JP4353775B2 - Power supply device for small motor - Google Patents

Description

  The present invention is a small motor for supplying power to a motor by inserting an external power supply terminal provided outside the small motor into the motor body, and is a small motor having a contact portion that is integrated with a brush and that contacts the external power supply terminal. The present invention relates to a power supply apparatus.

Various types of power supply devices have been patented so far for the motor power supply device that forms an elastic terminal inside the motor body and inserts the external power supply terminal from the outside to bring the external power supply terminal into contact with the terminal to supply power to the motor. It has been filed as a utility model.
For example, Japanese Utility Model Publication No. 18266666 discloses a configuration in which a terminal that contacts an external power supply terminal and a brush that is integrally attached to the terminal are attached to the bracket.
Japanese Utility Model Publication No. 122,558 discloses a configuration in which a brush is elastically contacted and connected to a terminal that contacts an external power feeding terminal and an end portion of the terminal.
Utility model publication No. 182666 in 1988 Utility model publication No. 122,558

In a configuration in which power is supplied by inserting such an external power supply terminal into the motor body, the contact portion of the terminal that comes into contact with the external power supply terminal is inside the motor, and a process for soldering or crimping the contact portion is performed later. Cannot be added. For this reason, the contact between the external power supply terminal and the power supply apparatus must be ensured, but it is difficult to maintain a reliable and stable contact because the component parts are small.
It is an object of the present invention to provide a power supply device that is in a small motor and can reliably and stably maintain a contact state with an external power supply terminal.

A power supply device for a small motor according to the present invention is a small motor including a cylindrical case in which a rotor is accommodated and a bracket attached to an opening end thereof, and is provided on the bracket. In a power supply device for a small motor that is fed with an external power supply terminal inserted into an insertion port, the brush device includes a sliding portion that is in sliding contact with the rotor and a connection portion that is connected to the external power supply terminal. The connecting portion is configured by a fixed piece fixed to the bracket and a contact piece that comes into contact with the external power supply terminal, and the contact piece has a predetermined width in the direction of the rotation axis of the motor. A first contact piece having a first width and a second width smaller than the first contact piece are formed by a plurality of slits formed in a circumferential direction from an end side of the contact piece, and formed by a cylindrical surface. Wherein the contact piece is formed.
Since the first contact piece has relatively high rigidity, the external power supply terminal and the motor body are in contact with each other while being fixed, and the second contact piece is more flexible than the first contact piece, so that the external power supply terminal is elastically elastic. Contact with.
Further, by projecting the end of the second contact piece from the end side of the first contact piece as described in claim 2, the second contact piece can be made without relatively affecting the insertion force of the external power supply terminal. Contact can be made more reliably.

According to the present invention, when the external power supply terminal is inserted from the insertion port of the bracket and comes into contact with the contact piece, it contacts the contact portions formed in different widths, and the contact state according to each width is brought about. A reliable contact state with the power supply terminal can be maintained.
For example, since the contact pressure is strong in the wide contact part, the external power supply terminal is securely held by the motor due to its strength, and in the narrow contact part, the dimensions of the external power supply terminal and the contact piece are due to its flexibility. Even if variations occur, reliable contact is possible.

In the small motor M, a casing is formed by a case 1 and a bracket 2 in which a rotor (not shown) is accommodated, and a brush device 3 is attached to the bracket 2 to form a power feeding device.
In the brush device 3, the sliding portion 5 in which the carbon brush 53 is attached to the end portion of the leaf spring material 51 and the connecting portion 4 in which the contact piece 41 with which the external power supply terminal P contacts are formed integrally. 2 is fixed. The contact piece 41 is formed in a cylindrical surface at a contact portion with the external power supply terminal P, and is divided into a plurality of contact pieces 41a and 41b by a radial slit.
Since the contact piece 41a as the first contact piece formed with a wide width contacts the external power supply terminal P with a strong force when the external power supply terminal P is inserted, it has a function of fixing the motor M and the external power supply terminal P. Further, since the contact piece 41b as the second contact piece formed with a narrow width is more flexible than the contact piece 41a, the contact piece 41b is in contact with the external feed terminal P in response to variations in thickness or deformation of the external feed terminal P. can do.
That is, the contact piece 41 is divided so as to have different widths, and when the external power supply terminal P comes into contact with the contact piece 41, it comes into contact with the function of each width.
FIG. 1 shows a brush device that constitutes a power feeding device of the present invention. FIG. 1 (a) is a side view thereof, and FIG. 1 (b) is a plan view of a connecting portion viewed from the direction of arrow B in FIG.
FIG. 2 shows a configuration of a power feeding device in which the brush device shown in FIG. 1 is fixed to a bracket.
FIG. 3 shows a small motor using the power feeding device of the present invention.
FIG. 4 shows another embodiment of the contact piece of the brush device. FIG. 4 (a) is a side view thereof, and FIG. 4 (b) is a plan view of the connecting portion viewed from the direction of arrow B in FIG.

The power supply apparatus of the present invention will be described with reference to FIGS.
In the small motor M, a rotor (not shown) having a rotating shaft 11 is accommodated in a cylindrical case 1 whose one end is closed. The rotor is housed in the case 1 so that one end of the rotating shaft 11 is rotatably supported by a bearing provided in the case 1 and the other end is rotatably supported by a bearing 22 provided in the bracket 2. A commutator (not shown) is formed on the bracket side of the rotor, and a carbon brush 53 described later contacts.
The outer surface of the bracket 2 is provided with as many insertion ports 2a as the number of the external power supply terminals P into which the external power supply terminals P for supplying power to the motor M are inserted. The external power supply terminal P is a plate-shaped power supply terminal as shown in the figure, and is two in the case of a DC motor.
The bracket 2 is formed by plastic resin molding and is attached to the opening end of the case 1. A bearing 22 is attached to the inner center of the bracket 2 by a plurality of ribs 23 to rotatably support one end of the rotating shaft.
These configurations are general and will not be described in detail.

A pair of brush devices 3 are attached to the inside of the bracket 2. Since the brush device 3 has a symmetrical shape with respect to the center line including the rotation shaft 11, the configuration of one of the brush devices 3 (left side in FIG. 2) will be described. The brush device 3 on the right side of FIG. 2 shows a state where the external power feeding terminal P is inserted and the contact piece 41 is bent.
The brush device 3 includes a sliding portion 5 made of a leaf spring material 51 to which a carbon brush 53 is attached, and a connecting portion 4 in which a contact piece 41 with which an external power supply terminal P contacts is formed. The leaf spring material 51 is formed by a spring portion 51a for elastically pressing the brush 53 to the commutator piece of the rotor R, and an attachment portion 52 that is bent substantially at right angles to the spring portion 51a and fixed to the connection portion 4. Has been. The leaf spring material 51 is a thin plate of a spring material such as beryllium steel, phosphor bronze, or white, and the brush 53 is in stable contact with the commutator piece.

In the connecting portion 4, a contact piece 41 is formed from a flat fixed portion 42 through a base portion 44 that is parallel to the rotating shaft 11 and bent at a substantially right angle. The contact piece 41 is formed by a part of one cylindrical surface centering on an axis parallel to the rotation shaft 11, and is formed outside the fixed portion 42 with a bend parallel to the base portion 44. As long as the contact piece 41 has a cylindrical shape in the vicinity of the portion in contact with the external power supply terminal P and its vicinity, the other portion may be a flat surface.
An attachment portion 52 of the leaf spring material 51 is in contact with and fixed to the fixing portion 42. The fixing method is performed by a method of electrical conduction such as welding or caulking.
The connecting portion 4 is formed of a spring plate material such as a brass plate material, phosphor bronze, or white and white, but is required to have higher rigidity than the spring portion 51a. In this embodiment, a brass plate material having a thickness of 0.3 mm is used.
When the leaf spring material 51 and the connection portion 4 are integrally formed of the same material, the rigidity may be lowered by making the shape of the spring portion 51a thinner or longer.

The brush device 3 is attached to the bracket 2 by fixing the fixing portion 42 inside the bracket 2.
The bracket 2 has a first convex portion 25a and a second convex portion 26a raised from the bottom surface 2b to the inside, and the fixing portion 42 to which the mounting portion 52 is attached is connected to the first convex portion 25a and the second convex portion 26a. The brush device 3 is fixed to the bracket 2 with the gap therebetween.
The first convex portion 25a is formed at a position where the outer end portion 25b supports up to the base portion 42, and the second convex portion 26a is sandwiched between the base portion 42 and the spring portion 51a, and thus is formed slightly smaller than the first convex portion 25a. . The attachment position of the brush device 3 is a position where the top 41e is bent inward by a predetermined amount when the external power supply terminal P is inserted from the insertion port 2a.

The contact piece 41 is formed by a part of a cylindrical surface with an axis parallel to the rotation shaft 11 as a center. The outer shape is formed in a substantially rectangular shape with the side 41c being substantially parallel to the axis. The contact piece 41 is divided into a plurality of contact pieces by a circumferential cutout groove 41d formed on the cylindrical surface. In the embodiment shown in FIG. 1, two contact pieces 41a are formed by two notch grooves 41d with the contact piece 41b interposed therebetween.
The notched groove 41d is opened end side 41c side also forms to the base 4 4 near past the top 41e to ensure the deflection. But bending the groove end 41g to avoid the influence of machining so as not reach to the base 4 4.
The contact piece 41a is formed wider than the contact piece 41b. In this embodiment, the width of the contact piece 41a is 2 mm, whereas the width of the contact piece 41b is 0.5 mm, and the ratio is four to one. The difference in width is preferably about 2 to 1 to 5 to 1 for the reason described later.

According to this contact piece 41a, since the width of the contact piece 41a is relatively wide, when the external power feeding terminal P is inserted, the holding strength with respect to the motor M is mainly secured by the contact piece 41a. Here, the operation will be described with reference to FIGS.
When the external power supply terminal P is inserted into the motor M, the external power supply terminal P contacts the vicinity of the top portion 41e of the contact piece 41, and when further inserted, the contact piece 41 is bent while pushing the top portion 41e toward the rotating shaft 11. At that time, the external power supply terminal P is supported from the outside by the external power supply terminal support wall 27 raised from the bottom surface 2 b of the bracket 2.
When the insertion of the external power supply terminal P is completed, the contact piece 41 is bent by the maximum amount.

Since the contact piece 41b is separated from the contact piece 41a by the notch groove 41d, the deflection is different, and the contact piece 41b can be in contact with the external power supply terminal P by a different deflection.
That is, the contact pieces 41a independently hold the external power supply terminal P with respect to the motor M while ensuring the electrical connection between the external power supply terminal P and the brush device 3, and the contact pieces 41b are in contact with the external power supply terminal P with different elasticity. . Since the contact piece 41b has a small change in pressure in contact with the external power supply terminal P with respect to the bending amount, reliable conduction is ensured.
Normally, the end 41c is formed in parallel with the rotating shaft 11. However, even when the end 41c is twisted with respect to the rotating shaft 11 due to variations in parts, for example, the contact piece 41 is formed by the notch groove 41d. Since they are separated, they can contact the external power supply terminals P, respectively.
In this embodiment, since the narrow contact piece 41b is arranged at the center of the contact piece 41, a good contact state can be maintained even when the insertion position of the external power supply terminal P varies in the rotation axis direction. .
Further, in FIG. 1, the narrow contact piece 41b is arranged at the center, but the center contact piece can be widened and the width of the contact pieces on both sides can be reduced. In the case where the insertion position of the external power supply terminal does not vary relatively, the same effect can be obtained with this configuration.

FIG. 4 is a diagram showing a brush device 3A according to another embodiment of the connecting portion. Components having the same configuration as in the first embodiment and having the same function are denoted by the same reference numerals and description thereof is omitted.
In the contact piece 46, two contact pieces 46b are formed by the two notched grooves 46d with the contact piece 46a interposed therebetween. Similar to the first embodiment, the contact piece 46b is narrower than the contact piece 46a at a ratio of about 2: 1 to 5: 1.
The contact piece 46b has a shape in which the tip 46c protrudes from the end side 41c. When the external power supply terminal P is inserted, the tip 46c comes into contact with the support surface 28a of the contact piece support wall 28 and bends in that state. As a result, the number of places to be supported increases as compared to the connection piece 46a, so that the load increases even with the same amount of deflection.
However, since the contact piece 46b is less elastic than the contact piece 46a, the insertion force of the external power supply terminal P is relatively unaffected even if the tip 46c is supported. Further, since the change in the contact pressure to the external power supply terminal P with respect to the amount of bending is relatively small, the external power supply terminal P can be contacted stably.

FIG. 1 shows a brush device that constitutes a power feeding device of the present invention. FIG. 1 (a) is a side view thereof, and FIG. 1 (b) is a plan view of a connecting portion viewed from the direction of arrow B in FIG. FIG. 2 shows a configuration of a power feeding device in which the brush device shown in FIG. 1 is fixed to a bracket. FIG. 3 shows a small motor using the power feeding device of the present invention. FIG. 4 shows another embodiment of the contact piece of the brush device. FIG. 4 (a) is a side view thereof, and FIG. 4 (b) is a plan view of the connecting portion viewed from the direction of arrow B in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Bracket 2a Insert 3 Brush apparatus 4 Connection part 41, 41a, 41b Contact piece 41d Notch groove

Claims (2)

  In a power supply device for a small motor, which is a small motor composed of a cylindrical case in which a rotor is accommodated and a bracket attached to an opening end of the rotor, and an external power supply terminal is inserted into an insertion port provided in the bracket The bracket is provided with a brush device that includes a sliding portion that is in sliding contact with the rotor and a connection portion that is connected to the external power supply terminal, and the connection portion is in contact with a fixed portion that is fixed to the bracket and the external power supply terminal. The contact piece is formed of a cylindrical surface having a predetermined width in the direction of the rotation axis of the motor, and is formed in the circumferential direction from the end of the contact piece. A power supply device for a small motor, wherein a plurality of slits form a first contact piece having a first width and a second contact piece having a second width smaller than the first contact piece.   The power supply device for a small motor according to claim 1, wherein an end portion of the second contact piece protrudes from an end side of the first contact piece.

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