JP5362284B2 - Small motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized motor with brushes, which has high reliability of electrical connection, without deforming inside terminals 21 to the extent of being equal to or more than the plastic deformation, and then, without reducing the contact reliability, even when outside terminals 24 are inserted in an obliquely inclined manner. <P>SOLUTION: In the small-sized motor having a synthetic resin-made bracket 10 which includes the brushes 13 which are slidably engaged with commutators and the inside terminals 21 electrically connected to these brushes 13, ribs 23 are molded integrally with the bracket 10 in the vicinity of positions in the elastically deforming direction of the inside terminals 21, and face the inside terminals 21, when the outside terminals 24 are inserted. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a small motor used in audio equipment, video equipment, automobile electrical equipment, and the like, and more particularly to a bracket structure of a small motor with a brush.

  Conventionally, small motors have been widely used in various devices, and small motors with brushes are used in automobiles as electrical components such as electric mirrors and door locks.

  FIG. 5 shows a conventional small motor (for example, see Patent Document 1). FIG. 6 shows the structure of the bracket of the motor shown in FIG.

  The structure of this conventional small motor will be described. An armature core 2 is caulked and fixed to the shaft 1, and a winding 4 is applied to the armature core 2 via an insulator 3. A commutator 5 is attached to the shaft 1. A bearing 8 is press-fitted and fixed to the frame 7, and a magnet 9 is inserted and simultaneously fixed by a magnet fixing spring 6 to constitute a frame assembly.

  A bearing plate 11 is press-fitted and fixed to the bracket 10, and a terminal plate 14 to which a brush leaf spring 12 is fixed is inserted and fixed. As a measure against overcurrent, an arm terminal 16 is disposed via a positive temperature coefficient thermistor 15 to assemble the bracket. It is composed.

  The positive temperature coefficient thermistor 15 is press-fitted between the positive temperature coefficient thermistor insertion wall 18 of the bracket 10, and the protrusion provided on the arm terminal 16 and a part of the electrode of the positive temperature coefficient thermistor 15 are electrically connected by the solder 20. doing. The positive temperature coefficient thermistor 15 is press-fitted and fixed in the recess 19.

  The brush assembly 17 includes a terminal plate 14, an arm terminal 16, a brush leaf spring 12, and a carbon brush 13. Then, a pair of external terminals 24 (see FIG. 7) is inserted from an external terminal insertion port (not shown) and is in electrical contact with the internal terminal 21.

JP 2004-254399 A

  However, in the conventional small motor, when the external terminal is inserted into the external terminal insertion port, the internal terminal 21 is likely to be deformed depending on the insertion angle of the external terminal, and the external terminal 24 is inclined as shown in FIG. When inserted, the internal terminal 21 is deformed more than plastic deformation. As a result, the spring pressure of the internal terminal 21 is reduced, and the motor characteristics are deteriorated due to interruption of power supply to the small motor or poor contact. There is a risk of doing.

  In view of the above points, the object of the present invention is to make electrical connection without lowering the contact reliability without causing the internal terminal to deform more than plastic deformation even when the external terminal is inserted obliquely. It is to provide a small motor with a brush having high reliability.

In order to achieve the above object, the present invention provides a case in which a magnet is fixed to an inner peripheral surface, a rotor comprising an armature core and a commutator around which a coil is wound, and the commutator and a sliding member. In a small motor comprising a brush to be joined and a synthetic resin bracket having an internal terminal electrically connected to the brush, the brush is attached to one end of an arm terminal made of an electrically conductive material having elasticity. A pair of brush assemblies having the internal terminal at the other end of the arm terminal is press-fitted and fixed to the bracket, and ribs are provided in the vicinity of the internal terminal in a direction in which the internal terminal is elastically deformed. When the external terminal is inserted in a first predetermined direction toward the internal terminal when the external terminal is inserted and connected to the internal terminal when formed integrally with the bracket, When the internal terminal is not in contact with the rib and the external terminal is inserted in the second predetermined direction different from the first predetermined direction toward the internal terminal, the internal terminal After being deformed by being pushed by the terminal, the rib contacts and stops and further deformation is prevented, and the rib has a shape in contact with the internal terminal in a plane .

  According to the present invention, in the small motor according to claim 1, the tip end portion of the internal terminal is divided into two, and the rib is formed in the vicinity of the internal terminal on the lower side.

  According to the present invention, in the small motor according to claim 1 or 2, a positive temperature coefficient thermistor for controlling current to the coil is sandwiched and electrically connected to at least one side of the brush assembly. And

  According to the present invention, even when the external terminal is inserted obliquely, the internal terminal is not deformed more than plastic deformation, the contact reliability is not lowered, and the reliability of electrical connection is high. A small motor with a brush can be provided.

  That is, according to the small motor of the present invention, since the rib is formed integrally with the bracket in the vicinity of the internal terminal, when the external terminal is tilted and inserted, the rib functions as a stopper. It prevents the elastic deformation of the terminal from being deformed more than plastic deformation. For this reason, as a result of the constant pressure contact between the internal terminal and the external terminal, it is possible to provide a small motor with high reliability of electrical connection between the internal terminal and the external terminal.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing the structure of an embodiment of a small motor according to the present invention. 2A and 2B are diagrams showing the structure of the bracket of the small motor shown in FIG. 1, wherein FIG. 2A is a side view of the bracket viewed from the external terminal insertion port side, and FIG. 2B shows the structure inside the bracket. FIG. FIG. 3 is a cross-sectional perspective view taken along line AA in FIG. 1, FIG. 2 and FIG. 3, the same parts as those of the conventional structure shown in FIG. 5 and FIG.

  The structure of the small motor 30 with a brush according to this embodiment will be described. The laminated armature core 2 is caulked and fixed to the shaft 1, and the winding 4 is wound around the armature core 2 via the insulator 3. Yes. A commutator 5 is attached to the shaft 1. A bearing 8 for supporting one end of the shaft 1 is press-fitted and fixed to a bottomed hollow cylindrical frame 7 made of a metal material, and a magnet 9 is fixed to the inner peripheral surface of the frame 7.

  A bearing 11 for supporting the other end of the shaft 1 is press-fitted and fixed to the bottom of a bracket 10 made of synthetic resin (for example, nylon resin), and further, a pair of terminal plate 14, arm terminal 16, A brush assembly 17 having a brush leaf spring 12, a carbon brush 13 and an internal terminal 21 is press-fitted and fixed to the bracket 10. The bearings 8 and 11 may be metal bearings or ball bearings.

  The arm terminal 16 is made of a conductive material having elasticity (for example, a copper alloy such as phosphor bronze for spring and beryllium copper), and a carbon brush 13 is fixed to one end thereof, and an internal terminal is attached to the other end. 21 is formed.

  The tip of the internal terminal 21 is bent into a substantially V shape, and the entire internal terminal 21 is formed in a substantially S shape. A positive temperature coefficient thermistor 15 for controlling the current to the winding 4 is press-fitted and fixed to one side of the pair of arm terminals 16, and the arm terminal 16 on which the positive temperature coefficient thermistor 15 is mounted is connected to the brush leaf spring 12. The arm terminal 16 and the internal terminal 21 are not formed integrally, but are divided in the middle of the arm terminal 16, and the positive temperature coefficient thermistor 15 is sandwiched between the divided portions. One end of the arm terminal 16 and one end of the arm terminal 16 are in contact with and electrically connected to the side surface of the positive temperature coefficient thermistor 15, respectively.

  Reference numeral 26 denotes an anti-vibration rubber for suppressing fluttering of the carbon brush 13 during rotation of the motor 30 and acts as an anti-vibration function of the carbon brush 13.

  The small motor 30 according to this embodiment is different from the conventional one in the structure of the bracket 10. In the bracket 10 of this embodiment, when the external terminal 24 is inserted from the external terminal insertion port 25, the internal terminal 21 is bent and elastically deformed by being pushed by the external terminal 24, and is in the vicinity of the internal terminal 21. The rib 23 is formed integrally with the bracket 10.

  As shown in FIG. 3, in the present embodiment, a slit 22 is formed at the intermediate portion of the tip portion of the internal terminal 21, and the tip portion of the internal terminal 21 is vertically divided into an upper internal terminal 21a and a lower internal terminal 21b. The rib 23 is formed in the vicinity of the lower internal terminal 21b. This is because the position of the external terminal insertion opening 25 is located at the lower internal terminal 21b portion, but it is long in the axial direction so that the rib 23 faces both the upper internal terminal 21a and the lower internal terminal 21b. Of course, it may be formed.

  The bracket 10 is attached by being fitted into the opening of the frame 7. Thus, power can be supplied from the external DC power source to the winding 4 wound around the armature core 2 via the internal terminal 21, the arm terminal 16, the carbon brush 13, and the commutator 5.

  FIG. 4 is a diagram showing an elastic deformation state of the internal terminal 21 when the external terminal 24 is inserted. FIG. 4 is a diagram showing a state in which the external terminal 24 is normally inserted from the external terminal insertion port 25 (a state in which the external terminal 24 is inserted into the external terminal insertion port 25 at a right angle).

  As shown in FIG. 4, when the external terminal 24 is inserted into the external terminal insertion opening 25, the internal terminal 21 is bent and elastically deformed by being pressed against the external terminal 24 by the thickness of the external terminal 24. In this embodiment, even in this case, the internal terminal 21 that has been bent and elastically deformed does not come into contact with the rib 23, and a predetermined gap (clearance) is formed between the internal terminal 21 and the rib 23. The shape of the rib 23 is set.

  Therefore, since the external terminal 24 is held by the spring pressure of the internal terminal 21, the internal terminal 21 is brought into constant pressure contact with the external terminal 24, so that electrical connection between the internal terminal 21 and the external terminal 24 is achieved. A small motor with high reliability can be provided.

  Further, when the external terminal 24 is inclined and inserted into the external terminal insertion port 25, the internal terminal 21 is bent and elastically deformed. However, the rib 23 functions as a stopper so that the internal terminal 21 is elastically deformed. It is possible to prevent deformation beyond plastic deformation. For this reason, according to the present embodiment, the predetermined spring pressure is maintained without lowering the spring pressure of the internal terminal 21, so that the internal terminal 21 is pressed into contact with the external terminal 24 as a result. A small motor with high reliability of electrical connection between the internal terminal 21 and the external terminal 24 can be provided.

  As shown in FIG. 4 and the like, the shape of the rib 23 facing the internal terminal 21 is a shape that comes into contact with the internal terminal 21 in a plane when the internal terminal 21 is bent and elastically deformed by being pressed by the external terminal 24. Is preferred.

  According to the present invention, a small motor that does not reduce the spring pressure of the internal terminal can be produced at low cost, and it is effective to provide a small motor that is inexpensive and highly reliable.

It is a figure which shows the structure of one Example of the small motor based on this invention. It is a figure which shows the structure of the bracket of the small motor shown in FIG. It is a cross-sectional perspective view in the AA location in FIG. In FIG. 1, it is a figure which shows the elastic deformation state of an internal terminal at the time of inserting an external terminal. It is the figure which showed the structure of the conventional small motor. It is the figure which showed the structure of the bracket of the motor shown in FIG. In the conventional small motor, it is the figure which showed the state in which the external terminal was inclined and inserted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft 2 Amateur core 3 Insulator 4 Winding 5 Commutator 6 Magnet fixed spring 7 Frame 8 Bearing 9 Magnet 10 Bracket 11 Bearing 12 Brush leaf spring 13 Carbon brush 14 Terminal plate 15 Positive temperature coefficient thermistor 16 Arm terminal 17 Brush assembly 19 Recessed part 21 Internal terminal 21a Upper internal terminal 21b Lower internal terminal 22 Slit 23 Rib 24 External terminal 25 External terminal insertion port 26 Anti-vibration rubber 30 Motor

Claims (3)

A case where a magnet is fixed to the inner peripheral surface;
A rotor composed of an amateur core and a commutator around which a coil is wound;
A synthetic resin bracket comprising a brush slidingly engaged with the commutator and an internal terminal electrically connected to the brush;
In a small motor consisting of
The brush is held at one end of an arm terminal made of a conductive material having elasticity, and a pair of brush assemblies provided with the internal terminal at the other end of the arm terminal is press-fitted and fixed to the bracket, and the internal terminal is elastic In a deforming direction, a rib is formed integrally with the bracket at a location near the internal terminal,
When the external terminal is inserted and connected to the internal terminal, when the external terminal is inserted in the first predetermined direction toward the internal terminal, the internal terminal does not contact the rib, When the external terminal is inserted in the second predetermined direction different from the first predetermined direction toward the internal terminal, the internal terminal is pushed by the external terminal and deformed to the rib. Stops in contact, prevents further deformation ,
The small motor according to claim 1, wherein the rib has a shape in contact with the internal terminal in a plane .   The small motor according to claim 1, wherein a tip end portion of the internal terminal is divided into two, and the rib is formed in a vicinity of the internal terminal facing the lower side.   3. The small motor according to claim 1, wherein a positive temperature coefficient thermistor for controlling current to the coil is sandwiched and electrically connected to at least one side of the brush assembly.

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