RU2343433C1 - Thermal fuse (thermal indicator) for internal-combustion engine temperature overriding testing - Google Patents

Abstract

FIELD: physics, measurement.

SUBSTANCE: thermal fuse (thermal indicator) refers to pyrometric technics for peak temperature testing of objects, hard-to-reach and actuated machine elements and can be applied in propulsion engineering where temperature of single structure components is to be measured. Technical result is reached by that thermal indicator is represented with crystalline chemical - phthalic anhydride with melting temperature +130.8°C and percentage in thermal indicator 100%.

EFFECT: design of thermal fuse (thermal indicator) allowing for ICE temperature overriding testing.

Description

The invention relates to a temperature measuring technique for determining the maximum temperature of objects, inaccessible and moving parts of machines and can be used in engine building, where it is necessary to accurately measure the temperature of individual structural elements.

Known methods for measuring temperatures, for example pistons of internal combustion engines, namely the method of thermocouples and the method of fusible indicator inserts. The application of the thermocouple method encounters well-known difficulties associated with the creation of a reliable current collection device. The second method is based on the use of a number of eutectic alloys, the melting points of which are known in advance. Fusible inserts are made in the form of thin-walled aluminum capsules filled with alloy. This method is time consuming since the temperature at the selected point is measured by installing a group of three to four inserts with adjacent melting points. The average value of the melting temperatures of two indicators adjacent to the melting temperature is taken as the measured temperature at the studied point, of which one melted and the other did not melt. In addition, such methods are very laborious, but they are not acceptable, where the temperature must be determined accurately.

A less laborious method for determining temperatures using thermal indicator paints is known, but even in this method the measurement error is 6 ° C, which is not always permissible.

There is also a method of determining the maximum temperature of objects in hard-to-reach places of parts, taken as a prototype (SU 1435960, G01K 11/00, 12.23.85). According to this method, when heating a thermal indicator in the form of a tablet, which is produced by pressing a mixture of powders of pure elements, annequilibrium mixture is annealed. By changing the magnetization of the thermal indicator in the form of a tablet, the maximum temperature of the object is determined.

However, the application of this method is difficult due to its complexity and also determines the temperature inaccurately.

The aim of this invention is the creation of such a fusible insert, which will determine the temperature rise of the internal combustion engine over the permissible value.

For example, when operating a V-92C2 diesel engine, the maximum allowable temperature of the coolant must not exceed 125 ° C, otherwise this leads to overheating of the engine, which is a violation of the operating conditions. Thus, such a fusible insert (thermal indicator), which has an absolutely definite and accurate melting point due to the crystalline structure of the chemical substance, should serve as a “witness” to the overheating of the coolant.

The problem is achieved in that a fusible insert (thermal indicator) for determining the temperature excess of the internal combustion engine above the permissible value, consisting of a crystalline chemical substance in the form of a tablet, which is produced by pressing, the authors propose using crystalline chemical substance phthalic anhydride with a melting point of 130, 8 ° C, the percentage of which in the thermal indicator is 100%.

Phthalic anhydride - anhydride of benzene-1,2 - dicarboxylic acid (GOST 7119-77). Its melting point is 130.8 ° C. Its percentage in the thermal indicator is 100%.

When conducting a search by sources of patent and scientific and technical information, no thermal indicator was detected using phthalic anhydride, which allows us to conclude that the proposed invention meets the criterion of "novelty."

Concrete example

A preform is melted from a chemical substance (in crystalline state) - phthalic anhydride (100%), for example, in the form of a rod, then a fuse insert (thermal indicator) in the form of tablets (capsules) is pressed from its fragments at a pressure of 6 MPa, while the fuse insert reaches the necessary strength. Then it is installed on the control object, namely in the part of the engine cooling system and fixed with glue to the previously prepared nests.

When the engine is running, the temperature of the coolant in the system should not exceed 125 ° C, this thermal indicator serves as a "witness" of overheating, which has an absolutely defined and accurate melting temperature due to the crystal structure of the chemical.

Thus, a fusible insert in the form of a tablet made of phthalic anhydride allows you to determine the temperature with an accuracy of ± 1 ° C, which will allow you to diagnose the cause of engine failure and indicate a violation of the engine operating mode.

The proposed fusible insert (thermal indicator) can be obtained on an industrial scale, therefore, it meets the criterion of "industrial applicability".

Claims (1)

Fusible insert (thermal indicator) for determining the temperature of the internal combustion engine exceeding the permissible value, consisting of a crystalline chemical substance in the form of a tablet, which is produced by pressing, characterized in that phthalic anhydride with a melting point of 130.8 ° is used as the specified crystalline chemical C, the content of which in the thermal indicator is 100%.