JPH01154967U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram showing an embodiment of this invention. FIG. 2 is a hydraulic circuit diagram of a conventional anti-lock device. Figures 3 and 4 are
1 is a diagram showing a conventional device that is an improved version of the device shown in FIG.
Figure 3 shows the normal brake operation state, and the fourth
The figure shows a reduced pressure state under anti-lock control. In the figure, 1 is a master cylinder, 2 is a wheel brake, 3 is a main flow path, 5 is a circulation path, 6 is a circulation pump, 7 is an electromagnetic discharge valve, 10 is a flow rate control switching valve, 1
1 is an inlet port, 12 is a second outlet port, 13 is a first outlet port, 14 is a housing, 16 is a spool, 17 is a return spring, 21 and 22 are orifices, 25 is a bypass path, and 26 is an opening/closing means. Note that in each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] A main flow path leading from the master cylinder to the wheel brakes, and a recirculation path that branches from the main flow path and joins the main flow path closer to the master cylinder than the branch point. a reflux pump that is provided in the reflux path and sends fluid toward the confluence point; a discharge valve that is provided between the branch point and the reflux pump that selectively opens and closes the flow path; and a discharge valve that selectively opens and closes the flow path. a flow control switching valve that is provided at a point and selectively opens and closes a flow path from the master cylinder to the wheel brake; the flow control switching valve includes: an inlet port facing the master cylinder side, an inlet port facing the wheel brake side; a housing having a first outlet port facing the discharge valve side and a second outlet port facing the discharge valve side and forming a storage space therein; a spool arranged to form a fluid passage including an orifice therein; and a return spring biasing the spool in one direction; each element constituting the flow rate control switching valve includes: , so as to achieve the following operations: when the anti-lock control is inactive, the spool is brought to the inactive position by the biasing force of the return spring, thereby connecting the inlet port and the first A large flow path is formed between the main flow path and the orifice to allow a large flow of fluid to pass through, and when the discharge valve is opened during anti-lock control pressure reduction, the fluid flows from the main flow path through the orifice. A fluid flow toward the circulation path is formed, and a pressure difference is generated before and after the orifice. Due to this pressure difference, the spool slides against the biasing force of the return spring, causing the large flow to flow. the fluid acting on the wheel brake is discharged to the return flow path by closing the flow path and at the same time forming a reduced pressure flow path from the first outlet port to the second outlet port, thereby controlling the anti-lock control. When the discharge valve is closed and the flow of fluid in the pressure reduction flow path is stopped during pressure increase, a small flow path is formed from the main flow path passing through the orifice to the wheel brake. When a pressure difference is generated before and after the orifice, and the biasing force against the spool due to this pressure difference exceeds the biasing force of the return spring, the spool moves beyond the flow rate adjustment position and closes the small flow path. is closed, and if the biasing force against the spool due to the differential pressure is less than the biasing force of the return spring, the spool returns to the flow rate adjustment position and brings the small flow path into communication, As a result, the flow rate of the liquid passing through the small flow path is controlled by the pressure difference before and after the orifice, which is determined by the biasing force of the return spring and the effective area of the spool. In the anti-lock control actuator for a vehicle, the mutual positional relationship of which is selected, the main flow path from the master cylinder to the flow rate control switching valve, and the circulation path from the flow rate control switching valve to the discharge valve. 1. An actuator for anti-lock control of a vehicle, comprising: a bypass path connecting said bypass path; and an opening/closing means provided in said bypass path for selectively opening and closing communication of said bypass path.