JPS589564A - Manufacture of transistor motor - Google Patents

Abstract

PURPOSE:To improve the accuracy of the positioning of a magnetic flux detecting element by integrally forming the magnetic flux detecting element and a circuit substrate by an insulator manufactured through resin molding. CONSTITUTION:A die to which projecting sections 13a for holding the magnetic detecting element 10 are shaped is prepared while inserting holes 8d for inserting the projecting sections 13a are formed previously to the circuit substrate 8. The magnetic detecting element 10 is inserted into the projecting sections 13a, and the circuit substrate 8 and the magnetic detecting element 10 are shaped integrally by the insulator 11 under a condition that the circuit substrate 8 is inserted. Accordingly, the transistor motor having high reliability can be manufactured because the accuracy of the positioning of the magnetic flux detecting element can be improved and the external pressure in case of molding can be relaxed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in the method of manufacturing transistor motors.

As is well known, a transistor motor has the characteristics of a DC motor, and is also called a brushless motor, a semiconductor motor, or a Hall element motor. In a DC motor, a rotor generally consists of an armature winding and a commutator.

On the other hand, in a transistor motor, the rotor serves as a magnetic field, and the armature windings and the like are provided on the stator side. In addition, a transistor motor is a DC motor whose commutator is replaced with a transistor or thyristor, and whose brushes are replaced with a Hall element (position sensor), making it a brushless motor that does not include any mechanical contact parts in the electrical circuit. be.

1A and 1B are illustrative views of a conventional transistor motor, in particular, FIG. 1A shows a plan view thereof;
Figure B shows its longitudinal cross-sectional view. In construction, the rotor disk 1 is made of, for example, a soft iron plate. A rotating shaft (shaft) 2 is fixed to the center of the rotor disc 1 . On one side of the rotor disk 1, there are a plurality of (
In the figure, four rotor magnets 3 are integrally fixed.

The rotor magnet 3 is alternately magnetized to N pole and S pole at every 45 degrees of mechanical angle. Here, the rotor disk 1 also serves as a magnetic circuit for the rotor magnets 3. The shaft 2 is rotatably supported by a metal bearing 4.

The metal bearing 4 is made of something like an oil-impregnated sintered alloy,
It supports the shaft 2 and is fitted and integrated with the bearing housing 5. A base plate 6 is fixed to a circumferential portion of the lower end of the bearing housing 5 . The base plate 6 is
It is made of an electromagnetic soft iron plate, and as shown in the figure, through holes 6a are bored in the four corners of the rectangular shape for attaching the transistor motor to the device. That is, the base plate 6
The center portion of the bearing housing 5 is caulked and fixed to the bearing housing 5.

Thereby, the metal bearing 4, the bearing housing 5, and the base plate 6 are made into an integral structure. Metal bearing.

A bushing 7 is inserted into the shaft 2 in the lower portion of the shaft 4 . This prevents the shaft 3- from coming off the metal bearing 4.

On the base plate 6 facing the rotor magnet 3, a circuit board 8 is formed by adhesion or the like. A stator coil 9 and a magnetic flux detection element 10 are formed on the circuit board 8 at predetermined positions by adhesion or the like.

The circuit board 8 forms a circuit pattern of a drive control circuit (not shown) for the transistor motor and a circuit pattern for subsequent circuits. When the drive control circuit is provided externally, connection terminals for the external drive control circuit and a circuit pattern for connecting the connection terminals to the stator coil and the magnetic flux detection element 10 are formed on one circuit board 8. By the way, since the base plate 6 also serves as the magnetic circuit of the rotor magnet 3, the structure is such that the magnetic flux passing through the space of the magnetic circuit cuts the stator coil 9 and the magnetic flux detection element 10.

The operation of rotating the transistor motor in the above-described configuration will be described. The magnetic flux detection element 10 detects the magnetic flux of the rotor magnet 3 and provides its output to the drive control circuit. The drive control circuit supplies a drive current to the stator coil 9 based on the magnetic flux detection output. As a result, the transistor motor becomes a two-phase eight-pole synchronous motor, and the rotor magnet 3, that is, the rotor disc 2, rotates and outputs rotational force to the outside.

However, in the conventional transistor motor, the stator coil 9 and the magnetic flux detection element 10 are simply pasted onto the circuit board 8, and therefore cannot be attached with sufficient strength. Further, in order to provide sufficient strength to the circuit board 8, its thickness must be increased, and therefore the rotor magnet 3
The distance (gap) between the base plate 6 and the base plate 6 becomes larger. Therefore, there was a problem in that magnetic resistance increased and the efficiency of the motor deteriorated. Another problem was that the stator coil 9 was easily vibrated by the drive current.

There were problems in that it was not possible to make accurate decisions, the mechanical precision of each part was poor, and productivity was poor.

Therefore, an object of the present invention is to manufacture a transistor motor that can solve the problems of conventional transistor motors, can accurately position magnetic flux detection elements, improve mechanical accuracy, and has excellent productivity. The purpose is to provide a method.

In summary, the present invention includes preparing a mold in which a protrusion for holding a magnetic flux detection element is formed, and forming an insertion hole for inserting the protrusion into a circuit board. In this method, at least the circuit board and the magnetic flux detecting element are integrally molded with the magnetic flux detecting element inserted into the magnetic flux detecting element and the circuit board inserted into the magnetic flux detecting element.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows an exploded perspective view of a transistor motor manufactured according to the present invention.

FIG. 3 is an exploded perspective view schematically showing the relationship among the circuit board, stator coil, and magnetic flux detection element.

FIG. 4 is a longitudinal sectional view of a transistor motor manufactured according to the present invention.

Next, with reference to FIGS. 2 to 4, the background of this invention and the specific structure of a transistor motor manufactured by this invention will be described. The rotor side, consisting of the rotor disk 1, shaft 2, and rotor magnet 3, is constructed in the same manner as the conventional one shown in FIG. 1B.

The transistor motor manufactured by this invention is the first
The difference from FIG. A and FIG. 1B is that the rotor side is constructed as follows. That is, holes 83 for inserting the stator coils 9 are formed in the circuit board 8 by the number of stator coils 9. Further, a through hole 8b, which is slightly larger in diameter than the metal bearing 4, is bored in the center of the circuit board 8. Further, a U-shaped hole 8d is bored at a position on the circuit board 8 where the magnetic flux detection element 10 is mounted. Although not shown, a copper film circuit pattern for wiring the stator coil 9 and the magnetic detection element 10 is formed on the circuit board 8.

This circuit pattern is connected to external connection terminal 8C.

Then, the stator coil 9 is inserted into the hole 8a of the circuit board 8. Further, the metal bearing 4 is inserted into the through hole 8C of the circuit board 8. Thereafter, the circuit board 8, the magnetic flux detection element 10, the stator coil 9, and the metal bearing 4 are placed in a mold and integrally molded with an insulator 11 made of plastic or the like.

The method of integrally molding the circuit board 8 and the magnetic flux detection element 10 with the insulator 11, the manufacturing method which is a feature of this invention, will be explained in detail later with reference to FIGS. 5 to 8. do.

By configuring as described above, the metal bearing 4, the circuit board 8, and the stator coil 9 are integrally fixed by the insulator 11. Here, the insulator 11 is made of an insulating material such as plastic, for example a thermosetting epoxy resin. Therefore, the insulator 11. The shape of the circuit board 8 is larger than the outer shape of the circuit board 8 so as to surround the circumferential edge of the circuit board 8, and a part of the circumferential edge of the circuit board 8 is fitted into the insulator 1. The upper surface of the peripheral portion of is higher than the circuit board 8. More preferably, mounting holes 11λ for mounting on a device using a transistor motor are formed in the corners (four corners in the illustration) of the insulator 11. Note that instead of the mounting hole 11λ, a mounting ear or a U-shaped groove may be formed.

Thereafter, a stator plate 12 made of a magnetic material (for example, an electromagnetic soft iron plate) is fixed to the back surface of the insulator 11. This stator plate 12 becomes a part of the magnetic circuit of the rotor magnet 3. Therefore, the coil 9 and the magnetic flux detection element 10 are arranged so as to cut the magnetic flux passing through the space from the rotor magnet 3 to the stator plate 12.

By the way, as the material of the insulator 11, a resin that hardens at 160° C. is selected, for example. The metal bearing 4 is filled with oil that does not deteriorate during molding. It is necessary to select a material for the circuit board 8 that does not deform or change in quality at the molding temperature. The stator coil 9 is an insulator that does not change in quality at the molding temperature, and the material is selected so that the coil molded body does not come apart.

The magnetic flux detection element 10 is made of a material that does not deform or change in quality at the molding temperature.

Next, a method of manufacturing a transistor motor, which is a feature of the present invention, will be described with reference to FIGS. 5 to 8.

FIG. 5 is a perspective view showing a magnetic flux detection element holding portion of a molding die used in the manufacturing method of the present invention.

In the figure, in order to hold the magnetic flux detecting element 10, a U-shaped hole 8d is formed in the circuit board 8 so as to sandwich the magnetic flux detecting element from both sides. This hole becomes a hole into which the U-shaped protrusion of the mold is inserted, as will be described later.

FIG. 6 is a partial perspective view showing the magnetic flux detection element holding portion of the molding die used in the manufacturing method of the present invention. In the figure, the mold 13 has a U-shaped protrusion 13 at a portion of the circuit board 8 facing the position where the magnetic flux sensing element φ sound is to be formed.
a is formed. This projection 13a is a perspective view showing the state after molding with resin or the like.

FIG. 8 is an exploded perspective view showing a characteristic part of the manufacturing method which is a feature of the present invention. 7 and 8, in the manufacturing method of the present invention, a magnetic flux detecting element 10 is attached in advance to a portion of the circuit board 8 sandwiched between the U-shaped holes 8d. Then, the terminal portion of the magnetic flux detection element 10 is electrically connected (for example, soldered) to a circuit pattern formed on the circuit board 8. Then, the circuit board 8 is placed into the mold 13 so that the hole 8d is inserted into the protrusion 13a of the mold 13. Therefore, the magnetic flux detection element 10 is engaged with the protrusion 13m. Furthermore, the circuit board 8 placed in the mold
The metal bearing 4 is inserted into the hole 8b. After that, place plastic (for example, thermosetting epoxy resin) into mold 1.
3, the insulator 11 is molded. That is, the metal bearing 4, the circuit board 8, and the magnetic flux detection element 10 are integrally fixed to the insulator 11.

Then, the integrally formed insulator 11 is removed from the mold 13. At this time, the insulator 1 with the protrusion 13a removed
The unformed portion, ie, the hollow portion, serves to prevent external force from being applied to the magnetic flux detection element 10. After that, the metal bearing 41 is attached to the rotating shaft 2 of the rotor plate 1.
is inserted. A bushing 7 is inserted into the rotating shaft 2 at the lower portion of the metal bearing 4. This prevents the rotating shaft 2 from coming off.

A perspective view of the transistor motor constructed by the manufacturing method described above is shown in FIG.

A longitudinal sectional view thereof is shown in FIG.

As described above, by integrally forming the magnetic flux detecting element 10 and the circuit board 8 with the insulator 11 made by resin molding, the positioning accuracy of the magnetic flux detecting element 10 can be improved, and reliability can be improved by easing the external pressure during molding. This has the advantage of being able to produce transistor motors with high performance. In addition, the magnetic flux detection element 1
0, the positioning accuracy of the metal bearing 4, stator coil 9, etc. can be improved, and there are also advantages such as being suitable for mass production.

As described above, according to the present invention, the magnetic flux detection element can be accurately positioned, the assembly accuracy of other parts can be improved, and the strength after assembly can be increased, making it suitable for mass production. be done.

[Brief explanation of the drawing]

FIGS. 1A and 1B are diagrams of conventional transistor motors. FIG. 2 is a perspective view of a transistor motor manufactured according to the present invention. FIG. 3 is an exploded perspective view of the circuit board and stator coil. FIG. 4 is a longitudinal sectional view of a transistor motor manufactured according to the present invention. FIG. 5 is a diagram showing the relationship between the circuit board 8 and the magnetoresistive element used in the manufacturing method of the present invention. FIG. 6 is a partial perspective view showing the holding portion of the magnetic flux detection element of the molding die. FIG. 7 is a partial perspective view showing the magnetic flux detection element mounted on the circuit board. FIG. 8 shows five circuit boards for explaining the manufacturing method of this invention.
FIG. 3 is a partial perspective view showing a state of connection with a mold. In the figure, 1 is the rotor disk, 2 is the rotating shaft (shaft)
, 3 is a rotor magnet, 4 is a metal bearing, 8 is a circuit board, 9
10 is a stator coil, 1o is a magnetic flux detection element, 11 is an insulator, 12 is a stator plate, and 13 is a mold. Agent Makoto Kuzuno - (1 other person) Kan 5 Kotakubo No. 7 Paste 0 8th Introductory Procedures Amendment (Spontaneous 21 Name of Invention Method for Manufacturing Transistor Motor 3, Person Making Amendment (1) 5. Amendment Contents of amendments to the claims column of the specification to be stopped and the detailed description of the invention (1) The "Claims" of the specification are as shown in the attached sheet. (2) The specification is as follows. 2. Claims: A rotor disk fixed to a rotating shaft, a rotor magnet fixed to one side of the rotor disk, at least two stator coils, the stator coil facing the rotor magnet. a circuit board formed with a circuit pattern for electrically connecting a stator coil, a magnetic flux detection element provided on the circuit board, the bearing, the stator coil, the circuit board, and the magnetic flux detection element. A method of manufacturing a transistor motor including an insulator held integrally with the circuit board, and a stator plate fixed to the insulator so as to face a stator coil formed on the circuit board, the circuit board comprising: , a U-shaped hole for holding the magnetic flux detection element in the mold is formed, and a slightly smaller U-shaped protrusion is also formed in the U-shaped hole formed in the circuit board. A method of manufacturing a transistor motor, wherein the insulator is molded with the magnetic flux detection element inserted into a mold and the circuit board inserted into the mold.

Claims (1)

[Claims] A rotor disk fixed to a rotating shaft. At least two rotor magnets are fixed to one side of the rotor disc. At least two stator coils. a circuit board on which the stator coil is formed to face the rotor magnet and a circuit pattern for electrically connecting the stator coil; a magnetic flux detection element provided on the circuit board; the bearing, the stator coil, and the stator coil; An insulator that integrally holds the circuit board and the magnetic flux detection element. and a method for manufacturing a transistor motor including a stator plate fixed to the insulator so as to face a stator coil formed on the circuit board, the circuit board including the magnetic flux detection element in a mold. The magnetic flux detection element is inserted into a mold in which a U-shaped hole for holding the circuit board is formed, and a U-shaped protrusion that is slightly smaller than the U-shaped hole formed in the circuit board is formed. A method of manufacturing a transistor motor, further comprising molding the insulator while the circuit board is inserted into a mold.