JP4650708B2 - Tube focusing body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tube converging body in which tubes made of a plurality of fluororesins are converging, and in particular, when a tube converging body is formed by externally fitting a sleeve to a tube bundle in which the tubes are bundled and fusing them together, the tube and the sleeve It is related with the tube focusing body which improved the joint strength between.
[0002]
[Prior art]
Conventionally, fluororesin tube bundling bodies equipped with a fluororesin sleeve on the outer periphery of the end of a tube bundle formed by bundling a plurality of fluororesin tubes focus on its chemical resistance and heat resistance. Or it is used for the heat exchanger for high temperature, and it is used also as a deaeration pipe | tube for chemical | medical solutions or a pure water from surfaces, such as chemical resistance and non-contamination.
[0003]
Examples of the fluororesin tube converging body as described above include hot-melt fluorine such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) or FEP (tetrafluoroethylene-hexafluoropropylene copolymer). A plurality of tubes made of resin are bundled, and a sleeve made of ethylene tetrafluoride resin is fitted around the outer periphery of the bundled tube, and the tube and the sleeve are heated at this end portion. By holding the inside at atmospheric pressure and reducing the outside to give a pressure difference between the inside and outside of the tube, the wall surfaces of the adjacent tubes that are bundled together expand, and the wall surfaces of these tubes are preferably in a honeycomb shape. Deformed and fused, and the wall of the tube is also fused to the inner circumference of the sleeve. Is a tube bundle of comprising has been proposed.
[0004]
However, at the end of the tube converging body as described above, the ethylene tetrafluoride resin forming the sleeve and the tube bundle are not easily fused, and the bonding strength between the outer periphery of the end of the tube bundle and the sleeve There was a problem that became insufficient.
[0005]
Therefore, for example, a heat-melting fluororesin material of the same type as the material forming the tube is disposed between the outer periphery of the end of the tube bundle in which the tubes made of heat-melting fluororesin are bundled and the inner periphery of the sleeve It has been attempted to improve the bonding strength between the outer periphery of the end of the tube bundle and the sleeve by heating and melting the tube.
[0006]
However, even when the above-described method is used, the bonding strength between the tube and the sleeve is not sufficient, and when a large force is applied, the sleeve is detached from the end of the tube focusing body. There was a problem.
[0007]
[Problems to be solved by the invention]
Therefore, the present invention has been made in view of the above-described problems, and the problem is that a sleeve is externally fitted to the outer periphery of an end portion of a tube bundle formed by bundling a plurality of tubes made of a heat-meltable fluororesin. To provide a tube converging body that fuses and integrates a tube bundle and a sleeve, and has a sufficient bonding strength between the outer periphery of the end of the tube bundle and the sleeve. is there.
[0008]
[Means for Solving the Problems]
The above problems are solved by the present invention. That is, the tube bundling body according to the present invention forms a tube bundle by bundling a plurality of tubes made of heat-melting fluororesin, and a heat-shrinkable tube made of heat-melting fluororesin is fitted on the outer periphery of the end of the tube bundle. Then, the gap between the outer periphery of the tube bundle and the heat shrinkable tube is filled with a filler that is a heat-meltable fluororesin, and the outer periphery of the end of the tube bundle to which the heat shrinkable tube is externally fitted is made of fluororesin. At least one groove is provided on the inner periphery of the sleeve, and a sleeve formed by heat-sealing a thin layer of a heat-meltable fluororesin is externally fitted to the inner periphery, and an end portion of the tube bundle The tube bundling body is characterized in that the tube bundle and the sleeve are fused and integrated by heating a portion where the sleeve is fitted on the outer periphery.
[0009]
【Example】
Hereinafter, the present invention will be described based on one embodiment with reference to the accompanying drawings. FIG. 1 is a sectional end view of an embodiment of a tube focusing body according to the present invention.
[0010]
As shown in FIG. 1, the tube focusing body 1 includes a tube bundle 2A formed by bundling a plurality of tubes 2, and a sleeve 3 that is fitted on the outer periphery of the end of the tube bundle 2A.
The tube 2 is made of a heat-meltable fluororesin such as PFA or FEP (in this embodiment, PFA is used), and the sleeve 3 is made of a fluororesin such as tetrafluoroethylene resin. At least one or more single-stage grooves 4 are provided in the circumferential direction on the inner periphery 3a of the sleeve 3, and the inner periphery 3a of the sleeve 3 and the end of the tube bundle 2A are interposed through the grooves 4. The outer periphery of the part is fused.
[0011]
In the above embodiment, the groove 4 is provided in the circumferential direction of the inner periphery 3a of the sleeve 3. However, the present invention is not limited to this, and a single stage is provided on the inner periphery 3a of the sleeve 3. Instead of the groove 4, the spiral continuous groove 4 or the groove 4 having a predetermined length may be formed in the axial direction or at an angle with respect to the axial direction.
[0012]
Hereinafter, the production of the tube focusing body 1 will be described with reference to FIGS.
First, a heat shrinkable tube 5 made of PFA or FEP (in this embodiment, FEP is used) is fitted on the outer periphery of the end of a tube bundle 2A formed by bundling a plurality of tubes 2, and this heat shrinkable tube 5 is For example, each tube 2 is tightened from the outside by being heated and contracted at a temperature of about 150 ° C. with a heater or the like, and the tube bundle 2A is prevented from being scattered as well as being prevented from moving.
[0013]
Next, the sleeve 3 is externally fitted on the outer periphery of the end portion of the tube bundle 2A to which the heat shrinkable tube 5 is externally fitted. Preferably, before the sleeve 3 is fitted onto the tube bundle 2A, a thin layer (not shown) of a heat-melting fluororesin such as PFA or FEP is previously provided on the inner periphery including the groove 4 of the sleeve 3. It is formed by heat fusion. By doing so, when the tube bundle 2A and the sleeve 3 are heat-sealed, both of them are easily fused.
[0014]
Next, at the end of the tube bundle 2A with the sleeve 3 fitted, for example, PFA or FEP which is a heat-melting fluororesin (FEP in this embodiment) is inserted into the gap between the outer periphery of the tube bundle 2A and the heat shrinkable tube 5. Used) (see FIG. 2).
[0015]
Next, the portion where the sleeve 3 is fitted on the outer periphery of the end of the tube bundle 2A is heated by a fusion heater to melt the FEP of the filler 6 and the outer peripheral surface of the PFA tube.
Next, while maintaining the inside of the heated tube 2 at atmospheric pressure, the outside is decompressed to give a pressure difference between the inside and outside of the tube 2. As a result, the FEP heat-shrinkable tube 5 and the filler 6 disposed between the outer periphery of the end of the tube bundle 2A and the inner periphery 3a of the sleeve 3 are expanded while the wall surfaces of the adjacent tubes 2 that are bundled are expanded. It melts, fills and closes the gap, and also fills the groove 4 provided in the inner periphery 3a of the sleeve 3, and the wall surfaces of these tubes 2 are preferably deformed and fused in a honeycomb shape. The two wall surfaces are also integrally fused to the inner periphery 3a of the sleeve 3 (see FIG. 3).
[0016]
At this time, that is, at the time of heating, the tube converging body 1 formed in this way is filled with the above-described thin layer of PFA or FEP in the groove 4 provided in the inner periphery 3a of the sleeve 3 at the end portion. Since the tube bundle 2A and the sleeve 3 are fused and integrated, not only the joining force by the fusion but also the joining force by the anchor effect is generated, and the end outer periphery of the tube bundle 2A and the inner periphery 3a of the sleeve are joined. The strength can be very sufficient.
[0017]
【The invention's effect】
As described above, according to the tube focusing body of the present invention, the tube bundle is fused and integrated through the heat-meltable fluororesin filled in the groove provided on the inner periphery of the sleeve made of tetrafluoroethylene resin. Therefore, not only the bonding force by fusion but also the bonding force by the anchor effect is generated, and the tube bundle and the sleeve can have a very sufficient bonding strength.
[Brief description of the drawings]
FIG. 1 is an end cross-sectional view of one embodiment of a tube focusing body according to the present invention.
FIG. 2 is an end view of the tube focusing body shown in FIG. 1 before heating.
FIG. 3 is an end view after heating of the tube focusing body shown in FIG. 2;
[Explanation of symbols]
1: Tube bundle, 2: Tube, 2A: Tube bundle 3: Sleeve, 3a: Inner circumference, 4: Groove, 5: Heat-shrinkable tube, 6: Filler

Claims (1)

A tube bundle is formed by bundling a plurality of tubes made of heat-meltable fluororesin, and a heat-shrinkable tube made of heat-meltable fluororesin is externally fitted to the outer periphery of the end of the tube bundle. The gap between the heat-shrinkable tube and the heat-shrinkable fluororesin is filled with a filler, and the outer periphery of the end of the tube bundle on which the heat-shrinkable tube is externally fitted is provided on the inner periphery of the sleeve made of fluororesin. A sleeve formed by heat-sealing a thin layer of a heat-meltable fluororesin on the inner circumference, and heating the portion where the sleeve is fitted on the outer circumference of the end of the tube bundle By doing so, the tube bundle and the sleeve are fused and integrated.

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