JP6494678B2 - Hose connection member - Google Patents

Description

  The present invention relates to a hose connection member having a connection portion that is inserted into a hose so as to lock the hose.

  This type of hose connecting member is formed by a plurality of annular grooves provided on the outer peripheral surface of a tubular connecting portion inserted into a flexible hose, as shown in Patent Document 1, for example. It has a shape having an annular edge and a locking surface extending inward in the radial direction and facing rearward. More specifically, each annular groove has a front surface that extends inward in the radial direction from the outer peripheral surface of the connection portion and faces rearward, and a rear surface that is inclined rearward toward the outer side in the radial direction. The part surface and the rear surface are continued at an acute angle or via a concave curved surface. When the connecting portion is press-fitted into the hose from the front end surface side, the connecting portion enters the hose while expanding the inner peripheral surface of the hose by the rear surface of each annular groove. When the hose is connected to the connecting portion, the inner peripheral surface of the hose is deformed into a shape that approximately matches the shape of each annular groove of the connecting portion, and the inner peripheral surface of the hose protrudes into the annular groove. If a force that pulls out the hose from the connection part after connection is applied between the hose connection part and the hose, the hose is pulled out by receiving a resistance force by the inner peripheral surface of the hose being locked to each front part surface. Is deterred.

JP-A-10-68486

  In the conventional hose connecting member as described above, for example, when a force in the same direction acts on the connecting portion by pulling the hose laterally with respect to the longitudinal axis of the connecting portion, a bending moment acts on the connecting portion. . As a result, the stress accompanying the bending moment is concentrated at 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 radius of curvature, and the connection portion may be broken with this as a base point. In particular, the greatest force acts on the annular groove located farthest from the front end face, so the stress is concentrated most at the acute angle part or curved surface of the annular groove at this position, and in most cases, cracks enter from here. The connection was broken. In order to prevent such damage, it is conceivable to reduce the inner diameter of the connection portion and increase the wall thickness of the connection portion. However, doing so will unfavorably increase the resistance of the fluid flowing therethrough because the fluid passage becomes narrower. Alternatively, it is conceivable to make the annular groove shallower, but in this case, the front surface for preventing the hose from coming off becomes smaller, and it becomes difficult to obtain a shape that can obtain a sufficient locking force for the hose. It becomes easy to come off. Furthermore, it is conceivable to change the material constituting the connection part to one with higher strength, but such a change usually increases the material cost and is used for a specific application such as a physics and chemistry instrument. The material that can be used is limited to a specific resin, and the material cannot be easily changed.

  Accordingly, in view of the above-described problems of the prior art, the present invention provides a hose connection member that relaxes stress concentration in the annular groove of the connection portion and has greater strength with respect to a lateral force on the connection portion. The purpose is to provide.

That is, the present invention
A hose connection member comprising a tubular connection portion inserted into the hose and adapted to lock the hose,
The connecting portion has a front end surface and an outer peripheral surface that extends rearward from the front end surface and engages an inner peripheral surface of the hose;
The outer peripheral surface has a first annular groove and a second annular groove located in front of the first annular groove in the direction of the longitudinal axis of the connecting portion, and each of the first and second annular grooves is A hose retaining front surface that extends radially inward and faces rearward, a concave curved surface that continues to the front surface, and a rear surface that extends rearward after the curved surface, A hose connection member is provided, wherein a minimum curvature radius of the curved surface of the first annular groove is larger than a minimum curvature radius of the curved surface of the second annular groove.

  In the hose connection member, since the minimum curvature radius of the curved surface of the first annular groove far from the front end surface of the connection portion is larger than the minimum curvature radius of the curved surface of the second annular groove close to the front end surface, The stress concentration on the curved surface of the first annular groove to which a large force acts when a bending moment in the transverse direction with respect to the longitudinal axis acts on the portion can be relaxed. On the other hand, when the radius of curvature of the curved surface is increased, it becomes difficult to make the front surface for hose removal prevention into a shape that can obtain a sufficient locking force with respect to the inner peripheral surface of the hose. In the second annular groove in which only a small force acts, the curvature radius of the curved surface is relatively small, so that the front surface can be shaped to obtain a sufficient locking force. That is, in the hose connecting member, the hose is shaped so that a sufficient locking force can be obtained on the front surface by reducing the minimum radius of curvature of the curved portion in the second annular groove in the front where a relatively small force acts. The strength against bending moment can be reduced by increasing the minimum radius of curvature of the curved portion to alleviate stress concentration in the rear first annular groove where relatively large force tends to act while preventing it from coming off easily. It becomes possible to improve.

  Specifically, the front surface of the first annular groove can extend obliquely toward the rear.

  Further, the front surface of the first annular groove is a concave surface continuously following the curved surface of the first annular groove, and the curvature radius is constant by the front surface and the curved surface of the first annular groove. It is possible to form a concave surface.

  With such a configuration, the radius of curvature of the curved surface in the first annular groove can be increased to further relax the stress concentration.

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

  With such a configuration, it is possible to increase the locking force with respect to the inner peripheral surface of the hose on the front surface of the second annular groove.

  The outer peripheral surface further includes a third annular groove positioned forward in the direction of the longitudinal axis relative to the second annular groove, and the third annular groove extends inward in the radial direction and faces rearward. A hose retaining front surface, a concave curved surface following the front surface, and a rear surface extending rearward after the curved surface, and a minimum curvature of the curved portion of the second annular groove The radius may be larger than the minimum radius of curvature of the curved portion of the third annular groove.

  At this time, the front surface of the third annular groove can extend substantially perpendicular to the longitudinal axis.

  Specifically, the depth of each annular groove can be made substantially the same.

  More specifically, a tubular main body extending from the connecting portion at a substantially right angle to the longitudinal axis can be provided so as to be L-shaped as a whole.

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

It is sectional drawing of the hose connection member which concerns on one Embodiment of this invention. It is an expanded sectional view of the connection part of the hose connection member of FIG.

  As shown in FIG. 1, a hose connection member 10 according to an embodiment of the present invention is connected to a tubular connection portion 12 inserted into a flexible hose 1 and a longitudinal axis L of the connection portion 12. It has a tubular main body portion 14 extending from the connection portion 12 at a substantially right angle, and has an L-shape as a whole. The plug member 16 is attached to the main body 14 so as to be rotatable about the longitudinal axis M of the main body 14 in a state where the plug member 16 is sealed by the seal ring 18. A corresponding socket member (not shown) is detachably connected to the plug member 16. The hose connection member 10 is entirely made of resin.

  The connecting portion 12 includes a front end surface 20, an outer peripheral surface 22 that extends rearward from the front end surface 20 and engages with the inner peripheral surface 2 of the hose 1, and an inner periphery that extends rearward from the front end surface 20 and defines a fluid passage 24. Surface 26. As shown in FIG. 2, the first annular groove 31 and the second annular groove 32 are formed on the outer peripheral surface 22 in order from the rear side (left side in the drawing) to the front (right side in the drawing) of the connection portion 12. , And a third annular groove 33, and a first annular edge 41, a second annular edge 42, and a third annular edge 43 are formed by these first to third annular grooves 31-33.

  The foremost third annular groove 33 extends at a right angle toward the inner side in the radial direction with respect to the longitudinal axis L, and faces the rear surface 33a, the concave curved surface 33b, and the rear surface. And a rear surface 33c extending obliquely outward in the radial direction. Similarly, the second annular groove 32 extends at a right angle toward the inner side in the radial direction with respect to the longitudinal axis L and faces the rear surface 32a, the concave curved surface 32b following the front surface 32a, and further toward the rear. And a rear surface 33c extending obliquely outward in the radial direction. 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 increased. Is larger than the radius of curvature of the curved portion 33 b 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. The front surface 31a extends from the outer peripheral surface 22 while being bent obliquely inward in the radial direction from the outer peripheral surface 22 to the curved surface. Continuing from 31b, a curved surface 31b and a concave surface having a constant radius of curvature are formed. The curvature radius of the curved surface 31 b of the first annular groove 31 is larger than the curvature radius of the curved surface 32 b of the second annular groove 32. The first to third annular grooves 31-33 have different shapes but the same depth.

  When the connecting portion 12 is press-fitted into the hose 1, as shown in FIG. 1, the first to third annular edges 41-43 bite into the inner peripheral surface 2 of the hose 1 and the first to third annular grooves 31-33. In this state, the inner peripheral surface 2 of the hose 1 protrudes. When the hose 1 receives a force in the direction in which the hose 1 is pulled out from the connecting portion 12, the hose 1 is locked by the first to third annular edges 41-43 and the front surfaces 31a-33a extending from the first to third annular edges 41-43. Resistance is generated. That is, each front surface 31a-33a functions as a locking surface for hose removal prevention. In particular, in the third annular groove 33, a large locking force with respect to the inner peripheral surface 2 of the hose 1 is generated by the front surface 33 a extending vertically from the acute third annular edge 43. In the second annular groove 32, a relatively large locking force is generated in the same manner, although not as much as the third annular groove 33. In the first annular groove 31, the front surface 31 a may be inclined radially outward toward the front, so that a large locking force cannot be generated. Although the locking forces in the first to third annular grooves 31-33 are different from each other, the locking force is large enough to obtain a sufficient retaining effect on the hose 1 as a whole.

  When the hose 1 connected to the connecting portion 12 is pulled in the lateral direction with respect to the longitudinal axis L and a lateral force is applied in the vicinity of the front end face 20, a bending moment in the same direction is applied to the connecting portion 12. Works. The force generated in the connecting portion 12 by this bending moment basically increases as the distance from the front end face 20 increases rearward. In particular, stress concentrates on a concave surface portion having a small curvature radius, and a large force acts. In the conventional hose connection member, the annular groove forming the annular edge has the same shape, and the front surface and the rear surface thereof continue through an acute angle portion or a curved surface having a small curvature radius. A large force acts on the acute angle portion or the curved portion in the annular groove farthest from the front end surface due to the stress concentration. Therefore, a crack may enter from that part and the connection part may be damaged. On the other hand, in the hose connection member 10, the curved surface 31 b in the first annular groove 31 farthest from the front end surface 20 is a concave surface having a relatively large curvature radius, so that stress is less likely to concentrate and is larger. It is designed not to break against bending moments. On the other hand, in the second annular groove 32 and the third annular groove 33 on the front side where a very large force does not act, the front surface perpendicular to the longitudinal axis L can be obtained by reducing the curvature radius of the curved surfaces 32b and 33b. 32a and 33a can be taken large so that a large locking force with respect to the hose 1 can be obtained so that the hose 1 does not come off easily.

  When the conventional hose connection member in which all the annular grooves have the same shape as the third annular groove 33 of the hose connection member 10 and the hose connection member 10 are compared, the hose connection member 10 is more It has already been confirmed by actual products that it can withstand larger bending moments. In addition, in the case of having a connecting portion such as the hose connecting member 10, even if the inner diameter is increased and the wall thickness of the connecting portion is reduced, the hose connecting member 10 still withstands a larger bending moment than the conventional hose connecting member. It is also confirmed that. That is, in the hose connection member 10, it is possible to make the fluid passage 24 larger and reduce the fluid resistance while providing sufficient strength against the bending moment.

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, the number of annular grooves may be two, or four or more. In the above embodiment, the front surface 31a of the first annular groove 31 is a concave surface integrated with the curved surface 31b. However, the front surface is a surface perpendicular to the longitudinal axis L or straight. Other shapes are possible, such as an inclined surface. Moreover, the curvature radius of the curved surface in each annular groove does not need to be constant. When the radius of curvature of the curved surface differs depending on the location, 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. The depth of each annular groove is not necessarily the same, and the strength against the bending moment may be further increased by increasing the wall thickness by making the rear annular groove shallow. Furthermore, the entire shape of the hose connecting member may be a straight shape instead of an L shape. The present invention is particularly effective in a resinous hose connection member that is difficult to obtain a large strength, but can naturally be applied to a metal hose connection member.

Hose 1; inner peripheral surface 2;
Hose connecting member 10; connecting portion 12; body portion 14; plug member 16; seal ring 18; front end surface 20; outer peripheral surface 22; fluid passage 24; inner peripheral surface 26; first annular groove 31; Rear surface 31c; second annular groove 32; front surface 32a; curved surface 32b; rear surface 32c; third annular groove 33; front surface 33a; curved surface 33b; A second annular edge 42; a third annular edge 43;
Longitudinal axis L; longitudinal axis M;

Claims (8)

A hose connection member comprising a tubular connection portion inserted into the hose and adapted to lock the hose,
The connecting portion has a front end surface and an outer peripheral surface that extends rearward from the front end surface and engages an inner peripheral surface of the hose;
The outer peripheral surface has a first annular groove and a second annular groove located in front of the first annular groove in the direction of the longitudinal axis of the connecting portion, and each of the first and second annular grooves is A hose retaining front surface that extends radially inward and faces rearward, a concave curved surface that continues to the front surface, and a rear surface that extends rearward after the curved surface, A hose connecting member, wherein a minimum curvature radius of the curved surface of the first annular groove is larger than a minimum curvature radius of the curved surface of the second annular groove.   The hose connection member according to claim 1, wherein the front surface of the first annular groove extends obliquely toward the rear.   The front surface of the first annular groove is a concave surface that continues to the curved surface of the first annular groove, and the concave surface having a constant curvature radius by the front surface and the curved surface of the first annular groove. The hose connection member according to claim 1, wherein the hose connection member is formed.   The hose connection member according to any one of claims 1 to 3, wherein the front surface of the second annular groove extends substantially at right angles to the longitudinal axis.   The hose that the outer peripheral surface further has a third annular groove positioned forward in the direction of the longitudinal axis than the second annular groove, and the third annular groove extends radially inward and faces the rear. A front surface for retaining, a concave curved surface that follows the front surface, and a rear surface that extends rearward after the curved surface, and a minimum radius of curvature of the curved portion of the second annular groove is The hose connection member according to any one of claims 1 to 4, wherein the hose connection member is configured to be larger than a minimum radius of curvature of the curved portion of the third annular groove.   The hose connection member according to claim 5, wherein the front surface of the third annular groove extends substantially perpendicular to the longitudinal axis.   The hose connecting member according to any one of claims 1 to 6, wherein each annular groove has substantially the same depth. The hose connection member according to any one of claims 1 to 7, comprising a tubular main body portion extending substantially perpendicularly to the longitudinal axis from the connection portion and having an L shape as a whole.

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