Patent
Brake control system for automotive vehicles
| العنوان: | Brake control system for automotive vehicles |
|---|---|
| Patent Number: | 5,273,348 |
| تاريخ النشر: | December 28, 1993 |
| Appl. No: | 07/869,455 |
| Application Filed: | April 17, 1992 |
| مستخلص: | A brake control system for automotive vehicles, comprises a master cylinder, a wheel cylinder, an external hydraulic pressure source for generating an external hydraulic pressure, an electronically controlled hydraulic pressure control valve connected to the external hydraulic pressure source, for converting the external hydraulic pressure to a control pressure, a hydraulic pressure multiplier unit connected to the hydraulic pressure control valve for generating a wheel-cylinder pressure higher than the master-cylinder pressure by multiplying the control pressure, and a spool biasing force restricting mechanism for restricting the magnitude of a spool biasing force created by the master-cylinder pressure to a designated upper limit only when the master-cylinder pressure exceeds a predetermined pressure level sufficient to provide a maximum wheel-cylinder pressure. |
| Inventors: | Yagi, Eiji (Kanagawa, JPX); Inoue, Naohiko (Kanagawa, JPX); Shiokawa, Shoji (Kanagawa, JPX) |
| Assignees: | Nissan Motor Co., Ltd. (Yokohama, JPX) |
| Claim: | What is claimed is |
| Claim: | 1. A brake control system for automotive vehicles, comprising |
| Claim: | a master cylinder for generating a master-cylinder pressure depending on a brake-pedal depressing force; |
| Claim: | a wheel cylinder associated with each vehicle wheel for generating braking force for said vehicle wheel; |
| Claim: | an external hydraulic pressure source for generating an external hydraulic pressure; |
| Claim: | an electronically controlled hydraulic pressure control valve connected to said external hydraulic pressure source, for converting said external hydraulic pressure to a control pressure, said hydraulic pressure control valve including a spool slidably enclosed therein for increasing said control pressure via one axial movement thereof and for decreasing said control pressure via the other axial movement thereof; and |
| Claim: | means for restricting the magnitude of a spool biasing force created by said master-cylinder pressure to a designated upper limit only when said master-cylinder pressure exceeds a predetermined pressure level sufficient to provide a maximum wheel-cylinder pressure. |
| Claim: | 2. The brake control system as set forth in claim 1, which further comprises a brake controller for generating a control signal depending on a vehicle driving condition, and an electromagnetic two-position solenoid valve connected to said external hydraulic pressure source and said hydraulic pressure control valve, for providing said one axial movement of said spool in response to said control signal generated during quick acceleration in the absence of said master-cylinder pressure. |
| Claim: | 3. The brake control system as set forth in claim 1, which further comprises a hydraulic pressure multiplier unit connected to said hydraulic pressure control valve for generating a wheel-cylinder pressure higher than said master-cylinder pressure by multiplying said control pressure. |
| Claim: | 4. The brake control system as set forth in claim 3, which further comprises a pilot-operated cut-off valve responsive to said control pressure output from said hydraulic pressure control valve, such that said cut-off valve is held in a closed state in the presence of said control pressure, for preventing said master-cylinder pressure from being directly supplied to said wheel cylinder and for permitting the multiplied hydraulic pressure created by said multiplier unit to be supplied to said wheel cylinder, and said cut-off valve is held in a fully open state in the absence of said control pressure, for permitting said master-cylinder pressure to be directly supplied to said wheel cylinder. |
| Claim: | 5. A brake control system for automotive vehicles, comprising |
| Claim: | an electronically controlled hydraulic pressure control valve connected to said external hydraulic pressure source, for converting said external hydraulic pressure to a control pressure, said hydraulic pressure control valve including a spool slidably enclosed therein for increasing said control pressure via one axial movement thereof and for decreasing said control pressure via the other axial movement thereof, a pressure chamber receiving said master-cylinder pressure for providing said one axial movement by a spool biasing force created by said master-cylinder pressure, and an electronically operated actuator associated with said spool for providing said other axial movement; and |
| Claim: | means for restricting the magnitude of said spool biasing force created by said master-cylinder pressure to a designated upper limit only when said master-cylinder pressure exceeds a predetermined pressure level sufficient to provide a maximum wheel-cylinder pressure. |
| Claim: | 6. The brake control system as set forth in claim 5, wherein said restricting means includes an elastic member arranged between said spool and a plunger responsive to said master-cylinder pressure for providing said one axial movement of said spool, and includes a stopper for restricting a maximum stroke of said plunger so as to receive a portion of said spool biasing force created by said master-cylinder pressure higher than said predetermined pressure level. |
| Claim: | 7. The brake control system as set forth in claim 6, which further comprises a piston provided in said hydraulic pressure control valve, for buffering quick application of said master-cylinder pressure onto said plunger by way of an expansion of volumetric capacity of said pressure chamber, and an elastic member attached to a pressure surface of said piston facing said pressure chamber for effectively buffering said quick application of said master-cylinder pressure. |
| Claim: | 8. The brake control system as set forth in claim 5, which further comprises a hydraulic pressure multiplier unit connected to said hydraulic pressure control valve for generating a wheel-cylinder pressure higher than said master-cylinder pressure by multiplying said control pressure with a designated multiplication factor. |
| Current U.S. Class: | 303/13; 3031/192; 3031/171 |
| Current International Class: | B60T 840; B60T 1536 |
| Patent References Cited: | 5163474 November 1992 Rizk 5221126 June 1993 Inoue |
| Primary Examiner: | Oberleitner, Robert J. |
| Assistant Examiner: | Ballato, Josie A. |
| Attorney, Agent or Firm: | Foley & Lardner |
| رقم الانضمام: | edspgr.05273348 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |