JP2781212B2 - Solenoid valve device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic valve device, and more particularly to a technique that is effective when applied to a hold valve used in a brake control device such as an antilock control device for a vehicle.

[Conventional technology]

The anti-lock control device of a vehicle is intended to prevent wheel lock at the time of sudden braking of the vehicle, to prevent the turning of the vehicle body and inability to steer, and to shorten the braking distance. As a conventional anti-lock control device for a vehicle, For example, there is the one shown in FIG. This anti-lock control device is a normally open electromagnetic valve device (hold valve) between the master cylinder M / C1 and the wheel cylinder W / C2 in response to a command from the control unit when there is a risk of locking the wheel during braking. A normally closed electromagnetic valve device (decay valve) 105 between the cylinder 104, the wheel cylinder W / C2, and the reservoir 106 is opened and closed to maintain the brake fluid pressure of the wheel cylinder W / C2.
Reduce pressure or increase pressure to prevent wheel lock.

[Problems to be solved by the invention]

However, in the above control device, sufficient consideration has not been given to a change in control characteristics caused by a pressure difference between the master cylinder M / C1 and the wheel cylinder W / C2.

That is, first, in the above control device, in the operating state, the pressurization rate to W / C2 changes in proportion to the magnitude of the differential pressure between the pressure of M / C1 and the pressure of W / C2 (control pressure). Was. That is, when the differential pressure between M / C1 and W / C2 is large, the pressurizing rate is large, and when it is small, the pressurizing rate is small. Such a change in the pressurization rate directly affects the braking force of W / C2, and when the pressurization rate is small, there is a concern that the control becomes unstable such that a sufficient braking force cannot be obtained.

Secondly, in the above control device, since the orifice 10 is provided in the brake passage 3 immediately before the hold valve 104, the pressure transmission characteristic of the brake system is not so good, and when the brake pedal is suddenly pressurized during traveling. Thus, there is a possibility that a sufficient braking force may not be obtained, and the driver's feeling of pressing the brake is not good.

[Means for solving the problem]

The present invention has the following means in order to solve the above problems.

That is, the master cylinder M / C1 and the wheel cylinder W /
An electromagnetic valve device (4) interposed in a brake passage (3) between the solenoid valve (C2) and the solenoid valve (5) for opening and closing the brake passage (3), wherein a casing (6) having a solenoid (5) disposed therearound, and an inner yoke movable in the casing (6) 7, a plunger 8 accommodated in the inner yoke 7, and a rod 11 that opens and closes an orifice 10 formed in the inner yoke 7 in conjunction with the plunger 8. The electromagnetic valve device 4 has a structure in which the position in the casing 6 changes according to a predetermined pressure ratio between the master cylinder M / C1 and the wheel cylinder W / C2.

[Action]

According to the above-described means, the inner yoke 7 has M / C1 and W / C
Since the position changes depending on the predetermined pressure ratio with respect to C2, the volume on the W / C2 side is compressed across the orifice 10, so that the sense of pressurizing the brake pedal during sudden braking during traveling, that is, (fluid pressure Transfer characteristics) can be improved.

Also, the casing 6 and the inner yoke 7 are provided with magnetic portions 12a and 12b, respectively, and the contact area between the two magnetic portions 12a and 12b is made variable according to the change in the position of the inner yoke 7, so that the magnetic path of the magnetic path is improved. Since the width can be varied, that is, the action characteristics of the electromagnetic force can be varied, the difference in the pressurization rate due to the variation in the pressure ratio between the M / C1 and the W / C2 can be reduced.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b).

Note that the overall configuration of the antilock control device described in the present embodiment is the same as that of the conventional art, and therefore, the description will be made with reference to FIG.

The electromagnetic valve device 4 of the present embodiment is interposed in the brake passage 3 between the M / C1 and the W / C2 and functions as a hold valve. The electromagnetic valve device 4 includes a casing 6
The casing 6 itself has an inner yoke 7 slidable in the axial direction in the casing 6.
One end surface (the upper end surface in the figure) of the inner yoke 7
It is urged in the other end direction (downward in the figure) by a first spring 13 housed between the casing 6 and the upper surface.
Inside the inner yoke 7, there is provided a plunger 8 connected to a rod 11, and this plunger 8 is urged upward in FIG.

The tip of the rod 11 faces the orifice 10 opened at the lower end of the inner yoke 7,
The orifice 10 is operable to close the orifice 10 by an electromagnetic force generated by energization of a solenoid 5 arranged around the orifice.

Note that the inner yoke is used when the driver releases the brake pedal and tries to reduce the pressure in W / C2.
Spherical one-way valve that allows only M / C1 fluid flow from C2 side
Has 15

The outer peripheral surface of the inner yoke is sealed by an O-ring 16, and the pressure of the lower end surface of the inner yoke 7 from the M / C1 side and the urging force of the first spring 13 cause the shaft of the inner yoke 7 in the casing 6 to move. The direction position is made to fluctuate.

Therefore, when the pressure from the M / C1 side is smaller than the sum of the pressure from the W / C2 and the urging force of the first spring 13, the inner yoke 7 is moved as shown in FIG. It is located on the M / C1 side (downward in the figure) by the urging force of the first spring 13. A ring-shaped stopper 17 for preventing the inner yoke 7 from dropping is fitted near the inner peripheral end of the casing 6.

When the pressure from the M / C1 side is greater than the sum of the pressure from the W / C2 and the biasing force of the first spring 13, the inner yoke 7 is moved as shown in FIG. It is located on the W / C2 side (upper side in the figure) against the urging force of the first spring 13.

As described above, in the present embodiment, the position of the inner yoke 7 in the casing 6 changes due to the difference in the predetermined pressure ratio between the M / C1 and the W / C2. That is, when the pressure on the W / C2 side is low, first, the pressure from the M / C1 acts on the end face of the inner yoke 7 on the orifice 10 side. Here, since the orifice 10 exists, the pressurized fluid is not immediately circulated in the W / C2 direction, and the inner yoke 7 is moved against the first spring 13.
Move to W / C2 side (upward in the figure). As the inner yoke 7 moves in the W / C2 direction, the volume of the W / C2 is first compressed, and thereafter the W / C2 is passed through the orifice 10.
Pressurization to is continued. Therefore, the pedal press feeling (fluid pressure transmission characteristic) for the driver at the time of rapid pressurization during running of the vehicle is always stable regardless of the internal pressure state of W / C2.

On the other hand, in the present embodiment, magnetic portions 12a and 12b having the same axial length are provided in a part of the casing 6 and the inner yoke 7 corresponding to the solenoid 5. The magnetic portions 12a and 12b are provided at corresponding positions of the casing 6 and the inner yoke 7, and when the inner yoke 7 is located on the W / C2 side in the casing 6, the magnetic portions 12a and 12b are in contact with each other. They are arranged so that the contact area is large.

The strength of the electromagnetic force for moving the plunger 8 in the inner yoke 7 depends on the magnetic conductivity of a magnetic circuit composed of the solenoid 5 and the plunger 8 in the inner yoke 7. One characteristic of this embodiment is that the positional relationship between the pair of magnetic portions 12a and 12b changes due to the change in the position of the inner yoke 7, so that the width of the magnetic path in the magnetic circuit is variable. The point is.

In the state of FIG. 1A, the inner yoke 7 is located in the lower part of the casing 6 by the urging force of the first spring 13, and the contact area between the magnetic parts 12a and 12b is small. The magnetic path is also narrow. In the state shown in FIG. 3A, the pressure in the W / C2 is relatively high as described above. At this time, the solenoid 5
In the ON state, since the magnetic path is narrow, the movement responsiveness of the plunger 8 is relatively suppressed. However, the response when the solenoid 5 is turned off is good.

On the other hand, in the state shown in FIG.
Is located at the top of the figure against the urging force of the first spring 13 due to the pressure from the M / C 1. At this time, both magnetic parts
Since the contact area between 12a and 12b is large, the magnetic path is also wide. Therefore, the responsiveness when the solenoid 5 is turned on is improved as compared with the case of FIG. 1 (a).

As described above, in this embodiment, the responsiveness of the plunger 8 is made variable by making the width of the magnetic path variable, and the M / C1
The difference of the pressurization rate from to W / C2 is reduced.

Therefore, in this embodiment, a stable braking characteristic can be obtained in the operating state of the antilock control device.

〔The invention's effect〕

According to the present invention, it is possible to stabilize the pressurization rate for W / C2 when the antilock control device is operating, so that good control characteristics can be obtained.

Also, even when the antilock control device is not operating,
Since the pressure transmission characteristics from the M / C1 to the W / C2 can be enhanced, a sufficient braking force can be obtained and the driver's feeling of pressurizing the brake can be improved.

[Brief description of the drawings]

1 (a) and 1 (b) are cross-sectional views showing an electromagnetic valve device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a schematic configuration of a brake assist system according to the embodiment and the prior art. . 1 Master cylinder M / C 2 Wheel cylinder W / C 3 Brake passage 4 Electromagnetic valve device (hold valve) 5 Solenoid 6 Casing 7 Inner yoke 8 …… plunger, 10… orifice, 11 …… rod, 12a …… magnetic part, 12b …… magnetic part, 13 …… spring, 14 …… spring, 15 …… one-way spherical valve, 16 …… 0 ring, 17 Stopper 104 Electromagnetic valve device (hold valve) 105 Decay valve

Claims (1)

(57) [Claims] 1. A master cylinder M / C1 and a wheel cylinder W /
An electromagnetic valve device (4) interposed in a brake passage (3) between the solenoid valve (C2) and the solenoid valve (5) for opening and closing the brake passage (3), wherein a casing (6) having a solenoid (5) disposed therearound, and an inner yoke movable in the casing (6) 7, a plunger 8 accommodated in the inner yoke 7, and a rod 11 that opens and closes an orifice 10 formed in the inner yoke 7 in conjunction with the plunger 8. An electromagnetic valve device (4) characterized in that the position in the casing (6) changes according to a predetermined pressure ratio between the master cylinder (M / C1) and the wheel cylinder (W / C2).