JP2624941C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid coupling used in a gas supply device used in an industrial manufacturing device such as a semiconductor manufacturing device. The present invention relates to a highly airtight gas coupling used in a device for supplying a toxic gas. 2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, thermal diffusion has been performed on a silicon base using a supertoxic gas such as silane, arsine, phosphine, or diborane as an impurity source. Also, pyrophoric gases are used. For example, the lethal dose of arsine is 0.5 ppm, and a small amount of leakage leads to personal injury. Therefore, pipes for these gases are connected by welding in order to prevent leakage. On the other hand, in a method of connecting pipes without using welding, a joint shown in FIG. 10 has been used for piping of non-toxic gas such as compressed air. Pipes 5 and 7 are inserted into both ends of the through hole of the body 6. A male screw 6a is formed on the outer periphery of the body 6, and a female screw 1a formed inside the cap nut 1 is fastened to the male screw 6a. A large chamfered portion is formed at each of the entrances of the through holes of the body 6, and a wedge-shaped sleeve 12 is fitted into the chamfered portion. A through hole is formed at the center of the sleeve 12 and is fitted to the pipes 5 and 7. A seat 11 for stopping rotation is in contact with the bottom surface of the sleeve 12. Seat 1
The end face opposite to 1 is in contact with the inner end face of the cap nut 1. A through hole is formed at the center of the sleeve 12 and is fitted to the pipes 5 and 7. In the joint having such a configuration, when the cap nut 1 is screwed into the body 6 with a predetermined torque, the sleeve 12 is pressed inward by the body 6 and the pipes 5, 7
And the pipes 5 and 7 are deformed. Thereby, the adhesiveness between the outer peripheral surfaces of the pipes 5 and 7 and the inner surface of the sleeve 12 and the adhesiveness between the outer peripheral surface of the sleeve 12 and the inner surface of the chamfered portion of the body 6 are ensured, and the airtightness of the joint is ensured. However, the joint shown in FIG. 10 has the following problems. (1) The airtightness is not sufficient, and it is dangerous to use for toxic gas piping. (2) Since the pipes 5 and 7 cannot be removed without being removed from the body 6 when removing them, it is necessary to provide an extra escape portion in the pipe, which is wasteful. (3) Once fastened, the pipe will be crushed and deformed, resulting in poor airtightness when removed and reassembled. In spite of the above problems, it is necessary to use a joint in the case of connection with a valve or the like. Therefore, the joint shown in FIG. 11 is used with great care in a semiconductor manufacturing process that handles toxic gas and the like. I have. On the other hand, in recent years, a joint disclosed in Japanese Patent Publication No. 2-46830 or the like, which can maintain high airtightness, has been used as means for solving the above problems. Here, in this joint, since the sleeve used has a special shape, the sleeve and the pipe for piping have been connected by welding. However, when a toxic gas is used as an impurity source for thermal diffusion, the following problems arise when the pipes are connected by welding. (1) Floating elements are generated by welding and mixed into the wafer as metal impurities, which impairs device reliability. (2) Many gases serving as impurity sources are corrosive, and pipes are usually made of SUS.
Although a material is used, the material of the welded portion changes due to welding, and the material is easily corroded.
Therefore, particles are generated, and the defective product rate due to the pattern defect increases. (3) Skilled welding is required for welding SUS pipes, and it has not been easy to secure skilled welding workers in the construction of semiconductor manufacturing processes and the like. In order to solve these problems, the present applicant has proposed new fluid couplings in JP-A-5-313283 and JP-A-5-313284. [0007] However, the fluid coupling disclosed in the above-mentioned JP-A-5-313283 and JP-A-5-313284 has the following problems. That is, since the number of components to be attached is large, there has been a case where the incorporation of components is forgotten. Even when a toxic gas is used, after assembly, the test is performed by flowing an inert gas, so there is no concern about the human body, but re-assembly is required, which is inefficient. Further, since the sleeve that forms the ferrule by fitting into the groove of the pipe has a structure having one split groove in order to attach the sleeve to the pipe, the thrust of the sleeve is transmitted to the ferrule on average. Therefore, there is a possibility that non-uniformity may occur in the seal with the gasket. Also, in the semiconductor process in which the fluid coupling is installed, many pipes are disposed in close contact with each other, and a wrench is fitted around the outer periphery of the cap nut, and the cap nut is screwed, as in the related art. The work was difficult and it took a lot of time to remove and install the cap nut. An object of the present invention is to solve the above-mentioned problems and to provide a fluid coupling used in a semiconductor manufacturing process or the like in which generation of metal impurities and particles is small, mounting is easy, and assembly errors are small. I do. Means for Solving the Problems In order to achieve this object, a fluid coupling according to the present invention has the following configuration. (1) A cap nut having a female screw formed on the inside, a pipe having a mirror-finished surface on the end face and a groove formed on the outer circumference , a rotating wheel having a trapezoidal cross section, and an inside of the cap nut
A fixed wheel abutting on an end face, an end face having a large area of the rotating wheel,
A plurality of balls held by a cap nut and a surface opposite to the surface in contact with the cap nut.
That the first ferrule part is fitted into the groove of the outer circumference of the pipe, and a second ferrule part in cross-section positioned on the ball side small end faces a plurality of areas a wedge-shaped, is fitted to the end of the pipe, It has a gasket with which the entire circumference of the pipe end surface abuts, and a body with a mirror-finished surface formed on the end surface and an external thread formed on the outer circumference. In contact, the male screw of the body and the female screw of the cap nut are fastened with a predetermined torque. (2) A cap nut having an internal thread formed therein, a first pipe having a mirror-finished surface formed on an end face and a groove formed on the outer periphery , a rotating wheel having a trapezoidal cross section, and the cap nut of
A fixed wheel that abuts an inner end surface, an end surface having a large area of the rotating wheel,
Consisting of a plurality of balls held on the surface opposite to the surface in contact with the cap nut
The first ferrule part for the first pipe to be fit into the groove on the outer periphery of the first pipe,
The second ferrule part for the first pipe whose cross-section is wedge-shaped and the small end face is located on the side of the plurality of balls for the first pipe, a body with an external thread formed on the outer circumference, and a mirror-finished surface on the end face A second pipe with a groove formed on the outer periphery and a trapezoidal
Rotating wheel, a fixed wheel that abuts the inner end face of the cap nut, and an end with a large rotating wheel area.
Balls held between the surface and the surface opposite to the surface in contact with the cap nut of the fixed ring
A first ferrule part for a second pipe, which is composed of: a second wedge-shaped cross-sectional end face having a small area, and a plurality of ball faces for the second pipe. A second ferrule part for a second pipe located in the first pipe or a gasket that is fitted to the end of the second pipe, the entire circumference of the first pipe end face and the second pipe end face abuts from both sides, The male screw of the body and the female screw of the cap nut are fastened with a predetermined torque. (3) The fluid coupling according to the above (1) or (2), wherein the second ferrule part has two or more grooves evenly arranged on an outer periphery. (4) The fluid coupling according to (1) or (2), wherein two or more wrench holes are formed in an end surface of the cap nut. The assembling method of the present invention having the above-described configuration will be described. The pipe with the second ferrule part and the gasket mounted is inserted into the cap nut on which the first ferrule part is mounted, and the cap nut is screwed into the body. At this time, the inner peripheral diameter of the second ferrule part is the same as the outer diameter of the pipe, but the inner diameter is expanded by elastic deformation due to two or more grooves evenly arranged on the outer circumference, and fits into the outer peripheral groove of the pipe. Are combined. With the body fixed so that it does not rotate, the cap nut is screwed in until the specified torque is reached. When the cap nut is screwed into the body, the thrust is transmitted to the pipe by the first ferrule part and the second ferrule part. At this time, coaxial rotation of the cap nut and the pipe is prevented by the thrust bearing formed on the first ferrule part. Further, since the pipe is positioned by the first ferrule part and the second ferrule part with respect to the cap nut, the end face of the pipe and the end face of the body are accurately aligned. Here, the end surface of the pipe and the end surface of the body are mirror-finished by roller burnishing, so that the adhesion between each and the gasket is improved, and the airtightness of the joint is improved. The SUS material has a Vickers hardness of about 180, but can be made to have a Vickers hardness of about 300 by roller burnishing. Thus, even if the pipe end face and the body end face are pressed against the gasket by the strong pressing force, the pipe end face and the body end face are not deformed, and thus can be used repeatedly. The gasket is pressed from both sides by the end face of the pipe and the end face of the body. The gasket is made of soft metal, and is pressed against the high hardness pipe end face and body end face,
Each can adhere well. At this time, since the groove of the second ferrule part is uniformly formed on the outer periphery, the thrust of the second ferrule part acts uniformly on the first ferrule part, so that the pipe end face is pressed by the gasket with an equal force, There is no danger of gasket leakage. If the cap nut is removed, the connection can be easily released by simply sliding the pipe sideways. Further, when the cap nut is screwed in, the protrusion of the spanner is engaged with the spanner hole formed in the end face of the cap nut and the cap nut can be screwed in, so that the cap nut can be easily screwed even in a narrow space. Further, since the torque can be transmitted uniformly, the sealing force can be stabilized. Hereinafter, a fluid coupling according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a sectional view of an embodiment in which pipes are connected to both ends of a body. FIG. 3 is an exploded perspective view showing the configuration of the main parts of the joint. FIG. 8 is a cross-sectional view showing the structure of the first ferrule part 3 in which a thrust ball bearing 9 is integrally formed at one end. The rotating wheel 10 of the thrust ball bearing 9 is extended in a direction parallel to the axis, and an inclined surface 10 a is formed on the extended inner surface of the rotating wheel 10. A thrust ball bearing 9 is provided on the inner end surface of the cap nut 1 having the female screw 1a formed inside.
The first ferrule part 3 is fitted in the direction in which the fixed ring contacts. Here, as shown in the sectional view (a) and the side view (b) of FIG. 5, six spanner holes 31 are formed on the end face of the cap nut 1 at equal intervals on the circumference. A pipe 5 is mounted inside the first ferrule part 3. As shown in FIG. 7, the end face of the pipe 5 is chamfered, and the tip end face 5b is mirror-finished by roll burnishing. In addition, a groove 5 a is cut in the peripheral surface of the pipe 5. The sleeve 2 as the second ferrule part shown in FIG. 9 is fitted in the groove 5a. FIG. 9A shows a plan view, and FIG. 9B shows a side view. The wedge-shaped inclination of the sleeve 2 forms the same angle as the inclination of the inner surface of the first ferrule part. Six grooves 2a are formed on the outer periphery of the sleeve 2 at equal intervals of 60 degrees. The thickness of the outer wall 2b formed between the groove 2a and the inner diameter is 0.15 mm. The sleeve 2 has a wedge-shaped cross section and an end surface having a small area is located on the thrust ball bearing 9 side. The first ferrule 3 part and the sleeve 2 are fitted together to form a ferrule. A gasket 4 is attached with an inner surface fitted to the end of the pipe 5 and an inner end surface in contact with the entire periphery of the pipe end surface 5b. Further, the end face 6b is subjected to roll burnishing, and the male screw 6a of the body 6 having the male screw 6a formed on the outer periphery is fastened to the female screw 1a of the cap nut 1. The end surface 6b of the body 6 is in contact with the surface of the gasket 4 opposite to the surface of the gasket 4 in contact with the pipe end surface 5b. The mounting configuration of the pipe 7 on the opposite side is the same as that of the pipe 5, and the description is omitted. Next, the operation of the fluid coupling having the above configuration will be described. The pipes 5 and 7 to be connected are cut to a length that is actually used, and chamfered on an end face, followed by roller burnishing. Roll burnishing can be easily performed by a portable roll burnishing machine or the like. By mirror finishing by roller burnishing, the adhesion between the pipe end face 5b and the gasket 4 is improved, and the airtightness of the joint is enhanced. The Vickers hardness of the SUS material is about 180, but the Vickers hardness can be made about 300 by performing roller burnishing. Thus, even if the pipe end face 5b is pressed against the gasket with a strong pressing force, the pipe end face 5b is not deformed, and can be used repeatedly. In addition, a groove 5 a shown in FIG. 7 is cut in the peripheral surface of the pipe 5 by processing with a lathe or the like. Thus, if there is a lathe or the like, the pipe itself that needs to be connected can be easily processed on the spot. The sleeve 2 is mounted in the groove 5a of the pipe 5. At this time, the outer diameter of the pipe 5 and the inner diameter of the sleeve 2 are almost the same, but six grooves 2a are formed at equal intervals on the outer periphery of the sleeve 2, and the thickness of the outer wall 2b is as thin as 0.15 mm. Since the outer wall 2b is elastically deformed, the sleeve 2 can be easily mounted in the groove 5a. The first ferrule part 3 is mounted so as to fit with the inclination of the outer surface of the sleeve 2.
The gasket 4 is fitted to the end of the pipe 5. With the sleeve 2 and the gasket 4 attached, the pipes 5 and 7 are inserted into the cap nut 1 on which the first ferrule part 3 is attached, and the cap nut 1 is screwed into the body 6. Here, the spanner 40 shown in FIG. 6 is used. Spanner 4
Numeral 0 is composed of a spanner main body 33 and a handle 32. Four protrusions 34 corresponding to the spanner holes 31 of the cap nut 1 are formed in the spanner main body 33, and an escape portion 38 for escape of the pipe is formed in the center. The protrusion 34 of the spanner 40 is engaged with the spanner hole 31 of the cap nut 1 and the handle 3
By rotating the cap 2, the cap nut 1 can be screwed into the body 6. Here, since the wrench 40 can be engaged with the wrench hole formed in the end face of the cap nut 1 and screwed in, the screw can be easily screwed in even when there is an obstacle in the surroundings. . Further, with the body 6 fixed so as not to rotate, the cap nut 1 is screwed in until the predetermined torque is reached. Propulsion force when screwing the cap nut 1 into the body 6 is transmitted to the pipes 5 and 7 via the sleeve 2 and the first ferrule part 3. That is, the sleeve 2 constituting the ferrule is fitted in the groove 5b formed on the outer periphery of the pipe, and the first ferrule part 3 transmits the propulsive force by the sleeve 2 by the action of the wedge. 3 can transmit strong propulsion to the pipe. Here, since the wrench 40 is engaged with the wrench hole drilled in the end face of the cap nut 1 and screwed in, the torque can be transmitted uniformly to the cap nut 1. The driving force transmitted to the component 3 can be made constant. Further, since the pipe 5 is positioned with respect to the cap nut 1 by the first ferrule part 3 and the sleeve 2, the end face 5b of the pipe and the end face 6b of the body 6 are accurately aligned. Here, the body end face 6b is mirror-finished by roller burnishing,
The adhesion between the body end surface 6b and the gasket 4 is improved, and the airtightness of the joint is improved. The Vickers hardness of the SUS material is about 180, but the Vickers hardness can be made about 300 by performing roller burnishing. Thus, even if the body end face 6b is pressed against the gasket with a strong pressing force, the body end face 6b is not deformed, and can be used repeatedly. The gasket 4 is pressed from both sides by the end face 5b of the pipe and the end face 6b of the body 6. The gasket 4 is made of nickel in the present embodiment, and is pressed against the end face 5b of the pipe having high hardness and the end face 6b of the body 6 so that they can be in close contact with each other. Since the gasket 4 is deformed once assembled, it is replaced with a new gasket 4 when reassembling. Since the position of the gasket 4 according to the present embodiment is determined only by fitting it into the pipe 5, the replacement of the gasket 4 is extremely easy. When the cap nut 1 is screwed into the body 6, the first ferrule part 3 is attached, so that the pipe 5 is prevented from rotating together with the cap nut 1, so that the pipe end face 5b and the gasket 4 No rubbing occurs between the gaskets 4 or between the gasket 4 and the body end surface 6b, and no particles are generated. According to the fluid coupling having the above-described structure, the first ferrule part 3 and the sleeve 2 can be easily mounted by performing a simple additional process on an ordinary pipe, so that the pipe can be welded without welding. They can be connected in a highly airtight state. In addition, if the cap nut 1 is removed, the connection can be easily released simply by sliding the pipe 5 sideways, so that there is no need to provide an extra relief in the pipe, and the cost can be reduced. Further, since the thrust ball bearing 9 is formed at one end of the first ferrule part 3, the number of parts can be reduced, and troubles caused by forgetting to attach parts can be reduced. Further, since the six grooves 21 provided on the outer periphery of the sleeve 2 are uniformly arranged on the circumference, the thrust of the sleeve 2 can be transmitted uniformly to the first ferrule part 3, and the gasket 4 Can be improved in adhesion. Further, since the pipe end face 5b and the body end face 6b are finished by roller burnishing, the adhesion with the gasket 4 is good, and the fluid coupling can be configured with high airtightness. In addition, since the hardness of the pipe end face 5b and the body end face 6b is high, the gasket 4 is considered to be deformed. Next, a second embodiment will be described with reference to a sectional view shown in FIG. 2 and an exploded perspective view shown in FIG. A second embodiment is a fluid coupling performed using a single cap nut to connect a set of pipes. A thrust ball bearing 9a is provided on the inner end surface of the cap nut 1 having the female screw 1a formed inside.
The first ferrule part 3a is fitted so that the first ferrule part 3a contacts. Here, as shown in the sectional view (a) and the side view (b) of FIG. 5, six spanner holes 31 are formed on the end face of the cap nut 1 at equal intervals on the circumference. A pipe 5, which is a first pipe, is mounted inside the first ferrule part 3a. As shown in FIG. 4, the end face of the pipe 5 is chamfered, and the end face 5b is mirror-finished by roll burnishing. In addition, a groove 5 a is cut in the peripheral surface of the pipe 5. A sleeve 2a having six grooves in the longitudinal direction and having a wedge-shaped cross section is fitted into the groove 5a. First ferrule part 3a having the same inclination on the inner surface as the wedge-shaped inclination of sleeve 2a
Are fitted to the sleeve 2a. The first ferrule part 3a and the sleeve 2a are fitted to form a ferrule. The sleeve 2a has a wedge-shaped cross-section and an end surface having a small area.
It is located on the a side. A gasket 4 is attached with an inner surface fitted to the end of the pipe 5 and an inner end surface in contact with the entire periphery of the pipe end surface 5b. Inside the cap nut 1, a pipe 7, which is a second pipe having a roll burnishing finished surface formed on an end face, is attached. The end surface of the pipe 7 is mirror-finished by roll burnishing similarly to the end surface 5b of the pipe. In addition, a groove 7 a is cut in the peripheral surface of the pipe 7. A sleeve 2b having six grooves in the longitudinal direction and having a wedge-shaped cross section is fitted into the groove 7a. The first ferrule part 3b having the same inclination on the inner surface as the wedge-shaped inclination of the sleeve 2b is fitted to the sleeve 2b. The first ferrule part 3b and the sleeve 2b are fitted to form a ferrule. The sleeve 2b has a wedge-shaped cross section and an end surface having a small area is located on the thrust ball bearing 9b side. The first ferrule part 3b is attached such that the end surface having a trapezoidal cross section and a large area comes into contact with the thrust ball bearing 9b. The end surface of the body 8 having the external thread 8a formed on the outer periphery is in contact with the thrust ball bearing 9b. Next, the operation of the second embodiment will be described. With the body 8 fixed so as not to rotate, the cap nut 1 is screwed in until the predetermined torque is reached. Here, the spanner 40 shown in FIG. 6 is used. The spanner 40 includes a spanner body 33 and a handle 32. Four protrusions 34 corresponding to the spanner holes 31 of the cap nut 1 are formed in the spanner main body 33, and an escape portion 38 for escape of the pipe is formed in the center. The protrusion 34 of the spanner 40 is engaged with the spanner hole 31 of the cap nut 1 and the handle 3
By rotating the cap 2, the cap nut 1 can be screwed into the body 6. Propulsion force when the cap nut 1 is screwed into the body 6 is transmitted to the pipes 5 and 7 via the respective ferrules. Since the sleeves 2a and 2b constituting the ferrule are fitted in the grooves 5a and 7a formed on the outer periphery of the pipe, the ferrule can transmit a strong propulsive force to the pipe. At this time, since the pipes 5 and 7 are positioned by the ferrule with respect to the cap nut 1, the end face 5b of the first pipe and the end face 7b of the second pipe are accurately aligned. Further, a pair of pipes 5 and 7 are abutted and pressed with the gasket 4 therebetween. Both the pipe end faces 5b and 7b are subjected to roller burnishing, and the gasket 4 made of nickel is deformed and adheres to the pipe end faces 5b and 7b, so that the airtightness is improved. According to the above embodiment, since the airtightness is high, there is no danger even when a highly toxic gas is used in the semiconductor manufacturing process. Further, if the cap nut is removed, the pipe can be easily removed simply by sliding it sideways, so that maintenance is easy. Further, since the thrust ball bearings 9a, 9b are formed at one end of the first ferrule components 3a, 3b, the number of components can be reduced, and troubles caused by forgetting to attach components can be reduced. In addition, since the six grooves 21 provided on the outer circumference of the sleeves 2a and 2b are evenly arranged on the circumference, the thrust of the sleeves 2a and 2b can reduce the thrust of the first ferrule parts 3a and 2b.
3b can be transmitted uniformly, and the adhesion with the gasket 4 can be improved. Further, since the wrench 40 can be engaged with the wrench hole formed in the end face of the cap nut 1 and screwed in, the screw can be easily screwed in even when there is an obstacle in the surroundings. . Further, since the wrench 40 is engaged with the wrench hole formed in the end face of the cap nut 1 and is screwed in, the torque can be transmitted uniformly to the cap nut 1. 3 can be made constant, and the sealing force can be stabilized. As is clear from the above description, according to the fluid coupling of the present invention, the first ferrule part and the second ferrule can be easily formed only by performing a simple alteration on an ordinary pipe. Since parts can be mounted, pipes can be connected in a highly airtight state without welding, so floating elements are generated by welding and mixed into the wafer as metal impurities, and the reliability of the device is reduced. Without impairing the performance, and because the thrust bearing is formed at one end of the first ferrule part, the number of parts is reduced,
Troubles such as forgetting to mount parts can be reduced. Further, since the plurality of grooves provided on the outer periphery of the second ferrule part are uniformly arranged on the circumference, the thrust of the second ferrule part is transmitted uniformly to the first ferrule part. Therefore, the adhesion with the gasket can be improved, and the airtightness can be improved. In addition, since there is no change in the material due to welding, no particles are generated, and the defective product rate due to pattern defects is reduced. In addition, the assembly is easy, and a skilled welding worker is not required in the construction of the semiconductor manufacturing process, and the construction can be performed efficiently. Further, if the cap nut is removed, the connection can be easily released simply by sliding the pipe sideways, so that there is no need to provide an extra relief in the pipe, and the cost can be reduced.

[Brief description of the drawings]     FIG.   1 is a cross-sectional view illustrating a configuration of a fluid coupling according to a first embodiment of the present invention.     FIG. 2   FIG. 6 is a cross-sectional view illustrating a configuration of a fluid coupling according to a second embodiment of the present invention.     FIG. 3   FIG. 2 is an exploded perspective view showing a configuration of a main part of the first embodiment.     FIG. 4   FIG. 9 is an exploded perspective view showing a configuration of a main part of the second embodiment.     FIG. 5   It is drawing which shows the shape of a cap nut.     FIG. 6   It is an external view which shows the shape of the spanner for cap nuts.     FIG. 7   It is sectional drawing of a pipe end part.     FIG. 8   It is sectional drawing which shows the structure of a 1st ferrule part.     FIG. 9   It is the top view and side view which show the structure of a sleeve.     FIG. 10   It is sectional drawing which shows the structure of the conventional fluid coupling.     [Explanation of symbols] 1 Cap nut 2 sleeve 3 First ferrule parts 4 Gasket 5,7 pipe 6,8 body 9 Thrust bearing 31 Wrench hole

Claims (1)

Claims: 1. A cap nut having a female screw formed inside, a pipe having a mirror-finished surface formed on an end face and a groove formed on the outer circumference , a rotating wheel having a trapezoidal cross section, A fixed ring abutting the inner end face of the cap nut;
The opposite end face of the rotating wheel having a large area and the surface of the fixed wheel abutting on the cap nut.
A plurality of balls held by the side surface and more constructed first ferrule part, fitted in the groove of the outer periphery of said pipe, small end face of the area section is a wedge-shaped plurality of balls side A second ferrule part, a gasket fitted to the end of the pipe and contacting the entire circumference of the pipe end face, and a body having a mirror-finished surface on the end face and a male screw formed on the outer circumference. An end face of the body abuts on a surface of the gasket opposite to a surface on which the pipe abuts, and a male screw of the body and a female screw of the cap nut are fastened with a predetermined torque. Characteristic fluid coupling. 2. A cap nut having a female screw formed inside, a first pipe having a mirror-finished surface formed on an end face and a groove formed on an outer periphery , a rotating wheel having a trapezoidal cross section, and A fixed ring that abuts the inner end face and the front
The opposite end face of the rotating wheel having a large area and the surface of the fixed wheel abutting on the cap nut.
A first ferrule part for a first pipe composed of a plurality of balls held by the side surface; an end face fitted in the groove on the outer periphery of the first pipe, having a wedge-shaped cross section and a small area A second ferrule part for the first pipe located on the plurality of balls for the first pipe, a body having an external thread formed on the outer periphery, a mirror-finished surface formed on the end face and a groove formed on the outer circumference. Two pipes , a rotating wheel having a trapezoidal cross section, a fixed wheel abutting on the inner end face of the cap nut,
The opposite end face of the rotating wheel having a large area and the surface of the fixed wheel abutting on the cap nut.
A first ferrule part for a second pipe composed of a plurality of balls held by the side surface; an end face fitted in the groove on the outer periphery of the second pipe, having a wedge-shaped cross section and a small area A second ferrule part for the second pipe located on the ball side for the second pipe, fitted to an end of the first pipe or the second pipe, the first pipe end face and the second pipe A fluid coupling, comprising: a gasket whose entire periphery of an end face abuts from both sides, wherein a male screw of the body and a female screw of the cap nut are fastened with a predetermined torque. 3. The fluid coupling according to claim 1, wherein the second ferrule part has two or more grooves evenly arranged on an outer periphery. 4. The fluid coupling according to claim 1, wherein two or more wrench holes are formed in an end face of the cap nut.