JPS6350794Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a semiconductor heater using a positive temperature characteristic thermistor.

As a heater using a positive temperature characteristic thermistor (hereinafter referred to as a PTC thermistor), one in which the PTC thermistor is clamped between upper and lower electrode plates is already known.

In such heaters, it is necessary to apply a pressing force when clamping the PTC thermistor between the electrode plates, and without such pressing force, there is a risk that the thermistor itself may crack or an arc may occur. . This pressing force requires approximately 15 kg of force.

Conventionally, as shown in FIG. 1, the configuration for applying the above-mentioned pressing force is to install a plate 4 above the upper electrode plate 2 of the upper and lower electrode plates 2 and 3 of the PTC thermistor 1, and to connect the plate 4 to the upper electrode plate 2. A coil spring 5 is interposed between the plates 4, and bolts 6 are passed through the plates 4, the upper electrode plate 2, and the lower electrode plate 3, and are secured with nuts.
The urging force of the coil spring 5 was applied.

As another conventional example, as shown in FIG. 2, an insulator 7 having a substantially T-shaped cross section is fitted near the head of a bolt 6 passing through the upper and lower electrode plates 2 and 3 of the PTC thermistor 1. There is also a device in which the protrusion of the insulator 7 presses the center of the plate spring 8, which has a V-shaped cross section, toward the electrode plate 2, thereby applying a pressing force between the electrode plates 1 and 2.

However, since both of the above two conventional examples require a spring body separate from the electrode plate and are tightened with bolts, the number of parts is large, the structure is complex, and as a result, the assembly process increases and is time-consuming. Such is the case.

The purpose of this invention is to eliminate the above disadvantages,
To provide a semiconductor heater which has a structure in which a PTC thermistor can be pressed by upper and lower electrode plates, has a simple structure, and is easy to assemble.

According to this invention, this purpose is to provide a semiconductor heater in which a plurality of positive temperature characteristic thermistors are arranged in parallel at intervals, and the upper and lower ends are clamped by electrode plates.
The upper electrode plate, which is made of a continuous body of a plurality of discs that fit into the upper part of the thermistor, is cut out at the junction and both ends of the discs to form a band-shaped joint, and the tip of this joint is extended downward. A fitting hole is formed at the tip of the locking piece, and the fitting hole is integrally formed on the outside of the flange provided on both sides of the insulating base on which the lower electrode plate is placed. This is achieved by fitting the projecting arrowhead-shaped projection and pressing the positive temperature characteristic thermistor with both electrodes.

Hereinafter, embodiments of this invention will be described in detail with reference to the drawings.

FIG. 3 is a longitudinal sectional view of the embodiment, and FIG. 4 is a plan view. In the heater of this invention, a plurality of disc-shaped PTC thermistors 1 are arranged at intervals, and the upper surface of the thermistor 1 is fitted onto the thermistor 1. Place the upper electrode plate 2 having an annular bulge 9 that fits together, place the lower electrode plate 3 on the lower surface of the thermistor 1, insert the thermistor 1 between both electrode plates 2 and 3, and then place the lower electrode plate 3 on the lower surface of the thermistor 1. Placed on a heat-resistant insulating base 10, the insulating base 1
0 is attached to a base 11 made of synthetic resin.

Connection terminals 12 and 12' from a power source are screwed to the ends of the upper electrode plate 2 and the lower electrode plate 3.

Further, FIG. 5 is a plan view of the upper electrode plate 2, and FIG. 6 is a longitudinal cross-sectional view. , 13'', the joining part and both ends of the disks 13, 13', 13'' are cut out to form a band-shaped joining part 14, and the joining part 1
A fitting hole 16 is provided at the tip of the locking piece 15 by bending the extension of the locking piece 4 downward at a right angle.

On the other hand, as shown in FIG. 3, flanges projecting upward and downward are provided on both sides of the heat-resistant insulating base 10, and a downward arrowhead-shaped projection 10A is integrally formed on the outside of the flanges. When assembling, the locking pieces 15, 15 on both sides of the upper electrode plate 2 are pushed downward while holding the base 10 and bending the connecting parts 14, 14 downward. Then, the protrusion 10A of the base plate 10 is inserted into the fitting hole 16 of the locking piece 15.

At this time, the locking piece 15 is inserted along the outside of the flange, and since the lower electrode plate 3 is placed inside this flange, the locking piece 15 of the upper electrode plate 2
A collar is interposed between the upper electrode plate 5 and the lower electrode plate 3, and as a result, there is no possibility that the upper electrode plate 2 will come into contact with the lower electrode plate 3. Furthermore, when the locking piece 15 is lowered along the flange, the fitting hole 16 matches and fits into the position of the projection 10A, so positioning can be performed very easily.

With this configuration, the upper electrode plate 2 itself acts as a leaf spring, and this spring force can press the PTC thermistor 1 and the lower electrode plate 3 placed between the electrode plate 2 and the substrate 10 against the substrate 10. As a result, the PTC thermistor 1 between the upper and lower electrode plates 2 and 3
will be pressed.

As described above, the semiconductor heater of this invention has a structure in which the PTC thermistor is clamped between the upper and lower electrode plates, and the locking protrusion of the upper electrode plate is fitted into the insulating base on which the lower electrode plate is placed. Therefore, both electrode plates can be used without using a special spring body.
The PTC thermistor can be pressed, and the assembly of the heater itself is simple, requires fewer steps, and is finished at a low cost.

Furthermore, even if there is variation in the thickness of the PTC thermistor, since the joint portion is formed into a band shape, the variation can be absorbed by the bending allowance and an appropriate pressing force can be ensured.

[Brief explanation of the drawing]

1 and 2 are longitudinal side views showing a conventional example, FIG. 3 is a longitudinal side view showing an embodiment of the semiconductor heater of this invention, FIG. 4 is a plan view of the same, and FIG. 5 is a view of the upper electrode plate. The plan view and FIG. 6 are longitudinal sectional side views of the same. 1... PTC thermistor, 2... Upper electrode plate,
3... Lower electrode plate, 9... Annular bulge, 10...
Insulating base, 10A...arrowhead-shaped projection, 11... base, 12, 12'... connection terminal, 13, 13', 1
3″...disk, 14...joint part, 15...locking piece,
16... Fitting hole.

Claims (1)

[Scope of utility model registration request] In a semiconductor heater in which a plurality of positive temperature characteristic thermistors are arranged in parallel at intervals, and the upper and lower sides of the thermistors are clamped by electrode plates, an upper electrode plate consisting of a continuous body of a plurality of discs fitting the upper part of the thermistor, A band-shaped joint is formed by notching the joint and both ends of the disk, the tip of the joint extends downward to form a locking piece, and a fitting hole is formed at the top of the locking piece. This fitting hole is fitted with an arrowhead-shaped protrusion integrally protruding from the outside of the flange provided on both sides of the insulating base on which the lower electrode plate is mounted, and the positive temperature characteristic thermistor is pressed by both electrodes. A semiconductor heater characterized by: