JP2007309503A - Stainless steel joint for resin tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relatively inexpensive stainless steel joint for resin tubes having a simple structure wherein the resin tube is prevented from turning together with a nut, and a cut is prevented from occurring in the tube. <P>SOLUTION: In the nut 12, a first internal circumferential surface 12a and a second internal circumferential surface are provided. Between the internal circumferential surfaces, a wall-like step is formed axially perpendicularly to the joint. Between the external circumferential surfaces of a large diameter part 16a and a small diameter part 16b in a sleeve 16, a wall-like step is formed axially perpendicularly to the joint. A thrust washer 20 is provided in an annular space 20s surrounded by the first internal circumferential surface, the external circumferential surface of the small diameter part, and two vertical walls. When the nut is turned in the state in which the resin tube 18 is inserted beforehand in the insert part of the nut, the torque to the nut is hardly transmitted to the sleeve part, because in the thrust washer, contact frictional-force acts between the internal circumferential surface of the sleeve and the external circumferential surface of the resin tube, and besides, the coefficient of friction is low. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention preferably relates to a stainless steel joint for a resin tube used in a semiconductor manufacturing apparatus.

In semiconductor manufacturing equipment, fluids such as clean air, pure water, temperature-controlled water, and organic chemicals are used.
Resin tubes such as fluororesin tubes and polyurethane tubes are used for the pipes that carry these fluids. Stainless steel joints for resin tubes are used for joints that connect these resin tubes in consideration of oil and impurities. Is used.

Conventionally, the structure of the joint used for the resin tube is shown in FIGS.
FIG. 4 shows a cross-sectional view along the axial direction of a union joint (a pair of symmetrical symmetrical joints). In FIG. 4, tightening nuts 12 and 14 are arranged on the left and right of the joint body 10. As will be described later, the end portions of the inserted resin tubes 18 are pressed and pressed against the insert portions of the joint body by the movement of the sleeve 16. 5 and 6 are enlarged views of the structure of the left side portion of the union joint shown in FIG. 4. FIG. 5 shows an initial state of tightening with a nut, and FIG. 6 shows a completed state of tightening.

  In FIG. 5, the insert portion at the left end of the joint body 10 includes a bulging portion 10 b and a right recess 10 a adjacent to the bulging portion 10 b. On the right side adjacent to the insert portion, an external thread is formed on the outer periphery, and the engaging portion 10c that engages with the engaging portion 12b on the nut 12 side, and adjacent to the engaging portion 10c and more than the engaging portion 10c. A spanner hooking portion 10d is formed on the outer periphery with a large diameter.

Reference numeral 10e is a vertical surface formed on the side of the spanner hooking portion 10d, and when the end surface 12c of the nut 12 comes into contact, the fastening to the resin tube 18 is completed.
The sleeve 16 is locked at a step portion formed at the inner left end of the nut 12. The sleeve 16 includes a large-diameter portion 16a, a small-diameter portion 16b, and an expanded portion 16c. The expanding portion 16c is formed by inserting the sleeve 16 into the nut 12 and then expanding the left end side of the sleeve 16 from the inside using a predetermined jig.
Therefore, the sleeve 16 does not come out of the nut 12 by the expanded portion 16c and the large diameter portion 16a.

  In FIG. 1 of Patent Document 1, a male screw portion for coupling is formed on the left outer peripheral portion of a joint body for a resin tube. The structure on the right side of the joint portion is the same as that shown in FIGS.

On the other hand, in FIG. 1 and FIG. 2 of Patent Document 2, although it is not a joint for a resin tube, an outward flange 13 at the end of the second tubular joint member 2 and an inward flange 11 at the end of the nut 4 In the middle, a joint structure provided with a thrust ball bearing 6 for preventing rotation is shown.
JP2005-164018 JP-A-8-21573

The stainless steel joint according to Patent Document 1 described above still has the following problems when used for a resin tube. That is,
When the nut is screwed into the joint body, the resin tube is rotated in the rotation direction of the nut, and the piping of the resin tube is twisted. If vibration occurs in the twisted state, the piping may be broken.
In this case, it is conceivable to use the thrust ball bearing disclosed in Patent Document 2 as a means for preventing the rotation. However, the size of the nut becomes longer to accommodate the thrust ball bearing, and the thrust is increased. The ball bearings themselves are relatively expensive and structurally have moving parts, so there are problems such as lubrication and other maintenance problems.

  Therefore, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to prevent the resin tube from being turned around and to prevent the resin tube from being cut, and to simplify the process. The object of the present invention is to provide a stainless steel joint for a resin tube that has a structure and is relatively inexpensive.

Means to solve the problem

In order to achieve the above object, a stainless steel joint for resin tubes according to the present invention is as follows.
A joint for resin tubes,
At least on one side, from the end side, an insert portion having a bulging portion having an outer diameter larger than the inner diameter of the resin tube, a male screw is formed on the outer peripheral portion adjacent to the insert portion and larger in diameter than the insert portion. A stainless steel joint body formed by forming an engaging portion and a spanner hanging portion on the outer peripheral portion adjacent to the engaging portion and having a larger diameter than the engaging portion;
An engaging portion in which a female thread is formed on the inner peripheral surface of the opening on one end side so as to be screwed to the male screw, a first inner peripheral surface portion adjacent to the engaging portion and having an inner diameter smaller than the inner diameter of the engaging portion, From a first step portion having a second inner peripheral surface portion adjacent to the inner peripheral surface portion and having an inner diameter smaller than that of the first inner peripheral surface portion, and a vertical wall formed between the first inner peripheral surface portion and the second inner peripheral surface portion. A stainless steel nut,
The sleeve is inserted in the vicinity of the first step portion of the nut, and the outer surface thereof has a large diameter portion that is slidably contacted with the first inner peripheral surface portion, and is slidable with the second inner peripheral surface portion. A second step portion having a small diameter portion to be inserted and a vertical wall formed between the large diameter portion and the small diameter portion is formed, and the inner diameter of the inner peripheral surface is larger than the outer diameter of the resin tube. A small sleeve,
A ring-shaped thrust washer disposed between each vertical wall forming the first and second step portions;
It is characterized by comprising.

In this case, the length of the small-diameter portion of the sleeve is dimensioned so that the end surface of the small-diameter portion protrudes outside the nut in a state where the thrust washer and the sleeve are inserted into the nut. The inner diameter is formed to be expanded, and the thrust washer and the sleeve can be prevented from being detached from the nut.
Further, in that case, when the end surface of the first inner circumferential surface formed on the nut comes into contact with the side surface formed between the engaging portion and the spanner hooking portion of the joint body, The length of the insert portion can be set so that the fastening for the resin tube is completed.
In that case, the thrust washer may be formed of a resin material having a friction coefficient in a range of 0.05 to 0.08.

The invention's effect

Stainless steel joints for resin tubes according to the present invention are:
A joint for a resin tube, at least on one side, from an end side thereof, an insert portion having a bulging portion having an outer diameter larger than the inner diameter of the resin tube, adjacent to the insert portion and having a diameter larger than that of the insert portion An engagement portion having a large male screw formed on the outer peripheral portion, a stainless steel joint body adjacent to the engagement portion and having a diameter larger than that of the engagement portion and a spanner hooking portion formed on the outer peripheral portion; and the male screw An engagement portion in which a female thread is formed on the inner peripheral surface of the opening on one end side so as to be screwed together, a first inner peripheral surface portion that is adjacent to the engagement portion and has an inner diameter smaller than the inner diameter of the engagement portion, and the first inner periphery Stainless steel comprising a second inner peripheral surface portion adjacent to the surface portion and having an inner diameter smaller than the first inner peripheral surface portion, and a first step portion having a vertical wall formed between the first inner peripheral surface portion and the second inner peripheral surface portion. And a sleeve inserted in the vicinity of the first step of the nut. Thus, on the outer surface, a large-diameter portion that is slidably inserted into the first inner peripheral surface portion, a small-diameter portion that is slidably inserted into the second inner peripheral surface portion, and the large-diameter portion and the diameter. A second step portion having a vertical wall formed between the first portion and the second portion, and an inner diameter of the second peripheral portion formed smaller than an outer diameter of the resin tube; and the first and second portions Since the ring-shaped thrust washer is arranged between the vertical walls forming the step of the nut, the nut is rotated by interposing the thrust washer of the low friction material between the nut and the sleeve. Sometimes the sliding is improved and the rotational force is not easily transmitted to the sleeve and the resin tube. As a result, the resin tube does not rotate, and the resin tube can be prevented from being twisted.
Further, the tube can be prevented from being damaged by the vibration of the resin tube, and the thrust washer is relatively easy to manufacture and the manufacturing cost is low.

1 and 2 show an axial section of a stainless steel joint for resin tubes according to the present invention. 1 shows an initial state of resin tube tightening, and FIG. 2 shows a completed state of the tightening.
1 and FIG. 2, the same reference numerals as those illustrated in FIG. 5 and FIG. 6 as the prior art indicate the corresponding components, and accordingly, FIG. 5 and FIG. 6 have already been described. The description of the elements will be omitted because they are duplicated, and in the following, some of them will be duplicated but mainly the differences will be explained.

  In FIG. 1A, the outer peripheral surface of the large diameter portion 16a of the sleeve 16 faces the first inner peripheral surface portion 12a formed inside the nut 12 so as to be slidable. Similarly, the outer peripheral surface of the small diameter portion 16b of the sleeve 16 is opposed to the second inner peripheral surface portion of the nut 12 so as to be slidable. Between the first inner peripheral surface portion 12a and the second inner peripheral surface portion of the nut 12, a step portion is formed by a wall perpendicular to the axial direction of the joint, while the outer peripheral surface and the small diameter portion of the large diameter portion 16a of the sleeve 16 are formed. Between the outer peripheral surface of 16b, the step part by the wall perpendicular | vertical with respect to the axial direction of a joint is formed.

Reference numeral 20 s is a ring-shaped space surrounded by the outer peripheral surface of the first inner peripheral surface portion 12 a and the small diameter portion 16 b and two vertical walls, and a ring-shaped thrust washer 20 is disposed in the space 20 s. Yes. FIG. 1B shows a cross section of a ring-shaped thrust washer 20.
The thrust washer 20 is made of Teflon (registered trademark of DuPont, USA) and has a friction coefficient of 0.05 to 0.08. Other usable resins include trifluoroethylene chloride resin, polyacetal and the like.

  In FIG. 1A, in the state where the resin tube 18 is inserted in advance into the nut 12 that holds the sleeve 16 and the thrust washer 20 so as not to be detached, a joint is attached to the right end of the resin tube 18 as shown in the figure. The bulging part 10b of the insert part of the main body 10 is inserted. In this state, the nut 12 is moved to the right until the engagement portion 12b of the nut 12 abuts on the engagement portion 10c on the joint body 10 side, and after the abutment, the nut 12 is rotated to screw the screw portions of the respective engagement portions. Let me. The nut 12 is rotated until the distal end portion (the right end portion in the figure) of the large diameter portion 16a of the sleeve 16 reaches the vicinity of the bulging portion 10b, but the nut 12 is rotated between the vertical wall on the nut side and the vertical wall on the sleeve side. The thrust washer 20 has a contact frictional force between the inner peripheral surface of the sleeve 16 and the outer peripheral surface of the resin tube 18, and because of its low friction coefficient, the rotational force on the nut side is hardly transmitted to the sleeve portion side. Therefore, the sleeve 16 does not rotate but moves straight (moves in the right direction in the figure).

Eventually, as shown in FIG. 1 (a), when the distal end portion (the right end portion in the figure) of the large diameter portion 16a of the sleeve 16 reaches the vicinity of the bulging portion 10b, the resin tube raised by the bulging portion 10b. The outer peripheral surface 18 resists the forward movement of the distal end portion of the large diameter portion 16 a of the sleeve 16.
When the sleeve 16 further moves against this resistance force, the contact friction force between the inner peripheral surface of the sleeve 16 and the outer peripheral surface of the resin tube 18 and between the inner peripheral surface of the resin tube 18 and the outer peripheral surface of the bulging portion 10b is further increased. Become. Even in such a state, since the friction coefficient between the both side surfaces of the thrust washer 20 and the respective vertical walls is small, the rotational force of the nut 12 is not transmitted to the sleeve 16 but only the straight movement is transmitted. . That is, the resin tube 18 is avoided from being routed through the sleeve 16.

  FIG. 2 shows a state where the tightening of the resin tube 18 by the nut 12 is completed. As shown in the figure, in this state, the resin tube 18 between the outer peripheral surface of the bulging portion 10b and the inner peripheral surface of the sleeve 16 is squeezed between the two peripheral surfaces, and is crimped, thereby being extruded. A part of 18a enters the recess 10a. This tightening is completed when the right end surface 12c of the nut 12 and the side surface 10e of the spanner hooking portion 10d of the joint body 10 just contact each other. Therefore, the axial lengths of the bulging portion 10b and the concave portion 10a, that is, the length of the insert portion can be set in advance. By doing so, the actual tightening operation is simplified because it is only necessary to pay attention to whether or not the nut 12 is in contact with the joint body 10.

FIG. 3 is a list showing the results of a resin tube tightening test. In the left column, a conventional joint (Φ10 × Φ8) which is a standard product and a joint (Φ10 × Φ8) of the present invention which is an improved product are shown in the left column. For each, the results are shown when three tightening operations are performed in succession. There are two types of resin tube materials used in the test: tetrafluoroethylene resin (PTFE) and perfluoroalkoxy polymer (PFA). The amount of rotation during rotation was measured visually.
As shown in FIG. 3, in the case of the improved product, in any resin tube, the rotation in each tightening operation could not be observed.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these exemplified contents, and those skilled in the art can implement various modifications based on them. is there.

It is an axial direction cross section of the stainless steel joint for resin tubes by this invention, Comprising: (a) is a figure which shows the initial state of clamping, (b) is sectional drawing of a ring-shaped thrust washer. It is an axial direction cross section of the stainless steel joint for resin tubes by this invention, Comprising: It is a figure which shows the completion state of clamping. It is a list | wrist which shows the result of the fastening test of the conventional standard joint and the improved joint by this invention. It is an axial sectional view showing a state where tightening is completed by a conventional union joint used for a resin tube. It is a figure which shows the structure of the conventional coupling used for resin tubes, and shows the initial state of fastening. It is a figure which shows the structure of the conventional coupling used for the resin tube, Comprising: The completion state of fastening is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Joint main body 10a Recessed part 10b Swelling part 10c Engaging part 10d Spanner hooking part 10e Side surface 12 Nut 12a 1st inner peripheral surface part 12b Engaging part 12c End surface 16 Sleeve 16a Large diameter part 16b Small diameter part 16c Expansion part 18 Resin tube 18a Resin portion 20 Thrust washer 20s Ring-shaped space

Claims (4)

A joint for resin tubes,
At least on one side, from the end side, an insert portion having a bulging portion having an outer diameter larger than the inner diameter of the resin tube, a male screw is formed on the outer peripheral portion adjacent to the insert portion and larger in diameter than the insert portion. A stainless steel joint body formed by forming an engaging portion and a spanner hanging portion on the outer peripheral portion adjacent to the engaging portion and having a larger diameter than the engaging portion;
An engaging portion in which a female thread is formed on the inner peripheral surface of the opening on one end side so as to be screwed to the male screw, a first inner peripheral surface portion adjacent to the engaging portion and having an inner diameter smaller than the inner diameter of the engaging portion, From a first step portion having a second inner peripheral surface portion adjacent to the inner peripheral surface portion and having an inner diameter smaller than that of the first inner peripheral surface portion, and a vertical wall formed between the first inner peripheral surface portion and the second inner peripheral surface portion. A stainless steel nut,
The sleeve is inserted in the vicinity of the first step portion of the nut, and the outer surface thereof has a large diameter portion that is slidably contacted with the first inner peripheral surface portion, and is slidable with the second inner peripheral surface portion. A second step portion having a small-diameter portion to be inserted and a vertical wall formed between the large-diameter portion and the small-diameter portion is formed, and an inner peripheral surface inner diameter thereof is larger than an outer diameter of the resin tube. A small sleeve,
A ring-shaped thrust washer disposed between each vertical wall forming the first and second step portions;
A stainless steel joint for resin tubes characterized by comprising: The length of the small-diameter portion of the sleeve is dimensioned such that the end face of the small-diameter portion protrudes outside the nut when the thrust washer and the sleeve are inserted into the nut, and the inner diameter of the end surface is not pushed. The stainless steel joint for a resin tube according to claim 1, wherein the stainless steel joint is formed so as to be spread, and the thrust washer and the sleeve are configured to prevent detachment from the nut. When the end surface on one end side of the first inner peripheral surface formed on the nut comes into contact with the side surface formed between the engaging portion and the spanner hanging portion of the joint body, the resin tube The length of the said insert part is set so that clamping may be completed, The stainless steel coupling for resin tubes described in Claim 1 or 2 characterized by the above-mentioned. The stainless steel joint for a resin tube according to any one of claims 1 to 3, wherein the thrust washer is formed of a resin material having a friction coefficient preferably in a range of 0.05 to 0.08.

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