JP7577621B2 - Hose connection pipe and hose fixing structure - Google Patents

Description

This disclosure relates to a hose connection pipe to which a hose is connected, and a hose fixing structure that fixes the hose and the hose connection pipe.

Conventionally, this type of hose connection pipe is known to have multiple annular locking projections on its outer periphery (see, for example, Patent Document 1).

Patent No. 5516011 (paragraphs [0018] to [0025], Figures 1 and 2)

However, the conventional hose connection pipes described above have a large insertion resistance to the hose, which can make it difficult to connect them to the hose. There is a need to develop technology that allows them to be inserted into a hose with less insertion resistance than before.

The first aspect achieved to solve the above problem is a hose connection pipe that is inserted into the inside of a hose from the front end side and has multiple annular locking projections formed on its outer circumferential surface, each of the annular locking projections has a front slope that narrows in diameter from its tip toward the front end, and the front slope has a different width depending on the circumferential position, and the hose connection pipe is provided with an introduction section with a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the front end side, and the front slope of the annular locking projection intersects with the outer circumferential surface of the introduction section.

FIG. 1 is a side cross-sectional view of a hose joint according to a first embodiment; Exploded view of a hose joint Perspective view of a hose joint (A) A side view of a hose clamp held in an expanded state by a clip, and (B) A side view of the hose clamp released from the clip. Front perspective view of the hose connection pipe Rear perspective view of the hose connection pipe Side cross-sectional view of the nozzle A side view of the nozzle section as seen from the axial direction of the horizontal reference axis. A side view of the nozzle portion as viewed from one side in the axial direction of the vertical reference axis. FIG. 13 is a side view of the nozzle portion as viewed from the other axial direction of the vertical reference axis. Side view of a hose connection pipe with a hose attached 10 is a side view of a hose joint according to a second embodiment; 11 is a side view of a hose joint according to a third embodiment; FIG. 13 is a side cross-sectional view of a hose joint according to a fourth embodiment. 4 is a side view of a hose joint according to another embodiment; 4A, 4B, and 4C are enlarged cross-sectional side views of an annular locking protrusion according to another embodiment.

[First embodiment]
A first embodiment of a hose joint 10 having a hose fixing structure of the present disclosure will be described below with reference to Figures 1 to 11. The hose joint 10 of this embodiment is for connecting a hose 90 and a piping device 99, and is formed by assembling a plurality of parts such as a base sleeve 30, a hose connection pipe 11, and a cylindrical cover 40, as shown in Figure 1. In the following description, the direction parallel to the central axis J1 of the hose joint 10 will be referred to as the "front-rear direction", the tip side of the hose joint 10 (right side in Figure 1) will be referred to simply as the "front side", and the base end side (left side in Figure 1) will be referred to simply as the "rear side".

The base sleeve 30 is made of, for example, metal, has a cylindrical shape extending in the front-rear direction, and has a regular hexagonal flange portion 30F in the axial middle. In addition, a threaded portion 30N is provided on the outer peripheral surface of the base sleeve 30 rearward of the flange portion 30F, and this is screwed into a threaded hole (not shown) of the piping device 99 to connect the hose fitting 10 to the piping device 99.

The outer peripheral surface of the base sleeve 30 forward of the flange portion 30F constitutes the front end connecting portion 31. The front end connecting portion 31 is gradually tapered in diameter from the rear end to the front, with a large diameter portion 31A, a medium diameter portion 31B, and a small diameter portion 31C in that order. An annular protrusion 31T protrudes laterally from the front edge of the outer peripheral surface of the small diameter portion 31C and the medium diameter portion 31B. Furthermore, the portion forward of the small diameter portion 31C constitutes a tapered portion 31D.

The piping device 99 may be any device that has a flow path through which a fluid flows, and may simply be a pipe. The connection between the hose fitting 10 and the piping device 99 does not have to be a screw structure, and may be, for example, a flange connection, a press fit, or other means. The fluid that flows through the hose 90 and the piping device 99 may be a liquid, a gas, or a gas-liquid mixture. Furthermore, the base sleeve 30 may be made of resin.

The hose connection pipe 11 is, for example, a resin injection molded product, and is structured such that the rear end of a pipe that extends straight in the front-rear direction is expanded in diameter to include a rear end connection section 13. The rear end connection section 13 is fitted to a position where the rear end surface overlaps the step surface between the large diameter section 31A and the medium diameter section 31B of the front end connection section 31 described above, and is prevented from coming off the front end connection section 31 by the annular protrusion 31T of the medium diameter section 31B of the front end connection section 31 engaging with the engagement groove 13A formed on the inner surface of the rear end connection section 13. In addition, an O-ring 80 is provided between the small diameter section 31C of the front end connection section 31 and the rear end connection section 13.

The front end of the rear end connecting part 13 is a tapered part 13B that tapers forward. The inner surface of the tapered part 13B is provided with an annular recess 13C that receives the tapered part 31D of the front end connecting part 31. The outer surface of the tapered part 31D abuts against the inner tapered surface of the annular recess 13C, and this abutment and the engagement between the annular protrusion 31T and the engagement groove 13A described above restrict the inclination of the hose connection pipe 11 relative to the base sleeve 30.

The portion of the hose connection pipe 11 in front of the tapered portion 13B is the nozzle portion 12 that is inserted inside the hose 90. The structure of the nozzle portion 12 will be described in detail later. Note that the hose connection pipe 11 in this embodiment is a molded product made of resin, but it may also be a machined or forged metal part. In addition, the hose connection pipe 11 and the base sleeve 30 may be integrated together.

The cylindrical cover 40 is, for example, an injection-molded product of transparent resin, and as shown in FIG. 2, has a structure with a bulging portion 43 that bulges upward in the range from the rear end of the cylindrical body 40H extending in the front-rear direction to the front end. The cylindrical cover 40 may also be made of a non-transparent resin. In the following description, the side of the hose fitting 10 from which the bulging portion 43 protrudes will simply be referred to as the "upper side."

The bulge 43 extends in the front-rear direction with a constant width smaller than the diameter of the cylinder 40H, with a closed rear end and an open front end. The ceiling of the bulge 43 also extends in the front-rear direction with a cross section that bulges outward in an arc shape.

The rear side of the bulge 43 of the cylindrical cover 40 is the rear end connection part 42, which is fitted to the outside of the hose connection pipe 11 as shown in FIG. 1. The rear end surface of the rear end connection part 42 is overlapped with the front surface of the flange part 30F of the base sleeve 30, and the annular protrusion 31T of the large diameter part 31A of the front end connection part 31 is engaged with the engagement groove 42A formed on the inner surface of the rear end connection part 42. The inner peripheral surface of the rear end connection part 42 is overlapped with the outer peripheral surface of the rear end connection part 13 of the hose connection pipe 11, and the stepped surface formed on the inner peripheral surface of the rear end connection part 42 is overlapped from the front side with the stepped surface formed on the outer peripheral surface of the rear end connection part 13 of the hose connection pipe 11, so that the cylindrical cover 40 reinforces the prevention of the hose connection pipe 11 from coming off the base sleeve 30.

The portion of the cylindrical cover 40 forward of the rear end connecting portion 42, i.e., the portion where the bulge 43 is formed, forms the hood portion 41 that surrounds the nozzle portion 12 of the hose connection pipe 11. The hose clamp 60 and clip 70 shown in FIG. 1 are housed within the hood portion 41, and a cap 50 is fitted to the front end of the hood portion 41 to secure them within the hood portion 41.

As shown in FIG. 2, the hose clamp 60 has a ring body 61 made of rolled strip-shaped sheet metal, and a pair of gripping portions 63 that extend outward from both ends of the strip-shaped sheet metal that constitutes the ring body 61. One end of the strip-shaped sheet metal is received in a notch 61K formed in the other end, and both ends of the strip-shaped sheet metal overlap in the circumferential direction. The notch 61K is drilled up to a position near the tip of one of the gripping portions 63, so that one of the gripping portions 63 has a gate-shaped structure. The pair of gripping portions 63 are normally spaced apart and facing each other, and when they are pinched together by a tool (not shown) or the like and brought closer to each other, the ring body 61 elastically deforms to an expanded diameter state. A clip 70 is used to hold the hose clamp 60 in the expanded diameter state.

The clip 70 is made of sheet metal and has a pair of clamping pieces 72 bent forward at a right angle from the upper end of a support base 71 that is placed over the rear surface of the hose clamp 60. The tips of the pair of gripping parts 63 of the hose clamp 60 in the expanded state are placed between the pair of clamping pieces 72 to prevent them from moving away from each other, thereby maintaining the hose clamp 60 in the expanded state as described above. The support base 71 is also provided with a pair of pressure-receiving pieces 73 that are spread apart to straddle the nozzle part 12.

As shown in FIG. 1, the hose clamp 60 is expanded and housed in the hood portion 41 together with the clip 70. The pair of gripping portions 63 of the hose clamp 60 and the upper portion of the clip 70 are housed in the bulging portion 43. The rear surface of the ring body 61 is placed against the stepped surface 44 formed in the hood portion 41.

The cap 50 is a molded resin product, and has a lid portion 51 that covers the front surface of the hood portion 41, and an outer fitting wall 52 that protrudes rearward from the outer edge of the lid portion 51. As shown in FIG. 1, the outer fitting wall 52 is fitted to the outside of the front end portion of the hood portion 41, and the front end surface of the hood portion 41 is butted against the rear surface of the lid portion 51.

An inner fitting wall 53A, which is slightly smaller than the outer fitting wall 52, protrudes from the rear surface of the lid portion 51 and fits inside the hood portion 41. An arch-shaped connecting wall 53C is inserted between the left and right opposing surfaces of the inner fitting wall 53A, and a closed cylindrical tube wall 53 is formed from the connecting wall 53C and a part of the inner fitting wall 53A to fit inside the cylindrical body 40H of the tubular cover 40. The inside of the tube wall 53 forms a hose insertion hole 51A that penetrates the cap 50 in the front-rear direction, and as shown in Figure 3, the front end of the nozzle portion 12 is loosely fitted into the hose insertion hole 51A, and the front end surface of the nozzle portion 12 and the front surface of the cap 50 are arranged approximately flush with each other (see Figure 1).

As shown in FIG. 2, a pair of locking projections 54 (only one of the locking projections 54 is shown in FIG. 2) protrude from both the left and right sides of the cylindrical wall 53, and these locking projections 54 engage with a pair of locking holes 41A formed in the hood portion 41 to prevent the cap 50 from slipping off the hood portion 41. Also, as shown in FIG. 1, the front surface of the ring body 61 is placed against the rear end surface of the cylindrical wall 53, and the hose clamp 60 is positioned in both the front and rear directions within the hood portion 41 by this cylindrical wall 53 and the step surface 44 within the hood portion 41 described above.

The above is an explanation of the configuration of the hose coupling 10 other than the nozzle portion 12. In this hose coupling 10, the hose 90 is inserted from the hose insertion hole 51A to the outside of the nozzle portion 12, and the hose 90 presses the pressed piece 73 of the clip 70, releasing the retention of the expanded diameter state of the hose clamp 60 by the clip 70. Specifically, when the pressed piece 73 is pressed by the hose 90, the clip 70 is rotated upward with the tip end of the pair of clamping pieces 72 that clamp the pair of knobs 63 as a fulcrum, and as shown as a change from FIG. 4(A) to FIG. 4(B), the corner of the upper end of the clip 70 abuts against the inner surface of the hood portion 41, and from there the clip 70 rotates with the corner of the upper end as a fulcrum, and the tip end of the pair of clamping pieces 72 moves downward. As a result, one of the pair of clamping pieces 72 shifts into the notch 61K of the hose clamp 60, one of the gripping parts 63 comes out from between the pair of clamping pieces 72, the hose clamp 60 elastically restores to a reduced diameter state, and the hose 90 is clamped from the outside.

Next, the configuration of the nozzle part 12 in the hose connection pipe 11 will be described in detail. As shown in FIG. 1, a pair of annular locking projections 20A, 20B protrude from the middle part of the outer peripheral surface of the nozzle part 12 in the front-rear direction. Then, as described above, when the nozzle part 12 is inserted into the hose 90 and the hose 90 is fastened from the outside by the clip 70, the annular locking projections 20A, 20B bite into the inner surface of the hose 90, sealing the gap between the nozzle part 12 and the hose 90. The nozzle part 12 also has an introduction part 16 provided in front of the annular locking projections 20A, 20B, and a base end side annular projection 15 formed to protrude rearward from the annular locking projections 20A, 20B. A base part 12S of the nozzle part 12 with a uniform outer diameter is provided between the front and rear of the base end side annular projection 15 and the pair of annular locking projections 20A, 20B.

In the following description, the reference axis that is perpendicular to the central axis J1 (hereinafter simply referred to as "central axis J1") of the hose connection pipe 11 and extends in the vertical direction in Figs. 1 and 5 is referred to as the vertical reference axis J2, and the reference axis that is perpendicular to both the vertical reference axis J2 and the central axis J1 is referred to as the horizontal reference axis J3. In addition, of the pair of annular locking projections 20A, 20B, the parts related to the front annular locking projection 20A are distinguished by adding "A" to the end of the reference number, while the parts related to the rear annular locking projection 20B are distinguished by adding "B" to the end of the reference number.

As shown in Figs. 5 and 6, both annular locking protrusions 20A, 20B are annular and surround the nozzle portion 12, and the width in the direction of the central axis J1 varies depending on the circumferential position. In addition, the annular locking protrusions 20A, 20B are symmetrical with respect to an imaginary reference plane H1 including the central axis J1 and the vertical reference axis J2. Furthermore, as shown in Fig. 7, the cross-sectional shape of the annular locking protrusions 20A, 20B at any position in the circumferential direction is an approximately right-angled triangle, and has front inclined surfaces 21A, 21B that constitute the surfaces facing the front side, and rearward facing surfaces 22A, 22B that constitute the surfaces facing the rear side. The rear end edges 23A, 23B of the front inclined surfaces 21A, 21B and the front end edges 24A, 24B of the front inclined surfaces 21A, 21B are not parallel to each other, and the width of the front inclined surfaces 21A, 21B varies in the circumferential direction.

Here, "rear end edges 23A, 23B of the front inclined surfaces 21A, 21B" refers to a line connecting the tip points that are farthest from the central axis J1 of the hose connection pipe 11 at each circumferential position on the annular locking projections 20A, 20B. In this embodiment, the corners where the front inclined surfaces 21A, 21B and the rearward facing surfaces 22A, 22B of the annular locking projections 20A, 20B intersect are the rear end edges 23A, 23B of the front inclined surfaces 21A, 21B (see FIG. 7). The rear end edges 23A, 23B are the areas that are pressed most strongly when the nozzle portion 12 is inserted into the hose 90.

The "front edge 24A, 24B of the front inclined surface 21A, 21B" refers to the front end of the annular locking projection 20A, 20B, and in this embodiment, refers to the intersection line between the front inclined surface 21A, 21B and the outer circumferential surface of the portion forward of the annular locking projection 20A, 20B (the introduction portion 16 or the base portion 12S) (see FIG. 7). In particular, the front edge 24A is the portion that the tip of the hose 90 first rides up when the nozzle portion 12 is inserted into the hose 90.

Specifically, as shown in FIG. 8, the rear edge 23B of the front inclined surface 21B of the rear annular locking projection 20B is arranged so as to be inclined about an axis parallel to the horizontal reference axis J3 with respect to the central axis J1. Here, of the two positions where the reference plane H1 and the outer peripheral surface of the nozzle portion 12 intersect, if the position below the central axis J1 of the hose connection pipe 11 is defined as the first position and the position above the central axis J1 of the hose connection pipe 11 is defined as the second position, the rear edge 23B is inclined in a direction along the rear imaginary straight line 28B connecting the first position S1 and the second position S2 on the rear edge 23B. The rear imaginary straight line 28B extends forward from the first position S1 toward the second position S2.

On the other hand, the front edge 24B of the front inclined surface 21B of the rear annular locking projection 20B is arranged so as to be inclined in the opposite direction to the rear edge 23B around an axis parallel to the horizontal reference axis J3 with respect to the central axis J1. In other words, the front edge 24B is inclined in a direction along a front imaginary straight line 29B connecting the first position Q1 and the second position Q2 on the front edge 24B, and the front imaginary straight line 29B extends toward the rear as it moves from the first position Q1 to the second position Q2.

The front imaginary straight line 29B and the rear imaginary straight line 28B are arranged so that the width of the front inclined surface 21B gradually narrows from the first position to the second position. Also, the rear end edge 23B and the front end edge 24B are circular with the center on the central axis J1 when viewed in the axial direction of the central axis J1. The rear annular locking protrusion 20B corresponds to the "second annular locking protrusion" in the claims.

As shown in Fig. 8, the rear end edge 23B and the front end edge 24B of the front side inclined surface 21B of the annular locking projection 20B are curved so as to bulge forward between the first position Q1, S1 and the second position Q2, S2 when viewed from the axial direction of the horizontal reference axis J3. As shown in Fig. 9, when viewed from one side in the axial direction of the vertical reference axis J2, the rear end edge 23B is curved so as to bulge slightly forward between two end points away from the central axis J1, while the front end edge 24B is curved so as to bulge rearward between two end points away from the central axis J1. Furthermore, as shown in FIG. 10, when viewed from the other side in the axial direction of the vertical reference axis J2, the rear end edge 23B is curved so that it bulges toward the rear between the two end points away from the central axis J1, while the front end edge 24B is curved so that it bulges slightly toward the front between the two end points away from the central axis J1.

As shown in FIG. 8, the rear edge 23A of the front inclined surface 21A of the front annular locking projection 20A is arranged so as to be inclined in the opposite direction to the rear edge 23B of the annular locking projection 20B around an axis parallel to the horizontal reference axis J3 with respect to the central axis J1. In other words, the rear edge 23A is inclined in a direction along a rear imaginary straight line 28A connecting the first position R1 and the second position R2 on the rear edge 23A, and the rear imaginary straight line 28A extends toward the rear as it moves from the first position R1 toward the second position R2.

The front edge 24A of the front inclined surface 21A of the front annular locking projection 20A is arranged so as to be inclined in the same direction as the rear edge 23A around an axis parallel to the horizontal reference axis J3 with respect to the central axis J1. In other words, the front edge 24A is inclined in a direction along a front imaginary straight line 29A connecting the first position P1 and the second position P2 on the front edge 24A, and the front imaginary straight line 29A also extends rearward from the first position P1 toward the second position P2, similar to the rear imaginary straight line 28A.

However, the front imaginary straight line 29A and the rear imaginary straight line 28A are inclined at different inclination angles around an axis parallel to the horizontal reference axis J3 with respect to the central axis J1, and as a result, the front imaginary straight line 29A and the rear imaginary straight line 28A are arranged so that the width of the front inclined surface 21A gradually increases from the first position to the second position. In addition, the rear end edge 23A and the front end edge 24A of the front inclined surface 21A also have a circular shape centered on the central axis J1 when viewed in the axial direction of the central axis J1. The front annular locking protrusion 20A corresponds to the "first annular locking protrusion" in the claims.

The rear end edge 23A and the front end edge 24A of the front inclined surface 21A of the front annular locking projection 20A are also curved so as to bulge forward between the first position P1, R1 and the second position P2, R2 when viewed from the axial direction of the horizontal reference axis J3, as shown in Fig. 8. Furthermore, when viewed from one side of the vertical reference axis J2, as shown in Fig. 9, the rear end edge 23A and the front end edge 24A are curved so as to bulge slightly backward between two end points away from the central axis J1, and when viewed from the other side of the vertical reference axis J2, as shown in Fig. 10, the rear end edge 23A and the front end edge 24A are curved so as to bulge slightly forward between two end points away from the central axis J1.

The front virtual straight line 29A of the front annular locking protrusion 20A and the front virtual straight line 29B of the rear annular locking protrusion 20B are approximately parallel. The distance between the second positions P2, R2, which are the furthest parts between the rear end edge 23A and the front end edge 24A of the front annular locking protrusion 20A, is slightly larger than the distance between the second positions Q2, S2, which are the closest parts between the rear end edge 23B and the front end edge 24B of the rear annular locking protrusion 20B (see FIG. 9), and the distance between the second positions P1, R1, which are the closest parts between the rear end edge 23A and the front end edge 24A of the front annular locking protrusion 20A, is slightly smaller than the distance between the second positions Q2, S2, which are the closest parts between the rear end edge 23B and the front end edge 24B of the rear annular locking protrusion 20B.

In addition, the rear annular locking protrusion 20B protrudes slightly more from the base portion 12S of the nozzle portion 12 than the front annular locking protrusion 20A. In other words, the outer diameter of the circle of the rear end edge 23B of the rear annular locking protrusion 20B as viewed from the axial direction of the central axis J1 is slightly larger than the outer diameter of the circle of the rear end edge 23A of the front annular locking protrusion 20A as viewed from the axial direction of the central axis J1. Furthermore, the front end edge 24B of the rear annular locking protrusion 20B is the boundary line between the base portion 12S of the nozzle portion 12 and the annular locking protrusion 20B, so the outer diameter of the front end edge 24B is the same as the outer diameter of the base portion 12S of the nozzle portion 12. On the other hand, the front end edge 24A of the front annular locking protrusion 20A is the boundary line with the introduction portion 16 and is larger than the outer diameter of the base portion 12S of the nozzle portion 12.

In addition, the rear surfaces 22A, 22B of both annular locking projections 20A, 20B are parallel to the horizontal reference axis J3. This allows, for example, when injection molding the hose connection pipe 11, to simplify the structure of the mold structure for molding the hose connection pipe 11 with the plane including the central axis J1 and the vertical reference axis J2 as the parting line.

The gradient of the front slopes 21A, 21B of the annular locking projections 20A, 20B is maximum where the widths of the front slopes 21A, 21B are minimum, and minimum where the widths of the front slopes 21A, 21B are maximum. The gradient of the front slope 21A of the front annular locking projection 20A where the width is minimum is, for example, 8° to 13°, and the gradient of the front slope 21A where the width is maximum is, for example, 3° to 8°. On the other hand, the gradient of the front slope 21B of the rear annular locking projection 20B where the width is minimum is, for example, 27° to 32°, and the gradient of the front slope 21B where the width is maximum is, for example, 2° to 7°.

The outer peripheral surface of the introduction section 16 intersects with the front inclined surface 21A of the front annular locking protrusion 20A, and has approximately the same outer diameter as the front end of the front annular locking protrusion 20A, and extends forward from the annular locking protrusion 20A in a straight or tapered shape with a gradient of 0° to 1°. The axial length of the introduction section 16 is longer than the maximum width of either of the annular locking protrusions 20A and 20B, and the entire nozzle section 12, except for the front end of the part that is received in the hose insertion hole 51A, becomes the introduction section 16. The front end of the part of the nozzle section 12 that is received in the hose insertion hole 51A becomes a tapered section 17 that tapers from the introduction section 16. The part of the inner surface of the hose insertion hole 51A that surrounds the introduction section 16 becomes a guide hole section 18 by a cylindrical tube wall 53 provided in the cap 50.

The base-end annular protrusion 15 is in the shape of a ring that surrounds the nozzle portion 12. The cross-sectional shape of the base-end annular protrusion 15 is a substantially right-angled triangle, with the inclined surface 15A of the base-end annular protrusion 15 facing forward. The tip of the base-end annular protrusion 15 is rounded. Furthermore, the outer diameter of the base-end annular protrusion 15 is substantially the same as or slightly larger than the introduction portion 16, and is slightly smaller than the outer diameter of the front annular locking protrusion 20A as viewed in the axial direction of the central axis J1.

This concludes the description of the configuration of the hose fitting 10 of this embodiment. Next, the effects of the hose fitting 10 will be described. As shown in FIG. 1, the hose fitting 10 is first connected to the piping device 99 by screwing the threaded portion 30N into the threaded hole of the piping device 99. In this state, the hose 90 is inserted through the hose insertion hole 51A of the hose fitting 10 to the outside of the hose connection pipe 11.

Specifically, when the hose 90 is inserted onto the outside of the hose connection pipe 11, the introduction section 16, which extends straight and has a substantially uniform outer diameter following the tapered section 17 at the front end of the hose connection pipe 11, enters the hose 90, correcting the hose 90 to a state in which it extends straight on the same axis as the hose connection pipe 11. The hose 90 is also supported from the outside by the guide hole section 18 of the hose insertion hole 51A, correcting it to a state in which it extends straight.

Then, the tip of the hose 90 reaches the front edge 24A of the front inclined surface 21A of the front annular locking protrusion 20A. Here, the front edge 24A is inclined with respect to the axial direction of the central axis J1, which is the direction of insertion into the hose 90, so the tip of the hose 90 first rides up a part of the circumferential direction of the front inclined surface 21A, and the annular locking protrusion 20A gradually enters the hose 90 as the riding position moves in the circumferential direction. In addition, the rear edge 23A of the front inclined surface 21A of the annular locking protrusion 20A is also inclined with respect to the axial direction of the central axis J1, which is the direction of insertion into the hose 90, so the position where the tip of the hose 90 rides up the rear edge 23A of the front inclined surface 21A also moves gradually in the circumferential direction as the annular locking protrusion 20A gradually enters the hose 90.

At this time, with a conventional hose connection pipe, the annular locking protrusion enters the hose 90 all at once from a state where it is evenly abutting the entire tip surface of the hose 90, and a large insertion resistance is applied. However, with the hose connection pipe 11 of this embodiment, the part where the annular locking protrusion 20A is strongly pressed against the hose 90 moves gradually in the circumferential direction as it enters the hose 90, so the insertion resistance is dispersed and smaller than in the past. In addition, the rear end edge 23A of the front inclined surface 21A of the front annular locking protrusion 20A is circular when viewed from the axial direction of the central axis J1, so that when the entire annular locking protrusion 20A enters the hose 90, the entire circumferential direction of the annular locking protrusion 20A is pressed almost evenly against the inner surface of the hose 90, and a high sealing performance is obtained.

The entire front annular locking protrusion 20A enters the hose 90, followed by the rear annular locking protrusion 20B. Here, the front edge 24B and rear edge 23B of the front inclined surface 21B of the rear annular locking protrusion 20B are also inclined with respect to the axial direction of the central axis J1, so that the annular locking protrusion 20B is inserted into the hose 90 with less insertion resistance than before, just like the front annular locking protrusion 20A. Moreover, the rear annular locking protrusion 20B enters the hose 90 more smoothly because the inclination of the front inclined surface 21B at the portion where the front edge 24B is located furthest forward is the smallest. In addition, the rear end edge 23B of the front inclined surface 21B is also circular when viewed in the axial direction of the central axis J1, and is larger in outer diameter than the circle of the rear end edge 23A of the front annular locking protrusion 20A, so that the annular locking protrusion 20B is pressed evenly and strongly against the entire circumference of the hose 90, providing a high level of sealing.

When the hose 90 is further inserted after both annular locking projections 20A, 20B have entered the hose 90, the tip of the hose 90 reaches the base-side annular projection 15. At this time, the hose 90 has already been enlarged by the annular locking projection 20B, which has a larger outer diameter than the base-side annular projection 15, so the base-side annular projection 15 smoothly enters the hose 90. In addition, the tip of the base-side annular projection 15 has an R-shaped surface, so the base-side annular projection 15 also smoothly enters the hose 90 in this respect. The inclination of the hose 90 with respect to the hose connection pipe 11 is regulated by the cooperation of the base-side annular projection 15 and the introduction portion 16 separated from it.

When the base end annular protrusion 15 enters the inside, the hose 90 comes into contact with the pressed piece 73 of the clip 70 as shown in FIG. 4(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 shrinks in diameter and deforms, tightening the hose 90 and fixing it to the hose connection pipe 11 (see FIG. 11). This completes the connection between the hose fitting 10 and the hose 90, and the hose fitting 10 connects the piping equipment 99 and the hose 90.

As described above, in the hose coupling 10 of this embodiment, the rear end edges 23A, 23B of the front inclined surfaces 21A, 21B of the multiple annular locking projections 20A, 20B are inclined with respect to the insertion direction into the hose 90, and this configuration reduces insertion resistance when inserting the hose 90 compared to conventional configurations, making it easier to connect the hose 90. In addition, the inclinations of the rear end edges 23A, 23B of the front inclined surfaces 21A, 21B of both annular locking projections 20A, 20B are in opposite directions to each other, which is highly effective in preventing the hose 90 from rotating relative to the hose connection pipe 11. Furthermore, the rear end edges 23A, 23B of the front inclined surfaces 21A, 21B of both annular locking protrusions 20A, 20B are circular when viewed in the axial direction of the central axis J1, and both annular locking protrusions 20A, 20B are positioned in an area that is entirely surrounded by the hose clamp 60, so that high sealing performance can be obtained by both annular locking protrusions 20A, 20B when the hose clamp 60 is tightened.

In addition, the rear end edges 23A, 23B and the front end edges 24A, 24B of the front inclined surfaces 21A, 21B of each annular locking protrusion 20A, 20B are not parallel to each other, and the gradient of the front inclined surfaces 21A, 21B changes in the circumferential direction. This improves the ease of inserting the hose connection pipe 11 into the hose 90 at the point where the gradient is smallest, and increases the engagement force against the inner surface of the hose 90 at the point where the gradient is largest.

In addition, the direction of inclination of the rear end edge 23A of the front slope 21A of the front annular locking protrusion 20A and the front end edge 24B of the front slope 21B of the rear annular locking protrusion 20B are the same, so the dead space between adjacent annular locking protrusions 20A, 20B can be reduced.

[Second embodiment]
This embodiment is shown in Fig. 12, and differs from the first embodiment only in the shape of the front annular locking projection 20A of the hose connection pipe 11B. The rear end edge 23A of the front inclined surface 21A of the annular locking projection 20A of the hose connection pipe 11B is the same as the annular locking projection 20A of the hose connection pipe 11 of the above embodiment, and the rear imaginary straight line 28A extends rearward from the first position R1 to the second position R2. On the other hand, the front end edge 24A of the front inclined surface 21A of the hose connection pipe 11B extends forward from the first position P1 to the second position P2. That is, in this embodiment, the front annular locking projection 20A has substantially the same shape as the rear annular locking projection 20B rotated 180° around the central axis J1.

According to the configuration of this embodiment, the front annular locking protrusion 20A, like the rear annular locking protrusion 20B, has the smallest slope of the front inclined surface 21A at the portion located at the front end, so that the front annular locking protrusion 20A also smoothly enters the hose 90, just like the rear annular locking protrusion 20B.

[Third embodiment]
This embodiment is shown in Fig. 13, and differs from the first and second embodiments only in the structure of the hose connection pipe 11C. The hose connection pipe 11C does not have the base end side annular protrusion 15 of the hose connection pipe 11B of the second embodiment, and instead has an annular locking protrusion 20C that is rotated 180° around the central axis J1 behind the rear annular locking protrusion 20B.

The number of annular locking protrusions provided on the hose connection pipe 11 is not limited to two or three, but may be four or more.

[Fourth embodiment]
This embodiment is shown in Fig. 14, and has a structure in which a ring 81 is fitted to the nozzle portion 12 of a hose coupling 10A having the same structure as the first embodiment. The ring 81 is made of, for example, foamed resin and has a cylindrical shape. The ring 81 is sized to fit just in the gap between the nozzle portion 12 and the hose insertion hole 51A, and in an unused hose coupling 10, it is arranged at a position straddling the inside of the hose clamp 60 and the inside of the hose insertion hole 51A, supports the hose clamp 60 in a state in which it is centered relative to the nozzle portion 12, and regulates the intrusion of foreign matter from the hose insertion hole 51A. Then, the ring 81 is pushed by the hose 90 inserted into the hose insertion hole 51A and moves, and is crushed between the clip 70 and the hose 90 until the base end side annular protrusion 15 enters the hose 90. When the hose 90 is further inserted from that state, the clip 70 is removed from the knob portion 63 of the hose clamp 60 as in the first embodiment.

[Other embodiments]
(1) In each of the above embodiments, the rear end edges 23A, 23B and the front end edges 24A, 24B of the front side inclined surfaces 21A, 21B of the annular locking projections 20A, 20B have a three-dimensionally curved shape, but the rear end edges 23A, 23B and the front end edges 24A, 24B may have a shape that fits within a two-dimensional plane without being three-dimensionally curved or bent. Also, there may be a mixture of annular locking projections having front side inclined surfaces 21A, 21B with three-dimensionally curved rear end edges 23A, 23B and front end edges 24A, 24B and annular locking projections having front side inclined surfaces 21A, 21B with rear end edges and front end edges that fit within a two-dimensional plane.

(2) In the first embodiment, the hose connection pipe 11 forms part of the hose fitting 10 and is surrounded by the cylindrical cover 40, but the above structure may be applied to a hose connection pipe that is not surrounded by a cylindrical cover and does not form part of a hose fitting. Specifically, the end of a pipe such as a gas pipe or water pipe may be used as a hose connection pipe, and may be provided with a plurality of annular locking projections, as described above. In addition, to secure a hose to the hose connection pipe, for example, a hose clamp that is tightened with a worm screw or a hose clamp that maintains a tightened state with a latch structure like a cable tie may be used.

(3) In the first embodiment, the introduction portion 16 has a larger outer diameter than the base portion 12S of the nozzle portion 12, but the outer diameter of the introduction portion 16 may be the same as that of the base portion 12S. If the outer diameter of the introduction portion 16 is the same as that of the base portion 12S, the base end side annular protrusion 15 may be eliminated, or the base end side annular protrusion 15 may be made to have approximately the same outer diameter as the annular locking protrusion 20B.

(4) In each of the above embodiments, the front end edges 24A, 24B of the front inclined surfaces 21A, 21B of the annular locking projections 20A, 20B have a curved shape that bulges toward the front between the first position and the second position when viewed in the axial direction of the horizontal reference axis J3. However, as shown in FIG. 15, the front end edges 24A, 24B may have a curved shape that bulges toward the rear.

In addition, the rear end edges 23A, 23B of the annular locking projections 20A, 20B may be curved so as to bulge toward the rear between the first position and the second position when viewed in the axial direction of the horizontal reference axis J3.

(5) In each of the above embodiments, the front end edge 24A of the front inclined surface 21A of the front annular locking projection 20A of the hose connection pipe has a front imaginary straight line 29A that is inclined at a different inclination angle relative to the central axis J1 in the same direction as or in the opposite direction to the rear imaginary straight line 28A, but may be perpendicular to the central axis J1.

(6) In the first embodiment, the front end surface of the nozzle 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, as long as the introduction portion 16 is received within the hose insertion hole 51A.

(7) In the first embodiment, the outer diameter of the circle of the rear end edge 23B of the front inclined surface 21B of the rear annular locking protrusion 20B as viewed in the axial direction of the central axis J1 was larger than the outer diameter of the circle of the rear end edge 23A of the front inclined surface 21A of the front annular locking protrusion 20A as viewed in the axial direction of the central axis J1, but they may be the same diameter.

(8) In the first embodiment, the annular locking projections 20A, 20B have corners formed by the intersection of the front inclined surfaces 21A, 21B and the rearward facing surfaces 22A, 22B. However, as shown in FIG. 16A, the corners may be chamfered. In this case, the intersection line between the chamfered surface 21M and the front inclined surfaces 21A, 21B becomes the rear end edge 23T, which is a line connecting the tip points farthest from the central axis J1 of the hose connection pipe 11 at each circumferential position on the annular locking projections 20A, 20B.

16B, the front inclined surfaces 21A, 21B and the rearward surfaces 22A, 22B may be connected by a curved surface 21R. In this case, a line connecting points on the curved surface 21R that are farthest from the central axis J1 of the hose connection pipe 11 in the direction of the central axis J1 in the circumferential direction forms the rear end edge 23U.
《 》

(9) As shown in Fig. 16C, the front inclined surfaces 21A, 21B of the annular locking projections 20A, 20B may be connected to the outer circumferential surface of the portion forward of the front inclined surfaces 21A, 21B (the introduction portion 16 or the base portion 12S) by a curved surface 21K. In this case, the intersection line between the curved surface 21K and the introduction portion 16 or the base portion 12S may be the front edge 24V.
<Additional Notes>
The following describes the group of features extracted from the above embodiment, while indicating effects, etc., as necessary. Note that, in the following, for ease of understanding, the corresponding configurations in the above embodiment are appropriately indicated in parentheses, but the present invention is not limited to the specific configurations indicated in parentheses.

For example, the following features 1 to 18 relate to "a hose connection pipe to which a hose is connected, and a hose fixing structure for fixing the hose and the hose connection pipe," and can be considered to have been made in response to the problem that, in the background art of "a hose connection pipe of this type that has a plurality of annular locking projections on its outer circumferential surface (see, for example, Patent No. 5,516,011 (paragraphs [0018] to [0025], Figures 1 and 2))," "the above-mentioned conventional hose connection pipes have a large resistance to insertion into the hose, making it difficult to connect them to the hose. In response to this, there is a demand for the development of technology that allows insertion into a hose with less insertion resistance than before."

[Feature 1]
A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer peripheral surface forward of the annular locking projection at the front end side of the hose connection pipe, and the front slope of the annular locking projection intersects with the outer peripheral surface of the introduction portion.

In the feature 1, the front side inclined surface of the multiple annular locking projections of the hose connection pipe has a different width depending on the circumferential position. That is, one or both of the front end edge and the rear end edge of the front side inclined surface are inclined with respect to the insertion direction of the hose. Here, in the conventional hose connection pipe, the annular locking projection enters the hose all at once from a state in which it is in contact with the tip of the hose evenly in the entire circumferential direction, whereas in the technology disclosed herein, for example, when the rear end edge of the front side inclined surface is inclined, the part of the tip of the hose against which the annular locking projection is most strongly pressed is not the entire circumferential direction but a part, and the annular locking projection enters the hose while the part being pressed changes in the circumferential direction as the insertion proceeds. Also, when the front end edge of the front side inclined surface is inclined, the part where the tip of the hose first rides up on the front side inclined surface is a part in the circumferential direction, and the annular locking projection 20 enters the hose while the part that rides up changes in the circumferential direction as the insertion proceeds. That is, the insertion resistance when inserting into the hose is reduced compared to the conventional art, making the hose connection work easier. In addition, an introduction portion is provided forward of the front-most annular locking protrusion, which has a cylindrical or tapered outer peripheral surface and with which the front slope of the annular locking protrusion intersects, so that the inclination of the hose relative to the hose connection pipe is regulated by the introduction portion.
[Feature 2]
2. The hose connection pipe according to claim 1, wherein the plurality of annular locking projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connection pipe.

In feature 2, the annular locking projection has a shape that is symmetrical with respect to a reference plane that includes the central axis of the hose connection pipe, so that the hose is less likely to tilt relative to the hose connection pipe when inserted into the hose.

[Feature 3]
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
The hose connection pipe according to feature 2, wherein a front imaginary straight line connecting the first position and the second position at the front end edge of the front side slope and a rear imaginary straight line connecting the first position and the second position at the rear end edge of the front side slope have a positional relationship in which they move away from one of the first position and the second position toward the other.

[Feature 4]
4. The hose connection pipe according to claim 3, wherein the front imaginary straight line extends toward the front side or the rear side as it moves from one of the first position and the second position to the other.

[Feature 5]
5. The hose connection pipe according to claim 3 or 4, wherein the rear imaginary straight line extends toward the front side or the rear side as it moves from one of the first position and the second position to the other.

[Feature 6]
6. A hose connection pipe according to any one of features 3 to 5, wherein the annular locking protrusion includes a first annular locking protrusion in which the front imaginary straight line and the rear imaginary straight line extend toward the same side, either the front side or the rear side, as they move from one of the first position and the second position to the other.

[Feature 7]
7. A hose connection pipe according to any one of features 3 to 6, wherein the annular locking protrusion includes a second annular locking protrusion in which the front imaginary straight line and the rear imaginary straight line extend toward one side and the other side of the front and rear as they move from one of the first position and the second position to the other.

In features 3 to 7, the annular locking projection can enter the hose in such a way that the portion where the tip of the hose first rides up onto the front slope and the portion where it is pressed most strongly move gradually in the circumferential direction, further reducing the insertion resistance when inserting the hose.

[Feature 8]
The hose connection pipe according to any one of features 3 to 7, wherein the annular locking protrusion includes a front annular locking protrusion whose front sloped surface gradually becomes wider from the first position to the second position, and a rear annular locking protrusion arranged rearward of the front annular locking protrusion and whose front sloped surface gradually becomes wider from the second position to the first position.

In feature 8, the width of the front slope of the front annular locking protrusion gradually increases from the first position to the second position, while the width of the front slope of the rear annular locking protrusion gradually increases from the second position to the first position. In other words, the dead space between adjacent annular locking protrusions can be reduced.

[Feature 9]
9. The hose connection pipe according to feature 8, wherein the rear imaginary straight line of the front annular locking protrusion and the rear imaginary straight line of the rear annular locking protrusion extend toward one side and the other side of the front and rear sides as they move from one of the first position and the second position to the other.

In feature 9, the rear virtual straight line of the front annular locking protrusion and the rear virtual straight line of the rear annular locking protrusion extend toward one side of the front and one side of the rear as they move from one of the first position and the second position to the other. This prevents the hose from rotating relative to the hose connection pipe when the hose rotates around the central axis of the hose connection pipe, and prevents the hose connection pipe from coming off the hose.

[Feature 10]
10. The hose connection pipe according to feature 8 or 9, wherein the rear imaginary straight line of the front annular locking protrusion and the front imaginary straight line of the rear annular locking protrusion extend toward the same front or rear side as they move from one of the first position and the second position to the other.

In feature 10, the rear virtual straight line of the front annular locking protrusion and the front virtual straight line of the rear annular locking protrusion extend toward the same front or rear side as they move from one of the first position and the second position to the other, so that the dead space between adjacent annular locking protrusions can be further reduced.

[Feature 11]
A hose connection pipe according to any one of features 3 to 10, wherein when the annular locking protrusion is viewed from a radial direction of the hose connection pipe passing through the first position and a third position 90 degrees away from the second position, the rear end edge of the front inclined surface is curved so as to bulge toward the front side.

Feature 11 makes it difficult for the hose connection pipe to fall off the hose, and improves the sealing between the hose and the hose connection pipe.

[Feature 12]
12. A hose connection pipe according to any one of features 3 to 11, wherein when the annular locking protrusion is viewed from a radial direction of the hose connection pipe passing through the first position and a third position 90 degrees away from the second position, the front end edge of the front inclined surface is curved so as to bulge toward the front.

[Feature 13]
13. The hose connection pipe according to any one of Features 1 to 12, wherein the hose connection pipe is provided with a base-end annular protrusion protruding from an outer peripheral surface of the hose connection pipe rearward of the annular locking protrusion at the rearmost end of the hose connection pipe and having a circular shape with approximately the same outer diameter as the introduction portion.

In feature 13, the inclination of the hose relative to the hose connection pipe is restricted by cooperation between the introduction section and the base end annular protrusion that protrudes rearward from the annular locking protrusion at the rear end of the outer peripheral surface of the hose connection pipe.

[Feature 14]
14. The hose connection pipe according to any one of features 1 to 13, wherein the annular locking projection has a rearward surface that intersects with the front inclined surface at an acute angle and faces rearward.

In feature 14, the annular locking protrusion intersects with the front slope at an acute angle and has a rearward facing surface that faces rearward, making it easier for the annular locking protrusion to bite into the inner surface of the hose, and making it difficult for the hose connection pipe to come off the hose.

[Feature 15]
15. A hose connection pipe according to any one of features 1 to 14, wherein the distance from the central axis of the hose connection pipe to the rear end edge of the front inclined surface is uniform around the entire circumference of the central axis of the hose connection pipe.

In feature 15, the distance from the central axis to the rear edge of the front slope is uniform around the entire circumference of the central axis of the hose connection pipe, so that a substantially uniform contact pressure can be obtained in the circumferential direction, resulting in high sealing performance. In addition, this results in a shape in which the gradient of the front slope changes in the circumferential direction, which has the effect of improving the ease of inserting the hose connection pipe into the hose where the gradient is smallest, and increasing the retaining force against the inner surface of the hose where the gradient is largest.

[Feature 16]
A hose connection pipe according to any one of features 1 to 15;
a ring-shaped hose clamp that surrounds the ring-shaped locking projection from the outside and tightens the hose from the outside to press it against the ring-shaped locking projection.

In feature 16, the hose is clamped from the outside by a hose clamp that surrounds the annular locking protrusion from the outside, and is pressed against the annular locking protrusion, fixing the hose to the hose connection pipe. The annular locking protrusion then bites into the hose, providing a high level of sealing.

[Feature 17]
The hose clamp is configured such that, when not in use, it is elastically deformed to an expanded state and held by the clip, and when in use, it is released from the hold by the clip and elastically returns to its original state to clamp the hose,
a cylindrical cover that surrounds the hose connection pipe 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 passes,
17. The hose fixing structure according to feature 16, wherein the tip of the hose inserted outside the hose connection pipe pushes the clip to release it from the hose clamp.

In feature 17, simply inserting the hose through the hose insertion hole onto the outside of the hose connection pipe causes the hose to push the clip and release it from the hose clamp, and the hose is then secured to the hose connection pipe by the hose clamp.

[Feature 18]
18. The hose fastening structure according to claim 17, wherein the hose insertion hole is provided with a guide hole portion formed of a cylindrical wall surrounding the outside of the introduction portion.

In feature 18, the guide hole portion of the hose insertion hole in the cap also regulates the inclination of the hose relative to the hose connection pipe.

Note that although specific examples of the technology included in the scope of the claims are disclosed in this specification and drawings, 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 separately.

10, 10A Hose joint 11, 11B, 11C Hose connection pipe 15 Base end side annular protrusion 16 Introduction portion 18 Guide hole portion 20A Front side annular locking protrusion (first annular locking protrusion)
20B Rear annular locking protrusion (second annular locking protrusion)
20C Annular locking projection 21A, 21B Front inclined surface 22A, 22B Rear surface 23A, 23B Rear end edge 24A, 24B Front end edge 28A, 28B Rear imaginary straight line 29A, 29B Front imaginary straight line 40 Cylindrical cover 50 Cap 51A Hose insertion hole 60 Hose clamp 70 Clip 90 Hose H1 Reference plane P1, Q1, R1, S1 First position P2, Q2, R2, S2 Second position

Claims (6)

A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion ,
The plurality of annular engaging projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connecting pipe,
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
a front virtual straight line connecting the first position and the second position at a front end edge of the front slope and a rear virtual straight line connecting the first position and the second position at a rear end edge of the front slope have a positional relationship in which one of the first position and the second position moves away from the other,
The front imaginary straight line extends toward the front or rear as it moves from one of the first position and the second position to the other . A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion,
The plurality of annular engaging projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connecting pipe ,
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
a front virtual straight line connecting the first position and the second position at a front end edge of the front slope and a rear virtual straight line connecting the first position and the second position at a rear end edge of the front slope have a positional relationship in which one of the first position and the second position moves away from the other,
The hose connection pipe includes a first annular locking protrusion in which the front imaginary straight line and the rear imaginary straight line extend toward the same side, either the front side or the rear side, as they move from one of the first position and the second position to the other . A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion,
The plurality of annular engaging projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connecting pipe,
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
a front virtual straight line connecting the first position and the second position at a front end edge of the front slope and a rear virtual straight line connecting the first position and the second position at a rear end edge of the front slope have a positional relationship in which one of the first position and the second position moves away from the other,
The hose connection pipe includes a second annular locking protrusion in which the front imaginary straight line and the rear imaginary straight line extend toward one side and the other side of the front and rear as they move from one of the first position and the second position to the other . A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion,
The plurality of annular engaging projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connecting pipe,
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
a front virtual straight line connecting the first position and the second position at a front end edge of the front slope and a rear virtual straight line connecting the first position and the second position at a rear end edge of the front slope have a positional relationship in which one of the first position and the second position moves away from the other,
the annular locking protrusion includes a front annular locking protrusion, the width of the front inclined surface of which gradually increases from the first position to the second position, and a rear annular locking protrusion, the rear annular locking protrusion being disposed rearward of the front annular locking protrusion, the width of the front inclined surface of which gradually increases from the second position to the first position,
a hose connection pipe in which the rear imaginary straight line of the front annular locking protrusion and the front imaginary straight line of the rear annular locking protrusion extend toward the same side, either the front or the rear, as they move from one of the first position and the second position to the other . A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion,
The plurality of annular engaging projections are shaped symmetrically with respect to a reference plane including a central axis of the hose connecting pipe,
When two positions where the reference plane and the outer circumferential surface of the hose connection pipe intersect are defined as a first position and a second position,
a front virtual straight line connecting the first position and the second position at a front end edge of the front slope and a rear virtual straight line connecting the first position and the second position at a rear end edge of the front slope have a positional relationship in which one of the first position and the second position moves away from the other,
When the annular locking protrusion is viewed from a radial direction of the hose connection pipe passing through the first position and a third position that is 90 degrees away from the second position, the front end edge of the front inclined surface of the hose connection pipe is curved so as to bulge toward the front side . A hose connection pipe that is inserted into the inside of a hose from the front end side and has a plurality of annular locking projections formed on its outer circumferential surface,
Each of the annular locking projections has a front inclined surface that decreases in diameter from its tip toward the front end,
The front inclined surface has a width that varies depending on a circumferential position,
The hose connection pipe is provided with an introduction portion having a cylindrical or tapered outer circumferential surface forward of the annular locking projection at the most forward end side, and the front side inclined surface of the annular locking projection intersects with the outer circumferential surface of the introduction portion,
The hose connection pipe is provided with a base end side annular protrusion protruding from an outer peripheral surface of the hose connection pipe rearward of the annular locking protrusion at the rearmost end of the hose connection pipe and having a circular shape with approximately the same outer diameter as the introduction portion .

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