JP2562781B2 - Resin tube connection structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for a resin tube which is applied to connection of a flow path pipe for a fluid such as a socket, an elbow, a tee, etc., particularly a flow path pipe for a high purity fluid. it relates to.

[0002]

As the connection structure of the Related Art This type of resin tube, the conventional general, the joint body 1 of cylindrical shape as shown in FIG. 9
A meltable resin joint 104 such as PFA or PVDF in which a cylindrical portion 103 that is fitted to the outer peripheral surface of the one end portion 102a of the resin tube 102 is integrally formed on the end surface of 01 is used.

More specifically, the one end portion 102a of the resin tube 102 is inserted into the tubular portion 103 of the resin joint 104 so that their inner peripheral surfaces are flush with each other, and the end surface of the tubular portion 103 is also inserted. The outer peripheral surface of the resin tube 102 is welded through the resin material 105 such as PFA.

[0004]

In the conventional resin tube connection structure having the above-mentioned structure, the resin tube 10 is used.
The tubular portion 10 of the joint 104 is directly attached to the one end 102a of the second pipe 102.
Since it is simply inserted into the inside of No. 3 and welded, the sealing property is poor. Particularly, since the one end surface 102b of the resin tube 102 is a cut surface by manual work, as shown in FIG. 10 , it is difficult to form a right angle with respect to the axis, and the surface is often inclined with respect to the axis. , One end surface 102b of the resin tube 102 and a joint 104 facing the one end surface 102b.
A substantially V-shaped gap S is generated between the inner peripheral surface of the tubular portion 103 of the joint 104 and the outer peripheral surface of the resin tube 102 of the joint 104. S
It is easy to get into 1 and cause a liquid pool. Then, when an external vibration or the like is received, there arises a problem that the chemical liquid or dust that has accumulated and deteriorated in the portion S1 flows out into the resin tube 102 to reduce the purity of the fluid such as the chemical liquid.

Also, one end portion 102 of the resin tube 102
Since the outer peripheral surface of a is only in contact with the inner peripheral surface of the cylindrical portion 103 of the joint 104, the retaining force is weak and the resin material 10
If peeling occurs due to poor welding due to No. 5, the resin tube 102 may come off.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to remarkably improve the sealing property and prevent the generation of liquid pool, and to improve the welding strength of the resin tube.
It is an object of the present invention to provide a resin tube connection structure that can improve the degree of reliability and greatly improve the reliability against disconnection.

[0007]

[Means for Solving the Problems] To achieve the above object
In the resin tube connection structure according to the invention of claim 1 ,
The end of the tubular joint body and the resin tube from this end
Between the cylindrical protrusion that extends along the outer peripheral surface of the
An annular long groove extending inward in the axial direction is formed in the fitting body part to be placed.
Is formed in the annular long groove on one end side of the resin tube.
The expanded diameter part formed is press-fitted and the cylinder
At the tip of the protrusion, the diameter gradually decreases inward in the axial direction.
Taper surface is formed, and this taper surface and resin tube
The outer peripheral surface of one end of the is welded with resin .

The resin tube according to the invention of claim 2
The connection structure of is the end part of the tubular joint body and this end part.
Cylindrical protrusions extending from the outer peripheral surface of the resin tube
Extends inward in the axial direction at the joint body located between the
An annular long groove is formed, and the resin tube is formed in the annular long groove.
If the expanded diameter portion formed on one end side of the
In both cases, the tip portion of the cylindrical protrusion is heat-deformed,
The deformed portion is fused to the outer peripheral surface of one end of the resin tube.
It is what

[0009] Here, in the connection structure for a resin tube for fixing by press-fitting one end enlarged diameter portion of the resin tube into the annular long groove of the joint body, as claimed in claim 3, the rising of the enlarged diameter portion of the resin tube It is preferable to form a taper surface at the outer end of the joint main body corresponding to the inner peripheral surface of the portion, the taper surface having a gradually decreasing diameter from the outer end toward the inner side in the axial direction and reaching the inner peripheral surface of the joint main body. better rather, also, as of claim 4
In addition, the inclination angle of the tapered surface with respect to the axis is 20 ° to 6
It is desirable to set it to 0 °.

[0010]

According to the inventions of claims 1 and 2, the expanded diameter portion formed at one end of the resin tube is connected to the joint side.
An annular length formed by extending inward in the axial direction on the joint body part of
Not only press fit into the groove, but also on the outer peripheral surface of the resin tube.
Formed at the tip of the cylindrical protrusion on the joint side that is extended along
Taper surface that gradually decreases in diameter in the axial direction
And the outer peripheral surface of one end of the resin tube by resin welding (contract
(Requirement 1), heating the tip of the tubular protrusion on the joint side
By deforming, the deformed part is the outer circumference of one end of the resin tube
By fusing to the surface (in the case of claim 2),
A long creepage distance can be secured between the expanded diameter part and the annular long groove.
And the inner peripheral surface of the rising part of the expanded part on the resin tube side and this
The seal part is attached to the crimping part with the tapered surface on the joint side corresponding to
Be formed, and further, the cylindrical protrusion on the joint side and the resin
Synergistic work of increasing the joint strength with the outer surface of the tube
The use, together with the whole of the seal is enhanced, reservoir
Is also prevented from occurring, which does not reduce the purity of the fluid,
In addition, the retaining force for the resin tube is strengthened and
Maintaining the desired sealability over a period of time
Is possible.

In addition, the structure as described in claim 3,
That is, the outer end of the joint body gradually decreases inward in the axial direction.
By adding a configuration that forms a tapered surface that reaches the inner diameter of the joint body, it is possible to ensure that a liquid pool is generated between the outer end of the joint body and the inner circumference of the resin tube.
It can be prevented.

In particular, the inclination angle of the taper surface is defined by claim 4.
As described above, when the angle is set to 20 ° to 60 °, it is possible to more reliably reduce the liquid pool.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a longitudinal sectional view showing the connection structure of the resin tube according to an embodiment of the present invention. In the figure , joint 1
Is the tubular projection 5 formed along the outer circumferential surface of the end portion 4a of the end portion of the joint body 2 of cylindrical shape made of a synthetic resin as the tube 4 from the end portion (FIG. 2), such as PFA while
An annular ring extending inward in the axial direction on the joint body located at
The long groove 22 is formed, and the cylindrical protrusion 5 is formed.
The tip of the taper has a diameter that gradually decreases inward in the axial direction.
A superface 26 is formed.

On the other hand, the resin tube 4 is made of PFA or P
Ri Do from the heat meltable synthetic resin such as VDF, this
As shown in FIG. 2, one end 4a side of the resin tube 4 of
The flared portion 21 is formed by flare processing. this
Corresponding to the inner peripheral surface 23 of the rising portion 21A of the expanded diameter portion 21
The outer end of the joint body 2 is tapered along the inner peripheral surface 23.
A surface 24 is formed.

When the resin tube 4 is connected to the joint 1, the expanded diameter portion 21 of the resin tube 4 is connected as shown in FIG.
, Press-fitted into the annular long groove 22 on the joint 1 side, and then on the joint 1 side
Do not heat and deform the cylindrical protruding part 5 of the
The resin surface 26 and the outer peripheral surface of the one end 4a of the resin tube 4 are connected to each other.
By welding and fixing with the fat material 11, the joint 1 and the resin
Connect to tube 4. In this case, the resin tube 4
Corresponding to the inner peripheral surface 23 of the rising portion 21A of the expanded diameter portion 21
The seal portion S is attached to the pressure-bonded portion with the tapered surface 24 on the joint 1 side.
4 is formed, and between the enlarged diameter portion 4a and the annular long groove 22.
A relatively long creepage distance can be obtained at. This connection
The expanded diameter portion 21 in the structure can be easily molded.
Has the advantage that the cost of the connection part can be reduced.
It

FIG . 3 is based on the structure shown in FIG. 1 and has a rising portion 21 of the expanded diameter portion 21 of the resin tube 4.
Corresponding to A, as shown in FIG. 4 , the outer end of the joint body 2 has a taper that gradually decreases in diameter inward from the outer end toward the inner peripheral surface of the joint body 2. The surface 25 is formed. As shown in FIG. 1 , the outer end of the joint body 2 has the tapered surface 24 on the joint 1 side corresponding to the rising portion 21A and the inner peripheral surface 23 of the rising portion 21A as it is.
In the case where the inner peripheral surface of the resin tube 4 and the inner peripheral surface 24 of the rising portion 21 are both provided with a small gap G (see FIG. 4 ) with respect to the outer end of the joint body 2, It is easy to generate and becomes a liquid pool.

On the other hand, when the tapered surface 25 is formed on the outer end of the joint body 2 as shown in FIG. 3 , the small gap G is not formed, and the generation of the liquid pool is prevented, and the alteration is caused. It is possible to safely handle the distribution of chemicals that you want to avoid. Also, when welding with resin material 11
When the resin tube 4 is heated to 300 ° C. or higher and then cooled and contracted, the edge portion P at the position where the tapered surface 24 on the joint body 2 side and the tapered surface 25 intersect (see FIG. 4 ).
Is the inner peripheral surface 23 of the rising portion 21A of the resin tube 4.
It is possible to exert a sealing effect by a high contact pressure by press-contacting with. Here, the inclination angle θ2 (see FIG. 7) of the tapered surface 25 with respect to the axis is preferably selected within the range of 20 ° to 60 °, and if it is smaller than 20 °, the thickness of the tapered surface 24 becomes thin. Since the pressure contact force weakens, the edge part P
The sealing effect due to is also weakened. Further, if it is larger than 60 °, stagnation of the liquid is likely to occur near the tapered surface 25. Therefore, it is most preferable to set the angle to about 45 °.

5 and 6 show another embodiment of the present invention.
FIG. 3 is a vertical cross-sectional view showing a connection structure of a resin tube
A flared enlarged portion 21 on one end side of the tube 4,
As shown in FIG. 5, after being press-fitted into the annular long groove 22 on the joint 1 side,
The cylindrical protruding portion 5 on the joint 1 side is deformed by heating to deform the deformed portion.
As shown in FIG. 6, the one end portion 4a of the resin tube 4 is
After crimping to the outer peripheral surface, the tip of the cylindrical protruding portion 5 and the resin tube are
The outer peripheral surface of one end 4a of the bump 4 is welded with the resin material 11.
By connecting the joint 1 and the resin tube 4 with
is there. In this case, not only the bonding sites between the outer peripheral surface of the one end portion 4a of the cylindrical protrusion 5 of the joint 1 side and the resin tube 4,
The seal portion S4 is formed at the crimping portion between the inner peripheral surface 23 of the rising portion 21A of the expanded diameter portion 21 of the resin tube 4 and the corresponding tapered surface 24 on the joint 1 side, and the expanded diameter portion 4a and the annular long groove are formed. 22 Ri Do that relatively long creepage distance can be obtained between the sealing property and bonding strength can be further enhanced.

[0019] Also in the connection structure as in FIGs. 5 and 6, as shown in FIG. 3, the outer end of the joint body 2, to form a similar tapered surface 25 and described above, at the site It is preferable to prevent the generation of the liquid pool.

By the way, in each of the above embodiments, that is, in the annular long groove 22 on the joint body 2 side, the expanded diameter portion 21 of the resin tube 4 is provided.
7 , the inclination angle α of the taper surface 24 on the joint body 2 side that abuts the inner peripheral surface 23 of the rising portion 21A of the expanded diameter portion 21 is 20 to 45 ° as shown in FIG.
It is preferable to set it within the range of, preferably 30 °. When the inclination angle α is less than 20 °, the retaining force of the expanded diameter portion 21 of the resin tube 4 with respect to the annular long groove 22 becomes weak,
Further, when the angle exceeds 45 °, the expanded diameter portion 21 of the resin tube 4
Molding becomes difficult.

FIG. 8 shows an application example of the above-mentioned resin tube connection structure. For example, pipe joints 32 and 3 are respectively provided at predetermined connection portions of a T-shaped welded joint body 31 for connecting flow paths of fluid equipment pipes.
3 is connected, and the resin tube 4 is connected to the other connecting portion to form the welded pipe component 34.

[0022]

As described above, claim 1 and claim 2 are as follows.
According to the invention described in (1) , it is formed on one end side of the resin tube.
The expanded diameter portion extends axially inward to the joint body on the joint side.
Not only press-fit into the annular long groove formed by
A tubular shape on the joint side that extends along the outer peripheral surface of the tube.
Gradually inward in the axial direction formed on the tip of the protrusion
The taper surface with a small diameter and the outer peripheral surface of one end of the resin tube
Resin welding or heating of the tip of the tubular protrusion on the joint side
By deforming, the deformed part is the outer circumference of one end of the resin tube
By fusion bonding to the surface, the expanded diameter portion and the annular long groove
A long creepage distance can be secured between the resin tube side
The inner peripheral surface of the rising part of the expanded part of and the corresponding joint side
The seal part should be formed at the crimping part with the taper surface.
Between the cylindrical projection on the joint side and the outer peripheral surface of the resin tube.
Due to the synergistic effect of increasing the bonding strength, it is possible to exert a very excellent sealing effect compared to the conventional one.
Together, can it to prevent a disadvantage that generation and such as reduction of fluid purity with that of the liquid reservoir. Moreover, the joint strength between the resin tube and the joint body is increased to prevent it from coming off.
It is possible to strengthen the
The effect of being able to stably maintain reliability and reliability .

According to the third and fourth aspects of the present invention, in addition to the above effects, it is ensured that a liquid pool is generated at the connection portion between the inner peripheral surface of the joint body and the inner peripheral surface of the resin tube. Therefore, it is possible to obtain a connection structure which is very useful for handling a high-purity fluid.

[Brief description of drawings]

FIG. 1 is a semi-longitudinal sectional view showing a resin tube connection structure according to an embodiment of the present invention .

[Figure 2] Semi-longitudinal section of resin tube used for the same connection structure
It is a side view.

FIG. 3 is a view showing a resin tube connection according to another embodiment of the present invention .
It is a semi-longitudinal sectional view showing a structure.

FIG. 4 is an enlarged cross-sectional view of a main part of the above embodiment.

FIG. 5: Connection of resin tube according to another embodiment of the present invention
It is a semi-longitudinal sectional view showing a state before connection of the structures.

FIG. 6 is a semi-longitudinal section showing a connection completed state in the above embodiment .
It is a side view.

FIG. 7 is a main part in each of the embodiments of FIGS.
FIG. 7 is an enlarged cross-sectional view for explaining the angle of the tapered surface of the taper.

[FIG. 8] The resin tube connection structure of the present invention is used as a piping component.
It is sectional drawing of the applied example.

[FIG. 9] Half-longitudinal section showing a conventional resin tube connection structure
It is a side view.

FIG. 10 is an explanatory view of a cut surface of a conventional resin tube.
It

[Explanation of symbols]

1 joint 2 joint body 4 resin tube 4a one end of resin tube 5 tubular protrusion 11 resin material 21 for welding 21 expanded diameter portion 21A rising portion 22 annular long groove 25 taper surface θ2 inclination angle

Claims (4)

(57) [Claims] 1. An end portion of a tubular joint body and whether this end portion is
Cylindrical protrusions extending from the outer peripheral surface of the resin tube
Extends inward in the axial direction at the joint body located between the
An annular long groove is formed, and the resin tube is formed in the annular long groove.
If the expanded diameter portion formed on one end side of the
At the same time, at the tip of the above-mentioned tubular protrusion, face inward in the axial direction.
Taper surface is formed that gradually decreases in diameter.
A resin tube connection structure characterized in that the outer peripheral surface of one end of the resin tube is resin-welded . 2. An end portion of a tubular joint body and whether the end portion is
Cylindrical protrusions extending from the outer peripheral surface of the resin tube
Extends inward in the axial direction at the joint body located between the
An annular long groove is formed, and the resin tube is formed in the annular long groove.
If the expanded diameter portion formed on one end side of the
In both cases, the tip portion of the cylindrical protrusion is heat-deformed,
The deformed portion is fused to the outer peripheral surface of one end of the resin tube.
The resin tube connection structure is characterized in that 3. The outer diameter of the joint main body corresponding to the inner peripheral surface of the rising portion of the expanded diameter portion of the resin tube is gradually reduced from the outer end inward in the axial direction, and the diameter of the joint main body is gradually reduced. claim tapered surface extending up to the inner circumferential surface is formed 1
Alternatively, the resin tube connection structure according to item 2 . 4. The resin tube connection structure according to claim 3, wherein an inclination angle of the tapered surface with respect to the axis is set to 20 ° to 60 °.