JPH0176363U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the present invention applied to an electrically controlled hydraulic brake system for automobiles, and is a front cross-sectional view of a pressure intensifier, and Fig. It is a graph showing pressure characteristics. FIG. 3 is a front sectional view partially showing a pressure intensifier different in aspect from the above embodiment. 10: Brake pedal, 12: Electromagnetic hydraulic pressure control valve, 14: Front wheel cylinder, 20: Solenoid, 22: Accumulator, 24: Control device, 52: Pressure intensifier, 66: Large diameter piston, 68: Small diameter piston, 82: Spring, 84: 1st chamber,
102: Cup seal, 104: Second chamber, 106
: Third chamber, 128: Pressure booster, 136: Open/close valve.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Provided between the hydraulic pressure source and the brake cylinder, the hydraulic pressure of the hydraulic pressure source is controlled to an appropriate level by controlling the excitation current of the solenoid, and is supplied to the brake cylinder. A stepped piston is provided between the electromagnetic hydraulic pressure control device and the brake cylinder, and has a small diameter portion and a large diameter portion formed in the front and rear, and has a large diameter piston. A brake fluid pressure control device including an electromagnetic fluid pressure control device in which a primary chamber at the rear of the section is connected to an electromagnetic hydraulic pressure control device, and a pressure intensifier in which a secondary chamber at the front of the small diameter section is connected to a brake cylinder. (2) The pressure intensifier is connected to (a) biasing means for biasing the stepped piston to a backward end position with a predetermined force, and (b) the primary chamber and the secondary chamber. , when the stepped piston is at the backward end position, liquid is allowed to flow in both directions between the two chambers, but when the stepped piston moves forward a certain distance against the biasing means, at least the secondary chamber is allowed to flow. A brake fluid pressure control device according to claim 1, which includes a flow control device for blocking the flow of fluid from the primary chamber to the primary chamber. (3) The pressure booster includes (a) a communication passage communicating with the secondary chamber, (b) a valve seat provided at a position that partitions the communication passage and the secondary chamber, and (c) the valve seat. When it is spaced apart from the valve seat, it allows liquid to flow in both directions between the secondary chamber and the communication passage, but when it is seated on the valve seat, it allows liquid to flow in both directions from the secondary chamber to the communication passage. The valve device has a valve element that blocks the flow of liquid, and the relative position of the valve seat and the valve element is changed by axial movement of the stepped piston. 3. The brake fluid pressure control device according to claim 2, wherein the valve device constitutes the flow control device together with a fluid passage connecting the communication passage to the primary chamber.