JPH04306587A - Induction heat emitting roller device - Google Patents

Abstract

PURPOSE:To avoid generation of a steep temp. gradient in that part of a thermal load which is close to the lug end and alter the cooling division corresponding to the width by cooling the surface of a roller free from thermal load with circulation of refrigerant, and equipping a bulkhead with movability. CONSTITUTION:Distilled water as a gas/liquid two-phase thermo-medium is encapsulated in jacket chambers 5 furnished inside of the peripheral wall of a roller 1, and deep hole 15 is provided between chambers 5 in parallel with them, and a bulkhead 16 is installed movably within the hole 15. A magnetic flux generating mechanism 6 includes an induction coil 9, which is finely divided in fragments and can adjust the energization current independently, and this coil 9 is connected with AC power supply 12 via a controller 13. The bulkhead 16 is in advance moved to that position of a thermal load 10 corresponding to near the lug end, and refrigerant is fed circulatively into the hole 15 when it is sensed that the temp. of the external circumferential wall has become higher than the temp. of the peripheral wall contacted by the thermal load 10. Thus the thermal load 10 is precluded from steep temp. gradient around the lug end, and the cooling division can be changed in compliance with the width.

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

[Prior Art] In an induction heating roller device, an electromagnetic induction coil is installed inside a rotating hollow roller.
The roller's peripheral wall generates Joule heat using an induced current, and a gas-liquid two-phase heating medium is sealed in the gap provided in the thick wall of the roller's peripheral wall to ensure uniform surface temperature of the roller. Things are already well known.

By the way, when this type of roller device is used for drying, rolling, or heating copper plates or other metal plates in the paper manufacturing process, the amount of heat load is generally quite large. The treated product, which causes a heat load, can be considered to produce a heat-absorbing effect that is approximately evenly distributed over the entire width in contact with the treated product within a fixed working width within the surface length of the roller.

However, with both ends of the heat absorption width as boundaries,
a non-heat-absorbed area on the outer circumferential surface of the roller;
That is, since there are areas on both sides of the edges of the treated product that are not in contact with the treated product, the surface temperature of these areas tends to be higher than the temperature of the heat-absorbing width.

[0005] This tendency is exacerbated as the amount of heat load increases. Finally, the surface of the roller near both ends of the treated product begins to exhibit a steep temperature gradient. The occurrence of such a temperature gradient makes it difficult to achieve the objective of uniformly heating the treated product over its entire width.

[0006] In addition, if the application is to be applied to a rolling machine or the like in which a plurality of rollers are placed one on top of the other with their axes parallel to each other to generate nip pressure between each roller, another problem arises. occurs.

[0007] For example, thin processed products such as paper,
When passing the processed product between rollers under nip pressure, if the temperature near both ends of the roller is higher than the center, the difference in thermal expansion in the diametrical direction of the rollers corresponding to the temperature will cause the processed product to This causes an overpressure state, which impairs the high quality of the processed product.

[0008] Furthermore, the roller on the other side to be nipped is not a heat-generating roller, but has a surface made of material other than metal, such as rubber,
Made of elastic material such as plastic,
Or one coated with a material that has a relatively low heat resistance (
Hereinafter, it will simply be referred to as an elastic roller. ), the surface temperature of these elastic rollers in the area in contact with the treatment product is insulated by the treatment product and does not heat up as much.

However, the elastic roller in contact with the vicinity of both ends of the roller that does not contact the processed product receives heat directly from the heat generating roller, and as mentioned above, the vicinity of both ends of the roller is a high temperature area. Thermal deterioration occurs on the surface of the material, impairing its physical and mechanical properties. In extreme cases, the surface may burst during operation, causing an accident with scattering.

[0010] Such problems are further exacerbated if the surface length of the roller becomes larger than the width of the processed product. In other words, when processing several types of products with different widths using a roller with a constant surface length, the narrower the width of the product, the more noticeable the problems described above will occur.

Ideally, there should be little or no area at either end of the roller that is not removed by the product being treated. However, as mentioned above, this method cannot be used when processing products having different width dimensions, and it is not practical to eliminate the extra surface length at both ends of the roller as a practical problem in operation.

From the above point of view, in the past, the induction coil installed inside the roller is divided into a plurality of parts in the axial direction, and each part is made into an independent magnetic flux generating mechanism, so that both ends of the roller are not subjected to thermal load. Attempts have also been made to avoid high temperatures near both ends of the roller by appropriately reducing the input to the induction coils located near the ends.

[0013] Regarding rollers using heating methods other than induction heating rollers, a rotary joint for cooling is provided at the end of the drive shaft of the roller, and the refrigerant is forced to circulate only at both ends of the roller. It is also possible to cool the roller by spraying a mist of cooling water onto both ends of the outer peripheral surface of the roller from outside the roller.

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 it is still not possible to eliminate the steep temperature gradient at both ends of the processed product, or to overcome the problem of overpressure tendency and underpressure due to overcooling.

In other words, in the case of an induction heating roller, a heat equalizing effect is achieved by a heating medium sealed inside the peripheral wall of the roller. This soaking effect extends beyond the width of the processed product to the end areas of the roller. This is what hinders the solution of the problems mentioned above.

To explain the reason for this, when a jacket chamber in which a heating medium is enclosed is provided on the peripheral wall of the roller, it is desirable that the jacket chamber be provided at a position as close as possible to the outer peripheral surface of the roller. However, considering the load applied to the roller, a certain amount of remaining thickness must be ensured. Therefore, there is naturally a limit to reducing the thermal resistance in the radial direction of the roller from the wall surface of the jacket chamber in contact with the heating medium to the outer peripheral surface of the roller.

Even if the internal temperature of the jacket chamber is maintained at the same temperature in the area with and without heat load, the difference in heat flux from there to the outer peripheral surface of the roller varies between the two areas. This results in a temperature difference that appears on the roller surface. Therefore, as described above, even if induced heat generation is eliminated in areas corresponding to areas with no heat load, as long as there is a heat equalizing effect by the heating medium, the temperature in those areas will increase.

[0018]

SUMMARY OF THE INVENTION An object of the present invention is to avoid the occurrence of a steep temperature gradient at both ends of the roller in a configuration in which the roller is provided with a jacket chamber.

[0019]

[Means for Solving the Problems] The present invention provides jacket chambers extending in the axial direction of the peripheral wall of the roller and containing a gas-liquid two-phase heating medium therein, independently of each other. A plurality of deep holes are provided along the circumferential direction, and a plurality of deep holes are provided at both ends of the peripheral wall of the roller in parallel with the jacket chamber, and a refrigerant is circulated inside these deep holes to cool both ends of the roller. A feature is that a partition wall is provided in the hole, and the partition wall is movable along the deep hole.

[0020]

[Operation] When a refrigerant is circulated through the deep holes, both ends of the roller are cooled by the refrigerant. The cooling range due to this is
This is up to the location of the septum within the deep hole. Therefore, by making this partition wall movable, the cooling range can be adjusted freely.

[0021] If the position of this partition wall is set near the ends of both ends of the heat load, the area outside the ends of both ends will be cooled by this refrigerant, and a rise in temperature will be prevented. . As a result, the temperature difference between the area where the heat load is present and the area where there is no heat load is reduced.

[0022]

[Embodiment] An embodiment of the present invention will be explained with reference to the drawings. Reference numeral 1 denotes a roller, and 2 a drive shaft integrally attached to both sides thereof, which is rotatably supported by a machine base 4 through a bearing 3. Reference numeral 5 denotes a plurality of jacket chambers provided independently of each other inside the peripheral wall of the roller 1, and these are formed by drilling along the axial direction of the roller 1, for example, with a drill. Inside the jacket chamber 5, a gas-liquid two-phase heating medium such as distilled water is sealed.

Reference numeral 6 denotes a magnetic flux generating mechanism, which is supported by a support rod 7. The support rod 7 is inserted into the drive shaft 2 and supported by the drive shaft 2 via a bearing 8 . 9 is an induction coil constituting the magnetic flux generation mechanism. The induction coils 9 at both ends of the roller 1 along the axial direction are segmented. The input power or excitation current of the subdivided induction coils is adjusted independently of each other.

Reference numeral 10 denotes a heat load, which is transferred while being attached to the surface of the roller 1 as shown in FIG. 11 is a rotating transformer for taking out the output of a thermometer installed on the peripheral wall of the roller 1; 12 is an AC power source for exciting current of the induction coil 9; this is connected to each induction coil 9 via a controller 13; . 14 is a motor for rotating the drive shaft 2.

A plurality of deep holes 15 are provided at both ends of the peripheral wall of the roller 1 in parallel with the jacket chamber 3. This is located between each jacket chamber 3 as shown in FIG. A partition wall 16 is installed inside each deep hole 15.

The partition wall 16 is movable within the deep hole 15. FIG. 3 shows a specific example of making the partition wall 16 movable.
and shown in FIG. The partition wall 16 is inserted through a rotatable spline shaft 17 having a rectangular cross section, and as the spline shaft 18 rotates, the partition wall 16 also rotates.

A threaded portion is formed on the outer periphery of the partition wall 16, and this threaded portion engages with a threaded portion within the deep hole 16. The outer end of the spline shaft 18 extends to the outside of the drive shaft 2. When this outer end is rotated from the outside, the partition wall 16 rotates and moves within the deep hole 16.

Reference numeral 19 is a refrigerant supply path, and 20 is a recirculation path, which communicates with a rotary joint 21. The refrigerant supplied from the rotary joint 21 to the supply path 19 flows through the deep hole 2 from the inner cylinder 22.
0, its progress is blocked by the partition wall 16, and then it is discharged from the reflux path 20 via the rotary joint 21. Both ends of the roller 1 are cooled by this circulation of the coolant.

The partition wall 16 is moved in advance to a position corresponding to the vicinity of the ear end of the heat load 10. In the process of the heat load 10 coming into contact with the heat generating roller 1, the temperature of the peripheral wall outside the edge of the heat load 10 becomes higher than that of the peripheral wall in contact with the heat load 10, using a thermometer. When detected by, for example, the refrigerant is circulated within the deep hole 15. This circulation reduces the temperature difference between the area in contact with the heat load 10 and the area not in contact with it.

[0030]

Since there is no need for the roller to generate heat in areas of the surface of the roller where there is no thermal load, the subdivided induction coils corresponding to such areas are more efficient than the induction coils in areas where there is a thermal load. Reduce input. In some cases, the input may be completely omitted.

As explained above, according to the present invention, the temperature of the surface of the roller where there is no heat load is lowered by cooling it through the circulation of refrigerant. It is possible to avoid a steep temperature gradient in the vicinity, and since the partition wall is movable, the area cooled by the refrigerant can be changed in accordance with the width of the heat load.

[Brief explanation of drawings]

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

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a sectional view showing an example of a partition wall moving mechanism.

FIG. 4 is a cross-sectional view of FIG. 3;

[Explanation of symbols]

1 Roller 5 Jacket room 6 Magnetic flux generation mechanism 9 Induction coil 10 Heat load 15 Deep hole 16 Partition wall

Claims (1)

[Claims] Claim 1: A jacket chamber, which extends in the axial direction of the roller and has a gas-liquid two-phase heating medium sealed therein, is provided in the circumferential wall of the roller, which has an induction heating mechanism installed therein. A plurality of deep holes are provided along the circumferential direction, a plurality of deep holes are provided at both ends of the peripheral wall of the roller in parallel with the jacket chamber, and a refrigerant is circulated inside the deep holes to cool both ends of the roller. The induction heating roller device is further characterized in that a partition wall is provided in the deep hole, and the partition wall is movable along the deep hole so that the area cooled by the refrigerant can be adjusted.