JP4190712B2 - Induction heating roller device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating roller device including a jacket chamber in which a gas-liquid two-phase heat medium is sealed inside a peripheral wall of a rotating roller.
[0002]
[Prior art]
In the induction heating roller device, an induction heating mechanism is arranged inside a hollow roller and is excited by an AC power source to induce a current in the peripheral wall of the roller, so that the roller is heated by this induced current. In this case, the induction current tends to concentrate on the central portion in the axial direction of the induction heating mechanism forming the magnetic circuit, i.e., the peripheral wall portion of the roller facing the magnetic center. It is already well known that it is the highest in the central part of the induction heating mechanism and becomes lower for a while as it approaches both ends.
[0003]
In order to improve the temperature distribution based on such heat generation distribution so as to be uniform along the axial direction of the roller, a number of hollow holes are provided inside the peripheral wall of the roller, which is used as a jacket chamber. The gas-liquid two-phase heat medium is sealed under reduced pressure. According to this, mainly based on the soaking action by the latent heat transfer of the heat medium. The temperature distribution around the outside of the roller is made uniform.
[0004]
However, if the sealed part of the jacket chamber in which the heat medium is sealed is damaged for some reason, air is mixed in from the damaged part, or the heat medium is a substance other than the heat medium due to thermal decomposition. Or a chemical reaction occurs between the inner wall surface of the jacket chamber and the heat medium, and a gas other than the heat medium is generated. When such a situation occurs, the movement of the latent heat of the heat medium is hindered, resulting in insufficient soaking action, and as a result, the temperature distribution around the outer periphery of the roller becomes non-uniform. If the operation is continued with this as it is, it may cause an unexpected accident that the object to be processed cannot be uniformly heated.
[0005]
[Problems to be solved by the invention]
It is an object of the present invention to detect an abnormal movement of latent heat of a heat medium due to a breakage in a sealing portion of a jacket chamber, and to prevent an unexpected accident based on the breakage of the jacket chamber.
[0006]
[Means for Solving the Problems]
According to the present invention, in a configuration in which a plurality of jacket chambers in which a gas-liquid two-phase heat medium is enclosed is provided in a peripheral wall of a rotating roller, a plurality of locations on different roller peripheral walls along the axial direction of the roller are provided. The temperature detection means for detecting the temperature, the deviation detection means for detecting the difference between the detection values by the temperature detection means, the detection value by the deviation detection means is compared with the reference value, and the difference between the two values exceeds the predetermined value Comparing means for generating a signal at the time, and determining that the sealed portion of the jacket chamber is broken when the comparing means generates a signal .
[0007]
If the sealing part of the jacket chamber is normal, the temperature of each outer peripheral portion of the peripheral wall along the axial center direction of the roller becomes substantially equal due to the action of the gas-liquid two-phase heat medium in the jacket chamber. The temperature detection values by the detection means are substantially equal, and therefore the output of the deviation detection means is a value equal to or less than a predetermined value. If the difference between the output value from the deviation detection means and the reference value at this time is equal to or less than a predetermined value, no output signal is output from the comparison circuit.
[0008]
However, if the movement of the latent heat of the heat medium becomes abnormal because the sealed part of the jacket chamber is broken, for example, air is mixed into the inside from the broken part, the movement of the latent heat by the heat medium in the jacket chamber is Therefore, the temperature of the outer peripheral portion of the peripheral wall along the axial direction of the roller becomes non-uniform. As a result, a difference occurs in the detection value by each deviation detecting means. When the difference between these values exceeds a predetermined value, the comparison means detects this and issues an output signal. The occurrence of a defect in the sealed portion of the jacket chamber can be known from the generation of this output signal.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a roller, and journals 2 are connected to both ends thereof. The journal 2 is rotatably supported by a machine base 4 via a bearing 3 and is rotated by a driving force from the outside. An induction heating mechanism 5 includes an iron core 6 and an induction coil 7 wound around the iron core 6. When the induction coil 7 is excited by an AC power supply, the roller 1 generates induction heat.
[0010]
The induction heating mechanism 5 is supported inside the roller 1 by a hollow support rod 8. The support rod 8 is constrained in rotation, and is disposed along the rotation center axis of the roller 1 by being inserted into the journal 2. The journal 2 is supported by the journal 2 via the bearing 9, and the journal 2, and thus the roller 1, is rotatable with respect to the support rod 8.
[0011]
Reference numeral 10 denotes a lead wire drawn from the induction coil 7 in order to connect the induction coil 7 to an external AC power source. The lead wire 10 passes through the inside of the support rod 8 and is drawn out from the outer end of the support rod 8. The drawn end is connected to an AC power source directly or via an external terminal. A jacket chamber 11 is formed on the peripheral wall of the roller 1 along the circumferential direction, and a gas-liquid two-phase heat medium is sealed under reduced pressure. Each jacket chamber 11 is formed so as to extend along the axial direction of the roller 1 as shown in the figure.
[0012]
Reference numerals 13 and 14 denote temperature sensors, which are constituted by thermocouples, for example. Each temperature sensor is set to measure different temperatures along the axial direction of the roller 1 in accordance with the present invention. Specifically, one temperature sensor 13 detects the temperature near the center of the roller 1 along the axial direction, and the other temperature sensor 14 detects the temperature near the end of the roller 1. It is set to the position to perform. Actually, each temperature sensor is set by making a hole in the peripheral wall of the roller 1 between the jacket chamber 11 and the outer peripheral surface of the roller 1 and inserting each temperature sensor therein. Reference numerals 15 and 16 denote lead wires of the temperature sensors 13 and 14, respectively.
[0013]
The temperature detected by each temperature sensor is taken out of the roller 1. Although any means can be used for this extraction, the example in the figure shows an example using a rotary transformer. A support frame 17 is integrally attached to one end of the journal 2, and the rotation side coils 19 to 21 of the rotary transformer 18 are supported on the support frame 17. A support frame 22 is attached to the support rod 8, and fixed side coils 23 to 25 of the rotary transformer 18 are attached to the support frame 22 so as to face the respective rotation side coils 19 to 21.
[0014]
Further, signal converters 26 and 27 are installed on the support frame 17. The lead wire 15 is connected to the signal converter 26 via the connection terminal 28, and the voltage corresponding to the temperature detected by the temperature sensor 13 is converted into a temperature signal by the signal converter 26 and given to the rotating coil 20. It is done. Similarly, the lead wire 16 is connected to the signal converter 27 via the connection terminal 29, and the voltage corresponding to the temperature detected by the temperature sensor 14 is converted into a temperature signal by the signal converter 27, and the rotating side coil 19. Given to.
[0015]
The stationary coils 23 to 25 are connected to a receptacle 31 installed on the support frame 22 and are led out to the outside through a plug 32 connected to the receptacle 31. The fixed side coil 25 is supplied with operating power via a plug 32. The supplied electric power is sent to the signal converters 26 and 27 through the rotation side coil 21 and used for these operation power sources.
[0016]
The temperature signals sent to the stationary coils 23 and 24 are sent to the deviation detection circuit 33, where the difference in magnitude between the two temperature signals is detected. The detected signal is sent to the comparison circuit 34 where it is compared with the reference voltage of the reference power source 35. When the difference between the magnitude of the signal from the deviation detection circuit 33 and the reference voltage of the reference power supply 35 is a small value not more than a predetermined range, no output signal is sent to the output circuit 35.
[0017]
When the sealing state of the jacket chamber 11 is normal, the surface temperature of the roller 1 is substantially uniform along the axial direction, and therefore the detected values by the temperature sensors 13 and 14 are not greatly different, and therefore the comparison is made. No output signal is sent from the circuit 34 to the output circuit 35.
[0018]
However, if the sealing of the jacket chamber 11 is impaired, the movement of latent heat by the heat medium is hindered, and the surface temperature of the roller 1 is different at various locations along the axial direction. Therefore, a large difference also occurs in the detection values by the temperature sensors 13 and 14, thereby causing a difference in the input values of the deviation detection circuit 33. A signal corresponding to the difference is sent to the comparison circuit 34. If the signal exceeds the reference value, an output is output from the comparison circuit 34 and sent to the output circuit 35.
[0019]
As a result, the output circuit 35 operates, so that it can be known that the sealing of the jacket chamber 11 has been impaired. In practice, an alarm is generated by the operation of the output circuit 35, and the rotation of the roller 1 may be stopped to stop its operation.
[0020]
In the example shown in the figure, two temperature sensors are used, but three or more temperature sensors may be used. The larger the number, the more conveniently the temperature difference between each part of the roller 1 can be detected. Further, instead of the rotary transformer 18, a temperature signal may be sent to the fixed side using a slip ring.
[0021]
【The invention's effect】
As described above, according to the present invention, the surface temperature of the roller is detected at each different location, and the breakage of the sealed portion of the jacket chamber is detected from each temperature difference. It is possible to avoid an unexpected accident based on the damage of the device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of FIG.
FIG. 3 is a circuit diagram showing an example of control means.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Roller shell 5 Induction heating mechanism 11 Jacket chamber 13 Temperature sensor 14 Temperature sensor 33 Deviation detection circuit 34 Comparison circuit

Claims (1)

In an induction heating roller device provided with an induction heating mechanism inside, and provided with a plurality of jacket chambers in which a gas-liquid two-phase heat medium is enclosed, on a peripheral wall of a rotating roller, the axial direction of the roller is aligned A temperature detecting means for detecting temperatures at a plurality of locations on different roller peripheral walls, a deviation detecting means for detecting a difference between detected values by the respective temperature detecting means, and comparing the detected value by the deviation detecting means with a reference value, An induction heating roller device comprising comparison means for generating a signal when the difference between the values exceeds a predetermined value, and determining that the sealed portion of the jacket chamber is broken when the comparison means generates a signal .

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