JP2020148293A - Electromagnetic proportional valve - Google Patents

Abstract

To provide a drive device in which a manual pin and a position of drawing out a power cable do not interfere with each other.SOLUTION: An electromagnetic proportional valve comprises a hollow housing 11 extending in an axial direction, a drive member 16 that is provided in the housing so as to be movable in the axial direction and drives a spool 22, and a pin 19 having a pin inclined surface inclined with respect to the axial direction. This pin comprises a pint that can move from a first position that is not in contact with the drive member in a radial direction orthogonal to the axial direction to a second position that is inward in the radial direction with respect to the first position and where the pin inclined surface 19b is in contact with the drive member.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an electromagnetic proportional valve.

There is known an electromagnetic proportional valve that controls the supply and discharge of pilot oil to be supplied to the hydraulic equipment to be controlled by adjusting the exciting current applied to the solenoid actuator and moving the position of the spool. Such an electromagnetic proportional valve is disclosed in Japanese Patent Application Laid-Open No. 2017-020541 (Patent Document 1).

In an electromagnetic proportional valve, if the electrical system for controlling the solenoid actuator fails, the spool may become difficult or impossible to move. For this reason, the electromagnetic proportional valve may be provided with a manual pin for manually changing the spool position. An electromagnetic proportional valve provided with such a manual pin is disclosed in Japanese Patent Application Laid-Open No. 2000-274547 (Patent Document 2).

JP-A-2017-020541 Japanese Unexamined Patent Publication No. 2000-274547

As shown in Patent Document 2, the power cable for supplying electric power to the solenoid coil may be arranged on the side surface of the housing accommodating the solenoid coil. The electromagnetic proportional valve may be used as a pilot valve for supplying a control pressure to the directional control valve. In construction machinery, multiple directional control valves are arranged so that their axial directions are parallel to each other. Therefore, when the power cable is pulled out from the side surface of the housing, the directional control valve operates under the control pressure of the electromagnetic proportional valve. It becomes difficult to arrange them compactly.

For this reason, it is conceivable that the power cable is pulled out from the end face at the axial end instead of the side surface of the housing. However, when the power cable is pulled out from the axial end face of the housing, the position where the power cable is pulled out interferes with the position where the manual pin is arranged. As described above, in the conventional electromagnetic proportional valve provided with the manual pin for manually adjusting the spool position, there is a problem that it is difficult to pull out the power cable from the end face of the housing.

It is an object of the present disclosure to provide a novel electromagnetic proportional valve capable of alleviating or solving at least a part of the conventional problems described above. One of the more specific objects of the present disclosure is to allow a power cable to be drawn from an axial end in an electromagnetic proportional valve provided with a manual pin for manually driving the spool. Objectives other than those mentioned above in the present disclosure will be manifested throughout the description herein.

The drive device according to the embodiment of the present invention includes a solenoid coil provided in the hollow portion of the housing and a spool provided in the hollow portion and movable in the axial direction by applying an exciting current to the solenoid coil. It has a driving member to be driven and a pin inclined surface inclined with respect to the axial direction, and is in the radial direction from the first position not in contact with the driving member in the radial direction orthogonal to the axial direction to the first position. It includes a pin that is inward and can be moved to a second position where the pin inclined surface is in contact with the driving member.

The solenoid proportional valve according to the embodiment of the present invention has a spool that can move in the axial direction, a valve unit that controls a control pressure to a controlled object by the movement of the spool, a housing having a hollow portion, and the hollow portion. With respect to the solenoid coil provided in the portion, the drive member provided in the hollow portion and driving the spool by moving in the axial direction by applying an exciting current to the solenoid coil, and the axial direction. The pin inclined surface has an inclined pin inclined surface, and the pin inclined surface is inward in the radial direction from the first position not in contact with the driving member in the radial direction orthogonal to the axial direction from the first position. It is provided with a pin that can be moved to a second position in contact with.

In one embodiment of the present invention, when the driving member has a driving member inclined surface having a shape complementary to the pin inclined surface and the pin is in the second position, the pin inclined surface is the driving member inclined surface. It is in contact with the face.

The solenoid proportional valve according to the embodiment of the present invention has a spool that can move in the axial direction, a valve unit that controls a control pressure to a controlled object by the movement of the spool, a housing having a hollow portion, and the hollow portion. The solenoid coil provided in the portion and the drive member provided in the hollow portion and driving the spool by moving in the axial direction by applying an exciting current to the solenoid coil are orthogonal to the axial direction. In the radial direction, it is possible to move from a first position not in contact with the drive member to a second position inward in the radial direction from the first position and in contact with the drive member, and at the second position, the drive member is movable. It is provided with a pin that exerts a thrust in the axial direction with respect to the above.

In one embodiment of the invention, a connector is provided that closes the opening of the housing, and the pin is provided between the connector and the housing.

In one embodiment of the invention, the connector has a flat surface extending parallel to the axial direction, and the pins are provided on the flat surface.

In one embodiment of the invention, the connector houses a portion of a cable for applying an exciting current to the solenoid coil.

The pin has a convex portion that protrudes outward in the radial direction from the connector.

The solenoid proportional valve according to the embodiment of the present invention has a spool that can move in the axial direction, a valve unit that controls a control pressure to a controlled object by the movement of the spool, a housing having a hollow portion, and the hollow portion. The solenoid coil provided in the portion, the drive member provided in the hollow portion and moving in the axial direction by applying an exciting current to the solenoid coil, and the opening of the housing are closed. From a first position which is provided between the connector and the housing and has a pin inclined surface inclined with respect to the axial direction and does not come into contact with the driving member in the radial direction orthogonal to the axial direction. A pin that is inward in the radial direction from the first position and is movable to a second position where the pin inclined surface is in contact with the driving member, and a solenoid coil having at least a part thereof housed in the connector. A cable for applying an exciting current is provided.

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 present disclosure, in an electromagnetic proportional valve including a manual pin for manually driving a spool, a power cable can be drawn from an axial end.

It is sectional drawing which shows typically the cross section along the axial direction of a part of the electromagnetic proportional valve 1 by one Embodiment of this invention. In FIG. 1, the pin 19 is in the first position not in contact with the plunger 16. It is sectional drawing which shows typically the cross section along the axial direction of a part of the electromagnetic proportional valve 1 by one Embodiment of this invention. In FIG. 2, the pin 19 is in the second position in contact with the plunger 16. It is a figure which shows typically the end face of the electromagnetic proportional valve 1 of FIG. It is a figure which shows typically the drive member and the pin provided in the electromagnetic proportional valve by another embodiment of this invention. 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 3. The electromagnetic proportional valve 1 includes a drive device 10 and a valve unit 20. The drive device 10 and the valve unit 20 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 and back directions in the present specification, the front-back direction shown in FIG. 1 is used as a reference unless it is understood separately in the context. Therefore, the valve unit 20 is arranged in front of the drive device 10.

The electromagnetic proportional valve 1 communicates a hydraulic device with a hydraulic source to supply oil from the hydraulic source to the hydraulic device, and communicates the hydraulic device with a tank for storing oil to supply oil from the hydraulic device to the tank. It is maintained in one of three states: the discharge position to discharge and the neutral position to shut off the hydraulic equipment from the hydraulic source and tank.

The valve unit 20 includes a hollow valve body 21 extending along an axial direction along the central axis A, and a spool 22 provided inside the valve body 21. The valve body 21 has a pressure source port that communicates with the pressure source, a tank port that communicates with the tank, and a control port that outputs a control pressure to the hydraulic equipment to be controlled. Illustrations are omitted for all ports.

The drive device 10 controls the position of the spool 22 in the axial direction by applying an axial thrust to the spool 22. The drive device 10 includes a hollow housing 11, a connector 12, a solenoid coil 14 provided in the hollow portion of the housing 11, a plunger 16 driven by the solenoid coil 14, and a cylindrical member 15 that guides the plunger 16. A drive rod 17 extending forward from the front end of the plunger 16 and a fixed iron core 18 are provided. The plunger 16 and the drive rod 17 are also provided in the hollow portion of the housing 11.

The housing 11 has a bottomed cylindrical shape extending along the central axis A direction. The front of the housing 11 opens toward the valve unit 20. The front opening of the housing 11 is sealed by the fixed iron core 18 and other sealing members. The bottom wall 11b of the housing 11 has a through hole extending in the axial direction. This through hole is closed by the connector 12.

The cylindrical member 15 has a bottomed cylindrical shape extending in the axial direction. The inner diameter of the cylindrical member 15 is substantially equal to the outer diameter of the large diameter portion 16a of the plunger 16. The cylindrical member 15 has a through hole 15a on its side surface for receiving the pin 19.

As shown in FIG. 3, the connector 12 has an upper wall 12a having a substantially rectangular shape when viewed from the direction of the central axis A, and a bottom wall arranged axially apart from the upper wall 12a. It has a 12b and four side walls 12c connecting the upper wall 12a and the bottom wall 12b. The upper wall 12a, the bottom wall 12b, and the side wall 12c define the internal space of the connector 12. The upper wall 12a has a through hole. The side wall 12c is generally flat. The side wall 12c has a flat flat surface. The connector 12 accommodates a part of the cable 13 in its internal space. Although not shown, the cable 13 is electrically connected to the solenoid coil 14. The solenoid coil 14 is excited based on a control signal input from a controller (not shown) via a cable 13. The connector 12 has a through hole extending in the axial direction, and the cable 13 is pulled out from the through hole.

Both the plunger 16 and the drive rod 17 are arranged on the central axis A. The plunger 16 and the drive rod 17 may have an integral one-piece structure. The plunger 16 and the drive rod 17 are provided so as to be movable in the axial direction. The drive rod 17 extends axially forward from the plunger 16. The tip end (front end) of the drive rod 17 is in contact with the base end (rear end) of the spool 22. Since the spool 22 is constantly urged rearward in the axial direction by a return spring (not shown), the contact between the drive rod 17 and the spool 22 is maintained.

At least a part of the plunger 16 is made of a magnetic material. At least a part of the plunger 16 is arranged inside the solenoid coil 14 in the radial direction. The plunger 16 is driven by the solenoid coil 14. That is, the plunger 16 can move in the axial direction by being driven by the solenoid coil 14. Specifically, the plunger 16 is attracted to the fixed iron core 18 by applying an exciting current to the solenoid coil 14. As a result, the plunger 16 and the drive rod 17 move forward in the axial direction to exert a thrust forward in the axial direction on the spool 22. In this way, the spool 22 is driven by the plunger 16 and the drive rod 17. In the present specification, a member that drives the spool 22 by electrical control is referred to as a driving member. Since the spool 22 is driven by the axial movement of the plunger 16 and the drive rod 17, the plunger 16 and the drive rod 17 are examples of drive members. The drive member may include a member other than the plunger 16 and the drive rod 17. The pin 19, which will be described later, is not included in the driving member because it is manually moved and is not electrically driven.

The spool 22 driven by the plunger 16 and the drive rod 17 moves forward in the axial direction. When the supply of the exciting current to the solenoid coil 14 is cut off, the spool 22 moves backward in the axial direction together with the plunger 16 and the drive rod 17 due to the unforced force from the urging member. In this way, by applying an exciting current to the solenoid coil 14, the position of the spool 22 in the axial direction can be changed, whereby the electromagnetic proportional valve 1 is switched to either the supply position, the discharge position, or the neutral position. be able to.

The bottom wall 11b of the housing 11 has a groove 11c on a part of its outer surface. The groove 11 extends radially on the outer surface of the bottom wall 11b. One of the four side walls 12c of the connector 12 is provided with a through hole 12c1 for receiving a pin. The pin 19 is provided in the groove 11. A part of the pin 19 extends from the outer space of the housing 11 through the through hole 12c1 to the inner space of the housing 11. As described above, the pin 19 is provided between the housing 11 and the connector 12. The pin 19 has a convex portion 19a that protrudes radially outward from the outer surface of the side wall 12c when viewed from the central axis A.

The pin 19 can move radially along the groove 11. FIG. 1 shows the pin 19 located at the first position in the radial direction, and FIG. 2 shows the pin 19 located at the second position in the radial direction. The second position of the pin 19 is a position inward in the radial direction from the first position. As shown in FIG. 1, the pin 19 does not contact the plunger 16 in the first position. When the pin 19 is located at the first position, the pin 19 is provided at a position that does not interfere with the stroke range of the plunger 16. As shown in FIG. 2, the pin 19 is in contact with the plunger 16 when it is located at the second position, which is radially inward from the first position. The pin 19 has a pin inclined surface 19b that is inclined with respect to the central axis A. The pin inclined surface 19b is a surface inside the pin 19 in the radial direction. The pin inclined surface 19b connects the first radial direction surface 19c and the second radial direction surface 19d of the surfaces of the pin 19 which are parallel to the radial direction and perpendicular to the axial direction. The first radial surface 19c is axially rearward of the second radial surface 19d. The pin inclined surface 19a is inclined so that the radial length of the first radial surface 19c is longer than the radial length of the second radial surface 19d. The position of the pin 19 shown in FIG. 2 is an example of the second position. The second position is the position where the pin 19 is in contact with the plunger 16. When the pin 19 is pushed inward in the radial direction from the first position, the pin inclined surface 19a first contacts the plunger 16 at the contact start position in the radial direction. The second position means a position inward in the radial direction from the contact start position.

When the pin 19 is in contact with the tip (rear end) of the plunger 16 on the pin inclined surface 19a, the pin 19 is further pushed inward in the radial direction to cause an axial thrust from the pin 19 to the plunger 16. Can act. Therefore, even if the plunger 16 cannot be driven by the solenoid coil 14 due to a defect in the electrical system, the plunger 16 and the drive rod 17 are pushed inward in the radial direction by, for example, being operated by an operator. Can be moved in the axial direction, and as a result, the position of the spool 22 can be switched.

A driving member and a pin in contact with the driving member in another embodiment will be described with reference to FIG. FIG. 4 is a diagram schematically showing a drive member and a pin provided in an electromagnetic proportional valve according to another embodiment of the present invention. The drive member shown in FIG. 4 has a plunger 116 and a drive rod 117 extending forward from the front end of the plunger 116. The plunger 116 has a drive member inclined surface 116a having a shape complementary to the pin inclined surface of the pin 119 at the rear end. In the illustrated embodiment, the drive member inclined surface 116a is inclined with respect to the central axis A at the same angle as the pin inclined surface 119a. The pin 119 pushed inward in the radial direction to the second position comes into contact with the driven member inclined surface 116a of the plunger 116 on the pin inclined surface 119a. When the pin inclined surface 119a of the pin 119 and the driving member inclined surface 116a of the plunger 116 are in contact with each other, the pin 119 is further pushed inward in the radial direction, so that the thrust in the axial direction from the pin 119 to the plunger 116 Can act.

Subsequently, the operation of the electromagnetic proportional valve 1 will be described. When the solenoid coil 14 is not excited, the spool 22 is maintained in the ejection position. From this state, when the solenoid coil 14 is excited, the plunger 16 is driven, and the plunger 16 moves forward along with the drive rod 17 in the axial direction. At this time, since the front end of the drive rod 17 is in contact with the spool 22, a thrust forward in the axial direction acts on the spool 22. This thrust causes the spool 22 to reach the neutral position from the discharge position. When a larger exciting current is applied to the solenoid coil 14, the plunger 16 and the drive rod 17 further move forward in the axial direction. By the thrust received from the drive rod 27, the spool 22 reaches the supply position, and the control pressure is supplied to the hydraulic device to be controlled.

When the plunger 16 cannot be driven by applying the exciting current to the solenoid coil 14 due to a malfunction of the electric system or other reasons, the operation of pushing the pin 19 or the pin 119 inward in the radial direction is performed by the operator. As a result, the plunger 16 is moved in the axial direction, whereby the position of the spool 22 can be switched.

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 according to the above embodiment has a hollow housing 11 extending in the axial direction, a plugger 16 and a drive rod 17 which are provided in the housing 11 so as to be movable in the axial direction and drive the spool 22, and the drive rod 17 in the axial direction. A pin 19 having a pin inclined surface that is inclined with respect to the pin 19 is provided. The pin 19 is located inward in the radial direction from the first position where the pin 19 and the plunger 16 do not contact in the radial direction by the operation of the operator, and the pin inclined surface 19b contacts the plunger 16. It can be moved to the second position. Therefore, even if the plunger cannot be electrically controlled due to a malfunction of the electric system or the like, the position of the spool 22 can be switched by operating the pin 19. Since the moving direction of the pin 19 is the radial direction perpendicular to the axial direction, it is easy to avoid interference between the pin 19 and the cable 13 pulled out in the axial direction.

In the above embodiment, the plunger 116 has a drive member inclined surface 116a having a shape complementary to the pin inclined surface 119a. As a result, when the pin 119 comes into contact with the plunger 116, it becomes a surface contact, so that damage to the pin 119 and the plunger 116 can be suppressed.

In the above embodiment, the side wall 12c of the connector 12 has a flat surface extending parallel to the axial direction, and the pin 19 is provided on the flat surface. Since the side surface of the housing 11 often has a cylindrical shape, it is often difficult to provide the pin 19 on the side surface of the housing 11. In the above embodiment, the pin 19 is attached to the flat surface of the side wall 12c of the connector 12, so that the pin 19 can be easily attached.

The pin 19 has a convex portion 19a that protrudes radially outward from the connector 12. As a result, the operator can easily operate the pin 19.

The dimensions, materials, arrangements, and steps of each component described herein are not limited to those expressly described in the embodiments, and each component is within the scope of the present invention. It can be transformed to have any size, material, arrangement, and process. 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 movement of the pin 19 inward in the radial direction does not have to be a linear movement. For example, the pins 19 and 119 may move inward in the radial direction by revolving around the axis. The shapes of pins 19 and 119 are not limited to those explicitly shown herein. The pins 19 and 119 have an arbitrary shape that can give an axial thrust to the plungers 16 and 116 when pushed further inward in the radial direction from the position in contact with the plungers 16 and 116. obtain.

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 12 Connector 13 Cable 14 Solenoid coil 16,116 Plunger 17 Drive rod 19,119 Pin 19a Convex part 19b, 119b Pin inclined surface 20 Valve unit 22 Spool 116a Drive member inclined surface

Claims (11)

Solenoid coil provided in the hollow part of the housing and
A drive member provided in the hollow portion and driving a spool that can move in the axial direction by applying an exciting current to the solenoid coil.
The pin has a pin inclined surface that is inclined with respect to the axial direction, and is located inward in the radial direction from the first position that does not contact the driving member in the radial direction orthogonal to the axial direction. A pin whose inclined surface can be moved to a second position in contact with the driving member,
A drive device equipped with. A valve unit that has a spool that can move in the axial direction and controls the control pressure to the controlled object by moving the spool.
A housing with a hollow part and
A solenoid coil provided in the hollow portion and
A drive member provided in the hollow portion and driving the spool by moving in the axial direction by applying an exciting current to the solenoid coil.
The pin has a pin inclined surface that is inclined with respect to the axial direction, and is located inward in the radial direction from the first position that does not contact the driving member in the radial direction orthogonal to the axial direction. A pin whose inclined surface can be moved to a second position in contact with the driving member,
Electromagnetic proportional valve equipped with. The driving member has a driving member inclined surface having a shape complementary to the pin inclined surface, and when the pin is in the second position, the pin inclined surface is in contact with the driving member inclined surface.
The electromagnetic proportional valve according to claim 2. A valve unit that has a spool that can move in the axial direction and controls the control pressure to the controlled object by moving the spool.
A housing with a hollow part and
A solenoid coil provided in the hollow portion and
A drive member provided in the hollow portion and driving the spool by moving in the axial direction by applying an exciting current to the solenoid coil.
In the radial direction orthogonal to the axial direction, it is possible to move from the first position not in contact with the driving member to the second position inward in the radial direction from the first position and in contact with the driving member. A pin that exerts an axial thrust on the driving member at two positions,
Electromagnetic proportional valve equipped with. A connector for closing the opening of the housing is provided.
The pin is provided between the connector and the housing.
The electromagnetic proportional valve according to any one of claims 2 to 4. The connector has a flat surface extending parallel to the axial direction.
The pin is provided on the flat surface.
The electromagnetic proportional valve according to claim 5. The connector houses a portion of a cable for applying an exciting current to the solenoid coil.
The electromagnetic proportional valve according to claim 5 or 6. The pin has a protrusion that projects radially outward from the connector.
The electromagnetic proportional valve according to any one of claims 5 to 7. A directional control valve including the electromagnetic proportional valve according to any one of claims 2 to 8. A construction machine including the direction switching valve according to claim 9. A valve unit that has a spool that can move in the axial direction and controls the control pressure to the controlled object by moving the spool.
A housing with a hollow part and
A solenoid coil provided in the hollow portion and
A drive member provided in the hollow portion and driving the spool by moving in the axial direction by applying an exciting current to the solenoid coil.
A connector that closes the opening of the housing and
The first position to the first position which is provided between the connector and the housing and has a pin inclined surface inclined with respect to the axial direction and does not come into contact with the driving member in a radial direction orthogonal to the axial direction. A pin that is inward in the radial direction and is movable to a second position where the pin inclined surface is in contact with the driving member.
A cable for applying an exciting current to the solenoid coil, at least a part of which is housed in the connector.
Electromagnetic proportional valve equipped with.

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