Abstract: A disc brake device in which uneven wear on the brake pads is prevented. Each brake pad has a set pin hole at one end in which a set pin is fitted, and a torque-receiving component for receiving braking torque in the other end. The pistons for pressing the brake pads are composed of first and second pistons. A center of the first piston near the set pin is located further inside from the middle of the sliding range of the brake pads, and the distance from the set pin is extended.

Abstract: A disc brake device in which uneven wear on the brake pads is prevented. Each brake pad has a set pin hole at one end in which a set pin is fitted, and a torque-receiving component for receiving braking torque in the other end. The pistons for pressing the brake pads are composed of first and second pistons. A center of the first piston near the set pin is located further inside from the middle of the sliding range of the brake pads, and the distance from the set pin is extended.

Abstract: The ABS is provided with a modulator, and when the ABS is activated, control of the caliper pressure by the driver, is modified by the operation of the modulator having the aforementioned inlet valve (normally closed to a pressurized fluid source) and aforementioned outlet valve (normally open to a fluid exit), both controlled by the above-described control logic circuit. The modulator increases or decreases the caliper pressure, in response to changes in the pressurized fluid, regulated by such valves. Depending on the operation of the control logic circuit described above, three events may occur. When the inlet and outlet valves are not operated (i.e. their normal state), the modulator releases pressurized fluid through the output valve, and increases caliper pressure, to increase braking up to a predetermined maximum. If only the outlet valve is operated (i.e. both the inlet and outlet valves are closed), the modulator remains in a constant state and likewise, the caliper pressure is kept constant.

Abstract: A method and apparatus for controlling brakes using a reciprocating cut valve actuated by an expander piston that is moved via a crank pin on a crank shaft. The cut valve cuts off caliper pressure and adjusts the volume and pressure of an output hydraulic chamber to effectuate antilock braking. When changing from antilock braking to normal braking, the movement of the expander piston is controlled by repeatedly changing a crank angle of the crank pin during specified time intervals. The rate of increase in caliper pressure can be set according to (1) detected brake operation which is detected from a present crank angle and a target crank angle and (2) the frictional state of the road surface which is estimated from vehicle acceleration/deceleration.

Abstract: A target slippage ratio setting device has sensors respectively mounted on driven and driving wheels so as to detect rotational velocities thereof, a body accelerometer attached to a main body of a vehicle, a steering angle sensor mounted on a handle, and a control unit. In the target slippage ratio setting device, a target slippage ratio at which the optimum braking force is obtained, can be determined from a coefficient of friction calculated by a friction coefficient calculating circuit, a banking angle calculated by a banking angle calculating circuit and an estimated velocity of the vehicle calculated by an estimated vehicle velocity calculating circuit, based on the peripheral velocities of the front and rear wheels and the acceleration or deceleration of the vehicle.

Abstract: A brake control system for obtaining the optimal slippage ratio for stable braking of a vehicle, has a friction coefficient detecting device, a target slippage ratio setting device, a correction coefficient setting device and a target slippage ratio correcting device. The friction coefficient detecting device detects the coefficient of friction between each of wheels and a road surface. The target slippage ratio setting device sets up a target slippage ratio based on the coefficient of friction. The correction coefficient setting device detects the rate of change in the coefficient of friction and sets a first correction coefficient for calculating the target slippage ratio based on the rate of change in the coefficient of friction. The target slippage ratio correcting device multiplies the target slippage ratio by the first correction coefficient thereby to correct the target slippage ratio. Thus, the vehicle can be smoothly driven.

Abstract: A device for controlling the braking force of a motorcycle in two controlling modes: a normal mode and an antilocking mode, comprises tachometers mounted on front and rear wheels of the motorcycle, an accelerometer mounted on the motorcycle body, and a control circuit. The control circuit calculates a peripheral acceleration of each wheel based on the peripheral velocity of each wheel, and a slippage ratio of each wheel based on the peripheral velocity of the wheel and the acceleration of the motorcycle body. When the slippage ratio and the peripheral acceleration of one wheel meets given conditions, the control circuit starts, prior to entering into the antilocking mode from the normal mode, to calculate the coefficient of friction between the road surface and the one wheel. For the other wheel, the coefficient of friction is calculated in the same manner.

Abstract: A method of and an apparatus for estimating a vehicle velocity, which are suitable for use in a vehicle. Velocities of drive wheels and follower wheels of the vehicle are determined and the fastest one of the so-determined velocities is selected. The velocity of the vehicle is estimated based on the fastest wheel velocity thus selected. The above respective processes are repeatedly executed at given time intervals. Thus, when the estimated vehicle velocity is faster than each of the velocities of the follower wheels and lower than the fastest wheel velocity, the estimated vehicle velocity determined immediately before the above estimating process is set as a desired estimated vehicle velocity. Accordingly, a high-accuracy estimated vehicle velocity corresponding to an actual vehicle velocity can be obtained, thereby making it possible to control brakes and driving forces with high accuracy using the estimated vehicle velocity.

Abstract: A road surface condition sensor for judging if there is an appreciable unevenness on a road surface to provide a desirable braking performance for a vehicle, which comprises a vehicle speed estimating circuit for estimating the running speed of the vehicle, a steering angle sensor for detecting a steering angle of the vehicle, and a judging circuit for making a judgement as to whether the magnitude of a time-derivative of the steering angle indicative of the unevenness of a road surface is greater than a threshold value which is determined according to the estimated running speed of the vehicle, and for outputting a road surface condition signal representing results of the judgement.