JPH0121098Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic pressure control solenoid valve for anti-skid that prevents wheel locking during vehicle braking.

Generally, when the proper slip ratio between the wheels and the road surface is not maintained during vehicle braking and the wheel braking force becomes relatively excessive, the wheels lock, which causes the vehicle's running direction to become unstable. It has been known.

In order to prevent skids caused by such wheel locks, various anti-skid control devices have been provided that appropriately control brake fluid pressure reduction and pressure increase as wheel rotation recovers. However, the present invention relates to an improvement of an anti-skid control device that is equipped with a liquid reflux mechanism in the form of a hydraulic pump.

Generally, the basic configuration of this type of device is to install an electromagnetic valve mechanism for hydraulic pressure control in the communication path from the master cylinder, which is the hydraulic pressure source, to the wheel cylinder of the brake device, and to open the communication when the occurrence of wheel lock is detected. At the same time, the fluid pressure return path including the hydraulic pump bypass-connected from the wheel cylinder to the master cylinder side is opened, and this liquid return lowers the brake fluid pressure value in the foil cylinder. The opening and closing of these communication passages is normally performed using a solenoid that is energized by a signal from an electrical control circuit that detects whether the wheels are locked.

By the way, in this type of solenoid valve mechanism that opens and closes the communication passage, it is normal for unbalanced hydraulic pressure to act on the movable body such as the valve body. Because the movable body is moved electromagnetically, power consumption increases, and this also depends on the state of brake fluid pressure generation (high and low fluid pressure values), so it can also handle high fluid pressure conditions. Therefore, it is necessary to secure a sufficiently large amount of electric power, and in practice this has sometimes become a major constraint on other mechanisms installed in the vehicle.

From this point of view, the present invention was made with the purpose of providing a hydraulic control solenoid valve for antenna skids with a simple configuration that consumes as little power as possible. A first liquid chamber (liquid chamber a), a second liquid chamber (liquid chamber b) communicating with the foil cylinder of the brake device, and a third liquid chamber (liquid chamber c) communicating with the liquid reflux system to the master cylinder side. , a normally open first valve part and orifice connecting the first liquid chamber and the second liquid chamber, and a normally closed second valve part connecting the second liquid chamber and the third liquid chamber. ,
and an excitation solenoid that switches opening and closing of the first valve part and the second valve part in response to an input of an anti-skid signal; In the hydraulic control solenoid valve for anti-skid, which releases brake pressure to lower the brake pressure, and then restores and increases the brake pressure via the orifice, the first valve part has the following features:
A first valve seat that partitions the first liquid chamber and the second liquid chamber, a first valve body in the first liquid chamber that is pushed by the first valve seat, and a spring force of a set spring that closes the first valve body. and a balance piston that is moved by the excitation of a solenoid to release the separation of the first valve element from the first valve seat, and the second valve part a second valve seat made of an elastic cylindrical body that partitions a second liquid chamber and a third liquid chamber; and a second valve body formed on the shaft of the balance piston and fitted into the cylinder of the second valve seat. This is a hydraulic pressure control solenoid valve for anti-skid, characterized in that the hydraulic pressure receiving areas in both axial directions facing the second and third liquid chambers of the balance piston are balanced.

The present invention will be described below based on embodiments shown in the drawings.

In the figure, 1 is a valve body, and a storage chamber 2 for a solenoid valve mechanism formed in the body is connected to a master cylinder (not shown) via an input port 3, and is connected to a master cylinder (not shown) via an output port 4. It is connected to a foil cylinder of a brake device (not shown), and is further connected to a predetermined pump (for example, an electromagnetic pump) that recirculates liquid to the master cylinder side via a liquid recirculation port 5.

The inside of the storage chamber 2 is divided into the following liquid chambers a, b, and c by a first valve part and a second valve part which are excited and operated by a solenoid 6. That is, the liquid chamber a is communicated with the master cylinder via the input port 3, and the liquid chamber b is communicated with the master cylinder via the normally open first valve part.
The liquid chamber b is communicated with the foil cylinder via the output port 4, and is separated from the liquid chamber c via a normally closed second valve part.
This liquid chamber c is communicated with a pump via a liquid return port 5.

Next, the specific structure of the solenoid valve mechanism will be explained.
Reference numeral 7 denotes an excitation iron core fixed to the inner cylindrical portion of the solenoid 6, and a cylinder 8 passing through the shaft is formed at the center of the shaft, and a balance piston 9 is slidably fitted to the cylinder 8.

Reference numeral 10 denotes a hollow stepped cylindrical housing fixed together with the iron core 7, and a first valve seat 11, which is a first valve seat for forming a first valve portion, is provided at the small diameter end on the front end side of the housing. is fixed. The valve seat 11 also serves as a seal by abutting against the inner wall of the valve body 1. Further, an elastic cylindrical second valve seat 12, which is a first valve seat for forming a second valve portion, is assembled and fixed to the small diameter inner cylinder of the housing 10 by a hold spring 13. The two-valve seat 12 forms a seal by fitting a shaft-shaped valve body into the inner diameter portion.

Reference numeral 14 denotes a first valve body in the liquid chamber a which cooperates with the first valve seat 11 to constitute the first valve part.
The balance piston 9 is normally pushed in a direction away from the first valve seat 11 by the tip of the balance piston 9 protruding from the tip of the small-diameter cylindrical portion of the housing 10, and is locked at the initial rest position shown in the figure. When the pressing force against the biasing spring 15 is released due to the downward movement of the balance piston 9 in the figure, the normally open type comes into contact with the first valve seat 11 and cuts off communication between the liquid chambers a and b. It consists of: Reference numeral 16 denotes an orifice that communicates between the liquid chambers a and b separately from the first valve portion.

The balance piston 9 is biased by a spring force so as to press the first valve body 14 by a set spring 17 stretched between the large diameter cylindrical portion of the housing 10 and the iron core 7. A vertical passage 18 extending through both ends is formed.

Further, a second valve body (portion) 19 that cooperates with the second valve seat 12 to constitute a second valve portion is formed in a part of the shaft portion of the balance piston 9. 12 indicates that the second valve seat 1 is moved when the downward movement of the balance piston 9 exceeds the stroke for closing the first valve portion.
It is set up so that it comes out from 2. Therefore, at this time, liquid chambers b and c, which are normally closed, are communicated with each other.

Reference numeral 20 denotes an armature that moves the balance piston 9 downward in the figure by the excitation of the solenoid 6, and is a thick-walled cylindrical body that is slidably fitted to the large-diameter inner cylindrical portion of the housing 10, and its inner diameter flange is It is provided so as to be engaged with the outer circumferential flange of the balance piston 9 to perform the movement. The accommodation portion of the armature 20 surrounded by the large-diameter inner cylinder of the housing 10 and the outer periphery of the balance piston 9 is connected to a chamber surrounded by the stepped portion outer periphery of the housing 10 and the inner wall of the valve body 1 through a flow path 21. These form the liquid chamber c. 22 is a piston cup, 2
3 is a sealing member.

According to the above configuration, the fluid pressure from the master cylinder is directly transmitted to the wheel cylinder of the brake device by the fluid chambers a and b, which are normally in communication via the first valve part, and the fluid pressure from the master cylinder is directly transmitted to the wheel cylinder of the brake device. Chamber c is in a blocked state.

When the lock of the wheels is detected by an appropriate electric circuit as the vehicle is braked, an anti-skid signal is input to the solenoid 6, which is energized, and the balance piston 9 resists the spring force of the set spring 17 as shown in the figure. moved downward. Therefore, the communication between the first valve part and the second valve part is reversed, the hydraulic pressure in the liquid chamber b escapes to the liquid chamber c side, and the brake hydraulic pressure is lowered. When the wheel lock due to the drop in brake fluid pressure is released, the excitation of the solenoid 6 is stopped, and the balance piston 9 returns to its initial position. When the first valve body 14 is aligned, the movement of the first valve body 14 is stopped at that position without opening the first valve part due to an imbalance in the hydraulic pressure in both axial directions acting on the first valve body 14. That is, the hydraulic pressure from the liquid chamber b that acts on the seal cross-sectional area of the first valve portion is reduced, and the hydraulic pressure from the liquid chamber a side is increased.

After this, the liquid pressure in the liquid chamber b gradually increases through the orifice 16, and when the acting forces in both axial directions acting on the first valve body 14 and the balance piston 9 are balanced, the first valve part is opened, and each movable member is shown in the figure. It will return to its initial resting position.

In the above operation, if the sealing cross-sectional area of the second valve body portion 19 of the balance piston 9, which is a movable member, is provided so as to be approximately balanced with the radial inner cross-sectional area of the shaft portion that slides into the cylinder 8 of the iron core 7, The hydraulic pressure in both axial directions acting on the balance piston 9 is always balanced regardless of its operating stage, and as a result, the excitation movement force obtained by the solenoid 6 resists only the spring force of the set spring 17. Therefore, it is possible to obtain the effect that the excitation power needs to be sufficiently small.

The above-mentioned hydraulic control solenoid valve for anti-skid according to the present invention has a simple structure with few moving parts compared to this type of solenoid valve, and also has low power consumption, so its practical benefits are It is extremely large.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of a hydraulic pressure control solenoid valve showing an embodiment of the present invention. 1: Valve body, 2: Storage chamber, 3: Input port, 4: Output port, 5: Liquid return port, 6: Solenoid, 7: Iron core, 8: Cylinder, 9: Balance piston, 10: Housing, 11: First Valve seat, 12: Second valve seat, 13: Hold spring, 14: First valve body, 15: Biasing spring, 16: Orifice, 17: Set spring, 18: Vertical flow path, 19: Second valve body part ,2
0: amateur, 21: piston cup, 22:
Seal member.

Claims (1)

[Claims for Utility Model Registration] A first liquid chamber communicating with the master cylinder, a second liquid chamber communicating with the foil cylinder of the brake device, and a third liquid chamber communicating with the liquid return system to the master cylinder side;
a normally open first valve section and orifice that connect the first liquid chamber and the second liquid chamber; a normally closed second valve section that connects the second liquid chamber and the third liquid chamber; and an excitation solenoid that switches opening and closing of the first valve part and the second valve part in response to an input of an anti-skid signal; In the hydraulic pressure control solenoid valve for anti-skid, which releases brake pressure to lower the brake pressure and then restores and increases the brake pressure via the orifice, the first valve part is configured to connect the first fluid chamber and the second fluid chamber. a first valve seat that partitions the first valve seat, a first valve body in the first liquid chamber that is pushed by the first valve seat, and a spring force of a set spring to separate the first valve body from the first valve seat; A balance piston that is moved by the excitation of a solenoid to release the first valve body from the first valve seat, and the second valve section partitions the second liquid chamber and the third liquid chamber. a second valve seat made of an elastic cylindrical body, and a second valve body formed on the shaft of the balance piston and fitted into the cylinder of the second valve seat; A hydraulic pressure control solenoid valve for anti-skid, characterized in that the hydraulic pressure receiving areas in both axial directions facing the second liquid chamber and the third liquid chamber are balanced.