JP2731983B2 - Induction heating roller device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating roller device.

[0002]

2. Description of the Related Art In an induction heating roller device, a coil for electromagnetic induction is installed inside a rotating hollow roller.
The peripheral wall of the roller is caused to generate Joule heat by the induced current, and a gas-liquid two-phase heat medium is sealed in a gap formed in a thick portion of the peripheral wall of the roller, so that the surface temperature of the roller is equalized. Things are already well known.

When such a roller device is used for drying and rolling in a papermaking process or for heating a steel plate or other metal plate, the heat load is generally considerably large. It can be seen that the treatment product which is subjected to the heat load has a substantially uniform distribution of the heat-removing action over the entire width where the treatment product is in contact at a certain working width within the surface length of the roller.

[0004] However, at both ends of the heat removal width,
Unheated area on the outer surface of the roller,
That is, since there is an area on both sides outside the ear end of the treated product, which is not in contact with the treated product, the surface temperature in that area tends to be higher than the temperature of the heat removal width part.

[0005] This tendency is promoted as the heat load increases. Eventually, the surface of the roller near both ends of the treated product will exhibit a steep temperature gradient. The generation of such a temperature gradient makes it difficult to achieve the purpose of heating uniformly over the entire width direction of the processed product.

In addition, when a plurality of rollers are superimposed with their respective axes parallel to each other and applied to a rolling apparatus or the like in which a nip pressure is generated between the rollers, another problem occurs. Is generated.

For example, a thin processed product such as paper is
When passing between rollers with nipple pressure, if the temperature near the both ends is higher than the center of the roller, the difference in thermal expansion in the diametric direction of the roller corresponding to that temperature will cause both ear ends of the processed product Only the overpressure state causes deterioration of the quality of the processed product.

The roller on the other side to be nipped is not a heat roller, but has a surface made of a material other than metal, such as rubber.
Those made of elastic material such as plastic,
Alternatively, in the case of coating with a material having a relatively low heat-resistant temperature (hereinafter simply referred to as an elastic roller), the surface temperature of these elastic rollers in the area where the processing product contacts is insulated by the processing product and is not heated much.

However, the elastic roller which is in contact with the vicinity of both ends of the roller which does not come into contact with the processed product is directly transferred from the heat-generating roller, and as described above, the vicinity of both ends of the roller is a high-temperature area. Causes thermal degradation and impairs physical and mechanical properties. In extreme cases, accidents can occur where the surface ruptures and flies during operation.

[0010] These problems are further increased when the surface length of the roller is larger than the width of the processed product. In other words, when several kinds of processed products having different widths are to be processed by the rollers having a constant surface length, the above-described remarkable inconvenience occurs as the width of the product becomes narrower.

Ideally, it is desirable that there be no or few areas at both ends of the roller that are not deprived of heat by the processed product. However, as described above, it is not possible to cope with the case of processing several kinds of processed products having different width dimensions, and it is not practical to eliminate the marginal surface lengths at both ends of the roller as a practical problem in operation.

In view of the above, conventionally, the induction coil installed inside the roller is divided into a plurality of parts in the axial direction, and each is formed as an independent magnetic flux generating mechanism. Attempts have been made to avoid high temperatures near both ends of the roller by appropriately reducing the input to the induction coil located near the roller.

In the case of a roller using a heating method other than the induction heating roller, a rotary joint for cooling is provided at the end of the drive shaft of the roller, and the refrigerant is circulated only at both ends of the roller to forcibly. Cooling has also been considered in which cooling is performed by spraying mist-like cooling water onto both ends of the outer peripheral surface of the roller from outside the roller.

[0014] Although these attempts have shown some success, they have not yet achieved a uniform temperature distribution or a uniform nip pressure over the entire width of the processed product. This is because steep temperature gradients at both ends of the processed product cannot be eliminated yet, or problems of overpressure tendency and insufficient pressure due to overcooling cannot be eliminated.

That is, in the case of the induction heating roller, a uniform heat action is exhibited by a heat medium sealed inside the roller peripheral wall. This soaking action extends beyond the width dimension of the processed product to both end regions of the roller. This prevents the above-mentioned problems from being solved.

The reason is as follows. When the jacket chamber in which the heat medium is sealed is provided on the peripheral wall of the roller, it is desirable to provide the position as close as possible to the outer peripheral surface of the roller. However, in consideration of the load applied to the roller, it is necessary to secure a certain amount of remaining wall thickness. Therefore, there is naturally a limit in reducing the thermal resistance in the radial direction of the roller from the wall surface of the jacket chamber in contact with the heat medium to the outer peripheral surface of the roller.

[0017] Even if the temperature inside the jacket chamber is maintained at the same temperature in the area where the heat load is applied and in the area where the heat load is not applied, the internal temperature of the jacket chamber is changed according to the difference in heat flux from the area to the outer peripheral surface of the roller. And appears on the roller surface as a temperature difference. Therefore, as described above, even if the induction heat generation is eliminated in a portion corresponding to an area where there is no heat load, the temperature in that area increases as long as there is a soaking action by the heat medium.

[0018]

SUMMARY OF THE INVENTION According to the present invention, in a configuration in which a roller is provided with a jacket chamber, a soaking effect by a heat medium sealed inside acts on only an area where a heat load exists, and It is an object of the present invention to prevent the load from reaching both ends of the roller where no load is present, thereby avoiding a steep temperature gradient near the ear end of the thermal load.

[0019]

SUMMARY OF THE INVENTION According to the present invention, a jacket chamber, which extends in the axial direction on the peripheral wall of a roller and has a gas-liquid two-phase heat medium enclosed therein, is provided independently of each other. A plurality of partitions are provided along the circumferential direction, partition walls movable along the axial direction of the roller are incorporated at both ends of each jacket chamber, and both ends of the roller among the induction coils provided inside the roller. Subdivide the induction coil located in
The input of each of the subdivided induction coils can be adjusted independently, the partition is moved to a position corresponding to the ear end of the heat load, the position is set, and the position corresponding to the ear end of the heat load is adjusted. The input of the subdivided induction coil outside the location is adjusted to be smaller than that of the induction coil inside the subdivision.

[0020]

Since it is not necessary to heat the roller in the surface area of the roller where there is no heat load, the segmented induction coil corresponding to such area is more intense than the induction coil in the area where the heat load is present. Reduce input. In some cases, the input may not be required.

When the heat medium sealed in the jacket chamber boils according to the heat generated by the rollers, steam is generated. The vapor touches the low temperature part of the wall of the jacket chamber and condenses and liquefies.
The liquid refluxes to the high temperature part and evaporates again. This operation is continuously performed to perform a soaking function.

Here, the partition is moved according to the width of the heat load, and set at a position corresponding to the lug end of the heat load.
As described above, if the steam flow path in the jacket chamber is shielded by the partition wall over a length corresponding to the width of the thermal load, the heat equalizing function by the heat medium does not extend beyond the partition wall. Therefore, the heat transfer effect by the heating medium does not work on the roller surface in the area where there is no heat load, which is located outside the both ear ends of the heat load. Also, the input of the induction coil, which is also in the area without heat load, is reduced or stopped.

As described above, the difference between the surface temperature of the roller in the area without heat load and the surface temperature of the roller in the area with heat load is reduced, the steep temperature gradient between them is eliminated, and the heat load is reduced in the width direction. Is uniformly heated.
In addition, since the surface temperature of the roller in the area where there is no heat load does not rise, radial expansion does not occur, and overpressure only at both ears is avoided.

It is sufficient that the shielding efficiency of the partition wall is reduced to a cross-sectional area of the flow passage such that the steam flow velocity exceeds the sonic velocity. Thus, it is not necessary for the part of the jacket chamber in the longitudinal direction to be completely airtightly shielded by the partition wall. The position where the partition wall is installed should be set with reference to the boundary of the heat load. However, in actuality, the optimum position is finely adjusted according to the degree of the heat load or the positional relationship with the induction coil. It is necessary to find out.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 is a roller, 2 is a drive shaft integrally mounted on both sides thereof, and 3 is a plurality of jacket chambers provided independently of each other inside the peripheral wall of the roller 1, which is, for example, a shaft of the roller 1 by a drill. It is formed by drilling along the direction. The inside of the jacket chamber 3 is filled with a gas-liquid two-phase heat medium such as distilled water.

A magnetic flux generating mechanism 4 is supported by a support rod 5. The support rod 5 is inserted into the drive shaft 2 and is supported by the drive shaft 2 via a bearing 6. Reference numeral 7 denotes an induction coil constituting a magnetic flux generating mechanism. The induction coils at both ends along the axial direction of the roller 1 are subdivided. The subdivided induction coils are configured such that the input power, that is, the exciting current is adjusted independently of each other.

Numeral 8 denotes a heat load which is transferred while being in contact with the surface of the roller 1 as shown in FIG. Reference numeral 9 denotes a temperature sensor for measuring the temperature inside the roller 1, and the measured value is taken out to the outside via the rotary transformer 10.

Reference numeral 11 denotes an AC power supply for exciting current of the induction coil 7, which is connected to each induction coil 7 via a controller 12. Reference numeral 13 denotes a motor for rotating the drive shaft 2, 1
Reference numeral 4 denotes a bearing that rotatably supports the drive shaft 2 on the machine base 15.

Reference numeral 16 denotes a pair of partition walls arranged in each jacket chamber 3. The two partition walls 16 can move forward and backward in the jacket chamber 3 from the outside, and can be stopped at an arbitrary position.

FIGS. 3 and 4 show specific examples. Partition wall 1
6 is a spline shaft 1 rotatable by a bearing 17
The partition 16 is also rotated by the rotation of the spline shaft 18. Partition wall 1
The outer periphery of 6 is formed with a threaded portion, which is attached to the end of the jacket chamber 3 and has the threaded portion of a tubular feed screw 19 having a threaded portion formed on the inner surface. I'm biting.

A magnet cylinder 20 is attached to the outer end of the spline shaft 18, and this magnet cylinder 20 faces a magnet bar 22 via a bush 21 fixed to the roller 1. The magnet bar 22 is attached to a rotating shaft 23 that is drawn out of the roller 1. Rotating shaft 23
Are rotatable by bearings 24.

When the rotating shaft 23 is rotated as shown in the figure, the magnet bar 22 rotates, and thereby the magnet cylinder 20 magnetically coupled to the magnet bar 22 and thus the spline shaft 18 rotate. By this rotation, the partition 16 moves while rotating along the feed screw 19. Rotating shaft 23
Is stopped, the partition 16 stops at that position and stops.

[0033]

As described above, according to the present invention, the partition wall is made movable so that the range in which the soaking effect by the heat medium in the jacket chamber works corresponds to the width of the heat load. Steep temperature gradients near the edge of the ear can be avoided, so that the heating temperature of the heat load can be made uniform, and there is no excess or deficiency of the pressure applied to the heat load, enabling high quality processing This has the effect of becoming

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a cross-sectional view showing an example of a partition driving mechanism.

FIG. 4 is a transverse sectional view taken along line AA of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roller 3 Jacket room 4 Magnetic flux generation mechanism 7 Induction coil 8 Thermal load 16 Partition wall

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kozo Okamoto 40, Nishino Rikyucho, Yamashina-ku, Kyoto City Inside Tokuden Corporation (56) References (JP, U)

Claims (1)

(57) [Claims] 1. A plurality of jacket chambers extending in the axial direction of a peripheral wall of a roller and enclosing a gas-liquid two-phase heat medium therein, independently of each other along the circumferential direction of the roller. A partition wall movable along the axial direction of the roller at both ends of each of the jacket chambers, and among the induction coils for a magnetic flux generating mechanism provided inside the roller, of the roller, The induction coils located at both ends are subdivided, and the input of each subdivided induction coil can be adjusted independently, and the partition is moved to the position corresponding to the ear end of the heat load, and the position is adjusted. And set
An induction heating roller device wherein the input of the subdivided induction coil outside the portion corresponding to the ear end of the heat load is adjusted to be smaller than that of the induction coil inside the induction coil.