JPH058469Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a temperature measuring device for a heating furnace such as a sintering furnace for firing ceramics, metal powder, etc., for example.

[Prior art] For example, in a sintering furnace, when sintering a workpiece, temperature control such as temperature rise and temperature maintenance is important, so it is necessary to measure the temperature of the heating chamber in which the workpiece is set. A temperature measuring device is provided. FIG. 3 is a sectional view showing a part of a sintering furnace equipped with a conventional temperature measuring device.

Reference numeral 1 denotes a furnace body, and a heat insulating wall 2 is installed inside the furnace body 1, and a heat insulating wall 2 is installed inside the furnace body 1 to prevent wax that evaporates during the degreasing process of the processed material from diffusing into the furnace. An inner case (insulating material) 3 made of graphite or the like is installed, and the inside of this inner case 3 is used as a heating chamber 4. The furnace body 1 and the heat insulating wall 2 have through holes 1a and 2a for temperature measurement, and a hollow flange body 5 is fixed to the through hole 1a of the furnace body 1. The opening of the flange portion 5a of the flange body 5 is covered with heat-resistant glass 6, and a lid body 7 having a see-through hole 7a in the center is bolted to the flange portion 5a.

To measure the temperature of the heating chamber 4, the heat receiving port 8a of the radiation thermometer 8 is placed so as to face the outer wall of the inner case 3 through the see-through port 7a, and the radiant energy of the outer wall of the inner case 3 is measured. It was carried out by

[Problems to be solved by the invention] However, since the temperature measuring device described above does not directly measure the temperature of the heating chamber 4 but measures the temperature of the outer wall of the inner case 3, There was a difference between the actual temperature in the heating chamber and the measured temperature, which caused problems in operational temperature control.

Further, the radiation thermometer measures the radiant heat of the inner case 3, but when the inner case 3 is made of a different material, the radiant energy changes as the emissivity changes. This has caused variations in the measured temperatures, making accurate temperature measurement difficult.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and the present invention has been made in order to solve the above problems. The temperature at the bottom of the cylinder is measured from outside the furnace using a radiation thermometer.

[Operation] By measuring the temperature at the bottom of the cylinder, it is possible to accurately measure the temperature inside the heating chamber in which the object to be processed is set, since the emissivity at the bottom of the cylinder is constant.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows the overall structure of the sintering furnace.
The figure shows an enlarged view of the part of this sintering furnace equipped with a temperature measuring device.

The structure of this furnace is almost the same as that in Figure 3,
In the figure, 1 is a furnace body, 2 is a heat insulating wall, 3 is an inner case (insulating material), and 4 is a heating chamber. Note that 9 is a heater provided between the heat insulating wall 2 and the inner case 3, and W is an object to be processed installed in the heating chamber 4.

A temperature measuring device according to the present invention, designated by reference numeral 10, is provided at the bottom of the furnace, and its structure will be explained below.

The furnace body 1 and the heat insulating wall 2 are provided with through holes 1a and 2a similar to those shown in FIG. 3, and the inner case 3 is also provided with a through hole 3a.
is provided.

A hollow flange body 11 that communicates between the inside and outside of the furnace is fixed to the through hole 1a of the furnace body 1. The opening of the flange portion 11a of the flange body 11 is formed with a recess 11b having a diameter slightly larger than the inner diameter of the flange body 11.

The through holes leading from the outside of the furnace body 1 to the heating chamber 4, which are formed by the through holes 1a, 2a, 3a of the furnace body 1, the heat insulating wall 2, the inner case 3, and the flange body 11, are filled with graphite or the like. A bottomed cylindrical body 12 made of a heat-resistant material has a bottom 12.
a is positioned and inserted into the heating chamber 4. Note that the through hole 3a of the inner case 3 is connected to the cylindrical body 1.
2, and is closed by the cylindrical body 12 to maintain the airtightness of the heating chamber 4.

A flange portion 12b is formed at the open end of this cylindrical body 12, and this flange portion 12b is connected to the flange body 11.
It is fitted into a recess 11b formed in the opening of. This opening is covered with heat-resistant glass 6, and by bolting the lid 7 to the flange 11, the cylindrical body 12 and the glass 6 are fixed in this state. There is a see-through hole 7 in the center of the lid 7.
a is formed. Note that 13 is an O-ring for maintaining airtightness inside the furnace.

To measure the temperature of the heating chamber 4 of the sintering furnace configured as described above, a radiation thermometer 8 is installed outside the furnace body 1.
is arranged so that its heat receiving port 8a faces the bottom 12a of the cylindrical body 12, and the temperature inside the heating chamber 4 is measured by measuring the temperature of the bottom 12a.

According to such a temperature measuring device 10, the cylindrical body 12
Since the bottom portion 12a is located inside the heating chamber 4, the temperature of the bottom portion 12a is approximately the same as that of the heating chamber 4. Therefore, since measuring the temperature of the bottom portion 12a means measuring the temperature of the heating chamber 4, the temperature of the heating chamber 4 can be accurately known. Therefore, the difference between the actual temperature of the heating chamber 4 and the measured temperature, which occurs particularly during the temperature rise, can be eliminated, unlike in the conventional case, and the operation will not be hindered.

In addition, instead of measuring the temperature of the inner case 3 like in the past, the temperature of the bottom 12a of the cylindrical body 12, which has a constant emissivity, is measured, so even if the material of the inner case 3 is changed, stable and accurate measurement can be achieved. Temperature is possible.

Furthermore, the cylindrical body 12 is open to the outside of the furnace body 1, and the bottom part 12a where the temperature is measured is isolated from the inside of the furnace by the peripheral wall of the cylindrical body 12, so it is not affected by the gas in the furnace. Temperature measurements can be taken without

[Effect of the invention] As explained above, according to the temperature measuring device for a heating furnace such as a sintering furnace of the invention, a bottomed cylinder can be inserted from outside the furnace body so that the bottom part is located inside the heating chamber. However, the temperature at the bottom of the cylinder, where the emissivity is constant, was measured from outside the furnace using a radiation thermometer.
The temperature at the bottom of this cylinder is approximately the same as the temperature in the heating chamber, so measuring the temperature at the bottom means measuring the temperature in the heating chamber, and it is difficult to know the temperature in the heating chamber accurately. can. Therefore,
It is possible to eliminate the difference between the actual temperature in the heating chamber and the measured temperature that occurred in the conventional method, especially during the temperature rise, making it possible to accurately control the temperature of the workpiece during the sintering process, for example. This has the effect of enabling more effective operations.

Furthermore, since temperature can be measured without being affected by changes in the emissivity of the heat insulating material due to changes in the material of the heat insulating material, stable temperature measurements can be made no matter what material the heat insulating material is used.

Furthermore, the cylinder is open to the outside of the furnace body, and the bottom part where the temperature is measured is isolated from the inside of the furnace by the peripheral wall of the cylinder, so it is not affected by gases etc. outside the heating chamber. Temperature measurement can be performed without

[Brief explanation of the drawing]

1 and 2 are diagrams showing an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view showing the structure of the entire sintering furnace, FIG. 2 is an enlarged sectional view of the temperature measuring device, FIG. 3 is a sectional view showing a conventional technique. 1...Furnace body, 3...Inner case (insulation material),
4... Heating chamber, 8... Radiation thermometer, 10... Temperature measuring device, 12... Bottomed cylindrical body, 12a... Bottom part.

Claims (1)

[Scope of utility model registration request] In a heating furnace such as a sintering furnace in which a heating chamber is formed inside the furnace body by a heat insulating material and a workpiece is heated inside the heating chamber, a heat-resistant bottomed Heating of a sintering furnace, etc., characterized in that a cylindrical body is inserted so that its bottom is located inside the heating chamber, and the temperature at the bottom of the cylindrical body is measured from outside the furnace body with a radiation thermometer. Temperature measuring device in the furnace.