JPH08202206A - Image carrier for image forming device - Google Patents

Abstract

PURPOSE: To prevent a vibration and an abnormal sound from occurring as well as irregular rotation, and to easily fix a vibration proof body inside the drum without requiring a bonding work, by providing a heavy vibration proof body inside a drum. CONSTITUTION: This image carrier is constituted that the vibration proof body 6 consisting of a number of heavy weight members 8 whose specific gravity is large, dispersedly embedded in an elastic member 7 capable of freely bending, is force-fitted inside the drum 1. Otherwise, the image carrier is constituted that the heavy vibration proof body provided with the shaft type heavy weight member having the large specific gravity, in the center of the elastic member capable of freely bending integrated with projecting parts on the outer periphery, is force-fitted into the drum 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image carrier of an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, there is an image forming apparatus which forms an image on the outer periphery of an image carrier by an electrophotographic method and transfers the image onto a transfer sheet. FIG. 9 shows a conventional configuration example of an image carrier used in such an image forming apparatus. In a commonly used image carrier, flanges 102 having a spindle 101 as a center are fixed to both ends of a drum 100, and a gear 103 for transmitting a rotation of a motor (not shown) is fixed to one of the spindles 101. The insert 104 inside
Is a structure that is fixedly provided. As the insert 104,
For example, it is known to use a highly rigid member such as aluminum or an elastic member such as rubber.

Further, as described in JP-A-5-35166, there is an invention in which a weight member having a high weight density is held on the inner circumference of a drum (image holding member) via a cylindrical elastic member. .

[0004]

When an alternating electric field is applied to the image carrier by a charger in order to charge the surface of the image carrier before forming an electrostatic latent image, the image carrier vibrates and oscillates. Occurs. In the case of a contact type charger, an elastic member such as rubber is used to bring the charging blade formed of an elastic member into contact with the surface of the image carrier or to wipe off the toner remaining on the surface of the image carrier. When the cleaning blade formed in step 1 is brought into contact with the image carrier, the image carrier vibrates and abnormal noise is generated. Moreover, the image bearing member receives the resistance of the charging blade and the cleaning blade, which causes uneven rotation.

Such a problem can be improved in FIG. 9 when a member having a high weight density is selected as the insert 104. However, since a member having a high weight density has high rigidity, it is fixed by adhesion. Without it, it is difficult to secure it securely. However, in the fixing method by adhesion, it takes a long time for the adhesive to harden, and the mounting position is displaced during that time, or a defective product in which the adhesive adheres to the surface of the drum 100 is likely to occur.

When an elastic member such as rubber is used as the insert 104, the insert 104 can be press-fitted into the inner circumference of the drum 100, so that workability in manufacturing is improved. However, since the elastic member has a low weight density, it is impossible to suppress the above-mentioned vibration and abnormal noise.

As described in JP-A-5-35166, when a weight member having a high weight density is held on the inner circumference of a drum (image holding member) via a cylindrical elastic member, It is possible to suppress the generation of vibration and abnormal noise. However, since the thick weight member is fitted in the center of the elastic member, the thickness of the elastic member is limited. As a result, even if the elastic member is press-fitted into the drum, the ratio of the compression allowance at the time of press-fitting with respect to the thickness of the elastic member increases, the resistance when press-fitting the elastic member into the drum increases, and workability deteriorates. Is expected.

[0008]

According to the first aspect of the present invention,
A drum having an image forming surface for forming an image on its surface is provided, and a flexible elastic member whose outer diameter is set to a size slightly larger than the inner diameter of the drum has a large specific gravity larger than the specific gravity of this elastic member. An image bearing member of an image forming apparatus is provided in which a vibration isolator having a weight member dispersed and embedded therein is provided, and the vibration isolator is press-fitted into the inner circumference of the drum.

A second aspect of the invention is the image carrier of the image forming apparatus according to the first aspect of the invention, in which the protrusion is integrally formed on the outer periphery of the elastic member.

A third aspect of the present invention is the image carrier of the image forming apparatus according to the second aspect, wherein the protrusion is formed in a rib shape along the longitudinal direction of the drum.

According to a fourth aspect of the present invention, a drum having an image forming surface on which an image is formed is provided on the surface, a protrusion is integrally formed on the outer periphery, and the outer diameter is set to be slightly larger than the inner diameter of the drum. An image forming apparatus in which a vibration isolator having a shaft-shaped weight member having a specific gravity larger than the specific gravity of the elastic member is provided in the center of the flexed elastic member, and the vibration isolator is press-fitted into the inner circumference of the drum. Image carrier.

[0012]

According to the first aspect of the present invention, since the elastic member can be bent and the vibration isolator can be press-fitted into the drum, the bonding work can be omitted. In this case, since the thickness of the elastic member before press-fitting is equal to or larger than the radius of the inner circumference of the drum, it is possible to reduce the ratio of the compression allowance of the elastic member to the radius of the elastic member before press-fitting. The press-fit resistance of the vibration isolator can be reduced. Further, since a large number of weight members having a high specific gravity are dispersed and embedded in the elastic member, the weight of the entire vibration isolator is increased to cause vibration,
It is possible to suppress generation of abnormal noise and uneven rotation.
Furthermore, since the weight member can be embedded in the elastic member at the same time when the vibration isolator is molded, the manufacturing process of the vibration isolator can be shortened.

According to the second aspect of the present invention, since the elastic member has the protrusion on the outer peripheral surface, the contact area between the vibration isolator and the drum is reduced, and the press-fit resistance of the vibration isolator to the drum is further reduced. It is possible to make it smaller.

According to the third aspect of the present invention, since the protrusion has a rib shape along the longitudinal direction of the drum, the press-fitting resistance largely changes after one end of the vibration isolator is press-fitted into the drum. It is possible to easily press the vibration isolator into the drum without doing so. Moreover, it becomes possible to mold the vibration isolator using a simple molding die having a structure that employs a mold splitting structure along the axial direction of the vibration isolator.

According to the fourth aspect of the present invention, since the elastic member can be bent and the vibration isolator can be press-fitted into the drum, the bonding work can be omitted. in this case,
Since the protrusion is present on the outer peripheral surface of the elastic member, the contact area between the vibration isolator and the drum can be reduced, and the press-fit resistance of the vibration isolator into the drum can be reduced. Further, since the shaft-shaped weight member having a high specific gravity is provided at the center of the elastic member, it is possible to increase the weight of the entire vibration isolator and suppress the occurrence of vibration, abnormal noise, and rotation unevenness.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described with reference to FIG. Reference numeral 1 is a cylindrical drum. This drum 1
An image forming surface (photosensitive layer) 2 for forming an image is formed on the surface of the disk, a disk-shaped flange 4 having a support shaft 3 is fixedly fitted to both ends, and one support shaft 3 has a motor. A gear 5 driven by (not shown) is fixedly fitted. Further, at the center of the drum 1, the length of the drum 1 is approximately 3
The vibration isolator 6 having a length of one-half is press-fitted. This vibration isolator 6 is a flexible elastic member 7 whose outer diameter before being press-fitted into the drum 1 is set to be slightly larger than the inner diameter of the drum 1.
In addition, a large number of weight members 8 made of iron, stainless steel, or the like having a specific gravity larger than that of the elastic member 7 are dispersed and embedded. In this example, the elastic member 7 was formed of synthetic rubber made of EPDM (ethylene / propylene copolymer) having excellent weather resistance, ozone resistance, heat resistance, and chemical resistance.

In such a structure, when assembling, the elastic member 7 can be bent to press the vibration isolator 6 into the inner periphery of the drum 1, so that the vibration isolator 6 is inserted into the inner periphery of the drum 1. It is possible to omit the bonding work for fixing. In this case, the radius before the press-fitting of the elastic member 7 is the drum 1
Since it is equal to or larger than the radius of the inner circumference of the elastic member 7, the ratio of the compression margin of the elastic member 7 to the radius before the elastic member 7 is press-fitted can be reduced, and therefore the press-fit resistance of the vibration isolator 6 to the drum 1 can be reduced. The press-fitting work can be facilitated.

Further, since a large number of weight members having a high specific gravity are dispersed and embedded in the elastic member 7, the weight of the vibration isolator 6 as a whole is increased to suppress the occurrence of vibrations, abnormal noises and uneven rotation. Is possible. Further, when molding the vibration isolator 6, the weight member 8 having fine particles in the molding material of the elastic member 7 is used.
It is possible to embed the weight member 8 in the elastic member 7 at the same time when the vibration isolator 6 is molded by a method such as mixing. Therefore, the manufacturing process of the vibration isolator 6 can be shortened.

Next, each embodiment of the invention described in claim 2 will be described with reference to FIGS. The same parts as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted (the same applies hereinafter). The vibration isolator 6 shown in FIGS. 2 to 4 has a plurality of protrusions 9 or 10 or a plurality of protrusions 11 integrally formed on the outer periphery of the elastic member 7.

According to this structure, since any one of the protrusions 9, 10, and 11 is present on the outer peripheral surface of the elastic member 7, the contact area between the vibration isolator 6 and the drum 1 is reduced, and the drum 1 is reduced. It is possible to further reduce the press-fitting resistance of the vibration isolator 6 into the.

In particular, as shown in FIG. 2, since the protrusion 9 has a rib-like shape along the longitudinal direction of the drum 1 and has a semicircular cross section, one end of the vibration isolator 6 is attached to the drum 1. After the press-fitting, the vibration-proof body 6 can be easily press-fitted into the drum 1 without the press-fitting resistance largely changing. Moreover, it becomes possible to mold the vibration isolator 6 using a simple molding die having a structure that employs a mold splitting structure along the axial direction of the vibration isolator 6. These are the effects corresponding to the invention of claim 3.

Further, as shown in FIG. 3, when the protrusion 10 having a semicircular cross section is formed in a spiral shape on the outer periphery of the elastic member 7, the vibration isolator 6 is pressed in the axial direction while being rotated. As a result, it is possible to easily press fit the drum 1. Although the spiral protrusion 10 is continuous from one end to the other end of the elastic member 7 like a single line, even if a plurality of such continuous protrusions 10 are arranged in parallel. Good.
Further, a plurality of protrusions having a predetermined length may be intermittently formed along the spiral.

Next, each embodiment of the invention described in claim 4 will be described with reference to FIGS. The vibration isolator 12 shown in FIGS. 5 to 7 has a shaft-shaped weight member 14 made of iron or stainless steel having a specific gravity larger than the specific gravity of the elastic member 13 at the center of the elastic member 13 which is bendable. Further, any of the vibration isolator 12 has a plurality of protrusions 9 or 10 or a large number of protrusions 11 integrally formed on the outer periphery of the elastic member 13. As shown in FIG. 5, the vibration isolator 12 having the protrusion 9 is pressed against the inner circumference of the drum 1 similar to that of the above embodiment. Both the vibration isolator 12 having the protrusion 10 shown in FIG. 6 and the vibration isolator 12 having the protrusion 11 shown in FIG. 7 are press-fitted into the inner circumference of the drum 1, although the state is not shown. In this example, the elastic member 13 was molded from synthetic rubber made of EPDM (ethylene / propylene copolymer) having excellent weather resistance, ozone resistance, heat resistance, and chemical resistance.

With this structure, the vibration isolator 12 can be press-fitted into the drum 1 by bending the elastic member 13, so that the vibration isolator 12 is bonded to the inner periphery of the drum 1. The work can be omitted. In this case, since any of the protrusions 9, 10, and 11 is present on the outer peripheral surface of the elastic member 13, the contact area between the vibration isolator 12 and the drum 1 is reduced, and the vibration isolator 12 is press-fitted into the drum 1. It is possible to reduce the resistance. In this case, the protrusions 9, 10 and 11 have different shapes, but the effect of the shape of the protrusions 9 and 10 is the same as that of the above-described embodiment described with reference to FIGS. 2 and 3.

The elastic member 13 is a weight member 14 having a shaft shape.
When the length of the elastic member 13 is longer than both ends of the elastic member 13, the end portion of the elastic member 13 can be freely deformed, so that it becomes difficult to grip the end portion of the elastic member 13 when the vibration isolator 12 is press-fitted into the drum 1. By setting the length of the weight member 14 so as to match at least both ends of the elastic member 13 or to have a length slightly protruding, it is possible to facilitate gripping.

Further, since the shaft-shaped weight member 14 having a high specific gravity is provided at the center of the elastic member 13, the vibration isolator 1 is provided.
2 It is possible to increase the weight of the whole 2 and to suppress the occurrence of vibration, abnormal noise and uneven rotation.

The outer diameter of the shaft-shaped weight member 14 is set to be slightly larger than the inner diameter of the elastic member 13, so that the weight member 14 can be pressed into the center of the elastic member 13 without using an adhesive. it can. In this case, as shown in FIG. 8, the vibration isolator 12 having the protrusion 9 (or the protrusions 10 and 11).
May be divided into a plurality of parts, and one shaft-shaped weight member 14 may be press-fitted into each vibration isolator 12.

[0028]

According to the first aspect of the present invention, the vibration isolator, which is a flexible elastic member in which a large number of weight members having a large specific gravity are dispersed and embedded, is press-fitted into the drum. Therefore, it is possible to omit the bonding work for fixing the vibration isolator in the drum. In this case, since the thickness of the elastic member before press-fitting is equal to or larger than the radius of the inner circumference of the drum, it is possible to reduce the ratio of the compression allowance of the elastic member to the radius of the elastic member before press-fitting. The press-fit resistance of the vibration isolator can be reduced. Further, since a large number of weight members having a high specific gravity are dispersed and embedded in the elastic member, it is possible to increase the weight of the entire vibration isolator and suppress vibrations, abnormal noises, and uneven rotation. Further, since the weight member can be embedded in the elastic member at the same time when the vibration isolator is molded, the manufacturing process of the vibration isolator can be shortened.

According to the second aspect of the invention, since the elastic member has the protrusion on the outer peripheral surface, the contact area between the vibration isolator and the drum is reduced, and the press-fit resistance of the vibration isolator to the drum is further reduced. Can be made smaller.

According to the third aspect of the present invention, since the projection has a rib shape along the longitudinal direction of the drum, the press-fitting resistance largely changes after one end of the vibration isolator is press-fitted into the drum. The vibration-proof body can be easily press-fitted into the drum without doing so. Moreover, the vibration isolator can be easily molded by using a simple molding die having a structure that employs a mold splitting structure along the axial direction of the vibration isolator.

According to the fourth aspect of the present invention, the vibration isolator having the shaft-shaped weight member having a large specific gravity at the center of the flexible elastic member integrally formed with the protrusion on the outer periphery is press-fitted into the drum. Since the configuration is adopted, it becomes possible to omit the bonding work for fixing the vibration isolator in the drum. In this case, since the protrusion exists on the outer peripheral surface of the elastic member, the contact area between the vibration isolator and the drum can be reduced, and the press-fit resistance of the vibration isolator into the drum can be reduced. Further, since the shaft-shaped weight member having a high specific gravity is provided at the center of the elastic member, it is possible to increase the weight of the entire vibration isolator and suppress the occurrence of vibration, abnormal noise, and rotation irregularity.

[Brief description of drawings]

1 shows an embodiment of the invention according to claim 1,
(A) is a perspective view, (b) is a vertical sectional front view, and (c) is a vertical sectional side view.

2A and 2B show an embodiment of the invention described in claims 2 and 3, wherein FIG. 2A is a perspective view of a vibration isolator, and FIG. 2B is a longitudinal side view thereof.

FIG. 3 is a perspective view of a vibration isolator showing an embodiment of the invention according to claim 2;

FIG. 4 is a perspective view of a vibration isolator showing an embodiment of the invention according to claim 2;

FIG. 5 is a perspective view showing an embodiment of the invention described in claim 4.

FIG. 6 is a perspective view of a vibration isolator showing an embodiment of the invention according to claim 4;

FIG. 7 is a perspective view of a vibration isolator showing an embodiment of the invention according to claim 4;

FIG. 8 is a perspective view of a vibration isolator showing a modified example of the invention according to claim 4;

FIG. 9 is a vertical sectional front view showing a conventional example.

[Explanation of symbols]

 1 Drum 2 Image Forming Surface 6 Vibration Isolator 7 Elastic Member 8 Weight Member 9-11 Projection 12 Vibration Isolator 13 Elastic Member 14 Weight Member

Claims (4)

[Claims] 1. A drum having an image forming surface on which an image is formed is provided, and a flexible elastic member having an outer diameter slightly larger than an inner diameter of the drum has a specific gravity larger than that of the elastic member. An image carrier for an image forming apparatus, comprising: a vibration isolator, in which a large number of weight members having a specific gravity are dispersed and embedded, and the vibration isolator is press-fitted into the inner circumference of the drum. 2. The image carrier of the image forming apparatus according to claim 1, wherein a protrusion is integrally formed on the outer periphery of the elastic member. 3. The image carrier of the image forming apparatus according to claim 2, wherein the protrusion is formed in a rib shape along the longitudinal direction of the drum. 4. A drum having an image forming surface for forming an image on the surface thereof is provided, and a protrusion is integrally formed on the outer periphery, and an outer diameter is set to be slightly larger than the inner diameter of the drum and is flexible. An image forming apparatus characterized in that a vibration isolator having a shaft-shaped weight member having a specific gravity larger than that of the elastic member is provided at the center of the elastic member, and the vibration isolator is press-fitted into the inner circumference of the drum. Image carrier.