JPH0431721Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a temperature-sensitive reed switch device used as a temperature switch in, for example, an electric pot.

[Technical background of the invention and its problems] Conventionally, as a temperature-sensitive reed switch device used as a temperature switch in electric pots, etc., an annular permanent magnet and an annular temperature-sensitive magnetic body are arranged around the outer periphery of the reed switch to form a reed switch element. consists of
A first lead wire connected to one lead piece of the reed switch with a crimp terminal is folded back along the reed switch element, and a second lead wire is connected to the other lead piece of the reed switch with a crimp terminal.
The lead wires of the first,
It is known that the second lead wires are respectively connected to a pair of connection terminals provided on a terminal board attached to the case opening.

This type of conventional temperature-sensitive reed switch device is
Since the first and second lead wires are drawn out in the same direction, there are advantages such as ease of handling and connection. Since the first lead wire is disposed in the first lead wire, a gap is created between the magnetic body and the case, resulting in poor thermal conductivity and the provision of a terminal plate, which has the disadvantage that the product becomes larger in the longitudinal direction.

In addition, since this temperature-sensitive reed switch device is exposed to high temperature and high humidity hot water and steam, it also has the disadvantage that the glass tube is easily broken due to the difference in thermal expansion coefficient between the epoxy resin filled in the case and the glass tube of the reed switch. It was hot.

Further, in the above-mentioned temperature-sensitive reed switch device, it is possible to improve the insulation of the connecting portion between the first lead piece and the first lead wire and the connecting portion between the second lead piece and the second lead wire with respect to the case. Also known are devices in which these connecting portions are covered with an insulating cap.

However, such a configuration has the problem of increasing the number of parts and complicating the assembly process.

[Purpose of the invention] The present invention has been made in view of the above circumstances, and it has a simplified configuration, allows the device itself to be miniaturized, has no risk of damage, and has good airtightness and thermal conductivity. The purpose of this invention is to provide an excellent temperature-sensitive reed switch device.

[Summary of the invention] The outline of the invention for achieving the above object is to provide a temperature-sensitive reed switch element in which an annular permanent magnet and an annular temperature-sensitive magnetic body are arranged around the outer periphery of the reed switch;
A cylindrical case with a bottom that houses this temperature-sensitive reed switch element, and first and second leads connected to each lead piece of the reed switch and whose tips are led out from the opening of the case. A hard silicone coated lead wire filled in a case so as to include the temperature-sensitive reed switch element and at least a part of the connection between one lead piece of the reed switch and the second coated lead wire. It comprises a large first casting agent and a second casting agent that is more flexible than the first casting agent and is filled in the range from above the first casting agent to the opening of the case. It is characterized by:

[Embodiments of the invention] Examples of the invention will be described below with reference to the drawings.

FIG. 1 shows a cross section of a temperature-sensitive reed switch device, which has a temperature-sensitive reed switch element 1 and a case 2 for housing the temperature-sensitive reed switch element 1. There is.

The temperature-sensitive reed switch element 1 includes a reed switch 3 and two annular permanent magnets 6 arranged at a distance from each other around the outer circumference of the reed switch 3.
a, 6b, and an annular temperature-sensitive magnetic body 7 held between the tubes.

The first lead piece 3a of the reed switch 3 and the exposed tip 4a of the first silicon-coated lead wire 4 arranged along the reed switch 3 are crimped and connected by a first crimp terminal 5a. The second lead piece 3b of the reed switch 3 is crimp-connected to the second silicon-coated lead wire 8 by a second crimp terminal 5b, and both the first and second silicon-coated lead wires 4 and 8 are connected to the reed switch 3. He is trying to lead out to the second lead piece 3b side.

The annular permanent magnets 6a, 6b and the annular temperature-sensitive magnetic body 7 are both cylindrical as shown in FIG. A groove 10 for inserting one silicon-coated lead wire 4 is formed. Then, annular permanent magnets 6a and 6b are arranged concentrically on both sides of the annular temperature-sensitive magnetic body 7, and a reed switch 3 is placed in each circular hole 9, and a reed switch 3 is placed in each groove 10.
These annular permanent magnets 6a, 6 are connected by passing the first silicon-covered lead wire 4 through the
b and the annular temperature-sensitive magnetic body 7 are arranged around the outer periphery of the reed switch 3 and the first silicon-coated lead wire 4.

The opening of the case 2 is provided with a circular flange 2a made of non-magnetic metal and having a cylindrical shape with a bottom and a protrusion 2b provided on the opening side.

In addition, the case 2 forms an insulating portion 11 between the crimp terminal 5a crimped to the first lead piece 3a of the reed switch 2 and the case bottom 2c.
The reed switch element 1 is housed in such a way that the first and second silicon-coated lead wires 4 and 8 protrude outward from the opening of the case 2.

Then, in the range from the end of the first crimp terminal 5a to a part of the second crimp terminal 5b in the case 2,
A first casting agent 12 made of silicone rubber, which is a catalytic curing type and has high hardness and little elongation, is filled.

In addition, a second molding agent made of silicone rubber, which is softer, more elongated, and has better airtightness than the first molding agent 12, is placed in the range from the upper end of the first molding agent 12 to the opening of the case 2. A molding agent 13 is filled.

Since this second casting agent 13 is filled in order to maintain the airtightness of the opening of the case 2, it does not need to be so deep in quantity, and may be of a reactive type that reacts with moisture in the air.

The case 2 of these first and second casting agents 12 and 13 is made of metal, and the lead wires (first and second silicon-coated lead wires 4 and 8) are both coated with silicon. Therefore, silicone rubber is optimal in terms of adhesion and adhesion, and has a structure with excellent heat resistance.

The insulating part 11 is made of a silicone rubber casting agent of the same type as the first casting agent 12 so as to have a sufficient function as an insulating material between the first crimp terminal 5a and the case bottom 2c. It is formed by filling it to a predetermined thickness.

Further, both the exposed tip portion 4a of the first silicon-covered lead wire 4 and the first lead piece 3a are connected to the first silicon-covered lead wire 4.
The crimp terminal 5a is crimped so that it does not protrude from the end of the crimp terminal 5a toward the insulating part 11. With such a crimping structure, the exposed tip 4a of the first silicon-coated lead wire 4 and the lead piece 3a This prevents the metal from coming into contact with the inner circumferential surface of the case 2 or damaging the insulating section 11.

In addition, in FIGS. 1 and 2, 14 is a crimp terminal 15a.
16 is an external connection lead wire connected to the second silicone covered lead wire 8 by a crimp terminal 15b, and 17 is the tip of the external connection lead wire 16. 18 is a tube coated on the outer periphery of the first silicone-covered lead wire 4, the crimp terminal 15a and the external connection lead wire 14, and 19 is the second silicone-covered lead wire 8, the crimp terminal 5b and the external connection lead. This is a tube that covers the outer periphery of the wire 16.

In the temperature-sensitive reed switch device having the above configuration, since the first silicon-coated lead wire 4 passes through the inside of the annular permanent magnets 6a, 6b and the annular temperature-sensitive magnetic body 7 together with the reed switch 3, the outer periphery of these and the case are Since the gap between the case 2 and the inner circumferential surface of the case 2 is small, and the case 2 is made of metal, heat from the outside of the case 2 is conducted to the annular temperature-sensitive magnetic body 7 without loss, resulting in a high thermal conductivity. It has good sensitivity as a temperature sensor.

Moreover, the first and second silicon-coated lead wires 4,
8, the bending stress generated in the first and second silicon-coated lead wires 4 and 8 due to this bending force is absorbed by the second casting agent 13, which is flexible and easy to stretch. 1. The second silicon-covered lead wires 4 and 8 are not torn, and the second
The first casting agent 12, which is harder than the second casting agent 13, is placed from a part of the crimp terminal 5b to the reed switch 3 side.
, the above-mentioned bending stress is not applied to the glass tube of the reed switch 3 via the reed piece 3b, and therefore, breakage of the glass tube is prevented.

Furthermore, since the opening of the case 2 is filled with the first casting agent 13, the temperature-sensitive reed switch section 1
is housed in this case 2 in a well-tight state. In addition to this airtightness, the contact part of the reed switch 3 is sealed in a glass tube, so it can withstand high-temperature and humid atmospheres, low-temperature atmospheres,
Furthermore, this temperature-sensitive reed switch device can fully perform its functions even in harsh environments such as environments with a lot of moisture.

Also, in the case 2, the first crimp terminal 5a
Since the insulating part 11 is formed between the case bottom 2c and the lead piece 3a and the exposed tip 4a do not protrude outward from the end of the first crimp terminal 5a, the insulating part 11 is formed between the It becomes safe without destroying 11. Moreover, there is no need to provide a terminal plate in the case opening, and the overall size can be reduced.

Further, by providing the protrusion 2b on the flange 2a of the opening of the case 2, it is possible to prevent the entire device from rotating when this temperature-sensitive reed switch device is incorporated into an electric pot or the like.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

For example, in the embodiment described above, the second crimp terminal 5
Although a case has been described in which the first casting agent 12 is filled up to a part of the second crimp terminal 5b, it is also possible to fill the first casting agent 12 to include the entire second crimp terminal 5b.

Further, although the case where the insulating part 11 is formed with the same type of casting agent as the first casting agent 12 has been described, it is also possible to form this with insulating paper, and instead of providing the insulating part 11, the first casting agent 12 is formed. crimp terminal 5
This can also be carried out by covering the area around a with an insulating cap.

Further, although the flange 2a of the case 2 is provided to facilitate attachment, the flange may not necessarily be provided by adopting another attachment method.

Further, the covered lead wire 4 does not necessarily need to be placed inside a permanent magnet or a magnetic body, and may be drawn upward along the outer circumferential surface.

[Effects of the invention] According to the invention described in detail above, the reed switch element is fixed in the case by the first casting agent having a high hardness, and the reed switch element is fixed in the case from the upper end of the first casting agent to the case opening. Since the second casting agent, which is flexible and has excellent airtightness, is filled throughout the area, if bending stress is applied to the first and second silicon-coated lead wires,
This bending force is absorbed by the flexible second casting agent, and the glass tube that makes up the reed switch is protected by the hard first casting agent. It is possible to provide a temperature-sensitive reed switch device which can be housed in a case, and which eliminates the need for a terminal plate at the opening of the case, thereby simplifying and downsizing the device itself and preventing damage.

In addition, since the first silicon-covered lead wire passes through the annular permanent magnet and the annular temperature-sensitive magnetic body together with the reed switch, the outer periphery of the annular temperature-sensitive magnetic body can be brought close to the inner peripheral surface of the case, and thermal conductivity is improved. It is also possible to provide an excellent temperature-sensitive reed switch device.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the temperature-sensitive reed switch device of the present invention, Fig. 2 is a front view of the same, and Fig. 3 is a sectional view showing an embodiment of the temperature-sensitive reed switch device of the present invention.
4 is a cross-sectional view taken along the line -- in FIG. 2, FIG. 4 is a cross-sectional view taken along the line -- in FIG. 2, and FIG. 5 is an exploded perspective view showing an annular permanent magnet and an annular temperature-sensitive magnetic body of a reed switch element. DESCRIPTION OF SYMBOLS 1... Temperature-sensitive reed switch element, 2... Case, 3... Reed switch, 4... First silicone coated lead wire, 5a... First crimp terminal, 5b
. . . Second crimp terminal, 6a, 6b .
casting agent, 13...second casting agent.

Claims (1)

[Scope of utility model registration request] A temperature-sensitive reed switch element in which an annular permanent magnet and an annular temperature-sensitive magnetic body are arranged around the outer periphery of the reed switch, a bottomed cylindrical case housing the temperature-sensitive reed switch element, and each reed piece of the reed switch. First and second silicon-covered lead wires are connected to each other and have their tips led outward from the opening of the case, the temperature-sensitive reed switch element, at least one lead piece of the reed switch, and A first casting agent having a high hardness is filled in the case so as to include a part of the connection part with the silicon-coated lead wire of No. 2, and a part of the first casting agent reaches the opening of the case from above the first casting agent. A temperature-sensitive reed switch device comprising: a second casting agent that is more flexible than the first casting agent;