JPH1032970A - Micro motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and the manufacturing cost by providing a function for mounting a motor to another structure in addition to a function for ensuring the mechanical strength of an entire motor by housing each component in the motor body of a micro motor. SOLUTION: A motor body 44 of a micro motor (a stepping motor at this embodiment) with a shaft (rotary shaft) 20 comprises a cylindrical part 70 for maintaining the mechanical strength of the entire motor by housing each component of the motor and a flat-plate-shaped bracket part 71 with holes 72a and 72b for mounting the motor to another structure body. The motor body 44 is manufactured by curling one portion of, for example, a stainless sheet material by a roll and is made of one part. Also, a pair of conductor patterns K1 and K2 and a pair of conductor patterns K3 and K4 that are connected to both terminals of a pair of coils of the motor are formed on the bracket part 71.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, and more particularly to an improved technique for a small-diameter micromotor suitable for precision equipment such as watches and cameras, medical equipment, and the like.

[0002]

2. Description of the Related Art Examples of this type of micromotor are shown in FIGS. 21A and 21B, respectively.
The micromotor shown in FIG. 21A has a shaft (rotating shaft) from one end of a cylindrical motor body 100 as an exterior.
A bracket (flange) 102, which is a part that is protruded from the motor main body 100 and is separate from the motor main body 100, is integrally fixed to the motor main body 100 by, for example, welding in a state orthogonal to the shaft 101. The bracket 102 is for mounting the motor on another structure (part of a product), and has a pair of holes 104a and 104b through which screws (not shown) used at that time pass. Note that reference numeral 1
Reference numeral 03 denotes a lead wire (motor harness) for supplying power to the motor or sending a drive signal, and some of the devices include a harness bracket (not shown) for supporting the motor harness.

In the micromotor shown in FIG. 21 (b), a shaft (lead screw) 106 projects from one end of a motor body 105, and a bracket 107, which is a separate component from the motor body 105, is parallel to the shaft 106. Is fixed to the motor body 105 in the
10a and 110b. In this example, the bracket 107 includes a bearing (shaft support) 107a for rotatably supporting the tip (free end) of the shaft 106 to reduce runout (radial and axial directions). More specifically, one end of the bracket 107 is bent to form a bearing portion 107a that rises substantially perpendicularly from the bracket main body 107. The bearing portion 107a has a guide shaft 108 extending parallel to the shaft 106.
Is supported. The moving piece 109 is screwed and connected to the shaft 106 and is movably inserted along the guide shaft 108. With such a configuration, the movable piece 109 can be reciprocated along the guide shaft 108 by, for example, rotating the shaft 106 forward and backward.

[0004]

As described above, in the conventional micromotor, a motor body and a bracket are separately manufactured, and then a bracket, which is a part separate from the motor body, is fixed to the motor body. Therefore, there is a problem that the number of parts and the number of manufacturing steps are increased, and it takes time and effort for positioning when joining the two, and as a result, the manufacturing cost of the micromotor increases.

[0005] The harness bracket further increases the component cost and assembly cost. Furthermore, motor manufacturers and users are liable to cause a failure (such as disconnection) particularly at the root of the motor harness when a force is applied to the motor harness during product handling. More specifically, manufacturers and users inadvertently pull the motor harness during transport of the motor, causing breaks.In addition, when mounting micromotors on a printed circuit board, the manufacturer attaches the motor bracket to the printed circuit board. After fixing the motor harness to the circuit on the printed circuit board, the motor harness is also inadvertently pulled.

The present invention has been made in view of the above-mentioned problems of the prior art. In addition to the function of housing the components of the motor in the motor body and ensuring the mechanical strength of the entire motor, the present invention By providing the function of a bracket for mounting the motor to another structure, the number of parts and manufacturing cost are reduced, and by providing a circuit pattern on the bracket, the motor harness is abolished and disconnection may occur. There is no aim to provide a micromotor.

[0007]

According to the present invention, there is provided a micromotor according to the present invention, wherein a motor body as an exterior of the motor accommodates a motor structural component and secures mechanical strength of the entire motor. It is composed of a cylindrical portion and a bracket portion for fixing the motor to another structure. The bracket portion has a motor circuit pattern formed thereon, and the motor body is bent into a part of a plate material. The cylindrical portion is formed by processing, and the remaining portion is formed as the bracket portion. Also,
The bracket part is substantially flat, and a part thereof
A bearing for rotatably supporting the shaft of the motor is integrally formed by bending.

Furthermore, the motor is a stepping motor, as a motor component, a magnet fixed coaxially to said shaft, a pair of soft magnetic material that is disposed on the shaft coaxially in the axial direction on both sides of the magnet Bobbins, A-phase and B-phase coils respectively wound around these bobbins, and a short plate whose bottom plate is fixed to the magnet-side end of each bobbin and faces a part of the outer peripheral surface of the magnet. A yoke made of a soft magnetic material having pole teeth, one end of which is detachably coupled to the end of each bobbin opposite to the magnet, and the other end of which faces the other part of the outer peripheral surface of the magnet A long pole tooth made of a soft magnetic material, and a pole tooth support made of a non-magnetic material disposed coaxially around the outer periphery of the magnet; The short pole teeth are integrally fixed to the pole tooth support, and the short pole teeth are removably inserted into pole tooth receiving portions formed on the pole tooth support, respectively. The pattern is composed of four conductor patterns each having one end electrically connected to the four coil ends of both coils. A connector to which the other end of each conductor pattern is electrically connected is mounted on the bracket.

According to the operation of the present invention, the motor body is formed into a conventional cylindrical portion by bending a part of one sheet material.
Since the remaining part is a bracket part, the number of parts of the motor body is one. Therefore, positioning and joining of both the cylindrical portion and the bracket portion are not required.
Also, since the circuit pattern is formed on the bracket part instead of the conventional motor harness, the circuit pattern is not damaged by handling the motor with the motor body when transporting the motor or mounting it on another structure. .

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) FIGS. 1 (a), 1 (b) and 1 (c)
1 is a perspective view, a plan view, and a side view of a first embodiment of a micromotor of the present invention, respectively. As shown in FIG. 1, in this micromotor, a motor body 44 as an exterior thereof accommodates a motor structural component (not shown) to be described later and has a cylindrical portion (curl portion) 70 for ensuring the mechanical strength of the entire motor. And a flat plate-shaped bracket portion (mount portion) 71 for fixing the motor to another structure (for example, a printed circuit board). The manufacturing process of the motor main body 44 will be described later. Note that the micromotor of this example is a microstepping motor in which the outer diameter of the cylindrical portion 70 is about 4 mm, but is not limited to this.

A shaft (rotating shaft) 20 is connected to one end of the motor.
Project from the motor and two ends of the coil from both ends of the motor.
Both ends (coil ends) 39a and 39b and both ends (coil ends) 39c and 39d of the book are provided. The details of the internal structure of the motor will be described later. Holes 72a and 72b are formed in the corners of the bracket 71, respectively. The holes 72a and 72b are for a screw (not shown) for fixing the motor body 44 to another structure (not shown) to penetrate. When the bracket portion 71 is fixed to another structure by welding or the like, the holes 72a, 7
There is no need to open 2b.

In the present embodiment, the motor body 44 is made of a non-magnetic material such as stainless steel or aluminum. However, if the motor body as an exterior has a function as a magnetic circuit, iron or the like is used. It is necessary to be made of a soft magnetic material from the viewpoint of magnetic characteristics described later.

A further feature of the present embodiment is that a circuit pattern including _four conductor patterns K ₁ , K ₂ , K ₃ , and K ₄ is printed on the bracket 71. One end of the pair of conductor patterns K ₁ and K ₂ reaches near one opening of the cylindrical portion 70, and the other end reaches near the end of the bracket portion 71 on the side opposite to the cylindrical portion 70. One end of the pair of conductor patterns K ₃ and K ₄ reaches near the other opening of the cylindrical portion 70, and the other end reaches near the end of the bracket portion 71 on the side opposite to the cylindrical portion 70. The pair of coil end 39a, 39b are electrically connected by soldering to one end of a pair of conductor patterns K _1, K _2,
A pair of coil end 39c remains, 39d is on one end of a pair of conductor patterns K _3, K ₄ are electrically connected by soldering. Each of the conductor patterns K ₁ , K ₂ , K ₃ , and K ₄ is formed in an L-shape, and the other ends thereof are arranged, and a harness (not shown) on the product side is soldered. In addition,
The circuit pattern described above is formed on the bracket portion 71 after forming the cylindrical portion 70 on the motor main body 44 as described later in this example. However, the circuit pattern is not limited to this. After the formation, the cylindrical portion 70 may be formed on the flat plate.

In order to manufacture the motor body 44, first, as shown in FIG. 2A, a plate 73 of a required size, for example, made of stainless steel is prepared, and as shown in FIG. Holes 72a and 72b are respectively formed in the corners on one end side of the plate member 73 by a drill or the like. Finally, as shown in FIG. 2C, when the cylindrical portion 70 is formed from the other end side of the plate member 73 by drawing or bending with a roll, portions other than the cylindrical portion 70 become flat bracket portions 71. .
In addition, the processing cost is lower in the case of bending using a roll than in the case of drawing. By welding the front end 72c of the cylindrical portion 70 to the bracket portion 71, the gap between the two may be eliminated. This prevents dust from entering the motor. As described above, the motor body 44 of the micromotor is formed by bending a part of one sheet material to form the conventional cylindrical portion 70 and the remaining portion as the bracket portion 71. Therefore, the number of parts of the motor body is one. It can be easily manufactured as well as individual pieces. Further, positioning and joining of both the cylindrical portion 70 and the bracket portion 71 are not required. As a result, the manufacturing cost of the micromotor can be reduced, and the productivity is improved.

As shown in FIG. 3, a circuit pattern is formed on the bracket 71 using a general circuit pattern forming technique. 3 (a) to 3 (e) are cross-sectional views taken along the line YY in FIG. 1 (b) for explaining a process of forming a circuit pattern. More specifically, first, as shown in FIG. 3A, an insulating layer 71 is formed on the bracket 71 by printing , for example.
a is formed. Epoxy resin, polyimide resin, and other engineering plastics can be used for the insulating layer 71a. If the bracket 71 is formed of an insulating material, the insulating layer 71a is not required. Next, as shown in FIG. 3B, a copper foil 71b is attached on the insulating layer 71a using an adhesive, and
As shown in (c), a copper foil 71c is further formed on the copper foil 71b by a plating method. Next, as shown in FIG. 3D, portions other than the conductive patterns K ₁ , K ₂ , K ₃ , and K ₄ of the copper foils 71b and 71c are removed by an etching method. As shown in (e), the resist film 71d is covered with, for example, an epoxy resin.

Thus, instead of the conventional motor harness, the conductor patterns K ₁ , K ₂ ,
Since K ₃ and K ₄ are formed, the motor is mounted on the motor main body 44 when the motor is transported or mounted on another structure.
, The conductor patterns K ₁ , K ₂ ,
No damage such as disconnection of K ₃ and K ₄ occurs.

FIG. 4 shows a modification of FIG. 1B, in which the other end of each of the conductor patterns K ₁ , K ₂ , K ₃ and K ₄ is provided on the end of the bracket 71 opposite to the cylindrical portion 70. Are fixed to a connector K having terminals electrically connected to each other. In this example, when the motor is mounted on another structure (product), it is only necessary to fit the connector K of the motor to the connector (not shown) on the product side, and soldering of the harness on the product side becomes unnecessary.

Next, an example of the motor components and the internal structure of the micromotor of this embodiment will be described. FIG.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a micromotor according to the present invention. In the figure, reference numeral 20 denotes a shaft. At the center of the shaft 20, a cylindrical magnet 22 magnetized in four poles in the circumferential direction is coaxially fixed. A pair of bobbins 26A (A phase) and 26B (B phase) having the same shape are arranged adjacent to both sides of the magnet 22 and are passed through the shaft 20. Also, on both sides of the magnet, washers 65A and 65B for improving rotational sliding properties.
Is rotatably inserted into the shaft 20.

As shown in FIG. 6, the bobbins 26A and 26B have a cylindrical winding portion 36 having an inner diameter larger than the outer diameter of the shaft 20, and a base end portion of the winding portion 36 (the magnet 22 and Is formed on the opposite side), and a press-fit projection 28 projecting in the axial direction from the base end.
And the whole is integrally formed of a soft magnetic material such as pure iron. And each winding part 36 of bobbin 26A, 26B
Are wound with coils 38A and 38B (omitted in FIG. 6).

A U-shaped yoke 34 is attached to the tips of the bobbins 26A and 26B. The yoke 34 is formed of a soft magnetic material such as pure iron, and has a pair of short pole teeth 50A, 5A rising from the bottom plate and both ends thereof.
0B, and a through hole is formed at the center of the bottom plate portion. As shown in FIG. 9, the bobbins 26A, 26 in which flange portions 32 (locking portions) are formed in advance are formed in the through holes.
B is inserted and the tip is caulked to form a locking portion 33. The yoke 34 is
, And vertically supported with respect to the axis. The angle of the yoke 34 may be adjusted at the time of assembly by loosely caulking.

As shown in FIG. 6, the flange portion 30 has a shape in which both sides of a disk are cut out in parallel, and a pair of pole teeth abuts with long pole teeth 48A, 48B at both ends in the major diameter direction. A contact surface 30A is formed. Also, the yoke 34
Is fixed so that the angle around the axis is shifted by 90 ° with respect to the flange portion 30, and the bobbins 26A and 26B are arranged such that the flange portions 30 of each other are shifted by 45 °.

The press-fit projection 28 has a coaxial cylindrical shape having a diameter larger than that of the winding portion 36 and has a cylindrical shape as shown in FIG.
As shown in FIG. 2, bearings 24 such as annular metal bearings are press-fitted coaxially.
Are rotatably supported at both ends.

On the other hand, surrounding the outer periphery of the magnet 22,
As shown in FIG. 5, a cylindrical member 46 is arranged non-contacting and coaxial. As shown in FIG. 6, the cylindrical member 46 is formed by integrally fixing two sets of long pole teeth 48A and 48B by a cylindrical pole tooth support 52 made of a non-magnetic material such as resin. The outer diameter of the pole tooth support 52 is substantially equal to the inner diameter of the cylindrical portion 70 of the motor body (motor case) 44, and the cylindrical member 46 is supported in the cylindrical portion 70 without play.

As shown in FIG. 8, the long pole teeth 48A of the cylindrical member 46 and the long pole teeth 48B are each
80 ° apart. The pole tooth support 52 has pole tooth receiving portions 53A and 53B for inserting the short pole teeth 50A and 50B of the yoke 34 between the long pole teeth 48A and between the long pole teeth 48B, respectively. ing. Long pole teeth 48A (or 48B) in phase and pole tooth storage 5
3A (or 53B) are 90 ° out of phase with each other,
A gap having a constant width is provided between them. The A-phase side pole teeth 48A and the pole tooth storage section 53A are out of phase by 45 ° with the B-phase side pole teeth 48B and pole tooth storage sections 53B, and a certain gap is provided therebetween. I have.
And the short pole teeth 50A,
When 50B is inserted, the long pole teeth 48A, 48B are brought into contact with the pole tooth contact surfaces 30 of the flange portions 30 of the bobbins 26A, 26B.
A contacts each other without any gap. The long pole teeth 48A, 48B and the short pole teeth 50A, 50
0B has the same thickness and width, and the magnet 2
2 are equal to each other.

In the pole tooth support 52 of this example, the pole tooth receiving portions 53A, 53B are formed on the inner peripheral surface of the pole tooth support 52, and the inner peripheral surfaces of the long pole teeth 48A, 48B are the pole tooth support. It is flush with the inner peripheral surface of the body 52 and care is taken to minimize the amount of separation between the magnet 22 and each pole tooth. However, the present invention is not limited to this embodiment.
Long teeth 48A, 48B and pole teeth accommodating portions 53A, 53B may be formed along the outer peripheral surface of the pole teeth, or the long pole teeth 48 may be formed at the center in the thickness direction of the peripheral wall of the pole tooth support 52.
A, 48B, and a pole tooth receiving slit into which the short pole teeth 50A, 50B are inserted may be formed.

In this example, the in-phase pole teeth are 4
The number of pole teeth is not limited to four, but may be another number. The material of the motor body 44 may be a resin, aluminum, stainless steel, or the like that has sufficient structural strength and is capable of firmly holding the housed parts in a predetermined portion, such as a crimping method. It is desirable to be formed of a non-magnetic material.

As shown in FIG. 5, supporting members 40A and 40B are further disposed outside the bobbins 26A and 26B (on the side opposite to the magnet 22). These support members 40A, 40B have a columnar shape having a center hole, and a press-fitting concave portion 42 is formed on the side facing the bobbins 26A, 26B coaxially with the center line. The press-fit projections 28 of the bobbins 26A, 26B are press-fitted into these press-fit recesses 42, and the support members 40A, 40B and the bobbins 26A, 2
6B are positioned coaxially. In the support members 40A and 40B of this example, as shown in FIG. 9, a bearing accommodating portion 45 is formed coaxially behind the press-fitting concave portion 42, and the bearing 24 is press-fitted into the press-fitting convex portion 28. Instead, the bearing 24 can be press-fitted into the bearing accommodating portion 45.

The bobbins 26A of the support members 40A, 40B,
A pair of positioning projections 41 are formed on the end surface on the 26B side as shown in FIG. 6, and the side surfaces of these positioning projections 41 contact the side surfaces of the flange portion 30 as shown in FIG. 7. , The angles of the bobbins 26A and 26B around the axis are accurately defined. In addition, long pole teeth 48A, 48
The tip of B is also positioned between the positioning projections 41 and positioned. The outer peripheral surfaces of these positioning projections 41 are stepped portions having a relatively small diameter in order to facilitate insertion into the cylindrical portion 70 of the motor body 44.

As shown in FIGS. 1, 5 and 7, reference numerals 39a and 39b denote both ends of one coil 38A, and reference numerals 39c and 39d denote both ends of the other coil 38B. Then, on the outer peripheral surfaces of the support members 40A and 40B,
As shown in FIG. 7, a pair of coil ends 39a, 39b of the coils 38A, 38B and a pair of grooves 43, 43 for passing a pair of coil ends 39c, 39d are formed, respectively. Coil ends 39a, 39b and coil ends 39c, 3
9d, a pair of conductor patterns K ₁ ,
By applying a voltage to K ₂ and a pair of conductor patterns K ₃ and K ₄ respectively, the coils 38 A and 38 B can be excited.

According to the stepping motor having the above configuration, all of the long pole teeth 48A and 48B are fixed to the cylindrical pole tooth support 52 in advance, while the short pole teeth 50A and 48B are fixed.
50B is a pole tooth receiving portion 53 formed on a pole tooth support 52
Since the pole teeth are inserted into the magnets A and 53B, all the pole teeth are positioned on the outer periphery of the magnet 22, and the positional accuracy between the pole teeth on the outer periphery of the magnet can be increased, so that the rotor rotation accuracy can be improved.

The long pole teeth 48A, 48B are fixed to the pole tooth support 52 in advance, while the short pole teeth 50A, 48A are difficult to integrally form with the pole tooth support 52 because of their small size.
50B is formed as a single part as the yoke 34 and attached to the ends of the bobbins 26A and 26B. Therefore, when assembling the motor, the yoke 3 is held while holding the bobbins 26A and 26B.
Four short pole teeth 50A, 50B are inserted into the groove 53 of the pole tooth support 52.
A, 53B and the long pole teeth 48A, 48
B can be brought into contact with the pole tooth contact surface 30A of the bobbins 26A, 26B. Therefore, a high degree of positioning is possible with a simple operation, and assembling workability and productivity can be improved.

The bobbins 26 are provided in the through holes of the yokes 34.
The yoke 34 is fixed by sandwiching the yoke 34 between the flange portion 32 and the locking portion 33 by inserting the tip portions of the A and 26B and caulking these tip portions to form the locking portion 33.
It is easy to assemble and inexpensive, and has the advantage that the angle of the yoke 34 can be freely adjusted.

The press-fitting protrusions 28 formed at the ends of the bobbins 26A, 26B are connected to the support members 40A, 40B.
Of the bobbin 26A, 26B and each of the support members 40A, 40B are relatively positioned, and the bearing 24 is press-fitted into the press-fitting convex portion 28. It is positioned coaxially, and each support member 40
Since the A and 40B are fixed to the cylindrical motor body 44, it is easy to align the bobbins 26A and 26B and the shaft 20 with high accuracy, and further, the pole teeth 48 and
The air gap between the magnet 50 and the magnet 22 is kept uniform, and the bobbins 26A, 26B and the pole teeth 48, 5
By ensuring the coupling with zero, non-uniformity of the magnetic balance does not occur, and the rotor rotation accuracy can be improved from this point as well.

In this embodiment, the bobbin 26
Since the bearing 24 is fixed in the protrusion 28 for press fitting of A and 26B, a large distance from the end of the stepping motor to the bearing 24 can be secured, and noise and vibration generated by the bearing 24 are reduced accordingly. High effect. Further, the support member 40
By forming the positioning projections 41 on the A and 40B, it is easy to adjust the angles of the bobbins 26A and 26B, so that the assemblability can be improved from this point as well.

The internal structure of the motor is not limited to the above embodiment, but may be changed as needed, for example, as described below. That is, in the first embodiment, FIG.
As shown in FIG. 6, short pole teeth 50A, 50 of the yoke 34 are provided on a jaw 52A provided on the inner peripheral surface of the pole tooth support 52.
B shows a state in which the pole tooth support 52 is positioned by abutting B. However, when the short pole teeth 50A, 50B of the yoke 34 are inserted into the pole tooth support 52, the pole teeth 50A, 50B and the inner peripheral surface of the pole tooth support 52 should be used.
The inner peripheral surface of the pole tooth support 52 is scraped by the sliding contact with the outer peripheral surface of the pole tooth support 52, and this shaving is generated by the jaw 52 of the pole tooth support 52.
A and the short pole teeth 50A, 50B intervene, and as a result, the positioning accuracy of the pole tooth support 52 may be deteriorated. This has been solved by a modification described below.

FIG. 11 is a longitudinal sectional view showing a modified example of the micromotor of the first embodiment, and the same reference numerals are given to portions having the same structure as in FIG. As shown in FIGS. 11 and 12, instead of the jaw 52A (see FIGS. 5 and 6), the end face of the pole tooth support 52 is brought into contact with the outer peripheral surface of the bottom wall of the yoke 34. Flange 67 to be positioned
A, 67B are provided. Thereby, when assembling the stepping motor, the yoke 34 is
When the short pole teeth 50A and 50B are inserted, the pole tooth support 5
The end face 2 is positioned in the axial direction by contacting the flange portions 67A and 67B.

Next, a method of assembling the micromotor according to the present invention will be described by taking the above-mentioned modified example as an example. First, as shown in FIG. 11, the bearing 24 is press-fitted into the bearing accommodating portion 45 of the support member 40A (step S1 in FIG. 16).
reference). As shown in FIG. 12 (a), the press-fitting convex portion 28 of the bobbin 26A is moved in the direction of the arrow to
When it is press-fitted, the state shown in FIG.
8, step S2). At this time, the press-fitting is performed so that the Z portion and the short pole teeth 50A in FIG.

Thereafter, as shown in FIG.
A coil 38A is wound around the winding portion A, and its coil end 39
a, 39b are passed through a pair of grooves 43, 43 of the support member 40A (see step S3 in FIG. 18). The coil 38
The winding direction of A is indicated by an arrow X. At this time, care should be taken to prevent the coil 38A from being disconnected or sagged. Further, a continuity check of the coil ends 39a and 39b and an appearance inspection such as adhesion of foreign matter are performed, and a bobbin assembly is obtained as described above. In FIG. 13, reference numeral 62A denotes a shaft through hole through which the shaft 20 (see FIG. 11) passes through the support member 40A.

In parallel with steps S1 to S3, FIG.
As shown in FIG. 4A, the magnet rotor 22 is press-fitted into the shaft 20 (see step S6 in FIG. 18). At this time, the bending of the shaft 20 and the magnet rotor 22
Check that there are no cracks, chips, foreign matter, etc. Then, the magnet rotor 22 is magnetized (see step S7 in FIG. 18), and dust is removed from the magnet rotor 22 (FIG. 18).
Step S8) and its confirmation (see step S9 in FIG. 18) are sequentially performed. As shown in FIG. 14B, the washers 65A and 65B are inserted into the shaft 20 from both sides of the magnet rotor 22, respectively, to obtain a rotor assembly (see step S10 in FIG. 18).

Thereafter, as shown in FIG. 15A, the pole tooth support 52 and the pole assembly including the four long pole teeth 48A and 48B are moved in the direction of the arrow, and
As shown in FIG. 15C through the state shown in FIG. 15B, the end face of the pole tooth support 52 and the flange 67 of the short pole tooth 50A are formed.
A is abutted and positioned in the axial direction. At this time, care is taken so that the coil 38A is not disconnected. Here, as shown by the arrow, it is confirmed that there is no rattling of the pole assembly. Thus, a coil and a pole assembly are obtained.

Next, as shown in FIG. 16A, the rotor assembly is inserted into the coil and pole assembly to obtain an assembly shown in FIG. 16B. Here, the magnet rotor 22 is not chipped or scratched.
To attract the pole assembly, securely hold the pole assembly,
Furthermore, care is taken so that the washers 65A and 65B do not fall off the shaft 20. As shown in FIG. 16C, when the motor main body 44 is put on the assembly from one end side, the state shown in FIG. 16D is obtained.

Thereafter, as shown in FIG. 17A, another bobbin assembly is inserted from the other end of the motor main body 44 to obtain a temporary assembly shown in FIG. 17B. Here, it is confirmed that the support members 40B at both ends (one of the support members is not shown) do not protrude from the end of the cylindrical portion 70 of the motor main body 44. As shown in FIG. 17 (c), the two ends of the cylindrical portion 70 are placed in two places at a total of four places,
A, 66B, caulking (see step S11 in FIG. 18). Here, in addition to confirming that there is no backlash in the support member 40B (one of the support members is not shown), it is also necessary to confirm that the thrust play of the shaft 20 can be secured to a specified value and that the shaft 20 rotates smoothly. Confirm. In FIGS. 16 and 17, the circuit pattern of the bracket 71 is not shown.
Finally, after performing operation confirmation, torque confirmation, angle accuracy inspection, marking, and packing processes (step S12 in FIG. 18).
(See FIG. 18, step S13).

(Second Embodiment) FIG. 19 is a perspective view of a micromotor according to a second embodiment of the present invention, and FIG. 20 is a view showing a process of manufacturing the motor main body shown in FIG. As shown in FIG. 19, the flat bracket portion 82 of the motor body (motor case) 80 includes a bearing portion 84 for supporting the distal end of a motor shaft (lead screw in this example) 85. One end of a guide shaft 86 is supported by the bearing portion 84, and a movable piece 87 is movably inserted along the guide shaft 86, and
Is screwed into. Reference numerals 88a and 88b indicate a pair of coil ends protruding from one end of the motor. FIG.
9, a circuit pattern (not shown) similar to that of FIG. 1 is provided, and the internal structure of the motor is the same as that of the first embodiment.

In the manufacturing process of the motor body 80, first, as shown in FIG. 20A, a plate material 90 of a required size, for example, made of stainless steel, is prepared, and a corner shown by a dashed line 91 is cut off. Also, as shown by the dashed line 92, the opposite corner is cut out in an L-shape. Next, as shown in FIG. 20B, a pair of holes 83 is formed on one end side (left side) of the plate member 90.
a and 83b are formed by a drill or the like.
4, two holes 89a and 89b are formed by a drill or the like. One hole 89a is for supporting the shaft 85 (see FIG. 19), and the other hole 89b is for supporting the guide shaft 8
6 (see FIG. 19). In addition,
A dashed line indicated by a reference numeral 93 in FIG. 20B indicates a boundary between a cylindrical portion 81 and a bracket portion 82 described later.
Further, as shown in FIG. 20 (c), from the other end side of the plate material 90, by drawing or bending by a roll,
When the cylindrical portion 81 is formed, a portion other than the cylindrical portion 81 becomes a flat bracket portion 82. The bearing portion 84 is bent vertically upward. In this example, the bearing portion 84 for supporting the shaft 85 of the motor can be easily formed by bending the bracket portion 82. Finally, similarly to the first embodiment, a circuit pattern (not shown) is formed on the bracket portion 82.

In the second embodiment, the motor body 80 is provided with the bearing portion 84 at a position facing the cylindrical portion 81, so that the method of assembling the motor is slightly different from that described above. That is, the assembly shown in FIG. 16B is inserted from the opening of the cylindrical portion 81 of the motor main body 80 of this example opposite to the bearing portion 84, and the tip of the shaft 85 is inserted into the hole 89 a of the bearing portion 84. To support.

[0046]

Since the present invention is configured as described above, it has the following effects. According to the first aspect of the present invention, the motor body of the micromotor is formed by bending a part of a single plate to form a conventional cylindrical portion and the remaining portion is a bracket portion. Can be easily manufactured. Further, positioning and joining of both the cylindrical portion and the bracket portion are unnecessary. As a result, the manufacturing cost of the micromotor can be reduced, and the productivity is improved. Furthermore, a circuit pattern is formed on the bracket part, and the conventional motor harness and harness bracket are eliminated, so that the number of parts is further reduced, and the motor is connected to the motor when the motor is transported or mounted on other structures. Handling by holding the main body does not damage the circuit pattern such as disconnection, and enhances reliability. According to the second aspect of the present invention, in addition to the above effects, the bearing for supporting the motor shaft can be easily formed by bending the bracket, so that the manufacturing cost is not increased. According to the third aspect of the present invention, in addition to the above effects, an inexpensive and highly reliable stepping motor can be provided by applying the present invention to a stepping motor having high rotor rotation accuracy and improved assembling workability. The invention described in claim 4 is
In addition to the above effects, by connecting both ends of the motor coil to the circuit pattern, the complicated wiring of the motor harness as in the related art is eliminated, and the motor can be easily mounted even in a narrow mounting portion.

[Brief description of the drawings]

1 (a), 1 (b) and 1 (c) are a perspective view, a plan view and a side view, respectively, of a first embodiment of a micromotor according to the present invention.

FIG. 2 is a view showing a process of manufacturing the motor main body shown in FIG.

FIG. 3 is a view showing a process of forming a circuit pattern on a bracket portion.

FIG. 4A shows an example in which a connector connected to an end of a circuit pattern is provided on a bracket portion.

FIG. 5 is a longitudinal sectional view showing the micromotor of the first embodiment.

FIG. 6 is an exploded perspective view showing a pole tooth, a bobbin, and a support member of the embodiment.

FIG. 7 is a perspective view showing an assembled state of the pole teeth, the bobbin, and the support member of the embodiment.

FIG. 8 is a cross-sectional view showing a pole tooth support and pole teeth of the embodiment.

FIG. 9 is a longitudinal sectional view of the bobbin and the support member of the embodiment.

FIG. 10 is a front view of the bobbin and the support member of the embodiment.

FIG. 11 is a longitudinal sectional view showing a modification of the micromotor according to the first embodiment.

FIG. 12 shows an assembly of the micromotor of FIG.
It is a figure for explaining a process of press-fitting a bobbin to a support member.

FIG. 13 shows an assembly of the micromotor of FIG.
It is a figure for explaining a winding process.

FIG. 14A is a view for explaining a magnet press-fitting step in assembling the micromotor of FIG. 11;
(B) is a figure for demonstrating a washer insertion process.

FIG. 15 shows an assembly of the micromotor of FIG.
It is a figure for explaining a process of attaching a pole assembly to a bobbin assembly.

FIG. 16 shows an assembly of the micromotor of FIG.
It is a figure for explaining a process of attaching a rotor assembly to a pole assembly, and a motor case covering process.

FIG. 17 shows an assembly of the micromotor of FIG.
It is a figure for explaining a bobbin assembly insertion process and a motor case caulking process.

18 is an assembly process diagram of the micromotor of FIG.

FIG. 19 is a perspective view of a micromotor according to a second embodiment of the present invention.

20 is a view illustrating a process of manufacturing the motor main body illustrated in FIG. 19;

FIG. 21 is a perspective view of a conventional micromotor.

[Explanation of symbols]

K ₁ , K ₂ , K ₃ , K ₄ Conductor pattern K connector 20, 85 Shaft 22 Magnet rotor 24 Bearing 26 A, 26 B Bobbin 28 Press-fit projection 30, 32 Flange 30 A Polar tooth contact surface 33 Locking portion 34 Yoke 36 Winding part 38A, 38B Coil 39a-39d Coil end 40A, 40B Support member 41 Positioning convex part (positioning engaging part) 42 Press-fitting concave part 43 Groove part 44, 80 Motor body (motor case, exterior) 45 Bearing press-fitting Concave portion 46 cylindrical member 48A, 48B long pole tooth 50A, 50B short pole tooth 52 pole tooth support 52A jaw 53A, 53B pole tooth receiving portion 62A shaft through hole 65A, 65B washer 66A, 66B crimping portion 67A, 67B Flange part (jaw part) 70, 81 Cylindrical part 71, 82. Bracket part 72a, 72b, 83a, 83b Hole 73, 90 Plate 84 Bearing part 86 Guide shaft 87 Moving piece

Claims (4)

[Claims] A motor body as an exterior of a motor includes a cylindrical portion for accommodating a motor structural component and ensuring mechanical strength of the entire motor, and a bracket portion for fixing the motor to another structure. A motor circuit pattern is formed on the bracket portion, and further, the motor body is formed by bending a part of a plate material into the cylindrical portion, and the remaining portion is formed as the bracket portion. A micromotor characterized by the following. 2. A bracket according to claim 1, wherein said bracket is substantially flat, and a bearing for rotatably supporting a shaft of said motor is formed integrally with a part of said bracket. The described micromotor. 3. The motor is a stepping motor, the motor comprising a magnet fixed coaxially to the shaft and a pair of soft magnetic materials disposed coaxially with the shaft on both axial sides of the magnet. Bobbins, A-phase and B-phase coils respectively wound around these bobbins, and a short plate whose bottom plate is fixed to the magnet-side end of each bobbin and faces a part of the outer peripheral surface of the magnet. A yoke made of a soft magnetic material having pole teeth, one end of which is detachably coupled to the end of each bobbin opposite to the magnet, and the other end of which faces the other part of the outer peripheral surface of the magnet A long pole tooth made of a soft magnetic material, and a pole tooth support made of a non-magnetic material disposed coaxially around the outer periphery of the magnet; The short pole teeth are integrally fixed to a tooth support, and the short pole teeth are removably inserted into pole tooth receiving portions formed on the pole tooth support, respectively. , One end of both coils
3. The micromotor according to claim 1, comprising four conductor patterns electrically connected to the respective coil ends. 4. The micromotor according to claim 3, wherein a connector to which the other end of each conductor pattern is electrically connected is mounted on the bracket portion.