JPS62184219A - Elastic roller - Google Patents

Abstract

PURPOSE:To improve performance by providing an elastic layer with a plurality of holes extending in the axial direction in such a manner as to be unsymmetrical about the radial line, wherein an arbitrary radial line pierces through one of the holes. CONSTITUTION:An elastic layer 1 comprises a cylindrical basic layer portion 2 formed in surface contact with a core bar member 26, a plurality of support portions 3 extended from the basic layer portion 2 outward in the radial direction and a cylindrical surface layer portion 4 for connecting the support portions to each other. The support portions 3 are disposed at equal spaces in the peripheral direction, and extended parallel to the core bar member 26 in the axial direction. Thus, a plurality of holes 5 parallel to the core bar member 26 are formed by the support portions 3, the outer surface of the basic layer portion 2 and the inner surface of the surface layer portion 4. The holes 5 are set unsymmetrical about the radial lines 6, and an arbitrary radial line 7 is always pierced through the hole 5. Accordingly, the performance of an elastic roller can be remarkably improved.

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 web area and the web area 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 in which a cylindrical elastic layer of an elastic material is integrally formed around a shaft-shaped core metal member, and the elastic layer includes a plurality of cylindrical elastic layers extending in the axial direction. holes are provided at equal intervals in the circumferential direction, and the shape of the holes in a cross section perpendicular to the axis is asymmetrical with respect to the radius line of the elastic roller, and any radius line always lies with one of the holes. It is characterized by being formed so as to pass through the hole.

(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 an embodiment of the present invention, FIG. 2 is a side view of the elastic roller, and FIG. 3 is a sectional view of a molding device during molding of the elastic roller.

As shown in FIGS. 1 and 2, the elastic roller of this embodiment has a cylindrical elastic layer l 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 26A and 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 includes a cylindrical base layer portion 2 formed in contact with a core member 26, a plurality of support portions 3 extending radially outward from the base layer portion 2, and each support portion 3. It consists of a cylindrical surface layer part 4 in which . The support columns 3 are arranged at equal positions in the circumferential direction and extend substantially parallel to the core metal member 26 in the axial direction. Thus, a plurality of holes 5 are formed by the above-mentioned support portion 3, the outer surface of the base layer portion 2, and the inner surface of the surface layer portion 4, which are parallel to the core metal member.

The support portion 3 has an elastic roller radius vA6 as shown in FIG.
The hole 5 is set asymmetrically with respect to the radius line 6 by having an inclination angle α to It is formed to penetrate through. Inclination angle α of the support column 3
Basically, the thickness t is determined relatively so as to satisfy the above conditions, but in actual design, the above conditions are included in conjunction with the thickness of the base layer part 2 and the surface layer part, The hardness is set to a value that provides the desired hardness for the elastic roller.

In this embodiment, when the elastic roller comes into contact with the other party, since the support column 3 is inclined, it is easily bent, that is, the roller as a whole is easily deformed, and the radius at any angle is Since the holes are arranged so that the wire 7 always passes through one of the holes 5, the degree of deformation is almost the same at any position in the circumferential direction, and the surface layer 4 has a constant thickness.
This further makes the degree of deformation in the circumferential direction more uniform. Moreover, even in such a state, the surface layer portion 4 maintains a predetermined surface strength.

In this embodiment, the hole 5 has a deformed trapezoidal shape as shown in FIG. 2, but as shown in FIG. Alternatively, other shapes may be used.

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. 3 is a schematic sectional view of the heating roller fixing device.

The fixing roller 40 is made of a cylindrical aluminum core material with an outer diameter of 25 mm and a wall thickness of 1.4 m, and a fluororesin coating is provided on the circumferential surface of the core material to a thickness of about 25 μm. A 1.1 kW halogen heater is provided as the heating element 42, and a temperature detection sensor 4 is installed on the circumferential surface of the fixing roller.
1, the NTC thermistor is brought into contact with the fixing roller 40.
The temperature is controlled to maintain the outer peripheral surface 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 is made of stainless steel with an outer diameter of Ion■, has a cross-sectional shape as shown in FIG. 2 or 3, and has an outer diameter of 24 mm.
The fin has a lotus-like elastic layer with an effective circumferential length of 23,011 Il and a wall thickness of 7 m, and the hardness measured at the surface layer is 27゜ (
A roller of 0.300 g (measured at a constant load of 300 g) is used.

The pressure roller 26 is rotationally driven in the direction of arrow a by a drive device (not shown) at a circumferential speed of 66++n/s, and is supported so as to be freely driven by the fixing roller 40. At the pressure contact portion between the two rollers, a fixing process is performed by heating and pressurizing the transfer material 51 having the toner 52 made of resin or the like while nipping and conveying the transfer material 51 . Such a fixing device can fix A4 size paper (8
0g/? ) was fixed 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, stable fixing performance was achieved with no wrinkles or uneven fixing. was obtained, and its durability was confirmed.

The elastic roller shown in this embodiment 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 cleaning roller for a photoreceptor. , or a platen roller.

(Effects of the Invention) As described above, the present invention provides a plurality of holes extending in the axial direction in the elastic layer, makes the holes asymmetrical with respect to the radius line, and furthermore, allows any radius line to pass through any of the holes. Therefore, by selecting the size and shape 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. becomes. As a result, the functionality of the device using the elastic roller is further improved, and the durability of the elastic roller is extended.
This has the effect of reducing the effort required to maintain the equipment, which in turn 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. 1......Elastic layer 5...Vacancy 6.7...Radius line

Claims (1)

[Scope of Claims] An elastic roller that is formed integrally with the core metal member in the form of a cylindrical elastic layer made of an elastic material around a shaft-shaped core metal member, the elastic layer having a cylindrical elastic layer formed in the axial direction. A plurality of extending holes are provided at equal intervals in the circumferential direction, and the holes have a shape in a cross section perpendicular to the axis that is asymmetrical with respect to the radius line of the elastic roller, and any radius line is always aligned with either of the two. An elastic roller formed to penetrate through holes in the elastic roller.