JPS5849490Y2 - heat pipe roller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pipe roller used, for example, as a fixing roller in an electrophotographic apparatus.

A heat transfer medium sealed in a reduced pressure space absorbs latent heat in the evaporation section, evaporates, releases this latent heat of vaporization in the condensation section, becomes liquefied, and then flows back to the evaporation section, repeating the cycle to produce a heat transfer effect. Heat pipes have come to be widely used in various fields because of their excellent thermal properties.

The heat pipe roller shown in FIG. 1 is an example of one used in a heat fixing device of an electrophotographic device such as a copying machine. The outer cylinder 2 is integrated with the inner and outer cylinders 1 and 2.
It consists of a heat transfer medium, that is, a working fluid 4, which is sealed in the space formed between the two after being depressurized.

By the way, the amount of working fluid in the heat pipe is normally sealed in an extremely small amount in order to increase the effective condensation area and improve thermal uniformity.

For this reason, in the above-mentioned device, when the roller stops operating, the inner cylinder 1 does not come into contact with the working fluid 4, and the inner cylinder 1 becomes empty, so that almost no heat is exchanged and the heat uniformity, which is essential for a fixing device, is not achieved. Not only is it damaged, but the inner cylinder 1
There is also the risk of causing a burnout accident due to heating.

The purpose of the present invention is to eliminate the drawbacks of the conventional devices mentioned above.The present invention is a heat exchanger with a structure such that working fluid is always supplied to the inner cylinder regardless of whether the roller is activated or not. Our goal is to provide pipe rollers.

Hereinafter, the details of the present invention will be explained based on the drawings.

Figures 2 and 3 show an embodiment of the present invention, and the reference numeral 10 in the figure is a heat pipe roller (outer cylinder) made of ordinary steel or stainless steel, the surface of which prevents toner from sticking. Coating 10a is applied.

Reference numeral 11 denotes an inner cylinder equipped with a heater inside, and its material is stainless steel or painted or plated ordinary steel.

Reference numeral 12 designates end caps welded to both ends of these cylinders 10 and 11, thereby keeping the space inside the cylinders 10 and 11 airtight.

Reference numeral 13 designates a nozzle provided on one side of the end cap 12. After reducing the pressure in the space and filling a working fluid 14 such as naphthalene, quinoline, diphenyl, Dowsum A, etc., this nozzle 13 is sealed. A nozzle holder 15 made of solder or resin is poured into the nozzle 13.
This prevents the airtightness of the internal space from being destroyed by the external structure.

16 is a wick made of two to three layers of wire mesh that covers the outer peripheral surface of the inner cylinder 11, and 17 is a plurality of wicks that fit into the space between the outer cylinder 10 and the inner cylinder 11 and extend along their longitudinal direction. Although four coil springs 17 are shown in FIG. 3, two coil springs are sufficient as long as they can support the wick 16 covering the outer peripheral surface of the inner cylinder 11.

18 is a wick made of one or two layers of wire mesh that covers the outer periphery of this coil spring.

In the above-described configuration, when the heat pipe roller rotates in the direction of the arrow in FIG.
The liquid working fluid 14 accumulated on the inner bottom surface of the cylinder is pumped up and supplied to the surface of the inner cylinder 11.

The supplied working fluid 14 absorbs latent heat on the inner cylinder 11 and immediately vaporizes, and flows between the coil springs 17 in the axial direction, while also passing through the gap between the wicks 18 of the coil springs 17 and flowing into the adjacent space. , thus uniformly heating the surface of the outer cylinder 10.

Further, during the stoppage, the wick 18 on the coil spring 17 located at the inner bottom of the outer cylinder 10 moves the liquid working fluid 14
is supplied to the outer peripheral surface of the inner cylinder 11 by capillary action, while the working fluid 14 condensed on the inner peripheral surface of the outer cylinder 10 is captured by the wick 18 of another coil spring 17 and circulated to the surface of the inner cylinder 11.

What is shown in FIGS. 4 and 5 constitutes a second embodiment of the present invention. In this embodiment, the wick 16 on the surface of the inner cylinder 11 is supported by another coil spring 19. Another coil spring 20 is placed along the inner circumferential surface of the outer cylinder 10, and the pitch of both coil springs 19 and 20 is made to have an integer ratio relationship with the pitch of the coil spring 18' for circulating the working fluid. As a result, both coil springs 1
The liquid circulation coil spring 18' can be mounted in a predetermined position while being rotated using the guides 9 and 20.

As described above, according to the present invention, several coil springs covered with a wick are provided in the axial direction between the outer cylinder and the inner cylinder, so when the heat pipe roller rotates, the coil springs pumps up the liquid working fluid that has accumulated on the inner bottom surface of the outer cylinder and supplies it to the inner cylinder surface that has a heat source, preventing the inner cylinder from drying out, and the working fluid vaporized here uniformly heats the outer cylinder. become.

In addition, even when the heat pipe roller stops rotating, the wick of the coil spring that is in contact with the liquid working fluid supplies the working fluid to the wick on the inner cylinder surface through its capillary action. Liquid supply is ensured even if the liquid does not come into contact with the liquid working fluid.

Moreover, this coil spring does not only supply the above-mentioned working fluid, but also holds the wick on the surface of the inner cylinder by its own elasticity, so the wick will not shift even if the roller is used for a long time. Furthermore, the heat pipe roller can be easily installed in both cylinders by rotating the coil spring and using its screw action, which provides excellent effects as a heat pipe roller.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a conventional heat pipe roller, FIGS. 2 and 3 are a side view and a front view showing a heat pipe roller according to an embodiment of the present invention, and FIG.
FIG. 5 is a side view and a front view showing a cross section of another embodiment of the present invention. 10... Outer cylinder, 11... Inner cylinder, 12.
...End cap, 14...Working fluid, 16.18...Wick, 17...
coil spring.

Claims (1)

[Scope of utility model registration request] In a heat pipe roller in which a working fluid is sealed in a space formed by an outer cylinder and an inner cylinder, a wick is coated on the outer peripheral surface of the inner cylinder, and a plurality of coil springs whose surfaces are covered with a wick are placed between the two cylinders. A heat pipe roller characterized in that it extends inside and in the axial direction.