JPS609818A - Calibrating device for thermometer in heat treating furnace - Google Patents

Abstract

PURPOSE:To avert the measuring error that arises in a temp. measuring system by positioning the detecting end of a radiation thermometer and a test piece for calibration provided with a thermometer so as to face each other via a conveyor for conveying a material to be heat treated and calibrating the thermometer at all times. CONSTITUTION:A pipe 2 is conveyed by a conveyor 6 in a heat treating furnace 1 and a two-color thermometer 8 is operated by a finger position detector 14A to detect the temp. of the pipe 2 upon arrival of the pipe 2 at an optical rod 9. When there is no pipe 2 right under the rod 9, light is made incident from a test piece 11 for calibration to the rod 9 and when a finger 4 approaches to a finger position detector 14B, the signal is fed to a synchronizing signal generator 15, which feeds the signals from the thermometer 8 and a thermocouple thermometer 13 to a regulator 16. The signal from the thermometer 8 is calibrated with the signal from the thermometer 13 as a reference in the regulator 16 and the calibration signal is returned from the regulator 16 to the thermometer 8, by which the thermometer 8 is adjusted.

Description

[Detailed description of the invention] The present invention relates to a thermometer calibration device in a heat treatment furnace.

When a tube is formed by centrifugal casting or the like, the metal structure is stabilized by heat treating the tube after casting. At this time, in order to maintain the quality of the tube, it is necessary to control the temperature during heat treatment, and therefore the temperature of the tube in the heat treatment furnace must be measured. Normally, pipes are heat treated while being slowly transported through a heat treatment furnace using a conveyor device such as a chain conveyor, but conventionally, a detection end for a radiation thermometer such as an optical rod was installed at several points in the furnace. , the temperature is measured when the tube reaches the detection end 1d. However, there is a problem in that measurement errors tend to gradually increase due to deterioration of pressure at the detection end installed in the furnace.

Therefore, an object of the present invention is to constantly calibrate a radiation thermometer that measures the temperature of a heat-treated object such as a pipe, and to suppress measurement errors as much as possible.

To achieve this object, the present invention provides a heat treatment furnace in which an object to be heat treated is heat treated while being conveyed by a conveyor device, and a detection end of a radiation thermometer for measuring the temperature of the object to be heat treated is connected to the conveyor device in the heat treatment furnace. Set up facing each other,
A calibration test piece with a thermocouple is provided on the side opposite to the detection end with respect to the irradiated object being transported by the conveyor device.

Therefore, after a certain heat-treated object passes the position corresponding to the detection end, the detection end detects the temperature of the calibration test piece until the next heat-processed object arrives, and the temperature level at this time is Because it is calibrated with the temperature water level by thermocouple,
Measurement errors occurring in the temperature measurement system can be constantly avoided.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 and 2, (1) is a heat treatment furnace, and is provided with a pair of skid rails (3) that can horizontally support a tube (2) as an object to be heat treated. Between both skid rails (3) is a pipe (2) and
) is provided with a pair of finger chains (5) having equally pitched fingers (4), and these skid rails (3) and finger chains (5) constitute a conveyor device (6). There is. The p1 skid rail (3) and finger chain (5) are
7), the pipe (2) is conveyed while constantly being in contact with the fingers (4).

An optical rod (9) serving as a detection end of a two-color thermometer (radiation thermometer) (8) is provided at a position facing the conveyor device (6) that connects Vc-h inside the furnace (1). 10 is connected to the two-color thermometer (8).

In addition, between the two skid rails (3) located opposite the optical rod (9), this skid rail
3) A plate-shaped calibration test piece 0B is provided at a position below the top surface. A thermocouple @ is attached to the calibration test piece αB, and the configuration is such that the temperature of the calibration test piece 011 can be measured with the thermocouple.

Outside the furnace (1), there is a proximity switch etc. for detecting the position of the tube (2) (therefore, the position of the finger (4)) inside the furnace (1) using the pitch of the fingers (4). A pair of finger position detectors (14A) (14B) are provided. When the detector (14A) detects the finger (4), a tube (
Rain detector (1) is positioned so that the pipe (2) is located directly under the optical rod (9) when the detector (14B) detects the finger (4).
4A) (14B) are positioned in advance. Note that %4 is a synchronizing signal generator that receives signals from the detectors (14A) and (14B) to operate the two-color thermometer (8) and thermocouple thermometer 0, and [16 is the signal from the two-color thermometer (8)]. This is a regulator for sending a calibration signal to the two-color thermometer (8) as a reference for the signal from the thermocouple thermometer 1 and the signal from the thermocouple j.

In the above configuration, the tube (2) is heat treated while being gradually conveyed through the heat treatment furnace (1) by the conveyor device (6). When the fake tube (2) reaches just below the optical rod (9), this is detected by the finger position detector (14A), and the two-color thermometer (8) is activated by the signal from the synchronization signal generator G9. The temperature of the tube (2) is detected based on the light emitted from the tube (2).

On the other hand, when the tube +2) is not located directly below the optical rod (9), the light from the calibration test piece ttn is incident on the optical rod (9).

At this time, the finger position detector (14B) shows the finger (
4) approaches, this signal is sent to the synchronous signal generator ((to), and the synchronous signal causes the two-color thermometer (8) and thermocouple thermometer 0 to
and regulator aO are operated at the same time, and both temperatures are changed (8) d
The signal from is sent to regulator σG. Inside the regulator αυ, a two-color thermometer (8
) is calibrated, and the calibration signal is returned from the regulator α0 to the two-color thermometer (8) for adjustment of this two-color thermometer (8).

In this way, according to the present invention, the two-color thermometer (8) is constantly calibrated by the thermocouple (to), so as shown in FIG. 3, compared to the conventional case without calibration, hand,
The absolute value of the measurement error when measuring the temperature of the tube (2) is suppressed from gradually increasing over time.

However, it is necessary to periodically replace the calibration test piece ctn to maintain calibration accuracy. . In addition, the regulator (I
Since there is a limit to the adjustable range due to G, the optical rod (9) must be replaced in that case.

As described above, according to the present invention, after a certain object to be heat-treated passes the position corresponding to the detection end, until the object to be heated by fire arrives, the detection end detects the entire temperature of the calibration test piece, Moreover, since the temperature water level at this time is calibrated with the temperature water level obtained by the thermocouple, measurement errors caused by the temperature measurement system IC can be constantly avoided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention, FIG. 2 is a side sectional view thereof, and FIG. 3 is a diagram showing changes in measurement error. (1)...Heat treatment furnace, (2)...Pipe (material to be heat treated)
, (6)... Conveyor device, (8)... Two-color thermometer (radiation thermometer), +9)... Optical rod (detection end), σ1)... Calibration test piece, @.
...S couple, 0...thermocouple thermometer, (14A) (14]
3)...Finger position detector agent Yoshi Moriki
Hiroshi

Claims (1)

[Claims] 1. In a heat treatment furnace in which an object to be heat treated is heat treated while being conveyed by a conveyor device, a detection end of a radiation thermometer for measuring the temperature of the object to be heat treated is provided opposite to the conveyor device in the heat treatment furnace, and the conveyor device 1. A thermometer calibration device for use in a heat treatment furnace, characterized in that a calibration test piece with a thermocouple is provided on a side opposite to the detection end with respect to the object to be heat treated being transported by the furnace.