JPH1038122A - Electromagnetic valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supress as possible the magnetic reluctance in the gap through which the magnetic flux passes and enlarge as possible the passage area of the channel. SOLUTION: The electromagnetic valve 1 comprises a plunger 20 which opens and closes a discharge port C, a channel 44 communicated with the discharge port C, a core 31 disposed facing to the plunger 20, a magnetic coil 30 which forms a magnetic circuit connecting the plunger 20 with the core and moves the plunger 20 with a magnetic attracting force and a compression spring 25 which moves the plunger 20 in the opposite direction to the magnetic coil 30. In this case, a relative movement of the plunger 20 and the core 31 is allowed, and the gap through which the magnetic flux passes is formed at a position avoiding then channel 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve used for a hydraulic control device of an automatic transmission of a vehicle, for example.

[0002]

2. Description of the Related Art Generally, an automatic transmission is provided with a gear transmission mechanism and a friction engagement device.
Shifting is performed by release. An electromagnetic valve is used in a hydraulic control device that supplies hydraulic pressure to the friction engagement device,
By controlling the duty ratio of the solenoid valve, the hydraulic pressure acting on the friction engagement device is adjusted. An example of this solenoid valve is disclosed in Japanese Patent Application No. Hei 7-31860 previously proposed by the present applicant.
There is No. 7.

In this electromagnetic valve, a valve body made of a magnetic substance, an electromagnetic coil for moving the valve element, and a valve element moving in a direction opposite to the electromagnetic coil are placed inside a cylindrical yoke made of a magnetic substance. An elastic body to be made and a core as a magnetic body provided next to the valve body are arranged. The valve element and the core are arranged with a gap that allows relative movement. Further, inside the yoke, an inlet passage communicating with the hydraulic pressure source, an outlet passage communicating with the shift valve, and a discharge passage communicating with the oil pan are formed.

In the electromagnetic valve having the above structure, when the electromagnetic coil is turned off, the valve body is pressed in a predetermined direction by the elastic force of the elastic body, and the inflow port between the inlet flow path and the outlet flow path is opened. While being released, hydraulic pressure is supplied to the shift valve, and the discharge port between the outlet flow path and the discharge flow path is closed by the valve body. Further, when the electromagnetic coil is turned on, a magnetic circuit connecting the yoke, the valve body and the core is formed, and the valve body moves against the elastic force of the elastic body due to the magnetic attraction. as a result,
The inflow port is closed by the valve body, the discharge port is opened, and the hydraulic pressure supplied to the shift valve is discharged from the discharge flow path.

[0005]

In the above-described electromagnetic valve, since the valve element is moved by the magnetic attraction force, the response of the valve element depends on the strength of the magnetic attraction force. Therefore, it is desirable to reduce the magnetic resistance by setting the portion through which the magnetic flux passes, specifically, the gap between the valve element and the core as narrow as possible.

[0006] On the other hand, in the automatic transmission as described above, it may be required to quickly supply and discharge the hydraulic pressure acting on the shift valve. Therefore, it is desirable to increase the flow area of the flow path of the solenoid valve as much as possible and to secure a flow at a large flow rate.

However, in the conventional solenoid valve, the gap through which the magnetic flux passes forms a part of the flow path of the fluid. Therefore, it is possible to achieve both improvement of the operation response of the valve body and securing a large flow rate. could not.

The present invention has been made in view of the above circumstances, and is an electromagnetic valve capable of suppressing magnetic resistance in a gap through which a magnetic flux passes as much as possible and expanding a flow area of a flow path as much as possible. The purpose is to provide.

[0009]

In order to achieve the above object, the invention described in claim 1 provides a valve for opening and closing a port, a flow passage communicating with the port, and a valve. A magnetic body disposed to face, an electromagnetic coil that forms a magnetic circuit connecting the valve body and the magnetic body to move the valve body by magnetic attraction, and that the valve body is opposite to the electromagnetic coil. In an electromagnetic valve having an elastic body that moves in the direction, relative movement between the valve body and the magnetic body is allowed,
A gap through which the magnetic flux passes is formed at a position avoiding the flow path.

According to the first aspect of the present invention, the gap through which the magnetic flux passes is set as narrow as possible to suppress the magnetic resistance, and the magnetic attraction force acting on the valve body is increased to improve the operation response of the valve body. Let
In addition, the flow area of the flow path can be expanded as much as possible to ensure the flow of a large flow rate.

According to a second aspect of the present invention, the valve body is formed in a cylindrical shape, and the magnetic body is disposed inside the valve body.

According to the second aspect of the present invention, the same effect as in the first aspect can be obtained, and the arrangement space in the axial direction is reduced as much as possible by arranging the valve body and the magnetic body in the radial direction. This can contribute to downsizing of the solenoid valve.

[0013] The invention according to claim 3 is provided on the valve body,
A first pressure receiving surface on which fluid pressure in a direction opposite to the power of the electromagnetic coil or the elastic body acts, and a contact surface with which the valve element moved by the power of the electromagnetic coil or the elastic body abuts. A second pressure receiving surface provided on the valve body, and having a fluid pressure acting against a fluid pressure acting on the first pressure receiving surface in a state where the valve body is in contact with the contact surface. It is characterized by having.

According to the third aspect of the invention, the same operation as in the first or second aspect can be obtained, and when the valve body is in contact with the contact surface, it acts on the second pressure receiving surface. The fluid pressure reduces the fluid pressure acting on the first pressure receiving surface. Therefore, the magnetic attraction force of the electromagnetic coil or the elastic force of the elastic body required to move the valve body can be suppressed as much as possible, and the operation response of the valve body is further improved.

[0015]

Next, the present invention will be described with reference to the drawings. FIG. 1 shows a solenoid valve 1 according to one embodiment of the present invention.
FIG. 2 is an enlarged sectional view showing a main part of the solenoid valve 1. This electromagnetic valve 1 is used, for example, in a hydraulic control device of an automatic transmission (not shown).

In FIG. 1, reference numeral 2 denotes a yoke integrally formed of a magnetic material, for example, steel. The yoke 2 has a cylindrical large-diameter portion 3 and an inward flange 4 provided at one end of the large-diameter portion 3.
And a cylindrical small-diameter portion 5 protruding from the inner peripheral end of the flange 4 to the outside of the large-diameter portion 3. The large-diameter portion 3 and the small-diameter portion 5 are centered on the same axis A, and the small-diameter portion 5 is provided with a fixing hole 6 having a circular cross section penetrating around the axis A.

A cylindrical sleeve 7 protruding toward the inner space of the large-diameter portion 3 is provided on the inner peripheral end of the inward flange 4.
Is provided. The sleeve 7 is provided with a notch 8 extending from the outer peripheral surface to the inner peripheral surface.

An outlet channel 9 is formed in the small diameter portion 5.
An outlet channel 9 communicates with the notch 8. Outlet channel 9
Is connected to a shift valve (not shown) that supplies and shuts off hydraulic pressure to a friction engagement device of the automatic transmission. O-rings 10 and 11 are mounted on the outer periphery of the small diameter portion 5 to maintain the hermeticity of the mounting portion of the solenoid valve 1.

Further, a shaft 12 integrally formed of a nonmagnetic material, for example, plastic is inserted into the yoke 2. The shaft 12 has a first shaft portion 13 fitted and fixed in the fixing hole 6 and a first shaft portion 13 inside the large diameter portion 3.
A second shaft portion provided integrally with an end portion of the shaft portion;

Further, inside the shaft 12, there is provided an inlet channel 15 which reaches the second shaft portion 14 from the end face of the first shaft portion 13. In the first shaft portion 13, a plurality of flow paths 16 opened on the outer peripheral surface are formed, and the flow path 16 communicates with the inlet flow path 15. Further, an outward flange 17 is formed on the first shaft portion 13, and an abutting surface 18 is formed on an end of the flange 17. The contact surface 18 and the end surface of the sleeve 7 are set on substantially the same plane. The sleeve 7
Is formed with an annular concave portion 19, and the flange 17 is fitted into the concave portion 19.

On the other hand, on the outer periphery of the second shaft portion 14 of the shaft 12, a plunger 20 as a cylindrical valve body movable in the direction of the axis A is mounted. The plunger 20 is integrally formed of a magnetic material, for example, steel. The inner diameter of the plunger 20 is a value that slides on the second shaft portion 14 in a liquid-tight manner.

A first pressure receiving surface 21 which forms an inflow port B between the plunger 20 and the contact surface 18 is formed at an end of the plunger 20 on the sleeve 7 side. The inner diameter of the first pressure receiving surface 18 is set smaller than the outer diameter of the flange 17, and the outer diameter of the first pressure receiving surface 18 is set larger than the outer diameter of the flange 17.

A flange 22 is formed on the outer periphery of the flange 20 opposite to the sleeve 7.
An annular second pressure receiving surface 23 is formed at one of the flanges 22, that is, at a position opposite to the sleeve 7. Second
The pressure receiving surface 23 has an inclination such that the diameter decreases as the distance from the sleeve 7 increases. An annular contact surface 24 is formed on the inner peripheral side of the second pressure receiving surface 23. Contact surface 2
4 is substantially orthogonal to the axis A.

A compression spring 25 as an elastic body is mounted between the sleeve 7 and the flange 22, and the plunger 20 is pressed away from the sleeve 7 by the elastic force of the compression spring 25.

The bobbin 2 inserted inside the large diameter portion 3
Numeral 6 is a non-magnetic material such as plastic, which is integrally molded. The cylindrical portion 27 has one end attached to the outer periphery of the sleeve 7 and the outer portion provided on one end of the cylindrical portion 27, that is, the outer peripheral surface on the flange 4 side. It has an outward flange 28 and an outward flange 29 provided on the outer peripheral surface on the other end side of the cylindrical portion 27. The flange 28 is in contact with the inner surface of the flange 4,
An O-ring 3 is provided between the contact surfaces of the flange 28 and the flange 4.
0A is attached. An electromagnetic coil 30 is wound around the bobbin 26.

On the other hand, inside the large diameter portion 3, the shaft 12
And a core 31 integrally formed of a magnetic material, for example, steel, disposed about the same axis A as the center. The core 31 includes a shaft portion 32 and a flange 33 provided on the outer end side of the shaft portion 32. The yoke 2 is provided on the outer periphery of the flange 33.
The large diameter portion 3 is abutted, the end of the large diameter portion 3 is caulked inward, and the core 31 is fixed.

A concave portion 34 is formed at the tip of the shaft portion 32, and a convex portion 35 provided at an end of the second shaft portion 14 of the shaft 12 is fitted into the concave portion 34. In addition, a predetermined gap 38 is set between the outer peripheral surface 36 of the shaft portion 32 and the inner peripheral surface 37 of the plunger 20 to allow relative movement between the plunger 20 and the shaft portion 32 in the direction of the axis A and in the circumferential direction. doing.

An annular spacer 39 is disposed inside the bobbin 26, and the core 3 is provided inside the spacer 39.
One shaft portion 32 is inserted. The spacer 39 is integrally formed of a non-magnetic material, for example, plastic. Thus, the discharge channel 40 is formed between the shaft portion 32 and the spacer 39. The discharge channel 40 is the core 3
1 is connected to an oil pan (not shown) of the automatic transmission via a flow passage 41 provided in the automatic transmission.

Further, an annular contact surface 43 is formed at an end of the spacer 39 on the plunger 20 side.
The inner diameter of the contact surface 43 is set smaller than the outer diameter of the contact surface 24 of the plunger 20. The distance between the contact surface 43 of the spacer 39 and the contact surface 18 of the shaft 13 in the direction of the axis A is set to be longer than the length of the plunger 20 in the direction of the axis A.

Thus, the discharge port C is provided between the contact surface 24 of the plunger 20 and the contact surface 43 of the spacer 39.
The bobbin 26 and the plunger 20
A flow path 44 that connects the outlet flow path 9 and the discharge port C is formed between them. Further, the gap 38 is arranged at a position avoiding the flow path 44.

The outer periphery of the spacer 39 has an O-ring 4
4 is attached to maintain the hermeticity of the site. An annular concave portion 45 is formed in the core 33, and an end of the spacer 39 is fitted in the concave portion 45.

When the electromagnetic coil 30 is turned off, the plunger 20 is pressed toward the spacer 39 by the elastic force of the compression spring 25 as shown in FIG. Therefore, the contact surface 18 of the shaft 13 and the first pressure receiving surface 21 of the plunger 20 are separated, and the inflow port B is opened. Further, the contact surface 24 of the plunger 20 and the contact surface 43 of the core 31 abut, and the discharge port C is closed. As a result, the hydraulic pressure on the inlet channel 15 side is supplied to the shift valve via the outlet channel 9.

On the other hand, when the electromagnetic coil 30 is turned on, a magnetic circuit connecting the yoke 2, the plunger 20 and the core 31 is formed, and the magnetic attractive force causes the plunger 20 to resilient the compression spring 25 as shown in FIG. Shaft 1 against force
Move to the 3rd side. For this reason, the first pressure receiving surface 21 of the plunger 20 and the contact surface 18 of the shaft 13 contact to close the inflow port B, while the contact surface 24 of the plunger 20 is closed.
And the contact surface 44 of the core 31 is separated, and the discharge port C is opened.

As a result, the hydraulic pressure on the shift valve side
4. Discharged to the oil pan via the discharge port C. If the electromagnetic coil 30 is turned off from the state of FIG.
Of course.

As described above, in the solenoid valve 1, the relative movement between the plunger 20 and the core 32 is allowed, and the gap 38 through which the magnetic flux passes is located at a position avoiding the flow path 44. Therefore, if the magnetic resistance is suppressed by setting the gap 38 as narrow as possible, the magnetic attraction force for operating the plunger 20 is increased, and the operational response of the plunger 20 is improved. In addition, the flow area of the flow path 44 can be set as large as possible to ensure the flow of a large flow rate.

According to the solenoid valve 1, the shaft 32 of the core 31 is inserted into the plunger 20, and the shaft 32 of the core 31 is arranged in the radial direction. Can be reduced as much as possible, which can contribute to downsizing of the solenoid valve 1.

Further, a first pressure receiving surface 21 and a second pressure receiving surface 23 are formed at both ends of the plunger 20 in the direction of the axis A. Since a predetermined inclination is set on the second pressure receiving surface 23, the fluid pressure acts on the first pressure receiving surface 21 in the state of FIG.

The hydraulic pressure acting on the first pressure receiving surface 21 serves as power for pressing the plunger 20 toward the core 31, and the hydraulic pressure acting on the second hydraulic pressure surface 23 causes the plunger 20 to move the shaft 1.
Power to press to the 3 side cancels each other. For this reason, the electromagnetic coil 30 is turned on to move the plunger 20 to the shaft 13.
When the plunger 20 is moved to the side, the magnetic attraction required to overcome the fluid pressure acting on the plunger 20 and the first contact surface 21 can be suppressed as much as possible. Therefore, the plunger 20 is driven with as little power as possible.
Can be operated, and the operation responsiveness of the plunger 20 is further improved.

In the above embodiment, the plunger 2
A tension spring may be used as an elastic body for moving 0 to the core 31 side. Furthermore, a configuration in which the plunger 20 is moved by an elastic force of an elastomer other than the spring may be adopted.

A compression spring is mounted between the spacer 39 and the second pressure receiving surface 23, and the discharge port C is opened when the electromagnetic coil 30 is off, and the discharge port C is closed when the electromagnetic coil 30 is on. It is also possible to configure a solenoid valve having the configuration. In the case of such a configuration, the formation of the magnetic circuit and the opening of the discharge port C are performed at opposite timings. However, the effect of increasing the magnetic attraction force as much as possible and the effect of increasing the flow rate of the flow path 44 are obtained. Is obtained in the same manner as in the above embodiment.

[0041]

As described above, according to the first aspect of the present invention, the gap through which the magnetic flux passes is set as narrow as possible to suppress the magnetic resistance, and the magnetic attraction force acting on the valve body is increased to increase the valve attraction. The operation response of the body can be improved, and the flow area of the flow path can be expanded as much as possible to ensure the flow of a large flow rate.

According to the second aspect of the invention, the same effects as those of the first aspect can be obtained, and the arrangement space in the axial direction can be reduced as much as possible by arranging the valve body and the magnetic body in the radial direction. This can contribute to downsizing of the solenoid valve.

According to the third aspect of the invention, the same effects as those of the first or second aspect can be obtained, and when the valve element is in contact with the contact surface, the valve element acts on the second pressure receiving surface. The fluid pressure reduces the fluid pressure acting on the first pressure receiving surface. Therefore, the magnetic attraction force of the electromagnetic coil or the elastic force of the elastic body required to move the valve body can be suppressed as much as possible, and the operation response of the valve body is further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a solenoid valve according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the solenoid valve of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 18 Contact surface 20 Plunger (valve element) 21 1st pressure receiving surface 23 2nd pressure receiving surface 25 Compression spring (elastic body) 30 Electromagnetic coil 31 Core (magnetic body) 38 Gap 44 Flow path C discharge port

Claims (3)

[Claims] 1. A valve body for opening and closing a port, a flow path communicating with the port, a magnetic body disposed to face the valve body, and a magnetic circuit connecting the valve body and the magnetic body. An electromagnetic coil to move the valve body by magnetic attraction force,
An electromagnetic valve including an elastic body that moves the valve body in a direction opposite to the electromagnetic coil, wherein a relative gap between the valve body and the magnetic body is allowed, and a gap through which a magnetic flux passes is formed in the flow path. An electromagnetic valve characterized in that it is formed at a position avoiding the above. 2. The solenoid valve according to claim 1, wherein the valve body is formed in a cylindrical shape, and the magnetic body is disposed inside the valve body. 3. A first pressure receiving surface provided on the valve body, on which a fluid pressure in a direction opposite to a power of the electromagnetic coil or the elastic body acts, and moved by a power of the electromagnetic coil or the elastic body. A contact surface with which the valve body is in contact, and a valve provided on the valve body, and opposes a fluid pressure acting on the first pressure receiving surface in a state where the valve body is in contact with the contact surface. The electromagnetic valve according to claim 1, further comprising a second pressure receiving surface on which a fluid pressure acts.