JP5775277B2 - Swivel joint - Google Patents

Description

  The present invention relates to a swivel joint for connecting fluid piping.

  The swivel joint of the following Patent Document 1 includes a fixed portion to which piping such as a hose is connected, and a drill hole through which a fluid flows is provided in the core portion of the fixed portion. The rotating portion is coupled to the fixed portion so as to be swingable about the axis of the fixed portion, and a connecting hole and a communication hole through which a fluid flows are continuously provided in the core portion of the rotating portion. Yes. Further, a through hole is provided in the outer peripheral portion of the fixed portion, and the through hole penetrates the drill hole. For this reason, the fluid flows through the through hole between the fixed portion and the rotating portion.

  By the way, when an internal pressure is applied to the fixed portion by the fluid, a force that tends to extend in the axial direction of the fixed portion is strongly applied to the fixed portion.

  Here, in general, a plurality of through holes are provided, and each through hole is arranged so as to be shifted from the axial direction of the fixed portion. For this reason, in this arrangement of the through holes, if an internal pressure is applied in the fixed portion, the stress acting on the peripheral walls of the through holes and the through holes becomes difficult to be uniform. High stress acts on the edge of the outer periphery of the fixed part.

JP 2001-165372 A

  In view of the above facts, an object of the present invention is to provide a swivel joint that can reduce the stress applied to the shaft when an internal pressure is applied to the shaft.

The swivel joint according to claim 1, wherein one end portion is connected to the pipe, and the first flow path portion in which the fluid flows from the one end portion to the wall provided at the other end portion flows to the core portion. An annular groove is formed along the circumferential direction on the outer peripheral portion of the other end, and a through-hole penetrating the first flow path portion is formed along the circumferential direction on the bottom surface of the annular groove. A plurality of shafts provided on a circumferential line, and one end portion is connected to the other end portion of the shaft so as to be swingable about the axis of the shaft, and the other end is provided. A second flow path portion through which a fluid flows is formed, and a communication hole for continuously communicating the second flow path portion and the through hole is provided in the second flow path portion, and the other end comprising a housing part is connected to the other pipe, and the through hole is shaped in an elliptical shape With the said are arranged in the longitudinal direction of the elliptical shape in the axial direction of the shaft, said through-hole such that the axis line of the through hole is in the wall side of the shaft the axis of the communication hole is formed .

  In the swivel joint according to claim 1, one end portion of the shaft is connected to the pipe, and a first flow path portion through which a fluid flows from the one end portion of the shaft to the other end of the shaft is connected to the core portion of the shaft. It forms toward the wall provided in the edge part. A plurality of through holes penetrating the first flow path portion are provided in the outer peripheral portion of the other end portion of the shaft.

The housing is provided orthogonal to the shaft, and one end of the housing is connected to the other end of the shaft so as to be swingable about the axis of the shaft. In the housing, a second flow path portion through which a fluid flows is formed in the housing, and a communication hole that communicates the second flow path portion and the through hole of the shaft is provided continuously to the second flow path portion. . The other end of the housing is connected to another pipe.
The through hole is formed so that the axis of the through hole is closer to the shaft wall than the axis of the communication hole. For this reason, since a through-hole approaches the wall of a 1st flow-path part, a fluid becomes easy to flow to the communicating hole side via a through-hole. Thereby, the pressure loss of a swivel joint can be suppressed.

  By the way, usually, in order to maximize the flow path area and the maximum, the respective through holes are not arranged on the same circumferential line along the circumferential direction of the shaft. In addition, when an internal pressure is applied to the first flow path portion by the fluid, a force that tries to extend in the axial direction of the shaft is applied to the shaft by the internal pressure acting on the wall of the shaft. For this reason, if each through-hole is not arrange | positioned on the same circumference line, since the stress which acts on the surrounding wall of a through-hole and a through-hole will become difficult to become uniform, tensile bending will act on a shaft.

  On the other hand, in the invention according to the first aspect, the through holes are provided on the same circumferential line along the circumferential direction of the shaft. For this reason, each through-hole is not shifted and arranged in the axial direction of the shaft. As a result, when an internal pressure is applied to the first flow path portion by the fluid, the stress acting on the peripheral walls of the through holes and the through holes becomes substantially uniform. It can suppress that the stress which acts is high.

The through hole is formed so that the axis of the through hole is closer to the shaft wall than the axis of the communication hole. For this reason, since a through-hole approaches the wall of a 1st flow-path part, a fluid becomes easy to flow to the communicating hole side via a through-hole. Thereby, the pressure loss of a swivel joint can be suppressed.

Further, the through hole is formed in an elliptical shape, and is arranged with the longitudinal direction of the elliptical shape being the axial direction of the shaft. For this reason, it can suppress that the thickness in the circumferential direction of the shaft between a through-hole and a through-hole becomes thin. Thereby, the strength of the shaft can be increased.

It is a half section side view showing the swivel joint concerning a 1st embodiment of the present invention. It is a half cross section side view which shows the decomposition | disassembly state of the swivel joint which concerns on the 1st Embodiment of this invention. It is the perspective view which made the cross section the part which shows the swivel joint which concerns on the 1st Embodiment of this invention. (A) is a figure which shows the stress state in a through-hole at the time of shifting the through-hole of a swivel joint to the axial direction of a shaft, (B) is a figure of the swivel joint which concerns on the 1st Embodiment of this invention. It is a figure which shows the stress state in a through-hole. It is the schematic of the impact pressure test of the swivel joint which concerns on the 1st Embodiment of this invention. It is a half cross section side view which shows the swivel joint which concerns on the 2nd Embodiment of this invention.

  [First Embodiment]

  FIG. 1 shows a semi-sectional side view of a swivel joint 10 according to the first embodiment of the present invention, and FIG. 2 shows a swivel joint 10 according to the first embodiment of the present invention. The disassembled state is shown in a half sectional side view. FIG. 3 shows a perspective view of the swivel joint 10 according to the first embodiment of the present invention with a part thereof in cross section.

  The swivel joint 10 is used in an application in which a liquid flows at a predetermined pressure.

  As shown in FIGS. 1 to 3, the swivel joint 10 includes a substantially bottomed cylindrical shaft 12, and a first flow path portion 14 having a circular cross section through which a liquid flows is formed in the core portion of the shaft 12. Is formed. One side in the axial direction of the shaft 12 of the first flow path part 14 (the direction of the arrow A in FIGS. 1 to 3) is opened, and the other side in the axial direction of the shaft 12 of the first flow path part 14 (see FIGS. The arrow B direction side in FIG. 3 is closed to form a wall 14A. A male screw portion 18 is formed on the outer peripheral portion of the end portion 16 (one end portion) on one axial direction side of the shaft 12, and a pipe (not shown) is connected to the male screw portion 18. .

  A flange 20 having a hexagonal cross section as a rotation stop portion is provided on the other side in the axial direction of the shaft 12 of the end portion 16, and the flange 20 is formed to have a diameter larger than the outer diameter of the end portion 16.

The other side in the axial direction of the shaft 12 of the flange 20 is an end 22 (the other end). An annular groove ( concave portion 24 ) having a rectangular cross section is provided on the outer peripheral portion of the end portion 22 in the longitudinal intermediate portion of the end portion 22, and the annular groove ( concave portion 24 ) extends along the circumferential direction of the shaft 12. Is formed. A plurality of (four in the present embodiment) through holes 26 having a circular cross section are provided in the annular groove ( recess 24 ) , and the through holes 26 are penetrated by the first flow path portion 14. The through holes 26 are formed at predetermined intervals on a circumferential line 28 along the circumferential direction of the shaft 12.

  A first seal groove 30 having a rectangular cross section constituting the first seal portion is formed along the circumferential direction of the shaft 12 between the through hole 26 and the flange 20 on the outer peripheral portion of the end portion 22. . An O-ring 32 having a circular cross section that constitutes the first seal portion is provided in the first seal groove 30, and the O-ring 32 is formed in an annular shape in the circumferential direction of the shaft 12.

  A second seal groove 34 having a rectangular cross section constituting the second seal portion is formed along the circumferential direction of the shaft 12 between the through hole 26 and the first seal groove 30 on the outer peripheral portion of the end portion 22. The inner diameter of the second seal groove 34 is smaller than the inner diameter of the first seal groove 30. An O-ring 36 having a circular cross section that constitutes the second seal portion is provided in the second seal groove 34, and the O-ring 36 is formed in an annular shape in the circumferential direction of the shaft 12. A backup ring 38 is provided in the second seal groove 34 on the first seal groove 30 side from the O-ring 36, and the backup ring 38 is formed in an annular shape in the circumferential direction of the shaft 12.

  On the outer peripheral portion of the end portion 22, a fourth seal groove 40 having a rectangular cross section constituting the fourth seal portion is formed along the circumferential direction of the shaft 12 on the other side in the axial direction of the shaft 12 of the through hole 26. The inner diameter of the fourth seal groove 40 is the same as the inner diameter of the first seal groove 30. In the fourth seal groove 40, an O-ring 42 having a circular cross section constituting the fourth seal portion is provided, and the O-ring 42 is formed in an annular shape in the circumferential direction of the shaft 12.

  A third seal groove 44 having a rectangular cross section constituting the third seal portion is formed along the circumferential direction of the shaft 12 between the through hole 26 and the fourth seal groove 40 in the outer peripheral portion of the end portion 22. The inner diameter of the third seal groove 44 is smaller than the inner diameter of the fourth seal groove 40. In the third seal groove 44, an O-ring 46 having a circular cross section constituting the third seal portion is provided, and the O-ring 46 is formed in an annular shape in the circumferential direction of the shaft 12. A backup ring 48 is provided in the third seal groove 44 on the fourth seal groove 40 side from the O-ring 36, and the backup ring 48 is formed in an annular shape in the circumferential direction of the ring 12.

  A housing 50 is provided at the end 22 of the shaft 12. An arrangement hole 54 having a circular cross section is provided coaxially with respect to the shaft 12 at one end 52 (one end) on one axial side of the housing 50 (in the direction of arrow C in FIGS. 1 to 3). The inner peripheral portion of the arrangement hole 54 is slidable on the outer peripheral portion of the end portion 22 of the housing 50. For this reason, the housing 50 is disposed orthogonally to the shaft 12, and the housing 50 is connected to be swingable around the axis of the shaft 12.

When the housing 50 is swung around the axis of the shaft 12, the first seal portion, the second seal portion, the third seal portion, and the fourth seal portion described above are arranged on the inner peripheral portion of the arrangement hole 54. Therefore, the inner peripheral portion of the arrangement hole 54 and the outer peripheral portion of the end portion 22 are sealed by the first seal portion and the fourth seal portion, so that the inner peripheral portion and the end portion 22 of the arrangement hole 54 are sealed. Intrusion of dust or the like into the annular groove ( recessed portion 24 ) from between the outer peripheral portion is prevented. Further, the inner peripheral portion of the arrangement hole 54 and the outer peripheral portion of the end portion 22 are sealed by the second seal portion and the third seal portion, so that the inner peripheral portion of the arrangement hole 54 and the outer peripheral portion of the end portion 22 are Intrusion of liquid or the like into the annular groove ( recess 24 ) is prevented from between the gaps .

  The core (axis) of the housing 50 intersects the circumferential line 28 where the through hole 26 is disposed, and a second flow path portion 56 having a circular cross section through which the liquid flows is formed in the core of the housing 50. Is formed. A female screw portion 60 is formed on the inner peripheral portion of the end portion 58 (the other end portion) on the other side in the axial direction of the housing 50 (the arrow D direction side in FIGS. 1 to 3). Are connected to other pipes (not shown).

  In addition, a communication hole 62 having a circular cross section is provided in the core part of the housing 50 on one side in the axial direction of the housing 50 of the second flow path part 56, and the communication hole 62 is formed in the second flow path part 56. The inner diameter is smaller than the inner diameter of the second flow path portion 56 and is formed continuously with the second flow path portion 56. The communication hole 62 communicates between the second flow path portion 56 and the through hole 26 of the shaft 12.

  On the other hand, a washer 70 is provided coaxially with the shaft 12 at the tip of the end 22 of the shaft 12, and a stop ring 72 is provided on the opposite side of the washer 70 from the housing 50. The stop ring 72 restricts the movement of the shaft 12 of the housing 50 in the axial direction via the washer 70.

  With the above configuration, in the swivel joint 10 of the present embodiment, as shown by the arrow W1 or the arrow W2 in FIG. 1, between the first flow path portion 14 of the shaft 12 and the second flow path portion of the housing 50, The fluid flows through the through hole 26 of the shaft 12 and the communication hole of the housing 50.

(Function and effect)

  Next, the operation of the swivel joint 10 of the present invention will be described.

  A pipe is connected to the male screw portion 18 of the shaft 12, and another pipe is connected to the female screw portion 60 of the housing 50. In the swivel joint 10, the housing 50 is swingable about the axis of the shaft 12 (can rotate in the direction of arrow E in FIG. 1). For this reason, even when a twist or the like occurs in the pipe, the housing 50 swings around the axis of the shaft 12 to prevent the pipe from being damaged.

  Further, a through hole 26 penetrating the first flow path portion 14 is provided in the outer peripheral portion of the end portion 22 of the shaft 12, and the second flow path portion 56 and the through hole 26 are communicated with the housing 50. A communication hole 62 is provided. For this reason, as shown by an arrow W1 or an arrow W2 in FIG. 1, the through hole 26 of the shaft 12 and the communication of the housing 50 are communicated between the first flow path portion 14 of the shaft 12 and the second flow path portion of the housing 50. Fluid flows through the holes.

  By the way, when an internal pressure is applied to the first flow path portion 14 by the fluid, a force to extend in the axial direction of the shaft 12 is applied to the shaft 12 by the internal pressure applied to the wall 14A of the first flow path portion 14. . If each through-hole 26 is not arranged on the same circumferential line 28 (each through-hole 26 is displaced with respect to the axial direction of the shaft 12), the through-hole 26 and the through-hole Since the stress acting on the peripheral wall 26 is difficult to be uniform, tensile bending is likely to act on the shaft 12. For this reason, a high stress is applied to the edge of the through hole 26 on the outer peripheral side of the shaft 12.

  Here, the through hole 26 is provided on the same circumferential line 28 along the circumferential direction of the shaft 12. For this reason, the through-holes 26 are not displaced in the axial direction of the shaft 12. Thereby, when the internal pressure is applied to the first flow path portion 14 by the fluid, the stress acting on the peripheral wall of the through hole 26 and the through hole 26 becomes substantially uniform, so that the bending bending of the shaft 12 becomes difficult. .

  That is, as shown in FIG. 4A, when the through-hole 26 is shifted in the axial direction of the shaft 12 and the internal pressure (20 MPa × 1.5) is applied to the first flow path portion 14. The maximum stress (about 469.7 MPa) is applied to the edge of the through hole 26 on the outer peripheral side of the shaft 12. On the other hand, as shown in FIG. 4B, when the through holes 26 are arranged on the same circumferential line 28 and an internal pressure (20 MPa × 1.5) is applied to the first flow path portion 14, The maximum stress (about 402.2 MPa) is applied to the edge of the through hole 26 on the inner peripheral side of the shaft 12. For this reason, when the through holes 26 are arranged on the same circumferential line 28, the maximum stress applied to the shaft 12 is about 14 compared to the case where the through holes 26 are arranged shifted in the axial direction of the shaft 12. % Reduction.

  Thereby, it can suppress that the stress which acts on the shaft 12 becomes high. Therefore, the shaft 12 is suppressed from causing material fatigue, and the life of the swivel joint 10 can be greatly extended.

  Further, as described above, the through hole 26 is provided on the same circumferential line 28 along the circumferential direction of the shaft 12, so that the portion where the maximum stress is applied penetrates from the edge of the through hole 26 on the outer peripheral side of the shaft 12. The hole 26 is changed to the edge on the inner peripheral side of the shaft 12. For this reason, since it can suppress that the stress which concerns on the edge part of the shaft 12 outer peripheral side of the through-hole 26 becomes high, even when a bending load is applied to the shaft 12 as an external force, the bending of the shaft 12 can be suppressed.

  Further, when the housing 50 swings around the axis of the shaft 12, each through-hole 26 swings uniformly on the circumferential line 28 with respect to the housing 50, so that the pressure loss in the swivel joint 10 is reduced. Fluctuation can be reduced.

  Further, the following impact pressure test was performed as an evaluation of the swivel joint 10. As shown in FIG. 5, pipes are connected to the male screw portions 18 of the two swivel joints 10 and the swivel joint 10 is offset by 260 mm (a state in which an eccentric load (tensile load) is applied to the swivel joint 10) (20 .5 MPa × 1.5) impact pressure was repeatedly applied. As a result, it was confirmed that the shaft 12 was not broken at the number of impacts of 400,000 times. Thereby, even if the through holes 26 are arranged on the same circumferential line 28, the strength of the shaft 12 can be sufficiently secured.

[Second Embodiment]

  FIG. 6 shows a swivel joint 100 according to a second embodiment of the present invention in a half sectional side view.

  This embodiment has the same configuration as that of the first embodiment, but differs in the following points.

  The through hole 26 of the shaft 12 is provided on the other side in the axial direction of the shaft 12 (the arrow B direction side in FIG. 6) with respect to the axis of the housing 50. That is, the through hole 26 is arranged so that the axis of the through hole 26 is closer to the wall 14 </ b> A of the first flow path portion 14 than the axis of the housing 50.

  For this reason, in this embodiment, the same effect as in the first embodiment is obtained, and the through hole 26 of the shaft 12 is on the other side in the axial direction of the shaft 12 with respect to the axis of the housing 50 (FIG. 6). Since the through hole 26 approaches the wall 14A of the first flow path portion 14, the fluid easily flows to the communication hole 62 side through the through hole 26. Thereby, the pressure loss of the swivel joint 10 can be further suppressed.

  In the first embodiment and the second embodiment, the through hole 26 is formed in a circular cross section, but the cross sectional shape of the through hole 26 is not limited to this. For example, the through-hole 26 may be arranged so that the cross-sectional shape of the through-hole 26 is an elliptical shape and the longitudinal direction of the elliptical shape is the axial direction of the shaft 12. Thereby, it can suppress that the thickness in the circumferential direction of the shaft 12 between the through-hole 26 and the through-hole 26 becomes thin. Thereby, the strength of the shaft 12 can be further increased.

DESCRIPTION OF SYMBOLS 10 Swivel joint 12 Shaft 14 1st flow-path part 14A Wall 26 Through-hole 50 Housing 56 2nd flow-path part 62 Communication hole 100 Swivel joint

Claims (1)

One end is connected to the pipe, and a first flow path is formed through which fluid flows from one end to the wall provided at the other end, and the outer periphery of the other end. An annular groove extending in the circumferential direction is formed in the portion, and a shaft in which a plurality of through holes penetrating the first flow path portion are provided on the same circumferential line in the circumferential direction on the bottom surface of the annular groove; ,
A second flow path portion that is provided perpendicular to the shaft and has one end portion connected to the other end portion of the shaft so as to be swingable about the axis of the shaft, and a fluid flows from the other end portion; A housing that is formed and has a communication hole that is continuous with the second flow path portion and connects the second flow path portion and the through hole, and the other end portion of which is connected to another pipe; ,
The through hole is formed in an elliptical shape, and the longitudinal direction of the elliptical shape is arranged in the axial direction of the shaft, and the axial line of the through hole is closer to the shaft wall side than the axis of the communication hole. A swivel joint in which the through hole is formed.

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