A device for electrically connecting the windings of an electric motor to the printed circuit board of a motor control unit.

Abstract

An apparatus is provided for making electrical contact between an electric motor winding and a printed circuit board of a motor control unit. [Solution] The device for electrical contact between an electric motor winding and a printed circuit board of a motor control unit of the present invention comprises a conductor element (4) that can be arranged between a printed circuit board (2) and a housing (3) of an electric motor (1) thereby electrically contacting an electrical contact surface (12) of the printed circuit board (2) with an electric motor winding (13) of the electric motor (1), the conductor element (4) having a first connection element (5) with a contact bend (7) facing the contact surface (12) of the printed circuit board (2) and a second connection element (8) for electrical contact at a connection location (9) of the electric motor winding (13), the conductor element (4) being formed as an elastic structure (10) that compensates for the relative positioning of the contact surface (12) of the printed circuit board (2) with respect to the connection location (9) of the electric motor winding (13).

Description

Technical Field

[0001] The present invention relates to a device for electrically contacting an electric motor winding and a printed circuit board of a motor control unit. More specifically, the present invention relates to a device for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, which can compensate for the relative position between the electric motor winding and the printed circuit board of the motor control unit, is easy to assemble, and can simultaneously reduce the installation space.

Background Art

[0002] An engine control unit (ECU) for an electric motor is composed of electronic devices responsible for controlling, adjusting, and monitoring the motor functions. The components of the electronic devices are attached to a printed circuit board and are in electrical contact with each other. In order to electrically contact the electric motor winding and the printed circuit board of the motor control unit, an assembly device capable of correcting the relative position between the contact surface of the printed circuit board and the contact area of the motor is adopted. The position correction is necessary due to the manufacturing / assembly tolerances of each component manufactured by different manufacturers. Therefore, a displacement occurs between the electrical contact area on the electric motor and the contact surface on the printed circuit board of the motor control unit, and it is necessary to appropriately correct it with a device for electrical contact. In known solutions, such position or location correction is performed by a spring element in the form of a spiral spring enclosed in a housing element displaceable relative to each other between the motor control unit and the electrical contact area of the electric motor.

[0003] The electrical contact elements for electrically contacting the contact surfaces of the printed circuit board are received by a housing element that faces the contact surfaces of the printed circuit board in the assembled state. A pre-tension is applied to the spiral spring during assembly, and this pre-tension applies contact pressure to the contact surfaces of the motor control unit on the printed circuit board after assembly. In this way, the contact elements permanently contact the contact surfaces of the printed circuit board. Simultaneously, positional compensation is provided between the printed circuit board or motor control unit and the contact area for electrical contact of the electric motor windings by the longitudinal expansion of the spiral spring. The spiral spring is disconnected by the housing element and does not serve as a conductor between the printed circuit board and the electric motor windings. The contact pressure of the spiral spring acts on the retaining device against the contact surface. The reduced force of the inserted contact element, possessing elastic properties, acts on the actual contact surface.

[0004] Electrical contact elements provided for electrical contact can be formed as punched grids and have receptacles for conductors. These receptacles for conductors have traditionally been formed in the form of cable lugs, so that conductors that make contact at the end of an electric motor winding opposite the motor phase are connected to the electrical contact elements. Known solutions for electrically connecting electric motor windings to the printed circuit board of the motor control unit have multiple electrical interfaces, which consequently increases the risk of contact problems and ohmic losses. Furthermore, the large number of individual parts to be assembled also negatively impacts the assembly process. A further drawback is that sourcing individual parts involves increased expenses and higher costs.

[0005] From an assembly standpoint, there is also the problem that the receptacles (which may have the shape of cable lugs) formed on the electrical contact elements increase the installation space required for electrical contact with the conductor. In particular, the required space increases when the receptacles are formed radially relative to the contact surface of the control unit to make contact with the conductor. A further drawback of known solutions is that during the assembly of the conductor, deformation of the receptacle is required, for example, by crimping, in order to secure the conductor within the receptacle of the contact element for electrical contact of the electric motor winding. Insertion and securing of the conductor into the receptacle requires an additional assembly step. Furthermore, the connection between the receptacle of the electrical contact element and the conductor is susceptible to vibration. As a result, the conductor may detach from the receptacle at the connection point, thereby interrupting the electrical contact between the printed circuit board of the motor control unit and the electric motor winding. A solution is needed that can overcome the shortcomings known from prior art. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a device for electrically contacting the electric motor windings of an electric motor and the printed circuit board of a motor control unit, which can compensate for the relative position between the electric motor windings of the electric motor and the printed circuit board of the motor control unit, is easy to assemble, and simultaneously reduces the installation space. [Means for solving the problem]

[0007] This objective is achieved by an apparatus having the features described in claim 1. Further developments and advantageous embodiments are described in the dependent claims. An apparatus is provided for electrically contacting an electric motor winding with a printed circuit board of a motor control unit provided for controlling the electric motor. According to the present invention, the apparatus has a conductive element that can be placed between the printed circuit board of the motor control unit and the housing of the electric motor, thereby electrically contacting the electrical contact surface of the printed circuit board of the motor control unit with the electric motor winding of the electric motor. The conductive element has a first connecting element having a contact bend facing the contact surface of the printed circuit board. A second connecting element is provided at the end of the conductive element opposite to the first connecting element for electrically contacting the connection position of the electric motor winding. According to the present invention, the conductive element is formed as an elastic structure that compensates for the relative positional relationship of the contact surface of the printed circuit board with respect to the connection position of the electric motor winding.

[0008] According to the concept of the present invention, the conductive element that electrically connects the printed circuit board of the motor control unit to the electric motor winding is formed to be elastically deformable in at least a region, so that such a conductive element compensates for the relative misalignment of the printed circuit board with respect to the connection position of the electric motor winding. In other words, the conductive element has an elastic structure formed in a region that enables compensation for position or misalignment between the motor control unit and the electric motor, particularly between the printed circuit board of the motor control unit and the connection position of the electric motor winding on the electric motor.

[0009] Thus, the apparatus according to the present invention combines the function of a conductor for electrical contact between the printed circuit board of the motor control unit and the electric motor winding, and elastic deformability for tolerance compensation or positional compensation of the relative position of the printed circuit board of the motor control unit with respect to the electric motor winding. The elastic structure of the conductive element can preferably be formed between a first connecting element and a second connecting element. In this case, the elastic structure of the conductive element in the assembled state of the apparatus according to the present invention can have pretension in at least one spatial direction. Accordingly, the elastic structure can be formed so that tension is applied during assembly for placement between the conductive element and the motor housing in order to exert the desired pretension.

[0010] The contact surface of a printed circuit board is a conductive contact area capable of electrical contact with the contact bend portion of a conductive element. Typically, the contact surface is a metal surface area having a predetermined size and shape. The design of the apparatus according to the present invention provides that the elastic structure of the conductive element is formed to compensate for the relative positional relationship of the contact surface of the printed circuit board with respect to the connection position of the electric motor winding in all spatial directions. According to this design of elastic structure, the elasticity of the conductive element is provided in each spatial direction. The material used for conductive elements is suitable for changing its shape under the application of force and returning to its original shape when the force is removed.

[0011] According to one design of the apparatus according to the present invention, the conductive element is formed as a bent flat conductor in at least the region of the elastic structure, wherein the width of the flat conductor is greater than the thickness of the flat conductor. To achieve elastic deformability, the elastic structure of the conductive element can be helical. Preferably, the elastic structure of the conductive element can be formed as a spiral spring. In the region of the elastic structure formed as a spiral spring, the conductive element can have a round cross-section. Further design of the apparatus according to the present invention can provide that the elastic spring structure of the conductive element is serpentine. This design is particularly suitable for designing conductive elements in the form of a flat conductor where the width is greater than the thickness. The cross-section of the flat conductor can be rectangular or elliptical in the region of the elastic structure.

[0012] The shape and geometric design of the elastic structure are not particularly limited, as long as they can compensate for misalignment between the motor control unit's printed circuit board and the connection area of ​​the electric motor winding, and at the same time allow for elastic deformation such that a sufficiently high pretension acts on the motor control unit's printed circuit board and the surface facing the printed circuit board in order to ensure electrical contact between the motor control unit's printed circuit board and the electric motor winding.

[0013] The first and second connecting elements can be plastic parts molded on a conductive element. Thus, the connecting elements can be manufactured by injection molding. Preferably, the first connecting element may have a counter holder facing the surface of the printed circuit board, thereby limiting the contact pressure of the contact bending portion of the conductive element against the contact surface of the printed circuit board to the spring force exerted by the contact bending portion. As a result, the contact pressure of the contact bending portion against the contact surface of the printed circuit board is isolated from the contact pressure exerted on the printed circuit board by the elastic structure. The pressing force exerted by the elastic structure of the conductive element is directly transmitted to the printed circuit board by the counter holder.

[0014] In this case, the pressing force of the conductor element of the contact bend on the contact surface is substantially smaller than the pressing force exerted by the elastic structure of the elastic conductor element by the counter holder. The contact bend has an elastically flexible structure and is pressed against the contact surface of the printed circuit board during assembly of the device. The bend structure of the contact bend is formed on the end face of the first connecting element so as to protrude slightly beyond the counter holder positioned on the end face when the device is unassembled. During assembly of the device, the counter holder and the bend structure of the contact bend are pressed against the printed circuit board, and the spring movement of the bend structure is restricted by the counter holder. The bend structure of the contact bend can be advantageously formed to exert a contact pressure on the contact surface of the printed circuit board that is smaller than the contact pressure exerted on the surface of the printed circuit board by the pretension of the conductor element by the counter holder. The contact bending portion can preferably be a pressed part, particularly a lamellar comb.

[0015] Since the contact bending portion of the conductive element contacts the contact surface of the printed circuit board, electrical contact is provided between the conductive element and the printed circuit board. At the opposite end of the conductive element, electrical contact with the electric motor winding can be formed by various connections. For example, the electrical contact between the conductive element and the electric motor winding can be formed at the connection point by a welded connection, an insulating displacement connection, or a soldered connection.

[0016] An advantageous further development of the apparatus according to the present invention may be provided in which a conductive element is formed to be lockable with a first connecting element on a printed circuit board. In this case, a plug receptacle in the form of a plug housing can be formed on the printed circuit board, and the first connecting element forms a plug that can be inserted into the plug housing formed on the printed circuit board. Furthermore, a lock can be provided in such a way that the vertical surface formed on the first connecting element, which protrudes beyond the front edge of the counter holder, is formed to allow insertion into a printed circuit board.

[0017] Since the device according to the present invention is essentially integrally formed, the number of interfaces during electrical contact is reduced, and as a result, the risk of ohmic loss can be kept low. In other words, the integrated concept reduces losses due to transition resistance. Furthermore, integrating the elastic structure as a component of the conductive element is advantageous because it allows for a reduction in the overall size of the device compared to solutions known from the prior art. In addition, the device according to the present invention simplifies the assembly for electrical contact between the printed circuit board and the electric motor winding. The reduction in the assembly process leads to an overall cost reduction. Further details, features, and advantages of the design of the present invention will become apparent from the following description of exemplary embodiments with reference to the relevant drawings. [Brief explanation of the drawing]

[0018] [Figure 1] Schematic cross-sectional view of an exemplary embodiment of an apparatus according to the invention for electrically contacting an electric motor winding and a printed circuit board of a motor control unit. [Figure 2] Perspective view of an apparatus according to the invention for electrically contacting an electric motor winding and a printed circuit board of a motor control unit. [Figure 3] Schematic top view of a second exemplary embodiment of an apparatus according to the invention. [Figure 4] Schematic top view of a third exemplary embodiment of an apparatus according to the invention. **DETAILED DESCRIPTION OF THE INVENTION**

[0019] FIG. 1 is a schematic cross-sectional view of an exemplary embodiment of an apparatus according to the invention for electrically contacting an electric motor winding 13 of an electric motor 1 and a printed circuit board 2 of a motor control unit. In the illustrated example, the apparatus according to the invention is assembled between the printed circuit board 2 and a motor housing 3 of the electric motor 1. This apparatus has a conductor element 4 having a first connection element 5 at one end facing the printed circuit board 2. The first connection element 5 is a molded plastic part with an edge 6 formed on its end face and functions as a counterholder against the surface of the printed circuit board 2. The end of the conductor element 4 housed in the first connection element assumed to be 5 is formed as a contact bend 7 having a bending structure that contacts a contact surface 12 of the printed circuit board 2, thereby forming an electrical connection.

[0020] A second connection element 8 is formed at the opposite end of the conductor element 4, and this connection element 8 is also a molded plastic part. The second connection element 8 is geometrically formed to be received within a receptacle of the motor housing 3 of the electric motor 1. The connection end of the conductor element 4 is received by the second connection element 8 so as to contact the electric motor winding 13 at a connection location 9. The connection location 9 is a region formed in the motor housing 3 for contacting the conductor element 4 with the conductor of the electric motor winding 13.

[0021] The elastic structure 10 of the conductive element 4 is formed between the first connecting element 5 and the second connecting element 8. In the region of the elastic structure 10, the conductive element 4 is formed as a flat conductor bent into a meandering shape. The elastic structure 10 allows elastic deformation of the conductive element 4 in the region between the first connecting element 5 and the second connecting element 8, so that the relative positioning of the printed circuit board 2 with respect to the motor housing 3 or connection position 9 is compensated in both the axial and radial directions. The elastic structure 10 has a pretension force when assembled. Due to the pretension force exerted by the elastic structure, the first connecting element 5 is pressed against the contact area of ​​the printed circuit board 2 at the contact bend portion 7 formed on the end face of the connecting element 5.

[0022] The second connecting element 8, located at the opposite end of the conductive element 4, is held in place as a result of the contact pressure with the motor housing 3. The counter holder 6, formed in an edge shape on the end face of the first connecting element 5, transmits the pressing force exerted by the pretensioning force of the elastic structure 10 to the printed circuit board 10. In this way, the pressing force of the contact bending portion 7 against the contact surface of the printed circuit board 2 is separated from the pressing force exerted by the pretensioning force of the elastic structure 10.

[0023] Figure 2 is a perspective view of an apparatus according to the present invention for electrically connecting the electric motor windings of an electric motor 1 to a printed circuit board 2 of a motor control unit. In contrast to Figure 1, the printed circuit board 2 is not shown in the exemplary embodiment shown in Figure 2 in order to better illustrate the structure of the apparatus according to the present invention. The representation in Figure 2 shows an apparatus according to the present invention having a first connecting element 5 formed in the form of a circular plastic part molded on the conductive element 4 at the upper end of a conductive element 4. The connecting end of the conductive element 4 is formed in the form of a contact bend 7 to be received by the end face of the connecting element 5 facing the printed circuit board 2. The contact bend 7 has a bent structure that is slightly bent upward to contact the contact surface of the conductive element 2 and has a pressing element 11 that protrudes beyond the end face of the counter holder 6 of the first connecting element 5 in the disassembled state.

[0024] The second connecting element 8, formed at the opposite end of the conductive element 4, is a plastic part molded onto the conductive element 4 and is inserted into the electric motor housing 3 of the electric motor 1 so that the connecting end of the conductive element 4 at the connection position 9 can contact the electric motor winding of the electric motor 1. In the illustrated example, the conductive element 4 is formed as a meanderingly bent flat conductor between the first connecting element 5 and the second connecting element 8, and the meanderingly bent flat conductor forms an elastic structure 10 that allows the conductive element 4 to be elastically deformable in the region between the first connecting element and the second connecting element so that it can compensate for misalignment between the contact surface of the electrical circuit board 2 and the connection position 9 of the electric motor winding of the electric motor 1.

[0025] Figure 3 is a schematic plan view of a second exemplary embodiment of the apparatus according to the present invention, in which the elastic structure 10 of the conductive element 4 is helical. Figure 3 shows the apparatus according to the present invention in an assembled state, and the electrical printed circuit board 2 is not shown. The conductive element 4 is in contact with the electric motor winding 13 of the electric motor 1 (not shown) at connection position 9. At connection position 9, the conductive element 4 has a second connecting element 8 in the form of a molded plastic part. Reference numeral 12 indicates the contact area of ​​the printed circuit board 2 (not shown). The contact bend 7 is in contact with the printed circuit board 2 at the pressing element 11 in the contact area 12. In this case, the contact bend 7 is supported by the first connecting element 5. A counter holder 6 formed as the end projection of the first connecting element 5 limits the pressing force of the contact bend 7 against the contact area 12. The elastic structure 10 compensates for the positional difference between the connection position 9 and the contact area 12.

[0026] Figure 4 is a schematic plan view of a third exemplary embodiment of the apparatus according to the present invention. In contrast to the design shown in Figure 3, the conductive element 4 has a radially spiral spring in the region of the elastic structure 10. The elastic structure 10 in the form of a radial spiral spring compensates for the positional difference between the connection point 9 and the contact region 12. [Explanation of Symbols]

[0027] 1. Electric motor 2 Printed circuit boards 3 Motor Housing 4 Conductive elements 5. First connection element 6 Edge / Counter Holder 7 Contact bending portion 8. Second connection element 9. Connection location 10 Elastic structure 11 Pressure elements 12 Contact area / contact surface 13 Electric motor windings

Claims

1. A device for electrically contacting the electric motor winding (13) of an electric motor (1) with a printed circuit board (2) of a motor control unit (ECU), wherein the device has a conductive element (4) that can be positioned between the printed circuit board (2) and the housing (3) of the electric motor (1), thereby bringing the electrical contact surface (12) of the printed circuit board (2) and the electric motor winding (13) of the electric motor (1) into electrical contact, the conductive element (4) having a first connecting element (5) having a contact bending portion (7) facing the contact surface (12) of the printed circuit board (2), and a second connecting element (8) for making electrical contact at the connection position (9) of the electric motor winding (13), and the conductive element (4) being designed as an elastic structure (10) that compensates for the relative positioning of the contact surface (12) of the printed circuit board (2) with respect to the connection position (9) of the electric motor winding (13), The first connecting element (5) has a counter holder (6) facing the surface of the printed circuit board (2), and this counter holder limits the contact pressure of the contact bending portion (7) with respect to the contact surface (12) of the printed circuit board (2). A device for electrically connecting an electric motor winding to a printed circuit board of a motor control unit, characterized in that the first connecting element (5) and the second connecting element (8) are plastic parts.

2. The apparatus for electrically contacting an electric motor winding and a printed circuit board of a motor control unit according to claim 1, characterized in that the elastic structure (10) of the conductive element (4) is formed between the first connecting element (5) and the second connecting element (8).

3. The apparatus for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the elastic structure (10) of the conductive element (4) has a pretension force in at least one spatial direction when assembled, and the first connecting element (5) is pressed against the printed circuit board (2) by the pretension force, as described in claim 1 or 2.

4. The device for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, as described in claim 1, characterized in that the elastic structure (10) of the conductive element (4) is designed such that the relative position of the contact surface (12) of the printed circuit board with respect to the connection position (9) of the electric motor winding (13) can be compensated in all spatial directions.

5. The device for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the conductive element (4) is formed as a flat conductor bent in at least the region of the elastic structure (10), and the width of the cross-section of the flat conductor is greater than the thickness of the cross-section of the flat conductor.

6. The apparatus for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the elastic structure (10) of the conductive element (4) is helical.

7. The apparatus for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the elastic structure (10) of the conductive element (4) has a meandering shape.

8. The apparatus for electrically connecting an electric motor winding (13) to a printed circuit board of a motor control unit, as described in claim 1, characterized in that the electrical contact between the conductive element (4) and the electric motor winding (13) is formed by a welded connection, an insulating displacement connection, or a soldered connection.

9. The device for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the conductive element (4) can be locked to the printed circuit board (2) using the first connecting element (5).

10. The apparatus for electrically contacting an electric motor winding and a printed circuit board of a motor control unit, characterized in that the contact bending portion (7) is a die-cut part, as described in claim 1.

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