JPH064295Y2 - Temperature sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a temperature sensor, and more particularly to the shape of the outer peripheral surface of the temperature sensor.

[Conventional technology]

FIG. 3 is a diagram showing an example of a conventional temperature sensor, which is a terminal wire 2a made of Dumet wire which is led out from electrodes 9 and 10 provided on both surfaces of the thermistor element 1 so as to be parallel to each other. 2b, and the terminal wires 2a, 2b are lead wires 3a, 3 protruding from an external lead (harness) 3.
connected to b.

In this case, the thermistor element 1 and the electrodes 9 and 10 are
It is covered with a first molding material 4 such as a glass material, and the outer periphery thereof is covered with a buffer layer 30 such as silicon varnish or silicon rubber that absorbs mechanical shocks. Further, the first molding material 4 and the terminal wires 2a and 2b are , Lead wire 3a,
It is covered with the second molding material 5 including 3b.

In this case, the shape of the second molding material 5 is such that the outer lead 3 side has a larger diameter than the first molding material 4 side so as to have a larger diameter.
Has become.

The temperature of the evaporator can be detected by inserting such a temperature sensor between the fins 7 of the evaporator forming the vehicle air conditioner, for example. That is, when the temperature of the evaporator drops to near the freezing temperature, the electromagnetic clutch is turned off based on the output of this temperature sensor, and the cooling operation of the evaporator is stopped.
The freezing can be prevented.

In this case, since the bulging portion 6 contacts the fins 7 and 7, the heat Z transmitted from the outside via the external lead 3 is
Since it escapes to the fin, it is absorbed by this and becomes difficult to be detected by the thermistor element 1. Since the cold heat from the fin 7 is conducted to the thermistor element 1 through the air layer 8, this heat can be detected and the fin temperature can be detected.

However, such a structure has a drawback that the distance between the fin and the element 1 is long and the contact area with the element 1 is small, resulting in poor responsiveness.

A temperature sensor shown in Fig. 4 has also been proposed. In the terminal wires 2a and 2b derived from the electrodes 9 and 10, this is a linear extension of the terminal wire 2a and a terminal wire 2b.
It is bent in a U shape in the a direction and extended so as to be parallel to the terminal wire 2a. Terminal wire 2 shaped like this
When the a, 2b and the first molding material 4 are covered with the second molding material 5, a bulging portion 6 is formed in a portion corresponding to the thermistor element 1, and when the temperature sensor is inserted between the fins 7, 7. , The cold heat Y from the fins 7 is the first molding material 4
Since the first mold material 4 is too directly conducted to the first mold material 4, the first mold material 4 has a defect that it is cracked due to heat stress. Further, according to this type of temperature sensor, the heat Z from the side of the inner lead 3 is not absorbed by the fins 7 and is easily transmitted to the thermistor element 1, and the temperature detection accuracy is lowered.

Therefore, an object of the present invention is to improve the detection accuracy as well as to have good responsiveness and to be less susceptible to thermal damage.

[Means for Solving the Problems] In the present invention, the holding pieces 23x, which are located at positions substantially coincident with the portions C, C facing each other on the outer periphery of the first molding material, or outside the portions C, C, are provided. 23x is provided, and the second molding material 5 covers the holding pieces 23x, 23x to form the bulging portion T having a flat outer surface.

[Action]

The heat from the external lead wire 3 escapes to the fin 7 through the rear portion 12b side of the bulging portion and is absorbed. Cold heat from the fins 7 is applied to the thermistor element 1 from the front portion 12c side of the bulging portion.
Be transmitted to.

〔Example〕

FIG. 1 is a simplified configuration diagram showing an embodiment of a temperature sensor according to the present invention, and the same elements as those in FIG. 4 are designated by the same reference numerals.

In FIG. 1, lead wires 3a and 3b projecting from the external lead 3 in parallel with each other in the direction of the first molding material 4
The stepped portions 3c, 3c projecting outward are formed on the root side of the so as to be shaped into a substantially crank shape. The crank-shaped lead wires 3a, 3b form holding pieces 23x, 23x having a certain length, which is a feature of the present invention. The positions of the two holding pieces 23x, 23x are extended to positions which substantially coincide with the two points C, C of the first molding material 4 which face each other, or positions which are located outside the points C, C. . The terminal wires 2a and 2b are molded into a crank shape and then soldered to the inner surfaces of the holding pieces 23x and 23x with the solder 11.

The second molding material 5 is thus held by the holding pieces 23x, 2
By covering the entire area where 3x is formed, a bulge portion T having a flat surface 12a is formed between the thermistor element 1 and the external lead 3.

In this case, the diameter of the first molding material 4 side is small.

The outer shape of the bulging portion T of the second molding material 5 is the first
As shown in the figure, it is set in consideration of the size of the gap 7a between the fins 7 and 7, and the fins 7 and 7 are inserted in close contact with the inner surfaces thereof.

According to the above configuration, as shown in FIG.
The heat Z from the outside from the side causes the rear portion 12 of the bulging portion T
It is conducted to and absorbed by the fin 7 via the b side. As a result, external heat does not reach the thermistor element 1 so much, and the temperature detection accuracy can be improved. The cold heat Y from the fins 7 is conducted from the first molding material 4 to the thermistor element 1 through the front portion 12c side of the bulging portion T, so that the responsiveness is good unlike the conventional one, and the heat is 1
Since it is conducted to the molding material 4 through a relatively long path and is not directly conducted, it is possible to prevent the thermal stress applied to the first molding material 4.

As shown in FIG. 3, the terminal wires 2a and 2b may be straightly projected without being deformed in a crank shape and fixed to the root side of the lead wires 3a and 3b.

[Effects of the Invention] As described above, according to the present invention, the holding piece located at a position substantially coincident with the parts C, C facing each other on the outer periphery of the first molding material 4 or located on the outer periphery of the parts C, C. 23
x, 23x are provided, and the second molding material 5 is the holding piece 23.
Since the bulging portion T is formed so as to cover x and 23x,
The surface of the bulging portion T that abuts the fins 7, 7 is a flat surface so that thermal damage is not given and the response is good.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified configuration diagram showing an embodiment of a temperature sensor according to the present invention, FIG. 2 is a simplified configuration diagram showing another embodiment of a temperature sensor according to the present invention, FIG. FIG. 4 is a simplified block diagram showing an example of a conventional temperature sensor. 1 ... Thermistor element, 2a, 2b ... Terminal wire, 3 ...
External leads, 4 ... First molding material, 5 ... Second molding material, 3a, 3b ... Lead wire, 23x ... Holding piece.

Claims (3)

[Scope of utility model registration request] 1. Thermistor element 1 has electrodes 9 and 10 located on both sides thereof, terminal lines 2a and 2b extending from the electrodes 9 and 10 extending in parallel with each other, and the thermistor element 1. And the first molding material 4 for molding the electrodes 9 and 10 and the terminal wire 2 protruding from the external lead 3.
lead wires 3a and 3b connected to a and 2b, and the first
Mold material 4 and terminal wires 2a and 2b and lead wires 3a and 3
In the temperature sensor composed of the second molding material 5 for molding b, it extends substantially parallel to the terminal wires 2a, 2b, and the facing intervals are C and C facing each other on the outer circumference of the first molding material 4. Holding pieces 23x, 23 located substantially at the same position or outside the above-mentioned parts C, C
x is provided, and the second mold material 5 holds the holding pieces 23x, 23
A temperature sensor characterized in that bulges T, T are formed so as to cover x. 2. The holding pieces 23x, 23x are provided with lead wires 3a,
The utility model registration claim 1 characterized by being formed by bending the tip of 3b outward in a crank shape.
The temperature sensor according to the item. 3. The temperature sensor according to claim 1, wherein the outer surface of the bulging portion T of the second molding material 5 covering the outside of the holding pieces 23x, 23x is flat. .