JPH0644071Y2 - Heating roller heating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating device for a heating roller, and more particularly, to an induction heating type heating device for a heating roller that continuously heats a thermoplastic thread, film or the like.

(Prior Art) Generally, heating uniformity is used in a heating roller used for heat treatment of filamentous or film having thermoplasticity, for example, heat treatment such as direct spinning / drawing step of thermoplastic synthetic fiber or draw false twisting step. In addition, an induction heating type heating device which is excellent in performance such as controllability of heating temperature and thermal efficiency and is compact in structure is widely adopted as the heating source.

As a conventional heating device of this type, for example, FIGS.
The one shown in the figure is known. In FIG.
Reference numeral 1 is a bobbin of the heating device 2. The bobbin 1 is formed in a cylindrical shape, and a pair of flanges 1a and 1b are integrally provided at both ends thereof. The bobbin 1 is fixed to the housing 4 of the heating roller 3 via one flange 1a on the left side in the figure, and further, the cylindrical portion 1c of the bobbin 1 is covered with an insulator 5 wound around the outer periphery of the cylindrical portion 1c to form copper. A coil 7 is formed by winding an electric wire 6 made of aluminum, aluminum or the like. The flange
Insulators 8a and 8b are also attached to the inner surfaces of the coils 1a and 1b on the coil 7 side, so that the insulation between the electric wire 6 and the bobbin 1 is secured together with the above-mentioned insulator 5, and these insulators 5 and 8a and 8b are the heating device 2 of the heating roller 3 together with the bobbin 1 and the coil 7.
Are configured. Reference numeral 9 is a roll of the heating roller 3. The roll 9 accommodates the bobbin 1 and the coil 7, and is connected to the drive shaft 10 which is loosely fitted to the bobbin 1 and coaxially provided, through the flange portion 9a, and heats the heating shaft. When the drive shaft 10 is driven by the drive motor (not shown) of the roller 3, the roll 9
Is adapted to rotate with the drive shaft 10. When an AC voltage is applied to the electric wire 6, an alternating magnetic field is generated around the electric wire 6, and the roll 9 and the flange portion of the bobbin 1
The magnetic flux passes through the magnetic path having the loop of 1a, the cylindrical portion 1c and the flange portion 1b. At the same time, an induction current based on an electromagnetic induction action flows in the roll 9 to heat the roll 9, and the object to be heated that engages with the outer periphery of the roll 9 as the roll 9 rotates,
For example, the above-mentioned thermoplastic synthetic fiber or the like can be continuously heat-treated. On the other hand, FIG. 10 and FIG. 11 are sectional views taken along line XX and XI-XI in FIG. 9, respectively, showing the assembled state of the bobbin 1, the insulators 5, 8b and the coil 7. As shown in FIGS. 10 and 11, the bobbin 1 is provided with a slit 11 having end surfaces 11a and 11b parallel to each other in the axial direction across the flange 1a, the cylindrical portion 1c and the flange 1b. The slit 11 formed on the bobbin 1 is coupled with the selection of the material forming the bobbin 1,
It has a function of partially inhibiting the flow of the induced current generated in the bobbin 1 when the voltage of the electric wire 6 is applied and suppressing the heat generation of the bobbin 1. The material forming the bobbin 1 is an iron alloy having excellent magnetic permeability as a magnetic path, a small amount of self-heating due to an electromagnetic induction action, and a low cost. Further, in FIG. 11, only the slit 11 formed in the flange 1b of the bobbin 1 is shown, but it goes without saying that the similar slit 11 is also formed in the opposing flange 1a.

(Problems to be solved by the invention) However, in such a conventional heating roller heating device, the slit 11 formed in the bobbin 1 is opened, and the end surface 11a and the end surface 11b are the circumference of the bobbin 1, respectively. Since the coil 7 was wound with the free end of the direction formed, the insulation interposed between the bobbin 1 and the coil 7 as shown in each of the following (i) to (iii) Body 5,
The insulators 8a and 8b are damaged or worn, and the coil 7 and the bobbin 1 are short-circuited to each other, which hinders the operation of the heating roller 3.

(I) When an AC voltage is applied to the coil 7, an alternating force in the radial direction acts on the coil-shaped electric wire 6 and the diameter of the coil 7 fluctuates periodically, which causes the cylindrical portion 1c of the bobbin 1 to move. The wound insulator 5 together with the coil 7 causes a reciprocal movement deviation in the circumferential direction with respect to the bobbin 1. At this time, since the slit 11 of the bobbin 1 is open, the insulator 5 is damaged by repeated shearing force by the edge portion formed by the end faces 11a and 11b, and the coil 7 and the bobbin 1 are short-circuited to each other. In this case, a method of suppressing the damage of the insulator 5 by chamfering the corners of the edge portions of the end faces 11a and 11b can be considered, but the chamfering process is difficult due to the material of the bobbin 1, and even if the chamfering is Even if possible, the bite of the insulator 5 into the slit 11 still remains,
It is hard to say that it is a fundamental solution.

(Ii) When the coil 7 is mounted on the bobbin 1, the wire 6 is wound around the bobbin 1 by applying a predetermined tensile force in order to maintain the shape of the coil 7, but the end faces 11a and 11b of the slit 11 are Since the bobbin 1 forms the free end in the circumferential direction as described above, the bobbin 1 is deformed so that the end faces 11a and 11b are close to each other when the electric wire 6 is wound, that is, the width of the slit 11 is reduced. Cause Therefore, the restoring force of the deformation of the bobbin 1 and the winding tension of the electric wire 6 are in balance with each other, and when the heating roller 3 is operated, as described in the item (i),
When the diameter of the coil 7 fluctuates periodically, the above-mentioned equilibrium is broken and a displacement in the circumferential direction occurs between the electric wire 6 and the bobbin 1. At this time, since one of the flanges 1a and 1b of the bobbin 1 is fixed to the housing 4, the electric wire 6
There is no slip between the flange 1a and the flange 1a, but the other flange b is free. Therefore, a circumferential slip occurs between the wire 6 and the flange 1b, and the insulator 5 on the side of the flange 1b held between the wire 6 and the bobbin 1 and the insulator 8b in the vicinity thereof are repeatedly generated. The bobbin 1 is worn due to slippage and the coil 7 and the bobbin 1 are short-circuited to each other.

(Iii) At the time of manufacturing, the electric wires 6 of the coil 7 are wound around the bobbin 1 so as to be in close contact with each other in the axial direction, and the linear expansion coefficient of copper, aluminum or the like forming the electric wire 6 is the same as that of the iron alloy forming the bobbin 1. Since the linear expansion coefficient is larger than the linear expansion coefficient, when the bobbin 1 and the electric wire 6 are heated during the operation of the heating roller 3, the axial length of the coil 7 becomes larger than the interplanar distance between the flanges 1a and 1b of the bobbin 1. Therefore, a large surface pressure is generated on the insulators 8a and 8b by being pressed by the coil 7. Especially the flange 1b
As described in (ii), the insulator 8b in the state of being pressed against the flange 1b under the large surface pressure described above,
Since the wire 6 and the flange 1b of the bobbin 1 are properly subjected to repeated slips, they are rapidly worn and the coil 7
And bobbin 1 short circuit each other.

(Object of the Invention) The present invention has been made against the background of the above-mentioned problems of the prior art. In the first invention of the present invention, the second insulator is inserted into the slit of the bobbin. Thus, in the second invention, by providing the connecting member on the non-fixed side flange of the bobbin, and in the third invention, by inserting the elastic member between the bobbin and the flange, both of them are attached to the bobbin. An object of the present invention is to provide a heating device for a heating roller that eliminates damage or wear of the provided insulator and does not hinder the operation of the heating roller.

(Means for Solving the Problem) In order to achieve the above object, a heating device for a heating roller according to a first aspect of the present invention has a cylindrical bobbin having a slit along its axis and an outer circumference of the bobbin. In a heating device for a heating roller, which comprises a coil wound on a surface thereof with a first insulator interposed therebetween, the coil is fitted and fixed in the slit of the bobbin, and is continuously and smoothly formed on the outer peripheral surface of the bobbin. It is characterized in that a second insulator having an outer surface is provided.

Further, in order to achieve the above-mentioned object, the heating device for the heating roller according to the second aspect of the present invention also has a cylindrical main body integrally formed with a fixed side flange and a non-fixed side flange at both ends, and has a main body along the axis. And a bobbin in which a slit is formed across both the flanges and a coil is wound around the main body via an insulator, and a pair of end portions that are provided with the slit sandwiched between the non-fixed side flanges and that face each other. In a heating device for a heating roller having the above, a pair of end portions of the non-fixed side flange are connected and fixed to each other and a connecting member made of a material having high electric resistance is provided. .

Further, in order to achieve the above-mentioned object, the heating device for the heating roller according to the third aspect of the present invention also has a cylindrical body integrally formed with a fixed side flange and a non-fixed side flange at both ends, and has a slit along the axis. A heating device for a heating roller, comprising: a bobbin having a hole formed therein; and a coil in which an electric wire made of a material having a linear expansion coefficient larger than that of the bobbin is wound around the bobbin via an insulator, When an elastic member is interposed between the coil on either the fixed side flange or the non-fixed side flange of the bobbin and the coil and the bobbin are heated, the difference in the coefficient of linear expansion between the electric wire of the coil and the material of the bobbin. The thermal expansion in the axial direction of the coil caused by the above is absorbed by the deformation of the elastic member.

(Operation) In the first aspect of the present invention, the second insulator is fitted and fixed in the slit of the cylindrical bobbin, and the outer surface of the second insulator is smooth and continuous with the outer peripheral surface of the bobbin. Therefore, even if an AC voltage is applied to the coil and the coil diameter changes, the edge portion of the slit does not damage the first insulator. Therefore, the coil and the bobbin are prevented from being short-circuited, and the normal operation of the heating roller is always ensured.

Further, in the second invention, since the non-fixed side flange of the flanges on both ends of the bobbin is provided with the connecting member for connecting the both ends formed by the slit, the coil diameter is increased by applying an AC voltage to the coil. Does not cause a slip between the coil electric wire and the non-fixed side flange, and the abrasion of the insulator attached to the flange and the insulator in the vicinity thereof is eliminated. Therefore, similar to the first invention, the short circuit between the coil and the bobbin is prevented and the normal operation of the heating roller is ensured.

Further, in the third invention, the elastic member is interposed between the flange of the bobbin and the coil, and when the coil and the bobbin are heated, the thermal expansion in the axial direction of the coil caused by the difference in the linear expansion coefficient of these materials. Is absorbed by the deformation of the elastic member, so that when the insulator attached to the flange is pressed against the coil, the coil and the bobbin are not slipped due to the fluctuation of the coil diameter, and the insulator suddenly moves. Wear is eliminated. Therefore, similar to the first and second inventions, the short circuit between the coil and the bobbin is prevented, and the normal operation of the heating roller is always ensured.

(Example) Hereinafter, the present invention will be described with reference to the drawings.

1 and 2 are views showing a first embodiment of a heating device for a heating roller according to the first invention of the present invention. First, the configuration will be described.

In FIG. 1, reference numeral 21 is a cylindrical bobbin, and a pair of flanges 21a and 21b are integrally formed at both ends of the bobbin 21 in the axial direction. Of the pair of flanges 21a, 21b, one flange 21a on the left side in the drawing is not shown,
It is fixed to the housing 23 of the heating roller 22 by a bobbin, and the bobbin 21 is supported by the housing 23 in a cantilever state via the bobbin and the flange 21a. Bobbin 21
2 is a strip slit defined by a pair of end faces 24a, 24b parallel to each other as shown in FIG. 2 along the axis XX.
A sheet-shaped first insulator 25 is wound around the outer peripheral surface 21c of the bobbin 21, and the electric wires 26 are wound around the outer periphery of the first insulator 25 in a state in which they are closely attached to each other. And a coil 27 is formed. That is, coil 27 is bobbin 21
The outer peripheral surface 21c is wound around the bobbin 21 via the first insulator 25. Although not shown in FIGS. 1 and 2, it goes without saying that the outer periphery of the electric wire 26 is covered with an insulator. Further, in FIG. 1, reference numerals 28, 28a and 29 denote rolls of the heating roller 22, respectively.
It is the flange of the roll and the drive shaft of the heating roller 22, and the roll 28, the flange 28a and the drive shaft 29 have the same structure and function as the roll 9, the flange 9a and the drive shaft 10 shown in FIG. Since they are similar to each other, detailed description thereof will be omitted in this embodiment. Further, the bobbin 21, the first insulator 25, and the coil 27 described above constitute the heating device 30 of the heating roller 22, and the material forming the bobbin 21 is an iron alloy having excellent magnetic permeability, and the wire 26 of the coil 27 is formed. Similar to the conventional example, the element wire is made of a conductive material such as copper or aluminum.

In FIG. 1, reference numeral 31 is a second insulator fitted in the slit 24 of the bobbin 21, and the second insulator 31 is an axis line XX.
Along the entire length of the bobbin 21. Then, as shown in FIG. 2, the end faces 24a and 2 of the slit 24 are
Stepped portions 24c and 24d are formed on the 4b so as to face each other so as to increase the width of the slit 24, and the second insulator 31 fitted into the slit 24 abuts on the stepped portions 24c and 24d so that the bobbin 21 of It is designed to be fixed in the radial direction. Further, the outer surface 31a of the second insulator 31 that is in close contact with the first insulator 25 has a bobbin 21
It has the same diameter as the outer peripheral surface 21c of the
Edge portions 24e, 24f formed between the end surfaces 24a, 24b of the four and the outer peripheral surface 21c are covered with the second insulator 31 so that the outer surface 31a is smoothly continuous with the outer peripheral surface 21c of the bobbin 21. ing.

Next, the operation will be described.

In FIG. 1, an AC voltage is applied to the electric wire 26 of the coil 27, an alternating magnetic field is generated around the coil 27, and the heating roller 22
And the magnetic flux passes through the magnetic path having the bobbin 21 as a loop.
Along with this, a current based on an electromagnetic induction action flows in the roll 28 to heat the roll 28, and at the same time, the roll 28 is rotationally driven via a drive shaft 29 by a drive motor (not shown). Although not shown in the drawing, an object to be heated, for example, a thermoplastic synthetic fiber or the like is brought into contact with and driven on the outer periphery of the roll 28, and a continuous heat treatment of the object to be heated is performed. On the other hand, when an alternating voltage is applied to the coil 27, an alternating force in the radial direction acts on the electric wire 26 and the diameter of the coil 27 fluctuates periodically, which causes the first insulator 25 wound around the bobbin 21. Together with the coil 27, a reciprocal movement deviation occurs in the circumferential direction with respect to the bobbin 21. At this time, the slit 24 of the bobbin 21 has a second
The insulator 31 is fitted and fixed, and further, the outer surface 31a of the second insulator 31 smoothly continues to the outer peripheral surface 21c of the bobbin 21 so that the edge portions 24e and 24f formed by the slit 24 are covered. Therefore, the first insulator 25 is formed by the edge portions 24e and 24f.
Is not subjected to shearing force, and damage to the first insulator 25 is eliminated.

As described above, in this embodiment, the second insulator 31 is fitted and fixed in the slit 24 of the cylindrical bobbin 21, and
The outer surface 31a of the insulator 31 is coaxial with and has the same diameter as the outer peripheral surface 21c of the bobbin 21, that is, since the outer peripheral surface 21c is formed continuously and smoothly on the outer peripheral surface 21c, an AC voltage is applied to the coil 27 to change the diameter of the coil 27. The first edge 24e, 24f of the slit 24 when making
Damage to the insulator 25 can be eliminated. As a result, it is possible to prevent a short circuit between the coil and the bobbin 21 and always ensure normal operation of the heating roller 22.

FIG. 3 shows a second part of the heating device for the heating roller according to the first invention.
It is a figure which shows an Example. As shown in FIG. 3, in this embodiment, the outer surface 31a of the second insulator 31 fitted and fixed in the slit 24 of the bobbin 21 is continuous with the outer peripheral surface 21c of the bobbin 21 from the outer peripheral surface 21c. Is also formed in a smooth convex shape on the outer side, that is, on the side of the first insulator 25. Other configurations and operations are the same as those of the first embodiment shown in FIGS. 1 and 2, and therefore the same effects as those of the first embodiment can be obtained.

FIG. 4 is a third drawing of a heating device for a heating roller according to the first invention.
It is a figure which shows an Example. As shown in FIG. 4, in the present embodiment, the outer surface 31a of the second insulator 31 fitted and fixed in the slit 24 of the bobbin 21 is continuous with the outer peripheral surface 21c of the bobbin 21 from the outer peripheral surface 21c. Is also formed inwardly with a smooth concave shape. Other configurations and operations are similar to those of the first embodiment shown in FIGS. 1 and 2, and therefore, the same effects as those of the first embodiment can be obtained in this embodiment as well.

FIG. 5 is a fourth drawing of the heating device for the heating roller according to the first invention.
It is a figure which shows an Example. In FIG. 5, reference numeral 32 is the second
The sheet member 32 is a sheet member interposed between the insulator 31 and the first insulator 25, and the sheet member 32 is made of a material having excellent sliding characteristics and heat resistance, such as Teflon. For this reason, the first insulator is changed as the diameter of the coil 27 changes.
When the sheet 25 is displaced in the circumferential direction, the sheet member 32 allows the first insulator 25 to move smoothly on the second insulator 31, and particularly the outside of the second insulator 31. This is effective when the surface 31a has the structure shown in the second embodiment. Other configurations and operations are the same as those of the first embodiment shown in FIGS. 1 and 2, and therefore, it is needless to say that the same effects as those of the first embodiment can be obtained in this embodiment.

6 and 7 are views showing an embodiment of a heating device for a heating roller according to the second aspect of the present invention. First,
Although the configuration will be described, the configuration of this embodiment has a slit except for a connecting member 41, a pair of bolts 42, a main body 43 of the bobbin 21, a pair of end portions 44a and 44b and insulators 45, 46a, and 46b, which will be described later. Stepped portions 24c and 24d of 24, second insulator 31 and outer surface 31a
It is the same as the first embodiment of the first invention shown in FIGS. 1 and 2 except for the above. Therefore, the same reference numerals are given to FIGS. 6 and 7 and the description thereof is omitted. It should be noted that the flanges 21a and 21b of the bobbin 21 constitute the fixed side flange and the non-fixed side flange in the second invention integrally formed at both ends of the cylindrical main body 43 of the bobbin 21, respectively.
Is constituted by the fixed side flange 21a, the non-fixed side flange 21b and the main body 43 described above. Also, the slit 24
Is bored along the axis XX along the main body 43, the fixed side flange 21a, and the non-fixed side flange 21b, and the coil 27
Is wound around the main body 43 of the bobbin 21 via the insulator 45 wound around the main body 43.

In FIG. 7, a slit 24 is provided on the non-fixed side flange 21b.
A pair of end portions 44a, 44b facing each other with the pair of bolts in between are provided.
Both ends of the connecting member 41 are fixed via 42, and the end portion 44
The a and 44b are connected and fixed to each other by a connecting member 41. The connecting member 41 is made of a material having high electric resistance, such as nickel material, chrome material, or ceramics. In addition, in FIG. 6, insulators 46a, 46b
Is the fixed side flange 21a and the non-fixed side flange 2 respectively.
It is attached to the inner surface of 1b in a sheet shape and insulates the coil 27 and the bobbin 21 together with the insulator 45.

Next, the operation will be described.

In FIG. 6, as in the first embodiment of the first invention, an alternating voltage is applied to the coil 27 to heat the roll 28, and the roll 28 is rotationally driven to heat the object to be heated (not shown). . At this time, the coil 27 is applied by applying the AC voltage.
If the diameter of the wire fluctuates, as described in detail in (ii) of (Problems to be solved by the invention), a deviation tends to occur between the electric wire 26 and the bobbin 21, but in the present embodiment, the non-fixing side flange Since the end portions 44a, 44b of the 21b are connected and fixed to each other by the connecting member 41, circumferential slip between the electric wire 26 of the coil 27 and the non-fixed side flange 21b is eliminated. Therefore, the insulator 46b sandwiched between the coil 27 and the non-fixed side flange 21b and the insulator on the non-fixed side flange 21b side are held.
The wear of 45 is eliminated and a short circuit between the coil 27 and the bobbin 21 can be prevented. As described above, the connecting member
Since 41 is made of a material having a high electric resistance, when the voltage of the coil 27 is applied, the flow of the induced current generated in the bobbin 21 is partially obstructed together with the slit 24, so that the bobbin
It is possible to suppress the heat generation of 21.

Thus, in the present embodiment, the connecting member 4 for connecting and fixing the end portions 44a, 44b to the non-fixed side flange 21b of the bobbin 21.
Since 1 is provided, it is possible to eliminate the slip between the electric wire 26 and the non-fixed side flange 21b that occurs when the AC voltage is applied to the coil 27 and the diameter of the coil 27 changes, and at the same time,
The wear of the insulator 46b of the non-fixed side flange 21b and the insulator 45 in the vicinity thereof can be eliminated. As a result, the bobbin 21 and the coil 27 can be prevented from being short-circuited and the normal operation of the heating roller 22 can be ensured as in the respective embodiments of the first invention.

FIG. 8 is a view showing an embodiment of a heating device for a heating roller according to the third aspect of the present invention. First, the structure will be described. In the present embodiment, the structure other than the elastic member 51 shown in FIG. 8 to be described later is the same as the second device shown in FIG. 6 except the connecting member 41 and the bolt 42. Since this is the same as the embodiment, the same reference numerals are given to FIG. 8 and the description thereof is omitted. Further, in the present embodiment, the electric wire 26 of the coil 27 is made of a material of the bobbin 21, that is, a material having a linear expansion coefficient larger than that of the iron alloy, such as copper or aluminum. Further, the elastic member 51 is provided on the outer surface of the insulator 46b between the fixed side flange 21a and the non-fixed side flange 21b of the bobbin 21, between the non-fixed side flange 21b and the coil 27 in the present embodiment. It is installed. on the other hand,
While the heating roller 22 is in operation, the bobbin 21 and the coil 27 are heated and expand along the axis XX, but as described above, the linear expansion coefficient of the material of the electric wire 26 of the coil 27 is equal to that of the material of the bobbin 21. Since it is larger than the linear expansion coefficient, the axial length of the coil 27 becomes larger than the entire axial length of the bobbin 21. Then, the bobbin 21 and the coil 27 in operation of the heating roller 22
Axial length of coil 27 and bobbin 21 at maximum temperature of
Is ΔL, the thickness t of the elastic member 51 in the direction of the axis line XX is ΔL due to elastic deformation of the elastic member 51.
Is set to a size that can absorb. Therefore, in this embodiment, when the heating roller 22 is operated, the elastic member 51 is deformed due to the thermal expansion of the coil 27 in the direction of the axis XX, which is caused by the difference in the coefficient of linear expansion between the electric wire 26 of the coil 27 and the material of the bobbin 21. Is configured to absorb by. The material of the elastic member 51 is an elastic body having heat resistance,
For example, it is composed of Teflon or the like.

Next, the operation will be described.

In FIG. 8, as in the first embodiment of the first invention, an alternating voltage is applied to the coil 27 to heat the roll 28, and the roll 28 is rotatably driven to heat the object to be heated (not shown). Be seen. At this time, the bobbin 21 and the coil 27 are heated, and since the linear expansion coefficient of the material forming the electric wire 26 of the coil 27 is larger than the linear expansion coefficient of the bobbin 21, the axial length of the coil 27 is the axis of the bobbin 21. Although it becomes longer than the total length in the direction, the elastic member 51 is elastically deformed in the direction of the axis XX by being pressed by the bobbin 21 and absorbs the difference between these lengths. Therefore, the insulators 46a and 46b are not pressed by the coil 27. Particularly, in the insulator 46b, the electric wire of the coil 27 caused by the variation of the diameter of the coil 27 shown in the embodiment of the second invention. The synergistic effect due to the slip between the 26 and the anti-fixing side flange 21b is suppressed, and the sudden wear of the insulator 46 is eliminated.

Thus, in the present embodiment, the elastic member 51 is interposed between the fixed side flange 21a or the non-fixed side flange 21b of the bobbin 21 and the coil 27, and when the coil 27 and the bobbin 21 are heated, the coil The thermal expansion in the axial direction of the coil 27 caused by the difference in the linear expansion coefficient between the electric wire 26 of 27 and the material of the bobbin 21 is absorbed by the deformation of the elastic member 51. For this reason,
The insulator 46b attached to the non-fixed side flange 21b is the coil.
It is possible to prevent the coil 27 and the bobbin 21 from slipping due to fluctuations in the diameter of the coil 27 while being pressed by the 27, and it is possible to prevent abrupt wear of the insulator 46b. As a result, in the present embodiment as well, similar to the respective embodiments of the first and second inventions, it is possible to prevent a short circuit between the coil 27 and the bobbin 21, and to ensure the normal operation of the heating roller 22. it can.

(Effects) According to the first aspect of the present invention, the second insulator is fitted and fixed in the slit of the cylindrical bobbin, and the outer surface of the second insulator is continuous with the outer peripheral surface of the bobbin. Therefore, the problem described in the above item (i), that is, the damage of the first insulator due to the edge portion of the slit when the coil diameter changes due to the application of the AC voltage to the coil is eliminated. be able to. Therefore, it is possible to prevent a short circuit between the coil and the bobbin, and it is possible to always ensure normal operation of the heating roller.

Further, according to the second invention, since the non-fixing side flange of the flanges at both ends of the bobbin is provided with the connecting member for connecting and fixing both end portions formed by the slits, it is described in the above (ii). The problem, that is, the slip between the electric wire of the coil and the non-fixed side flange, which occurs when the coil diameter changes due to the application of an alternating voltage to the coil, can be eliminated, and at the same time, the insulator and its attached to the flange. It is possible to eliminate the wear of the nearby insulator. Therefore, similar to the first invention, it is possible to prevent a short circuit between the coil and the bobbin, and to always ensure the normal operation of the heating roller.

Further, according to the third invention, an elastic member is interposed between the flange of the bobbin and the coil, and when the coil and the bobbin are heated, the thermal expansion in the axial direction of the coil caused by the difference in the linear expansion coefficient of these materials. Are absorbed by the deformation of the elastic member. Therefore, it is possible to eliminate the problem described in the above (iii), that is, the coil and the bobbin are slipped due to the change in the coil diameter when the insulator attached to the flange is pressed against the coil. Therefore, the rapid wear of the insulator can be eliminated. Therefore, also in the present invention, like the first and second inventions, it is possible to prevent a short circuit between the coil and the bobbin,
The normal operation of the heating roller can always be ensured.

[Brief description of drawings]

1 and 2 are views showing a first embodiment of a heating device for a heating roller according to the first invention of the present invention.
Is a front sectional view thereof, FIG. 2 is an enlarged sectional view of an essential part taken along the line AA of FIG. 1, and FIG. 3, FIG. 4 and FIG.
FIG. 3 is an enlarged cross-sectional view of an essential part similar to FIG. 2 showing second, third and fourth embodiments of the heating device for the heating roller according to the invention. 6 and 7 are views showing an embodiment of a heating device for a heating roller according to the second invention. FIG. 6 is a front sectional view thereof, and FIG. 7 is a VII-VII arrow of FIG. FIG. 8 is a front sectional view showing an embodiment of the heating device for the heating roller according to the third invention. 9 to 11 are views showing a conventional example, and FIG. 9 is a front sectional view thereof, FIG. 10 and FIG.
FIG. 11 is an enlarged cross-sectional view of the main part taken along arrows XX and XI-XI of FIG. 21 …… bobbin, 21a …… flange (fixed side flange), 21b …… flange (non-fixed side flange), 21c …… outer peripheral surface, 22 …… heating roller, 24 …… slit, 25 …… first insulator , 26 …… electric wire, 27 …… coil, 30 …… heating device, 31 …… second insulator, 31a …… outer surface, 41 …… connecting member, 43 …… body, 44a, 44b …… end, 45, 46a, 46b ... Insulator, 51 ... Elastic member.

Claims (3)

[Scope of utility model registration request] 1. A heating device for a heating roller, comprising: a cylindrical bobbin having a slit formed along an axis thereof; and a coil wound around an outer peripheral surface of the bobbin via a first insulator, A heating device for a heating roller, comprising a second insulator fitted and fixed in the slit of the bobbin and having an outer surface which is continuously and smoothly formed on the outer peripheral surface of the bobbin. 2. A cylindrical main body integrally formed with a fixed side flange and a non-fixed side flange at both ends, and a slit is formed along the axis along the main body and the both flanges, and the main body is made of an insulator. In a heating device for a heating roller, the bobbin having a coil wound therethrough, and a pair of end portions provided with a slit sandwiched between the non-fixed side flanges and facing each other, in the non-fixed side flange. A heating device for a heating roller, wherein a pair of end portions are connected and fixed to each other and a connecting member made of a material having high electric resistance is provided. 3. A bobbin having a cylindrical body integrally formed with a fixed side flange and a non-fixed side flange at both ends and having a slit formed along the axis, and a linear expansion coefficient larger than that of the bobbin material. A coil in which an electric wire made of a material having a coil is wound around a bobbin through an insulator, and a coil with one of a fixed side flange and a non-fixed side flange of the bobbin. The elastic member is interposed between the coil and the bobbin, and when the coil and the bobbin are heated, the deformation of the elastic member absorbs the thermal expansion in the axial direction of the coil caused by the difference in the coefficient of linear expansion between the material of the coil and the material of the bobbin. A heating device for a heating roller.