JPH0810118B2 - Heating device temperature control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heating device for heating a material to be heated, and particularly to a temperature control device for controlling the temperature of the heating device.

2. Description of the Related Art Generally, a temperature control device for a heating device that heats a material to be heated detects the ambient temperature in the heating device by a thermocouple, a resistance temperature detector, etc., so that the ambient temperature matches a preset temperature. In addition, the heat source of the heating device, that is, the supply current of the heater and the burner, the amount of combustion, and the like are usually feedback-controlled.

Problems to be Solved by the Invention However, since such a conventional temperature control device does not directly detect the temperature of the material to be heated, it is possible to accurately heat the material to be heated to a predetermined heating temperature. There were times when you couldn't. That is, it is effective when the heating time is long and the temperature of the material to be heated is equal to the ambient temperature in the heating device, or there is a constant relationship between them, but direct current heating or induction heating is effective. When there is no direct relationship between the temperature of the heated material and the ambient temperature, or when there is a large temperature difference between them due to high-speed heating, the actual temperature of the heated material matches the preset heating temperature. Therefore, it is difficult to control the temperature of the heating device.

On the other hand, instead of detecting the ambient temperature in the heating device, it is proposed in JP-A-61-107088 that the actual temperature of the material to be heated is directly detected by a radiation thermometer. Since the temperature detecting portion is easily contaminated by water vapor or foreign matter in the device, it is necessary to take countermeasures against it, which is not always satisfactory. In addition, since the radiation thermometer intermittently detects the temperature of the material to be heated, a conventional temperature controller that controls the temperature of the heating device based on a continuous signal (analog signal) that represents the ambient temperature is used. It was no longer possible to do so, and a major equipment change was necessary.

Means for Solving the Problems The present invention has been made to solve the above problems, and its gist is to heat a material to be heated supplied at a constant time interval for a predetermined time. A device for controlling the temperature of a heating device to be discharged later, (a) measuring an actual temperature of the material to be heated intermittently discharged from the heating device and outputting a temperature signal representing the actual temperature. And a modulator for holding the temperature signal intermittently output from the radiation thermometer until the next temperature signal is output and converting the temperature signal into a continuous signal, and (c) the modulation. A temperature controller for controlling the temperature of the heating device so that the actual temperature of the material to be heated coincides with a predetermined heating temperature based on a continuous signal output from the heater.

In such a temperature control device, the actual temperature of the material to be heated is measured by the radiation thermometer, and the temperature of the heating device is adjusted so that the actual temperature matches the predetermined heating temperature. Is controlled so that even if there is no direct relationship between the ambient temperature in the heating device and the temperature of the material to be heated, or if the temperature difference between them is large, the material to be heated can be heated in a predetermined manner. Can be heated to temperature with high accuracy. Moreover, in the present invention, since the temperature of the heated material discharged from the heating device is measured, the contamination of the temperature detection unit is significantly larger than that in the case of measuring the temperature of the heated material in the heating device. Therefore, the equipment for reducing the contamination of the detection unit is not necessarily required, and high temperature measurement accuracy can be obtained and excellent temperature control can be performed.

Further, in the present invention, since the temperature signal intermittently output from the radiation thermometer is converted into a continuous signal by the modulator, it is possible to perform temperature control using an analog temperature controller, There is an advantage that the conventional temperature control equipment that controls the temperature at the ambient temperature which is a continuous signal can be used as it is.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a combustion type heating device, which includes a heating furnace 12, a burner 14, a fuel supply facility 16, and an air supply facility 18.
It has. The heating furnace 12 is a rotary furnace that accommodates and heats a large number of shaft-shaped materials to be heated 26, and the materials to be heated 26 are supplied at a predetermined constant time interval from a supply device (not shown). Every time the material 26 to be heated is supplied, the material 26 to be heated heated for a predetermined time is discharged one by one. The burner 14 is a fuel supply facility.
The material to be heated 26 in the heating furnace 12 is heated at high speed by mixing and burning heavy oil and air supplied from the control valve 16 and the air supply equipment 18 through the control valves 20 and 22, respectively. Then, the temperature in the heating furnace 12, that is, the burner
The combustion amount of 14 is controlled by changing the opening degree of the control valves 20 and 22, and the opening degree of the control valves 20 and 22 is automatically adjusted by the temperature control device 24. It is like this.

The temperature control device 24 includes a radiation thermometer 28 for measuring the temperature of the heated material 26 discharged from the heating furnace 12, a modulator 30, a temperature controller 32, and a control motor 34. The radiation thermometer 28 is arranged at a preset temperature measurement position near the discharge position of the material 26 to be heated, and measures the actual temperature of the material 26 to be heated based on the thermal radiation energy radiated from the material 26 to be heated. Then, the temperature signal ST representing the actual temperature is supplied to the modulator 30. The graph of the thermometer output shown at the top of FIG. 2 shows the output signal output from the radiation thermometer 28. The heated material 26 discharged from the heating furnace 12 passes through the temperature measurement position. The output signal is intermittently increased each time the temperature is changed, and the value at that time corresponds to the temperature signal ST representing the actual temperature of the individual material 26 to be heated. The material to be heated 26 discharged from the heating furnace 12 is passed through the temperature measuring position by a conveyer or the like, and is further carried out to a subsequent process for performing hot forging processing and the like.

The modulator 30 converts the temperature signal ST intermittently supplied from the radiation thermometer 28 every time the material 26 to be heated discharged from the heating furnace 12 is passed through the temperature measuring position into a continuous signal STC and changes the temperature. Output to the controller 32. When one temperature signal ST _n is supplied from the radiation thermometer 28, the temperature signal ST is held and output until the next temperature signal ST _{n + 1} is supplied. It has become. In this case, the temperature signal ST fluctuates as one material 26 to be heated passes through the temperature measuring position,
30 outputs a continuous signal STC based on the maximum temperature, average temperature, minimum temperature, etc. of the material 26 to be heated. The graph of the modulator output in FIG. 2 shows the output signal output from the modulator 30, and the portion shown after time t _{3 in} the graph corresponds to the continuous signal STC. In this embodiment, the heating target material 26 is discharged from the heating furnace 12 one by one. However, when a plurality of heating target materials 26 are discharged at the same time, one of the heating target materials 26 is discharged. Even if the continuous signal STC is output based on the temperature of the heating material 26, the maximum temperature, the average temperature, and
Alternatively, the continuous signal STC may be output based on the maximum temperature or the like.

The above-mentioned temperature signal ST is supplied to the modulator 30 as a continuous signal ST.
Various functions are provided in addition to the conversion to C, and its front panel 35 has a display 36, an upper limit temperature setter 38, a lower limit temperature setter 40, as shown in FIG. Preheat temperature setter 42, response speed setter 44, push buttons 46 and 48 for switching the output mode to automatic or manual, push button 50 for raising or lowering the output signal in the manual mode
And 52, and a power switch 54. Indicator 36
Is for displaying the temperature represented by the output signal of the modulator 30 regardless of the automatic mode or the manual mode. For example, when the continuous signal STC is output in the automatic mode, the material to be heated represented by the continuous signal STC is displayed. 26 actual temperatures are displayed. The upper limit temperature setter 38 and the lower limit temperature setter 40 are for setting the upper limit temperature T _U and the lower limit temperature T _L of the temperature range in which the temperature signal ST supplied from the radiation thermometer 28 should be converted into the continuous signal STC. Is a temperature signal that does not fall within this temperature range.
ST is removed as noise prior to conversion to a continuous signal STC. For example, the two temperature signals ST 'shown in the graph showing the thermometer output of FIG.
It is thought that it was output when a scale etc. dropped from the conveyor passed the temperature measurement position by the conveyor,
Since neither of them is within the above temperature range, they are removed as noise, and the graph of the modulator output shown below, that is, the continuous signal STC, is not affected by those temperature signals ST ′ and the actual output signal is not affected. A temperature signal representing the temperature of the heating material 26
It is output based on ST only. The upper limit temperature T _U and the lower limit temperature T _L are preset based on the target temperature T _M set in the temperature controller 32.

The preheating temperature setting device 42 is for setting the preheating temperature of the heating furnace 12, and the temperature signal ST in the automatic mode.
Until is supplied, an output signal representing this preheating temperature is output to the temperature controller 32. The part before the time t ₃ of the modulator output graph of FIG. 2 is an output signal representing this preheating temperature, and the temperature in the heating furnace 12 becomes the same as or slightly higher than the target temperature T _M. Is set as follows. Further, the response speed setting unit 44 is for setting the changing speed when changing the value of the continuous signal STC according to the newly supplied temperature signal ST, and sets it based on a predetermined changing speed. It can be increased or decreased.

The push buttons 46 and 48 for switching the output mode are
For example, when igniting or extinguishing the burner 14, or when adjusting the preheat temperature, for enabling the output signal to be manually operated when the temperature signal ST is not supplied from the radiation thermometer 28. However, when the push buttons 50 and 52 are pushed while the manual push button 48 is pushed, the output signal is raised or lowered. Further, when the automatic push button 46 is pressed, an output signal representing the preheat temperature set by the preheat temperature setter 42 is output, and the temperature signal ST is continuously supplied from the radiation thermometer 28. The signal STC is output.

Returning to FIG. 1, the temperature controller 32 is supplied with an output signal including the continuous signal STC from the modulator 30,
The temperature represented by the modulator output signal is compared with a preset target temperature T _M, and the deviations thereof are eliminated, in other words, the temperature represented by the modulator output signal and the target temperature T _M match. Contact signal for operating the control motor 34 to increase or decrease the combustion amount of the burner 14
Output SS. That is, as is clear from the graph showing the modulator output and the temperature controller contact output in FIG. 2, the temperature represented by the modulator output signal (continuous signal STC) is the target temperature T _M.
If the temperature is higher than the above, the contact signal SS in the direction of closing the control valves 20, 22 is output only for the time corresponding to the deviation, and if the temperature represented by the modulator output signal is lower than the target temperature T _M , The contact signal SS for opening the control valves 20, 22 is output only for the time corresponding to the deviation. The target temperature T _M is the heating temperature of the material 26 to be heated and is preset by a setting device (not shown).

The control motor 34 to which the contact signal SS is supplied has a crank arm 56 attached to its output shaft,
It is connected to the opening / closing shaft of the control valves 20, 22 via 8, levers 60, 62. Then, as the crank arm 56 is rotated in accordance with the contact signal SS supplied from the temperature controller 32, the open / close shafts of the control valves 20 and 22 are rotated by an angle proportional to the rotation angle of the crank arm 56. Fuel supply equipment 16, air supply equipment 18
The flow rates of heavy oil and air supplied from each are controlled. Further, from the control motor 34, a position signal SX indicating the rotation angle of the crank arm 56 is sent to the temperature controller.
Feedback is provided to 32. The graph of the control motor output in FIG. 2 shows the change in the angle of the crank arm 56.

Next, the operation of the temperature control device 24 configured as above will be described.

First, the modulator 30 is set to the manual mode by the push button 48,
The burner 14 is burned by manually operating the modulator output signal with the push buttons 50 and 52. After that, the automatic mode is set by the push button 46 to raise the temperature in the heating furnace 12 to a predetermined preheating temperature, and the material to be heated 26 in the heating furnace 12 is heated.
Start supplying. The time t _{1 in} FIG. 2 is the time at this time.

The material to be heated 26 is supplied into the heating furnace 12 at a predetermined constant time interval, and when the number reaches the capacity of the heating furnace 12, the material to be heated is first supplied and heated for a predetermined time. The material 26 is discharged from the heating furnace 12 every time a new material 26 to be heated is supplied into the heating furnace 12. Figure 2 time
t ₂ is the time when the first heated material 26 is discharged from the heating furnace 12.

When the material to be heated 26 discharged from the heating furnace 12 is passed through the temperature measuring position, the actual temperature of the material to be heated 26 is measured by the radiation thermometer 28, and the temperature signal ST representing the temperature is modulated by the modulator. Supplied to 30. The time t _{3 in} FIG. 2 is the time at this time.

The modulator 30 converts the temperature signal ST into a continuous signal STC and outputs the continuous signal STC to the temperature controller 32.
The contact signal SS is output based on the deviation between the actual temperature of the material to be heated 26 represented by STC and the target temperature T _M. Then, by operating the control motor 34 in accordance with the contact signal SS, the opening degree of the control valves 20, 22 is adjusted, the combustion amount of the burner 14, that is, the temperature in the heating furnace 12, the actual material 26 to be heated 26. The temperature is controlled so as to match the target temperature T _M.

Thereafter, based on the temperature signal ST output from the radiation thermometer 28 every time one heated material 26 is discharged from the heating furnace 12, the actual temperature of the heated material 26 is made to match the target temperature T _M. Moreover, the temperature in the heating furnace 12 is continuously controlled. The graph of the estimated temperature inside the furnace shown at the bottom of FIG. 2 shows the estimated value of the temperature inside the heating furnace 12 controlled in this way.

When the heating of the material 26 to be heated by the heating device 10 is completed, the output mode of the modulator 30 may be set to the manual mode and the push buttons 50 and 52 may be pressed to stop the combustion of the burner 14.

In this way, the temperature control device 24 of the present embodiment is the heating furnace 12
The actual temperature of the heated material 26 discharged from the furnace is measured, and the temperature in the heating furnace 12 is controlled so that the actual temperature matches the predetermined heating temperature, that is, the target temperature T _M. Therefore, even if there is a large temperature difference between the ambient temperature in the heating furnace 12 and the actual temperature of the material to be heated 26 in high-speed heating or the like, the material to be heated 26 can be heated to a predetermined heating temperature with high accuracy. is there.

Further, since the temperature control device 24 is configured to measure the temperature of the heated material 26 discharged from the heating furnace 12, as compared with the case of measuring the temperature of the heated material 26 in the heating furnace 12. The temperature measurement accuracy is high, excellent temperature control can be performed, and equipment for preventing contamination of the detection unit is not necessarily required.

On the other hand, in this embodiment, since the temperature signal ST intermittently output from the radiation thermometer 28 is converted into the continuous signal STC by the modulator 30, temperature control is performed using an analog temperature controller. Therefore, there is an advantage that the conventional temperature control equipment which controls the temperature at the ambient temperature which is a continuous signal can be used as it is.

Further, in the modulator 30 of the present embodiment, among the temperature signals ST supplied from the radiation thermometer 28, those that do not fall within the constant temperature range determined by the upper limit temperature T _U and the lower limit temperature T _{L are} regarded as noise. Material to be heated because it is designed to be removed
The temperature control in the heating furnace 12 is not impaired by the scale or the like dropped from 26.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the temperature control device 24 of the heating device 10 for heating by the burner 14 has been described.
Of course, a heater can be used instead of 14.
The present invention can be similarly applied to a temperature control device for a heating device using other heating means such as direct current heating or induction heating.

Further, in the above-mentioned embodiment, the temperature of all the heated material 26 discharged from the heating furnace 12 is measured to control the temperature in the heating furnace 12, but at the discharge time interval of the heated material 26. Accordingly, the temperature of the material to be heated 26 may be measured every other line or every two lines.

In the above embodiment, the temperature of the material to be heated 26 is measured in the process of passing the temperature measuring position, but the material to be heated 26 is temporarily stopped at the temperature measuring position for temperature measurement. You can also do it.

Further, in the above embodiment, the temperature signal ST output from the radiation thermometer 28 outside the predetermined temperature range is designed to be removed as noise. It is also possible to provide other noise removing means such as removing noise based on the interval. Needless to say, the effects of the present invention can be obtained without the function of removing such noise and the function of manually adjusting the combustion amount of the burner 14.

Although not illustrated one by one, the present invention can be carried out in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a heating device including a temperature control device according to an embodiment of the present invention. FIG. 2 is a time chart explaining the operation of the apparatus shown in FIG. FIG. 3 is a diagram showing the front panel of the modulator in the apparatus of FIG. 10: Heating device, 24: Temperature control device 26: Material to be heated, 28: Radiation thermometer 30: Modulator, 32: Temperature controller 34: Control motor ST: Temperature signal, STC: Continuous signal T _M : Target temperature ( Heating temperature)

Claims (1)

[Claims] 1. A device for controlling the temperature of a heating device, which heats a material to be heated supplied at a constant time interval for a predetermined time and then discharges it, wherein the material to be heated is intermittently discharged from the heating device. A radiation thermometer that measures the actual temperature of the material and outputs a temperature signal that represents the actual temperature, and holds the temperature signal that is intermittently output from the radiation thermometer until the next temperature signal is output. Based on the continuous signal output from the modulator, the temperature of the heating device is adjusted so that the actual temperature of the material to be heated matches a predetermined heating temperature. And a temperature controller for controlling the temperature controller of the heating device.