JPS62110093A - Pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe joint whose main body is made of synthetic resin, and particularly to a pipe joint with improved drawing strength, airtightness, etc.

[Conventional technology]

Generally polypropylene, polyamide, polyacetal,
Pipe fittings made of synthetic resins such as polyvinyl chloride have several superior properties compared to metal fittings made of stainless steel, brass, etc., such as superior chemical resistance and corrosion resistance, as well as being lighter in weight. Therefore, it is widely used in physical and chemical equipment, analytical equipment, medical equipment, food thieves, paint sprayers, chemical plants, etc. Among these, pipe fittings made of fluororesin have many excellent properties such as chemical resistance, non-contamination, heat and cold resistance, and non-adhesiveness, so in recent years high cleanliness has been required, especially in semiconductor manufacturing equipment. Used for piping systems.

As such a pipe joint, for example, Utility Model Publication No. 60-=1169
Publication No. 1 discloses a synthetic resin tool body (joint body) in which a threaded portion is formed on the outer periphery of the end of a pipe-shaped main body provided with a round hole, and a tool body screw threaded on the inner surface that is screwed into the threaded portion. The outer periphery of the f-tube deforms the tube inserted into the round hole by tightening the tightening nut and deforming one end of the tool part body by the inclined part. In a tube joint that is connected inwardly as shown in FIG. A circumferentially formed pipe fitting is disclosed.

[The problem that the invention attempts to solve]

However, in such pipe joints, it is disadvantageous to provide a square groove inside the tapered part of the joint body, which facilitates the inward deformation of the end of the body and prevents pressure resistance.

Although we are trying to improve the pull-out strength, it is true that square grooves are installed.
Although the above characteristics are improved compared to those without it, it is still not sufficient, especially if the joint body is formed of fluororesin and the pipe body is connected with a fluororesin tube.In this case, both Because it has low friction, it has the disadvantage of being slippery and easily falling off when hooked, so it is desired to improve its pull-out strength. Furthermore, since the pull-out strength is not sufficient, the airtightness is also not sufficient, and there are still several problems that need to be improved.

In order to increase the pull-out strength, a groove is carved on the outer circumferential surface of the pipe body to be connected, and the tip of the ferrule that is integrated with the tightening nut is bitten into the groove to fix the pipe body. It has been proposed to flare the end and sandwich a portion of the flare between the tapered surface of the tightening nand and the tapered surface of the fitting body, but this requires special processing on the pipe body, so it is difficult to connect. It has the disadvantage that it is time-consuming, and its pull-out strength is not always sufficient.

The purpose of the present invention is to eliminate the drawbacks of the prior art and provide an economical pipe joint made of wood that has excellent pull-out strength and airtightness, and does not require any special processing on the pipe body during connection. .

[Means for solving problems]

The present invention has been made in view of the above-mentioned problems of the prior art. Therefore, according to the present invention, an inner cylindrical part that has an annular convex portion on the outer circumferential surface and fits inside the tube body, and an inner cylindrical part that an outer cylindrical part that is located closer to the end of the tubular body than the annular convex part and that presses the tubular body from the outer peripheral surface; In preparation for this, there is a joint body made of synthetic resin, and the clamping force receiver of the outer cylindrical part that is locked to the joint body goes up to the clamping force imparting part that engages with the joint body, reduces the diameter of the outer cylindrical part, and presses the outer cylindrical part. A pipe joint is provided with a tightening tool for pressing the part against the outer circumferential surface of the pipe body.

In this configuration, it is advantageous if the tightening force receiving portion of the joint body is formed into a tapered shape, and the tightening force receiving portion that engages with the tightening force receiving portion is formed into a tapered hole. Furthermore, the annular convex part of the inner cylinder part is composed of a tapered part whose diameter increases from the tip of the inner cylinder part in the direction of insertion of the pipe body, and a straight part continuing from this taper part, and also forms a fastener and is screwed into the joint body. It is preferable to provide the tightening nut to be fitted with a second tapered hole and a straight hole in sequence following the tapered hole that engages with the tapered part of the outer cylinder of the joint body, and good.

In addition, the tightening nut that forms the fastener together with the joint body may also be made of synthetic resin, and if both are made of fluororesin, it will be particularly effective in terms of chemical resistance, corrosion resistance, non-contamination, etc. It will be excellent.

[Effect]

According to this invention, as described above, a tube body receiving groove is formed at the end by the inner tube portion and the outer tube portion, and furthermore, the inner tube portion has an annular convex portion on the outer circumferential surface, and the outer tube portion has an annular convex portion. The clamping force receiver is provided with, for example, a tapered portion at its end, and is located closer to the end of the tube than the annular convex portion of the inner cylinder portion, so that the inserted tube is held against the outer circumferential surface. The joint body made of synthetic resin has a pressing part that presses from the outside, and the clamping force receiver of the outer cylindrical part of this joint body has, for example, a tapered hole part as a clamping force imparting part that engages with the outer cylindrical part of the joint body. The diameter of the outer cylindrical portion is reduced by the tapered hole portion by screwing into the external threaded portion formed in the outer cylindrical portion, and the pressing portion of the outer cylindrical portion is inserted into the tube groove. A clamping force imparting part provided inside the clamping force receiving part of the outer cylinder part engages with the clamping force receiving part of the outer cylinder part, deforms the outer cylinder part inward from its tip, and presses the pressing part in the direction of the thickness of the tube body. As a result, the inner cylinder part and the pressing part are clamped and locked.

In this case, the tube body is pressed from the outer peripheral surface in the tube thickness direction by the pressing part of the outer cylinder part on the tube end side of the annular convex part of the inner cylinder part, and the pressure part provided on the outer peripheral surface of the inner cylinder part In addition to being hooked to the annular convex portion and prevented from moving in the direction in which the tube is pulled out, the outer tube portion and the inner tube portion are substantially concentrically formed integrally with the joint body. As a result of the axial center of the inserted tube being stabilized and securely locked, the pull-out strength is significantly improved, and the airtightness is also significantly improved.

Therefore, it is particularly preferable that the joint body is made of a slippery material such as fluororesin, and a predetermined pull-out strength can be obtained even when connecting a tube body made of fluororesin.

In addition, it is advantageous if the tightening force receiving portion of the joint body is formed into a tapered shape, and the tightening force imparting portion of the tightening nut is formed into a tapered hole, since this allows smooth inward deformation of the outer cylindrical portion. Furthermore, the annular convex part of the inner cylindrical part of the joint body is composed of a tapered part whose diameter increases from the tip in the direction of insertion of the pipe, and a straight part continuing from this tapered part, and the tapered part of the outer cylindrical part is used as a tightening nut. If a second tapered hole and a straight hole are provided following the tapered hole that engages with the nut, in addition to the above effects, when tightening the tightening nut, the inner periphery of the tightening nut Due to the presence of the second tapered hole provided on the surface, the inner peripheral surface of the tightening pad will not get caught on the tube body and cause damage to the tube body, making it possible to tighten the tube smoothly. The body is clamped and locked with the straight part of the annular convex part of the inner cylinder part and the straight hole part of the inner circumferential surface of the tightening nand, and the drawing strength V7x and airtightness are further improved.

Furthermore, if the tube body receiving groove of the joint body formed by the inner tube portion and the outer tube portion is formed into a tapered groove whose diameter increases in the tube insertion direction, the pull-out strength is further improved.

〔Example〕

FIG. 1 is a vertical sectional side view showing a state in which a plastic tube 2 is inserted as a pipe body into a pipe fitting 1 according to the present invention and tightening is completed. It is composed of. In the embodiment, the joint body IO is made of synthetic resin,
It has a tapered part 11 as an annular convex part whose diameter increases from the tip toward the insertion direction of the tube body 2 on the outer peripheral surface, and an inner cylinder part 12 that fits inside the tube body 2 and this inner cylinder part 12. An outer cylindrical portion 14 is provided at one end to form a tube receiving groove 13 which is substantially concentrically surrounded and for receiving the tube 2 therebetween. Further, in this outer cylinder part 14, a tip part 15 as a pressing part that presses the inserted pipe body 2 from the outer peripheral surface is connected to a step part 15 on the end side of the pipe body 2 of the tapered part 11 of the inner cylinder part 12.
A tapered portion 17 as a tightening force receiver is provided on the outer circumferential surface of the distal end portion 15, and a male screw portion 18 is formed on the outer circumferential surface of the base portion. On the other hand, the tightening nut 20
It has a female threaded part 21 which is screwed into the male threaded part 18, and further, following this female threaded part 21, there is a tapered hole part as a tightening force imparting part which engages with the tapered part I7 of the outer cylinder part 14 of the joint body 10. It is equipped with 22.

Next, the manner of use of the pipe joint 1 according to the present invention will be explained based on FIGS. 1 and 2. Note that FIG. 1 shows the state before the tightening is completed, and FIG. 2 shows the state after the tightening is completed.

As shown in Figure 1, first tighten the Nand 2
0 is inserted into the tube body receiving 1 of the joint body IO.
After inserting the tightening nut 20 into the joint body 10
Screw it into the male threaded part 18 of and tighten it. As this tightening nut 20 is tightened, the tapered hole 22 of the tightening nut 20 comes into contact with the tapered portion 17 of the outer cylinder section 14, and as the tightening nut 20 is further tightened, the joint body l
The outer cylindrical portion 14 of O is deformed inward from its tip 15 to be reduced in diameter, and as a result of pressing the tube 2 from the outer peripheral surface, the tube 2 is separated from the tip 15 of the outer cylindrical portion 14 and the inner cylindrical portion 12. It is clamped and locked by the , and has good pull-out strength and airtightness. Furthermore, in addition to the above-mentioned functions and effects, the tube body 2 has a distal end portion 1 of the outer tube portion 14 on the tube end side of the annular convex portion 11 of the inner tube portion 12.
5 strongly presses from the outer peripheral surface in the thickness direction of the tube body 2, so that the edge of the stepped portion 16 of the annular convex portion 11 is caught on the inner circumferential surface of the tube body 2, and as a result, the pull-out strength is significantly improved. .

Figs. 2 and 3 are longitudinal sectional side views showing other embodiments of the pipe joint according to the present invention. In the figure, the fitting main body 30 of the pipe fitting 3 is connected to the tip of the inner cylindrical portion 31 from the tip to the tube body 2.
An annular convex portion 34 is provided, which includes a tapered portion 32 whose diameter increases in the direction of insertion, and a straight portion 33 continuing from the tapered portion 32. On the other hand, tighten the tightening nut 4
0 has a second tapered hole 42 following the tapered hole 41 as a tightening force imparting portion, and a straight hole 43.
The structure is equipped with

In the case of such a configuration, in addition to the functions and effects described in the above embodiment, the inserted tube 2 can be inserted into the straight hole 43 of the tightening pad 40 and the straight portion 33 of the annular convex portion 34 of the joint body 30. As a result of being clamped and locked,
The pull-out strength and airtightness are even better. In addition,
In this case, it is of course possible to use a spherical surface instead of the second tapered hole 12 provided in the tightening nut 40 for smooth tightening.

In the two embodiments described above, the tightening force receiving part of the joint body and the tightening force imparting part of the tightening nut are respectively a tapered part and a tapered hole that engages with this tapered part. It may be formed into a spherical shape, or both may be made into a spherical shape, and furthermore, the tube insertion groove can be changed to an arbitrary shape.

Also, the composite +# that forms the fitting body! Various resins such as polyacecool, polyamide, polypropylene, and polyvinyl chloride can be used for the fingers, but with the structure of the present invention, +M fingers with a small friction coefficient such as fluorine resin can be used. Even when used, sufficient pull-out strength and airtightness are ensured, so the practical effect is extremely large. Note that the tightening nut does not necessarily need to be made of synthetic resin, and may be made of metal such as stainless steel, for example.

〔Effect of the invention〕

As explained above, according to the present invention, a tube body receiving groove is formed at the end of the inner tube portion and the outer tube portion, and furthermore, the inner tube portion has an annular convex portion on the outer peripheral surface, and the outer tube portion has an annular convex portion. The part is equipped with a clamping force receiving part at its tip, and a pressing part that presses the inserted tube from the outer circumferential surface, or a synthetic resin part located closer to the end of the tube than the annular convex part of the inner tube. The clamping force receiver of the joint body and the outer cylindrical part of this joint body has a clamping force imparting part that engages with the joint body, and the outer cylinder part is deformed inwardly by the clamping force imparting part when screwed onto the joint body. Since it is a pipe joint that is equipped with a tightening nut that presses the pressing part of the outer cylinder part against the outer peripheral surface of the pipe body, it has excellent pull-out strength and airtightness, and it is especially suitable for fittings made of slippery resins and resins such as fluororesin. Even when the main body is formed and a plastic tube made of the same material as the pipe body is connected, sufficient pull-out strength and airtightness can be ensured, resulting in a highly reliable pipe joint.

In addition, there is no need to perform special processing such as flaring or grooving on the end of the tube, and simply insert the tube into the annular groove of the joint body and tighten the tightening nut, making the connection easy and workable. Furthermore, it can be used repeatedly and has a small number of parts, making it an economical pipe fitting.

Note that the present invention is not limited to the above-mentioned embodiments, and may include, for example, changing the shape and position of the annular convex portion, making the joint body into an elbow shape, and even changing the shape of the joint body. Of course, various modifications are possible within the technical idea of the invention, such as selection of the fastening tool and change of the shape of the fastening nut.

[Brief explanation of drawings]

FIG. 1 is a longitudinal side view showing a state in which a plastic duplex is inserted into a pipe joint according to the present invention, FIG. 2 is a longitudinal side view showing a state in which the connection is completed by tightening the tightening nut, and FIG. FIG. 3 is a vertical side view showing a connected deafness of a different embodiment of a pipe joint according to the invention. 1.3 Pipe joint, 10.30: Joint body, II,
34. Annular convex portion, 12. 31: Inner cylinder portion, 13; Tube body receiving groove, 14. outer cylinder part, 15, pressing part,
17 Tightening force receiving part, 20.40 Tightening nand, 22.42: Tightening force imparting part.

Claims (1)

[Scope of Claims] (1) An inner cylindrical portion having an annular convex portion on its outer circumferential surface and fitting inside the tube body, and an inner cylindrical portion having an annular convex portion on the outer circumferential surface and fitting inside the tube body, and a tube portion located on the end side of the tube body from the annular convex portion of the inner cylindrical portion. It has a pressing part that presses the body from the outer circumferential surface, and has a tightening force receiving part on the outer peripheral surface of the end part for pressing the pressing part, and substantially concentrically surrounds the inner cylinder part and has a clamping force receiving part on the outer peripheral surface of the end. A joint body made of synthetic resin, the end of which is provided with an outer cylindrical portion that forms a pipe body receiving groove, and a tightening force imparting portion that is latched to the joint body and engages with a tightening force receiving portion of the outer cylindrical portion. A pipe joint comprising a tightening tool that reduces the diameter of an outer cylinder part and presses a pressing part of the outer cylinder part against the outer peripheral surface of the pipe body. (2) In the pipe joint according to claim 1, the tightening force receiving part of the outer cylinder part of the joint body is a tapered part whose diameter increases in the direction of insertion of the pipe body, and the tightening tool is attached to the joint body. A pipe joint comprising a tightening nut that is screwed together, and the tightening force imparting part thereof is a tapered hole part whose diameter increases in the direction of insertion of the pipe body. (3) In the pipe joint according to claim 2, the annular convex portion of the inner cylindrical portion of the joint body has a tapered portion whose diameter increases from the tip in the direction of insertion of the pipe, and a straight portion continuing from the tapered portion. The tightening nut is characterized in that it has a tapered hole that engages with the tapered portion of the outer cylinder of the joint body, a second tapered hole that follows the second taper hole, and a straight hole that continues from the second tapered hole. pipe fittings. (4) The pipe joint according to any one of claims 1 to 3, characterized in that the pressing part of the joint body is the tip of the outer cylinder part. The pipe joint according to any one of items 1 to 4, wherein the pipe receiving groove of the joint body is a tapered groove whose diameter increases in the direction of insertion of the pipe. (6) The pipe joint according to any one of claims 2 to 5, wherein the tightening nut is made of synthetic resin. (7) The pipe joint according to any one of claims 2 to 6, wherein the joint body and the tightening nut are made of fluororesin.