Joints

Abstract

To prevent a nut from coming off from a pipe member before a joint is used.SOLUTION: A joint includes: a pipe member having a flange at a rear end; and a nut which is fitted onto the outer side of the pipe member from the front side and has a contact surface, with which the flange contacts, therein. The joint includes: outer surface protrusions each formed at a middle portion as seen in an anteroposterior direction, through which the nut passes, of the pipe member and protruding outward; and protrusion passing passages each of which is formed at a portion positioned forward of the contact surface of the nut and through each of which the outer surface protrusion may pass.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a fitting. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a so-called union joint has been known in which a nut rotatably engaged with one end of a pipe member is tightened onto another pipe member to connect the pipe members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Jitsuzen 57-165879 (Fig. 1 etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] With the conventional joints described above, there is a need for a solution to the problem that the nut may fall off the pipe member before the joint is used. [Means for solving the problem]

[0005] One aspect of the invention made to solve the above problem is a fitting comprising a pipe member having a flange at its rear end, and a nut that is inserted from the front onto the outside of the pipe member and has an internal abutment surface against which the flange abuts, the fitting comprising an outer surface protrusion that is formed in a mid-portion of the pipe member in the fore-and-aft direction through which the nut passes and that protrudes outward, and a protrusion passage that is formed in a portion of the nut forward from the abutment surface and through which the outer surface protrusion can pass. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a cross-sectional side view of a fitting according to one embodiment of the present disclosure; [Figure 2] Perspective view of the joint [Figure 3] Exploded perspective view of the joint [Figure 4] 1 is a perspective view of a pipe member and a nut through which the pipe member is inserted; [Figure 5] Rear perspective view of the joint [Figure 6] 1 is a perspective view of a pipe member when a hose is clamped to a hose connection portion by a hose clamp; [Figure 7] A side cross-sectional view of the fitting when it is tightened by the hose clamp and the annular protrusion is biting into the inner surface of the hose. [Figure 8] (A) Side view of the fitting when the hose is inserted into the hose clamp in the expanded state. (B) Side view of the fitting when the hose pushes the clip and the hose clamp changes to the contracted state. [Figure 9] Cross section of the joint taken along line AA in Figure 1 [Figure 10] (A) Front view of the nut, (B) Rear view of the nut [Figure 11] Cross section of the joint taken along line BB in Figure 9 [Figure 12] (A) A front view of the nut when it is positioned at a specific rotational position relative to the pipe member. (B) A front view of the nut when it is rotated 45 degrees from the specific rotational position relative to the pipe member. DETAILED DESCRIPTION OF THE INVENTION

[0007] As shown in FIG. 1, a fitting 10 according to one embodiment of the present disclosure connects a hose 90 and a piping device 99, and is formed by assembling a plurality of parts, such as a nut 50 and a cylindrical cover 40, to a pipe member 80 (see FIGS. 1 to 3).

[0008] The pipe member 80 has a straight cylindrical structure. In this embodiment, the pipe member 80 has an equipment connection portion 30 at one axial end thereof that is connected to a piping device 99 (see FIG. 1 ), and a hose connection portion 12 at the other axial end thereof that is connected to a hose 90. A nut 50 that is fitted onto one end of the pipe member 80 and secured to the one end is threaded onto a male thread portion provided at the end of the piping device 99, thereby connecting the pipe member 80 to the piping device 99. Hereinafter, the direction parallel to the central axis J1 of the pipe member 80 will be referred to as the "front-rear direction H0," the hose connection portion 12 side (the right side in FIG. 1 ) as the "front side," and the equipment connection portion 30 side as the "rear side," as appropriate.

[0009] The piping device 99 may be any device that has a flow path through which a fluid flows, and may be simple piping. The hose 90 may have a single-layer structure made of resin or the like, or a multi-layer structure. In the latter case, the hose 90 may include a metal layer made of aluminum or the like. The fluid that flows through the hose 90 and the piping device 99 is not particularly limited, and may be, for example, a liquid, a gas, or a gas-liquid mixture.

[0010] In this embodiment, the pipe member 80 has a reduced diameter section 13D, which reduces the diameter of the front side, at a midpoint in the axial direction (see FIGS. 1 and 4). The above-mentioned hose connection part 12 is provided in a portion of the pipe member 80 that has a smaller diameter and is forward of the reduced diameter section 13D. The hose connection part 12 is inserted inside the hose 90, and in this state, the hose 90 is fastened to the hose connection part 12 from the outside by a hose clamp 60, which will be described later, thereby connecting the hose connection part 12 to the hose 90 in a manner that prevents it from coming loose (see FIGS. 6 and 7).

[0011] For example, the hose connection portion 12 is provided with an annular protrusion 20 that protrudes outward (see FIGS. 3 and 4). When the hose 90 is fastened to the hose connection portion 12 by the hose clamp 60 as described above, the annular protrusion 20 bites into the inner surface of the hose 90 and seals the gap between the hose 90 and the hose connection portion 12 (see FIG. 7). For example, the annular protrusions 20 may be provided at multiple locations in the front-rear direction, and in this embodiment, two annular protrusions 20 are provided (see FIG. 4). For example, the ridge lines that connect the portions of these annular protrusions 20 that are farthest from the central axis J1 in the circumferential direction form a circle when viewed from the front-rear direction H0 and are inclined with respect to the central axis J1 (for example, inclined in opposite directions).

[0012] An elastic ring 29 (e.g., an O-ring) that seals between the hose 90 and the hose connecting portion 12 may be fitted onto the outer peripheral surface of the hose connecting portion 12 (see FIGS. 1 and 5). The elastic ring 29 may be received in an annular groove extending in the circumferential direction of the hose connecting portion 12. For example, the elastic ring 29 is disposed between two annular protrusions 20. Preferably, the elastic ring 29 protrudes from the outer peripheral surface of the hose connecting portion 12, and the outer diameter, which is the distance between the protruding tip and the central axis J1, is larger than the outer diameter of the annular protrusions 20. In this way, when the hose connecting portion 12 is inserted inside the hose 90, the elastic ring 29 comes into close contact with the inner surface of the hose 90, sealing between the hose 90 and the hose connecting portion 12 (see FIG. 7), thereby improving the sealing performance therebetween.

[0013] 1 and 4, a flange 30F that protrudes outward is formed at the rear end of the pipe member 80. In this embodiment, a large diameter section 39 that is larger in diameter than the hose connection section 12 is provided in the pipe member 80 rearward of the reduced diameter section 13D, and the flange 30F is provided at the rear end of the large diameter section 39 (i.e., at the device connection section 30). In this embodiment, an annular groove 38 is formed in the outer peripheral surface of a portion of the large diameter section 39 that is forward of the flange 30F. As will be described later, a nut 50 engages with the annular groove 38.

[0014] An outer surface protrusion 32 is formed in a middle portion of the pipe member 80 in the front-rear direction H0. In this embodiment, the outer surface protrusion 32 protrudes from the outer peripheral surface of a portion of the large diameter portion 39 that is forward of the annular groove 38. The outer surface protrusions 32 may be provided at multiple locations around the circumference of the pipe member 80, and in this embodiment, they are arranged at equal intervals around the circumference of the pipe member 80. In this embodiment, the outer surface protrusions 32 extend in the front-rear direction H0 from the front end of the large diameter portion 39 to near the annular groove 38, and the front end surface of the outer surface protrusion 32 is an extension of the tapered surface that is the front end surface of the reduced diameter portion 13. Note that, for example, the rear end surface of the outer surface protrusion 32 is a stepped surface that rises from the outer peripheral surface of the large diameter portion 39.

[0015] The outer surface (i.e., the protruding tip surface) of the outer surface protrusion 32 has a curved surface that bulges outward. In this embodiment, the outer surface of the outer surface protrusion 32 has an arcuate surface 33 as this curved surface. For example, the arcuate surfaces 33 of the multiple outer surface protrusions 32 are arranged so as to be included in a common imaginary cylindrical surface centered on the central axis J1 (see FIG. 9). In this embodiment, two types of arcuate surfaces 33 are provided: a small-diameter arcuate surface 33A and a large-diameter arcuate surface 33B having a larger diameter (see FIG. 4). The outer surface of the outer surface protrusion 32 is composed of, from the front end, the small-diameter arcuate surface 33A, a stepped surface 32D, and a large-diameter arcuate surface 33B. As a result, the outer diameter of the outer surface of the outer surface protrusion 32 increases from the front side to the rear side of the outer surface protrusion 32. For example, the stepped surface 32D is arranged on an imaginary conical surface centered on the central axis J1.

[0016] 9, in the example of this embodiment, the outer surface protrusions 32 protrude radially outward from the pipe member 80 when viewed from the front, and both side surfaces of the outer surface protrusions 32 are arranged on imaginary planes parallel to the front-rear direction H0 and are parallel to each other. In the example of this embodiment, four outer surface protrusions 32 are provided, and one pair of outer surface protrusions 32 protrudes in opposite directions from each other in a first direction H1 perpendicular to the front-rear direction H0, and another pair of outer surface protrusions 32 protrudes in opposite directions from each other in a second direction H2 perpendicular to both the front-rear direction H0 and the first direction H1.

[0017] In this embodiment, the pipe member 80 is an integrally molded product made of resin (for example, an injection-molded product). The outer surface of the pipe member 80 (i.e., the outer surface protrusions 32 and the annular protrusions 20) have a shape that allows them to be demolded in the first direction H1 or the second direction H2. Therefore, when manufacturing the pipe member 80 by injection molding or the like, the mold for molding the pipe member 80 can be demolded in the first direction H1 or the second direction H2, thereby facilitating the formation of protrusions on the outer peripheral surface of the pipe member 80, such as the outer surface protrusions 32 and the annular protrusions 20. The pipe member 80 may also be made of metal (for example, it may be a machined product or a forged product).

[0018] Next, the components around the pipe member 80 in the joint 10, such as the nut 50 and the cylindrical cover 40, will be described.

[0019] 4, the nut 50 has a configuration in which protrusions 52 protrude forward from an annular nut body 50H having a female threaded hole therethrough. The protrusions 52 may be provided at multiple locations around the circumferential direction of the nut 50, and in this embodiment, the protrusions 52 are arranged at equal intervals around the circumferential direction of the nut 50. A substantially hexagonal protrusion 50F is provided at the rear end of the nut body 50H for rotating the nut 50 with a tool or the like.

[0020] In this embodiment, as shown in FIG. 10(A), the protrusion 52 has a generally arcuate shape when viewed from the front. Also, in this embodiment, as shown in FIG. 11, the protrusion 52 has an inward protrusion 52U that protrudes from the front end surface of the nut body 50H toward the inside of the nut 50, and a front protrusion 52M that extends forward from the inner protrusion tip of the inward protrusion 52U. An engaging protrusion 52T that protrudes toward the inside of the nut 50 is formed at the front protrusion tip of the front protrusion 52M, and this engaging protrusion 52T engages with the annular groove 38 of the pipe member 80. This allows the nut 50 to be rotatably attached to the pipe member 80 and restricts movement of the pipe member 80 in the axial direction. In this state, the inner abutment surface 50M of the nut 50 abuts against the flange 30F of the pipe member 80 from the front side, preventing the nut 50 from slipping off the pipe member 80 toward the rear. In this embodiment, the abutment surface 50M is a stepped surface provided on the rear surface of the inward protrusion 52U (see Figures 10(B) and 11). In this embodiment, the large diameter portion 39 of the pipe member 80 is fitted onto the inner surfaces of the front protrusions 52M of the multiple protrusions 52. The front end of the inner peripheral surface of the nut main body 50H is fitted onto the flange 30F of the pipe member 80. This prevents the nut 50 from rattling in the radial direction of the pipe member 80. When the nut 50 is attached to the pipe member 80, it protrudes rearward beyond the rear end of the pipe member 80.

[0021] A fitting groove 58 extending in the circumferential direction of the nut 50 is formed on the outer surface of the protrusion 52 of the nut 50 (see FIG. 4). More specifically, the fitting groove 58 is formed between a front end projection 53 that projects outward from the front end of the front-side projection 52M of the protrusion 52 and a forward-facing surface 52S of the inner projection 52U that faces the front end projection 53 from behind (see FIG. 11). In this embodiment, the fitting grooves 58 of the multiple protrusions 52 are arranged on the same imaginary circle. As will be described later, the cylindrical cover 40 is fitted into the fitting groove 58.

[0022] 1, an annular packing 88 is sandwiched between the rear end of the pipe member 80 and the end of the piping equipment 99 to seal the gap between them. For example, before the fitting 10 is used (for example, at the time of distribution), the packing 88 may be attached to the fitting 10. In this case, for example, the packing 88 may be placed inside the nut 50 attached to the pipe member 80 from the rear side, and then a cover member may be fitted into the rear end opening of the nut 50 to store the packing 88 so that it does not fall out.

[0023] As shown in FIGS. 2 and 3, the cylindrical cover 40 surrounds the pipe member 80 and has a cylindrical cover main body 40H extending in the front-rear direction H0. The bulging portion 43 bulges from a portion of the circumferential direction of the outer peripheral surface of the cover main body 40H. The bulging portion 43 is disposed on the outer peripheral surface of the cover main body 40H, from the front end to a position near the rear end. 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 this embodiment, the cylindrical cover 40 is made of a transparent resin (e.g., an injection-molded product), but may also be made of an opaque resin. The bulging portion 43 bulges from the cover main body 40H in a direction perpendicular to the front-rear direction H0 (e.g., a first direction H1).

[0024] A cover rear connecting portion 42 is provided on the cover main body 40H rearward of the bulging portion 43, and the cover rear connecting portion 42 is fitted to the outside of the pipe member 80 and the nut 50. Specifically, as shown in FIGS. 1 and 11 , the cover rear connecting portion 42 of the cylindrical cover 40 is fitted to straddle the pipe member 80 and the nut 50 in the front-to-rear direction H0. A rear end projection 40T is formed at the rear end of the cover rear connecting portion 42, projecting inward from the rear end opening of the cylindrical cover 40, and this rear end projection 40T is fitted into the fitting groove portion 58 of the nut 50. In this way, the cylindrical cover 40 is attached to the nut 50, and movement of the cylindrical cover 40 in the front-to-rear direction H0 is restricted.

[0025] As shown in Fig. 9, the inner circumferential surface of the cover rear connecting portion 42 is fitted into the arcuate surface 33 of the outer surface protrusion 32 of the pipe member 80. This allows the cylindrical cover 40 to be supported from the inside by the outer surface protrusion 32, making it possible to reduce rattling of the cylindrical cover 40 in the radial direction of the pipe member 80 and stably support the cylindrical cover 40. Also, as shown in Fig. 1, the inner circumferential surface of the cover rear connecting portion 42 is provided with a stepped surface that abuts from the front against the stepped surface 32D of the outer surface protrusion 32 of the pipe member 80, and the abutment of these stepped surfaces strengthens the positioning of the cylindrical cover 40 in the front-to-rear direction.

[0026] The portion of the cylindrical cover 40 forward of the cover rear connecting portion 42, i.e., the portion including the bulge 43, forms an enclosing portion 41 that encloses the hose connection portion 12. The hose clamp 60 and clip 70 shown in FIG. 1 are housed within the enclosing portion 41. A cap 81 is fitted to the front end of the cylindrical cover 40 to secure the hose clamp 60 and the clip 70 within the enclosing portion 41, and the cap 81 covers the front-end opening of the cylindrical cover 40. A hose insertion hole 81A is disposed coaxially with the pipe member 80 and is formed through the cap 81 for inserting a hose 90 into the cylindrical cover 40. The front end of the hose connection portion 12 is inserted into the hose insertion hole 81A, and a gap is provided between the inner circumferential surface of the hose insertion hole 81A and the outer circumferential surface of the hose connection portion 12 to allow the hose 90 to be inserted. Note that, for example, the front end surface of the hose connection portion 12 and the front end surface of the cap 81 are substantially flush with each other. In this embodiment, the cap 81 is a molded product made of resin, but it may also be made of metal, for example.

[0027] 6, the hose clamp 60 is formed, for example, by rolling a strip of sheet metal 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 in one end of the hose clamp 60, and gripping piece 63B at the other end of the hose clamp 60, which is narrower, is inserted into and protrudes from the through hole 61K, so that both ends of the hose clamp 60 cross each other.

[0028] 3 and 5, 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 end of the upper side (the side where bulging portion 43 bulges) of support base 71 which is placed on the rear side of hose clamp 60. In addition, support base 71 is provided with a pair of pressure-receiving pieces 73 which are spread apart downward so as to straddle hose connection portion 12.

[0029] 1 and 5, 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 81, and is positioned in the front-to-rear direction H0 within the enclosing portion 41 (see FIG. 1).

[0030] When the pair of gripping pieces 63A, 63B are clamped and brought close to each other, the hose clamp 60 undergoes elastic deformation to assume an expanded diameter state. When the hose 90 is not inserted, the clip 70 is positioned so that the pair of gripping pieces 63A, 63B are clamped between the pair of clamping pieces 72, preventing the pair of gripping pieces 63A, 63B from moving apart, thereby maintaining the hose clamp 60 in an expanded diameter state (see FIG. 5). When the hose 90 is inserted between the hose connection portion 12 and the hose clamp 60 through the hose insertion hole 81A and the clip 70 is pressed by the hose 90, the clip 70 disengages from the hose clamp 60, and the clamping pieces 63A, 63B are released from the clamp 60. The hose clamp 60 then elastically returns to its contracted diameter state, clamping the hose 90 and pressing it against the outer surface of the hose connection portion 12 (see FIGS. 6 and 7).

[0031] In more detail, when the hose 90 is inserted as described above, the hose 90 presses the pair of pressed pieces 73 of the clip 70, as shown in the transition from FIG. 8(A) to FIG. 8(B). This causes the clip 70 to rotate around the portions of the pair of clamping pieces 72 that clamp the pair of knobs 63A, 63B as fulcrums, so that the support base 71 faces upward. 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. This causes the pair of clamping pieces 72 to disengage from the pair of knobs 63A, 63B, and the clip 70 is released from the hose clamp 60. In this embodiment, one of the pair of clamping pieces 72 is shorter than the other clamping piece 72, and this shorter clamping piece 72 is disposed on the narrower gripping piece 63B side (see FIG. 5). This makes it possible for the one clamping piece 72 to be easily detached from the narrower gripping piece 63B.

[0032] Thus, with the coupling 10 of this embodiment, by inserting the hose connection portion 12 further into the hose 90, the retention of the hose clamp 60 by the clip 70 is released and the hose clamp 60 contracts in diameter, tightening and fixing the hose 90 to the hose connection portion 12 (see FIG. 7). Therefore, with the coupling 10 of this embodiment, the hose 90 can be easily fixed to the hose connection portion 12 by the hose clamp 60 simply by inserting the hose 90 into the cylindrical cover 40 through the hose insertion hole 81A and inserting the hose connection portion 12 into the hose 90.

[0033] However, after the pipe member 80 is passed through the nut 50, the nut 50 may fall off the pipe member 80 to the front before the joint 10 is used (for example, before the cylindrical cover 40 is attached, etc.). In contrast, in the joint 10 of this embodiment, the outer surface protrusion 32 is formed on the pipe member 80, which makes it possible to prevent the nut 50 from falling off.

[0034] To prevent the nut from falling off the pipe member, it is conceivable to form a retaining protrusion such as outer surface protrusion 32 on the pipe member. However, this can cause a problem in that the retaining protrusion makes it difficult to insert the nut onto the outside of the pipe member from the front. Therefore, for example, it is conceivable to separate the pipe member into two parts, a front part and a rear part (i.e., a rear part with a flange through which the nut is passed, and a front part with a retaining protrusion). After the nut is passed through the rear part, the front part is connected to the rear part, and the retaining protrusion on the front part prevents the nut from falling off to the front. However, in this case, having multiple pipe parts increases the number of parts (e.g., requires sealing members between the two parts) and increases the number of sealing points.

[0035] To address this issue, it is possible to mold the pipe member as a single unit, in which case the height of the retaining projections may be reduced so that the nut can climb over them. However, this may result in a gap being too large between the pipe member and the cylindrical cover 40, making it difficult to support the cylindrical cover 40 from the inside, which may cause the cylindrical cover 40 to rattle.

[0036] To solve these problems, in the joint 10 of this embodiment, the pipe member 80 and the nut 50 are provided with the following characteristic configuration. That is, the nut 50 is formed with a protrusion passage 51 through which the outer surface protrusion 32 of the pipe member 80 can pass when the pipe member 80 is passed through the nut 50 (see FIGS. 4 and 12). Specifically, the protrusion passage 51 is provided in a portion of the nut 50 forward of the position of the abutment surface 50M. In the example of this embodiment, the protrusion passage 51 is disposed between the protrusion pieces 52 and is adjacent to the protrusion pieces 52 in the circumferential direction of the nut 50.

[0037] As shown in Figure 12(A), the outer surface protrusions 32 can pass through the protrusion passages 51 when the nut 50 is positioned at a specific rotational position (hereinafter referred to as the "specific rotational position" where appropriate) relative to the pipe member 80. In the example of the same figure, the nut 50 is positioned at this specific rotational position as many times as there are protrusions 52 during one rotation of the nut 50. For example, in the example of the same figure, four protrusions 52 (i.e., protrusion passages 51) are provided, and the nut 50 is positioned at the specific rotational position four times during one rotation, every 90 degrees.

[0038] When the nut 50 is assembled to the pipe member 80, the rotational position of the nut 50 relative to the pipe member 80 is set to a specific rotational position, and then the nut 50 is inserted from the front side to the outside of the pipe member 80 and passed to the rear side (see FIG. 4). At this time, as described above, the protrusion passage 51 is provided, so that the outer surface protrusions 32 located in the middle portion of the pipe member 80 in the front-to-rear direction H0 through which the nut 50 passes pass by the nut 50, allowing the nut 50 to pass (see FIG. 12(A)). Note that, for example, the shape of the outer surface protrusions 32 when viewed from the front side may be such that they fit into gaps between adjacent protrusion pieces 52 when the nut 50 passes. Furthermore, when the nut 50 passes, the protruding tips of the outer surface protrusions 32 may be positioned close to the inner surface of the nut main body 50H, or the portions of the outer peripheral surface of the pipe member 80 between the outer surface protrusions 32 may be positioned close to the protrusion pieces 52. In the example of this embodiment, the tapered surface at the front end of the reduced diameter portion 13D of the pipe member 80 and the front end surface of the outer surface protrusion 32, which is its extended surface, are formed so as to gradually move toward the rear as they move away from the central axis J1, so that even if the nut 50 hits these surfaces during the above-mentioned passage, it is possible to easily guide the nut 50 toward the rear.

[0039] When the nut 50 is moved further rearward relative to the pipe member 80, it abuts against the flange F and engages with the annular groove 38, thereby being assembled to the pipe member 80. At this time, although movement of the nut 50 in the front-to-rear direction H0 is restricted, rotation relative to the pipe member 80 is possible, and therefore the nut 50 can be placed in a rotation position other than the specific rotation position (hereinafter referred to as the "general rotation position" as appropriate). Then, as shown in FIG. 12(B), when the nut 50 is placed in the general rotation position (for example, when rotated 45 degrees clockwise), the protrusion 52 of the nut 50 faces the outer surface protrusion 32 of the pipe member 80 from behind. In this embodiment, by providing the outer surface protrusions 32, the maximum radius of the outer periphery of the portion of the pipe member 80 excluding the flange 30F (i.e., the maximum distance between the central axis J1 and the protruding tip of the outer surface protrusions 32) is larger than the minimum radius of the inner periphery of the nut 50 (i.e., the minimum distance between the central axis J1 and the protrusion pieces 52). Therefore, when the nut 50 is placed in the normal rotation position, the nut 50 is prevented from slipping off to the front. This makes it possible to prevent the nut 50 from slipping off from the pipe member 80.

[0040] Furthermore, in the normal rotation position, the protrusion 52 of the nut 50 is positioned close to the outer surface protrusion 32 of the pipe member 80 from the rear and butts against it, so even if the nut 50 comes out of the annular groove 38, the flange 30F and the outer surface protrusion 32 can restrict movement of the nut 50 in the fore-and-aft direction H0.

[0041] Furthermore, according to the joint 10 of this embodiment, the protrusions 52 and protrusion passages 51 allow the nut 50 to pass over the outer surface protrusions 32 when the nut 50 is positioned at a specific rotational position, eliminating the need to limit the protruding height of the outer surface protrusions 32 to a height that the nut 50 (specifically, the protrusions 52) can overcome. Therefore, the protruding height of the outer surface protrusions 32 can be set to a height that allows the tubular cover 40 to be supported from the inside, thereby reducing rattling of the tubular cover 40. Furthermore, even for conventional tubular covers used in pipe members in which the protruding height of the retaining protrusions is increased by connecting multiple parts at the front and rear, the joint 10 of this embodiment can prevent excessive gaps from forming between the tubular cover and the outer surface protrusions 32, thereby enhancing the versatility of such tubular covers. Furthermore, because the pipe member 80 is a single-piece molded product, the number of parts can be reduced compared to a case in which the pipe member 80 is made up of multiple parts.

[0042] In the joint 10 of this embodiment, the nut 50 engages with the annular groove 38, which also prevents the nut 50 from falling off. In this embodiment, the protrusions 52 are in a natural, undeformed state when engaged with the annular groove 38 (see FIG. 11 ). Therefore, until the protrusions 52 engage with the annular groove 38, the engaging protrusions 52T abut against the outer peripheral surface of the large diameter portion 39 of the pipe member 80, causing the protrusions 52 to elastically deform outward. Then, when the engaging protrusions 52T of the protrusions 52 fit into the annular groove 38, the protrusions 52 elastically return to their original position inward. Therefore, in order for the engaging protrusions 52T to disengage from the annular groove 38, the protrusions 52 must be elastically deformed outward. This makes it difficult for the engaging protrusions 52T to disengage from the annular groove 38, stabilizing the position of the nut 50 in the front-to-rear direction H0. For example, the nut 50 may be made of resin or metal, but it is preferable if one of the nut 50 and the pipe member 80 is made of resin and the other is made of metal, as this is thought to make it easier to engage the protrusion 52 of the nut 50 with the annular groove 38 of the pipe member 80.

[0043] 3 and 4, once the nut 50 is assembled to the pipe member 80, the cylindrical cover 40 is attached by fitting it from the front into the fitting groove 58 of the nut 50. The hose clamp 60, which is held in an expanded diameter state by the clip 70, is housed in the cylindrical cover 40, and the front end opening of the cylindrical cover 40 is closed with the cap 81. In this manner, the fitting 10 is assembled. According to the fitting 10 of this embodiment, because the pipe member 80 is a one-piece molded product, the number of parts can be reduced compared to when the pipe member 80 is made up of multiple parts, making it possible to easily assemble the fitting 10.

[0044] [Other embodiments] (1) In the above embodiment, the protruding tip of the outer surface protrusion 32 is fitted into the inner surface of the tubular cover 40, and the outer surface protrusion 32 can support the tubular cover 40 from the inside. However, there may be a gap between the outer surface protrusion 32 and the tubular cover 40, and the outer surface protrusion 32 may not be able to support the tubular cover 40 from the inside.

[0045] (2) The cylindrical cover 40, the hose clamp 60, and the clip 70 are not limited to the configurations of the above embodiment. The cylindrical cover 40 does not have to be provided on the joint 10. For example, instead of the cylindrical cover 40, an insulating member or a heat-retaining member may be provided as an outer member surrounding the pipe member 80. The clip 70 does not have to be provided on the joint 10, and the clip 70 and the hose clamp 60 do not have to be provided. In addition, instead of the hose clamp 60, for example, a hose clamp that is tightened with a worm screw, or a hose clamp that maintains its tightened state with a latch structure like a cable tie, may be used.

[0046] (3) In the above embodiment, the front end of the pipe member 80 is connected to the hose 90. However, the front end of the pipe member 80 may be provided with a male or female threaded portion, which may be threadedly connected to the end of another piping device (e.g., a pipe, etc.).

[0047] (4) In the above embodiment, the pipe member 80 is an integrally molded product, but it may be made up of a plurality of connected parts.

[0048] (5) In the above embodiment, the outer surface of the pipe member 80 has a shape that can be punched in the first direction H1 or the second direction H2, but it may have a shape that cannot be punched. In this case, for example, the pipe member 80 may be formed using a 3D printer or the like.

[0049] (6) In the above embodiment, the outer surface of the outer surface protrusion 32 has an arcuate surface. However, the shape of the outer surface protrusion 32 is not limited thereto, and may have, for example, a curved surface other than an arc (for example, a tapered surface, a hemispherical surface, etc.). Even in this case, for example, by providing the outer surface protrusions 32 at multiple locations around the circumference of the pipe member 80, it becomes possible to fit the tips of these multiple outer surface protrusions 32 into the inner surface of an outer member that surrounds the pipe member 80, such as the cylindrical cover 40. Furthermore, in the above embodiment, the curved surfaces of the outer surfaces of the multiple outer surface protrusions 32 are included in a common imaginary cylindrical surface. However, they may be included in a common imaginary conical surface, or may not be included in either a common imaginary cylindrical surface or a common imaginary conical surface.

[0050] (7) In the above embodiment, the outer diameter of the outer surface of the outer protrusion 32 increases from the front side to the rear side, but it does not have to increase and may be constant, for example (i.e., the outer surface of the outer protrusion 32 may be an arcuate surface without a stepped surface 32D). Note that, for example, the outer diameter of the outer surface of the outer protrusion 32 may increase in multiple steps from the front side to the rear side.

[0051] (8) There may be only one outer surface protrusion 32, or a number other than four may be provided. Providing a plurality of outer surface protrusions 32 makes it possible to more stably support the cylindrical cover 40 from the inside. Also, in the above embodiment, the pipe member 80 does not have to be provided with an outer surface protrusion 32. Even in this case, the provision of the annular groove 38 makes it possible to prevent the nut 50 from falling off the pipe member 80 to the front. Also, in the above embodiment, the annular groove 38 does not have to be provided.

[0052] (9) The nut 50 is not limited to the configuration of the above embodiment. The nut 50 may have only one protrusion 52, or a number other than four. In the above embodiment, the nut 50 has the protrusion 52 protruding forward. However, for example, the nut 50 may have a protrusion protruding inward instead of forward, and a protrusion passage 51 circumferentially adjacent to the protrusion. Furthermore, for example, instead of the protrusion 52, a protrusion (e.g., an arc-shaped protrusion) protruding inward from the nut 50 and having a portion of the circumferential portion of the ring removed may be provided, and the protrusion passage 51 may be formed by the removed portion. Furthermore, the outer peripheral surface of the nut body 50 may have a fitting groove 58 into which the cylindrical cover 40 is fitted. In these configurations, the shape and number of the protrusion passages 51 may be designed according to the outer surface protrusions 32 of the pipe member 80.

[0053] (10) The pipe member 80 is not limited to the configuration of the above embodiment. For example, the pipe member 80 may not have the reduced diameter portion 13D.

[0054] <Additional Notes> The following describes the group of features extracted from the above embodiment, highlighting their effects as necessary.

[0055] For example, the following group of features can be considered to have been conceived in response to the problem that "with the above-mentioned conventional couplings, the nut may fall off the pipe member before the coupling is used, and a solution to this problem is desired," in relation to the background art that states, "Conventionally, so-called union couplings have been known in which a nut rotatably engaged on one end of a pipe member is tightened onto another pipe member to connect the pipe members (see, for example, Utility Model Application No. 57-165879 (Figure 1, etc.))." The following group of features can also be considered to have been conceived in response to the problem that "there is a need for the development of a new, unprecedented coupling."

[0056] [Feature 1] a pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass.

[0057] According to feature 1, the outer surface protrusion can prevent the nut from falling off the pipe member.

[0058] [Feature 2] 2. The coupling according to claim 1, further comprising an outer member surrounding the pipe member and supported from the inside by the outer surface protrusion.

[0059] In feature 2, since the outer member is supported from the inside by the outer surface protrusions, it is possible to stabilize the support of the outer member.

[0060] [Feature 3] 2. The joint according to claim 1, wherein the outer surface of the outer protrusion is provided with an arcuate surface into which an outer member that surrounds the pipe member is fitted.

[0061] In feature 3, since the outer member is fitted onto the arcuate surface of the outer surface protrusion, it is possible to stabilize the support of the outer member.

[0062] [Feature 4] 4. The joint according to feature 2 or 3, wherein the nut has a fitting groove into which the outer member is fitted.

[0063] According to the fourth feature, it is possible to stabilize the support of the outer member by the nut.

[0064] [Feature 5] A joint according to any one of Features 1 to 4, wherein the nut is provided with a protrusion that protrudes forward adjacent to the protrusion passage.

[0065] According to the fifth feature, it is possible to allow the outer surface protrusion of the pipe member to pass over the protrusion of the nut.

[0066] [Feature 6] 6. A joint according to Feature 5, wherein an annular groove is formed on the outer circumferential surface of the pipe member, and the protruding piece engages with the flange when the flange is in contact with the contact surface.

[0067] According to feature 6, it is possible to further prevent the nut from falling off the pipe member.

[0068] [Feature 7] a hose connection portion provided at a front end portion of the pipe member and adapted to be inserted into a hose; a hose clamp that fastens the hose to the hose connection portion from the outside; and a clip that clamps a pair of gripping pieces of the hose clamp to elastically deform the hose clamp and maintain the expanded diameter state, and releases the clamping when the hose connection portion is inserted further and pressed against the hose.

[0069] As in Feature 7, the coupling may be connected to a hose.

[0070] [Feature 8] a pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, A joint in which an annular groove is formed on the outer peripheral surface of the pipe member, with which the nut engages when the flange is in contact with the contact surface.

[0071] Although the present 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 also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone. [Explanation of symbols]

[0072] 10 Joints 30F flange 32 External protrusion 32D step surface 33 Arc Surface 38 Annular groove 40 Cylindrical cover 50 nuts 50M Contact surface 51 Protrusion passageway 52 Projection piece 58 Fitting groove 60 Hose clamp 70 clips 80 Pipe members 90 Horse

Claims

1. a pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; an outer member that surrounds the pipe member and is supported from inside by the outer surface protrusion, The nut has a fitting groove formed therein into which the outer member is fitted.

2. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; an outer surface of the outer surface protrusion is provided with an arcuate surface into which an outer member that surrounds the pipe member is fitted; The nut has a fitting groove formed therein into which the outer member is fitted.

3. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; The nut is provided with a protrusion that protrudes forward adjacent to the protrusion passage, A joint in which an annular groove is formed on the outer peripheral surface of the pipe member, with which the protruding piece engages when the flange is in contact with the contact surface.

4. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; a hose connection portion provided at a front end portion of the pipe member and adapted to be inserted into a hose; a hose clamp that fastens the hose to the hose connection portion from the outside; a clip that clamps a pair of gripping pieces of the hose clamp to elastically deform the hose clamp and hold it in an expanded diameter state, and releases the clamping when the hose connection portion is inserted deeper and pressed against the hose.

5. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; A joint including an outer member that surrounds the pipe member forward of the nut and is supported from the inside by the outer surface protrusion.

6. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; The outer surface of the outer protrusion is provided with an arcuate surface into which an outer member that surrounds the pipe member forward of the nut is fitted.

7. A pipe member having a flange at a rear end thereof; a nut inserted from the front side onto the outside of the pipe member and having an abutment surface thereon against which the flange abuts, an outer surface protrusion formed in a middle portion of the pipe member in the front-rear direction through which the nut passes and protruding outward; a protrusion passage formed in a front portion of the nut from the abutment surface, through which the outer surface protrusion can pass; The nut is provided with a protrusion that protrudes forward adjacent to the protrusion passage.

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