Valve device

Abstract

A valve device according to an embodiment includes a valve body (6) and a housing (2). The housing (2) includes a spool hole into which the spool (6) is inserted, and a sensor port (32), a first actuator port (31a) and a second actuator port (31b) on a surface of the housing (2). In addition, the housing (2) comprises: a first actuator passage (81) from the spool hole to a first actuator port (31a); a second actuator passage (82) from the spool bore to a second actuator port (31b); and a sensor passage (34) communicating the first actuator passage (81) and the sensor port (32).

Description

Technical Field

[0001] The present disclosure relates to a valve device interposed between a hydraulic pump and a hydraulic actuator in a hydraulic circuit. Background Art

[0002] At present, a valve device for controlling the supply and discharge of working fluid to a hydraulic actuator is used in a hydraulic circuit. The valve device includes a valve core and a housing that slidably holds the valve core.

[0003] For example, Japanese Patent Publication No. 11-190044 discloses a valve device in which a plurality of valve cores are held in a housing in a row, and a pair of actuator ports are provided for each valve core on a side surface of the housing that faces a direction orthogonal to the arrangement surface of the valve cores. In addition, in Patent Document 1, the housing is referred to as a "main body block". Summary of the invention

[0004] At present, when detecting the supply pressure of the working fluid to the hydraulic actuator or the discharge pressure from the hydraulic actuator, a pressure gauge is provided on the working fluid piping between the valve device and the hydraulic actuator. In contrast, it is sometimes desirable to install a pressure gauge on the valve device to detect the supply pressure to the hydraulic actuator or the discharge pressure from the hydraulic actuator.

[0005] Therefore, an object of the present disclosure is to provide a valve device capable of mounting a pressure gauge for detecting a supply pressure to a hydraulic actuator or a discharge pressure from the hydraulic actuator.

[0006] The present disclosure provides a valve device, comprising a valve core and a shell that can slidably hold the valve core, the shell comprising: a valve core hole for inserting the valve core; a sensor port, a first actuator port and a second actuator port on the surface of the shell; a first actuator passage from the valve core hole to the first actuator port; a second actuator passage from the valve core hole to the second actuator port; and a sensor passage connecting the first actuator passage and the sensor port.

[0007] According to the present disclosure, there is provided a valve device capable of mounting a pressure gauge for detecting a supply pressure to a hydraulic actuator or a discharge pressure from the hydraulic actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view of a valve device according to one embodiment; Figure 2 is a cross-sectional view of the valve device; Figure 3 a circuit diagram which is a part of the valve device; Figure 4 This is a circuit diagram of a portion of a valve device according to a modified example. DETAILED DESCRIPTION

[0009] Figure 1 FIG. 2 shows a valve device 1 according to an embodiment. In this embodiment, the valve device 1 is used for a plurality of hydraulic actuators 7. For the hydraulic actuator 7, see Figure 3 That is, the valve device 1 is interposed between the hydraulic pump and the plurality of hydraulic actuators 7 in the hydraulic circuit. However, the valve device 1 may also be used for one hydraulic actuator 7.

[0010] like Figure 3 As shown, the hydraulic actuator 7 includes a hydraulic cylinder 7A that drives the driven object in the direction of gravity and the direction against gravity. The hydraulic cylinder 7A includes: a first working chamber 71 that supplies working fluid when the driven object is driven in the direction against gravity; and a second working chamber 72 that supplies working fluid when the driven object is driven in the direction of gravity. In this embodiment, the rod side chamber is the first working chamber 71 and the head side chamber is the second working chamber 72, but it can also be the opposite of this embodiment, where the head side chamber is the first working chamber 71 and the rod side chamber is the second working chamber 72.

[0011] In addition, the gravity direction and the counter-gravity direction do not necessarily have to be the vertical direction, and may be a direction inclined relative to the vertical direction. Or when the driven object swings around a horizontal axis, the gravity direction and the counter-gravity direction may also be a circumferential direction centered on the horizontal axis. For example, when the valve device 1 is mounted on a hydraulic excavator, the hydraulic cylinder 7A is a boom cylinder or a dipper arm cylinder. The boom cylinder pitches the boom as the driven object, and the dipper arm cylinder swings the dipper arm as the driven object.

[0012] like Figure 1 and Figure 2 As shown, the valve device 1 includes the same number of valve cores 6 as the number of hydraulic actuators 7 and a housing 2 that slidably holds the valve cores 6. In this embodiment, the number of valve cores 6 is six. However, the number of valve cores 6 may be more than one and less than five or more than seven.

[0013] In this embodiment, if Figure 2 As shown, the valve core 6A corresponding to the hydraulic cylinder 7A among the valve cores 6 is divided into a first valve core 61 and a second valve core 62. The first valve core 61 and the second valve core 62 are coaxially located, the outer end faces of the first valve core 61 and the second valve core 62 face opposite sides, and the inner end faces of the first valve core 61 and the second valve core 62 face each other. The five valve cores 6 other than the valve core 6A are integrally extended across two transverse passages 16 of the tank passage 15 described later.

[0014] In this embodiment, the valve elements 6 are held in the housing 2 in a state of being arranged in one row. However, the valve elements 6 may be held in the housing 2 in a state of being arranged in two rows.

[0015] The housing 2 is substantially in the shape of a rectangular parallelepiped, and includes a first side surface 21 and a second side surface 22 facing opposite sides along the axial direction of the valve core 6; a third side surface 23 and a fourth side surface 24 facing opposite sides along a direction orthogonal to the axial direction and arrangement direction of the valve core 6; and a first end surface 25 and a second end surface 26 facing opposite sides along the arrangement direction of the valve core 6. The first side surface 21, the second side surface 22, the third side surface 23, the fourth side surface 24, the first end surface 25, and the second end surface 26 constitute the surface of the housing 2.

[0016] The housing 2 includes a plurality of valve core holes 20 into which the valve cores 6 are inserted. Each valve core hole 20 passes through the housing 2 and opens at the first side surface 21 and the second side surface 22.

[0017] In this embodiment, a pump port and a tank port are formed on the fourth side surface 24 of the housing 2. The pump port is connected to the hydraulic pump through a pipe, and the tank port is connected to the tank through a pipe. However, the pump port and the tank port may also be formed on the first end surface 25 or the second end surface 26.

[0018] The housing 2 is provided with: a pump passage 11 from the pump port to all the valve core holes 20; and a tank passage 15 from all the valve core holes 20 to the tank port. The pump passage 11 includes: a transverse passage 12 extending in the arrangement direction of the valve core 6 near the center of the valve core hole 20; an inflow passage connecting the transverse passage 12 and the pump port; and a plurality of distribution passages 13 connecting the transverse passage 12 and the valve core hole 20 respectively. A check valve 14 is provided on the distribution passage 13. The tank passage 15 includes: two transverse passages 16 extending in the arrangement direction of the valve core 6 in the form of passing through the two ends of the valve core hole 20; and an outflow passage connecting the transverse passage 16 and the tank port.

[0019] A pair of actuator ports 31 is formed on the third side surface 23 of the housing 2 for each valve element 6. The pair of actuator ports 31 are connected to the corresponding hydraulic actuator 7 through piping.

[0020] The housing 2 is provided with a pair of actuator passages 8 from the valve core hole 20 to the actuator port 31 for each valve core hole 20. Each valve core 6 blocks the actuator passage 8 from the pump passage 11 and the tank passage 15 in the neutral position. When the valve core 6 moves, one side of the actuator passage 8 communicates with the pump passage 11 and the other side communicates with the tank passage 15.

[0021] like Figure 2 and Figure 3 As shown, the housing 2 is provided with a pair of overflow passages 91 and 92 respectively connecting the actuator passage 8 and the transverse passage 16 of the tank passage 15. Overflow valves 93 and 94 with check valves are provided on the overflow passages 91 and 92, respectively. Figure 2 In order to simplify the illustration, the relief passage 91 and the relief valve 93 are omitted.

[0022] like Figure 1 and Figure 2 As shown, the first side surface 21 of the housing 2 is provided with the same number of container-shaped covers 41 as the valve cores 6. Each cover 41 forms a first pilot chamber 4A facing one end face of the corresponding valve core 6. With respect to the valve core 6A, the outer end face of the first valve core 61 faces the first pilot chamber 4A.

[0023] A spring 44 for maintaining the valve body 6 in a neutral position is arranged in each cover 41. With respect to the valve body 6A, the spring 44 maintains the first valve body 61 in a neutral position. The structure around the spring 44 is well known, and thus detailed description thereof is omitted.

[0024] On the other hand, a block 42 extending along the arrangement direction of the valve core 6 is mounted on the second side surface 22 of the housing 2. On the contact surface of the block 42 with the housing 2, recesses are provided at positions corresponding to the valve core 6 other than the valve core 6A, and these recesses form a second pilot chamber 4B to which the other end surface of the valve core 6 other than the valve core 6A faces.

[0025] The block 42 has a through hole 42a at a position corresponding to the valve body 6A, and the through hole 42a is closed by the cover 43. The cover 43 and the through hole 42a of the block 42 form the second pilot chamber 4B to which the other end face of the valve body 6A, that is, the outer end face of the second valve body 62 faces.

[0026] A spring 45 for maintaining the second valve body 62 at a neutral position is arranged in the through hole 42a. The structure around the spring 45 is well known, and thus detailed description thereof is omitted.

[0027] The third pilot chamber 4C is formed between the inner end surfaces of the first valve body 61 and the second valve body 62 of the valve body 6A.

[0028] The valve device 1 further includes the same number of first electromagnetic proportional valves 51 as the valve core 6, the same number of second electromagnetic proportional valves 52 as the valve core 6, and a third electromagnetic proportional valve 53 for the valve core 6A. Figure 3 As shown, the first electromagnetic proportional valve 51 is connected to the first pilot chamber 4A of the corresponding valve core 6 through the pilot passage 2a, and the second electromagnetic proportional valve 52 is connected to the second pilot chamber 4B of the corresponding valve core 6 through the pilot passage 2b. The third electromagnetic proportional valve 53 is connected to the third pilot chamber 4C of the valve core 6A through the pilot passage 2c.

[0029] In this embodiment, a block 50 extending along the arrangement direction of the valve core 6 is installed at the end of the first side surface 21 side of the fourth side surface 24 of the housing 2. All the first electromagnetic proportional valves 51, the second electromagnetic proportional valve 52 for the valve core 6A, and the third electromagnetic proportional valve 53 are installed on the block 50. The second electromagnetic proportional valve 52 other than the second electromagnetic proportional valve 52 for the valve core 6A is installed on the block 42.

[0030] In addition, the structures of the cover 41 and the blocks 42 and 50, and the installation methods of the first electromagnetic proportional valve 51, the second electromagnetic proportional valve 52 and the third electromagnetic proportional valve 53 can be adaptively changed.

[0031] A primary pressure passage 17 and a drain passage 18 are provided in at least one of the blocks 50 and 42 . The primary pressure passage 17 and the drain passage 18 are connected to the first electromagnetic proportional valve 51 , the second electromagnetic proportional valve 52 , and the third electromagnetic proportional valve 53 .

[0032] Each first electromagnetic proportional valve 51 outputs a secondary pressure to the first pilot chamber 4A of the corresponding valve core 6 or communicates the first pilot chamber 4A with the exhaust passage 18. Each second electromagnetic proportional valve 52 outputs a secondary pressure to the second pilot chamber 4B of the corresponding valve core 6 or communicates the second pilot chamber 4B with the exhaust passage 18. The third electromagnetic proportional valve 53 outputs a secondary pressure to the third pilot chamber 4C of the valve core 6A or communicates the third pilot chamber 4C with the exhaust passage 18.

[0033] That is, the valve bodies 6 other than the valve body 6A are driven by the first and second electromagnetic proportional valves 51 and 52. The first valve body 61 of the valve body 6A is driven by the first and third electromagnetic proportional valves 51 and 53, and the second valve body 62 is driven by the second and third electromagnetic proportional valves 52 and 53.

[0034] Describing the structure related to the valve core 6A in more detail, the first actuator port 31a of the pair of actuator ports 31 is connected to the first working chamber 71 of the hydraulic cylinder 7A through piping, and the second actuator port 31b is connected to the second working chamber 72 of the hydraulic cylinder 7A through piping. That is, one of the pair of actuator passages 8 is the first actuator passage 81 from the valve core hole 20 to the first actuator port 31a, and the other is the second actuator passage 82 from the valve core hole 20 to the second actuator port 31b.

[0035] The first valve element 61 switches whether the first actuator passage 81 communicates with the pump passage 11 or the tank passage 15 , and the second valve element 62 switches whether the second actuator passage 82 communicates with the pump passage 11 or the tank passage 15 .

[0036] In this embodiment, when the first valve core 61 and the second valve core 62 move away from each other, the pump passage 11 communicates with the first actuator passage 81, and the second actuator passage 82 communicates with the tank passage 15. Conversely, when the first valve core 61 and the second valve core 62 move toward each other, the pump passage 11 communicates with the second actuator passage 82, and the first actuator passage 81 communicates with the tank passage 15.

[0037] However, contrary to the present embodiment, when the first valve core 61 and the second valve core 62 move toward each other, the first actuator passage 81 and the second actuator passage 82 are connected to the pump passage 11 and the tank passage 15, respectively, and when the first valve core 61 and the second valve core 62 move away from each other, the second actuator passage 82 and the first actuator passage 81 are connected to the pump passage 11 and the tank passage 15, respectively.

[0038] A lock valve 83 is provided in the first actuator passage 81 through which the working fluid flows toward the valve core hole 20 when the driven object moves in the gravity direction. The lock valve 83 closes the first actuator passage 81 while the hydraulic cylinder 7A is stopped.

[0039] Specifically, the lock valve 83 is a poppet valve having a back pressure chamber, and the back pressure chamber is connected to the on-off valve 85 via the first communication passage 84. The on-off valve 85 is connected to a portion of the first actuator passage 81 between the lock valve 83 and the first actuator port 31a via the second communication passage 86, and is connected to the drain passage 18 via the third communication passage 87.

[0040] The on-off valve 85 is located at a locked position for connecting the first communication passage 84 with the second communication passage 86 when the hydraulic cylinder 7A is stopped, and is switched to an unlocked position for connecting the first communication passage 84 with the third communication passage 87 when the hydraulic cylinder 7A is operated. In the example, the on-off valve 85 is an electromagnetic valve actuated by an electric signal, but the on-off valve 85 may also be actuated by a pilot pressure.

[0041] In this embodiment, only the hydraulic cylinder 7A is the object of detecting the supply pressure or the discharge pressure, and the first sensor port 32 and the second sensor port 33 are formed on the first side surface 21 of the housing 2. However, one or both of the first sensor port 32 and the second sensor port 33 may be formed on the second side surface 22.

[0042] The housing 2 is provided with a first sensor passage 34 communicating with the first actuator passage 81 and the first sensor port 32 and a second sensor passage 35 communicating with the second actuator passage 82 and the second sensor port 33. The first sensor passage 34 is connected to the first actuator passage 81 between the valve core hole 20 and the lock valve 83.

[0043] As described above, in the valve device 1 of the present embodiment, since there is a first sensor port 32 on the first side surface 21 which is a part of the surface of the housing 2, and the first sensor port 32 is connected to the first actuator passage 81 through the first sensor passage 34, if a pressure gauge is installed on the first sensor port 32, the supply pressure when the working oil is supplied to the hydraulic cylinder 7A through the first actuator passage 81 or the discharge pressure when the working fluid is discharged from the hydraulic cylinder 7A through the first actuator passage 81 can be detected by the pressure gauge.

[0044] In addition, in the present embodiment, the first actuator passage 81 is provided with a lock valve 83, so when the lock valve 83 closes the first actuator passage 81, the working fluid is prevented from flowing from the first actuator port 31a to the valve core hole 20. Therefore, even if a problem occurs in the first sensor port 32 or the pressure gauge attached to the first sensor port 32, the first actuator passage 81 can be closed by the lock valve 83, and the working fluid from the first actuator port 31a can be prevented from leaking from the first sensor port 32. In addition, the first actuator passage 81 is connected to the first working chamber 71 pressurized by the dead weight of the driven object in the hydraulic cylinder 7A, so the working fluid can be prevented from leaking from the first sensor port 32 due to the dead weight of the driven object during the stop of the hydraulic cylinder 7A.

[0045] Furthermore, in the present embodiment, there is a second sensor port 33 on the first side surface 21 of the housing 2, and the second sensor port 33 is connected to the second actuator passage 82 through the second sensor passage 35. Therefore, if a pressure gauge is installed on the second sensor port 33, the supply pressure when the working fluid is supplied to the hydraulic cylinder 7A through the second actuator passage 82 or the discharge pressure when the working fluid is discharged from the hydraulic cylinder 7A through the second actuator passage 82 can be detected by the pressure gauge.

[0046] In addition, in the present embodiment, the valve core 6A for the hydraulic cylinder 7A is a split type divided into a first valve core 61 and a second valve core 62, so that independent metering control can be performed through the liquid inlet (meter-in) side and the liquid outlet (meter-out) side.

[0047] <Modification> The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure.

[0048] For example, the second sensor port 33 and the second sensor passage 35 may be omitted, and only the first sensor port 32 and the first sensor passage 34 may be used. Alternatively, on the contrary, the first sensor port 32 and the first sensor passage 34 may be omitted, and only the second sensor port 33 and the second sensor passage 35 may be used.

[0049] Furthermore, the hydraulic actuator 7 connected to the first actuator port 31a and the second actuator port 31b, that is, the hydraulic actuator 7 as the detection object of the supply pressure or the discharge pressure, may be a hydraulic cylinder other than the hydraulic cylinder 7A that drives the driven object in the gravity direction and the anti-gravity direction. Alternatively, the hydraulic actuator 7 as the detection object of the supply pressure or the discharge pressure may be a hydraulic motor.

[0050] In addition, if Figure 4As shown in FIG. 1 , the valve core 6 for the hydraulic actuator 7 as the detection target of the supply pressure or the discharge pressure may be an integral type extending across the two cross-sections 16 of the tank passage 15. That is, all the hydraulic actuators 7 may be the detection targets of the supply pressure or the discharge pressure. In this case, the total number of sensor ports on the first side surface 21 and the second side surface 22 of the housing 2 is not less than 1 time and not more than 2 times the total number of the valve core 6.

[0051] Furthermore, the first sensor port 32 need not necessarily be formed on the first side surface 21 or the second side surface 22, and may be formed on the fourth side surface 24, the first end surface 25, or the second end surface 26. Similarly, the second sensor port 33 need not necessarily be formed on the first side surface 21 or the second side surface 22, and may be formed on the fourth side surface 24, the first end surface 25, or the second end surface 26.

[0052] Summary As a first form, the present disclosure provides a valve device, comprising a valve core and a shell that can slidably hold the valve core; the shell includes: a valve core hole for inserting the valve core; a sensor port, a first actuator port and a second actuator port on the surface of the shell; a first actuator passage from the valve core hole to the first actuator port; a second actuator passage from the valve core hole to the second actuator port; and a sensor passage connecting the first actuator passage and the sensor port.

[0053] According to the above structure, there is a sensor port on the surface of the shell, and the sensor port is connected to the first actuator passage through the sensor passage. Therefore, if a pressure gauge is installed on the sensor port, the supply pressure when the working oil is supplied to the hydraulic actuator through the first actuator passage or the discharge pressure when the working fluid is discharged from the hydraulic actuator through the first actuator passage can be detected through the pressure gauge.

[0054] As a second form, in the first form, for example, the shell includes: a first side surface and a second side surface facing opposite sides along the axial direction of the valve core; and a third side surface and a fourth side surface facing opposite sides along a direction orthogonal to the axial direction of the valve core; the sensor port is formed on the first side surface or the second side surface, and the first actuator port and the second actuator port are formed on the third side surface.

[0055] As a third aspect, in the first or second aspect, a lock valve for opening and closing the first actuator passage may be provided on the first actuator passage, and the sensor passage is connected to the first actuator passage between the valve core hole and the lock valve. According to this structure, when the lock valve closes the first actuator passage, the working fluid is prevented from flowing from the first actuator port to the valve core hole. Therefore, even if the sensor port or the pressure gauge installed on the sensor port fails, the first actuator passage can be closed by the lock valve, thereby preventing the working fluid from the first actuator port from leaking from the sensor port.

[0056] As a fourth aspect, in the third aspect, the valve device may be used for a hydraulic cylinder, the hydraulic cylinder including a first working chamber for supplying working fluid when the driven object is driven in the direction against gravity and a second working chamber for supplying working fluid when the driven object is driven in the direction of gravity; the first actuator port is connected to the first working chamber, the second actuator port is connected to the second working chamber, and the lock valve closes the first actuator passage during the stop period of the hydraulic cylinder. According to this structure, leakage of working fluid from the sensor port caused by the deadweight of the driven object during the stop period of the hydraulic cylinder can be prevented.

[0057] As a fifth aspect, in any one of the first to fourth aspects, the sensor port may be a first sensor port, the sensor passage may be a first sensor passage, and the housing may include a second sensor port on a surface of the housing and a second sensor passage connecting the second actuator passage and the second sensor port. According to this structure, if a pressure gauge is installed on the second sensor port, the pressure gauge can detect the supply pressure when the working fluid is supplied to the hydraulic actuator through the second actuator passage or the discharge pressure when the working fluid is discharged from the hydraulic actuator through the second actuator passage.

[0058] As a sixth aspect, in any one of the first to fifth aspects, the valve core may include: a first valve core that switches which of the pump passage and the tank passage the first actuator passage is connected to; and a second valve core that switches which of the pump passage and the tank passage the second actuator passage is connected to. According to this structure, independent metering control can be performed by the liquid inlet side and the liquid outlet side.

Claims

1. A valve device, characterized in that: having a valve core; and a housing capable of slidably retaining the valve core; The housing comprises: a valve core hole for inserting the valve core; a sensor port, a first actuator port, and a second actuator port on a surface of the housing; a first actuator passage from the spool bore to the first actuator port; a second actuator passage from the spool bore to the second actuator port; and A sensor passage connects the first actuator passage and the sensor port.

2. The valve device according to claim 1, characterized in that The housing comprises: A first side surface and a second side surface facing opposite sides along the axial direction of the valve core; and A third side surface and a fourth side surface facing opposite sides along a direction orthogonal to the axial direction of the valve core; The sensor port is formed on the first side or the second side; The first actuator port and the second actuator port are formed on the third side.

3. The valve device according to claim 1 or 2, characterized in that: The first actuator passage is provided with a locking valve for opening and closing the first actuator passage; The sensor passage is connected to the first actuator passage between the valve core hole and the latch valve.

4. The valve device according to claim 3, characterized in that The valve device is used for a hydraulic cylinder, the hydraulic cylinder comprising a first working chamber for supplying working fluid when a driven object is driven in a direction counter to gravity, and a second working chamber for supplying working fluid when the driven object is driven in a direction of gravity; The first actuator port is connected to the first working chamber, and the second actuator port is connected to the second working chamber; the lock valve closes the first actuator passage during the stop of the hydraulic cylinder.

5. The valve device according to claim 1 or 2, characterized in that: The sensor port is a first sensor port, and the sensor passage is a first sensor passage; The housing comprises: a second sensor port on a surface of the housing; and A second sensor passage communicates between the second actuator passage and the second sensor port.

6. The valve device according to claim 1 or 2, characterized in that: The valve element includes: a first valve element that switches which of a pump passage and a tank passage the first actuator passage communicates with; and a second valve element that switches which of the pump passage and the tank passage the second actuator passage communicates with.

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