JPS59211925A - Method of producing blowing detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an air blow detection device that combines a temperature sensor constructed of a temperature-sensitive magnetic material, a reed switch, and a permanent magnet, and a heater element.

This type of blower-button device is mainly used to detect abnormal stoppage of cooling fans in power supply equipment, etc., and uses a normal resistor as a stopper element. The temperature rose abnormally, posing a safety problem. However, there is also the problem that the glass sealing door is easily damaged.

(2) In order to solve the above problems, the present invention uses a positive temperature coefficient thermistor having a self-temperature holding function as a heater element,
An object of the present invention is to provide an air blowing detection device that ensures thermal safety when a fan stops abnormally.

The invention is also easy to assemble and has a low defect rate.

Therefore, an inexpensive airflow detection device is provided.

The present invention provides an air blow detection system comprising a temperature switch composed of a temperature-sensitive magnetic body, a reed switch, and a permanent magnet, a heater element that heats the temperature-sensitive magnetic body, and a rectangular insulating frame that holds these elements. In the device, a positive temperature coefficient thermistor having a self-temperature holding function is used as the heater element, and when the temperature switch is installed in the frame, the connection between the lead of the reed switch and the lead wire connection terminal is improved.

The present invention will be explained in detail below.

FIG. 1 is a front view of a blowing air detection device obtained according to the present invention, and FIG. 2 is an exploded perspective view thereof. This device is mounted on both legs of a U-shaped temperature-sensitive magnetic body 4.

The magnetic poles are aligned in the axial direction and a spacer 6 made of a gap or a non-magnetic material is placed on the outer circumference of the reed switch 7.
It consists of a temperature switch constructed with two permanent magnets 5 and 5' fitted together, a positive temperature coefficient thermistor 3, a first electrode plate 1 and an n-type second electrode plate 2 to which a power supply is connected. A heater element and a rectangular insulating main frame for holding the heater element 9. It consists of an auxiliary frame body 10 made of the same material.

In the temperature switch, the open ends of the temperature-sensitive magnetic body 4 are fitted into grooves 91 and 91' provided in the main frame body 9, and the leads 71 and 71' of the reed switch 7 and the lead wires welded to the ends of these leads. The connection terminals 8, 8' are fitted into grooves 92, 92' provided in the main frame 9 and held therein. The electrode plate 1 is
One end is fitted into a groove 93' provided in the inner wall of the main frame 9, and the other end is used as a lead wire connection terminal 81 and fitted into a groove 93 provided in the main frame 9. That is, this electrode plate 1 is installed so as to be in close contact with the outer surface of the closed end side of the temperature-sensitive magnetic body 4 of the temperature switch held by the main frame 9, and holds the temperature switch. Further, one end of the electrode plate 2 on the same side as the lead wire connection terminal 81 of the electrode plate 1 is fitted into a groove 94 provided in the inner wall of the main frame 9, and the other end is fitted with the lead wire connection terminal 81.
2 and is fitted into a groove 94' provided in the main frame body 9. The electrode plate 2 is prevented from shifting in the plane direction by protrusions 21, 21' and protrusions 22° 22' formed between the upper side of the electrode plate 1 and the positive temperature coefficient thermistor 3. An auxiliary frame 10 is fixed to the main frame 9 by adhesive or welding to prevent the temperature switch and heater element from falling off.

95.95' is a mounting piece for the main body of the device.

This device uses the mounting pieces 95 and 95' to attach the main frame 9
The electrode plate 1 and the electrode plate 2 are installed in a ventilation passage so that air can pass through them, and a power source is connected to the electrode plate 1 and the electrode plate 2. In addition, 19. The positive characteristic '-mix x l 3 generates heat.' When there is air blown at a prison wind speed, the temperature of the closed end 41 of the temperature-sensitive magnetic body 4 is The temperature is suppressed to one point or less, and the entire temperature-sensitive magnetic body 4 (5) exhibits ferromagnetism. Therefore, the permanent magnet 5°5'
Most of the magnetic flux flows through the temperature-sensitive magnetic body 4, and only a small amount of magnetic flux flows through the contact portion of the reed switch 7, so the reed switch 7 is in an open state.

When the wind speed becomes lower than the rated wind speed from this state, the temperature of the positive temperature coefficient thermistor 3 increases because heat dissipation due to the air flow decreases. Following this, the temperature of the electrode plate 1 and the closed end 41 of the temperature-sensitive magnetic body 4 also rises, and when the temperature of the closed end 41 reaches the Curie temperature Tc, it becomes paramagnetic. Due to this,
Most of the magnetic flux from the permanent magnets 5, 5' flows into the reeds of the reed switch 7, so that the contacts are not closed, and the electric circuit connected to the terminals 8, 8/ detects a decrease in air flow. be done.

On the other hand, since the positive temperature coefficient thermistor 3 is stably maintained at a predetermined constant temperature higher than the self-temperature holding device IJ1 temperature Tc, the conventional air blowing detection device which uses a resistor heating element as a heater element Thermal safety when the air blowing is stopped is significantly improved compared to the previous model.

By the way, especially when assembling the 9-piece device.

When setting the temperature switch on the main frame 9, care must be taken not to damage the lead switch 7. i.e. 9
Leads 71.71 of reed switch 7 during assembly
In mass production, it is important to minimize the stress applied to the glass sealing part and prevent glass breakage.

Therefore, in the present invention, when setting the flow rate switch, the leads 71, 71' of the reed switch 7 and the lead wire connection terminals 8, 8' are separately set in the grooves 92, 92' of the main frame 9, and the After fixing the frame 10, the leads 71, 7
The projecting portions 72, 72' extending outward from the main frame body 9 of 1' and the lead wire connection terminals 8, 8' are connected by spot welding from the outside. According to this method, the leads 71, The stress applied to the reed switch 71' is greatly reduced, and the defective rate due to breakage of the reed switch can be greatly improved.

Figure 3 shows welding electrodes 11 and 12 applied from the outside (7). FIG. 3 is a diagram showing a method of spot welding.

The lower electrode 12 has a curved portion to avoid contact with the lead wire connection terminal 81, and the upper end surface is provided with a groove corresponding to the lead diameter of the reed switch 7 to prevent positional deviation during welding. I try not to.

As described above, according to the two aspects of the present invention, thermal safety is high.

It is possible to provide an air blowing detection device that is easy to assemble, greatly reduces breakage of the reed switch, improves yield, and is therefore inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a front view of a blowing air detection device obtained according to the present invention;
FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a diagram showing a spot welding method. In the figure, 1.2: electrode plate, 3: positive temperature coefficient thermistor.

Claims (1)

[Claims] 1) A reed switch with two permanent magnets fitted around the outer periphery of the reed switch with their magnetic poles aligned in the axial direction and spaced apart from each other at a constant distance is a substantially U-shaped magnetic body. In the air blowing detection device, the temperature switch includes a temperature switch installed between both legs, a heater element that heats the temperature-sensitive magnetic material, and a rectangular insulating frame that holds them. The ends of both legs of the body are fitted into grooves provided in the inner wall of the frame, and the leads of the reed switch are led out of the frame through the grooves provided in the frame. These two electrode plates are mounted on the frame so that a positive temperature coefficient thermistor is sandwiched between the electrode plates and one electrode plate is in contact with the outer surface of the closed end side of the temperature-sensitive magnetic body, and the reed switch (1 ) The connection terminal is inserted and the lead of the reed switch protruding outside the frame is connected to the lead wire connection terminal by external slit welding after each component is assembled. Method 5 of manufacturing a blowing air detection device characterized by
Six.