A vacuum operated brake booster, comprises a casing including a base defining at least one hole, and at least one tube extending through the casing and configured to receive a screw for fastening the brake booster to a wall of a passenger compartment of a vehicle. The tube defines a rear end with a peripheral fold forming a rear groove, and an extension extending beyond the rear groove, the extension defining a first outer edge and being configured to be folded toward an outer side of the tube to form a crimping lip. The at least one hole is bordered by a recessed ring having a form complementary to that of the rear groove of the rear end of the at least one tube. The extension is configured to be folded above a second outer edge of the recessed ring and blocked in the groove.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A control device for an electric vacuum pump that generates a negative pressure includes a negative-pressure detector for detecting the negative pressure generated by the electric vacuum pump and a pump stop control unit that is adapted to stop the electric vacuum pump when the negative pressure detected by the negative-pressure detector is not less than a predetermined value. The pump stop control unit is configured to determine an OFF timing at a present stage of the electric vacuum pump based on reference pump-filling-performance data, which is data about a reference negative pressure ratio relative to an elapsed time at an initial stage of the electric vacuum pump, and by referring to present pump-filling-performance data, which is data about a present negative pressure ratio relative to an elapsed time at the present stage of the electric vacuum pump.

An abnormality diagnostic device and an abnormality diagnostic method for a booster according to the present invention: determine that a negative pressure sensor operates normally, when an output of the negative pressure sensor changes in response to a decrease in intake pressure; determine that a negative pressure pump operates normally, when the pressure in a negative pressure chamber is decreased by operating the negative pressure pump, and the pressure decrease is determined by the negative pressure sensor determined to be normal; determine that the negative pressure pump is abnormal when the pressure decrease is not determined by the negative pressure sensor; and determine that a negative pressure leakage has occurred, when the pressure in the negative pressure chamber, which has been decreased by the negative pressure pump, is not maintained.

A check valve of this negative pressure-type booster device is provided with: a cylindrical section that is integrally formed with a shell disposed on one side, communicates with a connection pipe, and is formed in a cylindrical shape protruding toward the inside of a housing; and a valve body section that is disposed inside the cylindrical section, and is axially fitted, within the cylindrical section, to the cylindrical section such that air is permitted to flow from a negative pressure chamber to the connection pipe while the air is prohibited from flowing from the connection pipe to the negative pressure chamber.

A motor vehicle having a bulkhead includes: a brake unit, a housing of which is fastenable to the bulkhead of the motor vehicle. An actuating member for actuation of the brake unit extends through the bulkhead. A radial flange is provided on a housing surface facing toward the bulkhead. On the bulkhead, there is provided at least one corresponding fastening element which at least partially engages around the radial flange.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A vacuum brake booster for a motor vehicle brake system, comprising a displaceable force input member that is coupled to or can be coupled to a brake pedal, a chamber arrangement arranged in a booster housing having at least one working chamber and at least one vacuum chamber, which are separated from one another via at least one movable wall, a control valve assembly that can be actuated by the force input member, and a force output member for transmitting an operating force to a downstream brake system. The at least one working chamber can be fluidically connected optionally to a negative pressure source or the atmosphere by way of the control valve assembly. The control valve assembly comprises a control valve housing, in which an actuating piston that is coupled with the force input member s displaceably arranged, and a first valve seat, and a second valve seat. Upon an actuation of the force input member, a throttle sleeve can be displaced from the initial position relative to the control valve housing by a predetermined functional path. During the displacement, the throttle sleeve is in abutment with the actuating piston such that a fluidic connection between the at least one working chamber and the ambient atmosphere by way of a throttle window is present. Upon exceeding the functional path, the throttle sleeve lifts off the actuating piston.