JPS62251516A - Elastic roller - Google Patents

Abstract

PURPOSE:To obtain the uniformly distributed elasticity value as desired of a roller for a copying machine or the like, by providing an elastic layer consisting of a base part, a hole layer part, which is formed in such a way that any radius-line penetrates at least two holes at the same time, and a surface layer. CONSTITUTION:An elastic layer 1 consisting of a base layer part 2, a hole layer part 3, which is made up of holes 5 formed with a plurality of strut parts 3A extending diagonally outward in the radial direction, and a surface layer part 4 having uniform thickness of 0.3mm or greater, is formed in turn around a core metal member 26. In this hole layer part 3, an angle of inclination alphaand thickness t of a strut 3A are determined in such a manner that any radius- line 6 or 7 penetrates at least two of the holes 5 at the same time. Thus, an elastic roller having a very low hardness as desired can be obtained, and the elasticity value of the roller is uniform over the entire peripheral surface, thereby ensuring a certain, fixed surface hardness. As a result, the durability can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an elastic roller that elastically contacts a counterpart.

(Prior Art and Problems) When an elastic roller comes into pressure contact with an opponent, it is required to elastically deform at the contact portion. In many cases, such elastic rollers are desired to be easily elastically deformed, have a large contact area, and have nearly uniform contact pressure at any position within that range. Further, such an elastic roller may be rotating at a constant speed, and in this case, the contact portion moves, but it is required that the contact pressure is always constant over time. For example, examples of elastic rollers that rotate at a constant speed include a pressure roller of a fixing device in a copying machine, a cleaning roller for a photoreceptor, and examples of elastic rollers that are used in a non-rotating state include a platen roller.

Conventionally, elastic rollers for the above-mentioned applications include rollers in which the elastic layer formed around the core metal member serving as the shaft is solid, for example, made of a single material, and the material itself is low hardness rubber, or rollers with a surface layer A roller with a rubber layer of a certain hardness and a sponge between it and a cored metal was used. However, in the case of the single solid low hardness rubber roller mentioned above,
When used for a long time, the strength and strength of the material decrease due to its own weakness.
It is known that durability deteriorates, and there is a limit to this. On the other hand, in the case of a roller with a sponge inside, the sponge is formed by foaming, but it is difficult to make the dimensional stability, hardness, foam density, porosity, and foam structure uniform, and the elasticity This has an adverse effect on the uniformity of the roller properties. Therefore, it was considered to make a normal elastic rubber roller into a lotus stem structure with holes parallel to the core metal member without using the above sponge, but an appropriate structure was not developed and the hole area A difference in hardness occurs between the support region between the adjacent holes, and this appears as unevenness in the roller properties, causing problems in the properties of devices using elastic rollers. It had been requested.

(Means for Solving the Problems) An object of the present invention is to solve the above-mentioned problems and provide an elastic roller with low hardness, constant contact within the range of contact with the other party, and excellent durability. It is structured as follows.

The present invention provides an elastic roller having a cylindrical elastic layer made of an elastic material around a ring-shaped core member, the elastic layer comprising a base layer portion, a hole peripheral portion, and a hole circumferential portion formed in sequence around the core member. A hole is formed in the circumference of the hole so that an arbitrary radius line of the elastic roller passes through the hole two holes above, and the surface layer has a thickness of 0.3 or more. It is characterized by certain things.

Furthermore, when the elastic roller is required to have uniform and good thermal conductivity, such as the fixing roller of a copying machine,
The thickness of the surface layer portion is preferably 2 ml or less.

(Example) Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a perspective view of an elastic roller according to one embodiment of the present invention, FIG. 2 is a side view of the elastic roller, and FIG. 3 is a side view of an elastic roller according to another embodiment.

As shown in FIGS. 1 and 2, the elastic roller of this embodiment has a cylindrical elastic member N1 formed integrally with the shaft-shaped core member 26 around the core member 26. As shown in FIGS.

The core member 26 has a cylindrical shape, and stepped end portions 26^, 26B are provided at both ends to be rotatably supported when used as an elastic roller.

The elastic layer 1 is integrally formed with the core member 26 except for the ends 26A and 26B.

The elastic layer 1 is made of an elastic material such as synthetic resin or rubber, and includes a cylindrical base layer portion 2 formed in contact with the core member 26;
A plurality of struts 3A extending radially outward from the base layer 2 form a hole peripheral portion 3 having holes 5, and a surface layer 4 having a uniform thickness thereon. The above pillar part 3
A is arranged at equal positions in the circumferential direction and extends substantially parallel to the core metal member 26 in the axial direction. Thus, a plurality of holes 5 which are parallel to the core metal member are formed by the above-mentioned support portions 38, the outer surface of the base layer portion 2, and the inner surface of the surface layer portion 4.

The above-mentioned support portion 3A is the radius line 6 of the elastic roller as shown in
The holes 5 are set asymmetrically with respect to the radius line 6 by having an inclination angle α to It is formed so as to penetrate through the holes 5 described above. In this embodiment, two holes 7 are penetrated as shown in FIG.

The inclination angle α and the thickness L of the support column 3A are basically determined relative to each other so as to satisfy the above conditions, but in actual design, the base layer 2 and the surface layer are Together with the thickness of the portion 4, the hardness is set to a value that provides the desired hardness for the elastic roller.

In the elastic layer as described above, the thickness of the surface layer 4 is 0.3
mm or more. In this example,
When the elastic roller comes into contact with the other party, the holes are arranged so that the radius line 7 at any angle always passes through two or more holes 5. The degree of deformation is the same, and in the case of the same figure, since the support column 3A is inclined, it is easily bent, and the roller as a whole is easily deformed. Furthermore, the thickness of the surface layer portion 4 is 0.
Since 3 mm or more is secured, the degree of deformation in the circumferential direction is further made uniform, and there is no difference in the degree of deformation between the vicinity of the hole and the vicinity of the support portion. Moreover, even in such a state, the surface layer portion 4 still maintains a predetermined surface strength.

As for the above-mentioned elastic rollers, tests were conducted on various size values, and the results showed that the lower limit value of the above surface layer was 0.3 dragons, without being greatly influenced by the outer diameter of the elastic roller or the material of the elastic layer. It was confirmed that the

For example, when used as a fixing roller in a copying machine, it has been found that if the thickness of the surface layer is 0.3 ms, no deterioration in fixing performance such as uneven fixing or paper wrinkles will occur as described later.

Also, when using an elastic roller as a fixing roller,
Uniform and good heat conduction is required, and it has been confirmed that in order to satisfy this requirement, it is desirable that the thickness of the surface layer be 2 mm or less.

FIG. 3 is another embodiment showing other possibilities regarding the shape and arrangement of the holes. In the figure, each hole has a substantially rectangular shape and is symmetrical with respect to a radius line. The holes are arranged radially in the inner hole 8. Intermediate hole 9 and outer hole 1o
They are lined up in three rows, and each row has holes 8, 9, and 10.
are arranged so that a radius line 1) at an arbitrary corner position passes through at least two holes.

In this example, since the number of holes increases with the number of rows,
The elastic roller is easily deformed, and its deformation characteristics are almost the same everywhere.

The performance of the elastic roller obtained in the above example was confirmed by using it in a fixing device of a copying machine, etc., and specific numerical values are shown here. FIG. 4 is a schematic sectional view of the heating roller fixing device.

The fixing roller 40 has an outer diameter of 251. A fluororesin coating is provided on the circumferential surface of a cylindrical aluminum core material with a thickness of 1.41) 1 to a thickness of about 25 μm, and a heating element 42 of 1.1 kW is installed inside the fixing roller 40. A halogen heater is provided, and an NTC thermistor as a temperature detection sensor 41 is brought into contact with the circumferential surface of the fixing roller.
Temperature control is performed to maintain the outer peripheral surface of 0 at approximately 180°C. An elastic roller of the present invention is in opposing pressure contact with the fixing roller 40 as a pressure roller 45 with a total pressure of about 6 kg. This pressure roller 45 has an outer diameter of 24 mm and has a cross-sectional shape as shown in FIG.
A lotus-shaped elastic layer with an effective circumferential length of 230 mm and a wall thickness of 7 mm is provided, and the hardness measured at the surface layer is 27 (Asker-0).
A roller with a constant load of 300g (7 measurements) is used.

The pressure roller 45 is supported by a drive device (not shown) so as to be able to follow the fixing roller 40, which is rotationally driven in the direction of arrow a at a circumferential speed of 66+n/s. At the pressure contact portion between both rollers, a fixing process is performed by heating and pressurizing the recording material 51 having the toner image 52 made of resin or the like while nipping and conveying the recording material 51 . Such a fixing device fixes A4 size paper (
80g/rrr) at a frequency of 8 sheets per minute, good fixing performance was obtained, and even after fixing 200,000 sheets of paper of the above size, no wrinkles or uneven fixing occurred. Stable fixing performance was obtained and its durability was also confirmed.

The elastic roller shown in this example can be widely used as a general elastic roller, but examples of its use include not only the pressure roller of the fixing device in a copying machine as described above, but also the roller for conveyance, the photoreceptor, etc. For example, a cleaning roller for cleaning or a platen roller may be used.

(Effects of the Invention) As described above, the present invention provides a plurality of holes extending in the axial direction in an elastic layer, and arranges the arbitrary radius line to penetrate two or more holes, thereby reducing the thickness of the surface layer. Since it is 0.3m or more,
By selecting the size, shape, etc. of the holes, an elastic roller with extremely low hardness and a desired value can be obtained, and the above-mentioned value of the elastic roller is uniform no matter where it is located, and the surface hardness is constant. can be ensured.

As a result, the functions of the device using the elastic roller are further improved, the durability of the elastic roller is extended, and the maintenance effort of the device is reduced, which greatly contributes to cost savings.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is an external perspective view of an elastic roller as one embodiment, FIG. 2 is a side view of the elastic roller of FIG. 1, and FIG. 3 is an elastic roller of another embodiment. FIG. 4, a side view of the roller, is a schematic view showing an example in which the elastic roller of the above embodiment is used as a pressure roller of a fixing device. l・・・・・・・・・・・・Elastic layer 2・・・・・・
・・・・・・・・・Base layer part 3・・・・・・・・・・・・
...Void peripheral part 4... Surface layer part 5; 8, 9.10... Void 6.7; 1)... ...Radius line 26...
......Core member patent applicant
Canon Co., Ltd. Representative Patent Attorney Toru Fujioka Figure 1

Claims (2)

[Claims] (1) In an elastic roller having a cylindrical elastic layer made of an elastic material around a shaft-shaped core member, the elastic layer includes a base layer portion, a porous layer portion, and a hole layer portion formed sequentially around the core member. and a surface layer, in which holes are formed such that an arbitrary radius line of the elastic roller passes through two or more holes, and the surface layer has a thickness of 0.3 mm or more. An elastic roller characterized by: (2) The elastic roller according to claim (1), wherein the surface layer portion has a thickness of 2 mm or less.