Heat crimped joint

Abstract

To provide a heat caulked coupling body capable of constraining a coupling member in an axial direction and a radial direction of a boss part only by heat caulking in one direction.SOLUTION: A heat caulked coupling body includes: a connector 51 as a coupling member having a body part 52 and a resin boss part 53 protruding from the body part 52; and a case 42 as a member to be coupled having a through hole 45 through which the boss part 53 is inserted. A thermally deformed part 55 having an outer diameter larger than that of the through hole 45 is formed at a tip of the boss part 53. An edge part 46 of the through hole 45 on a side opposite to the body part 52 is formed with two or more recesses 47 spaced apart in a circumferential direction. A part of the thermally deformed part 55 is filled in the recess 47.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to heat staked joints. [Background technology]

[0002] A known example of a combined assembly of a joining member and a joinee member is described in Patent Document 1. In Patent Document 1, the joining member and the joinee member are joined by press-fitting a terminal holder as the joining member into a housing portion of a base body as the joinee member. The outer peripheral surface of the terminal holder is formed with multiple protrusions that come into contact with the inner peripheral surface of the housing portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-124021 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have considered fixing a joining member to a joined member by heat crimping. Heat crimping is a method of joining a joining member to a joined member by inserting a resin boss portion of the joining member into a through-hole in the joined member and then heating the tip of the boss to expand it radially. However, heat crimping has the problem that the seating surface at the tip of the boss slides relative to the joined member, making it impossible to constrain the joining member radially. Possible solutions include, for example, performing heat crimping from multiple directions, or press-fitting the joining member into the joined member as in prior art document 1, but these methods result in a complex and large structure.

[0005] The present invention has been made in consideration of the above points, and its object is to provide a heat-stakingly joined body that can restrain a joining member in the axial and radial directions of a boss portion by heat staking in only one direction. [Means for solving the problem]

[0006] The thermally caulked assembly of the present invention includes a connecting member (51) having a main body (52) and a resin boss (53) protruding from the main body, and a connected member (42) having a through hole (45) through which the boss is inserted, and is applied to a mechanically and electrically integrated drive device (10) in which a motor (20) and a control unit (40) are integrally provided. A thermally deformed portion (55) having an outer diameter larger than that of the through hole is formed at the tip of the boss. Recesses (47) are formed at two or more circumferentially spaced locations on an edge (46) of the through hole opposite the main body. A portion of the thermally deformed portion fills the recess. The connecting member is a connector, and the connected member is a case of the control unit, and has a fixed part (43) fixed to the housing (31) of the motor and a radial part (44) extending from the fixed part to the motor. Outside and motor side Protruding The boss part of the main body is formed on the surface where it is covered. and a connector holding portion (44) having a through hole. The connector is located between a cover (61) that covers one side of the control unit in the motor axial direction and the connector holding portion, with its opening exposed to the outside from between the cover and the connector holding portion, and the boss portion located to the side of the motor.

[0007] This allows the thermally deformable portion to engage with the recessed portion in the radial direction of the boss portion, preventing the bearing surface of the thermally deformable portion from sliding relative to the joined member, making it possible to restrain the joining member in the axial and radial directions of the boss portion with only one-directional thermal staking. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a longitudinal sectional view of the drive device according to the first embodiment. [Figure 2] FIG. 2 is a view of the connector and case in FIG. 1 as seen from the direction of arrow II. [Figure 3] Enlarged view of part III in Figure 2. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 3. [Figure 5] Cross-sectional view of line VV in Figure 3. [Figure 6] FIG. 5 is a diagram showing the state of the boss portion of FIG. 4 before being heat-stakingly fastened; [Figure 7] FIG. 10 is a longitudinal sectional view of a drive device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, several embodiments will be described with reference to the drawings. The same reference numerals will be used to designate substantially the same components among the embodiments, and the description thereof will be omitted.

[0010] [First embodiment] 1, the drive device 10 is an electromechanical integrated type in which the motor 20 and the control unit 40 are integrally provided. The control unit 40 controls the motor 20 to generate a desired torque based on information input from the outside and information such as the motor current detected inside the control unit 40. The torque of the motor 20 is output to the outside from the output end of the rotating shaft 26.

[0011] The motor 20 includes a stator 21, a rotor 25, and a housing 31 that accommodates them. The stator 21 has a stator core 22 fixed to the housing 31 and a winding set 23 assembled to the stator core 22. The winding set 23 is connected to a control unit 40 via lead wires (not shown). The rotor 25 has a rotating shaft 26 supported by a rear bearing 36 and a front bearing 35, and a rotor core 27 fixed to the rotating shaft 26. The rotor 25 is provided inside the stator 21 and is rotatable relative to the stator 21. A permanent magnet 37 is provided on one end of the rotating shaft 26.

[0012] The housing 31 has a cylindrical motor case 32, a front end frame 33 provided at one end of the motor case 32, and a rear end frame 34 provided at the other end of the motor case 32. The front end frame 33 and the rear end frame 34 are fastened to each other with bolts (not shown). The rear end frame 34 also functions as a heat sink for the control unit 40.

[0013] Hereinafter, the direction parallel to the rotation axis O of the rotating shaft 26 will be referred to as the motor axial direction, the direction perpendicular to the rotation axis O will be referred to as the motor radial direction, and the direction around the rotation axis O will be referred to as the motor circumferential direction.

[0014] The control unit 40 is provided on one side of the motor 20 in the motor axial direction, and includes a circuit board 41, a case 42, a connector 51, terminals 57, and a cover 61. Various electronic components are mounted on the circuit board 41. Although not shown, these various electronic components include, for example, a rotation angle sensor that detects the rotation angle of the rotating shaft 26 based on the magnetism of the permanent magnet 37, a motor drive element that performs a switching operation to switch the energized state of the motor 20, and a control circuit that performs calculations based on information from the outside or the rotation angle sensor, etc., and issues commands to the motor drive element, etc.

[0015] The case 42 has a fixed portion 43 fixed to the rear end frame 34 and a connector holding portion 44 provided to protrude from the fixed portion 43 in the motor radial direction. The fixed portion 43 is formed in an annular shape and is fixed to the rear end frame 34 together with the circuit board 41 by screws 62. The connector 51 is disposed on the outer side of the fixed portion 43 in the motor radial direction. The connector holding portion 44 is provided to cover the connector 51 on the other side of the connector 51 in the motor axial direction.

[0016] The connector 51 holds a plurality of terminals 57. The plurality of terminals 57 includes signal terminals connected to signal lines of the board 41 and power terminals connected to power lines of the board 41. The terminals 57 extend from the connector 51 to the board 41 and are electrically connected to the board 41 by solder 63. The cover 61 is provided so as to cover the board 41 on one side of the case 42 and the connector 51 in the motor axial direction, and is fixed to the case 42 by, for example, adhesive.

[0017] As shown in Figures 1 and 2, the connector 51 and the case 42 are joined by thermal crimping to form a thermally crimped assembly 65. The connector 51 has a main body 52 that holds terminals 57 and bosses 53 that protrude from the main body 52. ​​In the first embodiment, the entire connector 51 is made of resin. The connector 51 is provided with three bosses 53. The bosses 53 protrude in the axial direction of the motor.

[0018] Hereinafter, the direction parallel to the axis of the boss portion 53 will be referred to as the boss axial direction. The boss axial direction is parallel to the motor axial direction. The direction perpendicular to the axis of the boss portion 53 will be referred to as the boss radial direction. The direction around the axis of the boss portion 53 will be referred to as the boss circumferential direction.

[0019] As shown in FIGS. 1 to 4, the connector holding portion 44 has a through hole 45 through which the boss portion 53 is inserted. The through hole 45 is a circular hole that penetrates in the boss axial direction. The boss portion 53 has a cylindrical base end portion 54 located within the through hole 45 and a thermally deformed portion 55 having an outer diameter larger than that of the through hole 45. The thermally deformed portion 55 is formed at the tip of the boss portion 53. The main body portion 52 abuts against the connector holding portion 44 from one side in the boss axial direction. In addition, a seat surface 56 of the thermally deformed portion 55 abuts against the connector holding portion 44 from the other side in the boss axial direction. This restrains the connector 51 relative to the case 42 in the boss axial direction.

[0020] Here, we will explain the problems with conventional fastening methods using heat crimping. Conventional heat crimping has the problem that the seating surface at the tip of the boss portion slides relative to the member to be joined, making it impossible to constrain the joining member in the radial direction of the boss portion. In other words, in the case of the first embodiment, if the seating surface 56 of the thermally deformable portion 55 slides relative to the connector holding portion 44, the connector 51 cannot be constrained relative to the case 42 in the radial direction of the boss. As a result, a load is applied to the solder 63, which may cause a break. Possible solutions include, for example, heat crimping from multiple directions or additionally press-fitting the joining member into the member to be joined, but these methods result in a complex and large structure.

[0021] In the first embodiment, the above problem is solved as follows. Four recesses 47 are formed at equal intervals in the circumferential direction on an edge 46 of the through hole 45 opposite the main body 52. ​​The recesses 47 are formed in the shape of slits extending in the boss radial direction. As shown in FIG. 5, the cross section of the recess 47 in the boss circumferential direction is rectangular. The recess 47 has a surface 48 parallel to the insertion direction of the boss 53 (i.e., the boss axial direction). As shown in FIGS. 4 and 5, the recess 47 is partially filled with the thermally deformed portion 55. The above filling does not necessarily mean that the entire recess 47 is filled; it is sufficient that the thermally deformed portion 55 and the recess 47 are engaged on both sides in the circumferential direction. This restrains the connector 51 in the boss radial direction relative to the case 42.

[0022] 6, the heat crimping is performed by inserting the boss portion 53 into the through-hole 45, and then heating the tip portion 58 of the boss portion 53 to expand it in the radial direction. At this time, part of the molten tip portion 58 flows into the recess 47 and solidifies, and the inside of the recess 47 is filled with the thermally deformed portion 55, thereby completing the radial constraint of the boss. With the boss portion 53 inserted into the through-hole 45, the volume of the portion of the boss portion 53 protruding from the case 42 is larger than the space around the edge portion 46.

[0023] (effect) As described above, in the first embodiment, recesses 47 are formed in two or more circumferentially spaced locations on edge 46 of through hole 45 on the side opposite main body 52. ​​A portion of thermally deformed portion 55 is filled in recess 47. As a result, thermally deformed portion 55 engages with recess 47 in the boss radial direction, thereby preventing seat surface 56 of thermally deformed portion 55 from sliding relative to case 42. Therefore, connector 51 can be restrained in the boss axial direction and the boss radial direction by thermally crimping only in one direction (i.e., the boss axial direction).

[0024] In the first embodiment, four recesses 47 are formed at equal intervals in the circumferential direction, thereby increasing the restraining force of connector 51 in the boss radial direction.

[0025] In the first embodiment, the recess 47 has a surface 48 that is parallel to the insertion direction of the boss 53. The thermally deformed portion 55 engages with the surface 48. This increases the restraining force of the connector 51 in the boss radial direction.

[0026] In the first embodiment, the case 42 serving as the coupled member has a fixed portion 43 fixed to the rear frame end 34 and a connector holding portion 44 that protrudes from the fixed portion 43 in the motor radial direction and has a through-hole 45. If the overhanging connector were integrally formed with the case, deformation due to warping caused by shrinkage after resin molding would increase, resulting in reduced dimensional accuracy. However, if a configuration is adopted in which part of the thermally deformable portion 55 fills the recess 47, the case 42 and the connector 51 can be separated, allowing the case 42 to be replaced with a material such as a metal material that is less susceptible to deformation after molding. Furthermore, even if the case 42 and the connector 51 are separated, the two can be coupled with minimal increase in size.

[0027] [Second embodiment] As shown in Figure 7, It is a reference form In the second embodiment, a noise blocking plate 67 is provided inside the cover 61. The cover 61 and the noise blocking plate 67 are joined by heat caulking to form a heat caulked joint 68. The cover 61 is provided with a boss portion 53, which is configured similarly to the boss portion 53 of the connector 51. This makes it possible to restrain the noise blocking plate 67 in both the boss axial direction and the boss radial direction by heat caulking in only one direction.

[0028] Furthermore, if the noise blocking plate 67 is fixed to the cover 61 by insert molding, the difference in linear expansion between the two may cause the cover 61 to crack. Furthermore, if the noise blocking plate 67 is fixed by conventional heat caulking, the bearing surface at the tip of the boss may slip, causing noise. These problems can be solved in the second embodiment.

[0029] [Other embodiments] In other embodiments, a portion of the connector may be made of resin. At least the boss portion may be made of resin. The connector may have two or less boss portions or four or more boss portions.

[0030] In other embodiments, the recesses on the edge of the through hole may be formed in two or more locations spaced apart in the circumferential direction. The recesses may penetrate the boss in the axial direction. The cross-sectional shape of the recesses in the circumferential direction of the boss is not limited to a rectangle, and may be other shapes such as a triangle or hemisphere. The surface of the recess that engages with the thermally deformable portion is not limited to a flat surface, and may be a curved surface.

[0031] The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0032] 42 case (joined member), 45 through hole, 46 edge portion, 47 recess portion, 51 connector (coupling member), 52 main body portion, 53 boss portion, 55 thermally deformed portion, 61 Cover (connecting member), 65, 68 Heat caulking connecting body, 67 Noise blocking plate (combined member).

Claims

1. A thermally caulked joint body comprising: a joint member (51) having a main body (52) and a resin boss (53) protruding from the main body; and a jointed member (42) having a through hole (45) through which the boss is inserted, The present invention is applied to a mechanically and electrically integrated drive device (10) in which a motor (20) and a control unit (40) are integrally provided, A thermally deformed portion (55) having an outer diameter larger than that of the through hole is formed at the tip of the boss portion, An edge portion (46) of the through hole on the opposite side to the main body portion has recesses (47) formed at two or more locations spaced apart in the circumferential direction, a part of the thermally deformed portion is filled in the recess, the coupling member is a connector, The coupled member is a case of the control unit, and has a fixed portion (43) fixed to the housing (31) of the motor, and a connector holding portion (44) provided with the through hole, protruding from the fixed portion radially outward of the motor and toward the motor, and covering a surface of the main body on which the boss portion is formed; The connector is a heat-sealed joint between a cover (61) covering one side of the control unit in the motor axial direction and the connector holding portion, with the opening exposed to the outside from between the cover and the connector holding portion, and the boss portion located to the side of the motor.

2. 2. The heat staking joint according to claim 1, wherein four of said recesses are formed at equal intervals in the circumferential direction.

3. The recess has a surface (48) parallel to the insertion direction of the boss portion, The heat staked joint of claim 1 or 2, wherein the heat deformation engages the surface.

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