CN112636514A

CN112636514A - Method for producing a motor vehicle actuator

Info

Publication number: CN112636514A
Application number: CN202011338606.8A
Authority: CN
Inventors: 彼得·皮佐拉
Original assignee: Bozewalsburg Automotive Parts Europe
Current assignee: Bose Bamberg Auto Parts Co ltd
Priority date: 2015-07-21
Filing date: 2016-07-21
Publication date: 2021-04-09
Anticipated expiration: 2036-07-21
Also published as: DE102015213753B4; CN106374665B; DE102015213753A1; CN106374665A

Abstract

The invention relates to a method for producing a servo drive of a motor vehicle, wherein the servo drive (2) of the motor vehicle comprises a transmission unit (6) having a transmission housing (4) and a motor unit (10) having a motor housing (8), wherein the motor housing (8) is produced with a rough contact surface (50), wherein an axial play compensation between the motor unit (10) and the transmission unit (6) is carried out, wherein the contact surface (48) of the transmission housing is at least partially melted, wherein the contact surface (48) of the transmission housing is melted into the contact surface (50) of the motor housing, and wherein the contact surface (48) of the transmission housing is cooled.

Description

Method for producing a motor vehicle actuator

The present application is a divisional application of an invention patent application having an application date of 2016, 7, 21, entitled "method for manufacturing a motor vehicle servo drive" and an application number of 201610579805.5.

Technical Field

The invention relates to a method for producing a motor vehicle servo drive comprising a transmission unit having a transmission housing and having a motor unit having a motor housing. The invention also relates to a motor vehicle servo drive produced according to said method.

Background

The motor vehicle actuating drive is used, for example, as a window lift drive or as a drive for operating a sunroof. A motor vehicle servo drive typically has a motor unit and a transmission unit. The gear unit conventionally comprises a worm gear, which is arranged in a gear housing made of plastic and has a worm wheel and a drive shaft realized as a worm shaft. The motor unit expediently has an electric motor arranged in a motor housing, which is provided with a motor shaft and a rotor group, which is fixed on the motor shaft and contains a large number of laminations.

The known drive shaft of a motor vehicle servo drive is milled directly onto the motor shaft. In order to compensate for tolerances resulting from manufacturing, an axial play compensation element is typically provided, which is positioned between the drive shaft and the transmission housing on an end region of the drive shaft facing away from the motor shaft and/or between the motor shaft and the motor housing on an end region of the motor shaft facing away from the drive shaft.

In order to produce or install known motor vehicle servo drives, a conventional pot-shaped motor housing is screwed to the transmission housing. To which the necessary sealing means between the motor housing and the transmission housing are connected in order to avoid fluid infiltration into the electric motor. Furthermore, the fixing screws required for screwing must be inserted and screwed in the installation direction that is turned by 90 degrees. This requires a relatively high expenditure and a relatively high cost for the installation of the known motor vehicle actuating drive.

Disclosure of Invention

The object of the invention is to provide a method for producing a motor vehicle servo drive, which is improved with regard to the installation outlay. Furthermore, a motor vehicle actuating drive produced according to this method is to be described.

This object is achieved by a method having the features of claim 1. In the case of a motor vehicle actuating drive produced according to this method, this object is achieved according to the invention by the features of claim 5. Advantageous developments and embodiments are the subject matter of the respective dependent claims.

According to the method, for producing a motor vehicle servo drive comprising a transmission unit having a transmission housing and a motor unit having a motor housing, it is provided that the motor housing is produced with a rough contact surface on the transmission housing side. Subsequently, axial clearance compensation between the motor unit and the transmission unit is performed during mounting to compensate for tolerances caused by manufacturing. In order to fix the motor housing to the transmission housing, it is provided that the motor housing-side contact surface of the transmission housing is at least partially melted (anschmelzen) or melted (aufschmelzen) and that the at least partially liquefied contact surface of the transmission housing is melted into the roughened structure of the contact surface of the motor housing. Finally, the contact surface of the gear housing is cooled, wherein the melted gear housing material is solidified or hardened. In this way, a reliable and, in addition, fluid-tight connection is produced between the two housings, wherein the rough structure of the contact surface of the motor housing engages in the material of the gear housing in a barb-like and mechanically secure manner.

By fusing the gear housing to the motor housing, on the one hand, screwing is dispensed with, as a result of which the mounting direction of the motor housing relative to the gear housing is likewise changed in an advantageous manner. Furthermore, the receptacle required for the fastening screw is thereby eliminated, thereby providing an additional degree of freedom with respect to the axial play compensation between the units. In particular, the need for additional sealing devices is eliminated, since the engaged connection between the motor housing and the transmission housing already seals the interior of the housing of the assembled motor vehicle servo drive in a fluid-tight manner. The installation of the motor vehicle servo drive is thereby significantly simplified, which advantageously translates into a production cost.

Since the motor housing and the transmission housing can be joined together by melting in a substantially precise manner to a certain extent, the manufacturing costs are thereby further reduced in a suitable manner since the axial play compensation which can be achieved thereby during installation also eliminates an additional axial play compensation element between the motor unit and the transmission unit.

By means of the axial play compensation, the transmission of torque from the motor shaft to the drive shaft is improved on the one hand. On the other hand, during operation of the motor vehicle servo drive, the occurrence of switching noises is likewise avoided or at least significantly reduced. In the case of a typical installation of a servo drive of a motor vehicle, the comfort of the user of the motor vehicle is thereby likewise increased in an advantageous manner.

The rough contact surface is produced, for example, together with the motor housing or is subsequently applied to the motor housing by a roughening process. A rough or roughened surface or structure is to be understood in particular as a deviation in shape due to irregularities or the like, whereby in particular the surface which is in contact with the contact surface of the transmission housing in the installed state is increased. The surface enlargement has a positive effect on the retention between the transmission housing and the motor housing. In particular, the irregularities should on the one hand be sufficiently deep that the material of the gear housing can be melted in smoothly and thus a secure hold is ensured by the tightening. On the other hand, the unevenness should not be carried out too deeply, so that gaps or unfilled areas do not occur as a result of inadequate melting-in due to the sometimes high viscosity of the melted or fused material.

In order to ensure that the melted material of the contact surface of the gear housing, after cooling, establishes a particularly strong and reliable connection with the rough contact surface of the motor housing, the two contact surfaces are pressed together in a preferred development in the state in which the contact surface of the gear housing is melted. This ensures that the liquefied transmission housing material flows around the coarse structure in a good manner, so that a particularly large surface of the contact surfaces of the motor housing is wetted with the liquefied material, which in the cooled/hardened state results on the one hand in a better retention and on the other hand in a better fluid-tight seal between the contact surfaces.

The gear housing is in particular a plastic part produced by injection molding, preferably made of a thermoplastic, for example a polyamide material, and has a tubular opening in the region of the contact surface. The contact surface is preferably embodied here as a thickening of the plastic material in the region of the end-side opening. In a suitable manner, the plastic material of the gear housing has a lower melting temperature than the metal material of the motor housing.

The motor housing is expediently made of a metal material and can be made of a sheet metal material, for example, in a deep-drawn manner. The contact surface of the motor housing is preferably roughened by means of sandblasting. In addition to spraying, other roughening methods, such as knurling, laser treatment, spark erosion, chemical roughening/etching or brushing, are likewise conceivable.

In a preferred embodiment, however, the roughness of the contact surface is formed in particular by an introduced or formed rear insert element (hindrifflement). A rear insert element is to be understood to mean, in particular, a surface shape and/or a surface structure on or around which the molten plastic of the transmission housing can be fused or which can be anchored and/or fastened in the cooled state. The hook-shaped rear-engaging element is preferably adapted and designed to better engage the surface between the plastic-like contact surface of the gear housing and the metal contact surface of the motor housing. The roughness of the contact surface is therefore determined essentially by the dimensions and density and the inclination of the rear embedded element. In an inexpensive embodiment, the rear insert element is, for example, a hook-shaped structure which is introduced into the contact surface by means of a stamping process.

In an advantageous embodiment of the method, the metal motor housing can therefore be heated for the purpose of heating and melting the contact surface of the gear housing. When the heated contact surface of the motor housing is pressed against the contact surface of the gear mechanism housing, the plastic of the gear mechanism housing is melted and flows into the rough structure of the contact surface of the motor housing or flows around it.

Alternatively, in an equally advantageous embodiment, the gear housing in the region of the contact surface can be heated, preferably the contact surfaces between the motor housing and the gear housing are joined together, in particular during the laser welding process.

In one possible embodiment of the motor vehicle actuating drive, the motor housing is at least partially inserted into the transmission housing. The motor housing is inserted into a tubular opening of the transmission housing, in particular in the region of the roughened contact surface. In a preferred embodiment, the contact surface of the gear housing is an open collar-like projection, wherein the motor housing contacts the projection from the inside. The length or depth of the projections, or the variable insertion depth of the motor housing that can be achieved thereby, makes it possible to achieve an axial play compensation between the transmission unit and the motor unit during the installation of the motor vehicle servo drive in a particularly simple manner and in a structurally simple manner.

In an advantageous alternative embodiment, the contact surfaces of the motor housing and the gear housing are embodied as end-side flanges facing each other, which are preferably suitable for establishing a weld between the gear housing plastic and the metal of the motor housing. In a preferred refinement, the contact surface of the transmission housing has, in particular, a circumferentially extending, projecting elevation as a local melted region. The tab-like projections lead to a targeted introduction of thermal energy in the manner of an energy-conducting sensor, which enables a controlled and dimensionally stable melting.

In an advantageous embodiment, the contact surface of the motor housing has a rear-cutting element (hindschneidnung element) which is engaged behind by a plug of the contact surface of the transmission housing in a form-locking (Fromschluss) connection.

In a preferred embodiment, the metal flange of the motor housing has a number of recesses as filling openings, through which the molten plastic of the flange of the gear housing can flow during production. The recess is in particular a through-opening of the flange of the motor housing, so that the molten material can pass through the recess at least partially to the further flange side. The fusible plug formed by the molten material after cooling therefore engages behind the motor housing flange in the installed state, and thus a form-locking connection or a hot-fill fastening of the transmission housing to the motor housing can be achieved.

The advantages achieved with the invention are in particular the elimination of length tolerances, since the motor housing and the transmission housing can be joined to a precise extent. The tolerances of the individual components can thus be compensated for simply during installation. Furthermore, the sealing points and the screw elements with the corresponding components and tolerances are eliminated due to the fluid-tight melt connection. The motor vehicle actuating drive produced according to the method can therefore be produced particularly simply and inexpensively.

The method according to the invention is not limited to joining the motor housing and the transmission housing together. In particular, the method can be used in general for connecting a (preferably metallic) functional unit and a (preferably plastic) housing unit. It is important that the surface of the functional unit contact surface is correspondingly roughened, so that on the one hand a particularly large surface for melting into the housing unit material is obtained and on the other hand a roughened surface is achieved which is in close contact with the cooled housing unit material. The necessary roughness depends on the respective forces in the different possible applications, wherein the roughening is also selected according to the costs of the production technology.

Drawings

Embodiments of the invention are explained in detail below with the aid of the figures. Wherein:

fig. 1 shows a perspective view of a servo drive of a motor vehicle, which comprises a transmission unit with a transmission housing and a motor unit with a motor housing;

fig. 2 shows the motor vehicle actuating drive according to fig. 1 in a perspective exploded view;

fig. 3 shows a longitudinal section of a servo drive of a motor vehicle;

fig. 4 shows a second embodiment of a servo drive of a motor vehicle in a longitudinal section;

fig. 5 shows an embodiment of the motor vehicle actuating drive according to fig. 4 in an exploded perspective view;

fig. 6 shows a third embodiment of a servo drive of a motor vehicle in a longitudinal section; and is

Fig. 7a to 7c show the contact surfaces of the motor housing with different surface roughness in a schematic and simplified side view.

Parts that correspond to one another are always provided with the same reference numerals in all figures.

Detailed Description

Fig. 1 shows a motor vehicle actuating drive 2, which comprises a transmission unit 6 having a transmission housing 4 and a motor unit 10 having a motor housing 8. In the present exemplary embodiment, the motor vehicle actuating drive 2 is, for example, a window lift drive, a seat adjustment drive or a sunroof drive.

The motor housing 8 is, for example, a metallic pole pot produced by deep drawing from a sheet metal material. As can be seen in fig. 2 and 3, the motor unit 10 arranged inside the motor housing 8 comprises an electric motor 12 having a motor shaft 16 carrying a rotor or mover 14, which is rotatably supported in a rotor-side spherical bearing 18 and a transmission-side sliding or sintered bearing (sinterager) 20. The permanent magnets 22, which are held azimuthally fixed in the motor housing 8, form the stator of the electric motor 12.

A commutator having a commutator shaft, not shown in detail, is arranged fixedly on the motor shaft 16 relative to the shaft between the rotor 14 and the slide bearing 20. The commutator is rubbed with a brush system 26, which in this embodiment comprises two carbon brushes 24.

The brush system 26 is arranged in a pot-shaped supporting housing 28, which is inserted with its pot wall 30 into the motor housing 8 via a housing opening 32 in a form-fitting manner. The housing bottom 34 covers the housing opening 32 of the motor housing virtually completely.

On the housing side of the motor unit 10 opposite the support housing 28, the motor housing 8 is closed on the bottom side with the formation of a bearing shield 36 in which the spherical bearing 18 is seated and held. In the region of a central shaft opening 38 provided in the carrier housing 28, the central shaft opening is surrounded by a housing collar 40 which projects beyond the housing bottom 34.

The motor shaft 16, which projects from the support housing 28 beyond the central shaft opening 38, closes the motor housing 8 with the inserted support housing 28 as completely as possible with the formation of the smallest possible annular gap 42. In the installed state, the motor shaft 16 projects into the transmission housing 4 in the axial direction a. On the shaft end side, the motor shaft 16 is coupled in terms of drive to a drive shaft 44 of the gear unit 6, which is realized as a worm shaft. The drive shaft 44 engages with a worm gear, not shown in detail, of a worm drive of the gear unit 6.

The support housing 28 and the motor housing 8 (as can be seen in particular in fig. 3) are at least partially inserted into the transmission housing 4 in the installed state. For this purpose, the gear housing 4 has a tubular opening 46 with a collar-like projection as an abutment surface 48. The gear housing 4 is in particular an injection-molded part made of a thermoplastic plastic material.

The region of the motor housing 8 outside the inserted housing is a motor housing-side contact surface 50 which comes into contact with a contact surface 48 on the inner wall side of the projection. In the inserted state, in the exemplary embodiment shown, a hollow-cylindrical air gap is formed as an axial gap 52 between the collar-like contact surface 48 and the housing outer side of the tank wall 30, in which air gap the motor housing 8 is inserted so as to be axially displaceable during assembly. Further, a second air gap in the form of a hollow cylinder is provided as a second axial gap 56 between the housing bottom 34 and the inner wall portion 54 of the opening 46. The

axial play

52 and 56 can compensate for manufacturing tolerances or possible manufacturing inaccuracies of the drive shaft 44 and/or the motor shaft 16 during installation. As a result, no additional axial play compensation element is required in the production of the motor vehicle servo drive 2.

The contact surface 50 is roughened by means of sandblasting, i.e. the roughness of the contact surface 50 and the surface increase due to irregularities or the like.

For mounting the motor vehicle servo drive 2, the contact surface 50 is inserted into the contact surface 48, wherein, as can be seen in fig. 3, the support housing 28 of the brush system 26 is supported on the motor side in the axial direction a on the permanent magnet 22 of the electric motor 12. Possible manufacturing inaccuracies between the motor unit 10 and the transmission unit 6 are then compensated for by means of the

axial clearances

52 and 56, and the motor housing 8 is positioned substantially to some extent on or in the transmission housing 4. Thereby, on the one hand, the transmission of torque from the motor shaft 16 to the transmission shaft 44 is improved. Furthermore, the occurrence of switching noises is thereby also avoided or at least significantly reduced.

In order to fix the motor housing 8 to the gear housing 4, the contact surface 48 is heated outside the gear housing by a laser welding process which takes place over substantially the entire circumference and is pressed substantially perpendicularly radially against the contact surface 50. By heating, the plastic material of the abutment surface 48 is at least partially melted. The liquefied plastic material flows or circulates through the roughened structure of the contact surface 50. Finally, the connecting point is cooled, so that the plastic of the contact surface 48 solidifies again and the contact surfaces 48 and 50 are joined together. This provides a mechanically very strong and also fluid-tight connection between the transmission housing 4 and the motor housing 8, wherein the plastic of the contact surface 48 engages in the roughened surface of the contact surface 50.

An alternative embodiment of the motor vehicle actuating drive 2 is explained in detail below with reference to fig. 4 and 5. This embodiment differs from the previously described embodiment primarily in the design of the contact surfaces 48 and 50, which in this embodiment are designed as end-side flanges facing each other.

In this embodiment, the contact surface 48 additionally has a projecting bead 58 extending in the circumferential direction as an energy-conducting sensor. A substantially hollow cylindrical projection 58 is formed substantially integrally on the abutment surface 48.

In the mounted state, the carrier housing 28 of the brush system 26 is in turn supported on the permanent magnet 22 of the electric motor 12 on the motor unit side in the axial direction a. In order to adjust and compensate for the axial play between the motor unit 10 and the transmission unit 6, which is caused in particular on account of manufacturing tolerances, in this embodiment only the axial play 56 between the housing floor 34 and the inner wall 54 is used. The end-side contact surface 50 of the metal flange is likewise roughened in the present exemplary embodiment.

In order to fix the motor housing 8 to the transmission housing 4, the flange of the contact surface 48 is heated on the side facing away from the motor housing 8 by a laser welding process which takes place over substantially the entire circumference and presses the flange of the contact surface 50 axially. A targeted introduction of thermal energy in the region of the contact surface 50 is provided by the projections 58. This enables the contact surface 48 to be melted and fixed on the contact surface 50 in a controlled and dimensionally precise manner.

One possible modification of this embodiment is schematically shown in fig. 6. In the present exemplary embodiment, the flange of the contact surface 50 has a number of undercut elements 60 as clearance-like filling openings. During the melt-fastening of the contact surface 48 to the contact surface 50, the liquefied plastic material can flow through the rear-cutting element 60, so that in the installed state the rear-cutting element 60 is positively engaged behind by a plug 62 formed from the flowing and solidified plastic material.

The roughness of the contact surface 50 for different surface preparations is shown in a schematic manner in the following with reference to fig. 7a to 7 c. Fig. 7a shows an exemplary polished metal surface 64, which has a comparatively small roughness. The surface may be roughened for better welding purposes, for example, by spraying with sand or steel. The resulting mountain-and valley-shaped surface structures 66 are schematically shown in fig. 7 b. Fig. 7c shows a number of hook-shaped rear insert elements 68 which are introduced into or onto the contact surface 50, for example by means of a microstructuring or stamping process and a deformation process. By way of example, only one rear-insert element 68 is provided with a reference numeral in the figures.

The invention is not limited to the embodiments described before. In particular, a person skilled in the art can derive therefrom further variants of the invention without leaving the subject matter of the invention. Furthermore, in particular, all individual features described in connection with the exemplary embodiments can also be combined with one another in other ways without leaving the subject matter of the invention.

List of reference numerals

2 servo driving device for motor vehicle

4 Transmission device shell

6 Transmission unit

8 Motor casing

10 Motor Unit

12 electric motor

14 rotor

16 motor shaft

18 spherical bearing

20 sliding bearing

22 permanent magnet

24 carbon brush

26 brush system

28 load-bearing housing

30 tank wall part

32 shell opening

34 bottom of the shell

36 bearing guard board

38 shaft opening

40 casing ring

42 annular space

44 drive shaft

46 opening

48 contact surface

50 abutting surface

52 axial clearance

54 inner wall portion

56 axial clearance

58 lobe

60 back cut element

62 fusible plug

64 metal surface

66 surface structure

68 rear embedded element

Axial direction A

Claims

1. A method for producing a motor vehicle servo drive (2) comprising a transmission unit (6) having a transmission housing (4) and a motor unit (10) having a motor housing (8),

in the method, the motor housing (8) is produced with a rough contact surface (50), wherein the contact surface (50) of the motor housing is embodied as a flange,

-in the method, an axial play compensation between the motor unit (10) and the transmission unit (6) is performed,

in the method, the contact surface (48) of the transmission housing is embodied as a flange and is at least partially melted,

in the method, an abutment surface (48) of the transmission housing is melted into an abutment surface (50) of the motor housing, and

-in the method, the abutment surface (48) of the transmission housing is cooled.

2. The method of claim 1,

the melted contact surface (48) of the transmission housing and the contact surface (50) of the motor housing are pressed together.

3. The method according to claim 1 or 2,

the motor housing (8) is heated in order to melt the contact surface (48) of the gear housing.

4. The method according to claim 1 or 2,

the abutment surface (48) of the transmission housing and the abutment surface (50) of the motor housing are laser welded.

5. A motor vehicle servo drive (2) produced according to the method of one of claims 1 to 4, comprising a transmission unit (6) having a transmission housing (4) and a motor unit (10) having a motor housing (8), wherein the contact surfaces (50, 48) of the motor housing and the transmission housing are embodied as flanges.

6. Motor vehicle servo drive (2) according to claim 5,

the roughness of the contact surface (50) is formed by a number of inserted rear-mounted elements (68).

7. Motor vehicle servo drive (2) according to claim 5 or 6,

the motor housing (8) is at least partially inserted into the transmission housing (4).

8. Motor vehicle servo drive (2) according to claim 5 or 6,

the contact surface (48) of the transmission housing has a circumferentially extending protruding projection (58).

9. Motor vehicle servo drive (2) according to claim 5, 6 or 8,

the contact surface (50) of the motor housing has at least one undercut element (60) which is engaged behind, in particular in a form-locking manner, by a plug (62) of the contact surface (48) of the transmission housing.