JPH10196867A - Tube coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To tightly hold resinous tubes against their falling-off with a tube coupling with improved sealing performance, which is constituted of a smaller number of component parts for its lower manufacturing costs. SOLUTION: A tube coupling body A involves a pipe part on the side of tube coupling, which comprises a swelling portion 10a on the outer periphery at its opening for receiving an expanded resinous tube C force-fitted thereon, a consecutive pipelike portion 10b having outside diameters smaller than the maximum outside diameter of the swelling part 10a and larger than the inside diameter of the tube C for holding the tube C expanded, and a consecutive externally threaded portion 10c. With the tube C being fitted over the swelling portion 10a and the pipelike portion 10b, a pressure ring B loosely fitted on the tube C in advance is brought into mesh at its internally threaded portion 12 with the externally threaded portion 10c until its tube insertion port butts against the swelling portion 10a to thereby press a portion 11a of the tube C forward and thus produce a seal portion 13 in the tube C. The tube C is thus sealed under its close contact with the swelling portion 10a and the pipelike portion 10b at two positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a valve, a pump,
The present invention relates to improvement of a joint for a resin tube used for connecting a fluid device such as a tank and a flow meter.

[0002]

2. Description of the Related Art Conventionally, a joint shown in FIGS. 4 and 5 has been known as this kind of joint for a resin tube. This tube joint comprises a tubular joint body 1 and a resin tube 2.
The inner ring 3 is press-fitted into the inside of the inner ring 3 and a cap nut-shaped pressing ring 4. The inner ring 3 has a mountain-shaped bulging portion 3a formed on the outer periphery thereof,
After the distal end portion of the resin tube 2 into which the inner ring 3 is press-fitted, is fitted into the enlarged-diameter receiving port 1a inside the joint main body 1, the pressing ring 4 previously inserted through the tube side is screwed into the screw portion of the joint main body 1. By screwing the inner ring 3
A seal portion b in which the tube tip protruding portion of the inner ring 3 is pressed against the inner portion of the receiving port 1a, a seal portion b in which the bulging portion 3a of the inner ring 3 is pressed against the inner surface of the tube, and a bulging portion in the tube insertion opening edge of the pressing ring A seal portion d for pressing the tube portion inserted into the portion 3a is formed, and leakage of fluid is prevented by these seal portions.

[0003]

The joint having the above-described structure has a structure in which three parts, ie, a joint body, an inner ring, and a press ring, are combined. Therefore, the number of parts is large and the cost is high, instead of a simple structure. There is. Further, in assembling the three parts, it is necessary to first perform a troublesome and troublesome work of press-fitting the inner ring into the tube, so that the workability is poor.

The present invention has been made to solve the above-mentioned drawbacks of the conventional resin tube joint,
A main object of the present invention is to provide a resin tube joint that can reduce the number of parts compared to conventional products, reduce costs, improve assembling workability, and ensure good sealing performance. .

[0005]

A tube joint according to the present invention has a bulging portion for expanding a diameter of a resin tube inserted into an outer periphery of a tube opening in a tube connecting side tube portion and holding the tube in a press-fit state. A tubular portion having a bulge portion, a tubing portion smaller than the maximum outer diameter of the bulge portion, larger than the inner diameter of the tube, a tube portion for expanding the tube and holding the tube in a press-fit state, and a male thread portion following the tubular portion. Of the joint body and the male thread part of the joint body, and presses the tube part fitted into the bulging part out of the tube part fitted over the bulging part and the tubular part by screwing. And a pressing wheel that provides a pressing sealing force.

[0006]

1 and 2 show a preferred embodiment of the present invention. A is a tubular joint body, B is a press wheel, and C is a resin tube. The tube connection side tube portion of the joint body A is for expanding the resin tube C around the outer periphery of the tube opening and holding it in a press-fit state. The bulging portion 10a and the bulging portion 10
Following a, it is smaller than the maximum outer diameter of the bulging portion but larger than the inner diameter of the tube, and has a tubular portion 10b for expanding the tube and holding it in a press-fit state, and a male thread portion 10c following the tubular portion. After the resin tube C is fitted over the bulging portion 10a and the cylindrical portion 10b, the female screw portion 1 of the pressing wheel B previously inserted through the tube is inserted.
2 is screwed into the male screw portion 10c of the joint body A, and the push ring is screwed forward so that the bulging portion 10a is inserted into the tube insertion opening of the push ring B.
The tube portion 13a, which is inserted in a larger diameter, is pressed toward the bulging portion.

[0007]

1 and 2 show an embodiment in which the present invention is applied to a tube joint of a chemical pipe in a semiconductor manufacturing apparatus. In FIGS. 1 and 2, A is PFA, PTFE, ETFE,
Tubular joint body made of fluororesin having excellent properties of chemical resistance and heat resistance such as PVDF, B is a cap nut type press ring made of similar fluororesin, and C is made of similar fluororesin Tube.

[0008] The tube connecting side tube portion of the joint body A is
A swelling portion 10a having a semicircular cross section for holding the resin tube C in the press-fit state by expanding the diameter of the resin tube C around the outer periphery of the tube opening. The swelling portion is smaller than the maximum outer diameter of the swelling portion, but larger than the inner diameter of the tube. The structure has a tubular portion 10b to be held in a press-fit state and a male screw portion 10c following the tubular portion. Reference numeral 10d denotes a male screw portion which is screwed to a device main body (not shown).

In order to connect the tube C to the joint body A, the tube C is fitted over the bulging portion 10a and the tubular portion 10b of the tube connecting side tube portion of the joint body A. As a result, the tube portion 1 whose diameter has been expanded and inserted into the bulging portion 10a
The tube 1a is in close contact with the bulging portion 10a and is held in a retaining state, and the tube portion 11b inserted into the tubular portion 10b with a larger diameter is also held in close contact with the tubular portion 10b. Thereafter, the female screw portion 12 of the pressing wheel B, which has been inserted into the tube C in advance, is screwed into the male screw portion 10c on the joint body side,
By screwing the push ring, the tube insertion opening of the push ring B presses the tube portion 11a, which is inserted into the swelling portion 10a in a diameter-expanding manner, toward the swelling portion. It is formed.

According to the above construction, the inner ring constituting the conventional tube joint can be omitted, so that the cost can be reduced by reducing the number of parts. In addition, since the troublesome and troublesome work of press-fitting the inner ring into the tube is not required, the assembling workability can be improved and good sealing performance can be ensured.

Further, according to the configuration, the tube C inserted into the tube connecting side tube portion of the joint body A has the bulging portion 1.
At 0a, a sealing action and a retaining action due to a strong adhesion force are obtained, and further, a sealing action due to adhesion is obtained even at the subsequent tubular portion 10b, and the tube insertion opening portion of the pressing wheel B is expanded and fitted to the bulging portion 10a. The sealing portion 13 that presses the inserted tube portion provides a strong local sealing action.

FIG. 3 shows another embodiment of the present invention. This embodiment is a configuration example in which a bulging portion 10a integrally formed on the tube connecting side of the joint body A has a mountain-shaped cross section. Even when the bulging portion is formed in a mountain shape in cross section, the same operation and effect as described above can be obtained.

[0013]

As described above in detail, according to the present invention, the number of parts can be reduced and the cost can be reduced, the resin tube can be held in a strong retaining state, and good sealing can be achieved. A joint for a tube that can ensure the performance is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a resin tube joint according to an embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view of a resin tube before insertion.

FIG. 3 is a cross-sectional view of a tube joint showing another embodiment of the present invention.

FIG. 4 is a sectional view of a conventional tube joint.

FIG. 5 is an exploded cross-sectional view of an inner ring and a joint body into which a resin tube is inserted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint main body which forms the conventional tube joint 1a Tube socket 2 Resin tube 3 Inner ring 3a Swelling part 4 Press ring A Joint body 10a Swell part 10b Tubular part 10c which constitutes the present invention. Screw part 10d Male screw part to be screwed to the device side 11a Tube part inserted into the bulging part 11b Tube part inserted into the tubular part 12 Female screw part of pressing ring 13 Seal part B Pressing ring C Resin tube

Claims (1)

[Claims] 1. A swelling portion for increasing the diameter of a resin tube inserted into the outer periphery of a tube opening in a tube connection side tube portion and holding the resin tube in a press-fit state, and a swelling portion following the swelling portion. A tubular joint body having a tubular portion smaller than the maximum outer diameter and larger than the tube inner diameter, for expanding the tube and holding the tube in a press-fit state, and a tubular joint body having a male thread portion following the tubular portion; and a male thread portion of the joint body And a pressing ring that presses the tube portion fitted into the bulging portion of the tube portion fitted over the bulging portion and the tubular portion by screwing to apply a pressing sealing force. A tube fitting characterized by the following: