JP2003056549A - Coupling device for dissimilar materials, and roller for imaging device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling device of different materials capable of maintaining coupling strength even in high temperature, which can be manufactured at low cost, and a roller for an image forming device using the device. SOLUTION: A first member, and a second member fitted into the first member are provided, and the first member comprises material having a thermal expansion coefficient larger than that of the second member. The first member is provided with an engagement hole part to compose one of a fitting-in part for fitting in, and the second member is provided with an engagement shaft part fitted into the engagement hole part, composing the other part of a fitting-in part. The first member is provided with a protrusion, and the second member is provided with a recess, where the protrusion on the first member is fixed when the second member is fitted into the first member. When the first member undergoes thermal expansion, the protrusion is also expanded to be pressed strongly to the recess in the second member, and separation of the first member and the second member from each other can thus be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining device for dissimilar materials and a roller for an image forming apparatus using the device.

[0002]

2. Description of the Related Art This cleaning roller comprises a roller body 1 and a shaft member 2, as shown in FIG. The roller body 1 has a fitting hole 3 at one end.
The fitting hole 3 is a cylindrical hole. The shaft member 2 has a fitting shaft portion 4 at one end. The fitting shaft portion 4 is a cylindrical shaft, and the shaft member 2 is joined to the roller body 1 by press-fitting the fitting shaft portion 4 into the fitting hole portion 2. Roller body 1
Also, a fitting hole is provided at the opposite end (not shown), and another shaft member 2 is joined to the roller body 1 by pressing the cylindrical shaft into the fitting hole. The incorporation in the image forming apparatus is performed by holding the shaft 5 extending from each shaft member 2 in a bearing in the image forming apparatus main body.

The roller body 1 is made of an aluminum material from the viewpoint of thermal conductivity and weight reduction, and the shaft member 2 is made of an iron material from the viewpoint of wear resistance. The press-fitting is performed by forming the fitting hole portion 3 of the roller body 1 and the fitting shaft portion 4 of the shaft member 2 with, for example, a diameter of 8 mm and a tolerance of H7 / s6, and fitting them tightly together.

[0004]

Since the cleaning roller is in contact with the fixing roller, the surface temperature may reach 200 ° C. Since the coefficient of thermal expansion of the aluminum-based material is larger than that of the iron-based material, when the inner diameter of the fitting hole portion 3 of the roller body 1 is 8 mm, for example, it is 0 at the maximum with the fitting shaft portion 4 of the shaft member 2. Even if the dimensional difference of 0.016 mm is generated and the interference fit is in the room temperature, the clearance fit may occur at the temperature of 200 ° C. and the shaft member may come off. In order to prevent this, the shaft member 2 is attached to the roller body 1
After being press-fitted in, the spring pin 6 as a stopper is press-fitted to prevent the roller body 1 and the shaft member 2 from being separated, as shown in FIG. However, in such a structure, not only the spring pin 6 but also the processing of the pin hole and the pin engagement are costly.

An object of the present invention is to provide a joining device for dissimilar materials and a roller for an image forming apparatus using the device, which can obtain required strength even at a high temperature and can be manufactured at a lower cost. To do.

[0006]

In order to achieve the above-mentioned object, a connecting device for dissimilar materials according to the present invention comprises a first member and a second member press-fitted into the first member. One member is made of a material having a thermal expansion coefficient larger than that of the second member, the first member has a fitting hole portion that constitutes one of the press-fitting portions for the press-fitting, and the second member is the press-fitting portion. The first member is provided with a projection, and the second member is press-fitted into the first member when the second member is press-fitted into the first member. It has a dent that fits into the projection of.

In order to achieve the above object, in the dissimilar material coupling device of the present invention, in the dissimilar material coupling device described above, the protrusion constitutes part of the press-fitting portion of the first member and the second member. is doing.

In order to achieve the above object, the dissimilar material joining device of the present invention comprises a first member and a second member press-fitted into the first member, and the first member is the second member. In a coupling device for dissimilar materials made of a material having a larger thermal expansion coefficient than a member, the first member has a fitting hole portion in the form of a ring-shaped hole that constitutes one of the press-fitting portions for the press-fitting. A second member is provided with a fitting shaft portion in the form of a ring-shaped projection that constitutes the other of the press-fitting portions, and the fitting hole portion and the fitting shaft portion have a projection and a ring in the ring-shaped hole. It is press-fitted by fitting it into the recess on the protrusion.

In order to achieve the above object, the roller of the image forming apparatus of the present invention comprises a roller body and a shaft member press-fitted into the roller body, and the roller body has a coefficient of thermal expansion larger than that of the shaft member. A fitting hole portion made of a large material, the fitting hole portion constituting one of the press-fitting portions for the press-fitting, and a fitting shaft portion press-fitted into the fitting hole portion constituting the other of the press-fitting portions. In the roller of the image forming apparatus, the roller body has a protrusion in the fitting hole portion, the shaft member has a recess on the fitting shaft portion, and the protrusion and the recess are fitted to each other to fit the fitting hole portion. The mating shaft part is press-fitted.

In the roller of this image forming apparatus, the protrusion may be disposed coaxially with the fitting hole portion, the recess may be disposed coaxially with the fitting shaft portion, and the protrusion may be a cylindrical protrusion and the fitting hole portion may be The protrusion may be a cylindrical hole coaxially arranged, the recess may be a cylindrical hole, and the fitting shaft portion may be a cylindrical protrusion coaxially arranged with the recess.

[0011]

In the joining device for different materials of the present invention, since the coefficient of thermal expansion of the first member is larger than that of the second member in a high temperature environment, the thermal expansion of the first member is larger than that of the second member, and the fitting is performed. Even if the hole portion and the fitting shaft portion are in a loose fit state, the protrusion of the first member thermally expands and is strongly pressed against the recess of the second member. The second member does not separate. And these projections and depressions are the fitting projections of the second member in the fitting fittings of the first member, or the fitting fittings of the second member in the fitting fittings of the second member. Since they are press-fitted when they are press-fitted, no extra work is required to join these members.

In this coupling device, the protrusion may form a part of the press-fitting portion between the first member and the second member,
By doing so, the protrusion can be processed together with the fitting hole of the first member, and the fitting shaft part and the recess of the second member can be processed together, so that the processing cost can be reduced.

In the following coupling device for dissimilar materials, even if the first member thermally expands more than the second member, the fitting hole portion and the fitting shaft portion may be loosely fitted. Since the protrusion in the fitting hole also thermally expands and is strongly pressed against the recess in the fitting shaft of the second member, the first member and the second member are not separated. Then, in a low temperature environment, even if the first member is thermally contracted, the fitting hole portion of the first member is reduced in diameter and is crimped to the fitting shaft portion of the second member. The member and the second member do not separate.

The roller of the image forming apparatus of the present invention is
Even if the roller body thermally expands more than the shaft member and the fitting hole and the fitting shaft part come into a loose fit state, the protrusion of the roller body expands and is strong against the recess in the shaft member. Since it is pressed, the roller body and the shaft member are not separated.
Since these projections and depressions are pressed into the roller body when the shaft member or the roller body is pressed into the shaft body, no extra labor is required for assembly.

In this roller, when the protrusion is coaxially arranged with the fitting hole portion and the recess is coaxially arranged with the fitting shaft portion,
When the rollers are machined, they can be machined together, reducing the machining cost, and the protrusions are cylindrical protrusions and the fitting holes are cylindrical holes coaxially arranged with the protrusions. If the recess is made from a cylindrical hole and the fitting shaft part is made of a cylindrical protrusion coaxially arranged with the recess, the fitting hole part and the projection, and the fitting shaft part and the recess can be machined by turning, respectively. Rollers can be manufactured at low cost.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, referring to FIGS.
An embodiment of the dissimilar material bonding apparatus of the present invention and an image forming apparatus roller using the apparatus will be described.

The joining device for dissimilar materials shown in FIGS. 1 to 8 is a cleaning roller of an electrophotographic copying machine. This cleaning roller is for the purpose of removing the offset toner, and has a heat pipe inserted therein and is installed inside the copying machine in proximity to the fixing roller.

The cleaning roller according to the present invention is shown in FIG.
As shown in FIG. 3, the roller body 10 and the shaft member 20 press-fitted into the roller body 10 are provided.

The roller body 10 is made of an aluminum material and is in the form of a solid roller or roll. The roller body 10 is, as shown in FIG.
Fitting holes 11 are provided at both ends.

The shaft member 20 is made of an iron material,
A shaft member body 21 and a shaft 22 are provided. Shaft member body 2
A fitting shaft portion 23 is provided at an end portion opposite to the end portion of the shaft 22 in the first embodiment. The fitting shaft portion 23, together with the fitting hole portion 11 of the roller body 10, constitutes a press-fitting portion.
The shaft member 20 is joined to the roller body 10 by press-fitting the fitting shaft portion 23 into the fitting hole portion 11. Although not shown, the opposite end (not shown) of the roller body 10 has the same structure, and another shaft member 20 having the same structure is press-fitted.

Further, in this cleaning roller, the fitting hole 11 of the roller body 10 is provided with the projection 12, and the fitting shaft portion 23 of the shaft member 20 is provided with the recess 24. The shaft member 20 is also coupled to the roller body 10 by these recesses 24 and the fitting shaft portion 23. explain in detail.

The fitting hole portion 11 of the roller body 10 is in the form of a ring-shaped hole as shown in FIGS. The protrusion 12 is formed by the central protrusion of the fitting hole portion 11 and has the form of a cylindrical protrusion. The fitting hole 11 and the projection 12 share the central axis with the roller body 10.

The shaft member 20 is provided with a shaft member main body 21 as shown in FIGS. The shaft member body 21 is in the form of a cylinder having the same diameter as the roller body 10. The shaft 22 is integrally formed at one end of the shaft member main body 21. The shaft 22 also has a cylindrical shape and shares the central axis with the shaft member main body 21. The fitting shaft portion 23 is integrally formed at the opposite end of the shaft member body 21. The fitting shaft portion 23 also has a cylindrical shape and has the same outer diameter as the inner diameter of the fitting hole portion 11 of the roller body 10 or a slightly larger outer diameter. The height is slightly smaller than the depth of the fitting hole 11. The recess 24 is provided on the top surface of the fitting shaft portion 23. The recess 24 also has a cylindrical hole, and the shaft member main body 2
1, the shaft 22, and the fitting shaft portion 23 are arranged coaxially. The inner diameter of the recess 24 is equal to or slightly larger than the outer diameter of the protrusion 12 of the roller body 10. The depth of the recess 12 is slightly lower than the height of the protrusion 12 of the roller body 10.

The roller body 10 is manufactured, for example, by cutting a rod or bar made of an aluminum material. The shaft member 20 is manufactured by cutting a rod or bar made of an iron material, for example. At this time, the fitting hole portion 11 and the protrusion 12
Has a cylindrical shape, that is, since it is composed of a rotating body, it can be machined together with the roller body 10 by a lathe and the like, and the fitting shaft portion 23 and the recess 24 also have a cylindrical shape. , The shaft member main body 21, the shaft 22, and the fitting shaft portion 23 can be machined by a lathe or the like.

As described above, the roller body 10 and the shaft member 20 are provided at both ends of the roller body 10 with the shaft member 20.
Are joined by press fitting. When the shaft member 20 is press-fitted into the roller body 10, the fitting shaft portion 23 of the shaft member 20 is fit into the fitting hole portion 11 of the roller body 10, and at the same time, the recess 24 in the fitting shaft portion 23 is fitted. The protrusions 12 in the holes 11 are fitted together.

The cleaning roller formed by press-fitting the shaft member 20 into the roller body 10 is installed inside the copying machine in contact with the fixing roller having the heat pipe inserted therein, and the shaft 22 serves as a bearing in the copying machine body. Retained.

When the copying machine is operated, the cleaning roller according to the present invention is in contact with the fixing roller, and thus is heated by the heat generated from the fixing roller. The roller body 10 is made of an aluminum-based material and has a coefficient of thermal expansion larger than that of the shaft member 20 made of an iron-based material.
Thermally expands more than the shaft member 20. However, protrusion 1
The diameter of 2 also becomes large, and the projection 12 is strongly pressed against the inner wall of the recess 24 of the shaft member 20 by this thermal expansion. Therefore, even if the temperature rises, the roller body 10 and the shaft member 20
And do not loosen.

FIG. 7 shows this cleaning roller.
FIG. 8 shows the relationship between the press-fitting margin and the press-fitting strength of the fitting hole portion 11 and the projection 12 at room temperature, and FIG. 8 shows the relationship between the press-fitting margin and the press-fitting strength at a temperature of 200 ° C., respectively.

In this, the fitting hole portion 11 of the roller body 10 has an inner diameter a of 10 mm and a tolerance of 0, -0.02 mm.
Is. The protrusion 12 in the fitting hole 11 has an outer diameter b of 8 m.
m, the tolerance is +0.03, +0.01 mm. The fitting shaft portion 23 of the shaft member 20 has an outer diameter c of 10 mm and a tolerance of +.
It is 0.03 + 0.01 mm. The recess 24 in the fitting shaft portion 23 has an inner diameter d of 8 mm and a tolerance of 0, -0.02 mm.
Is.

The shaft member 20 has the fitting shaft portion 2 at room temperature.
3 is press-fitted into the fitting hole portion 11 of the roller body 10 by interference fit, and the recess 24 of the shaft member 20 is press-fitted into the protrusion 12 of the roller body 10 by interference fit.

When the minimum fitting margin is 0.01 mm, the torque for rotating the shaft member 20 with respect to the roller body 10 is 1 N · m, as shown in FIG. And
The force for pulling out the shaft member 20 from the roller body 10 is 40N.

Even if the cleaning roller is heated to maintain the temperature of 200 ° C., as shown in FIG. 8, the minimum fitting margin of 0.01 mm does not change from room temperature to a torque of 1 N · m and the pulling force also changes to room temperature. Not 40N has been obtained. This is because the pressure that presses the outer peripheral surface of the protrusion 12 of the roller body 10 against the inner surface of the recess 24 of the shaft member 20 increases.

Although the cleaning roller of the image forming apparatus has been described above, when it is used in another apparatus, the same configuration can provide a bonding apparatus for different materials that does not come out even in a low temperature environment. This will be described with reference to FIG. When the roller body 10 is the first member and the shaft member 20 is the second member, the first member 10 is fitted with the fitting hole portion 11 having the projection 12, and the second member 20 is fitted with the recess 24. When the mating shaft portions 23 are provided respectively, the first member 10
Even if the thermal expansion occurs, the protrusion 12 causes the depression 24 of the second member 20.
Is strongly pressed against the first member 10 and the second member 20.
Not only do not separate from each other, but also in a low temperature environment, the first member 10 contracts, the fitting hole portion 11 contracts in diameter, and the fitting shaft portion 23 is crimped. Second member 2
Not separated from 0.

[0034]

As described above, according to the present invention, a member having a large coefficient of thermal expansion has a projection, and a member having a small coefficient of thermal expansion has a recess, and these projections and recesses are fitted together, When the temperature rises, the protrusions thermally expand,
Since these members are pressed against the recesses to prevent separation of these members, it is possible to obtain a bonding device for different materials and a roller for an image forming device, which has a bonding strength that is the same as that at room temperature even under high temperature use conditions.

[Brief description of drawings]

FIG. 1 shows an embodiment of a dissimilar material bonding structure of the present invention, and is a front view in which a cleaning roller having the bonding structure is partially omitted.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is a vertical cross-sectional view of a roller body that constitutes the cleaning roller shown in FIG.

FIG. 4 is a right side view of the roller body shown in FIG.

5 is a front view of a shaft member forming the cleaning roller shown in FIG. 1. FIG.

6 is a left side view of the shaft member shown in FIG.

7 is a diagram showing the relationship between the press-fitting margin and the press-fitting strength of the cleaning roller shown in FIG. 1 at room temperature.

8 is a diagram showing the relationship between the press-fitting margin and the press-fitting strength of the cleaning roller shown in FIG. 1 at a temperature of 200 ° C.

FIG. 9 is a vertical cross-sectional view showing a conventional dissimilar material bonding structure, in which a part of a cleaning roller having the bonding structure is shown in a front view and a part thereof is omitted.

FIG. 10 is a longitudinal sectional view showing another example of a conventional dissimilar material bonding structure, a part of which is shown in a front view and a part of which is omitted.

[Explanation of symbols]

10 ... First member (roller body) 11 ... Mating hole 12 ... Protrusion 20 ... Second member (shaft member) 23 ... Mating shaft 24 ... dent

Claims (6)

[Claims] 1. A first member comprising a first member and a second member press-fitted into the first member, wherein the first member is made of a material having a coefficient of thermal expansion larger than that of the second member. Includes a fitting hole portion that constitutes one of the press-fitting portions for the press-fitting, and the second member has a fitting shaft portion that is press-fitted into the fitting hole portion that constitutes the other of the press-fitting portions. In the member coupling device,
The first member has a protrusion, and the second member has a recess that is fitted into the protrusion of the first member when the second member is press-fitted into the first member. apparatus. 2. The connecting device for dissimilar materials according to claim 1, wherein the protrusion constitutes part of a press-fitting portion between the first member and the second member. 3. A heterogeneous material comprising a first member and a second member press-fitted into the first member, wherein the first member is made of a material having a thermal expansion coefficient larger than that of the second member. In the coupling device, the first member is provided with a fitting hole portion in the form of a ring-shaped hole that constitutes one of the press-fitting portions for the press-fitting, and the second member is a ring that constitutes the other of the press-fitting portions. A fitting shaft portion in the form of a ring-shaped projection is provided, and the fitting hole portion and the fitting shaft portion are press-fitted by fitting the projection in the ring-shaped hole and the recess on the ring-shaped projection. A joining device for dissimilar materials. 4. A fitting which comprises a roller body and a shaft member press-fitted into the roller body, wherein the roller body is made of a material having a thermal expansion coefficient larger than that of the shaft member, and which constitutes one of the press-fitting portions for the press-fitting. In a roller of an image forming apparatus including a hole, and a shaft member having a fitting shaft portion press-fitted into a fitting hole portion that constitutes the other of the press-fitting portions, the roller body includes a protrusion in the fitting hole portion. In the image forming apparatus, the shaft member has a recess on the fitting shaft portion, and the projection and the recess are fitted to each other, and the fitting hole portion and the fitting shaft portion are press-fitted. roller. 5. The roller of the image forming apparatus according to claim 4, wherein the protrusion is arranged coaxially with the fitting hole portion, and the recess is arranged coaxially with the fitting shaft portion. 6. The projection comprises a cylindrical projection, the fitting hole portion comprises a cylindrical hole coaxially arranged with the projection, the recess comprises a cylindrical hole, and the fitting shaft portion comprises a cylindrical projection coaxially arranged with the recess. The roller of the image forming apparatus according to claim 4.