JPS5883223A - Contactless type surface temperature detector - Google Patents

Abstract

PURPOSE:To obtain a detector which has excellent responsiveness and is adaptable to both flat plate-like and wire-like objects to be measured by providing the 3rd thermocouple in the space in a reflecting mirror having a semispherical inside surface, connecting the 2nd and the 3rd thermocouples differentially and providing a heater for heating of heating elements. CONSTITUTION:A controller 15 which controls electric power supply to a heater 6 so as to eliminate temp. differences in the detection temps. of the 3rd thermocouple 13 and the 2nd thermocouple 12 is connected to each negative terminal of the thermocouple 13 and the thermocouple 12. The thermocouple 13 and the thermocouple 12 are differentially connected. According to such connections, the temp. difference T18-T12 between the temps. T18 and T12 detected by the temp. measuring contacts of the respective thermocouples can be detected. The 1st thermocouple 11 is further differentially connected to the 3rd thermocouple 13. Thus if the temp. detected by the thermocouple 11 is defined as T11, a composite detected temp. Tm is displayed on an indicator 17. Since a heat receiving element 8 and a surface 16 to be measured are of an equal temp. under a thermal equil. state, Tm=T11=T16 and the temp. T16 of the surface 16 is displayed on the indicator 17.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface temperature detector that measures the temperature of the surface of a rotating or moving object in a non-contact manner.

Conventionally known as a heat flow compensation type thermometer, it has a non-contact heat-receiving element that approaches the measured surface of a moving object and a heating element located outside of this heat-receiving element, and actively heats the heating element. By doing so, a thermal equilibrium state is maintained with no thermal gradient from the surface to be measured to the heat receiving element, and from this heat receiving element to the heating element outside of it, and under this state, the temperature of the heat receiving element, and therefore the surface to be measured. Measurements have already been provided to measure the temperature of .

In the conventional measurement described above, the responsiveness of the detector tends to deteriorate as a result of the heat capacity of the heat receiving element.

In order to avoid this deterioration in response, a type without a heat receiving element is also provided. If the moving object is a linear object, even if the heat-receiving element is omitted in this way, the above objective of preventing the response deterioration can be achieved by configuring the heating element in a shape that surrounds the linear object. It can also be reached. However, if the moving body is in the shape of a flat plate or a rotating roller, it is impossible to give the heating element a shape that surrounds it. In this case, if a configuration without a heat receiving element is forcibly adopted, the accompanying airflow induced by the movement of the surface to be measured will directly affect the measurement location of the detector, making the measurement unstable and causing errors.

Therefore, an object of the present invention is to avoid deterioration of thermal response even though it has a heat receiving element, and also to enable a configuration that surrounds a linear moving body by using an additional device, that is, an attachment. It is an object of the present invention to provide a surface temperature detector capable of detecting the temperature of a linear object in addition to a flat plate-like or roller-like object in a non-contact manner and with high responsiveness during its movement.

In order to achieve the above object, the present invention includes a hemispherical reflecting mirror heating element whose inner surface is a reflective surface, a flat plate-shaped heat receiving element provided to close this reflecting mirror, and an outer side of the heat receiving element. A cover or attachment lf is detachably provided to surround the heat receiving element, and first and second attachments are provided on the circular surface of the heat receiving element.
2 thermocouples are installed, and a 30th thermocouple is installed in the space inside the reflector.
A thermocouple is provided, the second and third thermocouples are differentially connected, the first thermocouple is additionally connected to this connection, the outer periphery of the reflecting mirror is covered with a case, and a heater for heating the heating element is installed. It is prepared.

In FIG. 1, (1) is a cylindrical case made of a heat-resistant material, such as stainless steel. (2)
There is also a cap made of a similar material, which also has a cylindrical shape and is fixed to the case (1) by a set screw (3). Inside the cap (2) is a terminal plate (4) with a screw (
5) It is properly installed.

(6) indicates the lead wire outlet.

The case (1) has thin lashes (7) protruding from the inner peripheral edge of the lower end. A disc-shaped heat-receiving element (8) made of a thin, cost-effective plate is brought into contact with and supported by the boxwood (7) from inside the case.

A hemispherical heating element (9) is placed on the periphery of the heat receiving element (8).
and the outer peripheral surface of the heating element (9) and the case (1).
) is sandwiched between the ring αq and the inner circumferential surface of the case (1).
fixed inside. The heating element (9) is made of a thin aluminum plate with low heat capacity and good thermal conductivity. (ll
a) is the lead wire of the first thermocouple (117 (Fig. 2),
12a) shows the lead wire of the second thermocouple α2, and (13a) shows the lead wire of the third thermocouple 03. The lead wires of these thermocouples are connected to each other on the upper terminal board (4) as shown in the figure, supported by respective terminals (llb) (12b) (13b), and further connected to lead wires (not shown). It is guided from the outlet (6) to each device described below.

Note that a heater α knob is attached so as to surround the outer periphery of the case (1).

As shown in Fig. 2, the heat receiving element (8) has a first thermocouple (I
ll, and a second thermocouple Q2+ are attached so that their respective thermal junctions are located at the center of the heat receiving element (8).

For this attachment, the lead wire portion is adhered to the peripheral edge of the heat receiving element (8) using, for example, adhesive tape.

Returning to Figure 1, add the third thermocouple (+31 is the heating element (9)
A hot junction is positioned within the heating element through the hole in the top of the heating element.

Next, the connection of each thermocouple will be explained. In FIG. 3, α force is a thermocouple temperature indicator according to the type of thermocouple used in the present invention, and It is connected to one pole of the second thermocouple az as shown. (As will be described later, 151 is a zero temperature controller that controls the power supply to the heater (6) so that there is no difference in temperature detected by the third thermocouple αJ and the second thermocouple 02. This controller C1
51 is connected to each negative pole of the third thermocouple 03 and the second thermocouple Q7J as shown by solid lines in the figure. The third thermocouple α3 and the second thermocouple (121) are differentially connected as shown by solid lines in the figure.

With this connection, the temperature difference T18-T12 between the temperatures Tta and 'l'tt detected by the temperature measuring junctions of the respective thermocouples can be detected. A first thermocouple Ou is further differentially connected to this differentially connected third thermocouple α3 as shown by the solid line in the figure.

Therefore, if the detected temperature of the first thermocouple 0υ is fT11, the composite detected temperature - on the indicator ll) is Tm = Tll
'-(T18- Ttz) = 'pt1+T12-
T18 is displayed.

Therefore, the object to be measured Oe is held so that heat receiving grooves, heat convection, and heat radiation are sufficiently generated on the surface to be measured without any loss.

At this time, the second thermocouple (121) detects the temperature Txw of the heat receiving element (8) by receiving heat from the surface to be measured (161).

Further, the third thermocouple 03 detects the internal temperature T1B of the auxiliary element (9) lE3. 3rd thermocouple Q3] and 2nd thermocouple (
Since 121 is a differential connection, the detected temperature of each thermocouple is
'ta TI2 (D An electromotive force corresponding to the temperature difference Tts - T12 is input to the zero level controller 09.
9 operates by supplying power to the heater α when the temperature T1m inside the heating element (9) detected by the third thermocouple 0 is lower than the heat receiving element temperature 'f1z detected by the second thermocouple 0z. This temperature difference T1 is reduced by heating the heating element (9)
This is an operation to control 8-Txg to zero. Therefore, in the detector of the present invention in which the heat receiving element (8) is set to have extremely low loss in terms of heat exchange between the surface to be measured (1o) and the space within the heating element (9), the heat receiving element (8) is (8), and further from the heat receiving element (8) to the heating element (9).
) The temperature gradient up to that point disappears and a state of thermal equilibrium is reached.

In other words, the measured surface aeo mixture T16 and the heat receiving element (8
) temperature TI2 and the temperature T1 in the space near the heating element (9)
g has the relationship T16 = T12 = 'l'ta. Under this relationship, the composite detected temperature TXO by connecting the three pairs of thermocouples described above is Tm == Tll +T12
-T1a=T11. Therefore, the temperature T on the indicator αη
ll is displayed. By the way, is the temperature Tll detected by the first thermocouple αυ the same as the temperature Tll detected by the second thermocouple G? The temperature of the heat receiving element detected at J is T12, and under the above-mentioned thermal equilibrium state, both the heat receiving element (8) and the surface to be measured αe are at the same temperature, but Tm = TIl.
= T16, and the indicator α shows the temperature 7 of the surface to be measured H.
When 1g is displayed, it becomes K.

Next, the case where the thermal equilibrium state is not established will be explained below.

The heat-receiving element is a thin piece of mica that has relatively good thermal conductivity and small heat capacity, and the periphery of the heat-receiving element is supported on the same thin boxwood (7) of the case. Since the temperature is close to that of the heat-receiving element due to the heat generated by the heater attached to the case, there is extremely little heat dissipation to the mica fiber (7). Furthermore, a heat receiving element (8
) and the heating element (9), the three pairs of thermocouple wires have a small heat capacity but a small heat loss, so that temperature measurement by the thermocouple is accurate. Therefore, if the temperature of the surface to be measured 061 suddenly changes during measurement by bringing the heat receiving element close to the surface to be measured, that is, the thermal equilibrium state disappears and the surface to be measured and the heat receiving element (8) and the heating element (8) change. 9) When a temperature gradient occurs in the space surrounded by , the composite temperature Tm of the three pairs of thermocouple connections of the detector of the present invention until a new state of thermal equilibrium is restored will be considered. The heat-receiving element (8) has extremely little loss in heat transfer in the space between the surface to be measured Q61 and the heating element (9). Therefore, the surface to be measured αe and the heat receiving element (8
The magnitude of the temperature gradient between the elements and the change in the height direction change to the same extent as that between the heat receiving element (8) and the space near the heating element (9). In other words, the surface to be measured 061
temperature at T16 first and second thermocouple? The temperature of the heat-receiving element (8) to be evacuated by 111 is Tll or T12 (Tll:
T12), heating element (9) whose temperature is measured by the third thermocouple
), when the temperature of the space near Tl11, Tlg>T11
(or T12), T12>T18 Conversely, Tlg (T
In the case of ll (or T12), the direction of the temperature gradient is Tl-2<Tta, and both of its magnitudes are T16-To
= Tl 2 - Tl 8. Transforming the above formula, T16 = Tll + Ttz - Tta
becomes. By the way, number one. The combined detected temperature frost by each of the second and third thermocouples is Tm = Tll - (']['ts
-T12)='let+T12-T18, so T16zTm is obtained.

Here, when T16 > Tll (or Ttg), T12
>T18, so T12-Ti1l) Q,
When Ti6 (Ttt (or Tl2)), T12 ('
l'ts, so T12-T18<0.

In the end, the temperature of the heat receiving element (8) whose temperature is measured by the second thermocouple O3 is equal to the temperature Tll of the heat receiving element (8) whose temperature is measured by the first thermocouple 0υ.
Temperature T1g '6 of the space near the heating element (9) measured by the third thermocouple (131) is subtracted from the temperature 'l'12, and the temperature TI2-T1g is added when T16>Tll, and T16<Tll When subtracted, K means that the temperature gradient between the surface to be measured Oe and the heat receiving element (8), including its direction, has been compensated for.Therefore, the combined detected temperature Tm is between the temperature T16 of the surface to be measured Be. The relationship Tm-:T16 is obtained for Tm-:T16.As described above, the temperature measurement of the surface to be measured by the detector of the present invention is accurate and responsive when the temperature is not in thermal equilibrium. This can solve the problem of poor responsiveness until a thermal equilibrium state is reached, which is a drawback of heat-receiving element-equipped detectors for preventing measurement instability.

As described above, the detector of the present invention can achieve the above-mentioned object of the present invention by detecting the temperature of the object to be measured (161). )
This has the advantage that a simple structure that only adjusts the zero position of the output from the second thermocouple (12"1-) is sufficient.

Next, one further feature of the present invention will be explained below.

FIG. 4 shows the attachment 03 of the device of the invention.

In the figure, ■ is an angled arm protruding from the case (υ). The protruding piece (C) of the cover (A) is removably attached to the free end of the arm ■ with a screw Cυ. The cover (A) Inside, a reflecting mirror c!41 is housed as shown by the dotted line.The reflecting mirror @ has a hemispherical shape similar to the heating element (9) shown by the dotted line, and the inner surface is used as a heat reflecting surface to form the heating element (9). and are placed opposite each other as shown.

There is a slight gap between the case (1) and the cover (sha).
! 81 and the attachment (1!J is the case (υ
It is attached to the By moving the linear object within this gap, the temperature of the moving linear object is measured. The cover @ and case (υ) of the attachment α prevent airflow accompanying the linear object, prevent disturbances in measurement conditions, and enable accurate temperature detection.

As explained above, the detector of the present invention has excellent responsiveness and can be applied to objects to be measured such as flat or linear objects. This has the advantage of simplifying the process.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the detector of the present invention, Fig. 2 is a plan view of a part thereof, Fig. 3 is a wiring diagram of the thermocouple of the detector, and Fig. 4 is the same with an attachment attached. FIG. 3 is a front view of the detector. l...Case, 2...Cap, 3.5...Screw, 4...Terminal board, 6...Lead wire outlet, 7...
Brim, 8... Heat receiving element, 9... Heating element, iib...
・First thermocouple, 12b... Second thermocouple, 13b...
Third thermocouple, 14 ・+:-ta, 11a, l 2a,
13a...Lead wire, 1 lbm, 12bff
i, 13bl''・Terminal, 15... Zero position controller, 16... Measured object, 17... Indicator. Patent applicant: Rika Kogyo Co., Ltd. Representative Patent Attorney K. Gomi Figure 1 16 'M2 Figure 1 Figure 3 7 Figure 4

Claims (1)

[Scope of Claims] (υ A cylindrical case with one side closed and the other side open with a protruding edge, housed in the case, having a hemispherical shape that also opens at the opening of the case, and heating the inner surface. A heating element with a reflective surface, a flat heat receiving element supported on the solid line of the case so as to close the opening of this heating element and the opening of the case in common. In a space surrounded by the heat receiving element and the heating element, the first and twentieth thermocouples are attached to the inner surface of the heat receiving element, and the temperature measuring contact is located at the center of the heat receiving element, and are electrically insulated from each other. A third thermocouple is provided in close proximity to the heating element and has a temperature measuring junction located on the center line between the heat receiving element and the heating element.The third thermocouple measures the temperature of the space near the heating element. When the temperature is lower than the temperature of the heat receiving element measured by the second thermocouple, the temperature is measured by these two thermocouples by supplying power to the heater attached to the case and heating the heating element. The third and second thermocouples are connected differentially so as to serve as inputs to a zero-level temperature controller that has a built-in heater supply device that controls the temperature difference between A first thermocouple is differentially connected to the thermocouple, and an indicator is provided that continuously indicates the temperature of the surface to be measured by the series combined electromotive force of the first, second, and third thermocouples. (2) Case (a cylindrical shape with outer and inner diameters that match υ; attachments that can be attached and detached from each other at the opening in the case; housed in the attachment and attached to the opening of the attachment; A hemispherical reflector with a heat-reflecting surface on its inner surface opens in the same direction, and a lid detector is located at the opening edge of this reflector and attachment.