JP2008148457A - Connection structure for resolver and brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably weld a terminal of a resolver. <P>SOLUTION: In a resolver stator 26A, a plurality of harness connecting terminals 56 are arranged and welded to connector terminals 63 of a connector 27 one by one. Each harness connecting terminal 56 has a tongue 56A formed of a step, and the width of the tongue 56A is half or smaller than that of the other part. Each tongue has a long and thin shape. Each connector terminal 63 is so constituted that a pair of protrusions 64 are extended so that the tongue 56A can be received. Positioning is facilitated by inserting the tongue 56A between the pair of protrusions 64. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resolver connection structure and a brushless motor using the same.

The resolver used as means for detecting the rotor position of the motor is composed of a resolver rotor fixed to the rotating shaft of the rotor and a resolver stator fixed to the stator side. The resolver stator has a plurality of coils, and the windings of the coils are electrically connected to the connector. The output signal of the resolver is input to a motor control device via a connector and used for rotation control (see, for example, Patent Document 1).
Here, some resolver stators have a terminal holding portion integrally formed with a harness connection terminal connected to a connector (see, for example, Patent Document 2). A coil winding is wound around one end of the harness connection terminal, and a connector terminal is connected to the other end. It is known that arc welding is used to connect the harness connection terminal and the connector terminal.
JP 2005-61865 A JP 2005-184952 A

However, a plurality of harness connection terminals are provided according to the number of coils, and a plurality of terminals on the connector side are also provided corresponding to this, whereas the space for arranging the terminals is limited, It took time and effort to arrange the terminals so that they did not contact each other. In arc welding, it was difficult to set the welding conditions and required skill to reliably weld the terminals by controlling heat transfer. For example, if the amount of heat applied to the terminal becomes too large, the terminal melts and falls off in large quantities, and the welding shape becomes unstable. For this reason, detailed confirmation work by visual inspection was necessary after welding.
The present invention has been made in view of such circumstances, and a main object of the present invention is to enable reliable welding of a resolver terminal.

The invention according to claim 1 of the present invention that solves the above-described problems includes a plurality of first terminals connected to a stator-side coil of a resolver that detects a rotational position of a motor, and a connector that extracts an electrical signal of the resolver In the resolver connection structure for electrically connecting each of the plurality of second terminals arranged corresponding to the arrangement of the first terminals to each of the first terminals, the first terminals and the second terminals Resolver connection structure characterized in that the end of one terminal is bent substantially parallel to the axis of the motor and welded in surface contact with the end of the other terminal extending substantially parallel to the axis of the motor; did.
In this resolver connection structure, since the respective end portions of the first and second terminals are welded after being brought into surface contact with each other in parallel, the terminals are positioned and welded. Moreover, it is easy to control the heat transfer between the surface contact terminals.

According to a second aspect of the present invention, in the resolver connection structure according to the first aspect, the first terminal and the second terminal are provided with a pair of protruding pieces capable of receiving the other terminal. It is characterized by that.
In this resolver connection structure, by inserting the other terminal between the pair of protruding pieces, the terminals are positioned and do not come into contact with other terminals. The terminal provided with the protruding piece may be a first terminal or a second terminal.

According to a third aspect of the present invention, there is provided the resolver connection structure according to the first or second aspect, wherein the first terminal and the other terminal of the second terminal have a tongue portion whose width is reduced by a step. It is characterized by having.
In this resolver connection structure, heat transmitted from the tongue piece during arc welding is diffused in a wide portion on the base end side of the step, and the amount of melting of the tongue piece is adjusted.

According to a fourth aspect of the present invention, in the resolver connection structure according to any one of the first to third aspects, the tongue piece is formed by reducing the width of the other terminal to half or less. The length of the tongue piece is 3 to 5 times the thickness in the direction orthogonal to the width direction of the other terminal.
In this resolver connection structure, the tongue piece is sufficiently narrower than the wide portion on the base end side of the step and has an elongated shape, so that the amount of melting by heat transfer can be easily adjusted.

According to a fifth aspect of the invention, in the resolver connection structure according to any one of the first to fourth aspects, at least one of the one terminal and the other terminal is inclined in a direction approaching each other. It is characterized by that.
In this resolver connection structure, since the terminals are inclined toward each other, the terminals can be brought into close contact with each other even when there is a dimensional error.

According to a sixth aspect of the present invention, the connector is electrically connected to the stator of the resolver using the resolver connection structure according to any one of the first to fifth aspects, and the rotor is rotated. In some cases, the brushless motor is configured such that a signal generated in the resolver is output through the connector in accordance with the rotational position of the resolver rotor fixed to the rotor.
In this brushless motor, since each of the first terminal and the second terminal is securely welded, the rotation of the signal generated by the resolver can be reliably taken out.

  According to the present invention, the plurality of first terminals on the resolver side and the plurality of second terminals on the connector side are welded in surface contact with each other, so that the heat transfer between the terminals can be easily controlled and the welding shape is reduced. Stabilize.

The best mode for carrying out the invention will be described in detail with reference to the drawings.
FIG. 1 shows a brushless motor used in an electric power steering apparatus. The brushless motor 1 includes a stator 2 and a rotor 3 disposed in the stator 2, and the rotor 3 is rotatably supported by a bracket 4 fixed to the stator 2. A rotor shaft (not shown) can be inserted into the rotor 3. The rack shaft forms a rack and pinion mechanism in the gear box, and is movable in the axial direction of the brushless motor 1 in accordance with the operation of the steering wheel. Both ends of the rack shaft are connected to the wheels of the vehicle via a knuckle arm or the like.

  In the stator 2, a stator core 12 is press-fitted and fixed to the inner periphery of a cylindrical stator housing 11. The stator housing 11 is formed with screw holes 13 at the respective peripheral edge portions of the released both ends, so that the bracket 4 and other brackets (not shown) can be fixed. An end portion on the side of the bracket 4 is formed with an inlay portion 11 </ b> A used when the stamper is joined to the bracket 4.

The stator core 12 has a plurality of teeth 14 extending from an annular outer peripheral portion toward the center. A coil 16 is wound around each tooth 14 after the insulator 15 is mounted. The stator core 12 of this embodiment is skewed with respect to the axis. When the stator 2 is manufactured, a core unit having a shape in which the stator core 12 is divided into a plurality of parts in the circumferential direction is manufactured, and after winding the coil 16, the plurality of core units are joined to form the stator core 12.
The winding of each coil 16 is connected to a terminal 17 disposed on the opposite side of the open end to which the bracket 4 is fixed. The terminal 17 is electrically connected to a connection terminal 18 protruding from the side of the stator housing 11 so that a current can be supplied from an external power source.

  The bracket 4 has a cylindrical shape and is fixed to the stator housing 11 with screws 22. At the end of the bracket 4, there is a joint 4 </ b> A that fits into the spigot 11 </ b> A when abutting against the stator housing 11, and a packing 23 such as an O-ring is mounted in a groove carved on the outer periphery of the joint 4 </ b> A. Has been. The other end of the bracket 4 opens so that the rack shaft can be inserted. A bearing 25 is press-fitted into the bracket 4 on the opening side. A resolver stator 26 </ b> A of a resolver 26 that detects the rotational position of the rotor 3 is fixed to the stator 2 side of the bearing 25. A connector 27 for taking out an electric signal from the resolver stator 26A is fixed to the side portion of the bracket 4.

The rotor 3 has a rotating shaft 31 formed of a hollow shaft. One end of the rotating shaft 31 is pivotally supported by a bearing 25 press-fitted into the bracket 4. A resolver rotor 26 </ b> B constituting the resolver 26 is fixed to the outer periphery on one end side. The resolver rotor 26B has a configuration in which permanent magnets are arranged so that magnetic poles are alternately arranged in the circumferential direction. Further, a rotor magnet 33 made of an annular permanent magnet is fixed by a bracket 34 through a metal plate laminated body 32 at a position facing the stator core 12 on the outer periphery of the rotating shaft 31. The rotor magnet 33 has a plurality of magnetic poles arranged in the circumferential direction.
A ball nut (not shown) is fixed to the end of the rotating shaft 31. This ball nut constitutes a ball nut mechanism by interposing a plurality of balls with a ball screw formed on a part of the rack shaft. The ball nut is rotatably supported by a bearing provided on a bracket (not shown) fixed to the stator housing 11.

  Here, the resolver stator 26 </ b> A has a core 51 configured by laminating plates made of a magnetic material, and teeth extend inward in the radial direction of the core 51. The teeth are arranged at equal intervals in the circumferential direction, and a coil 54 is wound around each of which the insulator 53 is mounted. The windings of the coils 54 are wound so that three coils are formed on a plurality of teeth, and the end portions of the windings of the respective coils 54 are terminal holdings formed by protruding part of the insulator 53. It is pulled out to the part 55. As shown in FIGS. 1 and 2, six harness connection terminals 56 are integrally formed in the terminal holding portion 55 according to the number of winding ends of the coil 54. One end of the winding of the coil 54 is fixed one by one. The resolver stator 26A is coated with resin so as to cover the connection portion between the harness connection terminal 56 and the end of the coil 54 and the entire coil 54, and protects the connection portion and the winding.

  The harness connection terminal 56 is a first terminal that has conductivity and penetrates the terminal holding portion 55 made of an insulator in the axial direction of the brushless motor 1. As shown in FIG. 3, one end of the harness connection terminal 56 forms a tongue piece 56A by reducing the width from WB to WA. The length of the tongue piece 56 </ b> A is H along the length direction of the harness connection terminal 56. The harness connection terminal 56 has a width WA: width WB = 1: 2 or more and a thickness D: height H = 1: 3-5. The thickness D is a dimension in a direction orthogonal to the width WA, the width WB, and the height H. With such a shape, the amount of melting can be easily controlled during arc welding as will be described later.

  As shown in FIG. 1, the connector 27 has a receiving portion 61 into which a signal cable can be fitted at one end, and the other end is inserted into the bracket 4 after being bent halfway. In addition, a flange portion 62 that is brought into close contact with the outer surface of the bracket 4 is extended to the outer periphery on the other end portion side, and six connector terminals 63 penetrate from one end portion to the other end portion as conductive second terminals. Are integrally molded. Each connector terminal 63 is bent in accordance with the outer shape of the connector 27 and is arranged in 3 × 2 rows in the receiving portion 61 so that it can be connected to a signal cable (not shown). As shown in FIG. 2, the other end portions of the connector terminals 63 are arranged in a line in accordance with the arrangement of the harness connection terminals 56. As shown in FIGS. 1 and 2, the end 63A of the connector terminal 63 at this position is bent in an approximately L shape from the radial direction to the axial direction of the brushless motor 1, and protrudes left and right from the vicinity of the tip. The piece 64 is integrally extended. The pair of projecting pieces 64 extend substantially radially inward of the brushless motor 1.

  The protruding length of the protruding piece 64 is larger than the thickness of the tongue piece 56 </ b> A of the harness connection terminal 56. The distance between the opposing end surfaces of the pair of projecting pieces 64 is the same as or slightly larger than the width of the tongue piece 56A, and smaller than the width WA of the wide portion 56C of the harness connection terminal 56. For this reason, as shown in FIG. 4, the tongue piece 56 </ b> A can be inserted between the pair of protruding pieces 64. At this time, the tongue piece 56 </ b> A comes into surface contact with the end portion 63 </ b> A of the connector terminal 63. The tip of the tongue piece 56 </ b> A of the harness connection terminal 56 and the tip of the connector terminal 63 are substantially equal. When the terminals 56 and 63 are combined, the protruding piece 64 may be abutted against the stepped portion 56B of the harness connecting terminal 56 by the tongue piece 56A.

Next, the operation of this embodiment will be described.
When connecting the resolver stator 26A and the connector 27, the harness connection terminal 56 and the connector terminal 63 are arc-welded. One tongue piece 56A of the harness connection terminal 56 is inserted between the protruding pieces 64 of each connector terminal 63 one by one. Since both the end portion 63A of the connector terminal 63 and the tongue piece 56A are arranged in parallel in the axial direction, the end portion 63A and the tongue piece 56A are in surface contact. The harness connection terminal 56 is connected to the ground, and the torch is disposed at a predetermined position. It is assumed that optimum conditions such as torch position, electrode length, and electrode position are set in advance.

  While flowing an inert gas, a predetermined current and voltage are applied to the torch, and an arc is blown from the torch. The arc falls on the tongue piece 56A of the harness connection terminal 56 connected to the ground, a large current flows where the arc falls, heat is generated, and the portion is melted. The end portion 63A of the connector terminal 63 in surface contact with the tongue piece 56A is also melted by heat transfer, and the tongue piece 56A and the end portion 63A are welded. At this time, in the harness connection terminal 56, the heat generated in the tongue piece 56A is diffused in the wide portion 56C on the base end side from the stepped portion 56B, so that the amount of melting is controlled. As a result, detachment due to excessive melting of the tongue piece 56A is prevented, and instability of the shape of the welded portion is suppressed.

According to this embodiment, the tongue piece 56 which is the end portion of the harness connection terminal 56 and the end portion 63A of the connector terminal 63 are brought into surface contact to facilitate control of heat transfer between the end portions. The shape can be stabilized. In addition, since the harness connection terminal 56 is provided with a step to control the amount of melting during arc welding, it is possible to prevent dropping and shape variation due to melting. The occurrence of defective products is suppressed and the yield is improved. By stabilizing the shape of the welded portion, the visual confirmation after welding can be reduced or simplified.
Since the pair of protruding pieces 64 capable of receiving the harness connection terminal 56 are provided on the connector terminal 63, positioning of the harness connection terminal 56 is facilitated and contact with the adjacent harness connection terminal 56 can be reliably prevented. The positioning operation is facilitated, the working efficiency is improved, and the reliability of the resolver 26 can be improved.
Since the shape of the tongue piece 56A is the above-described shape, the amount of melting can be controlled more easily. When the width of the tongue piece 56A exceeds the above-described range, the tongue piece 56A is easily melted and detached, or heat cannot be diffused.

  Here, the modification of the shape of the harness connection terminal 56 is shown in FIG. The harness connection terminal 56 is inclined toward the connector terminal 63 on the proximal end side with respect to the tongue piece 56A. At the time of arc welding, the tongue piece 56A is arranged to be pressed against the end portion 63A. Even when there is a dimensional error in the terminals 56 and 63, the tongue piece 56A and the end portion 63A are in surface contact with each other, so that arc welding can be performed more reliably. Other effects are the same as described above. The position, length, and inclination angle of the inclined portion can be arbitrarily set.

Note that the present invention can be widely applied without being limited to the above-described embodiment.
For example, in the embodiment, the protruding piece 64 is provided on the connector terminal 63 as one terminal, and the tongue piece 56A is provided on the harness connection terminal 56 as the other terminal. A pair of protruding pieces capable of receiving the tongue pieces of the connector terminals 63 may be provided on the harness connection terminals 56. The dimension of the tongue piece and the protruding piece is preferably in the above-described range. When the harness connection terminal 56 extends in the radial direction, the terminal end may be bent substantially parallel to the axis of the brushless motor 1.
The connector terminal 63 may be inclined toward the harness connection terminal 56. Even when the tongue piece and the protruding piece are formed on any of the terminals 56 and 63, a dimensional error can be absorbed. Both the harness connection terminal 56 and the connector terminal 63 may be inclined in a direction toward each other.
The motor provided in the resolver 26 is not limited to the form shown in FIG. A brushless motor in which a stator is fixed to a bottomed cylindrical housing and a rotor is rotatably supported may be used.

It is sectional drawing of the motor using the connection structure of the resolver which concerns on embodiment of this invention. It is a figure which shows the state connected with arrangement | positioning of each terminal of a resolver and a connector terminal. It is a perspective view of a harness connection terminal. It is the figure which has arrange | positioned the tongue piece of the harness connection terminal between the protrusion pieces of the connector terminal. It is the figure which inclined the harness connection terminal toward the connector terminal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless motor 3 Rotor 26 Resolver 26A Resolver stator 26B Resolver rotor 27 Connector 54 Coil 56 Harness connection terminal (1st terminal or 2nd terminal)
56A tongue 63 connector terminal (first terminal or second terminal)
64 Projection piece WA, WB Width H Height D Thickness

Claims (6)

A plurality of first terminals connected to a stator-side coil of a resolver for detecting the rotational position of the motor, and a plurality of connectors arranged to correspond to the arrangement of the first terminals on a connector for taking out an electrical signal of the resolver In the connection structure of the resolver that electrically connects the second terminals one by one,
The end of one terminal of the first terminal and the second terminal is bent substantially parallel to the axis of the motor and brought into surface contact with the end of the other terminal extending substantially parallel to the axis of the motor. Resolver connection structure characterized by welding.   The resolver connection structure according to claim 1, wherein a pair of projecting pieces capable of receiving the other terminal are provided on one of the first terminal and the second terminal.   3. The resolver connection structure according to claim 1, wherein the other terminal of the first terminal and the second terminal has a tongue piece whose width is reduced by a step. 4.   The tongue piece is formed by reducing the width of the other terminal to half or less, and the length of the tongue piece is 3 to 5 times the thickness in the direction perpendicular to the width direction of the other terminal. The resolver connection structure according to any one of claims 1 to 3, wherein:   5. The resolver connection structure according to claim 1, wherein at least one of the one terminal and the other terminal is inclined in a direction approaching each other. 6.   When the connector is electrically connected to the stator of the resolver using the resolver connection structure according to any one of claims 1 to 5, the rotor is fixed to the rotor when the rotor is rotated. A brushless motor configured such that a signal generated in the resolver is output through the connector in accordance with the rotational position of the resolver rotor.

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