JP3035467U - Small motor - Google Patents

Abstract

(57) [PROBLEMS] To provide a small motor in which constituent members can be shared without changing the design of constituent members even for electric noise canceling elements having different sizes. A motor case formed of a metal material in a hollow cylindrical shape with a bottom and having a permanent magnet fixed to the inner peripheral surface thereof,
A brush arm including a rotor including an armature facing the permanent magnet and a commutator, a brush fitted in an opening of the motor case and slidably engaged with the commutator, and the brush arm. A small motor comprising a case lid provided with an input terminal electrically connected to, a pair of brush arms facing each other in a direction orthogonal to a rotor axis, or between input terminals in the case lid. A groove communicating with each other is provided, and the electric noise canceling element and the compression coil spring are inserted into the groove, whereby the brush arms or the input terminals are electrically connected via the electric noise canceling element.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a small motor used for audio equipment, video equipment, automobile electrical equipment, and the like, and in particular, it can be miniaturized, the constituent members can be shared, and electrical noise can be reduced. The present invention relates to a small motor that can be reduced.

[0002]

[Prior art]

 FIG. 4 is a partial cross-sectional side view showing an example of a small motor which is the subject of the present invention. In FIG. 4, reference numeral 31 denotes a motor case, which is formed of a metal material such as soft iron into a hollow cylindrical shape with a bottom and has an arc segment-shaped permanent magnet 32 fixed to the inner peripheral surface thereof. Reference numeral 33 denotes a case lid, which is formed of, for example, a thermoplastic resin material so as to be fitted into the opening of the motor case 31. Next, 34 is a rotor, which is composed of an armature 35 facing the permanent magnet 32 and a commutator 36, and is rotatably supported by bearings 37 and 38 provided on the motor case 31 and the case lid 33, respectively. It is being touched.

Reference numeral 39 denotes a brush arm, which is provided in the case lid 33, and is provided with a brush 40 formed of a conductive material in a plate shape and slidably engaged with the commutator 36. An input terminal 41, which is electrically connected to the brush arm 39, is provided in the case lid 33, and is connected to the armature 35 from the external DC power source via the brush arm 39, the brush 40, and the commutator 36. Power can be supplied.

With the above configuration, when current is supplied to the armature 35, a rotational force is applied to the armature 35 existing in the magnetic field formed by the permanent magnet 32 fixed to the inner peripheral surface of the motor case 31. Since the rotor 34 is provided, the rotor 34 can be rotated and various devices connected to the rotor 34 can be driven.

As a means for reducing electric noise in the small motor as described above, for example, as shown in FIG. 5, a motor case 31 and one input terminal 41 are formed in a flat plate shape from a conductive material. There is a configuration in which the ground terminal 42 is used for connection. Also, as shown in FIG. 6, there is also a configuration in which a capacitor 44 is connected between a pair of input terminals 41, 41 via a lead wire 43.

In the configuration shown in FIG. 5 and FIG. 6, the components for reducing electrical noise, such as the ground terminal 42 and the capacitor 44, are attached to the outside of the small motor. It is necessary to secure an extra space inside the equipment or device that uses a small motor as a drive source. Further, since the shape and the mounting position of the component for reducing the electric noise are not fixed, there is a problem that it is necessary to provide more space than necessary.

Further, since there is no commonality among the constituent members for reducing the electric noise, the jigs and tools for the mounting work and the worker in charge are separate when a plurality of kinds of constituent members are required. However, there is a problem that production efficiency is reduced.

The structure shown in FIG. 6 has a drawback that the work of connecting the lead wire 43 of the capacitor 44 to the input terminal 41 is extremely complicated. That is, since the mounting portion of the capacitor 44 is an extremely narrow space, it requires skill to perform the soldering work, the lead wire 43 leading and cutting work, and the like, which are inevitably involved in the connection work, and the time and man-hours increase, which results in cost reduction. There is a problem that it becomes high. In addition, since soldering is performed in the narrow space, the connection state is likely to be unstable, and the resistance to vibration or shock during use is insufficient, and the reliability of electrical connection tends to be insufficient. Points also exist.

In order to solve the above problems, the present applicant has already applied for the structure shown in FIGS. 7 and 8 (Japanese Patent Application No. 5-672). FIG. 7 is an inner end view showing a case lid according to an embodiment of the improved device, and FIG. 8 is a sectional view taken along the line AA in FIG. 7, and the same portions are designated by the same reference numerals as those in FIGS. 4 to 6. Show. In FIGS. 7 and 8, reference numeral 1 denotes a groove, which is provided on the case cover 33 on the input terminal 41 side. That is, the concave groove 1 includes a plane parallel to the motor axis and is formed in a flat shape so as to open to the motor case (not shown) side. The side surfaces of the groove 1 are made to face the side surfaces of the pair of input terminals 41, 41.

Reference numeral 2 denotes a spring, which is made of a conductive material such as copper or copper alloy so as to have a substantially U-shaped projection on a plane and is inserted in the groove 1. Reference numeral 3 denotes a chip laminated type capacitor, which is formed, for example, in the shape of a thin rectangular parallelepiped and is inserted in the concave groove 1. With this configuration, the elastic force of the spring 2 holds the capacitor 3 together with the spring 2 between the pair of input terminals 41, 41 to form a circuit for reducing electrical noise. It is preferable to project the projection 4 on the inner surface of the input terminal 41 in order to secure the electrical connection with the spring 2 and the capacitor 3.

In addition to the above, the present applicant has also applied for a configuration shown in FIGS. 9 to 11 (Japanese Patent Application No. 6-52356). FIG. 9 is an inner end view showing a case lid in the embodiment of the improved device, and FIGS. 10 and 11 are a sectional view taken along the line BB and an enlarged view taken along the line CC in FIG. 4 to 8 are designated by the same reference numerals. 9 to 11, the ground terminal 5 is formed of a band material or hoop material made of the above-described conductive material, and has a substantially U-shaped locking portion 11 in the middle portion, and this locking portion. One of 11 is extended and divided into two forks, and a spring portion 12 formed into a substantially W-shaped projection on a plane and a sandwiching portion 13 formed at a free end of the spring portion 12 are formed. And are configured as one.

The locking portion 11 and the spring portion 12 are each elastically deformable. Next, the case lid 33 is provided with a groove 6 having a width dimension corresponding to the width dimension of the locking portion 11 of the ground terminal 5 and a fitting portion 7 into which the locking portion 11 can be fitted.

With the above configuration, when the ground terminal 5 is fitted to the fitting portion 7 of the case lid 33 via the locking portion 11 and is press-fitted along the groove 6, it is provided on one of the sandwiching portions 13. The keyhole-shaped groove 14 comes into contact with one of the input terminals 41 and the spring portion 12 is elastically deformed, so that the ground terminal 5 is pushed to the innermost portion of the case lid 33. In this case, even if the spring portion 12 is elastically deformed, since the edge portion of the locking portion 11 is held by the groove 6, a load imbalance occurs in which only one of the input terminals 41 is pressed and sandwiched. However, the contact state with the input terminal 41 can be completely maintained without the ground terminal 1 becoming unstable.

After the ground terminal 5 is press-fitted into the case lid 33 and the case lid 33 is fitted into the motor case 31 as shown in FIG. 4, the locking portion 11 comes into contact with the motor case 31 and electrical connection is established. Reserved. In this case, in order to ensure the electrical connection between the ground terminal 5 and the motor case 31, a protrusion 16 may be provided on the contact surface of the locking portion 11 with the motor case 31, for example, by cutting and raising means. preferable.

Reference numeral 15 is a capacitor, which is formed of, for example, a chip laminated ceramic. That is, one input terminal 41 is pressed and sandwiched by the one sandwiching portion 13 of the ground terminal 5, and the capacitor 15 is connected between the other sandwiching portion 13 of the ground terminal 5 and the other input terminal 41. It is configured to be pressed and sandwiched.

In this case, the elasticity of the spring portion 12 of the ground terminal 5 exerts a pressing force on the capacitor 15 in the axial direction of the case lid 33 and in the direction perpendicular to the axial line. It is securely held between and the electrical connection is secured. With the above configuration, two measures against electrical noise are implemented, one of which is the ground connection of the input terminal 41 of the small motor and the other is the interposition of the capacitor 15 between the input terminals 41 and 41, which is expected to improve the motor performance. You can do it.

[0017]

[Problems to be solved by the device]

 However, the spring 2 for pressing and holding the capacitors 3 and 15 and the spring portion 12 of the ground terminal 5 in the above-mentioned improved device are basically U-shaped springs. Since this U-shaped spring utilizes the bending characteristics of the constituent materials, the elastic deformation range is narrower than that of coil springs that utilize torsional characteristics. Therefore, the size of the capacitor that can be handled by one type of U-shaped spring is limited, so it is not versatile, and it is easy to make a dedicated design for each specific capacitor, and it is necessary to prepare many types of U-shaped springs. There is.

Further, as is clear from the shapes of the spring 2 in FIG. 8 and the flange portion 12 of the ground terminal 5 in FIG. 10, the U-shaped spring has a comparatively large area occupied by a projected shape on a plane. Therefore, it is also a cause of hindering miniaturization. In order to further increase the elastic deformation range, it is necessary to make the U-shape larger, which not only increases the above-mentioned occupied area, but in some cases, the U-shaped spring is placed in the narrow case lid 33. However, there is a problem that the required area for housing can not be secured.

Depending on the specifications of the small motor, even if the case lid 33 has the same size, it is necessary to incorporate the capacitors 3 and 15 having different sizes. In such a case, one kind of U-shaped spring cannot cope. There is a problem that the design of the case lid 33 needs to be changed according to the shape of the U-shaped spring.

The present invention solves the above-mentioned problems existing in the prior art, and it is not necessary to change the design of the components even for electrical noise canceling elements having different sizes, and the components can be used in common. An object is to provide a motor.

[0021]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, a motor case formed of a metallic material in the shape of a hollow cylinder with a bottom and having a permanent magnet fixed to the inner peripheral surface thereof, and an armature facing the permanent magnet. And a commutator, a brush arm having a brush fitted in the opening of the motor case and slidably engaged with the commutator, and electrically connected to the brush arm. A small motor comprising a case lid provided with an input terminal, wherein the rotor is rotatably supported via a bearing provided on the bottom of the motor case and the case lid. , A groove communicating between a pair of brush arms facing each other in the direction orthogonal to the rotor axis or between the input terminals is provided, and the electric noise canceling element and the compression coil spring are inserted into the groove. The bra Electrically connected via the electrical noise cancellation device between the arms or between the input terminals, employing the technical means of.

In the present invention, the groove into which the electric noise canceling element and the compression coil spring are inserted may be directly provided in the case lid, or may be incorporated in the case lid to be integrated with the case lid. It may be provided in the brush holder. Further, the input terminal is not limited to the one protruding outward from the case lid, but may be in the form of an internal terminal provided inside the case lid into which the external power supply terminal is inserted.

[0023]

[Embodiment of the invention]

 1 is a partial cross-sectional side view showing an embodiment of the present invention, and FIG. 2 is a partial cross-sectional inner end view showing a case lid in FIG. 1, and the same parts are the same as those in FIGS. It shows with a code. In FIG. 1 and FIG. 2, the brush arm 39 is made of a conductive elastic material such as copper or a copper alloy, and is formed into a substantially U-shape as a whole. Is formed into a substantially flat connecting portion 30 along the inner end surface of the case lid 33, and its free end is exposed to the vicinity of the internal terminal 17, and is inserted into the case lid 33 via the brush holder 18. To do.

Next, the internal terminal 17 is formed of a conductive elastic material similar to that of the brush arm 39, and the extending portion into the case lid 33 is a connecting portion 19 formed in a substantially V shape. Reference numeral 20 denotes a locking groove, which is provided near the portion of the case lid 33 into which the external power supply terminal 21 is inserted, in a direction along the end surface of the case lid 33. For example, the width dimension is slightly larger than the width dimension of the internal terminal 17. And a depth dimension corresponding to the thickness dimension of the internal terminal 17. Reference numeral 22 denotes a protrusion, for example, two protrusions are provided on the side of the connecting portion 19 that contacts the brush arm 39.

A groove 23 communicating with a pair of brush arms 39, 39 is provided in the brush holder 18, and an electric noise canceling element 24 such as a chip type varistor / capacitor or a surge absorber is provided in the groove 23. And the compression coil spring 25 are linearly or vertically inserted and housed to electrically connect between the pair of brush arms 39, 39. The brush holder 18 is integrally assembled in the case lid 33 by holder pins 26 provided on the case lid 33.

With the above configuration, the connection portion 19 of the left internal terminal 17 in FIG. 2 is connected to the engagement groove 20 and the engagement portion 27 provided on the case lid 33, and the connection portion 30 of the brush arm 39. In between, it is interposed in an elastically deformed state. Therefore, since the connecting portion 19 pushes the connecting portion 30 of the brush arm 39 outward by the elastic force, the electrical connection between the internal terminal 17 and the brush arm 39 can be secured. By providing the projection 22 on the connecting portion 19, the electrical connection can be made more reliable.

Next, 28 is a positive temperature coefficient thermistor, which is formed in a plate shape, and is sandwiched and held between the connecting portion 19 of the internal terminal 17 and the connecting portion 30 of the brush arm 39 on the right side in FIG. To be done. In this case, it is preferable to provide the projection 29 on the side of the connecting portion 30 of the brush arm 39 that comes into contact with the positive temperature coefficient thermistor 28 in order to make the electrical connection more reliable.

Since the vicinity of the end of the internal terminal 17 which faces the external power supply terminal 21 is fitted into the locking groove 20 provided in the case lid 33, for example, the insertion or insertion of the external power supply terminal 21 may be performed. Even when a force in a direction orthogonal to the end surface of the case lid 33 is applied at the time of removal, the internal terminal 17 does not move and the restrained state is maintained.

FIG. 3 is an inner end view showing a case lid according to another embodiment of the present invention, and the same parts are designated by the same reference numerals as those in FIG. The one shown in FIG. 3 is one in which the groove 23 is directly provided in the case lid 33, and the other structure is the same as that shown in FIG. Therefore, the action is also the same.

In the embodiment of the invention described above, an example in which the electric noise canceling element 24 and the compression coil spring 25 are inserted between the pair of brush arms 39, 39 has been described, but the invention is not limited to this. However, in the case where the motor cover 33 is provided with the input terminal 41 protruding to the outside as shown in FIGS. 7 to 10, the electrical noise canceling element 24 and the compression coil spring 25 are provided between the pair of input terminals 41, 41. It is also possible to insert and. Depending on the specifications of the small motor, as shown in FIG. 12, the positive temperature coefficient thermistor 28 in FIGS. 2 and 3 may be omitted.

[0031]

[Effect of the invention]

 Since the present invention has the configuration and operation as described above, the following effects can be obtained.

(1) Compared with the conventional U-shaped spring, the length of the groove for housing the spring and the dimension of the depth can be reduced, which saves space and downsizes the whole. be able to.

(2) Since the compression coil spring has a wide elastic deformation range, the same motor lid can be used for electric noise canceling elements having different dimensions, and no design change is required, resulting in a low production cost. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing an embodiment of the present invention.

2 is a partial cross-sectional inner end view showing the case lid in FIG. 1. FIG.

FIG. 3 is an inner end view showing a case lid according to another embodiment of the present invention.

FIG. 4 is a partial cross-sectional side view showing an example of a small motor to which the present invention is applied.

FIG. 5 is a plan view showing an example of an electric noise reduction unit in a conventional small motor.

FIG. 6 is a plan view showing another example of the electric noise reduction means in the conventional small motor.

FIG. 7 is an inner end view showing the case lid in the embodiment of the improved device.

FIG. 8 is a sectional view taken along line AA in FIG. 7;

FIG. 9 is an inner end view showing a case lid according to another embodiment of the invention.

FIG. 10 is a sectional view taken along line BB in FIG. 9;

11 is an enlarged cross-sectional view taken along line CC in FIG.

FIG. 12 is an inner end view showing a case lid according to still another embodiment of the present invention.

[Explanation of symbols]

 23 groove 24 electric noise canceling element 25 compression coil spring 31 motor case 33 case lid 39 brush arm

Claims (1)

[Utility model registration claims] 1. A motor case (31) formed of a metallic material in a hollow cylindrical shape with a bottom and having a permanent magnet (32) fixed to the inner peripheral surface thereof, and an armature (32) facing the permanent magnet (32). Rotor (34) consisting of 35) and commutator (36)
A brush arm (39) fitted with an opening of the motor case (31) and provided with a brush (40) slidably engaged with the commutator (36), and the brush arm (39). Bearings (37), (38), which include a case lid (33) provided with an electrically connected input terminal, and which are provided on the bottom of the motor case (31) and the case lid (33). A small motor in which the rotor (34) is rotatably supported via a pair of brush arms (39), (39) facing each other in the direction orthogonal to the rotor axis in the case lid (33). ) Or between the input terminals is provided with a groove (23).
3) By inserting the electric noise canceling element (24) and the compression coil spring (25) into the brush arm (39), (39) or between the input terminals via the electric noise canceling element (24). A small motor characterized by being electrically connected to the motor.