JPH0439490A - Tube joint - Google Patents

Abstract

PURPOSE:To hold a tube in the liquid-tight condition relative to a joint body and prevent the tube from being drawn out of the joint body by tightly nipping the intermediate part of large diameter section of the tube with the outer peripheral surface of a groove ring of the connection and the inner peripheral surface of a projecting ring to form a tube bending part. CONSTITUTION:A tube 1 is formed on one end with a large diameter part 2 by the use of a hot molding jig (a). A joint body 4 formed with a groove ring 3 and molded of fluorine resin is inserted in the large diameter part at a inserting part 5. A ring 6 formed on the inner surface previously loose fitted on the tube 1 with a projecting ring 6a is moved downward by the use of a moving-down jig to press fit the projecting ring 6a onto the outer peripheral surface of the inserting part 5 of the joint body 4 while putting the large diameter part 2 between the ring 6a and the body 4. Then, the large diameter part 2 of the tube 1 is firmly nipped by the outer peripheral surface of the groove ring 3 of the inserting part 5 and the inner peripheral surface of the projecting ring 6a of the ring 6 to form a tube bending part 7, and provide a tube joint according to this invention. Thus, the tube 1 is held in the liquid-tight condition relative to the joint body 4 and the tube 1 is not drawn out of the joint body 4 by an external force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tube joint, and more specifically to a tube joint suitable as a joint for synthetic resin tubes, particularly fluororesin tubes.

[Prior art] This type of tube joint has been conventionally used, for example, in the
Some of them are described in Japanese Patent No. 52391.

This conventional technology consists of a joint body, a cap nut for attaching a synthetic resin hard pipe to the joint body, and a trapezoidal seal ring that fits into a tapered hole communicating with a pipe insertion hole in the joint body. and a trapezoidal taper ring provided with a wide slanted groove that fits into the taper hole communicating with the female threaded portion of the cap nut, applying a compressive force to the pipe in the direction of its center and deforming the outer circumference of the pipe. This pipe joint is characterized in that it is fixed by holding the pipe joint in place.

[Problems to be Solved by the Invention] The conventional technology described above measures sealing and prevention by inserting a taper ring or seal ring into the tube, but since there is no insert inside the tube, There were problems in that the biting was weak, the tube easily came off from the joint body, and the sealing performance changed with temperature cycles, so so-called "retightening" was required, making maintenance troublesome.

In order to eliminate the above-mentioned problems, this invention inserts a pre-formed large-diameter portion of the tube into an insertion portion protruding from the joint body, and inserts a ring loosely inserted into the tube in advance. By sandwiching the large diameter part between the protruding rings and firmly press-fitting it into the groove ring of the joint body by resisting the elasticity of each material of the tube, insertion part, or ring, or by utilizing the heat recovery properties of each material. , a tube in which the intermediate portion of the large diameter portion is tightly sandwiched between the outer circumferential surface of the groove ring of the insertion portion of the joint body and the inner circumferential surface of the protruding ring of the ring, forming a tube bent portion for preventing slippage and maintaining liquid tightness. The purpose is to provide fittings.

[Means for Solving the Problems] An object of the present invention described above is to attach a tube by forming a deformed part on the tube to form a tube joint that prevents the tube from coming off. A large diameter part is formed at the end of the tube made of aluminum, and the insertion part of the fitting body, which has a groove ring and is made of fluororesin or the like, is inserted into the large diameter part, and is loosely inserted into the tube. , and by press-fitting a ring having a protruding ring made of fluororesin or the like into the groove ring of the insertion part of the joint body with the large diameter part sandwiched between the protrusions, the middle part of the large diameter part of the tube can be fixed. This is accomplished by tightly sandwiching the tube between the outer circumferential surface of the groove ring of the insertion portion and the inner circumferential surface of the protruding ring of the ring to form a tube bending portion.

Further, a cap nut, which has been inserted into the tube in advance, is screwed into the male thread portion formed in the insertion portion of the joint body using its female thread portion, and the tube is inserted into the end surface of the insertion portion using the inner surface of the shoulder portion of the cap nut. It is also possible to hold the refraction tightly.

[Function] After inserting a ring with a protrusion into the tube in advance, insert the large diameter portion previously formed in the tube into the insertion portion of the joint body, and insert the large diameter portion formed in the insertion portion into the insertion portion. By firmly press-fitting the ring to the outer peripheral surface of the groove ring with its protruding ring against the elasticity of the material of each member or by utilizing the heat recovery property of each material, the intermediate portion of the large diameter portion A tube bending portion can be formed which is tightly sandwiched between the outer circumferential surface of the groove ring of the joint body and the inner circumferential surface of the protruding ring of the ring.

Since this tube bending part is tightly held between the protruding corner part of the ring and the corner part of the groove ring, the tube is kept liquid-tight with respect to the joint body, and the tube and ring cannot come out from the joint body. There is no.

Furthermore, since the large diameter portion is surrounded by a ring, the end portion of the tube can be protected.

Furthermore, by tightly bending and holding the middle part of the tube protruding from the end face of the insertion part of the joint body to the above end face with the inner surface of the shoulder of the cap nut, the tube and other rings will not come out of the joint body. do not have.

[Example] Examples will be described with reference to the drawings.

First of all, the basic structure of this invention is that the tube is attached by forming a deformed part on the tube to form a tube joint that prevents it from coming off, and is made of plastic such as fluororesin as shown in Figure 1. 2 and 3 using a heat forming jig a as shown in the same figure at the end of the tube 1.
A large diameter portion 2 as shown in the figure is formed.

Then, a joint body 4 molded from fluororesin as shown in FIG. 4 with a groove ring 3 formed in the large diameter portion 2 is inserted through its insertion portion 5. As shown in FIG.

Further, as shown in FIG. 4, a ring 6 having a protruding ring 6a on the inner surface, which has been loosely inserted into the tube 1 in advance, is moved down using a lowering jig, and after passing through the state shown in FIG. Press fit of the protruding ring 6a onto the outer circumferential surface of the insertion portion 5 of the joint body 4 with the diameter portion 2 in between begins.

Then, as the above-mentioned press-fitting continues, the large diameter portion 2 of the tube 1 is tightly sandwiched between the outer circumferential surface of the groove ring 3 of the insertion portion 5 and the inner circumferential surface of the protruding ring 6a of the ring 6, as shown in FIG. A tube bent portion 7 as shown is formed to obtain a tube joint according to the present invention.

Further, the cap nut 8 inserted into the tube I is screwed into the male thread portion 5a formed in advance on the joint body 4 with its female thread portion 8a, and the inner surface of the shoulder portion 9 of the cap nut 8 As shown in the figure, another example of the tube joint according to the present invention is constructed by tightly pressing the tube 1 against the end face of the insertion portion 5 to further bend and hold the intermediate portion of the tube 1.

The ring 6 is made of plastic such as fluororesin or metal, and the joint body 4 is made of metal or plastic such as fluororesin.

FIG. 8 shows still another embodiment of the present invention, in which the insertion portion 5 of two couplings 4.4 is omitted in place of the coupling body 4 of the previous embodiment and the male threaded portion 5a is omitted. , 5 are connected by a tube 1 via a ring 6 with a protrusion or the like.

In this case, the tube 1 may have the same diameter as the insertion portion of the joint, as shown by the chain line, and the large diameter portion 2 may not be formed.

In other words, in this case, the inner diameter of the ring 6 is expanded in advance using a heating jig or the like to a larger diameter than the diameter of the tube 1 (the part shown by the imaginary line), and then the ring 6 is inserted into the groove ring 3 with the tube 1 in between. By reheating the ring 6 together with the protrusion 6a with the protrusion 6a of the ring 6 already enlarged, the diameter can be reduced as shown in FIG. The tube 1 can be tightly jointed to the joint body 4 in the same way as when the ring 6 is mechanically press-fitted into the insertion portion 5 by sandwiching the portion 2 using the press-fitting jig.

In FIG. 8, portions with the same reference numerals as those in the above embodiment indicate portions having the same effect.

The structure of the present invention is as described above. Next, the usage condition and operation of the tube joint according to the present invention will be explained below.

First, the ring 6 is inserted into the tube 1 in advance, and then the tube 1 is preformed as shown in FIG. 3 through the conditions shown in FIGS. 1 and 2 using a heat forming jig a. The large diameter portion 2 is inserted into the insertion portion 5 of the joint body 4 as shown in FIG.

Then, the ring 6 is held in the state shown in FIG. It is possible to firmly fit the protruding ring 6a by forcefully pressing it in against the pressure or by utilizing the heating diameter shrinking property of the ring, and as shown in FIG. A tube bent portion 7 can be formed as shown in FIG. 6, tightly sandwiched between the outer circumferential surface of the groove ring 3 of the insertion portion 5 and the inner circumferential surface of the protruding ring 6a of the ring 6.

The tube bent portion 7 is tightly held between the corner of the groove ring 3 and the corner of the protrusion 6a of the ring 6, as shown in FIG. It is held and does not come off from the insertion part 5 of the joint body 4.

Furthermore, the middle part of the tube 1 protruding from the end face of the insertion part 5 of the joint body 4 is tightly bent and held at the end face by the inner surface of the shoulder part 9 of the cap nut 8, as shown in FIG.
The tube 1 and other rings 6 will not come out of the joint body 4.

In the example shown in Fig. 8, the protruding ring 6a of the ring 6 is tightly fitted into the groove ring 3 of the joint body 4 with the tube 1 between them, so even if the cap nut 8 is omitted, the ring 6 and the tube can be easily removed from the joint 4. 1 never escapes from delusion.

Furthermore, if the ring 6 is made of fluororesin, by actively utilizing its thermal deformability, the ring 6 and the protruding ring 6a can be heated and expanded to the diameter of the tube large diameter portion 2 or an inner diameter slightly larger than this diameter. The diameter of the ring 6 is increased in advance using a diameter jig, and this ring 6 is loosely inserted into the tube l, and the protruding ring 6a faces the groove ring 3 with the large diameter portion 2 of the tube in between. 6
By reheating and reducing the diameter, the protruding ring 6a can be press-fitted onto the outer circumferential surface of the grooved ring 3 with the tube 1 tightly sandwiched between them, as shown in FIG.

Particularly in this case, the ring 5 does not have to be forcefully mechanically or physically press-fitted as in the previous embodiment, so that the press-fitting operation can be carried out even more easily.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

After inserting the ring 6 into the tube 1 in advance, insert the large diameter portion 2, which is previously formed in the tube 1, into the joint body A at its insertion portion 5, and insert the ring 6 with its protrusion. By forcefully press-fitting the tube 1 with the large diameter portion 2 in between, resisting the elasticity of each material of the tube ring 6 and the insertion portion 5, it is possible to fit the tube with a single click, or to attach it in advance. By heating the ring 6, which has been increased in diameter through initial heating, and reducing the diameter after insertion, the large diameter portion 2 can be tightly clamped and fitted.

Therefore, a tube bent portion 7 is formed in the middle of the large diameter portion 2 of the tube 1, which is tightly sandwiched between the outer circumferential surface of the groove ring 3 of the insertion portion 5 of the joint body 4 and the inner circumferential surface of the protruding ring 6a of the ring 6. can do.

This tube bent portion 7 is a protruding ring 6a of the ring 6.
and the corner of the groove ring 3, and the other part of the large diameter tube 2 is tightly sandwiched between the inner circumferential surface of the ring 6 and the outer circumferential surface of the insertion part 5. Therefore, the tube 1 is kept liquid-tight with respect to the joint body 4, and the tube 1 does not come out of the joint body 4 due to external force, so the sealing performance and pull-out strength are not deteriorated due to temperature cycles or changes over time. The first effect is that maintenance is easy because so-called "retightening" is not required.

In particular, in this invention, even without using a cap nut, the tube can be reliably joined to the joint body by locking the tube with a single snap using a ring with a protrusion, or by reducing the diameter by reheating the ring. The workability at the construction site when connecting pipes is greatly improved compared to the conventional example, and since most of the end of the tube 1 is surrounded by the ring 6, the end of the tube 1 can be protected. 2
It has the effect of

According to claim 2, in addition to the above-mentioned effects, the intermediate portion of the tube 1 protruding from the end face of the insertion portion 5 of the joint body 4 is tightly bent at the end face at the inner surface of the shoulder portion 9 of the cap nut 8. By holding the ring 6, the tube 1 and other rings 6 are prevented from slipping out from the joint body 4, which has the effect of stably maintaining the function of the joint over a long period of time.

[Brief explanation of drawings]

Each of the figures shows an embodiment of the present invention. Figure 1 is a cross-sectional view of a tube and a heat-forming jig, and Figure 2 is a tube that is press-fitted into a heat-forming jig to form a large diameter part. cross section,
3 and 4 are cross-sectional views showing the procedure for inserting the tube into the joint body, respectively, and FIG. 5 is a cross-sectional view showing the moment when the ring is press-fitted into the joint body with the tube in between,
Figure 6 is a sectional view of a tube fitting with a ring press-fitted into it, Figure 7 is a sectional view of a tube fitting with a cap nut screwed together, and Figure 8 is a sectional view of a tube fitting with a cap nut screwed into it.
The figure is a sectional view showing another example of the tube joint. 1...Tube 2...Large diameter part 3...Groove ring 4...Joint body 5...Insertion part 5a...Male thread part 6...Ring 6a...Protrusion ring 7 ...Tube bent part 8...Fall nut 8a...Female thread part 9...Shoulder Applicant: Flowel Co., Ltd.

Claims (1)

[Claims] 1. A tube joint in which the tube is prevented from coming off by forming a deformed portion when the tube is attached,
A large diameter portion 2 is formed at the end of a tube 1 made of plastic such as fluororesin, and a groove ring 3 is formed within this large diameter portion 2, and a joint body 4 made of fluororesin or the like is inserted. 5, and a ring 6 which is loosely inserted into the tube 1 and has a protrusion 6a made of fluororesin etc. is inserted into the insertion part 5 of the joint body 4, with the large diameter part 2 sandwiched between the protrusion 6a. By press-fitting into the groove ring 3 of the tube 1, the intermediate portion of the large diameter portion 2 of the tube 1 is tightly connected to the outer peripheral surface of the groove ring 3 of the insertion portion 5 and the inner peripheral surface of the protrusion ring 6a of the ring 6. A tube joint formed by sandwiching the tube to form a tube bending section 7. 2. Screw the cap nut 8, which has been inserted into the tube 1 in advance, into the male thread portion 5a formed on the joint body 4 with its female thread portion 8a, and then tighten the tube 1 with the inner surface of the shoulder portion 9 of the cap nut 8. 2. The tube joint according to claim 1, wherein the insertion portion 5 is tightly bent and held at the end face thereof.