Electric motor device

Abstract

To provide an electric motor device that reduces the number of parts and assembly processes.SOLUTION: According to the present invention, in one embodiment, a control board is fixed to a connector block, the connector block is coupled to a side wall of a motor housing at the periphery of the control board, and preferably, terminals of an electric motor are press-fit into through-holes of the control board in a press-fit direction parallel to a shaft of the electric motor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric motor device. [Background technology]

[0002] The drive device disclosed in Patent Document 1 includes a motor, a control unit arranged coaxially with the motor and controlling the drive of the motor, a connector unit for connecting the control unit to an external connector, and a cover made of a separate member from the connector unit that covers the control unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-187079 Summary of the Invention [Problem to be solved by the invention]

[0004] In the drive device disclosed in Patent Document 1, the connector block provided with the connector is shaped so that the solder joints are exposed for the purpose of soldering the motor terminals to the control board. Furthermore, in order to close off the space in which the control board is housed, it is covered with a cover member separate from the connector block, which poses the problem of requiring a large number of parts and assembly steps.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electric motor device that can reduce the number of parts and assembly steps. [Means for solving the problem]

[0006] In one aspect of the electric motor device according to the present invention, the control board is fixed to the connector block, and the connector block is coupled to a side wall of the motor housing at the outer periphery of the control board. [Effects of the Invention]

[0007] According to the present invention, the number of parts and assembly steps of the electric motor device can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is an external perspective view of the electric motor device. [Figure 2] FIG. 2 is a vertical cross-sectional view of the electric motor device. [Figure 3] FIG. 2 is an enlarged cross-sectional view of the connector block. [Figure 4] FIG. 2 is an enlarged cross-sectional view of the connector block. [Figure 5] 4 is a cross-sectional view showing a connection structure of a terminal of an electric motor to a control board. FIG. [Figure 6] 5A to 5C are diagrams illustrating an assembly process of the electric motor device. [Figure 7] FIG. 4 is a diagram showing the dimensional relationship in the electric motor device. [Figure 8] 10A and 10B are diagrams illustrating the process of separating the connector block from the motor unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric motor device according to an embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view showing an external appearance of an electric motor device 10 according to an embodiment of the present invention. The electric motor device 10 is, for example, a device that applies a steering assist force to a steering mechanism in an electric power steering device of a vehicle.

[0010] The electric motor device 10 includes a motor section 20 and a connector block 30 . The motor section 20 includes an electric motor 21 such as a three-phase brushless DC motor housed inside a cylindrical motor housing 22. The electric motor 21 is accommodated in the motor housing 22 so that the central axis of the cylindrical accommodation chamber of the motor housing 22 and the output shaft 21A are substantially aligned.

[0011] An output shaft 21A of the electric motor 21 protrudes from one end of the motor housing 22 in the motor axial direction, and in the case of an electric power steering device, the portion of the output shaft 21A protruding from the motor housing 22 is connected to a transmission mechanism. The rotation of the electric motor 21 is transmitted to the rack bar of the vehicle via a transmission mechanism, and the torque generated by the electric motor 21 causes the rack bar to move axially, and as the rack bar moves axially, the direction of the vehicle's tires (tire angle) is changed.

[0012] The connector block 30 includes a plurality of connectors 31 for connecting a control board 50 shown in FIG. 2, which will be described later, to an external device. The connector block 30 is coupled to the side wall of the motor housing 22 on the side opposite to the side from which the output shaft 21A protrudes. In other words, the control board 50 and the external device are electrically connected by fitting a connector provided at one end of a harness, one end of which is connected to the external device, into the connector 31 of the connector block 30.

[0013] The external device connected to the control board 50 via the connector 31 is a battery as a power source, another electronic control device, or the like. The control board 50 is a board on which circuit components for controlling the driving of the electric motor 21 are mounted, and the circuit components mounted on the control board 50 include a microcomputer, a power supply IC, a pre-driver circuit, and the like.

[0014] FIG. 2 is a vertical cross-sectional view of the electric motor device 10, and FIGS. 3 and 4 are enlarged views of the connector block 30 shown in FIG. The electric motor 21 is housed in the motor housing 22 with the output shaft 21A supported by bearings 41 and 42. The side of the connector block 30 opposite the connector 31 has a disk-shaped recess, and the open end of this disk-shaped recess 32 fits into the open end of the motor housing 22, thereby closing off the space that houses the control board 50 and the electric motor 21.

[0015] The control board 50 is fixed at a predetermined position in the disk-shaped recess 32 of the connector block 30 so that the mounting surface is perpendicular to the output shaft 21A and coaxial with the electric motor 21. More specifically, the control board 50 is positioned and fixed by a plurality of bosses 33 erected from the bottom surface of the disk-shaped recess 32 . In other words, the electric motor device 10 is configured by arranging the electric motor 21, the control board 50, and the connector block 30 in the axial direction of the output shaft 21A of the electric motor 21 in that order, and the connector block 30 is connected to the side wall of the motor housing 22 on the outer periphery of the control board 50.

[0016] The control board 50 is electrically connected to a plurality of terminals 31A of the connector 31 and a plurality of terminals 21B of the electric motor 21. Terminals 31A of connector 31 extend from connector 31 toward control board 50 in a direction parallel to output shaft 21A, and are inserted into through holes in control board 50 and soldered thereto.

[0017] On the other hand, the terminal 21B of the electric motor 21 extends from the electric motor 21 toward the control board 50 in a direction parallel to the output shaft 21A. Here, the terminals 21B of the electric motor 21 are press-fit terminals. The terminals 21B of the electric motor 21 are press-fitted into through holes in the control board 50 fixed to the connector block 30 with the direction parallel to the output shaft 21A as the press-fit direction, and are connected to the control board 50 without soldering.

[0018] The fixing member for fixing the control board 50 to the connector block 30 will be described below. The terminals 21B of the electric motor 21 are press-fit terminals, and the press-fit direction is the direction in which the control board 50 is pressed against the boss 33. Therefore, a large fixing force is not required for connection of terminal 21B, and soldering terminal 31A of connector 31 to control board 50 can be used to fix control board 50 to connector block 30. In this case, the terminals 31A of the connector 31 and the solder that electrically connects the terminals 31A to the control board 50 serve as fixing members that fix the control board 50 to the connector block 30.

[0019] Furthermore, for example, by threading a male screw (fixing member) inserted into a through hole provided in the control board 50 into a female screw provided in the boss 33, the control board 50 can be fixed to the boss 33 with the screw. In this case, the screws serve as fixing members for the control board 50. Furthermore, as a fixing member for fixing the control board 50 to the connector block 30, a snap fit or the like can be used, which fixes the control board 50 by fitting it in using the elasticity of the material.

[0020] A magnetic rotation angle sensor 60 for detecting the motor rotation angle is provided on the surface (rear surface) of the control board 50 facing the electric motor 21. The rotation angle sensor 60 is provided on the rear surface of the control board 50 at a portion where an extension line of the output shaft 21A intersects. A magnet attached to the end of the output shaft 21A faces the rotation angle sensor 60 across a predetermined gap, and the rotation angle sensor 60 detects changes in the magnetic field caused by the rotation of the magnet, thereby detecting the motor rotation angle.

[0021] FIG. 5 is an enlarged cross-sectional view showing the connection structure of the terminal 21B of the electric motor 21 to the control board 50. As shown in FIG. The plurality of terminals 21B of the electric motor 21 extend from the electric motor 21 toward the control board 50 and are inserted into through holes 51 provided in the control board 50. Then, the elastic deformation portion 21C (elastic contact) of the terminal 21B is press-fitted into the through-hole 51 of the control board 50, and the elastic deformation portion 21C is brought into close contact with the inner surface of the through-hole 51, whereby the terminal 21B is electrically connected to the control board 50.

[0022] That is, the terminals 21B of the electric motor 21 are press-fitted into the through holes 51 of the control board 50 fixed to the connector block 30 with the direction parallel to the axis of the electric motor 21 as the press-fit direction. It should be noted that FIG. 5 shows one embodiment of the press-fit terminal, and press-fit terminals of various known shapes and structures can be appropriately selected and used.

[0023] FIG. 6 shows an outline of the assembly process for the electric motor device 10. First, in the first step, the terminals 31A of the connector 31 are inserted into the through holes of the control board 50, and the control board 50 is positioned by the bosses 33. Then, the tip of the terminal 31A of the connector 31 protruding from the electric motor 21 side of the control board 50 is soldered to the control board 50. Here, the control board 50 can be fixed to the connector block 30 using fixing members such as screws.

[0024] Next, in the second step, the connector block 30 to which the control board 50 is fixed is joined to the motor housing 22. In detail, the connector block 30 to which the control board 50 is fixed is moved along the axial direction of the electric motor 21, and the lower open end of the connector block 30 is fitted inside the upper open end of the motor housing 22, thereby connecting the connector block 30 and the motor housing 22. In other words, the connector block 30 and the motor housing 22 are directly connected to form a closed space that accommodates the control board 50 and the electric motor 21.

[0025] In the process of fitting the connector block 30 to the motor housing 22, the terminals 21B of the electric motor 21 are pressed into the through holes 51 (see Figure 5) of the control board 50, and the terminals 21B of the electric motor 21 are electrically connected to the control board 50 by a solderless connection. Then, in the third step, the connector block 30 is fixed to the motor housing 22 using screws (screws 70 shown in FIGS. 1-4) or caulking, thereby completing the assembly process of the electric motor device 10.

[0026] Here, in order to facilitate the operation of press-fitting the terminal 21B of the electric motor 21 into the through-hole 51 of the control board 50 in the second step, the connector block 30 is engaged with the motor housing 22 before the terminal 21B is inserted into the through-hole 51. FIG. 7 shows the dimensional relationships for realizing the above fitting operation.

[0027] The connector block 30 integrally includes a fitting portion 34 that fits into the motor housing 22. The fitting portion 34 is a cylindrical portion that protrudes from the lower surface 30A (the surface on the side of the electric motor 21) of the connector block 30, and is a portion (inner cylindrical portion) that is fitted inside the upper open end of the motor housing 22.

[0028] As shown in FIG. 7, the distance from the lower surface 30A of the connector block 30 to the upper surface 50A of the control board 50 is defined as A, the protruding height of the fitting portion 34 from the lower surface 30A of the connector block 30 is defined as B, and the distance from the lower surface 50B of the control board 50 to the tip of the terminal 21B when the press-fitting of the terminal 21B into the through-hole 51 is completed is defined as C. Here, the electric motor device 10 is configured such that A + C < B. As a result, before the terminal 21B is inserted into the through-hole 51, the fitting portion 34 of the connector block 30 is engaged with the motor housing 22, and the positioning of the connector block 30 is executed, so that the insertion of the terminal 21B into the through-hole 51 can be easily performed.

[0029] In the motor housing 22, the fitting portion 22A, which is the portion where the fitting portion 34 of the connector block 30 is fitted, can be integrally formed with the motor housing 22, or the fitting portion 22A and other portions can be formed as two parts. That is, the motor housing 22 can be formed by a cylindrical first housing (main body portion) that houses the electric motor 21 and an annular second housing (fitting portion 22A) that is coupled to the opening edge of the first housing. In this case, the fitting portion 34 of the connector block 30 is coupled to the second housing (fitting portion 22A).

[0030] However, if the fixing force of the fixing member that fixes the control board 50 to the connector block 30 is set to be greater than the holding force of the terminal 21B of the electric motor 21 in the press-fit state relative to the through hole 51 of the control board 50, the connector block 30 and the motor section 20 can be separated after assembling the electric motor device 10. FIG. 8 shows the process of separating the connector block 30 and the motor section 20. For example, when the control board 50 is fixed to the connector block 30 with screws, the fixing force of the control board 50 is greater than the holding force of the terminals 21B.

[0031] In the electric motor device 10 in which such fixing and holding forces are set, the motor section 20 and the connector block 30 are brought into a state in which they can be separated (for example, by removing the fixing screws 70 shown in Figures 1 to 4), and then a force is applied to pull the connector block 30 away from the motor section 20. Then, while the control board 50 remains fixed to the connector block 30, the terminal 21B of the electric motor 21 is pulled out from the through hole 51 of the control board 50, and the connector block 30 to which the control board 50 is fixed is separated from the motor housing 22 that houses the electric motor 21, i.e., the motor section 20.

[0032] The following describes the effects of the electric motor device 10. First, the connector block 30 covers the open end of the motor housing 22, and the direct connection between the connector block 30 and the motor housing 22 closes the storage space for the control board 50 and the electric motor 21, so there is no need to close the storage space using a cover member separate from the connector block 30 and the motor housing 22. Therefore, compared to when a cover member separate from the connector block 30 and the motor housing 22 is used, the number of parts and the number of assembly steps can be reduced.

[0033] That is, by employing press-fit terminals as the terminals 21B of the electric motor 21 and connecting the terminals 21B to the control board 50 without soldering, the work of soldering the terminals 21B of the electric motor 21 is no longer necessary. Therefore, there is no need to provide a recess in the connector block 30 to expose the soldering portion of the terminal 21B for the soldering operation of the terminal 21B, and a cover member to cover the recess is not required, and further, the sealing area can be reduced.

[0034] Furthermore, it is possible to eliminate the need for screws for fixing the control board 50 to the connector block 30, and the terminals 21B of the electric motor 21 are connected without soldering, eliminating the need for soldering the terminals 21B. As a result, the cost and size of the electric motor device 10 can be reduced, and the reliability of the sealing performance can be improved by reducing the number of sealing parts.

[0035] Furthermore, if the fixing force for fixing the control board 50 to the connector block 30 is set to be greater than the holding force of the terminal 21B of the electric motor 21 against the through hole 51 of the control board 50, the connector block 30 to which the control board 50 is fixed can be separated from the motor housing 22 containing the electric motor 21 after assembly. Therefore, for example, when the electric motor 21 breaks down, the connector block 30 to which the control board 50 is fixed can be removed and reused, thereby reducing the cost of defective work. Furthermore, since the control board 50 is fixed to the connector block 30, the connector block 30 and the control board 50 can be inspected as a unit, and a unit that passes the inspection can be assembled into the motor housing 22.

[0036] Furthermore, when the motor housing 22 is composed of two parts, a cylindrical first housing (main body) that accommodates the electric motor 21 and an annular second housing (fitting portion 22A) that is connected to the opening edge of the first housing, by using the first housing as a common part and providing multiple shapes of second housing, the variety of connecting portions with the connector block 30 can be easily expanded.

[0037] The technical ideas explained in the above embodiments can be used in appropriate combinations as long as no contradiction occurs. Furthermore, although the contents of the present invention have been specifically described with reference to preferred embodiments, it is obvious that a person skilled in the art can adopt various modified embodiments based on the basic technical idea and teachings of the present invention. [Explanation of symbols]

[0038] 10... electric motor device, 20... motor section, 21... electric motor, 22... motor housing, 30... connector block, 31... connector, 50... control board

Claims

1. An electric motor; a control board on which circuit components for driving and controlling the electric motor are mounted; a connector block including a connector for connecting the control board to an external device; a motor housing that accommodates the electric motor; and the control board is fixed to the connector block; The connector block is coupled to a side wall of the motor housing at an outer periphery of the control board. Electric motor device.

2. 2. The electric motor device according to claim 1, The terminals of the electric motor are press-fitted into the through holes of the control board with a direction parallel to the shaft of the electric motor as a press-fitting direction. Electric motor device.

3. 3. The electric motor device according to claim 2, a fixing force of the control board to the connector block is set to be greater than a holding force of the terminals of the electric motor in a press-fit state in the through holes of the control board; Electric motor device.

4. 4. The electric motor device according to claim 3, The connector block and the motor housing are directly coupled to form a closed space that accommodates the control board and the electric motor. Electric motor device.

5. 5. The electric motor device according to claim 4, the motor housing is formed of a cylindrical first housing that accommodates the electric motor and an annular second housing that is connected to an opening edge of the first housing, the connector block is coupled to the second housing; Electric motor device.

6. 3. The electric motor device according to claim 2, the connector block includes a fitting portion that is fitted to the motor housing, The fitting portion is adapted to engage with the motor housing before the terminals of the electric motor are inserted into the through holes of the control board. Electric motor device.

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