JP7654374B2 - Electromagnetic proportional valve, fluid system and construction machinery - Google Patents

Description

The present invention relates to an electromagnetic proportional valve, a fluid system, and a construction machine.

An increasing number of fluid systems, such as hydraulic circuits in construction machinery, are equipped with electrically controlled electromagnetic proportional valves. An electromagnetic proportional valve, for example, comprises an electromagnetic coil (solenoid), a rod driven by the electromagnetic coil, a spool that moves when pressed by the rod, and a return spring that returns the spool to its original position. The spool blocks and connects each of the ports connected to the pilot flow path to which hydraulic oil is supplied from the hydraulic pump, the control port that adjusts the opening of the hydraulic oil to the actuator to be driven, and the drain port that is connected to a tank that stores the return oil.

Japanese Utility Model Application Publication No. 4-036183

It is necessary to detect the pressure of the hydraulic oil in order to electrically control the solenoid proportional valve. For example, the solenoid proportional valve described in Patent Document 1 has a drain port, a control port, and a pilot port in a direction perpendicular to the direction of movement of the spool. When detecting the pressure of the control port and pilot port in a solenoid proportional valve having such a configuration, it is necessary to provide a pressure detection unit separately from the solenoid proportional valve. This leads to a complicated hydraulic circuit, and there is a possibility that the complicated hydraulic circuit will become larger.

The present invention provides an electromagnetic proportional valve that can simplify the structure for electrical control and can be made compact, as well as a fluid system and construction machinery that use this electromagnetic proportional valve.

The electromagnetic proportional valve according to one aspect of the present invention comprises a valve section and a drive unit that drives the valve section in response to a drive current, and the drive unit comprises a detection section that detects information regarding the state of at least one of the valve section and the drive unit, and a control section that controls the drive current based on the detection result of the detection section.

In this way, by providing the detection unit and control unit in the electromagnetic proportional valve itself, the electromagnetic proportional valve can be made smaller without creating extra space outside the electromagnetic proportional valve. In addition, the configuration of the entire fluid system can be simplified. The detection unit only needs to detect information related to the state of at least one of the valve unit and the drive unit, such as the pressure of the working fluid, or the movement acceleration, distortion, temperature, etc. of the spool of the electromagnetic proportional valve, or other information necessary to control the electromagnetic proportional valve.

In the above configuration, the valve unit includes a spool having a through hole along the axial direction through which the working fluid from the pump port passes, the drive unit includes an electric drive unit that drives the spool, and the control unit may control the drive of the electric drive unit.

In the above configuration, the information may be the pressure of the working fluid passing through the through hole.

In the above configuration, the spool, the electric drive unit, the detection unit, and the control unit may be arranged in this order along the axial direction.

In the above configuration, the electric drive unit may include a case that houses a rod that pushes the spool, the detection unit, and the control unit, and the detection unit may detect the pressure of the working fluid at the pump port.

In the above configuration, the control unit may include a communication unit for transmitting and receiving data to and from other control units.

A fluid system according to another aspect of the present invention includes a fluid pump that discharges a working fluid, a control valve that switches the output destination of the working fluid, an actuator that is driven by the working fluid supplied from the control valve, and an electromagnetic proportional valve that applies a control pressure of the working fluid to the control valve. The electromagnetic proportional valve includes a valve unit and a drive unit that drives the valve unit in response to a drive current. The valve unit includes a spool that has a through hole along the axial direction and through which the working fluid passes. The drive unit includes a detection unit that detects information regarding the state of at least one of the valve unit and the drive unit, a control unit that controls the drive current based on the detection result of the detection unit, and an electric drive unit that drives the spool with the drive current. The electric drive unit includes a rod that pushes the spool, a case that houses the detection unit and the control unit, and the detection unit detects the control pressure.

By configuring it in this way, the electromagnetic proportional valve can be made smaller without creating extra space outside the valve. In addition, the configuration of the entire fluid system can be simplified.

A fluid system according to another aspect of the present invention includes a fluid pump that discharges a working fluid, a control valve that switches the output destination of the working fluid, an actuator that is driven by the working fluid supplied from the control valve, and an electromagnetic proportional valve that applies a control pressure of the working fluid to the control valve. The electromagnetic proportional valve includes a valve unit and a drive unit that drives the valve unit in response to a drive current. The valve unit includes a spool that has a through hole along the axial direction and through which the working fluid passes. The drive unit includes a detection unit that detects information regarding the state of at least one of the valve unit and the drive unit, a control unit that controls the drive current based on the detection result of the detection unit, and an electric drive unit that drives the spool with the drive current. The electric drive unit includes a rod that pushes the spool, a case that houses the detection unit and the control unit, and the detection unit detects the control pressure.

By configuring it in this way, the solenoid proportional valve can be controlled based on the control pressure in addition to the pressure of the working fluid at the pump port.

A construction machine according to another aspect of the present invention comprises a fluid system and a vehicle body on which the fluid system is mounted. The fluid system comprises a fluid pump that discharges a working fluid, a control valve that switches the output destination of the working fluid, an actuator that is driven by the working fluid supplied from the control valve, and an electromagnetic proportional valve that applies a control pressure of the working fluid to the control valve. The electromagnetic proportional valve comprises a valve unit and a drive unit that drives the valve unit in response to a drive current. The valve unit comprises a spool having a through hole along the axial direction and through which the working fluid from the pump port passes. The drive unit comprises a detection unit that detects information regarding the state of at least one of the valve unit and the drive unit, a control unit that controls the drive current based on the detection result of the detection unit, and an electric drive unit that drives the spool by the drive current. The electric drive unit comprises a rod that pushes the spool, a case that houses the detection unit and the control unit, and the detection unit detects the pressure of the working fluid at the pump port.

By configuring it in this way, the control pressure of the working fluid by the electromagnetic proportional valve can be controlled with high precision, providing a construction machine with excellent operability.

The present invention simplifies and miniaturizes the structure for electrically controlling the electromagnetic proportional valve, the fluid system, and the construction machine.

1 is a schematic configuration diagram of a construction machine according to an embodiment of the present invention. FIG. 1 is a configuration diagram of a hydraulic system according to an embodiment of the present invention. 1 is a schematic configuration diagram of an electromagnetic proportional valve according to an embodiment of the present invention; 5 is an explanatory diagram of the operation of the solenoid proportional valve according to the embodiment of the present invention. FIG. FIG. 11 is a schematic configuration diagram of a hydraulic system according to a modified example of the embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings.

<Construction machinery>
FIG. 1 is a schematic configuration diagram of a construction machine 100.
1, the construction machine 100 is, for example, a hydraulic excavator. The construction machine 100 includes a revolving body (an example of a vehicle body in the claims) 101, a running body (an example of a vehicle body in the claims) 102 provided below the revolving body 101, and a hydraulic system (an example of a fluid system in the claims) 1.

The rotating body 101 rotates above the running body 102. The rotating body 101 includes a cab 103 on which an operator can ride, a boom 104 having one end connected to the rotating body 101 so as to be freely swingable, an arm 105 having one end connected to the other end (tip) of the boom 104 so as to be freely swingable, a bucket 106 connected to the other end (tip) of the arm 105 so as to be freely swingable, and an operating unit 108 operated by the operator. The rotating body 101, the boom 104, the arm 105, and the bucket 106 are driven by hydraulic oil (an example of the hydraulic fluid in the claims) supplied from the hydraulic system 1.

<Hydraulic system>
FIG. 2 is a configuration diagram of the hydraulic system 1.
As shown in FIG. 2, the hydraulic system 1 includes an engine 120 as a drive source, a hydraulic pump (an example of a fluid pump in the claims) 130 driven by the engine 120, a plurality of actuators 140 that operate various parts of the construction machine 100, a control valve 500 that switches the operation of the plurality of actuators 140, an electromagnetic proportional valve 150 that applies a control pressure of hydraulic oil to the control valve 500, a tank 160 that stores hydraulic oil, and a relief valve 300 for adjusting pressure.

The engine 120 is an internal combustion engine that uses gasoline or diesel fuel. The engine 120 has an output shaft 121. The output shaft 121 is connected to a hydraulic pump 130.
A pipe Q is connected to the hydraulic pump 130. The hydraulic pump 130 is driven by the output shaft 121 to discharge hydraulic oil to the pipe Q. A control valve 500 and an electromagnetic proportional valve 150 are connected to the pipe Q.

In this embodiment, the engine 120 is used as the driving source of hydraulic oil, but instead of the engine 120, an electric motor that uses a power source such as a storage battery as a power source may also be used as the driving source. The engine 120 may also be used together with a generator that charges the storage battery or is used as a power source.

The control valve 500 is connected to a plurality of actuators 140 via a branched pipe Q. A plurality of control valves 500 are provided, and the hydraulic pressure of the hydraulic oil flowing through the pipe Q is switched by a plurality of spools in response to a switching operation of the operation unit 108, to supply hydraulic oil to the plurality of actuators 140. The plurality of actuators 140 include hydraulic cylinders that drive the boom 104, arm 105, bucket 106, etc., and a hydraulic motor that drives the rotating body 101.

The relief valve 300 releases pressure when the pressure of the hydraulic oil in the hydraulic circuit (in the pipe Q) of the hydraulic system 1 reaches or exceeds a preset value.
The solenoid proportional valve 150 moves a spool with the hydraulic pressure of the hydraulic oil from a pilot pump (not shown) based on the operation amount of the operation unit 108, and supplies the hydraulic oil from the hydraulic pump 130 to the actuator 140. The solenoid proportional valve 150 will be described in detail below.

<Solenoid proportional valve>
FIG. 3 is a schematic diagram of the proportional solenoid valve 150.
3, the electromagnetic proportional valve 150 controls the valve opening to move a spool of a control valve 500 and adjust the flow rate of hydraulic oil from the hydraulic pump 130 to the actuator 140. The electromagnetic proportional valve 150 includes a valve unit 10 for applying a control pressure of the hydraulic oil to the control valve 500, and a drive unit 20 for driving the valve unit 10 in response to a drive current.
The drive device unit 20 includes a detection unit 170 that detects information regarding the state of the electromagnetic proportional valve 150, a control unit 200 that generates a control signal (controls the drive current) based on the detection result of the detection unit 170 and the operation amount of the operation unit 108, and an electric drive unit 151 that drives the valve unit 10 based on the control signal generated by the control unit 200.

The detection unit 170 detects, for example, the pilot pressure of the hydraulic oil flowing through the pump port RP connected to the valve unit 10 as described below, as information regarding the state of the valve unit 10. The detection value detected by the detection unit 170 is fed back to the control unit 200.

The electric drive unit 151 includes, for example, an electromagnetic coil 152 (solenoid) serving as a drive source, a rod 153 driven by the electromagnetic coil 152, and a case 154 serving as an exterior. The case 154 is formed to cover the opening of a spool hole H (described later) formed in the valve unit 10. The electromagnetic coil 152 (electric drive unit 151), the detection unit 170, and the control unit 200 are arranged and stored in the case 154 in this order from the valve unit 10 side. In addition, a partition wall 149 is provided in the case 154 to divide the inside of the case 154 into a first room K1 in which the electric drive unit 151 and the detection unit 170 are arranged, and a second room K2 in which the control unit 200 is arranged.

The electromagnetic coil 152 is formed into a cylindrical shape by winding copper wire around an iron core. The electromagnetic coil 152 generates a magnetic field by passing electricity through the copper wire.

The rod 153 is made of metal and formed into a rod shape. The rod 153 is also called a plunger. The axial direction of the rod 153 and the axial direction of the electromagnetic coil 152 coincide with each other. The rod 153 is arranged so as to be freely movable in the axial direction within the electromagnetic coil 152. One end 153A of the rod 153 on the valve unit 10 side abuts against the other end S2 of the spool S of the valve unit 10, which will be described later.

A protruding portion 153T protruding radially outward is formed on the outer circumferential surface of the rod 153. A magnetic field of an electromagnetic coil 152 is applied to this protruding portion 153T.
The protrusion 153T of the rod 153 is disposed slightly offset from the neutral axis L of the electromagnetic coil 152 toward the other end 153B of the rod 153. Therefore, when the electromagnetic coil 152 is energized, the protrusion 153T (rod 153) is attracted by the magnetic field generated by the electromagnetic coil 152 and moves in the direction of the neutral axis L of the electromagnetic coil 152 (toward the valve portion 10). As a result, the rod 153 pushes the spool S of the valve portion 10, which will be described later.

The amount of electricity passing through the electromagnetic coil 152 is proportionally controlled according to the amount of operation of the operating unit 108, and is also controlled based on the detection value detected by the detection unit 170. As a result, the amount of protrusion of the rod 153 is adjusted by the electromagnetic coil 152. The details of the effect of adjusting the amount of protrusion of the rod 153 will be described later.

The valve section 10 includes, for example, a cylindrical valve body 155 accommodated in a valve accommodation hole 12 formed in a casing 11 of a control valve 500 constituting the hydraulic system 1, a flange portion 13 provided on the drive unit 20 side of the valve body 155, a spool S movably accommodated in a spool hole H formed in the valve body 155, and a return spring G that returns the moved spool S to its original position.

A pump port RP is provided in the casing 11, to which a pipe Q is connected and into which hydraulic oil flows from a pilot pump (gear pump) (not shown). The pilot pump and the hydraulic pump 130 are connected in tandem to an output shaft 121 of the engine 120, and the pilot pump is also driven by the output shaft 121.
The casing 11 is provided with a drain port RD connected to a flow path leading to the tank 160, and a control port RA connected to a flow path leading to the spool of the control valve 500. Note that "communicating" (making it communicate, passing through) refers to allowing hydraulic oil (i.e., fluid) to flow. For example, "a flow path leading to the tank 160" refers to a flow path configured to allow hydraulic oil to flow between that flow path and the tank 160.

The spool hole H of the valve body 155 penetrates the valve body 155 in the axial direction. The spool hole H is arranged in the order of a first through hole H1, a second through hole H2, a third through hole H3, and a fourth through hole H4 from one end 155A of the valve body 155 opposite the drive unit 20. The inner diameter of the second through hole H2 is larger than the inner diameter of the first through hole H1. The inner diameter of the third through hole H3 is larger than the inner diameter of the second through hole H2. The inner diameter of the fourth through hole H4 is larger than the inner diameter of the third through hole H3.

A return spring G is disposed in the second through hole H2. The return spring G is an elastic member such as a coil spring. One end GA of the return spring G on the first through hole H1 side is in contact with the step surface between the first through hole H1 and the second through hole H2. This restricts the movement of the return spring G toward the first through hole H1 side.

The first through hole H1 communicates with the pump port RP. The valve body 155 is formed with an actuator communication hole 156 that radially communicates the third through hole H3 with the control port RA. The valve body 155 is also formed with a drain communication hole 157 that radially communicates the fourth through hole H4 with the drain port RD.
A plurality of seal members 158 are provided on the outer circumferential surface of the valve body 155, i.e., between the valve body 155 and the casing 11, to prevent the first through-hole H1, the actuator communication hole 156, and the drain communication hole 157 from communicating with each other on the outer circumferential surface side of the valve body 155. An example of the seal members 158 is an O-ring.

The flange portion 13 connects the valve body 155 and the drive unit 20, and also serves to attach the solenoid proportional valve 150 to the casing 11. A seal member 159 is provided between the flange portion 13 and the casing 11. An example of the seal member 159 is an O-ring. The seal member 159 ensures sealing between the flange portion 13 and the casing 11.
The flange portion 13 is provided so as to close the opening on the drive unit 20 side of the fourth through hole H4 formed in the valve body 155. A through hole 13A is formed in the radial center of the flange portion 13, through which one end 153A of a rod 153 constituting the drive unit 20 is passed.

A disk-shaped support block 14 is provided on the inner surface of the flange portion 13 on the valve body 155 side. The support block 14 defines a fourth through hole H4. A through hole 14A that leads to the through hole 13A is formed in the radial center of the support block 14. The through hole 14A supports the other end S2 of the spool S on the drive unit 20 side so that it can move freely in the axial direction. As a result, one end 153A of the rod 153 that constitutes the drive unit 20 and the other end S2 of the spool S come into contact with each other via the through hole 14A.

The spool S is formed, for example, from metal in a rod shape. One end S1 of the spool S opposite to the drive unit 20 is supported in the second through hole H2 of the valve body 155 so as to be freely movable.
The other end GB of the return spring G disposed in the second through hole H2 of the valve body 155 is in contact with one end S1 of the spool S. The return spring G is disposed in a compressed state by this one end S1 and a step surface between the first through hole H1 and the second through hole H2 in the valve body 155. The restoring force of the return spring G constantly presses the spool S toward the drive unit 20.

A through hole SH is formed in the spool S along the axial direction. The through hole SH communicates with the pump port RP via a first through hole H1 of the valve body 155.
A protrusion S3 having a diameter larger than both ends S1, S2 of the spool S is formed in most of the axial center of the spool S. The protrusion S3 is inserted into a third through hole H3 of the valve body 155 so as to be freely movable in the axial direction.

The protruding portion S3 has a step S4 on the other end S2 side. The step S4 is located inside the fourth through hole H4. The pressure of the drain port RD acts on the step S4.
The protrusion S3 has a step S5 on the one end S1 side. The step S5 is located inside the third through hole H3. The pressure of the control port RA acts on the step S5.
Furthermore, the protrusion S3 is formed with a groove-like notch SN (first flow passage) extending along the axial direction. The notch SN forms a closed end SN1 on the step S4 side that does not lead to the step S4. The notch SN also forms an open end SN2 on the step S5 side that leads to the step S5.

Three second flow paths S6 that communicate with the through holes SH are formed in the protruding portion S3. The second flow paths S6 are formed in a direction perpendicular to the through holes SH. The three second flow paths S6 are arranged at equal intervals in the circumferential direction at positions that avoid the notches SN.

<Operation of solenoid proportional valve>
Next, the operation of the proportional solenoid valve 150 will be described.
First, as shown in Fig. 3, when the electric drive unit 151 is not driven, the spool S is in a neutral position (original position) due to the restoring force of the return spring G. In the neutral position of the spool S, the third through hole H3 and the fourth through hole H4 are communicated by the spool S. That is, the closed end SN1 of the notch SN is positioned in the fourth through hole H4. The open end SN2 is positioned in the third through hole H3. As a result, the notch SN communicates the third through hole H3 and the fourth through hole H4. As a result, in the neutral position of the spool S, the notch SN communicates the drain port RD and the control port RA.

In addition, when the spool S is in the neutral position, the third through hole H3 and the first through hole H1 are blocked by the spool S. That is, the second flow path S6 is housed in the third through hole H3, and the opening of the second flow path S6 is blocked by the inner peripheral surface of the third through hole H3. In addition, one end S1 of the spool S is inserted into the second through hole H2, so the third through hole H3 and the first through hole H1 are separated by one end S1 of the spool S. As a result, when the spool S is in the neutral position, the drain port RD and the control port RA are blocked from the pump port RP.

The hydraulic oil flowing in from the pump port RP flows into the through hole SH via the first through hole H1 and fills the first chamber K1 in the case 154 of the electric drive unit 151 from the other end S2 of the spool S, generating hydraulic pressure. The detection unit 170 detects the pressure (pilot pressure) of the hydraulic oil in the first chamber K1 in the case 154. Note that a partition wall 149 is provided in the case 154 to divide the inside of the case 154 into the first chamber K1 in which the electric drive unit 151 and the detection unit 170 are located and the second chamber K2 in which the control unit 200 is located. This prevents the hydraulic oil from filling the second chamber K2 in which the control unit 200 is located.

Next, a case where the rod 153 is driven by the electric drive unit 151 will be described with reference to FIG.
FIG. 4 is a diagram illustrating the operation of the solenoid proportional valve 150, and corresponds to the above-mentioned FIG.
As shown in FIG. 4, when the electromagnetic coil 152 of the electric drive unit 151 is energized, the rod 153 is moved toward the valve unit 10. Then, the rod 153 pushes the spool S toward the opposite side to the drive unit 20. The spool S moves in a direction that compresses and deforms the return spring G. At this time, the size of the opening of the second flow path S6 that communicates with the third through hole H3 increases according to the amount of movement of the spool S. This allows the pump port RP to communicate with the third through hole H3 via the first through hole H1, the through hole SH, and the second flow path S6. As a result, the spool S communicates between the pump port RP and the control port RA and adjusts the flow rate of the hydraulic oil flowing to the control port RA.

At this time, the hydraulic oil flowing in from the pump port RP flows from the pump port RP through the first through hole H1, the second flow passage S6, and the third through hole H3 to the control port RA. The detection unit 170 detects the pressure of the hydraulic oil in the first chamber K1 in the case 154.
When the movement of the spool S is completed, the closed end SN1 of the notch SN is accommodated in the third through hole H3, and therefore the third through hole H3 and the fourth through hole H4 are blocked off. That is, the spool S blocks off the drain port RD and the control port RA.

In addition, in the above-mentioned state of the spool S, the detection unit 170 can also perform detection as follows. That is, the detection unit 170 detects the force transmitted from the other end S2 of the spool S to the rod 153. The pressure of the hydraulic oil supplied from the pump port RP acts on one end S1 of the spool S. Therefore, the detection unit 170 in the case 154 can directly detect the pressure (pilot pressure) of the pump port RP in accordance with the amount of movement of the spool S.

The control unit 200 generates a control signal based on the detection value detected by the detection unit 170, and controls the driving of the electric drive unit 151 based on this control signal. This makes it possible to appropriately adjust the flow rate of the hydraulic oil flowing through the control port RA.
The control valve 500 is driven by the hydraulic oil flowing through the control port RA. In other words, adjusting the flow rate of the hydraulic oil flowing through the control port RA means adjusting the control pressure of the hydraulic oil for controlling the drive of the control valve 500. The control unit 200 controls the control pressure of the hydraulic oil to the control valve 500.

In this way, the flow rate of hydraulic oil supplied to the desired actuator 140 is adjusted by the solenoid proportional valve 150. Each actuator 140 is driven by hydraulic oil supplied via the control valve 500.

As described above, the electromagnetic proportional valve 150 includes a detection unit 170 and a control unit 200. By providing the detection unit 170 and the control unit 200 in the electromagnetic proportional valve 150 itself, the electromagnetic proportional valve 150 can be made smaller without creating extra space outside the electromagnetic proportional valve 150. In addition, the configuration of the hydraulic system 1 as a whole can be simplified.

The control unit 200 controls the drive of the electric drive unit 151 for driving the spool S (valve unit 10). In the solenoid proportional valve 150, the pump port RP is connected to a through hole SH formed in the spool S, and the detection unit 170 can easily detect the pressure (pilot pressure) of the hydraulic oil flowing through the pump port RP according to the amount of movement of the spool S by detecting the force applied to the rod 153 abutting against the spool S. In other words, according to the solenoid proportional valve 150, the detection unit 170 detects the pressure applied to the spool S to which the pump port RP is connected in the direction of movement, so that the device configuration for detecting the pilot pressure can be simplified.

The electromagnetic coil 152 (electrical driving unit 151), the detection unit 170, and the control unit 200 are arranged and stored in a line in this order from the valve unit 10 side within a case 154 of the electric driving unit 151. This allows the driving device unit 20 to be made as small as possible, and each unit constituting the driving device unit 20 can be easily integrated.
Furthermore, hydraulic oil flows into the case 154 through the through hole SH of the spool S. Since the detection unit 170 is disposed adjacent to the electromagnetic coil 152 (electrical drive unit 151), the path through which the hydraulic oil reaches the detection unit 170 is not unnecessarily long, which reduces hysteresis and improves the responsiveness of the detection unit 170. Furthermore, the detection unit 170 has a simple structure and can easily detect the pressure of the hydraulic oil flowing through the pump port RP.

In addition, the construction machine 100 equipped with the hydraulic system 1 as described above can control the hydraulic oil control pressure by the electromagnetic proportional valve 150 with high precision, improving operability.

[Modification]
The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.
For example, in the above embodiment, a case where hydraulic oil is used as the working fluid and the hydraulic system 1 is applied as the fluid system is described. However, the present invention is not limited to this, and the working fluid may be other than hydraulic oil. The configuration of the electromagnetic proportional valve 150 described above can be adopted in various fluid systems according to the type of working fluid. Even in the case of the hydraulic system 1, the hydraulic system 1 may be applied not only to construction machinery but also to other devices that use a working fluid, such as a hydraulic press.

In the above embodiment, the detection unit 170 detects the pilot pressure of the hydraulic oil flowing through the pump port RP as information related to the state of the valve unit 10. However, this is not limited to the above, and the detection unit 170 only needs to detect information related to the state of at least one of the valve unit 10 and the drive unit 20 required to control the solenoid proportional valve 150. For example, the detection unit 170 may detect the position of the spool S, the movement acceleration of the spool S, the distortion of the spool S, the temperature of the spool S, the control pressure of the hydraulic oil for controlling the drive of the control valve 500, etc. as information related to the state of the valve unit 10.

In addition, instead of detecting the pilot pressure of the hydraulic oil flowing through the pump port RP as information regarding the state of the valve unit 10, the detection unit 170 may detect the pressure of the hydraulic oil passing through a through hole SH formed in the spool S. This is because the hydraulic oil flowing in from the pump port RP flows into the through hole SH via the first through hole H1 and fills the first chamber K1 in the case 154 of the electric drive unit 151 from the other end S2 of the spool S, generating hydraulic pressure. Therefore, detecting the pressure of the hydraulic oil passing through the through hole SH is equivalent to detecting the pilot pressure of the hydraulic oil flowing through the pump port RP.

The temperature of the hydraulic oil may also be used as information on the state of the valve unit 10 and the drive unit 20. For example, the temperature of the hydraulic oil in the spool S is information on the state of the valve unit 10, and the temperature of the hydraulic oil in the case 154 is information on the state of the drive unit 20. The temperature of any part of the drive unit 20 is information on the state of the drive unit 20.
Specific examples of the temperature of any part of the drive unit 20 include the temperature of the hydraulic oil in the electric drive unit 151, the temperatures of the electromagnetic coil 152 and rod 153 constituting the electric drive unit 151, and the temperature of the case 154 itself. In addition, the detection unit 170 may detect the position of the rod 153, the moving speed of the rod 153, etc. as information on the state of the drive unit 20.

In the above embodiment, the control unit 200 controls the drive of the electric drive unit 151. However, this is not limited to the above, and the control unit 200 may also include a communication unit 30 (see FIG. 5). An example of the communication unit 30 is described below.

FIG. 5 is a schematic diagram showing a modified example of the hydraulic system 1. As shown in FIG.
5, the hydraulic system 1 may be configured to drive and control a plurality of electromagnetic proportional valves 150 by an integrated controller (an example of another control unit in the claims) 40. A communication unit 30 provided in the control unit 200 of each electromagnetic proportional valve 150 communicates with the integrated controller 40. This allows the integrated controller 40 to control each electromagnetic proportional valve 150 in an integrated manner. Furthermore, by providing the communication unit 30 in the control unit 200 in advance, the integrated controller 40 and the electromagnetic proportional valves 150 can communicate with each other without making major improvements to the integrated controller 40. This allows a user-friendly hydraulic system 1 to be provided.

In the above embodiment, the solenoid proportional valve 150 is used to apply the control pressure of the hydraulic oil to the control valve 500. However, this is not limited to this, and the configuration of the solenoid proportional valve 150 can be adopted in various configurations of solenoid proportional valves for controlling the control pressure of the hydraulic oil to fluid equipment (hydraulic equipment).

In the above embodiment, the spool hole H of the valve body 155 is arranged in this order from the end 155A of the valve body 155 opposite to the drive unit 20. The first through hole H1 is connected to the pump port RP. The valve body 155 has an actuator communication hole 156 that connects the third through hole H3 and the control port RA in the radial direction. However, this is not limited to this, and the pump port RP and the control port RA may be configured in reverse. That is, the first through hole H1 and the control port RA may be connected, and the third through hole H3 and the pump port RP may be connected in the radial direction. In this case, the detection unit 170 detects, for example, the pressure of the hydraulic oil flowing through the control port RA. Even in this configuration, the same effect as the above embodiment is achieved. In addition, the solenoid proportional valve can be controlled based on the control pressure to the control valve 500 in addition to the pilot pressure of the hydraulic oil flowing through the pump port RP.

1...hydraulic system (fluid system), 10...valve section, 20...drive unit section, 30...communication section, 40...integrated controller (other control section), 100...construction machine, 101...rotating body (vehicle body), 102...traveling body (vehicle body), 130...hydraulic pump (fluid pump), 140...actuator, 150...electromagnetic proportional valve, 151...electric drive section, 153...rod, 154...case, 170...detection section, 200...control section, 500...control valve, RA...control port, RD...drain port, RP...pump port, S...spool, S1...one end, S2...other end, SH...through hole

Claims (5)

a casing provided with a pump port and having a valve receiving hole communicating with the pump port;
a valve unit provided in the casing and a drive unit that drives the valve unit in response to a drive current;
Equipped with
The valve portion is
A cylindrical valve body accommodated in the valve accommodation hole;
a spool movably accommodated in a spool hole formed in the valve body along the axial direction;
a return spring that is accommodated in the spool hole and elastically pushes the spool toward an opposite side to the pump port;
Equipped with
The spool has a through hole along an axial direction through which the working fluid from the pump port passes,
the drive unit is provided at one end of the valve unit opposite to the pump port in the axial direction,
The drive unit includes:
a detection unit that detects a pressure of the working fluid passing through the through hole;
a control unit that controls the drive current based on a detection result of the detection unit;
an electric drive for driving the spool;
Equipped with
the electric drive unit includes a case provided at the one end of the valve unit,
The case accommodates , within the same space, a rod that pushes the spool from the side opposite to the pump port , the detection unit, and the control unit,
The same space and the through hole are in communication with each other,
the detection unit detects a pressure of the working fluid leaking from the pump port through the through hole between the spool and the rod and filling the case ,
The control unit is an electromagnetic proportional valve that controls the drive of the electric drive unit. The proportional solenoid valve according to claim 1 , wherein the spool, the electric driving unit, the detection unit, and the control unit are arranged in this order along the axial direction. The solenoid proportional valve according to claim 1 or 2, wherein the control unit is provided with a communication unit for transmitting and receiving data to and from other control units. A fluid pump that discharges a working fluid;
a control valve that switches an output destination of the working fluid;
an actuator driven by the working fluid supplied from the control valve;
an electromagnetic proportional valve that applies a control pressure of the working fluid to the control valve;
The solenoid proportional valve is
a casing provided with a pump port and having a valve receiving hole communicating with the pump port;
a valve unit provided in the casing and a drive unit that drives the valve unit in response to a drive current;
Equipped with
The valve portion is
A cylindrical valve body accommodated in the valve accommodation hole;
a spool movably accommodated in a spool hole formed in the valve body along the axial direction;
a return spring that is accommodated in the spool hole and elastically pushes the spool toward an opposite side to the pump port;
Equipped with
The spool has a through hole along an axial direction through which the working fluid from the pump port passes,
the drive unit is provided at one end of the valve unit opposite to the pump port in the axial direction,
The drive unit includes:
a detection unit that detects a pressure of the working fluid passing through the through hole;
a control unit that controls the drive current based on a detection result of the detection unit;
an electric drive for driving the spool;
Equipped with
the electric drive unit includes a case provided at the one end of the valve unit,
The case accommodates , within the same space, a rod that pushes the spool from the side opposite to the pump port , the detection unit, and the control unit,
The same space and the through hole are in communication with each other,
The detection unit is a fluid system that detects the pressure of the working fluid that leaks from the pump port through the through hole between the spool and the rod and fills the case . A fluid system;
A vehicle body on which the fluid system is mounted; and
Equipped with
The fluid system comprises:
A fluid pump that discharges a working fluid;
a control valve that switches an output destination of the working fluid;
an actuator driven by the working fluid supplied from the control valve;
an electromagnetic proportional valve that applies a control pressure of the working fluid to the control valve;
Equipped with
The solenoid proportional valve is
a casing provided with a pump port and having a valve receiving hole communicating with the pump port;
a valve unit provided in the casing and a drive unit that drives the valve unit in response to a drive current;
Equipped with
The valve portion is
A cylindrical valve body accommodated in the valve accommodation hole;
a spool movably accommodated in a spool hole formed in the valve body along the axial direction;
a return spring that is accommodated in the spool hole and elastically pushes the spool toward an opposite side to the pump port;
Equipped with
The spool has a through hole along an axial direction through which the working fluid from the pump port passes,
the drive unit is provided at one end of the valve unit opposite to the pump port in the axial direction,
The drive unit includes:
a detection unit that detects a pressure of the working fluid passing through the through hole;
a control unit that controls the drive current based on a detection result of the detection unit;
an electric drive for driving the spool;
Equipped with
the electric drive unit includes a case provided at the one end of the valve unit,
The case accommodates , within the same space, a rod that pushes the spool from the side opposite to the pump port , the detection unit, and the control unit,
The same space and the through hole are in communication with each other,
The detection unit detects the pressure of the working fluid that leaks from the pump port through the through hole , between the spool and the rod, and fills the case .

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