JP3041899U - Tube fitting - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To tightly tighten a tube expanded portion inserted in a groove ring of a fitting body to the fitting body with a cap nut so that a tube bending portion connected to the tube expanded portion has an acute angle hole of the cap nut. The edge is tightly pressed against the acute-angled tip of the tubular portion of the joint body to form the tube retaining portion and the airtight holding portion, and the inner peripheral surface of the acute-angled portion of the tubular portion 5A is formed into the deformation preventing chamfered slope 5B. Eliminate dead water pools. SOLUTION: To prevent the tube from coming off by forming a tube expanded portion near the end of a fluororesin tube and fastening the bent portion to the joint body with a cap nut,
The tubular portion 5 of the hard resin joint body 4 having the groove ring 3 on the inner peripheral surface of the expanded diameter portion 2 of the tube 1 is inserted, and most of the expanded tube portion 2 is inserted into the groove ring 3. Then, the tube bending portion 2a is formed by the hard cap nut 6 screwed into the male screw portion 4a of the joint body 4 on the outside of the groove ring, and the shoulder portion 6A of the cap nut 6 is formed with an acute-angled hole edge 6a. By tightly pressing the tip 5A of the tubular portion 5 to form a tube retaining portion and an airtight holding portion, the inner peripheral surface of the tubular tip 5A was formed as a deformation preventing chamfered slope 5B.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a tube joint suitable as a joint for a fluororesin tube that controls a flow path of a cleaning liquid such as pure water used in a clean room at a high-density semiconductor chip manufacturing site or the like, and other general chemical liquids.

[0002]

[Prior art]

 As a tube joint of this type, there is a tube joint described in, for example, Japanese Utility Model Laid-Open No. 4-122882.

According to this conventional technique, in a tube joint in which a deformed portion is formed in a tube to prevent the tube from coming off, an outer collar and a large diameter portion are formed at the end of the tube made of fluororesin, and Insert the insertion tube of the joint body having the groove ring in the large diameter portion, and insert most of the ring loosely inserted in the large diameter portion into the groove ring to screw it into the male screw portion of the joint body. Prevent the tube from coming off by pressing the ring tightly against the outer collar with the inserted cap nut, and press the middle part of the tube tightly against the end face of the insertion tube with the inner surface of the shoulder of the cap nut. It is a tube joint formed by forming a tube bending portion.

[0004]

[Problems to be solved by the device]

 The process of heat work for forming a deformed portion in the tube in this conventional technique requires two times and takes time, and when heating unevenness occurs due to heating convection, the shape of the outer collar becomes uneven, There was a case where imbalance occurred during tightening, and stable tightening could not be achieved, so it required skill for heating.

Also, after forming the large-diameter portion, when the mold is removed and time passes, the tube bending portion gradually contracts and does not sufficiently enter the insertion tube, so that heat remains in the large-diameter portion. Since it had to be quickly pushed into the fitting insertion tube while it was in progress, there were many problems that agile work was required.

In addition to this, as described in Japanese Utility Model Laid-Open No. 62-86489, a tapered expanded portion is formed in a tube, and a shape-retaining ring is press-fitted inside the expanded portion, and the inclined surface of the expanded portion is slanted on the cap nut. A tube joint in which the tube is prevented from coming off by tightening the surface of the joint body is also well known. However, in this conventional example, since there is no means for tightening the joint refraction part of the tube expanded portion and the tube to the joint body, the tube or pipe can easily come out of the joint at high temperature, and the airtight liquid tightness of the joint is poor. Especially when the tube is made of a material with a large outer surface such as a tube made of fluororesin, the tube often comes off, and the "nut" of the cap nut over time also becomes large.

Furthermore, in the conventional example described in the above-mentioned Japanese Utility Model Laid-Open No. 4-122882, the tubular body, the ring, and the tube are deformed with the passage of time during use at high temperature, and the tube As a result of a gap occurring at the contact surface between the inner surface and another member, a small amount of liquid pool is created, so-called "dead water" is stored, and fine particles for polishing are caught in the deformed gap part and grow up. However, there was a problem that the diameter of the tube was reduced.

In order to eliminate the above-mentioned problems, the present invention connects the expanded diameter portion of the tube inserted in the groove ring of the joint body to the expanded diameter portion of the tube by tightly tightening the cap nut with the joint main body. The tube bending portion is tightly pressed against the sharp tip of the tubular portion of the joint body with the sharp hole edge of the cap nut to form the tube retaining portion and the airtight holding portion, and the inner peripheral surface of the tubular tip 5A is liquid. The purpose is to eliminate dead water pools by forming chamfered slopes 5B for pooling prevention.

[0009]

[Means for Solving the Problems]

 The above-mentioned object of the present invention is to expand the tube in order to prevent the tube from being pulled out by forming a tube expanded part near the end of the fluororesin tube and tightening the bent part to the joint body with a cap nut. While inserting the tubular part of the hard resin joint body that has a groove ring on the inner peripheral surface of the diameter part, insert most of the tube expanded diameter part into the groove ring, and insert the joint on the outside of this groove ring. With a hard cap nut screwed into the male thread of the main body, the tube bend part is tightly pressed against the tip of the tubular part of the joint body with a hole edge that forms an acute angle on the shoulder of the cap nut to form a tube retaining part. This can be achieved by forming an airtight holding portion and forming a chamfered slope for preventing deformation on the inner peripheral surface of the tip of the tubular portion.

[0010]

[Embodiment of the invention]

 An embodiment of the present invention will be described with reference to the drawings. First, as shown in each of FIGS. 1 to 5, the basic form of the present invention is to heat the vicinity of the end of a fluororesin tube 1 called polytetrafluorofluoroethylene (PTFE) or PFA. As shown in FIG. 2, the tube expanding portion 2 is forcibly press-fitted into the expanding jig A.

Then, the tubular portion 5 of the joint body 4 made of a hard resin such as fluororesin or polypropylene having the groove ring 3 as shown in FIG. 3 is inserted into the inner peripheral surface of the expanded tube portion 2 as shown in FIG. At the same time, most of the tube expanded portion 2 is inserted into the groove ring 3.

[0012] Next, as shown in Figs. 4 and 5, a hard cap nut 6 made of fluororesin or polypropylene screwed into the male screw portion 4a of the joint body 4 on the outside of the groove ring 3 is used to expand the tube diameter. As shown in FIG. 5 and FIG. 1, the tube bending portion 2a connected to the portion 2 is formed on the shoulder portion 6A of the cap nut 6 at an acute angle from the outer surface thereof to the sharp edge 5A of the tubular portion 5 of the joint main body 4 by the hole edge 6a. The tube is tightly pressed to form the tube retainer and the airtight retainer.

In addition, a chamfered chamfer 5B for preventing deformation is formed on the inner peripheral surface of the tip 5A of the tubular portion so that a thin portion is not formed near the tip 5A. A tube joint according to the present invention as shown in Fig. 1 was constructed in which bending deformation was prevented, gaps between tubes were prevented from occurring, and liquid pool did not occur.

[0014]

【Example】

 The material of each component described above can be appropriately determined according to the type of fluid flowing in the tube 1 and the joint main body 4, and the tube 1 is excluded when carrying out under relatively rough use conditions. If the other member is formed of a tough material such as metal, the strength thereof is also increased. In addition, when carrying out under severe operating conditions, such as in ultra-high-density semiconductor chip manufacturing sites, all of the components including the tube 1 are made of fluororesin such as PTFE or PFA. , It could be used as a flow path for cleaning liquid of semiconductor chips when manufacturing high-density VLSI chips (large-scale integrated circuits).

[0015]

[Effect of the invention]

 Since the present invention adopts the above-described embodiment, the following effects can be obtained. The tube bending portion 2a inserted into the groove ring 3 of the joint body 4 is tightly tightened from its outer surface to the tubular portion 5 of the joint body 4 with the cap nut 6, so that the tube bending portion 2a is attached to the shoulder portion 6A of the cap nut 6. Since the sharp edge 5a of the tubular portion 5 of the joint body 4 was tightly pressed by the sharply formed hole edge 6a to form the strict tube retaining portion and the airtight holding portion, the tube 1 was It has a first effect that it can be used safely for a long period of time without being loosened or pulled out inadvertently because it is tightly air-tight and liquid-tight and tightly connected to the joint body 4.

Further, particularly in the present invention, since the chamfered slope 5B for preventing deformation is formed on the inner peripheral surface of the tip portion 5A of the tubular portion of the joint body 4, even if it is used at a high temperature, the tubular body may be subjected to a temperature cycle or the like. Since it is possible to prevent inward bending deformation near the tip of the shape and eliminate so-called dead water pool, cleaning solution such as pure water is not contaminated and it can be safely applied to the cleaning route of ultra-high density LSI chip products. There is also an industrial effect.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical side view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of forming a tube expanded portion in the present invention.

FIG. 3 is a vertical cross-sectional side view showing an example of the process of assembling a tube joint according to the present invention.

FIG. 4 is a vertical cross-sectional side view showing an example of the process of assembling a tube joint according to the present invention.

FIG. 5 is a vertical sectional side view showing an example of an assembled product of the tube joint according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 tube 2 tube expansion part 2a tube bending part 3 groove ring 4 joint body 4a male thread part 5 tubular part of joint body 5A tip of tubular part 5B chamfered bevel to prevent deformation near tip of tubular part 6 cap nut 6A Shoulder portion of the cap nut 6a Hole edge formed at an acute angle on the shoulder portion of the cap nut

Claims (1)

[Utility model registration claims] 1. A tube joint in which a tube expanded portion is formed near the end of a fluororesin tube and the bent portion is fastened to the joint body with a cap nut to prevent the tube from coming off The cylindrical portion 5 of the hard resin joint body 4 having the groove ring 3 on the inner peripheral surface of the diameter portion 2 is inserted, and most of the tube expanded diameter portion 2 is inserted into the groove ring 3, With the hard cap nut 6 screwed into the male screw portion 4a of the joint body 4 on the outside of the ring, the tube bending portion 2
a is tightly pressed against the tip 5A of the tubular portion 5 of the joint body 4 by the hole edge 6a formed in the shoulder portion 6A of the cap nut 6 to form a tube retaining portion and an airtight holding portion, and A tube joint in which the inner peripheral surface of the tip portion 5A of the tubular portion is a chamfered slope 5B for preventing deformation.