JP2020133803A - Electromagnetic proportional valve - Google Patents

Abstract

To detect control pressure of an electromagnetic proportional valve with a simplified mechanism without providing a gauge port or joint outside the electromagnetic proportional valve.SOLUTION: An electromagnetic proportional valve 1 comprises: a valve unit 30 that has a spool 70 that can move in an axial direction, and a control port part ap that is arranged on one side of the spool 70 in the axial direction and supplies control pressure to a control target; a drive device 10 that has a solenoid coil 23 that is arranged on the other side of the spool 70 in the axial direction and changes the control pressure by an exciting current, and a pressure receiving chamber that accommodates the solenoid coil 23 and is connected to the control port part ap; and a pressure sensor 15 that detects the control pressure in the pressure receiving chamber.SELECTED DRAWING: Figure 2

Description

The present disclosure primarily relates to electromagnetic proportional valves.

An electromagnetic proportional valve that adjusts the supply and discharge of pilot oil supplied to a controlled hydraulic device according to an exciting current is known. A conventional electromagnetic proportional valve includes a valve body that accommodates a spool that can move in the axial direction, and a drive device that drives the spool. In such an electromagnetic proportional valve, by switching the position of the spool in the axial direction, the control pressure according to the position of the spool can be supplied to the hydraulic device to be controlled.

The electromagnetic proportional valve is used as a pilot valve in a directional control valve as disclosed in Japanese Patent Application Laid-Open No. 2005-188707 (Patent Document 1). In the directional control valve described in the same publication, the spool position of the main spool is switched by the control pressure supplied from the electromagnetic proportional valve.

In order to calibrate the control pressure output from the electromagnetic proportional valve, it is necessary to monitor this control pressure. Conventionally, as described in Japanese Patent Application Laid-Open No. 2001-289202 (Patent Document 2), the control pressure output from the electromagnetic proportional valve to the connection block between the electromagnetic proportional valve and the valve structure to be controlled. The control pressure is detected by providing a gauge port for taking out the gauge port and attaching a pressure sensor for measuring the control pressure to this gauge port.

Japanese Unexamined Patent Publication No. 2005-188707 Japanese Unexamined Patent Publication No. 2001-289202

As described above, in order to detect the control pressure output from the conventional electromagnetic proportional valve, it is necessary to provide a gauge port in the connection block or provide a joint for attaching the pressure sensor to the connection block.

One of the objects of the present disclosure is to simplify the mechanism for detecting the control pressure of the electromagnetic proportional valve. One of the objects of the present disclosure is to enable the control pressure of the electromagnetic proportional valve to be detected without providing a gauge port or a joint outside the electromagnetic proportional valve. Objectives other than those mentioned above in the present disclosure will be manifested throughout the description herein.

The solenoid proportional valve according to the embodiment of the present invention has a spool that can move in the axial direction and a control port portion that is arranged on one side of the spool in the axial direction and supplies control pressure to a controlled object. A unit, a solenoid coil arranged on the other side of the spool in the axial direction and changing the control pressure by an exciting current, and a pressure receiving chamber accommodating the solenoid coil and connected to the control port portion. A drive device having a

The electromagnetic proportional valve according to the embodiment of the present invention includes a pressure sensor that detects the control pressure in the pressure receiving chamber.

The solenoid proportional valve according to the embodiment of the present invention is movably housed in a valve body, a control port portion arranged on one side in the axial direction of the valve body, and a position in the axial direction. A valve unit having a spool that changes the control pressure of the control port portion, and a spool that is arranged on the opposite side of the control port portion with respect to the valve unit, and the axial position of the spool is changed by an exciting current. It is provided with a drive device having a solenoid coil to be operated, a housing for accommodating the solenoid coil, and a pressure receiving chamber in the housing and connected to the control port portion.

In one embodiment of the invention, the housing comprises a pressure sensor that detects the control pressure in the pressure receiving chamber.

The electromagnetic proportional valve according to one embodiment of the present invention covers the pressure sensor and includes a lid attached to the housing.

In one embodiment of the invention, the drive unit comprises a drive rod that defines at least a portion of the pressure receiving chamber.

In one embodiment of the present invention, the drive unit defines at least a part of the pressure receiving chamber and includes a plunger provided on the drive rod.

The solenoid proportional valve according to the embodiment of the present invention is movably housed in a valve body, a control port portion arranged on one side of the valve body in the axial direction, and a position in the axial direction. A valve unit having a spool that changes the control pressure of the control port portion, and a spool that is arranged on the opposite side of the control port portion with respect to the valve unit, and the axial position of the spool is changed by an exciting current. A drive device having a solenoid coil to be operated, a housing for accommodating the solenoid coil, and a pressure receiving chamber in the housing and connected to the control port portion, and a pressure sensor for detecting the control pressure in the pressure receiving chamber. And a lid portion that covers the pressure sensor and is attached to the housing.

The directional control valve according to the embodiment of the present invention includes any of the above electromagnetic proportional valves.

The construction machine according to the embodiment of the present invention includes the above-mentioned direction switching valve.

According to the embodiment of the present invention, the control pressure output from the electromagnetic proportional valve can be detected without providing a gauge port or a joint outside the electromagnetic proportional valve.

It is a figure which shows typically the appearance of the electromagnetic proportional valve by one Embodiment of this invention. It is a vertical sectional view of the electromagnetic proportional valve of FIG. In FIG. 2, the spool is in the neutral position. It is a vertical sectional view of the electromagnetic proportional valve of FIG. In FIG. 2, the spool is in the supply position. It is a vertical sectional view of the electromagnetic proportional valve of FIG. In FIG. 2, the spool is in the discharge position. It is a block diagram explaining the directional control valve including the electromagnetic proportional valve of FIG. It is a block diagram explaining the construction machine provided with the direction switching valve of FIG.

Hereinafter, various embodiments of the present invention will be described with reference to the drawings as appropriate. The components common to the plurality of drawings are designated by the same reference numerals throughout the plurality of drawings. It should be noted that each drawing is not always drawn to the correct scale for convenience of explanation. In each drawing, some components may be omitted for convenience of explanation.

The electromagnetic proportional valve 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram schematically showing the appearance of the electromagnetic proportional valve 1 according to the embodiment of the present invention, and FIGS. 2 to 4 are vertical cross-sectional views of the electromagnetic proportional valve 1.

As shown in the figure, the electromagnetic proportional valve 1 includes a drive device 10 and a valve unit 30. The drive device 10 and the valve unit 30 are arranged along the central axis A. In the present specification, the direction along the central axis A may be simply referred to as "axial direction". When referring to the front-back direction in the axial direction in the present specification, the front-back direction shown in FIGS. 1 to 4 is used as a reference unless otherwise understood in the context. According to this usage, the valve unit 30 is located in front of the drive device 10.

The valve unit 30 includes a hollow valve body 40 extending in the axial direction and a spool 70 provided on the valve body 40 so as to be movable in the axial direction.

The drive device 10 drives the spool 70 and controls the position of the spool 70 in the axial direction. The drive device 10 includes a hollow housing 11, a lid portion 12, a pressure sensor 15, a solenoid coil 23, a fixed iron core 24, a plunger 26, and a drive rod 27 provided on the plunger 26. ..

The housing 11 has a cylindrical shape extending along the central axis A direction. The housing 11 has an outer wall 11a for partitioning the inner space and the outer space, and a guide wall 11b. The outer wall 11a has a cylindrical shape. The guide wall 11b has a cylindrical shape that is concentric with the outer wall 11a and has a smaller diameter than the outer wall 11a. The guide wall 11b is provided at a position radially separated from the outer wall 11a. As a result, a space is defined between the outer wall 11a and the guide wall 11b. The solenoid coil 23 is supported in the space between the outer wall 11a and the guide wall 11b.

The housing 11 has a through hole extending in the axial direction. In other words, the housing 11 is hollow, and its internal space opens to the front and rear of the housing 11. The front opening of the housing 11 is sealed by a fixed iron core 24. The rear opening of the housing 11 is sealed by the lid 12. The lid 12 keeps the pressure receiving chamber at a controlled pressure by sealing the opening at the rear of the housing 11. The lid portion 12 is a member other than the above for closing the cap, the lid body, the seal, and the opening at the rear of the housing 11 to maintain the pressure receiving chamber at the control pressure. The lid portion 12 may be integrated with the housing 11. In other words, the lid portion 12 and the housing 11 may have an integral one-piece structure. In addition to the fixed iron core 24 and the lid portion 12, a sealing member is used as necessary to seal the opening of the housing 11. The shape and arrangement of the lid 12 is not limited to those expressly described herein. The lid 12 may seal the rear opening of the housing 11 in cooperation with other members.

Both the plunger 26 and the drive rod 27 are arranged on the central axis A in a cylindrical space defined by the guide wall 11b. Both the plunger 26 and the drive rod 27 are provided so as to be movable in the front-rear direction along the central axis A. The plunger 26 and the drive rod 27 may have an integral one-piece structure. The drive rod 27 extends axially forward from the plunger 26. In the illustrated embodiment, the drive rod 27 protrudes slightly rearward in the axial direction from the plunger 26. The drive rod 27 is a rod-shaped member extending along the central axis A.

At least a part of the plunger 26 is made of a magnetic material. At least a part of the plunger 26 is arranged inside the solenoid coil 23 in the radial direction. The plunger 26 has a through hole 26a extending in the axial direction at a position shifted radially outward from the central axis A.

The internal space of the housing 11 is partitioned by the plunger 26. Specifically, the internal section of the housing 11 includes a first solenoid chamber 14a located on the rear side of the plunger 26 in the axial direction and a second solenoid chamber 14b located on the front side of the plunger 26 in the axial direction. It is partitioned. The first solenoid chamber 14a and the second solenoid chamber 14b are connected by a through hole 26a. In this way, the through hole 26a connects the first solenoid chamber 14a and the second solenoid chamber 14b. In the present specification, the flow path of the hydraulic oil defined by the through hole 26a may be referred to as a first connection flow path cp1.

The pressure sensor 15 is a sensor that detects the pressure in the first solenoid chamber 14a. The pressure sensor 15 transmits a detection signal indicating the detected pressure to a controller (not shown). In one embodiment, the pressure sensor 15 is provided so that at least a part thereof is exposed to the first solenoid chamber 14a. In the illustrated embodiment, the lower surface 15a of the pressure sensor 15 may be partially exposed to the first solenoid chamber 14a, or the entire lower surface 15a may be exposed to the first solenoid chamber 14a. The lower surface 15a of the pressure sensor 15 may have a stainless diaphragm, a silicon diaphragm, or a diaphragm other than these. The pressure sensor 15 may include a strain gauge that converts a change in electrical resistance caused by deformation of the diaphragm into an electrical signal. The pressure sensor applicable to the present invention is not limited to that explicitly described herein.

In the illustrated embodiment, the pressure sensor 15 is provided on the lid 12. At least a part of the pressure sensor 15 is covered by the lid portion 12. The installation location of the pressure sensor 15 is not limited to the position shown in the figure. The pressure sensor 15 may be provided at another position on the cap 15. The pressure sensor 15 may be provided on a component of the electromagnetic proportional valve 1 other than the lid portion 12. The pressure sensor 15 may be provided in the housing. For example, the pressure sensor 15 may be attached to the inner peripheral surface of the housing 11.

The solenoid coil 23 is excited based on a control signal input from a controller (not shown). The controller includes a processor that performs various arithmetic processes, a memory that stores various programs and various data, and a device interface. The device interface is connected to the solenoid coil 23, the pressure sensor 15, and other devices. The controller drives the plunger 26 and the drive rod 27 by outputting a control signal (control pulse) to the solenoid coil 23, thereby switching the position of the spool 70. The controller identifies the control pressure output to the control port unit a, which will be described later, based on the detection signal from the pressure sensor 15.

The fixed iron core 24 has a substantially cylindrical shape. The fixed iron core 24 has a through hole extending in the axial direction at the center in the radial direction thereof. A drive rod 27 is inserted into this through hole. The drive rod 27 can enter the internal space of the valve unit 30 from the fixed iron core 24. The tip (front end) of the drive rod 27 is in contact with the base end (rear end) of the spool 70.

The fixed iron core 24 has a through hole 24a extending in the axial direction at a position shifted radially outward from the central axis A. The through hole 24a is provided at a position facing the through hole 26a. The second solenoid chamber 14b and the spare chamber 41 described later are connected by a through hole 24a. The second solenoid chamber 14b and the spare chamber 41 are connected by the through hole 24a. In the present specification, the flow path defined by the through hole 24a may be referred to as a second connection flow path cp2.

The plunger 26 is driven by the solenoid coil 23. That is, the plunger 26 can move in the axial direction by being driven by the solenoid coil 23. Specifically, when an exciting current is applied to the solenoid coil 23, the plunger 26 is attracted to the fixed iron core 24, whereby the plunger 26 and the drive rod 27 move forward in the axial direction. When the drive rod 27 moves forward in the axial direction, the spool 70 is pushed forward in the axial direction by the drive rod 27. In this way, the spool 70 is driven by the drive unit having the solenoid coil 23, the fixed iron core 24, the plunger 26, and the drive rod 27.

Next, the valve unit 30 will be described. As described above, the valve unit 30 includes a valve body 40 and a spool 70 movably provided on the valve body 40. The valve body 40 has a through hole 40a extending in the axial direction. The through hole 40a extends axially from the front end to the rear end of the valve body 40. The valve body 40 has a recess 40b in the radial center of the rear end. The spare chamber 41 is defined by the upper surface of the valve body 40 that defines the recess 40b, the front surface of the fixed iron core 24, the drive rod 27, and the spool 70.

The valve body 40 has a pressure source port portion pp connected to the pressure source P, a tank port portion tp connected to the tank T, and a control port portion ap to which the control pressure is output. The control port portion ap is arranged on one side (front) of the spool 70 or the valve body 40 in the axial direction. A solenoid coil 23 is provided on the other side (rear) of the spool 70 in the axial direction. The control port portion a consists of a region near the front end of the through hole 40a. The control port unit ap is connected to the hydraulic device to be controlled via a flow path (not shown). As a result, the control pressure is supplied to the hydraulic equipment to be controlled by the control port unit ap.

The spool 70 has an axial shape extending in the axial direction. The spool 70 is provided in the through hole 40a so as to be movable in the axial direction. The rear end of the spool 70 is in contact with the tip of the drive rod 27. The spool 70 has a through hole 70a extending along the central axis A. The through hole 70a extends from the front end 70b of the spool to the rear end 70c. The spool 70 has a plurality of flow paths through which hydraulic oil flows. In the illustrated embodiment, the through hole 70a of the spool 70 defines the main flow path mp through which the hydraulic oil flows. The main flow path mp extends from the front end 70b of the spool to the rear end 70c. Therefore, the main flow path mp is open to the control port portion ap. Further, the spool 70 has a first branch flow path bp1 and a second branch flow path bp2 extending from the main flow path mp to the outer surface of the spool 70. The spool 70 has a third connection flow path cp3 that connects the main flow path mp and the spare chamber 41 near the rear end in the axial direction.

The valve unit 30 has an urging member 80 arranged in the valve body 40. The urging member 80 urges the spool 70 toward the drive rod 27. In other words, the urging member 80 urges the spool 70 rearward along the central axis A. The urging member 80 is, for example, a compression spring.

The spool 70 is in constant contact with the drive rod 27 due to the axially rearward urging force received from the urging member 80. Therefore, when the drive rod 27 moves forward along the central axis A, the spool 70 also moves forward along the central axis with respect to the valve body 40 due to the thrust from the drive rod 27. On the contrary, when the drive rod 27 moves rearward along the central axis A, the spool 70 moves rearward along the central axis A while being in contact with the drive rod 70 due to the urging force from the urging member 80. The thrust acting from the drive rod 27 to the spool 70 has a magnitude corresponding to the exciting current of the solenoid coil 23. Therefore, the position of the spool 70 in the axial direction can be controlled by adjusting the magnitude of the exciting current applied to the solenoid coil 23.

The spool 70 is switched to at least one of a neutral position, a supply position, or a discharge position. FIG. 2 shows the electromagnetic proportional valve 1 in which the spool 70 is in the neutral position, FIG. 3 shows the electromagnetic proportional valve 1 in which the spool 70 is in the supply position, and FIG. 4 shows the electromagnetic proportional valve 1 in which the spool 70 is in the discharge position. 1 is shown.

When the spool 70 is located in the neutral position shown in FIG. 2, the ports pp, tp, ap are cut off from each other. In this case, hydraulic oil is not supplied or discharged to the hydraulic equipment connected to the control port unit a.

When the spool 70 is located at the supply position shown in FIG. 3, the control port portion ap is connected to the pressure source port portion pp via the main flow path mp and the first branch flow path bp1, and the tank port portion tp It is blocked from other ports pp and ap. As a result, hydraulic oil is supplied from the pressure source P to the hydraulic equipment. Further, the control port unit ap is the first solenoid via the main flow path mp, the third connection flow path cp3, the spare chamber 41, the second connection flow path cp2, the second solenoid chamber 14b, and the first connection flow path cp1. Since it is connected to the chamber 14a, when the spool 70 is located at the supply position, the first solenoid chamber 14a is maintained at the control pressure which is the pressure of the hydraulic oil in the control port portion ap. Since the first solenoid chamber 14a and the space between the first solenoid chamber 14a and the control port portion ap (for example, the second solenoid chamber 14b) are maintained at the control pressure of the control port portion ap, these Part or all of the space is a pressure receiving chamber. For example, at least one of the first solenoid chamber 14a and the second solenoid chamber 14b is a pressure receiving chamber maintained by the control pressure of the control port portion a. The solenoid coil 23 is housed in this pressure receiving chamber. At least a part of this pressure receiving chamber is defined by a drive rod 27. At least a part of this pressure receiving chamber is defined by the plunger 26.

When the spool 70 is located at the discharge position shown in FIG. 4, the control port portion ap is connected to the tank port portion tp via the main flow path mp and the first branch flow path bp1, and the pressure source port portion pp. Is blocked from other ports tp and ap. As a result, oil is discharged from the hydraulic equipment to the tank T.

Subsequently, the operation of the electromagnetic proportional valve 1 will be described. When the solenoid coil 23 is not excited, the urging force of the urging member 80 keeps the spool 70 in the discharge position shown in FIG. At this time, as described above, the flow path from the control port portion ap to the tank port portion tp via the main flow path mp of the spool 70 and the second branch flow path bp2 is opened. Therefore, the oil is recovered from the hydraulic equipment connected to the control port portion ap to the tank T connected to the tank port portion tp.

From this state, when the solenoid coil 23 is excited, the plunger 26 is driven, and the plunger 26 moves axially forward together with the drive rod 27 against the urging force from the urging member 80. At this time, since the front end of the drive rod 27 is in contact with the spool 70, a thrust forward in the axial direction acts on the spool 70. This thrust causes the spool 70 to reach the neutral position shown in FIG. 2 from the discharge position. When the spool 70 is located in the neutral position, the connection between the first branch flow path bp1 and the pressure source port portion pp is cut off, and the connection between the second branch flow path bp2 and the tank port portion tp is also cut off. Therefore, when the spool 70 is located in the neutral position, the oil is not discharged from the hydraulic equipment connected to the control port portion ap and the oil is not supplied to the hydraulic equipment.

When a larger exciting current is applied to the solenoid coil 23, the plunger 26 and the drive rod 27 further move forward in the axial direction. Due to the thrust received from the drive rod 27, the spool 70 reaches the supply position shown in FIG. When the spool 70 is located at the supply position, the flow path from the control port portion ap to the pressure source port portion pp via the main flow path mp of the spool 70 and the first branch flow path bp1 is opened. As a result, oil is supplied from the pressure source P connected to the pressure source port portion pp to the hydraulic equipment connected to the control port portion ap. When the spool 70 is located at the supply position, the amount of oil supplied from the pressure source P to the hydraulic equipment is the area where the first branch flow path bp1 and the pressure source port portion pp overlap, that is, the pressure of the first branch flow path bp1. It changes according to the amount of wrap with the source port portion pp. More specifically, the larger the exciting current, the larger the amount of lap between the first branch flow path bp1 and the pressure source port portion pp, and more oil flows from the pressure source port portion pp to the control port portion ap. Therefore, the larger the exciting current flow, the larger the control pressure output to the control port unit ap.

As described above, the control port unit ap passes through the main flow path mp, the third connection flow path cp3, the spare chamber 41, the second connection flow path cp2, the second solenoid chamber 14b, and the first connection flow path cp1. It is connected to the first solenoid chamber 14a. Therefore, while the spool 70 is located at the supply position, the first solenoid chamber 14a is maintained at the control pressure output from the control port unit ap. The pressure in the first solenoid chamber 14a is detected by the pressure sensor 15, and an electric signal indicating the detected pressure is output from the pressure sensor 15 to the controller. As described above, the control pressure output from the electromagnetic proportional valve 1 can be detected without attaching a gauge port or an external pressure sensor between the electromagnetic proportional valve 1 and the hydraulic device to be controlled. ..

Subsequently, an application example of the electromagnetic proportional valve 1 will be described with reference to FIGS. 5 and 6. FIG. 5 is a block diagram illustrating a directional control valve 100 including an electromagnetic proportional valve 1. As shown in the figure, the directional control valve 100 includes an electromagnetic proportional valve 1 and a valve structure 2 that operates by a control pressure supplied from the electromagnetic proportional valve 1. The valve structure 2 includes a main spool, and the amount of hydraulic oil supplied to a hydraulic cylinder (not shown) is adjusted by switching the position of the main spool according to the control pressure output from the electromagnetic proportional valve 1.

FIG. 6 is a block diagram illustrating a construction machine 200 including a direction switching valve 100. The construction machine 200 includes a direction switching valve 100. A construction machine is, for example, a hydraulic excavator operated by hydraulic pressure. The construction machine 200 includes various hydraulic cylinders. The hydraulic cylinder included in the construction machine 200 includes a boom cylinder for driving the boom, an arm cylinder for driving the arm, a bucket cylinder for driving the bucket, and other hydraulic cylinders. The direction switching valve 100 controls the amount of hydraulic oil supplied to the hydraulic cylinder provided in the construction machine 200.

Subsequently, the action and effect of the above embodiment will be described. The electromagnetic proportional valve 1 includes a pressure receiving chamber maintained at a control pressure supplied to a controlled object, and a pressure sensor 15 for detecting the control pressure in the pressure receiving chamber. This eliminates the need to provide a gauge port for taking out control pressure and a joint for attaching a pressure sensor to the outside of the electromagnetic proportional valve 1. Therefore, according to the electromagnetic proportional valve 1 according to the above embodiment, the control pressure output by the electromagnetic proportional valve 1 can be detected by a simple mechanism. Further, since the gauge port and the joint for the pressure sensor are not required, the connection block between the electromagnetic proportional valve 1 and the hydraulic device to be controlled can be made compact.

In the above embodiment, the pressure receiving chamber is, for example, at least one of the first solenoid chamber 14a and the second solenoid chamber 14b. In the illustrated embodiment, the pressure sensor 15 detects the pressure in the first solenoid chamber 14a. The pressure sensor 15 may be provided so as to detect the pressure in the second solenoid chamber 14b. In this case, the pressure sensor 15 may be provided so as to be exposed to the second solenoid chamber 14b. Two pressure sensors 15 may be provided to detect the control pressure in each of the first solenoid chamber 14a and the second solenoid chamber 14b.

In the above embodiment, the pressure sensor 15 is provided in the housing 11. As a result, it is not necessary to provide a pressure sensor outside the electromagnetic proportional valve 1. Therefore, the control pressure of the electromagnetic proportional valve can be detected by a compact mechanism.

In the above embodiment, the pressure sensor 15 is provided on the lid 12 that seals the opening of the housing 11. By providing the pressure sensor 15 on the cap that seals the opening, the pressure sensor 15 is provided at a position close to the surface of the housing 11. As a result, the detection signal of the pressure sensor 15 can be easily taken out to the outside. For example, when a signal line is provided between the pressure sensor 15 and the controller and the detection signal of the pressure sensor 15 is transmitted to the controller via this signal line, the signal line can be easily routed.

The dimensions, materials, and arrangement of each component described herein are not limited to those expressly described in the embodiments, and each component may be included within the scope of the present invention. Can be transformed to have the dimensions, materials, and arrangement of. In addition, components not explicitly described in the present specification may be added to the described embodiments, or some of the components described in each embodiment may be omitted.

Specific shapes, arrangements, functions, and materials of the components of the drive device 10 and the valve unit 30 specified in the present specification and the accompanying drawings are examples. Unless contrary to the gist of the present invention, the shape, arrangement, function, and material of each component of the drive device 10 and the valve unit 30 can be changed as appropriate. For example, the drive device 10 may drive the drive rod so that the drive rod 27 moves rearward in the axial direction when an exciting current is passed through the solenoid coil 23.

1 Electromagnetic proportional valve 10 Drive device 11 Housing 12 Lid 14a First solenoid chamber 14a
14b 2nd solenoid chamber 14b
15 Pressure sensor 23 Solenoid coil 24 Fixed iron core 26 Plunger 27 Drive rod 30 Valve unit 40 Valve body 70 Spool P Pressure source T Tank ap Control port part pp Pressure source port part tp Tank port part mp Main flow path cp1 First connection flow Road cp2 2nd connection flow path cp3 3rd connection flow path

Claims (10)

A valve unit having a spool that can move in the axial direction and a control port unit that is arranged on one side of the spool in the axial direction and supplies control pressure to a controlled object.
A drive having a solenoid coil arranged on the other side of the spool in the axial direction and changing the control pressure by an exciting current, and a pressure receiving chamber accommodating the solenoid coil and connected to the control port portion. With the device
Electromagnetic proportional valve equipped with. The electromagnetic proportional valve according to claim 1, further comprising a pressure sensor that detects the control pressure in the pressure receiving chamber. A valve body, a control port portion arranged on one side in the axial direction of the valve body, and a spool that is movably housed in the valve body and changes the control pressure of the control port portion depending on the axial position. And, with a valve unit,
A solenoid coil arranged on the opposite side of the control port portion with respect to the valve unit and changing the axial position of the spool by an exciting current, a housing for accommodating the solenoid coil, and a housing inside the housing. A drive device having a pressure receiving chamber connected to the control port unit, and
Electromagnetic proportional valve equipped with. The electromagnetic proportional valve according to claim 3, wherein the housing includes a pressure sensor that detects the control pressure in the pressure receiving chamber. The electromagnetic proportional valve according to claim 4, further comprising a lid portion that covers the pressure sensor and is attached to a housing. The electromagnetic proportional valve according to any one of claims 3 to 5, wherein the drive unit includes a drive rod that defines at least a part of the pressure receiving chamber. The electromagnetic proportional valve according to any one of claims 3 to 6, wherein the drive unit defines at least a part of the pressure receiving chamber and includes a plunger provided on the drive rod. A valve body, a control port portion arranged on one side in the axial direction of the valve body, and a spool that is movably housed in the valve body and changes the control pressure of the control port portion depending on the axial position. And, with a valve unit,
A solenoid coil arranged on the opposite side of the control port portion with respect to the valve unit and changing the axial position of the spool by an exciting current, a housing for accommodating the solenoid coil, and the housing inside the housing. A drive device having a pressure receiving chamber connected to a control port unit, and
A pressure sensor that detects the control pressure in the pressure receiving chamber, and
A lid that covers the pressure sensor and is attached to the housing,
Electromagnetic proportional valve equipped with. A directional control valve including the electromagnetic proportional valve according to any one of claims 1 to 8. A construction machine provided with the direction switching valve according to claim 9.

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