JPH07322570A - Miniature motor - Google Patents

Abstract

PURPOSE:To prevent the interference with other structural member by connecting a connecting member and the other input terminal with a brush through a pigtail wire and abutting the arm part of a torsional coil spring against the outer end of the brush so that the pigtail wire is twisted about the arm part. CONSTITUTION:An input terminal 8, a connecting member 16 and a brush holder 15 are fixed to a case cap 6 which is then inserted into a positive characteristic thermister 49. Consequently, the input terminal 8 touches the connecting member 16 at a raised tongue part 24 and a protrusion 22 on the fixed piece 21. When the positive characteristic thermister 49 is inserted between the input terminal 8 and the connecting member 16, the raised tongue part 24 and the protrusion 22 on the fixed piece 21 touch the surface. A pigtail wire 14 is then bonded, at the end part, to a terminal 18 at the connecting part 16 by soldering, for example, such that the pigtail wire 14 is twisted about the arm part 13a of a torsional coil spring 13. Since the length of the pigtail wire is minimized and undesired bulging is prevented, interference with other compositional members can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor used in, for example, household electric equipment, precision equipment, power tools, electric equipment for automobiles, etc. The present invention relates to a small motor capable of preventing interference with constituent members and stably moving a power feeding brush.

[0002]

2. Description of the Related Art FIG. 10 is a vertical sectional front view of an essential part showing an example of a conventional small motor. In FIG. 10, reference numeral 1 denotes a case, which is formed of a metal material such as soft iron into a hollow cylindrical shape with a bottom, and has an inner peripheral surface to which a permanent magnet 2 formed in an arc segment shape is fixed. A rotor 5 having an armature core 3 and a commutator 4 facing the permanent magnet 2 can be provided in the case 1. Next, 6 is a case cap, which is made of an insulating material such as a resin material, and is fitted into the opening of the case 1.

A brush 45 has, for example, a rectangular cross section, is formed in a hollow rectangular tube shape, and is slidably inserted in a brush holder 15 provided on the inner end surface of the case cap 6. Further, it is provided so as to be slidably engaged with the commutator 4.

Reference numeral 46 is a varistor, which is formed, for example, in a ring shape, is coaxially fixed between the armature core 3 and the commutator 4, and is electrically connected between the two to eliminate electrical noise. Have an effect.

Reference numeral 13 is a torsion coil spring, which is a brush 4
5 is for pressing the commutator 4 to the commutator 4. An input terminal 8 is fixed so as to penetrate the case cap 6, and is electrically connected to the brush 45 via the pigtail line 14 on the inner end side of the case cap 6. 9,
Reference numeral 10 denotes a bearing, which is fixed to the bottom portion of the case 1 and the central portion of the case cap 6, and which constitutes the rotor 11,
12 is rotatably supported.

With the above structure, the current is supplied from the input terminal 8 to the winding wound around the armature core 3 via the pigtail wire 14 and the brush 45, the commutator 4 forming the rotor 5. As a result, a rotational force is applied to the rotor 5 existing in the magnetic field formed by the permanent magnet 2 fixed to the inner peripheral surface of the case 1, so that the rotor 5 can be rotated and the output side shaft 11 An external device (not shown) can be driven via the.

In the small-sized motor having the above structure, as a means for connecting the input terminal 8 and the pigtail wire 14, the pigtail wire 1 whose one end is embedded and connected to the brush 45 is used.
There is also a means for directly connecting the other end of 4 to the input terminal 8 by soldering or the like, but there is a means for fixing the coupler terminal to the other end of the pigtail wire 14 and connecting it to the input terminal 8 via this coupler terminal ( See, for example, Japanese Utility Model Laid-Open No. 3-7655). There is also a means for locking the middle portion of the pigtail line 14 with the pigtail holder in order to prevent the brush 45 from protruding from the brush holder 15 when the pigtail line 14 and the input terminal 8 are connected (for example, a real one). See Kaihei 5-7656).

[0008]

In the conventional structure described above, when the length of the pigtail wire 14 is large, the intermediate portion of the pigtail wire 14 has the armature core 3
Therefore, the varistor 46 provided on the armature core 3 or between the armature core 3 and the commutator 4 is bulged to the side.
May increase the mechanical noise, and in extreme cases, the rotor 5 may be unable to rotate.

On the other hand, when the pigtail line is short, there is a problem that the sliding of the brush 45 in the brush holder 15 is hindered and the contact state between the brush 45 and the commutator 4 becomes unstable.

FIG. 11 is an enlarged explanatory view of the main part showing the vicinity of the brush holder 15, and the same parts are designated by the same reference numerals as those in FIG. In FIG. 11, the brush 45 is urged to the left by the torsion coil spring 13 to slide, but when the pigtail line 14 is short, the connecting portion 14a of the pigtail line 14 with the brush 45 is a chain line. It moves on an arc locus C ₁ centered on the connecting portion 14b with the input terminal 8 as shown. Therefore, there are problems that the sliding of the brush 45 in the brush holder 15 is obstructed and the life of the brush is abnormally shortened.

When the pigtail wire 14 and the input terminal 8 are connected by soldering, the solder flows to the pigtail wire 14 side, so that the hardened portion 14c is formed in the vicinity of the connection portion 14b. As a result, the pigtail wire 14 is formed. The movement locus of the connection portion 14a of the brush 14 with the brush 45 becomes an arc locus C _{2 of a} smaller radius, further aggravating the above problem.

In recent years, small motors require not only reduction of mechanical noise but also reduction of electrical noise. Therefore, as shown in FIG. 10, varistor 46 and other electrical noise canceling elements. Must be installed. Further, since the motor is required to be further downsized, the distance between the rotor 5 and the power feeding device including the brush 45 is becoming narrower. There is a demand for stable sliding means. Therefore, connecting or locking the pigtail line 14 by the means as described in the above publication is almost impossible in a narrow internal space, not only causes an increase in the number of parts, but also impedes downsizing on the contrary. There is a problem.

The present invention solves the problems existing in the above-mentioned prior art, prevents interference between the pigtail wire and the other components of the power feeding device, and allows the brush for power feeding to slide smoothly. It is intended to provide a small motor.

[0014]

In order to achieve the above object, first of all, in the first aspect of the present invention, there is provided a case formed of a metallic material in a hollow cylindrical shape having a bottom and a permanent magnet fixed to the inner peripheral surface thereof. A rotor having an armature core facing the permanent magnet and a commutator; and a case cap fitted in the opening of the case, and the case cap is slidably engaged with the commutator. A pair of brush holders for holding the brush, and a pair of input terminals electrically connected to the brush directly via a pigtail line or via another conductive member. In a small motor in which the rotor is rotatably supported via bearings provided on the bottom and the case cap, a connecting member made of a conductive material is provided on the inner end surface of the case cap, and one of the connecting member and the connecting member is provided. Connect the terminal directly or via another conductive member, connect this connecting member and the other terminal to the brush via a pigtail wire, and connect the arm portion of the torsion coil spring to the outer end of the brush. A technical means is adopted in which the brush is formed so as to be in contact with the commutator and the arm is provided so as to be entangled with the pigtail line.

Next, in the second aspect of the invention, a case formed of a metallic material in the shape of a hollow cylinder having a bottom and a permanent magnet fixed to the inner peripheral surface, an armature core facing the permanent magnet, and a commutator. A rotor provided with a case cap and a case cap fitted in the opening of the case. The case cap holds a brush slidably engaged with the commutator.
A pair of brush holders and a pair of input terminals electrically connected to the brush directly or via another conductive member are provided, and provided at the bottom of the case and the case cap. In a small motor in which the rotor is rotatably supported via a bearing, a pair of connecting members made of a conductive material are provided on the inner end surface of the case cap in an insulating manner, and one connecting member One input terminal is connected via another conductive member, the other connecting member is directly connected to the other input terminal, a capacitor is connected between the connecting members, and the connecting member and the brush are connected via a pigtail wire. The arm of the torsion coil spring is brought into contact with the outer end of the brush to urge the brush toward the commutator, and the pigtail wire is entangled with these arms. To be interposed, was adopted the technical means that.

In the above invention, the projection shapes of the pair of brush holders and the pair of connecting members with respect to the end surface of the case cap can be formed point-symmetrically with respect to the motor axis.

Next, in the above invention, the positive temperature coefficient thermistor can be sandwiched between one terminal of the connecting member and the input terminal. Further, according to a third aspect of the present invention, there is provided a case formed of a metallic material in the shape of a hollow cylinder having a bottom and having a permanent magnet fixed to the inner peripheral surface thereof, an armature core facing the permanent magnet, and a commutator. A pair of brush holders for holding a brush slidably engaged with the commutator, the pair of brush holders, and a brush and a pigtail. A small motor that is provided with a pair of input terminals that are directly connected to each other via a wire, and that rotatably supports the rotor through bearings provided on the bottom of the case and the case cap. The arm portion of the torsion coil spring is brought into contact with the outer end of the brush so as to urge the brush toward the commutator side, and the arm portion is interposed so as to entangle the pigtail wire. It adopted the means.

[0018]

[Function] With the above configuration, the length of the pigtail line is
The size of the brush can be set so that the brush can smoothly slide in the brush holder, and the middle portion of the pigtail line can be prevented from undesirably bulging. Also, the pigtail wire can move with the arm part of the torsion coil spring,
Abnormal application of external force to the brush can be avoided, and the brush can slide smoothly.

[0019]

1 and 3 are respectively an inner end view and an outer end view showing a case cap according to a first embodiment of the present invention,
2 is a sectional side view taken along the line AA in FIG. 1, and is indicated by the same reference numeral as in FIG. 1 to 3, the brush holder 15 has a substantially U-shaped end face made of a conductive material as will be described later, and is placed and fixed on the mounting portion 6a slightly protruding from the inner end face of the case cap 6. Piece 2
It is fixed to the case cap 6 through 0. The brush 45 is slidably held in the brush holder 15 in a groove 6b provided on the surface of the mounting portion 6a. The arm portion 13a of the torsion coil spring 13 is formed so as to contact the rear end portion of the brush 45 and urge the brush 45 toward the center. Four
Reference numeral 9 is a positive temperature coefficient thermistor, and 50 is a capacitor.

Next, reference numeral 16 denotes a connecting member, which is made of a conductive material and has a substantially U-shaped plane as will be described later. The inner end surface of the case cap 6 is insulated from the brush holder 15 via the fixing piece 21. Fixed to. The connection member 16 has a pair of terminals 17, 17 for connecting the capacitor 50 and a terminal 18 for connecting the pigtail line 14, respectively, to the case cap 6
It is integrally provided so as to project from the inner end face side of the.

The input terminal 8 is provided with a stopper portion (not shown), a cut-and-raised tongue portion 24, and a cut-and-raised tongue portion 52, which are fixed to the case cap 6 so as to penetrate the case cap 6, as will be described later. , One end is formed so as to project into the connecting member 41. The input terminals 8 and 8 are the connecting members 1
Each of the 6 is connected via an open end 16a and a positive temperature coefficient thermistor 49, and directly to the open end 16b.

Next, a capacitor 50 is connected between the terminals 17 of the connecting member 16 via a lead wire 60,
The pigtail wire 14 of the brush 45 is connected to the terminal 18. With the above configuration, power can be supplied to the connecting member 16 directly from the input terminal 8 or via the positive temperature coefficient thermistor 49, and further to the pair of brushes 45 via the pigtail line 14, and the pair of brushes 45, A capacitor 50 is connected in parallel between 45. Therefore, it is possible to prevent the small motor from overheating and prevent electrical noise.

FIG. 4 is an enlarged explanatory view showing the brush holder 15 in FIGS. 1 to 3, where (a) is a plane and (b) is a plan view.
Indicates the end face. In FIG. 4, the brush holder 15 is provided with an opening 15a for moving the pigtail line 14 shown in FIG. 1 and FIG. 20 is integrally projected.
The brush holder 15 thus formed is fixed by inserting the fixing piece 20 into the mounting hole 25 provided in the case cap 6 as shown in FIG. 3 and then bending the tip end thereof.

FIG. 5 shows the connecting member 1 shown in FIGS.
6A and 6B are enlarged explanatory views showing 6, and FIG.
(C) shows the B direction arrow view and C direction arrow view in (a), respectively. In FIG. 5, the connecting member 16 has a substantially U-shaped plan.
It is formed in a letter shape, and the open ends 16a and 16b are slightly extended outward. Since the positive characteristic thermistor 49 is provided on the open end 16a side as shown in FIGS. 1 and 2, the length dimension is formed to be slightly smaller than the other open end 16b.

At the edges of the open ends 16a and 16b, a pair of terminals 17 is bent upward to integrally project, and the terminals 1
Notch 17a is provided in 7. The terminal 18 is bent upward at the other edge of the open end 16b so as to integrally project.
The terminal 18 is provided with a punching bent portion 18a.

Next, reference numeral 21 is a fixing piece, which is integrally formed by bending downward at the substantially U-shaped intermediate portion and the end portions of the open ends 16a and 16b. The side surface of the fixed piece 21 has a protrusion 21 having a width slightly larger than the width of the mounting hole formed in the case cap 6 shown in FIGS.
a is provided. Reference numeral 22 denotes a protrusion, which is the open end 16a, 16
It is provided on the outer surface of the fixed piece 21 provided in b. Open end 16a
A part of the lower end portion of the fixed piece 21 provided in the above is bent outward to form the pressing piece 21b.

Next, FIG. 6 is an enlarged explanatory view showing the input terminal 8 in FIGS. 1 to 3, (a) showing a plane and (b) showing a side surface. In FIG. 6, reference numeral 23 denotes a stopper portion, which is a portion formed above the input terminal 8 (on the inner end surface side of the case cap 6) to have a width dimension larger than that of the intermediate portion, and as shown in FIG. This is for fixing the input terminal 8 to the case cap 6 by inserting it, positioning it, and bending the cut-and-raised tongue portion 52 at a right angle. Two
Reference numeral 4 denotes a cut-and-raised tongue portion, which is provided near the upper end portion of the input terminal 8. Reference numeral 26 is a slit groove for connecting, for example, a capacitor or other functional element.

The input terminal 8, the connecting member 16 and the brush holder 15 formed as described above are attached to the case cap 6 shown in FIGS. 1 to 3, and the positive temperature coefficient thermistor 49 is mounted.
The insertion of ensures the electrical connection between these members. That is, the input terminal 8 and the connecting member 16 are
The cut and raised tongue portion 24 and the protrusion 22 of the fixed piece 21 come into contact with each other.
When the PTC thermistor 49 is inserted between the input terminal 8 and the connecting member 16, the cut and raised tongue piece 24 and the projection 22 of the fixed piece 21 come into contact with the surface of the PTC thermistor 49. . In this case, the positive temperature coefficient thermistor 4 in FIG.
Even if an external force acts in the pull-out direction on 9, the cut-and-raised tongue piece portion 24 provided on the input terminal 8 acts so as to bite into the surface of the positive temperature coefficient thermistor 49, so that the retaining function can be increased. Further, since the pressing piece 21b provided on the fixed piece 21 of the connecting member 16 contacts the surface of the positive temperature coefficient thermistor 49,
The stability of the connection with the positive temperature coefficient thermistor 49 can be increased.

Next, the end of the pigtail wire 14 is fixed to the terminal 18 of the connecting member 16 by soldering or the like. In this case, as shown in FIGS. 1 and 2, the arm of the torsion coil spring 13 is formed. The pigtail wire 14 is inserted in the portion 13a so as to be entwined. That is, in FIG. 1, the pigtail line 14 is moved from the upper end of the brush 45 to the arm 1
The terminals 18 are entwined through the lower part of 3a. Therefore, it is desirable that the torsion coil spring 13 and the terminal 18 be provided on the inner end surface of the case cap 6 on the same side as the brush holder 15 and in the vicinity thereof.

With the above structure, the pigtail line 14 is formed with a margin, and an undesired bulging phenomenon is prevented. Further, even when the brush 45 moves in the brush holder 15, the pigtail line 14 and the arm portion 13a move or swing in cooperation with each other, so that abnormal tension is not applied to the pigtail line 14. Therefore, smooth sliding of the brush 45 in the brush holder 15 can be ensured.

FIG. 7 is an inner end view showing a case cap 6 according to a second embodiment of the present invention. The same parts are shown in FIG.
The same reference numerals are used. In FIG. 7, the connecting member 16
Is omitted, and one of the pigtail wires 14 is directly connected to one of the input terminals 8 and is the same as the above embodiment. Therefore, the sliding of the brush 45 in the brush holder 15 can be ensured smoothly, and the undesired swelling of the pigtail line 14 and the occurrence of abnormal tension can be prevented.

8 and 9 are inner end views showing the case cap 6 in the third and fourth embodiments of the present invention, respectively, and the same parts are designated by the same reference numerals as those in FIG. As shown in FIGS. 8 and 9, by arranging the input terminals 8 in axial symmetry or the like, both pigtail wires 14 can be input without using the connecting member 16 as shown in FIGS. 1 and 7. You may make it connect directly to the terminal 8.

In the present invention, the brush holder 15 may be provided with a terminal portion so as to project to connect the pigtail wire 14, and a choke coil may be connected between this terminal portion and the terminal 18 of the connecting member 16. Alternatively, the positive temperature coefficient thermistor 49 may be omitted and the input terminal 8 and the connecting member 16 may be directly connected. The control electric element can be selected and mounted.

[0034]

EFFECTS OF THE INVENTION Since the present invention has the structure and operation as described above, the following effects can be achieved.

(1) Since the pigtail wire for supplying electric power to the brush has the minimum required length and can prevent undesired bulging, it is possible to prevent interference with other constituent members.

(2) Since no abnormal tension or external force due to the pigtail line is applied to the brush, the brush slides smoothly and the brush and the commutator can be brought into stable contact with each other. Therefore, the motor characteristics can be stabilized and the life can be extended.

(3) Even if the distance between the rotor and the power feeding device is small, interference between the two can be prevented, so that the motor can be downsized. (4) Since the projected shape of the connecting member on the end surface of the case cap is formed point-symmetrically with respect to the motor axis, it is possible to reduce the number of component parts and reduce parts management cost and manufacturing cost. It can be reduced.

[Brief description of drawings]

FIG. 1 is an inner end view showing a case cap according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional side view taken along the line AA in FIG.

FIG. 3 is an outer end view showing the case cap according to the first embodiment of the present invention.

FIG. 4 is an enlarged explanatory view showing the brush holder 15 in FIGS. 1 to 3, (a) showing a plane and (b) showing an end face.

5A and 5B are enlarged explanatory views showing a connecting member 16 in FIGS. 1 to 3, and FIG. 5A is a plan view, and FIGS. 5B and 5C are B direction arrow views and C direction arrow views in FIG. 5A, respectively. Show.

FIG. 6 is an enlarged explanatory view showing an input terminal 8 in FIGS. 1 to 3, (a) showing a plane and (b) showing a side surface.

FIG. 7 is a case cap 6 according to a second embodiment of the present invention.
It is an inner end view which shows.

FIG. 8 is a case cap 6 according to a third embodiment of the present invention.
It is an inner end view which shows.

FIG. 9 is a case cap 6 according to a fourth embodiment of the present invention.
It is an inner end view which shows.

FIG. 10 is a vertical cross-sectional front view of essential parts showing an example of a conventional small motor.

FIG. 11 is an enlarged explanatory view of the essential parts showing the vicinity of the brush holder 15.

[Explanation of symbols]

 6 Case Cap 13 Torsion Coil Spring 13a Arm Part 14 Pigtail Line 15 Brush Holder 16 Connection Member

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[Procedure amendment]

[Submission date] February 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

In order to achieve the above object, first of all, in the first aspect of the present invention, there is provided a case formed of a metallic material in a hollow cylindrical shape having a bottom and a permanent magnet fixed to the inner peripheral surface thereof. A rotor having an armature core facing the permanent magnet and a commutator; and a case cap fitted in the opening of the case, and the case cap is slidably engaged with the commutator. And a pair of input terminals that are electrically connected to the brush directly via a pigtail line or via another conductive member, and a bottom portion of the case. In a small motor in which the rotor is rotatably supported by bearings provided on the case cap and the case cap, a connecting member made of a conductive material is provided on the inner end surface of the case cap, and one of the connecting member and the connecting member is provided. Together they are connected via a directly or other conductive member and a terminal, the connecting member and the other
Connect the input terminal and brush via the pigtail line,
A technique in which the arm portion of the torsion coil spring is brought into contact with the outer end portion of the brush so as to bias the brush toward the commutator side, and the arm portion is interposed so as to entangle the pigtail line. Adopted the automatic means.

Claims (5)

[Claims] 1. A case (1) which is made of a metal material in a hollow cylindrical shape with a bottom and has a permanent magnet (2) fixed to its inner peripheral surface, and an armature core (which faces the permanent magnet (2). 3) and a commutator (4), and a rotor (5), and a case cap (6) fitted into the opening of the case (1). A pair of brush holders (15) holding a brush (45) slidably engaged with the commutator (4), said brush (45)
And a pair of input terminals (8), (8) electrically connected to each other directly via a pigtail wire (14) or via another conductive member, and to the bottom of the case (1). Bearings (9), (1 provided on the case cap (6)
0) In a small motor in which the rotor (5) is rotatably supported via a connecting member (16) made of a conductive material on the inner end surface of the case cap (6), and the connecting member (16) is provided. And one input terminal (8) are connected directly or via another conductive member, and the connection member (16) and the other terminal and the brush (45) are connected via a pigtail line (14). Then, the arm portion (13a) of the torsion coil spring (13) is brought into contact with the outer end portion of the brush (45) and the brush (4
5) A small motor characterized in that 5) is formed so as to be urged toward the commutator (4) side, and that the pigtail line (14) is entangled in these arm parts (13a). 2. A case (1) which is made of a metallic material and has a bottomed hollow cylindrical shape and which has a permanent magnet (2) fixedly attached to its inner peripheral surface, and an armature core (which faces the permanent magnet (2). 3) and a commutator (4), and a rotor (5), and a case cap (6) fitted into the opening of the case (1). A pair of brush holders (15) holding a brush (45) slidably engaged with the commutator (4), said brush (45)
And a pair of input terminals (8), (8) electrically connected to each other directly via a pigtail wire (14) or via another conductive member, and to the bottom of the case (1). Bearings (9), (1 provided on the case cap (6)
0), the rotor (5) is rotatably supported by a small motor, and a pair of connecting members (16) made of a conductive material are insulated from each other on the inner end surface of the case cap (6). While being provided, one connection member (16) and one input terminal (8) are connected via another conductive member, and the other connection member (16) and the other input terminal (8) are directly connected. , Connection member (1
A capacitor (50) is connected between 6) and (16) to connect the connecting member (16) and the brush (45) to the pigtail wire (1).
4), and the arm portion (13a) of the torsion coil spring (13) is brought into contact with the outer end portion of the brush (45) to urge the brush (45) toward the commutator (4) side. A small motor, characterized in that it is formed in the same manner, and the pigtail line (14) is entangled in these arm portions (13a). 3. The projection shape of the pair of brush holders (15) and the pair of connecting members (16) with respect to the end face of the case cap (6) is formed symmetrically with respect to the motor axis. The small motor according to claim 2. 4. One fixing piece (2) of the connecting member (16).
1) and the input terminal (8) between the positive temperature coefficient thermistor (4
The small motor according to any one of claims 1 to 3, wherein 9) is sandwiched. 5. A case (1) formed of a metal material in a hollow cylindrical shape with a bottom and having a permanent magnet (2) fixed to the inner peripheral surface thereof, and an armature core (2) facing the permanent magnet (2). 3) and a commutator (4), and a rotor (5), and a case cap (6) fitted into the opening of the case (1). A pair of brush holders (15) holding a brush (45) slidably engaged with the commutator (4), said brush (45)
And a pair of input terminals (8), (8) directly connected to each other via a pigtail line (14), and a bearing (provided on the bottom of the case (1) and the case cap (6) ( In a small motor in which the rotor (5) is rotatably supported via 9) and (10), the arm portion (13a) of the torsion coil spring (13) is applied to the outer end portion of the brush (45). The brush (45) is formed so as to be in contact with the commutator (4) and is urged toward the commutator (4) side, and the pigtail line (14) is entwined with these arm portions (13a). A small motor that does.