JP2002190374A - Temperature-sensing method and mechanism for high- frequency induction heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and surely sense the heating temperature of a heated material via a temperature sensor, using a simple process and constitution. SOLUTION: A temperature-sensing method and a mechanism for a high-frequency induction heating apparatus comprises a heating final power output circuit 46 for driving a heating coil 30 for heating a tool holder 2 through electromagnetic induction, a switchover circuit 56 for inputting the temperature of the tool holder 12, which is sensed via the infrared temperature sensor 32, only when the heating coil 30 is stopped, and a CPU control circuit 44 for determining whether the input temperature of the tool holder 12 has reached a preset heating temperature and controlling the heating final power output circuit 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature for a high-frequency induction heating apparatus for detecting the heating temperature of a material to be heated by a contact or non-contact type temperature sensor when the material to be heated is subjected to electromagnetic induction heating. The present invention relates to a detection method and an apparatus.

2. Description of the Related Art For example, in a shrink-fit type tool holder,
When heating a tool holder which is a material to be heated, generally, a method of heating the tool holder with hot air using an electric heater or the like is widely used. However, it takes a considerable amount of time to heat the tool holder to a desired temperature by hot air heating. Therefore, a high-frequency induction heating apparatus using induction heating is employed. High-frequency induction heating devices use induction heating by electricity.A high-frequency current is passed through a heating coil to create an alternating magnetic field, and a conductive material to be heated is placed in the alternating magnetic field to produce an electromagnetic induction. The heating target material is heated by generating Joule heat.

However, in electromagnetic induction heating using high frequency (hereinafter referred to as high frequency induction heating), the tool holder is rapidly heated, so that even if the heating time is slightly increased, the tool holder is not heated. However, the temperature tends to be higher than the temperature required for attaching and detaching the blade tool. When attaching and detaching a cemented carbide blade tool with a general steel tool holder, it is necessary to heat the tool holder to about 200 ° C. to 400 ° C. Temperature range is reached. For this reason, even if it is slight, if the temperature control is incorrect, the tool holder will be at or above the heat treatment temperature (500 ° C. to 800 ° C.) of the steel material as its own material,
Heat treatment such as quenching, tempering or normalizing is performed. As a result, a problem has been pointed out that distortion occurs due to thermal residual stress associated with the heat treatment state in the gripping portion of the blade tool, thereby deforming the blade tool gripping portion of the tool holder and making it impossible to grip and detach the blade tool. I have. Therefore, when performing high-frequency induction heating of the tool holder, it is necessary to control the heating temperature with high precision so that the gripping portion of the tool holder is not heated to its own heat treatment temperature. For this reason, a method of managing the heating time of the tool holder by a timer or a program can be considered, but it is not possible to cope with the change of the type of the tool holder or the type of the blade tool, and furthermore, the temperature change of the tool holder itself. There is a problem that can not be addressed.
On the other hand, there is a method of detecting temperature by sensation by radiant heat. However, accurate temperature control is impossible, and there is a limit in visual temperature control. There is also a method in which a temperature chalk is applied to a tool holder, and the heating temperature is detected from the melting of the temperature chalk. However, this kind of work is considerably complicated and has a disadvantage that it is not suitable for practical use. Therefore, to detect the heating temperature, it is optimal to use a temperature sensor. The temperature sensor monitors the temperature of the tool holder while performing high-frequency induction heating on the tool holder. It is desirable to stop heating when the temperature is reached. As this type of temperature sensor, a thermistor temperature sensor and an infrared temperature sensor are suitable, but the following problems occur when actually used. That is, when the above-mentioned thermistor is used, the temperature detecting section of the thermistor must be brought into direct contact with a material to be heated such as a tool holder. At that time, the thermistor is composed of an oxide such as iron, manganese, nickel, or titanium.
The thermistor itself is affected by electromagnetic induction,
Accurate temperature detection may not be possible. On the other hand, an infrared temperature sensor detects the amount of infrared energy radiated from a measurement target (tool holder) as a voltage value by a thermo element, and can detect the temperature of the measurement target in a non-contact state. it can. For this reason, the infrared temperature sensor is disposed apart from the heating coil through which the high frequency flows so as not to be affected by the electromagnetic induction. However, the infrared temperature sensor detects radiation emitted from the object to be measured, and if a shield is interposed between the infrared temperature sensor and the object to be measured, the measurement accuracy of the radiation decreases. . Therefore, it is necessary to arrange the infrared temperature sensor between the windings of the heating coil or in the heating coil in order to make the infrared temperature sensor face and approach the object to be measured. It has been pointed out that the infrared temperature sensor itself is heated, which makes accurate temperature detection difficult. The present invention is intended to solve this kind of problem, and is a simple process and configuration for a high-frequency induction heating device that can accurately and reliably detect the heating temperature of a material to be heated via a temperature sensor. It is an object to provide a temperature detection method and mechanism.

According to the temperature detecting method and mechanism for a high-frequency induction heating device according to the present invention, a high-frequency induction heating device is driven to heat a material to be heated by electromagnetic induction. Only when the driving is stopped, the temperature of the material to be heated is detected via the temperature sensor. Therefore, when measuring the temperature of the material to be heated by the temperature sensor, the temperature sensor itself is not affected by the electromagnetic induction, and the temperature sensor can be arranged at a desired measurement position with respect to the material to be heated. . This makes it possible to accurately and reliably detect the heating temperature of the material to be heated via the temperature sensor with a simple control and configuration.
Further, the temperature sensor is a non-contact infrared temperature sensor, and the infrared temperature sensor is arranged at a position close to a heating coil constituting the high-frequency induction heating device, that is, at a position where the temperature detection of the material to be heated is optimally performed. Is done. The infrared temperature sensor turns off the sensor circuit during heating affected by electromagnetic induction, or with the sensor circuit turned on,
Do not import detected values. When detecting the temperature, the heating is temporarily stopped, and the temperature is measured during that time. Here, since the infrared temperature sensor returns to the normal state in about several milliseconds after the electromagnetic induction is stopped, the temperature measurement processing by the infrared temperature sensor is actually performed instantaneously. In addition, the detection value of the infrared temperature sensor is taken into the electronic circuit and can be determined in a very short time, and the process from taking of the detection value to the determination is performed in about several milliseconds. For this reason, the heating stop time required for the temperature detection processing by the infrared temperature sensor is very short, and the entire heating time does not become long, so that efficient heating processing can be performed. Furthermore, a condensing lens is provided on the incident surface side of the infrared temperature sensor. In the infrared temperature sensor, thermal energy radiated from the material to be heated and thermal energy of reflection reflected around the material are detected, and in order to detect an accurate temperature of the material to be heated, It is necessary to detect only the heat energy radiated from the material to be heated itself. Therefore, by disposing a condenser lens on the incident surface side of the infrared temperature sensor, heat energy radiated from the material to be heated can be received over the entire viewing angle of the infrared temperature sensor, and the temperature of the material to be heated can be reduced. Can be detected with high accuracy. In addition, since the hood is provided so as to cover the front of the condensing lens, it is possible to prevent reflected heat and other unnecessary radiant heat from entering as much as possible. It becomes possible to measure accurately. Further, the surface of the material to be heated is subjected to a blackening treatment. In order to prevent heat energy reflected from the material to be heated from entering the infrared temperature sensor, it is desirable to lower the reflectance of the material to be heated. For this reason, by applying a black or black dyeing paint to the surface of the material to be heated, there is almost no reflection, and it is possible to prevent heat energy other than heat energy due to radiation from entering the infrared temperature sensor. Furthermore, the surface of the material to be heated is subjected to a concavo-convex treatment. The higher the rate at which heat is radiated from the metal surface, that is, the higher the heat emissivity, the higher the rate of radiant heat compared to the reflected heat. Therefore, when the surface of the material to be heated is made glossless, the ratio of radiant heat is increased, and the accuracy of temperature measurement is improved. Therefore, in order to make the surface of the material to be heated rough and glossy, the surface of the material to be heated is subjected to unevenness treatment. Further, the temperature sensor is a thermistor temperature sensor, and when heating the material to be heated, the thermistor temperature sensor is disposed outside a heating coil constituting a high-frequency induction heating device, while heating the material to be heated. Is stopped, the thermistor temperature sensor contacts the material to be heated. Thus, the thermistor temperature sensor itself is prevented from being heated, and the temperature of the material to be heated can be detected with high accuracy and reliability.

FIG. 1 shows a high-frequency induction heating apparatus 1 to which a temperature detecting method according to a first embodiment of the present invention is applied.
It is a perspective view which shows the whole of No. 0. High frequency induction heating device 10
To be heated, for example, the tool holder 12
Is made of steel, and the tool holder 12
A carbide cutting tool 16 such as a drill or a reamer is shrink-fitted to the cutting tool holding portion 14 through the high frequency induction heating device 10. The high-frequency induction heating apparatus 10 includes a base 22 provided with an operation unit 20, and a control unit 40 described later is provided in the base 22. A table 24 for arranging a plurality of tool holders 12 is provided on the base 22, and a heating head 26 is supported by a casing 28 so as to be able to move up and down. The heating head 26 includes a heating coil 30 that covers the tool holder 12 and heats the tool holder 12 by electromagnetic induction.
And a non-contact type temperature sensor for detecting the heating temperature of the sensor, for example, an infrared temperature sensor 32. As shown in FIG. 2, the infrared temperature sensor 32 includes a thermoelement 36 mounted on a holder 34, and a condenser lens 37 is provided on the incident surface side of the thermoelement 36 via a cylinder 38. Will be arranged. In the holder 34, a passage 39 to which a cooling medium such as cooling air is supplied is formed. The heating coil 30
It has a spiral shape, and an infrared temperature sensor 32 is provided corresponding to the gap. In addition to the heating coil 30, for example, a distribution-type heating coil 30a shown in FIG. 3 and a distribution-type heating coil 30b shown in FIG. 4 can be used. In any case, the infrared temperature sensor 32 Are arranged corresponding to the gaps. FIG. 5 is a circuit diagram of the control unit 40 included in the high-frequency induction heating device 10. The control unit 40 controls each circuit based on a control signal input from the operation panel 42, and includes a CPU control circuit 44 for confirming operation and performing various determinations. The CPU control circuit 44 monitors the electrical output of the electromagnetic induction heating and its overcurrent, and also controls the level meter to display the temperature corresponding to the input voltage from the infrared temperature sensor 32 on the LED. The control unit 40 includes a heating final power output circuit 46 that generates an output power for heating the tool holder 12 with the heating coil 30. The heating final power output circuit 46 is controlled based on an instruction from the CPU control circuit 44. The oscillation output level is supplied from each monitoring circuit 48 of the pre-driver. The oscillation frequency is 100KHZ ~ 20
It is set arbitrarily within the range of 0 KHZ. This pre-driver monitoring circuit 48 is used for ON / OF of overcurrent and heating power.
It has a mechanism for checking F. Infrared temperature sensor 32
Is connected to a sensor reference bias circuit 50. The sensor reference bias circuit 50 is a circuit for setting a reference voltage and an amplification factor of an output value from the infrared temperature sensor 32. For example, a reference voltage of 25 ° C. is 1.0V, and a reference voltage of 350 ° C. is 2.5V. , The magnification (gain) is about 0.05 V per 10 ° C. The sensor output value from the infrared temperature sensor 32 is sent to a sensor output amplifier circuit 52, which doubles the sensor output value and supplies it to a sensor output final amplifier circuit 54. The sensor output final amplifying circuit 54
The function of shifting the input voltage to 1.0 V or less when there is an input voltage of 25 ° C., taking out the difference between the voltage at 25 ° C. and the measured voltage, amplifying the difference, and supplying it to the CPU control circuit 44 Having. As a result, amplification about 6 times with high accuracy within the range of 0.8 V to 10 V is possible. A sensor reference bias / fixed stable voltage circuit / switch circuit (hereinafter referred to as a switching circuit) 56 is connected to the sensor reference bias circuit 50, the sensor output amplifier circuit 52, and the sensor output final amplifier circuit 54. The switching circuit 56 is a circuit for outputting an inverted output of a signal from each monitoring circuit 48 of the pre-driver. When a heating signal is input from each monitoring circuit 48 of the pre-driver, the operation of the circuit is turned off.
F to stop the processing of the output value from the infrared temperature sensor 32, and when there is no heating signal from each of the pre-driver monitoring circuits 48, turn on the operation of the circuit to process the output value from the infrared temperature sensor 32. To work. FIG. 6 is an explanatory diagram of the sensor reference bias circuit 50 and the sensor output amplifier circuit 52, and is actually configured by a single power supply operational amplifier IC circuit. In the reference bias circuit 50 for the sensor, the V.V. The output is 1/2 voltage of D. The resistor R7 is a variable resistor that sets the voltage of the infrared temperature sensor 32. In the sensor output amplifier circuit 52, the amplification ratio is determined by the ratio of the resistance R1 and the resistance R2. FIG. 7 is a diagram showing an operation ON / OFF circuit of the infrared temperature sensor 32. Q1 and Q2 are:
It is a switching transistor. When the switching signal is H, heating is being performed, and when the switching signal is L, heating is OFF.
The operation of the high-frequency induction heating apparatus 10 according to the first embodiment configured as described above will be described below. First,
As shown in FIG. 1, the heating head 26
When the tool holder 12 is disposed corresponding to the above, the heating head 26 descends, and the blade tool gripping portion 14, which is a heating portion of the tool holder 12, is positioned in the heating head 26. Specifically, as shown in FIG. 2, the heating coil 30 provided on the heating head 26 is externally provided on the blade tool gripping part 14, and the infrared temperature sensor 32 is provided between the heating coils 30, that is, It is arranged at a position directly facing the blade tool gripping portion 14. Then, CP
The U control circuit 44 sends a signal to each pre-driver monitoring circuit 48 based on control information such as work information and heating temperature input from the operation panel 42. Circuit 46
Is supplied with the oscillation output level. In the heating final power output circuit 46, the tool holder 12 is
Is generated, and the output power is supplied to the heating coil 30. Therefore, while the electromagnetic induction heating of the blade tool gripping portion 14 of the tool holder 12 is started, a heating signal is input from the monitoring circuit 48 of each pre-driver to the switching circuit 56, and the switching circuit 56
Is turned off. Therefore, the monitoring circuit 48 and the switching circuit 5 of the pre-driver are controlled by the CPU control circuit 44.
When the heating stop signal is sent to 6, the supply of the output power from the heating final power output circuit 46 to the heating coil 30 is stopped, and the operation of the switching circuit 56 is turned on. Accordingly, the sensor output value from the infrared temperature sensor 32 is sent to the sensor output amplification circuit 52, where the sensor output value is doubled, and then supplied to the sensor output final amplification circuit 54. Further, the sensor output final amplifying circuit 54 supplies the detected sensor output value to the CPU control circuit 44 as a predetermined voltage value. The CPU control circuit 44 determines whether or not the heating temperature of the blade tool gripper 14 has reached the set temperature based on the voltage taken from the sensor output final amplification circuit 54. And
If it is determined that the detected heating temperature is lower than the set temperature, a heating signal is sent to the switching circuit 56 and the predriver monitoring circuits 48. As a result, the output power is supplied to the heating coil 30, and the electromagnetic induction heating of the blade tool gripping portion 14 of the tool holder 12 is restarted, while the operation of the switching circuit 56 is turned off. Similarly, a heating stop signal is sent from the CPU control circuit 44 to the predriver monitoring circuits 48 and the switching circuit 56, and the heating coil 3
In a state where the electromagnetic induction heating by 0 is stopped, the heating temperature of the blade tool gripping portion 14 is detected. Each of the above steps is performed until the heating temperature of the blade tool gripper 14 reaches the set temperature. Thus, in the first embodiment, the heating tool 30 heats the blade tool grip 14 by electromagnetic induction, and the heating coil 30 heats the blade tool grip 14.
With the heating of the infrared temperature sensor 32 temporarily stopped,
Is used to detect the heating temperature of the blade tool gripping portion 14. For this reason, even if the infrared temperature sensor 32 is arranged at a desired measurement position with respect to the blade tool gripping portion 14, the infrared temperature sensor 32 is not affected by electromagnetic induction,
This has the effect that the heating temperature can be accurately detected. That is, as shown in FIG. 8, the output value of the infrared temperature sensor 32 is greatly disturbed by the influence of electromagnetic induction when the heating energization to the heating coil 30 is turned on, and it is difficult to accurately detect the temperature. . On the other hand, the heating coil 3
0 is turned off, the infrared temperature sensor 3
The output value of 2 immediately reaches the normal state in about several milliseconds, and the temperature detection process can be performed with high accuracy. Thus, the heating temperature of the blade tool gripping portion 14 can be detected with high accuracy and efficiency through the infrared temperature sensor 32 with a simple control and configuration. Further, the infrared temperature sensor 3
A condensing lens 37 is disposed on the side of the incident surface 2. The infrared temperature sensor 32 detects the thermal energy radiated from the tool holder 12 and the reflected thermal energy reflected around the tool holder 12 and entering. Therefore, by arranging the condenser lens 37 on the incident surface side of the infrared temperature sensor 32, it is possible to receive the heat energy radiated from the tool holder 12 over the entire viewing angle of the infrared temperature sensor 32, The temperature of the holder 12 can be detected with high accuracy. Further, when the surface of the blade tool gripping portion 14 of the tool holder 12 is subjected to blackening treatment with black or black paint, there is almost no reflection from the surface of the blade tool gripping portion 14 and the infrared temperature sensor 32 Can prevent heat energy other than heat energy due to radiation from entering. Further, if the surface of the blade tool gripping portion 14 is subjected to unevenness processing, it becomes possible to make the surface of the blade tool gripping portion 14 dull, so that the ratio of radiant heat increases and the temperature measurement is performed. The advantage is that the accuracy is improved. FIG. 9 is an explanatory view of a main part of a high-frequency induction heating device 80 to which the temperature detection method according to the second embodiment of the present invention is applied, and FIG. It is principal part explanatory drawing of the high frequency induction heating apparatus 90 to which the method is applied. Note that the same components as those of the high-frequency induction heating device 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the high-frequency induction heating device 80 shown in FIG. 9, a hood cylinder (hood portion) 82 that covers the condenser lens 37 and protrudes forward is provided. The hood cylinder 82 is relatively long, for example, is set to 30 mm to 80 mm, and is made of a material that is not easily affected by electromagnetic induction.
For example, it is made of an aluminum material. Hood cylinder 82
May be coated with a black paint to prevent unnecessary reflection of heat. The hood cylinder 82 may incorporate a cooling air pipe or a cooling water pipe as necessary to prevent a rise in temperature of the hood cylinder 82 itself. In the high-frequency induction heating device 90 shown in FIG. 10, a hood member (hood portion) 92 that covers the condenser lens 37 and protrudes forward is provided. The hood member 92 has a relatively long hole 94, and the light-collecting lens 37 is arranged to enter the hole 94 by a predetermined distance. In the high-frequency induction heating devices 80 and 90 configured as above, the focusing lens 37
A hood cylinder 82 and a hood member 92 are provided so as to cover and prevent reflected heat and other unnecessary radiant heat from entering as much as possible, so that radiant heat from the tool holder 12 can be accurately measured. It becomes possible to do. FIG. 11 is an explanatory view of a main part of a high-frequency induction heating apparatus 100 to which the temperature detection method according to the fourth embodiment of the present invention is applied. Note that the same components as those of the high-frequency induction heating device 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The high-frequency induction heating device 100 includes the tool holder 12
A contact-type temperature sensor for detecting a heating temperature of the heater, for example, a thermistor temperature sensor 102, and a drive unit capable of moving the thermistor temperature sensor 102 between an outside position of the heating coil 30 and a position contacting the tool holder 12. 10
4 is provided. The thermistor temperature sensor 102 is housed in, for example, a long cylindrical body 106 made of aluminum. , The rear end of the cylindrical body 106 is slidably connected. In the high-frequency induction heating apparatus 100 configured as described above, when the tool holder 12 is subjected to electromagnetic induction heating via the heating coil 30, the thermistor temperature sensor 102 operates under the action of the air cylinder 108 constituting the drive unit 104. It is arranged outside the heating coil 30.
When the heating of the tool holder 12 is stopped,
Under the action of the air cylinder 108, the thermistor temperature sensor 102 moves toward the tool holder 12 and comes into contact with the tool holder 12. Thereby, in the fourth embodiment,
It is possible to effectively prevent the thermistor temperature sensor 102 itself from being heated, and to obtain an effect that the heating temperature of the tool holder 12 can be accurately and reliably detected.

According to the method and the apparatus for detecting the temperature of the high-frequency induction heating apparatus according to the present invention, the high-frequency induction heating apparatus is driven to heat the material to be heated by electromagnetic induction, and the driving of the high-frequency induction heating apparatus is stopped. Only when the temperature of the material to be heated is detected via the temperature sensor. Therefore, when measuring the temperature of the material to be heated by the temperature sensor, the temperature sensor itself is not affected by the electromagnetic induction, and the temperature sensor can be arranged at a desired measurement position with respect to the material to be heated. . This makes it possible to accurately and reliably detect the heating temperature of the material to be heated via the temperature sensor with a simple control and configuration.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire high-frequency induction heating apparatus to which a temperature detection method according to a first embodiment of the present invention is applied.

FIG. 2 is an explanatory view of a main part of a heating coil and an infrared temperature sensor constituting the high-frequency induction heating device.

FIG. 3 is an explanatory diagram of another heating coil.

FIG. 4 is an explanatory view of still another heating coil.

FIG. 5 is an explanatory circuit diagram of a control unit included in the high-frequency induction heating device.

FIG. 6 is an explanatory diagram of a sensor reference bias circuit and a sensor output amplifier circuit.

FIG. 7 is a diagram showing an operation ON / OFF circuit of the infrared temperature sensor.

FIG. 8 is an explanatory diagram of an output value of the infrared temperature sensor.

FIG. 9 is an explanatory view of a main part of a high-frequency induction heating device to which a temperature detection method according to a second embodiment of the present invention is applied.

FIG. 10 is an explanatory view of a main part of a high-frequency induction heating device to which a temperature detection method according to a third embodiment of the present invention is applied.

FIG. 11 is an explanatory view of a main part of a high-frequency induction heating device to which a temperature detection method according to a fourth embodiment of the present invention is applied. 10, 80, 90, 100 High frequency induction heating device 12 Tool holder 14 Blade tool gripper 16 Carbide blade tool 26 Heating head 30, 30a, 30b Heating coil 32 Infrared temperature sensor 34 Holder 36 ... Thermo element body 37 ... Condensing lens 40 ... Control unit 44 ... CPU control circuit 46 ... Heating final power output circuit 48 ... Pre-driver monitoring circuits 50 ... Sensor reference bias circuit 52 ... Sensor output amplifier circuit 54 ... Sensor output Final amplification circuit 56 ... Switching circuit 82 ... Hood cylinder 92 ... Hood member 94 ... Hole 102 ... Thermistor temperature sensor 104 ... Driver 106 ... Cylinder 108 ... Air cylinder

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G01K 7/00 G01K 7/00 J F term (reference) 2F056 GJ04 2G066 AC11 BA09 BA22 BA57 BB07 BC15 CA20 3K059 AC33 AD04 AD28 AD29

Claims (14)

[Claims] A temperature detecting method for a high frequency induction heating device for detecting a heating temperature of a material to be heated by a contact type or non-contact type temperature sensor when electromagnetically heating the material to be heated, A step of driving the high-frequency induction heating device to perform electromagnetic induction heating of the material to be heated, and a step of stopping the driving of the high-frequency induction heating device and detecting the temperature of the material to be heated via the temperature sensor; A step of repeatedly performing the above steps until the detected temperature of the material to be heated reaches a preset heating temperature. 2. The temperature detecting method according to claim 1, wherein said temperature sensor is a non-contact infrared temperature sensor. 3. A temperature detecting method for a high-frequency induction heating apparatus according to claim 2, wherein a condenser lens is provided on an incident surface side of said infrared temperature sensor. 4. A temperature detecting method for a high-frequency induction heating apparatus according to claim 3, further comprising a hood portion projecting forward so as to cover said focusing lens. 5. A temperature detecting method for a high-frequency induction heating apparatus according to claim 1, wherein a blackening process is performed on a surface of the material to be heated. 6. A temperature detecting method for a high-frequency induction heating device according to claim 1, wherein the surface of the material to be heated is subjected to a surface roughening treatment. 7. A temperature detecting method according to claim 1, wherein said temperature sensor is a thermistor temperature sensor, and said heating means comprises a heating means for connecting said thermistor temperature sensor to said high-frequency induction heating device when heating said material to be heated. A temperature detecting method for a high-frequency induction heating device, comprising: disposing the thermistor temperature sensor in contact with the material to be heated when the material to be heated is stopped while being disposed outside the coil. 8. A temperature detecting mechanism for a high-frequency induction heating device for detecting a heating temperature of a material to be heated by a contact or non-contact type temperature sensor when the material to be heated is subjected to electromagnetic induction heating, An output circuit that drives the high-frequency induction heating device to electromagnetically heat the material to be heated, and only when the driving of the high-frequency induction heating device is stopped,
A switching circuit for inputting the temperature of the material to be heated detected via the temperature sensor; and determining whether or not the input temperature of the material to be heated has reached a preset heating temperature. And a control circuit for controlling the output circuit. A temperature detection mechanism for a high-frequency induction heating device, comprising: 9. The temperature detecting device according to claim 8, wherein said temperature sensor is a non-contact type infrared temperature sensor. 10. The temperature detecting device according to claim 9, wherein
A temperature detecting device for a high-frequency induction heating device, wherein a condensing lens is disposed on an incident surface side of the infrared temperature sensor. 11. A temperature detecting device for a high-frequency induction heating device according to claim 10, wherein a hood portion projecting forward is provided so as to cover said focusing lens. 12. A temperature detecting device for a high-frequency induction heating device according to claim 8, wherein a blackening treatment is performed on a surface of said material to be heated. 13. A temperature detecting device for a high-frequency induction heating device according to claim 8, wherein the surface of said material to be heated is subjected to an unevenness treatment. 14. The temperature detecting device according to claim 8, wherein
The temperature sensor is a thermistor temperature sensor, and when heating the material to be heated, the thermistor temperature sensor is disposed outside a heating coil that constitutes the high-frequency induction heating device, while heating the material to be heated. A temperature detecting device for a high-frequency induction heating device, comprising: a driving unit capable of moving the thermistor temperature sensor forward and backward so that the thermistor temperature sensor is brought into contact with the material to be heated when the operation is stopped.