JP2002039469A - Tube joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube joint offering simple joint construction for connecting a tube in a excellent workable manner, preventing incomplete joint due to an error in working in a foreseeable manner when a tube is flared to be joined to a tube connection of a joint body, and hardly causing looseness or liquid leakage at a seal portion resulting from the vibration of the tube due to the pulsation of a transfer liquid. SOLUTION: The resin tube joint comprises a joint body 1 having a fluid passage 2, a tube connection and a fixed screw. Connection is carried out by arranging a large-diameter end 62 formed on the tube 61 on the tube connection and threading, tightening and connecting a nut 10 passing through the outer periphery of the tube 61 to the fixed screw. The tube connection has a contact portion 20 as a connection hole 3 formed in the inner periphery using the fixed screw as a female screw 5 for receiving the large-diameter end 62 into the connection hole 3, to be put in pressure contact with the inner periphery of the large-diameter end 61. The nut 10 tightens a male screw 16 on the outer periphery to the female screw 6 and thrusts the large-diameter end 62 against the contact portion 20 at a nut end 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint made of resin which is suitable for transferring chemicals, pure water and the like in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a large amount of various chemicals and pure water are used, and the chemicals and pure water are transferred to each process by a method such as a pump or a gas pump. In this transfer, a resin tube and a pipe joint having excellent chemical resistance and heat resistance are used. As a pipe joint, there is no danger of liquid leakage from the seal portion or detachment of the tube due to vibration due to transfer pressure or pulsation of the pump, and there is no danger of deposits etc. due to construction from the viewpoint of maintaining the purity of the transfer liquid. In addition, there is a demand that there is no liquid pool inside the joint, and the precision is becoming more and more strict in accordance with the progress of automation of the manufacturing process.
At present, as shown in FIGS. 5 (a) to 5 (c), a joint structure in which a pipe tube is flared and connected by any method is mainly used. In the respective drawings, the same or corresponding parts are denoted by the same reference numerals.

[0005] That is, the pipe joint shown in FIG.
0 and a nut 55 with a female screw 56. The joint main body 50 has a fluid passage 51, connecting cylinder portions 52 having outer diameters on both sides reduced in diameter, and a male screw 53 formed on the outer periphery in front of each connecting cylinder portion 52 (on the middle side of the main body). Tube 60
The end portion is formed in the enlarged diameter end portion 60a by flaring, and the connecting tubular portion 52 is inserted into the enlarged diameter end portion 60a, and the nut 55 is screwed into the male screw 53 and the female screw 56 on the nut inner diameter side. It is connected to the joint body 50 by tightening through the joint. Although this structure is simple, the fixing force is weak against the force applied in the direction in which the tube 60 comes out. For example, when the tube is used for transferring a high-temperature liquid, the connecting tubular portion 52 is thermally deformed, and the tube 60 comes out and the diameter increases. Liquid leakage easily occurs from a seal portion between the end portion 60a and the connecting cylinder portion 52. 5 (b) and 5
(C) is such that the tube does not come off or the liquid does not leak as compared with the above structure. (B) is a tube 6
0 is press-fitted into the inner diameter to form an enlarged end portion 60b having an arc of a section (having an arc in the middle).
0b is sandwiched between the ring 57 and the inner diameter of the connecting cylinder 58A by tightening the nut 55. In (c), the tube 60 forms an enlarged-diameter end portion 60c having a substantially O-shaped cross section, and a sleeve 59 is further press-fitted into the inner diameter of the enlarged-diameter end portion 60c in a protruding state. Are inserted into the inner diameter of the connecting cylindrical portion 58B together with the protruding portion of the sleeve 59.
And the inner diameter of the connecting cylinder 58B.

[0004]

In the above-described pipe joint, in order to normally exhibit the sealing effect using the enlarged diameter end portions (60a, 60b, 60c), the center line of the fluid passage 51 on the joint body side is required. And the center line of the tube 60 and the enlarged end must match, but in fact, due to a work error during flaring, the characteristics of the resin processing deviate more than the design value, and the enlarged end and the connecting cylinder The connection with the part may be incomplete. Even in such a case, except that the above-mentioned connection is not possible, there is some play between the inner diameter of the nut 55 and the outer diameter of the tube 60, and the insertion amount of the enlarged-diameter end portion into the connecting cylinder portion is small. Since the screw 55 is screwed into the male screw 53 on the joint body side, the incomplete connection cannot be seen from the appearance. Such pipe construction causes the tube to come off with the passage of time due to the liquid temperature, heat cycle, transfer pressure, vibration and the like during use, causing liquid leakage and impairing safety. Also, in the conventional structure, the seal portion (around the joint between the enlarged diameter end portion and the connection cylinder portion) is located inside the nut,
As shown in FIGS. 5 (b) and 5 (c), since the distance between the fulcrum A and the fulcrum A, which is the nut penetrating portion of the tube 60, is very short, the influence of the vibration of the tube 60 due to, for example, the transfer pressure fluctuation or pulsation. The tube has a drawback that it is susceptible to loosening and liquid leakage, and the tube must be supported by a dedicated member in a place where vibration is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. The object of the present invention is to provide a simple joint structure and easy tube connection work, and furthermore, to flare the tube to form a tube connecting portion of the joint body. When joining, to prevent incomplete joining due to the above work mistakes in advance and prevent it,
An object of the present invention is to realize a pipe joint in which loosening of a seal portion and leakage of liquid due to vibration of a tube due to pulsation of a transfer liquid are less likely to occur.

[0006]

In order to achieve the above object, according to the present invention, as shown in FIG. 1 and the like, a joint body 1 has a fluid passage 2, a pipe connecting portion and a fixing screw, and is formed in a tube 61. The enlarged diameter end portion 62 is disposed in the pipe connecting portion, and a nut 10 passed through the outer periphery of the tube 61 is screwed to a fixing screw and connected by tightening. A connection hole 3 formed on the inner periphery of the fixing screw as a female screw 5, the contact portion 20 receiving the enlarged diameter end 62 into the connection hole 3 and being pressed against the inner periphery of the enlarged diameter end 61. And the nut 10 has an external male screw 16
Is tightened to the female screw 6, and the enlarged end portion 62 is pressed toward the contact portion 20 by the nut tip 15.

This structural feature is characterized in that the nut 10 is
To make it easier to secure the nut inside diameter by pushing it into the inside of the tube, to make it possible to know in advance the above-mentioned incomplete connection together with the tube guide function that regulates tube vibration, and to lengthen the surface of the entire joint. Without (this is
For example, assuming that the surface between the joints is the same, it means that the inner diameter of the nut functioning as a tube guide can be lengthened.) The tube vibration fulcrum is provided at a position away from the seal portion so that the adverse effects of vibration can be minimized. That is, the enlarged diameter end portion 62 can be reliably sealed by the contact portion 20. In detail, it is also excellent in terms of eliminating factors such as deposits caused by construction, a liquid pool at the enlarged-diameter end portion 62, and reducing a dead space (a portion where the transfer liquid comes into contact).

The present invention described above is more preferably embodied as in claims 2 to 4. First, the male screw 16 of the nut 10 is formed to be longer than the female screw 6 of the pipe connecting portion 3, and is screwed along the male screw 16 so as to correspond to the joint body 1. This is a configuration having an auxiliary nut 17 with a female screw 18 abutting on the end face.
This reliably prevents the nut 10 from being loosened by the tightening force of the auxiliary nut 17. The auxiliary nut 17 aims at the double nut effect in the fixing technique, and the auxiliary nut 17 which could not be adopted in the conventional structure of FIG. 5 can be adopted by the present invention. Can be improved. Second
In addition, the enlarged diameter end portion 62 includes an inclined base portion 62a whose diameter gradually increases toward the distal end, and a large-diameter cylindrical portion 62b in which the distal end side of the inclined base portion 62a is formed into a substantially perfect circle. The inner end surface 7 intersects the passage 2 at a substantially right angle, and the contact portion 20 is arranged on the inner end surface 7. In this case, since the contact portion 20 abuts on the inner end face 7 perpendicular to the fluid passage 2 and the inner end face 7 can be formed simply and accurately, the processing accuracy and the nut are different from those shown in FIG. Due to excessive tightening, a problem can be solved in which a step is formed between the fluid passage 2 and the contact portion 20 and liquid pool is easily generated. Third, the contact portion 20 has a flange portion 22 that presses against the end face of the enlarged diameter end portion 62, and an insertion tube portion 21 that makes the inner diameter of the enlarged diameter end portion 62 substantially match the inner diameter of the tube of the non-expanded portion. And a bush having at least In this case, the pressing force of the distal end face 15 of the nut 10 is not shown in FIG.
As shown in the enlarged view of FIG. 3, the seal surfaces A and B act most strongly, and the seal structure is optimal. Fourth, the contact portion may be integrally engaged and held in advance with the inner end face 7 as shown in FIG. 3A, or may be formed integrally with the joint body 1 as shown in FIG. 3B. is there. In this case, it is possible to further reduce the generation of deposits due to the construction and improve the reliability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the pipe joint of the embodiment in a used state, and FIG. 2 shows a detailed structure thereof and a tube connection operation procedure. This pipe joint includes a joint body 1, two nuts 10, and two bushes 20 as abutting portions. These are resin molded products excellent in chemical resistance, heat resistance, durability and the like together with the tube 61 to be connected.

(Member structure) The joint body 1 has a circular or rectangular outer periphery, and has a fluid passage 2 inside and a connecting hole 3 as a pipe connecting portion on both sides. The fluid passage 2 is provided in the middle along the center line and has a minimum inner diameter. The connection hole 3 includes a hole 4 located on the inner side of the hole, that is, the fluid passage 2 side,
A hole 5 having an inner diameter larger than the hole 4 is provided on the inlet side, and a female screw 6 is formed on the inner periphery of the hole 5. The hole 4 is shorter in length than the hole 5, can receive the bush 20 and the enlarged diameter end 62 of the tube 61, and forms an inner end surface 7 that intersects the fluid passage 2 at a substantially right angle. .

The nut 10 has an inner periphery formed in a flush hole 11 penetrating the tube 61 from one end to the other end.
The outer periphery has an insertion section 12 and an operation section 13. The insertion part 12 is a part inserted into the connection hole 3. here,
A taper 15 is provided between a part of the distal end surface 14 and the hole 11, and a male screw 16 screwed with the female screw 6 is formed on the outer periphery. The operating portion 13 has a diameter larger than that of the insertion portion 12, and the nut 10 is screwed into the male screw 16 and the female screw 6 by using the operation portion 13, and is mounted in the hole 5.

The bush 20 is disposed in the hole 4 and has a flange 22 provided at one end of the insertion tube 21. The insertion tube portion 21 is larger than the outer diameter of the tube 61, for example, and is press-fitted into a corresponding end of the tube 61 to be integrated. That is, the outer periphery of the insertion tube portion 21 is tightly engaged with the inner periphery of the enlarged diameter end portion 62, the tip surface is tapered 23, and the inclined base 62 a of the enlarged diameter end portion 62 a
Is pressed tightly. The inner circumference is an inner diameter that is flush with the inner circumference (non-expanded portion) of the tube 61 and the fluid passage 2 when the insertion cylinder 21 is engaged with the enlarged diameter end 62. The flange portion 22 is formed to have an outer diameter corresponding to the hole portion 4 as shown on the right side of FIG. 2, and the outer end surface is in close contact with the inner end surface 7 as shown in FIG. .

The tube 61 has an enlarged end 62 formed by flaring using a dedicated jig or by press-fitting the bush 20. The enlarged diameter end portion 62 includes an inclined base portion 62a whose diameter gradually increases toward the distal end, and a large-diameter cylindrical portion 62b in which the distal end side of the inclined base portion 62a is formed into a substantially perfect circle. Here, the enlarged diameter end portion 62a is
Is formed, the inner surface of the inclined base portion 62 a closely contacts the taper 23 of the bush 20. The outer surface of the large-diameter cylindrical portion 62b also closely contacts the outer periphery of the insertion cylindrical portion 21 of the bush 20. The processing of the enlarged diameter end portion 62 and the incorporation of the nut 10 into the tube 61 are performed when the tube 61 is long and the other end of the tube 61 is already connected.
After the nut 10 is inserted into the tube 61, the enlarged end 6
2 are formed to integrate the bush 20.
Thereafter, the tube 61 and the bush 20 are connected to the joint body 1.
Next, the connection procedure will be described together with the main operation.

(Connection Procedure and Operation) In the connection operation, the nut 10 is connected to the male screw 16 by the nut 10 while the enlarged-diameter end portion 62 is inserted into the connection hole 3 and the flange portion 22 of the bush 20 is in contact with the inner end surface 7. It is screwed into the female screw 6 on the main body 1 side and tightened. In this case, first, the expanded end portion 62 is inserted into the connection hole 3 from the state with the bush 20 as shown on the left side of FIG. 2, and the bush 20 is inserted into the hole portion as shown on the right side of FIG. There is a mode in which the side that becomes the enlarged-diameter end portion 62 is inserted into the connection hole 3 after engaging and holding in advance with the connection hole 4. In any case, for example, the bushing 20 is press-fitted into the tube 61 in a state where the corresponding end or the slightly enlarged end of the tube 61 is heated and softened to form the enlarged end 62, as shown in FIG. For the structures b) and (c), the generation of deposits and the like due to the construction is largely eliminated. In addition, incomplete construction can be detected in advance as follows. That is,
The tube 61 is positioned by the engagement of the bush 62 with the hole 4 and the contact of the flange 22 with the inner end face 7. From this state, the nut 10 is screwed into the female screw 6 with the male screw 16 being screwed. In this case, if there is a mistake in the work of attaching the bush 20 to the enlarged diameter end portion 62, the bush 20 bends into the enlarged diameter end portion 62,
The end face of the flange portion 22 (this end face becomes the sealing surface A in surface contact with the inner end face 7 as shown in the enlarged view of FIG. 1) and the enlarged diameter end portion 6
When the end faces of the fluid flow paths 2 are not parallel,
The center line of the connection hole 3 does not coincide with the center line of the tube 61 at the time of assembly. In such a state, since the inner diameter of the nut is long, the female screw 6 of the joint body 1 and the male screw 16 of the nut 10 do not mesh well, and the screwing of the nut 10 cannot be smoothly performed. Incomplete construction that can cause liquid leakage can be detected in advance.

When the tightening of the nut 10 is completed, the taper 15 which is the tip of the nut comes into surface contact with the inclined base 62a of the enlarged diameter end 62 as shown in the enlarged view of FIG. With the inclined base portion 62a interposed between the tip taper 23 and the enlarged diameter end portion 62, sealing is performed with a clamping force corresponding to the tightening force of the nut 10. That is, in this sealing structure, surface contact between the inner end surface 7 and the flange portion 22 (seal surface A) and surface contact between the taper 23 and the inclined base portion 62a (seal surface B) mainly function. In addition, it is assumed that, in the use state of FIG. 1, a pulsation (pulsation flow) is generated in the liquid feed by a pressure feed pump or the like, and the tube 61 vibrates violently. In this joint structure, the nut 10 is screwed into the connection hole 3 of the joint body 1 via the male / female screws 16, 6, and the enlarged end 62 of the tube 61 is formed at the nut tip (taper 15).
(The inclined base portion 62a) is pressed, and a seal portion (seal surface A, seal surface B) exists at a position close to the inclined portion. Since the nut 10 is located inside the joint body 1, the overall length of the nut 10 can be increased without increasing the distance between the surfaces of the entire joint. The inner diameter of this long nut 10 (hole 1
1) plays a role of a pressing guide of the tube 61 (regulating the tube 61 so as not to vibrate). Since the vibration fulcrum of the tube 61 is the outer end of the nut hole 11,
Due to the function of the pressing guide, the vibration of the tube 61 hardly affects the sealing surfaces A and B on the tip side of the nut, and the long nut hole 11 performs the same function as the support member of the tube 61.

(Modification 1) FIG. 3 shows a modification of the above embodiment.
An example is shown, (a) changes the shape of the bush 20,
(B) is a configuration example in which the bush 20 is formed integrally with the joint body 1. In each figure, the left side is a tube 61
Are connected, and the right side shows a state in which the tube 61 and the nut 10 are omitted. In these descriptions,
The same members and parts as in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The bush 20A shown in FIG. 3A has a flange 24 added to the outer periphery of the flange 22 of the bush 20.
This is an extension of the above-mentioned sealing surface A and the like. Collar 24
Are projected substantially parallel to the insertion tube portion 21 and form a predetermined gap with the insertion tube portion 21. The large-diameter cylindrical portion 62b of the enlarged-diameter end portion 62 is inserted into the gap. On the other hand, the bush 2 shown in FIG.
0B is formed integrally by two-color molding or the like at the time of resin molding to simplify the joint body 1, and at the same time, deposits and the like generated when a ring or sleeve is press-fitted (flared) to a tube as in the conventional case. The cause of occurrence is minimized. Reference numeral 25 corresponds to the insertion tube portion 21, and reference numeral 26 corresponds to the flange portion 22.

(Modification 2) FIG. 4 shows another configuration example in which the above embodiment is further modified in the same manner as in FIG. In the description of FIG. 4, substantially the same members and portions as those of the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted. 1 differs from the pipe joint of FIG. 1 in that an auxiliary nut 17 with a female thread 18 is used together with the nut 10 and that the form of the bush 20C is changed.

The nut 10 shown in FIG. 4 has an insertion portion 12 with a male screw 16 longer than that shown in FIG.
A part of the male screw 16 can be exposed and arranged in a state where the female screw 6 is screwed to the maximum via the male screw 16. In this embodiment, the nut 10 is used as the auxiliary nut 1
7 is fastened to the female screw 6 of the joint body 1 in the assembled state. Thereafter, the auxiliary nut 17 is tightened until it comes into close contact with the corresponding end face of the joint body 1 through the screwing of the female screw 18 and the male screw 16 of the nut 10. On the other hand, the bush 20C shown in FIG. 4 is different from the bush 20 shown in FIG.
3a, and the flange portion 22 is further substantially L-shaped.
It has an engaging portion 23 which is bent and extended. Correspondingly, the inner end face 7 of the joint body 1 has an engaging portion 23
Is provided with a receiving portion 7a having a concave cross section for inserting the. In the sealing structure, the sealing surface A in FIG. 1 can be increased by an amount corresponding to the surface contact between the receiving portion 7a and the engaging portion 23.

In the above-described structure, when the nut 10 and the auxiliary nut 17 are completely tightened, the taper 15 at the tip of the nut comes into surface contact with the inclined base portion 62a of the enlarged-diameter end portion 62 as shown in the enlarged view of FIG. With the surface B), the inclined base portion 62a is sandwiched between the projecting portion 23a of the bush 20C and the tip taper 23 widely secured, and the enlarged-diameter end portion 62 responds to the tightening force of the nut 10 and the auxiliary nut 17. Sealed by pinching force. In addition, in this structure, since the flange portion 22 is in pressure contact with the inner end surface 7 and the sealing surface A is long including projections and depressions due to the engaging portion between the engaging portion 23 and the receiving portion 7a, the sealing performance is improved. It is excellent. In addition, since the tightening force of the auxiliary nut 17 is also applied, careless loosening of the nut 10 is prevented, and reliability can be improved. As described above, the present invention only needs to include the technical elements specified in claims 1 to 5, and can be variously modified as necessary.

[0021]

As described above, in the pipe joint of the present invention, in addition to being simpler in construction and easier to construct than the structures shown in FIGS. 5B and 5C, the entire length of the nut can be made longer. Since the tube penetrates the long inner diameter (the tube guide action that regulates the vibration of the tube with the longer inner diameter) and presses the tip of the nut against the enlarged diameter end, the center line of the fluid flow path and the connection hole and the center line of the tube are aligned. If there is a misalignment of the enlarged diameter end, it is impossible to assemble the female screw and nut on the joint body side, and the incomplete connection that causes the above-mentioned liquid leakage can be prevented beforehand, thus providing a more secure As a result, a reasonable chemical solution transfer is realized. This is because if the tube guide action is obtained by increasing the minimum inner diameter of the conventional nut shown in FIG. 5, the distance between the surfaces of the entire joint becomes longer, and the semiconductor must be installed in a narrow space. This is because it is not suitable for a piping form for transferring a chemical solution or the like, and in order to effectively use the space of the clean room, the piping including the device must be compactly constructed. As described above, the present invention is based on the tube vibration as a measure to prevent incomplete connection, and at the same time, as a compact measure to eliminate or reduce the support member attached to the conventional tube by the tube guide function. It is excellent as a measure to prevent the tube from coming off and liquid leakage, and at the same time, as a measure to prevent the generation of deposits and the like due to the increasingly strictly required construction. A nut can be added, which can improve the quality and reliability of the resin pipe joint.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a pipe joint to which the present invention is applied in a used state.

FIG. 2 is a longitudinal sectional view showing an operation example of connecting a tube to the pipe joint.

FIG. 3 is a longitudinal sectional view showing two modified examples of the pipe joint.

FIG. 4 is a view showing an example in which the pipe joint is further modified.

FIG. 5 is a view showing three examples of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Joint main body 2 ... Fluid passage 3 ... Connection hole (pipe connection part) 4 ... Hole forming the inner end surface of the connection hole 5 ... Hole on the near side of the connection hole 6 ... Female screw 10 ... Nut 11 ... Hole (inner diameter) 12 insertion part 13 operation part 15 taper (tip part) 16 male screw 17 auxiliary nut 18 female screw of auxiliary nut 20, 20A, 20B bush (contact part) 21 insertion cylinder Part 22 ... Flange part 60, 61 ... Tube 62 ... Large diameter end part 62a ... Inclined base part 62b ... Large diameter cylindrical part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Ishii 2-285-67 Kamiyama-cho, Funabashi-shi, Chiba F-term (reference) 3H015 CA00 3H017 HA14

Claims (5)

[Claims] 1. A joint body having a fluid passage, a pipe connecting portion, and a fixing screw, an enlarged end formed in a tube is disposed in the tube connecting portion, and a nut passed through the outer periphery of the tube is fixed. In a resin-made pipe joint that is screwed and connected to a screw, the pipe connection portion is a connection hole formed on an inner periphery with the fixing screw as a female screw, and the enlarged diameter end portion is inserted into the connection hole. The nut has an abutting portion which is pressed against the inner periphery of the enlarged diameter end portion, and the nut tightens an outer male screw on the outer periphery to the female screw so that the enlarged diameter end portion is fixed to the abutting portion side at a nut tip. A pipe joint characterized by being pressed to: 2. An external thread of the nut is formed longer than an internal thread of the pipe connecting portion, and is screwed along the external thread so as to abut on a corresponding end face of the joint body. 2. An auxiliary nut having an internal thread having a female thread.
The pipe joint described in the above. 3. The enlarged diameter end portion includes an inclined base portion having a diameter gradually increasing toward a tip end, and a large-diameter cylindrical portion having a tip end side of the inclined base portion formed into a substantially perfect circle, wherein the connection hole is formed between the fluid passage and the fluid passage. The pipe joint according to claim 1, further comprising an inner end surface intersecting at a substantially right angle, wherein the contact portion is disposed on the inner end surface. 4. The contact portion has at least a flange portion that presses against the end face of the enlarged diameter end portion, and an insertion tube portion that makes the inner diameter of the enlarged diameter portion substantially match the inner diameter of the tube of the non-increased diameter portion. The pipe joint according to claim 2, wherein the pipe joint is a bush. 5. The pipe joint according to claim 3, wherein the contact portion is provided integrally with the inner end face.