JP2000092790A - Manufacture of motor with thermal fuse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a motor, with a thermal fuse, by an ordinary heating molding operation without using a solvent such as alcohol or the like. SOLUTION: A coil 4 and a coil 5 which are adjacent are connected by a sufficiently long connecting wire 2 via a thermal fuse 1. When the coil 4 and the coil 5 are heated and welded, the thermal fuse 1 is not heated, In addition, a substitute 6 for the thermal fuse 1 or a tubular object 7 whose thermal conductivity is good is inserted in such a way that a gap 3 between the coils 4, 5, in which the thermal fuse 1 is arrange, does not become narrow after their molding operation. The thermal fuse 1 is inserted into a space from which the substitute 6 is removed after their molding operation or into the inside of the tubular object 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a motor with a thermal fuse having a function of preventing the risk of abnormal heat generation.

[0002]

2. Description of the Related Art As a safety measure against motor heating,
Conventionally, a thermal protection method, an impedance protection method, a thermal fuse method, and the like have been adopted.

[0003] The thermal protection system is a system in which a thermal protector is built in a motor and a power supply circuit is cut off when the operating temperature of the motor is reached.

[0004] The impedance protection system is a system in which a change in a coil and impedance at the time of heat generation is detected, and the power supply circuit is cut off when the impedance reaches a set value.

In both the thermal protection method and the impedance protection method, if the motor temperature falls below the set value, the power supply circuit can be restored again. If such abnormal temperature conditions are repeated, a short circuit occurs due to deterioration of the coil insulation, and depending on the environment, ignition may occur. There is a possibility.

In the thermal fuse system, when the operating temperature is reached, the power supply circuit is cut off in the same manner as in other systems, but it does not return even when the temperature is lowered. High safety.

[0007] The wound coil only needs an extra space and does not have the required external dimensional accuracy, so that the coil is pressed into a predetermined shape, and at the same time, the fusion varnish applied to the winding is melted by heating, and after cooling, the coil is added. It is necessary to be able to maintain the shape when pressed. Heating is performed by passing a necessary current through the coil. Since the heat molding is generally performed at a temperature higher than the operating temperature of the thermal fuse, the thermal fuse cannot be left at a position where the thermal fuse is normally used.
For this reason, in a conventional motor with a thermal fuse, the varnish is melted not by heating but by alcohol. In this case, even without heating, there is a possibility that the thermal fuse may be damaged by pressurization.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to manufacture a motor with a thermal fuse which can be set in an optimum position by ordinary heat molding without using a solvent such as alcohol.

[0009]

Means for Solving the Problems By connecting the windings of adjacent coils with a long wire through a thermal fuse, the thermal fuse is prevented from being heated at the time of forming the coil by heating, and the thermal fuse is formed at the time of molding. Insert a substitute for a thermal fuse or a tube with good thermal conductivity so that the gap between the coils to be placed is not narrowed, remove the substitute after molding, and when the temperature of the coil has dropped, The thermal fuse is inserted into the space from which the substitute has been removed or into the tubular body.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Since a motor with a thermal fuse cannot use a heat molding method, a method using a large amount of a solvent such as alcohol is used. However, the present invention makes it possible to use a heat molding method. Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011]

1 is a side view of a completed stator of a motor with a thermal fuse according to the present invention, and FIG. 2 is a front view thereof. A thermal fuse 1 is connected to the connection line 2 between the coils 4 and 5.
Are inserted and connected, and are arranged in the gap 3. Since this location has the least effect of the cooling effect of the outer wall, it is the location where the temperatures of the coils 4 and 5 can be measured most faithfully.

FIG. 3 shows a state in which molding is performed after winding. FIG.

[A] shows that the coils 4 and 5 are greatly swollen in the axial direction before molding, and to obtain a predetermined size, FIG.

As shown in [b], it is necessary to press-mold this in the axial direction and fix the shape after molding. Forming jigs 8 and 9 are used to form the coil into a predetermined shape. When pressed in the axial direction, the coils 4 and 5 tend to deform in a direction perpendicular to the pressing direction, as indicated by the arrows in FIG. Therefore, the gap 3 into which the thermal fuse 1 is to be inserted is narrowed.

In order to fix the shapes of the coils 4 and 5 after molding, the coils 4 and 5 are heated at the time of molding to melt the applied varnish, cooled after molding and cooled again to separate the varnish into coils. 4 and 5 need to be integrated. The temperature of the coils 4 and 5 at this time is naturally higher than the temperature at the time of use of the motor, and when the thermal fuse 1 is exposed to this temperature, it operates and the motor becomes unusable.

The heating is performed by passing a necessary current through the coils 4 and 5. At this time, thermal fuse 1
As shown in FIG. 5, is placed in a place away from the coils 4 and 5 and below the operating temperature. For this purpose, the connection line 2 between the coils 4 and 5 is made sufficiently long.

In order to prevent the gap 3 from being narrowed by the pressurization, the substitute 6 of the thermal fuse 1 is inserted and placed. After the pressurization, the substitute 6 is removed before the varnish solidifies, and the temperature of the gap 3 is reduced. When the temperature falls below the operating temperature of the thermal fuse 1,
The thermal fuse 1 is inserted into the gap 3. Thus, a motor with a thermal fuse can be manufactured by a heat molding method.

FIGS. 6 and 7 use a tubular member 7 made of a material having good thermal conductivity. Before the heat molding, the tubular article 7 is inserted into the gap 3, and during the heat molding, the thermal fuse 1 is placed in a position not affected by heat.
Is inserted into the tubular article 7. Since the tubular object 7 is made of a material having good thermal conductivity, the thermal fuse 1 can operate normally.

[0017]

According to the present invention, a heat-molding method cannot be performed with a motor having a thermal fuse without using a solvent such as alcohol. A motor with a thermal fuse can be manufactured by a superior manufacturing method, such as making the wire connecting adjacent coils sufficiently long so that the thermal fuse can be placed at a remote location where it will not be heated during use and heat molding. Has the effect of

[Brief description of the drawings]

FIG. 1 is a side view (lower half is a cross-sectional view) in which a thermal fuse is inserted.

FIG. 2 is a front view in which a thermal fuse is inserted.

FIG. 3

[A] It is a side view before molding.

FIG. 2B is a side view after molding.

FIG. 4 is a front view showing a direction in which a winding is deformed by pressure.

FIG. 5 is a front view showing a thermal fuse connected by a long wire.

FIG. 6 is a front view using a tubular material having good thermal conductivity.

FIG. 7 is a side view in which a thermal fuse is inserted into a tubular object (the lower half is a sectional view).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal fuse 2 Connection line 3 Air gap 4 Coil 5 Coil 6 Alternative to thermal fuse 7 Tubular material with good thermal conductivity 8 Molding jig 9 Molding jig

Claims (2)

[Claims] An electric wire in a portion connecting a thermal fuse and an adjacent coil is made sufficiently long, and is located at a position away from the coil so that the thermal fuse is not heated to an operating temperature during heat molding of the coil. Insert a substitute to secure a space for accommodating the thermal fuse so that the gap between the coils where the thermal fuse is placed after molding and the coil is not narrowed during molding, remove the substitute after molding, and remove the thermal fuse. A method for manufacturing a motor with a thermal fuse, wherein a thermal fuse is inserted in place of the substitute when the temperature of the coil falls below the operating temperature of the motor. 2. The electric wire at a portion connecting the thermal fuse and the adjacent coil is made sufficiently long, and is sufficiently separated from the coil so that the thermal fuse is not heated to the operating temperature when the coil is formed by heating. Insert a tubular material made of a material with good heat conductivity, with an inside dimension enough to insert the thermal fuse, so that the gap between the coils where the thermal fuse is placed after molding is not narrowed during molding. A method for manufacturing a motor with a thermal fuse, wherein the thermal fuse is inserted into the inside of the tubular article when the temperature of the coil falls below the operating temperature of the post-thermal fuse.