JP2004092915A - Pipe fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe fitting made of synthetic resin at a portion contacting with fluid and maintaining a fluid leakage prevention performance even if time elapses. <P>SOLUTION: An annular recess part 7 is installed on an end face of a first synthetic resin fitting member 2, and an annular projection part 8 is installed on an end face of a second synthetic resin fitting member 3, and the projection part 8 is fitted with an opening of the recess part 7 fitted with a synthetic resin gasket 4. Under a condition that the pipe fitting 1 is properly fastened, an inner face of the recess part 7 of the first fitting member 2 is brought into close contact with an outer face of the projection part 8 of the second fitting member 3 via the gasket 4 approximately entirely. An inner radial portion 3d from the recess part of the end face of the first fitting member 2 is brought into close contact with an inner radial portion 3d from the projection part of the end face of the second fitting member 2 approximately entirely. An outer radial portion 2e from the recess part of the end face of the first fitting member 2 is brought into close contact with an outer radial portion 3e from the projection part of the end face of the second fitting member 3 approximately entirely. <P>COPYRIGHT: (C)2004,JPO

Description

発 明 The present invention relates to a pipe joint, and more particularly to a pipe joint for connecting joint members made of synthetic resin by screw means.

For example, in a fluid control device for manufacturing semiconductors, a pipe joint including a pair of tubular joint members, an annular gasket interposed between butted end surfaces of the two joint members, and a screw means for connecting the two joint members is often used. Have been. In this type of pipe joint, the tubular joint member and the gasket are generally made of metal, for example, stainless steel such as SUS316L.
JP-A-08-128574 JP 04-102791 A JP 54-117930 A Microfilm of Japanese Utility Model Application No. 55-189826 (Japanese Utility Model Application Laid-Open No. 57-112162) Microfilm of Japanese Utility Model Application No. 60-198269 (Japanese Utility Model Application Laid-Open No. 62-106091) JP 06-241362 A

In the conventional stainless steel pipe fittings described above, various fluids are flowed in the semiconductor manufacturing process, and some fluids that have a high property of corroding metals, such as ammonium acid fluoride, are included. Improvements are required. Therefore, it is conceivable that each member of the pipe joint is formed of a synthetic resin such as PFA instead of a metal such as stainless steel. (Stress relaxation, cold flow, etc.) is large, and the surface pressure generated between members at the abutting portion gradually decreases, which may cause fluid leakage.

An object of the present invention is to provide a pipe joint in which a portion that comes into contact with a fluid is made of a synthetic resin and a fluid leakage preventing performance is maintained even after a lapse of time.

A pipe joint according to a first aspect of the present invention includes first and second synthetic resin tubular joint members, a synthetic resin gasket interposed between butted portions of the two joint members, and screw means for connecting the two joint members. In the pipe joint, an annular concave portion is provided on the butt end surface of the first joint member so that an opening remains in a state where the gasket is entirely fitted, and an annular convex portion is provided on the butt end surface of the second joint member. The convex portion is fitted in the opening of the concave portion in which the gasket is fitted. When the pipe joint is properly tightened, the inner surface of the concave portion of the first joint member and the outer surface of the convex portion of the second joint member are provided. Are in close contact with each other over the entire surface via the gasket, and a portion radially inward of the concave portion of the butt end surface of the first joint member and a radially inner portion of the convex portion of the butt end surface of the second joint member. And that the portion of the first joint member radially outward from the concave portion of the mating end surface and the portion of the second joint member radially outside the convex portion of the mating end surface almost completely adhere to each other. It is a feature.

A pipe joint according to a second aspect of the present invention is a pipe joint comprising first and second synthetic resin tubular joint members and a screw means for connecting the two joint members, wherein an annular end face of the first joint member is provided. A concave portion is provided, and an annular convex portion is provided on a butt end surface of the second joint member. In a properly tightened state of the pipe joint, the convex portion of the second joint member fits into the concave portion of the first joint member. The inner surface and the outer surface of the convex portion are almost completely adhered to each other, and a portion radially inside the concave portion of the butt end surface of the first joint member and a radially inner portion than the convex portion of the butt end surface of the second joint member are formed. It is in close contact with almost the entire surface, and a portion radially outside the concave portion of the butt end surface of the first joint member and a portion radially outside the convex portion of the butt end surface of the second joint member are also adhered almost entirely. To do That.

In the pipe joint according to the second invention, the convex portion of the second joint member includes an integrated portion integrally formed with the second joint member, and a separate body portion formed separately from the integrated portion. When the joint is properly tightened, the protrusion integrated portion of the second joint member may be in close contact with the protrusion separate portion of the second joint member.

A pipe joint according to a third aspect of the present invention includes first and second synthetic resin tubular joint members, a synthetic resin gasket interposed between butted portions of the two joint members, and screw means for connecting the two joint members. In the pipe joint, an annular concave portion for forming a gasket storage portion in which a gasket is stored when the joint members are butted with each other is provided on a butt end face of each joint member, In the tightened state, substantially the entire inner surface of the concave portion of the first joint member is in close contact with the gasket, the surface of the gasket exposed from the concave portion is in close contact with substantially the entire inner surface of the concave portion of the second joint member, and The portion radially inside the concave portion of the butted end surface of the second joint member and the portion radially inside the concave portion of the butted end surface of the second joint member are almost completely adhered to each other, and the first joint member Radially outside portion of the recess of the feeder matching end faces radially outside portion of the concave portion of the butt end face of the second joint member is also characterized in that the intimate contact with substantially the entire surface.

In the pipe joint according to the third aspect of the present invention, a portion radially inward of the concave portion of the butt end surface of the first joint member protrudes axially more than a radially outer portion thereof than the concave portion of the butt end surface of the second joint member. The radially inner portion may also protrude more axially than the radially outer portion, and the radially inner portion of the butt end face of the first joint member may be flush with the bottom surface of the recess. The outer portion in the radial direction projects axially from the bottom surface of the concave portion, and the portion radially inward of the concave portion of the mating end face of the second joint member projects axially from the bottom surface of the concave portion. The portion may be recessed in the axial direction from the bottom surface of the concave portion, and furthermore, the portion radially inside the concave portion of the butt end surface of the first joint member is further concaved from the bottom surface of the concave portion, and Part is concave Axially protrudes from the bottom surface of the second joint member, a portion radially inward of the concave portion of the butt end surface of the second joint member protrudes axially beyond the bottom surface of the concave portion, and a radially outer portion further axially protrudes from the bottom surface of the concave portion. It may be concave in the direction.

Each of the pipe joints according to the above inventions has, when the pipe joint is tightened by hand, a portion radially inside the concave portion of the butt end surface of the first joint member and a convex portion or concave portion of the butt end surface of the second joint member. A first gap exists between the inner part in the direction and the radially outer part of the butt end surface of the first joint member and the convex part or concave part of the butt end surface of the second joint member. It is preferable that a second gap larger than the first gap exists between the outer portion and the outer portion. In this manner, in the properly tightened state, there are a part where the surface pressure is large, a part where the surface pressure is medium and a part where the surface pressure is small, and in the first half of the use period, the pressure in the part where the surface pressure is large decreases. However, during this period, since the pressure drop in the portion where the surface pressure is medium is suppressed, the fluid leakage prevention performance of a predetermined level or more can be maintained for a long time.

The first gap is preferably from 0.1 mm to 0.4 mm, more preferably from 0.15 mm to 0.3 mm. The second gap is preferably 0.2 mm or more and 0.6 mm or less, more preferably 0.25 mm or more and 0.5 mm or less. Also. The difference between the second gap and the first gap is preferably 0.05 mm or more and 0.3 mm or less, more preferably 0.1 mm or more and 0.2 mm or less.

In the pipe joint of each of the above inventions, a flange portion is provided at a butt end of each joint member, and the screw means includes an annular external thread member having a distal end surface in contact with the flange portion of one of the joint members. There may be a cap nut which is fitted from the other joint member side, a top wall abuts on a flange portion of the joint member, and is screwed to the male screw member. The male screw member and the cap nut do not come into contact with the fluid flowing in the joint member, and may be made of metal or synthetic resin. By tightening the cap nut with respect to the male screw member, the flange portion of each joint member is pushed inward in the axial direction, whereby the two joint members are fluid-tightly connected to each other.

Also, in the pipe joint of each of the above inventions, at least one of between the external thread member and the flange portion of the joint member and between the top wall of the cap nut and the flange portion of the joint member, one of the joint members is connected to the other. An urging member for urging toward the joint member may be interposed, and an annular gap is formed between the inner diameter of the cap nut and the outer diameter of the flange portion of both joint members. An annular spacer is housed therein, and at least one of between the top wall of the cap nut and the spacer and between the male screw member and the spacer is urged toward the other joint member. May be interposed. With this configuration, even if the joint member and the gasket made of synthetic resin change with time (stress relaxation, cold flow, etc.), one joint member is constantly urged toward the other joint member, and therefore the fluid It is possible to maintain the surface pressure that greatly affects the leakage prevention performance, and the fluid leakage prevention performance is more reliably ensured.

Further, it is preferable that a thrust ring made of synthetic resin is interposed between the top wall of the cap nut and the flange of the joint member. With this configuration, when the cap nut is rotated and tightened, the thrust ring slides against the cap nut and the joint member in a state of contact with the cap nut and the joint member, and the cap nut and the joint member rotate together. Is prevented.

In this case, the outer diameter of the thrust ring is made larger than the inner diameter of the cap nut, and an annular recess for accommodating the outer peripheral edge of the thrust ring may be formed on the inner circumference of the cap nut.

The thickness of the thrust ring is preferably equal to or smaller than that of the gasket, and is preferably as thin as possible from the viewpoint of stress relaxation.

As a synthetic resin constituting each joint member, for example, a fluororesin such as PFA is exemplified, and as a synthetic resin constituting the gasket, a fluororesin such as PTFE is exemplified, but other FEP, PCTFE , ETFE or other fluororesin, or other synthetic resin, and the joint member and the gasket may be of the same material. Further, the synthetic resin forming the thrust ring is, for example, a material similar to that of the gasket, but may be a synthetic resin having a smaller sliding friction coefficient (easier to slide).

According to the pipe joints of the first to third aspects of the present invention, a pipe joint can be obtained in which the fluid leakage prevention performance is maintained even after a lapse of time, even though the portion in contact with the fluid is made of synthetic resin. The pipe joint of the second invention has the advantage that the number of parts can be further reduced, and the pipe joint of the third invention has the advantage that the gasket can be easily removed when disassembling the pipe joint.

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the pipe joint of the first invention. As shown in FIG. 1, the pipe joint (1) is made by abutting the two joint members (2) and (3) with the first synthetic resin tubular member (2) and the second synthetic resin tubular member (3). A gasket (4) made of a synthetic resin having a rectangular cross section interposed between the portions, an externally threaded member (5) fitted to the second joint member (3), and a first joint member (2) side. The cap nut (6) is fitted and screwed to the screw member (5).

Each joint member (2) (3) has a constant inner diameter over the entire length and is equal to each other, the thick portion (2a) (3a) closer to the butted portion, and the thin portion (2a) (3a) far from the butted portion ( 2b) and (3b), and flange portions (2c) and (3c) provided at the butted ends of the thick portions (2a) and (3a).

、 A circular recess (7) having a rectangular cross section is provided at a radially intermediate portion of the butted end face of the first joint member (2). An annular convex portion (8) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the second joint member (3).

The male screw member (5) and the cap nut (6) are made of metal, and a hexagonal column-shaped flange portion (5a) is provided at the end of the male screw member (5) opposite to the butted portion. At the end opposite to the butted portion of the cap nut, a perforated disk-shaped top wall (6a) is provided. The inner diameter of the male screw member (5) is substantially equal to the outer diameter of the thick portion (3a) of the second joint member (3), and the inner diameter of the top wall (6a) of the cap nut (6) is the first joint member. The outer diameter of the thick portion (2a) of (2) is substantially equal to that of (2). When the cap nut (6) is tightened against the male thread member (5), the male thread member (5) pushes the flange portion (3c) of the second joint member (3) inward in the axial direction, and the cap nut is (6) pushes the flange portion (2c) of the first joint member (2) inward in the axial direction, whereby the joint members (2) and (3) are brought into close contact with each other via the gasket (4).

The inner diameter of the concave portion (7) of the first joint member (2), the convex portion (8) of the second joint member (3), and the inner diameter of the gasket (4) are almost the same, and the concave portion of the first joint member (2). (7), the outer diameter of the projection (8) of the second joint member (3) and the outer diameter of the gasket (4) are also substantially equal. The recess of the recess (7) is larger than the protrusion of the protrusion (8), and the thickness of the gasket (4) is smaller than the recess of the recess (7). The amount of depression of the concave portion (7) is slightly smaller than the sum of the amount of protrusion of the convex portion (8) and the thickness of the gasket (4).

FIG. 2A shows a state in which the cap nut (6) is manually tightened to the male screw member (5), and FIG. 2B shows a state in which the cap nut (6) is further properly tightened using a spanner or the like. Is shown.

As shown in FIG. 2A, when the pipe joint (1) is manually tightened, the entire gasket (4) is fitted into the recess (7) of the first joint member (2), The convex portion (8) of the joint member (3) presses the gasket (4) against the bottom surface of the concave portion (7). Then, a portion (2d) radially inner than the concave portion (7) of the butt end surface of the first joint member (2) and a radially inner portion (2d) of the convex portion (8) of the butt end surface of the second joint member (3). A first gap (G1) exists between the first joint member (2d) and the portion (2e) radially outside the concave portion (7) of the butt end face of the first joint member (2). A second gap (G2) larger than the first gap (G1) exists between the butt end surface of the member (3) and a portion (3e) radially outside of the projection (8). I have. To give an example of specific dimensions, the radially inner portion (2d) and the radially outer portion (2e) of the recess (7) of the first joint member (2) are flush with each other, and the recess (7) The dent amount is 1.5 mm, and the radially inner portion (3d) of the convex portion (8) of the second joint member (3) projects in the axial direction by 0.2 mm more than the radially outer portion (3e). The protrusion amount of the portion (8) is 0.8 mm based on the radially inner portion (3d), the thickness of the gasket (4) is 1 mm, the first gap (G1) is 0.3 mm, and the second gap ( G2) is 0.5 mm.

As shown in FIG. 2 (b), when the pipe joint (1) is properly tightened, the gasket (4) and the protrusions of the second joint member (3) are inserted into the recesses (7) of the first joint member (2). (8) The whole is fitted, and the inner surface of the concave portion (7) of the first joint member (2) and the outer surface of the convex portion (8) of the second joint member (3) are almost all over the gasket (4). At the same time, the portion (2d) radially inward of the concave portion (7) of the butt end face of the first joint member (2) and the convex portion (8) of the butt end face of the second joint member (3) in the radial direction The inner part (3d) is in close contact with almost the entire surface, and the part (2e) radially outside the recess (7) of the butt end face of the first joint member (2) and the butt end face of the second joint member (3) The portion (3e) radially outside of the convex portion (8) is also in close contact with almost the entire surface.

FIGS. 3 and 4 show an embodiment of the pipe joint of the second invention. As shown in FIG. 3, the pipe joint (11) was fitted to the first tubular joint member (12) made of synthetic resin, the second tubular joint member (13) made of synthetic resin, and the second joint member (13). An annular male screw member (5) and a cap nut (6) fitted from the first joint member (12) side and screwed to the screw member (5).

Each joint member (12) (13) has a constant inner diameter over the entire length and is equal to each other, a thick portion (12a) (13a) closer to the butted portion, and a thin portion (12a) (13a) far from the butted portion. 12b) and (13b), and flange portions (12c) and (13c) provided at the butted ends of the thick portions (12a) and (13a).

、 An annular concave portion (17) having a rectangular cross section is provided at a radially intermediate portion of the butt end surface of the first joint member (12). An annular convex portion (18) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the second joint member (13).

The male screw member (5) and the cap nut (6) are made of metal, and a hexagonal column-shaped flange portion (5a) is provided at the end of the male screw member (5) opposite to the butted portion. At the end opposite to the butted portion of the cap nut, a perforated disk-shaped top wall (6a) is provided. The inner diameter of the male screw member (5) is substantially equal to the outer diameter of the thick portion (13a) of the second joint member (13), and the inner diameter of the top wall (6a) of the cap nut (6) is the first joint member. The outer diameter of the thick portion (12a) of (12) is substantially equal to that of (12). When the cap nut (6) is tightened against the male thread member (5), the male thread member (5) pushes the flange portion (13c) of the second joint member (13) inward in the axial direction, and the cap nut is (6) pushes the flange portion (12c) of the first joint member (12) inward in the axial direction, whereby the joint members (12) and (13) are connected to the concave portion (17) and the convex portion (18). Are brought into close contact with each other.

The inner diameters of the concave portion (17) of the first joint member (12) and the convex portion (18) of the second joint member (13) are substantially equal to each other. The outer diameters of the convex portions (18) of the two joint members (13) are also substantially equal. The concave amount of the concave portion (17) is slightly smaller than the convex amount of the convex portion (18).

FIG. 4 shows a state in which the cap nut (6) is manually tightened to the male screw member (5). As shown in the figure, when the pipe joint (11) is manually tightened, the convex portion (18) of the second joint member (13) is fitted into the concave portion (17) of the first joint member (12). The tip of the projection (18) presses the bottom of the recess (17). Then, a portion (12d) radially inward of the concave portion (17) of the butt end surface of the first joint member (12) and a radially inner portion of the convex portion (18) of the butt end surface of the second joint member (13). A first gap (G1) exists between the first joint member (13d) and a portion (12e) radially outside the recess (17) of the butt end face of the first joint member (12) and the second joint (G1). A second gap (G2) larger than the first gap (G1) exists between the butt end surface of the member (13) and a portion (13e) radially outside of the projection (18). I have. To give an example of specific dimensions, the radially inner portion (12d) and the radially outer portion (12e) of the concave portion (17) of the first joint member (12) are flush with each other, and the concave portion (17) The dent amount is 1.5 mm, and the radially inner portion (13d) of the convex portion (18) of the second joint member (3) projects in the axial direction by 0.2 mm more than the radially outer portion (13e). The protrusion amount of the portion (18) is 1.8 mm with reference to the radially inner portion (13d), the first gap (G1) is 0.3 mm, and the second gap (G2) is 0.5 mm.

In the proper tightening state further tightened from the state of FIG. 4, the entire convex portion (18) of the second joint member (13) is fitted in the concave portion (17) of the first joint member (12). The inner surface of the concave portion (17) of the member (12) and the outer surface of the convex portion (18) of the second joint member (13) are in close contact with almost the entire surface, and the concave portion (17) of the butt end surface of the first joint member (12) Also, the radially inner portion (12d) and the radially inner portion (13d) of the protruding portion (18) of the butted end face of the second joint member (13) are in close contact with substantially the entire surface, and the first joint member (12 The part (12e) radially outside of the concave part (17) of the butted end face of ()) and the part (13e) radially outside of the convex part (18) of the butted end face of the second joint member (13) are almost all over. Adhering.

FIG. 5 shows a first embodiment of the pipe joint of the third invention. As shown in FIG. 5, the pipe joint (21) is formed by abutting the first tubular joint member (22) made of synthetic resin and the second tubular joint member (23) made of synthetic resin with both joint members (22) and (23). A gasket (24) made of synthetic resin having a rectangular cross section interposed in the portion, an external male screw member (5) fitted to the second joint member (23), and a first joint member (22) side. The cap nut (6) is fitted and screwed to the screw member (5).

Each of the joint members (22) and (23) has a constant inner diameter over the entire length equally and has a thick portion (22a) (23a) closer to the butted portion and a thin portion (farther from the butted portion). (Not shown), and flange portions (22c) (23c) provided at the butted ends of the thick portions (22a) (23a).

、 An annular concave portion (27) having a rectangular cross section is provided at a radially intermediate portion of the butt end surface of the first joint member (22). An annular concave portion (28) having a rectangular cross section is also provided at a radially intermediate portion of the butted end surface of the second joint member (23). A portion (22d) radially inward of the concave portion (27) of the butt end surface of the first joint member (22) projects slightly axially from a radially outer portion (22e), and the second joint member ( The portion (23d) radially inward of the concave portion (28) of the butted end face of (23) also slightly projects in the axial direction from the radially outer portion (23e). The two recesses (27) and (28) form a gasket storage portion (26) for storing the gasket (24) when the joint members (22) and (23) abut against each other.

The male screw member (5) and the cap nut (6) are made of metal, and a hexagonal column-shaped flange portion (5a) is provided at the end of the male screw member (5) opposite to the butted portion. At the end opposite to the butted portion of the cap nut, a perforated disk-shaped top wall (6a) is provided. The inner diameter of the male screw member (5) is substantially equal to the outer diameter of the thick portion (23a) of the second joint member (23), and the inner diameter of the top wall (6a) of the cap nut (6) is the first joint member. The outer diameter of the thick portion (22a) of (22) is made substantially equal. When the cap nut (6) is tightened against the male thread member (5), the male thread member (5) pushes the flange portion (23c) of the second joint member (23) inward in the axial direction, and the cap nut (6) pushes the flange portion (22c) of the first joint member (22) inward in the axial direction, whereby the joint members (22) and (23) are brought into close contact with each other via the gasket (24).

The inner diameter of the concave portion (27) of the first joint member (22), the concave portion (28) of the second joint member (23), and the inner diameter of the gasket (24) are substantially the same, and the concave portion (27) of the first joint member (22). 27), the outer diameter of the concave portion (28) of the second joint member (23) and the outer diameter of the gasket (24) are also substantially equal. The sum of the concave amounts of the two concave portions (27) and (28) based on the radially inner portions (22d) and (23d) of the joint members (22) and (23) is slightly smaller than the thickness of the gasket (24). ing.

FIG. 5 shows a state in which the cap nut (6) is manually tightened to the male screw member (5). In the manually tightened state of the pipe joint (21), the concave portion (27) of the first joint member (22) is shown. ), About half of the gasket (24) is fitted therein, and the other half of the gasket (24) is fitted in the recess (28) of the second joint member (23). The gasket (24) is pressed by the bottom surface of the concave portion (27) of the member (22) and the bottom surface of the concave portion (28) of the second joint member (23). Then, a portion (22d) radially inner than the concave portion (27) of the butt end surface of the first joint member (22) and a portion radially inner than the concave portion (28) of the butt end surface of the second joint member (23). (23d), there is a first gap (G1), and a portion (22e) of the first joint member (22) radially outside the recess (27) at the butt end face and the second joint member. A second gap (G2) larger than the first gap (G1) exists between the butt end face of (23) and a portion (23e) radially outside of the concave portion (28). To give an example of specific dimensions, the radially inner portions (22d) and (23d) of the concave portions (27) and (28) of the joint members (22) and (23) are radially outer portions (22e) and (23e). Projecting in the axial direction more than 0.1 mm, the recess amount of the recesses (27) and (28) is 1.15 mm based on the radially inner portions (22d) and (23d), and the thickness of the gasket (4) is 2 mm. , The first gap (G1) is 0.3 mm, and the second gap (G2) is 0.5 mm.

When further tightening from the state of FIG. 5, first, a portion (22d) radially inward of the concave portion (27) of the butt end surface of the first joint member (22) and the butt end surface of the second joint member (23) will be described. When the portion (23d) radially inward of the concave portion (28) is in close contact with almost the entire surface and further tightened to make the pipe joint (21) properly tightened, the concave portions (27) and (27) of the first joint member (22) The entire gasket (24) fits into the gasket accommodating recess (26) formed by the recess (28) of the second joint member (23), and almost the entire inner surface of the recess (27) of the first joint member (22) The surface of the gasket (24), which is in close contact with the gasket (24) and is exposed from the concave portion (27) of the first joint member (22), adheres to almost the entire inner surface of the concave portion (28) of the second joint member (23). At the same time, a portion (22e) radially outside of the concave portion (27) of the butt end surface of the first joint member (22) and the concave portion (28) of the butt end surface of the second joint member (23) are smaller than the concave portion (28). Outward portion (23e) is also in close contact with substantially the entire surface.

FIG. 6 shows a second embodiment of the pipe joint of the third invention. As shown in FIG. 6, the pipe joint (31) is made by abutting the first tubular joint member (32) made of synthetic resin and the second tubular joint member (33) made of synthetic resin with both joint members (32) and (33). A gasket (34) made of a synthetic resin having a rectangular cross section interposed between the portions, an external male screw member (5) fitted to the second joint member (33), and a first joint member (32) side. The cap nut (6) is fitted and screwed to the screw member (5).

Each of the joint members (32) and (33) has a constant inner diameter over the entire length and is equal to each other, and includes a thick portion (32a) (33a) closer to the butted portion and a thin portion (far) from the butted portion ( (Not shown) and flange portions (32c) (33c) provided at the butted ends of the thick portions (32a) (33a).

、 An annular concave portion (37) having a rectangular cross section is provided at a radially intermediate portion of the butt end face of the first joint member (32). An annular concave portion (38) having a rectangular cross section is also provided at a radially intermediate portion of the butted end surface of the second joint member (33). A portion (32d) radially inward of the concave portion (37) of the butt end surface of the first joint member (32) is flush with the bottom surface of the concave portion (37), and a radially outer portion (32e) is concave portion (37e). ) Protrudes in the axial direction from the bottom surface of the second joint member (33), a portion (33d) radially inward of the concave portion (38) of the butt end surface of the second joint member (33) protrudes in the axial direction from the bottom surface of the concave portion (38), The radially outer portion (33e) is axially recessed from the bottom surface of the recess (38). The two concave portions (37) and (38), the radially outer portion (32e) of the first joint member (32) and the radially inner portion (33d) of the second joint member (33) form the joint member (32) ( 33) A gasket storage portion (36) for storing a gasket (34) when butted against each other is formed.

The male screw member (5) and the cap nut (6) are made of metal, and a hexagonal column-shaped flange portion (5a) is provided at the end of the male screw member (5) opposite to the butted portion. At the end opposite to the butted portion of the cap nut, a perforated disk-shaped top wall (6a) is provided. The inner diameter of the male screw member (5) is substantially equal to the outer diameter of the thick portion (33a) of the second joint member (33), and the inner diameter of the top wall (6a) of the cap nut (6) is the first joint member. The outer diameter of the thick portion (32a) of (32) is substantially equal to that of (32). When the cap nut (6) is tightened against the male screw member (5), the male screw member (5) pushes the flange portion (33c) of the second joint member (33) inward in the axial direction, and the cap nut (6) pushes the flange portion (32c) of the first joint member (32) inward in the axial direction, whereby the joint members (32) and (33) are brought into close contact with each other via the gasket (34).

The inner diameters of the concave portion (37) of the first joint member (32), the concave portion (38) of the second joint member (33), and the gasket (34) are substantially equal, and the concave portions (37) of the first joint member (32) are substantially the same. 37), the outer diameter of the concave portion (38) of the second joint member (33) and the outer diameter of the gasket (34) are substantially the same. The concave amount of the concave portion (37) of the first joint member (32) is slightly larger than the thickness of the gasket (34), and the concave amount of the concave portion (38) of the second joint member (33) is smaller than that of the gasket (34). It is slightly smaller than the thickness.

FIG. 6 shows a state in which the cap nut (6) is manually tightened to the male screw member (5). In a state in which the pipe joint (31) is manually tightened, the gasket (24) is stored in the gasket accommodating portion (36). ) Is fitted, and the gasket (34) is pressed by the bottom surface of the recess (37) of the first joint member (32) and the bottom surface of the recess (38) of the second joint member (33). Then, a portion (32d) radially inner than the concave portion (37) of the butt end surface of the first joint member (32) and a portion radially inner than the concave portion (38) of the butt end surface of the second joint member (33). (33d), there is a first gap (G1), and a portion (32e) of the first joint member (32) radially outside of the concave portion (37) of the butt end face and the second joint member (32). A second gap (G2) larger than the first gap (G1) exists between the butt end face of (33) and a portion (33e) radially outside of the concave portion (38). To give an example of specific dimensions, the protrusion amount of the radially outer portion (32e) of the first joint member (32) is 1.5 mm based on the bottom surface of the concave portion (37), and the second joint member ( The protrusion amount of the radially inner portion (33d) of the 33) is 0.7 mm based on the bottom surface of the concave portion (38), and the concave amount of the radially outer portion (33e) of the second joint member (33) is The thickness of the gasket (34) is 1 mm, the first gap (G1) is 0.3 mm, and the second gap (G2) is 0.5 mm based on the bottom of the recess (38).

When further tightening from the state of FIG. 6, first, the part (32d) radially inside the recess (37) of the butt end face of the first joint member (32) and the butt end face of the second joint member (33) are When the portion (33d) radially inward of the concave portion (38) is in close contact with almost the entire surface and further tightened to make the pipe joint (31) properly tightened, the two concave portions (37) and (38), the first joint member The entire gasket (34) fits into the gasket accommodating recess (36) by the radially outer portion (32e) of the (32) and the radially inner portion (33d) of the second joint member (33). (36) The inner surface and the outer surface of the gasket (34) are in close contact over substantially the entire surface, and a portion (32e) radially outside of the concave portion (37) of the butt end surface of the first joint member (32) and the second joint member (32). A portion (33e) radially outside of the concave portion (38) of the abutting end face of 33) is in close contact with almost the entire surface.

FIG. 7 shows a third embodiment of the pipe joint of the third invention. As shown in FIG. 7, the pipe joint (41) is abutting the first tubular joint member (42) made of synthetic resin and the second tubular joint member (43) made of synthetic resin with both joint members (42) and (43). A gasket (44) made of synthetic resin having a rectangular cross section interposed between the portions, an annular external thread member (5) fitted to the second joint member (43), and a first joint member (32) side. The cap nut (6) is fitted and screwed to the screw member (5).

Each of the joint members (42) and (43) has a constant inner diameter over the entire length and is equal to each other, and has a thick portion (42a) (43a) closer to the butted portion and a thin portion (far) from the butted portion ( (Not shown), and flange portions (42c) (43c) provided at the butted ends of the thick portions (42a) (43a).

環状 An annular concave portion (47) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the first joint member (42). An annular concave portion (48) having a rectangular cross section is also provided at a radially intermediate portion of the butt end surface of the second joint member (43). A portion (42d) radially inward of the concave portion (47) of the butt end surface of the first joint member (42) is further concaved from the bottom surface of the concave portion (37), and a radially outer portion (42e) is concaved (47e). ) Protrudes axially from the bottom surface. A portion (43d) radially inner than the concave portion (48) of the butt end surface of the second joint member (43) projects axially beyond the bottom surface of the concave portion (48), and a radially outer portion (43e) has a concave portion (43e). 48) It is recessed in the axial direction from the bottom surface. The two concave portions (47) and (48), the radially outer portion (42e) of the first joint member (42) and the radially inner portion (43d) of the second joint member (43) form the joint member (42) ( 43) A gasket storage portion (46) for storing a gasket (44) when butted against each other is formed.

The male screw member (5) and the cap nut (6) are made of metal, and a hexagonal column-shaped flange portion (5a) is provided at the end of the male screw member (5) opposite to the butted portion. At the end opposite to the butted portion of the cap nut, a perforated disk-shaped top wall (6a) is provided. The inner diameter of the male screw member (5) is substantially equal to the outer diameter of the thick portion (43a) of the second joint member (43), and the inner diameter of the top wall (6a) of the cap nut (6) is the first joint member. The outer diameter of the thick portion (42a) of (42) is substantially equal. When the cap nut (6) is tightened against the male screw member (5), the male screw member (5) pushes the flange portion (43c) of the second joint member (43) inward in the axial direction, and the cap nut (6) pushes the flange portion (42c) of the first joint member (42) inward in the axial direction, whereby the joint members (42) and (43) are brought into close contact with each other via the gasket (44).

The inner diameter of the concave portion (47) of the first joint member (42), the concave portion (48) of the second joint member (43), and the inner diameter of the gasket (44) are almost the same, and the concave portion (47) of the first joint member (42). 47), the outer diameter of the concave portion (48) of the second joint member (43) and the outer diameter of the gasket (44) are substantially the same. The concave amount of the concave portion (47) of the first joint member (42) is slightly larger than the thickness of the gasket (44), and the concave amount of the concave portion (48) of the second joint member (43) is also smaller than that of the gasket (44). It is slightly larger than the thickness.

FIG. 7 shows a state in which the cap nut (6) is manually tightened to the male screw member (5). When the pipe joint (41) is manually tightened, the gasket (44) is stored in the gasket storage portion (46). ) Is entirely fitted, and the gasket (44) is pressed by the bottom surface of the concave portion (47) of the first joint member (42) and the bottom surface of the concave portion (48) of the second joint member (43). Then, a portion (42d) radially inner than the concave portion (47) of the butt end surface of the first joint member (42) and a portion radially inner than the concave portion (48) of the butt end surface of the second joint member (43). (43d), there is a first gap (G1), a portion (42e) of the first joint member (42) radially outside the recess (47) at the butted end face and the second joint member (42). There is a second gap (G2) larger than the first gap (G1) between the butted end face of (43) and a portion (43e) radially outside of the concave portion (48). To give an example of specific dimensions, the protrusion amount of the radially outer portion (42e) of the first joint member (42) is 1.5 mm based on the bottom surface of the concave portion (47), and the first joint member ( The amount of depression of the radially inner portion (42d) of (42) is 0.8 mm based on the bottom surface of the concave portion (47), and the amount of protrusion of the radially inner portion (43d) of the second joint member (43) is , 1.5 mm with respect to the bottom surface of the concave portion (48), the amount of dent of the radially outer portion (43e) of the second joint member (43) is 1.0 mm with respect to the bottom surface of the concave portion (48), (44) has a thickness of 1 mm, a first gap (G1) of 0.3 mm, and a second gap (G2) of 0.5 mm.

When further tightening from the state of FIG. 7, first, a portion (42d) radially inward of the concave portion (47) of the butt end surface of the first joint member (42) and the butt end surface of the second joint member (43) are formed. When the portion (43d) radially inward of the concave portion (48) is in close contact with almost the entire surface, and further tightened to make the pipe joint (41) properly tightened, the two concave portions (47) and (48), the first joint member The entire gasket (44) fits into the gasket storage recess (46) by the radially outer portion (42e) of (42) and the radially inner portion (43d) of the second joint member (43), (46) The inner surface and the outer surface of the gasket (44) are in close contact over substantially the entire surface, and the portion (42e) radially outside the recess (47) of the butt end surface of the first joint member (42) and the second joint member ( A portion (43e) radially outward of the concave portion (48) of the butted end face of 43) is in close contact with almost the entire surface.

FIG. 8 shows another embodiment of the pipe joint of the first invention. As shown in FIG. 8, the pipe joint (51) is abutted between the first tubular joint member (52) made of synthetic resin and the second tubular joint member (53) made of synthetic resin, and both joint members (52) and (53). A gasket (54) made of a synthetic resin having a rectangular cross section interposed between the portions, an externally threaded member (55) fitted to the second joint member (53), and a first joint member (52) side The cap nut (56) is fitted and screwed to the screw member (55).

Each joint member (52) (53) has a constant inner diameter over the entire length and is equal to each other, a thick portion (52a) (53a) closer to the butt portion, and a thin portion (far) from the butt portion. 52b) and (53b), and flange portions (52c) and (53c) provided at the butted ends of the thick portions (52a) and (53a).

環状 A circular recess (57) having a rectangular cross section is provided at a radially intermediate portion of the butted end face of the first joint member (52). An annular convex portion (58) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the second joint member (53).

The male screw member (55) and the cap nut (56) are made of metal, and a hexagonal column-shaped flange portion (55a) is provided at the end of the male screw member (55) opposite to the butted portion. At the end opposite to the butted portion of the cap nut (56), a perforated disk-shaped top wall (56a) is provided. The inner diameter of the male screw member (55) is substantially equal to the outer diameter of the thick portion (53a) of the second joint member (53), and the inner diameter of the top wall (56a) of the cap nut (56) is the first joint member. The outer diameter of the thick portion (52a) of (52) is substantially equal to that of (52).

In this embodiment, the outer diameter of the male screw member (55) and the inner diameter of the cap nut (56) are made larger than the outer diameters of the flange portions (52c) (53c) of both joint members (52) (53). A gap is formed between the inner diameter of the cap nut (56) and the outer diameter of the flange portions (52c) (53c) of the joint members (52) (53). An annular spacer (59) is accommodated in this gap. And, between the top wall of the cap nut (56) and the flange portion (52c) of the first joint member (52) and the spacer (59), the flange portion (52c) of the first joint member (52) is (2) An annular disc spring (50) and a spring washer (60) as urging members for urging toward the joint member (53) make the spring washer (60) the flange portion (52c) and the spacer (59) side. Is provided. The axial length of the spacer (59) is slightly smaller than the sum of the axial lengths of the flange portions (52c) and (53c) of the joint members (52) and (53).

When the cap nut (56) is tightened against the male screw member (55), the male screw member (55) pushes the flange portion (53c) of the second joint member (53) inward in the axial direction, and the cap nut (56) pushes the flange portion (52c) of the first joint member (52) inward in the axial direction via the disc spring (50) and the spring washer (60), whereby the two joint members (52) (53 ) Are brought into close contact with each other via a gasket (54).

The inner diameter of the concave portion (57) of the first joint member (52), the convex portion (58) of the second joint member (53), and the inner diameter of the gasket (54) are almost the same, and the concave portion of the first joint member (52). (57), the outer diameter of the projection (58) of the second joint member (53) and the outer diameter of the gasket (54) are also substantially equal. The concave amount of the concave portion (57) is larger than the convex amount of the convex portion (58), and the thickness of the gasket (54) is smaller than the concave amount of the concave portion (57). The amount of depression of the concave portion (57) is slightly smaller than the sum of the amount of protrusion of the convex portion (58) and the thickness of the gasket (54).

FIG. 8 shows a state in which the cap nut (56) is manually tightened to the male screw member (55). The configuration of the pipe joint (51) except for the spacer (59) and the urging members (50) and (60) is the same as that of the embodiment shown in FIGS. Therefore, although not described in detail, when the pipe joint (51) is manually tightened, the entire gasket (54) is fitted into the concave portion (57) of the first joint member (52), and the second joint member The convex portion (58) of (53) presses the gasket (54) against the bottom surface of the concave portion (57), and the portion radially inner than the concave portion (57) of the butt end surface of the first joint member (52) and the first A first gap (G1) exists between the butt end surface of the joint member (53) and a portion radially inward of the convex portion (58), and the butt end surface of the first joint member (52) has a first gap (G1). The first gap (G1) is located between the portion radially outside the concave portion (57) and the portion radially outside the convex portion (58) of the butt end face of the second joint member (53). There is a large second gap (G2). Then, when the pipe joint (51) is properly tightened, the gasket (54) and the entire protrusion (58) of the second joint member (53) fit into the recess (57) of the first joint member (52). The inner surface of the concave portion (57) of the first joint member (52) and the outer surface of the convex portion (58) of the second joint member (53) are in close contact with each other almost entirely via the gasket (54). A portion radially inside the concave portion (57) of the butt end surface of (52) and a portion radially inner than the convex portion (58) of the butt end surface of the second joint member (53) are in close contact with almost the entire surface, A substantially radially outer portion of the butt end surface of the first joint member (52) outside the concave portion (57) and a portion of the butt end surface of the second joint member (53) radially outside the convex portion (58) are almost entirely covered. It is made to adhere.

According to the pipe joint (51) of this embodiment, even if the synthetic resin joint members (52) and (53) and the gasket (54) change over time, the first joint member (52) can be replaced by the second joint member (53). , The spring is constantly urged by the disc spring (50), so that it is possible to maintain the surface pressure that greatly affects the fluid leakage prevention performance.

FIG. 9 shows still another embodiment of the pipe joint of the first invention. As shown in FIG. 9, the pipe joint (61) is formed by abutting the first tubular joint member (62) made of synthetic resin and the second tubular joint member (63) made of synthetic resin with both joint members (62) and (63). An annular gasket (64) made of a synthetic resin having a rectangular cross section interposed in the portion, an annular male screw member (55) fitted to the second joint member (63), and a first joint member (62) side. The cap nut (56) is fitted and screwed to the screw member (55).

Each joint member (62) (63) has a constant inner diameter over the entire length and is equal to each other, a thick portion (62a) (63a) closer to the butted portion, and a thin portion (62) far from the butted portion ( 62b) and (63b), and flange portions (62c) and (63c) provided at the butted ends of the thick portions (62a) and (63a).

環状 An annular concave portion (67) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the first joint member (62). An annular convex portion (68) having a rectangular cross section is provided at a radially intermediate portion of the butted end surface of the second joint member (63).

The male screw member (55) and the cap nut (56) are made of metal, and a hexagonal column-shaped flange portion (55a) is provided at the end of the male screw member (55) opposite to the butted portion. At the end opposite to the butted portion of the cap nut (56), a perforated disk-shaped top wall (56a) is provided. The inner diameter of the male screw member (55) is substantially equal to the outer diameter of the thick portion (63a) of the second joint member (63), and the inner diameter of the top wall (66a) of the cap nut (66) is the first joint member. The outer diameter of the thick portion (62a) of (62) is made substantially equal.

In this embodiment, the outer diameter of the male screw member (55) and the inner diameter of the cap nut (56) are larger than the outer diameters of the flange portions (62c) and (63c) of the joint members (62) and (63). A gap is formed between the inner diameter of the nut (56) and the outer diameter of the flange portions (62c) (63c) of the joint members (62) (63). An annular spacer (69) is accommodated in this gap. And, between the top wall of the cap nut (56) and the flange portion (62c) of the first joint member (62) and the spacer (69), the flange portion (62c) of the first joint member (62) is (2) An annular disc spring (70) and a spring washer (71) as urging members for urging toward the joint member (63) make the spring washer (71) the flange portion (62c) and the spacer (69) side. Is provided. Also, between the male screw member (55), the flange portion (63c) of the second joint member (63) and the spacer (69), the flange portion (63c) of the second joint member (63) is connected to the first joint member. An annular disc spring (72) and a spring washer (73) as urging members for urging toward the member (62) are provided with the spring washer (73) facing the flange portion (63c) and the spacer (69). ing. The axial length of the spacer (69) is slightly smaller than the sum of the axial lengths of the flange portions (62c) (63c) of the joint members (62) (63).

When the cap nut (56) is tightened with respect to the male screw member (55), the male screw member (55) attaches the flange portion (63c) of the second joint member (63) to the disc spring (70) and the spring washer ( Pushes inward in the axial direction through (71), and the cap nut (56) pushes the flange portion (62c) of the first joint member (62) inward in the axial direction through the disc spring (72) and the spring washer (73). As a result, the joint members (62) and (63) are brought into close contact with each other via the gasket (64).

The inner diameter of the concave portion (67) of the first joint member (62), the convex portion (68) of the second joint member (63), and the inner diameter of the gasket (64) are almost the same, and the concave portion of the first joint member (62). (67), the outer diameter of the projection (68) of the second joint member (63) and the outer diameter of the gasket (64) are also substantially equal. The concave amount of the concave portion (67) is larger than the projecting amount of the convex portion (68), and the thickness of the gasket (64) is smaller than the concave amount of the concave portion (67). The concave amount of the concave portion (67) is slightly smaller than the sum of the projecting amount of the convex portion (68) and the thickness of the gasket (64).

FIG. 9 shows a state in which the cap nut (56) is manually tightened to the male screw member (55). The configuration of the pipe joint (51) except for the spacer (69) and the urging members (70) (71) (72) (73) is the same as that of the embodiment shown in FIGS. Therefore, although not described in detail, when the pipe joint (61) is manually tightened, the entire gasket (64) is fitted into the concave portion (67) of the first joint member (62), and the second joint member ( The projection (68) of the first coupling member (63) presses the gasket (64) against the bottom surface of the recess (67), and the portion (radially inward of the recess (67) of the butt end face of the first joint member (62) ( 62d) and a portion (63d) radially inner than the projection (68) of the butted end face of the second joint member (63) has a first gap (G1). A portion (62e) of the butt end surface of (62) radially outside the recess (67) and a portion (63e) of the second joint member (63) radially outside the convex portion (68) of the butt end surface. Between them, there is a second gap (G2) larger than the first gap (G1). When the pipe joint (61) is properly tightened, the gasket (64) and the entire projection (68) of the second joint member (63) fit into the recess (67) of the first joint member (62). The inner surface of the concave portion (67) of the first joint member (62) and the outer surface of the convex portion (68) of the second joint member (63) are in close contact with almost the entire surface via a gasket (64). A portion (62d) radially inner than the concave portion (67) of the butt end surface of (62) and a portion (63d) radially inner than the convex portion (68) of the butt end surface of the second joint member (63) are formed. It is in close contact with almost the entire surface, and is smaller than a portion (62e) radially outside the concave portion (67) of the butt end surface of the first joint member (62) and the convex portion (68) of the butt end surface of the second joint member (63). The radially outer portion (63e) is also in close contact with almost the entire surface.

According to the pipe joint (61) of this embodiment, even if the synthetic resin joint members (62) and (63) and the gasket (64) change over time, the first joint member (62) can be replaced by the second joint member (63). And the second joint member (63) is constantly urged toward the first joint member (62) by the disc spring (72). It is possible to maintain the surface pressure that greatly affects the leakage prevention performance.

Although FIGS. 8 and 9 have been described as other embodiments of the pipe joint according to the first invention, these embodiments differ from those of FIGS. 1 and 2 in the pipe joint according to the second invention. The present invention can be applied to the joint embodiment and each embodiment of the pipe joint according to the third invention. Further, the spacers (59) and (69) can be omitted. For example, in the embodiment shown in FIG. 1, a configuration in which a disc spring is added can be adopted. By using the spacers (59) and (69), the diameters of the disc springs (50), (70) and (72) can be increased. As the urging member, a coil spring may be used instead of the disc springs (50), (70), (72) and the spring washers (60), (71), (73).

FIG. 10 shows still another embodiment of the pipe joint of the first invention. As shown in FIG. 10, this pipe joint (1) is made of a first tubular joint member (2) made of synthetic resin and a second tubular joint member (3) made of synthetic resin, and both joint members (2) and (3). An annular synthetic resin gasket (4) having a rectangular cross section interposed at the butted portion, an annular external thread member (5) fitted to the second joint member (3), and a first joint member (2) side Between the cap nut (6) screwed into the screw member (5) and the top wall (6a) of the cap nut (6) and the flange portion (2c) of the first joint member (2). And a thrust ring (9) made of synthetic resin interposed therebetween.

相違 The difference between this embodiment and the first embodiment is only the presence or absence of the thrust ring (9). The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 10 is a view corresponding to FIG. 2A, and shows a state in which the cap nut (6) is manually tightened to the male screw member (5).

The thrust ring (9) is formed of the same material as the gasket (4) or a material having a smaller coefficient of sliding friction than the gasket (4), and the thickness thereof is equal to or smaller than the gasket (4), for example, the gasket (4) It is about half of the thickness. The inner diameter of the thrust ring (9) is substantially equal to the hole diameter of the top wall (6a) of the cap nut (6), and the outer diameter is substantially equal to the outer diameter of the flange portion (2c) of the first joint member (2). Have been made equal. The thrust ring (9) is annular, but may be C-shaped which is not a perfect annular ring.

According to the pipe joint (1) of this embodiment, when the cap nut (6) is rotated and tightened, the thrust ring (9) is attached to the inner surface of the top wall (6a) of the cap nut (6) and the first joint. The member (2) slides against the flange portion (2c) while being in contact with the side surface thereof, and the cap nut (6) and the first joint member (2) are prevented from rotating together. A similar thrust ring (9) can be provided between the distal end surface of the male screw member (5) and the second joint member (3).

FIG. 11 shows another embodiment of the pipe joint (1) shown in FIG. This pipe joint (1) has a cross section interposed at a butt portion of the first tubular joint member (2) made of synthetic resin and the second tubular joint member (3) made of synthetic resin and both joint members (2) and (3). Is a square, annular synthetic resin gasket (4), an annular external thread member (5) fitted to the second joint member (3), and a thread member fitted from the first joint member (2) side. A cap nut (6) screwed to (5), and a synthetic resin material interposed between a top wall (6a) inner surface of the cap nut (6) and a flange portion (2c) of the first joint member (2). Thrust ring (10).

The only difference between this embodiment and the first embodiment is the presence or absence of the thrust ring (10) and the presence or absence of additional processing on the cap nut (6). The description is omitted by attaching the reference numerals. FIG. 11 is a view corresponding to FIG. 2A and shows a state in which the cap nut (6) is manually tightened to the male screw member (5).

The thrust ring (10) is formed of the same material as the gasket (4) or a material having a smaller coefficient of sliding friction than the gasket (4), and the thickness thereof is equal to or smaller than the gasket (4), for example, the gasket (4) It is about half of the thickness. The inner diameter of the thrust ring (10) is substantially equal to the hole diameter of the top wall (6a) of the cap nut (6), and the outer diameter is larger than the outer diameter of the flange portion (2c) of the first joint member (2). Has been done. The thrust ring (10) is annular, but may be C-shaped which is not a perfect annular ring.

As the outer diameter of the thrust ring (10) is made larger than the outer diameter of the flange portion (2c) of the first joint member (2), the thrust ring (10) is provided on the inner periphery of the cap nut (6). An annular recess (6b) is formed along the inner surface of the top wall (6a) to accommodate the outer peripheral edge of the upper wall (6). The outer diameter of the annular recess (6b) is substantially equal to the outer diameter of the thrust ring (10). Since the thrust ring (10) is made of a synthetic resin, the thrust ring (10) has some elasticity, and its outer peripheral edge is formed along the inner surface of the top wall (6a) of the cap nut (6) in this recess (6b). ). Therefore, the thrust ring (10) is prevented from being forgotten to be inserted, and the thrust ring (10) is prevented from falling off when the cap nut (6) is removed.

According to the pipe joint (1) of this embodiment, when the cap nut (6) is rotated and tightened, the thrust ring (10) is attached to the inner surface of the top wall (6a) of the cap nut (6) and the first joint. The member (2) slides against the flange portion (2c) while being in contact with the side surface thereof, and the cap nut (6) and the first joint member (2) are prevented from rotating together. A thrust ring (9) similar to that shown in FIG. 10 can be provided between the distal end surface of the male screw member (5) and the second joint member (3).

Although FIGS. 10 and 11 have been described as other embodiments of the pipe joint according to the first invention, these embodiments differ from those of FIGS. The present invention can be applied to the joint embodiment and each embodiment of the pipe joint according to the third invention.

It is a longitudinal section showing an embodiment of a pipe joint by the 1st invention. It is an expanded longitudinal sectional view of the same principal part, (a) has shown the state tightened by hand, (b) has shown the appropriate tightening state, respectively. It is a longitudinal section showing an embodiment of a pipe joint by a 2nd invention. It is an expanded longitudinal cross-sectional view of the principal part. It is a longitudinal section showing a 1st embodiment of a pipe joint by a 3rd invention. It is a longitudinal section showing a 2nd embodiment of the pipe joint by a 3rd invention. It is a longitudinal section showing an embodiment of a pipe joint by a 3rd invention. It is a longitudinal section showing other embodiments of a pipe joint by the 1st invention. FIG. 6 is a longitudinal sectional view showing still another embodiment of the pipe joint according to the first invention. FIG. 6 is a longitudinal sectional view showing still another embodiment of the pipe joint according to the first invention. FIG. 6 is a longitudinal sectional view showing still another embodiment of the pipe joint according to the first invention.

Explanation of reference numerals

(1) (11) (21) (31) (41) (51) (61) Fitting
(2) (12) (22) (32) (42) (52) (62) First joint member
(2c) (12c) (22c) (32c) (42c) (52c) (62c) Flange
(2d) (12d) (22d) (32d) (42d) (52d) (62d) Radially inner part
(2e) (12e) (22e) (32e) (42e) (52e) (62e) Radially outer part
(3) (13) (23) (33) (43) (53) (63) Second joint member
(3c) (13c) (23c) (33c) (43c) (53c) (63c) Flange
(3d) (13d) (23d) (33d) (43d) (53d) (63d) Radially inner part
(3e) (13e) (23e) (33e) (43e) (53e) (63e) Radially outer part
(4) (24) (34) (44) (54) (64) Gasket
(5) (55) Male thread member
(6) (56) Cap nut
(6a) (56a) Top wall
(6b) Annular recess
(7) (17) (27) (37) (47) (57) (67) Recess
(8) (18) (58) (68) Convex
(9) (10) Thrust ring
(26) (36) (46) Gasket storage section
(28) (38) (48) Recess
(50) (70) (72) Disc spring
(60) (71) (73) Spring washer
(G1) First gap
(G2) Second gap

Claims (13)

A pipe joint comprising first and second synthetic resin tubular joint members, a synthetic resin gasket interposed between butted portions of the two joint members, and screw means for connecting the two joint members. An annular concave portion is provided on the mating end surface of the member so that the opening remains in a state where the entire gasket is fitted, and an annular convex portion is provided on the mating end surface of the second joint member. The convex portion is fitted into the opening of the recessed portion, and in the properly tightened state of the pipe joint, the inner surface of the concave portion of the first joint member and the outer surface of the convex portion of the second joint member are substantially all over the gasket. At the same time, the portion radially inside the concave portion of the butt end surface of the first joint member and the radially inner portion of the convex portion of the butt end surface of the second joint member closely adhere over the entire surface. Pipe fitting, characterized in that the adhesion at the butted end faces radially outside portion of the convex portion of the butted end faces radially outside portion of the recess of the hand member and the second coupling member is also almost the entire surface. In a pipe joint comprising first and second synthetic resin tubular joint members and a screw means for connecting the two joint members, an annular concave portion is provided on a butt end face of the first joint member, and a second joint is provided. An annular convex portion is provided on the butt end surface of the member, and in a properly tightened state of the pipe joint, the convex portion of the second joint member fits into the concave portion of the first joint member, so that the inner surface of the concave portion and the outer surface of the convex portion are substantially all over. And a portion radially inward of the concave portion of the butt end surface of the first joint member and a radially inner portion of the convex portion of the butt end surface of the second joint member are in close contact with almost the entire surface of the first joint member. A pipe joint characterized in that a portion radially outward of a concave portion of a butt end surface of a member and a portion radially outward of a convex portion of a butt end surface of a second joint member are substantially entirely adhered to each other. In a pipe joint comprising first and second synthetic resin tubular joint members, a synthetic resin gasket interposed between butted portions of the two joint members, and a screw means for connecting the two joint members, each joint member comprises Are provided with annular recesses for forming a gasket storage portion in which a gasket is stored when the joint members are abutted with each other, and when the pipe joint is properly tightened, the first joint member has Almost the entire inner surface of the concave portion is in close contact with the gasket, the surface of the gasket exposed from the concave portion is in close contact with almost the entire inner surface of the concave portion of the second joint member, and is more radial than the concave portion of the butt end surface of the first joint member. The inner part and the radially inner part of the concave part of the butt end face of the second joint member are in close contact with almost the entire surface, and have a diameter larger than that of the concave part of the butt end face of the first joint member. Toward the outer portion and pipe fittings, characterized in that also the adhesion almost entirely radially outside portion of the concave portion of the butt end face of the second joint member. A portion radially inward of the concave portion of the butt end surface of the first joint member projects more axially than a radially outer portion, and a radially inner portion of the concave portion of the butt end surface of the second joint member also extends in the radial direction. The pipe joint according to claim 3, wherein the pipe joint protrudes in an axial direction from an outer portion. The portion of the butt end face of the first joint member radially inside the recess is flush with the bottom surface of the recess, and the portion of the butt end face of the first joint member projects axially beyond the bottom surface of the recess. 4. The pipe joint according to claim 3, wherein a portion radially inward of the concave portion protrudes in the axial direction from a bottom surface of the concave portion, and a radially outer portion is concave in the axial direction of the bottom surface of the concave portion. The portion of the butt end face of the first joint member radially inward of the recess is further recessed from the bottom surface of the recess, and the portion of the butt end surface of the first joint member projects axially beyond the bottom surface of the recess. 4. The pipe joint according to claim 3, wherein a portion radially inner than the concave portion protrudes in the axial direction from a bottom surface of the concave portion, and a radially outer portion is further depressed in the axial direction from the bottom surface of the concave portion. In a state in which the pipe joint is manually tightened, a portion between a portion radially inside the concave portion of the butt end surface of the first joint member and a portion radially inside the convex portion of the butt end surface of the second joint member, The first gap exists between a portion radially outside the concave portion of the butt end surface of the first joint member and a portion radially outside the convex portion of the butt end surface of the second joint member. 3. A fitting according to claim 1 or 2, wherein a second gap larger than is present. In a state where the pipe joint is manually tightened, the first joint member has a first radially inner portion between the concave portion of the butt end surface of the first joint member and a radially inner portion of the concave portion of the butt end surface of the second joint member. And a gap between the portion radially outside the concave portion of the butt end surface of the first joint member and the portion radially outside the concave portion of the butt end surface of the second joint member. 7. The fitting according to claim 3, wherein a large second gap is present. A flange portion is provided at a butt end of each joint member, and the screw means is fitted from an annular external thread member whose leading end surface abuts on the flange portion of one of the joint members and the other joint member side. 9. The pipe joint according to claim 1, further comprising a cap nut which is inserted and has a top wall abutting against a flange portion of the joint member and screwed to a male screw member. At least one of between the male screw member and the flange portion of the joint member and between the top wall of the cap nut and the flange portion of the joint member biases one joint member toward the other joint member. 10. The pipe joint according to claim 9, wherein a biasing member is interposed. An annular gap is formed between the inner diameter of the cap nut and the outer diameter of the flange portion of both joint members, and an annular spacer is accommodated in this gap. The pipe joint according to claim 9, wherein an urging member for urging one of the joint members toward the other of the joint members is interposed between at least one of the member and the spacer. The pipe joint according to claim 9, wherein a thrust ring made of synthetic resin is interposed between the top wall of the cap nut and the flange portion of the joint member. 13. The pipe joint according to claim 12, wherein the outer diameter of the thrust ring is larger than the inner diameter of the cap nut, and an annular recess for receiving the outer peripheral edge of the thrust ring is formed on the inner circumference of the cap nut.

Images