JP6498428B2 - Joint connection structure - Google Patents

Description

  The present invention relates to a joint connection structure.

  Conventionally, a joint to which a tubular body is connected is known.

  The following Patent Document 1 discloses a joint provided with a male seat surface whose outer diameter is gradually enlarged from the distal end portion toward the axial intermediate portion side on the distal end portion side in the axial direction of the metal joint body. Is disclosed. In this joint, a nut is rotatably provided on the distal end side of the joint body, and a threaded portion of a metal tube (adapter) is screwed onto the nut. The tubular body is formed with a female sheet surface whose inner diameter is gradually reduced from the axial tip toward the middle side, and when the threaded portion of the tubular body is screwed onto the nut, The seat surface of the body is pressed against the seat surface of the joint body.

Japanese Patent Laying-Open No. 2008-89161 (for example, FIG. 5)

  In the joint described in Patent Document 1, the male seat surface of the joint body and the female seat surface of the tubular body are set to have shapes having substantially the same inclination angle with respect to the axial direction. The fastening force (axial pressing force) suppresses liquid leakage from the inside.

  In the joint, for example, when the inclination angle with respect to the axial direction of the joint is 30 degrees, the sheet surface is 30 + 0 degrees to 30-0.5 degrees with respect to the axial direction, and the sheet surface of the tubular body is 30 + 0. Designed between 5 degrees and 30-0 degrees. Thus, the two are always in line contact with each other on the same circumference of the sheet surface (when further pressed, the belt contacts).

  However, the machine and equipment to which the joint is mounted are always accompanied by vibrations (particularly construction machines, etc.), and the threaded portion of the nut may be loosened during use. On the other hand, for example, it is conceivable to increase the strength of the joint and the tube and increase the fastening force, but there is a limit to improving the strength.

  Moreover, when the threaded part of the nut is loosened, a minute liquid leak occurs, and there is a possibility that blackened bleeding around the fastening part is confirmed. On the other hand, a structure in which an O-ring type flange is provided at a portion of the joint body facing the tubular body or a structure in which an O-ring is added to the seat surface can be considered, but the cost increases and the joint is made compact. It becomes difficult.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a joint connection structure capable of suppressing loosening of a screw fastening of a connection member and suppressing fluid leakage.

In order to solve the above problems, the joint connection structure according to the first aspect of the present invention is a tube in which a first inclined surface having an inner diameter gradually reduced from an axial tip toward an intermediate portion is formed. A joint body to which the body is connected, and an axially leading end portion of the joint body, the outer diameter is gradually enlarged from the leading end portion toward the intermediate portion side in the axial direction, and the first inclined surface is pressed A second inclined surface, a connecting member that is rotatably provided on the tip end side of the joint body, and that is fastened to a threaded portion of the tubular body, and is provided along the circumferential direction on the second inclined surface. An intermediate portion that is provided on the first inclined surface of the tubular body and is axially more axial than the groove portion of the second inclined surface when the threaded portion of the tubular body is fastened to the connecting member. It possesses a corner portion bites into the site of the side, the middle of the second axial direction than the inclined surface of the joint body Side vertical wall portion is provided radially inwardly on to the fitting body, in a position across from the groove in the vertical wall portion, the concave portion along the axial direction is formed.

  According to the first aspect of the invention, the axially distal end portion of the joint body is provided with the second inclined surface whose outer diameter is gradually enlarged from the distal end portion toward the axially intermediate portion side. Yes. A connecting member is rotatably provided on the side of the distal end portion of the joint body, and a threaded portion of the tubular body is fastened to the connecting member. The tubular body is formed with a first inclined surface whose inner diameter is gradually reduced from the axial front end toward the intermediate portion side, and the first inclined surface of the tubular body is pressed against the second inclined surface of the joint body. The The second inclined surface is provided with a groove portion along the circumferential direction, and when the threaded portion of the tubular body is fastened to the connecting member, the portion on the distal end side in the axial direction from the groove portion of the second inclined surface. At least a part of the first inclined surface of the tubular body is in pressure contact with at least a part of the tube. At the same time, starting from the groove part, the part on the intermediate part side in the axial direction from the groove part of the second inclined surface falls toward the part on the tip part side in the axial direction from the groove part. Thereby, the corner | angular part provided in the 1st inclined surface of the tubular body bites into the site | part of the intermediate part side of an axial direction rather than the groove part of a 2nd inclined surface.

In this configuration, the corner portion of the tubular body bites into a portion closer to the intermediate portion in the axial direction than the groove portion of the second inclined surface, thereby suppressing the looseness of the thread portion of the tubular body connected to the connecting member. For this reason, it is possible to suppress fluid leakage (micro-leakage) due to loosening of the threaded portion of the tubular body. In addition, at least a part of the first inclined surface of the tubular body is pressed against at least a part of the portion closer to the distal end side in the axial direction than the groove portion of the second inclined surface, and the corner portion of the tubular body is the second inclined surface. The fluid sealing effect can be improved by biting into a portion closer to the intermediate portion in the axial direction than the groove portion. Furthermore, a vertical wall portion is provided radially inward from the second inclined surface of the joint body on the intermediate side in the axial direction, and the joint body has an axial direction at a position extending from the groove portion to the vertical wall portion. A recess is formed along the line. For this reason, it can promote that the site | part of the intermediate part side of an axial direction rather than the groove part of a 2nd inclined surface falls down in the direction of the site | part of the front end part side of an axial direction rather than a groove part.

  According to a second aspect of the present invention, in the joint connection structure according to the first aspect, a length along the second inclined surface of a portion of the second inclined surface closer to the intermediate portion in the axial direction than the groove portion. However, it is shorter than the length along the 2nd inclined surface of the site | part of the said front-end | tip part side rather than the said groove part of the said 2nd inclined surface.

  According to the second aspect of the present invention, the length along the second inclined surface of the portion on the intermediate portion side in the axial direction from the groove portion of the second inclined surface is longer than the groove portion of the second inclined surface. It is shorter than the length along the second inclined surface of the side portion. As a result, the portion on the intermediate portion side in the axial direction with respect to the groove portion of the second inclined surface tends to fall and deform from the groove portion toward the portion on the tip end side in the axial direction from the groove portion.

  According to a third aspect of the present invention, in the joint connection structure according to the first or second aspect, the groove is formed in a U shape in a sectional view along the axial direction of the joint main body. .

  According to invention of Claim 3, the groove part is formed in the U-shape by the cross sectional view along the axial direction of the said joint main body, and is the intermediate part side of an axial direction rather than the groove part of a 2nd inclined surface. This part is easily deformed in the direction of narrowing the groove. For this reason, starting from the groove portion, the portion on the intermediate portion side in the axial direction relative to the groove portion of the second inclined surface is easily collapsed and deformed in the direction of the portion on the tip end portion side in the axial direction from the groove portion. Further, since the groove portion is formed in a U shape in a cross-sectional view, it is possible to avoid the occurrence of notches, cracks, and the like from the groove portion to the inside of the joint body during deformation.

According to a fourth aspect of the present invention, in the joint connection structure according to any one of the first to third aspects, the vertical wall portion has a protrusion that protrudes radially inward of the connection member. Is locked.

  According to the fourth aspect of the present invention, the vertical wall portion is provided on the intermediate portion side in the axial direction from the second inclined surface of the joint body so as to be engaged with the protruding portion protruding radially inward of the connecting member. The vertical wall portion prevents the connection member from coming off from the joint body. Furthermore, it is possible to reduce the thickness between the longitudinal wall portion and the portion on the intermediate portion side in the axial direction from the groove portion of the second inclined surface in the joint body. Thereby, starting from the groove part, the part on the intermediate part side in the axial direction from the groove part of the second inclined surface is more reliably tilted and deformed more easily in the direction of the part on the tip part side in the axial direction than the groove part.

  According to the joint connection structure of the present invention, loosening of the screw fastening of the connection member can be suppressed and fluid leakage can be suppressed.

It is a half cut sectional view showing a joint to which a connection structure of a joint concerning a 1st embodiment of the present invention is applied. It is a half cut sectional view showing the connection structure of the joint concerning a 1st embodiment of the present invention. It is an expansion perspective view which shows the 2nd inclined surface vicinity of the coupling main body used for the coupling shown in FIG. It is an expanded sectional view showing the 2nd inclined surface neighborhood of a joint main part in the process in which a pipe is fastened to a nut used for a joint shown in Drawing 1. FIG. 4 is a schematic view showing a state where a portion on the intermediate portion side in the axial direction from the groove portion of the second inclined surface of the joint main body shown in FIG. 4 is tilted toward a portion on the tip portion side in the axial direction from the groove portion of the second inclined surface. FIG. It is a perspective view which shows the 2nd inclined surface vicinity of the coupling main body used for the connection structure of the coupling which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the connection state of the 2nd inclined surface of the joint main body applied to the connection structure of the joint which concerns on a comparative example, and the 1st inclined surface of a tubular body.

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

  FIG. 1 shows a joint 10 to which a joint connection structure S2 according to the first embodiment of the present invention is applied. As shown in FIG. 1, the joint 10 includes a metal joint body (metal body) 12 having a core 12 </ b> A into which the inner side of the end of the hose 14 is inserted on one end side in the axial direction, and the joint body. 12, and a metal caulking part (clamp) 16 that extends along the twelve core parts 12 </ b> A and is disposed outside the hose 14. The joint body 12 is formed in a substantially cylindrical shape, and a flow path 18 through which a fluid (for example, a liquid) passes is formed.

  On the outer peripheral surface on the intermediate portion side in the axial direction from the core portion 12A of the joint main body 12, a concave portion 12B recessed inward in the radial direction is formed. The caulking portion 16 is formed with a protruding portion 16A that protrudes radially inward on one end side in the axial direction. The protruding portion 16A is engaged with the concave portion 12B of the joint body 12 so that the caulking portion 16 is It is attached to the joint body 12. When the crimping portion 16 is crimped from the outside, the hose 14 is pressed and fixed to the core portion 12 </ b> A of the joint body 12.

  The axial end of the core portion 12A of the joint body 12, that is, the insertion end side into the hose 14 is tapered, so that the inside of the hose 14 can be easily inserted into the core portion 12A. When the hose 14 is inserted between the core portion 12 </ b> A and the caulking portion 16, the hose 14 can be inserted until the tip end portion 14 </ b> A of the hose 14 contacts the side wall of the joint body 12 or the inner portion of the caulking portion 16. .

  On the outer peripheral surface of the core portion 12A, a sawtooth portion 13 having a sawtooth shape in sectional view is formed. The direction of the teeth of the sawtooth portion 13 is formed such that the inclination angle in the pull-out direction of the hose 14 is larger than the inclination angle in the insertion direction of the hose 14 with respect to the axial direction of the core portion 12A. That is, the direction of the teeth of the sawtooth portion 13 is set so that resistance is generated against inadvertent disconnection of the hose 14 in a state where the inside of the hose 14 is inserted into the core portion 12A.

  A substantially hexagonal enlarged diameter portion 12 </ b> C protruding outward in the radial direction is provided at the axial intermediate portion of the joint body 12. Further, a nut 20 as a connecting member that is rotatably supported with respect to the joint body 12 is provided on the side of the joint body 12 in the axial tip portion 12D (the other end in the direction opposite to the core 12A). It has been.

  A protruding portion 20 </ b> A that protrudes inward in the radial direction is formed at the end of the nut 20 on the back side in the axial direction (on the caulking portion 16 side). On the outer peripheral surface (between the enlarged diameter portion 12C and the distal end portion 12D) on the intermediate portion side in the axial direction with respect to the distal end portion 12D of the joint body 12, a recessed portion 22 that is recessed radially inward is formed. Twenty protrusions 20 </ b> A are inserted into the recesses 22 of the joint body 12. A vertical wall portion 22 </ b> A is formed along the substantially radial direction on the tip end portion 12 </ b> D side in the axial direction inside the hollow portion 22. Since the vertical wall on the intermediate portion side in the axial direction of the protruding portion 20A of the nut 20 is locked to the vertical wall portion 22A of the recessed portion 22 of the joint body 12, the nut 20 is prevented from coming off from the joint body 12. ing. The nut 20 is formed with a female screw portion 20B on the side opposite to the protruding portion 20A in the axial direction.

  As shown in FIG. 2, by rotating the nut 20, the male screw portion 30 </ b> B of the tube body 30 described later is fastened (screwed) to the female screw portion 20 </ b> B of the nut 20, whereby the joint 10 is connected to the tube body 30. To be connected. When connecting the tubular body 30 by rotating the nut 20, the male threaded portion 30 </ b> B of the tubular body 30 is easily attached to the female threaded portion 20 </ b> B of the nut 20 by applying a spanner to the enlarged diameter portion 12 </ b> C and fixing the joint body 12. Can be screwed together.

  As shown in FIG. 1, a sheet as a second inclined surface against which a sheet surface 34 (see FIG. 2) as a first inclined surface of the tubular body 30 is pressed on the outer peripheral surface of the distal end portion 12 </ b> D of the joint body 12. A surface 24 is formed. The seat surface 24 is an inclined surface (tapered surface) whose outer diameter is gradually increased from the distal end portion 12D of the joint body 12 toward the intermediate portion side in the axial direction. In this embodiment, the angle of the seat surface (male seat surface) 24 with respect to the axial direction of the joint body 12 is set to 30 °, for example (30 ° male seat type). The angle of the seat surface 24 with respect to the axial direction of the joint body 12 can be changed.

  As shown in FIG. 2, a male screw portion 30 </ b> B as a screw portion is formed at one axial end portion (tip portion) 30 </ b> A of the tube body 30. Further, the other end 30C in the axial direction of the tube body 30 is formed with a male screw portion 30D to which another pipe (not shown) is connected. A flow path 32 through which a fluid (for example, a liquid) passes is formed at the center of the tube body 30. A substantially hexagonal enlarged diameter portion 30E that protrudes radially outward is provided at the axial intermediate portion of the tubular body 30, and a spanner is hung on the enlarged diameter portion 30E to connect the tubular body 30 to the nut 20 or the like. Can be done.

  A sheet surface 34 as a first inclined surface having an inner diameter gradually reduced from the distal end portion 30A toward the intermediate portion side in the axial direction is formed at the distal end portion 30A as the axial distal end of the tube body 30. The angle of the seat surface 34 with respect to the axial direction of the tubular body 30 is set to be substantially the same as the angle of the seat surface 24 with respect to the axial direction of the joint body 12. The seat surface 34 of the tubular body 30 is pressed against the seat surface 24 of the joint body 12 in a state where the male thread portion 30B of the tubular body 30 is connected to the female thread portion 20B of the nut 20. In the present embodiment, the angle of the seat surface 24 with respect to the axial direction of the joint body 12 is designed to be 30 + 0 degrees to 30-0.5 degrees, and the angle of the seat surface 34 with respect to the axial direction of the tubular body 30 is 30 + 0. Designed between 5 degrees and 30-0 degrees.

  As shown in FIGS. 3 and 4, a groove portion 26 is provided in the seat surface 24 of the joint body 12 along the circumferential direction. The groove 26 is formed in a substantially U shape in a sectional view along the axial direction of the joint body 12 (see FIG. 4). The groove portion 26 is provided at a position near the outer edge in the radial direction on the seat surface 24. In other words, the length along the sheet surface 24 of the portion 24A in the axial direction intermediate portion side with respect to the groove portion 26 of the sheet surface 24 is the sheet of the portion 24B on the tip portion 12D side in the axial direction with respect to the groove portion 26 of the sheet surface 24. It is shorter than the length along the surface 24. The position of the groove portion 26 is preferably a position that is not so far away from the outer peripheral surface 12E adjacent to the seat surface 24 of the joint body 12.

  As for the dimensions of the groove 26, for example, when the hose 14 has an inner diameter φ12 mm (diameter 1/2), the width (axial width) is preferably 1.0 mm and the depth is preferably about 2.0 mm. In addition, the dimension and shape of the groove part 26 can be changed. Further, in the joint body 12, the length between the edge of the portion 24 </ b> A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 and the vertical wall portion 22 </ b> A (the axial length of the outer peripheral surface 12 </ b> E) is compared. Is set short.

  Thereby, as shown in FIG. 5, when the male screw portion 30B of the tube body 30 is fastened to the female screw portion 20B of the nut 20, the pressure contact is made in the first contact region 40, and as shown by the arrow B, Starting from the groove portion 26, a portion (a radially outer portion) 24 </ b> A in the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is a portion (a radially inner portion) on the tip portion 12 </ b> D side in the axial direction from the groove portion 26. ) Fall in the direction of 24B. That is, since the groove portion 26 is formed along the circumferential direction of the sheet surface 24, the region 24 </ b> A on the axially intermediate portion side of the groove portion 26 of the sheet surface 24 is formed so that the interval between the inner surface of the groove portion 26 is narrowed. In addition, it is deformed by falling in the direction of the portion 24B on the tip portion 12D side in the axial direction from the groove portion 26.

  Further, a corner portion 36 is provided on the edge of the sheet surface 34 of the tubular body 30 at a position facing the portion 24 </ b> A on the axial direction intermediate portion side with respect to the groove portion 26 of the sheet surface 24 in the axial direction. In the present embodiment, the corner portion 36 has a protruding shape in a cross-sectional view along the axial direction of the tubular body 30. Thereby, when the male thread portion 30B of the tube body 30 is fastened to the female thread portion 20B of the nut 20, the corner portion of the tube body 30 is caused by the collapse of the portion 24A on the axial direction intermediate side with respect to the groove portion 26 of the seat surface 24. 36 bites into a portion 24 </ b> A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24.

  Next, the operation and effect of the joint connection structure S2 of the present embodiment will be described.

  As shown in FIGS. 1 and 2, the axially distal end portion 12 </ b> D of the joint body 12 of the joint 10 has a sheet surface whose outer diameter is gradually enlarged from the distal end portion 12 </ b> D toward the axially intermediate portion side. 24 is provided. A groove portion 26 is provided in the sheet surface 24 along the circumferential direction. The nut 20 is rotatably provided on the side of the distal end portion 12D of the joint body 12, and the male screw portion 30B of the tube body 30 is fastened to the female screw portion 20B of the nut 20 (see FIG. 2). As shown in FIG. 4, the tube body 30 is provided with a sheet surface 34 whose inner diameter is gradually reduced from the axial tip portion 30 </ b> A toward the intermediate portion side. The sheet surface 34 of the tubular body 30 is pressed against the sheet surface 24 of the joint body 12 by being tightened.

  When the female screw portion 20B of the nut 20 is further tightened to the male screw portion 30B of the tube body 30, at least a part of the sheet surface 34 of the tube body 30 is more distal than the groove portion 26 of the sheet surface 24 as shown in FIG. At least a part of the portion 24B on the side of the portion 12D is press-contacted by a linear or belt-like first contact region 40. At that time, as indicated by an arrow B, the portion 24A on the axially intermediate portion side of the groove portion 26 of the seat surface 24 is more axially positioned than the groove portion 26 of the seat surface 24 with the groove portion 26 of the joint body 12 as a starting point. It falls down in the direction of the site | part 24B by the side of front-end | tip part 12D. As a result, the corner portion 36 provided at the edge of the sheet surface 34 of the tubular body 30 bites into the portion 24 </ b> A on the axially intermediate portion side of the groove portion 26 of the sheet surface 24. For this reason, the vicinity of the corner portion 36 of the tubular body 30 is brought into pressure contact with the portion 24 </ b> A closer to the axial direction intermediate portion than the groove portion 26 of the seat surface 24 in the second contact region 42.

  In such a joint connection structure S <b> 2, the corner portion 36 of the tubular body 30 bites into the portion 24 </ b> A on the axial direction intermediate side with respect to the groove portion 26 of the seat surface 24, so that the vibration of the machine and equipment when the joint 10 is used. Thus, the male screw portion 30B of the tubular body 30 fastened to the female screw portion 20B of the nut 20 is suppressed from loosening. For this reason, the leakage (fluid leak) of the fluid by the loosening of the internal thread part 20B of the nut 20 can be suppressed.

  Further, the sheet surface 34 of the tubular body 30 is pressed into contact with the portion 24B on the distal end portion 12D side of the groove portion 26 of the sheet surface 24 in the linear or strip-shaped first contact region 40, and the corner portion of the tubular body 30 36 bites into a portion 24 </ b> A on the axially intermediate portion side of the groove portion 26 of the seat surface 24. As a result, the vicinity of the corner portion 36 of the tubular body 30 is brought into pressure contact with the portion 24 </ b> A closer to the axially intermediate portion than the groove portion 26 of the seat surface 24 in the second contact region 42. That is, since the sheet surface 34 of the tubular body 30 contacts the sheet surface 24 of the joint body 12 in the first contact region 40 and the second contact region 42 along the circumferential direction, the fluid sealing effect can be improved. It is possible to more effectively suppress fluid leakage (microleakage).

  Further, in the joint body 12, the length along the sheet surface 24 of the portion 24 </ b> A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is the length of the portion 24 </ b> B on the tip end portion 12 </ b> D side of the groove portion 26 of the seat surface 24. It is shorter than the length along the sheet surface 24. Accordingly, the portion 24A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is easily deformed starting from the groove portion 26, and the portion 24A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is The surface 24 is more easily deformed by falling in the direction of the region 24B on the tip 12D side than the groove 26 of the surface 24.

  Further, since the groove portion 26 is formed in a substantially U shape in a cross-sectional view along the axial direction of the joint body 12, the portion 24 </ b> A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is formed in the groove portion 26. It becomes easy to deform in the direction of narrowing. For this reason, starting from the groove portion 26, the portion 24A on the intermediate side in the axial direction from the groove portion 26 of the seat surface 24 falls down in the direction of the portion 24B on the front end portion 12D side from the groove portion 26 of the seat surface 24 and is easily deformed. . Further, since the groove portion 26 is formed in a substantially U shape in a sectional view, for example, the groove portion is more deformed when the joint body 12 is deformed than in a case where the groove portion is formed in a V shape in a sectional view. It is possible to avoid the occurrence of notches, cracks and the like from the inside of the joint body 12 from 26.

  Further, the joint main body 12 is provided with a vertical wall portion 22 </ b> A to which a protruding portion 20 </ b> A that protrudes inward in the radial direction of the nut 20 is latched on the intermediate portion side in the axial direction from the seat surface 24. With the vertical wall portion 22A, the thickness between the portion 24A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 and the vertical wall portion 22A can be reduced. As a result, the portion 24 </ b> A closer to the axial direction intermediate portion than the groove portion 26 of the sheet surface 24 is easily deformed starting from the groove portion 26. For this reason, the portion 24A in the axial direction intermediate portion side of the groove portion 26 of the seat surface 24 is more reliably tilted and deformed in the direction of the portion 24B of the front end portion 12D side than the groove portion 26 of the seat surface 24.

  FIG. 7 is a cross-sectional view showing the vicinity of the joint sheet surface in the joint connection structure S100 of the comparative example. As shown in FIG. 7, in the joint connection structure S100 of the comparative example, the outer diameter gradually increases from the distal end portion 12D toward the axial intermediate portion side toward the distal end portion 12D of the joint main body 104 constituting the joint 102. A sheet surface (inclined surface) 106 that is enlarged is provided. The sheet surface 106 is not provided with a groove.

  In the joint connection structure S <b> 100, when the male thread portion 30 </ b> B of the tube body 30 is fastened to the female thread portion 20 </ b> B of the nut 20, the seat surface 34 of the tubular body 30 is pressed against the seat surface 106 of the joint body 104. At that time, at least a part of the sheet surface 34 of the tube body 30 is pressed into contact with a portion of the sheet surface 106 of the joint body 104 on the tip end 12D side in a linear or belt-like contact region 110. At this time, if the sheet surface 34 of the tubular body 30 is strongly pressed against the sheet surface 106 by tightening the nut 20, a band-shaped contact region 110 is formed. This contact area 110 is closer to the center of the joint body 104.

  A machine or facility to which the joint 102 to which the joint connection structure S100 is applied is always accompanied by vibrations (particularly construction machines), and the female thread portion 20B of the nut 20 may be loosened during use. . In contrast, for example, it is conceivable to increase the strength of the joint 102 and the pipe body 30 and increase the fastening force, but there is a limit to the improvement of the strength.

  On the other hand, in the joint connection structure S <b> 2 of the present embodiment, the portion 24 </ b> A on the axial direction intermediate side from the groove portion 26 of the seat surface 24 starts from the groove portion 26 of the joint body 12. It will fall in the direction of the part 24B on the tip 12D side. As a result, the corner portion 36 of the tubular body 30 bites into the portion 24A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24, thereby suppressing loosening of the male thread portion 30B of the tubular body 30 connected to the nut 20. be able to. Further, the sheet surface 34 of the tubular body 30 is pressed against the portion 24B on the distal end portion 12D side with respect to the groove portion 26 of the sheet surface 24 in the linear or strip-shaped first contact region 40, and the corner portion of the tubular body 30 is provided. In the second contact region 42, the vicinity of 36 is brought into pressure contact with a portion 24 </ b> A on the axial direction intermediate portion side of the groove portion 26 of the seat surface 24. Thereby, the sealing effect can be improved and leakage of fluid can be suppressed.

  Next, the joint connection structure according to the second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 6 is a perspective view showing the vicinity of the seat surface (second inclined surface) 24 of the joint body 54 used in the joint connection structure S52 of the second embodiment. As shown in FIG. 6, the groove surface 26 is formed along the circumferential direction on the seat surface 24 of the joint main body 54, and the position straddling the vertical wall portion 22 </ b> A (see FIG. 3) of the recessed portion 22 from the groove portion 26. In addition, a recess (split) 56 is formed along the axial direction. The recess 56 is formed so as to divide the outer peripheral surface of the portion 24 </ b> A on the axially intermediate portion side of the sheet surface 24. In the present embodiment, the recesses 56 are provided at three positions in the circumferential direction of the joint main body 54, that is, at positions where the outer peripheral surface of the joint main body 54 is divided at about 120 degrees. For example, the recess 56 has a circumferential width of 1.0 mm and a depth substantially equal to the depth of the groove 26 (about 2.0 mm).

  In such a joint connection structure S52, three concave portions 56 are formed along the axial direction at positions extending from the groove portion 26 of the joint main body 54 to the vertical wall portion 22A of the recess portion 22 (see FIG. 3). Thus, when the female threaded portion 20B of the nut 20 is fastened to the male threaded portion 30B of the tubular body 30 (see FIG. 2), the region 24A on the axially intermediate portion side of the grooved portion 26 of the seat surface 24 starts from the grooved portion 26. However, it is possible to promote the fall of the sheet surface 24 in the direction of the portion 24B closer to the distal end portion 12D than the groove portion 26 is. Therefore, the corner 20 (see FIG. 5) of the tubular body 30 surely bites into the portion 24A on the axially intermediate portion side of the groove portion 26 of the seat surface 24, and the nut 20 to which the male thread portion 30B of the tubular body 30 is fastened. The looseness of the female screw portion 20B (see FIG. 3) can be suppressed. In the joint connection structure S52, the concave portion 56 is provided in the joint main body 54 so that the role of the seal portion by the second contact region 42 is eliminated.

  In the first and second embodiments, a substantially U-shaped groove portion 26 is provided on the seat surface (second inclined surface) 24 in a sectional view along the axial direction of the joint body. The shape, position, and size are not limited to the configurations of the first and second embodiments, and can be changed.

  In the first and second embodiments, the joint 10 used for the joint connection structures S2 and S52 is described. However, the present invention is not limited to the joint 10, and the components of the joint can be changed. It is.

  Further, in the first and second embodiments, the angle of the sheet surface (second inclined surface) 24 and the angle of the sheet surface 34 of the tubular body 30 with respect to the axial direction of the joint body are about 30 degrees. However, the present invention is not limited to this, and the angle of the seat surface (second inclined surface) and the angle of the tube surface (first inclined surface) with respect to the axial direction of the joint body can be changed.

  Moreover, in 2nd Embodiment, although the three recessed parts 56 are provided along the axial direction in the position ranging from the groove part 26 of the coupling main body 54 to the vertical wall part 22A of the hollow part 22, this invention is limited to this. However, the number and size of the recesses 56 can be changed.

S2 Joint connection structure 10 Joint 12 Joint body 12D Tip 20 Nut (connection member)
20A Protrusion 20B Female thread 22A Vertical wall 24 Sheet surface (second inclined surface)
24A Axis portion 24B Axis portion 24B Axis tip portion portion 26 Groove 30 Tube 30A Tip portion (Axial tip)
30B Male thread part (Screw part)
34 Seat surface (first inclined surface)
36 Corner S52 Joint Connection Structure 54 Joint Body 56 Recess

Claims (4)

A joint body to which a tubular body formed with a first inclined surface having an inner diameter gradually reduced from the axial tip toward the intermediate side is connected;
A second inclined surface provided at an axial tip of the joint body, an outer diameter gradually increasing from the tip toward the intermediate side in the axial direction, and the first inclined surface being pressed;
A connecting member that is rotatably provided on the side of the tip of the joint body, and to which the threaded portion of the tubular body is fastened;
A groove provided along the circumferential direction on the second inclined surface;
Provided on the first inclined surface of the tubular body, and when the threaded portion of the tubular body is fastened to the connecting member, it bites into a portion of the second inclined surface closer to the intermediate portion in the axial direction than the groove portion. The corners,
I have a,
A vertical wall portion is provided radially inward on the intermediate portion side in the axial direction from the second inclined surface of the joint body,
A joint connection structure in which a recess is formed in the joint body along the axial direction at a position extending from the groove to the vertical wall .   The length along the second inclined surface of the portion on the intermediate portion side in the axial direction from the groove portion of the second inclined surface is the length of the portion on the tip portion side of the groove portion of the second inclined surface. The joint connection structure according to claim 1, wherein the joint connection structure is shorter than a length along the second inclined surface.   The joint connection structure according to claim 1, wherein the groove is formed in a U shape in a cross-sectional view along the axial direction of the joint body. The joint connection structure according to any one of claims 1 to 3 , wherein a protrusion projecting radially inward of the connection member is locked to the vertical wall portion .

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