JPH07218349A - Hot water sensor - Google Patents

Abstract

PURPOSE:To increase mechanical strength of a thermistor in a hot water sensor. CONSTITUTION:A thermistor 1 is supported by a recessed part 7a of a spacer 7, folded parts 2c and 2d at the end of a pair of lead wires 2a and 2b which are separately provided on both surfaces of the spacer 7 are strained and are hung to lead folding parts 7b and 7b of the spacer 7, and the thermistor 1 is mounted to the spacer 7. The spacer 7 functions as a core material for increasing mechanical strength and electrically insulates the area between a pair of lead wires 2a and 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water sensor using a thermistor.

[0002]

2. Description of the Related Art A thermistor has a characteristic that its resistance value changes with changes in ambient temperature, and is used in various temperature sensors. A conventional hot water sensor that measures the temperature of hot water using a thermistor is shown in FIGS.

Conventionally, a hot water sensor of this type has two lead wires 2 led out from a thermistor 1 as shown in FIG.
The lead wires 3a and 3b are soldered to a and 2b, respectively, and the thermistor 1 and the lead wires 2a and 2b, and the outer periphery of the connecting portion between the lead wires 2a and 2b and the lead wires 3a and 3b are resin-coated with a resin coating portion 4. As shown in FIG. 6, these were assembled in the hollow metal case 5 and filled with the resin 6.

[0004]

By the way, the diameter of the thermistor 1 is about 0.9 mm, and the diameter of the lead wires 2a and 2b drawn out from the thermistor 1 is about 0.2 m.
Since the diameter is m, the diameter of the resin coat portion 4 covering the outer circumferences of the lead wires 2a and 2b is as thin as about 0.5 mm, and these have weak mechanical strength.

Therefore, the thermistor 1 coated with resin
When it was assembled in the case 5, it was easily broken, and the lead wires 2a and 2b were easily broken.

Further, since the lead wires 2a and 2b are free in the middle part, there is a drawback that they are contacted by receiving the resin injection pressure at the time of resin filling, resulting in a short circuit accident. In order to solve this problem, actual Kaihei 2-67237
In the above-mentioned Japanese Patent, an insulating member is added between the lead wires 2a and 2b. However, since the end of the lead wire is not fixed to the insulating member by using the insulating member, the lead wire
There is a possibility that the gap between a and 2b may be expanded to apply an unreasonable force to the lead wire pull-out end from the thermistor to break the sealing glass of the thermistor, thereby deteriorating the hermetic sealing property of the thermistor.

Further, since the resin 6 covering the outer periphery of the thermistor 1 is thick, there is a problem that the thermal response of the thermistor 1 is poor.

An object of the present invention is to provide a hot water sensor having improved mechanical strength.

[0009]

In order to achieve the above object, a hot water sensor according to the present invention is a hot water sensor having a thermistor, a spacer, a resin coating portion, and a case, and the thermistor comprises a pair. It has a lead wire and outputs a measurement signal of the measured water temperature from the lead wire.The spacer is an insulating plate inserted between the lead wires forming a pair of the thermistors. Has a concave portion and a lead-back portion, and the concave portion is provided at one of the opposite end edges located in the length direction of the spacer, and is applied to the end surface of the thermistor sandwiched by the pair of lead wires, and the thermistor is The lead folding portion is a notch that is provided as a pair at the other opposing end edge located in the length direction of the spacer and that tensions and hooks the folding portion at the end of the paired lead wire. , Thermistor , It is supported in the recess of the spacer,
It is attached to the spacer by tensioning and hooking the ends of the paired lead wires that are divided and added on both sides of the spacer, and the resin coat part is the outer periphery of the thermistor and the spacer. Is covered with a resin, and the case houses a thermistor and a spacer covered with the resin inside.

In addition, the resin coat portion is formed by coating the outer periphery of the spacer and the lead wire coated with the undercoat material with a resin, and the undercoat material imparts waterproofness and water resistance.

Further, the resin coating portion has a tip diameter reducing portion whose diameter is reduced according to the external dimensions of the thermistor, and the case is diameter reduced according to the external dimension of the tip diameter reducing portion of the resin coating portion. It also has a tip reduced diameter portion.

Further, in the hot water sensor having a thermistor locating portion, the thermistor locating portion is provided in the fitting portion between the case and the spacer, and the resin-coated thermistor is fixed in the tip reduced diameter portion of the case. It is a thing.

[0013]

Operation: An insulating spacer is inserted between the pair of lead wires of the thermistor. The thermistor is supported by the recessed portion of the spacer, the folded portions at the ends of the paired lead wires that are separately added to both sides of the spacer are tensioned and hooked on the lead folded portions of the spacer, and the thermistor is attached to the spacer. The spacer functions as a core material that enhances mechanical strength, and electrically insulates the pair of lead wires.

[0014]

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

Referring to FIG. 1, the hot water sensor according to the present invention comprises a thermistor 1, a spacer 7, and a resin coating portion 4.
And a case 5.

The thermistor 1 comprises a pair of lead wires 2a,
2b, the measured signal of water temperature is measured by the lead wire 2a,
It is output from 2b.

The spacer 7 is an insulating plate inserted between the lead wires 2a and 2b forming a pair of the thermistor 1. The spacer 7 of the embodiment shown in FIG. 1 is an insulating plate made of, for example, a glass epoxy laminated plate and having a thickness of 0.2 mm, and has a concave portion 7a and a lead folded portion 7b at opposite end edges in the length direction. is doing. The recessed portion 7a is provided on one of the opposing end edges 7c located in the length direction of the spacer 7, and forms a pair of lead wires 2
It is applied to the end face of the thermistor 1 sandwiched between a and 2b,
It is a recess that supports the thermistor 1. The lead folded portion 7b is provided in a pair with the other opposing end edge 7d located in the length direction of the spacer 7, and a notch for tensioning and hooking the folded portion 2c, 2d at the end of the paired lead wire. Has become.

The thermistor 1 is supported by the concave portion 7a of the spacer 7 by using the spacer 7 having the above-mentioned structure, and the terminal folded-back portions 2c of the paired lead wires 2a and 2b are separately attached to both surfaces of the spacer 7. 2d is the lead-back portion 7b of the spacer 7.
It is attached to the spacer 7 by being hooked on. Further, the lead wires 2a and 2b hooked on the lead turn-back portion 7b of the spacer 7 are connected to the turn-back portions 2c and 2d of the lead wires 2a and 2b.
b is soldered.

Further, the spacer 7 has a narrow width at the tip end portion for supporting the thermistor 1, and a thermistor position-out portion 7e is provided at the step between the tip end portion and the rear end portion.

The resin coat portion 4 covers the spacer 7 and the thermistor 1 with resin in accordance with the outer shapes of the thermistor 7 and the spacer 1, and the tip reduced diameter portion 4a whose diameter is reduced according to the outer dimensions of the thermistor 1. have. The resin coating portion 4 takes in the connecting portions of the lead wires 2a and 2b and the lead wires 3a and 3b, and these are also resin coated. At the time of resin coating by the resin coating portion 4, a waterproof and water resistant undercoat material is applied to the connection portion of the spacer 7 and the thermistor 1, the lead wires 2a and 2b, and the lead wires 2a and 2b and the lead wires 3a and 3b. To be done.

The case 5 is a thermistor 1 coated with resin.
And the spacer 7 are housed. The case shown in FIG. 1 is made of stainless steel and has a tip reduced diameter portion 5a having a diameter reduced according to the outer dimensions of the tip reduced diameter portion 4a of the resin coating portion 4, and the tip reduced diameter portion 5a is coated with resin. Contains the thermistor 1. Further, the case 5 is molded in conformity with the outer shape of the spacer 7 from the reduced-diameter portion 5a at the front end to the rear end portion, and the resin coating portion 4 obtained by coating the spacer 7 with the resin comes into close contact with the inner surface of the case 5. . Case 5
Is provided with a thermistor locating portion 5b at the step between the front end portion and the rear end portion.
By aligning b with the positioning portion 7e of the spacer 7, the thermistor 1 is fixed in the tip reduced diameter portion 5a of the case 5. In addition, the case 5 is provided with a ring groove 5c for preventing the pull-out from the peripheral surface of the case 5 in the outward direction.

In the embodiment, in order to assemble the hot water sensor of the present invention, first, as shown in FIG. 2, the spacer 7 is inserted between the lead wires 2a and 2b forming a pair of the thermistor 1, and the thermistor is inserted into the recess 7a of the spacer 7. 1, the lead wires 2a and 2b forming a pair of the thermistor 1 are separately attached to the front surface and the back surface of the spacer 7, and the ends of the lead wires 2a and 2b are separately provided to the two lead folded portions 7b of the spacer 7. The wires are tensioned and folded back, and the lead lines 3a and 3b are soldered to the folded portions (see FIG. 3).

Next, as shown in FIG. 4, the outer periphery of the thermistor 1 and the spacer 7 is resin-coated with a resin coating portion 4.

Next, as shown in FIG. 1, the thermistor 1 and the spacer 7 coated with resin are incorporated into the case 5. In this case, the thermistor positioning portion 7e of the spacer 7 is used as a reference, and the thermistor positioning portion 5a of the case 5 is aligned with the thermistor positioning portion 7e.
Is fixed to the tip reduced diameter portion 5a of the case 5.

As shown in FIG. 1, the resin 6 is injected from the opening side of the case 5, and a part of the resin 6 is filled in the ring groove 5b of the case 5 to close the opening of the case 5 and to prevent Prevent the retainer.

[0026]

As described above, according to the present invention, since the thermistor is attached to the spacer, the spacer functions as a core material, and the mechanical strength of the resin-coated thermistor can be increased, and the lead wire can be used. It is possible to prevent disconnection accidents.

Further, since the insulating spacer is inserted between the lead wires forming a pair of the thermistors, the lead wires can be electrically insulated from each other, and a lead wire short circuit accident when the thermistor is coated with resin is prevented. Can be prevented.

Further, since the ends of the lead wires forming a pair of the thermistors are tensioned and hooked on the lead folded portions of the spacer, an unreasonable force is not applied to the lead wire lead-out end from the thermistor, and the thermistor It is possible to prevent breakage of the sealing glass and maintain the airtight sealing property of the thermistor.

Further, since the thermistor lead wires are provided on both sides of the spacer, it is possible to improve the coverage of the waterproof and water resistant undercoat material.

Further, since the resin coat portion and case surrounding the outer periphery of the thermistor are reduced in diameter, it is possible to reduce the thickness of the resin and improve the thermal response of the thermistor.

Further, since the thermistor is fixed to the position inside the case by the thermistor positioning portion, the thermistor can be easily positioned within the case and the breakage at the time of inserting the case can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the order of assembling the hot water sensor according to the present invention.

FIG. 3 is a cross-sectional view showing the order of assembling the hot water sensor according to the present invention.

FIG. 4 is a cross-sectional view showing the order of assembling the hot water sensor according to the present invention.

FIG. 5 is a cross-sectional view showing a resin-coated thermistor in a conventional example.

FIG. 6 is a cross-sectional view showing a conventional hot water sensor.

[Explanation of symbols]

 1 Thermistor 2a, 2b Lead wire 3a, 3b Lead wire 4 Resin coat part 5 Case 6 Resin 7 Spacer 7a Recessed part 7b Lead folding part

Claims (4)

[Claims] 1. A hot water sensor having a thermistor, a spacer, a resin coating portion, and a case, wherein the thermistor has a pair of lead wires, and outputs a measurement signal of the measured water temperature from the lead wires. The spacer is an insulating plate that is inserted between the lead wires forming a pair of the thermistors, and has a recess and a lead turn-back portion at opposite end edges in the length direction. Is a dent that is provided on one of the opposite edges and that is applied to the end face of the thermistor sandwiched by the pair of lead wires and that supports the thermistor. Is a notch that is provided as a pair on the opposite edge of the pair and that tensions and hooks the folded portion at the end of the paired lead wire.The thermistor is supported by the recess of the spacer and is attached separately on both sides of the spacer. A pair The end of the lead wire is attached to the spacer by tensioning and hooking the end of the lead wire to the lead return part of the spacer.The resin coat part covers the thermistor and the outer periphery of the spacer with resin, and the case is A hot water sensor in which a thermistor coated with resin and a spacer are housed inside. 2. The resin coating portion is formed by coating the outer circumference of a spacer and a lead wire coated with an undercoat material with a resin, and the undercoat material imparts waterproofness and water resistance. The hot water sensor according to claim 1. 3. The resin coating portion has a tip diameter reducing portion whose diameter is reduced according to the external dimensions of the thermistor, and the case is reduced in diameter according to the external dimension of the resin coating portion. The hot water sensor according to claim 1 or 2, wherein the hot water sensor has a tip reduced diameter portion. 4. A hot water sensor having a thermistor locating portion, wherein the thermistor locating portion is provided at a fitting portion between a case and a spacer, and fixes a resin-coated thermistor in a tip reduced diameter portion of the case. It is a thing, The hot water sensor of Claim 3 characterized by the above-mentioned.