JP2603109Y2 - motor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor,
The present invention relates to a step motor.

[0002]

2. Description of the Related Art FIGS. 7A and 7B are a longitudinal sectional view and a back view of an example of a conventional step motor, respectively. FIG. 1A is a longitudinal sectional view taken along line AA of FIG. 1B. The stepping motor 20 shown in FIG. 1 is a PM type (permanent magnet type) stepping motor, and generally includes a rotor 1 made of a permanent magnet made of a magnetic material whose outer peripheral surface is multipolar magnetized, and yoke 2 a to 2 d in order to generate an alternating magnetic field in the stator mold 12 and the yoke 2 a to 2 d are integrally formed form a yoke 2 a to 2 d, the yoke 2 a to 2 d which are disposed through the air gap between And a fixed plate 8 'made of a magnetic material for fixing a bearing 7 supporting a shaft 5 integrally fixed to the rotor 1 to the stator. Is done.

The rotor 1 has a cylindrical shape whose upper part is closed, and the upper surface of the inner wall of the rotor 1 is pressed upward by a spring 4. The spring 4 causes the rotor 1 to rotate due to an alternating magnetic field generated in the yokes 2a to 2d by the coils 3a and 3b.
It is provided in order to prevent vibration.

In order to use the alternating magnetic field generated in the yokes 2a to 2d efficiently, a case 9 made of a magnetic material is used.
It is provided so as to cover the stator so as to be in contact with the outer periphery of a to 2d. The case 9 and the fixing plate 8 'are fixed by caulking the case 9 at three caulking portions 9a to 9c.

[0005]

In the conventional motor described above, the yokes 2a to 2d are integrally formed of resin for the purpose of reducing the number of assembly steps and the cost by reducing the members for fixing the yokes. The stator mold 12 is formed. Not apply force directly to yoke 2a~2d in order to prevent here that each yoke yokes 2a~2d is deformed when retrieving product from prevention and resin formed shape at mold to fall out of the stator mold 12 In order to secure so-called gates and protrusions, resin portions 12b and 12a are provided at the uppermost and lowermost portions of the yokes 2a to 2d. This resin part 1
The yoke 2a and the fixing plate 8 '
There is no contact between Therefore, the magnetic path of the magnetic field generated in the yoke 2a and the fixed plate 8 'is interrupted between both, and the effective use of the alternating magnetic field is hindered. Therefore, there is a problem that the output torque of the step motor 20 is reduced.

FIG. 8 shows the VIII- of the caulking portion 9a in FIG.
FIG. 8 shows an enlarged vertical sectional view along the line VIII. As shown in the figure, a resin portion 12a is interposed between the yoke 2a and the fixing plate 8 ', and thereby a gap is formed at an end between the yoke 2a and the fixing plate 8'. In this state, caulking is performed, that is, the caulking portion 9a is hit with a kind of a tool called a caulking tool from the lower left direction in FIG.
The end of the fixing plate 8 'is deformed so as to narrow the gap as shown by the broken line. Due to the deformation of the fixing plate 8, the bearing 7
Therefore, the air gap between the rotor 1 and the yokes 2b, 2c varies, so that the output torque of the step motor 20 is reduced and the variation of the output torque is increased.

The present invention has been made in view of the above problems, and has as its object to provide a motor capable of effectively utilizing an alternating magnetic field formed by a coil and thereby increasing output torque. I do.

[0008]

According to the present invention, a rotor having a multipolar magnetized outer peripheral surface and a yoke wound with a coil and integrally formed of a molding material are provided facing the outer periphery of the rotor. the structure of the stator that is, the bearings supporting the shaft are integrally provided to the rotor Ri Na more and the fixing plate to be fixed to the stator, the fixing plate in the axial direction one end side of the yoke Provided
In ing Te motor, the fixing plate and the magnetic body, the yaw
At both ends in the axial direction of the mold
And the end of the mold
Is set only comprising constitutes a protrusion that abuts against the said yoke to the fixed plate spaced and over click.

[0009]

[Function] In the present invention , a molding is provided at both ends of the yoke in the axial direction.
Since the mold end made of metal is provided integrally, the yoke
Can be prevented from falling out of the stator mold.
A so-called gate when removing a product from a mold during resin molding,
The protrusion can be secured. Also, one end of the yoke in the axial direction
Yo by the mold end portion to the provided fixed plate and magnetic
Since the protruding portion that comes into contact with the yoke is provided on the fixed plate separated from the yoke, the magnetic field concentrates on the protruding portion, thereby reducing the leakage of the magnetic field from between the yoke and the fixed plate .

[0010]

1A and 1B are a vertical sectional view and a bottom view, respectively, of an embodiment of the present invention. FIG. 1A is a cross-sectional view taken along line AA of FIG. 1B. 7, the same components as those of the conventional step motor 20 shown in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. The difference between the fixing plate 8 of the stepping motor 10 in FIG. 7 and the fixing plate 8 ′ of the stepping motor 20 in FIG.
The point is that the protruding portions 8a to 8e are provided on the 0 fixing plate 8.

Here, a more detailed configuration of the step motor 10 will be described. FIG. 2 shows a cross-sectional view of FIG. FIG. 3 is a perspective view of the yokes 2b and 2d in FIG.
The yokes 2a, 2c are disposed with the yokes 2b, 2d in FIG. FIG. 4 shows a side view of the relationship between each of the yokes 2b, 2d and each of the yokes 2a, 2c.
As shown in FIG. 3, each of the yokes 2a to 2c has a configuration in which six pole teeth portions are formed on an inner peripheral side of a substantially disk shape and intermittently protrude in a direction perpendicular to the disk. These yokes 2a to 2d are arranged in order so that the respective disks are parallel to each other, and the pole teeth portion has a slight gap between the opposing yokes 2a, 2b and 2c, 2d as shown in FIG. , And are configured to mesh with each other alternately. Also, between the upper and lower pairs of the yokes 2a, 2b and 2c, 2d, the arrangement of the respective pole teeth is shifted by an angle of half the distance between the centers of the adjacent pole teeth. I have. That is, the gap between the pole teeth of the yokes 2a, 2b and the center of one of the pole teeth of the yokes 2c, 2d coincide with each other.

The coils 3a and 3b are connected to the yokes 2a and 2b.
And 2c and 2d are wound so as to surround the meshed portions of the pole teeth. These coils 3
When a current is passed through a and b, a magnetic field is generated between the upper and lower yokes having the pole teeth meshed with each other.
Therefore, different types of magnetic poles are generated in the upper and lower yokes engaged with each other. That is, different types of magnetic poles are generated in the pole teeth adjacent to each other with a small gap as described above. The pole teeth engaged as described above are vertically aligned with respect to each of the two sets of yokes 2a, 2b or 2c, 2d.
There are four, and the number of magnetic poles generated in each of the two sets of yokes is 24. Among them, there are 12 pairs of different types of magnetic poles.

Reference numeral 13 denotes an external connection terminal, which is connected to the coils 3a and 3b within the stator mold 12. In this embodiment, there are six external connection terminals 13, three of which are connected to the coil 3a, and the remaining three of which are connected to the coil 3b. Further coil 3
Each of a and 3b is composed of two coils, and one end and the other end of the two coils are bundled, overlapped, and wound by the same number of turns. One end of one of the two coils and the other end of the other coil are respectively connected to two terminals of the corresponding three terminals 13, and the other end of the one coil And one end of the other one are bundled and connected in common to the remaining one terminal.

Power is supplied to a terminal to which the two coils are connected in common among the three terminals, and the other two terminals are grounded via different switch circuits. With the above connection, the direction of the current flowing through each of the two coils is reversed by closing each of the two switch circuits. Therefore, the directions of the magnetic fields generated by the respective coils are reversed. Thus, the direction of the magnetic field generated in the yoke around which these coils are wound by opening and closing the switch circuit can be controlled.

The substantially cylindrical rotor 1 has a circumferential angle of 360 ° divided into 12 equal parts, and is magnetized so that different types of magnetic poles are adjacent to each other. That is, the aforementioned yoke 2a
Twelve magnetic poles equal to the number of magnetic poles generated in .about.2d are magnetized.

Next, the operation of the step motor 10 having the above configuration will be described. As described above, the magnetic poles are alternately generated in the upper and lower two sets of yokes 2a to 2d for the stator and the rotor 1 at predetermined intervals by the control of the switch circuits connected to the coils 3a and 3b. That is, for example, first, magnetic poles are generated only in the yokes 2a and 2b,
It is repeated that magnetic poles are generated only in c and 2d. The magnetic pole generated in each yoke is inverted each time. Due to the attraction and repulsion generated between the magnetic poles generated in these yokes 2a to 2d and the magnetic poles of the rotor 1, the two sets of yokes 2a, 2b and 2c,
At each switching timing of the magnetic pole generation during 2d, the rotor 1 rotates by half the angle between the adjacent magnetic poles.

The screw holes 8g and 8h provided on the lower left and upper right of the fixing plate 8 in FIG. 1B are used for fixing the step motor 10 to a device to which the step motor 10 is applied. Also, the step motor 10
Is transmitted by connecting a portion of the shaft 5 exposed below the bearing 7 by a predetermined mechanism of a device to which the step motor 10 is applied.

Next, among the configurations of the stepping motor 10, a configuration having features of the present invention will be described in detail. FIG.
Is an enlarged view of a portion V in FIG. The protruding portions 8a to 8e are hatched portions in FIG. 1B of the fixing plate 8 made of sheet metal, that is, portions corresponding to the caulking portions 9a to 9c of the circular portion where the fixing plate 8 contacts the case 9, and a caulking portion. A total of five portions, one between 9a and 9b and one between the caulking portions 9c and 9a, project upward in FIG. 5 by a height h slightly smaller than the thickness t of the sheet metal. It is formed by pressing. The height h is equal to the thickness of the resin portion 12a of the stator mold 12 (the molding material) covering the bottom surface of the yoke 2a below the bottom surface of the yoke 2a. Therefore, as shown in FIG. 5, the upper surface of the protruding portion 8a contacts the bottom surface of the yoke 2a. Similarly, the upper surfaces of the protruding portions 8b to 8e abut on the bottom surface of the yoke 2a at their respective positions.

FIG. 6 shows VI-V of the caulking portion 9a in FIG.
An enlarged sectional view along line I is shown. As shown in the drawing, the upper surface of the protruding portion 8e is configured to abut on the bottom surface of the yoke 2a, so that the fixing plate 8 is not deformed when the caulking portion 9a is caulked as described above. Similarly, in the caulking portions 9b and 9c, the upper surfaces of the protruding portions 8b and 8c respectively correspond to the yoke 2a.
Since the fixing plate 8 is in contact with the bottom surface of the fixing plate 8, the fixing plate 8 is not deformed.

By providing the protruding portions 8a to 8e on the fixing plate 8 in this manner, the fixing plate 8 contacts the bottom surface of the yoke 2a at the portion where the fixing plate 8 contacts the case 9. Therefore, a magnetic path is formed between the fixed plate 8 and the yoke 2a at these portions, and leakage of the alternating magnetic field from between these portions is prevented. Therefore, the alternating magnetic field formed by the coils 3a and 3b is effectively used, and the output torque of the step motor 10 is increased.

Further, since the fixing plate 8 is brought into contact with the yoke 2a at the caulking portions 9a to 9c, the fixing plate 8 is not deformed when the fixing plate 8 and the case 9 are fixed by caulking. The bearing 7 does not tilt, and the air gap between the rotor 1 and the yokes 2b, 2c does not vary.
Can be smoothly rotated without reducing the output torque of the motor.

The present invention can be applied not only to the PM type stepping motor but also to other types of motors in which the mutual relationship between the yoke, the case and the fixing plate is similar to that of the present embodiment.

[0023]

According to the present invention as described above, the yoke shaft
Mold ends made of molding material are integrated at both ends in the direction
The yoke falls off the stator mold
And remove the product from the mold during resin molding.
So-called gates and protrusions can be secured when ejecting
This eliminates the need to apply force directly to the yoke,
Shape can be prevented. Further, Mo and the fixing plate and the magnetic body
The fixed plate, which is separated from the yoke by the metal end, is provided with a projection that abuts the yoke to reduce the leakage of the magnetic field from between the yoke and the fixed plate, so that the alternating magnetic field formed by the coil can be effectively used. It can be utilized to draw out high output torque .

[Brief description of the drawings]

FIG. 1 is a diagram of one embodiment of the present invention.

FIG. 2 is a cross-sectional view of FIG.

FIG. 3 is a perspective view of a main part yoke of FIG.

FIG. 4 is a partial side view of a main part of the yoke in FIG. 1;

FIG. 5 is an enlarged view of a portion V in FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 1;

FIG. 7 is a diagram of an example of the related art.

FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2a-2d Yoke 3a, 3b Coil 5 Shaft 7 Bearing 8 Fixing plate 8a-8e Projection part 9 Case 9a-9c Caulking part 10, 20 PM type step motor 12 Stator mold (mold material)

Claims (1)

(57) [Scope of request for utility model registration] 1. A rotor having a configuration in which a rotor whose outer peripheral surface is multipolar magnetized and a yoke in which a coil is wound and integrally formed of a molding material are provided to face the outer periphery of the rotor. fixing plate more Ri name for fixing the bearings supporting the shaft are integrally provided on said rotor to said stator, said fixed plate said yaw
A motor provided at one end of the yoke in the axial direction , wherein the fixing plate is made of a magnetic material, and the motor is provided at both ends of the yoke in the axial direction.
With the mold end made of mold material
The solid body separated from the yoke by the mold end.
Motor comprising only setting the protruding portion abuts against the said yoke Teiita.