JPH02126827A - Tube for pipe line - Google Patents

Abstract

PURPOSE:To enhance secure airtightness and durability while keeping a good slidability on the inner surface by making the percentage of the area occupied by blow holes to the surface area on the inside of a pipe-line tube formed from polytetrafluoroethylene of expandable foaming property different from that on the outside thereof. CONSTITUTION:By making an airtight layer 2 of the part in the radial direction along the entire inner circumferential surface of a single-layer tube consisting of PTFE having an expandable foaming property, airtightness can be added. In other words, by reducing the percentage of the area occupied by blow holes to the surface area on the inside layer of a tube 1 consisting of PTFE having an expandable foaming property as compared with that on the outside, airtightness as well as slidability thereof can be ensured. And, since the inner surface part of pipe-line tube 1 is not only made of PTFE, but also is formed in a dense layer, not only a good slidability can be maintained on the inner surface thereof, but also the characteristic such as chemical resistance specific to PTFE is not impaired. Further, since a part of the thickness of the pipe-line tube 1 on the inner side is formed by fusion as an airtight layer 2, the flexibility of the pipe-line tube 1 can be sufficiently maintained without increasing the thickness thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a conduit tube used for a forceps channel of an endoscope.

[Prior Art] For example, a tube used for a channel for inserting a treatment instrument in an endoscope is frequently bent, so it has sufficient flexibility and has excellent inner surface slipperiness. Durability is also required to maintain airtightness and the shape of the lumen. For this reason, polytetrafluoroethylene (hereinafter referred to as PTFE) has conventionally been widely used as a material that satisfies these requirements.

However, this PTFE generally has high hardness, and when used for a conduit with a relatively large diameter, such as a tube for a treatment instrument insertion channel, it becomes difficult to curve the curved part on the distal end of the endoscope insertion part. , resulting in large resistance and reducing bending operability. Furthermore, if the tube is made thin in order to avoid this, there is the disadvantage that it becomes more likely to kink.

Therefore, Japanese Patent Publication No. 59-49464 and Japanese Patent Application Laid-open No. 62-
As in Japanese Patent No. 200301, a tube has been proposed that uses stretched and foamed PTFE and further includes a means for maintaining airtightness on the outer periphery.

Figure 15 shows its structure.
A three-layer tube having an inner layer 71 made of E, an airtight layer 72 made of fluororubber etc. adhered to the outer periphery of the inner layer 71, and an outer layer 73 formed by winding a tape made of PTFE around the outer periphery. It is.

Then, as shown in FIG. 16, the inner layer 71 is stretched in the axial direction as shown by the arrow E1E'' to form continuous or discontinuous pores 74, and rigid portions 75 of PTFE with high hardness are connected by fibrin 76. Because of this structure, a flexible tube can be formed.

[Problems to be Solved by the Invention] By the way, in order to add airtightness to the above-mentioned product, when the inner layer 71 is coated with or impregnated with fluororubber, etc., the rigid part 75 of PTFH on the outer periphery of the inner layer 71 is damaged. The larger the percentage shown, the more anchors (i.e.
This is advantageous in terms of ensuring airtightness and improving durability.

However, if the rigid part 75 of PTFE is increased in this way, the inner layer 71 will become extremely soft, making it impossible to secure the lumen during bending, and the inner circumferential surface of the inner layer 71 may have the same effect as the outer circumferential portion. Since pores 74 are formed in the inner surface, body fluids and disinfectant solution tend to get stuck thereto, and the slipperiness of the inner surface sometimes deteriorates.

In addition, as a means to prevent this, it is possible to coat the inner periphery of the inner layer 71 by crosslinking various kinds of elastomers, as shown in Japanese Patent Application Laid-Open No. 59-25725, but this method A significant decrease in slipperiness is unavoidable.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a conduit tube that can ensure good airtightness and improve durability while ensuring good slipperiness on the inner surface. It's about doing.

[Means and effects for solving the problem] In order to solve the above problem, the first invention provides a conduit tube made of expanded polytetrafluoroethylene. The ratio of pores to the surface area is different.

Further, the second invention is a multilayer pipe tube having an innermost layer made of expanded polytetrafluoroethylene, wherein the innermost layer has a ratio of pores to the surface area of the inner and outer layers. It is a different version.

Therefore, at least the inner surface of the tube can ensure good sliding properties and improve durability. Furthermore, ensure appropriate flexibility. Further, when the expanded PTFE layer and the airtight member are tightly bonded, sufficient bonding strength can be obtained and durability can be improved.

[Embodiment] FIG. 1 shows a first embodiment of the present invention. The conduit tube 1 of this embodiment is formed of a single-layer flexible tube made of expanded foaming PTFE. and,
The radially inner layer along the entire inner circumference is made of the PTF.
By heating H above the melting point to melt it, the bubbles in the porous microstructure are defoamed, thereby forming the airtight layer 2.

In other words, stretchable PTFE has a porous microstructure in which a large number of fine nodules are bonded to each other by fine fibers, and open cells (pores) are formed between them. When this is heated and melted, the open cells form. is crushed to form an airtight layer. To form this airtight layer 2, for example, a core metal having an outer diameter approximately equal to the inner diameter of the conduit tube 1 is heated to a temperature higher than the melting point of the PTFH and brought into contact with the inner surface of the conduit tube 1 for a predetermined period of time. This can be done by

Figure 1A is an enlarged cross-sectional view showing a model of the structure.
It is configured such that the FE rigid portions 5 are connected with fibrin 6, and furthermore, the outer side 7a has a smaller proportion of pores than the molten inner side 7b.

According to the conduit tube 1 of this embodiment, although it is formed of a single-layer tube made of stretchable PTFE, the radial portion along the entire inner circumference is covered with an airtight layer. 2, it was possible to add airtightness. That is, since the ratio of pores to the surface area of the inner layer of the tube 1 made of expanded PTFE can be made smaller than that of the outer layer, it is possible to ensure not only airtightness but also slipperiness.

In other words, the inner surface of the conduit tube 1 is still P T F E' and a dense layer is formed, so the inner surface can maintain good slipperiness and
The properties of the PTFE, such as chemical resistance, are not impaired.

In addition, since a part of the conduit tube 1 in the right direction (in this embodiment, the inner surface layer) is formed as the airtight layer 2 by melting, the wall thickness of the conduit tube 1 is not increased and the Flexibility can be maintained sufficiently.

FIG. 2 shows a second embodiment of the invention. The conduit tube 1 of this embodiment is formed of a single-layer flexible tube made of expanded foaming PTFE as in the first embodiment, but the airtight layer 2 is The difference is in the points formed on the parts.

As a method of forming this airtight layer 2, the conduit tube 1
A heating die with an inner diameter that is approximately the same as the outer diameter of the PTFE
This can be done by heating the material to a temperature higher than its melting point and contacting it with the outer surface of the conduit tube 1 for a predetermined period of time.

This embodiment can also provide the same effects as the first embodiment, such as securing slipperiness and chemical resistance. Furthermore, when the second embodiment is used in an endoscope or the like and a treatment instrument is passed through, even if the inner surface of the instrument is scraped, the airtight layer 2 is not affected. Therefore, there is no need to worry about water leakage.

FIG. 3 shows a third embodiment of the invention. The conduit tube 1 of this embodiment is a single-layer inner layer tube 1a made of expanded foaming PTFE similar to that of the first embodiment.
An intermediate layer 3 made of fluororubber is formed on the outer periphery of the inner tube 1a, and an outer skin 4 made of the same material as the inner layer tube 1a is provided around the outer periphery of the intermediate layer 3. Wrap and form. Airtight layers 2a and 2b similar to those described above are formed on the entire inner circumference of the inner tube 1a and the entire outer circumference of the outer skin 4, respectively. Therefore, this embodiment is a combination of the first and second embodiments described above via the intermediate layer 3, and the effects of the respective embodiments described above are synergistic. Furthermore, since the inner tube 1a and the outer skin 4 are provided, it can withstand severe use such as repeated bending, maintains its airtightness, and improves reliability.

Note that in this third embodiment, the intermediate layer 3 may be formed of other elastomers. In addition, the airtight layer 2b of the outer skin 4
It doesn't have to be. Further, the outer skin 4 may be formed of another elastomer, or may be reinforced by replacing or adding metal flex or braid.

Furthermore, it may have four or more layers.

FIG. 4 shows a conduit tube 1 according to a fourth embodiment of the present invention. The conduit tube 1 of this embodiment has an airtight intermediate layer 3 made of fluororubber formed around the outer periphery of a single-layer inner tube 1a made of expanded foaming PTFE, as in the third embodiment. The outer periphery of the intermediate layer 3 is made of PTFE.
It is formed by sequentially laminating the outer skin 4 consisting of
is formed by wrapping a tape-like material, for example. Inner layer tube 1a by the anchor of the intermediate layer 3
The outer skin 4 is in close contact with the intermediate layer 3.

In this embodiment, an airtight layer called the intermediate layer 3 is added to further improve airtightness.

In addition, as a method for forming the airtight layer in each of the above embodiments, in addition to heating the core metal and using a thermal die, the PTFE
Once a portion of the tube is melted, a laser probe is inserted into the tube and irradiated.

A fluid at a temperature above its melting point is passed through the tube. Furthermore, it is conceivable to irradiate the outer periphery of the tube with infrared rays to heat it. Further, the airtight layer may be formed during the formation of the tube instead of being formed after the tube made of expanded expandable PTFE is formed. For example, during the drawing operation through the core metal, the core metal may be heated to a temperature higher than the melting temperature and simultaneously formed.

5 to 10 show a fifth embodiment of the present invention. FIG. 5 shows an endoscope 11 in which the conduit tube of the present invention is applied to a treatment instrument insertion tube 34, which will be described later. The main body of this endoscope 11 includes an operating section 12 and an insertion section 13.
The insertion section 13 is formed by sequentially connecting a curved tube section 15 and a distal end forming section 16 to the distal end of a flexible tube 14. Further, a light guide cable 17 is connected to the operating section 12, and a connector (not shown) for connecting to a light source device (not shown) is attached to the extending end of the light guide cable 17. Further, the operation section 12 is provided with an eyepiece section 18, an air/water supply switching button 19, a suction switching button 20, a forceps plug 21, and the like.

Further, FIG. 6 shows the structure near the tip of the insertion portion 13. That is, a plurality of through holes are appropriately formed in the main body member 22 of the distal end component 16 along its axial direction, and these are used to open the objective optical system 23, the air/water supply nozzle 24, and the distal opening of the forceps insertion channel. 25. An illumination optical system, etc. (not shown) is provided. The objective optical system 23 is mounted in a tube 26, and a tip cap 27 of an image guide fiber 28 is connected and fixed to the tube 26.

Then, the objective optical system 23 and the image guide fiber 28
are optically coupled. Note that this image guide fiber 28 is guided to the eyepiece section 18 through the insertion section 13 and the operation section 12. Further, the outer periphery of the image guide fiber 28 is covered over almost its entire length with an exterior tube 29 made of silicone rubber, for example.

In addition, the tip component 16 to which the air and water supply nozzle 14 is attached
An air and water supply tube 31 is connected to the rear end of the through hole through a tube 30. This air and water supply tube 31
is led through the insertion section 13, the operating section 12, and the light guide cable 17 to a connector (not shown), through which it is connected to an air pump (not shown).

A curved tube portion 15 is provided on the outer periphery of the main body member 22 of the tip structure portion 16.
One end of the bending rubber 32 is fitted and this portion is fixed with a thread. A curved object 33 is provided inside the curved rubber 32 in the curved pipe portion 15 .

On the other hand, the treatment instrument insertion tube 34 is fitted into the through hole forming the distal end side opening 25, and its distal end is fitted into the tube 35 and fastened with a thread 36 to be fixed. This tube 34 branches into two within the operating section 12,
One of them communicates with the forceps plug 21 described above to form a treatment instrument insertion passage.

The other branched one is connected to a base provided on the connector (not shown) through the light guide cable 7 via a suction switching mechanism including the suction switching button 20. Then, it is connected to a predetermined suction pump through this cap.

FIG. 7 shows an enlarged view of the tube 34.

This tube 34 is constructed by providing an airtight layer 38 made of an airtight elastic material such as fluororubber or vinylidene chloride on the outer periphery of an inner layer 37 made of stretched and foamed PTFE. An outer layer 39 is coated to improve the performance. This outer layer 39 is constructed by wrapping a tape made of stretched and foamed PTFE.

The inner layer 37 is made of stretched and foamed PT as described above.
It consists of FE, and a model of its structure is shown in FIG. That is, it is configured such that the PTFE rigid portion 41 is connected with fibrin 42. Furthermore, fibrin 42 occupies a larger proportion of the total surface area on the outer side 40a of the inner layer 37 than on the inner side 40b. In other words, the proportion of pores on the inner side 40b is smaller than on the outer side 40a.

For example, the method shown in FIGS. 9 and 10
What is shown in the figure can be considered. The method shown in FIG. 9 is obtained by mechanically stretching a PTFE tube 43 shaped like a drum as shown by the solid line in the axial direction shown by arrows F and F'.

Further, in the method shown in FIG. 10, the PTFE tube 43 is transferred in the axial direction indicated by arrows a, b, a', and b' while being sandwiched between the inner and outer stretching rollers 44a and 44b, and then the outer stretching roller 44a This is obtained by mechanically stretching the inner stretching roller 44b at a rotational speed higher than that of the inner stretching roller 44b. Since the outer side is stretched at a larger rate than the inner side, the tube 34 having the above structure is obtained.

Inner layer 3 in the tube 34 in this fifth embodiment
7 is made of PTFE, and the outer side 40a is the inner side 4
This structure has a larger proportion of fibrin 42 to the total surface area than 0b. Therefore, on the outer circumferential side of the inner layer 37, the large pores make it easy to bite, that is, to easily form an anchor. In addition, on the inner circumferential side of the inner layer 37, the PTFE rigid portion 41 has a large porosity and small porosity, which makes it difficult to bite.

According to the tube 34 of this fifth embodiment, the airtight layer 38 is tightly adhered to the inner layer 37 by the anchor due to the large pores on the outer circumferential side of the inner layer 37, and does not peel off even when subjected to repeated bending action. . This improves the ability to ensure airtightness in that area.

In addition, the basic structure of the inner layer 37 in which the PTFE rigid part 41 is connected by the single link 42 does not change, and the overall proportion of the PTFE rigid part 41 and the single link 42 does not change significantly. On the other hand, the proportion of fibrin 42 is large on the outer side 40a, but on the contrary, it is decreased on the outer side 40b, so that body fluids and disinfectant solution are less likely to get stuck, and the slipperiness of the inner surface can be easily maintained.

FIGS. 11 to 14 show an embodiment of the Jim 6 of the present invention. This embodiment is an example applied to an electronic endoscope 50. This electronic endoscope 50 is substantially similar to that of the above embodiment, but as shown in FIG. is provided. Further, a cable 17a provided with a video processor connector 53 branches off from the light guide cable 17. The video processor connector 53 is connected to a video processor 55 attached to the light source device 54. Further, a color monitor 46 is connected to the video processor 55.

On the other hand, as shown in FIG. 12, a solid-state image sensor 57 is installed in the tip component 16 at the imaging point of the objective optical system 23. This solid-state image sensor 57 is connected to a transmission cable 58.
is connected. Since the observation field is thus electrically imaged, the image guide fiber 28 as described above is not used.

In addition, in the case of this sixth embodiment, the treatment instrument insertion tube 5
The configuration of No. 9 is as shown in FIG. That is, the airtight layer 38 and the outer layer 39 are the same as those of the fifth embodiment, but the inner layer 37 is different as follows. That is, the inner layer 37 is divided into an inner low foam layer 60 and an outer high foam layer 61. In the low foam layer 60 and the high foam layer 61, the ratio of 1 fiber 42 in the PTFE rigid part 41 is different, and naturally, compared to the low foam layer 60, the high foam layer 61 has less fibrin in the PTFE rigid part 41. 42 has a large proportion. However, when looking at the treatment instrument insertion tube 59 as a whole,
The ratio of fibrin 42 to the total surface area of the outer side 40a is larger than that of the inner side 40b.

In other words, the relationship is similar to that of the above embodiment. Therefore, the same effects as described above can be obtained.

In addition to forming the inner layer 37, 60 of the tube 59 by the method shown in FIG. 8 or FIG. There may be. Further, even in the case of the fifth and sixth embodiments, the inner surface portion of the tube 59 may be melted after the same stretching process to reduce the proportion of porosity.

Further, in the sixth embodiment, the low foaming layer 6° and the high foaming layer 61 were simply laminated, but they may be chemically treated to bond or adhere to each other. Furthermore, the low foam layer 6o and the high foam layer 61 may be slidable, and only the inner low foam layer 6o may be replaced (disposable).

Further, the conduit tube of the present invention is also applicable to tubes for medical equipment other than those described above, catheters, and the like.

[Effect of the invention] As explained above, in the conduit tube of the present invention,
The above-mentioned stretchable polytetrafluoroethylene (PTFE)
), but the inner and outer surfaces account for different proportions of the surface area, so at least the inner surface of the tube can ensure good slipperiness, as well as ensure the tube has appropriate flexibility and durability. You can improve your sexuality.

Furthermore, when the airtight member is tightly bonded to the expanded PTFE tube, sufficient bonding strength can be obtained, and the durability of the tube can be improved.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conduit tube showing a first embodiment of the present invention, FIG. 1A is an enlarged sectional view of a thick walled portion of the conduit tube of the first embodiment, and FIG. 3 is a side sectional view of a conduit tube showing a second embodiment of the present invention, FIG. 3 is a side sectional view of a conduit tube showing a third embodiment of the present invention, and FIG.
The figure is a side sectional view of a conduit tube showing a fourth embodiment of the present invention, and Figs. 5 to 10 show a fifth embodiment of the present invention, and Fig. 5 shows the entire endoscope. 6 is a side sectional view of the vicinity of the tip of the endoscope, FIG. 7 is a side sectional view of the tube for inserting the treatment instrument, FIG. 8 is an enlarged sectional view of the thick part of the tube, and FIG. 10 and 10 are explanatory diagrams of the manufacturing method of the tube, FIGS. 11 to 14 show a sixth embodiment of the present invention, FIG. 11 is a perspective view of the entire endoscope, and FIG. 12 is a perspective view of the entire endoscope. Fig. 13 is a side sectional view of the tube for inserting the treatment instrument, Fig. 14 is an enlarged sectional view of the thick part of the tube, and Fig. 15 is the conventional conduit. The side sectional view of the tube, FIG. 16, is an enlarged sectional view of the thick portion of the tube. 1... Conduit tube, 1a... Inner layer tube, 2
゜2a, 2b...airtight layer, 3...middle layer, 4...
Outer skin, 34... Tube, 37... Inner layer, 38...
・Airtight layer, 39...Outer layer, 59...Treatment instrument insertion tube, 60...Low foam layer, 61...High foam layer, h.
...Stomata. Applicant's representative Patent attorney Atsushi Tsuboi Figure 1A Figure 1A Diagram 1゜Indication of case relationship

Claims (2)

[Claims] (1) A tube for conduits made of expanded polytetrafluoroethylene, characterized in that the ratio of pores to the surface area of the tube is different between the inside and outside of the tube. (2) In a multilayer pipe tube having an innermost layer made of expanded polytetrafluoroethylene, the innermost layer has different ratios of pores to its surface area between the inner and outer layers. A conduit tube characterized by: