JPH11132357A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve in which suction force of a plunger can be finely adjusted and a pressure characteristic lowering pressure by a characteristic curve whose inclination is gently and largely extended by high control current is obtained. SOLUTION: A recessed and chipped part 14 having a straight surface 16 parallel to the axis of a plunger 10 is provided on a solenoid core 8 opposed to a tapered surface 12 formed at the plunger 10 of a solenoid operating a pressure control valve. Suction force of the plunger 10 is adjusted by the setting of air gap amount of the plunger 10 and the solenoid core 8 by a tapered surface angle θ1 of the plunger 10 and the depth S and the length L of the recessed and chipped part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve which controls a fluid pressure by a pressure fluid control valve operated by a solenoid.

[0002]

2. Description of the Related Art As an electromagnetic valve for controlling the pressure of a fluid, as shown in FIG. A pressure control valve 1 comprising a spring 7 which slidably fits a spool 6 for controlling the throttle of the pressure derivation port 5 and urges the spool 6 in a direction in which it contacts a plunger 10 of a solenoid 2 described later; The pressure control valve 1 is actuated in the throttle direction by being slidably fitted in a shaft hole formed in a solenoid core 8 around which a solenoid coil 9 is wound and attracted by a control current applied to the solenoid coil 9. There is provided a plunger 10 and a solenoid 2 comprising a disc spring 11 for supporting one end of the plunger 10.

As shown in FIG. 7, the plunger 10 and the solenoid core 8 have a tapered surface 12 inclined at an angle θ1 in the axial direction on the outer periphery of the suction-movement-side end face of the plunger 10. The shaft hole 13 has a straight surface parallel to the axis of the plunger 10 and faces the tapered surface 12 with a predetermined air gap G.

The above-mentioned solenoid valve draws the plunger 10 by the control current applied to the solenoid coil 9 to operate the spool 6 of the pressure control valve 1 in the direction of throttle (to the right in the drawing). The pressure of the fluid introduced from the control port is controlled and is derived from the control pressure derivation port 5.

[0005]

The solenoid valve of this type has different pressure characteristics for the purpose of use. The pressure characteristics of the above-described conventional solenoid valve are based on the tapered surface 12 of the plunger 10.
Is adjusted by changing the diameter of the feedback chamber into which the control pressure is guided and the spring constant of the spring 7, as shown in FIG.

In the above-described conventional method of changing the pressure characteristic, even if the suction force is adjusted by changing the angle θ1 of the tapered surface 12 of the plunger 10 and changing the air gap amount G,
The change in the suction force in the stroke range of the plunger 10 is only proportional to the control current applied to the solenoid coil 9, and the suction force in the stroke range of the plunger 10 cannot be finely performed. As a result, as shown in FIG. 8, the pressure characteristic due to the change in the control current i is represented by a solid curve a.
The characteristic curve (c in FIG. 5) in which the slope of the dotted curve b is steeper than that of the solid curve a can be changed, but the slope of the curve is steeper than that of the solid curve a on the higher control current side. Cannot be adjusted to obtain
For the purpose of using the solenoid valve, there is a case where it is necessary to control the pressure characteristic to decrease the pressure by a characteristic curve that is gradually increased and gradually expanded on the high control current side, and the solenoid valve that can obtain such a pressure characteristic is used. Is required. For example, when used for a transmission clutch,
In order to make the connection and disconnection of the clutch smooth and reduce the shock at the time of shifting, an electromagnetic valve having such pressure characteristics is desired.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to make it possible to finely adjust the attraction force of a plunger and to reduce the pressure with a characteristic curve which is gradually extended by making the slope gentle with a high control current. It is an object of the present invention to provide a solenoid valve which can be obtained.

[0008]

The gist of the present invention to achieve the above object is to form a pressure control valve for controlling the pressure of a supplied fluid and a solenoid core wound with a solenoid coil. A solenoid having a plunger fitted slidably in a shaft hole and actuated by a control current applied to the solenoid coil to operate a throttle of the pressure control valve; A tapered surface inclined in the axial direction is formed on the outer periphery of the end face of the solenoid, and a concave notch having a straight surface parallel to the axis of the plunger is provided on the solenoid core facing the tapered surface. The plunger suction is performed by setting the air gap between the plunger and the solenoid core based on the depth of the straight surface of the concave notch and the length of the concave notch. Adjust force, it is characterized in that the control pressure of the pressure control valve and to control the pressure characteristics according to the suction force of the plunger.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a pressure control valve 1 and reference numeral 2 denotes a solenoid that operates the pressure control valve 1.

As the pressure control valve 1, for example, the supply pressure introduction port 4 and the control pressure derivation port 5 are throttled in a valve housing 3 having a supply pressure introduction port 4 and a control pressure derivation port 5. The spool 6 is slidably fitted, and includes a spring 7 for urging the spool 6 in a direction in which the spool 6 comes into contact with a plunger 10 of the solenoid 2 described later.

The solenoid 2 has a solenoid coil 9
Is slidably fitted in a shaft hole formed in a solenoid core 8 on which the pressure control valve 1 is wound, and is sucked by a control current applied to the solenoid coil 9 so that the pressure control valve 1 is throttled (rightward in the drawing). A disc spring 11 for supporting one end of the plunger 10
It is a configuration consisting of Thus, when the applied control current of the solenoid coil 9 is zero, the plunger 10 is positioned at the leftmost retreating end in FIG.

Therefore, in the present invention, as shown in FIG. 2, a tapered surface 12 inclined at an angle .theta.1 in the axial direction is formed on the outer periphery of the end surface of the plunger 10 on the suction movement side.
The shaft surface 13 of the solenoid core 8 facing the inclined surface 2 has an inclined surface 15 inclined at an angle θ2 in a direction opposite to the tapered surface 12.
And a straight surface 16 having a depth S, which is parallel to the axis of the plunger 10 and is continuous with the inclined surface 15, and which has a length L between the inclined surface 15 and the straight surface 16.
4 is provided.

The operation of the present invention with the above configuration will be described. The position of the plunger 10 when the control current applied to the solenoid coil 9 is zero is the initial position of the retracted end as shown in FIGS. 2A and 3A, and the position of the tapered surface 12 of the plunger 10 A part thereof overlaps a part of the shaft hole 13 of the solenoid core 8.

When the control current i is applied to the solenoid coil 9 from the above state to gradually increase the current value, the attraction force F of the plunger 10 by the solenoid core 8 gradually increases in proportion to the current value as shown in FIG. The plunger 10 is moved to the intermediate position as shown in FIGS. 2B and 3B.
FIG. 4 is a characteristic diagram of the plunger's attraction force showing the stroke x of the plunger 10 and the attraction force F applied to the plunger 10 when a certain control current i is applied. In the stroke of the plunger 10 from the initial position A to the intermediate position B, the tapered surface 12 of the plunger 10 and the solenoid core 8
Of the shaft hole 13 of the plunger 1 gradually increases.
The attraction force F of 0 gradually increases in an inclined straight line as the current value increases.

However, when the current value is further increased and the plunger 10 passes the intermediate position B, the plunger 1
The tapered surface 12 of the plunger 10 enters the zone of the concave portion 14 of the solenoid core 8, and the tapered surface 12 of the plunger 10 faces the straight surface 16 of the concave portion 14. Reduce flow.

As a result, although the suction force F of the plunger 10 gradually increases, the plunger 10 has a stroke end C (the stroke end C is a control stroke end, and the plunger 10 is mechanically movable). (Not at the end)
At position 4, the suction force F tends to decrease by increasing the air gap amount. That is, as shown in FIG. 4, the stroke of the plunger 10 and the suction force F between the initial position A and the stroke end C shown in FIG. f changes like the slope line F2, and after passing the intermediate position B until reaching the stroke end C, changes like the slope line F1 of the relatively steep angle e (> f). Accordingly, the attractive force F when a high control current ic is applied to the solenoid coil 9 is Fc 'on the inclined line F1' of the angle f indicated by the dotted line, whereas it is Fc in the present invention. F can be reduced.

As shown in FIG. 5, the control pressure in the pressure control valve 1 due to such a change in the suction force of the plunger 10 is a characteristic curve in which the slope is made gentler and larger than the conventional curve a at a high control current indicated by a dotted line. A pressure characteristic of decreasing the pressure is obtained at c.

Attraction force F1 of the inclination line at the relatively steep angle e
Is determined by the depth S of the recess 14 and the inclined surface 15, and the gentle angle f
Is the inclination angle θ of the tapered surface of the plunger 10.
1, and the stroke g is the length L of the concave notch 14.
Is determined by Therefore, the suction force F of the plunger 10 is adjusted by appropriately setting the inclination angle θ1 of the tapered surface of the plunger 10, the depth S of the recess 14, the inclined surface 15 and the length L. A wide range of pressure characteristics shown in FIG. 5 can be handled according to the suction force.

In the above-described embodiment, the pressure control valve 1 is described as a spool valve. However, the present invention is not limited to the spool valve, and controls the throttle of a needle valve or other fluid passage operated by a solenoid. It is possible to apply to the configuration.

Further, in the above embodiment, the suction force is adjusted by forming the inclined surface 15 inclined at the angle θ2 on the solenoid core 8, but when the accuracy is not required, the angle θ2 is set to 90 °. It may be.

[0021]

As described above, according to the present invention, a concave notch having a straight surface parallel to the axis of the plunger is provided on the solenoid core facing the tapered surface of the plunger.
Since the suction force of the plunger is adjusted by setting the amount of air gap between the plunger and the solenoid core based on the taper surface angle of the plunger and the depth and length of the concave notch, the suction force of the plunger can be reduced. It can be adjusted and can cope with a wide range of pressure characteristics. Further, the required pressure characteristics can be easily obtained by tuning the shape of the concave portion. Further, even in the current solenoid valve, a desired pressure characteristic can be easily obtained only by forming a concave notch in the solenoid core.

[Brief description of the drawings]

FIG. 1 is a sectional view of a solenoid valve according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the present invention.

FIG. 3 is a cross-sectional view illustrating the operation of the present invention.

FIG. 4 is a drawing of a suction force characteristic of the plunger according to the present invention.

FIG. 5 is a control pressure characteristic diagram according to the present invention.

FIG. 6 is a sectional view of a conventional solenoid valve.

FIG. 7 is an enlarged cross-sectional view of a conventional main part.

FIG. 8 is a conventional control pressure characteristic diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure control valve 2 Solenoid 8 Solenoid core 9 Solenoid coil 10 Plunger 12 Tapered surface 13 Shaft hole 14 Depressed portion 16 Straight surface

Claims (2)

[Claims] 1. A pressure control valve for controlling a pressure of a supplied fluid, and a control applied to the solenoid coil slidably fitted in a shaft hole formed in a solenoid core wound with a solenoid coil. A solenoid provided with a plunger for actuating the throttle of the pressure control valve by being attracted by an electric current, wherein a tapered surface inclined in the axial direction is formed on an outer periphery of an end surface of the plunger on a suction moving side, A concave notch having a straight surface parallel to the axis of the plunger is provided on the solenoid core facing the surface, and the angle depends on the taper surface angle of the plunger, the depth of the straight surface of the concave notch, and the length of the concave notch. The suction force of the plunger is adjusted by setting the air gap between the plunger and the solenoid core, and the control pressure of the pressure control valve is adjusted by the suction of the plunger. Solenoid valve being characterized in that so as to control the pressure characteristic corresponding to the force. 2. The solenoid valve according to claim 1, wherein the pressure control valve for controlling the pressure of the supplied fluid is a spool valve operated by the plunger.