JP5452950B2 - Universal joint - Google Patents

Description

  The present invention relates to a universal joint that connects one pipe and the other pipe while changing the direction.

  Conventionally, when a power cable or a communication cable is buried underground or disposed on the ground, a protective tube that accommodates the cable and protects it from rainwater, groundwater, or the like is used.

  This protective tube is formed by connecting linear members, but when actually installed, it is often necessary to avoid obstacles that were not anticipated at first. For this reason, the universal joint which changes a direction in the joint location which connects one pipe | tube and the other pipe | tube is used.

  As such a universal joint, for example, Patent Document 1 includes a first annular member having a spherical inner surface and a second annular member having a spherical outer surface that fits the first annular member. A universal joint that is configured to be changeable with respect to each other and that includes stopper means that resists a force in a direction that separates the first annular member and the second annular member is disclosed.

  According to this configuration, when the separating force is small, the separation can be prevented by contact between the spherical inner surface and the spherical outer surface, and when the force is large, the separation can be prevented by the stopper means.

Japanese Patent Laid-Open No. 10-185044

  By the way, in addition to having a predetermined strength, the protective tube and the universal joint are required to be watertight against the external water pressure and the internal water pressure at the joint location.

  For this reason, in the above-described configuration of Patent Document 1, an O-ring is fitted between the spherical inner surface and the spherical outer surface to ensure water blocking.

  However, when actually constructing, even if an attempt is made to rotate the first annular member relative to the second annular member with the O-ring fitted, both members will contact and interfere with each other. There was a problem that it was difficult to rotate.

  Therefore, an object of the present invention is to provide a universal joint that can be easily rotated and has good workability.

In order to achieve the above object, the universal joint of the present invention includes an outer tube portion having a spherical inner surface, an inner tube portion having a spherical outer surface that is rotatably fitted to the inner surface of the outer tube portion, An angle adjustable universal joint comprising: an annular elastic member fitted into the outer surface of the inner cylinder part and in contact with the inner surface of the outer cylinder part,
When the inner cylinder part is rotated relative to the outer cylinder part, the portion of the outer surface of the inner cylinder part that contacts the inner surface of the outer cylinder part is chamfered ,
The end portion on the large diameter side of the outer tube portion is expanded in diameter than the spherical inner surface, and the outer tube side receiving portion into which the end portion of the tube to be connected is fitted is screwed,
The inner cylinder part is configured to be pushed in the axial direction to a position where it hits the outer cylinder side receiving part inside the end of the outer cylinder part on the enlarged diameter side,
Further, when the inner cylinder portion is pushed in the axial direction, the entire outer peripheral edge of the front end surface of the inner cylinder portion is arranged inside the end portion of the outer cylinder portion on the enlarged diameter side and the outer cylinder side receiving port. A chamfering for preventing the inner cylinder part from being turned by being fitted into a corner part of the inner cylinder part is provided on the outer peripheral edge of the front end surface of the inner cylinder part. .
Further, in the outer cylindrical portion, the outer tube side socket portion end of the connected tube is fitted and is screwed, the rear end surface or the outer tube side socket portion of the outer cylindrical portion It is preferable that either one of the abutting surfaces is provided with a groove portion that is continuously recessed in the axial direction in the circumferential direction, and the other is provided with a protrusion portion that fits into the groove portion.
And the inner cylinder side receptacle part by which the edge part of the other pipe to be connected is fitted to the inner cylinder part is screwed, and the rear end surface of the inner cylinder part or the inner cylinder side receptacle part It is preferable that either one of the abutting surfaces is provided with a groove portion that is recessed in the axial direction continuously in the circumferential direction, and the other is provided with a protrusion portion that fits into the groove portion.
Moreover, it is preferable that the outer diameter of the annular elastic member fitted in the inner cylinder part is formed smaller than the inner diameter of the outer cylinder part on the enlarged diameter side .

As described above, the universal joint of the present invention includes the outer tube portion, the inner tube portion, and the annular elastic member, and the inner tube portion is rotated when the inner tube portion is rotated relative to the outer tube portion. The part which contacts the inner surface of the outer cylinder part of the outer surface is chamfered.
Therefore, it is possible to smoothly rotate the portion where the two members are in contact with each other during the rotation without pressing strongly and preventing the rotation.
The outer cylinder side end of the outer cylinder has a larger diameter than the spherical inner surface, and the outer cylinder side receiving part into which the end of the pipe to be connected is fitted is screwed into the inner cylinder. Is pushed in the axial direction (back side) to the position where it hits the outer cylinder side receiving part inside the end of the outer cylinder part on the enlarged diameter side, thereby reducing the reaction force and reducing the inner cylinder part. It can be rotated.
At this time, by chamfering the outer peripheral edge of the distal end surface of the inner cylindrical portion, when the inner cylindrical portion is pushed in the axial direction, the entire outer peripheral edge of the distal end surface of the inner cylindrical portion is expanded in diameter. It is possible to prevent the inner cylinder part from becoming unable to rotate by being fitted into the corners between the inside of the end part on the other side and the tip part of the outer cylinder side receiving part.
That is, the outer peripheral edge of the front end surface of the inner cylinder portion is chamfered as described above, so that the inner cylinder portion can be smoothly rotated even when the inner cylinder portion is rotated relative to the outer cylinder portion during construction. be able to.
Furthermore, the outer cylinder side receiving part into which the end part of the pipe to be connected is fitted is screwed to the outer cylinder part, and either the rear end surface of the outer cylinder part or the abutting surface of the outer cylinder side receiving part One is provided with a groove that is recessed in the axial direction continuously in the circumferential direction, and the other is provided with a protrusion that fits into the groove, so that the protrusion can be securely fitted into the groove with the caulking agent accumulated. The water can be stopped.
And the inner cylinder side receptacle part by which the edge part of the other pipe to be connected is fitted is screwed to the inner cylinder part, and the abutting surface of the rear end surface of the inner cylinder part or the inner cylinder side receptacle part Since either one of the groove portion is provided with a groove portion that is continuously recessed in the circumferential direction in the circumferential direction, and the other portion is provided with a protrusion portion that fits into the groove portion, the protrusion portion and the main body of the inner cylinder side receiving portion, The water can be surely stopped by fitting the groove with the caulking agent accumulated in between.
Further, the outer diameter of the annular elastic member fitted into the inner cylinder portion is formed to be smaller than the inner diameter of the outer cylinder portion on the enlarged diameter side , so that the inner cylinder portion is fitted inside the outer cylinder portion during construction. In this case, it is easy to fit and the annular elastic member can be prevented from being damaged.

It is an expanded sectional view which expands and demonstrates the structure of the universal joint of embodiment of this invention. It is sectional drawing explaining the structure of the universal joint of embodiment of this invention. It is a disassembled perspective view which decomposes | disassembles and demonstrates the structure of the universal joint of embodiment of this invention. It is sectional drawing explaining the structure of an outer cylinder part. It is sectional drawing explaining the structure of an inner cylinder part. It is sectional drawing explaining the structure of an outside receptacle part. It is sectional drawing explaining the structure of an inner side opening part. It is explanatory drawing explaining the effect | action of the universal joint of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the whole structure of the universal joint 1 of this invention is demonstrated using FIG.

  The universal joint 1 of the present invention is a joint for connecting while changing the axial direction of one pipe 71 and the other pipe 72 in a predetermined angular range (± 5 degrees) freely in the vertical and horizontal directions (see FIG. 8). 2, a short cylindrical outer cylinder portion 2 having a spherical inner surface 21, and a short cylindrical shape having a spherical outer surface 31 slidably fitted inside the outer cylindrical portion 2. Screwed into the inner cylinder part 3, the annular elastic member 60 fitted in a crushed state between the outer surface 31 of the inner cylinder part 3 and the inner surface 21 of the outer cylinder part 2, and the rear end side of the outer cylinder part 2 The outer cylinder side receiving part 4 into which one pipe 71 is inserted, and the inner cylinder side receiving part 5 into which the other pipe 72 is inserted by being screwed to the rear end side of the inner cylinder part 3. I have.

  In the present embodiment, the front end of the outer cylinder portion 2 refers to the end portion on the side overlapping the inner cylinder portion 3, and the rear end of the outer cylinder portion 2 is screwed into the outer cylinder side receiving portion 4. The end on the mating side shall be said. Similarly, the front end of the inner cylinder portion 3 refers to an end portion on the side overlapping the outer cylinder portion 2, and the rear end of the inner cylinder portion 3 is screwed into the inner cylinder side receiving portion 5. It shall mean the end of the side.

  These constituent members are fitted in the order shown in FIG. 3, and the inner surface 21 of the outer tube portion 2 and the annular elastic member 60 slide along the outer surface 31 of the inner tube portion 3. The direction has been changed while securing water.

  The outer cylindrical portion 2 is formed of a synthetic resin such as polyvinyl chloride. As shown in FIG. 4, the outer cylindrical portion 2 is provided inside a short cylindrical main body portion 20 having a smoothly changing diameter and inside the main body portion 20. The spherical inner surface 21 is formed, a screwing groove 24 provided on the inner peripheral surface on the large diameter side, and a protrusion 23 provided on the rear end surface 22 on the large diameter side. .

  The spherical inner surface 21 is formed in a concentric shape having the same center as the spherical outer surface 31 of the inner cylinder portion 3 in a state in which the inner cylinder portion 3 is incorporated, and the inner cylinder portion with respect to the outer cylinder portion 2. Even when 3 rotates around this center, it can rotate without interfering with each other.

Further, the protrusion 23 of the rear end surface 22 is formed as a small protrusion having a fan-shaped cross section of 90 degrees protruding in the axial direction continuously in the circumferential direction, and is provided on the abutting surface 41 of the outer cylinder side receiving portion 4. It fits into the groove 42 formed.

  And the inner cylinder part 3 is formed by synthetic resins, such as polyvinyl chloride, and as shown in FIG. 5, the short cylindrical main body part 30 and the spherical outer surface provided in the outer side of the main body part 30 31, a chamfered outer peripheral edge 33 of the front end surface 32, a pair of annular convex portions 34 a and 34 b forming an annular groove portion 34 c for fitting the annular elastic member 60, and a groove portion 36 provided on the rear end surface 35. And a threading groove 37 provided on the outer peripheral surface on the rear end side.

  In addition, the spherical outer surface 31 is formed in a concentric shape having the same center as the spherical inner surface 21 of the outer cylinder part 2 in a state of being incorporated in the outer cylinder part 2, and is Even when the cylindrical portion 3 is rotated around this center, it can be rotated without interfering with each other.

  Further, the front end surface 32 is mainly configured as a flat surface inclined slightly inward, but the inner and outer peripheral edges viewed in the member thickness direction are chamfered, and in particular, the outer peripheral edge 33 rotates smoothly. Thus, the cross-section is chamfered in a circular arc shape larger than other portions. Note that this chamfering is not limited to an arc shape, and may be any cross-sectional shape as long as it is curved.

On the other hand, the groove portion 36 of the rear end surface 35 is formed as a groove having a semicircular arc section that is recessed in the axial direction continuously in the circumferential direction, and the inner side of the groove portion 36 protrudes toward the rear end side.

  Further, the annular elastic member 60 is a so-called O-ring, and is formed into an annular shape having a slightly smaller diameter than the annular groove portion 34c of the inner cylinder portion 3 by an elastic material such as synthetic rubber, as shown in FIGS. Is formed. Accordingly, the portion that is fitted into the annular groove portion 34c while being stretched and protrudes outside the annular groove portion 34c contacts the inner surface 21 of the outer cylinder portion 2 while being elastically deformed.

  And the outer cylinder side receptacle part 4 is formed by synthetic resins, such as polyvinyl chloride, and as shown in FIG. 6, it was provided in the outer peripheral surface of the short cylindrical main-body part 40 and the front-end | tip part. A threaded groove 43; an abutting surface 41 which stands upright at the end of the threaded groove 43 and abuts on the rear end surface 22 of the outer cylinder part 2; a groove part 42 which is continuously provided in the circumferential direction on the abutting surface 41; And a stopper 44 positioned at the inner surface end for receiving the distal end surface of the tube 71 (see FIG. 8) to be inserted.

The groove portion 42 of the abutting surface 41 is formed as a groove having a 90-degree sector cross section that is recessed in the axial direction continuously in the circumferential direction, and fits into the protrusion portion 23 provided on the rear end surface 22 of the outer cylinder portion 2. Match.

  Moreover, the inner cylinder side receiving part 5 is formed by synthetic resins, such as polyvinyl chloride, and was provided in the inner periphery of the short cylindrical main-body part 50 and the front-end | tip part, as shown in FIG. A threaded groove 53; an abutting surface 51 which stands upright at the end of the threaded groove 53 and abuts on the rear end surface 35 of the inner cylindrical part 3; and a projecting part 52 which is provided continuously on the abutting surface 51 in the circumferential direction. And a stopper 54 for receiving the distal end surface of the inserted tube 72 (see FIG. 8).

The protrusion 52 of the abutting surface 51 is formed as a protrusion having a semicircular cross section that protrudes in the axial direction continuously in the circumferential direction, and fits into a groove 36 provided on the rear end surface 35 of the inner cylinder portion 3. To do.

  And each above-mentioned structural member is assembled as shown in FIG.

  That is, first, the annular elastic member 60 stretched by hand is fitted into the annular groove 34 c of the outer surface 31 of the inner cylinder part 3, and the inner cylinder part 3 is fitted into the outer cylinder part 2 in this state.

  At this time, the outer diameter R1 of the annular elastic member 60 fitted into the inner cylinder portion 3 is formed to be smaller than the inner diameter R2 on the enlarged diameter side of the outer cylinder portion 2, so that the annular elastic member 60 is provided. Can be inserted halfway without contacting the outer cylinder 2.

  Eventually, the annular elastic member 60 comes into contact at a substantially central position of the spherical inner surface 21 in which the diameter of the outer cylinder portion 2 is reduced, thereby ensuring adhesion and water stoppage.

  Then, since the screwing groove 37 of the rear end part of the inner cylinder part 3 protrudes from the front end side of the outer cylinder part 2, the silicon type is formed in the screwing groove 37 and the screwing groove 53 of the inner cylinder side receiving part 5. Apply a caulking agent and then screw together.

  When assembling, the outer cylinder part 2 and the inner cylinder part 3 (integral member) that are made integral are difficult to hold in a fixed posture. It holds, and the integral member is screwed onto it from above.

  In this embodiment, in addition to applying the caulking agent to the screw grooves 37 and 53, the caulking agent is dammed up by the protrusion 52, so that a predetermined amount of the caulking agent is also accumulated on the abutting surface 51. In this state, the inner cylinder part 3 is screwed from above the inner cylinder side receiving part 5.

  As a result, not only the gap between the screwing grooves 37 and 53 is stopped as in the conventional case, but the gap is also stopped by the groove 36 and the protrusion 52.

  On the other hand, since a screwing groove 24 is provided on the inner peripheral surface on the rear end side of the outer cylinder part 2, silicon-based caulking is formed in the screwing groove 24 and the screwing groove 43 of the outer cylinder side receiving part 4. Screw on after applying the material.

  When assembling, the outer cylinder part 2 and the inner cylinder part 3 that are integrally formed are difficult to hold in a fixed posture, so the outer cylinder side receiving part 4 is held on the table with the outer cylinder side receiving part 4 down. The integral member and the inner cylinder side receiving part 5 are screwed together from above.

  In this embodiment, in addition to applying the caulking agent to the screwing grooves 24 and 43, the integral member and the inner cylinder side from above the outer cylinder side receiving portion 4 with the caulking agent accumulated in the groove portion 42. Screw the receiving part 5.

  As a result, not only the gap between the screwing grooves 24 and 43 is stopped as in the conventional case, but the gap is also stopped by the groove 42 and the protrusion 23.

  Next, the operation of the universal joint 1 of the present embodiment will be described.

  As described above, the universal joint 1 according to the present embodiment includes an outer cylinder portion 2 having a spherical inner surface 21 and an inner cylinder having a spherical outer surface 31 that is rotatably fitted to the inner surface 21 of the outer cylinder portion 2. And an annular elastic member 60 that is fitted in the annular groove 34c of the outer surface 31 of the inner cylinder part 3 and slidably contacts the inner surface 21 of the outer cylinder part 2.

  Therefore, since this annular elastic member 60 seals the gap between the outer cylinder part 2 and the inner cylinder part 3, even when embedded in the ground, it is possible to ensure water-stopping against internal water pressure and external water pressure. it can.

  In addition, the outer tube portion 2 and the inner tube portion 3 are relatively rotated so that their axial directions can be refracted by a predetermined angle θ (usually about 5 degrees) (see FIG. 8). Even when an obstacle or the like that has not occurred appears at a planned installation location, it is possible to change the direction in which the pipes 71 and 72 are laid to bypass the obstacle.

  The universal joint 1 according to the present embodiment includes the outer cylinder part 2, the inner cylinder part 3, and the annular elastic member 60, and in addition, the inner cylinder part 3 is rotated relative to the outer cylinder part 2. When moving, the portion of the outer surface 31 of the inner tube portion 3 that contacts the inner surface 21 of the outer tube portion 2 is chamfered.

  Therefore, even when the inner cylinder part 3 is rotated relative to the outer cylinder part 2 at the time of assembly, the part where both members come into contact with each other is strongly pressed so that the rotation is not hindered. Can do.

  That is, since the outer cylinder part 2 and the inner cylinder part 3 between which the annular elastic member 60 is sandwiched are required to resist water-stopping and pulling-out force, the inner surface 21 and the outer surface 31 have a spherical shape having the same center. Is formed.

  Then, in a state where the annular elastic member 60 is merely fitted and not refracted, the annular elastic member 60 and the inner surface 21 and the annular elastic member 60 and the outer surface 31 are in contact with each other, but the inner surface 21 and the outer surface 31 are a minute distance. Just keep it parallel.

In a normal construction, since the reaction force of the annular elastic member 60 is large and difficult to rotate in a straight state where the universal joint 1 is not refracted, the inner cylinder part 3 is used as the stopper 44 of the outer cylinder side receiving part 4. The inner cylinder part 3 is rotated after pushing in once to the position which abuts and making reaction force small.

  8, the outer peripheral edge 33 of the front end surface 32 of the inner cylinder part 3 and the front end surface of the outer cylinder side receiving part 4 come into contact with each other, but conventionally the outer peripheral edge 33 is chamfered. Therefore, it has been difficult for the outer peripheral edge 33 to fit into the corner portion and rotate.

  Therefore, if the outer peripheral edge 33 is chamfered and formed into a curved surface as in the present embodiment, the outer peripheral edge 33 can be smoothly rotated without fitting into the corner portion. Become.

  In addition, even if the outer peripheral edge 33 repeatedly contacts the inner surface, the outer peripheral edge 33 locally contacts, so that the end surface of the outer cylinder side receiving portion 4 is not scraped off and durability is improved. .

  Furthermore, if the outer peripheral edge 33 is chamfered to have a curved surface, the outer peripheral edge 33 does not rotate as a fulcrum and the position of the annular elastic member 60 does not float, and the water stoppage is improved.

  That is, conventionally, the outer peripheral edge 33 comes into contact with the inner surface 21 of the outer cylinder portion 2 and rotates with the outer peripheral edge 33 as a fulcrum, so that the inner cylinder portion 3 floats at the position of the annular elastic member 60 and stops. There was a risk that the aqueous solution could not be retained (see part A in FIG. 8).

  In contrast, as in the present embodiment, if the outer peripheral edge 33 is chamfered in a curved shape, the outer peripheral edge 33 does not come into contact, and even if the vicinity of the outer peripheral edge 33 comes into contact, it is rotated. As a result, the position of the fulcrum also moves, so that it does not float at the position of the annular elastic member 60.

  Thus, when the outer peripheral edge 33 of the front end surface 32 of the inner cylinder part 3 is chamfered, the inner cylinder part 3 can be rotated relative to the outer cylinder part 2 during construction with a very simple configuration. Can also be rotated smoothly.

  Further, the outer cylinder side receiving portion 4 is screwed to the outer cylinder portion 2, and the outer cylinder side receiving portion 4 is provided with a groove 42 on the abutting surface 41 that abuts the outer cylinder portion 2, and the outer cylinder portion 2. Since the projecting portion 23 is provided on the rear end surface 22 that abuts against the abutting surface 41, the projecting portion 23 can be fitted with the caulking agent in the groove portion 42 to ensure water stoppage.

  In other words, the water-stopping of the gap between the screwing grooves 24 and 43 has been performed in the past. However, if the screwing grooves 24 and 43 are not carefully tightened, the gap becomes non-uniform and is completely removed. In some cases, it was not possible to stop the water.

  Therefore, it is possible to achieve more reliable water stop by providing the groove 42 and the protrusion 23 only for water stop and fitting them together to extrude the caulking agent.

  In this case, unlike the threaded grooves 24 and 43, the groove 42 and the protrusion 23 can be reliably fitted by abutting against each other while visually observing the paired end faces, so the reliability of water stoppage is greatly improved. Will be.

  Similarly, the inner cylinder side receiving part 5 is screwed to the inner cylinder part 3, and the inner cylinder side receiving part 5 is provided with a protrusion 52 on the abutting surface 51 that abuts the inner cylinder part 3, and the inner cylinder Since the groove portion 36 is provided in the rear end surface 35 that abuts against the abutment surface 51 in the portion 3, the groove portion 36 is fitted in a state where the caulking agent is accumulated between the projection portion 52 and the main body portion 50 of the inner cylinder side receiving portion 5. Together, it can stop water reliably.

  Thus, more reliable water stop can be achieved by providing the protrusion 52 and the groove 36 only for water stop and fitting them so as to extrude the caulking agent.

  Further, the outer diameter R1 of the annular elastic member 60 fitted into the inner cylinder part 3 is formed smaller than the inner diameter R2 of the outer cylinder part 2, so that the inner cylinder part 3 is fitted inside the outer cylinder part 2 during construction. When mating, it is easy to fit, and the annular elastic member 60 can be prevented from being damaged.

  Although not shown, the outer surface 31 of the inner cylindrical portion 3 is provided with a pair of annular convex portions 34a and 34b that form an annular groove portion 34c into which the annular elastic member 60 is fitted, but is provided on the rear end side. If the outer peripheral edge of the rear end surface of the annular convex portion 34b is chamfered, the inner cylindrical portion 3 can be rotated more smoothly when the inner cylindrical portion 3 is rotated relative to the outer cylindrical portion 2 during construction.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  For example, in the above-described embodiment, the case where only the outer peripheral edge 33 of the front end surface 32 of the inner cylindrical portion 3 is chamfered has been described. However, the present invention is not limited to this, and the rear end surface of the annular convex portion 34b on the rear end side. If the outer peripheral edge is chamfered, it can be rotated more smoothly.

  Moreover, although the said embodiment demonstrated the case where the groove part 42 was provided in the abutting surface 41 of the outer cylinder side receptacle part 4, and the projection part 23 was provided in the rear-end surface 22 of the outer cylinder part 2, it is limited to this. Instead, the projecting portion may be provided on the abutting surface 41 of the outer cylinder side receiving portion 4, and the groove portion may be provided on the rear end surface 22 of the outer cylinder portion 2.

  Furthermore, although the said embodiment demonstrated the case where the protrusion part 52 was provided in the abutting surface 51 of the inner cylinder side receptacle part 5, and the groove part 36 was provided in the rear-end surface 35 of the inner cylinder part 3, it is limited to this. Instead, the groove portion may be provided on the abutting surface 51 of the inner cylinder side receiving portion 5, and the protrusion portion may be provided on the rear end surface 35 of the inner cylinder portion 3.

R1 outer diameter R2 inner diameter 1 universal joint 2 outer cylinder part 21 inner surface 22 rear end face 23 projection part 3 inner cylinder part 31 outer surface 32 front end face 33 outer peripheral edge 35 rear end face 36 groove part 37 screwing groove 4 outer cylinder side receiving part 41 protrusion Abutting surface 42 Groove portion 5 Inner cylinder side receiving portion 51 Abutting surface 52 Protruding portion 60 Annular elastic members 71 and 72

Claims (4)

An outer cylinder part having a spherical inner surface, an inner cylinder part having a spherical outer surface that is rotatably fitted to the inner surface of the outer cylinder part, and an inner surface of the outer cylinder part fitted into the outer surface of the inner cylinder part An angle-adjustable universal joint comprising: an annular elastic member in contact with
When the inner cylinder part is rotated relative to the outer cylinder part, the portion of the outer surface of the inner cylinder part that contacts the inner surface of the outer cylinder part is chamfered ,
The end portion on the large diameter side of the outer tube portion is expanded in diameter than the spherical inner surface, and the outer tube side receiving portion into which the end portion of the tube to be connected is fitted is screwed,
The inner cylinder part is configured to be pushed in the axial direction to a position where it hits the outer cylinder side receiving part inside the end of the outer cylinder part on the enlarged diameter side,
Further, when the inner cylinder portion is pushed in the axial direction, the entire outer peripheral edge of the front end surface of the inner cylinder portion is arranged inside the end portion of the outer cylinder portion on the enlarged diameter side and the outer cylinder side receiving port. A chamfering for preventing the inner cylinder part from being turned by being fitted into a corner part of the inner cylinder part is provided on the outer peripheral edge of the front end surface of the inner cylinder part. Universal joint. The said outer cylindrical portion, the outer tube side socket portion end of the connected tube is fitted are screwed, the rear end surface or abutment surface of the outer tube side socket portion of the outer cylindrical portion 2. The universal joint according to claim 1 , wherein a groove portion recessed in the axial direction is provided in any one of the groove portions, and a protrusion portion fitted in the groove portion is provided in the other. An inner cylinder side receiving part into which an end of the other pipe to be connected is fitted is screwed to the inner cylinder part, and a rear end surface of the inner cylinder part or a protrusion of the inner cylinder side receiving part is inserted. 3. The groove according to claim 1 or 2 , wherein a groove portion recessed in the axial direction is provided continuously on one of the surfaces, and a protrusion that fits into the groove portion is provided on the other. The universal joint described. Outer diameter of the annular elastic member fitted in the inner cylindrical portion is any one of claims 1 to 3, characterized in that it is formed smaller than the inner diameter of the expanded diameter by side of the outer cylindrical portion The universal joint according to item.

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