JPS581864Y2 - heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device which is particularly effective for use in preventing dew condensation on the cylinder head of a video tape recorder (VTR).

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

1 and 2 are a perspective view and a side sectional view of the heating device of the present invention, and these are a cylinder head of a VTR in which a rotary head 11 and a fixed head 12 are combined and integrated, as shown in FIG. 3. It is attached to a part of the circumferential surface of the fixed head 12.

In the figure, 1 is made of a metal with good thermal conductivity that is curved with a radius that almost matches the roundness of the circumferential surface of the fixed head 12 so that the entire area is in contact with a part of the circumferential surface of the fixed head 12. The heat dissipation section 2 is a rectangular cylindrical case section also made of metal and integrally provided at approximately the center of the outer surface of the heat dissipation section 1.
The heat dissipating portion 1 is formed in an open shape at one end with the outer surface serving as a bottom wall.

3 is an insulating sheet of good thermal conductivity such as tetron, mica, mylar, etc., which is loaded in the inner bottom of this rectangular cylindrical case part 2;
Reference numeral 4 denotes a positive temperature coefficient thermistor which is mounted in the case portion 2 so that a portion thereof is in contact with the insulating sheet 3 and its lead wire 5 is projected outward; and 6 is a positive coefficient thermistor 5. This is an insulating resin with good thermal conductivity, such as a silicone resin, which is filled in the case portion 2 so as to fix and seal it.

γ is a mounting hole provided near both ends of the heat dissipation section 1.

Note that this may be a notch.

When the heating device configured as described above is actually attached to the fixed head of a VTR, the heat dissipation section 1 is brought into contact with a part of the outer peripheral surface of the fixed head 12, and the screws provided on the fixed head 12 are attached. The hole (not shown) and the heat dissipating portion 1 can be attached by aligning the hole 7 with the hole 7 and fitting the screw 8 therewith.

In this way, when a power source is connected to the lead wire 5 protruding from the case part 2, the positive temperature coefficient thermistor 4 generates heat, which is radiated from the heat dissipation part 1 to the fixed head 12, and also heats the rotating head 11 by heat conduction. .

If moisture condenses on the cylinder head of a VTR, its playback function deteriorates, so countermeasures have been taken up to now, such as a thermal switch system, a single dew sensor system, and a single hot air blower system.

The thermal switch method is a thermal reed switch (T
R8) and a cement resistance heater or sheath heater to maintain a constant temperature and prevent dew condensation.

However, this method requires two parts, resulting in high costs, and since the heating is performed intermittently by TR8, not only can the influence on other parts due to the opening and closing of the contacts not be ignored, but also the head The temperature of the body could not be kept constant and the full effect could not be obtained.

In addition, the one-type dew sensor uses a dew sensor to detect dew on the head and locks a separate operation button, which actively evaporates the condensed water using a heater, etc. Therefore, unless the dew condensation was removed by a manual operation, or unless it was allowed to dry naturally, it could not be restored, which caused many inconveniences.

Furthermore, the one-type hot air blower uses a blower to blow warm air onto the head to dry the head, but this requires a blower and a motor to rotate it, which has the disadvantage of being extremely expensive. Ta.

On the other hand, with the heating device of the present invention, the drawbacks of the conventional methods mentioned above can be solved at once, and the VTR can perform an extremely stable playback function.

The heating device of the present invention is basically constructed as shown in FIGS. 1 and 2, but its shape and structure can be modified as appropriate without departing from the purpose and effect.

For example, the heat dissipation part 1 and the case part 2 may be formed integrally. In this case, a single metal plate 20 is punched into the shape shown in the fourth figure, and the dotted line parts in the figure are each bent by 90 degrees. It can be formed by

Naturally, the portion that will become the heat dissipation section 1 must be curved.

Moreover, if the inner wall surface of the case part 2 is formed to be uneven as shown in FIG. 5, the insulating resin 6 will not come out after being filled and will be strong.

Further, the insulating sheet 3 loaded on the inner bottom of the case portion 2 may be plate-shaped, and the insulating sheet 3 of the positive temperature coefficient thermistor 4
The contact state is also arbitrary.

Furthermore, if the shape of the protrusion of the lead wire 5 of the PTC thermistor 4 is bent as shown in each figure,
Fixation with other lead wires, etc. becomes easier.

Although the above explanation has been given as a heating device for a cylinder head of a VTR, it can be easily applied to other devices, and the key is to curve or bend the shape of the heat dissipating section 1 so that it matches the surface to be heated. All you have to do is approximate it.

Furthermore, if the heat dissipation section is further curved when attached to the heated surface, the attachment can be made more secure.

As described above, in the heating device of the present invention, since the heat dissipation part is configured in advance so as to approximate the surface to be heated, the contact and fixation can be carried out extremely easily, and the heat of the PTC thermistor can be transferred well. It has the effect of being able to.

In addition, the present invention has a structure in which the positive temperature coefficient thermistor loaded in the case part is brought into contact with the bottom wall surface via an insulating sheet, so positioning of the positive temperature coefficient thermistor is reliable and easy, and heat transfer to the heated surface is achieved. Not only is it good and stable, but it is also easy to manufacture.
Practicality is the dog.

[Brief explanation of drawings]

1 and 2 are a perspective view and a side sectional view showing an embodiment of the heating device of the present invention, FIG. 3 is a perspective view showing the device of the present invention attached to the cylinder head of a VTR, and FIG. 4 , 5th
All figures are for showing the other side of the present invention. 1... Heat dissipation part, 2... Case part, 3
...Insulating sheet, 4...Positive characteristic thermistor, 5...Lead wire, 6...Insulating resin.

Claims (1)

[Scope of utility model registration request] A heat dissipating part having a shape approximately similar to the surface to be heated, a case part having an opening at one end provided in a part of the heat dissipating part with the heat dissipating part as a bottom wall, and a case part loaded in the inner bottom of the case part. an insulating sheet with good thermal conductivity, a positive temperature coefficient thermistor which is also loaded in the case part so that a portion thereof is in contact with the insulating sheet, and its lead wire is protruded outward; A heating device made of an insulating resin filled with a thermistor fixedly sealed inside a case.