JPS59168479A - Tube for attachment of roller for fixing device - Google Patents

Abstract

PURPOSE:To improve fixing performance and reduce a driving load by forming a tube for attachment which has a surface contacting a recording material tightly and an internal surface with slidability for a roller body. CONSTITUTION:When a fixing roller 1 consists of a fixing roller body manufactured individually and a heat-stripping resistance elastic coating 15, the contacting surfaces of the coating 15 and the surface layer sheet 14 of the roller body are both made of silicone rubber and the coefficient of friction is high. For this purpose, resin and oily resin having small coefficients of friction, etc., are provided at least on the internal surface of the coating 15. Further, a silicone lubricant is interposed between the surface layer sheet 14 and coating 15 to realize the relative movement between the roller body and the surface coating. Consequently, a pressure roller 2 is driven and the fixing roller 1 is driven to perform the fixation to improve the fixing performance and reduce the driving load.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting tube for a roller for a fixing device, and more particularly, to a mounting tube for a roller for a fixing device in which a roller body and a mounting tube can be attached to or detached from each other.

In general, elastic rollers have limited elasticity and properties depending on the application, so the range of materials that can be used is extremely limited, and many problems arise in manufacturing and use.

This elastic roller is often used as a presser roller or a fixing roller in image forming apparatuses (for example, printing machines, copying machines, facsimile machines, etc.). In a fixing device of an image forming apparatus, an unfixed image formed on a recording material using a powder or liquid developer is heated, pressurized, or heated and pressurized, and therefore the material for the fixing roller is subject to significant limitations.

Further, the surface of the fixing roller needs to have releasability so that objects to be fixed such as developer forming an unfixed image do not adhere thereto. However, since it is not possible to completely prevent IJ from adhesion of the fixing object, a cleaning member for cleaning the surface of the fixing roller and a separating claw for separating the recording material are brought into contact with the surface. These contact members rub the surface of the fixing roller.
This has caused problems such as scratches on the roller surface, deterioration of performance, and staining of the recording material during fixing. Furthermore, if a contact type temperature sensing element is used for a roller whose temperature is controlled such as a heated fixing roller, this problem not only increases, but also various problems due to poor fixing or abnormal temperature rise, or a decrease in the durability of the sensing element itself. was waking up.

A fixing roller that has deteriorated in this way is replaced with a new fixing roller because if it is used any longer, it will cause problems in image formation.

The fixing roller has a large diameter in order to form a predetermined pressure contact area for fixing, and is expensive because it is formed using many processes and many materials.

In addition, replacement is often required several to several dozen times during the life of the image forming apparatus main body, which imposes a heavy burden on the user.

Furthermore, even though only a portion of the surface of a deteriorated fixing roller has deteriorated, the entire roller must be replaced because the roller itself is a fixed, integrated type.

Therefore, not only is the cost of materials required for replacement extremely high, but it is also a waste of resources.

In order to solve this problem, it is conceivable to polish the surface of the fixing roller and reuse it, but this would result in variations in the diameter of the roller, which would change the fixing performance, making it unsuitable for practical use.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to save materials, costs, etc. in replacing the fixing roller, and to stably maintain the conditions required for the fixing roller. A further object of the present invention is to widen the selection range of materials that have physical properties necessary for the fixing roller, and to improve the performance of the fixing roller.

In order to achieve the above object, the present invention is characterized in that it has a roller body and an elastic surface layer that is detachable from the roller body.

Further, in general, in a fixing device, a roller is configured to have a desired diameter and a predetermined pressure or heat is applied to an object to be fixed, so a large load is applied when rotating the roller. Therefore, a large amount of driving force is required to drive the fixing device.

Furthermore, in an incompletely fixed type structure in which the roller body and the mounting tube can be attached and detached from each other as described above, uneven frictional effects occur between the roller body and the mounting tube when the roller is driven. The force can twist the device tubing and distort the image.

In view of the following two problems, the present invention provides a tube for mounting a fixing device roller that can reliably perform the fixing process of the fixing device roller and alleviate the above-mentioned unnecessary acting force. The 1st goal is to do something.

A feature of the present invention is that at least during rotation for fixing, a constant l'
tgt of the roller surface layer for the i device in the roller longitudinal direction
+ So that the domain can move stably in the circumferential direction of the roller,
It has a surface layer that is movable in the circumferential direction of the roller relative to the roller body.

In a typical example of the present invention, the relationship is such that the coefficient of friction between the object contacted by the roller surface and the outer surface of the mounting surface layer is greater than the coefficient of friction between the roller body and the inner surface of the mounting surface layer. This allows relative movement between the surface layer and the roller body.

In another representative example of the present invention, the inner surface of the surface layer and the outer surface of the roller body are kept slippery so that the surface layer has slippery properties with respect to the roller body, and the outer surface of the surface layer and the object to be contacted are This allows them to be moved in one piece.

Embodiments of the present invention will be described below with reference to the drawings. An example in which the present invention is applied to a pressure roller provided in a fixing device of an electrophotographic copying machine will be explained with reference to FIGS. 1 to 2(c).

FIG. 1 illustrates a cross section of the fixing device in the direction of roller rotation. A fixing roller 1 rotates by receiving a driving force from a driving source (not shown), and has a heating heater 13 such as a halogen heater inside. The fixing roller 1 has a heat-resistant releasable resin layer 11 such as tetrafluoroethylene resin on the outer peripheral surface of a hollow roller core 12 made of metal such as aluminum, stainless steel, or copper.
is provided with a thickness of 20 to 100p.

Reference numeral 2 denotes a pressure roller which rotates following the fixing roller 1, which, together with the fixing roller 1, nip and convey the submerged paper supporting the toner image T to perform the fixing process. Fixing roller 1. Pressure roller 2
is rotatably supported by the fixing device, and the pressure roller 2 is urged by a known pressure means so that at least the fixing surface of the pressure roller 2 comes into pressure contact with the fixing roller 1.

The configuration of the pressure roller 2 will be described in detail in FIGS. 2(a) to 2(c).
A roller body is provided with a relatively thick adhesive fixed to the roller body, and a relatively thin tube-shaped stretchable tL material with heat-resistant mold release properties is attached to the roller body so as to be removable and slippery. and a surface coating layer 23.

Rubber materials such as silicone rubber, fluororubber, a-mouth silicone rubber, urethane rubber, ethylene propylene rubber, and di-I-Ril rubber are suitable for this elastic layer 22. The main requirement for these rubber materials is rubber strength, and the roughness of the elastic layer 22 is preferably about 3 to 10 mm. The coating layer 23 is preferably made of a material that exhibits mold releasability, such as a silicone rubber tube, and has a thickness of 0401111111 to 3 m.
About m is good.

The configuration of the pressure roller 2 is such that a relatively thick elastic layer 22 on the roller body mainly secures a pressure contact area with the fixing roller, and a relatively thin heat-resistant and releasable surface coating provides surface heat resistance and surface releasability. It is held by a pressure roller 2.

A temperature sensing element 4 such as a thermistor or thermocouple is placed in contact with the outer peripheral surface of the fixing roller 1, and its detection signal is guided to a known control means (not shown) to control the temperature of the outer peripheral surface of the fixing roller 1 (heater). By controlling the output of 13 or its applied voltage, etc., the melting temperature of the l.ner image is maintained.

The separating means 5 that comes into contact with the circumferential surface of each roller has a plurality of separating claws 51 and 52 that reliably separate the recording material after fixing from the roller.

Reference numeral 6 denotes a cleaning member for removing foreign matter such as offset toner and paper powder stuck to the heating roller surface from the roller surface, and a cleaning web 61 made of heat-resistant nonwoven fabric such as Nomex or Himeron is used.

”2 The cleaning web 61 is made of silicone rubber.

The heating roller is brought into contact with a pressing roller 63 having elasticity such as fluorosilicone rubber, fluorosilicone rubber, or silicone rubber sponge. Further, this web 61 is moved from the supply roller 62 by a driven take-up reroller 65 so as to change its abutting position by a small amount, so that a new surface of the cleaning web 61 always comes into contact with the heating roller.

Next, a detailed description of the pressure roller 2 will be given with reference to Figure 2(a) to Figure 2(c).

A roller main body shown in FIG. 2(a) is manufactured as the main roller main body.

This is unvulcanized silicone rubber (KE-7424: manufactured by Shin-Etsu Chemical Co., Ltd.) mixed with a vulcanizing agent for a sufficient amount of 4 hours and then left to emit at room temperature for 3 days. After blasting a Flangeits stainless steel core metal with a diameter of 50 mm and an axial length of 320 mm, adhesive is applied to the surface.
[I left it for 5 hours in a 25°C environment, and then heated it at 120°C.
It is manufactured with a core metal that has been baked at C for 20 minutes.

The core bar was coated with L-uncured composition 1 and heated at a pressure of 150 kg/cm and a temperature of 170°C for 30 minutes.
Next vulcanization was performed (using a press vulcanizer). Furthermore, 200
After secondary vulcanization at °C for 4 hours, the outer diameter was 59 mm. +
Jf was cut to produce a roller body consisting of a metal core and an HTV silicone rubber layer.

Subsequently, a tube shown in FIG. 2(b) is manufactured as the bony covering layer 23.

The tube as layer 23 is filled with about 20w of silicone oil.
A room temperature vulcanizable (RTV) silicone rubber (KE-12, Shin-Etsu Chemical Co., Ltd.) containing t% was molded by injection molding into a tube shape having a curved surface parallel to the surface of the roller body.

In terms of specific numbers, the tube has a smaller inner diameter of 54+ nm, an outer diameter of 55 mm, and a total length of 330 mm than the uniform outer diameter of the roller main body of 59 mm and axial length of 320 mm, and has protrusions 231 that are 2 mm thick on the outside at both ends. Ta. The convex portion 231 at the end has the effect of preventing the coating layer 23 from slipping off from the roller body, and it is also possible to press this convex portion with a ring or the like.

It also serves as a support part when being worn, and has the effect of making it easier to wear.

The coating layer 23 produced as described above was attached to the roller main body using its elasticity to form a pressure roller having an outer diameter of 60 mm.

In addition, a lubricant (for example, silicone grease or high viscosity silicone oil (10,000C8 or higher, etc.) is applied between the coating layer 23 and the elastic layer 22 of the roller body to provide lubricity.
A heat-resistant lubricant (such as a heat-resistant lubricant such as

This lubricant supports the coating layer 23 so that it can move relative to the roller body in the circumferential direction. In other words, the coefficient of friction between the roller body and the coating layer 23 is reduced and the slipperiness is increased, and at least during fixing, the surface of the recording material or fixing roller that is contacted by the pressure roller 2 and the coating layer 23 move at approximately the same speed. Can be moved.

In the pressure roll 2, as described above, the coating layer 23 is removable and functionally separable from the roller body, so the material is can be selected. In addition, we were able to select the material in consideration of the physical strength (compression set, rubber elasticity, etc.) required for the roller body. Therefore, a pressure roll with good functionality could be manufactured without any major limitations. In the fixing device shown in FIG. 23 sheets of A3 size paper were pressed at a total pressure of 60 kg and the fixing roller surface temperature was 180±0.5°C.
The toner image was fixed on the recording material at a speed of 270 mm/5 ec in terms of peripheral speed of the roller. As a result, the coating layer 23
It was confirmed that the pressure roller 2 can be used without any problems because it can move relative to the elastic layer 22, and that it can improve fixing performance and give priority to releasability, resulting in less staining. Normally, the surface layer of the pressure roller is slightly abraded due to the separating claws and recording materials that come into contact with the surface, and there is a slight deterioration in mold releasability over time. Since it could be replaced with , the initial characteristics were restored and it could be used without any problems.

On the other hand, with conventional pressure rollers that place emphasis on rubber properties and have a single layer of HTV silicone rubber as a surface layer on the roller body, the surface becomes conspicuous and needs to be replaced sooner. As a countermeasure to this problem, even if vulcanized rubber was dipped in a release agent such as silicone oil to swell the rubber layer, the reroller was still easily stained. In addition, if the pressure roller is constructed by integrally fixing the RTV silicone rubber used for the coating layer 23 of the pressure roller 2 and the metal core, there will be less dirt, but the physical strength will not be obtained and the pressure roller will not be left under pressure. The surface of the roller was permanently deformed, and the dent caused abnormal noise during driving. Additionally, providing a pressure release mechanism would complicate the device.

This resulted in disadvantages such as increased size, increased cost, and decreased reliability. In addition, with the configuration of the pressure roller 2 mentioned above, two layers 22.2
3 (Lightly fixed and cannot be removed), if the thick HTV silicone rubber layer and thin RTV silicone rubber layer are integrally adhered to each other in this order on a metal core and molded, the roller manufacturing It is complicated and requires many man-hours, making it expensive.''-1 Even when only the surface layer of the RTV silicone rubber deteriorates, the entire pressure roll must be replaced with a new one, which is uneconomical.

Next, as a second embodiment of the present invention, an example in which the fixing member of the present invention is applied to a fixing roller will be described with reference to FIGS. 4 and 5(C).

First, the features of this example will be explained using FIGS. 3(a) and 3(b). In a fixing device that performs pressure and heat treatment by sandwiching and conveying an object to be fixed between at least a pair of opposing rollers, both the fixing roller on the side that contacts the toner image and the pressure roller that opposes it have an elastic material on their surfaces. If the coating is applied, good fixing performance can be obtained. This is due to the following reasons. FIG. 3(a) shows a fixing device having the configuration shown in FIG. 1, in which a heat-resistant release resin layer such as PFA resin is provided on the outer peripheral surface of a metal hollow roller core as the fixing roller 1 at a pressure of 20 to 100 l. A highly rigid roller is used as the pressure roller 2, and a relatively thick layer of elastic material such as silicone rubber is applied to the outer circumferential surface of the metal roller core (approximately 5 to 10 mm).
FIG. 2 is an enlarged schematic diagram of a nip portion when a recording material carrying a toner image is fixed using a system using a highly elastic roller. When the recording material P carrying the toner image T enters between the pair of rollers, the upper layer of the toner image T in contact with the fixing roller 1 is immediately softened and melted by the heat from the fixing roller having the heat source 13, and the toner particles are mixed together. Increase cohesion. However, in order for the toner in the lower layer, which is closer to the side of the recording material P, to receive sufficient heat to soften and melt, it usually takes a longer time (approximately 1/100 to 5/100 seconds) than the toner in the upper layer. Furthermore, when the toner enters the toner, the toner at the periphery of the image is dislodged or thrown out due to the supply of heat and the pressure between the pair of rollers that are in pressure contact with each other. In this case, since the toner in the lower layer of the toner image softens and melts more slowly than the toner in the upper layer, it has a weak cohesive force and is particularly susceptible to its effects.

At the same time, a gap S as shown in FIG. 3(a) is created between the fixing roller, the recording material, and the toner image. When the toner separated from the toner image as described above scatters in this gap S and adheres to the recording material, the image becomes distorted.
, or if it adheres to the fixing roller, it will cause an offset. Further, in FIG. 3(a), the broken line indicates the bulge in the toner image caused by the pressure after fixing.

As shown above, when the surface of the fixing roller has high rigidity, the gap S is large, resulting in poor heat transfer efficiency to the toner image, that is, poor fixing performance. In addition, the unmelted toner pushed out into the gap scatters onto the recording material and the fixing roller, resulting in a significant deterioration in image quality and many offsets.

Next, FIG. 3(b') shows a system using a relatively thin heat-resistant release elastic roller such as RTV silicone rubber as the fixing roller and a relatively thick elastic roller such as HTV silicone rubber as the pressure roller. FIG. 2 is an enlarged schematic diagram of a nip portion when copy paper bearing a toner image is fixed.

In this case, since the fixing roller 1 is an elastic body, the roller follows the convex portion of the toner on the copy paper, and the gap S becomes very small, so the heat transfer efficiency to the toner is good and the fixing The quality is very good. At the same time, the bulge D of the image is small, and since the gap S is very small, offset and blurring are also reduced. Further, since the offset is very small, the cleaning device shown in FIG. 1 is not necessarily required.

However, compared to the heat-resistant mold-releasing resin described above, the heat-resistant mold-releasing elastomer described above has lower physical strength, so it is more likely to wear out due to friction with separation claws, temperature detection sensors, etc. It is susceptible to performance deterioration such as breakage and deterioration over time, and in that case, the entire fixing roll needs to be replaced, resulting in inconveniences such as increased costs. In order to improve the above-mentioned disadvantages, attempts have been made to improve the physical strength by sacrificing the releasability to some extent, but this not only makes paper jams more likely to occur and reduces reliability, but also In some cases, the roller receives excessive pressure from jammed paper and is damaged.

Therefore, in this example, in a fixing roll provided with a heat-resistant release elastic layer on the surface, which has good fixing performance although its fire resistance is slightly inferior, the heat-resistant release elastic material surface coating and the roll body are used. The present invention provides a fixing roll having good fixing performance by being configured to be easily attachable and detachable.

FIG. 4 shows one of the fixing devices to which the fixing roll of the present invention can be applied.
This is an example. Components and functions similar to those in FIG. 1 are designated by the same numbers, and descriptions thereof will be omitted. In this embodiment, since the offset is very small, the cleaning member 6 shown in FIG. 1 can be removed. In this case, the extremely small amount of offset toner does not cause deterioration in image quality, and it is sufficient to deposit it on the image area of the recording material each time. That is, it is possible to cause the recording material to function as a cleaning member. Alternatively, a small amount of offset toner to the fixing roller is transferred to the pressure roller side when there is no recording material between the rollers, that is, the pressure roller acts as a cleaning roller for the fixing roller,
The toner attached to the pressure roller may be cleaned by a cleaning member 8 provided in contact with the pressure roller (FIG. 4 shows the latter structure). The cleaning member 8 may be a simple member such as felt. With such a configuration in which the cleaning member does not come into contact with the fixing roller, wear on the surface of the fixing roller can be reduced, and the life of the surface coating layer can be extended.

In Fig. 4, the pressure roller 2 has a total length of 3'30m+n, an outer diameter of 6, and an elastic layer 24 of HTV silicone rubber or the like is provided on the outer peripheral surface of a metal roller core 21 with flanges on both ends.
It is 0mm. The fixing roller 1 is manufactured by the following manufacturing method. To create the roller body, use unvulcanized heat-curable silicone rubber (TSE220-5U manufactured by Toshiba Silicone) along with a vulcanizing agent. F@Kneaded into an unvulcanized rubber sheet,
This unvulcanized rubber sheet was left at room temperature for 3 days and then prepared.

Next, an aluminum hollow core bar (A5056) 12 with an outer diameter of 58.0 mm, a wall thickness of 7 mm, and a total pipe length of 330 mm, with flanges on both ends, was subjected to a truss process, cleaned, coated with adhesive, and placed in a 25°C environment. Leave it for 5 hours, then 1
Baking was performed at 20°C for 20 minutes. After that, the core metal was covered with the unvulcanized rubber sheet, and the pressure was 150K.
g/Cm, secondary vulcanization was performed at a temperature of 170°C for 20 minutes, and then secondary vulcanization was performed at 200°C for 3 hours, and then roughly ground to an outer diameter of 59.4 mm in the shape shown in Figure 5 (a). This was used as the roller body.

Next, a procedure for creating the heat-resistant and releasable elastic coating 15 will be described.

After adding a vulcanizing agent to unvulcanized room temperature vulcanizable silicone rubber (TSE3503 manufactured by Toshiba Silicone Rubber), it was poured into a mold. After leaving for 3 days and demolding, it was heated to 140°C for 30 minutes, 160°C for 1 hour, 180°C for 2 hours, and 200°C for 3 hours.
After performing secondary vulcanization for an hour, the inner diameter was 54 mm as shown in FIG. 5(b). ．． 4mm, outer diameter 55.0mm, total length 340mm
mm (larger than the total length of the pipe).

A heat-resistant and releasable elastic coating 15 was attached to the fixing roller body individually prepared as described above, as shown in FIG. 5(c). In the above embodiment, the contact surfaces between the surface layer sheet 14 of the roller body and the heat-resistant, mold-releasing elastic coating 15 are both made of silicone rubber and have a high coefficient of friction, so a silicone-based lubricant is interposed between them to separate the roller body and the surface coating. This allows for relative movement with.

When the pressure roller 2 was driven by a fixator shown in FIG. 4 using the fixing roller of the present invention, and the fixing process was performed at the same speed as in the first embodiment with the fixing roller 1 driven, the results were very good. The results were obtained.

Also, if you replace the surface coating layer once every 50,000 sheets,
Even after running 300,000 sheets, the results were exactly the same as the initial results.

-1- The coating layer is a thin layer and the molding method is simple, so it can be manufactured at a very low cost. Also, Figure 3 (a
For the same reason as explained in L(b), the fixing roller provided better results in terms of fixing performance and image quality than rollers coated with so-called Teflon such as PFA and PTFE.

FIGS. 6(a), (b), and (C) are explanatory diagrams for explaining other embodiments of the present invention, in which four parts or convex parts as engaging parts are provided over the entire circumferential direction of the roller. Features include retention '8 of the roller body 30 and surface layer 40, which has the effect of preventing movement in the axial direction of the adhesion. still,
Among materials and configurations, descriptions of parts common to each of the above embodiments will be omitted.

The roller main body 30 shown in FIG. 6(a) has a circular groove 31a extending in the circumferential direction of the roller on the surface of the hollow core metal roller such as aluminum or stainless steel.

32a and 33a, which are spaced apart by #1. This groove is formed with a smooth surface and thus prevents the surface layer 40 (which will be described in detail) from moving in the axial direction.

The surface layer 40 shown in FIG. 6(b) has annular protruding surfaces 41a, 42a, and 43a on its interior, and is formed into a tube shape as a whole. so that the grooves 31a, 32a, 33a accommodate the protruding surfaces 41a, 42a, 43a,
The roller body 30 and the surface layer 40 are positioned in relation to each other. Although FIG. 6(b) shows a partial cross-section, when the surface layer 40 is engaged as shown in FIG. 6(C),
The entire circumferential surface of the roller body 30 (excluding the flange) is coated.

Below, numerical examples are shown in Figure 6 (a), (b),
(c) will be further explained. Outer diameter 57mm, wall thickness 7
mm, total #320 mm, aluminum (A5056) pipe was provided with concave grooves at three locations in the circumferential direction, and then separately prepared flange portions 17 and 18 were friction welded to the pipe portion. next,
The surface of the pipe part is plated with nickel chrome to a thickness of 3 mm to provide lubricity to the surface of the roller body, forming grooves 31a.

The roller main body 30 of the above fixing roller was manufactured with 32a and 33a having a diameter of 15 mm and a depth of 3 mm. Next, the surface layer 40 is made of the same material as the surface coating layer 23 shown in FIG. 2(b) (preferably a rubber material with a hardness of 40° or more), and is similarly injection molded to have an inner diameter of 57 mm and an outer diameter of 60 mm. , total length 320 mm, inner layer convex portion ll]4.
3 mm, height of convex part 2.4 mm (7) Fig. 6 (b)
A surface layer 40 shown in FIG.

In this embodiment, it is important that the surface coating layer and the recording material do not cause slippage when the fixing member is operated.
A fixed relative movement is possible between the roller body 30 and the roller body 30 in the circumferential direction.

1] - The recessed portion is a slip prevention means for preventing the surface layer 40 and the roller body 30 from slipping in the axial direction.

The male side is particularly effective when used as a fixing member on the friction driven side.

In this case, the ratio between the outer diameter of the roller body and the inner diameter of one surface layer is preferably 167 or less from the viewpoint of ease of installation and the strength of the surface layer, and in order to prevent the two from shifting in the axial direction during operation. It is preferable that it is 0.8 or more.

A more preferable range from the top of the fixing device is 1.05 or less,
It is 0.95 or more.

In this embodiment, since the circumferential misalignment between the roller main body and the surface layer is made actively movable, it is alleviated and does not become a problem, so that the optimum range described above can be easily selected.

It is also a preferred embodiment to reduce the total friction between the roller body 30 and the surface layer 40 in order to further facilitate relative movement between the roller body 30 and the surface layer 40. For example, in FIGS. 6(a), (b), and (c), a lubricant may be interposed between the roller body 30 and the surface layer 4o, or a resin or oil-based resin having a small coefficient of friction may be applied to at least the roller body 3o. or the inner surface of the surface layer 40 is suitable.

The arrangement may include only the engaging portion, only the roller surface area excluding the engaging portion, or a portion corresponding to the entire roller surface area.

Projecting surfaces 41a, 42a on the inner surface of the surface layer 40,
43a are provided evenly over the entire inner circumferential surface, but only the protruding portions 411° and 421 are left, and the other portions are provided so that the protruding surface has an uneven shape along the dividing line shown by the dashed line in FIG. 6(b). The portions 412 and 422 may be the same as other tubular tubes. This is preferable because the coefficient of friction between the roller body 30 and the surface layer 40 is similar and small, and a holding area for holding the lubricant can be formed. The engaging portions in the above example are provided with three engaging portions in the roller axial direction, but these are preferably arranged so as to equally divide the roller surface into four in the roller axial direction. More preferably, the steps S++ of each engaging portion are provided evenly in the longitudinal direction of the roller, so that the acting force is not shared equally, thereby improving the effect of preventing displacement and twisting in the axial direction.

Figure 7 (a), (b) is the same as Figure 6 (a), (b) c
7) All the engaging parts are increased, and as mentioned above, cat 3
5. This is an embodiment in which each roller body surface layer 40 has eight protrusions 45. The cross-sectional shape of one seedling and the protrusions in the roller axis direction is a rectangular shape in which parallel lines intersect each other at right angles, and is a similar shape that engages with the W. Furthermore, the intervals between the grooves or protrusions are approximately the same on the roller body and on the inner surface of the surface layer 40. Therefore, movement in the axial direction of the roller can be further prevented than in the above example. Furthermore, relative movement between the roller body and the surface layer in the circumferential direction of the roller can be made easier and more stable.

The trough diameter of the roller body and the trough diameter of the surface layer 40 may be set respectively according to the above example. It should be noted that at the end point of the roller surface, the above-mentioned engaging portion is fully 35. In terms of durability, it is preferable to not provide the protrusions 45 so that the outer diameter surface of the roller body is not covered with the surface layer.

As explained above, fixing performance is improved by forming the fixing device roller as a roller body and a surface layer that is removable from the roller body, and holding these so that they can move relative to each other in a vertical direction. At the same time, the driving load can be reduced by Φ￥.

As a means for suppressing the relative movement in the axial direction between the roller body and the surface layer on the male side, a groove, a protrusion, or a surface like a guide member is provided on one side. In this method, at least one of the surface of the roller body or the inner surface of the surface layer is roughened, in particular, a groove-like rough surface parallel to the circumferential direction of the roller or the recording material traveling direction is provided, and the amount of thermal expansion of the roller body is controlled by controlling the amount of thermal expansion of the surface layer. This also includes suppressing the amount of thermal expansion to a value greater than the amount of thermal expansion (effective for heat roller fixing).

A particularly effective roller configuration for the present invention is to use a roller for a fixing device having the above-mentioned roller body and a surface layer as a driven rotary roller of a pair of rollers that nip and convey a recording material, and the surface layer is at least in the same position as the recording material. The object of the present invention is to enable relative movement between the surface of the roller body and the inner surface of the surface layer so that the roller can rotate at a high speed. In other words, the configuration is such that the coefficient of friction between the surface of the roller body and the inner surface of the surface layer is smaller than the coefficient of friction between the recording material and the outer surface of the surface layer. In this case, the coefficient of friction includes the coefficient of friction that is reduced by inclusions such as lubricant. The mounting tube of the present invention has a surface that comes into contact with the recording material and has an electrodeposition property on the recording material, and an inner surface that has a sliding property on the roller body.

As described in ``2'' above, in the above embodiments, in the fixing member such as the fixing roller or cleaning roller that has a surface coating layer, the surface coating layer and the roller body are configured to be easily attachable and detachable, so that only the surface coating layer is removed. In case of deterioration, it is possible to replace only the surface coating layer, and the functions of the roller body and the surface coating layer can be designed separately, greatly improving the functions required for each. It has also become possible. Therefore, it was possible to provide a fixing device that performs good fixing over a long period of time. Further, in this embodiment, an example in which the present invention is applied to a pressure roller and a fixing roller of a heat fixing device has been described, but it goes without saying that the present invention can also be applied to a pressure fixing device having an elastic coating layer.

As explained above, the present invention is a tube for mounting a roller for a fixing device that has an epoch-making structure, so it is possible to reduce costs and materials, further improve characteristics according to the purpose, and improve It can maintain good fixing properties over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fixing device to which the present invention can be applied; FIGS. 2(a), 2(b), and 2(c) are partial explanatory views of an embodiment of the present invention; FIG. 3(a) and FIG. 3(b) are schematic diagrams for explaining the fixing properties of a fixing device to which the present invention is effectively applied, and FIG. 4 is an explanatory diagram of an embodiment to which the present invention is applied. FIG. 5(a), FIG. 5(b). FIG. 5(c) is a partial explanatory diagram of an embodiment of the present invention, and FIG.
FIG. 87(a), FIG. 6(b), and FIG. 6(C) are explanatory diagrams of other embodiments to which the present invention is applied, and FIG. 87(a), and FIG.
Figure (b) is an explanatory diagram of yet another embodiment of the present invention. 2 is a fixing roller, 2 is a pressure roller, 21 is a core metal, 22 is an elastic layer, and 23 is a coating layer. Applicant Canon Co., Ltd.

Claims (1)

[Claims] (1) In a mounting tube for a roller for a fixing device used in a fixing device that fixes an object to be fixed onto a recording material, the mounting tube has an inner surface treated so that it can slide on the circumferential surface of the roller. A tube for mounting a roller for a fixing device, characterized in that: