DE102016101878B4 - Actuator comprising an electric motor, and method for producing such an actuator - Google Patents

Abstract

Actuator (10) for an assembly of an internal combustion engine, wherein the actuator (10) comprises:- an electric motor (18) comprising:- a stator (60),- a rotor (56),- a drive shaft (54) connected to the rotor (56) and drivable via the electric motor (18), and- motor contact elements (44) which are plugged into the electric motor (18) and via which the electric motor (18) can be supplied with current, wherein the motor contact elements (44) are each formed from two bent plug contacts (64) which together form an omega contact (70),- a housing (14) which surrounds the electric motor (18) and which has an injection-molded housing part (22) with a shaft opening (28) at one axial end through which the drive shaft (54) of the electric motor (18) passes,- straight counter-contact elements (40) which are connected to the housing (14) or to a shaft opening (28) provided in the housing (14) provided circuit board protrude into the omega contacts (70), wherein the mating contact elements (40) are molded into the housing part (22), and- a plug (48) via which the electric motor (18) can be supplied with current.

Description

The present invention relates to an actuator having an electric motor and a method for producing such an actuator.

The electric motor comprises a stator, a rotor, a drive shaft connected to the rotor, which can be driven via the electric motor, and motor contact elements which are plugged into the electric motor and via which the electric motor can be supplied with current.

The present invention relates to an actuator which has the electric motor and a housing which surrounds the electric motor and which has an injection-molded housing part with a shaft opening at one axial end through which the drive shaft of the electric motor passes. In addition, the actuator has counter-contact elements which protrude from the housing or from a circuit board provided in the housing into the omega contacts, and has a plug via which the electric motor can be supplied with current.

The present invention further relates to a method for producing such an actuator. In a first method step, the housing including the housing part having the counter-contact elements is produced. The motor contact elements are then produced and pressed into the electric motor in a next step. The counter-contact elements are then connected to the motor contact elements.

Such actuators are used, for example, to adjust an exhaust gas recirculation valve.

From the US 2007/0103010 A1 An actuator for an exhaust gas recirculation valve is known in which an electric motor is provided in a housing. The electric motor has straight contacts which protrude from the motor and which are connected to connection contacts of a punched comb of a housing cover.

Out of DE 19637192 C2 An electric fan drive is known in which the stator windings are connected to the drive electronics via a plug connection.

Out of EP 1 441 431 B1 An electric drive motor with a two-part housing is known.

This state of the art has the disadvantage that the straight contacts are very stiff and hardly allow any oscillation. This problem is solved, for example, in the EN 10 2009 010 424 A1 , which suggests the use of Omega contacts on the housing.

From the EN 10 2009 010 424 A1 An actuator is known which is used, for example, as a servomotor for an exhaust gas recirculation valve. This actuator has a housing which accommodates an electric motor. The housing has an injection-molded housing part on one axial side which includes omega contacts for electrical contact with the electric motor. In order to avoid overmolding the omega contacts during the manufacture of the housing, they are protected during the injection molding process by protective caps which extend through the subsequent housing. These protective caps cause corresponding breakthroughs in the finished injection-molded body so that corrosive exhaust gas can reach the electric motor through the breakthroughs.

The object of the present invention is to create an actuator which has an electric motor which allows oscillating movements and in which the electric motor is nevertheless protected in a simple manner against corrosive exhaust gases. Furthermore, the invention is based on the object of specifying a method for producing such an actuator in which the complex protection of the contacts on the housing during production can be omitted by reliably preventing the omega contacts from being filled with plastic.

This object is achieved by an actuator having the features of claim 1 and a method for producing the actuator according to claim 6.

In the electric motor according to the invention, the motor contact elements are each formed from two bent plug contacts, which together form an omega contact. An omega contact according to the present invention is a contact which has two springy legs which are bent towards each other in such a way that an omega is formed. An omega contact has the advantage that the legs have a spring effect, so that an inserted contact does not lead to bending of the legs. The spring effect of the legs also makes it easier to compensate for assembly inaccuracies or oscillating movements or vibrations during operation. The two plug contacts are plugged into the electric motor in the usual way. Each plug contact forms half an omega contact. Consequently, the omega contact is formed from two identical plug contacts. This simplifies the manufacturing process of the punched and bent plug contacts, since only one type of plug contact is required. These plug contacts are formed into an axis of symmetry of the omega Contact is inserted into the electric motor in a mirror-inverted manner so that the omega contact is formed.

In the actuator according to the invention, the counter-contact elements protrude into the omega contacts of the electric motor according to the invention. This means that the counter-contact elements can be shaped as straight contacts. The straight contacts can therefore be overmolded without openings in the housing. Complex measures to protect the electric motor from corrosive exhaust gases or omega contacts when manufacturing the housing are therefore unnecessary. The electric motor is thus protected from corrosive exhaust gases in a simple way. Despite all this, oscillating movements are permitted due to the spring effect of the omega contacts on the electric motor.

The counter contact elements are molded into the housing part. The counter contact elements can thus be connected to the housing part in a sealing manner. The electric motor can thus be protected from corrosive exhaust gases.

The method according to the invention for producing an actuator comprises in particular the steps of bending stamped parts to form half an omega contact, pressing the stamped parts into the electric motor so that two bent stamped parts form an omega contact and inserting the counter-contact elements into the omega contacts. In the method according to the invention, the step of applying a protective cap to protect the contacts is no longer necessary. In addition, only one type of stamped and bent part is required to produce the omega contact. The actuator can therefore be produced more easily and economically using the method according to the invention.

Preferred embodiments of the actuator are specified in the subclaims.

In a preferred embodiment of the invention, the bent plug contacts of the electric motor extend essentially parallel to a rotation axis of the electric motor. According to the invention, the legs of the omega contact thus extend essentially parallel to the insertion direction. The feature that the plug contacts extend essentially parallel to the rotation axis of the electric motor is understood in the sense of the present invention to mean that the plug contacts extend in a main direction parallel to the rotation axis of the electric motor. However, this does not rule out the possibility that the plug contacts can also extend to a small extent in other directions. By bending in just one axial direction, plug contacts bent in this way enable the mating contact elements to be easily inserted.

In a further preferred embodiment of the invention, the bent plug contacts of the electric motor extend essentially orthogonally to a rotation axis of the electric motor. According to the invention, the "omega" formed by the legs of the omega contact is orthogonal to the rotation axis of the electric motor. This allows the space required by the omega contacts in the insertion direction to be minimized. The insertion depth of the counter contact element is also not limited by the omega contact. The feature that the plug contacts extend essentially orthogonally to the rotation axis of the electric motor is understood in the sense of the present invention to mean that the plug contacts extend in a main direction orthogonal to the rotation axis of the electric motor. However, this does not rule out the possibility that the plug contacts can also extend to a small extent in other directions.

Preferably, an electrical contact is made to the brush bridges of the electric motor by inserting the plug contacts into the electric motor. This makes it easy to establish an electrical connection to the brush bridges.

In a preferred embodiment of the actuator, the counter-contact elements of the actuator are plug contacts that extend essentially parallel to the axis of rotation. This allows the counter-contact elements to be connected to the plug contacts of the electric motor in the direction in which the electric motor is inserted into the housing of the actuator. This enables a simple electrical connection between the counter-contact elements and the plug contacts.

A preferred embodiment of the method includes the step of producing the housing by injection molding the housing part. The actuator can be easily manufactured by the step of injection molding the housing part. A high level of tightness can also be easily achieved by overmolding the straight counter-contact elements in the housing part.

• 1: Schnittansicht eines Aktors mit einem Elektromotor nach einem ersten Ausführungsbeispiels,
• 2: Draufsicht auf einen Elektromotor nach einem zweiten Ausführungsbeispiel, und
• 3: Seitenansicht des Elektromotors nach dem zweiten Ausführungsbeispiel

Further details and advantages of the present invention will become apparent from the following description of the embodiment in conjunction with the drawings, in which:

• 1 : Sectional view of an actuator with an electric motor according to a first embodiment,
• 2 : Top view of an electric motor according to a second embodiment, and
• 3 : Side view of the electric motor according to the second embodiment

1 shows an actuator 10 for a unit of an internal combustion engine. The actuator 10 has a cylindrical housing 14 which surrounds and accommodates an electric motor 18. At one axial end, the housing 14 has an injection-molded housing part 22. A shaft opening 28 is provided in the housing part 22.

A mounting opening 32 is provided in the housing 14 on a side of the housing 14 axially opposite the shaft opening 28. The electric motor 18 can be inserted into the housing 14 through this mounting opening 32. The mounting opening 32 is closed by a housing cover 35 after the electric motor 18 has been installed.

The injection-molded housing part 22 also has two conductor tracks 38 which are injected into the housing part 22 and whose ends serve as counter contact elements 40 and protrude from the housing part 22. They extend parallel to a rotation axis 42 of the electric motor 18. The counter contact elements 40 are each received in a motor contact element 44 which is plugged into the electric motor 18. This creates an electrical and a mechanical connection between the counter contact elements 40 and the motor contact elements 44. The housing 14 forms a plug 48 whose contact elements 52, which are formed on the ends of the conductor tracks 38 opposite the counter contact elements 40, are electrically connected to the counter contact elements 40 so that the electric motor 18 can be supplied with current via the plug 48.

The electric motor 18 has a drive shaft 54 that passes through the shaft opening 28 and on the end of which a drive gear 55 is arranged in a rotationally fixed manner. A rotor 56 of the electric motor 18 is mechanically connected to the drive shaft 54. The rotor 56 interacts with a stator 60 so that the rotor 56 is driven. The motor contact elements 44 are each formed from two curved plug contacts 64 that extend essentially parallel to the axis of rotation 42 of the electric motor 18. The plug contacts 64 are inserted into the electric motor 18 symmetrically to a central axis 68 of the motor contact element 44 so that both plug contacts 64 together form an omega contact 70. An end part 71 of the plug contacts 64 is thus inserted into the electric motor 18. At a free axial end of the plug contacts 64, the plug contacts 64 form an insertion area 72 for the counter contact elements 40 of the housing part 22. The insertion area 72 is formed in that the plug contacts 64 open towards one another at an outermost axial area of the free ends of the plug contacts 64.

2 shows a plan view of the electric motor 18 according to a second embodiment. This embodiment differs from the first embodiment according to 1 in that the plug contacts 64 extend essentially orthogonally to the axis of rotation 42 of the electric motor 18. The “omega” formed by the plug contacts 64 thus extends orthogonally to the axis of rotation 42 of the electric motor 18.

In 3 a side view of the electric motor 18 according to the second embodiment is shown. This figure shows in particular the insertion area 72 formed by the plug contacts 64. The insertion area 72 is formed at the free end of the plug contacts 64. The insertion area 72 is formed in that at an outermost area of the free ends of the plug contacts 64, the plug contacts 64 widen towards one another in the axial direction towards the counter contact elements 40.

The described actuator according to the invention can thus be protected against corrosive exhaust gases in a simple manner and can nevertheless be produced more economically.

The actuator according to the invention is not limited to the embodiment described above, so the housing part can be a cover of the housing that closes a mounting opening for the electric motor. The housing part also does not necessarily have to have the plug.

List of reference symbols

10

Actuator

14

Housing

18

Electric motor

22

Housing part

28

Shaft opening

32

Mounting opening

35

Housing cover

38

Conductor track

40

Counter contact elements

42

Rotation axis

44

Motor contact elements

48

Plug

52

Contact element

54

drive shaft

55

Drive gear

56

rotor

60

stator

64

Plug contact

68

Central axis

70

Omega Contact

71

end part

72

Introduction area

Claims (7)

Actuator (10) for an assembly of an internal combustion engine, wherein the actuator (10) comprises: - an electric motor (18) comprising: - a stator (60), - a rotor (56), - a drive shaft (54) connected to the rotor (56) and drivable via the electric motor (18), and - motor contact elements (44) which are plugged into the electric motor (18) and via which the electric motor (18) can be supplied with current, wherein the motor contact elements (44) are each formed from two bent plug contacts (64) which together form an omega contact (70), - a housing (14) which surrounds the electric motor (18) and which has an injection-molded housing part (22) with a shaft opening (28) at one axial end through which the drive shaft (54) of the electric motor (18) passes, - straight counter-contact elements (40) which are connected to the housing (14) or protrude from a circuit board provided in the housing (14) into the omega contacts (70), wherein the counter-contact elements (40) are molded into the housing part (22), and - a plug (48) via which the electric motor (18) can be supplied with current. Actuator (10) to Claim 1 , wherein the bent plug contacts (64) of the electric motor (18) extend substantially parallel to a rotation axis (42) of the electric motor (18). Actuator (10) to Claim 1 , wherein the bent plug contacts (64) of the electric motor (18) extend substantially orthogonally to a rotation axis (42) of the electric motor (18). Actuator (10) according to one of the Claims 1 until 3 , wherein by inserting the plug contacts (64) into the electric motor (18) an electrical contact is established with brush bridges of the electric motor (18). Actuator (10) according to one of the preceding claims, wherein the mating contact elements (40) are plug contacts which extend substantially parallel to the axis of rotation (42). Method for producing an actuator (10) according to one of the preceding claims, comprising the steps: - producing the housing (14) including the housing part having the mating contact elements, - producing stamped parts, - bending the stamped parts to form half an omega contact (70), - pressing the stamped parts into the electric motor (18) so that two bent stamped parts form an omega contact (70), and - inserting mating contact elements (40) into the omega contacts (70). Method for producing an actuator (10) according to Claim 6 , wherein the method step of producing the housing (14) comprises injection molding the housing part (22).

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