JP2755086B2 - Portable heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable heater used for partially drying a coating film of, for example, an automobile body, and more particularly to a method for accurately measuring the surface temperature of an object to be heated. The present invention relates to a portable heater having a temperature compensation function.

[0002]

2. Description of the Related Art Generally, when an object to be heated is heated using a heater that generates infrared rays, the temperature of the object to be heated is determined by the output of the heater, the distance between the heater and the object to be heated, and the temperature of the object to be heated. It changes according to the thickness or size of the object to be heated, the color of the object to be heated, and the like.

[0003] Therefore, in order to automatically control the temperature of the object to be heated, temperature measurement is required. As thermometers required for the temperature measurement, thermocouple type thermometers, radiation thermometers and the like have been conventionally used.

[0004]

In the case of the above-mentioned thermocouple type thermometer, it is necessary to bring the thermocouple portion into contact with the object to be heated, so that the uncured coating film or the like which cannot be brought into contact is formed. There is a problem that it cannot be used for measuring the temperature of a heated object. If a radiation thermometer is used, temperature can be measured in a non-contact manner.However, since the temperature of the heater body reflected on the object to be heated may be measured, the accurate temperature of the object to be heated is measured. There is a problem that it is difficult to measure.
As described above, there is a problem that it is extremely difficult to perform accurate automatic temperature control, that is, feedback control, with the conventional temperature measuring means.

Therefore, when controlling the temperature of the object to be heated, a method has been adopted in which each heating condition is manually adjusted based on experimental results obtained in advance and the temperature is adjusted to a desired temperature. However, errors in the setting of heating conditions, changes in environmental conditions, and the like cause a large variation in temperature, which causes poor quality.

Therefore, in the present invention, an infrared output wavelength generated from a heater is distinguished from an infrared input wavelength to be measured.
To solve the problem that accurate automatic temperature control of a heated object is enabled by measuring only a wavelength corresponding to the temperature of the heated object without measuring an infrared wavelength from a heater reflected on the heated object. Should be an issue to be addressed.

[0007]

A technical means for solving the above-mentioned problems is a portable heater which is used for partially heating an object to be heated and drying a coating film. An infrared irradiation type heater arranged to face the object to be heated;
A non-contact type temperature sensor that detects infrared rays radiated and reflected from the object to be heated and outputs an electric signal corresponding to the wavelength of the infrared ray, and an electric power corresponding to a short wavelength region among the infrared rays detected by the non-contact type temperature sensor A circuit breaker for interrupting a signal, an amplifier for amplifying an electric signal passing through the circuit breaker, and the heater if the maximum value of the electric signal amplified by the amplifier is equal to or less than a preset heating condition value. Increase current
While outputs a signal to pressure, if the heating condition value than the heat - a signal for reducing the energization current of motor controller - la and its control - on the basis of the said signal from the La arsenide - a motor And a current adjuster for adjusting the current flow.

[0008]

According to the portable heater having the above structure, infrared rays radiated and reflected from the object to be heated are detected by the non-contact type temperature sensor, and the electric signal corresponding to the wavelength of the detected infrared ray is detected from the non-contact type temperature sensor. Is output, the component of the electric signal corresponding to the wavelength in the short wavelength region, that is, the infrared wavelength from the heater is cut off by the circuit breaker, and after the electric signal passing through the circuit breaker is amplified by the amplifier, it is controlled. When the maximum value of the input electric signal is equal to or less than a preset heating condition value, the controller sends a signal to the current regulator to increase the current supplied to the heater. On the other hand, if the output is higher than the heating condition value, the heater current is reduced.
In order to output a signal to reduce the current, the current regulator adjusts the current supplied to the heater based on the signal. Therefore, the temperature of the object to be heated can be automatically controlled based on the wavelength of the infrared light radiated from the object without being affected by the infrared rays from the heater.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a layout diagram schematically showing the overall configuration of an embodiment of the present invention. As shown in FIG. 1, the portable heater PH is disposed to face the object to be heated E, and is generated by the heater A for generating infrared rays for heating the object to be heated E and the heater A. After detecting the reflected infrared ray α reflected from the object to be heated E and the infrared ray β having a wavelength corresponding to the temperature of the object to be heated E, and photoelectrically converting the detected infrared ray β, cuts off an electric signal corresponding to the reflected infrared ray α. A non-contact type temperature sensor B that amplifies and outputs only an electric signal corresponding to the emitted infrared ray β by blocking the reflected infrared ray α by incorporating a device or by arranging an optical interference filter on the front side. If the maximum value of the electric signal output from the non-contact type temperature sensor B is equal to or less than a preset heating condition value, a signal for increasing the current supplied to the heater A is output, while if the maximum value is equal to or greater than the heating condition value. If so, reduce the current flowing through heater A That a current regulator to adjust the current supplied from the power source to the motor A D - and La C, the control - - controller for outputting a signal for small <br/> based on the signal from the La C arsenide It is.

FIGS. 2A and 2B show the positional relationship between a heater A, a non-contact type temperature sensor B and an object to be heated E. FIG. 2A is a plan view and FIG. ) Is a front view. FIG.
(A) and (B), the heater A is formed in a rod shape, and the non-contact type temperature sensor B is disposed on the axis of the heater A.
Is arranged. If the heater A and the non-contact type temperature sensor B are arranged on the same axis as described above, even if the distances x1 and x2 between the heater A and the object to be heated E change, the non-contact type temperature sensor B Is always on the axis of the heater A, so that the measurement error can be minimized.

FIG. 3 shows the wavelength range of the reflected infrared ray α in which the infrared ray generated from the heater A is reflected on the object to be heated E and the radiation infrared ray β having a wavelength corresponding to the temperature of the object to be heated E together with the energy density. FIG. 3 is an explanatory diagram of the wavelength region shown. As shown in FIG. 3, since the infrared ray generated from the heater A has a short wavelength, the reflected infrared ray α reflected by the object to be heated E has a wavelength longer than that of the radiated infrared ray β having a wavelength corresponding to the temperature of the object to be heated E. Has become shorter. FIG. 4 schematically shows a state of receiving the reflected infrared ray α and the emitted infrared ray β.

Next, the operation of this embodiment will be described. When a power switch (not shown) is turned on and a current is supplied from the power source to the heater A via the current regulator D, infrared rays α are emitted from the heater A to the object E to be heated. E is heated. The object to be heated E is heated, and infrared rays β are emitted from the object to be heated E as the temperature increases.

In this state, when the reflected infrared ray α and the radiated infrared ray β of the object to be heated E are detected by the non-contact type temperature sensor B, as shown in the flowchart of FIG. In B, the reflected infrared ray α is eliminated by the action of the circuit breaker or the optical interference filter. Then, the amplified electric signal is output from the non-contact type temperature sensor B to the controller C in a state where only the electric signal corresponding to the radiated infrared ray β of the object E is amplified.

When the controller C receives the amplified electric signal, the controller C determines whether the maximum value of the signal is equal to or less than a preset heating condition value as shown in FIG.
If less heating condition value heat - while outputting <br/> Ru signal increases the current supplied data A, if the heating condition value or more heat - to output a signal for reducing the current supplied data A A current is passed from the current regulator D to the heater A by the
Is controlled to a desired temperature state, and after a predetermined time, energization of heater A is terminated. In the controller C, if the input amplified electric signal is divided into digital signals for each predetermined wavelength width, an arbitrary signal is selected from the digital signals and is compared with the heating condition value. It is also possible.

As described above, since the temperature of the object to be heated E can be always accurately measured and accurate feedback control can be performed, (1) the distance between the heater A and the object to be heated E, The temperature can be controlled to a desired value even if there are factors such as the thickness of the sheet E and the color of the object to be heated E which vary. (2) The object to be heated E can be brought to a desired temperature in a short time without overbaking even if a high-output heater A is used. (3) Even if the heater A is set at a short distance from the object to be heated E, the object to be heated E can be heated to a desired temperature in a short time without overbaking. Can be reduced. (4) Stepwise temperature rise control such as holding the object E at an intermediate temperature becomes possible. (5) If a microcomputer is used for the controller, it is easy to change the heating pattern, so that various forms of temperature rise control are possible.

[0016]

As described above, according to the present invention, the infrared output wavelength generated from the heater and the infrared input wavelength to be measured are distinguished, and the infrared wavelength from the heater reflected on the object to be heated is determined. Since only the wavelength corresponding to the temperature of the object to be heated can be measured without measurement, the temperature of the object to be heated can be accurately measured, and thus there is an effect that accurate automatic temperature control of the object to be heated can be performed.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 shows a heater A, a non-contact type temperature sensor B, and a heated object E.
3A and 3B are a plan view and a front view showing an arrangement relationship with the first embodiment.

FIG. 3 is a wavelength range explanatory diagram showing the wavelength ranges of the reflected infrared ray α of the infrared ray generated from the heater and the radiated infrared ray β of the object to be heated together with the energy density.

FIG. 4 is a schematic explanatory diagram of a light receiving state of reflected infrared light α and emitted infrared light β.

FIG. 5 is a temperature control flowchart of a portable heater.

FIG. 6 is an explanatory diagram of heating conditions.

[Explanation of symbols]

 PH Portable heater A Heater B Non-contact temperature sensor C Controller D Current regulator E Heated object

Claims (2)

(57) [Claims] 1. A portable heater used for partially heating an object to be heated and for drying a coating film, etc., wherein the infrared irradiation type heat source is arranged to face the object to be heated. A non-contact temperature sensor that detects infrared rays radiated and reflected from the object to be heated and outputs an electric signal corresponding to the wavelength of the infrared ray; and a short wavelength infrared ray detected by the non-contact type temperature sensor. A circuit breaker that blocks an electric signal corresponding to the region, an amplifier that amplifies the electric signal that has passed through the circuit breaker, and if the maximum value of the electric signal amplified by the amplifier is equal to or less than a preset heating condition value. the heat - while outputting a signal for increasing the energization current of motor, the heat if the heat condition value or - outputs a signal for reducing the energization current of motor controller - la and its control - the signal from La Based on Po is characterized in that a current regulator for regulating the electric current - Taburuhi - data. 2. A non-contact type temperature sensor is provided in front of a non-contact type temperature sensor instead of a circuit breaker, wherein an optical interference filter for passing only infrared rays having a long wavelength region among infrared rays emitted and reflected from an object to be heated is passed. The portable heater according to claim 1, wherein