JPH08262905A - Fixing roller for copying machine and its production - Google Patents

Abstract

PURPOSE: To provide a fixing roller for copying machines having a long life and a process for producing the roller. CONSTITUTION: This fixing roller for copying machines is formed by mounting a heat pipe 3 at a hollow hole 2 formed at the prescribed point of a metallic drum 1. The heat pipe 3 is mounted directly or via a good-conductive material at the hollow hole 2 formed at the point of the metallic drum 1 in tight contact therewith. The heat pipe is heated after insertion into the hollow hole and is brought into tight contact therewith by the vapor pressure of working fluid. The melt of a low melting metal is otherwise injected into the spacing between the hollow hole and the heat pipe. The heat transmission between the metallic drum 1 and the heat pipe 3 is stabilized over a long period and the life of the fixing roller is prolonged for added cost effectiveness. The fixing roller is producible by a simple operation of inserting a mere heating stage in mid-way or injecting the melt of the low melting metal into the spacing between the hollow hole and the heat pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roller for a copying machine and a manufacturing method thereof.

[0002]

2. Description of the Related Art In a copying machine, a fixing roller is charged to (+), and a positive and negative light from an object to be copied is applied to the fixing roller to leave a positive (+) charge only on a portion of the negative (character), and to -) Apply the charged toner by sprinkling it, and then contact the surface of the paper with it. Then, apply the (+) charge from the back side of the paper to transfer the toner to the paper, and heat fuse the toner to the paper. It is to be copied. The fixing roller is formed by coating the surface of an aluminum drum or the like with selenium having a photoelectric effect. And, a heat pipe is embedded near the surface of the drum, and by this heat pipe,
The surface temperature of the fixing roller is made uniform to make the charge amount uniform, that is, copy unevenness is prevented. The heat pipe, as is well known, is one in which a working fluid is enclosed in a sealed tubular body, and the working fluid absorbs heat and vaporizes on the endothermic side, and it moves to the low heat radiating side, Therefore, it is a heat transfer medium that radiates heat, liquefies, and returns to the endothermic side. In the fixing roller, the heat pipe has a function of promoting heat transfer from a high temperature portion to a low temperature portion of the fixing roller to make the surface temperature of the fixing roller uniform. In order to mount the heat pipe in the hollow hole provided in the metal drum, as shown in FIG. 3, the heat pipe 3 is coated on the surface thereof with silicone oil 6 having thermal conductivity and inserted into the hollow hole 2. Then, the opening of the hollow hole 2 is sealed with the adhesive 7. A slight gap is provided between the hollow hole 2 and the heat pipe 3 so that the heat pipe 3 can be smoothly inserted into the hollow hole 2.

[0003]

However, in the above-mentioned copying machine, the unevenness of copying occurs as it is used,
In that case, it was often improved by replacing the fixing roller. From this, the present inventor
As a result of diligent research on the cause of copy unevenness, it was found that the silicone oil applied to the heat pipe gradually deteriorates with use and fluidity decreases, causing the applied thickness to vary locally. Therefore, it was found that the heat transfer characteristics of the thin portion were deteriorated, and further research was conducted to complete the present invention. The present invention provides a long-life fixing roller for a copying machine and a method for manufacturing the fixing roller.

[0004]

According to a first aspect of the invention, the surface of a metal drum is coated with a metal material having a photoelectric effect, and a heat pipe is attached to a hollow hole provided at a predetermined position of the metal drum. A fixing roller for a copying machine, wherein a heat pipe is directly or closely attached to a hollow hole provided at a predetermined position of the metal drum through a good conductive material. It is a fixing roller.

In the present invention, a metal material such as solder, a high heat conductive resin, or the like is applied as the good conductive material interposed between the hollow hole and the heat pipe.

According to the second aspect of the present invention, a heat pipe is inserted into a hollow hole provided at a predetermined position of a metal drum, and then the heat pipe is heated and the container of the heat pipe is opened by the vapor pressure of the working liquid in the heat pipe. 2. The method of manufacturing a fixing roller for copying according to claim 1, wherein the heat pipe is expanded and brought into close contact with the inner surface of the hollow hole directly, and then the surface of the metal drum is coated with a metal element having a photoelectric effect. is there.

In the present invention, the heating temperature when the heat pipe is expanded is, for example, about 300 ° C. when the heat pipe container (container for working fluid) is copper metal. It is preferable to use a soft container having a small deformation resistance for the container, and an aluminum material or the like is preferable in addition to copper.

According to a third aspect of the present invention, a heat pipe is inserted into a hollow hole provided at a predetermined position of a metal drum, and then a molten metal of a low melting point metal is injected into a gap between the hollow hole and the heat pipe to solidify the molten metal. The method of manufacturing a fixing roller for a copying machine according to claim 1, wherein the surface of the metal drum is then coated with a metal element having a photoelectric effect.

In the invention of claim 2 or claim 3, the coating of the metal having a photoelectric effect on the surface of the metal drum is such that the temperature when the heat pipe is mounted in the hollow hole is the melting point of the metal having a photoelectric effect. In the above case, it is performed after the mounting is completed, but when the mounting temperature is lower than the melting point of the metal having the photoelectric effect, the coating may be performed before the mounting.

In the present invention, as the low melting point metal, wood metal (Bi-Pb-Sn-Cd system, mp71 ° C), rose alloy (Bi-Pb-Sn system, mp100 ° C), Bi-44wt% alloy (mp120 ° C)
℃), Sn-Pb type solder alloy, etc. When pouring the molten metal of low melting point metal, if the temperature of the metal drum and the heat pipe is heated to a temperature higher than the melting point of the low melting point metal, the gap between the hollow hole and the heat pipe is sufficiently filled with the low melting point metal. Has been preferred. When the melting point of the low melting point metal is lower than the melting point of a metal such as selenium that requires a photoelectric effect, it is possible to coat the surface of the metal drum with selenium before injecting the low melting point metal.

[0011]

In the fixing roller for a copying machine according to the present invention, a heat pipe is mounted in a hollow hole provided at a predetermined position of a metal drum, either directly or in close contact with a good conductive material. Therefore, the heat transfer between the metal drum and the heat pipe is stabilized over the entire surface of the metal drum, and the life of the fixing roller is improved. According to the invention of claim 2, the hollow hole and the heat pipe are inserted into the hollow hole provided at a predetermined position of the metal drum, and then the heat pipe is heated to vapor pressure the working fluid in the heat pipe. Since the heat pipe is expanded and brought into close contact with each other by the above method, and in the invention of claim 3, the operation is simple because the molten metal of the low melting point metal is injected into the gap between the hollow hole and the heat pipe and solidified.

[0012]

Embodiments of the present invention will be specifically described below with reference to FIGS. 1 and 2. (Embodiment 1) FIG. 1 is a sectional explanatory view showing a first embodiment of the present invention. A heat pipe 3 was inserted into a hollow hole 2 provided at a predetermined position of an aluminum drum 1, and the heat pipe 3 was placed in a hot air oven and heated to 300 ° C. The working liquid inside the heat pipe 3 evaporates to increase the internal pressure, and the container 4 of the heat pipe expands and comes into close contact with the inner surface of the hollow hole 2. A soft pure copper metal was used for the container 4 of the heat pipe 3. After mounting, the surface of the drum 1 was coated with selenium.

(Embodiment 2) FIG. 2 is a sectional view showing a second embodiment of the present invention. The heat pipe 3 is inserted into the hollow hole 2 provided at a predetermined location of the aluminum drum 1 and heated to 250 ° C., then the heat pipe 3 is positioned at the center of the hollow hole 2, and the gap is circumferentially formed. The Pb-40% Sn alloy solder (melting point: 237 ° C.) 5 was poured into the gap and solidified. After mounting, the surface of the drum was coated with selenium.

(Embodiment 3) A surface of an aluminum drum is coated with selenium, a heat pipe is inserted into a hollow hole provided at a predetermined position of the aluminum drum, and then the heat pipe is positioned at the center of the hollow hole. Then, gaps at equal intervals were opened in the circumferential direction, and the melt of the rose alloy (mp 100 ° C.) was injected into both gaps and solidified. In this case, since the melting point of the rose alloy was low, the rose alloy could be filled between the aluminum drum and the heat pipe without preheating by raising the melt temperature of the rose alloy. Also, since the Rose alloy is lower than the melting point of selenium, an aluminum drum precoated with selenium could be used.

When each of the fixing rollers thus obtained was attached to a copying machine and used, a high-quality copy without unevenness was obtained for a long period of time. The life of the fixing roller is tripled compared to the conventional one.

[0016]

As described above, according to the present invention,
The fixing roller has a long life and is economical. Further, the fixing roller can be manufactured by a simple operation of inserting a simple heating step in the middle or injecting a molten metal of a low-melting point metal into the gap between the hollow hole and the heat pipe, which has a remarkable industrial effect. Play.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of a method of mounting a heat pipe on a fixing roller of the present invention.

FIG. 2 is a vertical cross-sectional view showing a second embodiment of the mounting method of the heat pipe on the fixing roller of the present invention.

FIG. 3 is a vertical cross-sectional view showing a method of mounting a heat pipe on a conventional fixing roller.

[Explanation of symbols]

 1-Aluminum drum 2-Hole hole 3-Heat pipe 4-Heat pipe container 5-Solder 6-Silicone oil 7-Adhesive

Claims (4)

[Claims] 1. A fixing roller for a copying machine, wherein a metal material having a photoelectric effect is coated on a surface of a metal drum, and a heat pipe is attached to a hollow hole provided at a predetermined position of the metal drum. A fixing roller for a copying machine, characterized in that a heat pipe is attached to a hollow hole provided at a predetermined position of a drum making device, directly or in close contact with a good conductive material. 2. A heat pipe is inserted into a hollow hole provided at a predetermined position of a metal drum, and then the heat pipe is heated to expand the container of the heat pipe by the vapor pressure of the working fluid in the heat pipe. 2. The method of manufacturing a fixing roller for a copying machine according to claim 1, wherein a heat pipe is directly adhered to the inner surface of the hollow hole, and then the surface of the metal drum is coated with a metal material having a photoelectric effect. 3. A heat pipe is inserted into a hollow hole provided at a predetermined position of a metal drum, and then a molten metal of a low melting point metal is injected into a gap between the hollow hole and the heat pipe to solidify the metal. 2. The surface of the drum is coated with a metallic material having a photoelectric effect.
A method for manufacturing a fixing roller for a copying machine as described above. 4. The metal material having a photoelectric effect is coated on the surface of the metal drum before the heat pipe is attached to the hollow hole.
A method for manufacturing a fixing roller for a copying machine as described above.