JP2017057933A - Flexible tube and method for connecting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube capable of facilitating connection operation in connecting a tube end to a nipple of a pipe joint while reducing a pipe wall of the tube.SOLUTION: A flexible tube 1 is formed of rubber or thermoplastic elastomer. The flexible tube 1 has an inner pipe 11, an outer pipe 12, and a rib 13, and the inner pipe 11, the outer pipe 12, and the rib 13 are integrally molded by the same rubber or the thermoplastic elastomer. The inner pipe 11 is formed to have a substantially uniform thickness. The inner pipe 11 and the outer pipe 12 are concentrically arranged, and the inner pipe 11 and the outer pipe 12 are connected by the ribs 13 extending along a radial direction of the tube.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tube excellent in flexibility. In particular, the present invention relates to a flexible tube formed of rubber or thermoplastic elastomer.

Flexible tubes formed by extruding rubber and thermoplastic elastomers are used for applications such as sending liquids and gases, and transmitting pressure. Such a flexible tube is rich in flexibility, and the path can be set relatively freely, and by utilizing the flexibility of the tube wall, the nipple of the pipe joint can be pushed into the tube end and connected. High convenience.

A variety of such flexible tubes are known and are in practical use.
For example, Patent Document 1 discloses an elastomer tube formed so that a metal wire is embedded in a tube wall of the tube. According to the elastomer tube, the tube can be observed by visually observing the discoloration of the metal wire. It is disclosed that the degradation of can be detected.

JP 2013-57358 A

Although such a flexible tube can be used for various applications, in recent years, there have been applications and cases where thinning of the tube is required. For example, when a flexible tube is used for piping to a temperature measuring device for monitoring the liquid temperature, if the tube thickness is large, the heat capacity of the tube wall of the tube increases, and the accuracy of temperature measurement Responsiveness may be insufficient. Alternatively, when forming a flexible tube with an elastomer that is relatively inflexible, such as a fluorine-based elastomer, if the tube is thick, the tube wall will be difficult to stretch, making it difficult to attach the pipe joint to the nipple. There is a risk.

However, when the tube wall of the flexible tube is thinned, the tube wall tends to collapse. Further, when the tube wall of the flexible tube is thinned, the stiffness of the tube becomes weak, and there is a problem that the connection operation for pushing the tube becomes difficult when connecting to the nipple of the pipe joint.

An object of the present invention is to provide a flexible tube that is easy to connect when connecting a tube end to a nipple of a pipe joint while thinning the tube wall of the tube.

As a result of intensive studies, the inventor has made the flexible tube a double tube structure of an inner tube and an outer tube, and connects the inner tube and the outer tube with a plurality of ribs extending in the tube radial direction. The inventors have found that the above-mentioned problems can be solved by integrally molding a flexible tube, and have completed the present invention.

The present invention is a flexible tube formed of rubber or a thermoplastic elastomer, and the flexible tube has an inner tube, an outer tube, and a rib. It is integrally molded from the same rubber or thermoplastic elastomer, and the inner tube has a substantially uniform wall thickness. The inner tube and the outer tube are arranged concentrically. Between the inner tube and the outer tube, A flexible tube connected by a plurality of ribs extending along the radial direction of the tube (first invention).

In the first invention, the plurality of ribs are arranged radially so as to surround the entire circumference of the inner tube, and the thickness of the rib is equal to or less than the thickness of the inner tube at the portion where the rib and the inner tube are connected. The space surrounded by the outer peripheral surface of the inner tube, the ribs, and the inner peripheral surface of the outer tube extends along the hose axis direction in a rectangular cross section. It is preferable (second invention). In the first and second inventions, it is preferable that the foam layer is bonded and integrated to the outside of the outer tube (third invention).

Further, the present invention is a method of connecting the flexible tube of the first invention to a nipple of a pipe joint, wherein the inner tube, the rib and the outer tube are integrated at the tube end portion to be connected to the nipple. In this state, the flexible tube is connected to the nipple by pushing the inner tube at the tube end while expanding the diameter so that the nipple enters the inside of the inner tube (fourth invention).

According to the flexible tube of the present invention (first invention) and the flexible tube connection method of the present invention (fourth invention), while the tube wall of the flexible tube is made thin, The stiffness becomes high, and the connection operation for connecting the flexible tube to the nipple of the pipe joint becomes easy.

Furthermore, when it is made like 2nd invention, the heat capacity of a tube inner peripheral part can be made smaller, and the temperature change of the gas in a tube and a liquid can be suppressed more. Furthermore, when it is made like 3rd invention, the firmness of a flexible tube is raised more and connection operation becomes easier.

It is a figure which shows the shape of the flexible tube of 1st Embodiment. It is sectional drawing which shows the connection operation which connects the flexible tube of 1st Embodiment to the nipple of a pipe joint. It is a figure which shows the shape of the flexible tube of 2nd Embodiment. It is a figure which shows the shape of the flexible tube of 3rd Embodiment. It is a figure which shows the shape of the flexible tube of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to a flexible tube made of silicone rubber used for transporting a liquid in a physics and chemistry instrument or the like with reference to the drawings. The invention is not limited to the individual embodiments shown below, and can be carried out by changing the form. FIG. 1 shows a flexible tube 1 according to the first embodiment. FIG. 1 shows the end of the flexible tube 1. 3, 4, and 5 similarly show the tube ends. The flexible tube 1 is piped between a glass tube and a measuring instrument, and various liquids and gases are transported by the flexible tube 1.

The flexible tube 1 is formed of rubber or a thermoplastic elastomer, and is a flexible tube having elasticity on the tube wall. As a material constituting the flexible tube 1. For example, rubber materials such as silicone rubber and urethane rubber, and thermoplastic elastomers such as olefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, and styrene-based thermoplastic elastomer can be used. The flexible tube 1 can be manufactured by extruding these rubbers and thermoplastic elastomers, for example. In this embodiment, the flexible tube 1 is obtained by extruding silicone rubber.

The flexible tube 1 has an inner tube 11, an outer tube 12, and a plurality of ribs 13 and 13. Moreover, in the flexible tube 1, the inner tube | pipe 11, the outer tube | pipe 12, and the rib 13 are integrally molded by the same rubber | gum or the same thermoplastic elastomer. Preferably, the inner tube 11, the outer tube 12, and the rib 13 are integrally formed of non-foamed rubber or non-foamed thermoplastic elastomer.

The inner tube 11 and the outer tube 12 are each a flexible tube formed in a cylindrical shape. The thickness of the inner tube 11 is substantially uniform. That is, the inner tube 11 has a substantially uniform thickness both in the circumferential direction and in the axial direction. The flexible tube 1 is mainly used so that gas or liquid passes through the inside of the inner tube 11. In the present embodiment, the outer tube 12 is also formed with a substantially uniform thickness. In this embodiment, an inner tube having a thickness of 0.5 mm and an inner diameter of 8 mm and an outer tube having a thickness of 0.5 mm and an outer diameter of 12 mm are provided.

The inner tube 11 and the outer tube 12 are arranged concentrically so as to be spaced apart from each other so that the inner tube 11 is provided inside the outer tube 12. That is, the inner tube 11 and the outer tube 12 are formed in a double tubular shape. It is more preferable that the centers of the inner tube 11 and the outer tube 12 coincide with each other, but they may be eccentric from each other.

A space exists between the inner tube 11 and the outer tube 12, and the inner tube 11 and the outer tube 12 are connected by a plurality of ribs 13 and 13. The ribs 13, 13 are provided so as to protrude outward in the radial direction from the outer peripheral surface of the inner tube 11, that is, so as to extend along the radial direction of the tube. And the outer peripheral side edge part of the ribs 13 and 13 is connected with the outer tube | pipe 12. As shown in FIG. The ribs 13 are provided along the axial direction of the tube. As a result, the space S surrounded by the outer peripheral surface of the inner tube 11, the ribs 13 and 13, and the inner peripheral surface of the outer tube 12 extends along the hose axis direction in a predetermined cross section.

In the present embodiment, the ribs 13 and 13 are arranged with eight ribs radially so as to surround the entire circumference of the inner tube 11. In the present embodiment, the thickness of the rib 13 is substantially uniform over the radial direction. The ribs are preferably arranged equally so that the circumferential intervals are uniform. Moreover, it is preferable that the thickness of the rib 13 is equal to or less than the thickness of the inner tube 11 (2.5 times or less) at the portion where the rib 13 and the inner tube 11 are connected. In particular, it is preferably formed so as to be 1/3 to 2 times. Further, the space S surrounded by the outer peripheral surface of the inner tube 11, the ribs 13 and 13, and the inner peripheral surface of the outer tube 12 is rectangular with a cross section orthogonal to the axis of the tube as in this embodiment. It is preferable. In the present embodiment, the ribs 13 are provided with a thickness of 0.8 mm.

The flexible tube 1 can be formed using resin extrusion. Unextruded silicone rubber is extruded by an extruder using an extrusion die in which extrusion channels corresponding to the inner tube 11, outer tube 12, and ribs 13 and 13 of the flexible tube 1 are formed. A vulcanized tube is formed. Then, the silicone rubber is crosslinked to obtain the crosslinked flexible tube 1. Moreover, when a flexible tube is formed with a thermoplastic elastomer, a flexible tube is obtained by extruding a tube in a semi-molten state and cooling.

The flexible tube 1 is connected to a pipe joint of a physics and chemistry instrument, a glass tube, or the like, and can be used for transporting a liquid or gas and transmitting pressure. A connection operation for connecting the flexible tube 1 to the nipple 9 of the pipe joint will be described with reference to FIG. In FIG. 2, the nipple 9 and the tube 1 are shown in cross section. The nipple of the pipe joint may be made of metal or resin. Moreover, the nipple of a pipe joint may be directly formed in the edge part of a glass tube. The nipple 9 is formed in, for example, a tapered tapered tube. The connection between the flexible tube 1 and the nipple 9 is made by aligning the flexible tube 1 and the nipple 9 coaxially so that the nipple 9 enters the inside of the inner tube 11. It is done to push outward. Then, the inner tube 11 advances toward the inner side of the nipple while expanding and deforming so as to correspond to the tapered shape of the nipple 9, and the inner peripheral surface of the inner tube 11 and the outer peripheral surface (tapered surface) of the nipple 9 Are brought into close contact with each other to connect the flexible tube 1 and the nipple 9 of the pipe joint.

In this connection operation, the flexible tube 1 is used for connection in a state where the inner tube 11, the rib 13, and the outer tube 12 remain integrated at the tube end portion to be connected to the nipple 9. That is, the flexible tube 1 cut to a predetermined length is subjected to a connection operation as it is without detaching or peeling the outer tube 12 or the rib 13 from the inner tube 11, and the tube end of the inner tube 11 is removed. The part is connected to the nipple 9 while expanding the diameter. By connecting the inner pipe 11 while expanding the diameter, an appropriate connection strength can be obtained, and the airtightness and liquid tightness of the connection portion can be ensured.

The operation and effect of the flexible tube 1 will be described. The flexible tube 1 is easy to connect to the nipple of the pipe joint even if the pipe wall of the inner pipe 11 is thinned.

In the conventional flexible tube, when the tube wall is thinned, the stiffness of the tube becomes weak and the tube becomes soft. Then, even if it tries to push into a nipple while expanding the diameter of a tube wall, the tube wall of a tube will break down and it will become difficult to push into a nipple.

On the other hand, in the flexible tube 1, the double tube structure is maintained by the outer tube 12 and the rib 13 while the inner tube 11 is thinned, and the rib 13 extends in the tube axial direction and the inner tube 11. The outer tube 12 is connected. Further, the thickness of the inner tube 11 is formed substantially uniformly. With this structure, the inner tube 11 tends to extend in the circumferential direction, and as a result, the insertion resistance into the tapered nipple is reduced. Further, since the outer tube 12, the rib 13, and the inner tube 11 are connected and integrated, the inner tube 11 is not easily folded in the hose axial direction, and the stiffness of the inner tube 11 is increased. As a result, even if the thickness of the inner tube 11 is reduced, the connection operation of the flexible tube 1 to the pipe joint nipple 9 can be easily performed.

It is preferable that three or more ribs 13, preferably four or more, and particularly preferably six or more ribs 13 are provided so that the above-described effects are more effectively exhibited. Moreover, it is preferable that the ribs are arranged at equal intervals in the circumferential direction over the entire circumference of the inner tube so that the stiffness of the hose does not become weak at a specific portion in the circumferential direction. Further, as in the first embodiment, the rib 13 is preferably provided in parallel with the tube center axis so as to increase the stiffness at the time of pushing the inner tube more effectively. The rib 13 may be provided so as to form a loose spiral around the tube center axis.

Further, like the flexible tube 1 of the first embodiment, the thickness of the rib 12 is equal to or less than the thickness of the inner tube 11 at the portion where the rib 13 and the inner tube 11 are connected, that is, 2.5 times or less. Furthermore, a space S surrounded by the outer peripheral surface of the inner tube 11, the ribs 13, and the inner peripheral surface of the outer tube 12 extends along the hose axis direction in a rectangular cross section. If present, the heat capacity on the inner circumference side of the tube can be made particularly small, and the temperature change of the liquid or gas transported in the tube can be made smaller.

The invention is not limited to the embodiment described above, and can be implemented with various modifications. Although other embodiments of the invention will be described below, in the following description, portions different from the above-described embodiment will be mainly described, and detailed descriptions of the same portions will be omitted. Further, the embodiments described below can be implemented by combining some of them or replacing some of them.

In FIG. 3, the flexible tube 2 of 2nd Embodiment is shown. The structure of the inner tube 21, the outer tube 22, and the rib 23 of the flexible tube 2 of the present embodiment is configured similarly to the flexible tube 1 of the first embodiment except that the number of ribs is six. ing. Even in the flexible tube 2 of this embodiment, the operability of connection to the nipple is easy. In the present embodiment, the foamed resin foam layer 24 is bonded and integrated to the outer peripheral surface of the outer tube 22. Thus, the flexible tube may have members (for example, a foam layer, a protective layer, etc.) other than the inner tube, the outer tube, and the rib. The foamed layer 24 is preferably made of, for example, a foam of silicone rubber, and is preferably crosslinked and bonded to the outer peripheral surface of the outer tube 22 made of silicone rubber. The formation of the foam layer 24 may be performed simultaneously with the formation of the inner tube 21, the outer tube 22, and the rib 23 by using coextrusion, or the preformed inner tube 21, outer tube 22, and rib 23. The foamed layer 24 may be extruded and integrated later on the outer periphery.

If the foam layer 24 is bonded and integrated to the outer peripheral surface of the outer tube 22 of the flexible tube as in this embodiment, the stiffness of the integrated foam layer 24 and the outer tube 22 becomes stronger, thereby Since the stiffness of the rib 23 and the inner tube 22 is also strong, the connection operation when connecting the flexible tube 2 to the nipple of the pipe joint is particularly easy.

In FIG. 4, the flexible tube 3 of 3rd Embodiment is shown. The connection structure of the inner tube 31, the outer tube 32, and the rib 33 of the flexible tube 3 of the present embodiment is configured in the same manner as the flexible tube 1 of the first embodiment. Therefore, even the flexible tube 3 of this embodiment is easy to connect to the nipple. In the flexible tube 3 of the present embodiment, the thickness of the rib 33 changes in the radial direction. Specifically, the thickness of the rib 33 is set to be equal to or less than the thickness of the inner tube 31 at a portion connected to the inner tube 31, and the thickness of the rib 33 is increased toward the outer peripheral side of the tube. It has become. That is, the rib 33 is provided so as to have a wedge-shaped cross-sectional shape so as to be thin inside the tube and thick outside the tube.

Thus, by giving the thickness change of the rib 33, the heat capacity on the inner peripheral surface side of the tube can be further reduced while effectively enhancing the stiffness of the tube.

In FIG. 5, the flexible tube 4 of 4th Embodiment is shown. The structure of the inner tube 41, the outer tube 42, and the rib 43 of the flexible tube 4 of the present embodiment is configured in the same manner as the flexible tube 1 of the first embodiment except that there are three ribs. ing. In the present embodiment, since the number of ribs is three, the space surrounded by the inner tube 41, the outer tube 42, and the rib 43 has a fan shape. Even in the flexible tube 4 of the present embodiment, the stiffness of the inner tube 41 is increased, and the operability of connection to the nipple is easy. From the viewpoint of reducing the heat capacity of the inner circumference of the hose while increasing the stiffness when performing the connecting operation of the inner pipe, as in the flexible tubes 1, 2, 3 of the first to third embodiments. More preferably, the space surrounded by the inner tube, the outer tube, and the rib has a rectangular cross section. In addition, the cross-sectional shape of the space surrounded by the inner tube, the outer tube, and the rib may be a fan shape as in this embodiment, and may be triangular, elliptical, or circular depending on how the rib is provided. There may be.

In the description of the above embodiment, the example in which the flexible tube is used for piping of physics and chemistry equipment has been described. However, the flexible tube can be applied to applications other than those exemplified in the above embodiment. For example, the flexible tube of the said embodiment can be utilized as a flexible tube used in order to supply cooling water or warm water to a water pillow, a heat retention pad, etc.

In the description of the above embodiment, the use of the space S surrounded by the inner tube, the outer tube, and the ribs is not particularly mentioned, but a conductive wire or an identification line is inserted into the space S for use. It can also be used.

The flexible tube of the present invention can be used for various types of piping, and the connection work to the nipple of the pipe joint can be easily performed, so that the industrial utility value is high.

1, 2, 3, 4 Flexible tube 11, 21, 31, 41 Inner tube 12, 22, 32, 42 Outer tube 13, 23, 33, 43 Rib 24 Foam layer 9 Nipple

Claims (4)

A flexible tube formed of rubber or thermoplastic elastomer,
The flexible tube has an inner tube, an outer tube, and a rib,
The inner tube, outer tube and rib are integrally molded from the same rubber or thermoplastic elastomer.
The wall thickness of the inner pipe is formed almost uniformly,
A flexible tube in which an inner tube and an outer tube are arranged concentrically, and the inner tube and the outer tube are connected by a plurality of ribs extending along the radial direction of the tube. The plurality of ribs are arranged radially so as to surround the entire circumference of the inner tube,
In the part where the rib and the inner pipe are connected, the rib thickness is equal to or less than the inner pipe thickness,
The flexible tube according to claim 1, wherein a space surrounded by the outer peripheral surface of the inner tube, the rib, and the inner peripheral surface of the outer tube extends along the hose axis direction in a rectangular cross section. The flexible tube according to claim 1 or 2, wherein a foam layer is bonded and integrated on the outside of the outer tube. A method of connecting the flexible tube of claim 1 to a nipple of a fitting,
While expanding the diameter of the inner tube at the tube end so that the nipple is inside the inner tube while the inner tube, rib and outer tube remain integrated at the tube end to be connected to the nipple A tube connection method that pushes in and connects the flexible tube to the nipple.

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