Different diameter tube

Abstract

To provide a different diameter tube allowing for easy shape confirmation.SOLUTION: According to an embodiment, a different diameter tube 1 is provided. The different diameter tube 1 includes a small diameter part 2, a transition part 3, and a large diameter part 4. A length 3a of the transition part 3 along an axial direction is smaller than an outer diameter 4a of the large diameter part 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a reduced diameter tube. [Background technology]

[0002] Patent Document 1 describes a tubular member that is composed of a thin diameter portion, a tapered portion, and a thick diameter portion. However, when the length of the tapered portion of the tubular member is longer than the outer diameter of the thick diameter portion, it is difficult to distinguish the boundaries between the thin diameter portion and the tapered portion, and between the thick diameter portion and the tapered portion. This makes it difficult to check the shape during product inspection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7233810 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a different diameter tube whose shape can be easily confirmed. [Means for solving the problem]

[0005] According to an embodiment of the present invention, a reduced diameter tube is provided, the reduced diameter tube comprising a smaller diameter section, a transition section and a larger diameter section, the length of the transition section along an axial direction being smaller than the outer diameter of the larger diameter section. Effect of the Invention

[0006] According to an embodiment of the present invention, a different diameter tube whose shape can be easily confirmed can be provided. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic cross-sectional view showing an example of a variable diameter tube according to an embodiment. [Diagram 2]5A to 5C are schematic cross-sectional views showing an example of a method for manufacturing a reduced diameter tube according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] According to an embodiment, a reduced diameter tube is provided. The reduced diameter tube includes a small diameter section, a transition section, and a large diameter section. The length of the transition section along an axial direction is smaller than the outer diameter of the large diameter section.

[0009] Since the length of the transition portion along the axial direction is smaller than the outer diameter of the large diameter portion, it is easier to check the shape of the different diameter tube, which improves the ease of visual inspection and dimensional inspection of the different diameter tube.

[0010] The different diameter tube according to the embodiment will be further described with reference to the drawings.

[0011] 1 shows an example of a reduced diameter tube according to an embodiment. The x-axis direction is parallel to the axial direction of the reduced diameter tube. The y-axis direction is perpendicular to the x-axis direction. The z-axis direction is perpendicular to both the x-axis and y-axis directions.

[0012] The variable diameter tube 1 shown in Figure 1 comprises a small diameter section 2, a large diameter section 4, and a transition section 3 between the small diameter section 2 and the large diameter section 4. The outer diameter 2a of the small diameter section is smaller than the outer diameter 4a of the large diameter section. The length 3a of the transition section 3 is smaller than the outer diameter 4a of the large diameter section.

[0013] Additionally, the inner diameter 2b of the small diameter portion can be smaller than the inner diameter 4b of the large diameter portion. Furthermore, the thickness 2c of the small diameter portion can be smaller than the thickness 4c of the large diameter portion. Each of the small diameter portion 2 and the large diameter portion 4 can be substantially straight. The substantially straight shape means that the outer diameter is substantially constant over the entire length along the x-axis direction in that region.

[0014] In general, the smaller the outer diameter of a tube, the lower the visibility of the tube shape. Therefore, in a different diameter tube with a small outer diameter 4a of the large diameter part, the distance 3a between the small diameter part 2 and the large diameter part 4 is smaller than the outer diameter 4a of the large diameter part, so that the shape tends to be more easily confirmed effectively. The outer diameter 4a of the large diameter part of the different diameter tube is preferably 4.0 mm or less, and more preferably 1.0 mm or less. A different diameter tube with such a small outer diameter can be inserted into the human body, for example. The lower limit of the outer diameter 4a of the large diameter part can be set to, for example, 0.1 mm.

[0015] The larger the ratio of the outer diameter 4a of the large diameter portion to the outer diameter 2a of the small diameter portion, the easier it tends to be to distinguish the boundaries between the portions. For example, it is preferable that the value obtained by dividing the outer diameter 2a of the small diameter portion by the outer diameter 4a of the large diameter portion is 0.9 or less.

[0016] The tensile strength of the small diameter portion 2 is preferably greater than the tensile strength of the large diameter portion 4. The breaking strength of the small diameter portion 2 is also preferably greater than the breaking strength of the large diameter portion 4. With this configuration, a reduced diameter tube having a small diameter portion with a suppressed elongation rate and a flexible large diameter portion is obtained. If the elongation rate of the small diameter portion is suppressed, this is preferable because the small diameter portion is less likely to elongate when the reduced diameter tube is inserted into and pulled out of a narrow space.

[0017] The length and inner diameter of the small diameter portion 2 and the large diameter portion 4 are not particularly limited.

[0018] The transition portion 3 is a region that exists between the small diameter portion 2 and the large diameter portion 4 in the different diameter tube 1. The transition portion 3 can be a region that contacts the small diameter portion 2 and the large diameter portion 4 and occupies between the small diameter portion 2 and the large diameter portion 4. In other words, the different diameter tube 1 can be composed of the small diameter portion 2, the transition portion 3, and the large diameter portion 4, in that order from the end along the axial direction of the different diameter tube.

[0019] The axial length of the transition portion 3 may be 0. In this case, the shape of the transition portion 3 may be a step shape that connects the difference between the outer diameter of the large diameter portion and the outer diameter of the small diameter portion.

[0020] The transition portion 3 is preferably a tapered portion. Fig. 1 illustrates a reduced diameter tube having a tapered transition portion 3. In the following description, the tapered portion will be given the same reference numeral 3 as the transition portion.

[0021] The tapered portion 3 is present between the large diameter portion 4 and the small diameter portion 2 in the axial direction of the variable diameter tube, and may be a region having a tapered shape in which the outer diameter decreases from the large diameter portion side to the small diameter portion side.

[0022] The transition portion being a tapered portion makes it possible to prevent catching, for example, when inserting and withdrawing a tube with a different diameter into a narrow space such as inside a body, etc. Therefore, the tube with a different diameter can be smoothly inserted and withdrawn, which improves usability and is preferable.

[0023] The shorter the length 3a of the transition section (tapered section) along the axial direction (x-axis direction) of the different diameter tube, the easier it tends to be to check the shape of the different diameter tube. The length 3a of the tapered section is preferably 70% or less of the outer diameter 4a of the large diameter section. The length 3a of the transition section may be 0. In this case, the shape of the transition section may be a stepped shape.

[0024] The longer the length 3a of the transition section (tapered section), the less likely it is to get caught, for example, when inserting a tube of a different diameter into a narrow space. Therefore, it is preferable that the length 3a of the tapered section is 30% or more of the outer diameter 4a of the large diameter section.

[0025] In the different diameter tube 1, the thickness of the tapered portion 3 can decrease from the large diameter portion side toward the small diameter portion side. Specifically, when the tapered portion is cut along two planes perpendicular to the axial direction (x-axis direction) of the different diameter tube 1 and parallel to the y-axis direction and z-axis directions, if the thickness of the tapered portion at the cut surface located closer to the large diameter portion 4 is 34 and the thickness of the tapered portion at the cut surface located closer to the small diameter portion 2 is 32, the thickness 32 on the small diameter portion side can be smaller than the thickness 34 on the large diameter portion side.

[0026] The material of the tube with different diameters is not particularly limited. When the tube with different diameters is manufactured by a manufacturing method exemplified later, that is, a manufacturing method in which the original tube is heated and then stretched, the material of the tube with different diameters can be a material that softens when heated. For example, the material can be a thermoplastic resin, a thermoplastic elastomer, or the like. An example of the thermoplastic resin is a fluororesin. An example of the fluororesin is polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinylether copolymer resin (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP). Among them, PTFE is preferable.

[0027] <Measurement method> (Dimensional measurement) The dimensions of the reduced diameter tube, such as the outer diameter, inner diameter, wall thickness, and length, can be measured visually using a metal ruler.

[0028] It can be confirmed that the thickness of the tapered portion is thinner from the large diameter portion side to the small diameter portion side as follows. Cut the portion at the boundary between the small diameter portion and the tapered portion, and at the boundary between the tapered portion and the large diameter portion, and measure the thickness of each cut surface. If the small diameter portion is thinner by comparing these, it can be determined that the thickness of the tapered portion is thinner from the large diameter portion side to the small diameter portion side.

[0029] (Tensile test) The tensile strength can be measured by testing the tensile strength and elongation in a tensile test based on JIS K 7137. When performing a tensile test on a specific region of a reduced diameter tube, such as a small diameter portion, a large diameter portion, or a tapered portion, the relevant region is cut out from the reduced diameter tube in advance and used for the test.

[0030] <Manufacturing method> A method for manufacturing a tube with a different diameter according to an embodiment will be described. The method for manufacturing a tube with a different diameter is not particularly limited, but as an example, a method for manufacturing a tube with a different diameter by stretching an original tube will be described with reference to FIG. 2. FIG. 2 shows an original tube 10 having an outer diameter, an inner diameter, and a wall thickness corresponding to the large diameter portion of a desired tube with a different diameter, and having a substantially straight shape, being passed from one end of a mold 5 to the other end and then stretched in a traveling direction X. In the original tube 10 shown in FIG. 2, a region on the left side of the mold 5 (on the traveling direction X side) is stretched, and the outer diameter, inner diameter, and wall thickness are reduced.

[0031] First, the original tube and a mold are prepared.

[0032] The original tube may be, for example, a tube having an outer diameter corresponding to the large diameter portion of the desired different diameter tube. The inner diameter and wall thickness of the original tube may be, for example, dimensions corresponding to the large diameter portion of the desired different diameter tube. The original tube may have a substantially straight shape. The material of the original tube may be the same as that of the different diameter tube described above.

[0033] The internal shape of the mold 5 may have a shape corresponding to the shape of the tapered portion of the desired reduced diameter tube. For example, one end of the mold 5 may have an inner diameter corresponding to the outer diameter of the large diameter portion of the desired reduced diameter tube. The other end of the mold 5 may have an inner diameter corresponding to the outer diameter of the small diameter portion of the desired reduced diameter tube.

[0034] The tip of the original tube is passed through the mold. For example, the original tube is passed from the one end of the mold 5 to the other end. If the outer diameter of the original tube is larger than the inner diameter of the mold, the tip of the original tube is narrowed to a diameter that can pass through the mold. Specifically, the tip of the original tube may be narrowed by cutting with a blade, or the tip of the original tube may be narrowed by heating and then pulling.

[0035] Next, the original tube that has passed through the die 5 is stretched in the travelling direction X while the die 5 is heated. For example, as shown in FIG. 2, the die 5 can be covered with a heater 6 for heating. The travelling direction X can be a direction along the axial direction of the original tube 10. In this way, the portion of the original tube 10 that has passed through the die 5 is heated and softened. The softened portion is stretched while its outer diameter is restricted by the die 5, so that a small diameter portion can be formed. In this way, a reduced diameter tube 1 having a desired reduced diameter shape is obtained.

[0036] The reduced diameter tube 1 manufactured by the above manufacturing method has an elongated small diameter portion 2. Therefore, the wall thickness 2c of the small diameter portion can be smaller than the wall thickness 4c of the large diameter portion. Also, the tensile strength of the small diameter portion 2 can be greater than the tensile strength of the large diameter portion 4.

[0037] Furthermore, since the small diameter portion 2 of the reduced diameter tube 1 manufactured by the above manufacturing method is stretched, the outer diameter, inner diameter, or wall thickness can be approximately constant over the entire length along the x-axis direction of the small diameter portion 2. Furthermore, since the small diameter portion 2 is stretched, for example, molecules (not shown) of thermoplastic resin, thermoplastic elastomer, or the like that may be contained in the reduced diameter tube 1 can be oriented in the x-axis direction in the small diameter portion 2. Therefore, the strength of the reduced diameter tube 1 can be improved.

[0038] The stretching may be carried out before the film is completely softened to its melting point temperature, which may be called low temperature processing.

[0039] As described above, according to the embodiment, a different diameter tube whose shape can be easily confirmed can be provided.

[0040] The reduced diameter tube according to the embodiment can be used in various fields such as food, pharmaceutical, chemical, medical, and analytical equipment.

[0041] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0042] 1...Different diameter tube, 2...Small diameter section, 3...Transition section (tapered section), 4...Large diameter section.

Claims

1. A small diameter portion, a transition portion, and a large diameter portion, A reduced diameter tube, wherein the length of the transition section along the axial direction is smaller than the outer diameter of the large diameter section.

2. The reduced diameter tubing of claim 1 , wherein the transition section is a taper.

3. 3. The variable diameter tube according to claim 2, wherein the tapered portion has a wall thickness on the side of the small diameter portion that is thinner than a wall thickness on the side of the large diameter portion.

4. 2. The variable diameter tube according to claim 1, wherein the small diameter portion has a breaking strength greater than a breaking strength of the large diameter portion.

5. 2. The variable diameter tube according to claim 1, wherein a value obtained by dividing the outer diameter of the small diameter portion by the outer diameter of the large diameter portion is 0.9 or less.

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