JP6484200B2 - Swivel joint - Google Patents

Description

  The present invention relates to a swivel joint, and more particularly, to a swivel joint in which a plug member and a socket member are connected to each other via a plurality of balls so as to be relatively rotatable.

  As a conventional swivel joint, there is one in which a socket member and a plug member are rotatably connected via a plurality of balls arranged in a circumferential direction (Patent Document 1). In such a swivel joint, when the plug member side is the front and the socket member side is the rear, the socket member is provided with an annular holding surface facing inward and rearward, and on the plug member side so as to face it. Is provided with an annular holding surface facing the front outside, and a plurality of balls are sandwiched and held between these holding surfaces. Accordingly, the socket member and the plug member can be smoothly rotated via the ball, and the plug member inserted into the socket member is configured not to come out of the socket member. An annular seal member is disposed between the inner peripheral surface of the socket member and the outer peripheral surface of the plug member in a state of being crushed in the radial direction, and the internal fluid passage is sealed from the outside by the seal member. As described above, the socket member and the plug member are hermetically engaged so that the internal fluid does not leak to the outside.

JP 2011-169408 A

  In the conventional swivel joint as described above, in the longitudinal direction of the longitudinal axis, the socket member supports the ball only from the front and not from the rear, and the plug member supports only from the rear and supports from the front. Therefore, when the plug member receives a backward force that is relatively pushed into the socket member, the plug member is displaced rearward with respect to the socket member. That is, the socket member and the plug member have a backlash in the longitudinal direction of the longitudinal axis. With such rattling, when the relative bending force around the axis perpendicular to the longitudinal axis is applied between the socket member and the plug member, the socket member and the plug member are relatively tilted. It will also end up. When such tilting occurs, the sealing member is biased in the way it is crushed, the sealing engagement is partially insufficient, and the internal fluid may leak to the outside. Further, when the socket member and the plug member are in direct contact with a strong force and are relatively rotated in this state, the contact portion may be worn.

  In view of the above-described problems of the prior art, the present invention prevents relative displacement in the front-rear direction of the longitudinal axis between the socket member and the plug member, and tilting around the axis perpendicular to the longitudinal axis. An object of the present invention is to provide a swivel joint that is adapted to be used.

That is, the present invention
A cylindrical socket member having a front end opening, an insertion passage extending rearward from the front end opening, and a first fluid passage further extending from the insertion passage;
A plug member inserted into the insertion passage of the socket member, the rear end opening located in the socket member, and extending forward from the rear end opening, and the rear end opening of the socket body A cylindrical plug member having a second fluid passage communicating with the first fluid passage;
In the insertion passage, the socket member and the plug member are arranged side by side in the circumferential direction between the inner peripheral surface and the outer peripheral surface of the plug member, and the socket member and the plug member are relatively arranged around the longitudinal axis of the insertion passage. A plurality of balls rotatably coupled to the
A first sliding member disposed between the socket member and the plug member and sealingly engaging the socket member and the plug member to seal the first fluid passage and the second fluid passage from an external space; A sealing member,
The inner peripheral surface of the socket member faces the inner rear side and extends in the circumferential direction, and the annular first holding surface faces the inner front side and extends in the circumferential direction at a rear position of the first holding surface. An annular second holding surface that
The outer peripheral surface of the plug member faces the outer rear side and extends in the circumferential direction, and the annular third holding surface faces the outer front side and extends in the circumferential direction at a rear position of the third holding surface. An annular fourth holding surface,
A swivel joint is provided in which each of the plurality of balls is held by the first to fourth holding surfaces.

  In the swivel joint, a first holding surface facing the inner rear provided on the socket member, a second holding surface facing the inner front, and a third holding surface facing the outer rear provided on the plug member and the outer side. Since each of the plurality of balls is held by the four holding surfaces of the fourth holding surface facing forward, the longitudinal axis direction of the ket member and the plug member with respect to the ball and the radial direction perpendicular thereto Is fixed. Thereby, the relative displacement in the front-rear direction of the longitudinal axis between the socket member and the plug member and the relative tilt around the axis orthogonal to the longitudinal axis do not occur. Therefore, when an external force in the direction of the tilt is applied between the socket member and the plug member, the sliding amount of the sliding seal member is biased, and the sealing engagement is partially released and the internal fluid leaks. Can be prevented. It is also possible to prevent the contact portion from being worn by contact between the socket member and the plug member with a strong force and relative rotation in that state.

  Preferably, the plug member includes a cylindrical plug body portion, and a ball holding member mounted on the outer peripheral surface of the plug body portion so as to be displaceable in the front-rear direction of the longitudinal axis. The third holding surface can be formed on the surface.

  More preferably, the ball holding member includes a ball holding position where the third holding surface engages with the ball and the ball is held by the first to fourth holding surfaces, and forward from the ball holding position. It is possible to displace between a ball passage formation position that forms a passage that displaces and releases the engagement between the third holding surface and the ball and allows the ball to be taken out and inserted. can do.

  Since the ball holding member can be displaced in this manner, the position of the third holding surface and the pressing force on the ball can be adjusted, and the position of the ball is adjusted to be appropriately held by the four holding surfaces. It becomes easy. Further, it is possible to easily take out and insert the ball at the time of assembling work and maintenance.

  More preferably, a male screw part is formed on the outer peripheral surface of the plug main body part, and a female screw part screwed with the male screw part is formed on the inner peripheral surface of the ball holding member, and the ball holding member is connected to the plug By rotating in the circumferential direction with respect to the main body portion, the ball holding member can be displaced in the front-rear direction of the longitudinal axis with respect to the plug main body portion.

  Preferably, a fixing member that engages with the ball holding member and the plug main body portion and fixes the ball holding member so as not to rotate with respect to the plug main body portion can be further provided.

  With such a configuration, it is possible to prevent the ball holding member from being unintentionally displaced and maintain a state in which the ball is appropriately held by the four holding surfaces.

  Preferably, the first holding surface and the fourth holding surface may be inclined surfaces that face each other and extend in parallel.

  When pressure is applied in the fluid passage, the socket member receives force behind the plug member, and the force causes the first holding surface of the socket member and the fourth holding surface of the plug member to be pressed against the ball. Here, since the first holding surface and the fourth holding surface are parallel to each other, the force is basically received only by the first and fourth holding surfaces, and the other second And the third holding surface is not subjected to force. In particular, when the third support surface is constituted by a movable ball holding member, the position may be shifted when a large force is applied to the ball holding member. Since the ball holding member having the third support surface is not subjected to a force due to the internal pressure due to being parallel to the surface, the possibility of the above-described positional deviation is greatly reduced.

Preferably,
The first sliding seal member is disposed behind the ball to seal the first and second fluid passages with respect to the insertion passage;
A second sliding seal member may be further provided between the socket member and the plug member at a position in front of the ball and sealingly engaging the socket member and the plug member. it can.

  With such a configuration, the space in which the ball is disposed in the insertion path is blocked from the outside, so that the ball and the grease applied around the ball leak to the outside, or dust or dirt enters the ball from the outside. It is possible to prevent the rotation of the motor from being hindered.

  Hereinafter, embodiments of a swivel joint according to the present invention will be described with reference to the accompanying drawings.

It is side surface sectional drawing of the swivel joint which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view of the swivel joint of FIG. 1 in a state where a ball holding member is at a ball passage formation position.

  As shown in FIG. 1, the swivel joint 1 according to one embodiment of the present invention includes a socket member 10, a plug member 20 inserted into the socket member 10, an inner peripheral surface 10 a of the socket member 10, and a plug member 20. And a plurality of balls 26 arranged side by side in the circumferential direction. The socket member 10 and the plug member 20 are provided with connecting portions 2a and 2b for connecting pipes such as copper pipes and hoses, respectively. The socket member 10 and the plug member 20 are coupled so as to be relatively rotatable around the longitudinal axis L via a plurality of balls 26 so as to allow relative rotation of the tubes connected to each other. It has become.

  The socket member 10 includes a front end opening 12, an insertion passage 14 extending rearward (leftward in the figure) from the front end opening 12 in the direction of the longitudinal axis L, and a rear end connection extending further rearward from the insertion passage 14. This is a cylindrical member having a fluid passage (first fluid passage) 16 extending to the portion 2a. The plug member 20 includes a rear end opening 22 located in the socket member 10 and a fluid passage (second fluid passage) 24 extending forward (rightward in the drawing) in the direction of the longitudinal axis L from the rear end opening 22. It is a cylindrical member which has. The fluid passage 24 of the plug member 20 communicates with the fluid passage 16 of the socket member 10 at the rear end opening 22.

  An annular groove 30 extending in the circumferential direction is formed on the inner circumferential surface 10a of the socket member 10, and an annular groove 30 extending in the circumferential direction is inclined so that the side surface of the annular groove 30 faces the inner rear side. A first holding surface 32a and an annular second holding surface 32b that inclines so as to face the inner front and extend in the circumferential direction. Further, the outer peripheral surface 20a of the plug member 20 is inclined in a circumferential direction so as to face the outer rear side, and is inclined in the circumferential direction so as to face the outer front side. And an annular fourth holding surface 32d. Each ball 26 is supported and held by the first to fourth holding surfaces 32 a to 32 d in the insertion passage 14.

  The plug member 20 includes a cylindrical plug main body portion 34 that defines the fluid passage 24, and a collar member 36 and a ball holding member 38 that are disposed on the outer peripheral surface 34 a of the plug main body portion 34. The collar member 36 has an outer peripheral surface of the plug main body 34 between a C ring 40 attached to the plug main body 34 at a rear position thereof and a stepped portion 42 formed on the outer peripheral surface 34a of the plug main body 34. 20a. The fourth holding surface 32d is formed on the collar member 36. The ball holding member 38 is attached to the plug main body 34 by screwing a female screw portion 44 formed on the inner peripheral surface 38 a thereof with a male screw portion 46 formed on the outer peripheral surface 34 a of the plug main body portion 34. The third holding surface 32 c is formed on the ball holding member 38.

  The ball holding member 38 screwed to the plug main body 34 is rotated in the circumferential direction with respect to the plug main body 34, so that the ball holding position shown in FIG. 1 and the ball passage forming position shown in FIG. Thus, it can be displaced in the longitudinal direction of the longitudinal axis L. 2, the ball holding member 38 is displaced forward to form a passage 47 through which the ball 26 can pass, and the ball 26 can be taken out and inserted during assembly or maintenance. It becomes possible. If the ball holding member 38 is rotated and displaced rearward with the ball 26 inserted, the third holding surface 32c engages with the ball 26 and becomes the ball holding position of FIG. At this time, even if the positions of the collar member 36 and the plug main body 34 are deviated from the positions of FIG. 1, the ball 26, the collar member 36, The positions of the plug body 34 and the ball holding member 38 are automatically adjusted so that the first to fourth holding surfaces 32a to 32d are engaged with the ball 26 as shown in FIG. Adjusted to In order for the ball 26 to be held on the first to fourth holding surfaces 32a to 32d without rattling, the ball holding member 38 is in a state of pressing the ball 26 with an appropriate force by the third holding surface 32c. . Then, a set screw (fixing member) 48 is attached to the front end of the ball holding member 38, and the set screw 48 is engaged with the outer peripheral surface 34 a of the plug main body 34, whereby the ball holding member 38 is attached to the plug main body 34. It is fixed so as not to rotate. Thereby, the ball holding member 38 cannot be displaced in the front-rear direction, and each ball 26 is maintained in a state of being held by the first to fourth holding surfaces 32a-32d.

  An annular O-ring holding groove 50 is formed at a position behind the ball 26 on the inner peripheral surface 10 a of the socket member 10, and the inner peripheral surface 10 a of the socket member 10 is formed in the O-ring holding groove 50. An O-ring (first sliding seal member) 52 that sealably engages the outer peripheral surface 20a of the plug member 20 is disposed. By the O-ring 52, the fluid passage 16 of the socket member 10 and the fluid passage 24 of the plug member 20 are sealed with respect to the insertion passage 14 in which the ball 26 is disposed, and the internal fluid flowing through the fluid passages 16, 24 is sealed. Is prevented from leaking outside through the insertion passage 14. In addition, an annular O-ring holding groove 54 is formed on the outer peripheral surface 38 b of the ball holding member 38 of the plug member 20 at a position in front of the ball 26, and in the O-ring holding groove 54, the socket member 10. An O-ring (second sliding seal member) 56 for sealingly engaging the inner peripheral surface 10a and the outer peripheral surface 20a of the plug member 20 is disposed. By this O-ring 56, the portion of the insertion passage 14 where the ball 26 is disposed is sealed to the outside, and the grease applied to the ball 26 and its periphery leaks to the outside, or dust, dust, etc. from the outside Prevents the ball 26 from interfering with the rotation of the ball 26. When the socket member 10 and the plug member 20 rotate relatively around the longitudinal axis L, the O-rings 52 and 56 slide on the inner peripheral surface 10a of the socket member 10 or the outer peripheral surface 20a of the plug member 20. Maintain sealing engagement while moving. The socket member 10 and the plug member 20 are connected via the O-rings 52 and 56 and the ball 26, and are not in direct contact with each other.

  When pressure is applied in the fluid passages 16 and 24, the socket member 10 and the plug member 20 receive a force in a direction away from each other. That is, the socket member 10 receives a rearward force (leftward in the drawing), and the plug member 20 receives a forward force (rightward in the drawing). Accordingly, the force due to the internal pressure is mainly received by the first holding surface 32 a and the fourth holding surface 32 d through the ball 26. In the present embodiment, since the first holding surface 32a and the fourth holding surface 32d are inclined surfaces extending in parallel to face each other, a ball sandwiched between the first holding surface 32a and the fourth holding surface 32d. 26 is not pushed toward the second holding surface 32b or the third holding surface 32c, and the second holding surface 32b and the third holding surface 32c do not receive the force accompanying the internal pressure from the ball 26. Although the ball holding member 38 on which the third holding surface 32c is formed is fixed by the set screw 48, it is considered that the fixing is loosened and displaced when a large force is repeatedly applied, Since the force accompanying the internal pressure is not substantially applied to the third holding surface 32c, the ball holding member 38 is not unintentionally displaced by the force accompanying the internal pressure. Similarly, the second holding surface 32b and the third holding surface 32c are inclined surfaces that face each other and extend in parallel. Thus, since the first holding surface 32a and the fourth holding surface 32d, and the second holding surface 32b and the third holding surface 32c are parallel surfaces, the socket member 10 and the plug member 20 are long. The distance from the rotation center axis of each ball 26 when rotating relatively around the axis L to each contact point between the ball 26 and the first to fourth holding surfaces 32a to 32d becomes equal. Accordingly, the ball 26 smoothly rolls on the first to fourth holding surfaces 32a-32d without sliding on the first to fourth holding surfaces 32a-32d. The frictional resistance therebetween is reduced, and wear of the ball 26 and the first to fourth holding surfaces 32a to 32d is also suppressed. More specifically, the first holding surface 32a and the fourth holding surface 32d are surfaces inclined by 45 degrees with respect to the radial axis perpendicular to the longitudinal axis L, and the second holding surface 32b and the third holding surface 32d. The holding surface 32c is a surface inclined 45 degrees in the opposite direction. The rotation center axis of the ball 26 at this time is an axis parallel to the longitudinal axis L through the center of the ball 26.

  In the swivel joint 1, each ball 26 is supported by the first to fourth holding surfaces 32a to 32d as described above, and the socket member 10 and the plug member 20 respectively support the ball 26 from the front and rear. And hold. Thereby, relative displacement in the front-rear direction of the longitudinal axis L of the socket member 10 and the plug member 20 and tilting around the axis perpendicular to the longitudinal axis L do not occur. Therefore, even if a bending force is applied between the socket member 10 and the plug member 20, it does not tilt relatively. Thereby, the crushing amount of each O-ring 52, 56 is always maintained in a constant state, the crushing amount is biased as in the conventional swivel joint, the sealing is partially released, and the internal fluid leaks to the outside. Is prevented. In addition, the socket member 10 and the plug member 20 do not rotate relative to each other in a state where the socket member 10 and the plug member 20 are in direct contact with each other, and wear at the contact point is prevented.

  The present invention is not limited to the swivel joint 1 according to the above embodiment, and various modifications can be made. For example, an annular groove having a third holding surface 32c and a fourth holding surface 32d is formed on the outer peripheral surface 20a of the plug member 20, and the socket member 10 includes a separate ball holding member having the first holding surface 32a. The first holding surface 32a may be displaced in the direction of the longitudinal axis L with respect to the second holding surface 32b. In the above embodiment, the collar member 36 is a separate member from the plug body 34 for assembly reasons, but the collar member 36 may be designed to be a member integral with the plug body 34. . Furthermore, the first to fourth holding surfaces 32a to 32d can be surfaces having other shapes such as curved surfaces, instead of the inclined surfaces that are linear in the cross section of the drawing. Further, the socket member 10 and the plug member 20 do not necessarily have to be configured so as not to contact each other, and may be slid in partial contact. Even in this case, when the ball 26 is held by the first to fourth holding surfaces 32a to 32d, when the bending force is applied between the socket member 10 and the plug member 20, the contact portion thereof. Since the force received by the pressure does not change greatly, excessive sliding resistance and wear can be prevented. The overall shape of the swivel joint 1 may be appropriately changed according to the application, for example, the socket member 10 or the plug member 20 is an L-shaped member.

Swivel joint 1; connecting portions 2a and 2b; socket member 10; inner peripheral surface 10a; front end opening 12; insertion passage 14; fluid passage (first fluid passage) 16; plug member 20; outer peripheral surface 20a; Ball 26; annular groove 30; first holding surface 32a; second holding surface 32b; third holding surface 32c; fourth holding surface 32d; plug body 34; outer peripheral surface 34a; Ball member 38; inner peripheral surface 38a; outer peripheral surface 38b; C ring 40; stepped portion 42; female screw portion 44; male screw portion 46; passage 47; set screw (fixing member) 48; O-ring (first sliding seal member) 52; O-ring holding groove 54; O-ring (second sliding seal member) 56;
Longitudinal axis L

Claims (5)

A cylindrical socket member having a front end opening, an insertion passage extending rearward from the front end opening, and a first fluid passage further extending from the insertion passage;
A plug member inserted into the insertion passage of the socket member, the rear end opening located in the socket member, and extending forward from the rear end opening, and the socket member at the rear end opening A cylindrical plug member having a second fluid passage communicating with the first fluid passage;
In the insertion passage, the socket member and the plug member are arranged side by side in the circumferential direction between the inner peripheral surface and the outer peripheral surface of the plug member, and the socket member and the plug member are relatively arranged around the longitudinal axis of the insertion passage. A plurality of balls rotatably coupled to the
A first sliding member disposed between the socket member and the plug member and sealingly engaging the socket member and the plug member to seal the first fluid passage and the second fluid passage from an external space; A sealing member,
The inner peripheral surface of the socket member faces the inner rear side and extends in the circumferential direction, and the annular first holding surface faces the inner front side and extends in the circumferential direction at a rear position of the first holding surface. An annular second holding surface that
The outer peripheral surface of the plug member faces the outer rear side and extends in the circumferential direction, and the annular third holding surface faces the outer front side and extends in the circumferential direction at a rear position of the third holding surface. An annular fourth holding surface,
Each of the plurality of balls is held by the first to fourth holding surfaces;
The plug member includes a cylindrical plug main body, and a ball holding member attached to the outer peripheral surface of the plug main body so as to be displaceable in the longitudinal direction of the longitudinal axis. 3 holding surface is formed,
The ball holding member has a ball holding position in which the third holding surface is engaged with the ball and the ball is held by the first to fourth holding surfaces, and is displaced forward from the ball holding position. A ball passage forming position that forms a passage between the socket member and the third holding surface that releases the engagement between the ball and allows the ball to be taken out and inserted; A swivel joint that can be displaced on the outer circumference . A male screw portion is formed on the outer peripheral surface of the plug main body portion, and a female screw portion that is threadedly engaged with the male screw portion is formed on the inner peripheral surface of the ball holding member, and the ball holding member is attached to the plug main body portion. the ball holding member by rotating the circumferential direction Te is to be displaced in the longitudinal direction of the longitudinal axis with respect to the plug body, the swivel joint according to claim 1. The swivel joint according to claim 2 , further comprising a fixing member that engages with the ball holding member and the plug main body portion and fixes the ball holding member so as not to rotate with respect to the plug main body portion. The swivel joint according to any one of claims 1 to 3 , wherein the first holding surface and the fourth holding surface are inclined surfaces extending in parallel to face each other. The first sliding seal member is disposed behind the ball to seal the first and second fluid passages with respect to the insertion passage;
2. A second sliding seal member disposed between the socket member and the plug member at a position in front of the ball and further sealingly engaging the socket member and the plug member. The swivel joint according to any one of 4 .

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