JPS5915383Y2 - Blower motor rotation control device - Google Patents

Description

[Detailed description of the invention] This invention detects this temperature rise and interrupts the electric circuit to prevent overheating when the resistor for controlling the rotation of the blower motor overheats due to a failure of the motor or fan. The present invention relates to an improvement of a rotation control device for a blower motor to prevent such problems.

Conventionally, in order to prevent resistors from overheating,
A configuration is used in which a temperature fuse is provided above the temperature fuse to detect overheating.

With this configuration, there is a problem in that the temperature fuse must always be located above the resistor, since it will affect the sensing performance, and there is a problem in that the mounting location must be selected based on this constraint.

Therefore, in this invention, in order to eliminate the conventional defect of selecting the installation location, a heat conductive plate is installed that penetrates the inside of the coiled resistor built into the rotation control circuit of the blower motor. To provide a rotation control device for a blower motor that operates accurately by providing a temperature fuse at the end of the heat conduction plate so that heat can be accurately sensed no matter where the heat conduction plate is installed. It is something.

Next, an embodiment of this invention will be described with reference to the drawings.

In FIG. 1, a first embodiment of this invention is shown, in which a resistor 1 for controlling the rotation of the blower is arranged in a ventilation path through which air is blown by the rotation of the blower motor 3, as is well known. Built into the control circuit, rotation control switch 2
The switching operation switches between intervening and non-intervening, controls the current flowing to the blower motor 3, and controls the rotational speed using the current value.

The resistor 1 is formed into a coil shape with a gap in the winding direction, and one end is fixed to a substrate 4 which is covered with an insulating material, and the other end is fixed to one end of a heat conductive plate 5 described below, and the other end is fixed to the substrate 4. It is installed on top of 4.

One end of the thermally conductive plate 5 is fixed on the substrate 4, the other end is bent, and its tip is inserted into the above-described coiled resistor 1 without contacting it, and its through end 5a is removed by a temperature fuse 6. It is connected to the metal plate 7 which is biased in the direction.

The end of the heat conduction plate 5 that is in contact with the substrate 4 is connected to the fixed contact 2d of the rotation control switch 2, and the end of the resistor 1 that is in contact with the substrate 4 is connected to the fixed contact 2C, and The ends of 7 on the substrate 4 side are connected to the blower motor 3, respectively.

The rotation control switch 2 has the above-mentioned fixed contacts 2C92d and O.
The movable contact 2a is connected to the power source 8, and when the movable contact 2a is rotated from the OFF contact 2b in the figure and switched to the fixed contact 2C, the current flows through the resistor 1, Heat conduction plate 5, temperature fuse 6 and metal plate 7
, and the blower motor 3 is rotated at low speed.

Furthermore, when the movable contact 2a is switched to the fixed contact 2d, the current flows from the heat conduction plate 5, temperature fuse 6, and metal plate 7 to the blower motor 3 without passing through the resistor 1, and the blower motor 3 is rotated at high speed. Become so.

If the blower motor 3 malfunctions and locks up, the resistor 1 will overheat due to its Joule heat, and since there is no air to cool the resistor 1, the temperature of the heat conductive plate 5 will rise rapidly.
This heat is transferred to the temperature fuse 6, and the temperature fuse 6
is a metal plate 7 which is melted and biased in the direction of pre-caulking.
is displaced in the direction of the two-dot chain line, the contact between the heat conductive plate 5 and the metal plate 7 is broken, the rotation control circuit of the blower motor 3 is cut off, and overheating of the resistor 1 is prevented.

FIG. 2 shows a second embodiment of this invention, in which the rotation of the blower is controlled in three stages: low speed, medium speed, and high speed, and two coiled resistors 1a and lb are used. , the resistors 1a, lb are arranged in series on the substrate 4, one end of which is fixed on the substrate 4, and the other end of the heat conductive plate 5 is inserted into the coiled resistors 1a, lb. Penetrating end 5
a is connected to a metal plate 7 by a temperature fuse 6.

One end of the resistor 1a on the substrate 4 side is connected to the fixed contact 2d of the rotation control switch 2 via the heat conduction plate 5, and the other end is connected to the fixed contact 2C together with one end of the resistor 1b, so that the rotation control switch By switching by rotating the movable contact 2a of 2, the circuit passing through the resistors 1a and 1b is appropriately selected, and a desired current is passed through the blower motor 3 through the heat conduction plate 7, and the rotation of the blower motor 3 is controlled. The other points are the same as those of the previous embodiment.

As mentioned above, this idea involves inserting a heat-conducting plate as an element that constitutes the rotation control circuit of the blower motor into the coil-shaped part of the resistor for current limiting, and inserting a temperature fuse into the through-end of the heat-conducting plate. is placed in contact with the metal plate, and the resistor has a gap in the winding direction, allowing good air circulation to the heat conduction plate, and detecting the presence or absence of air with a temperature fuse via the heat conduction plate. The sensing ability is extremely good, and since the thermal conductive plate is inserted into the coiled resistor, the thermal sensing state is constant regardless of the position, so the mounting device Moreover, since the resistor has a gap in the winding direction, there are advantages such as low ventilation resistance.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of this invention, and FIG. 2 is a block diagram showing another embodiment of this invention. 1...Resistor, LA, LB...Resistor, 2...Rotation control switch, 3...Blower motor, 5... Heat conduction plate, 6...
temperature fuse.

Claims (1)

[Scope of utility model registration request] A resistor is disposed in a ventilation path through which air is blown by the rotation of the blower motor, and the resistor has a rotation control circuit that controls the number of rotations of the blower motor by changing the number of the resistors, and the resistor is coiled and A heat conductive plate is formed to have a shape with a gap in the winding direction, and a heat conductive plate is passed through the resistor without contact with the resistor, and a temperature fuse is provided at the end of the heat conductive plate to cut off electricity to the blower motor. A blower motor rotation control device featuring: