EP1095443A1

EP1095443A1 - Actuator with an electromotor and control electronics

Info

Publication number: EP1095443A1
Application number: EP99936357A
Authority: EP
Inventors: Frank Moskob
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1998-12-18
Filing date: 1999-05-29
Publication date: 2001-05-02
Also published as: WO2000038300A1; KR20010024934A; JP2002534046A; US6528915B1; DE19858627A1

Abstract

The aim of the invention is to provide a more sophisticated interference suppression circuit with two capacitors in what is known as a cy circuit, whereby a metallic electromotor housing is to be connected to the interference suppression circuit. According to the invention, a strip conductor (41) is provided on a circuit-board (33) in the region of the cross-section of the electromotor. A contact spring (37) originates from the strip conductor (41) and protrudes into the electromotor housing (10). An elastic free end (43) fits closely against the electromotor housing (10) establishing an electrical contact therewith. The strip conductor (41) is electrically connected to the radio interference suppression circuit.

Description

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Actuator with an electric motor and with control electronics

State of the art

The invention relates to an actuator with a

Electric motor and with control electronics according to the preamble of claim 1.

Through the publications US 4,384,223; DE 33 14 412 C2 and DE 196 54 352 AI it is notoriously known to arrange electrical interference suppression devices within metallic electric motor housings of so-called collector motors adjacent to the collectors and associated brushes and to interconnect them with the brushes and also with the metallic electric motor housings. To interconnect the interference suppression device with the metallic electric motor housings, spring tongues are carried by so-called brush holder plates, which, for example, can be formed to taper at their free ends in the manner of claws. This has the advantage that, for example, by

Relative movements of these claws relative to the electric motor housing on the occasion of the assembly by producing scratch marks good electrical contact is brought about. In a suppression circuit known from the document US 4,384,223 are as Interference suppression capacitors are used. Two capacitors are connected in series and the contact in the electric motor housing is connected to both capacitors. The respective other connection of each capacitor is connected to one of the brushes. Such an interference suppression circuit is also known under the name "Cy interference suppression circuit". In contrast to this, in the examples according to DE 33 14 412 C2 and DE 196 54 352 AI, a brush connected to an interference suppression circuit is as low-impedance as possible with the

Electric motor housing electrically connected according to the method "mass of the electric motor housing at one pole of the direct voltage network", the direct voltage network can be an on-board network of a vehicle. With such an interconnection of the electric motor housing with a brush, there is usually the restriction that the electric motor can only be operated in one direction of rotation is what is sufficient for a pump drive motor for a piston pump, for example a hydraulic vehicle brake system or a windshield wiper drive motor.

From the document DE 42 42 641 AI an actuator is known with an electric motor, which has a metallic electric motor housing, a shaft with armature and collector and brushes and a brush holder plate, and with control electronics for the electric motor, wherein electronic and electrical components with a conductor plate are connected and the conductor plate protrudes at right angles to the shaft and adjacent to the brush holders into a cross section of the electric motor housing and is protected outside of the electric motor housing by a control electronics housing. The actuator has, for example, a worm gear and is used, for example, to move a sliding roof. Accordingly, the electric motor must act in two different directions of rotation, what about the Control electronics is achieved. The control electronics are also set up in such a way that the sunroof can also assume selectable intermediate positions between constructively possible end positions. In the end positions, the electric motor is switched off. Because this electric motor has a collector and brushes, it may be necessary to arrange an interference suppression circuit, for example of a type that occurs in the prior art, in the actuator. The interference suppressor can be added to the control electronics, for example, and can be attached to the printed circuit board, for example.

Advantages of the invention

The actuator according to the invention with an electric motor and with control electronics according to the characterizing features of claim 1 has the advantage that the metallic electric motor housing can be electrically conductively connected to an interference suppression circuit designed, for example, as a Cy circuit, the interference suppression elements of which are contacted with the printed circuit board of the control electronics the assembly of the electric motor, which includes the plugging together of the electric motor housing and the brush holder plate with the addition of the conductor plate.

The measures listed in the dependent claims allow advantageous developments and improvements of the actuator specified in claim 1.

The actuator with the characterizing features of claim 2 has the advantage that within the electric motor housing, the conductor plate is a relative can take up a lot of space because only a cutout in the circuit board is required so that the thinnest rotating component of the electric motor, namely the shaft, does not collide with the circuit board.

The characterizing features of claim 3 result in good anchoring of the contact spring built in according to the invention in a brush carrier plate normally provided anyway. After assembling the brush carrier plate, the conductor plate can be aligned to the shaft and along this against the

Brush carrier plate are moved and assembled, with a contact tab then protruding through an opening in the conductor plate to be soldered to an associated conductor.

The characterizing features of claim 4 provide an alternative solution to the solvents according to claim 3. The characteristic opening in the brush holder plate can be produced by means of a relatively simple tool, which is why the contact spring is inserted into this opening in a later assembly process.

The characterizing features of claim 5 have the advantage that after the insertion of the contact spring into the opening, the contact spring is secured in a positive manner in the axial direction.

The characterizing features of claim 6 result in the

Advantage that the contact spring can be combined with the printed circuit board and soldered to a printed circuit board before the actuator is assembled. In this respect, the soldering can be carried out simultaneously with the production of other required soldered connections of the control electronics. Instead of the relatively narrow openings mentioned in FIGS

Brush carrier plates now receive the brush carrier plate a relatively large opening through which the contact spring can be inserted into the electric motor housing, for example without contact.

The characterizing features of claim 7 result in a good anchoring of the contact spring with the conductor plate for the purpose that the desired contact force, which acts in a tilting manner on the contact spring, does not lead to detachment from the conductor plate.

The characterizing features of claim 8 give the advantage that, when assembling the electric motor, the spring end of the contact spring causing the contact does not spit when it is passed through the brush holder plate and when it is inserted into the electric motor housing, as a result of which the contact spring can be inserted.

The characterizing features of claim 9 result in the advantage that the contact spring is largely protected from damage or bending impairing the contacting before and during assembly of the electric motor.

The feature of the characterizing claim 10 gives the advantage that, for example, when the contact spring is secured against tipping over on the printed circuit board, a sufficient pressing of the resilient free end onto the electric motor housing takes place. The starting ramp has the effect that towards the end of the insertion process of the contact spring into the electric motor housing, the freely resilient end is moved into the contact position in the radial direction of the electric motor housing. drawing

Three embodiments of the actuator according to the invention are shown in the drawing and described in more detail below. 1 shows a first embodiment in longitudinal section, FIG. 2 shows the detail according to the invention in FIG. 1 on an enlarged scale, FIG. 3 shows an alternative detail on an enlarged scale, FIG. 4 shows an end view of the embodiment according to FIG. 3, and FIG. 5 shows the third embodiment on an enlarged scale Scale.

Description of the embodiments

The actuator 2 according to the invention according to FIG. 1 has an electric motor 3, control electronics 4 and a mechanical gear 5 arranged downstream of the electric motor.

The electric motor 3 has an electric motor housing 10, which is essentially pot-shaped, and arranged in a stationary manner, permanent magnets 11, within the permanent magnets 11 an armature 13 carried by a shaft 12, a collector 14 assigned to the armature 13, two in a manner known per se brushes 15 that can be pressed onto collector 14, brush holders 16 assigned to brushes 15, a brush holder plate 17 carrying brush holders 16, and a first shaft bearing 18 and a second shaft bearing 19. Brush holder plate 16 axially adjoins the pot-like one

The electric motor housing 10 and in turn axially to the brush holder plate 17 is connected to the mechanical gear 5, the housing 20 of which acts as a cover for the electric motor 3 and thereby receives the second shaft bearing 19 such that it can be tilted. Through the second shaft bearing 19, the shaft 12 is extended to a worm shaft 21 which extends into the housing 20. This worm shaft 21 meshes with a worm wheel 22 which is mounted by means of a worm wheel shaft 23. This worm wheel shaft 23 drives a pinion 24 located outside the housing 20. The pinion 24 is used, for example, to move a sliding roof via flexible traction and pressure means, not shown. The pinion can also serve one

To move the window regulator. It can be seen that the gear 5 can move different objects and therefore another output element can also be connected to the worm wheel shaft 23 instead of the pinion 24.

The control electronics 4 is protected by a control electronics protective housing 30, with the control electronics protective housing 30 being assigned a protective housing cover 31 adjacent to the mechanical transmission 5. In the example it is

Control electronics protective housing 30 is combined via a bridge 32 with the brush holder plate 17 to form an integral component. The control electronics 4 have a printed circuit board 33 along this bridge 30

The conductor plate 33 is aligned with its plane at right angles to the shaft 12 and has an opening 35 so that the shaft 12 and a rotationally symmetrical permanent magnet body 34 which is stuck against rotation on the shaft 12 can rotate within the outline of the conductor plate 33. This opening 35 surrounds the

Permanent magnet body 34 with radial play. A Hall sensor 36 is positioned adjacent to the circumference of the permanent magnet body 34, which can have a north pole and a south pole on its circumference in a manner known per se. which is attached to the printed circuit board 33 via its connecting wires (not shown). This Hall sensor 36 belongs to the control electronics 4. In a manner not shown, the usually three connecting wires of the Hall sensor 36 are connected to electrical and electronic components, not shown, via conductor tracks, not shown, which are located on the conductor plate 33. Since the control electronics 4 are not the subject of the patent application, further information can be dispensed with.

In the area of the control electronics 4 and, for example, attached to the printed circuit board 33, radio interference suppression means 55, which correspond, for example, to the capacitor connection according to US Pat. No. 4,384,223. At least two capacitors are thus combined in a so-called cy interference suppression circuit and two capacitor connecting means are electrically assigned to two brushes 16. A so-called center tap of the capacitor combination is provided for contacting the metallic electric motor housing 10. For this purpose, in the exemplary embodiment according to FIG. 1 and the enlarged illustration in FIG. 2, a contact spring 37 is arranged in the brush holder plate 17, which is made of thermoplastic material, by extrusion-coating it

Contact spring 37. The contact spring 37 has a soldering lug 39 at one end 38 reaching the conductor track plate 33, which protrudes through an opening 40, which is better shown in FIG. 2, and thereby also through a conductor track 41, in order to provide a solder connection 42 to the conductor track 41 to be contacted. This conductor track 41 in turn is in electrical connection with the radio interference suppression means 55 described. In this case, the radio interference suppression means 55 can be designed using SMD technology, the term SMD for “surface mounted device” and thus for Mounting on the surface of the conductor plate 33 and the conductor 41 is available.

As can be seen in FIGS. 1 and 2, the contact spring 37 extends from the conductor plate 33, for example parallel to the shaft 12, into the metallic electric motor housing 10. The contact spring 37 has a resilient end 43 within the electric motor housing 10, which is connected to the printed circuit board 33 via a curved section 44, which in the installed state has a bend of essentially 150 °, via an end 38 forming a spring base. So that the resilient end 43 has sufficient contact force against the electric motor housing 10 in the illustrated state, the curved section 44 will be given an original curvature which is, for example, 20 ° smaller than that shown.

As can be seen from FIG. 1, axial mounting is provided due to the pot-like design of the electric motor housing 10 and the brush holder plate 17. In the example in FIG. 1, the combination of the armature 13 and the collector 14 with the associated longitudinal section of the shaft 12 is inserted into the electric motor housing 10, as a result of which the shaft 12 gets into the first bearing 18. Then, for example, the combination assembled from the brush holder plate 17 and the control electronics protective housing 30 is aligned with the electric motor housing 10 and moved along the worm shaft 21 against the electric motor housing 10. In this case, the contact spring 37 is then immersed in the electric motor housing 10, the resilient end 43 intended to make contact with the metallic electric motor housing 10 by elastic deformation, for example in the region of the curved section 44. The control electronics 4 can optionally already be installed in the control electronics housing 30 and the conductor plate 33 can already be combined with the brush holder plate 17. This has the advantage that the soldering lug 39 of the contact spring 37 can be soldered to the described conductor track 41 even before the brush holder plate 17 is united with the electric motor housing 10. As already mentioned in the introduction to the description, this soldering can, for example, take place simultaneously with the production of the other soldered connections, for example with that soldered connection which is used for

Bracket and electrical contact of the Hall sensor 36 with the conductor plate 33 leads. Thereafter, the mechanical gear 5 and the second shaft bearing 19, which is arranged such that it can be tilted, are aligned with the worm shaft 21 and finally axially mounted on the brush carrier plate 17 to form the cover.

The second exemplary embodiment according to FIGS. 3 and 4 differs from the exemplary embodiment according to FIGS. 1 and 2 in that the contact spring 37 is not overmolded in a form-fitting and material-locking manner. Rather, a channel 45 is provided only in a modified brush holder plate 17a. A contact spring 37a further developed, for example, by two resilient tongues 46 and 47 is pushed through this channel 45. The securing tongues 46 and 47 are formed from the material of the contact spring 37a and can be shaped by making U-shaped cuts and bending material out of the contour of the contact spring 37a. Since the contact spring 37a is inserted into the channel 45 with the soldering lug 39 ahead, the securing tongue 46 can already protrude from the contour of the contact spring 37a, as shown in FIG. 3. There are two possibilities for the securing tongue 47. The first option is to insert the resilient tongue 47 before inserting the contact spring 37a can already protrude from the contact spring 37a, so that when inserting the locking tongue 47 is pressed elastically into the contour of the contact spring 37a and then snaps into the securing position shown in Figure 3. The second possibility is to produce the deflection of the securing tongue 47, which can be seen in FIG. 3, after the contact spring 37a has been inserted into the channel 45.

Compared to the first embodiment of Figures 1 and 2 is additionally provided to protect against disadvantageous

Bending of the contact spring 37a before or during the assembly of a protective wall 48. This protective wall 48 protrudes from the brush holder plate 17a, has an essentially U-shaped outline that is open radially outward to the electric motor housing 10 and runs, for example, parallel to the shaft 12.

The third exemplary embodiment according to FIG. 5 saves attachment to the brush holder plate 17 or 17a, in which a contact spring 37b is secured against tipping on a modified printed circuit board 33b. For this purpose, the contact spring 37b has at least two soldering lugs 39b and 39c which can be inserted through the conductor track plate 33b. The solder lugs 39b and 39c are spaced apart so that soldering points 42b and 42c can withstand tilting of the contact spring 37b as a result of contact pressure on a lever arm. The two soldering lugs 39b and 39c, which are at a distance from one another, can be produced by slitting a piece of the length of the strip material from which the contact spring 37b is made so that one has at least two strips, one strip 49 being angled and then along the length Level of the conductor track plate 33b is arranged to run. The solder tail 39c connects to this strip 49. The brush carrier plate 17b has an opening 17c for passing the resilient end 43 of the contact spring 37. At the edge of this opening 17c, a protective wall 48c with an essentially U-shaped outline can in turn extend from the brush holder plate 17b.

In addition, a ramp 50 is also provided here in the protective wall 48c. The ramp 50 has its largest dimension at a free end 51 of the protective wall 48c. The ramp 51 extends at an angle to the longitudinal axis of the electric motor housing 10. This has the intended effect that after the resilient end 43 of the contact spring 37b has been passed through the opening 17c, the section 44 of the contact spring 37b comes into alignment with the ramp 50 and thereby to the electric motor housing 10 is supported. This results in a high contact force at the resilient end 43 without the contact spring 37b in the

The area of the strip 49, that is to say close to the printed circuit board 33b, suffers a disadvantageous bending.

It can be seen from the three exemplary embodiments that there are different possibilities for forming a contact spring with a resilient end 43 and electrically connecting it with interference suppression means for the purpose that the interference suppression means include the metallic electric motor housing 10.

Claims

Expectations

1.Actuator with an electric motor, which has a metallic electric motor housing, a shaft with armature and collector, brushes and a brush holder plate, and with control electronics for the electric motor, electronic and electrical components being connected to a conductor plate and the conductor plate transverse to the shaft and protrudes adjacent to the brush holder plate in a cross section of the electric motor housing and is protected outside the electric motor housing by a control electronics housing, characterized in that a conductor track (41) which is contacted with a radio interference suppressor and runs in the cross section of the electric motor housing with a contact spring (37, 37a, 37b) is contacted, wherein the contact spring (37, 37a, 37b) protrudes from the conductor plate (33, 33b) in the direction of the electric motor housing (10) and has a resilient end (43) which rests resiliently in the electric motor housing (10).

2. Actuator according to claim 1, characterized in that the brush holder plate (17, 17a, 17b) is arranged axially between the conductor plate (33, 33b) and the armature (13) and the contact spring (37, 37a, 37b) through the brush holder plate (17, 17a, 17b) is passed through.

3. Actuator according to claim 2, characterized in that the brush carrier plate (17) is a molded part made of insulating material and that the contact spring (37) is designed in the manner of a leaf spring and is integrally surrounded by the insulating material.

4. Actuator according to claim 2, characterized in that the first carrier plate (17a) made of insulating material has a channel (45) through which the contact spring (37a) is inserted.

5. Actuator according to claim 4, characterized in that the contact spring (37a) has at least one safety tongue (46, 47) directed against the brush holder plate (17a).

6. Actuator according to claim 1, characterized in that the contact spring (37c) has at least two solder lugs (39b, 39c) which can be plugged through the conductor track plate (33b) and which are at a distance from one another which is essentially in the radial direction of the electric motor housing (10). is aligned.

7. Actuator according to claim 6, characterized in that at least one connecting lug (39c) extends from a strip (49) projecting at an angle from the contact spring (37b).

8. Actuator according to claim 2, characterized in that the contact spring in the region of its resilient end has a substantially U-shaped curved section (44), the resilient end (43) extending radially outward to the electric motor housing (10) on the section (44) connects.

9. Actuator according to claim 1, 3, 4 or 6, characterized in that one of the brush holder plate (17, 17a, 17b) and along the contact spring (37, 37a, 37b) to the brush holder plate (17, 17a, 17b) molded protective wall (48) with an essentially U-shaped plan, which is open to the resilient end (43).

10. Actuator according to claim 9, characterized in that in the region of the free end (51) a ramp (50) is arranged, the smallest distance relative to

Inside of the electric motor housing (10) at the free end (51) of the protective wall (48) is provided.