JP4841852B2 - Quick connector for tube connection - Google Patents

Description

  The present invention relates to a quick connector used when a flexible tube made of resin, rubber or the like is connected to a mating pipe, and more particularly to a quick connector for connecting a flexible tube for fuel transportation to the mating pipe.

  Conventionally, for transporting fuel, for example, for transporting fuel in a fuel tank to the engine side, a quick connector for connecting a flexible tube made of resin, rubber, or the like to a mating pipe, ie, ( a) a connector main body having a tubular shape as a whole, a socket-like retainer holding portion for inserting a mating pipe on one side in the axial direction, and a tube connecting portion press-fitted into the tube on the other side; (B) The retainer holding part is held in a fixed state in the axial direction, and the engaging part on the inner peripheral side is axially engaged with the engaged part on the outer peripheral surface of the mating pipe to prevent the mating pipe from being removed. And (c) a seal member that is mounted inside the connector main body at the back of the tube connection side of the retainer holding portion and that contacts the outer peripheral surface of the inserted mating pipe to form a seal. And The tube connecting portion has an annular projection which forms a retaining tubes quick connector comprising a plurality of formed at intervals in the axial direction is used bites into the inner surface of the tube.

For example, Patent Document 1 below discloses this type of quick connector.
FIG. 8 specifically shows an example thereof.
In FIG. 8, reference numeral 200 denotes a quick connector for connecting the tube 202 of FIG. 9 to the mating pipe 204, and has a connector main body 206 (made of resin here).
The connector main body 206 has a cylindrical shape as a whole, a socket-like retainer holding portion 208 for inserting the mating pipe 204 on one side in the axial direction, and a tube connecting portion 210 that is press-fitted into the tube 202 on the other side. And a housing 212 between them.

The connector body 206 is provided with an O-ring 214 and a bushing 216 in the inner part of the tube connecting part 210 side of the retainer holding part 208, more specifically, in the housing 212. They are sealed against the surface by contacting them.
The retainer holding portion 208 is provided with an opening-shaped window portion 218, and the front end portion (the left end side in the drawing) of the outer peripheral side frame portion of the window portion 218 has a groove shape in a retainer 222 described later. This is an engaged portion 220 for engagement with the engaging portion 224.

The retainer 222 (here, made of resin) is a member that is separated from the connector main body 206 and is held by the retainer holding portion 208, and is elastically deformable in the radial direction.
The retainer 222 is engaged with the engaged portion 220 of the retainer holding portion 208 in the groove-like engaging portion 224 on the outer peripheral side, and is held in a fixed state in the axial direction by the retainer holding portion 208 by their engaging action. The
The retainer 222 also has an engaging portion 226 on the inner peripheral side made of an engaging claw, and this engaging portion 226 is pivoted to an engaged portion 228 made of an annular protrusion on the outer peripheral surface of the mating pipe 204. The mating pipe 204 inserted in the connector main body 206 is prevented from being pulled out by engaging in the direction.

The retainer 222 is further provided with an inner peripheral cam surface 230 and an outer peripheral cam surface 232 as engagement guides on the inner peripheral surface and the outer peripheral surface.
The inner peripheral cam surface 230 and the outer peripheral cam surface 232 work as follows.
That is, when the mating pipe 204 is inserted in the axial direction with the retainer 222 held by the retainer holding section 208, the inner peripheral cam surface 230 abuts the engaged section 228 of the mating pipe 204 and the insertion guide of the engaged section 228. And the retainer 222 is elastically expanded by a cam action.
When the engaged portion 228 passes through the engaging portion 226, the retainer 222 returns to the reduced diameter state, and the engaging portion 226 is engaged with the engaged portion 228 of the mating pipe 204 in the axial direction.
Here, the mating pipe 204 is prevented from being pulled out from the connector main body 206.

The retainer 222 can be attached to the mating pipe 204 in advance when the mating pipe 204 is inserted. In this case, when the mating pipe 204 is inserted into the connector main body 206, the outer peripheral cam surface 232 of the retainer 222 is retained by the retainer holding portion. The retainer 222 is elastically deformed in the reduced diameter direction by hitting the engaged portion 220 of 208.
When the outer peripheral engaging portion 224 reaches the engaged portion 220 of the retainer holding portion 208, the retainer 222 expands and the engaging portion 224 and the engaged portion 220 are engaged in the axial direction. It will be in the state.

The tube connecting portion 210 has a small diameter with respect to the housing 212. A wall 234 rises perpendicularly outward in the radial direction from the root.
The wall 234 serves to define the extrapolation length of the tube 202 by bringing the tip end surface of the tube 202 into contact therewith.

The tube connecting portion 210 is provided with a plurality of annular protrusions 238-1, 238-2, and 238-3 spaced apart from each other in the axial direction.
These annular protrusions 238-1, 238-2, and 238-3 bite into the inner surface of the tube 202 and prevent it from being removed, and have a sawtooth shape in cross section in which each tip forms an acute angle.
The portions between the annular projections 238-1, 238-2, and 238-3 of the tube connecting portion 210 are flat surfaces 240-1 and 240-2 that are parallel to the axial direction.
Further, the portion between the root of the tube connecting portion 210 and the innermost annular projection 238-3 closest to the root is also a flat surface 240-3 parallel to the axial direction, and further the most distal end side. A portion further on the tip side than the annular protrusion 238-1 is also a flat surface 240-4 parallel to the axial direction.
Here, the flat surfaces 240-1, 240-2, 240-3, and 240-4 have the same diameter.

In this way, flat surfaces 240-1, 240-2 are formed between the annular protrusions 238-1, 238-2, 238-3, and flat surfaces 240-4 having the same diameter at the front end portion and the rear end portion. , 240-3 is formed when the tube connecting portion 210 is press-fitted into the tube 202 and connected, so that the tube connecting portion 210 and the tube 202 can be brought into close contact with each other. This is because the removal force of 202 can be increased.
In detail, the tube 202 extrapolated to the tube connecting portion 210 is bent so that the inner surface thereof is in close contact with the flat surfaces 240-1, 240-2, 240-3, 240-4, and each annular protrusion 238-1 , 238-2, and 238-3 are deepened into the inner surface of the tube 202, and the effect of preventing the tube 202 from coming off is enhanced.
Further, the inner surface of the tube 202 is in close contact with the flat surfaces 240-1, 240-2, 240-3, and 240-4, and the contact area between the tube connecting portion 210 and the inner surface of the tube 202 is increased. The effect of preventing omission increases.

  Reference numeral 242 denotes an O-ring groove having a rectangular cross section, and an O-ring 246 for sealing with the tube 202 is attached thereto as shown in FIG.

  As shown in FIG. 9 (II), the quick connector 200 can be simply installed by press-fitting the tube connecting portion 210 into the tube 202 and inserting the mating pipe 204 into the connector main body 206 from the opposite side. 202 and the partner pipe 204 can be connected.

By the way, in this quick connector 200, there is a problem that stress tends to concentrate on the base portion of the tube connecting portion 210 having a small diameter, and this portion becomes a strong weak point portion.
The connector main body 206 and the tube connecting portion 210 become thicker or thinner depending on the diameter of the tube 202 to be connected. In either case, this problem occurs in common, but in particular, depending on the inner diameter of the tube 202. When the outer diameter of the tube connecting portion 210 is reduced, a large load is applied intensively to the base portion of the tube connecting portion 210. When a bending force or the like is applied from the tube 202 at the time of connecting the tube 202 or after the connection, the tube There is a problem that the connection part 210 may be broken at the base part. In particular, problems tend to occur when the inner diameter of the tube 202 is φ5 or less.
On the other hand, when the total length of the tube connecting portion 210 is longer than the inner diameter of the tube 202, more specifically, when the ratio of the total length of the tube connecting portion 210 to the inner diameter of the tube 202 is 5 or more, particularly 6 or more. There is a similar problem.

Patent Document 2 listed below discloses a tube connecting portion having a base cross-sectional shape having an R shape (arc shape).
However, according to experiments by the present inventors, it has been found that there is a problem that even when the root has such an R shape, the strength of the root portion cannot be sufficiently increased, and the problem of bending cannot be solved.

JP-A-7-71673 JP-A-11-2013355

  The present invention has been made for the purpose of providing a quick connector for tube connection in which the tube connection portion can be made strong and the tube connection portion does not break. is there.

  Thus, the present invention relates to a quick connector for connecting a tube for connecting a small diameter tube having an inner diameter of 5 mm or less, and is a member for connecting a flexible tube to a mating pipe. (A) a connector main body having a tubular shape as a whole, a retainer holding portion for inserting the mating pipe on one side in the axial direction, and a tube connecting portion press-fitted into the tube on the other side; (B) The retainer holding portion is held in a fixed state in the axial direction, and the engaging portion on the inner peripheral side is engaged with the engaged portion on the outer peripheral surface of the inserted mating pipe in the axial direction. A retainer that prevents the pipe from being removed; and (c) a seal mounted in contact with the outer peripheral surface of the inserted mating pipe that is attached to the inside of the connector body at the back of the tube connecting portion with respect to the retainer holding portion. Eggplant seal A quick connector in which a plurality of annular projections that bite into the inner surface of the tube and prevent the tube from being pulled out are formed at intervals in the axial direction. The portion has a ratio L / D of the length L of the tube connecting portion to the inner diameter D of the tube of 5 or more, and is further closest to the root of the tube connecting portion, as far as the tube is concerned. The portion from the annular protrusion of the portion to the root is a tapered surface that gradually increases in diameter toward the root. It is characterized in that the diameter is larger than the outer diameter of the valley between the protrusion and the annular protrusion except for the ring groove for the seal member.

  According to a second aspect of the present invention, in the first aspect, a flat surface parallel to the axial direction is provided between the annular projections in the tube connecting portion, and the innermost portion on the small diameter side of the tapered surface. The diameter on the side of the annular projection is larger than the flat surface.

According to a third aspect of the present invention, in any one of the first and second aspects, a wall that abuts the distal end surface of the tube from the root of the tube connecting portion rises radially outward, and the wall The extrapolated length of the tube is defined .

Effects and effects of the invention

As described above, according to the present invention, the portion extending from the innermost annular projection to the root of the tube connecting portion when viewed from the tube is a tapered surface that gradually increases in diameter toward the root, and the above-mentioned outermost portion of the tapered surface. The diameter on the small-diameter side on the annular projection side in the back is larger than the diameter between the annular projection on the tip side and the annular projection.
In the quick connector of the present invention, the root part from the annular projection at the innermost part of the tube connecting part where stress is most likely to concentrate to the root is generally thick and large diameter, and the thickness and diameter Since it has a shape that gradually increases toward the root, the base part can be made strong, even when a large bending force is applied to the tube connection part through the tube etc. during tube connection work or after tube connection It is possible to effectively prevent the tube connecting portion from being broken at the root portion.

In the present invention, a flat surface parallel to the axial direction is provided between the annular protrusion and the annular protrusion in the tube connecting portion, and the diameter of the innermost annular protrusion on the small diameter side of the tapered surface is The diameter can be made larger than the flat surface (Claim 2).
In this way, by providing a flat surface parallel to the axial direction between the annular protrusions, the tube inner surface extrapolated to the tube connection portion is brought into close contact with the flat surface, and the tube is pulled out more effectively. Can be prevented.

The present invention is particularly applicable to a quick connector in which a wall that abuts the distal end surface of the tube rises radially outward from the root of the tube connecting portion and defines the extrapolation length of the tube at the wall. The effect is great (claim 3).
In the quick connector of this form, stress concentration due to a bending force or the like applied through the tube or the like is likely to occur particularly in the base part of the tube connection part, and by applying the present invention to such a quick connector, It becomes possible to effectively prevent the tube connecting portion from being broken at the portion.

Also in the present invention, the tapered surface, the maximum diameter of the base side of the tube connecting portion, Ru can leave without the diameter substantially the same diameter of the distal end side of the annular projection of the annular projection of the innermost portion.
If the maximum diameter of the tapered surface is larger than the diameter of the annular protrusion on the tip side, the amount of biting into the tube by the annular protrusion on the tip side and the effect of preventing the removal based on this will decrease. .
However, according to the above , such a problem can be avoided.

Also in the present invention, the diameter of the annular projection of the deepest portion, which from Ru can be left without a larger diameter than the diameter of the distal end side of the annular projection.
In this way, by setting the diameter of the innermost annular projection to a large diameter, even when the portion extending from the innermost annular projection to the root of the tube connection portion becomes larger, the innermost portion It is possible to maintain a high amount of biting into the inner surface of the tube by the annular protrusion of the portion and the tube prevention effect due to this.

The diameter of the annular projection of the deepest portion in the present invention, which also can leave no larger in diameter than the maximum diameter of the base side in the radial and the tapered surface of the distal end of the annular projection than further in this case the maximum diameter of the base side of the tapered surface Ru can leave without the diameter substantially the same diameter of the annular projection of the distal end side.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1 to FIG. 3, 12 is a flexible tube (made of resin here) used for fuel transportation, and is used for small vehicles such as minicars and motorcycles, for example.
Here, the inner diameter of the tube 12 is D.
Reference numeral 10 denotes a quick connector for connecting the flexible tube 12 to a metal mating pipe 14.
Here, on the outer peripheral surface of the mating pipe 14, an engaged portion 16 including an annular protrusion is provided at a position near the tip.
In the present invention, the small vehicle means a motorcycle, a motor tricycle, an ATV (All Terrain Vehicle), and the like.

The quick connector 10 has a connector main body 18 (here, made of resin).
The connector main body 18 has a cylindrical shape as a whole, a socket-like retainer holding portion 20 for inserting the mating pipe 14 on one side in the axial direction, and a tube connection press-fitted into the tube 12 on the other side. Part 22 is provided with a housing 24 in the middle.
The housing 24 includes a seal holding portion 24a having a smaller diameter than the retainer holding portion 24 and a pipe support portion 24b having a smaller diameter than the seal holding portion 24a provided on the tube connection portion side.
An O-ring 26 and a bush 28 are attached to the seal holding portion 24a, and sealing is performed by contacting the outer peripheral surface of the mating pipe 14 inserted.

  The retainer holding portion 20 is provided with an opening-shaped window portion 30, and the front end portion (left end side in the figure) of the outer peripheral side frame portion of the window portion 30 is a groove shape in a retainer 34 described later. This is an engaged portion 32 for engagement with an engaging portion (an outer peripheral engaging portion) 36.

The retainer 34 is engaged with the engaged portion 32 of the retainer holding portion 20 at the groove-like engaging portion 36 on the outer peripheral side, and is held in a fixed state in the axial direction by the retainer holding portion 20 by their engaging action. The
The retainer 34 is also provided with an opening-shaped engaging portion (inner peripheral side engaging portion) 38 on the inner peripheral side, and the engaged portion 38 includes an annular protrusion of the mating pipe 14. By fitting the mating portion 16, the mating portion 16 is engaged with the engaged portion 16 in the axial direction to prevent the mating pipe 14 from coming off.

The retainer 34 is further provided with an inner peripheral cam surface 39 and an outer peripheral cam surface 40 as engagement guides on the inner peripheral surface and the outer peripheral surface.
The inner peripheral cam surface 39 and the outer peripheral cam surface 40 work as follows.
That is, when the mating pipe 14 is inserted in the axial direction with the retainer 34 held by the retainer holding section 20, the inner peripheral cam surface 39 hits the engaged part 16 of the mating pipe 14 to form an insertion guide, and the cam The retainer 34 is elastically expanded by the action.
When the engaged portion 16 reaches the engaging portion 38 having the opening shape, the retainer 34 returns from the elastically expanded state to the reduced diameter state, and the engaged portion 38 of the retainer 34 and the mating pipe 14 are engaged. It will be in the state which engaged the joint part 16 in the axial direction.
Here, the mating pipe 14 is secured from the connector body 18.

The retainer 34 can be attached to the mating pipe 14 in advance when the mating pipe 14 is inserted. In this case, when the mating pipe 14 is inserted into the connector main body 18, the outer peripheral cam surface 40 of the retainer 34 is held by the retainer holding portion. 20, hitting the engaged portion 32 to form an insertion guide, and the retainer 34 is elastically deformed in the reduced diameter direction.
When the outer engaging portion 36 reaches the engaged portion 32 of the retainer holding portion 20, the retainer 34 returns from the reduced diameter state to the expanded diameter state, and the engaging portion 36, the engaged portion 32, Is engaged in the axial direction.
The retainer 34 is provided with an operation knob 42 for deforming the retainer 34 in the diameter-reducing direction at the tip (left end in the figure).

Here, the retainer 34 is a resin member, and as a whole, has a C-ring shape that can be elastically deformed in the radial direction as shown in FIG. 3, and is engaged with the connector body 18 from the axial direction. The connector main body 18 is formed with a window portion in which the retainer is movable in the direction perpendicular to the axis, and the retainer is slid from the direction perpendicular to the axis to be engaged by the annular protrusion of the mating pipe 14. A retainer that engages the portion 16 may be used.
As long as the retainer is movable in the direction perpendicular to the axis, a wire or resin having a circular cross section or a rectangle may be formed into a ring shape or a staple shape by bending or molding. It is advantageous.

The tube connecting portion 22 has a small diameter with respect to the housing 24 as shown in detail in FIG.
A wall 44 rises at a right angle outward in the radial direction from the root toward the pipe support 24b.
The wall 44 serves to define the extrapolation length of the tube 12 by bringing the distal end surface of the tube 12 into contact therewith.

In the present embodiment, the tube connecting portion 22 is provided with two annular protrusions 46-1 and 46-2 spaced apart from each other in the axial direction.
Here, the total length of the tube connecting portion is L, and the inner diameter is d0.
These annular projections 46-1 and 46-2 are used to cut into the inner surface of the tube 12 and prevent it from being removed, and have a sawtooth shape in which each tip forms an acute angle.
A flat surface 48-1 parallel to the axial direction is formed in the trough between the annular projections 46-1 and 46-2, and the axial direction is also the same on the tip side from the annular projection 46-1. A flat surface 48-2 parallel to is formed.
Here, the flat surfaces 48-1 and 48-2 have the same outer diameter d1.

  An O-ring groove 50 having a rectangular cross section is provided between the annular protrusions 46-1 and 46-2, and a sealing O-ring 52 is fitted and attached thereto.

In the present embodiment, the annular projection 46-2, that is, the tapered surface 54 where the portion from the innermost annular projection 46-2 to the root of the tube connecting portion 22 as viewed from the tube 12 gradually expands toward the root. It is.
Further, the tapered surface 54 has a diameter d2 on the side of the annular projection 46-2 on the small diameter side that is larger than the diameter d1 of the flat surfaces 48-1 and 48-2.
On the other hand, the diameter d3 on the large diameter side of the tapered surface 54, that is, the diameter d3 on the root side of the tube connecting portion 22, is substantially the same as the diameter of the annular protrusions 46-1 and 46-2.

1 and 2, the quick connector 10 according to this embodiment press-fits the tube connecting portion 22 into the tube 12, and inserts the mating pipe 14 into the connector main body 18 from the retainer holding portion 20 side. Thus, the tube 12 and the mating pipe 14 can be easily connected.
At this time, the annular protrusions 46-1 and 46-2 in the tube connecting portion 22 are in a state of being bitten into the inner surface of the tube 12, and the tube 12 is well removed.
In this connected state, the inner surface of the tube 12 is in close contact with the flat surfaces 48-1 and 48-2 and the tapered surface 54 of the tube connecting portion 22 so that the annular protrusions 46-1 and 46-2 are prevented from coming off. Work effectively.

  According to the quick connector 10 of the present embodiment as described above, the root portion from the innermost annular projection 46-2 to the root of the tube connecting portion 22 where stress is most easily concentrated is generally thick and has a large diameter. In addition, since the thickness and diameter of the tube gradually increase toward the root, the base portion can have high strength, and the tube connecting portion can be connected through the tube 12 during or after the tube 12 is connected. Even when a large bending force or the like is applied to the tube 22, it is possible to effectively prevent the tube connecting portion 22 from being bent at the base portion.

  Further, in this embodiment, since the flat surface 48-1 parallel to the axial direction is provided between the annular protrusion 46-1 and the annular protrusion 46-2, the inner surface of the tube 12 extrapolated to the tube connecting portion 22 is The tube 12 can be prevented from coming off more effectively by being in close contact with the flat surface 48-1.

The following Table 1 shows the strength of the tube connection portion 22 in the quick connector 10 of the present embodiment shown in FIG. 5A, and the strength of the tube connection portion 22A in the quick connector 10A of the comparative example shown in FIG. It is shown in comparison.

In the quick connector 10 of the present embodiment, the (length) L dimension of the tube connecting portion 22 is 16 mm, the d0 dimension is φ2 mm, the d1 dimension is φ3.5 mm, the d2 dimension is φ4.5 mm, and the d3 dimension is φ5 mm (d0 ˜d3, L (see FIG. 4), the resin tube 12 to be connected has an (inner diameter) D dimension of 2.5 (see FIG. 1 for D). Therefore, the length L / D of the tube connecting portion with respect to the inner diameter of the resin tube 12 is 6.4.
On the other hand, the dimension corresponding to d1 in the comparative product was 3.5 mm, and the dimension corresponding to d3 was 5 mm.
In the quick connector 10A of the comparative example, a flat surface 56A is provided between the tapered surface 54A and the annular protrusion 46-2A. The flat surface 56A has an outer diameter of 4.5 mm.

FIG. 6 shows the strength measurement test method.
In this strength measurement test, the tube 12 made of resin is press-fitted to the tube connecting portions 22 and 22A at room temperature (23 ° C.), and the tube 12 is moved downward until the root portions of the tube connecting portions 22 and 22A are broken. While pulling at a constant speed (100 mm / min), the load was measured and the strength was measured.
As shown in Table 1, in this measurement test, the tube connecting portion 22 in the quick connector 10 of the present embodiment has high strength.

FIG. 7 shows another embodiment of the present invention. In this embodiment, the diameter of the annular protrusion 46-2 is made larger than the diameter of the other annular protrusion 46-1.
That is, this is an example in which the projecting height of the annular projection 46-2 at the innermost portion on the side close to the root in the tube connecting portion 22 is made higher than the projecting height of the annular projection 46-1 on the distal end side.
In the embodiment of FIG. 7, a slight R shape (arc shape) is given to the root of the tube connecting portion 22.
By giving such a slight R shape, the tube connecting portion 22 in the quick connector 10 can be further strengthened.
Preferably R is 0.2 to 1.5, more preferably R is 0.5 to 1.2.

  According to the embodiment shown in FIG. 7, since the diameter of the innermost annular protrusion 46-2 is larger than the diameter of the outermost annular protrusion 46-1, the innermost annular protrusion Even when the base portion from 46-2 to the root of the tube connecting portion 22 has a large diameter, the amount of biting into the inner surface of the tube 12 of the innermost annular projection 46-2 and the tube 12 thereby It is possible to maintain a high prevention effect.

  Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention can be configured in various modifications without departing from the spirit of the present invention.

It is sectional drawing which shows the quick connector of one Embodiment of this invention in the connection state with a tube and the other party pipe. It is a figure which shows the quick connector of the embodiment with a tube and the other party pipe in the state decomposed | disassembled into the connector main body and the retainer. It is a perspective view which shows the quick connector of the embodiment with a tube and the other party pipe in the state decomposed | disassembled into the connector main body and the retainer. It is an expanded sectional view of the important section of the embodiment. It is a figure which shows the quick connector of this embodiment used for the intensity | strength measurement of the tube connection part, and the quick connector of a comparative example. It is explanatory drawing of the method of an intensity | strength measurement test. It is a principal part expanded sectional view of other embodiment of this invention. It is a figure which shows an example of the conventional quick connector. It is explanatory drawing which shows a part of procedure of the tube connection by the quick connector of FIG.

DESCRIPTION OF SYMBOLS 10 Quick connector 12 Tube 14 Mating pipe 16 Engagement part 18 Connector main body 20 Retainer holding part 22 Tube connection part 26 O-ring (seal member)
28 Bush (seal member)
32 engaged part 34 retainer 36 engaging part (engagement part on the outer peripheral side)
38 Engagement part (inner peripheral side engagement part)
44 Wall 46-1, 46-2 Annular projection 48-1 Flat surface 54 Tapered surface

Claims (3)

A member for connecting a flexible tube to a mating pipe, (a) having a tubular shape as a whole and having a retainer holding portion for inserting the mating pipe on one side in the axial direction, A connector main body having a tube connection portion press-fitted into the tube, and (b) an engagement portion on the inner peripheral side of the inserted pipe that is held in the axially fixed state by the retainer holding portion. A retainer that engages the engaged portion of the outer peripheral surface in the axial direction and prevents the mating pipe from being removed; and (c) is mounted inside the connector body at the back of the tube connecting portion side of the retainer holding portion. And a sealing member that contacts and seals the outer peripheral surface of the inserted mating pipe, and the tube connecting portion bites into the inner surface of the tube to prevent the tube from being removed. Is axially spaced In the quick connector comprising a plurality of formed by Te,
The tube connecting portion has a ratio L / D of a length L of the tube connecting portion to an inner diameter D of the tube of 5 or more,
Furthermore, the portion from the annular projection at the innermost part viewed from the tube closest to the root of the tube connecting portion to the root is a tapered surface that gradually increases in diameter toward the root, and the tapered surface The diameter of the innermost annular protrusion on the small diameter side is larger than the outer diameter of the valley between the annular protrusion and the annular protrusion except for the ring groove for the seal member. A quick connector for connecting a tube for connecting a small diameter tube having an inner diameter of 5 mm or less.   In Claim 1, the flat surface parallel to an axial direction is provided between the annular projection in the tube connection part, and the diameter of the annular projection side of the innermost part of the taper surface on the small diameter side is provided. A quick connector for connecting a tube, characterized in that the diameter is larger than that of the flat surface. 3. A wall according to claim 1, wherein a wall that abuts the distal end surface of the tube is radially outward from the root of the tube connecting portion, and the extrapolation length of the tube is defined by the wall. Quick connector for tube connection, characterized in that are no to be.

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