JP3312559B2 - Cylindrical structure used for fixing device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a thin-walled cylindrical structure and a manufacturing method using the fixing device.

[0002]

2. Description of the Related Art In a copying machine using an electrophotographic process, it is necessary to fix an unfixed toner image formed on a recording sheet into a permanent image.
Conventionally, a solvent fixing method, a pressure fixing method, and a heat fixing method have been known.

[0003] The solvent fixing method has the drawbacks that the vapor of the solvent emanates, which causes many odors and hygiene problems.
The pressure fixing method has a disadvantage that the fixing property is poor as compared with other fixing methods, and that the pressure-sensitive toner used here is expensive. For this reason, at present, these two fixing methods have not been widely put to practical use.

Therefore, as a fixing method of an unfixed toner image in a copying machine using an electrophotographic process, a heat fixing method of melting a toner by heating and fusing the unfixed toner image onto a recording sheet is widely used. ing.

FIG. 1 is a diagram showing a schematic configuration of a fixing device using a heat fixing method. As shown in FIG. 1, the fixing device is provided with a heater 31 inside a cylindrical cored bar 32, and a heating roller 30 having a release layer 33 formed of a heat-resistant resin coating layer or a heat-resistant rubber coating layer on the outer peripheral surface thereof. And a pressure roller 40 which is disposed in pressure contact with the heating roller 30 and has a heat-resistant elastic layer 42 formed on the outer peripheral surface of a cylindrical metal core 41. In the fixing process of the unfixed toner image, the sheet 43 on which the unfixed toner image 44 is formed is inserted between the heating roller 30 and the pressure roller 40 to fix the toner agent additive by thermal melting.

[0006] The heating roller system for performing fixing by a heating roller such as a fixing device based on the heating fixing method has higher thermal efficiency as compared with the hot air fixing method and the oven fixing method of other heating fixing methods, and therefore has low power consumption (energy saving). It is most widely used at present because it is excellent in terms of speed and high speed, and has a low risk of flame due to paper jam.

[0007]

In the conventional heating roller type fixing device, the time required for raising the surface temperature of the heating roller from room temperature to a predetermined set temperature (hereinafter referred to as "warm-up time") is one. It takes a long time of 10 minutes to 10 minutes. Since the warm-up time is determined by the relationship between the heat capacity of the heating roller and the input power, the warm-up time can be reduced if the heat capacity of the heating roller is small and the input power is large. However, the heat capacity of the heating roller is limited by the rigidity of the roller, and the input power is limited by the restriction of the power consumption of the copying machine.

In general, the power that can be supplied exclusively for fixing is 3
The power is in the range of 00 W to 1000 W. To reduce the warm-up time with the power in this range, the roll heat capacity of the heating roller is reduced, and this method is most effective.

By the way, in order to reduce the roll heat capacity of the roller (cylindrical body) used in the fixing device, as the roll diameter and the thickness of the roll core are reduced, the roll rigidity is also reduced. By the way, the roll heat capacity is
While the roll rigidity is proportional to the square of the roll diameter, the roll rigidity is proportional to the fourth power of the roll diameter. When the roll stiffness is reduced, the roll is deformed in the axial direction (hereinafter, referred to as flexure) and in the circumferential direction (hereinafter, referred to as dent) with respect to the load applied to the roll to function as a fixing roller. Occurs. For this reason, when the roll diameter becomes equal to or less than a predetermined value, the roll rigidity rapidly decreases, and a load required for fixing cannot be obtained.

[0010] Among the two types of deformation as described above, in particular, when a roll dent occurs, the function of the fixing device,
That is, the function of the fixing process of the heat fixing method, specifically, the function of sandwiching and transporting the sheet as a heating roller,
The function of uniformly transferring heat to the toner layer is not performed at all, and the device does not function as a fixing device. For this reason, the thickness must be set so as to obtain a predetermined roll rigidity so that the roll is not dented.

Further, in order to obtain the specified fixing performance, the pressure in the nip portion of the roll pair of the heating roller and the pressure roller generally needs to be about 0.5 to 5.0 kg / cm. . If the pressure is lower than this, the gap due to the presence of irregularities on the paper or roll surface cannot be filled, and heat cannot be efficiently transmitted to the powder toner. For this reason, the toner surface after fixing becomes mottled, and the image quality deteriorates.

Since the total load applied between the two rolls for obtaining the pressure required for such fixing reaches 20 to 200 kg, the roll (cylindrical body) used as the heating roller is a heating roll that can withstand this load. Roll rigidity is required, and there is a natural limit to reducing the diameter and thickness of the roll.

On the other hand, various techniques have been proposed for preventing dents in thin rolls. Next, the technology to prevent dents in these rolls,
The problem in applying such a roll to a fixing device will be discussed.

As a first method, for example, Japanese Utility Model Application Laid-open No.
No. 128665, Japanese Utility Model Publication No. 61-4926, Japanese Patent Application Laid-Open No. 61-59381, Japanese Patent Application Laid-Open No. Hei 6-130845.
In some rolls, a reinforcing member for preventing dents is provided in the roll to increase the strength of the roll without increasing the heat capacity of the roll itself, as described in Japanese Patent Application Laid-Open Publication No. H10-163,086. FIG. 2 is a cross-sectional view illustrating a first example of the structure of a conventional fixing roller. In FIG. 2, 1 is an inner frame of a roll support member, 2 is a support rod supporting the inner frame, 3 is a roll (sleeve), 4 is a thermal insulator, 5 is a coil heater as a heating source,
Reference numeral 6 denotes an offset prevention layer as a release layer, and reference numeral 7 denotes a support shaft.

The fixing roller having the structure shown in FIG. 2 requires the support rod 2 for supporting the inner frame 1 of the reinforcing member for the roll 3 constituting the fixing roller, and requires a very large member having an internal reinforcing structure. Becomes For this reason, the size and cost of the apparatus is avoided which have not been. In addition, when a large member is placed in the fixing roll, the heat capacity of the entire fixing roll is expected to increase, which is not preferable from the viewpoint of reducing the warm-up time. In addition, since the contact portion between the inner frame 1 and the roll 3 must be formed of a thermal insulator 4 such as a resin, a material having a smaller coefficient of thermal expansion as compared with metal is actually
There is a possibility that a problem that the inner frame 1 falls off when the fixing roll is heated may occur.

FIG. 3 is a sectional view for explaining a second example of the structure of a conventional fixing roller. As a second method, as shown in FIG. 3, there is a method in which the thickness of the roll 8 is partially increased in the axial direction to provide a thick portion 9. Also, in this case,
As a modified example, there is a configuration in which a rib for reinforcement is provided in place of the thick portion 9 which is partially thickened in the axial direction. A specific example of the second method is described in, for example, Jpn.
949 and JP-A-57-155571 can be referred to.

Further, in the fixing roller having the structure as in the second method, since a partial thickness-thickening process is required in the axial direction inside the cylindrical structure, the partial thick portion is formed on the shaft. In the case of a heating roller for fixing, there is a problem that when the roller is heated, the temperature distribution in the axial direction becomes uneven and uniform fixing performance cannot be obtained. . In addition, there is also a problem that even in the production of rolls, a drawing method cannot be used to produce a seamless pipe, and it is rather expensive.

FIG. 4 is a sectional view for explaining a third example of the structure of the conventional fixing roller. As a third method, in order to increase the rigidity of a thin-walled cylindrical body, Japanese Patent Application Laid-Open No. 63-267952 has been proposed.
As described in Japanese Patent Application Laid-Open Publication No. H10-209, there is a device in which a solid pipe is inserted into a cylindrical body. As shown in FIG. 4, the roll (cylindrical body) in this case has a reinforcing rigid member 11 press-fitted from both ends of the conductive cylindrical member 10 as a photosensitive member to increase the rigidity of the conductive cylindrical member 10. It has become. Here, the contact charging conductive rubber roller 12
Functions as a pressure roller.

In the third method, the roll is substantially high in rigidity. However, since the reinforcing rigid member 11 is a solid member, when it is used as a fixing roller, a heat generating mechanism is provided inside the roll. And cannot be used in a heat roller type heat roller type fixing device. In addition, even when applied to a surface heat type (roll-to-type) fixing device that does not have a heat generation mechanism inside the roll, there is a loss of temperature rise on the surface due to heat conduction to the inside. ) Is not preferred. In addition, an increase in weight due to the reinforcing rigid member 11 is expected, and the roll rigidity is the same as the case where the thickness of the roll is designed to be large. Instead, another member is required, resulting in an increase in cost. I will. Also,
The reinforcing rigid member 11 is a member having a large heat capacity, and a member having a large heat capacity is provided inside the roll, which is not preferable from the viewpoint of reducing warm-up time.

FIG. 5 is a sectional view for explaining a fourth example of the structure of a conventional fixing roller. As a fourth method, for example, as described in Japanese Patent Application Laid-Open No. 1-126417, a thin-walled cylindrical structure here is formed by inscribing an inner core formed of a thin plate inside a thin-walled cylindrical outer cylinder. It is fixed. In this structure, as shown in FIG. 5, a triangular prism-shaped inner core 14 formed of a thin plate is replaced with a cylindrical outer cylinder 13.
It is structured so that it is inscribed inside and fixed. According to the structure of the fourth method, when it is used as a fixing roll of a heat fixing device, it is difficult to arrange a heating device of an infrared lamp as a heating source inside. Further, from the viewpoint of increasing the strength of the roll, the rigidity in the roll axis direction increases, but the dent in the roll circumferential direction due to the reduction in thickness is reduced by the inner core 14.
Is not sufficiently prevented at a part that is not inscribed, which is not preferable from the viewpoint of reliability.

The present invention has been made in view of the various problems described above, and it is an object of the present invention to provide a thin-walled cylindrical structure which receives an external force at a circumferential portion thereof, such as a fall-off of an internal reinforcing member. An object of the present invention is to provide a small, high-performance fixing device using a thin-walled cylindrical structure having a structure that does not cause a problem and sufficiently prevents circumferential dent due to thinning. It is another object of the present invention to provide a thin cylindrical structure used for a fixing device and a method for manufacturing the thin cylindrical structure.

Another object of the present invention is to use a fixing roll having a thin cylindrical structure as a fixing roll of a fixing device,
In order to obtain a predetermined strength, at least one or more support members are provided on the inner peripheral surface of the thin-walled cylindrical structure, or when the thickness is partially increased due to uneven thickness processing, An object of the present invention is to provide a fixing device that prevents local temperature unevenness on the surface of a fixing roll in a thick portion of a fixing portion and prevents a defect in fixing performance near a thick portion.

[0023]

In order to achieve the above-mentioned object, a heat roller type fixing apparatus using a thin cylindrical structure according to the present invention comprises, for example, a pressurizing device which presses against a fixing roll including a heater inside. In a fixing device that heat-fixes the recording paper by transferring an unfixed toner image to a pressurized region formed by a roll, at least one or more support members are provided inside the thin cylindrical structure as the fixing roll. Press fit
In addition, a cylindrical structure is used in which a part of the outer peripheral surface of the supporting member is held in pressure contact with the inner surface of the thin-walled cylindrical structure .

The cylindrical structure according to the present invention has a basic structure.
In a thin cylindrical structure that receives an external force at a circumferential portion, at least one or more support members are press-fitted into the thin cylindrical structure, and a part of an outer peripheral surface of the support member is formed on an inner surface of the cylindrical structure. Is held in a pressure contact state .

The cylindrical structure of this is, for example, in thin-wall cylindrical structure, when to dispose at least two said support member to said thin-walled cylindrical structure, the distance between the supporting member is P, said cylindrical structure When the length of the body is L, the outer diameter of the cylindrical structure is D, and the thickness of the cylindrical structure is t, L> 200 mm, t / D <0.02, P <150 m
It is desirable to satisfy the condition of m 2.

[0026] In the cylindrical structure in here, for example, the shape of the support member is a ring-shaped, Ri least partially notched shape or protruding der of the outer peripheral surface shape in the axial cross-section prior Symbol support member , also to be at least partially notched like or projection-like outer circumferential surface shape in the radial section of the support member.

In the method for manufacturing a cylindrical structure according to the present invention , when a plurality of support members are provided in a thin-walled cylindrical structure, the inner diameters of the respective support members are different, and the support members are arranged in order from the one having the larger inner diameter. It is characterized by the following. Further, in this case, the central axis of the cylindrical structure with the central axis of the support member substantially coaxially, the support member is disposed at a predetermined position of the cylindrical structure, after which the cylindrical structure plastically deformed The inner diameter of the cylindrical structure is reduced.

[0028] In the method of manufacturing the cylindrical structure, when arranging a plurality of support members to thin cylindrical structure, when inserting the support member into the interior of the thin cylindrical structure, of the support member The central axis is not parallel to the central axis of the thin cylindrical structure, and after the support member reaches a predetermined position of the thin cylindrical structure, the central axis of the support member and the central axis of the thin cylindrical structure are substantially It is characterized by being arranged coaxially.

In this case, in the method for manufacturing a cylindrical structure, at least one of the thin cylindrical structure and the support member is deformed in the circumferential direction, and the support member is disposed inside the thin cylindrical structure. Further, the shape of the support member of the thin cylindrical structure is an inverted crown shape at the inner diameter of the axial section.

In the fixing device using the cylindrical structure according to the present invention, an unfixed toner image is transferred to a pressing area formed by a pressing roll that presses against a fixing roll including a heater. the fixing device for heating and fixing by passing through a recording paper having a support member disposed inside the fixing roller, the thermal expansion coefficient is used as equal to or larger than the thermal expansion coefficient of the fixing roll, also Then, the end of the fixing roll is plastically deformed.

In this case, a fixing roll is used in which the support member is provided and the outer diameter of the fixing roll is processed to a predetermined thickness . Or, in the cylindrical structure of the thin, Ru with those outside diameter into a predetermined thickness after disposed support member. Also <br/>, in the fixing device, a mechanism for correcting the axial direction of the elastic deformation of the fixing role to be added.

The cylindrical structure according to the present invention is used for a fixing device.
In this case, for example , the fixing device heats and fixes by passing a transfer material carrying an unfixed toner image through a pressure contact area formed between a fixing roll having both ends pivotally supported and a pressure member pressed against the fixing roll. In the fixing device, when a thin cylindrical structure having one or more thick portions on the inner peripheral surface of the thin cylindrical structure is used as the fixing roll, the heat capacity of the protrusion of the thick portion of the thin cylindrical structure is reduced. C1 (cal / ° C) and the heat capacity of the roll part excluding the protruding part of the thick part C2 (cal / ° C)
Satisfies the condition of "(C1 / C2) <10" when the
It can be used effectively by configuring as follows .

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 6 and 7 are cross-sectional views illustrating the basic structure of a thin cylindrical structure used in the fixing device of the present invention. 6 and 7, 15 is a thin cylindrical structure, and 16 is a support member. That is, in the basic structure of the thin cylindrical structure used in the fixing device according to the present invention, as shown in FIG.
Is brought into contact with the inside of the thin-walled cylindrical structure 15 and is press-fitted, so that a part of the outer peripheral surface of the support member 16 is held in a pressed state against the inner surface of the thin-walled cylindrical structure 15.
At least one support member 16 is provided on the thin cylindrical structure 15. Here, since the support member 16 is held in a press-fitted state, the reduction in the circumferential rigidity of the cylindrical structure due to the thinning of the cylindrical body is greatly improved.

When the support members 16 are provided on the thin cylindrical structure 15, in order to more effectively increase the rigidity, the number of the support members is plural, and the distance between the respective support members 16 is shown in FIG. As shown in FIG. 5, the distance between the support members 16 is P, the length of the thin cylindrical structure 15 is L, the outer diameter of the cylindrical structure is D, and When the thickness of the structure 15 is t, L> 200 mm, t / D <0.02, P <150 m
m.

Next, a description will be given of the shape of the support member 16 provided in a state of being pressed into the thin cylindrical structure 15. FIG. 8 is a diagram illustrating a first example of the shape of the support member, and FIG. 9 is a diagram illustrating a second example of the shape of the support member.
FIG. 10 is a diagram illustrating a third example of the shape of the support member.

In order to increase the rigidity of the thin-walled cylindrical structure 15, a support member 16 disposed in a state of being press-fitted therein has:
For example, as shown in FIG. 8, the overall shape is a narrow cylindrical shape (ring shape). Further, when the support member is disposed inside, in order to prevent the support member from falling off due to deformation of the thin cylindrical structure, the outer peripheral surface of the support member has a cross section in the axial direction rather than a simple cylindrical shape. At least a part of the shape of the outer peripheral surface is notched or protruded, and when the support member is press-fitted, the protruding portion bites into a part of the inner surface of the thin cylindrical structure.

That is, as shown in FIG. 9, the support member 17 thus deformed has at least a part of the shape of the outer peripheral surface of the cross section in the axial direction formed in a cutout shape or a protrusion shape. In other words, the shape of the outer peripheral surface of the cross section in the axial direction is not circular. This also applies to the shape of the cross section in the radial direction. That is, as shown in FIG. 10, at least a part of the outer peripheral surface of the cross section in the radial direction of the support member 18 deformed in another form has a cutout shape or a protrusion shape. In other words, the shape of the outer peripheral surface of the cross section in the radial direction is not linear. By making the shape of the outer peripheral surface of the support member partially include such a protrusion, when the support member is press-fitted, the contact strength between the inner peripheral surface of the cylindrical structure and the outer peripheral surface of the support member is significantly improved. Thus, it is possible to prevent the support member from falling off.

Next, a description will be given of a method of manufacturing a cylindrical structure in which such a supporting member is pressed into a thin cylindrical structure and held. FIG. 11 is a diagram illustrating a first example of a method for manufacturing a cylindrical structure according to the present invention. When a plurality of support members are press-fitted into the thin cylindrical structure, for example, when three or more support members are press-fitted into the thin cylindrical structure, as shown in FIG. A plurality of support members in which the inner diameters of the support members 21 to 23 are gradually reduced are used. This allows
The support members 21 to 23 and the support jigs 25 to
27 without interference.
3 can be supported, and the plurality of support members 21 to 23 can be sequentially press-fitted by the press-fitting jig 24.

FIG. 12 is a view for explaining a second example of the method for manufacturing a thin cylindrical structure according to the present invention. In order to ensure that the support member is press-fitted into the thin-walled cylindrical structure and a part of the outer peripheral surface of the support member is pressed against the inner surface of the thin-walled cylindrical structure, the thin-walled cylindrical structure is used. In the body manufacturing method, as shown in FIG. 12, when manufacturing a thin-walled cylindrical structure provided with a plurality of support members, the axis of the support member 46 and the axis of the cylindrical structure 45 are made substantially coaxial. After being arranged at a predetermined position (press-fitted), plastic working is performed so as to reduce the outer diameter of the cylindrical structure 45. Thereby, the support member can be reliably brought into pressure contact with the cylindrical structure 45.

FIGS. 13 and 14 are views for explaining still another example of the method for manufacturing a thin cylindrical structure according to the present invention. In order to press-fit the support member into the thin-walled cylindrical structure and to keep a part of the outer peripheral surface of the support member pressed against the inner surface of the thin-walled cylindrical structure, the manufacturing method here is shown in FIG. As shown in FIG. 13, when the support member 51 is press-fitted and arranged in the thin-walled cylindrical structure 50, the support member 51 and the axis of the cylindrical structure 50 are non-parallel and arranged at a predetermined position. By changing the posture of the support member 51 so that the axis of the support member 51 and the axis of the cylindrical structure 50 are substantially coaxial, the contact area between the outer peripheral surface of the support member 51 and the inner peripheral surface of the cylindrical structure 50 increases, and The supporting member 51 can be press-fitted into the pressure contact state.

In this case, when arranging the support member on the cylindrical structure, that is, in the first half step shown in the upper part of FIG. 13, as shown in FIG. At least one of them is deformed in the circumferential direction, and the support member 51 is arranged at a predetermined position inside the cylindrical structure 50. By arranging them in such a deformed manner, workability is remarkably improved. That is, in the extent this Engineering, cylindrical structure 50 from the axial direction of the cylindrical structure 50
When the support member 51 is obliquely shaded, a large difference occurs between the maximum inner diameter of the cylindrical structure 50 and the minimum inner diameter of the support member 51. Therefore, the process of disposing the first half support member 51 on the cylindrical structure 51 is very easy to perform. Become.

Further, in order to further facilitate the operation of disposing the support member on the cylindrical structure, a cylindrical structure having an inverted crown shape at the inner diameter in the axial direction may be used. FIG. 15 is a diagram illustrating a fourth example of the method for manufacturing a thin-walled cylindrical structure according to the present invention. As shown in FIG. 15, a cylindrical structure 60 having an inverted crown shape at the inner diameter in the axial direction is used. By using the cylindrical structure 60 having such a shape, a plurality of support members 61 can be press-fitted sequentially from one side. In addition, the tolerance design between the inner diameter of the cylindrical structure 60 and the outer diameter of the support member 61 becomes very easy. In the display shown in FIG. 15, in order to facilitate understanding of the difference between the shape of the above-described cylindrical structure and the shape of the thin-walled cylindrical structure 60, the center part and the end part are drawn and displayed extremely differently. However, as in a dimension example of an embodiment (FIG. 29) described later, when the cylindrical structure 50 here is a cylindrical body having a length of 400 mm, the end portion has a diameter of 35.4 mm and the central portion has a diameter of 35.4 mm. The diameter is 35.0 mm.

By using a cylindrical structure with a reinforcing member capable of largely preventing circumferential dents due to such thinning in the fixing device, the warming of the worm can be achieved without increasing the size of the fixing device. The up time can be significantly reduced, and at the same time, the applied load can be significantly increased. Therefore, a fixing device having excellent fixing performance can be configured.

In the fixing device, it is assumed that heat is applied to the fixing roll of the cylindrical structure at the time of fixing. Therefore, during the heating process, the material of the cylindrical structure of the fixing roll and the material used as the supporting member are fixed. Due to the difference in the coefficient of thermal expansion, when the coefficient of thermal expansion of the support member is smaller than the coefficient of thermal expansion of the cylinder, the support member may fall off.

The possibility of such a drop is very small because the support member here is disposed in a state of being press-fitted into the thin-walled cylindrical body. This can be prevented by using a support member having a larger coefficient of thermal expansion than the coefficient of thermal expansion. In other words, by increasing the coefficient of thermal expansion of the support member compared to the fixing roll, the thermal expansion of the support member during heating increases, and the thermal stress of the contact portion increases. Therefore, the connection between the fixing roll and the support member becomes stronger. The concern of dropout is resolved.

When a plurality of supporting members are provided in the thin cylindrical structure, the supporting members at the ends of the cylindrical structure can be omitted by bending the ends of the thin cylindrical structure. . In other words, as shown in FIG. 16, in this case, the thin cylindrical structure 70 is formed by pressing the support member 71 disposed inside first into the inner surface of the cylindrical structure 70 and pressing the peripheral surface of the support member 71 into the inner surface of the cylindrical structure 70. After the supporting member is disposed in a state where a part of the thin cylindrical structure 70 is pressed, the supporting member at the both ends is replaced with the supporting member at the end, and the end 70a of the thin cylindrical structure 70 is replaced.
Is plastically deformed in the direction of the inside of the shaft, where it is easy to process, and bent. As a result, without impairing the dent prevention function,
The manufacturability can be improved and the cost can be reduced.

In the cylindrical structure according to the fixing device of the present invention, the support member is press-fitted to dispose the support member in a state of being pressed into the thin cylindrical structure. For this reason, when the degree of thinness is large (when the thickness is extremely thin), there is a possibility that the presence of the support member 81 becomes apparent on the outer peripheral surface of the cylindrical structure 80 as shown in FIG. In such a case, when such a cylindrical structure is used as a fixing roll, the non-uniform shape of the outer peripheral surface of the fixing roll causes deterioration of image quality. In this case, FIG.
As shown in FIG. 7, after the support member 81 is disposed on the thin-walled cylindrical structure 80, the outer diameter of the thin-walled cylindrical structure 80 is processed to a predetermined thickness, so that the thin-walled cylindrical structure 80 is used as a fixing roll. Eliminate non-uniformity of the outer shape of the fixing roll. Accordingly, when a thin cylindrical structure into which the support member is press-fitted is used as a fixing roll, a fixing roll having a favorable outer peripheral surface shape can be obtained.

By the way, reducing the thickness of the cylindrical structure is a very difficult process itself. The cause is mainly that dents occur in the cylindrical structure during processing, but in the structure of the cylindrical structure according to the present invention, the strength against dents is increased by arranging the support member. In the method of manufacturing a thin cylindrical structure,
As shown in FIG. 19, a cylindrical structure 90 having a certain thickness is provided.
, The support member 91 is first press-fitted.
After disposing the fixing roll, the outer diameter of the fixing roll may be processed to a predetermined thickness. Thereby, rather than thinning the cylindrical structure in the previous step (than when there is no support member),
The thickness can be significantly reduced.

Further, the effect of disposing the support member on the thin cylindrical structure can largely prevent the fixing roll from dent, but at the same time, the fixing roll is also deformed in the axial direction. Therefore, when the fixing roll is used as a fixing roll of a fixing device, it can be used up to the strength limit of the entire fixing roll by adding a conventionally known mechanism for correcting elastic deformation in the axial direction.

Next, the characteristics when the thin-walled cylindrical structure manufactured as described above is used as a fixing roll of a fixing device will be described. FIG. 20 is a diagram illustrating a roll load application device for the fixing roll. Here, the thin cylindrical roll 201 of the fixing roll has a diameter of 35 mm and a thickness of 0.55.
mm and a 335 mm long iron core. Both ends of the thin cylindrical roll 201 are supported by bearings 202. On the other hand, the iron load application bar 203 applies a load to the thin-walled cylindrical roll 201 by a load application mechanism (not shown) without causing bending having sufficient strength. A strain gauge was attached to the outer peripheral portion of the thin-walled cylindrical roll 201, and the axial and circumferential strain amounts at each location were measured using a cylindrical roll load applying device.

As shown in FIG. 21, the measurement positions are set at the end portion (A series) and the center portion (B
21 (A) and 21 (B), the upper part (subscript 1 series), the middle part (subscript 2 series), and the lower position (subscript 3 series), respectively. The position (A1, A2, A3, B
1, B2, B3), a strain gauge (manufactured by Kyowa Dengyo Co., Ltd .: not shown) was affixed, and the amount of strain in each of the axial and circumferential directions at each position was measured using the above-mentioned cylindrical roll load applying device. , And the measurement results are shown in FIGS.
(C).

The position of the sequence A here is roughly at the end,
The position of the B series is approximately at the center. In addition, the data of the strain amount showed an absolute value irrespective of compression or tension. As is clear from the measurement results in FIG. 22, the rate of increase of the strain amount is the largest at the center of the cylindrical roll and in the circumferential direction at the position (B3) in contact with the load application bar. It is. Naturally, permanent deformation (plastic deformation) occurs first in the same place and in the same direction.

Here, a support member having a thickness of 0.8 mm and a width of 2.0 mm as shown in FIG. 23 is press-fitted into a position corresponding to the position (B3) where the rate of increase of the strain amount is the largest. Was measured, the amount of strain in the circumferential direction at the center was 1/3. That is, the withstand pressure is about 3
That is, it has increased twice. The shape of the internal support member to be press-fitted does not necessarily have to be in contact with the inner surface of the thin-walled cylindrical roll, and even if the shape is deformed as shown in FIG. ) Did not occur. However, in consideration of ease of manufacture and cost, a ring-shaped one as shown in FIG. 23 described above is preferable.

Further, as a method of increasing the performance of preventing the dent of the thin-walled cylindrical roll, a plurality of support members are press-fitted and disposed inside the thin-walled cylindrical roll. In the case of a thin cylindrical roll supported at both ends, as the applied load is increased, the permanent deformation in the circumferential direction occurs before that in the axial direction. Therefore, it is preferable that the permanent set in the circumferential direction can be generated under the same load condition as that in the axial direction. That is, it means that the load bearing performance is improved.

FIG. 25 is a view for explaining an example of an experiment for measuring the degree of deformation when the arrangement positions of a plurality of support members on the thin cylindrical structure are changed. For example, as shown in FIG. 25A, two ring-shaped support members shown in FIG. 23 are provided at the center of a thin cylindrical roll, and the distance P between the two support members is changed. Then, the amount of strain at the position (B3) at the center of the thin cylindrical roll was measured in the same manner as described above, with an applied load of 100 kgf. According to the results, as shown in FIG. 25B, the amount of strain in the circumferential direction at the position of the center (B3) is the amount of strain in the axial direction when the distance P between the support members is 150 mm or less. And almost match. However, when the distance P between the support members is larger than 150 mm, the amount of strain in the axial direction at the central position (B3) becomes constant, and the difference between the amount of strain in the axial direction and the amount of strain in the circumferential direction becomes large. On the contrary, when the load is increased, the permanent set in the circumferential direction occurs first.

This tendency is related to the length L, the outer diameter D, and the thickness t of the thin-walled cylindrical roll. According to experiments performed by the present inventors, the conditions between these conditions are: L> 200 mm, And it turned out that it is optimal under the condition of t / D <0.02.

When reinforcing the thin cylindrical roll by providing a support member inside, how to press-fit the support member inside the thin cylindrical roll is a very important problem as described above. In the method of manufacturing a cylindrical structure used in the fixing device of the present invention, two points of "preventing the support member from falling off" and "press-fitting a plurality of support members" are particularly important.

First, a structure for preventing the support member pressed into the thin cylindrical roll from falling off will be described. The falling off of the support member pressed into the thin cylindrical roll mainly occurs due to the influence of external force. The external force is a constant load (static load) applied to the structure of the thin cylindrical roll, a load (dynamic load) due to vibration or rotation, or a load (impact force) caused by collision of an object. Occurs when is added. Therefore, in order to prevent the support member from falling off, the contact portion between the inner peripheral surface of the thin-walled cylindrical roll and the outer peripheral surface of the support member is held in a pressed state, so that the strength of the contact pressure is increased. .

For this purpose, the contact strength can be easily increased only by changing the shape of the outer peripheral surface of the support member. For example, as shown in FIG. 26, the supporting member is formed in a shape such that the cross section in the axial direction of the outer peripheral surface becomes a projection. When the support member having such a shape was pressed into a thin-walled cylindrical roll, there was no falling off due to external force.

Alternatively, as shown in FIG. 27, the outer peripheral surface is formed in a shape such that the cross section in the circumferential direction becomes a projection. When pressed into a thin cylindrical roll of a support member with such a shape,
There was no dropout due to external force. Two examples of the shape of the outer peripheral surface have been described as the shape of the support member. However, the shape is not particularly limited to the shape of the protrusion, and the contact portion between the inner surface of the thin cylindrical roller and the outer peripheral surface of the support member is not particularly limited. It is obvious that any other shape may be used as long as the shape enhances the engagement in the pressed state.

When reinforcing the thin cylindrical roll by providing a support member inside, how to press-fit the support member into the thin cylindrical roller is a very important problem as described above. In this case, "press-fitting a plurality of support members" is also very important. When the number of support members to be press-fitted into the thin cylindrical roller is one, the support member for the support member and the jig for pressing the support member are shown in FIG.
As shown in FIG. 8, a thin cylinder may be pressed from both sides of a thin cylindrical roll using a cylinder having a smaller outer diameter than the inner diameter of the thin cylindrical roll (which may be solid or hollow). However, at this time, the outer diameter of the support member is almost the same as the inner diameter of the thin cylindrical roll, or is slightly larger so as to be tightly fitted.

Therefore, as described with reference to FIG.
By inserting the support member obliquely with respect to the axis of the thin-walled cylindrical roll (so that the axis is non-parallel), friction acting between the inner peripheral surface of the thin-walled cylindrical roll and the outer peripheral surface of the support member is reduced. To facilitate press-fitting. Alternatively, as shown in FIG. 14, at least one of the support member and the thin-walled cylindrical roll is elastically deformed to form a clearance between the support member and the inner surface of the thin-walled cylindrical roll. Make it easy to do. Thereby, manufacturing workability is improved. Using a jig having the dimensions shown in FIG. 28, a support member as shown in FIG. 23 could be easily pressed into a thin cylindrical roll by these methods.

When there are a plurality of support members to be press-fitted into the thin cylindrical roll, the support member inserted first and the support member inserted later or the jig or the support member between the support member inserted first and the thin cylindrical roll are used. Interference problems occur. For example, the inner diameter is 34 mm, the outer diameter is 35 mm, and the length is 335 m
Four ring-shaped support members as shown in FIG. 23 were simultaneously arranged at predetermined positions on a thin iron roll of m, and swaged (drawn) as shown in FIG. However, there was no problem of interference with the press-fitting of a plurality. Further, as a method of avoiding interference between the support member and the jig, the shape of the support member is set to 2 mm, 3.5 mm, and 5 mm, as shown in FIG.
And the outer diameter of the supporting jig corresponding to this is 33.
8mm, 32.3mm, 30.8mm
When the support members were press-fitted in order by the manufacturing method shown in FIG. 11, no problem of interference occurred.

Further, as shown in FIG. 29, the inner diameter becomes a crown shape by bulge processing,
FIG. 30 shows a thin iron roll having a uniform thickness (0.4 mm).
As shown in FIG. 30 (C), a support member having a width of 0.8 mm and a support member having dimensions as shown in FIGS. 30 (a) and 30 (b) are press-fitted one by one in this order. No problem occurred, and press-fitting into a predetermined position was possible.

FIG. 31 is a sectional view for explaining the structure of a fixing device using a thin cylindrical structure according to an embodiment of the present invention. The fixing device shown in FIG. 31 includes a fixing roll 1 having a thin cylindrical structure.
01 is 40 mm in diameter, 0.25 mm in thickness, and 380 in length
An iron core 103 having a thickness of 30 mm is coated with a fluororesin (trade name of Teflon / Dupont) as a release layer to a thickness of 30 μm. Further, inside the fixing roll 101,
The support member 105 is press-fitted with an insertion interval of 80 mm.

At the center of the fixing roll 101, a heating source 106
A 100 v, 1000 w infrared lamp is provided, and this infrared lamp is controlled by a temperature controller (not shown) so that the temperature of the infrared lamp is always 150 ° C. by the temperature sensor 108. The warm-up time at this time can be 10 seconds because a thin cylindrical body is used as the fixing roller 101. Further, the fixing roll 101 is driven at 250 mm / s by a driving motor (not shown).
Driven at the speed of The pressure roll 102 has an outer diameter of 3
Iron core 104 having a thickness of 2 mm, a thickness of 6 mm, and a length of 380 mm
And a silicone rubber 107 having a thickness of 4.0 mm, and a total load of 50 kg is applied from the bearings at both ends.

When the nip area is measured in this state, the roll end nip is 6.0 mm and the roll center nip is 5.4 mm. With this configuration, a nip shape index of 0.9 can be obtained. In this state, when the unfixed toner image 109 imaged by the copier “Vision 550” manufactured by Fuji Xerox Co., Ltd. was fixed, sufficient fixability was obtained and no paper wrinkles were generated.

As a comparative example, when the above-mentioned pressure roll is used to rotate in contact with a conventional fixing roll in which the support member is not pressed into the above-mentioned fixing roll, the load is 10 kg, and permanent deformation due to dents occurs in the fixing roll. However, fixing was impossible.

In the case of thinning the cylindrical structure, in the case of a seamless steel pipe, drawing is performed with a thickness of about 0.7 mm or more.
Outer diameter processing is performed using a lathe or a centerless grinding machine.
However, there is a limit to reducing the thickness without deteriorating the roundness. The cause is dent deformation of the cylindrical structure as a workpiece due to a decrease in circumferential rigidity of the cylindrical structure. In the present invention, on the other hand, the support member is pressed into the inside of the cylindrical structure to prevent dent deformation.

A numerical example of a specific experiment will be described. In this experimental example, a thin cylindrical roll having an outer diameter of 3
An iron core having a size of 5.3 mm, an inner diameter of 33.9 mm, a thickness of 0.7 mm, and a length of 335 mm was used. The circularity at the center of the thin-walled cylindrical roll was 60 μm. Four support members having a thickness of 0.8 mm and a width of 2 mm illustrated in FIG. 23 were pressed into the thin cylindrical roll at regular intervals. And the outer diameter is 34.3
mm in-feed with a centerless grinder
As a result of grinding, it was possible to perform processing without any problem such as crack generation in the roll during the processing. The quality of the roll after processing is as follows: the outer diameter is 34.36 mm at the center, and the roundness is 8μ.
m and good.

As a comparative example, when the above-mentioned thin cylindrical roll was processed without press-fitting the support member, the quality of the roll after processing was as follows: the outer diameter was 35.54 mm at the center and the roundness was 250 μm. It was bad.

Further, in the fixing device shown in FIG. 31, as shown in FIG. 32, the pressure roll is changed to a roll supporting at the center. The fixing roll has a diameter of 30 mm, and the other numerical values are the same. Further, the insertion interval is set to 80 mm inside the thin fixing roll, the outer shape is 39.95 mm, and the width is 0.3 mm.
A support member having a thickness of 8 mm and a thickness of 3 mm is press-fitted. A total load of 80 kg was applied from the bearings at both ends. In this state, the deflection at the center of the fixing roll reached 0.05 mm, but this deflection was corrected by the pressure roll shown in FIG. 32, and the nip was measured. The roll center nip is 6.4 mm. With such a configuration, a nip shape index of 0.9 can be obtained. Further, no dent in the circumferential direction of the fixing roll was observed. In this state, when the unfixed toner image 9 imaged by "Visece 550" manufactured by Fuji Xerox Co., Ltd. was fixed, sufficient fixability was obtained and no paper wrinkles were generated.

By the way, as described above, in the embodiment of the present invention, the dent deformation of the cylindrical structure caused by the decrease in the rigidity of the cylindrical structure in the circumferential direction is prevented by the structure of the cylindrical structure. The support member is press-fitted inside to prevent dent deformation. When such a thin cylindrical structure is used as a fixing roll, the portion of the press-fitted support member becomes partially thick in the axial direction of the cylindrical structure, and this thick portion is used when the fixing roll is heated and started. In particular, at the start of use in the fixing device, local temperature unevenness on the surface of the fixing roll may be caused, which may cause deterioration in fixing performance.

In other words, in the case where a thin cylindrical structure which receives an external force at the circumferential portion is used as a fixing roll, the thickness of the inner circumferential surface is increased at least at one or more places so that the dent in the circumferential direction due to the thinning can be sufficiently achieved. When a thin fixing roll having a prevented structure is used, local temperature unevenness on the surface of the fixing roll may occur, and a fixing defect near the thick portion may occur. In contrast, in the embodiment of the present invention,
The condition of the heat capacity between the members in the thick part and the roll part is satisfied as follows.

In the embodiment of the fixing device according to the present invention, a toner image is carried on a pressing area formed between a fixing roll supported at both ends and a pressing member pressed against the fixing roll, and a transfer material is transferred. In a fixing device that passes and heat-fixes, in a fixing roll in which the fixing roll is a thin metal roll and the thickness of which is increased in at least one place in the axial direction, the heat capacity of the protruding portion of the thick portion is C1. (Cal /
C), and when the heat capacity of the roll portion excluding the protruding portion in the thick portion is C2 (cal / ° C), “(C1 / C2) <1
The material and shape satisfy the condition of “0”.

With this arrangement, when all the components of the fixing device are at almost room temperature, the first copy immediately after the power is turned on and started, the temperature unevenness particularly occurs in the vicinity of the thick portion, and the thick copy is performed. A phenomenon that the degree of fixing deteriorates in the vicinity of the portion has occurred, but this phenomenon can be prevented.

FIG. 33 is a view showing an example of a thin cylindrical structure having a thick part used as a fixing roll in the embodiment of the present invention. That is, as a result of press-fitting the support member into the thin-walled cylindrical structure to prevent dent deformation of the thin-walled cylindrical structure, FIG.
To the shows, those adapted to form a partially thick part in the axial direction of the cylindrical structure is used as a fixing roll wherein the fixing device.

In FIG. 33, reference numeral 301 denotes a roll portion of a metal fixing roll having a thin cylindrical structure, and 302 denotes a thick portion thereof. FIG. 34 is an enlarged view showing a thick portion of an axial cross section of the fixing roll of the fixing device in an enlarged manner.
Here, the projecting portion of the thick portion of the thin cylindrical structure used as the fixing roll is, as shown in FIG. 34, the projecting portion 304 of the portion projecting from a substantially uniform thickness occupying most of the fixing roll. The roll portion excluding the protruding portion at the thick portion refers to the flat portion 303 excluding the protruding portion 304 at the thick portion.

Here, an example in which the thickness is increased in the roll circumferential direction will be described. However, not only the thick portion having the shape as shown in FIG. Including. In addition, a roll having a helical thickness inside the roll is also included. Further, FIG. 34 shows the shape of the protruding portion 304 as a thick portion, which is a semi-circular cross section, but may also have a polygonal shape such as a rectangle, a triangle, or a trapezoid. However, the same can be applied.

FIG. 35 is a diagram showing the transition of the temperature rise from the time when the surface temperature of the thin portion roll and the surface temperature of the thick portion roll are started (when the power is turned on) to the time when the warm-up is completed. FIG. 36 is a diagram showing a temperature distribution immediately after warm-up near the thick portion of the fixing roll. As shown in FIG. 35, especially immediately after the power is turned on, since the temperature rise of the thin portion occupying most of the fixing roll rises faster than that of the thick portion, the heat accumulated in the fixing roll portion near the thick portion becomes thick. The phenomenon of flowing into the meat occurs. In other words, this is because among the structural materials (metals, resins, rubbers, ceramics, etc.), the thermal conductivity of metals is very large, and the effect of this phenomenon on the temperature distribution in the axial direction of the metallic fixing roll is extremely large. is there.

As a result, as shown in FIG. 36, the temperature distribution immediately after the warm-up near the thick portion becomes very uneven. FIG. 36 shows an enlarged view of the thick portion 305 corresponding to the temperature distribution of the roll surface temperature. As described above, the temperature distribution immediately after the warm-up in the vicinity of the thick part of the fixing roll becomes very uneven, so that when the fixing process is performed in this state, a fixing failure occurs near the thick part. Become.

However, in the heat inflow phenomenon immediately after the power is turned on, the present inventor has found that the ratio of the heat capacity of the protruding portion in the thick portion to the heat capacity of the roll portion excluding the protruding portion in the thick portion is dominant. It has been clarified from experimental results. Therefore, when the thin cylindrical structure here is used as a fixing roll in a fixing device, the heat capacity of the protruding portion of the thick portion is set to C1 (cal).
/ ° C), and when the heat capacity of the roll portion excluding the protruding portion in the thick portion is C2 (cal / ° C), “(C1 / C2)
By setting the heat capacity ratio in a range that satisfies the condition of <10, the unevenness in the axial temperature distribution is improved to a range that can be practically used.

Next, the results of experiments conducted by the present inventors will be specifically described. In this case, in order to facilitate understanding, a description will be given with reference to a comparative example with a conventional case where unevenness occurs in temperature distribution.

FIG. 37 is a view for explaining the shape of a thin cylindrical structure having a thick portion in a roll portion used as a fixing roll of a fixing device for comparison. As shown in FIG.
Here, the shape of the thin cylindrical structure of the fixing roll is a release layer 309 on the surface of the core of the iron thin cylindrical structure having a diameter of 35 mm, a thickness of the roll portion 306 of 0.3 mm, and a length of 335 mm. A PFA (perfluoroalkyl vinyl ether copolymer resin) having a thickness of 25 μm is used. In order to increase the rigidity of the inside of the roll part 306, a projection part 308 is provided by partially uneven thickness processing, and a thick part 307 having a width of 1 mm and a height of 4 mm including the projection part 308.
Are provided at four locations in the axial direction, and the intervals are provided at a pitch of 100 mm.

The thin-walled cylindrical structure having such a shape is mounted as a fixing roll of a fixing device (not shown), and the surface temperature of the central portion (non-thick portion) of the roll portion 306 and the surface temperature of the thick portion 307 are radiated. It was measured with a mold non-contact thermometer (manufactured by Keyence Corporation). Other conditions for the fixing device at the time of measurement are as follows: the set temperature is 170 ° C., the initial temperature of the fixing device is 25 ° C. (room temperature), the input power is 1000 W, and the fixing roll and the pressure roll are latched by the fixing roll. 170 ° C
And after reaching. After the latch, both rolls are driven to rotate. According to the experimental results in this case, the temperature transition 310 at the center and the temperature transition 311 at the thick portion shown in FIG. 38 were obtained.

In this case, as shown in FIG. 38, each temperature when the set temperature is reached (after 20 seconds) is set to about 3
There is a temperature difference of about 0 ° C. (hereinafter, referred to as a temperature drop ΔT). In a normal fixing device, in the case of black and white toner, the minimum fixing temperature is 150 ° C. to 160 ° C., and in this state, fixing failure occurs near the thick portion. Actually, after the temperature reached the set temperature under the same conditions, when the paper carrying the unfixed toner image was fixed by a copying machine "Vision 550" manufactured by Fuji Xerox Co., Ltd., a fixing defect occurred near the thick portion of the roll. .

Next, an embodiment in which the condition of the heat capacity ratio between the central portion and the thick portion of the fixing roll is set as described above will be described. Instead of forming the thick portion by the uneven thickness processing of the comparative example (FIG. 37) described above, in this embodiment,
A thick portion was similarly formed using a ring of a reinforcing member for increasing the rigidity of the thin cylindrical structure. Of course, the same results as in this embodiment can be applied to a fixing roll having a thick portion formed by uneven thickness processing as described in the comparative example (FIG. 37).

FIG. 39 is a cross-sectional view for explaining the shape of the structure of the fixing roll in which an experiment according to this embodiment was performed.
As shown in FIG. 39, when the roll thickness of the thin cylindrical structure 315 used as the fixing roll is T, and the shape parameters of the ring 314 of the reinforcing member are Rt for the ring thickness and Rw for the ring width, The numerical values of the parameters are “T = 0.3 mm, 0.5 mm, 1.0 mm” and “(Rt, Rw) = (1.0 mm, 2.0 mm), (1.
0 mm, 4.0 mm) and (1.0 mm, 6.0 mm) ". The other conditions were the same as those of the above-mentioned comparative example (set temperature: 180 ° C.), the temperature at the roll central portion 312 and the thick portion 313 was measured, and the temperature drop ΔT was measured. Figure 4 shows the experimental results in that case.
0 is shown.

In FIG. 40, the abscissa represents the heat capacity C1 (cal / ° C.) of the protruding portion of the thick portion and the heat capacity C2 of the roll portion excluding the protruding portion.
The heat capacity ratio “C1 / C2” with respect to (cal / ° C.) is taken, and the vertical axis represents the temperature drop of the thick portion (the difference between the surface temperature of the roll central portion 312 and the surface temperature of the thick portion 313). I have.

According to the experimental results in this case, as is apparent from FIG. 40, the heat capacity ratio “C1 / C2” is a numerical value “1”.
It became clear that the temperature drop amount of the thick portion was greatly reduced from 0 ”. In fact, the heat capacity ratio“ C1 /
The ring “(Rt,
Rw) = (1.0 mm, 2.0 mm) ”is disposed on a roll having a roll thickness T of 0.5 mm, and the set temperature is set to 180 ° C.
As in the comparative example, when a paper carrying an unfixed toner image was fixed by a copying machine “Vision 550” manufactured by Fuji Xerox Co., Ltd. Did not occur.

Further, when the material of the ring member forming the thick part was made of aluminum, copper, ordinary carbon steel, and carbon alloy steel, the temperature unevenness was examined.
The curve shown in FIG. From this, it was found that the temperature unevenness of the thick portion is more dominated by the effect of the heat capacity than the thermal conductivity of the thick portion.

[0092] Thus, in the embodiment as a fixing roll of the fixing device in this case, the cormorants I mentioned above, the fixing roll used in the fixing device, by a metal roll of thin cylindrical structures, used in the conventional As a result , a fixing device having a significantly shorter warm-up time than that of a fixing roll that has been used can be realized.

In the embodiment of the present invention, when a metal roll having a thin cylindrical structure is used, a roll having an uneven thickness portion on the inner peripheral surface of the roll is used to prevent dents in the circumferential direction. In this case, it is possible to prevent the occurrence of temperature unevenness immediately after the power is turned on due to the thick portion, and to provide a fixing device that does not cause a fixing failure. In addition, since the configuration itself has a feature, the cost of the fixing device does not increase.

[0094]

As described above, the cylindrical structure used in the fixing device of the present invention can dramatically improve the dent strength limit of a thin-walled cylindrical structure which receives an external force at the circumferential portion. Also, the manufacturing method is very easy, so that the use value is very high. Since the thin cylindrical structure is used as the fixing roll of the fixing device, heat loss due to the support member is hardly observed, so that the warm-up time can be greatly reduced. Since the dent strength limit is dramatically improved, the load applied between the fixing roll and the pressure roll can be increased, which can greatly contribute to speeding up the fixing device. Also, when applied to the fixing device,
There is an advantage that the impact on the volume, weight, and cost of the fixing device is small.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a fixing device using a heat fixing method;

FIG. 2 is a cross-sectional view illustrating a first example of the structure of a conventional fixing roller.

FIG. 3 is a cross-sectional view illustrating a second example of the structure of a conventional fixing roller.

FIG. 4 is a cross-sectional view illustrating a third example of the structure of a conventional fixing roller.

FIG. 5 is a sectional view illustrating a fourth example of the structure of a conventional fixing roller.

FIG. 6 is a first diagram illustrating a basic structure of a thin cylindrical structure used in the fixing device of the present invention,

FIG. 7 is a second diagram illustrating the basic structure of a thin cylindrical structure used in the fixing device of the present invention,

FIG. 8 is a diagram showing a first example of the shape of the support member;

FIG. 9 is a view showing a second example of the shape of the support member;

FIG. 10 is a view showing a third example of the shape of the support member;

FIG. 11 is a diagram illustrating a first example of a method for manufacturing a cylindrical structure according to the present invention;

FIG. 12 is a view for explaining a second example of the method for manufacturing a thin-walled cylindrical structure according to the present invention;

FIG. 13 is a first diagram illustrating a third example of the method for manufacturing a thin cylindrical structure according to the present invention;

FIG. 14 is a second diagram illustrating a third example of the method for manufacturing a thin cylindrical structure according to the present invention;

FIG. 15 is a view for explaining a fourth example of the method for manufacturing a thin-walled cylindrical structure according to the present invention;

FIG. 16 is a view for explaining a fifth example of the method for manufacturing a thin-walled cylindrical structure according to the present invention;

FIG. 17 is a view for explaining a state in which the presence of a support member becomes apparent on the outer peripheral surface of the cylindrical structure;

FIG. 18 is a first diagram illustrating a state in which the outer diameter of the thin-walled cylindrical structure is machined to a predetermined thickness after disposing the support member on the thin-walled cylindrical structure;

FIG. 19 is a view for explaining a state in which the outer diameter processing for further reducing the thickness after arranging the support member on the cylindrical structure,

FIG. 20 is a diagram illustrating a roll load applying device for a fixing roll;

FIG. 21 is a view for explaining a mounting position of a strain gauge for measuring a deformation of a thin cylindrical structure,

FIG. 22 is a diagram showing measurement results at each measurement position in FIG. 21;

FIG. 23 is a view showing a ring-shaped support member used in an experimental example;

FIG. 24 is a diagram showing an example of a deformed support member used in an experimental example;

FIG. 25 is a view for explaining an experimental example for measuring the degree of deformation when the arrangement positions of a plurality of support members are changed in a thin-walled cylindrical structure;

FIG. 26 is a diagram showing a first example of the shape of the deformed support member used in the experimental example;

FIG. 27 is a view showing a second example of the shape of the deformed support member used in the experimental example;

FIG. 28 is a diagram illustrating a pressing jig used in an experimental example;

FIG. 29 is a view for explaining an example of a deformed thin cylindrical structure used in an experimental example;

FIG. 30 is a view for explaining an example of a support member press-fitted into the cylindrical structure of FIG. 29;

FIG. 31 is a cross-sectional view illustrating a configuration of a fixing device using a thin cylindrical structure according to an embodiment of the present invention;

FIG. 32 is a view for explaining a modification of the pressure roll in the fixing device according to the embodiment of the present invention;

FIG. 33 is a view showing an example of a thin-walled cylindrical structure having a thick portion used as a fixing roll in an embodiment of the present invention;

FIG. 34 is an enlarged view showing a thick portion of an axial cross section of a fixing roll of the fixing device in an enlarged manner;

FIG. 35 is a diagram showing the transition of the temperature rise from the time when the surface temperature of the thin portion roll and the surface temperature of the thick portion roll are started (when the power is turned on) to the time when the warm-up ends

FIG. 36 is a diagram showing a temperature distribution immediately after warm-up near a thick portion of a fixing roll;

FIG. 37 is a view for explaining the shape of a thin-walled cylindrical structure having a thick portion in a roll portion used as a fixing roll of a fixing device for comparison;

FIG. 38 is a view showing an experimental result of a temperature change of a central portion and a temperature change of a thick portion of a fixing roll of a comparative example;

FIG. 39 is a cross-sectional view illustrating the shape of the structure of a fixing roll on which an experiment was performed.

FIG. 40 shows the heat capacity C1 of the protruding portion of the thick portion on the horizontal axis.
FIG. 9 is a diagram illustrating an experimental example in which the ratio of the heat capacity C2 of the roll portion excluding the protruding portion is set, and the vertical axis is the temperature drop amount of the thick portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inner frame of the support member of a roll, 2 ... Support rod which supports an inner frame, 3 ... Roll (sleeve), 4 ... Heat insulator, 5 ... Coil heater of a heating source, 6 ... Offset prevention layer of a release layer , 7
... Support shaft 8 ... Roll, 9 ... Thick part, 10 ... Conducting cylindrical member, 11 ... Reinforced rigid member, 12 ... Contact charging conductive rubber roller, 13 ... Cylindrical outer cylinder, 14 ... Inner core, 15 ... Thin wall Cylindrical structure, 16 support member, 17 deformed support member, 18 deformed support member, 20 thin cylindrical structure, 21-23 support member, 24 press-fitting jig, 25-2
7 ... support jig, 30 ... heating roller, 31 ... heater, 32
... Cylindrical core, 33 ... Release layer, 40 ... Pressing roller, 41
... Cylindrical core, 42 ... Heat-resistant elastic layer, 43 ... Sheet, 4
4 unfixed toner image, 45 cylindrical structure, 46 support member, 50 thin cylindrical structure, 51 support member, 60 cylindrical structure, 61 support member, 70 cylindrical structure, 71
Supporting member, 70a: end portion, 80: thin-walled cylindrical structure, 81
... support member, 90 ... cylindrical structure, 91 ... support member, 20
DESCRIPTION OF SYMBOLS 1 ... Thin cylindrical coil, 202 ... Bearing, 203 ... Weight application bar, 101 ... Fixing roll, 102 ... Pressure roller, 103 ... Iron core, 104 ... Iron core, 105 ... Support member, 106 ... Heat source, 107 ... Silicon Rubber, 10
8. Temperature sensor, 301 is a roll part, 302 is a thick part,
303 is a flat member, 304 is a protruding portion, 306 is a roll portion, 309 is a release layer, 308 is a protruding portion, 307 is a thick portion, 310 is a temperature transition of a central portion, 311 is a temperature transition of a thick portion. Reference numeral 312 denotes a roll central portion, and 313 denotes a thick portion.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Shoko 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (56) References JP-A-57-155571 (JP, A) JP-A-53-129655 ( JP, A) JP-A-59-30571 (JP, A) JP-A-4-105720 (JP, A) JP-A-7-241929 (JP, A) JP-A 2-277089 (JP, A) Hei 5-59473 (JP, U) Actually open Hei 4-65366 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) G03G 15/20

Claims (5)

(57) [Claims] At least one or more support members are press-fitted into a thin cylindrical structure, and a part of an outer peripheral surface of the support member is held in pressure contact with an inner surface of the thin cylindrical structure. In the method of manufacturing a cylindrical structure used for a fixing device, in a case where a plurality of support members are provided in a thin-walled cylindrical structure, the inner diameters of the respective support members are different, and the support members are arranged in order from a larger inner diameter. A method for manufacturing a cylindrical structure used for a fixing device . 2. The method for manufacturing a cylindrical structure used in a fixing device according to claim 1, wherein, when a plurality of support members are provided on the thin cylindrical structure, a center axis of the support member and the thin cylindrical structure. With the central axis of the body being substantially coaxial, the support member is disposed at a predetermined position of the thin cylindrical structure, and thereafter, the thin cylindrical structure is plastically deformed to reduce the inner diameter of the thin cylindrical structure. A method of manufacturing a cylindrical structure used for a fixing device . 3. The fixing device according to claim 1, wherein
In the method of manufacturing a cylindrical structure used for , when a plurality of support members are disposed in the thin cylindrical structure, when inserting the support member into the thin cylindrical structure, the central axis of the support member is The central axis of the thin-walled cylindrical structure is not parallel to the central axis of the thin-walled cylindrical structure, and after the support member reaches a predetermined position of the thin-walled cylindrical structure, the central axis of the support member and the central axis of the thin-walled cylindrical structure are substantially coaxial. A method for producing a cylindrical structure used in a fixing device, wherein the method comprises: 4. The method for manufacturing a cylindrical structure used in a fixing device according to claim 3, wherein at least one of the thin-walled cylindrical structure and the supporting member is deformed in a circumferential direction, and the inside of the cylindrical structure is formed. A method for manufacturing a cylindrical structure used for a fixing device, comprising providing a support member. 5. A fixing device in which a plurality of support members are press-fitted into a thin cylindrical structure, and a part of an outer peripheral surface of the support member is held in pressure contact with an inner surface of the thin cylindrical structure.
The fixing device according to claim 1, wherein the inner diameter of each of the plurality of support members disposed on the thin-walled cylindrical structure is different from each other, and the fixing members are arranged in order from the largest inner diameter. Cylindrical structure used for