JPH0689865B2 - Pipe fitting - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pipe joint, and more particularly to a pipe joint capable of performing a perfect seal without twisting.

[Background technology and its problems]

For example, in the field of semiconductor industry such as IC and LSI, the work is performed in a clean room in which fine particle dust is excluded, and the manufacturing / work environment and conditions are more severe. The special gas used in this semiconductor manufacturing is introduced from the outside of the clean room into the clean room through piping, but it is extremely disliked that molecules of other unnecessary gases such as air are mixed into this special gas, so it is extremely difficult to seal. In order to completely connect the pipes, not only the pipes themselves, but also the pipe fittings that connect the pipes to each other must be made extremely precise.

By the way, in a conventional general pipe joint, as shown in FIG. 6, a gasket 40 is interposed between a pair of joint pieces 10 and 20, and one joint piece 10 is fitted with a cap nut member 30 from the other joint piece 20 side. The joint pieces 10 and 20 were fastened by screwing.

That is, the ridges 22 of the other joint piece 20 and the ridges 12 of the one joint piece 10 are butted against each other while interposing and supporting the gasket 40, and then the through hole 38 is used in the other pipe 25. The female screw 33 of the cap nut member 30 that has been fitted and the male screw 11 of the one joint piece 10 are screwed together and the cap nut member
By rotating 30 the two ridges 12 and 22 are pressed so close to each other that they bite into the gasket 40, and thus both pipes
It was configured to connect 15,25.

Therefore, the above conventional pipe joint has the following problems.

That is, when the cap nut member 30 is rotated and tightened, the other joint piece 20 rotates together and twists the gasket 40 as the seal packing, which may damage the gasket 40. Not only that, but also the other pipe 25 connected to the other joint piece 20 is twisted, and the pipe itself is damaged. In this case, a metal C ring may be used as the gasket 40, and in this case, the metal C ring has a characteristic that it is deformed by twisting and the sealing force is significantly reduced, which is a particular problem. Furthermore, there is an economic drawback that it cannot be reused due to deformation.

Therefore, a structure in which a large number of balls are supported on the end surface of the other joint piece 20 and the balls are brought into contact with the inner end surface of the cap nut member 30 to prevent twisting of the other joint piece 20 is also considered. However, since the ball receiving surface of the other joint piece 20 and the ball receiving surface of the cap nut member 30 are both flat, the ball bites into these flat surfaces during tightening to form a groove, Alternatively, since the portion corresponding to each ball is dented and the plane becomes uneven, not only the proper tightening torque cannot be produced, but the gasket may be twisted. On the other hand, on the other hand, since the tightening force (pressing force) cannot be increased, there is a problem that the sealing property is poor.

Further, in pipes and fittings used in clean rooms and the like of the semiconductor industry, there are cases where the special gas flowing in the piping is changed, but in this case the inner surface roughness of the piping is rough, or the seal structure of the fitting is If not suitable,
Not only does it become a flow path resistance, but molecules of the gas used before stay in the irregularities of the inner surface of the pipe, or the front gas wraps around from the seal part of the joint to the back side of the seal,
There was an inconvenience that when the next changed gas was circulated, it gradually flowed out of the seal portion and was mixed with the newly circulated gas to cause a defect in the semiconductor product.

Therefore, the conventional pipe joint is unsuitable for use in clean room pipes and the like.

[Object of the Invention]

It is an object of the present invention to provide a pipe joint that can press a gasket with a large tightening force without causing deformation of a pipe or the like and ensure a perfect sealing property.

[Means and Actions for Solving Problems]

The present invention uses a thrust bearing capable of rotating while allowing a large thrust load, instead of supporting the ball on the other joint piece, and a slight deviation or inclination in the radial direction of the components of the thrust bearing is used. It is an object of the present invention to solve the above-mentioned conventional problems by providing a structure capable of stably supporting a thrust bearing in a cap nut member based on the result of a test study in which a predetermined purpose cannot be achieved if tightened as it is generated.

Therefore, while the male screw provided on one joint piece and the female screw of the cap nut member fitted on the other joint piece are screwed together, the gasket interposed between both joint pieces is pressed to press both pipes. In a pipe joint to be connected, it withstands a pressing force when the cap nut member is rotated to press the gasket with the both joint pieces and allows relative rotation between the other joint piece and the cap nut member. Position control means for mounting the thrust bearing in the cap nut member and for restricting the position of the thrust bearing at the bag bottom portion of the cap nut member regardless of the axial relative position of the other joint piece and the cap nut. The above-mentioned object is achieved by the configuration provided.

Therefore, since the thrust bearing is mounted inside the bottom portion of the cap nut member, the radial deviation is eliminated, and the position control restricting means prevents axial deviation or tilting. Even if both joint pieces are tightened with a large force, the cap nut member and the other joint piece can rotate relative to each other. A perfect seal is achieved because the gasket can be pressed strongly without inducing deformation or damage to the pipe.

〔Example〕

An embodiment of a pipe joint according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1 which is an overall configuration diagram of the pipe joint of this embodiment, one joint piece 10, the other joint piece 20, a cap nut member 30, a gasket 40 as a seal packing,
It is composed of a positioning device 50, a thrust bearing 60 and a position restricting means 70.

One joint piece 10 is provided integrally with the one pipe 15 and has two sets of concentric and different-diameter annular ridges 12a and 12b for pressing the gasket 40 on the distal end side. Is engraved. The other joint piece 20 is integral with the other pipe 25, and has two sets of annular ridges 22a, 22b having different concentric diameters for pressing the gasket 40 on the tip side. The convex portions 12a (12b) and 22a (22b) have the same diameter.

The three sets of ridges 12a, 12b, 22a, 22b are provided here because the large tightening force (pressing force) is ensured in relation to the thrust bearing 60, which will be described below. It is intended to further secure the sealing property while preventing it.

The cap nut member 30 has a hexagonal nut shape as a whole, the bag bottom side 37 is provided with an enlarged inner diameter portion 35, and the opening side 31.
A female screw 33 is engraved on this. Inner wall surface 39 on the bag bottom side 37
A through hole 38 is provided so as to intersect with each other. Further, the enlarged inner diameter portion 35 is provided with a groove 34 extending in the circumferential direction.

Here, the inner diameter De of the expanded inner diameter portion 35 is set to 13.5 mm, and the female screw 33
Is a 9 / 16-18 UNF screw engraved in a pilot hole with an inner diameter Ds of 12.9 mm. The axial dimension of the expanded inner diameter portion 35 will be described later in relation to the thrust bearing 60.

The gasket 40, which is a seal packing, has an annular shape having a hole 41 having an inner diameter equal to or larger than the inner diameter of the pipe 15 (25), and is formed by internal drawing from a nickel material. Double fitting piece 1
Both pipes 15 and 25 are watertightly connected and sealed by being pressed by both convex strips 12 (12a, 12b) and 22 (22a, 22b) of 0 and 20. Note that the cap nut member 30 at a position corresponding to the position of the gasket 40 mounted for inspection and the like is provided with a hole penetrating from the outside to the inside, but it is omitted in the drawing.

Next, the positioning device 50 includes a holding member 100 for holding the gasket 40, one positioning member 51 that engages with one joint piece 10, and another positioning member 55 that engages with the other joint piece 20. Composed of a gasket 40 and three parties 1
The 0, 40 and 20 are positioned concentrically. In this embodiment, as shown in FIG. 3, cylindrical inner surfaces 52 and 56 are formed on both ends of a spectacle-shaped steel plate by drawing, and the central portion is bent to form a concave holding portion 100 (FIG. 3 is a bent portion). (Shown later) is provided and integrally formed. Also,
The other positioning member 55 is provided with a claw portion 101 that supports the gasket 40 in an auxiliary manner. Therefore both positioning members 5
While holding the gasket 40 in a space corresponding to the thickness T of the gasket 40 between the holding portion 100 and the end surfaces 53,57
If the gasket 40 is supported by using, the three members 51, 40, 55 are integrated as a concentric core, and the lateral position of the gasket 40 in FIG. 3B is restricted by the claws 101, 101. Next, the inner surface 52 (52, 52) of the one positioning member 51 is guidedly engaged with the large-diameter portion 13 of the one joint piece 10 while being engaged with the inner surface 56 (56, 56, 56) of the other positioning member 55. 56) is fitted and engaged with the large-diameter portion 23 of the other joint piece 20, one of the joint piece 10, the gasket 40, and the other joint piece 20 can rotate the cap nut member 30 by the positioning device 50. Before moving both joint pieces (10, 20) to tighten them in the axial direction, they are supported concentrically.

That is, the positioning device 50 is formed so that it can be positioned by pressing the gaskets 40 from the left and right with the both convex strips 12, 22 as concentric cores before rotating the cap nut member 30. Therefore, even if there is a normal gap between the cap nut member 30 (through hole 38) and the other pipe 25, the cap nut member.
There is no room for misalignment between the ridges 12 and 23 sandwiching the gasket 40 while the 30 is rotating, and even if the inside cannot be visually confirmed, the three parties 10 (12), 40, 20 (22) The concentricity of is guaranteed. For this reason, a perfect seal can be achieved even if the two ridges 12 and 22 are each set as two sets 12a, 12b, 22a, 22b.

Further, the thrust bearing 60, which is a feature of the invention,
It has an outer diameter Do of 13.5 mm, contains 11 balls 60B, and is made of alloy steel as the main material and has a thrust load of 250 kg. Incidentally, in general, a thrust bearing of the same kind with an outer diameter of 12 mm can only allow a thrust load of approximately 142 kg. Similarly, when the outer diameter is 15 mm, a thrust load of 310 kg can be carried.

By the way, the thrust bearing 60 is
It is formed by including a pair of receiving plates 60A and 60C that receive B (held by a retainer (not shown)) on both sides.
The outer diameter of A and 60C is almost the same as the inner diameter De (13.5mm) of the expanded inner diameter portion 35, and the thrust bearing 60 is a cap nut member.
It is formed so as not to be radially offset within 30. further,
The receiving nuts 60A and 60C are notched on the opposite outer peripheral surface, and the cap nut member 3
Notch 61 of Dm, which is smaller than the inner diameter Ds of the female screw 33 of 0,
61 (shown by the chain double-dashed line in FIG. 1) is provided. The inner diameter Di is the inner diameter Dt of the through hole 38 of the cap nut member 30.
It is slightly smaller and allows the other tube 25 to pass through. In other words, the axial dimension L of the expanded inner diameter portion 35 of the cap nut member 30 is the entire thrust bearing 60 (60A, 60B, 60C).
After inserting the receiving plate 60A which is inserted integrally or as individual components into the final direction and the female screw 33 is laterally inserted, the receiving plate 60A is dimensioned so that it can be turned, that is, rotated. . In other words, thrust bearing 60 (60
A, 60B, 60C) can be inserted as a unit, L = Do, and when inserting the components individually, the dimension between the first receiving plate 60C and the last inserting plate 60A. To and
It is sufficient to add Do, that is, L = To + Do. But,
Considering that one side half is projected into the space provided with the female screw 33 to rotate, Can also be After all, it should be determined from the relationship between the inner diameter De of the expanded inner diameter portion 35 or the outer diameter Do of the thrust bearing 60 and the inner diameter Ds of the female screw 33 of the cap nut member 30. Therefore, It may be possible to

Further, the position restricting means 70 restricts the position of the thrust bearing 60 in the bag bottom portion 37 of the cap nut member 30, and secures a stable posture so that the thrust bearing 60 is not axially jammed or tilted. is there. Specifically, it is formed of a spring ring (see FIG. 2) fitted in a groove 34 extending in the circumferential direction of the expanded inner diameter portion 35 of the cap nut member 30. This position regulating means 70 is a thrust bearing.
Each of the 60 elements (60A, 60B, 60C) also has a function of being able to be set in the bag bottom portion 37 even in a mold which is not integrally formed in advance by using special parts.

Next, the operation of the pipe joint of the present invention will be described together with the assembling method.

First, the receiving plate 60C forming the thrust bear rig 60 is laterally oriented from the open side 31 of the cap nut member 30, that is, the cutouts 61, 61.
In the radial direction of the cap nut member 30 (notch 6
Through the space where the female screw 33 is provided (Dm ≤ Ds) so that 1,61 is in the vertical direction (Dm ≤ Ds), and insert into the expanded inner diameter portion 35 (De ≥
Do> Dm). Then, the backing plate 60C is placed 90
The receiving plate 60C is mounted in parallel so that the one surface side 62 of the receiving plate 60C abuts the inner wall surface 39 of the cap nut member 30.

Then, it was integrally supported by a retainer (not shown).
Attach the individual ball 60B from the open side. Subsequently, the receiving plate 60A to be finally inserted is inserted into the expanded inner diameter portion 35 in the same manner as when the receiving plate 60C is inserted, and is rotated by 90 degrees to change the direction and be mounted. Then, the thrust bearing 60 (60A, 60B, 60C) is rotated 90 degrees about the axis.

Continue to open the spring ring, which is the position control means 70, on the open side.
It is inserted from 31 and fitted into the groove 34 of the cap nut member 30, and the position of the thrust bearing 60 is restricted within the bag bottom portion 37. As a result, the thrust bearing 60 is held in a stable posture even when the posture of the cap nut member 30 is changed. In addition, the assembly with the other joint piece 20 can be facilitated.

Next, the assembly and operation of the positioning device 50 will be described. With the cap nut member 30 (with the thrust bearing 60 mounted) fitted on the other pipe 25 at the position offset to the right in FIG. 1, the gasket 40 has already been mounted and supported on the holding member 100. The other positioning member 55 of the positioning device 50 is fitted and engaged with the large-diameter portion 23 of the other joint piece 20 using the inner surfaces 56, 56, 56. After that, while moving one pipe 15 which is relatively flexible in the drawing in the radial direction (the right end of the other pipe 25 in FIG. 1 is fixed to a tank or the like in this embodiment), the one positioning member 51 is moved. The inner surface 52 (52, 52) is utilized to be fitted and engaged with the large diameter portion 13 of the one joint piece 10. That is,
By forcibly inserting both joint pieces 10, 20 into both positioning members 51, 55, the gasket 40 is fitted with both joint pieces 10, 2.
The 0 is positioned concentrically. Here, the annular ridges 12 (12a, 12b) and 22 (22a, 22b) of both joint pieces 10, 20
And means that the gasket 40 is brought into contact with the thick portion of the gasket 40 concentrically.

After that, the cap nut member 30 is rotated to connect the both pipes 15 and 25. As a result, it is assembled as shown in FIG. It should be noted that when the gasket 40 is tightened by the two pipes 15 and 25, the rotational force of the cap nut member 30 is transmitted to the other pipe 25 and the like, but in the present invention, the thrust bearing 60 is interposed, so the other pipe 25 There is no possibility of causing a twist in the above.

Therefore, according to this embodiment, the thrust bearing 60 that allows the relative rotation between the cap nut member 30 and the other joint piece 20 while bearing a large axial force.
Is provided, the gasket 40 can be tightened with a large pressing force without inducing deformation or damage to the joint piece 20, the pipe 25, etc., and a reliable seal can be achieved.

Further, since the thrust bearing 60 is supported in a stable posture in the bag bottom portion 37 of the cap nut member 30 by the position restricting means 70, the constituent elements of the thrust bearing 60 are not axially displaced or tilted, so that the thrust bearing 60 has a predetermined shape. The function is exerted, and the relative rotation and the like are further ensured. Further, since the position restricting means 70 is formed of a spring ring, it has an effect that the structure is simple and easy to handle, and that the entire pipe joint does not have to be large (large diameter). further,
Since the position of the thrust bearing 60 is restricted by the position restricting means 70 in the cap nut member 30 regardless of the relative positional relationship between the thrust bearing 60 and the other joint piece 20, the cap nut portion is previously formed.
If set in 30, it will be easier to assemble, such as inserting the other joint piece 20, and thrust bearing.
It is economical because it is possible to eliminate the inconvenience that the respective constituent elements 60A, 60B, 60C of 60 must be integrally formed in advance by special means.

Furthermore, since two sets of concentric annular projections 12a, 12b, 22a, 22b are provided at each end of both joint pieces 10, 20, the sealability with the gasket 40 is dramatically improved. be able to.

In particular, the thrust bearing 60 provided with notches 61, 61 (Dm) having a size equal to or less than the inner diameter Ds of the female screw 33 of the cap nut member 30 is inserted laterally from the open side 31 of the female screw 33, and The thrust vane ring 60 having an outer diameter Do larger than the inner diameter Ds of the female screw 33 because the turning direction is changed in the inner diameter expanded portion 35 having an inner diameter De larger than the inner diameter Ds to be mounted in the inner diameter expanded portion 35.
Can be attached to the cap nut member 30. Therefore, the allowable thrust load can be dramatically increased without increasing the size of the pipe joint, so that pipes that achieve a perfect seal can be connected. This means that the inner diameter De of the expanded inner diameter portion 35 can be further increased to further increase the thrust load. Therefore, even if the outer diameter of the pipe joint is restricted by the pipe or its equipment, the thrust load can be arbitrarily selected.
Since it does not cause twisting deformation or breakage, the productivity of the equipment that employs the pipe joint can be dramatically improved, and the service life can be extended. Further, the bag bottom side 37 of the bag nut member 30 has a large diameter and the receiving plates 60A, 60
Since it is sufficient to provide notches 61, 61 in C, it can be easily and economically adopted for existing pipe joints, and it is possible to eliminate the technical defect that suffered from leakage of fluid such as conventional gas and liquid. There is also. Furthermore, the troublesomeness of changing the design of the cap nut member 30 and the like each time to meet the specifications of the thrust bearing 60 corresponding to the allowable thrust load is eliminated, and the structure is simple and economical in practical use. The profit is great.

Furthermore, by simply engaging both joint pieces 10 and 20 around the gasket 40, which is a seal packing,
Since the positioning device 50 for positioning the 0 and 20 concentrically is provided, the gasket is not deformed or damaged even if the cap nut member 30 is rotated, so that a perfect seal can be guaranteed. Therefore, since the gasket 40 can be reused, the economic benefit is large. Further, since the positioning device 50 can regulate the positions of the three members 10, 40, 20 concentrically, the gasket 40 can be made small, so that there is an economic advantage even when formed from a nickel material or the like. Not only is it large, but it is effective for downsizing the entire pipe joint.

Further, in the positioning device 50, since the one positioning member 51 and the other positioning member 55 are integrally formed with the holding member 100 of the gasket 40, the joint piece corresponding to the expansion positioning members 51, 5 is formed. Since the concentricity of the three members 10, 40, 20 can be established simply by engaging the 10, 20, the assembly and disassembly work can be dramatically improved. In other words, the gasket 40 for temporary fixing is dropped during the work, misalignment is caused by increasing the clearance between the through hole 38 of the cap nut member 30 and the other tube 25, and the gasket 40 is deformed again. Since it is possible to avoid performing work and further repeating the leak test, quick work can be performed. This is useful for achieving early completion and smooth operation of the entire device that employs the pipe joint.

Furthermore, since the positioning device 50 can be integrally formed by press working or the like, it has a large strength, a simple structure, and easy mounting. Further, there is an effect that it can be immediately used for existing pipe joints.

In addition, according to the above embodiment, the thrust bearing
As for 60, the receiving plate 60A, the ball 60B, and the receiving plate 60C are inserted and mounted in this order, but the temporarily fixed whole (60A, 60B, 60C) may be inserted at one time. In this case, the axial length L of the expanded inner diameter portion 35 can be made smaller. Of course, the lateral direction of the thrust bearing 60 is the receiving plate.
Since the outer peripheral portion of 60A (60C) is not abutted against the female screw 33 and can be smoothly inserted without damaging the female screw 33, for example, the one side 62 of the receiving plate 60C is completely aligned with the axis of the cap nut member 30. It is not limited to be parallel.

Further, the position restricting means 70 includes the groove 34 provided in the cap nut member 30.
It was formed from a spring ring that is fitted to
The thrust bearing 60 is not limited to the spring ring as long as it can regulate the position of the thrust bearing 60 inside the bag bottom portion 37 in a stable posture. However, if the spring ring is used, the structure is simple and economical, and the overall size can be reduced.

Further, the annular projections 12 (12a, 12b) and 22 (22a, 22b) having different diameters and the same concentricity are provided on the tip side of each joint piece 10, 20,
The point is to work together with the introduction of the thrust bearing 60 to improve the sealing effect, so the ridges 12 (22)
The number is not limited to two, but may be three or more, and may be provided on the joint piece 10 (20) on either side.

Further, the gasket 40, which is a seal packing, is made of a nickel material, but the material form is not limited. However, when the gasket 40 is formed from an expensive material such as nickel, the economical effect of the main fitting is particularly high in that the gasket can be reused. At the same time, the ridges 12 and 22 of the joint pieces 10 and 20 can be freely selected in their shapes and the like. Of course,
The present invention is also applied to the case where the excessive pushing amount preventing means of the gasket 40 is adopted.

Furthermore, the positioning device 50 has the claws 101 and 10 shown in FIG.
Although the integrated molding structure with 1 is provided, as shown in FIGS. 4 (A) and 4 (B), recesses 54 and 57 are provided in both positioning members 51 and 55 in order to more reliably and stably support the gasket 40. It may have an integrally molded structure, or may be formed from a stepped cylindrical member with a bush 59 for adjusting the pipe diameter, as shown in FIG.
In this case, since the joint pieces 10, 20 can be aligned with a larger force, the work can be facilitated and the positioning device 50 itself can be inexpensive.

Needless to say, the pipe joint of the present invention is applicable to all industrial fields without limitation in pipe diameter, pipe fluid type and the like.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The present invention provides an excellent effect that a thrust bearing whose position is regulated is provided in the cap nut member, and the gasket can be pressed with a large tightening force without inducing deformation or damage to the joint constituent elements to ensure perfect sealability. Have.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional structural view showing an embodiment of a pipe joint according to the present invention, FIG. 2 is an external view of a position restricting means, and FIG. 3 is an external view of a positioning device. The whole side view, (B) is a front view based on the arrow line IIIB-IIIB of (A), FIG. 4 is an external view of a positioning device showing another embodiment, and (A) and (B) are (A) of FIG. 3, respectively
It corresponds to (B). FIG. 5 is a side sectional view of a positioning apparatus showing another embodiment, showing a case with a bush, and FIG. 6 is an overall sectional view of a conventional pipe joint. 10 …… One fitting piece, 11 …… Male thread, 12 (12a, 12
b) ...... ridge, 15 ...... one pipe, 20 ...... other joint piece, 22 (22a, 22b) ...... ridge, 25 ...... other pipe, 30
...... Bag nut member, 33 ...... female screw, 34 ...... groove, 40 ...... gasket, 50 ...... positioning device, 60 ...... thrust bearing, 70 ...... position regulation means.

Claims (3)

[Claims] 1. A male screw provided on one joint piece and a female screw of a cap nut member fitted on the other joint piece are screwed together, and a gasket interposed between the two joint pieces is pressed to both sides. In a pipe joint for connecting pipes, it withstands the pressing force when the cap nut member is rotated to press the gasket with the joint pieces, and the relative rotation between the other joint piece and the cap nut member is prevented. A position for mounting a permissible thrust bearing in the cap nut member and for regulating the position of the thrust bearing at the cap bottom of the cap nut member regardless of the axial relative position of the other joint piece and the cap nut member. A pipe joint characterized in that a regulating means is provided. 2. The position regulating means according to claim 1, wherein the position regulating means is formed of a spring ring engaged with a groove provided in an inner wall surface of the cap nut member. Pipe fittings. 3. The joint piece according to claim 1 or 2, wherein at least one joint piece of the both joint pieces can be pressed against and abutted on the gasket by a plurality of annular projections having different diameters. Pipe fittings characterized by being