Hose connection structure and fittings

Abstract

To provide a structure of a hose connection part in which a cylindrical insertion part can be connected to a hose, fluid can be caused to flow immediately, and which can be used.SOLUTION: A structure of a hose connection part includes: a cylindrical insertion part inserted to the inside of a hose; a seal annular projection which projects from an outer surface of the cylindrical insertion part, bites in the hose, and seals the hose and the cylindrical insertion part; a pair of groove formation projections which project from the outer surface of the cylindrical insertion part, in which an engaging radius to be a distance between a projection end and a central axis of the cylindrical insertion part is the engaging radius of the seal annular projection or smaller, and which form an annular groove mutually opposite in an axial direction of the cylindrical insertion part; and an elastic ring which is received by the annular groove, has an engaging radius larger than the engaging radii of the seal annular projection and the groove formation projection, is adhered to an inner surface of the hose, and seals between the hose and the cylindrical insertion part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a structure of a hose connection portion and a joint in which an annular protrusion protrudes from the outer surface of a cylindrical insertion portion that is inserted inside a hose. [Background technology]

[0002] Conventionally, as a structure of this kind of hose connection part, there is known one in which an annular protrusion is caused to bite into the hose to seal between the hose and a cylindrical insertion part (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-111066 A (Fig. 2, etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional hose connection structure, it takes time for the annular protrusion to fully bite into the hose and form a seal, so there is a problem in that the cylindrical insertion portion cannot be used to pass fluid through it immediately after connecting it to the hose. Therefore, the present disclosure provides a hose connection structure and a joint that allow the cylindrical insertion portion to be connected to the hose and used to pass fluid through it immediately. [Means for solving the problem]

[0005] One aspect of the invention made to solve the above problems is a hose connection structure comprising: a cylindrical insertion portion to be inserted inside a hose; a sealing annular protrusion protruding from the outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove forming protrusions protruding from the outer surface of the cylindrical insertion portion and having a fitting radius, which is the distance between the protruding tip and the central axis of the cylindrical insertion portion, that is less than or equal to the fitting radius of the sealing annular protrusion and that face each other in the axial direction of the cylindrical insertion portion to form an annular groove between them; and an elastic ring that is received in the annular groove and has a fitting radius greater than the fitting radius of the sealing annular protrusion and the groove forming protrusion, and that fits tightly against the inner surface of the hose to seal between the hose and the cylindrical insertion portion. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a side cross-sectional view of a joint having a hose connection structure according to an embodiment of the present disclosure. [Diagram 2] Exploded view of the joint [Diagram 3] Perspective view of the joint [Figure 4] A rear perspective view of the structure of the hose connection portion [Diagram 5] FIG. 1 is a perspective view of the base tube when the hose is clamped to the hose connection tube by the hose clamp; [Figure 6] A side cross-sectional view of the structure of a hose connection part when it is fastened by a hose clamp and the annular protrusion is biting into the inner surface of the hose. [Figure 7] (A) A side view of the fitting when a hose is inserted into the hose clamp in the expanded state, (B) A side view of the fitting when the hose pushes the clip and the hose clamp changes to the contracted state. [Figure 8] A front perspective view of the hose connection tube portion [Figure 9] Rear perspective view of the hose connection tube [Figure 10] Side view of the hose connection tube [Figure 11] Side cross-sectional view of the hose connection tube [Figure 12] Bottom view of hose connection tube [Figure 13] An enlarged side view of the elastic ring and its surroundings in the upper part of the hose connection tube. [Figure 14] An enlarged side view of the elastic ring and its surroundings at the lower part of the hose connection tube. [Figure 15] (A) A side view of the hose connection tube when the elastic ring is removed, (B) A bottom view of the hose connection tube when the elastic ring is removed DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] As shown in Fig. 1, a hose connection structure 10 according to an embodiment of the present disclosure is provided in a joint 100. The joint 100 of the present embodiment connects a hose 90 and a piping device 99, and is formed by assembling a plurality of parts, such as a cylindrical cover 40 and a cap 50, to a base cylindrical portion 80 (see Figs. 1 and 2).

[0008] The base tube portion 80 has a straight tube-shaped structure. One end of the base tube portion 80 has an equipment connection portion 30N connected to a piping device 99 (see FIG. 1), and the other end has a cylindrical insertion portion 12 connected to a hose 90. Hereinafter, the direction parallel to the central axis J1 of the base tube portion 80 will be referred to as the "front-rear direction H0", the cylindrical insertion portion 12 side (the right side in FIG. 1) will be referred to as the "front side", and the equipment connection portion 30N side will be referred to as the "rear side".

[0009] The piping device 99 may be any device having a flow path through which a fluid flows, and may be simply a pipe. The hose 90 may have a single-layer structure made of resin or the like, or may have a laminated structure. In the latter case, the hose 90 may include a metal layer made of aluminum or the like. The fluid flowing through the hose 90 and the piping device 99 may be a liquid, a gas, or a gas-liquid mixture.

[0010] In this embodiment, the base tube portion 80 has a tapered portion 13D at a midpoint in the axial direction, the tapered portion 13D narrowing the diameter toward the front end side. The portion of the base tube portion 80 forward of the tapered portion 13D forms the cylindrical tubular insertion portion 12. The tubular insertion portion 12 is inserted into the inside of the hose 90, and in this state, the hose 90 and the tubular insertion portion 12 are fastened from the outside by a hose clamp 60, which will be described later, so that the tubular insertion portion 12 is connected to the hose 90 in a manner that prevents it from coming loose (see FIGS. 5 and 6).

[0011] 1 and 3, the device connection part 30N is provided at the rear end of the base tubular part 80, and has a male threaded part on its outer circumferential surface. The male threaded part of the device connection part 30N is screwed into a female threaded hole (not shown) of a piping device 99 (see FIG. 1), thereby connecting the fitting 100 to the piping device 99. The connection between the fitting 100 and the piping device 99 does not have to be by screwing together threads, and may be, for example, by flange connection or press fitting, or may be something else.

[0012] As shown in FIG. 1, in this embodiment, the base tube portion 80 is formed by connecting the hose connection tube portion 11 and the device connection tube portion 30. The hose connection tube portion 11 has the above-mentioned tubular insertion portion 12 and the tapered portion 13D, and has a rear end connecting portion 13 that is larger in diameter than the tubular insertion portion 12 and is connected to the device connection tube portion 30 behind the tapered portion 13D. The device connection tube portion 30 has a regular hexagonal flange portion 30F (see FIG. 2) at a midpoint in the axial direction, and has the above-mentioned device connection portion 30N behind the flange portion 30F. As shown in FIG. 1, the device connection tube portion 30 has a front end connecting portion 31 that is connected to the hose connection tube portion 11 on the front side of the flange portion 30F. The front end connecting portion 31 of the device connection tube portion 30 has an outer peripheral surface that is gradually reduced in diameter, and is fitted inside the rear end connecting portion 13 of the hose connection tube portion 11. For example, the outer peripheral surface of the front end connecting portion 31 and the inner peripheral surface of the rear end connecting portion 13 are formed with uneven portions that engage with each other in the fore-and-aft direction H0, and the base cylindrical portion 80 is provided with an O-ring 19 that seals between the outer peripheral surface and the inner peripheral surface.

[0013] In this embodiment, the hose connection tubular part 11 is made of resin (for example, an injection molded part), but may be made of metal (for example, a machined or forged part). In this embodiment, the device connection tubular part 30 is made of metal, but may be made of resin. The base tubular part 80 does not have to be formed by connecting the hose connection tubular part 11 and the device connection tubular part 30, but may be, for example, integrally formed from resin or metal.

[0014] The cylindrical insertion portion 12 of the hose connection cylindrical portion 11 will be described in detail later. Before that, the components around the base cylindrical portion 80 of the joint 100, such as the cylindrical cover 40 and the cap 50, will be described.

[0015] As shown in FIG. 2, the cylindrical cover 40 has a configuration in which the bulging portion 43 bulges from a part of the circumferential direction of the outer peripheral surface of the cylindrical cover main body 40H extending in the front-rear direction H0. The bulging portion 43 is disposed in a range from the front end to a position near the rear end of the outer peripheral surface of the cover main body 40H. The bulging portion 43 has a hollow structure, and the internal space of the bulging portion 43 communicates with the internal space of the cover main body 40H. In the example of this embodiment, the cylindrical cover 40 is made of a transparent resin (for example, an injection molded product), but may be made of an opaque resin. The bulging portion 43 bulges from the cover main body 40H in a first direction perpendicular to the front-rear direction H0. Hereinafter, this first direction will be referred to as the vertical direction H1, and the side from which the bulging portion 43 protrudes in the vertical direction H1 will be referred to as the "upper side", and the opposite side will be referred to as the "lower side".

[0016] A cover rear end connecting part 42 is provided on the cylindrical cover 40 rearward of the bulging part 43, and the cover rear end connecting part 42 is fitted to the outside of the base cylindrical part 80. Specifically, as shown in Fig. 1, the cover rear end connecting part 42 of the cylindrical cover 40 is fitted across the connecting part between the hose connection cylindrical part 11 and the appliance connection cylindrical part 30, and is engaged with the outer circumferential surface of the front end connecting part 31 of the appliance connection cylindrical part 30 in the front-rear direction H0. Also, a step part is provided on the inner circumferential surface of the cover rear end connecting part 42 of the cylindrical cover 40, which abuts from the front against a step part on the outer circumferential surface of the rear end connecting part 13 of the hose connection cylindrical part 11, and the abutment of these step parts reinforces the prevention of the hose connection cylindrical part 11 from coming off the appliance connection cylindrical part 30.

[0017] The portion of the cylindrical cover 40 in front of the cover rear end connecting portion 42, i.e., the portion including the bulging portion 43, is an enclosing portion 41 that encloses the cylindrical insertion portion 12 of the hose connection cylindrical portion 11. The enclosing portion 41 houses the hose clamp 60 and the clip 70 shown in FIG. 1. In order to hold the hose clamp 60 and the clip 70 in the enclosing portion 41, a cap 50 is fitted to the front end of the cylindrical cover 40, and the front end opening of the cylindrical cover 40 is covered by the cap 50. The cap 50 is disposed coaxially with the base cylindrical portion 80, and a hose insertion hole 51A for inserting the hose 90 into the cylindrical cover 40 is formed through the cap 50. The front end of the cylindrical insertion portion 12 is inserted into the hose insertion hole 51A, and a gap is provided between the inner peripheral surface of the hose insertion hole 51A and the outer peripheral surface of the cylindrical insertion portion 12, through which the hose 90 can be inserted. For example, the front end surface of the cylindrical insertion portion 12 and the front end surface of the cap 50 are substantially flush with each other. In this embodiment, the cap 50 is a molded product made of resin, but may be made of metal, for example.

[0018] As shown in Fig. 5, the hose clamp 60 is, for example, formed by rolling a strip-shaped metal sheet into a ring shape. The hose clamp 60 has a pair of gripping pieces 63A, 63B that protrude radially outward from both ends, and these ends cross each other. For example, a through hole 61K is formed at one end of the hose clamp 60, and the gripping piece 63B at the other end of the hose clamp 60, which has a narrower width, is inserted into the through hole 61K and protrudes, so that both ends of the hose clamp 60 cross each other.

[0019] 4, clip 70 is made, for example, by bending a metal plate at a substantially right angle, and has a pair of clamping pieces 72 extending forward from the upper end of support base 71 which is placed on the rear side of hose clamp 60. Support base 71 also has a pair of pressed pieces 73 which open downward so as to straddle cylindrical insertion portion 12 (see FIG. 4).

[0020] 1 and 4, the pair of gripping pieces 63A, 63B of the hose clamp 60 and the upper part of the clip 70 are housed in the bulging portion 43. The hose clamp 60 is sandwiched between a stepped surface 44 formed on the inner surface of the enclosing portion 41 and the rear surface of the cap 50, and is positioned in the front-rear direction H0 within the enclosing portion 41 (see FIG. 1).

[0021] When the pair of gripping pieces 63A, 63B are brought closer to each other while being pinched, the hose clamp 60 is elastically deformed to assume an expanded diameter state. When the hose 90 is not inserted, the clip 70 is disposed so as to pinch the pair of gripping pieces 63A, 63B with the pair of pinching pieces 72, and prevents the pair of gripping pieces 63A, 63B from moving away from each other, thereby maintaining the hose clamp 60 in an expanded diameter state (see FIG. 4). When the hose 90 is inserted between the hose insertion hole 51A and the hose clamp 60 in this expanded diameter state, the clip 70 is released from the hose clamp 60 and the pair of gripping pieces 63A, 63B are released from being pinched. Then, the hose clamp 60 elastically returns to a contracted diameter state, and clamps the hose 90 to press it against the outer surface of the tubular insertion portion 12 (see FIGS. 5 and 6).

[0022] In more detail, when the hose 90 is inserted as described above, the pair of pressed pieces 73 of the clip 70 are pressed by the hose 90, as shown in the change from FIG. 7(A) to FIG. 7(B). Then, the clip 70 rotates so that the support base 71 faces upward, with the part of the pair of clamping pieces 72 that clamps the pair of knobs 63A, 63B as a fulcrum. Then, when the clip 70 abuts against the inner surface of the bulging portion 43, the clip 70 further rotates so as to move the pair of clamping pieces 72 downward. As a result, the pair of clamping pieces 72 are released from the pair of knob pieces 63A, 63B, and the clip 70 is released. One of the pair of clamping pieces 72 is shorter than the other clamping piece 72, and the shorter clamping piece 72 is disposed on the narrower knob piece 63B side (see FIG. 4). This makes it possible to easily remove the narrow gripping piece 63B from one of the clamping pieces 72.

[0023] Here, the hose connection structure 10 of this embodiment has a cylindrical insertion portion 12 and a sealing annular protrusion 20 (hereinafter simply referred to as "annular protrusion 20" as appropriate) protruding from the outer surface of the cylindrical insertion portion 12 (see Figs. 8 and 9). When the hose 90 is fastened to the cylindrical insertion portion 12 by the hose clamp 60 as described above, the annular protrusion 20 bites into the inner surface of the hose 90 to seal between the hose 90 and the cylindrical insertion portion 12 (see Fig. 6). Next, the configuration of the annular protrusion 20 will be described in detail.

[0024] 10 and 11, in the example of this embodiment, the annular protrusion 20 has a shape in which its protruding tip (i.e., the part farthest from the central axis J1) is disposed at the rear end of the annular protrusion 20. The annular protrusion 20 is shaped so that the amount of protrusion from the cylindrical insertion portion 12 gradually increases from the front end to the rear end (i.e., the outer circumferential surface gradually moves away from the central axis J1), and is substantially triangular in cross section (specifically, when a cross section cut in the radial direction at an arbitrary position in the circumferential direction of the cylindrical insertion portion 12 is viewed). In addition, the surface of the annular protrusion 20 facing the front side is an annular inclined surface 21 inclined with respect to the central axis J1, and the surface of the annular protrusion 20 facing the rear side is a stepped surface 22 rising from the outer circumferential surface of the cylindrical insertion portion 12.

[0025] In this embodiment, the annular protrusion 20 has a shape in which the width in the front-rear direction H0 changes in the circumferential direction. The front end line 24 of the annular protrusion 20 is disposed in a virtual plane perpendicular to the central axis J1 and is a circle centered on the central axis J1. On the other hand, the entire ridge line 23 of the protruding tip at the rear end of the annular protrusion 20 is inclined with respect to the central axis J1. When viewed from the front-rear direction H0 (the direction of the central axis J1), the ridge line 23 of the annular protrusion 20 has a circle centered on the central axis J1, and the distance between the protruding tip of the annular protrusion 20 and the central axis J1 is a constant fitting radius R (see Figures 13 and 14). The inclined surface 21 of the annular protrusion 20 has a shape in which the width in the front-rear direction H0 changes in the circumferential direction and the gradient also changes. The gradient of the inclined surface 21 is maximum at the portion where the width of the inclined surface 21 is minimum, and is minimum at the portion where the width of the inclined surface 21 is maximum. The ridge line 23 of the annular protrusion 20 is a line connecting the tip points of the annular protrusion 20 that are the furthest from the central axis J1 around the central axis J1.

[0026] As shown in FIG. 10, in this embodiment, the ridgeline 23 of the annular protrusion is formed to move toward one side (for example, the upper side) in a predetermined first direction (in this embodiment, the vertical direction H1) perpendicular to the central axis J1 and toward one side (front or rear) in the front-rear direction H0. That is, the front end point P, which is the frontmost point of the ridgeline 23 of the annular protrusion 20, and the rear end point Q, which is the rearmost point of the ridgeline 23, are the two points furthest apart on the ridgeline 23. The line segment connecting the front end point P and the rear end point Q is the longest major axis T among the line segments connecting the two points on the ridgeline 23, and obliquely intersects with the central axis J1. In this embodiment, the width of the annular protrusion 20 and the slope 21 in the front-rear direction H0 is smallest at a position including the front end point P and is largest at a position including the rear end point Q in the circumferential direction.

[0027] As shown in FIG. 10, in this embodiment, the ridge 23 of the annular protrusion 20 is curved so as to be convex toward the front with respect to the long axis T of the annular protrusion 20 when viewed from a second direction (hereinafter referred to as a lateral direction H2; see FIG. 12) perpendicular to the front-rear direction H0 and the first direction (up-down direction H1). Therefore, compared to a case in which the ridge 23 of the annular protrusion 20 is a perfect ellipse arranged in a virtual plane, it is possible to easily sharpen the protruding tip of the annular protrusion 20 near the front end point P and the rear end point Q, and it is possible to easily make the annular protrusion 20 bite into the inner surface of the hose 90. As shown in FIG. 12, in which the ridge 23 of the annular protrusion 20 is viewed from below, the ridge 23 of the annular protrusion 20 is curved so as to be convex toward the rear when viewed from the rear end point Q side in the up-down direction H1. The ridge 23 of the annular protrusion 20 is symmetrical in the lateral direction H2 with respect to the long axis T.

[0028] As shown in Fig. 10, the annular protrusions 20 are provided at multiple locations in the front-rear direction. In this embodiment, two annular protrusions are provided, a first annular protrusion 20A on the front side and a second annular protrusion 20B on the rear side, and the entire ridge lines 23 of these annular protrusions 20A, 20B are inclined in opposite directions to each other with respect to the central axis J1. In detail, when viewed from the lateral direction H2, the long axis T of the ridge line 23 of the first annular protrusion and the long axis T of the ridge line 23 of the second annular protrusion 20B are inclined in opposite directions to each other with respect to the central axis J1. In this embodiment, these long axes T are arranged in the same imaginary plane.

[0029] The entire ridge line 23 of the first annular protrusion 20A is inclined toward the rear as it moves upward in the vertical direction H1. The entire ridge line 23 of the second annular protrusion 20B is inclined toward the front as it moves upward in the vertical direction H1. In this embodiment, the front end lines of the first and second annular protrusions 20A and 20B form annular shapes and are each disposed in an imaginary plane perpendicular to the central axis J1. The front end line of the first annular protrusion 20A is located at the front end of the cylindrical insertion portion 12. The front end line 24 of the second annular protrusion 20B is located midway in the front-rear direction H0 of the cylindrical insertion portion 12.

[0030] In this embodiment, a cylindrical portion 12S having a constant outer diameter is formed on the rear side of the second annular protrusion 20B of the cylindrical insertion portion 12, and an annular protrusion 15 protrudes from a front position on the outer circumferential surface of the cylindrical portion 12S. The annular protrusion 15 is formed in a tapered shape that increases in diameter toward the rear side. The protruding tip of the annular protrusion 15 is, for example, R-chamfered.

[0031] However, in the conventional hose connection structure, it takes time for the annular projection 20 to fully bite into the hose 90 and form a seal. For example, this is particularly noticeable when the hose 90 is installed in a bent state. This has caused a problem in that the cylindrical insertion portion 12 cannot be used to pass fluids through it immediately after it is connected to the hose 90. Therefore, the hose connection structure 10 of this embodiment has the following characteristic configuration that allows the cylindrical insertion portion 12 to be used to pass fluids through it immediately after it is connected to the hose 90.

[0032] 10, an elastic ring 29 that seals between the hose 90 and the cylindrical insertion portion 12 is fitted onto the outer circumferential surface of the cylindrical insertion portion 12. In this embodiment, the elastic ring 29 is an O-ring. Also, in this embodiment, the elastic ring 29 is disposed between the first and second annular protrusions 20A, 20B.

[0033] The elastic ring 29 is received in an annular groove 29U (see Figures 15(A) and 15(B)) extending in the circumferential direction of the cylindrical insertion portion 12. The annular groove 29U is formed between a pair of groove-forming protrusions 27 protruding from the outer circumferential surface of the cylindrical insertion portion 12, and in this embodiment, is an O-ring groove. The groove-forming protrusions 27 protrude from the entire circumferential direction of the outer circumferential surface of the cylindrical insertion portion 12 and face each other in the front-rear direction H0. The opposing surfaces 27M, 27M of the groove-forming protrusions 27 are stepped surfaces that stand up from the outer circumferential surface of the cylindrical insertion portion 12, and in this embodiment, are parallel to each other (perpendicular to the central axis J1). The groove forming protrusions 27 are generally right-angled triangular in cross section (more specifically, when viewed in a cross section cut radially at any circumferential position of the cylindrical insertion portion 12), and are formed so that the ends closer to each other in the front-rear direction H0 are protruding tips, and the amount of protrusion gradually decreases on the sides farther away from each other. That is, an annular inclined surface 27A inclined with respect to the central axis J1 is formed on the outer circumferential surface of the groove forming protrusions 27 on the sides farther away from each other. The ridgeline of the protruding tips of the groove forming protrusions 27 is circular, centered on the central axis J1. The protruding tips of the groove forming protrusions 27 are, for example, R-chamfered.

[0034] In this embodiment, the rear groove-forming protrusion 27 is annular, radially perpendicular to the central axis J1, and has a tapered outer circumferential surface that tapers from the front end, which is the protruding tip, toward the rear end. The front-to-rear width of the rear groove-forming protrusion 27 is uniform in the circumferential direction of the cylindrical insertion portion 12.

[0035] In this embodiment, the front groove forming protrusion 27 is disposed such that the opposing surface 27M (see FIG. 15(A)), which is the rear end surface, is perpendicular to the central axis J1 and located at one position in the front-rear direction H0, while the annular front end line 27F of the front groove forming protrusion 27 is formed along the ridge line 23 of the first annular protrusion 20A and is inclined with respect to the central axis J1. Therefore, the front groove forming protrusion 27 has a shape in which the width in the front-rear direction H0 changes in the circumferential direction of the cylindrical insertion part 12. The width of the front groove forming protrusion 27 is narrowest at the upper end and widest at the lower end. The surface of the front groove forming protrusion 27 facing the front side is the above-mentioned annular inclined surface 27A inclined with respect to the central axis J1. This inclined surface 27A has a shape in which the width in the front-rear direction H0 changes and the gradient changes in the circumferential direction. The gradient of the inclined surface 27A is maximum at the portion (upper end) where the width of the inclined surface 27A is minimum, and is minimum at the portion (lower end) where the width of the inclined surface 27A is maximum.

[0036] As shown in Figures 13 and 14, the fitting radius M, which is the distance between the protruding tip of the groove forming protrusion 27 and the central axis J1 (i.e., the maximum outer diameter of the groove forming protrusion 27), is less than the above-mentioned fitting radius R of the annular protrusion 20. In this embodiment, the fitting radius M is smaller than the fitting radius R of the annular protrusion 20, but they may be the same. Also, in this embodiment, the fitting radius M of the groove forming protrusion 27 is larger than the outer diameter of the annular protrusion 15. The fitting radii M of a pair of groove forming protrusions 27 may be different from each other. Also, the fitting radii R of the first and second annular protrusions 20 may be different from each other.

[0037] Here, the elastic ring 29 protrudes from the outer circumferential surface of the cylindrical insertion portion 12, and a fitting radius L (i.e., the outer diameter of the elastic ring 29), which is the distance between the protruding tip and the central axis J1, is larger than both the fitting radius R of the annular protrusion 20 and the fitting radius M of the groove forming protrusion 27. Therefore, when the cylindrical insertion portion 12 is inserted into the inside of the hose 90, the elastic ring 29 comes into close contact with the inner surface of the hose 90 to seal between the hose 90 and the cylindrical insertion portion 12 (see FIG. 6).

[0038] In the hose connection structure 10 of this embodiment, the first and second annular protrusions 20A, 20B and the groove forming protrusion 27 (and therefore the elastic ring 29) are covered from the outside by the hose clamp 60. It is preferable that the area covered by the hose clamp 60 includes at least a portion of the first and second annular protrusions 20A, 20B, and it is more preferable that the entirety of the first and second annular protrusions 20A, 20B is included.

[0039] In this embodiment, the annular protrusion 20 and the groove forming protrusion 27 have a shape that allows them to be demolded in the horizontal direction H2. Therefore, when the hose connection tubular part 11 is formed by injection molding, the annular protrusion 20 and the groove forming protrusion 27 can be easily formed by demolding the mold for molding the hose connection tubular part 11 in the horizontal direction H2.

[0040] In the hose connection structure 10 of this embodiment, when the cylindrical insertion portion 12 is inserted into the inside of the hose 90 to connect the hose 90 and the cylindrical insertion portion 12, the sealing annular protrusion 20 protruding from the outer surface of the cylindrical insertion portion 12 bites into the hose 90, thereby sealing between the hose 90 and the cylindrical insertion portion 12, and the elastic ring 29 received in the annular groove 29U between a pair of groove forming protrusions 27 protruding from the outer surface of the cylindrical insertion portion 12 is also tightly attached to the inner surface of the hose 90, thereby sealing between the hose 90 and the cylindrical insertion portion 12. Here, even if it takes time for the sealing annular projection 20 to fully bite into the hose 90 and form a seal because the hose 90 is hard or the like, the fitting radius L of the elastic ring 29 is larger than the fitting radius R of the sealing annular projection 20, so that the elastic ring 29 adheres closely to the inner surface of the hose 90 to seal between the hose 90 and the cylindrical insertion portion 12, regardless of whether the sealing annular projection 20 has fully bitten into the hose 90. As a result, according to the hose connection structure 10 of this embodiment, it becomes possible to use the hose 90 by passing a fluid through it immediately after connecting the cylindrical insertion portion 12 to the hose 90.

[0041] In this embodiment, since the elastic ring 29 is an O-ring, sealing between the hose 90 and the cylindrical insertion portion 12 is easy. In addition, since the elastic ring 29 is disposed between the pair of annular protrusions 20, it is possible to suppress the elastic ring 29 from being excessively deformed by the hose 90, and it is possible to improve the durability of the elastic ring 29. Moreover, since the hose 90 is already expanded in diameter by the first annular protrusion 20A when the elastic ring 29 enters the hose 90, it is possible to smoothly enter the elastic ring 29 into the hose 90 compared to when the hose 90 is not already expanded in diameter. In addition, since the opposing surfaces 27M of the pair of groove forming protrusions 27 facing each other across the elastic ring 29 are parallel to each other, it is possible to make it difficult for the elastic ring 29 to come off the annular groove 29U. In addition, the surfaces of the pair of groove forming protrusions 27 facing opposite directions are inclined toward opposite directions (i.e., toward the first and second annular protrusions 20A, 20B) so as to reduce the protrusion amount of the pair of groove forming protrusions 27, so that the hose 90 is less likely to get caught when the hose 90 is inserted and the elastic ring 29 is less likely to fall off. It is also possible to prevent the annular protrusion 20 from becoming less likely to bite into the hose 90.

[0042] In this embodiment, the entire ridgeline 23 of the protruding tip of the annular protrusion 20 is inclined with respect to the central axis J1 of the cylindrical insertion portion 12. Therefore, it is possible to reduce the insertion resistance when inserting the cylindrical insertion portion 12 into the hose 90, compared to when the entire ridgeline 23 of the protruding tip of the annular protrusion 20 is disposed at one location in the axial direction of the cylindrical insertion portion 12. Moreover, the annular protrusion 20 has a shape in which the ridgeline 23 and the front end line 24 are not parallel, and the gradient of the slope 21 changes in the circumferential direction. Therefore, in the area where the gradient of the slope 21 is the smallest, it is possible to improve the ease of inserting the hose connection tube portion 11 into the hose 90, and in the area where the gradient of the slope 21 is the largest, the angle of the tip corner of the annular protrusion 20 becomes sharp, making it possible to increase the locking force against the inner surface of the hose 90.

[0043] Furthermore, since the ridge 23 of the front annular protrusion 20A is circular when viewed from the front-rear direction (the direction of the central axis J1), when the entire annular protrusion 20 enters the hose 90, the entire circumferential direction of the annular protrusion 20 is pressed almost evenly against the inner peripheral surface of the hose 90, making it possible to obtain high sealing performance. Furthermore, since the groove forming protrusion 27 and the annular protrusion 20 are in a range covered by the hose clamp 60 from the outside via the hose 90, it is possible to improve the sealing performance of the annular protrusion 20 by tightening the hose clamp 60.

[0044] As the insertion of the cylindrical insertion portion 12 into the hose 90 progresses further after the first and second annular protrusions 20A, 20B have entered the hose 90, the hose 90 reaches the annular protrusion 15. At this time, the hose 90 has already been expanded in diameter by the annular protrusions 20A, 20B, which have an outer diameter larger than that of the annular protrusion 15, so that the annular protrusion 15 can be smoothly inserted into the hose 90. In addition, the protruding tip of the annular protrusion 15 is R-chamfered, so that the annular protrusion 15 can be smoothly inserted into the hose 90. The annular protrusion 15 makes it possible to suppress the inclination of the hose 90 with respect to the hose connection tubular portion 11.

[0045] When the annular projection 15 enters the inside, the hose 90 comes into contact with the pressed piece 73 of the clip 70 as shown in Fig. 7(A). Then, by further inserting the hose 90, the retention of the hose clamp 60 by the clip 70 is released as described above, and the hose clamp 60 is deformed by reducing its diameter, tightening the hose 90 and fixing it to the hose connection tubular portion 11 (see Fig. 6). Thus, in this embodiment, simply by inserting the hose 90 into the tubular cover 40 from the hose insertion hole 15A and inserting the tubular insertion portion 12 into the hose 90, the hose 90 pushes the clip 70, removing it from the hose clamp 60, and the hose 90 can be fixed to the tubular insertion portion 12 by the hose clamp 60.

[0046] In addition, since the entire ridge lines 23 of the first and second annular protrusions 20A, 20B are inclined in opposite directions relative to the central axis J1 of the cylindrical insertion portion 12, it is possible to make it difficult for the hose 90 to rotate relative to the cylindrical insertion portion 12, and it is also possible to make it difficult for the hose 90 to come loose from the cylindrical insertion portion 12.

[0047] [Other embodiments] (1) The elastic ring 29 is not limited to an O-ring, and may be, for example, an oil seal or a ring having a lip protruding from its outer circumferential surface. The elastic ring 29 may have a rectangular cross section cut in the radial direction.

[0048] (2) In the above embodiment, two annular protrusions 20 are provided, but the number may be one or three or more. When a plurality of annular protrusions 20 are provided, the plurality of annular protrusions 20 may be disposed at a plurality of locations in the front-rear direction, including two locations on either side of a pair of groove-forming protrusions 27, or may be disposed only on one side of a pair of groove-forming protrusions 27 in the front-rear direction.

[0049] (3) In the above embodiment, the groove forming protrusion 27 has a cross section in the shape of a substantially right-angled triangle. However, this is not limited to this, and the cross section may be, for example, in the shape of a square.

[0050] (4) The cylindrical cover 40 does not have to be provided in the fitting 100 and the hose connection structure 10. Also, the clip 70, and the clip 70 and the hose clamp 60 do not have to be provided in the hose connection structure 10. Also, instead of the hose clamp 60, for example, a hose clamp that performs a tightening operation with a worm screw, or a hose clamp that maintains a tightened state with a latch structure like a cable tie, may be used.

[0051] (5) In the above embodiment, the rear end of the fitting 100 is provided with the equipment connection tubular portion 30 which is connected to the piping equipment 99. However, the rear end of the fitting 100 may also be provided with a hose connection tubular portion having, for example, something similar to the tubular insertion portion 12 which is connected to a hose.

[0052] (6) In the above embodiment, the hose connection structure 10 is provided in the fitting 100, but the hose connection structure 10 may constitute a part of the fluid device. In this case, the hose connection structure 10 may have a structure in which the cylindrical insertion portion 12 protrudes from the fluid device.

[0053] (7) In each of the above embodiments, the ridge line 23 of the annular protrusion 20 has a three-dimensionally curved shape, but the ridge line 23 may have a shape that fits within a two-dimensional plane without being three-dimensionally curved or bent. Also, annular protrusions 20 having ridge lines 23 that are three-dimensionally curved and annular protrusions 20 having ridge lines 23 that fit within a two-dimensional plane may be mixed.

[0054] (8) In the above embodiment, the entire ridge line 23 of the annular protrusion 20 is inclined with respect to the central axis J1, but the entire ridge line 23 of at least one annular protrusion 20 may be perpendicular to the central axis J1 (i.e., may be disposed in a virtual plane perpendicular to the central axis J1). Also, the ridge lines 23 of multiple annular protrusions 20 may be inclined to the same side with respect to the central axis J1.

[0055] (9) In the above embodiment, the entire front end line of the annular protrusion 20 may be inclined with respect to the central axis J1. In this case, the entire ridge line 23 of the annular protrusion 20 may be perpendicular to the central axis J1 or may be inclined (for example, may be parallel to the front end line of the annular protrusion 20).

[0056] (10) In the above embodiment, the front end surface of the tubular insertion portion 12 was positioned approximately flush with the front surface of the cap 50, but it may protrude beyond the front surface of the cap 50 or may be positioned rearward of the front surface of the cap 50.

[0057] <Additional Notes> The following describes the features extracted from the above embodiment, indicating their effects as necessary.

[0058] For example, the following features 1 to 9 relate to "a hose connection structure and fitting having an annular protrusion on the outer surface of a cylindrical insertion portion inserted into the inside of a hose," and can be considered to have been made with the objective of providing the following problem in relation to the background art that "conventionally, as a hose connection structure of this type, a structure in which the annular protrusion is caused to bite into the hose to seal between the hose and the cylindrical insertion portion is known (see, for example, JP 2000-111066 A (FIG. 2, etc.)).": "However, in the above-described conventional hose connection structure, it takes time for the annular protrusion to sufficiently bite into the hose to form a seal, so that the cylindrical insertion portion cannot be connected to the hose and immediately used to pass fluid therethrough. Therefore, the present disclosure provides a hose connection structure and fitting which enable the cylindrical insertion portion to be connected to a hose and immediately used to pass fluid therethrough."

[0059] [Feature 1] a cylindrical insertion portion that is inserted into the inside of the hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; an elastic ring that is received in the annular groove and has a fitting radius larger than the fitting radii of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against the inner surface of the hose to seal between the hose and the cylindrical insertion portion.

[0060] In the structure of the hose connection part of feature 1, when the cylindrical insertion part is inserted into the inside of the hose to connect the hose and the cylindrical insertion part, the sealing annular protrusion protruding from the outer surface of the cylindrical insertion part bites into the hose, sealing between the hose and the cylindrical insertion part, and the elastic ring received in the annular groove between the pair of groove-forming protrusions protruding from the outer surface of the cylindrical insertion part also fits tightly to the inner surface of the hose, sealing between the hose and the cylindrical insertion part. Here, even if it takes time for the sealing annular protrusion to fully bite into the hose and seal because the hose is hard, the fitting radius of the elastic ring is larger than that of the sealing annular protrusion, so that the elastic ring fits tightly to the inner surface of the hose and seals between the hose and the cylindrical insertion part regardless of whether the sealing annular protrusion is fully bitten into the hose. As a result, according to the structure of the hose connection part of feature 1, it is possible to use the hose by flowing a fluid immediately after connecting the cylindrical insertion part to the hose.

[0061] [Feature 2] 2. The hose connection structure according to claim 1, wherein the pair of groove-forming protrusions each have a cross section that is approximately a right-angled triangle, and the opposing faces of the groove-forming protrusions are parallel to each other.

[0062] In feature 2, since the opposing surfaces of the groove forming projection are parallel to each other, it is possible to make it difficult for the elastic ring to come off the annular groove.

[0063] [Feature 3] 3. The structure of a hose connection according to claim 1 or 2, wherein the elastic ring is an O-ring and the annular groove is an O-ring groove.

[0064] In feature 3, since the elastic ring is an O-ring, sealing between the hose and the cylindrical insertion portion is facilitated.

[0065] [Feature 4] 4. A hose connection structure according to any one of features 1 to 3, wherein the entire ridge line of the protruding tip of the sealing annular protrusion is inclined with respect to the central axis of the cylindrical insertion portion.

[0066] In feature 4, it is possible to reduce the insertion resistance when inserting the cylindrical insertion portion into the hose, compared to when the entire ridge line of the protruding tip of the sealing annular protrusion is positioned at one point in the axial direction of the axial cylindrical insertion portion.

[0067] [Feature 5] 5. A hose connection structure according to any one of features 1 to 4, wherein the sealing annular protrusions are arranged at a plurality of locations in the axial direction of the cylindrical insertion portion, including two locations sandwiching the pair of groove-forming protrusions.

[0068] In feature 5, since the elastic ring is disposed between a pair of sealing annular projections, it is possible to prevent the elastic ring from being excessively deformed by the hose, and it is possible to improve the durability of the elastic ring. In addition, since the hose is already expanded in diameter by one sealing annular projection when the elastic ring enters the hose, it is possible to allow the elastic ring to enter the hose more smoothly than when the hose is not already expanded in diameter.

[0069] [Feature 6] 6. The hose connection structure according to claim 5, wherein the pair of sealing annular protrusions arranged at the two locations have ridge lines that are inclined in opposite directions with respect to the central axis of the cylindrical insertion portion.

[0070] According to feature 6, it is possible to make it difficult for the hose to rotate with respect to the cylindrical insertion portion, and it is possible to make it difficult for the hose to come off from the cylindrical insertion portion.

[0071] [Feature 7] 7. A structure of a hose connection portion according to any one of features 1 to 6, further comprising a hose clamp that fastens the hose to the cylindrical insertion portion from the outside and covers the groove forming protrusion and the sealing annular protrusion from the outside via the hose.

[0072] In feature 7, since the groove-forming protrusion and the sealing annular protrusion are in an area that is covered from the outside by the hose clamp via the hose, it is possible to improve the sealing performance of the sealing annular protrusion by tightening the hose clamp.

[0073] [Feature 8] The hose clamp is configured to be elastically deformed to an expanded state and held by the clip when a hose is not inserted, and to be elastically restored to its original state when the hose is inserted, thereby clamping the hose; a cylindrical cover that surrounds the cylindrical insertion portion and houses the hose clamp and the clip therein; a cap that is fitted to the tip end of the cylindrical cover to prevent the hose clamp and the clip from coming off and has a hose insertion hole through which the hose is inserted, 8. The structure of a hose connection portion according to claim 7, wherein the clip is pushed by the hose inserted into the outside of the cylindrical insertion portion to be released from the hose clamp.

[0074] In feature 8, by simply inserting the hose through the hose insertion hole into the cylindrical cover and inserting the cylindrical insertion portion into the hose, the hose pushes the clip, releasing the clip from the hose clamp, and the hose can be fixed to the cylindrical insertion portion by the hose clamp.

[0075] [Feature 9] A fitting having a hose connection structure according to any one of features 1 to 8.

[0076] In addition, although this specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken alone. [Explanation of symbols]

[0077] 10 Hose connection structure 11 Hose connection tube 12 Cylindrical insertion part 20 Annular protrusion 27 Groove forming protrusion 29 Elastic Ring 29U Circular groove 40 Cylindrical cover 50 Cap 60 Hose clamp 70 clips 100 Joints

Claims

1. a resin cylindrical insertion portion that is inserted into the inside of the hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; a ring that is received in the annular groove and has a fitting radius larger than the fitting radius of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against an inner surface of the hose to seal between the hose and the cylindrical insertion portion, A structure of a hose connection portion that satisfies at least one of the following (1) and (2). (1) The entire ridge line of the protruding tip of the sealing annular projection is inclined with respect to the central axis of the cylindrical insertion portion. (2) A hose clamp is provided which fastens the hose to the cylindrical insertion portion from the outside and covers the groove forming protrusion and the sealing annular protrusion from the outside via the hose, The hose clamp is configured to be elastically deformed to an expanded state and held by the clip when a hose is not inserted, and to be elastically restored to its original state when the hose is inserted, thereby clamping the hose; a cylindrical cover that surrounds the cylindrical insertion portion and houses the hose clamp and the clip therein; a cap that is fitted to the tip end of the cylindrical cover to prevent the hose clamp and the clip from coming off and has a hose insertion hole through which the hose is inserted, The clip is pushed by the hose inserted into the outside of the cylindrical insertion portion and is disengaged from the hose clamp.

2. a cylindrical insertion portion that is inserted into the inside of the hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; a ring that is received in the annular groove and has a fitting radius larger than the fitting radius of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against an inner surface of the hose to seal between the hose and the cylindrical insertion portion, A hose connection structure in which, of the pair of groove-forming protrusions, the groove-forming protrusion on the tip side of the tubular insertion portion has a generally triangular cross-section in which the amount of protrusion from the tubular insertion portion increases from the tip side to the base end side of the tubular insertion portion, and the gradient of the outer peripheral surface of the groove-forming protrusion varies circumferentially of the tubular insertion portion.

3. A cylindrical insertion portion that is inserted into the inside of a hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; a ring that is received in the annular groove and has a fitting radius larger than the fitting radius of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against an inner surface of the hose to seal between the hose and the cylindrical insertion portion, The pair of groove forming protrusions each have a cross section of a substantially right-angled triangle, and the opposing faces of the groove forming protrusions are parallel to each other, A structure of a hose connection portion in which the entire ridge line of the protruding tip of the annular sealing projection is inclined with respect to the central axis of the cylindrical insertion portion.

4. A cylindrical insertion portion that is inserted into the inside of a hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; a ring that is received in the annular groove and has a fitting radius larger than the fitting radius of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against an inner surface of the hose to seal between the hose and the cylindrical insertion portion, The pair of groove forming protrusions each have a cross section of a substantially right-angled triangle, and the opposing faces of the groove forming protrusions are parallel to each other, A hose connection structure in which the sealing annular projections are arranged at a plurality of positions in the axial direction of the cylindrical insertion portion, including two positions sandwiching the pair of groove-forming projections.

5. A cylindrical insertion portion that is inserted into the inside of a hose; a sealing annular protrusion protruding from an outer surface of the cylindrical insertion portion and biting into the hose to seal between the hose and the cylindrical insertion portion; a pair of groove-forming protrusions protruding from an outer surface of the cylindrical insertion portion, the fitting radius being the distance between the protruding tip and the central axis of the cylindrical insertion portion being equal to or smaller than the fitting radius of the sealing annular protrusion, and the pair of groove-forming protrusions facing each other in the axial direction of the cylindrical insertion portion forming an annular groove between them; a ring that is received in the annular groove and has a fitting radius larger than the fitting radius of the sealing annular protrusion and the groove-forming protrusion, and that fits closely against an inner surface of the hose to seal between the hose and the cylindrical insertion portion, The pair of groove forming protrusions each have a cross section of a substantially right-angled triangle, and the opposing faces of the groove forming protrusions are parallel to each other, a hose clamp for clamping the hose to the cylindrical insertion portion from the outside and for covering the groove forming protrusion and the sealing annular protrusion from the outside via the hose, The hose clamp is configured to be elastically deformed to an expanded state and held by the clip when a hose is not inserted, and to be elastically restored to its original state when the hose is inserted, thereby clamping the hose; a cylindrical cover that surrounds the cylindrical insertion portion and houses the hose clamp and the clip therein; a cap that is fitted to the tip end of the cylindrical cover to prevent the hose clamp and the clip from coming off and has a hose insertion hole through which the hose is inserted, A structure of a hose connection portion in which the clip is pushed by the hose inserted into the outside of the cylindrical insertion portion and released from the hose clamp.

6. A fitting having the structure of a hose connection portion described in any one of claims 1 to 5.

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