JPH0672608B2 - Induction heating roller device - Google Patents

Description

The present invention relates to an induction heating roller device.

(Prior Art) It is well known that in this type of induction heating roller device, a jacket chamber in which a gas-liquid two-phase heat medium is sealed is provided inside the peripheral wall of the roller in order to make the temperature of the roller peripheral wall uniform. Has been. By the way, in this type of roller, when a relatively large heat load is applied or the width of the load is large, a roller having a large outer diameter or a large surface length is required. Along with this, the volume of the jacket chamber that encloses the heat medium is also increased.

However, when the volume of the jacket chamber is increased in this way, even if the jacket chamber contains the same vapor pressure, it is regarded as a pressure vessel, and therefore various applicable laws and regulations apply. Therefore, the container is subject to restrictions on the constituent materials of the roller, and is subject to regulations such as approval at the time of manufacture, performance inspection, and maintenance management.

Even if the pressure vessel is excluded from the applicable range, the roller is increased in size, so that a roller having high mechanical strength must be used. In particular, it is necessary to increase the pressure resistance strength of the cylindrical member inside the jacket chamber.

In order to solve this, as a jacket chamber, instead of being formed annularly on the peripheral wall of the roller as in the conventional case, on the peripheral wall,
It has been considered that a plurality of independent elongated holes extending in the axial direction of the roller are provided and a jacket chamber is formed in each elongated hole. As a result, the individual jacket chambers have a smaller volume than the conventional construction, and therefore are not applied as pressure vessels.

On the other hand, in this type of induction heating roller device, 2
When the next voltage is induced and a uniform current flows along the circumferential direction, the roller heats up. Therefore, based on this induced current, uniform heat generation energy is applied at all points in the circumferential direction of the roller, and the amount thereof is given by the product of the temperature rise and the mass of the object.

However, when manufacturing a roller, it is an unavoidable problem that the outer circumference and the inner circumference have an error in the diameter due to the precision of machining, and this appears as a difference in the wall thickness in the circumferential direction of the roller, and by extension, the roller. When viewed from the circumferential direction of, the difference in mass appears. Such a difference in mass appears as a rise temperature difference along the circumferential direction of the roller. That is, the thicker portion has a smaller rise width, and the thinner portion has a larger rise width.

When such a temperature difference occurs, not only the load to be heated is adversely affected, but also the mechanical accuracy of the roller itself is significantly deteriorated due to expansion and contraction due to this temperature difference. Therefore, it is desirable to avoid such a temperature difference as much as possible.

However, as described above, when the jacket chambers are formed independently of each other along the axial direction of the roller, the circumferential wall portion of the roller along the length direction of the jacket chamber is evened by the action of the heat medium in the jacket chamber. Even if heated, the jacket chambers are independent of each other, and heat exchange between the jacket chambers does not take place directly, but only indirectly through the peripheral wall of the rollers. Therefore, the temperature equalizing action along the circumferential direction of the roller is never performed by such a jacket chamber.

(Problems to be Solved by the Invention) Even when a plurality of jacket chambers independent from each other are installed inside the peripheral wall of the roller along the axial direction thereof,
The object is to prevent the temperature difference from occurring as much as possible along the circumferential direction of the roller.

(Means for Solving the Problems) The present invention seals a gas-liquid two-phase heat medium inside the jacket chamber along the circumferential direction of the roller, separately from the jacket chamber provided on the peripheral wall of the roller. It is characterized in that the above-mentioned jacket chamber is configured so that the temperature medium along the circumferential direction of the roller is avoided by the action of the heat medium in the jacket chamber.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings. 1 is a roller rotated by a rotary drive source (not shown), to which a shaft 2 is connected, and which is a bearing mounted on a fixed platen 3. It is rotatably supported by 4. A magnetic flux generating mechanism 5 is arranged inside the roller 1. The magnetic flux generating mechanism 5 is mainly composed of an induction coil 6 and an iron core 7 around which the induction coil 6 is wound, and this is supported by a fixed shaft 8.

The fixed shaft 8 is inserted into the shaft 2, and the shaft 2 is rotatably supported by the bearing 4A with respect to the fixed shaft 8.
When the induction coil 6 is excited by an AC power source, a current is induced in the peripheral wall of the roller 1, and the peripheral wall generates heat due to this current. Reference numeral 9 indicates a lead wire for the induction coil.

There is no particular difference between these structures and an ordinary device of this type. 10 is the first jacket chamber, which is the peripheral wall 1A of the roller 1.
Along the axial direction of the roller 1 and in the circumferential direction of the roller 1, a plurality of them are set independently of each other (see FIG. 2). The medium 11 is vacuum sealed.

Further, a second jacket chamber 12 is formed on the peripheral wall 1A of the roller 1 so as to be located inside the jacket chamber 10, and a gas-liquid two-phase heat medium 13 is sealed inside the second jacket chamber 12.
In the embodiment shown in FIGS. 1 to 4, the jacket chamber 12 extends in the axial direction of the roller 1 and the roller 1
It is formed in an annular shape around the circumference of.

As the heat medium 11 sealed in the jacket chamber 10, one having a relatively high vapor pressure and large latent heat, for example, distilled water is used, and the heat medium 13 sealed in the second jacket chamber 12 is used.
As the material, an organic heat medium having a high boiling point and a relatively low vapor pressure even at a high temperature is used.

In the above configuration, when the roller 1 generates heat by the magnetic flux heat generating mechanism 5, the heat medium 11 in the jacket chamber 10 evaporates,
Repeating condensation, the latent heat released during the condensation is the roller 1
Of the roller 1 to reach the surface of the peripheral wall 1A, and thereby the temperature of the peripheral wall portion of the roller 1 along the axial direction is equalized.

On the other hand, the heat medium 13 in the second jacket chamber 12 is also evaporated,
The condensation is repeated, and the latent heat released during the condensation reaches the surface of the peripheral wall 1A through the thick portion of the peripheral wall. Due to this heat, the temperature difference along the circumferential direction on the surface of the peripheral wall 1A becomes small, whereby the surface temperature in the circumferential direction is made uniform. Due to both latent heats as described above, the temperature of the peripheral wall of the roller 1 is made uniform over the entire surface.

According to an experiment by the present inventor, in the roller not provided with the jacket chamber 12, when the surface temperature is 250 ° C.
Whereas a temperature difference of 1.8 ° C. occurred, a jacket chamber 12 was provided according to the present invention, and an organic heat medium 13 was enclosed in the jacket chamber 12, and the temperature difference in the circumferential direction when the surface temperature was 250 ° C. It reached 0.3 ° C. The vapor pressure of the heat medium 13 in the jacket chamber 12 is a small value such as 0.2 kg / cm ² -G in gauge pressure, and therefore the jacket chamber 12 can be constructed with a relatively small compressive strength. Was confirmed.

In this case, distilled water having a boiling point of about 100 ° C. and a latent heat of 400 to 540 Kcal / kg is used as the heat medium 11 in the jacket chamber 10.
In the jacket room 12, the boiling point is about 248 ° C and the latent heat is 80K.
The organic heating medium of cal / kg was sealed under reduced pressure.

In the configuration shown in FIG. 2, there is no particular problem when the roller 1 is rotating at a low speed, but when it is rotating at a high speed, the centrifugal force acting on the heat medium 13 in the jacket chamber 12 becomes large. As a result, it adheres to the outer wall surface of the jacket chamber 12.

Therefore, the entire outer wall surface becomes the evaporation surface of the heat medium 13, and the entire inner wall surface becomes the condensation surface. Therefore, the latent heat released to the condensation surface is conducted to the peripheral wall 1A via the end plate 1B of the roller 1. This is inconvenient because the heat conduction efficiency is reduced.

To solve this, in the configuration shown in FIGS. 3 and 4, a plurality of grooves 15 extending in the axial direction of the roller 1 are formed on the outer wall surface of the jacket chamber 12. With this structure, when the roller 1 rotates at a high speed and the centrifugal force acts on the heat medium 13, the heat medium 13 enters the groove 15 as shown in FIG.
Therefore, the heat medium 13 does not adhere to the wall surface between the adjacent grooves 15.

As a result, even if the roller 1 rotates at high speed, the jacket chamber
A condensation surface will be secured on the outer wall surface of 12. Therefore, the latent heat released on the condensation surface is directly conducted to the surface of the peripheral wall 1A through the thick portion of the roller 1, so that the conduction efficiency does not decrease so much.

In the above embodiment, the jacket chamber 12 is formed in an annular shape, but instead of this, like the jacket chamber 10, the circumferential wall 1A of the roller 1 is arranged along the axial direction thereof and in the circumferential direction of the roller 1. A plurality of jacket rooms 12 may be installed next to each other. In that case, the respective end portions of the jacket chambers 12 are connected by the annular communication chamber 16 so as to communicate with each other. According to this, the heat medium 13 in each jacket chamber 12 communicates with each other through the communication chamber 16, so that the temperature difference in the circumferential direction of the roller 1 is reduced.

(Effect of the Invention) As described in detail above, according to the present invention, even when the jacket chambers independent from each other are provided along the axial direction of the roller, the temperature difference along the circumferential direction of the roller is reduced as much as possible. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view of the roller of the present invention, FIG. 3 is a cross-sectional view of the roller of another embodiment of the present invention, and FIG. FIG. 6 is a cross sectional view of the roller of FIG. 1 ... Roller, 1A ... Peripheral wall, 5 ... Magnetic flux generating mechanism, 10 ...
… First jacket room, 12 …… Second jacket room, 1
1,13 ... Heat medium,

Claims (1)

[Claims] 1. A plurality of independent first jacket chambers extending in the axial direction of the roller on a peripheral wall of the roller internally provided with a magnetic flux generating mechanism for induction heat generation, and inside the first jacket chamber. A second jacket chamber that is located and communicates along the circumferential direction of the roller is provided, and is generated inside the first jacket chamber at the time of evaporation and condensation due to heat generated by the magnetic flux generating mechanism. By the latent heat to heat the surface along the axial direction of the roller is high, vapor pressure is high, the gas-liquid two-phase heat medium with a large latent heat is sealed, and the inside of the second jacket chamber, A vapor-liquid two-phase organic material having a high boiling point and a low vapor pressure for soaking the surface along the circumferential direction of the roller by the latent heat generated at the time of evaporation and condensation based on the heat generation by the magnetic flux generating mechanism. Induction heating low by sealing the heat medium Apparatus.