JPS596360B2 - Method for manufacturing heat pipe rolls - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a heat pipe 20 used in copying machines and the like.

Generally, this type of heat pipe exchanges heat using the vapor of the internal heat transfer medium as a medium, so it is desirable that the wall thickness of the outer cylinder be as thin as possible.

However, it is difficult to form a thin-walled cylinder using a drawn material or the like, so 3 is formed into a thin wall by machining the outer peripheral surface of a material having a certain thickness. In this case, there are various problems such as chattering caused by resonance, thermal distortion caused by cutting heat during machining, etc., which makes it impossible to obtain roundness and warping. The present invention was developed in view of these points, and since the final product must be filled with a heat transfer liquid, the outer cylinder can be machined easily and with high precision using this heat transfer liquid. The purpose of the present invention is to provide a method for manufacturing a heat pipe that can be used in a heat pipe.

The present invention forms a pipe body with an outer cylinder whose outer peripheral surface is unprocessed, and pours a heat transfer liquid into the pipe body through an opening, and then, while the opening is open, the outer peripheral surface of the outer cylinder is The pipe is finished by machining, and after the completion of the finishing process, the heating medium liquid is heated to fill the pipe body with steam from the heating medium liquid, and the opening is sealed. .

Therefore, before finishing the outer cylinder, the heat transfer liquid is poured into the pipe body, and the outer circumferential surface of the outer cylinder is machined in that state, so there is no resonance phenomenon during machining, and this prevents rust. In addition, since there is no thermal distortion, it is possible to process highly circular products, and it is also possible to make the walls considerably thinner.The heat transfer liquid is then heated and sealed, so there is no waste in the process, and it is extremely effective. It is designed to increase productivity. Embodiments of the present invention will be described based on the drawings.

First, reference numeral 1 denotes a pipe body, and the pipe body 1 has an inner cylinder 4 fixed to the outer periphery of a pair of bosses 3 having a shaft part 2, and end plates 5 fixed to the outer periphery of both ends of the inner cylinder 4. This end plate 5
An outer cylinder 6 whose outer peripheral surface is unprocessed is fixed to the outer periphery of the cylinder. A hole T serving as an opening is formed in one end plate 5, and communicates the space 8 inside the pipe body 1 with the outside air. Note that the size S of the hole 7 is less than or equal to the surface area L of the entire heat pipe, preferably a hair. The following is desirable. Further, it is desirable that the thickness tl of the inner cylinder 4 has a ratio of 2 to the thickness of the finished outer cylinder 6 (0.3 to 3.0), preferably 2>1. After the pipe body 1 is formed in this manner, its airtightness is tested.

The test methods include connecting a helium detector to the hole 7 and spraying helium from the outside of the pipe body 1, or putting helium into a helium container. A method is employed in which helium is sealed, the hole 7 is temporarily closed, and leakage of helium is detected using a detector within the vacuum container. Of course, the gas body is not limited to helium.
In addition, the hole 7 serving as the opening may be provided in the end plate 5 or at any suitable position on the outer cylinder 6 or inner cylinder 4, but if the convenience of removing air is considered, the hole 7 may be provided in the end plate 5. Other positions are preferred. In the first step, a heat transfer liquid 9 is poured into the pipe body 1 in an amount that does not leak from the hole 7 when the pipe body 1 is held horizontally.

This heat transfer fluid 9 may be water, SK oil or KSK
Oil (manufactured by Izuemo Nippon Souken Co., Ltd.) is used.
1 The amount of heat transfer liquid 9 is 95% or less of the internal volume, preferably 90% or less of the internal volume.
% or less is preferable.

Next, while holding the shaft portion 2 of the pipe body 1, the vibrator body 1 is held horizontally and the unmachined outer peripheral surface is machined.

At this time, since the pipe body 12 is in an assembled state, the outer cylinder 6
It is much stronger and more rigid than a single piece, and as a result, the V1 resonance frequency is lowered and vibration against the tool is less likely to occur.Furthermore, the heat transfer fluid prevents heat generation during cutting, and the part Chattering due to seizing is also less likely to occur, and a liquid layer of heat transfer liquid 9 is formed on the inner peripheral surface of the outer cylinder 6, and this liquid layer has a vibration suppressing effect and lowers the resonance frequency. Since a large amount of energy is required to cause an object with a small natural frequency to resonate, cracks due to resonance do not occur when cutting with a cutting tool or the like. Furthermore, even if cutting heat or grinding heat is generated locally, cooling is effectively achieved by evaporation of the heat transfer liquid 9, and a high-precision finish is achieved without thermal distortion. Therefore, there is no need to apply cooling oil such as cutting oil from the outside. At this time, if both ends 6a of the outer cylinder 56 are notched as shown in FIG. 1, the end plate 5 and the outer cylinder 6 will have the same wall thickness, making welding easier. There is no cutting required, which is preferable for manufacturing sealed containers. The hole 7 may be closed immediately after the finishing of the outer circumferential surface of the outer cylinder 6 is completed, but if a long period of time has elapsed, the heat transfer liquid 9 may be drained and the inside cleaned at some point. The inside of the main body 1 is evacuated to temporarily seal the hole 7.

Then, the outer circumferential surface of the outer cylinder 6 is subjected to surface treatment with fluororesin or rubber. This surface treatment is for forming an offset prevention layer when used as a fixing roll, and does not necessarily need to be carried out as a next step after machining. Then, if the heat medium liquid 9 is discharged, a specified amount of the heat medium liquid 9 is put in through the hole 7, and if the heat medium liquid 9 is not discharged, when the amount does not reach the specified amount, A heating device such as a nichrome wire, an infrared lamp, or a halogen lamp is inserted into the center hole 10 of the pipe body 1 to boil the heat medium liquid 9.

This heating temperature is desirably higher than the boiling point of the heat transfer liquid 9. In this way, the space 8 is filled with the vapor of the heat transfer liquid 9, and the filled vapor is further heated by an appropriate heat source to further increase the internal pressure, and the air inside is exhausted. . In this state, the hole 7 is sealed. As this sealing means, a steel ball press-fitted with a taper pin having a hardness different from that of the end plate 5 is used. Another method is to weld a pipe to the hole 7 in advance and seal it by press-fitting a steel ball into the pipe or by chip-cutting the pipe. The material of this pipe is Fe, SUS,
These include Cu, Pb, and Ag. Alternatively, a screw may be formed in the hole 7 and the head screw may be firmly tightened with a metal or plastic packing interposed therebetween. Note that the heating means before sealing the hole 7 may be heated from the outer peripheral side using a heater or the like, or induction heating may be performed.

In the present invention, as described above, the pipe body is formed without finishing the outer circumferential surface, and then the heat transfer liquid is poured in to finish the outer circumferential surface, so that vibration does not occur due to resonance during machining. Further, since there is no thermal distortion, it is possible to perform processing with high roundness, the processing time can be shortened, and there is no need to increase the number of steps.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is a vertical cross-sectional side view of the pipe body, Fig. 2 is a longitudinal cross-sectional side view of the pipe body when it is processed with heat transfer liquid in it, and Fig. 3 is a longitudinal cross-sectional view when it is sealed. FIG. 1...Pipe body, 6...Outer cylinder, 7.
...hole (opening), 9... heat transfer liquid.

Claims (1)

[Claims] 1. A pipe body is formed with an outer cylinder whose outer peripheral surface is unprocessed, a heat transfer liquid is poured into the pipe body through an opening, and the outer peripheral surface of the outer cylinder is machined while the opening is left open. Finishing: After finishing this finishing step, the heating medium liquid is heated to fill the pipe body with vapor from the heating medium liquid, and the opening is sealed.