CN108626503B

CN108626503B - Hose connecting part

Info

Publication number: CN108626503B
Application number: CN201810161915.9A
Authority: CN
Inventors: 高桥阳一
Original assignee: Nitto Kohki Co Ltd
Current assignee: Nitto Kohki Co Ltd
Priority date: 2017-03-16
Filing date: 2018-02-26
Publication date: 2020-04-21
Anticipated expiration: 2038-02-26
Also published as: TWI657214B; JP6494678B2; JP2018155296A; CN108626503A; TW201835485A

Abstract

Disclosed is a hose connecting member which alleviates stress concentration at an annular groove of a connecting portion to have a greater strength against a force in a lateral direction of the connecting portion. The hose connection member (10) is provided with a first annular groove (31), a second annular groove (32), and a third annular groove (33) formed in a connection section (12). The curvature radius of the curved surface (32b) of the second annular groove (32) is larger than the curvature radius of the curved surface (33b) of the third annular groove (33), and the curvature radius of the curved surface (31b) of the first annular groove (31) is larger than the curvature radius of the curved surface (32b) of the second annular groove (32).

Description

Hose connecting part

Technical Field

The present invention relates to a hose connection member having a connection portion that is inserted into a hose and locks the hose.

Background

As shown in patent document 1, such a hose connection member is provided in the following shape: the outer peripheral surface of the tubular connecting portion inserted into the flexible hose is provided with a plurality of annular grooves, and the tubular connecting portion has an annular edge formed by the annular grooves and a locking surface extending radially inward from the annular edge and facing rearward. More specifically, each of the annular grooves has a front surface extending radially inward from the outer peripheral surface of the connecting portion and facing rearward, and a rear surface inclined radially outward and rearward, and the front surface and the rear surface are connected at an acute angle or are connected via a concavely curved surface. When the connection portion is pressed into the hose from the front end surface side, the connection portion enters the hose while expanding the inner peripheral surface diameter of the hose by the rear surface of each annular groove. When the hose is connected to the connection portion, the inner peripheral surface of the hose is deformed into a shape substantially corresponding to the shape of each annular groove of the connection portion, and the inner peripheral surface of the hose is in a state of protruding into the annular groove. When a force such as pulling the hose off the connection portion acts between the hose connection portion and the hose after connection, the inner peripheral surface of the hose is caught by the front surfaces, and the hose is prevented from being pulled off due to resistance.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 10-68486

Disclosure of Invention

In the conventional hose connection member as described above, for example, when the hose is stretched in a transverse direction with respect to the longitudinal axis of the connection portion and forces in the same direction act on the connection portion, a bending moment acts on the connection portion. Then, stress due to bending moment is concentrated on an acute angle portion between the front end surface and the rear end surface of the annular groove or a curved surface having a small curvature radius, and the connection portion may break at this point as a base point. In particular, since the largest force acts on the annular groove located farthest from the distal end face, stress is most concentrated on the acute angle portion or the curved surface of the annular groove at that position, and in most cases, a crack starts from this point, and the connection portion is broken. In order to prevent such damage, it is conceivable to reduce the inner diameter of the connection portion and to make the thickness of the connection portion thicker. However, this is not preferable because the fluid passage becomes narrow, and the resistance of the fluid flowing through the fluid passage becomes large. Alternatively, the annular groove may be formed to be shallower, but in this case, the front surface for the drop prevention of the hose becomes smaller, and it becomes difficult to form a shape capable of providing a sufficient locking force against the hose, and the hose is likely to drop. Further, it is conceivable to change the material constituting the connection portion to a material having higher strength, but such a change usually leads to an increase in material cost, and when the material is used for a specific application such as a physicochemical device, the usable material is limited to a specific resin, and the material cannot be easily changed.

In view of the above-described problems of the prior art, an object of the present invention is to provide a hose connecting member that alleviates stress concentration in an annular groove of a connecting portion and has a greater strength against a force in a lateral direction of the connecting portion.

That is, the present invention provides a hose connecting member including a tubular connecting portion inserted into a hose and locking the hose, wherein the connecting portion has a front end surface and an outer peripheral surface extending rearward from the front end surface and engaging with an inner peripheral surface of the hose, the outer peripheral surface has a first annular groove and a second annular groove located forward of the first annular groove in a longitudinal axis direction of the connecting portion, and the first annular groove and the second annular groove each have: a front surface for preventing the hose from falling off, extending to the inner side of the radius direction and facing to the rear; a concave curved surface continuing to the front surface; and a rear surface which is continuous with the curved surface and extends rearward, wherein a minimum radius of curvature of the curved surface of the first annular groove is larger than a minimum radius of curvature of the curved surface of the second annular groove.

In this hose connection member, the minimum radius of curvature of the curved surface of the first annular groove, which is farther from the distal end surface of the connection portion, is larger than the minimum radius of curvature of the curved surface of the second annular groove, which is closer to the distal end surface, so that it is possible to alleviate stress concentration on the curved surface of the first annular groove, which causes a large force to act when a bending moment in a lateral direction with respect to the longitudinal axis acts on the connection portion. On the other hand, when the radius of curvature of the curved surface is increased, it is difficult to form the front surface for preventing the tube from falling off in a shape that can obtain a sufficient locking force with respect to the inner peripheral surface of the tube, but the radius of curvature of the curved surface is relatively decreased in the second annular groove in which only a relatively small force acts, so that the front surface can be formed in a shape that can obtain a sufficient locking force. That is, in the hose connecting member, it is possible to: the second annular groove on the front side on which a relatively small force acts reduces the minimum radius of curvature of the bending portion and has a shape such that a sufficient locking force can be obtained on the front surface, thereby preventing the hose from easily falling off, and the first annular groove on the rear side on which a relatively large force acts easily increases the minimum radius of curvature of the bending portion, thereby alleviating stress concentration and improving the strength against the bending moment.

Specifically, the front surface of the first annular groove may extend obliquely rearward.

In addition, the front surface of the first annular groove may be a concave surface continuously continuing to the curved surface of the first annular groove, and a concave surface having a constant radius of curvature may be formed by the front surface of the first annular groove and the curved surface.

With this configuration, the radius of curvature of the curved surface in the first annular groove can be further increased, and stress concentration can be further alleviated.

Preferably, the front surface of the second annular groove may extend substantially at right angles to the longitudinal axis.

With this configuration, the locking force of the front surface of the second annular groove against the inner circumferential surface of the hose can be increased.

Further, the outer peripheral surface may further include a third annular groove located forward of the second annular groove in the direction of the longitudinal axis, the third annular groove including: a front surface for preventing the hose from falling off, extending to the inner side of the radius direction and facing to the rear; a concave curved surface continuing to the front surface; and a rear surface which is continuous with the curved surface and extends rearward, wherein a minimum radius of curvature of the curved portion of the second annular groove is larger than a minimum radius of curvature of the curved portion of the third annular groove.

In this case, the front surface of the third annular groove may extend substantially at right angles to the longitudinal axis.

Specifically, the first annular groove, the second annular groove, and the third annular groove may have substantially the same depth.

More specifically, the hose connection member may include a tubular body portion extending from the connection portion at a substantially right angle to the longitudinal axis, and the hose connection member may be formed in an L shape as a whole.

Hereinafter, embodiments of the hose connecting member according to the present invention will be described with reference to the drawings.

Drawings

Fig. 1 is a sectional view of a hose connecting part according to an embodiment of the present invention.

Fig. 2 is an enlarged sectional view of a coupling portion of the hose coupling part of fig. 1.

Description of the reference numerals

1: hose, 2: inner peripheral surface, 10: hose connecting part, 12: connection portion, 14: main body portion, 16: plug member, 18: seal ring, 20: front end face, 22: outer peripheral surface, 24: fluid passage, 26: inner peripheral surface, 31: first annular groove, 31 a: front face, 31 b: curved surface, 31 c: rear face, 32: second annular groove, 32 a: front face, 32 b: curved surface, 32 c: rear face, 33: third annular groove, 33 a: front face, 33 b: curved surface, 33 c: rear face, 41: first annular edge, 42: second annular edge, 43: third annular edge, L: longitudinal axis, M: a longitudinal axis.

Detailed Description

As shown in fig. 1, a hose connecting part 10 according to an embodiment of the present invention includes: a tubular connecting portion 12 inserted into the flexible hose 1, and a tubular body portion 14 extending from the connecting portion 12 at substantially right angles to a longitudinal axis L of the connecting portion 12; the overall shape is L-shaped. The main body 14 is provided with a plug member 16 rotatably about a longitudinal axis M of the main body 14 in a state sealed by a seal ring 18. A corresponding socket member (not shown) is detachably coupled to the plug member 16. The hose connecting part 10 is entirely formed of resin.

The connection portion 12 has: a front end surface 20 extending rearward from the front end surface 20 and engaging with an outer peripheral surface 22 of the inner peripheral surface 2 of the tube 1; and an inner circumferential surface 26 extending rearward from the front end surface 20 to define the fluid passage 24. As shown in fig. 2, the outer peripheral surface 22 is provided with a first annular groove 31, a second annular groove 32, and a third annular groove 33 in this order from the rear side (left side in the drawing) to the front (right side in the drawing) of the connecting portion 12, and the first to third annular grooves 31 to 33 form a first annular edge 41, a second annular edge 42, and a third annular edge 43.

The third annular groove 33 at the forefront has: a front surface 33a extending at a right angle to the longitudinal axis L radially inward and facing rearward; a concave curved surface 33b continuing to the front surface; and a rear portion surface 33c continuing to the curved surface and extending obliquely rearward and radially outward. Similarly, the second annular groove 32 includes: a front surface 32a extending at a right angle to the longitudinal axis L radially inward and facing rearward; a concave curved surface 32b continuing to the front surface; and a rear portion surface 33c continuing to the curved surface and extending obliquely rearward and radially outward. However, the front surface 32a of the second annular groove 32 extends only to a shallower position than the front surface 33a of the third annular groove 33, and the curvature radius of the curved portion 32b of the second annular groove 32 is formed larger than the curvature radius of the curved portion 33b of the third annular groove 33. The first annular groove 31 also has a front surface 31a, a curved surface 31b, and a rear surface 31c, and the front surface 31a extends continuously to the curved surface 31b while being curved obliquely inward in the radial direction from the outer peripheral surface 22, and forms one concave surface having a constant radius of curvature together with the curved surface 31 b. The radius of curvature of the curved surface 31b of the first annular groove 31 becomes larger than the radius of curvature of the curved surface 32b of the second annular groove 32. The first to third annular grooves 31 to 33 are different in shape and have the same depth.

When the connection portion 12 is pressed into the hose 1, as shown in fig. 1, the following state is achieved: the first to third annular edges 41 to 43 are engaged with the inner peripheral surface 2 of the hose 1, and the inner peripheral surface 2 of the hose 1 protrudes into the first to third annular grooves 31 to 33. When a force is applied in a direction in which the hose 1 is pulled out and removed from the connection portion 12, the first to third annular edges 41 to 43 and the front surfaces 31a to 33a extending from the annular edges engage with the hose 1, and a large resistance is generated in the direction of pulling out and removing. That is, the front surfaces 31a to 33a function as locking surfaces for preventing the hose from falling off. In particular, in the third annular groove 33, a large locking force is generated against the inner circumferential surface 2 of the hose 1 by the front surface 33a extending vertically and long from the acute-angled third annular edge 43. The second annular groove 32 is not as large as the third annular groove 33, but similarly generates a relatively large locking force. In the first annular groove 31, the front surface 31a is also deflected radially outward in the forward direction, but a large locking force cannot be generated. The first to third annular grooves 31 to 33 have different locking forces, but the locking force as a whole is large enough to obtain a sufficient anti-separation effect with respect to the hose 1.

When the hose 1 connected to the connection portion 12 is pulled in the lateral direction with respect to the longitudinal axis L and a force in the lateral direction is applied near the distal end surface 20, a bending moment in the same direction is applied to the connection portion 12. The force generated in the connecting portion 12 by the bending moment becomes substantially larger as it goes away from the front end surface 20 toward the rear. In particular, stress concentrates on a concave portion having a small radius of curvature to apply a large force. In the conventional hose connecting member, since the annular grooves forming the annular edges have the same shape and the front surface and the rear surface are connected to each other via the acute angle portion or the curved surface having a small radius of curvature, a large force acts on the acute angle portion or the curved portion of the annular groove farthest from the front end surface due to stress concentration. Therefore, cracks start from this portion, and the connection portion may be broken. In contrast, in the hose connecting part 10, since the curved surface 31b of the first annular groove 31 farthest from the distal end surface 20 is a concave surface having a relatively large radius of curvature, stress is less likely to concentrate, and the hose connecting part is not broken even with a large bending moment. On the other hand, in the second annular groove 32 and/or the third annular groove 33 on the front side where too large force does not act, the radius of curvature of the

curved surfaces

32b and 33b is reduced to increase the

front surfaces

32a and 33a perpendicular to the longitudinal axis L, thereby obtaining a large locking force against the hose 1 and making the hose 1 less likely to fall off.

In the case of comparing the existing hose connecting part and the hose connecting part 10 in which all the annular grooves are set to the same shape as the third annular groove 33 of the hose connecting part 10, it has been confirmed by a product actually produced that the hose connecting part 10 can endure a larger bending moment. In addition, it was confirmed that even if the inner diameter of the member having the connecting portion is increased and the thickness of the connecting portion is reduced, the member having the connecting portion such as the hose connecting member 10 can still receive a larger bending moment than the conventional hose connecting member. That is, the hose connecting member 10 can have sufficient strength against the bending moment, and the fluid passage 24 can be further increased to reduce the fluid resistance.

The present invention is not limited to the above embodiments, and various modifications can be made. For example, the number of the annular grooves may be 2 or 4 or more. In the above embodiment, the front surface 31a of the first annular groove 31 is formed as a concave surface integral with the curved surface 31b, but the front surface may be formed in another shape such as a surface perpendicular to the longitudinal axis L or a straight inclined surface. In addition, the radius of curvature of the curved surface of each annular groove need not be constant. When the curvature radius of the curved surface differs depending on the location, the minimum curvature radius of the curved surface of the first annular groove is made larger than the minimum curvature radius of the curved surface of the second annular groove. The depth of each annular groove need not be the same, and the rear annular groove may be made shallow to increase the thickness, thereby further increasing the strength against the bending moment. Further, the overall shape of the hose connection member may be a straight shape instead of the L-shape. The present invention is particularly effective in a resin hose connecting part which is difficult to obtain a large strength, but it is needless to say that the present invention can be applied to a metal hose connecting part.

Claims

1. A hose connecting member comprising a tubular connecting portion which is inserted into a hose and locks the hose, wherein,

the connecting part has a front end face and an outer peripheral face extending backward from the front end face and engaged with the inner peripheral face of the hose,

the outer peripheral surface has a first annular groove and a second annular groove located forward of the first annular groove in the direction of the longitudinal axis of the connecting portion,

the first annular groove and the second annular groove each have: a front surface for preventing the hose from falling off, extending to the inner side of the radius direction and facing to the rear; a concave curved surface continuing to the front surface; and a rear surface continuing to the curved surface and extending rearward,

the minimum radius of curvature of the curved surface of the first annular groove is set to be larger than the minimum radius of curvature of the curved surface of the second annular groove.

2. The hose connecting part according to claim 1,

the front surface of the first annular groove extends obliquely rearward.

3. The hose connecting part according to claim 1 or 2,

the front surface of the first annular groove is a concave surface continuously continuing to the curved surface of the first annular groove, and a concave surface having a constant radius of curvature is formed by the front surface of the first annular groove and the curved surface of the first annular groove.

4. The hose connecting part according to claim 1 or 2,

the front face of the second annular groove extends substantially at right angles to the longitudinal axis.

5. The hose connecting part according to claim 1 or 2,

the outer peripheral surface further has a third annular groove located further forward in the direction of the longitudinal axis than the second annular groove,

the third annular groove has: a front surface for preventing the hose from falling off, extending to the inner side of the radius direction and facing to the rear; a concave curved surface continuing to the front surface; and

a rear surface continuing to the curved surface and extending rearward,

a minimum radius of curvature of the curved surface of the second annular groove is set to be larger than a minimum radius of curvature of the curved surface of the third annular groove.

6. A hose connecting part according to claim 5,

the front face of the third annular groove extends substantially at right angles to the longitudinal axis.

7. A hose connecting part according to claim 5,

the first annular groove, the second annular groove, and the third annular groove have substantially the same depth.

8. The hose connecting part according to any one of claims 1 or 2,

the hose connecting member includes a tubular body portion extending from the connecting portion at a substantially right angle with respect to the longitudinal axis, and is formed in an L-shape as a whole.