Electromagnetic proportional valve

Abstract

To provide an electromagnetic proportional valve that allows forced operation of a control target and stop of the control target by operating a manual pin.SOLUTION: An electromagnetic proportional valve 30 includes: a valve unit 40 that has a proportional valve spool 24 movable in an axial direction and controls a control pressure on a control target via the movement of the proportional valve spool 24; a solenoid coil 33; a plunger that drives the proportional valve spool 24 by moving in the axial direction in response to an excitation current applied to the solenoid coil 33; and a manual pin 36 that moves the proportional valve spool 24 in the axial direction. When the manual pin 36 is moved into a first movement range, the proportional valve spool 24 is driven to output the control pressure from the valve unit 40 to the control target. When the manual pin 36 is further moved from the first movement range into a second movement range, the proportional valve spool 24 is driven to discharge the control pressure from the valve unit 40 to the control target.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a proportional solenoid valve. [Background technology]

[0002] The electromagnetic proportional valve described in Patent Document 1 controls the supply and discharge of pilot oil supplied to the hydraulic device to be controlled by adjusting the excitation current applied to the solenoid actuator to move the position of the spool.

[0003] In proportional solenoid valves, if a malfunction occurs in the electrical system that controls the solenoid actuator, it may become difficult or impossible to move the spool, so proportional solenoid valves are provided with a manual pin to manually change the position of the spool. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-274547 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the electromagnetic proportional valve described in Patent Document 1, the spool position changes to only one position when the manual pin is operated, so it is not possible to both forcibly operate and stop the controlled object. Therefore, there is a need for an electromagnetic proportional valve that allows both forcibly operating and stopping the controlled object by operating the manual pin. [Means for solving the problem]

[0006] The electromagnetic proportional valve that solves the above problem comprises a valve unit having a spool that is movable in the axial direction and controls the control pressure to the controlled object by moving the spool, a solenoid coil, a drive member that drives the spool by moving in the axial direction when an excitation current is applied to the solenoid coil, and a pin that moves the spool in the axial direction, and when the pin is moved into a first movement range, the spool is driven to output control pressure from the valve unit to the controlled object, and when the pin is moved from the first movement range further into a second movement range, the spool is driven to discharge control pressure from the valve unit to the controlled object.

[0007] According to the above configuration, by moving the pin into the first range of movement, the spool is driven to output control pressure from the valve unit to the controlled object. Then, by moving the pin from the first range of movement to the second range of movement, the spool is driven to discharge control pressure from the valve unit to the controlled object. Therefore, by operating the pin, it is possible to both forcibly operate the controlled object and stop the controlled object.

[0008] In the above-mentioned electromagnetic proportional valve, it is preferable that the valve unit is provided with a spring that biases the pin in the opposite direction, and when the pin is moved to the first movement range, a reaction force is applied to the spool by the control pressure output to the controlled object, and when the movement of the pin is released, the spring pushes back the pin together with the drive member.

[0009] In the above-mentioned electromagnetic proportional valve, it is preferable that the valve unit comprises a drain chamber from which the control pressure output to the controlled object is discharged, and a discharge passage connected to the drain chamber, and that the discharge passage is connected to the drain chamber when the pin moves to the second movement range, and that the discharge passage is cut off from the drain chamber when the pin is outside the second movement range.

[0010] In the above-mentioned electromagnetic proportional valve, it is preferable that the valve unit comprises a pressure chamber to which the control pressure is supplied from a pump and a control pressure passage that outputs the control pressure to the controlled object, and that when the spool is driven by movement of the drive member caused by application of an excitation current to the solenoid coil, the control pressure is output from the pressure chamber to the control pressure passage, and when the spool is driven by movement of the drive member caused by movement of the pin into the first movement range, the control pressure is output from the pressure chamber to the control pressure passage.

[0011] In the above-described proportional solenoid valve, the controlled object is preferably a directional control valve device that switches between supply and discharge of hydraulic oil supplied to an actuator. [Effects of the Invention]

[0012] According to the present invention, it is possible to both forcibly operate and stop the hydraulic equipment by operating the manual pin. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing the configuration of an embodiment of a directional control valve device including an electromagnetic proportional valve. [Figure 2] 4 is a cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. [Figure 3] 4 is a cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. [Figure 4] 4 is a cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. [Figure 5] 4 is a side view showing attachment and detachment of a snap pin of the electromagnetic proportional valve of the embodiment. FIG. [Figure 6] 4 is a cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. [Figure 7] 4 is a cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. [Figure 8] 4 is an enlarged cross-sectional view showing the operation of the electromagnetic proportional valve of the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Present embodiment) An embodiment of a directional control valve device including a solenoid proportional valve will be described below with reference to Figures 1 to 8. The solenoid proportional valve controls the control pressure to a controlled object, which is a directional control valve device that switches the supply and discharge of hydraulic oil supplied to an actuator.

[0015] (Directional switching valve device 1) As shown in Figure 1, the directional control valve device 1 includes a valve body block 10, a main spool 20, a solenoid proportional valve 30, and a relief valve 50. The valve body block 10 includes a main spool bore 11 and an actuator passage 13. The main spool 20 slides within the main spool bore 11. The actuator passage 13 opens to the main spool bore 11 and is connected to an actuator. The solenoid proportional valve 30 controls the supply of spool pressure that drives the main spool 20. The relief valve 50 opens and closes in response to the internal pressure of the actuator passage 13.

[0016] The valve body block 10 is a rectangular parallelepiped block body. The main spool hole 11 is formed inside the valve body block 10. The main spool hole 11 is a hole with a circular cross section. The main spool hole 11 opens from the valve body block 10 to the outside along the axial direction. The main spool 20 has a cylindrical shape. The main spool 20 is provided in the main spool hole 11 coaxially with the main spool hole 11. The main spool 20 is slidable within the main spool hole 11 along the axial direction of the main spool 20.

[0017] (Main spool 20) The main spool 20 has a plurality of lands 21 spaced apart from one another in the axial direction, and a plurality of notches 22 provided between the lands 21. The outer diameter of each land 21 is approximately the same as the inner diameter of the main spool bore 11. On the other hand, the outer diameter of each notch 22 is smaller than the inner diameter of the main spool bore 11.

[0018] When the land portion 21 is positioned so as to straddle the openings of two passages (described below) that open into the main spool bore 11 and completely block each opening, it blocks the flow of hydraulic oil between these two passages. In contrast, when the cutout portion 22 is positioned so as to straddle the openings, it forms a passage connecting these two passages and allows the flow of hydraulic oil. Note that the main spool 20 can not only switch between connecting and blocking the passages, but can also adjust the passage opening between the passages, in other words, the valve opening, depending on its position.

[0019] (Valve body block 10) The valve body block 10 has a main spool hole 11, a supply passage 12, and a tank passage 14. Hydraulic oil flows through these passages.

[0020] (Supply passage 12) The supply passage 12 is a passage for supplying hydraulic oil from a pump (not shown) to the actuator. The pump that supplies hydraulic oil to the supply passage 12 is different from the pump that supplies hydraulic oil to the electromagnetic proportional valve 30. Note that the pump that supplies hydraulic oil to the supply passage 12 and the pump that supplies hydraulic oil to the electromagnetic proportional valve 30 may be the same. In this case, it is preferable to provide a pressure reducing valve between the electromagnetic proportional valve 30 and the pump.

[0021] The supply passage 12 is a passage for supplying hydraulic oil flowing in from the pump to the actuator via the main spool bore 11 and the actuator passage 13. The supply passage 12 opens to the main spool bore 11. When the opening of the supply passage 12 to the main spool bore 11 is blocked by the land portion 21 of the main spool 20 (the state shown in Figure 1), the connection between the supply passage 12 and the main spool bore 11 / actuator passage 13 is cut off.

[0022] (Actuator passage 13) The actuator passage 13 is a passage that opens into the main spool hole 11 and is connected to the actuator. The actuator passage 13 opens into the main spool hole 11 along the radial direction of the main spool 20, and also opens to the outside of the valve body block 10 along the radial direction of the main spool 20.

[0023] (Tank Passage 14) The tank passage 14 is a passage that opens into the main spool hole 11 and is connected to a tank (not shown). The tank passage 14 is a passage for returning the hydraulic oil discharged from the actuator to the tank. The tank passage 14 is connected to or disconnected from the actuator passage 13 depending on the position of the main spool 20. The tank connected to the tank passage 14 is different from the tank to which the hydraulic oil is discharged from the solenoid proportional valve 30.

[0024] The opening of the tank passage 14 to the main spool bore 11 is positioned axially outward of the opening of the actuator passage 13 to the main spool bore 11. As a result, when the tank passage 14 is connected to the actuator passage 13, the hydraulic oil from the actuator passage 13 is discharged through the opening of the tank passage 14 to the main spool bore 11.

[0025] (Pressure chamber forming cover 16) The valve body block 10 includes a pressure chamber forming cover 16. The pressure chamber forming cover 16 has a main spool pressure chamber 17 and is fixed to the valve body block 10. A control pressure passage 15, which supplies control pressure from the solenoid proportional valve 30, is connected to the main spool pressure chamber 17. The control pressure passage 15 is formed in the valve body block 10. As a result, control pressure flows from the control pressure passage 15 into the main spool pressure chamber 17, causing the control pressure to act on an end of the main spool 20. Meanwhile, the end of the main spool 20 opposite the end to which the control pressure acts is biased to the left in the figure by a biasing member 23. As a result, the position of the main spool 20 can be adjusted by adjusting the control pressure in the main spool pressure chamber 17.

[0026] (state transition) The directional control valve device 1 can be shifted among a supply state, a neutral state, and a discharge state depending on the position of the main spool 20 in the main spool bore 11. In the supply state, the supply passage 12 and the actuator passage 13 are connected, and the actuator passage 13 and the tank passage 14 are blocked. In the neutral state, the supply passage 12 and the actuator passage 13 are blocked, and the actuator passage 13 and the tank passage 14 are blocked. In the discharge state, the actuator passage 13 and the tank passage 14 are connected, and the supply passage 12 and the actuator passage 13 are blocked.

[0027] (Solenoid proportional valve 30) 2, the solenoid proportional valve 30 includes a drive device 31 and a valve unit 40. The drive device 31 and the valve unit 40 are arranged coaxially.

[0028] (Valve unit 40) The valve unit 40 is provided in a space formed in the valve body block 10. The valve unit 40 includes a socket 41 and a proportional valve spool 42. The valve unit 40 has a first pressure chamber 45 connected to the pump 2, which is a pressure source, a second pressure chamber 46 that outputs control pressure to the main spool 20, which is the controlled object, and a drain chamber 47 connected to the tank 3. The second pressure chamber 46 is connected to a control pressure passage 15. Control pressure flows from the second pressure chamber 46 through the control pressure passage 15 into the main spool pressure chamber 17, thereby applying the control pressure to the end of the main spool 20. The connecting passage between the first pressure chamber 45 and the pump 2 and the connecting passage between the drain chamber 47 and the tank 3 are not shown in the figure.

[0029] The socket 41 is a cylindrical member and includes a first communication hole 41B and a second communication hole 41C. The first communication hole 41B extends radially and connects the proportional valve spool hole 41A to the first pressure chamber 45. The second communication hole 41C extends radially and connects the proportional valve spool hole 41A to the drain chamber 47. The proportional valve spool 42 is a cylindrical member with a bottom. The proportional valve spool 42 is inserted into the internal space of the socket 41. The outer diameter of the proportional valve spool 42 approximately matches the inner diameter of the socket 41. The proportional valve spool 42 includes an axial hole 42A and a radial hole 42B. The axial hole 42A extends in the axial direction of the proportional valve spool 42. The radial hole 42B is formed radially and is connected to the axial hole 42A. A through hole 42C is formed in the bottom of the proportional valve spool 42. A notch 42D is formed in the outer peripheral surface of the socket 41 on the drive rod 34A side. The socket 41 has a discharge hole 41D.

[0030] (Driver 31) The drive unit 31 applies an axial force to the proportional valve spool 42 to control the axial position of the proportional valve spool 42. The drive unit 31 includes a hollow housing 32, a solenoid coil 33, a plunger 34, and a cylindrical member 35. The solenoid coil 33 is provided in the hollow portion of the housing 32. The plunger 34 is driven by the solenoid coil 33 and includes a drive rod 34A extending from the plunger 34. The cylindrical member 35 guides the plunger 34.

[0031] The housing 32 has a cylindrical shape with a bottom. The opening of the housing 32 faces the valve unit 40. The cylindrical member 35 is inserted into the space of the valve unit 40 formed in the valve body block 10, and seals the space of the valve unit 40. A through hole 32A extending in the axial direction is formed in the bottom of the housing 32.

[0032] The cylindrical member 35 has a cylindrical shape with a bottom that extends in the axial direction. The inner diameter of the cylindrical member 35 is approximately equal to the outer diameter of the plunger 34. The inner diameter of the portion of the cylindrical member 35 through which the drive rod 34A passes is approximately equal to the outer diameter of the drive rod 34A.

[0033] The plunger 34 and drive rod 34A are provided so as to be movable in the axial direction. The drive rod 34A extends axially from the plunger 34. The tip (right end in the figure) of the drive rod 34A contacts the base end (left end in the figure) of the proportional valve spool 42. The proportional valve spool 42 is biased by a spring 43 in the direction opposite to the pushing direction of the manual pin 36. This maintains contact between the drive rod 34A and the proportional valve spool 42. The spring 43 corresponds to a biasing member. A groove is formed in the portion of the base end of the proportional valve spool 42 that contacts the drive rod 34A. This allows hydraulic oil to pass through even when the drive rod 34A contacts the base end of the proportional valve spool 42.

[0034] At least a portion of the plunger 34 is made of a magnetic material. At least a portion of the plunger 34 is disposed radially inward of the solenoid coil 33. The plunger 34 is driven by the solenoid coil 33. That is, the plunger 34 moves axially when driven by the solenoid coil 33. Specifically, when an excitation current is applied to the solenoid coil 33, the plunger 34 and the drive rod 34A move axially, thereby moving the proportional valve spool 42 to the right in the figure. In this way, the proportional valve spool 42 is driven by the plunger 34 and the drive rod 34A. A member that drives the proportional valve spool 42 by electrical control is called a drive member. Because the proportional valve spool 42 is driven by the axial movement of the plunger 34 and the drive rod 34A, the plunger 34 and the drive rod 34A are drive members. The drive member may include members other than the plunger 34 and the drive rod 34A. The manual pin 36 is moved manually and is not electrically driven, and is therefore not included in the driving members.

[0035] The proportional valve spool 42, driven by the plunger 34 and drive rod 34A, moves axially to the right in the drawing. At this time, control pressure is output from the second pressure chamber 46 to the control pressure passage 15. When the supply of excitation current to the solenoid coil 33 is stopped, the proportional valve spool 42, together with the plunger 34 and drive rod 34A, moves axially to the left in the drawing due to the biasing force of the spring 43. In this way, the axial position of the proportional valve spool 42 can be changed by applying excitation current to the solenoid coil 33.

[0036] (Relief valve 50) The relief valve 50 is provided in the valve body block 10. The relief valve 50 opens and closes the tank passage 14 provided in the valve body block 10 in response to the internal pressure of the actuator passage 13. When the relief valve 50 is open, the actuator passage 13 and the tank passage 14 are connected.

[0037] (Manual pin 36) The solenoid proportional valve 30 includes a manual pin 36. The manual pin 36 moves the proportional valve spool 42 in the axial direction. The manual pin 36 is a cylindrical member. The manual pin 36 is inserted into a through-hole 32A of the housing 32 and protrudes from the housing 32. The manual pin 36 is coaxial with the plunger 34 and can push the plunger 34 in the axial direction. As shown in FIG. 5, the manual pin 36 is fixed to the housing 32 by a snap pin 37. The manual pin 36 can be moved in the axial direction by removing the snap pin 37 during use. As shown in FIG. 2, the manual pin 36 has two fixing holes 36A formed therein. The manual pin 36 can be fixed at two positions corresponding to the fixing holes 36A. When the snap pin 37 is removed from the fixing holes 36A and the manual pin 36 is pushed into the housing 32, it comes into contact with the drive rod 34A of the plunger 34 and moves together with the plunger 34. The plunger 34 comes into contact with the proportional valve spool 42 and moves the proportional valve spool 42. When the proportional valve spool 42 moves axially to the far right in the drawing, the notch 42D is connected to the drain chamber 47 via the discharge hole 41D. When the proportional valve spool 42 is in a position other than the far right in the drawing, the notch 42D is disconnected from the drain chamber 47. The notch 42D corresponds to a discharge passage.

[0038] When the manual pin 36 is moved into the first movement range, the proportional valve spool 42 is driven to output the control pressure from the valve unit 40 to the main spool pressure chamber 17. The first movement range is the range in which the first pressure chamber 45 and the second pressure chamber 46 are communicated with each other. Specifically, the first movement range is the range in which the radial hole 42B of the proportional valve spool 42 and the first communication hole 41B of the socket 41 are communicated with each other. When the manual pin 36 is further moved from the first movement range to the second movement range, the proportional valve spool 42 is driven to discharge the control pressure from the valve unit 40 to the main spool pressure chamber 17. The second movement range is the range in which the second pressure chamber 46 and the drain chamber 47 are communicated with each other. Specifically, the second movement range is the range in which the notch 42D and the discharge hole 41D are communicated with each other.

[0039] (Action of this embodiment) Next, the operation of the directional control valve device 1 will be described. 3, when an excitation current is applied to the solenoid coil 33, the plunger 34 is driven to the right in the drawing, and together with the plunger 34, the proportional valve spool 42 is driven to the right in the drawing. At this time, control pressure is output from the first pressure chamber 45 to the control pressure passage 15 via the radial hole 42B and the axial hole 42A. The control pressure flows from the control pressure passage 15 into the main spool pressure chamber 17, and the control pressure acts on the end of the main spool 20. By pressing the main spool 20 to the right in the drawing, the directional control valve device 1 enters a supply state in which the supply passage 12 and the actuator passage 13 are connected.

[0040] 4, when the application of the excitation current to the solenoid coil 33 is stopped, the plunger 34 is driven to the left in the figure together with the proportional valve spool 42 by the biasing force of the spring 43. At this time, the control pressure is discharged from the control pressure passage 15 to the drain chamber 47 through the radial hole 42B and the axial hole 42A. When the control pressure is discharged from the main spool pressure chamber 17, the main spool 20 moves to the left in the figure by the biasing force of the biasing member 23. By moving the main spool 20 to the left in the figure, the directional control valve device 1 enters a neutral state in which the supply passage 12 and the actuator passage 13 are blocked.

[0041] If a malfunction occurs in the electrical system and the solenoid coil 33 is no longer able to drive the plunger 34, the main spool 20 can be driven by operating the manual pin 36. As shown in FIG. 5, the manual pin 36 becomes movable when the snap pin 37 is pulled out of the manual pin 36. Then, as shown in FIG. 6, slightly pushing the manual pin 36 drives the proportional valve spool 42 together with the plunger 34 to the right in the drawing. At this time, control pressure is output from the first pressure chamber 45 to the control pressure passage 15 via the radial hole 42B and the axial hole 42A. Control pressure flows from the control pressure passage 15 into the main spool pressure chamber 17, and the control pressure acts on the end of the main spool 20. By pressing the main spool 20 to the right in the drawing, the directional control valve device 1 enters a supply state in which the supply passage 12 and the actuator passage 13 are connected.

[0042] The manual pin 36 is pushed back to the left side in the figure by the reaction force of the second pressure chamber 46. Therefore, when the manual pin 36 is released from being pressed, it returns to its original position. The directional control valve device 1 is in the supply state only when the manual pin 36 is pressed in. Therefore, the actuator can be operated to a position where danger is avoided and then stopped.

[0043] As shown in Figures 7 and 8, when the manual pin 36 is further pressed, the proportional valve spool 42 is driven further to the right in the drawings together with the plunger 34. At this time, the radial hole 42B is blocked by the socket 41, blocking input from the first pressure chamber 45. The hydraulic oil in the second pressure chamber 46 passes through the axial hole 42A and through-hole 42C of the proportional valve spool 42, passes through the notch 42D, and is discharged from the discharge hole 41D to the drain chamber 47. When control pressure is discharged from the main spool pressure chamber 17, the main spool 20 moves to the left in the drawings due to the biasing force of the biasing member 23. By moving the main spool 20 to the left in the drawings, the directional control valve device 1 enters a neutral state in which the actuator passage 13 and the tank passage 14 are blocked. This allows the actuator to be safely stopped.

[0044] By inserting the snap pin 37 into the fixing hole 36A with the manual pin 36 pressed into the housing 32, the manual pin 36 can be fixed in the inserted state in the housing 32. Therefore, the actuator can be maintained in a stopped state.

[0045] (Effects of this embodiment) Next, the effects of this embodiment will be described. (1) By moving the manual pin 36 into the first movement range, the proportional valve spool 42 is driven to output hydraulic oil from the valve unit 40 to the main spool pressure chamber 17. By further moving the manual pin 36 from the first movement range to the second movement range, the proportional valve spool 42 is driven to discharge the control pressure from the valve unit 40 to the main spool pressure chamber 17. Therefore, by operating the manual pin 36, it is possible to both forcibly operate the directional control valve device 1 and stop the directional control valve device 1.

[0046] (2) When a reaction force is applied to the proportional valve spool 42 by the spring 43 and the movement of the manual pin 36 is released, the spring 43 pushes back the manual pin 36 together with the plunger 34. For this reason, the directional control valve device 1 can be operated only when the manual pin 36 is operated. Then, the operation of the directional control valve device 1 can be stopped by operating the directional control valve device 1 as much as necessary and then stopping the operation of the manual pin 36.

[0047] (3) Only when the manual pin 36 is moved to the second movement range does the notch 42D connect to the drain chamber 47. Therefore, when the manual pin 36 is moved to the second movement range, the hydraulic oil is discharged to the drain chamber 47, and the operation of the directional control valve device 1 can be stopped.

[0048] (4) When the proportional valve spool 42 is driven by the movement of the plunger 34 caused by application of an excitation current to the solenoid coil 33, hydraulic oil is output from the first pressure chamber 45 to the control pressure passage 15. Similarly, when the proportional valve spool 42 is driven by the movement of the plunger 34 caused by the manual pin 36 moving into the first movement range, control pressure is output from the first pressure chamber 45 to the control pressure passage 15.

[0049] (5) By operating the manual pin 36, the supply and discharge of hydraulic oil by the directional control valve device 1 can be switched, so that both the forced operation of the actuator and the stopping of the actuator are possible.

[0050] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0051] In the above embodiment, the manual pin 36 may be fixed by a snap pin 37 at a position where the manual pin 36 is slightly pushed in. In the above embodiment, the manual pin 36 is fixed by the snap pin 37. However, as long as the manual pin 36 can be fixed, it is not limited to the snap pin 37 and other shapes and configurations may be used.

[0052] In the above embodiment, the spring 43 is provided inside the socket 41 to bias the proportional valve spool 42 toward the drive unit 31. However, the spring may be provided in another position as long as it biases the proportional valve spool 42 in the opposite direction to the manual pin 36. For example, a spring may be provided between the cylindrical member 35 of the drive unit 31 and the proportional valve spool 42 to bias the proportional valve spool 42 toward the drive unit 31.

[0053] In the above embodiment, when the manual pin 36 moves to the second movement range, the proportional valve spool 42 moves and the notch 42D connects to the drain chamber 47. However, the passage is not limited to the notch 42D, and may be a radial hole or the like provided in the proportional valve spool 42, as long as it connects to the drain chamber 47 when the manual pin 36 moves to the second movement range.

[0054] In the above embodiment, the control pressure passage 15 may be omitted, and the second pressure chamber 46 may be directly connected to the main spool pressure chamber 17. Also, the second pressure chamber 46 and the main spool pressure chamber 17 may be combined into one pressure chamber.

[0055] In the above embodiment, the controlled object is the directional control valve device 1 that switches the supply and discharge of hydraulic oil supplied to the actuator. However, the controlled object may be any other controlled object as long as the control pressure is controlled by the valve unit 40.

[0056] In the above embodiments, if an object is made up of multiple objects, the multiple objects may be integrated, and conversely, if an object is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the object of the invention can be achieved. [Explanation of symbols]

[0057] 1...Directional switching valve device 2. Pump 3. Tank 10...Valve body block 11...Main spool hole 12…Supply passage 13...Actuator passage 14...Tank passage 15...Control pressure passage 16...Pressure chamber forming cover 17...Main spool pressure chamber 20...Main spool 21...Land section 22...Notch 23... Urging member 30...Solenoid proportional valve 31...Driver 32…Housing 32A…Through hole 33...Solenoid coil 34... Plunger as a driving member 34A...Drive rod 35...Cylindrical member 36...Manual pin 36A…Fixing hole 37...Snap pin 40...Valve unit 41...Socket 41A...Proportional valve spool hole 41B…1st communication hole 41C…Second communication hole 41D…Discharge hole 42...Proportional valve spool 42A…Axial hole 42B…Radial hole 42C...Through hole 42D...Notch as a discharge passage 43...Spring 45...First pressure chamber 46...Second pressure chamber 47...Drain chamber 50...Relief valve

Claims

1. a valve unit having a spool that is movable in an axial direction and that controls a control pressure to a controlled object by movement of the spool; A solenoid coil, a driving member that drives the spool by moving in the axial direction when an excitation current is applied to the solenoid coil; a pin that moves the spool in the axial direction, When the pin is moved to a first movement range, the spool is driven to output a control pressure from the valve unit to the controlled object, When the pin is moved from the first movement range to a second movement range, the spool is driven to discharge the control pressure from the valve unit to the controlled object. Solenoid proportional valve.

2. The valve unit includes a spring that biases the valve unit in a direction opposite to the pin. When the pin is moved to the first movement range, a reaction force is applied to the spool by the control pressure output to the controlled object, and when the movement of the pin is released, the pin is pushed back together with the driving member by the spring.

2. The proportional solenoid valve according to claim 1.

3. The valve unit includes a drain chamber to which the control pressure output to the controlled object is discharged; a discharge passage connected to the drain chamber, When the pin moves to the second movement range, the discharge passage is connected to the drain chamber, When the pin is outside the second movement range, the discharge passage is blocked from the drain chamber.

2. The proportional solenoid valve according to claim 1.

4. The valve unit includes a pressure chamber to which the control pressure is supplied from a pump; a control pressure passage for outputting a control pressure to the controlled object, When the spool is driven by the movement of the drive member caused by application of an excitation current to the solenoid coil, a control pressure is output from the pressure chamber to the control pressure passage, When the pin moves within the first movement range, the driving member moves, and the spool is driven, and a control pressure is output from the pressure chamber to the control pressure passage.

2. The proportional solenoid valve according to claim 1.

5. The controlled object is a directional control valve device that switches the supply and discharge of hydraulic oil supplied to an actuator. The proportional solenoid valve according to any one of claims 1 to 4.

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