JP5786073B1 - Flexible Tube - Google Patents

Abstract

A flexible tube having excellent electrical insulation and sealing properties is provided. A flexible tube 1 having a corrugated tube 12 in which large-diameter peaks 16 and small-diameter valleys 18 are alternately connected. At least one end of the corrugated tube has a rigid ring 22 fitted in the trough of the corrugated tube, and one peak 16a left outside the trough 18a in which the rigid ring is fitted in the central axis direction of the corrugated tube. Or it has a trough. The deformable ring 52 is fitted into one peak or valley remaining outside the valley where the rigid ring is fitted. [Selection] Figure 2

Description

  The present invention relates to a flexible tube having a corrugated tube (corrugated tube) in which a large-diameter peak and a small-diameter valley are alternately connected.

  As one form of the flexible tube, one or two crests located at the end of the corrugated pipe are deformed by crushing in the axial direction, and the deformed deformed part is pressed against the other pipe end via a gasket. Is disclosed in Japanese Patent Application Laid-Open No. H10-228707, which forms a seal with the counterpart pipe.

JP 2002-195478 A

  However, in the flexible tube, since the deformed portion is formed by crushing the corrugated tube, there is no axial elasticity (even if there is elasticity). In addition, it is difficult to say that the smoothness of the end face of the deformed portion in contact with the gasket is high. Therefore, it has been difficult to ensure a sufficient seal between the deformed portion and the gasket. Further, when the flexible tube is connected to the other party's pipe, the tightening bolt must be tightened uniformly and in several steps with a strong torque. Further, when tightened with a strong force, the gasket disposed between the flexible tube and the counterpart pipe may be damaged or broken.

  Therefore, the present invention has been made to solve the above-mentioned problems, and the flexible tube according to the present invention has a waveform in which a large-diameter peak (16) and a small-diameter valley (18) are alternately connected. It has a tube (12). At least one end of the corrugated tube (12) has a rigid ring (22) fitted in a trough (18a) of the corrugated tube (12) and the direction of the central axis (10) of the corrugated tube (12). It has one peak (16a) or valley left outside the valley (18a) in which the rigid ring (22) is fitted. A deformable ring (52) is fitted in one peak (16a) or valley remaining outside the valley (18a) in which the rigid ring (22) is fitted.

  According to the flexible tube thus configured, a smooth and stable sealing surface can be formed on the end surface of the flexible tube. In addition, since the elastic sealing surface is formed, the required sealing performance can be secured with a force that is a fraction of the tightening torque required for the current flexible tube.

FIG. 1 shows a flexible tube according to the present invention, FIG. 1 (a) is a side view, and FIG. 1 (b) is a partially enlarged view. FIG. 2 is a cross-sectional view showing the connection structure of the flexible tube shown in FIG. FIG. 2 is a cross-sectional view showing another connection structure of the flexible tube shown in FIG.

  Hereinafter, a flexible tube and a connection structure thereof according to the present invention will be described with reference to the accompanying drawings. In the following description, terms indicating the direction and position (for example, “one end”, “other end”, “left side”, “right side”, etc.) are used for convenience, but these are for ease of understanding of the invention. The technical scope of the present invention is not limited by the meaning of these terms. The following description is an example of one embodiment of the present invention, and does not limit the application or use of the present invention.

  As shown in FIG. 1, a flexible tube 1 according to the present invention is provided on a corrugated tube (corrugated tube) 12, a cylindrical blade 14 covering the outer periphery of the corrugated tube 12, and at least one end or both ends of the flexible tube 1. Connected structure 20. The description of the connection structure described below relates to the connection structure shown in the right side of FIG. 1A and the connection structure shown in FIG. 1B. However, the connection structure shown on the left side of FIG. Has a similar structure. Therefore, the description of the connection structure on the left side is omitted.

  In the illustrated flexible tube 1, the corrugated tube 12 is made of, for example, a thin tube made of stainless steel, and has a large-diameter peak portion 16 and a small-diameter valley portion 18 alternately and continuously in the tube axis direction (the direction of the central axis 10). Formed and flexible.

  The blade 14 is formed in a hollow cylindrical shape by braiding stainless steel (for example, SUS304) wire or strip. Instead of stainless steel, a synthetic resin material such as aramid fiber or polyester fiber may be used as the material.

  The connection structure 20 has a rigid ring 22. Although not limited, the rigid ring 22 is formed of a metal such as stainless steel or cast iron, and is located at the end of the flexible tube 1 and is the first peak portion on the outermost side (right side) with respect to the central axis direction. It fits into a first valley 18a formed between 16a and a second peak 16b on the inner side (left side). Preferably, in order to fit the rigid ring 22 into the valley portion 18, the rigid ring 22 is constituted by two halved ring portions obtained by dividing the rigid ring 22 into two along a plane including the central axis of the rigid ring, The halved ring part is fitted into the valley part 18 and combined.

  As shown in the drawing, the first peak portion 16a on the outermost side (right side) is not compressed in the direction of the central axis 10 in the illustrated state where the flexible tube 1 is not connected to another pipe. As will be described, a ring can be accommodated inside the first peak 16.

  As shown in the drawing, the rigid ring 22 has a size and a shape in which the radially outer half portion protrudes radially outward from the outer peripheral surface of the corrugated tube 12 in a state where the rigid ring 22 is fitted into the first valley portion 18. Preferably, the inner end portion of the rigid ring 22 is a curved surface having substantially the same curvature as the valley portion 18.

  In the rigid ring 22 of the illustrated embodiment, the right side surface 24 adjacent to the first peak portion 16 a is formed by a radial plane orthogonal to the central axis 10. On the other hand, in the left side surface 26 adjacent to the second peak portion 16b, the portion (inner diameter side portion) 28 located between the adjacent peak portions 16a and 16b is formed as a radial plane, but the waveform A portion (outer diameter side portion) 30 projecting radially outward from the tube 12 is formed by a mortar-shaped surface inclined leftward from the radially inner side to the outer side, and the thickness increases toward the radially outer side. It is like that.

  In order to fix the blade 14 to the rigid ring 22, first, the end of the blade 14 is covered on the rigid ring 22, and a blade pressing ring (fixing ring) 32 is fitted to the outside thereof. The blade pressing ring 32 includes a cylindrical portion 34 that extends parallel to the central axis 10 and a flange portion 36 that extends inward from the left end portion of the cylindrical portion 34. In the figure, the flange portion 36 is shown obliquely with respect to the radial direction of the central axis 10, but this is in a state after deformation, and the flange portion 36 before deformation extends on a plane perpendicular to the central axis 10. ing.

  The blade pressing ring 32 is pre-packaged on the blade 14 before the rigid ring 22 is mounted, and after the rigid ring 22 is mounted on the corrugated tube 12 and the end of the blade 14 is mounted on the outside thereof, the left side of the figure. It moves to the right side and is mounted on the rigid ring 22 and the blade portion that covers it. In this exterior state, the cylindrical portion 34 faces the outer peripheral surface of the rigid ring 22, and the flange portion 36 faces the mortar-like surface (part 30) of the rigid ring 22 (not shown, but in this state, The flange 36 is not deformed into a mortar shape and extends straight in the radial direction.) Finally, in order to integrate the rigid ring 22, the blade 14, and the blade holding ring 32, their right end portions are Welded 48.

  A flange (first flange) 38 is attached to the outside of the blade pressing ring 32. As shown in the figure, the flange 38 is an annular plate having the center axis 10 as the center, and a shape corresponding to the blade pressing ring 32 is provided in the inner diameter portion. More specifically, the flange inner diameter corner portion located on the outer side (right side) with respect to the direction of the central axis 10 has a shape corresponding to the rigid ring 22 and the blade pressing ring 32 after deformation, and is continuous in the circumferential direction. Step 40 is formed. As shown in the drawing, the stepped portion 40 has a cylindrical inner surface 42 extending in the circumferential direction and an inner side surface 44 extending radially inward from the left end portion of the cylindrical inner surface 42. As illustrated, the inner surface 44 is preferably formed in a mortar shape corresponding to the mortar-shaped surface of the rigid ring 22. Like the blade pressing ring 32, the flange 38 having the above configuration is externally mounted on the blade 14 before the rigid ring 22 is mounted. After the blade pressing ring 32 is externally fixed to the rigid ring 22, it is fixed from the left side. The blade moves to the right and is attached to the outside of the blade pressing ring 32.

  The flexible tube 1 configured as described above is connected to another pipe 50 as shown in FIG. At this time, first, the deformable ring 52 is arranged inside the first peak portion 16a of the flexible tube 1. The ring 52 is preferably attached when the flexible tube 1 is shipped. The material constituting the ring 52 is preferably an elastic material (for example, rubber, polytetrafluoroethylene (PTFE), plastic). The ring 52 may be a Teflon-coated rubber ring in which an elastic rubber is covered with polytetrafluoroethylene (PTFE). The ring 52 only needs to be deformable, and a ring formed of metal (for example, lead) can also be used.

  The pipe 50 includes a pipe (not shown) having a pipe diameter corresponding to the pipe diameter of the corrugated pipe 12, and a flange (second flange) 54 fixed to an end of the pipe. The flange 38 of the flexible tube 1 and the flange 54 of the pipe 50 are disposed to face each other via an annular gasket 56 therebetween. Bolts 58, 60 and 62 formed in the flanges 38 and 54 and the gasket 56 are respectively bolted. After the (connecting means) 64 is inserted, a nut (connecting means) 66 is screwed onto the bolt 64 and tightened.

  A so-called insulating bolt is preferably used for the bolt 64. In this case, as shown in detail in FIG. 2, for example, the insulating bolt 64 has an outer peripheral surface of the bolt body covered with an insulating material 80 such as a hard pyraflon, and between the bolt head 82 and the flange 38, Insulating washers 84 and 86 are disposed between the nut 66 and the flange 54, and an electrically insulating gasket is disposed on the gasket 56.

  By tightening the bolt 64 and the nut 66, as shown in FIG. 2, the flange 38 and the flange 54 approach each other, and the blade is interposed between the mortar surface of the flange 38 and the mortar surface of the rigid ring 22 facing the flange 38. The collar portion 36 of the presser ring 32 is sandwiched, and the collar portion 36 is deformed into a mortar shape. In addition, as shown in FIG. 2, the left side surface of the gasket 56 is pressed against the right side portion (corrugated tube end surface) 70 extending in the radial direction of the first peak portion 16a, and the first peak portion 16a is deformed in the axial direction. At the same time, the deformable ring 52 mounted inside the first peak 16a is compressed. At this time, the deformation of the portion (corrugated tube end face) 70 extending in the radial direction of the first peak 16a depends on the deformation of the rear ring 52. Therefore, the ring 52 functions as a cushioning material, and the deformation amount of the portion 70 extending in the radial direction of the first peak portion 16a and the contact force between the portion 70 extending in the outer radial direction and the gasket 56 are in each circumferential portion. As a result, a smooth surface that forms a good seal with the gasket 56 is obtained in the radially extending portion 70.

  Therefore, a good seal can be secured between the end face of the corrugated tube 12 (the portion 70 extending in the radial direction) and the gasket 56 without increasing the tightening force of the bolt 64 and the nut 66. As a result, piping connection becomes extremely easy.

  Further, a relatively hard solid PTFE gasket can be used instead of the non-asbestos packing having a high cushioning property. In this case, since the solid PTFE gasket is non-conductive, the effect of preventing electrolytic corrosion can be easily obtained by using an insulating bolt for the connecting means (bolt 64). Note that the material of the gasket need not be limited to a specific material (for example, PTFE) as long as the gasket has an insulating property.

  Further, as shown in FIG. 3, an annular spacer 72 having a predetermined thickness is disposed between the flange 38 of the flexible tube 1 and the gasket 56, and the end surface of the corrugated tube 12 (part 70 extending in the radial direction) is formed by the spacer 72. In addition, the amount of deformation of the deformable ring 52, and hence the tightening force, can be managed uniformly without depending on experience.

Experiment: A flexible tube (tube diameter 65A) shown in FIG. 1 was prototyped, and helium leakage was measured for the connection structure shown in FIG. The bolt tightening force was 25 N · m. In the flexible tube of the type shown in Patent Document 1, the bolt tightening force is usually 79 to 98 N · m. The gap between the flanges was 3.7 mm. As a result, it was well adapted to the standard of leak rate using helium (1 × 10 ⁻⁹ Pa · m ³ / s).

  In the above description, only one peak (first peak 16) is left on the outside (right side) of the rigid ring 22, but one peak 16 is left outside the rigid ring 22. In addition, another trough portion may be left and a deformable ring may be attached to the trough portion. Alternatively, two crests may be left outside the rigid ring 22 and the deformable ring may be attached to the crest located on the outermost side.

1: flexible tube 10: central axis 12: corrugated tube 14: blade 16: peak 16a: first peak 16b: second peak 18: valley 18a: first valley 20: connection structure 22: Rigid ring 24: Right side of rigid ring 26: Left side of rigid ring 32: Blade presser ring (fixing ring)
34: cylindrical part 36: collar part 38: flange (first flange)
40: Step 42: Cylindrical inner surface 44: Inner surface 48: Weld 50: Pipe 52: Deformable ring 54: Flange (second flange)
56: Gasket 58, 60, 62: Hole 64: Insulating bolt (connection means)
66: Nut (connection means)
70: part extending in the radial direction

Claims (6)

A flexible tube (1) having a corrugated tube (12) in which large-diameter peaks (16) and small-diameter valleys (18) are alternately connected,
At least one end of the corrugated tube (12) is
A rigid ring (22) fitted into a trough (18a) of the corrugated tube (12);
One crest (16a) or trough left outside the trough (18a) in which the rigid ring (22) is fitted with respect to the central axis (10) direction of the corrugated tube (12);
One of the peaks (16a) left outside the valley (18a) in which the rigid ring (22) is fitted, or a deformable ring (52) is fitted in the valley (18a). Features flexible tube.   The flexible tube according to claim 1, wherein the rigid ring (22) comprises a halved portion divided into two. The rigid ring (22) protrudes radially outward from the outer periphery of the corrugated tube (12),
The end of the blade (14) sheathed on the corrugated tube (12) is sheathed on the rigid ring (22),
The flexible tube according to claim 1 or 2, characterized in that a blade portion sheathed on the rigid ring (22) is fixed to the rigid ring (22) by a fixing ring (32). The corrugated tube (12) is externally provided with a flange (38),
The flange (38) and the fixing ring (32) have portions (36, 44) that abut against each other when the flange (38) is urged toward the end of the corrugated tube (12). The flexible tube according to claim 3.   One ridge (16a) left outside the valley (18a) in which the rigid ring (22) is fitted, or a deformable ring (52) is fitted in the valley. Item 5. The flexible tube according to any one of Items 1 to 4. (A) A flexible tube (1) having a corrugated tube (12) in which large-diameter peaks (16) and small-diameter valleys (18) are alternately connected,
At least one end of the corrugated tube (12) is
A rigid ring (22) fitted into a trough (18a) of the corrugated tube (12);
One crest (16a) or trough left outside the trough (18a) in which the rigid ring (22) is fitted with respect to the central axis (10) direction of the corrugated tube (12);
A crest (16a) left outside the trough (18a) in which the rigid ring (22) is fitted, or a deformable ring (52) fitted in the trough,
A flexible tube (1) having a first flange (38) sheathed on the rigid ring (22);
(B) Another pipe (50) to which the flexible tube (1) is connected,
A pipe (50) having a second flange (54) opposite the first flange (38);
(C) a gasket (56) disposed between the first and second flanges (38, 54), wherein the peak (16a) or the ridge (16a) in which the deformable ring (52) is fitted; A gasket (56) opposed to a radially extending portion (70) which is a radially extending portion (70) constituting the valley and located on the outermost side with respect to the central axis direction;
(D) by tightening the first and second flanges (38, 54), the ridge (16a) or the ridge (16a) in which the deformable ring (52) is fitted via the gasket (56); A connection structure of a flexible tube and piping, comprising connecting means (64, 66) for deforming a valley portion in the direction of the central axis.

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