Electromechanical brake booster and method for producing an electromechanical brake booster

An electromechanical brake booster, the second half housing being able to be centered on the first half housing by engaging a first mounting pin protruding from the first centering opening into the first insertion opening and by engaging a second mounting pin protruding from the second centering opening into the second insertion opening. A method for producing an electromechanical brake booster for a motor vehicle is also described.

FIELD

The present invention relates to an electromechanical brake booster for a motor vehicle. The present invention furthermore relates to a method for producing an electromechanical brake booster for a motor vehicle.

BACKGROUND INFORMATION

Future drive concepts of motor vehicles require alternative brake pressure buildup devices since little or no vacuum is available in order to operate a conventional vacuum brake booster. Electric motor brake boosters were developed for this purpose.

German Patent Application No. DE 10 2012 014 361 A1 describes a control device for a master brake cylinder of a motor vehicle, comprising a housing to be situated between the master brake cylinder and a brake pedal, through which a pressure organ for controlling a control piston of the master brake cylinder runs, an electric motor, a worm, which is driven by the electric motor and which intersects the pressure organ, and a gear unit situated in the housing, which couples the worm with the control piston so as to translate a rotary motion of the worm into a translatory motion of the control piston.

SUMMARY

An object of the present invention is to provide an improved electromechanical brake booster that has lower production costs and is simpler to produce.

An electromechanical brake booster for a motor vehicle and an electromechanical brake booster for a motor vehicle in accordance with the present invention are described herein.

The present invention provides an electromechanical brake booster for a motor vehicle, having a housing having a first half housing and a second half housing, in which an electric motor and a gear unit are situated, wherein a first centering opening and a second centering opening are developed on the first half housing and a first insertion opening and a second insertion opening are developed on the second half housing, the first centering opening being situated with respect to the first insertion opening and the second centering opening being situated with respect to the second insertion opening in such a way that it is possible to center the second half housing on the first half housing by engaging a first mounting pin protruding from the first centering opening into the first insertion opening and by engaging a second mounting pin protruding from the second centering opening into the second insertion opening and/or that it is possible to center the electric motor with respect to the gear unit by a bearing plate of the electromechanical brake booster in that the bearing plate fastened on an axle of a toothed wheel of the gear unit has a receiving opening into which a housing section of the electric motor is inserted.

The present invention furthermore provides a method for producing an electromechanical brake booster for a motor vehicle. The method comprises a provision of a first half housing and a second half housing of a housing in which it is possible to situate an electric motor and a gear unit; the method comprises furthermore a provision of a first centering opening and a second centering opening on the first half housing and a first insertion opening and a second insertion opening on the second half housing, the first centering opening being concentric with respect to the first insertion opening and the second centering opening being concentric with respect to the second insertion opening; the method comprises furthermore an engagement of a first mounting pin protruding from the first centering opening into the first insertion opening and an engagement of a second mounting pin protruding from the second centering opening into the second insertion opening for centering the first half housing on the second half housing; and/or a centering of the electric motor with respect to the gear unit by a bearing plate of the electromechanical brake booster by fastening the bearing plate on an axle of a toothed wheel of the gear unit and situating the bearing plate in such a way that a housing section of the electric motor is inserted into a receiving opening of the bearing plate.

In accordance with an embodiment of the present invention, the first half housing and the second half housing of the housing of the electromechanical brake booster are centered during the production of the electromechanical brake booster. The use of mounting pins makes it advantageously possible to center the first half housing and the second half housing in an assembly line of the electromechanical brake booster. It is thus possible to perform the production method efficiently.

Advantageous specific embodiments and developments result from the description herein with reference to the figures.

A preferred development of the present invention provides for a housing bottom of the first half housing to have a third centering opening, in which a third mounting pin is insertable for positioning the first half housing relative to the second half housing. It is thus possible to position the first half housing efficiently relative to the second half housing.

Another preferred development of the present invention provides for the third centering opening developed on the first half housing to have a bore introduced into a housing bottom, and the first centering opening developed on the first half housing, which is situated on a housing section of the first half housing across from the housing bottom, having a bore introduced into the housing section of the first half housing. The third centering opening developed on the first half housing and the first centering opening developed on the first half housing are preferably developed to be sturdy by being integrally developed with the first half housing.

Another preferred development of the present invention provides for the first centering opening and the third centering opening to be situated along a common longitudinal axis of the housing. This allows for a stable centering of the first half housing with respect to the second half housing without one of the half housings tilting.

Another preferred development of the present invention provides for first insertion opening developed in the second half housing to be developed as a passage, the first centering opening developed in the first half housing extending through the first insertion opening. The development of the first insertion opening developed in the second half housing as a passage achieves an improved stability of the first insertion opening with respect to transverse forces.

Another preferred development of the present invention provides for the second centering opening developed in the first half housing and the second insertion opening developed in the second half housing to be developed as an oblong hole, the second centering opening and the second insertion opening being oriented along a straight line extending between the second insertion opening and the first insertion opening. By developing the second centering opening developed in the first half housing and the second insertion opening developed in the second half housing as an oblong hole, a simple centering of the first half housing with respect to the second half housing is made possible.

Another preferred development of the present invention provides for the first mounting pin and/or the second mounting pin to be rigidly connected with the first half housing. This advantageously eliminates an insertion of the mounting pins into the respective centering openings.

Another preferred development of the present invention provides for the bearing plate to be press-fit in a recess developed in the first half housing. The bearing plate is thus able to be situated in the first half housing particularly in a way that saves space and that is fixed in place.

Another preferred development of the present invention provides for the bearing plate to define a center-to-center distance between the toothed wheel of the gear unit and the motor pinion of the electric motor. This makes it possible advantageously to achieve an exact engagement of the motor pinion of the electric motor with the toothed wheel of the gear unit.

Another preferred development of the present invention provides for the receiving opening developed in the bearing plate to receive the motor pinion of the electric motor. It is thus possible to position the motor pinion in such a way that it meshes with the toothed wheel of the gear unit.

The described embodiments and developments of the present invention may be combined with one another as desired.

Additional possible embodiments, developments and implementations of the present invention also include combinations of features of the present invention that are not explicitly mentioned above or below with respect to the exemplary embodiments.

Unless indicated otherwise, identical reference symbols in the figures indicate identical or functionally equivalent elements, parts or components.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1shows a perspective representation of a gear unit16of an electromechanical brake booster1for a motor vehicle according to a preferred specific embodiment of the present invention.

Gear unit16has an electric motor21or an electric motor/control unit assembly, a motor pinion22driving a graduated toothed wheel23or twin toothed wheel. Toothed wheel23in turn drives a toothed wheel24, which is connected to a spindle nut (not shown inFIG. 1). A bellows20is preferably situated around the spindle nut.

Toothed wheel23is rotationally mounted on an axle25. A ball bearing is preferably disposed between motor pinion22and electric motor21.

FIG. 2shows a perspective representation of a gear unit of the electromechanical brake booster for the motor vehicle according to the preferred specific embodiment of the present invention.

A bearing plate26is mounted or press-fit into the one half housing5. Axle25is rigidly connected both with first half housing5as well as with bearing plate26. It is possible to position or center electric motor21via a receiving opening27in bearing plate26. A housing section42of electric motor21is inserted into receiving opening27.

Electric motor21is preferably screw-fitted on a housing flange28. Alternatively, motor/control unit assembly21may also be connected with housing flange28in another suitable manner. As a result of the aforementioned construction, toothed wheel23, toothed wheel24, bearing plate26and electric motor21are centered or fastened directly via first half housing5. First half housing5is preferably made of aluminum. A second half housing8that is preferably made of plastic thus does not have to have a load-bearing function.

A center-to-center distance between toothed wheel23and the motor pinion (not shown inFIG. 2), which must be very precise, is ensured by bearing plate26. Bearing plate26is preferably developed as a stamped sheet metal part.

FIG. 3shows a part-sectional view of a housing of the electromechanical brake booster for the motor vehicle according to the preferred specific embodiment of the present invention.

First half housing5and second half housing8are preferably made of steel. Since no separate bearing plate is provided, first half housing5must be positioned exactly with respect to second half housing8.

First half housing5has a first centering opening34aand a second centering opening36a. Second half housing8has a first insertion opening (not shown inFIG. 3) and a second insertion opening (not shown inFIG. 3).

The first centering opening34ais situated preferably concentrically with respect to first insertion opening8a. Second centering opening36ais situated preferably concentrically with respect to second insertion opening36b.

Second half housing8is able to be centered on first half housing5by engaging a first mounting pin M1protruding from first centering opening34ainto first insertion opening8aand by engaging a second mounting pin M2protruding from second centering opening36a(not shown inFIG. 3) into second insertion opening36b.

A housing bottom5aof first half housing5preferably has a third centering opening34b, into which a third mounting pin M3is insertable for positioning first half housing5relative to second half housing8. First centering opening34aand third centering opening34bare preferably developed in the form of a bore or alternatively in the form of a cone. Alternatively, the respective mounting pin may have a bore for example and the respective centering opening may be developed in the form of a cone, which is insertable into the bore developed in the mounting pin.

First centering opening34aand third centering opening34bare preferably situated along a common longitudinal axis35of housing9.

FIG. 4shows a perspective representation of the housing of the electromechanical brake booster for the motor vehicle according to the preferred specific embodiment of the present invention.

Second half housing8is able to be centered with respect to first half housing5by engaging the second mounting pin M2protruding from second centering opening36ainto second insertion opening36b.

The first insertion opening8adeveloped in second half housing8is preferably developed as a passage, the first centering opening34adeveloped in first half housing5extending through first insertion opening8a.

The second centering opening36adeveloped in first half housing5and the second insertion opening36bdeveloped in second half housing8are preferably developed as oblong holes, the second centering opening36aand the second insertion opening36bbeing oriented along a straight line extending between second insertion opening36band first insertion opening8a.

First half housing5is preferably able to be screw-fitted to second half housing8by a plurality of bolts37.

FIG. 5shows a flow chart of a method for the assembly of the electromechanical brake booster for the motor vehicle according to the preferred specific embodiment of the present invention.

The method comprises a provision S1of a first half and a second half of a housing, in which an electric motor is operably connected to a spindle via a gear unit. The method furthermore comprises a provision S2of a first centering opening and a second centering opening on the first half housing and a first insertion opening and a second insertion opening on the second half housing, the first centering opening being concentrically situated with respect to the first insertion opening and the second centering opening being concentrically situated with respect to the second insertion opening.

The method furthermore comprises an engagement S3of a first mounting pin protruding from the first centering opening into the first insertion opening and of a second mounting pin protruding from the second centering opening into the second insertion opening for centering the second half housing on the first half housing and/or a centering S4of the electric motor with respect to the gear unit by a bearing plate of the electromechanical brake booster by fastening the bearing plate on an axle of a toothed wheel of the gear unit and situating the bearing plate in such a way that a motor pinion of the electric motor is inserted into a receiving opening of the bearing plate and that the motor pinion inserted into the receiving opening meshes with the toothed wheel of the gear unit.

Although the present invention was described above with reference to preferred exemplary embodiments, it is not limited to these and may be modified in numerous ways. In particular, the present invention may be changed or modified in many ways without deviating from the essence of the present invention.

For example, it is possible to situate the centering openings and/or the insertion openings in a different suitable position on the housing.

LIST OF REFERENCE SYMBOLS