JPS6245149Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a thermocouple thermometer for measuring liquid temperature, and more specifically, for measuring the temperature of liquids such as lubricating oil in automobile transmissions and cooling water in radiators. , relates to a thermocouple thermometer for measuring liquid temperature.

A thermocouple thermometer is a device that cuts one point of an electrical closed circuit, keeps one end at a constant temperature, and measures the temperature at the other end by measuring the thermoelectromotive force between the terminals. Metal combinations used include copper-constantan, chromel-alumel, platinum-platinum rhodium, etc. Depending on the purpose of use, two thermocouple wires can be used as a direct temperature measurement junction, Alternatively, there are those that are housed in a protective tube, and there are also so-called sheath type thermocouple thermometers in which thermocouple wires are mounted in stainless steel or the like and insulated with magnesia powder or the like. Among these, in order to satisfy conditions such as space constraints for measuring liquid temperature used in automobiles, etc., the type in which thermocouple wires are directly implanted at the temperature measurement point has been most commonly used. For example, FIG. 1 shows a conventional example in which a thermocouple thermometer is attached to a manual transmission case 1. The temperature of the liquid is measured by directly immersing it in the liquid. And thermocouple wire 6
The lead-out portion 6b is pulled out in a required direction from the hole 3a of the drain plug 3, and the thermocouple is connected between the compensating conductor 10 that covers the lead-out portion 6b and the drain plug 3, and on the temperature measuring portion 6a side that protrudes from the drain plug 3. A low-temperature cement 12 is adhesively sealed between the wire 6 and the drain plug 3 to prevent oil leakage.

Although the conventional thermocouple thermometers as described above have various advantages, in automobiles and the like, mechanical vibrations and shocks are difficult to avoid, and coupled with the large temperature changes at the temperature measurement points, the thermocouple wire 6 is easily broken, or malfunctions such as oil leakage from the parts sealed with the low-temperature cement 12 are likely to occur. When such malfunctions occur, not only is it impossible for the automobile to run, but there is also the problem that a great deal of time and effort is required for repair work, such as replacing the thermocouple wire 6 or bonding and hardening new low-temperature cement 12.

The present invention was developed in order to solve the problems of the above-mentioned conventional technology, and its purpose is to make installation and replacement easy, and to prevent disconnection of thermocouple wires and leakage of the liquid to be measured. The purpose of the present invention is to provide a highly reliable thermocouple thermometer for measuring liquid temperature.

The basic structure of the present invention to achieve this purpose is as follows:
A heat-resistant rubber on which a thermocouple wire is mounted is sealed in a cylindrical protection tube, and the temperature measuring part of the thermocouple wire protrudes from one end surface of the protection tube, and is fitted into the other end of the protection tube, on the inner periphery. The heat-resistant rubber is characterized in that a thread is formed and the heat-resistant rubber is compressed by a sleeve nut that is screwed into the female thread.

The operation and structure of an embodiment of the present invention will be explained below based on FIG. 2.

In FIG. 2, 1 is a manual transmission case, 2 is lubricating oil stored in the transmission case 1, and 3 is a drain plug. A protective tube 4 is screwed onto the protective tube 4 through the .

A heat-resistant rubber 7 on which a thermocouple wire 6 is mounted is enclosed within the upper end of the protective tube 4 . This heat-resistant rubber 7 is compressed by a sleeve nut 9 threaded onto the inner periphery of the lower end of the protection tube 4 and screwed into an internal thread 4a. That is, since the heat-resistant rubber 7 is compressed and sealed with a required sealing pressure, it can flexibly respond to thermal contraction and expansion of the protective tube 4 due to temperature changes. This sealing pressure can be adjusted in a screw-feed manner using a sleeve nut 9 via a guide plate 8, making it easy and convenient to adjust the pressure according to the conditions of the temperature measurement location, for example. There is.

Therefore, compared to the conventional installation method using low-temperature cement, the time required for adhesive curing and the effort required for installation and replacement can be significantly reduced, and it can also be installed in narrow temperature measurement locations, etc., which were traditionally difficult to install. It can be installed anywhere by simply screwing it in. Of course, leakage of the lubricating oil 2 from around the thermocouple wire 6 and the like is also prevented.

The heat-resistant rubber 7 is preferably made of a material with excellent oil resistance and aging resistance, such as NBR (nitrile butadiene rubber).

The heat-resistant rubber 7 electrically insulates the thermocouple wire 6 and firmly holds and mounts the thermocouple wire 6. The temperature measuring part 6a of the thermocouple wire 6 is a portion where the cut ends of two thermocouple wires 6 are joined together by spot welding.
The temperature measuring part 6a protrudes above the upper end surface of the protective tube 4, and is adapted to be directly immersed in the lubricating oil 2 to measure the temperature of the liquid.

Reference numeral 10 denotes a compensating conducting wire made of glass yarn and lead, which protects and covers the drawn-out portion 6b of the thermocouple wire 6 drawn out in a desired direction from the hole 3a of the drain plug 3. The compensating conductor 10 is not only stably held by the lead-out portion 6b of the thermocouple wire 6 and the insulating tape 11, but is also fixedly inserted into the sleeve nut 9, which is tightly and tightly attached to the sleeve nut 9, without any gaps. Therefore, it has sufficient strength against mechanical vibrations, shocks, and unexpected external tensile forces, and is therefore configured to reliably prevent the thermocouple wire 6 from breaking. ing.

As described above, the present invention provides the following excellent effects. That is, in the present invention, heat-resistant rubber on which the thermocouple wire is mounted is sealed in a protective tube, and this heat-resistant rubber is compressed by a sleeve nut, so that the thermocouple wire is protected from mechanical vibrations and shocks. It has sufficient strength against unexpected external tensile forces, and prevents the thermocouple wire from breaking. It also prevents leakage of the liquid to be measured, making it suitable for thermocouples for measuring liquid temperature. The reliability as a thermometer can be significantly improved compared to the conventional one. In addition, when replacing the installation, it can be installed simply by screwing it into place, such as in a temperature measurement point with a narrow space, which was traditionally considered difficult to install. Moreover, in this case, the heat-resistant rubber is not disposable but can be used repeatedly, which is economically advantageous.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an example of mounting a conventional thermocouple thermometer for measuring liquid temperature, and FIG. 2 is a sectional view showing an embodiment of the present invention. 4...Protection tube, 4a...Female thread, 6...Thermocouple wire, 6a...Temperature measuring part, 7...Heat-resistant rubber, 9...
…Sleeve nut.

Claims (1)

[Scope of utility model registration request] A heat-resistant rubber on which a thermocouple wire is mounted is sealed in a cylindrical protection tube, the temperature measuring part of the thermocouple wire protrudes from one end surface of the protection tube, and a female thread is provided on the inner periphery of the other end of the protection tube. 1. A thermocouple thermometer for measuring liquid temperature, characterized in that the heat-resistant rubber is compressed by a sleeve nut screwed into the female thread.