JPS6059814B2 - Manufacturing method for coreless motor rotor coil tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure of a coil cylinder used in a rotor of a coreless motor.

Conventionally, in order to highly exhibit the characteristics of a coreless motor, methods have been adopted in which a magnet with high magnetic flux density is used or coil wires are bundled and wound.

However, if a magnet with a high magnetic flux density is used, since such a magnet is effective, the cost of the motor as a whole will be high.Also, if a high-density coil cylinder is to be formed, the coil wire usually has a circular cross section. Since the copper wire is wound, a gap is formed between the outer peripheral surfaces of adjacent coil wires, and therefore, in a rotor having a coil tube with a limited diameter, the density of the coil winding is high. It was difficult to do so.

The present invention was made in view of this fact, and aims to provide a high-performance, low-cost coreless motor by increasing the coil winding density even when using low-performance, low-cost magnets. It is.

Hereinafter, the present invention will be explained based on the drawings. FIG. 1 is a perspective view showing the shape of the coil winding tube 2 of the coreless motor of the present invention, FIG. 3 is a cross-sectional view showing the deformed state of the coil wire, FIG. 4 is a cross-sectional view showing the state in which the peripheral wall of the coil winding tube 2 is placed in a mold to reduce its shape, and FIG. It is a vertical cross-sectional view of different examples of the mold. In the figure, numeral 1 denotes a coil wire, which is usually a copper wire with a circular cross section. 2 is a coil winding tube in which the coil wire 1 is wound into a cylindrical shape, and 3 is a rotor coil tube in which the peripheral wall of the coil winding tube 2 is formed into a wave shape.

In the coil winding tube 2, the coil wire 1 is disposed obliquely on the circumferential surface from a portion that becomes one end of the completed coil winding tube 2 to a portion that becomes the other end, and reaches the other end. It is formed into a double winding by folding it back so that it is reflected at the other end. Next, a method for forming the peripheral wall of the coil-wound tube 2 of the coreless motor of the present invention into a wave-like shape will be described.

That is, as shown in FIG. 4, the inner hollow part of the coil-wound tube 2 is formed with a shape that is much smaller than the inner shape of the coil-wound tube 2 and has a corrugated outer circumferential surface that is equal to the outer shape of the rotor to be formed. The center of the coil winding pipe 2 is inserted into the center of the coil winding pipe 2 with a pressing die 5 formed in a wave shape so as to correspond to the wave shaped part of the front core bar 4 from the outside of the circumferential wall of the coil winding pipe 2. Apply pressure in the direction.
Therefore, if the wave pattern of the pressing die 5 and the wave pattern of the core bar 4 are made to match and are pressed against the outer and inner surfaces of the coil winding tube 2, the peripheral wall of the coil winding tube 2 will also have a wave shape. is formed.
That is, to explain based on FIG. 3 which shows the main part of the cross section of the coil winding tube 2 before and after diameter reduction, in the state before pressurization, FIG.
As shown, the coil wires 1 on the outer circumference located slightly forward to the right correspond to each coil wire 1 on the inner circumference, forming a double stack arrangement. The corresponding coil wires 1 refer to the inner and outer coil wires 1 shown in the connected state in the drawings.
This coil-wound tube 2 is placed in a mold as shown in FIG. 5, and its diameter is reduced in the direction of the center as shown by the arrow (in this case, the elastic tube 6 described later is not used). When the coil wire 1 moves toward the center, it causes a movement such as counterclockwise rotation, and when the coil wire 1 on the outer circumference side moves toward the anti-center direction, it causes a movement such as clockwise rotation.
The coil wires 1 of each set are stacked one after another and are finally stacked in three rows as shown in FIG. 3c. As described above, the arrangement state of the coil wires 1 of the coil winding tube 2 is the third one.
As shown by the solid line in the figure, it is formed into a substantially wavy shape. That is, they are deformed into three rows stacked in the radial direction, and as the number of stacks increases, the diameter is reduced. In addition, FIG. 5 shows a different example of the mold for implementing the present invention, and is a cross-sectional view showing a state in which the coil winding 2 is placed in the mold to reduce its diameter.

As described above, the rotor coil tube of the coreless motor of the present invention is formed by winding coil wires having a circular cross section into a cylindrical shape to form a coil winding tube, and forming the rotor in the inner cavity of the coil winding tube. A core metal 4 whose outer circumferential surface is formed into a wave shape approximately equal to the outer diameter of the core metal is inserted, and a wave-shaped pressing die corresponding to the wave shape of the core metal is pressed against the outside of the peripheral wall of the coil winding tube. Since the inner side of the circumferential wall of the coil winding tube is pressed against the core metal to reduce the diameter of the circumferential wall of the coil winding tube in a wavy shape, the coil winding tube 2 is regulated by the outer diameter of the core metal 4. Although the inner diameter of the rotor coil cylinder is reduced to a limited diameter, by reducing the diameter of the peripheral wall in a wave shape, it is possible to aggregate the coil wires at a high density per unit length. Therefore, even when a low-performance, low-cost magnet is used, it is possible to provide a high-performance coreless motor.

Note that the type for reducing the diameter of the coil winding tube is not limited to the configuration shown in FIG. 4.

In the example shown in FIG. 5, a pressing die 5 made of an elastic cylinder with only a corrugated inner circumferential surface is formed in a circular recess of a die 9. The core bar 4 is fitted and accommodated in the protruding part)'', and the pressing mold 5 is pressed on the inner circumferential surface of the inner cavity.
The coil winding tube 2 is fit loosely into the core metal 4 in the inner cavity of the pressing die 5, and the coil winding tube 2 is held on the inner circumferential surface of the pressing die 5. If the upper end surface of the pressing mold 5 is pressed downward with the punch 7, the inner peripheral surface will correspond to the corrugation of the core metal 4 and the corrugation of the core metal 4. Since the coil tube 2 is elastically deformed inward so as to come into pressure contact with the metal core 4, the pressing force generated on the inner surface causes the coil winding tube 2 to contract in the radial direction and is brought into pressure contact with the core bar 4.
In this case, if the upper end surface of the coil winding tube 2 is always pressed with the push-down tool 8 and the movement of the coil winding tube 2 in the vertical direction is controlled, the diameter reduction can easily occur.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the shape of the coil winding tube of the coreless motor of the present invention, FIG. 2 is a perspective view showing the shape of the rotor coil tube with the coil winding tube reduced in diameter, and FIG. 3 is a perspective view showing the shape of the coil winding tube. FIG. 4 is a cross-sectional view showing a deformed state, and FIG. 4 is a cross-sectional view showing an example of a mold for implementing the present invention. FIG. FIG. 3 is a diagram showing a different example of a mold for carrying out the invention, and is a vertical cross-sectional view. DESCRIPTION OF SYMBOLS 1... Coil wire, 2... Coil winding tube, 3... Rotor coil tube, 4... Core metal, 5... Press mold, 7...
- Punch, 8...pushing tool, 9...die.

Claims (1)

[Claims] 1. A coil wire with a circular cross section is wound into a cylindrical shape to form a coil winding tube, and the outer peripheral surface is shaped into a wave shape approximately equal to the outer diameter of the rotor to be formed in the inner cavity of the coil winding tube. Insert the core metal formed into the core metal, and press a wave-shaped pressing die corresponding to the wave shape of the core metal to the outside of the peripheral wall of the coil-winding tube, so that the inside of the peripheral wall of the coil-winding tube becomes the core metal. A method for manufacturing a rotor coil tube for a coreless motor, which comprises compressing the circumferential wall of the coil tube to reduce its diameter in a wave-like manner.