JP2805610B2 - Manufacturing method of temperature detection end - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a temperature detecting end using a thermocouple for measuring the temperature of a blast furnace.

[0002]

2. Description of the Related Art In a conventional method for manufacturing a temperature detecting end using a thermocouple, a protective tube before a thermocouple is inserted is manufactured with its tip already sealed, and the tip is sealed. A thermocouple was later inserted into the protective tube to manufacture the temperature detecting end. When manufacturing a temperature detecting end with a bent protective tube, insert a thermocouple into a straight tubular quartz pipe whose tip is sealed in advance, then heat the quartz pipe at a predetermined position and heat it at a predetermined bending radius. It was bending.

[0003]

The conventional method of manufacturing the temperature detecting end is as described above, and when the protective tube is a straight tube, various methods are provided by cutting the rear end of the protective tube. A protective tube having the following dimensions could be procured relatively easily. However, when manufacturing a protective tube bent at an angle such as an L-shape, the longitudinal length of the L of the protective tube of the front end sealing already formed is reduced by cutting the rear end. It can be changed, but it is not possible to change the lateral length. In order to manufacture several types of protective tubes with different lateral dimensions, the same standard product is manufactured in advance, and the lateral portion of the protective tube is cut to a predetermined length later. Cannot be adopted because the horizontal length cannot be changed. Therefore, in the conventional manufacturing method, it is necessary to separately manufacture products having different standards for each dimension in the lateral direction, so that the cost is increased, and there are disadvantages that a large number of sizes must be prepared as stock.

In the above-described method in which a thermocouple is inserted into a straight tubular quartz pipe and then heated and bent at a predetermined position and a bending radius, the thermocouple is already inserted inside the quartz pipe. The accuracy of the product is hardly obtained due to the influence of the change of the bending process, and the thermocouple is exposed to a considerably high temperature, so that the accuracy may be reduced. According to the present invention, by preparing one kind of protection tube, a temperature detecting end capable of procuring L-shaped protection tubes having different lateral dimensions by a simple operation can be manufactured, and the bent temperature of the protection tube can be obtained. An object of the present invention is to supply a highly accurate product without being affected by a change in the state of bending of a protective tube when manufacturing a detection end and without exposing a thermocouple to high temperatures during bending.

[0005] Further, since a conventional protective tube is manufactured and supplied from the beginning with its tip sealed, when a thermocouple is inserted into the protective tube, the thermocouple is covered with an insulating member and is insulated. Since most of the members are porcelain insulators,
When the insulator at the distal end of the thermocouple collides with the sealed distal end of the protective tube due to an insertion error, there is a possibility that the insulator may break through that portion. Another object is to eliminate such a fear.

[0006]

Means for solving the problem of the present invention are as follows. A thermocouple is inserted into a protection tube having an open end until the tip of the thermocouple reaches a position near a position where the protection tube is to be sealed. After inserting the pair and fixing the thermocouple relatively to the protection tube so that the thermocouple does not enter or retreat from that position, heat the portion before the tip of the protection tube.
And stretch the heated part to reduce the temperature of the heated part.
After lowering and hardening the part, cut the part and keep it
The protection tube is sealed at a position ahead of the tip of the thermocouple by gradually heating the cut end of the protection tube.

[0007]

Next, an embodiment of the present invention will be described. The protection tube used in this embodiment is made of quartz and has a circular cross section. A thermocouple is inserted into the inside of a protective tube which has been bent into an L-shape and has an open end. The thermocouple is inserted into an insulator serving as an insulating member for isolating the thermocouples from each other. Since the insulator is formed by arranging a number of small insulators, the thermocouple can be freely bent. Therefore, a thermocouple can be inserted later into the protective tube bent in advance into an L-shape.

When the thermocouple is inserted into the protection tube, the length of the thermocouple is set to a value before the end of the thermocouple reaches a position close to the position where the protection tube is to be sealed.
Insert the thermocouple into the protective tube bent in the shape of a letter. Therefore, the tip of the thermocouple does not protrude from the open end of the protection tube. The thermocouple is fixed immovably relative to the protection tube so that the thermocouple inserted into the protection tube does not further enter or retract from the protection tube from that position.

For example, in the method of cutting and sealing at a position 3 to 5 cm away from the tip of the protective tube, the protective tube is held by a turning jig for a lathe and centered on an axis passing vertically through an end of the protective tube. While rotating the thermowell, a portion of 3-5 cm from the end of the thermowell is heated using an oxyhydrogen burner. When the heated portion of the protective tube becomes hot and becomes flexible, the heated portion is stretched by pulling the end of the protective tube while rotating the protective tube.

When the temperature of the stretched heated portion decreases and the quartz hardens, the stretched portion is cut to remove unnecessary pieces of the end portion of the protection tube. Since the cut end of the protective tube remains sharp, the end is rolled while slowly heating to seal the end. By this operation, the end of the protection tube of the finished product can be rounded like the bottom of the test tube.

[0011]

[Effect of the Invention A present invention is the above configuration, the coercive
Heat the part before the open end of the protective tube and heat it
Stretched part, then the temperature of the heated part falls
After the part has hardened, cut the part,
The protective tube is sealed by gradually heating the cut end of
You. Therefore, when the protection tube is bent in an L-shape, the dimensions of the protection tube whose end is sealed can be freely set only by manufacturing a protection tube of one standard.
Conventional products sealed the tip at the time of manufacturing the protective tube, so it was necessary to separately manufacture different standards for each dimension of the protective tube, so the cost was high, and it was necessary to prepare a large number of protective tubes in stock. did not become. According to the present invention, since protection tubes of various sizes can be procured by a protection tube of one standard, cost is not required, and the inconvenience of preparing protection tubes of many sizes can be solved.

Furthermore, since the tip of the protection tube is still open when the thermocouple is inserted into the protection tube, even if the thermocouple is inserted incorrectly, the tip may protrude from the opening of the protection tube. There is no risk of breaking through the tip of the protection tube. Conventionally, since a thermocouple was inserted into a protective tube whose tip was sealed in advance, there was a risk that the thermocouple might hit the distal end of the protective tube due to an insertion error and break the distal end. There is an effect that there is no fear.

[0013] Further, the operation of determining the dimensions of the protective tube and sealing the protective tube at that portion becomes easy and quick, and the sealed end can be rounded and smoothly finished like the bottom of the test tube.

In the conventional method in which a thermocouple is inserted into a straight tubular protective tube and then heated and bent at a predetermined position and a bending radius, the thermocouple is already inserted inside the protective tube.
The accuracy of the product is hardly obtained due to the influence of the change in the state of the heating bending process, and the thermocouple is exposed to a considerably high temperature, so that the accuracy may be reduced. The present invention is not affected by a change in the state of the bending process of the protective tube when manufacturing the bent temperature detecting end of the protective tube, and the thermocouple is not exposed to a high temperature during the bending process and has high precision. The effect is that products can be supplied.

Claims (1)

(57) [Claims] 1. A thermocouple is inserted into a protection tube having an open end until the tip of the thermocouple reaches a position near a position before the protection tube is to be sealed, and the thermocouple further enters or retreats from that position. after the thermocouple to not be fixed relative to the protective tube, heating the front portion than the tip of the protective tube
And stretch the heated part to reduce the temperature of the heated part.
After lowering and hardening the part, cut the part and keep it
A method of manufacturing a temperature detecting end, wherein the protection tube is sealed at a position ahead of a tip of a thermocouple by gradually heating a cut end of the protection tube.