Abstract: An electric motor is controlled according to the back and forth movement of an input rod, which is caused by brake pedal operation; a primary piston is propelled to generate hydraulic brake pressure in a master cylinder; and the hydraulic brake pressure is fed back to the input rod through an input piston. The input piston is resiliently held by springs with respect to the primary piston. A jump-in clearance is created between the input piston and the input rod by a rearward spring. At the initial stage of braking, hydraulic brake pressure is not transmitted to the input rod due to the jump-in clearance, which provides jump-in characteristics. The jump-in clearance can be set, regardless of the amount of a relative displacement between the primary piston and the input piston, so that the range of adjustment for regenerative braking can be set larger than the jump-in clearance.

Abstract: An electric motor is controlled according to the back and forth movement of an input rod, which is caused by brake pedal operation; a primary piston is propelled to generate hydraulic brake pressure in a master cylinder; and the hydraulic brake pressure is fed back to the input rod through an input piston. The input piston is resiliency held by springs with respect to the primary piston. A jump-in clearance is created between the input piston and the input rod by a rearward spring. At the initial stage of braking, hydraulic brake pressure is not transmitted to the input rod due to the jump-in clearance, which provides jump-in characteristics. The jump-in clearance can be set, regardless of the amount of a relative displacement between the primary piston and the input piston, so that the range of adjustment for regenerative braking can be set larger than the jump-in clearance.

Abstract: An abutment-plate portion of a main body portion of a biasing member, which faces a disc rotor in an axial direction, includes a pad-return portion for biasing a friction pad in a direction separating apart from the disc rotor, and upper and lower claw portions which are located separately on the upper and lower sides of the pad-return portion. The upper and lower claw portions of the biasing member are brought into abutment against upper and lower groove portions respectively with a frictional resistance When a lining of the friction pad is worn away and the friction pad is pressed in a direction approaching to the disc rotor in accordance with the wear of the lining, the movement of the entire biasing member in the direction approaching to the disc rotor inside a pad guide is allowed by the upper and lower claw portions serving as wear-following portions.

Abstract: When a driving force of a drive motor (21) becomes a maximum driving force even in the case where a brake pedal (5) is depressed by a large amount while a vehicle is in a stopped state, a second ECU (33) outputs a valve-closing command to a boost control valve (40, 40?) of an ESC (31) for a left front wheel (FL; front wheel 1L) and a right front wheel (FR; front wheel 1R). In this manner, a hydraulic pressure flowing from a master cylinder (8) through the ESC (31) to each wheel side is not supplied to wheel cylinders (3L, 3R) for the front wheels (1L, 1R) but is supplied only to wheel cylinders (4L, 4R) for rear wheels (2L, 2R). A hydraulic stiffness of the wheel cylinders (3L, 3R, 4L, 4R) is changed by stopping supply of a brake fluid to the wheel cylinders (3L, 3R).

Abstract: In response to depression of a brake pedal (6), an electric brake (5) mounted on the rear side starts to generate a braking force at the time of stroke h1 before a fluid pressure brake (4) mounted on the front side starts to generate a braking force when the stroke reaches stroke h2. Accordingly, the rear side is able to generate a braking force prior to the front side, whereby it is possible to reduce a rigid feeling, and therefore improve the pedal feeling.

Abstract: An abutment-plate portion of a main body portion of a biasing member, which faces a disc rotor in an axial direction, includes a pad-return portion for biasing a friction pad in a direction separating apart from the disc rotor, and upper and lower claw portions which are located separately on the upper and lower sides of the pad-return portion. The upper and lower claw portions of the biasing member are brought into abutment against upper and lower groove portions respectively with a frictional resistance When a lining of the friction pad is worn away and the friction pad is pressed in a direction approaching to the disc rotor in accordance with the wear of the lining, the movement of the entire biasing member in the direction approaching to the disc rotor inside a pad guide is allowed by the upper and lower claw portions serving as wear-following portions.

Abstract: An object of the present invention is to provide a brake device in which brake feeling can be improved. In response to depression of a brake pedal 6, an electric brake 5 mounted on the rear side starts to generate a braking force at the time of stroke h1 before a fluid pressure brake 4 mounted on the front side starts to generate a braking force when the stroke reaches stroke h2. In the conventional art, the braking force on the rear side is set according to the fluid pressure on the front side, and braking can be controlled only by the response of the fluid pressure. In the conventional art, an invalid stroke is long, and when the stroke enters a braking force zone where a braking force is generated according to a pedal stroke, the braking force suddenly increases relative to an advance of the stroke (rigid impression), whereby the driver often feels discomfort and pedal feeling is deteriorated.

Abstract: The present invention provides a brake booster that, although simple in construction, capable of adjusting the braking force derived by operation of a solenoid mechanism without worsening the braking response. In the brake booster according to the present invention, when a movable member (34) is shifted toward the rear side by electromagnetic force of a solenoid (31), the shifting movement is transmitted to a valve seat member (21) through pins (50) to open an atmospheric valve (27) through which air is introduced into a variable pressure chamber (9,10), whereby a pressure difference is created between the variable pressure chamber and a constant pressure chamber and generates booster output (thrust output force).

Abstract: A solenoid-controlled valve has first and second valve bodies axially movably provided in a bore of a cylinder. A first spring is interposed between an end of th valve and the first valve body, a second spring is interposed between the two valve bodies, and an electromagnetic force generating device has a movable member which causes the two valve bodies to move in association with each other. Valve opening and closing modes of the two valve bodies are changed in a plurality of stages according to the displacement of the movable member. A restricting portion restricts relative displacement of the two valve. bodies away from each other so that the influence of the urging force of the second spring on the driving force of the electromagnetic force generating device becomes zero in the valve opening and closing mode in the final stage.

Abstract: The present invention provides a control booster which is capable of appropriately detecting a pedal-operated brake operation during an automatic brake operation. For moving a stop key from a position on a side of a rear-side abutment surface (where a reaction force of a switch acting on a switch operating rod and a spring force of a switch spring are balanced) toward an intermediate position, when the stop key is located on a side of the rear-side abutment surface, only a return force of the spring acts on a contact operating element of the switch. On the other hand, when the stop key moves toward the intermediate position, an abutment portion is separated from the contact operating element (that is, the switch operating rod moves in a direction for separation relative to the switch), so that no load is applied to the contact operating element.

Abstract: In a cylinder body of a cylinder apparatus of the present invention for a brake fluid pressure control system, primary and secondary pistons having different pressure-receiving areas are provided. A pressure chamber between the primary and secondary pistons is communicated with a reservoir through flow passages formed between the cylinder body and a sleeve and between the sleeve and the secondary piston. In normal operation of the brake fluid pressure control system, the cylinder apparatus serves as a stroke simulator by releasing the fluid in the pressure chamber through the flow passages to the reservoir and contracting a spring in the pressure chamber. In the event of a failure of the system, the cylinder apparatus serves as a tandem master cylinder in which the flow passages are closed by a seal member in accordance with movement of the secondary piston, and the primary and secondary pistons move, while substantially no contraction of the spring in the pressure chamber occurs.

Abstract: The present invention provides a booster in which magnitude of output can be adjusted also by an operation of a solenoid mechanism. An armature (13) is shifted to the right (in FIG. 1) in opposition to a returning spring by applying electricity to a solenoid (39), with the result that a space (80) on one end of the armature is communicated with a constant pressure chamber (5) through a passage (T3). When an electromagnetic force acting on the armature (13) exceeds a predetermined value, a distal end of a valve member (28) is shifted to the right (in FIG. 1) via a cylindrical member (31) to open an atmospheric valve (34), thereby introducing the atmosphere into a variable pressure chamber (6). The pressure in the variable pressure chamber is applied to the other end of the armature and the difference in the pressure tends to move the armature toward its home position.

Abstract: A master cylinder realizes a stroke simulator function without the need to change the structure around a brake pedal and without impairing brake pedal feel, is easy to form by machining, and also facilitates a hydraulic fluid charging and air bleeding operation. A secondary piston is split to make the axial length thereof variable, thereby imparting the stroke simulator function to the secondary piston. By doing so, brake pedal feel is improved more than by separately adding a stroke simulator.

Abstract: The present invention provides a control booster which is capable of appropriately detecting a pedal-operated brake operation during an automatic brake operation. For moving a stop key from a position on a side of a rear-side abutment surface (where a reaction force of a switch acting on a switch operating rod and a spring force of a switch spring are balanced) toward an intermediate position, when the stop key is located on a side of the rear-side abutment surface, only a return force of the spring acts on a contact operating element of the switch. On the other hand, when the stop key moves toward the intermediate position, an abutment portion is separated from the contact operating element (that is, the switch operating rod moves in a direction for separation relative to the switch), so that no load is applied to the contact operating element.

Abstract: The present invention provides a brake booster that, although simple in construction, capable of adjusting the braking force derived by operation of a solenoid mechanism without worsening the braking response. In the brake booster according to the present invention, when a movable member (34) is shifted toward the rear side by electromagnetic force of a solenoid (31), the shifting movement is transmitted to a valve seat member (21) through pins (50) to open an atmospheric valve (27) through which air is introduced into a variable pressure chamber (9,10), whereby a pressure difference is created between the variable pressure chamber and a constant pressure chamber and generates booster output (thrust output force).

Abstract: When a stroke speed exceeds a reference value of a stroke speed threshold value, a solenoid is energized to tract an armature, thereby opening an atmospheric valve independently of the position of a plunger. Consequently, power pistons, together with an output rod, are moved forward by a thrust corresponding to a pressure difference between a constant-pressure chamber and a variable-pressure chamber to perform a full-power braking operation. A reaction-adjusting mechanism contributes to an improvement in safety by functioning in such a way that when the part of the reaction force from the output shaft that is transmitted to an input rod reaches a predetermined value, a boosting ratio is increased, so that the reference value of the stroke speed threshold value can be set high to prevent unnecessary braking.

Abstract: A brake control system includes a master cylinder for developing a brake fluid pressure in response to brake pedal displacement, wheel cylinders mounted to front and rear wheels and adapted to develop a braking force, an actuator for feeding the brake fluid pressure to the respective wheel cylinders, and a controller adapted to enable the actuator to provide a controlled brake fluid pressure to the respective wheel cylinders. Two switch valves are adapted to normally prevent fluid communication between the master cylinder and the wheel cylinders and in the event of a system failure, permit fluid communication between the master cylinder and the wheel cylinders and prevent fluid communication between the actuator and the wheel cylinders. The switch valves are mounted solely to the wheel cylinders of the front wheels.

Abstract: A fluid passage switching valve includes a core structure provided with an input passage extending from an input port. The input passage opens on an outer peripheral surface of the core structure at such a position that when a plunger is in a fluid cut-off position, the input passage is closed by an inner surface of the plunger, and as the plunger moves toward a fluid passing position, the input passage is opened and communicated with an input port-side fluid chamber. An output port is communicated with an output port-side fluid chamber. The plunger has a communicating bore which provides communication between the input and output port-side fluid chambers. The pressure-receiving area of the plunger in relation to the input port-side fluid chamber is approximately the same as that of the plunger in relation to the output port-side fluid chamber over the entire travel range of the plunger.

Abstract: A brake fluid pressure adjustment device is presented for controlling the wheel lock of a vehicle by controlling the flow of the brake fluid from the main fluid path to the bypass path by means of a pumping mechanism which is in constant operation. The pumping mechanism includes a suction valve which only allows a unidirectional flow of brake fluid from the pump, and a reservoir to the pump; an electromagnetic device which forces open the bypass path between the pump and the reservoir by attracting the bypass path control valve element in one direction; and a discharge valve which allows only the flow of brake fluid from the pump to the main fluid path. Therefore, by controlling the actions of the electromagnetic means, it is possible to control the decrease, holding and increase actions of the pressure adjustment device, without stopping and starting the pump.

Abstract: A load-responsive hydraulic control apparatus includes a valve operating member for opening a valve portion capable of permitting and preventing a master cylinder from communicating with the rear wheel cylinders of a rear wheel brake system. A plunger is provided for receiving hydraulic pressure from a branch path branched from the rear wheel brake system between the valve portion and the master cylinder and for opening the valve portion via the valve operating member when the received hydraulic pressure reaches predetermined hydraulic shifting pressure. An inertia valve blocks the branch path when predetermined deceleration is achieved.