JPH0628697Y2 - Blower detection device - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a blower detecting device in which a temperature switch composed of a temperature-sensitive magnetic material, a reed switch, and a permanent magnet is combined with a heater element.

[Problems to be solved by conventional techniques and devices]

This type of air flow detection device is mainly used for detecting abnormal stop of a cooling fan such as a power supply device as disclosed in Japanese Utility Model Publication No. 59-14733. However, the conventional one uses a normal resistor as the heater element, and the temperature of the resistor heating element abnormally rises when the fan stops abnormally, which is a problem in terms of safety.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a blast detection device that uses a positive temperature coefficient thermistor having a self-temperature-maintaining function as a heater element to solve the above-mentioned problems and ensures safety during abnormal fan stop. .

The present invention also aims to provide an air flow detection device that is easy to assemble and inexpensive.

[Means for solving problems]

The present invention is a reed switch having two permanent magnets arranged with their magnetic poles aligned in the axial direction and spaced at regular intervals. In a blower detecting device in which a switch and a heater element assembly for heating the temperature-sensitive magnetic body are mounted on an insulating frame, the heater element assembly includes a positive temperature coefficient thermistor and a closed end side of the temperature-sensitive magnetic body. A first electrode plate installed on the frame so as to be in close contact with the outer surface of the end of the
Second electrode plate erected on the frame so as to sandwich the positive temperature coefficient thermistor between the second electrode plate and the positive electrode thermistor, and the frame acting to press the second electrode plate to the positive temperature coefficient thermistor side. A crimping spring erected on the body, the first electrode plate is provided with a protrusion by folding back for holding the PTC thermistor, and the crimping spring holds the PTC thermistor. And a punching hole is provided in the second electrode plate at a position corresponding to the projecting piece of the crimp spring, and the first electrode plate and the crimp spring are combined. The positive temperature coefficient thermistor is held between the positive electrode and the second electrode plate.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof.

This device comprises an insulating tube 2 having a reed switch 1 through it, and two permanent magnets 3 and 3'arranged in the outer circumference of the insulating tube 2 with their magnetic poles aligned in the axial direction and a gap g.
-Shaped temperature-sensitive magnetic body 4, a temperature switch installed between both legs 41, 41 ', a positive temperature coefficient thermistor 5, and a first electrode plate 6 and a second electrode plate 7 for connecting a power source thereto, and crimping Spring 8
It is composed of a heater element assembly composed of, and an insulating frame 9 and an auxiliary frame 110 for holding them.

The temperature switch has a tenon-shaped open end of the temperature-sensitive magnetic body 4, which is inserted into the grooves 91, 91 'provided in the frame body 9 and fixed to the lead end of the reed switch 1 by soldering or spot welding. The terminals 11 and 11 ′ thus formed are inserted and held in the grooves 92 and 92 ′ provided in the frame body 9. First electrode plate 6
Has one end inserted into the groove 93 provided on the inner wall of the frame body 9,
The other end is inserted into a groove 93 'provided in the frame body 9 as a lead wire connecting end 61. That is, the electrode plate 6 is laid so as to be in close contact with the outer surface of the closed end side end portion 41 of the temperature-sensitive magnetic body 4 of the temperature switch held by the frame body 9. Regarding the second electrode plate 7 and the crimp spring 8, the punched portions 71, 71 ′ of the electrode plate 7 are protruded by cutting and raising the crimp spring 8 81, 81 ′.
Are set so that they penetrate. Then, both the connection terminal 72 of the electrode plate 7 and the edge of the crimp spring 8 on the same side thereof are inserted into the groove 93 of the frame body 9, while on the other side, only the edge of the crimp spring 8 is grooved on the frame body 9. It is inserted at 93 '. The second electrode plate 7 is mounted on the frame body 9 with the positive temperature coefficient thermistor 5 being sandwiched between the second electrode plate 7 and the first electrode plate 6. An auxiliary frame 110 is fixed to the frame body 9 by means such as adhesion or welding to prevent the temperature switch and the heater element assembly from falling off. Reference numerals 95 and 95 'are attachment pieces of the apparatus main body.

This device is installed in the ventilation passage so that the air flows through the frame body 9 by using the mounting pieces 95 and 95 ', and the power source is connected to the electrode plate 6 and the electrode plate 7. As a result, the positive temperature coefficient thermistor 5 generates heat, but when there is air blown at the rated wind speed, the heat is dissipated by the air blow, so that the temperature of the closed end portion 41 of the temperature-sensitive magnetic body 4 is suppressed below its Curie point. The entire warm magnetic body 4 exhibits ferromagnetism. For this reason, most of the magnetic flux from the permanent magnets 3 and 3'flows through the temperature-sensitive magnetic body 4 and the reed switch 1
Since only a small amount of magnetic flux flows through the contact portion of the reed switch 1, the reed switch 1 is in the open state.

When the wind speed is lower than the rated wind speed from this state, the heat dissipation due to the air flow is reduced, so that the temperature of the positive temperature coefficient thermistor 5 rises. Following this, the temperature of the electrode plate 6 and the closed end portion 41 of the temperature-sensitive magnetic body 4 also rises, and when the temperature of the closed end portion 41 reaches the Curie temperature Tc ₁ of the temperature-sensitive magnetic body, it becomes paramagnetic. As a result, most of the magnetic flux from the permanent magnets 3 and 3'flows into the reed of the reed switch 1 and the contacts are closed, and the electric circuit connected to the terminals 8 and 8'detects the decrease in air flow. .

On the other hand, since the positive temperature coefficient thermistor 5 is stably held at a predetermined constant temperature equal to or higher than its Curie temperature Tc ₂ by the self-temperature holding function, the conventional air flow detection device using a normal resistor heating element as a heater element. Compared with the above, the thermal safety at the time of stopping the ventilation is significantly improved.

Due to the function of the blower detection device, the PTC thermistor 5 is mechanically fixed, the electrode plate 6 and the electrode surface 51 of the PTC thermistor 5 are connected.
The state of electrical contact with the electrode plate 7 and the state of electrical contact between the electrode plate 7 and the electrode surface 52 of the positive temperature coefficient thermistor 5 are particularly important.

The mechanical fixing of the positive temperature coefficient thermistor 5 is important for ensuring stable heat conduction from the positive temperature coefficient thermistor 5 to the temperature-sensitive magnetic body 4 and obtaining a stable operation. The protrusions 62, 62 'formed by folding back the peripheral portion of 6 prevent vertical displacement with respect to the plane of the frame 9 of the positive temperature coefficient thermistor 5. On the other hand, punching parts 71, 7 of the electrode plate 7
The protrusions 81 and 81 ′ of the crimp spring 8 protruding from 1 ′ prevent the positive characteristic thermistor 5 from shifting in the lengthwise direction of the electrode plate 6, and the crimp spring 8 fixes the positive characteristic thermistor 5 in the thickness direction. Has been realized.

Regarding the electrical contact between each electrode plate and the surface of the positive temperature coefficient thermistor, it is particularly important that the contact state between the electrode plate and the surface of the positive temperature coefficient thermistor is that the electrode plate hits the center of the positive temperature coefficient thermistor electrode surface. The contact state is kept good.
In the present invention, the contact between the electrode surface 51 of the positive temperature coefficient thermistor 5 and the electrode plate 6 is maintained by the pressure contact force from the pressure contact spring 8. Regarding the contact between the electrode surface 52 of the PTC thermistor 5 and the electrode plate 7, the contact surface of the electrode plate 7 is bent toward the PTC thermistor side with a predetermined curvature (see FIG. 3), and the crimp spring 8 When a positive temperature coefficient thermistor is mounted in combination with the positive temperature coefficient thermistor, the electrode plate 7 is deformed so that the electrode plate 7 substantially contacts the central portions of both pole faces of the positive temperature coefficient thermistor.

That is, when the pressing force of the compression spring 8 acts on the electrode plate 7 curved upward, the curved portion of the electrode plate 7 tries to deform so as to be in flat contact with the electrode surface of the positive temperature coefficient thermistor 5. Since the projecting portions 71, 71 'of the surface 7 are penetrated by the projecting sides 81, 81' of the crimp spring 8, the projecting sides 81, 81 'make the curved portion of the electrode plate 7 completely flat. Is prevented.

FIG. 3 is a view showing the state of the electrode plate 6, the electrode plate 7, and the crimping spring 8 with the positive temperature coefficient thermistor removed, and FIG. 4 is the electrode plate 6 and the electrode plate 7 when the positive temperature coefficient thermistor 5 is mounted. FIG. 6 is a view showing a state of the crimp spring 8.

[Effect of device]

According to the present invention, the combination of the electrode plate 6 and the electrode plate 7 and the crimp spring 8 mechanically stabilizes the positive temperature coefficient thermistor 5 and makes good electrical contact between the electrode plate and the positive temperature coefficient thermistor electrode plate. Can be realized. Further, it is possible to provide an air blowing detection device which is easy and inexpensive to assemble and has a high safety and a stable function.

In particular, the crimp spring acts so as to strongly press the curved portion of the second electrode plate against the central portion of the positive temperature coefficient thermistor while preventing the deformation thereof, so that the electrical contact between the second electrode plate and the positive temperature coefficient thermistor is prevented. Good contact.

[Brief description of drawings]

FIG. 1 is an external view of an embodiment of a blower detecting device according to the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 shows the relationship between each electrode plate and a crimp spring before mounting a positive temperature coefficient thermistor. FIG. 4 and FIG. 4 are views for explaining the relationship between each electrode plate and the crimp spring after the PTC thermistor is attached. In the figure, 1: reed switch, 4: temperature-sensitive magnetic material, 5: positive temperature coefficient thermistor, 6: first electrode plate, 7: second electrode plate,
8: Crimping spring, 9: Insulating frame, 110: Auxiliary frame.

Claims (1)

[Scope of utility model registration request] 1. A reed switch having two U-shaped permanent magnets whose magnetic poles are aligned in the axial direction and which are mounted at regular intervals, between both legs of a substantially U-shaped temperature-sensitive magnetic body. In a blower detecting device in which an installed temperature switch and a heater element assembly for heating the temperature-sensitive magnetic body are mounted on an insulating frame, the heater element assembly is
The positive temperature coefficient thermistor and the positive temperature coefficient thermistor are provided between the first electrode plate installed on the frame so as to be in close contact with the outer surface of the closed end of the temperature-sensitive magnetic body, and the first electrode plate. A second electrode plate erected on the frame body so as to sandwich it, and a crimp spring erected on the frame body that acts to crimp the second electrode plate to the PTC thermistor side. The first electrode plate is provided with a protrusion by folding back for holding the PTC thermistor, and the crimp spring is provided with a protrusion by cutting and raising for holding the PTC thermistor. The second electrode plate is characterized in that the contact surface with respect to the PTC thermistor is bent toward the PTC thermistor with a predetermined curvature, and has a punched hole at a position corresponding to the protrusion of the crimp spring. Blower detection device.