JPH0220653Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an insulation block for a resistance temperature detector, which is used in a resistance temperature detector that detects the measured temperature from the change in resistance due to temperature of the resistance element, and insulates the conductor wire connected to the resistance element. It is related to.

Among the resistance temperature detectors, standard resistance temperature detectors include a four-conductor type having four conductive wires. In such a resistance temperature detector, insulation measures must be taken between each conductor. Further, during measurement, there is a temperature difference between the resistance element connected to one end of the conductive wire and the terminal portion connected to the other end of the conductive wire. This temperature difference makes it easy for convection to occur around the conductor, so it is necessary to take measures to prevent the occurrence of convection.

Conventionally, there have been insulating blocks for resistance temperature detectors provided with such insulation measures and convection prevention measures, for example, structures shown in FIGS. 1 and 2.
FIG. 1 is a sectional view taken along line AA in FIG. 2.

In these figures, 10 is a conducting wire, 20 is an insulating tube, and 30 is a convection prevention plate.

The conducting wire 10 is a platinum conducting wire, and has one end connected to a resistance element and the other end connected to a terminal portion (not shown). The terminal section is a connection terminal to a calculation section that calculates the measured temperature from the resistance change of the resistance element.

The insulating tube 20 is made of a highly heat-resistant insulating material, such as quartz, and has the conducting wire 10 inserted therein.

The convection prevention plate 30 is made of a highly heat-resistant insulating material, such as quartz, and is shaped like a button. The convection prevention plate 30 is provided with through holes 31 at predetermined intervals. A conducting wire 10 passes through the through hole 31. The convection prevention plate 30 is arranged so as to be in contact with both ends of the insulating tube 20. Insulating tube 20 and convection prevention plate 3
0 are stacked alternately along the conductor 10.

In such an insulating block for a resistance temperature detector, the insulating tube 20 provides insulation between the conductive wires, and the convection prevention plate 30 prevents convection from occurring around the conductive wire 10.

However, insulating blocks for resistance temperature detectors that are designed to prevent convection have the following problems.

(1) Since quartz is used as a constituent material and the convection prevention plate 30 must be processed into a button shape with four through holes 31, the cost is high.

(2) Since it is necessary to pass the conductive wires 10 through the insulating tube 20 one by one and then through the through hole 31, assembly is time-consuming.

(3) Resistance thermometers require rigorous cleaning after each assembly process in order to faithfully realize the physical characteristics of platinum conductive wire, but with this type of configuration, cleaning after complete assembly is particularly difficult. It is. That is, since the conducting wire 10 is inserted into the insulating tube 20, it is difficult to clean the inner surface of the insulating tube 20 and the surface of the conducting wire 10.

The present invention was made to solve these problems, and the purpose is to provide an insulation block for a resistance temperature detector that is inexpensive, easy to assemble and clean, and has measures to prevent convection. do.

The present invention provides an insulating block for a resistance temperature detector that insulates a conducting wire, one end of which is connected to a resistance element of the resistance temperature detector, and the other end of which is connected to an arithmetic unit that calculates a measured temperature from a change in resistance of the resistance element. The columnar part is formed into a columnar shape using a highly heat-resistant insulating material, and the part of the columnar part that is integrally formed with the flange and protrudes from the columnar part has through holes at predetermined intervals into which the conductive wires are inserted. The flange has an outer diameter approximately equal to the inner diameter of the protection tube in which the resistance element and the insulating block are placed, and the flange has a protective ring when the insulating block is inserted into the protection tube. The insulating block for a resistance temperature detector is characterized in that the space inside the tube is partitioned to prevent the generation of convection due to a temperature difference between both ends of the conductive wire, and the columnar portion provides insulation between the conductive wires.

FIG. 3 is a diagram showing the structure of an embodiment of the insulating block for a resistance temperature sensor according to the present invention, in which A is a front view and B is a side view.

In FIG. 3, 40 is an insulating block, 50 is a columnar portion, and 60 is a flange portion.

The insulating block 40 consists of a columnar part 50 and a collar part 60.

The columnar portion 50 is formed into a columnar shape using a highly heat-resistant insulating material, such as alumina porcelain.

The collar portion 60 has a disc-like shape, and the columnar portion 50
It is integrally formed in the shape of a flange. The collar portion 60 is also made of the same material as the columnar portion 50. Four through holes 61 into which conductive wires of a resistance temperature detector are inserted are provided in a portion of the flange portion 60 protruding from the columnar portion 50 at intervals such that the conductive wires are insulated. In addition,
A different number of through holes 61 may be provided depending on the required dielectric strength voltage.

FIG. 4 is a diagram showing a state in which the insulation block for a resistance temperature detector shown in FIG. 3 is attached to a resistance temperature detector.
In FIG. 4, the same parts as in FIGS. 1 to 3 are given the same reference numerals.

In FIG. 4, 70 is a resistance element, 80 is a terminal portion, and 90 is a protection tube.

In the insulating block 40, the conductive wires 10 are passed through the through holes 61 of the collar portion 60, and the conductive wires 10 are stacked in the length direction.

The conductive wire 10 has one end connected to the resistance element 70 and the other end connected to the terminal section 80.

The resistance value of the resistance element 70 changes depending on the temperature.

The terminal section 80 is connected to a calculation section (not shown) that calculates the measured temperature based on the resistance change of the resistance element 70.

Inside the protective tube 90, an insulating block 40 and a resistance element 70 are arranged. The inner diameter of the protection tube 90 and the outer diameter of the flange 60 of the insulating block 40 are approximately equal.

In the resistance temperature detector having such a configuration, the conducting wire 10 is
The resistance element 70 is connected to one end, and the terminal part 80 is connected to the other end, and is fixed in the protective tube 90 because it passes through the through hole 61 of the collar part 60.

Insulation between the conducting wires 10 is provided by the columnar portions 50.

When the resistance temperature detector is in use, there is a temperature difference between the resistance element 70 and the terminal portion 80. Due to this temperature difference, air convection is likely to occur within the protection tube 90. Since the inner diameter of the protective tube 90 and the outer diameter of the flange 60 are approximately equal, the flange 60 prevents air convection from occurring.

In addition, in the embodiment, a case has been described in which the columnar part 50 is formed in a cylindrical shape and the flange part 60 is formed in a disk shape, but the columnar part 50 and the flange part 60 may be formed in other shapes. good.

Further, in the embodiment, a case has been described in which the insulating block 40 is made of alumina porcelain, but the insulating block 40 may be made of other highly heat-resistant insulating materials.

According to the insulating block for a temperature sensing resistor having such a configuration and provided with measures to prevent convection, the following effects can be obtained.

The insulating block 40 is made of alumina porcelain and is integrally formed, so it is inexpensive.

Further, since the structure of the insulating block 40 is simple, it can be easily cleaned, and the cleaning effect of the resistance temperature sensor can be improved. In particular, since the conducting wire 10 is assembled in an exposed state, it can be easily cleaned.

Since the insulating block 40 has a simple structure and is integrally formed, it can also be easily assembled.

As explained above, according to the present invention, it is inexpensive,
It is possible to realize an insulating block for a resistance temperature detector that is easy to assemble and clean, and is provided with anti-insulation measures.

[Brief explanation of the drawing]

1 and 2 are structural sectional views of conventional examples of insulation blocks for resistance temperature detectors, FIG. 1 is a sectional view taken along the line A-A in FIG. 2, and FIG. 4 is a diagram showing the configuration of an embodiment of an insulating block for a temperature resistor, in which A is a front view, B is a side view, and FIG. It is a figure showing the state where it was attached. DESCRIPTION OF SYMBOLS 10... Conductor wire, 50... Column-shaped part, 60... Flange part, 61
...Through hole, 70...Resistance element.

Claims (1)

[Claims for Utility Model Registration] One end is connected to a resistance element of the resistance temperature sensor, and the other end is used for insulating a conducting wire connected to an arithmetic unit that calculates the measured temperature from the resistance change of the resistance element. The insulating block includes a columnar section made of a highly heat-resistant insulating material, and a through hole into which the conducting wire is inserted, which is integrally formed with the columnar section in the shape of a flange and protrudes from the columnar section. It consists of flanges provided at predetermined intervals, the outer diameter of the flanges is approximately equal to the inner diameter of the protective tube in which the resistance element and the insulating block are arranged, and the insulating block is inserted into the protective tube. 1. An insulating block for a resistance temperature detector, characterized in that the space within the protective tube is partitioned to prevent the generation of convection due to a temperature difference between both ends of the conductive wire, and the columnar portion provides insulation between the conductive wires.