JPH10301426A - Copying machine heating roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating roller for a copying machine whose heat conductivity is high. SOLUTION: Relating to the heating roller for the copying machine where the inside of a roller main body 1 is formed into a hollow chamber 2, and both ends of the roller main body 1 are formed into cylindrical shaft parts 3 communicating with the hollow chamber 2 and a heater is inserted into the hollow chamber 2 and both end parts are pivotally supported; the roller part of the roller main body 2 is constituted of an internal pipe 1a and an external pipe 1b. Relating to a double structure to hermetically seal end parts; the outer peripheral surface of the internal pipe 1a is made a projecting and recessed surface 6, and also a space part 5 between the internal pipe 1a and the external pipe 1b is filled with the liquid 7 of a specified quantity and the inside of the other space part 5 is made in a vacuum state or in a low pressure state close to the vacuum state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat roller for a copying machine, and more particularly to a heat roller for a copying machine with improved thermal conductivity.

[0002]

2. Description of the Related Art Conventionally, a heat roller used in a copying machine has a hollow structure for accommodating a heater therein, and is therefore made of a pipe material. If the temperature does not reach the surface temperature, the function of the copier is poorly started, so that a thin pipe material such as aluminum is used to improve heat conduction.

[0003] In the case of a heat roller, both ends must have necessary strength because they are rotatably supported via bearings. Therefore, conventionally, ends of a short hollow shaft member are inserted and fixed to both ends of a thin pipe material, and this shaft member is supported by a bearing.

[0004]

However, in the case of the conventional thin pipe material, when the wall thickness is reduced, the thermal conductivity is improved, but it is extremely difficult to polish the surface to obtain the surface accuracy. Increasing the wall thickness facilitates polishing of the surface, but on the other hand, there is a contradiction that thermal conductivity deteriorates.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat roller for a copying machine having a high thermal conductivity. In this case, a liquid is filled therein, and the liquid is used to enhance the thermal conductivity.

That is, according to the present invention, the inside of the roller body is formed in a hollow chamber, and both ends of the roller body are formed in a cylindrical shaft communicating with the hollow chamber, and a heater is inserted into the hollow chamber. In a heat roller for a copying machine in which both ends are supported, the roller portion of the roller body is composed of an inner tube and an outer tube, and these ends are sealed to form a double structure. The space between the inner tube and the outer tube is filled with a required amount of liquid, and the other space is set to a vacuum or a pressure close thereto.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a front sectional view of a heat roller for a copying machine according to the present invention, and FIG. 2 is a sectional view corresponding to AA in FIG.

In a heat roller for a copying machine, generally, the inside of a roller body 1 excluding a roller portion on the outer peripheral side is formed in a hollow chamber 2. A rod-shaped heater 4 such as a coil is inserted between the shaft portions 3 and 3 and the end thereof is supported in a roller.

The present invention relates to a heat roller for a copying machine as described above, wherein the roller portion of the roller body 1 is an inner tube 1a.
And an outer tube 1 fitted outside the inner tube 1a at an interval.
b) to form a double tube structure. That is, the roller portion of the roller body 1 has a structure in which the outer periphery is formed of the outer tube 1b, and the inner tube 1a smaller than the outer tube 1b is inserted inside the outer tube 1b.

In this case, a space 5 having a predetermined space is provided between the inner tube 1a and the outer tube 1b, and both ends of the inner tube 1a and the outer tube 1b are formed by flange portions extending from the shaft portion 3. It is kept in a sealed state by joining with 3a.

On the outer peripheral surface of the inner tube 1a facing the outer tube 1b, a fine uneven surface 6 is formed by, for example, an uneven line running in the axial direction, thereby increasing the area of the outer peripheral surface.

The inner tube 1a and the outer tube 1b are made of a material having good heat conductivity, such as aluminum or iron (stainless steel).

A space 5 between the inner tube 1a and the outer tube 1b is filled with a required amount of evaporable liquid 7 such as alcohol, and the remaining space 5 is set to a vacuum or a pressure close thereto. I have. In FIG. 1, reference numeral 8 denotes a bearing that supports the shaft portion 3.

Next, the operation will be described.

When the roller body 1 is rotated in the direction of the arrow by a rotating means such as a pulley or a belt (not shown) and the switch of the heater 4 is turned on, the inner tube 1a is uniformly heated through the hollow chamber 2. At this time, the outer peripheral surface of the inner tube 1a facing the outer tube 1b is formed on the fine gear-shaped uneven surface 6, so that the heat radiation area is large, and thus the space 5
The contact surface with the liquid 7 contained in the space 5 is also large, so that the liquid 7 located below the space 5 is approximately 1
Since it becomes an evaporating state in about 0 second, the outer tube 1
The outer peripheral surface of b is heated and rises to a temperature of about 230 ° C.

As described above, with the rotation of the roller body 1, the liquid 7 below the space portion 5 moves in the space portion 5 during rotation, and repeatedly evaporates and condenses. The outer peripheral surface of the tube 1b, that is, the roller surface is heated.

In this case, the detection of the surface temperature is performed by ON / OFF control of the switch of the heater 4.

The above-mentioned principle is that a heat pipe having excellent thermal characteristics, which has recently been recognized, can effectively exhibit an extremely high thermal conductivity.

In the case of a heat pipe, a structure having a large capillary force called a wick attached to the inner wall of the container is a gear-shaped uneven surface 6 formed on the inner tube 1a in the present invention. .

[0021]

As described above, according to the present invention, an extremely high thermal conductivity can be obtained as compared with a conventional mechanism of this type, so that excellent heating can be achieved in a short time and uniform temperature can be maintained. Has an effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat roller for a copying machine according to an embodiment of the present invention as viewed from the front.

FIG. 2 is a sectional view corresponding to AA in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roller main body 1a Inner tube 1b Outer tube 2 Hollow chamber 3 Shaft part 4 Heater 5 Space part 6 Uneven surface 7 Liquid

Claims (1)

[Claims] The roller body is formed in a hollow chamber, and both ends of the roller body are formed in a cylindrical shaft communicating with the hollow chamber. A heater is inserted into the hollow chamber and both ends thereof are formed. In a heat roller for a copying machine which bears a part, the roller part of the roller body is constituted by an inner tube and an outer tube, and these ends are sealed to form a double structure, and the outer peripheral surface of the inner tube has an uneven surface. A heat roller for a copying machine, wherein a space between the inner tube and the outer tube is filled with a required amount of liquid, and the other space is set to a vacuum or a pressure close thereto.