supplied and discharged to the actuator.

[0027] In addition, in the fluid pressure control device 100, the auxiliary valve block 50 is provided with an end surface ( Figure 1 The position of the upper end surface in the middle becomes the outer surface 1a ( Figure 1 The auxiliary valve block 50 is mounted relative to the main valve block 1 in a manner such that the auxiliary valve block 50 is further separated from the main spool valve 2 than the position of the auxiliary valve block 50 (the upper end surface in the main valve block 1). In other words, the size of the auxiliary valve block 50 and the mounting position thereof are not limited by the shape of the main valve block 1. In this way, the size of the auxiliary valve block 50 can be set relatively freely, and therefore, the pressure sensor 60 of various sizes can be adopted by changing the size of the pressure detection port 52 formed in the auxiliary valve block 50 to an arbitrary size without changing the structure on the main valve block 1 side. In addition, by appropriately changing the position where the auxiliary valve block 50 is mounted relative to the main valve block 1 and the direction in which the pressure detection port 52 extends, the pressure sensor 60 can be mounted in an arbitrary direction relative to the main valve block 1.

[0028] In addition, in the fluid pressure control device 100, the first pressure detection passage 41 is formed between the outer surface 1a of the main valve block 1, the overflow passage 31, and the relief valve 30. Thus, even if the relief valve 30 is provided on the main valve block 1, the first pressure detection passage 41 can be formed in a manner that does not interfere with the relief valve 30. In addition, the area between the outer surface 1a of the main valve block 1, the overflow passage 31, and the relief valve 30 is an area where the discharge passage 23 and the overflow passage 31 are not formed. Therefore, it is not necessary to avoid the discharge passage 23 and the overflow passage 31 when forming the first pressure detection passage 41, thereby increasing the degree of freedom in forming the oil passage of the first pressure detection passage 41.

[0029] In addition, the first pressure detection passage 41 and the auxiliary valve block 50 may be provided only for one of the actuator passages 21a and 21b. In addition, the main valve block 1 is not limited to the above structure, and may be a structure having at least one actuator passage 21, a main slide valve 2, and a first pressure detection passage 41, wherein the one actuator passage 21 is used for the flow of the working oil supplied to the actuator and discharged from the actuator, the main slide valve 2 switches the supply and discharge direction of the working oil supplied to the actuator and discharged from the actuator via the actuator passage 21, and the first pressure detection passage 41 is communicated with the actuator passage 21.

[0030] According to the above-described embodiment, the following effects are achieved.

[0031] In the fluid pressure control device 100, the pressure detection port 52 is formed on the sub-valve block 50 mounted on the main valve block 1, and the pressure sensor 60 is mounted. Thus, the pressure detection port 52 is not formed on the main valve block 1, and only the first pressure detection passage 41 is formed. Therefore, even if there is no space for forming the pressure detection port 52 on the main valve block 1, the pressure of the working oil supplied and discharged to the actuator can be detected by the pressure sensor 60 without increasing the size of the main valve block 1.

[0032] In the fluid pressure control device 100, even if the relief valve 30 is provided in the main valve block 1, the first pressure detection passage 41 can be formed in a manner that does not interfere with the relief valve 30. In addition, the first pressure detection passage 41 is formed in a region where the relief passage 31 is not formed in the main valve block 1, so the degree of freedom in forming the oil passage can be increased.

[0033] The structure, function, and effect of the embodiment of the present invention configured as above will be summarized and described.

[0034] A fluid pressure control device 100 for controlling an actuator driven by a working fluid ejected from a pump comprises: a main valve block 1; an auxiliary valve block 50, which is installed on the main valve block 1, the main valve block 1 having: an actuator passage 21, which is used for the flow of working fluid supplied to the actuator and discharged from the actuator; a main slide valve 2 as a valve body, which switches the supply and discharge direction of the working fluid supplied to the actuator via the actuator passage 21 and discharged from the actuator; a first pressure detection passage 41, which is connected to the actuator passage 21, the auxiliary valve block 50 having: a second pressure detection passage 51, which is connected to the first pressure detection passage 41; a pressure detection port 52, which is connected to the second pressure detection passage 51 and is provided for the installation of a pressure sensor 60 as a pressure detector.

[0035] In this structure, the pressure detection port 52 is formed on the sub-valve block 50 mounted on the main valve block 1, and the pressure sensor 60 is mounted. Thus, the pressure detection port 52 is not formed on the main valve block 1, and only the first pressure detection passage 41 is formed. Therefore, even if there is no space for forming the pressure detection port 52 on the main valve block 1, the pressure of the working oil supplied and discharged to the actuator can be detected by the pressure sensor 60 without increasing the size of the main valve block 1.

[0036] In addition, the main valve block 1 also has: a discharge passage 23, which is arranged on the side opposite to the actuator passage 21 across the main sliding valve 2 and is connected to the fluid box; an overflow passage 31, which connects the discharge passage 23 and the actuator passage 21; an overflow valve 30, which is arranged in the overflow passage 31, and a first pressure detection passage 41 is formed between the outer surface 1a of the actuator passage 21 in the main valve block 1, the overflow passage 31 and the overflow valve 30.

[0037] In this structure, even if the relief valve 30 is provided on the main valve block 1, the first pressure detection passage 41 can be formed in a manner that does not interfere with the relief valve 30. In addition, the first pressure detection passage 41 is formed in a region where the discharge passage 23 and the relief passage 31 are not formed in the main valve block 1, so the degree of freedom in forming the oil passage can be increased.

[0038] Although the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0039] This application claims the priority based on Japanese Patent Application No. 2022-160028 filed with the Japan Patent Office on October 4, 2022, and all the contents of the application are incorporated into this specification by reference.

Claims

1. A fluid pressure control device for controlling an actuator driven by a working fluid ejected from a pump, wherein: have: Main valve block; A secondary valve block, which is installed on the main valve block, The main valve block has: an actuator passage for flow of a working fluid supplied to and exhausted from the actuator; a valve body that switches supply and discharge directions of a working fluid that is supplied to the actuator through the actuator passage and discharged from the actuator; a first pressure detection passage, which is in communication with the actuator passage, The auxiliary valve block has: a second pressure detection passage, which is in communication with the first pressure detection passage; The pressure detection port is communicated with the second pressure detection passage and is used for installing a pressure detector.

2. The fluid pressure control device according to claim 1, wherein: The main valve block also has: a discharge passage, which is provided on the side opposite to the actuator passage across the valve body and communicates with the fluid tank; an overflow passage connecting the exhaust passage and the actuator passage; a relief valve disposed in the relief passage, The first pressure detection passage is formed between an outer surface of the main valve block, where the actuator passage opens, the relief passage, and the relief valve.

Images