JPH03712Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention includes a heat generating element such as a positive temperature coefficient thermistor that is thermally closely attached to a thermally conductive mounting board, and a refraction-molded heat sink is attached to the outer surface of the mounting board. Regarding hot air heaters.

As shown in FIGS. 1 and 2, such a conventional hot air heater has a heating element such as a positive temperature coefficient thermistor 2 tightly sandwiched between a pair of upper and lower mounting boards 1, 1, and Heat sinks 4, 4 bent in a zigzag shape are attached to the outer surfaces of the mounting substrates 1, 1 with an adhesive.
It has been considered to attach an arch-shaped holding frame 7 to the mounting board 1 by caulking it or fixing it with screws to prevent it from lifting up. However, the configuration as shown in FIG. 1 has disadvantages in terms of the long-term stability of the thermal connection between the heat sink 4 and the mounting board 1, the number of assembly steps, and the number of parts used. That is, in the configuration described above, the thermal bond between the heat sink 4 and the mounting board 1 is achieved by the adhesive, and it is difficult to obtain a long-term stable thermal bond with the adhesive alone. Therefore, thermal coupling is assisted by supporting the heat sink 4 with the holding frame 7, but if the horizontally long heat sink 4 is extended over its entire length,
It is difficult to support uniformly, and the holding frame 7
The supporting force of the central portion of the holding frame 7 is weaker than that of both ends, and therefore, although the rigidity of the holding frame 7 itself has been increased by protruding ribs 8 and the like, it cannot be said to be perfect.
Further, since the holding frame 7 is a post-assembled component, it is necessary to apply pressure with a jig or the like during the adhesive curing period in the step of adhering the heat radiating body 4, making assembly time-consuming.

The present invention has been made in view of the above-mentioned circumstances, and aims to eliminate the drawbacks of the conventional heat sink by improving the heat sink and the holding frame that supports the heat sink.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 3 is a perspective view showing the whole hot air heater of this embodiment, FIG. 4 is a vertical side view of FIG. 3, and FIG. 5 is an exploded view of FIG. In the figure, parts corresponding to those in FIGS. 1 and 2 are given the same reference numerals. The hot air heater of this embodiment basically has a pair of left and right heating elements, such as positive temperature coefficient thermistors 2, 2, between a pair of upper and lower mounting boards 1, 1 made of metal, for example, with excellent thermal conductivity. In addition to tightly sandwiching the mounting boards 1, 1, spacers 3, 3 are interposed between both ends of the mounting boards 1, 1, and a voltage is applied to the positive temperature coefficient thermistors 2, 2 to generate heat. To,
The respective heads of the heat sinks 4, 4, which are formed by bending and bending a thin metal band plate into a zigzag shape, are thermally and mechanically integrated with adhesive, and the heat sink 4 and the mounting board 1 are integrated. A large number of slits formed in between are arranged along the ventilation path, and the heat generated from the positive temperature coefficient thermistor 2 is radiated into the airflow via the mounting board 1 and the heat sink 4 to obtain hot air. . Note that the PTC thermistors 2, 2 may be energized by using the mounting substrates 1, 1 as terminal boards or electrode plates; in this case, the PTC thermistors 2, 2 are provided with an insulating exterior. The spacer 3 must be insulating.

Here, in the embodiment of the present invention, by modifying the mounting board 1 and the heat sink 4, the thermal coupling between the heat sink 4 and the mounting board 1 is ensured. That is, as shown in FIG.
The length h of the front and rear end sides 5 and 6 when viewed from the side of the heat dissipating body 4 is
It is configured in a trapezoidal shape with a difference in 1 and h2.
The final planar shape of the heat sink 4 obtained by bending the band-shaped metal plate as shown in FIG. 6 is as shown in FIG. It has a curved shape that is wider on the front end side 5 side with the height h1 than on the rear end side 6 side with the side surface height h2. Further, on the outer surface of the mounting board 1, an arch-shaped holding frame 7 whose plate surface is oriented in the ventilation direction is erected such that the arch portion thereof is located midway between the front and back of the mounting board 1. The arch opening height h3 of the holding frame 7 is approximately the middle value of the side heights h1 and h2 of the front and rear end sides 5 and 6 (h1<h3<h
2).

Next, the assembly of the heat sink 4 to the mounting board 1 will be explained. This installation begins with fixing the arch-shaped holding frame 7 to the outer surface of the mounting board 1. Next, insert the heat radiator 4 into the holding frame 7 from its tapered side, that is, the front end side 5 side of the side surface height h1, and insert the heat sink 4 into the holding frame 7 from the side surface height h1. The heat sink 4 is strongly driven into the opening. As a result, the heat sink 4 is strongly and uniformly pressed against the outer surface of the mounting board 1 over its entire length and is fixed. In addition, at this time, the heat sink 4
The planar shape of is, as mentioned above, its side height h
The first side has a curved shape that is wider, but since this heat sink 4 is driven from the rear end side 6 side at the side surface height h2, the curved shape is such that the side surfaces of each trapezoid are twisted. As a result, it is corrected, and when the driving is completed, it assumes a substantially straight shape and is restrained, as shown in FIG. Furthermore, in this case, if necessary, in order to securely fix the mounting board and the heat sink, the mounting board and the heat sink may be fixed with adhesive. In addition,
Reference numeral 9 in the figure is a stopper for preventing the heat sink 4 from being driven in too much. As shown in FIG. 7, the arch-shaped holding frame 7 can also be formed by cutting out and bending a single piece from the side of the mounting board 1. Furthermore, if the opening height at the center of the inner edge of the holding frame 7 is made slightly smaller than at both ends, the effect of pressing the heat sink at the center of the holding frame 7 will be further enhanced.

As described above, according to the present invention, an arch-shaped holding frame made of a thin plate is fixed to the outer surface of the mounting board, and the opening formed by the holding frame and the mounting board is filled when viewed from the side direction. Since the trapezoidal heat radiator is driven into place from its tapered side, the heat radiator is driven into the arch-shaped holding frame with a relatively light force, and the heat radiator is wedged into the holding frame. and the outer surface of the mounting board. In addition, the holding frame is a vertical plate member that receives the pressing reaction force of the radiator, so although it is a thin plate, it has high rigidity against the pressing reaction force and has little backward deformation in the middle of the arch, so it can press and support the radiator. It is possible to maintain good thermal coupling between the heat sink and the mounting board stably for a long period of time.

[Brief explanation of the drawing]

Figure 1 is an overall perspective view of a conventional example, and Figure 2 is a perspective view of a conventional example.
3 to 7 show an embodiment of the present invention, FIG. 3 is a perspective view showing the whole hot air heater according to the embodiment, and FIG. 4 is a vertical cross-section of FIG. 3. 5 is an exploded perspective view of FIG. 3, FIG. 6 is a perspective view showing a state in which the heat sink is in the process of being manufactured, and FIG. 7 is a perspective view of another embodiment of the mounting board. 1 is a mounting board, 2 is a positive temperature coefficient thermistor, 3 is a spacer, 4 is a heat sink, 5 and 6 are edges, and 7 is a holding frame.

Claims (1)

[Scope of Claim for Utility Model Registration] A hot air heater comprising a heating element closely mounted on a thermally conductive mounting board, and a heat radiator made of a bend-molded thin plate material attached to the outer surface of the mounting board. The side surface of the heat radiator is trapezoidal, and an arch-shaped holding frame made of a thin plate is fixed to the outer surface of the mounting board, and an opening for inserting the heat radiator is provided between the holding frame and the outer surface. A hot air heater characterized in that the opening height thereof is approximately an intermediate value of the side height of the heat radiating body.