JPH10281893A - Thermistor type temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermistor type temperature sensor requiring no soldering. SOLUTION: A temperature sensitive part 20 having a thermistor element 22 is arranged in an elevating/lowering case 10a having ceiling, a leaf spring piece 27 is set around the temperature sensitive part 20 and a spring 30 is disposed between the leaf spring piece 27 and a base part tubular body 2 wherein the temperature sensitive part 20 is brought into resilient contact with the ceiling face of the elevating/lowering case 10a through resilient action of the leaf spring piece. According to the structure, the temperature sensitive part 20 is supported by the urging force of the leaf spring piece and solder bonding is not required between the temperature sensitive part 20 and the elevating/ lowering case 10a. Consequently, the temperature sensitive part is prevented from falling even it it is heated up to a level higher than the melting point of solder brazing, filter metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermistor type temperature sensor which is most suitable for controlling the stop of heating of a gas stove, an electric heater or the like.

[0002]

2. Description of the Related Art As shown in FIG. 6, various types of thermistor type temperature sensors S (1) which are attached to the center of a gas burner B such as a gas stove A and used for controlling the heating stop thereof have been proposed. This thermistor type temperature sensor S
(1) The upper part of the base tube fixed to the gas burner B is supported by an upwardly urged upwardly urged elevating case incorporating a thermistor element by an elevating spring. When we hang heated container C such as pot or kettle,
The top surface of the lifting case resiliently contacts the bottom surface to secure contact.If the bottom surface overheats, the thermistor element detects the temperature and activates the heating stop function, such as stopping the gas stove or shutting off the power to the electric heating equipment. It is intended to prevent accidents such as generation of empty cooking, spilling due to heating, or gas leaks caused by fire extinguishing due to spilling.

A thermistor-type temperature sensor having such a configuration is disclosed in Japanese Utility Model Publication No. 5-41385, Japanese Patent Laid-Open No.
Various proposals have been made, such as No. 14727 and JP-A-57-147278.

[0004]

The thermistor-type temperature sensor described above has been widely used as a sensor for stopping heating of a gas stove or the like, and is therefore applied to various gas stoves having different design dimensions. Have been. However, in the conventional configuration, since the base tube has a single structure, it is necessary to manufacture the base tube for each design dimension. It had to be prepared and inventory management was troublesome.

Therefore, as shown in FIG. 7, the inventors of the present invention support a heavenly elevating case b above and below a base tube a attached to a fixed part so as to be able to move up and down, and furthermore, attach a thermistor element c. A thermistor-type temperature sensor S for stopping heating in which a temperature sensor d provided is fixed in an elevating case b by soldering e is proposed. In this configuration, an elevating spring f is provided between the elevating elevating case b and the base tube body a, and the upper end of the elevating spring f is brought into direct contact with the ceiling surface of the elevating elevating case b. This causes the urging force to act on the lifting case b.

The thermistor type temperature sensor is
It is arranged near the gas burner B and is used constantly in a high heat atmosphere. Therefore, as described above,
When the temperature sensor d is fixed in the elevating elevating case b by soldering e, when the temperature rises to a temperature near the melting temperature of the solder braze, the solder braze melts, and the joining force decreases, and the temperature rises. It has been found that the sensor d may fall off.

Further, in order to facilitate the work of soldering the temperature sensing element d to the elevating case b, the elevating case b is made up of a cylindrical part g and a cap h joined to the upper end thereof. After the temperature sensing element d is welded to the cap h, the peripheral edge of the cap h is joined to the edge of the cylindrical portion g by soldering i. Accordingly, there is a concern that the cap h may be decomposed due to the melting of the solder braze at the periphery of the cap h. An object of the present invention is to eliminate the problems of the conventional configuration.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an elevating type elevating case is supported on an upper portion of a base tube attached to a fixed portion so as to be able to ascend and descend, and a temperature sensor having a thermistor element is provided as an erecting type. A temperature sensor is disposed in the elevating case, a spring receiver is provided around the temperature sensor, an elevating spring is disposed between the spring receiver and the base tube, and the temperature sensor is attached to the ceiling of the elevating case. An elastic contact means for elastically contacting the surface is provided.

In this thermistor type temperature sensor, an overhead lift case is provided at the center of a gas burner of a gas stove or at a required position of an electric heating device so as to protrude slightly upward. Then, when a heated container such as a pan is hung on the stove in a state where the stove is arranged in this manner, the elevating case descends against the elevating spring, and the upper surface of the elevating case presses against the lower surface of the stove by the urging force. It will be. If the container to be heated is overheated, the heat of the container is conducted to the thermistor element via the sealing material, and the temperature of the thermistor element rises, causing a large change in the resistance value. Therefore, when the resistance value becomes equal to or less than the predetermined threshold value, the heating stop function is activated, and the heating operation of the stove is stopped. That is, in the case of a gas stove, the release of gas is automatically cut off, and in the case of an electric stove, the switch is automatically turned off. This can lead to gas leaks,
Empty cooking and boiling over can be prevented.

By the way, in such a configuration, the temperature sensor is resiliently brought into contact with the ceiling surface of the elevating case using the elevating spring. Therefore, the temperature sensor is supported by the urging force of the elevating spring, and there is no need to join the temperature sensor and the heavenly elevating case by soldering or the like. Therefore, even if the temperature sensor is heated at a temperature higher than the melting point of the solder braze, the temperature sensor does not fall off.

Further, since it is not necessary to solder the temperature sensor to the elevating case, the elevating case b
Need not be composed of the cylindrical portion g and the cap h.

Incidentally, even in this configuration, the temperature sensor may be fixed to the ceiling surface of the elevating case. In this case, the elevating spring urges the elevating case upward and has a function of a compensating spring for securing the temperature sensor in a high-temperature atmosphere. Further, since the pressure sensing state of the temperature sensing element is secured by the elevating spring, it can be easily joined by performing resistance welding in the assembled state. Therefore, even if the overhead lift case is integrally formed, there is no problem in the fixing operation.

Here, the temperature sensor is configured by holding a thermistor element inside the eccentric sensor tube and projecting a leaf spring piece serving as a spring receiving portion from the peripheral surface of the sensor tube. An elevating spring is disposed between the leaf spring piece and the base tube body, and the urging force of the elevating spring is applied to the temperature sensor. A spring engaging edge is formed around the periphery, the peripheral edge of the leaf spring piece is engaged with the protrusion, and the temperature sensor of the spring seat is elastically contacted with the ceiling surface of the elevating case by the spring action of the leaf spring piece. It can be configured as follows. In this configuration, since the leaf spring piece is formed integrally with the sensor cylinder to constitute the elastic contact means, it is not necessary to prepare another new component.

Further, a leaf spring projecting from the peripheral surface of the sensor cylinder with the spring engaging edge formed on the upper part of the elevating elevating case and the case engaging edge formed on the lower part. In addition to supporting the piece, the base rod is constituted by a small-diameter rod part and a large-diameter spring seat formed at the upper end of the rod part, and a support plate externally fitted to the small-diameter rod part is locked by a case. At the edge, it is locked in the elevating case, and in the elevating case, a leaf spring protruding from the peripheral surface of the sensor cylinder and an elevating spring are interposed between the spring seats, so that the base tube is made of metal. There is also proposed a configuration in which the heavenly-type lifting case is supported so as to be able to lift and lower.

Further, as a specific example of such a configuration, a spring engaging edge composed of a plurality of raised portions is formed on the upper inner peripheral surface of the heavenly-shaped elevating case, and the raised portion is formed on the lower inner peripheral surface. A case locking edge consisting of a plurality of ridges of the same angle is projected, and each ridge passes through the periphery of the flange-shaped leaf spring piece projected from the peripheral surface of the sensor cylinder and the support plate. Possible passage gaps,
Each ridge is formed at the same angle as the ridge, and by rotating the ridge after passing through the passage notch, each sensor cylinder and the support plate are moved to the position where they are locked to each locking edge. A configuration that can be mounted is proposed. In such a configuration, the ascending and descending case and the support plate can be assembled simply by mounting them on the ascending and descending case using a rotating jig or the like, and require soldering and metal processing after assembling. Therefore, the assembling can be easily performed.

[0016]

FIG. 1 shows a thermistor type temperature sensor 1a according to a first embodiment of the present invention. The thermistor-type temperature sensor 1 has an outer housing composed of a base tube 2 attached to a gas stove A (see FIG. 6) and the like, and a metal eccentric elevating case 10a supported on the upper part so as to be able to move up and down. The lifting and lowering case 10 contains the thermistor element 2
2 is provided with a temperature sensor 20 incorporating the same.

The elevating case 10a is formed by drawing a metal plate and has a horizontal top portion 11, a main cylindrical portion 12,
It has a perforated bottom 13 coupled to its lower part. Then, it is externally fitted to a large-diameter short cylindrical spring seat portion 6 linked to the upper end of the small-diameter rod portion 3 of the base tube body 2 and is held so as to be able to move up and down with respect to the spring seat portion 6. In addition, the hole diameter of the perforated bottom portion 13 is substantially equal to the outer diameter of the small diameter portion of the base tube 2.

A temperature sensor 2 is provided on the ceiling of the ceiling 11.
0 is abutted. As shown in FIG. 3, the temperature sensing element 20 has a thermistor element 22 from which two core wires 23 and 23 (0.35φ) are drawn out inside a hat-shaped sensor cylinder 21 opening downward. , And the sensor tube 21
The gap between the thermistor element 22 and the sealing member 25 is filled. As the sealing material 25, a material having good heat resistance and excellent thermal conductivity, such as a mixture of aluminum nitride powder or alumina powder in heat-resistant alumina cement or polyimide resin, is used.

From the periphery of the lower end of the sensor tube 21, a leaf spring piece 27 in the form of a flange, which is a slightly curved downward spring receiving portion, is formed. On the periphery of the leaf spring piece 27, four passage cutouts 28 are formed at intervals of 90 degrees. The passage notch 28 allows passage of four spring locking edges 15 formed of ridges projecting at an interval of 90 degrees on the upper inner peripheral surface of the elevating case 10a, thereby allowing the sensor cylinder 21 to move to the spring locking edge. 15. The leaf spring piece 27 is formed with a rotary hole 29 for inserting a rotary tool and rotating the rotary tool.

As shown in FIGS. 1 and 2, the spring locking edge 15 locks the edge of the leaf spring piece 27 of the sensor cylinder 21. At this locking position, the leaf spring piece 27 is compressed in the thickness direction, and the restoring elasticity causes the upper surface of the sensor cylinder 21 to be pressed against the lower surface of the top portion 11 of the elevating case 10a. In order to store the temperature sensing element 20 in the elevating case 10a, a rotary jig (not shown) is inserted into the rotary hole 29, and as described above, each spring locking edge 15 is inserted into the passage notch. 2 and pushed in from below to rotate the temperature sensor 20 at the position where the peripheral edge of the leaf spring piece 27 has passed the spring engagement edge 15 as shown by the arrow in FIG. Edge 1
What is necessary is just to make the 5 and the passage lacking part 28 do not match.

Further, after the elevating spring 30 is mounted between the leaf spring piece 27 and the spring seat 6, the lower edge of the main cylinder 12 is drawn to form the perforated bottom 13. Thus, the temperature sensor 20 and the elevating spring 30 are housed in the elevating case 10a, and the thermistor type temperature sensor 1a is assembled.

In this assembled state, the lifting spring 30
As a result, the lifting case 10a is urged upward, so that the step between the main cylindrical portion 12 and the perforated bottom portion 13 of the lifting case 10a is formed on the step surface formed by the spring seat 6 of the base tube body 2. By pressing from below, the steady position (the highest position) of the elevating case 10a with respect to the base tube 2 is defined. The elasticity of the elevating case 10a is smaller than the elasticity of the leaf spring piece 27, and is easily lowered by the weight of the heated container C placed on the gas stove A, so that the lower surface of the heated container C Then, the top part 11 of the lifting case 10a is brought into elastic contact.

In addition, a connector 35 is connected to the ends of the core wires 23 of the thermistor element 22 drawn out from the lower end of the main pipe 3. 4 and 5 show a thermistor type temperature sensor 1b according to a second embodiment of the present invention.
Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the metal elevating case 10b has a cylindrical shape with an open lower part, and the above-mentioned four spring engaging edges 15 are formed in the upper part. At the lower part, a case locking edge 40 is formed at the lower part, which is formed of a raised portion at 90-degree intervals like the spring locking edge 15. As described above, the temperature sensor 20 is mounted between the top 11 and the spring locking edge 15 in the elevating case 10b, and the support plate 42 is mounted on the case locking edge 40 as described above. . The support plate 42 has an insertion hole 43 formed at the center thereof, through which the small-diameter rod portion 3 is inserted, and a peripheral edge thereof similar to the passage cutout 28 formed in the leaf spring piece 27 of the temperature sensor 20. In addition, a passage notch 44 for passing through the case locking edge 40 is formed, and three turning holes 45 similar to the turning holes 29 are formed at equal angles.

The assembly of this embodiment will be described. First,
Passage notch 2 formed in leaf spring piece 27 of temperature sensor 20
8, the case spring edge 40 and the spring engagement edge 15 are sequentially passed, and the leaf spring piece 27 is rotated on the spring engagement edge 15 by a rotating jig as shown in FIG. Lifting case 1
0b so as to be locked to the spring locking edge 15. In this state, the leaf spring piece 27 is compressed and the upper surface of the sensor tube 21 is held at a position where the upper surface of the sensor tube 21 elastically contacts the inner surface of the top portion 11 due to the restoring elasticity. Next, the elevating spring 30 is mounted between the leaf spring piece 27 and the spring seat 6 in the elevating case 10b.
Note that the outer diameter of the spring seat 6 is slightly reduced so as not to engage with the case locking edge 40 so that the spring seat 6 can be mounted in the elevating case 10b. After that, the small-diameter rod portion 3 is inserted into the insertion hole 43 in advance, and the rotation jig is inserted into the rotation hole 45 of the support plate 42 that has been externally fitted to the small-diameter rod portion 3, and passes therethrough. The notch 44 and the case locking edge 40 are aligned and pushed in and rotated to make the case locking edge 40 and the passage notch 44 in an inconsistent state, and the peripheral edge of the support plate 42 is supported by the case locking edge 40. .

At this time, the urging force of the elevating spring 30 causes
The support plate 42 is engaged with the lower surface of the spring seat 6, and the case locking edge 40 is locked on the peripheral edge of the support plate 42, thereby defining the steady position of the lifting case 10b.

When the elevating case 10b is lowered due to the weight of the container C to be heated placed on the gas stove A in a state of being assembled to the gas stove described later, the support plate 42
Due to its own weight, it follows the ascending and descending case 10b while being locked by the case locking edge 40.
The support plate 42 may be fixed to the lower surface of the spring seat 6 after the assembly.

As described above, in the second embodiment, the temperature sensor 20 and the support plate 42 are assembled by simply mounting the temperature sensor 20 and the support plate 42 in the elevating case 10b using a rotary jig or the like. Therefore, the assembling can be easily performed without the need for soldering or metal processing after the assembling.

The thermistor-type temperature sensors 1a and 1b thus configured are connected to the base stove 2 by the gas stove A.
, Is fixed to the center of the gas burner B of the gas stove A, and the connector 35 is connected to a required control circuit device. At the time of this mounting, the lifting case 10a,
As shown in FIG. 6, the upper surface of the top portion 11 of the top 10b is located slightly above the lower surface of the heated container C placed on the gas stove A. When the heated container C is placed, the lifting spring 30
The upper and lower cases 10a, 10b are lowered to ensure that the upper surfaces of the lift cases 10a, 10b elastically contact the lower surface of the container C to be heated.

When the heated container C is heated in this mounted state, the heat is transferred to the top portion 11, the temperature sensor 20, and the sealing material 25.
Is transmitted to the thermistor element 22 through the resistor, and a resistance change in response to the temperature is caused. When the resistance falls below a preset threshold, the gas stove A is turned off,
Turn off the power to the electric heater. This causes the occurrence of empty cooking,
Accidents such as spills due to overheating or gas leaks caused by fire extinguishing due to spills are prevented beforehand.

[0031]

According to the present invention, an elevating type elevating case is supported on an upper part of a base tube attached to a fixed portion so as to be able to ascend and descend, and a temperature sensor having a thermistor element is mounted in the elevating type elevating case. The temperature sensor is provided with a spring receiving portion, and a lifting spring is provided between the spring receiving portion and the base tube, and the temperature sensor elastically contacts the ceiling surface of the lifting case. With the elastic contact means, the temperature sensor is supported by the urging force of the elastic contact means, and there is no need to join the temperature sensor and the heavenly elevating case by soldering or the like.
Even if the temperature sensor is heated at a temperature equal to or higher than the melting point of the solder braze, the temperature sensor does not fall off. Further, there is an excellent effect that the soldering step becomes unnecessary and the assembling is simplified.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a thermistor-type temperature sensor 1a according to a first embodiment.

2 is a cross-sectional view taken along the line II of FIG. 1;

FIG. 3 is a perspective view of the temperature sensor 20.

FIG. 4 is a vertical sectional side view of a thermistor-type temperature sensor 1b of a second embodiment.

FIG. 5 is an exploded perspective view of a thermistor type temperature sensor 1b according to a second embodiment.

FIG. 6 is a thermistor-type temperature sensor 1 for a gas stove.
It is a conceptual diagram which shows the assembly state of a and 1b.

FIG. 7 is a vertical sectional side view of a main part of a heating stop sensor having a conventional configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermistor type temperature sensor 2 Base tube 3 Small diameter rod part 6 Spring seat part 10a, 10b Elevating case 15 Spring engaging edge 20 Temperature sensor 22 Thermistor element 27 Leaf spring piece 28 Passage notch 29 Rotating hole 30 Elevating spring 40 Case locking edge 42 Support plate 44 Passage notch

Claims (4)

[Claims] 1. An upper part of a base tube attached to a fixing part,
The elevating type elevating case is supported so as to be able to move up and down, and a temperature sensor having a thermistor element is disposed in the elevating type elevating case, and a spring receiver is provided around the temperature sensor, and a spring receiver is provided. A rising / falling spring disposed between the temperature sensor and the base tube, and a resilient contact means for resiliently contacting the temperature sensor with the ceiling surface of the lifting / lowering case. 2. A temperature sensor, comprising: a thermistor element held inside an eccentric sensor tube; and a plate spring piece serving as a spring receiving portion protruding from a peripheral surface of the sensor tube. An elevating spring is disposed between the spring piece and the base tube body, and the urging force of the elevating spring is applied to the temperature sensor, and the elastic contact means is provided on the inner periphery of the upper part of the heavenly elevating case. A spring locking edge is formed, and the peripheral edge of the leaf spring piece is locked to the projection so that the temperature sensing element of the spring receiving portion is elastically contacted with the ceiling surface of the elevating case by the spring action of the leaf spring piece. The thermistor-type temperature sensor according to claim 1, wherein the temperature sensor is configured as follows. 3. A leaf spring formed by projecting a spring engaging edge at an upper portion of an elevating elevating case, projecting a case engaging edge at a lower portion, and projecting from a peripheral surface of the sensor cylinder at the spring engaging edge. In addition to supporting the piece, the base rod is constituted by a small-diameter rod part and a large-diameter spring seat formed at the upper end of the rod part, and a support plate externally fitted to the small-diameter rod part is locked by a case. At the edge, it is locked in the elevating case, and in the elevating case, a leaf spring protruding from the peripheral surface of the sensor cylinder and an elevating spring are interposed between the spring seats, so that the base tube is made of metal. The thermistor-type temperature sensor according to claim 2, wherein the heavenly-shaped lifting case is supported so as to be able to move up and down. 4. A plurality of projections having a plurality of projections formed on an upper inner peripheral surface of the elevating elevating case, and a plurality of projections having the same angle as the projections on the lower inner peripheral surface. Along with the case locking edge formed of a ridge, the peripheral edge of a flange-shaped leaf spring piece protruded from the peripheral surface of the sensor cylinder, and a support plate and a passage notch through which each ridge can pass, respectively. Each ridge is formed at the same angle as the ridge, and by rotating the ridge after passing through the passage notch, each sensor cylinder and the support plate are moved to the position where they are locked to each locking edge. The thermistor-type temperature sensor according to claim 3, wherein the temperature sensor can be mounted.