JPH0914481A - Hydraulic controlling solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve which controls a large amount of hydraulic pressure with satisfactory responsiveness. SOLUTION: A pair of electromagnetic coils 10a, 10b which operate an armature 1 in opposite directions are arranged across the armature 1. Elastic members 9a, 9b are arranged for elastically holding the armature 1 at an intermediate position between the electromagnetic coils 10a and 10b. An oil passage 12 is formed inside the armature 1, which is opened to a space 13 always communicated with one of ports 4, 5, 6 at one side, and communicates remaining two ports at the other side. A first interruption mechanism 14a interrupts the space 13 with respect to one of two ports, in the sate that the armature 1 is operated by one of the electromagnetic coils. A second interruption mechanism 14b interrupts the space 13 with respect to the other port in the state that the armature 1 is operated through carrying current to the other electromagnetic coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve for controlling hydraulic pressure for a hydraulic device such as a clutch whose engagement / release is controlled by hydraulic pressure, and more particularly to a solenoid three-way valve.

[0002]

BACKGROUND OF THE INVENTION It is well known that various solenoid valves are used to control automatic transmissions for vehicles, for example. As one example thereof, a three-way valve is known, which is configured to selectively connect an input port to which hydraulic pressure is supplied to an output port and a drain port. With this type of solenoid valve, hydraulic pressure is turned on / off. Not only OFF control but ON /
The output pressure can be adjusted by controlling the OFF duty ratio.

An example thereof is described in Japanese Patent Laid-Open No. 3-157576. This is because the three parts of the input port, the output port, and the drain port are made to communicate with the space that accommodates the ball as the valve element, and they are integrated with the elastically biased armature. When the ball is normally pressed by a certain pressing piece and the coil is energized,
The electromagnetic force causes the armature and the pressing piece to move backward to release the pressing of the ball.
As a valve portion accommodating the ball, when the ball is pushed by the pressing piece, the ball separates from the valve seat to communicate the input port with the output port, and the pressing piece closes the drain port. In the state where the ball is pressed by the pressing piece on the opposite side to the first valve part that has been changed to the opposite state, the ball comes into contact with the valve seat to block the input port from the space part, which is a block. It is configured to be attachable to and detachable from the second valve portion.

Therefore, in the solenoid valve described in this publication, the input port can be selectively shut off from the output port, so that the supply / shutdown of the hydraulic pressure to a predetermined hydraulic device connected to the output port, that is, ON / OFF. It is possible to control OFF. Further, by switching the ON / OFF in a short time and changing the duty ratio which is the ON / OFF ratio, the hydraulic pressure appearing at the output port can be appropriately controlled. Further, since the above-mentioned two types of valve parts can be selected as a blocked valve part, it is possible to switch between a normally open type and a normally closed type.

[0005]

The solenoid valve having the above-described structure is often used as a valve for outputting pilot pressure. However, since the output pressure can be controlled by controlling the duty as described above, the hydraulic clutch has recently been used. It is also used as a valve for directly controlling the hydraulic pressure supplied to the. When the engagement pressure of the clutch or the like is controlled in this way, the required amount of pressure oil becomes a large flow rate as compared with the pilot pressure, so that it is necessary to increase the opening area of the solenoid valve.

However, in the conventional solenoid valve described above, a member such as an armature or a ball that functions as a valve body is pressed in one direction by an elastic member such as a spring, and the armature is generated by the electromagnetic coil from this state. Since it is configured to move against the elastic force of the elastic member by the electromagnetic force, when the moving stroke of the valve body such as the ball is increased to secure the flow rate, the electromagnetic coil is turned on.
There is a problem that the valve element does not always follow the ON / OFF accurately and does not move, and the responsiveness deteriorates.

In order to eliminate such an inconvenience, it is conceivable to reduce the frequency of the pulse signal for controlling the electromagnetic coil. However, if this is done, vibration may occur in the valve element and pulsation in hydraulic pressure may occur. is there. The electromagnetic force generated by the electromagnetic coil must be sufficiently larger than the elastic force of the elastic member that is biased in the direction opposite to the electromagnetic force. If the value is increased, the electromagnetic coil for driving the valve element will have a large capacity and the power consumption will increase.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solenoid valve for hydraulic control capable of controlling a large flow rate of hydraulic pressure with good response.

[0009]

In order to achieve the above object, the present invention operates an armature by an electromagnetic force so that an output port to which hydraulic pressure is supplied becomes a drain port and an input port. In a hydraulic control solenoid valve that is switched to communicate with each other, a pair of electromagnetic coils for operating the armatures in opposite directions are arranged to face each other with the armature sandwiched therebetween, and the armature is elastically disposed at an intermediate position between the pair of electromagnetic coils. Is provided with an elastic member, and an oil passage opened in a space portion inside the armature, which always communicates with one of the three ports on the one hand and communicates with the other two ports on the other hand. Is formed, and the space portion is formed by the other electromagnetic coil while the armature is operated by the one electromagnetic coil. A first shut-off mechanism for shutting off one of the other ports, and the space portion of the other of the other two ports while the armature is operated by energizing the other electromagnetic coil. A second shutoff mechanism for shutting off the port is provided.

The solenoid valve according to the present invention is constructed so that two of the three, the input port, the output port and the drain port, are selectively connected. One of the ports is always in communication with the oil passage formed inside the armature, and the other two ports are in communication with each other through a predetermined space, and the oil passage is It opens to the space. Armature is
An intermediate position of each electromagnetic coil, that is, a state in which the first and second breaking mechanisms are not closed is held by the pair of elastic members. Therefore, when one electromagnetic coil is energized to excite it, the armature is elastic member. It is operated by the electromagnetic force generated by the electromagnetic coil against the elastic force of, and one of the breaking mechanisms is closed. That is, since the other two ports are blocked, the oil passage and the port communicating with the oil passage are communicated with one of the other two ports via the space. If the one electromagnetic coil is demagnetized and the other electromagnetic coil is excited from this state, the armature is moved by the restoring force of the elastic member and the electromagnetic force of the other electromagnetic coil, and the other breaking mechanism is closed. And the communication status of the port changes.

Therefore, in the solenoid valve according to the present invention, the armature itself functions as a valve body, and when the armature is moved to switch the communication state of the ports, the armature is caused to move by the inertia energy due to the restoring force of the elastic member. When it moves to the opposite side while crossing the neutral point and gradually decelerating, and reaches a region where the electromagnetic force is strong, the speed is increased again and the electromagnetic coil is attracted to the opposite side.
Therefore, even if the stroke is increased to allow a large amount of oil pressure to flow, the armature moves with good response and the oil pressure can be controlled as expected. Further, since the restoring force of the elastic member is used as the driving force for moving the armature, the power consumption can be reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described more concretely with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing an example in which the present invention is embodied, and a casing 2 in which an armature 1 is housed is formed as, for example, a hollow container having a circular cross section, and one end portion in the axial direction thereof is formed. A hollow shaft-shaped fitting portion 3 is formed so as to protrude. An output port 4 communicating with the inside is opened and formed at the tip of the fitting portion 3. An input port 5 communicating with the inside of the casing 2 is formed on the outer peripheral surface of the fitting portion 3 so as to open. Further, at the other end of the casing 2 in the axial direction, a drain port 6 communicating with the inside of the casing 2 is formed by opening.

The armature 1 housed inside the casing 2 has a disk-shaped portion (hereinafter referred to as a disk-shaped portion) 7 and a shaft portion 8 projecting from the central portion of both surfaces thereof.
a and 8b, the whole of which is made of a magnetic material. Both surfaces (upper and lower surfaces in FIG. 1) of the disk-shaped portion 7 are tapered so that the disk-shaped portion 7 becomes thinner on the outer peripheral side. Also, one of the shafts (see FIG.
The lower shaft portion of the above) is attached to the fitting portion 3a.
Is fitted so as to move back and forth in the axial direction while maintaining a liquid-tight state. Therefore, the armature 1 is held inside the casing 2 so as to move back and forth in the axial direction.

Further, coil springs 9a and 9b as elastic members are fitted around the outer circumferences of the shaft portions 8a and 8b, and the coil spring 9a on the lower side of the drawing abuts on the inner surface of the fitting portion 3. Armature 1 is pushed to the upper side of the figure, and the coil spring 9b on the upper side of the figure is
It contacts the inner surface of the casing 2 and pushes the armature 1 downward in the figure. Therefore, the armature 1 is held at a position where the elastic forces of these coil springs 9a and 9b are balanced.

Further, the core 11a which holds the electromagnetic coils 10a and 10b on both sides of the disk-shaped portion 7 of the armature 1 inside the casing 2 with a predetermined space between them. , 11b are arranged. The outer diameters of the cores 11a and 11b are substantially the same as the inner diameter of the casing 2, and the inner diameters of the coil springs 9a and 9b are the same.
It has a hollow cylindrical shape with a diameter larger than that of b. Therefore, these cores 11a and 11b are arranged inside the casing 2 in a state of being closely fitted to the upper and lower ends of the casing 2. Further, the respective tip portions of the cores 11a and 11b, that is, the tip portions on the disk-shaped portion 7 side are formed in a taper shape that matches the taper surface of the disk-shaped portion 7 facing each other.

Inside the armature 1, an oil passage 12 is formed which is open to the tip end surface of the lower shaft portion 8a in FIG. 1 and the outer peripheral surface of the disk-shaped portion 7. That is, the disk-shaped portion 7 is formed with a through hole penetrating in the diametrical direction so as to pass through the central portion thereof, and the shaft portion 8a is provided with a central axis line extending from the tip surface thereof to the central portion of the disk-shaped portion 7. Through holes are formed, and the oil passage 12 is formed by these through holes.

The armature 1 can be moved in the axial direction within a range in which the disk-shaped portion 7 abuts on the upper and lower cores 11a and 11b in the figure, and the inner diameter of the casing 2 is the moving range of the disk-shaped portion 7. It is bigger than other parts. Therefore, a space 13 in which the oil passage 12 is opened is formed here. Further, since the shaft portion 8a is closely fitted inside the fitting portion 3, the oil passage 12 formed inside the fitting portion 3 has the output port 4 formed at the tip portion of the fitting portion 3. Always in communication with.

As described above, the armature 1 can move in the axial direction and come into contact with the upper and lower cores 11a and 11b. When it comes into contact with either of the cores 11a and 11b, the opening of the oil passage 12 is formed. The space 13 that forms the space and the space in which the coil springs 9a and 9b are arranged are isolated from each other. Therefore, the armature 1 itself forms a valve body, and the tapered surfaces of the cores 11a and 11b form a valve seat, and these form the shutoff mechanisms 14a and 14b.

The casing 2 is attached to the valve body by screwing the fitting portion 3 into the valve body 15 of the hydraulic control device. In this state, the input port 5 is connected to the line pressure oil passage 16. The output port 4 is communicated with the clutch oil passage 17. FIG.
The structure when the hydraulic pressure of the clutch is controlled by the solenoid valve is schematically shown. The clutch oil passage 17 is communicated with the clutch chamber 18, and the line pressure oil passage 16 includes a hydraulic pump 19. Connected to the source 20,
Further, it communicates with the drain port 6 or the drain portion 21.

Next, the operation of the above solenoid valve will be described. When neither of the electromagnetic coils 10a and 10b is energized, the armature 1 is subjected to the elastic force of the pair of coil springs 9a and 9b which sandwich the armature 1 and the cores 11a of the armature 1a. , 1
It is held in a so-called neutral position where it does not come into contact with 1b either. Therefore, the input port 5 communicates with the output port 4 via the oil passage 12, and also communicates with the drain port 6 via the space 13.

In this state, for example, when the upper electromagnetic coil 10b of FIG. 1 is energized to excite it, the armature 1 is caused by the electromagnetic force of the upper arm coil spring 9 of FIG.
b is compressed, and the lower coil spring 9a is expanded while being moved upward, and is adsorbed to the core 11b (state shown in FIG. 1).

As the armature 1 moves in this way, the upper blocking mechanism 14b constituted by the taper surface of the disk-shaped portion 7 and the taper surface of the core 11b is closed, and the drain port 6 is closed. The portion 13 is shielded. That is, the input port 5 is communicated with the output port 4 via the oil passage 12, and the oil supplied from the line pressure oil passage 16 is supplied to the clutch chamber 18 via the clutch oil passage 17 to engage the clutch. .

On the contrary, on the contrary, the upper electromagnetic coil 10
The energization to b is stopped and the lower electromagnetic coil 10
If a is energized, that is, the upper electromagnetic coil 10b is turned off.
When the FF and the lower electromagnetic coil 10a are turned on, the upper electromagnetic coil 10b is turned off, so that the armature 1 is pushed down so that the elastic forces of the upper and lower coil springs 9a and 9b are balanced. Then, the armature 1 is pulled down by the electromagnetic force of the lower electromagnetic coil 10a beyond the neutral position by these coil springs 9a and 9b, and finally attracted to the lower core 11a. Therefore, since such movement of the armature 1 is caused not only by the electromagnetic force of the electromagnetic coil 10a but also by the return of the coil springs 9a, 9b, the amount of current flowing through the electromagnetic coil 10a may be small.

When the armature 1 is moved to the lower side of FIG. 1 in this way, the lower blocking mechanism 14a is closed, and the input port 5 is blocked from the space 13. That is, the output port 4 includes the oil passage 12 and the space 1.
3 to the drain port 6 through the clutch chamber 18
The pressure is released from and the clutch is released.

Therefore, in the solenoid valve described above, the armature 1 itself, which is held in the neutral position by the pair of coil springs 9a and 9b, functions as a valve body, so that the flow passage cross-sectional area can be widened in the valve open state. Further, even if the movement stroke of the armature 1 is increased in order to widen the flow channel cross-sectional area, the amount of current can be reduced in order to move the armature 1. In other words, since the armature 1 can be moved quickly, the hydraulic response becomes good.

According to the solenoid valve, the hydraulic pressure supplied to the clutch can be controlled to any pressure. That is, FIG. 3 shows ON / OFF of the upper and lower electromagnetic coils 10a and 10b.
It is a diagram showing a state of OFF, for example, the upper electromagnetic coil 10b is turned ON for a predetermined time and then turned OFF, and the lower electromagnetic coil 10a is turned ON. Thereafter, similarly, ON / OFF of the upper and lower electromagnetic coils 10a and 10b
Are switched alternately. With this control, the output port 4 is alternately communicated with the input port 5 and the drain port 6, so that the clutch chamber 18 is intermittently supplied with hydraulic pressure. Therefore, one of the electromagnetic coils 10a and 10b is turned off.
From the time of setting to N, the other electromagnetic coils 10a and 10b are turned to O
After N times, the one electromagnetic coil 10a, 10b is again provided.
Is set to 1 cycle, and the ON / OFF time ratio of one of the electromagnetic coils 10a and 10b, that is, the duty ratio is appropriately changed with the cycle of the 1 cycle fixed to a constant value. The oil pressure in the clutch chamber 18 changes to high or low according to the duty ratio.

The situation is shown in FIG. 4. When the upper electromagnetic coil 10b is ON, the input port 5 communicates with the output port 4 and the hydraulic pressure is supplied to the clutch. The higher the duty ratio, the higher the ratio of the time during which the hydraulic pressure is supplied to the clutch within a fixed time, and the higher the clutch pressure. The relationship between the duty ratio and the clutch pressure is almost proportional. In that case, the duty ratio of the lower electromagnetic coil 10b gradually decreases, contrary to the increase of the duty ratio of the upper electromagnetic coil 10b.

As described above, in the above solenoid valve, when the upper and lower electromagnetic coils 10a and 10b are switched ON / OFF, the electromagnetic coil 10a switched from ON to OFF.
The coil spring 9a (or 9b) arranged in parallel on the same side as (or 10b) acts so as to push the armature 1 in the axial direction. Therefore, from OFF to O
The other electromagnetic coil 10b (or 1 switched to N)
0a) can attract the armature 1 by a small electromagnetic force.

This will be described with reference to the drawings. When the armature 1 is in the neutral position, the elastic forces of the upper and lower coil springs 9a and 9b are balanced and the armature 1
Since no substantial elastic force is applied to move the armature 1 in this direction, in order to move the armature 1 from this position, one of the coil springs 9a (or 9b) associated with the displacement of the armature 1 is moved. Requires an electromagnetic force greater than the elastic force of. Therefore, when first moving the armature 1 up or down, the
It is necessary to increase the current value so that it is represented by the line marked "Large current".

After that, when the ON / OFF state is switched, the armature 1 is pushed by the elastic force of the compressed coil spring 9a (or 9b) to move to the opposite side, and is also excited. It is attracted by the electromagnetic force of the other electromagnetic coil 10b (or 10a). Therefore, the electromagnetic force required in that case is smaller than the electromagnetic force required to move from the neutral position to the one of the conventional electromagnetic coils, and its current value is represented by the line marked as "small current" in FIG. be able to. Since the suction force acting on the armature 1 is inversely proportional to the distance from the core, if the armature 1 is within the return limit range shown by the diagonal lines in FIG. 5, the armature 1 far from the core can be pulled back and adsorbed. The current value required in that case is shown by the line marked "small current" in FIG.

Therefore, the above-mentioned pulse signal for duty control for changing the clutch pressure, that is, a pulse signal of a predetermined frequency (for example, about 50 Hz) for driving the armature 1 is a high-frequency pulse signal of about 200 Hz which the armature 1 does not follow. Even if the electromagnetic wave is put on a certain carrier wave, the duty ratio of the carrier wave is set to a large value in the first time to increase the electromagnetic force, and from the second time and thereafter, even if the duty ratio is decreased to reduce the electromagnetic force, the armature 1 Can be substantially adsorbed on one core 11b (or 11a).

In FIG. 6, the duty ratio of the upper electromagnetic coil 10b is set to 100% at the first time, the duty ratio of the carrier wave of the control signals of the upper and lower electromagnetic coils 10a and 10b thereafter is reduced, and the hydraulic pressure is controlled. 2 shows an example in which the duty control for substantially turning on / off the upper and lower electromagnetic coils 10a and 10b is executed by a pulse signal at about 50 Hz. As is known from this figure, since the duty ratio of the carrier wave is reduced after the second time, the substantial current is small. Therefore, the power consumption of the solenoid valve can be reduced.

In the above embodiment, the case where the engagement pressure of the clutch is ON / OFF controlled or regulated has been described as an example, but the present invention is not limited to the above embodiment. It can be used when controlling the hydraulic pressure of a wide range of general hydraulic equipment such as a brake operated by hydraulic pressure. Further, in the above-mentioned embodiment, the disk-shaped portion is formed on the armature, and the blocking mechanism is formed by both sides of the disk-shaped portion and the core facing them. It suffices that the blocking mechanism be provided in the armature. Therefore, for example, the blocking mechanism may be configured by the shaft portion of the armature and a part of the core adjacent thereto. In that case, the oil passage formed inside the armature may be different from the shape shown in the above embodiment depending on the shape of the armature and the position of the blocking mechanism. Further, the elastic member in the present invention is not limited to the coil spring, and various kinds such as a disc spring-shaped member or a block-shaped member made of synthetic resin can be used as required. The present invention can be applied to a solenoid valve having three ports that are selectively communicated with each other, and the arrangement or communication relationship of these three ports is limited to that shown in the above embodiment. Not done.

[0034]

As described above, according to the solenoid valve of the present invention, the armature, which is held in a floating state at the so-called neutral position by the elastic member, is elastically moved by the electromagnetic force of the pair of electromagnetic coils which are arranged to face each other with the armature interposed therebetween. The member is moved against the elastic force of the member, and by this, one of the two blocking mechanisms is closed to switch the communication state of the two ports through the space portion. The elastic force of the elastic member can be used to drive the armature by switching OFF, and as a result, even when the movement stroke of the armature is increased to widen the internal flow passage cross-sectional area,
The armature moves quickly and the hydraulic response becomes good. Further, in that case, since the electromagnetic force required is small, it is possible to reduce power consumption.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a partial hydraulic circuit diagram of an example configured to control the hydraulic pressure of a clutch.

FIG. 3 is a diagram showing an ON / OFF state of upper and lower electromagnetic coils when duty control is performed on each electromagnetic coil to adjust hydraulic pressure.

FIG. 4 is a diagram showing a relationship between a duty ratio of upper and lower electromagnetic coils and a clutch pressure.

FIG. 5 is a diagram showing a relationship between elastic force according to each position of the armature and a current value for moving the armature.

FIG. 6 is a diagram showing a pulse signal for duty-controlling an electromagnetic coil for controlling hydraulic pressure and a duty ratio of a carrier wave of the pulse signal.

[Explanation of symbols]

 1 Armature 4 Output port 5 Input port 6 Drain port 9a, 9b Coil spring 10a, 10b Electromagnetic coil 12 Oil passage 13 Space part 14a, 14b Breaking mechanism

Claims (1)

[Claims] 1. A hydraulic control solenoid valve for operating an armature by an electromagnetic force to switch an output port to which hydraulic pressure is supplied between a drain port and an input port to communicate with each other, wherein the armatures are operated in directions opposite to each other. A pair of electromagnetic coils are arranged so as to face each other with the armature sandwiched therebetween, and an elastic member that elastically holds the armature at an intermediate position between the pair of electromagnetic coils is provided. One of the two ports is always in communication with the other port, and the other of the two ports is in communication with the other two ports. An oil passage is formed in the space, and the space is formed while the armature is operated by the one electromagnetic coil. A first blocking mechanism for blocking one of the other two ports from the other; A second shutoff mechanism is provided for shutting off the space from the other port of the other two ports in a state where the armature is operated by energizing the electromagnetic coil. Solenoid valve for hydraulic control.