Abstract: A brake fluid pressure control device which is simple in structure and inexpensive, which has the functions as both an antilock controller and a traction controller, and which is capable of automatically increasing braking pressure with pumps while the driver is treading the brake pedal. Shutoff valves serving as fluid sources for pumps are provided in a fluid circulation type antilock control device. When the brake pedal is treaden, the shutoff valves close under the master cylinder pressure. While the shutoff valves are closed, no fluid can be supplied to the pump. But in this state, changeover valves open, so that fluid can be supplied from the master cylinder to the pumps through the changeover valves. Check valves are further provided to prevent the fluid supplied to the pumps from flowing into dumped fluid reservoirs.

Abstract: A vehicle braking force controller for controlling braking force of a vehicle by changing brake fluid pressure effected by a fluid pressure controller has a deceleration detector and a computer. The computer calculates a vehicle deceleration, a target deceleration of the vehicle, and a pressure adjustment speed at which the brake fluid pressure increases or decreases using the target deceleration and the vehicle deceleration. The pressure adjustment speed calculator calculates the brake fluid pressure adjustment speed using a brake fluid pressure adjustment volume which is proportional to a difference between the detected vehicle deceleration and the calculated target deceleration, and a target tracking time representing a time required to adjust the brake fluid pressure with the pressure adjustment volume. The computer controls the brake fluid pressure according to the pressure adjustment speed.