JP4553463B2 - Induction heating roller device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heat roller device.
[0002]
[Prior art]
As is well known, in the induction heat roller device, an induction heat generation mechanism constituted by an iron core and an induction coil wound around the inside of a rotating hollow roller is disposed.
When the induction coil is excited by an AC power source, an alternating magnetic flux is induced in the roller and induction heat is generated.
[0003]
In such a configuration, when there are a plurality of induction coils and an AC voltage is applied to each of the induction coils, induction is performed on the central part of the induction coil in the axial direction, that is, on the peripheral wall of the roller portion facing the magnetic center. Current tends to concentrate. Therefore, the heat generation distribution appearing on the peripheral wall portion of the roller is highest at a location facing the vicinity of the central portion of the induction coil, and lowest at a location facing both ends of the induction coil. For this reason, when a plurality of induction coils are used, the heat generation distribution in the axial direction of the roller tends to fall in the roller portion facing between the adjacent induction coils.
[0004]
[Problems to be solved by the invention]
The present invention improves the non-uniformity of the heat distribution of the roller due to a decrease in the heat generation amount of the roller facing the space between the induction coils when the induction coil inside the roller is excited by the multiphase AC power source, and makes it flat It aims to plan.
[0005]
[Means for Solving the Problems]
The present invention relates to a rotating roller, a plurality of induction coils for an induction heating mechanism, which are arranged in series in the axial direction of the roller, inside the hollow of the roller, and the induction coil In the induction heating roller device comprising a multi-phase power source for exciting the two , the arranged induction coils are divided into a first induction coil and a second induction coil in order of arrangement, and the first induction coil and A first connection for connecting a plurality of induction coils comprising the second induction coil to each phase of the multiphase power supply, and a first connection for connecting the first induction coil to each phase of the multiphase power supply, a second changeover switch for switching the connection connected to a phase adjacent the second induction coil phases that respectively connect the first induction coil is provided, alternate switching of the selector switch at predetermined time intervals And characterized by being repeatedly.
[0006]
In the first connection application state, as in a normal induction heating roller device, the amount of heat generated by the roller in the portion facing the induction coil to which the voltage of the adjacent phase is applied is reduced, and the heat generation distribution in that portion. Will decline. In the second connection application state, a voltage having a phase difference different from the voltage applied to the adjacent induction coil is applied to the induction coil at the end. Regarding the intermediate induction coil, adjacent induction coils connected to different phases in the first connection application state are connected in parallel to the same one phase.
[0007]
For this reason, the peripheral wall portion of the roller in which the heat generation amount is small in the first connection application state has a large heat generation amount in the second connection application state. By alternately repeating the first and second connection application states, the heat generation amount on the peripheral wall of the roller is averaged, so that the heat generation distribution becomes uniform.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a roller. A journal 2 connected to the roller 1 is rotatably supported by a bearing 4 with respect to a gantry 3 and is driven to rotate by a rotation source (not shown). Reference numeral 5 denotes a jacket chamber formed in the thick portion of the roller 1, in which a gas-liquid two-phase heat medium is enclosed.
[0009]
In the hollow interior of the roller 1, an induction heating mechanism 8 configured by induction coils 61 to 66 and an iron core 7 around which these are wound is installed. Reference numeral 9 denotes a support rod that supports the induction heating mechanism 8, which is supported inside the journal 11 via a bearing 10. A lead wire 12 of the induction coil 5 is led out through the support rod 9 and connected to an external three-phase AC power source 13.
[0010]
The induction coils 61 to 66 are sequentially arranged in series inside the roller 1 and connected to the U, V, and W phases of the three-phase power source. FIG. 2 (a) shows the first connection application state, for example, induction coils 61 and 62 are in U phase, induction coils 63 and 64 are in V phase, induction coils 65 and 66 are in W phase, and in parallel, respectively. Connected.
[0011]
When a three-phase voltage is applied in this state, for example, the amount of heat generated in the portion of the roller 1 that is connected between the induction coils 61 and 62 that are connected to the same phase is slightly reduced. For example, the amount of heat generated in the portion of the roller 1 facing between the induction coils 62 and 63 that are connected to each other is greatly reduced. Such a decrease occurs because the phase difference between adjacent phase voltages is based on a large value of 120 degrees. A heat generation distribution curve A in FIG. 3 shows the distribution of the heat generation amount of the roller 1 at this time. Such a distribution phenomenon is not particularly different from a normal distribution. Note that the heat generation distribution curve of FIG. 3 shows a distribution corresponding to the position of each induction coil shown in the lower part.
[0012]
Next, the connection state of each induction coil is changed, the induction coils 62 and 63 are connected in parallel to the U phase, the induction coils 64 and 65 are connected to the V phase, and the induction coils 66 and 61 are connected to the V phase in parallel. FIG. 2B shows the connection state, that is, the second connection application state. When a three-phase voltage is applied in this state, for example, the induction coils 62 and 63 connected to the same phase face each other. The amount of heat generated in the portion of the roller 1 to be reduced is slightly reduced, but the amount of heat generated in the portion of the roller 1 facing the induction coils 63 and 64 connected to adjacent phases is greatly reduced. The heat generation distribution curve B of FIG. 3 shows the distribution of the heat generation amount of the roller 1 at this time.
[0013]
The first connection application state and the second connection application state are alternately switched every predetermined time. As a result, the heat generation amount of the roller portion is an average value of the heat generation amount in the first connection application state and the heat generation amount in the second connection application state. This makes it substantially uniform along the axial direction of the roller, so that the surface temperature of the roller is averaged. The heat generation distribution curve C in FIG. 3 shows the distribution of the heat generation amount of the roller 1 at this time. This switching exhibits the same phenomenon as when the induction coil is periodically swung along the axial direction of the roller 1.
[0014]
FIG. 4 shows a circuit diagram for switching between the first connection application state and the second connection application state. In the figure, reference numeral 21 denotes the change control device, and specifically, it mainly comprises twelve changeover switches 22. A semiconductor control circuit 23 controls the current value. As shown in the drawing, when each changeover switch 22 is in contact with the upper contact a, each induction coil is in a first connection application state. After this state has passed for a predetermined time, specifically, the time required for the roller surface temperature to stabilize (for example, about several minutes) , if this is switched to contact the lower b contact, the second The connection application state is established. This switching may be repeated alternately as described above.
[0015]
5 to 8 show another embodiment of the present invention. The example shown in FIGS. 2 to 4 uses a three-phase power supply as it is, so the phase difference remains 120 degrees. However, the examples shown in FIGS. The phase is reversed (this is the Y phase).
Thus, the phase difference between the V phase, the Y phase, and the W phase is set to 60 degrees. Thus, the smaller the phase difference is, the lower the decrease in the heat value of the rollers facing each other between the induction coils connected to the adjacent phases.
[0016]
In the embodiment shown here, the difference in the amount of heat generated by the magnetic flux flow based on the phase advance and delay is also avoided. That is, when a voltage with a different phase is applied to the adjacent induction coil to cause the roller to generate heat, a voltage whose phase is delayed is applied to the roller part facing the induction coil to which the voltage with the advanced phase is applied. The roller portion facing the induction coil tends to generate more heat. Therefore, if the voltage whose phase is advanced and the voltage which is delayed are applied alternately in time, the heat generation amount is averaged.
[0017]
Even when averaging is performed in this way, in order to set the phase difference between adjacent phases to 60 degrees, for example, the V phase of the U, V, and W phases is set to the Y phase as the opposite phase, and the U, Two induction coils 61 to 66 are connected in parallel to the Y and W phases, and are sequentially connected to form a first connection application state. Next, the W phase is reversed to the Z phase, the induction phase 61 is connected to the Y phase, the induction coils 62 and 63 are sequentially connected to the U phase, the induction coils 64 and 65 are switched to the Z phase, and the induction coil 66 is switched to the V phase. To be in a second connection application state. In this case, the induction coils 61 and 66 at the ends are connected to different phases.
[0018]
In this way, in the first and second connection application states, the phase difference between adjacent phases is 60 degrees, and in the first connection application state, from the U phase toward the Y phase and the W phase. The phase is advanced, and in the second connection application state, the phase is delayed toward the Y phase, the U phase, the Z phase, and the V phase. Therefore, if the first and second connection application states are alternately switched, the heat generation amount of the roller becomes uniform as in the first embodiment.
[0019]
5A and 5B show the connection states of the induction coils 61 to 63 showing the first connection application state, and FIGS. 6A and 6B show the second connection application state. The connection state of each induction coil 61-63 is shown. In FIG. 7, A shows the heat generation distribution of the roller in the first connection application state, B shows the heat generation distribution of the roller in the second connection application state, and C shows an averaged heat generation distribution curve.
[0020]
FIG. 8 is a circuit diagram for switching between the first connection application state and the second connection application state. As shown in the drawing, when each changeover switch 22 is in contact with the upper contact a, each induction coil is in a first connection application state. After this state has passed for a predetermined time, specifically, the time required for the roller surface temperature to stabilize (for example, about several minutes), if this is switched to contact the lower b contact, the second The connection application state is established. This switching may be repeated alternately as described above.
[0021]
In the second embodiment, each induction coil is a star connection, but may be a delta connection instead. FIG. 9 and FIG. 10 show the connection relationship for that purpose, FIG. 9 shows a first connection application state corresponding to FIG. 5, and FIG. 10 shows a second connection application state corresponding to FIG. FIG. 11 is a circuit diagram for switching the connection application state. When the changeover switch 22 is on the a contact side as shown in the figure, the induction coil is in the connection state of FIG. 9 and is switched to the b contact side. Will be in the connection state of FIG.
[0022]
Note each of the above embodiments but was an example in which both utilizing three-phase power supply is not limited thereto, Ru Oh applicable even when using a multi-phase power source by an integral multiple of three phases. Further, the phase difference applied to the adjacent induction coils is 120 degrees and 60 degrees, but is not limited to this, and may be, for example, 30 degrees. Furthermore, the number of induction coils is not limited to three, and may be 3n (an integer of 2 or more) according to the number of phases of the power source. Further, in the example shown in the figure, two induction coils are connected in parallel with each other. However, the present invention is not limited to this, and two induction coils may be connected in series.
[0023]
【The invention's effect】
As described above, according to the present invention, when the induction coil is excited by the multiphase AC power source, it is possible to eliminate the imbalance of the heat generation amount of the roller due to the phase difference between adjacent phases, and thus the surface temperature of the roller. There is an effect that can be made uniform.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a topographic map of an induction coil.
FIG. 3 is an explanatory diagram showing a relationship between an induction coil and a heat generation amount.
FIG. 4 is a wiring diagram showing an embodiment of the present invention.
FIG. 5 is a first topographic map showing another embodiment of the present invention.
FIG. 6 is also a second topographic map.
FIG. 7 is an explanatory view showing the relationship between the induction coil and the amount of heat generation.
FIG. 8 is also a wiring diagram.
FIG. 9 is a first topographic map showing still another embodiment of the present invention.
FIG. 10 is also a second topographic map.
FIG. 11 is also a wiring diagram.
[Explanation of symbols]
1 Roller 61-66 Induction coil 8 Induction heating mechanism 21 Switching control device

Claims (1)

A rotating roller, a plurality of induction coils for the induction heating mechanism, arranged in series in the axial direction of the roller in the hollow interior of the roller, and a plurality of coils for exciting the induction coil In the induction heating roller device comprising a phase power supply, the two induction coils arranged in order are divided into a first induction coil and a second induction coil in order of arrangement, and the first induction coil and the second induction coil are divided. A first connection for connecting a plurality of induction coils each consisting of an induction coil to each phase of the multiphase power supply, a first connection for connecting the first induction coil to each phase of the multiphase power supply, and the second induction a changeover switch for switching between the second connection connected to a phase adjacent the coil and each of the first phase of the induction coil connected in provided, repeatedly alternating switching of the selector switch at predetermined time intervals Comprising induction heating roller apparatus.

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