JPH02247532A - Temperature sensor - Google Patents

Abstract

PURPOSE:To obtain an sensor which is light and inexpensive and whose watertightness is excellent by providing protection resin which molds a temperature sensing part, a terminal and a lead wire and a holder which has a fitting part to a protection tube part and a part to be measured. CONSTITUTION:The protection resin 9 molds around a thermister 4, the terminal 5 and the lead wire 6. Besides, a hexagonal turning-stop and slipping-stop part 9a is formed to the protection resin 9. The holder 11 is molded to be formed on the protection resin 9 and formed of resin whose forming temperature is higher than that of the protection resin 9. Besides, the protection tube part 11a which covers around the thermister 4, a screw part 11b which screws the holder 11 to the wall part of a cylinder and a hexagonal tool bearing part 11c are formed to the holder 11. Since the holder 11 is formed of the resin in such a way, it is made light and inexpensive. Besides, since the forming temperature of the holder 11 is set at the forming temperature of the protection resin or more, the holder 11 is fused with the protection resin when it is formed. Therefore, the space between the holder 11 and the protection resin 9 becomes watertight and water is prevented from infiltrating. As the result, the lead wire is prevented from being short-circuited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a temperature sensor that measures temperature.

[Conventional technology]

Figure 3 shows a cross section of a conventional temperature sensor, a cooling water temperature sensor for automobiles, where 1 is the cylinder at the temperature sensor mounting part, 2
indicates the direction of cooling water flowing in the cylinder 1, and 3 is a temperature sensor that measures the temperature of the cooling water. 4 is a thermistor which is a temperature sensing part, 5 is a terminal, 6 is a lead wire connecting the thermistor and terminal 5, 7 is a brass holder, 7a
7b is a protective tube portion that protects the thermistor 4 of the holder 7, and 7b is a threaded portion that fastens the holder 7 to the wall of the cylinder 1.
7c is a hexagonal part that receives the tool when tightening, 8 is the holder 7, thermistor 4, terminal 5 and lead! 6, 7d is a notch for preventing rotation between the holder 7 and the protective resin 8, which is provided in the holder 7 as shown in FIG. 10 is a gap between the holder 7 and the protective resin 8.

The temperature sensor 7 configured and attached as described above is
Changes in the cooling water temperature are measured by changes in the resistance value of the thermistor 4 fixed within the protection tube section 7a.

[Problem to be solved by the invention]

The conventional temperature sensor is constructed as described above, and the holder 7 is made of brass and has a complicated outer shape, including a protection tube portion 7a, a threaded portion 7b, a hexagonal portion 70, etc. In addition, the internal shape of the protective resin 8 must include a rotation-preventing notch 7d and a cut-out recess 7e, which increases the amount of cutting required, making it time-consuming and expensive. Furthermore, there was a possibility that water would enter through the gap 10 between the protective resin 8 and the holder 7, causing a short circuit between the lead wires 6 near the thermistor 4.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a temperature sensor that is lightweight, inexpensive, and has good watertightness.

[Means to solve the problem]

The temperature sensor according to the present invention includes a protective resin for molding a temperature-sensing part, a terminal, and a lead wire, and a protective tube part that is molded on the protective resin with a resin having a temperature higher than the molding temperature of the protective resin to protect the temperature-sensing part. A holder is provided that has a mounting part for the part to be measured.

[Function] The holder in this invention is molded from resin. Further, the holder has a molding temperature higher than the protective resin, and the holder and the protective resin are welded together when the holder is molded.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows a cross-sectional view of the temperature sensor according to this embodiment, and 9 is a protective resin molded around the thermistor 4, terminal 5, and lead &lI6, and is made of NYLON 66G1.
It is formed from 5 etc. As shown in FIG. 2, the protective resin 9 is formed with a hexagonal detent portion 9a that protrudes in the radial direction. A holder 11 is molded on the protective resin 9, and is made of a resin such as PP5 (polyphenylene sulfide) whose molding temperature is higher than that of the protective resin 9. Threaded portion 11 for screwing onto the wall
b and a hexagonal tool light are formed with a portion 11c.

In the above configuration, the rotation/extraction stop portion 9a fits into the holder 11 and functions to prevent rotation and removal. or,
Since the temperature sensor of this embodiment is formed by resin molding twice, a complicated shape can be manufactured at low cost. In addition, since the holder 11 is molded at a temperature higher than the protective resin 9, the holder 11 and the protective resin 9 are welded together during molding of the holder 11, creating a watertight state, preventing water from entering and preventing a shoot-out accident. be done. Also, NYLON 66G
The specific gravity of No. 15 is about 1.5, the specific gravity of PPS is about 1.8, and the specific gravity of brass is smaller than 8.6, making it possible to reduce the weight of the temperature sensor.

In the above embodiment, an example of a cooling water temperature sensor for an automobile was shown, but the present invention can also be applied to an automatic transmission oil temperature sensor, etc.

〔Effect of the invention〕

As described above, according to the present invention, since the holder is molded with resin, it is lightweight and inexpensive, and since the molding temperature of the holder is higher than the molding temperature of the protective resin, it is welded to the protective resin during molding of the holder, and both The gap becomes watertight, preventing water from entering and preventing lead wire seat accidents.

[Brief explanation of drawings]

1 and 2 are a longitudinal sectional front view and a sectional view of the rotation and removal prevention structure of the temperature sensor according to the present invention, and FIGS. 3 and 4 are a longitudinal sectional front view and a sectional view of a conventional temperature sensor in an installed state. It is a partially vertical side view. 1... Cylinder, 4... Thermistor, 5... Terminal, 6... Lead wire, 9... Protective resin, 11...
...Holder, 11a...Protection tube section, llb...Threaded section. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A temperature-sensing part that senses the temperature of the part to be measured, a terminal connected to the temperature-sensing part via a lead wire, a protective resin that molds the temperature-sensing part, lead wire, and terminal, and a temperature higher than the molding temperature of this protective resin. 1. A temperature sensor comprising: a holder molded on a protective resin using resin, and having a protective tube portion for protecting a temperature-sensing portion and a mounting portion for attaching to a portion to be measured.