Methods for improving braking performance in electronically-controlled hydraulic brake systems

摘要

An electronically controlled vehicular hydraulic brake system provides anti-lock braking, traction control, and vehicle stability control. The system includes a hydraulic control unit (HCU) containing control valves and other components in fluid communication with wheel brakes. Low temperatures cause the viscosity of hydraulic fluid to increase. Performance of the braking system can be improved at low temperatures according to methods of this invention. A first preferred method of improving braking performance is to increase the brake fluid temperature inside the HCU. Several examples of methods to increase fluid temperature inside the HCU are presented. A second preferred method of improving braking performance is to preload the wheel brakes with a pressure that does not adversely affect normal driving. Several examples of methods to preload the wheel brakes are presented.