JP2939613B2 - Pipe fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for connecting pipes such as hoses and tubes.

[0002]

2. Description of the Related Art Conventionally, pipe joints for connecting pipes have been known.

[0003] As shown in Figs.
When the inserted pipe 30 moves integrally in the direction of the pipe insertion end in a state where the inserted pipe 30 is clamped between the holding cylinder 31 and the reciprocating thin cylinder 32,
The outer peripheral surface of the holding cylinder 31 comes into contact with the inner peripheral tapered surface 33 that accommodates them, and a pressing force in the radial direction is exerted on the pipe 30, whereby the pipe 30 is held by the pipe joint.

[0004] The holding cylinder 31 has a pipe insertion end on the side of the pipe 30.
The diameter of the pipe 30 is slightly larger than the outer circumference of the pipe 30 so that the pipe 30 can be easily inserted.The end of the holding cylinder 31 is slightly smaller than the outer circumference of the pipe 30 so that the pipe 30 is held in the inserted state. First, a holding force is generated at the end of the cylinder 31.

However, when the pipe 30 is inserted into the pipe joint, the end of the holding cylinder 31 which is slightly smaller in diameter than the outer circumference of the pipe 30 is deformed at a larger rate than the insertion end of the holding cylinder 31.・ It can be expanded. Since the end side of the holding cylinder 31 deformed and expanded at a large ratio comes into contact with the inner peripheral taper surface 33 more strongly than the insertion end side of the holding cylinder 31,
The pressing force on the pipe 30 generated on the insertion end side of the holding cylinder 31 is relatively weaker than that on the end side of the holding cylinder 31, so that there is a problem that the pipe 30 may easily come off from the pipe joint.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
An object of the present invention is to provide a pipe joint in which a pipe is harder to pull out than before.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

In the pipe joint according to the present invention, the outer peripheral surface of the holding cylinder becomes a plane substantially parallel to the inner peripheral taper surface for accommodating the pipe when the pipe is inserted between the advance / retreat thin cylinder and the holding cylinder,
When the inserted pipe moves in the direction of the pipe insertion end in a state where the pipe is pinched by the advance / retreat thin cylinder and the holding cylinder, almost the entire outer peripheral surface of the holding cylinder comes into contact with the inner peripheral taper surface, and the So that the pressing force in the diameter reducing direction is applied almost uniformly, and the inner diameter of the holding cylinder at the pipe insertion end side is larger than the outer circumference of the pipe.
It has a slightly larger diameter and is
The diameter is formed to be slightly smaller than the outer circumference of the pipe .

According to the pipe joint of the present invention, the outer peripheral surface of the holding cylinder is substantially parallel to the inner peripheral taper surface for accommodating the pipe in a state where the pipe is inserted between the advance / retreat thin tube and the holding cylinder. Becomes Then, when the inserted pipe moves in the direction of the pipe insertion end in a state where the inserted pipe is pinched by the advance / retreat thin cylinder and the holding cylinder,
Almost the entire outer peripheral surface of the holding cylinder comes into contact with the inner peripheral tapered surface.
In other words, since almost the entire outer peripheral surface of the holding cylinder comes into contact with the inner peripheral tapered surface, the pressing force in the radially-reducing direction is applied substantially uniformly to the pipe, so that the pipe is less likely to come off from the pipe joint than before.

If the inner diameter of the end of the holding cylinder on the side of the pipe insertion port is set slightly larger than the outer diameter of the pipe to be connected, it is very easy to introduce the pipe when inserting the pipe into the holding cylinder.

The outer diameter of the end of the holding cylinder on the side of the pipe insertion port is slightly smaller than the inner diameter of the inner peripheral taper surface at a position corresponding to the end of the holding cylinder on the side of the pipe insertion port in the axial direction when the end of the holding cylinder is located. It can also be set to a small diameter.

As described above, the outer diameter of the end of the holding tube on the side of the pipe insertion port is set such that the outer diameter of the inner peripheral taper surface at the position corresponding to the end of the side of the pipe insertion port in the axial direction when the holding tube is located at the end portion When the diameter is set to be slightly smaller than the inner diameter, the end of the holding cylinder on the side of the pipe insertion port has little room for displacement in the circumferential direction and is hardly eccentric, so that the holding cylinder does not shift in the circumferential direction and it is very easy to insert the pipe.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) As shown in FIGS. 1 to 4, the pipe joint of this embodiment is a joint end portion between a joint body 3 in which a socket 2 is crimped to a nipple 1 and joined, and a socket 2 of the nipple 1. It comprises an advance / retreat thin tube 4 inserted so as to be slidable in a certain range with respect to the vicinity, and a holding tube 5 interposed between the joint body 3 and the advance / retreat thin tube 4 so as to be able to advance and retreat.

The distal end of the socket 2 serves as a pipe insertion port, from which the pipe 6 is inserted into a pipe joint. The socket 2 has an inner peripheral taper surface 7 whose inner diameter decreases from the coupling end side with the nipple 1 toward the pipe insertion port side.
Is formed.

The advancing / retreating thin cylinder 4 is for externally fitting the pipe 6 inserted from the pipe insertion port. The sealing member 8 is provided around the pipe to secure airtightness and increase the frictional engagement force with the pipe 6. Is provided with a circumferential engaging groove 9. At the end where the pipe 6 is inserted, a step 10 is formed.

A pressing ring 11 is fitted in the terminal step 10. When the advance / retreat thin tube 4 moves in the pull-out direction, the step 10
, The pipe 6 and the holding cylinder 5 are pressed via the pressing ring 11.
In other words, the pipe 6 and the holding cylinder 5
Is forcibly moved in the exit direction.

As shown in FIG. 4, a plurality of circumferential locking claws 12 are provided on the inner peripheral surface of the holding cylinder 5 so that a large frictional engaging force acts in the direction in which the pipe 6 comes off. Also, slits 13 are provided alternately from both the forward and reverse directions with respect to the axis, so that when a pressing force is applied inward in the radial direction, the diameter is reduced more easily. The holding cylinder 5 can be made, for example, by injection molding of a synthetic resin.

The holding cylinder 5 is formed of an elastic member having a large coefficient of static friction in a cylindrical shape, and its inner periphery is inclined so that the inner diameter decreases from the pipe insertion port toward the terminal end. The inner diameter of the holding cylinder 5 on the pipe insertion end side is formed slightly larger than the outer circumference of the pipe 6, and the inner diameter on the terminal side of the holding cylinder 5 is formed slightly smaller than the outer circumference of the pipe 6.

In a state where the pipe 6 is inserted between the advance / retreat thin tube 4 and the holding tube 5, the outer peripheral surface of the holding tube 5 becomes a surface substantially parallel to the inner peripheral taper surface 7 for accommodating them. Thus, the angle θ between the inner peripheral surface and the outer peripheral surface of the holding cylinder 5 is set (see FIG. 1). Thereby, when the inserted pipe 6 is moved in the direction of the pipe insertion end in a state where it is clamped by the advance / retreat thin tube 4 and the holding tube 5, almost the entire outer peripheral surface of the holding tube 5 becomes the inner peripheral tapered surface 7. The contact makes it possible to apply a substantially uniform pressing force in the diameter reducing direction to the pipe 6.

Next, the use state of the pipe joint of this embodiment will be described.

The inserted pipe 6 is composed of a holding cylinder 5 and a reciprocating thin cylinder 4.
When they are integrally moved in the direction of the insertion end of the pipe while being pinched between them, the outer peripheral surface of the holding cylinder 5 comes into contact with the inner peripheral tapered surface 7 that accommodates them, and the pipe 6 is pushed in the radial direction. Pressure is exerted, which causes the pipe 6 to be held in the fitting.

More specifically, when a fluid pressure is applied to this pipe joint, the pipe 6 moves integrally with the pressing ring 11, the reciprocating thin cylinder 4 and the holding cylinder 5 in the pull-out direction, and the outer peripheral surface of the holding cylinder 5 is a socket. 2 is in contact with the inner peripheral tapered surface 7. The inner peripheral tapered surface 7 of the socket 2 is formed so that its inner diameter decreases from the coupling end side with the nipple 1 toward the pipe insertion port side. 2 receives a pressing force in the diameter reducing direction from the inner peripheral tapered surface 7. The pipe 6, whose inner surface is regulated by the reciprocating thin cylinder 4, receives a pressing force in the diameter-reducing direction by the holding cylinder 5 as it moves, and a frictional engagement force with the pipe 6 is generated by the pressing force from the holding cylinder 5. work.

By the way, in this pipe joint, when the pipe 6 is inserted between the advance / retreat thin tube 4 and the holding tube 5, the outer peripheral surface of the holding tube 5 is substantially in contact with the inner peripheral taper surface 7 for accommodating them. It is configured to be parallel surfaces. Therefore, when the inserted pipe 6 moves toward the pipe insertion end in a state where the inserted pipe 6 is sandwiched between the advance / retreat thin cylinder 4 and the holding cylinder 5, almost the entire outer peripheral surface of the holding cylinder 5 comes into contact with the inner peripheral tapered surface 7. The pressing force is applied in a state where the pipes 6 are in contact with each other, and the pressing force is applied more uniformly in the diameter reducing direction to the pipe 6 by contacting each other on the entire surface instead of locally as in the related art. So plumbing 6
Is held with a substantially uniform pressing force from the holding cylinder 5 as a whole, and there is an advantage that it is difficult to remove from the pipe joint.

Since the pipe insertion end side of the holding cylinder 5 is formed slightly larger in diameter than the outer circumference of the pipe 6, the pipe 6 can be easily inserted. The terminal end of the holding cylinder 5 is formed to have a slightly smaller diameter than the outer periphery of the pipe 6, so that the holding force is first generated at the terminal side of the holding cylinder 5 in a state where the pipe 6 is inserted, so that it is difficult to easily pull out. Therefore, when the pipe 6 has been inserted into the pipe joint but sufficient pressing force has not yet been exerted from the holding cylinder 5 and complete holding has not been performed, the machine under construction is moved or human There is an advantage that a situation in which the pipe 6 is pulled out of the pipe joint without being noticed at all is hard to occur by hooking the foot 6 with a foot. Second Embodiment Next, a second embodiment will be described focusing on differences from the first embodiment (not shown).

In this embodiment, the outer diameter (corresponding to the diameter d in FIG. 2) of the end portion of the holding cylinder 5 on the side of the pipe insertion port is changed in the axial direction when the holding cylinder 5 is located at the terminal end. The diameter is set slightly smaller than the inner diameter (corresponding to the diameter D in FIG. 2) of the inner peripheral tapered surface 7 at a position corresponding to the insertion port side end.

With this setting, the end of the holding cylinder 5 on the side of the pipe insertion port cannot be spatially displaced in the circumferential direction. Since the holding cylinder 5 can hardly be decentered even if the parts come into contact with each other, there is an advantage that the holding cylinder 5 does not shift in the circumferential direction and the pipe 6 can be very easily inserted.

[0027]

The present invention is configured as described above and has the following effects.

Since the entire outer peripheral surface of the holding cylinder comes into contact with the inner peripheral tapered surface, the pressing force in the diameter reducing direction is substantially uniformly applied to the pipe, so that the pipe is harder to come off from the pipe joint than before. Fittings can be provided.

The pipe insertion end side of the holding cylinder is from the outer circumference of the pipe.
Is also formed with a slightly larger diameter, so that piping can be easily inserted. Also
The end of the holding cylinder should be slightly smaller than the outer circumference of the pipe.
Cage, firstly held at the end side of the holding tube in a state of inserting the pipe
Since the force is generated and it changes to a state that it is difficult to pull out easily,
Although the pipe was inserted into the fitting, sufficient pressure was still applied from the holding cylinder
At the point when no power has been exerted and full retention has not been achieved
In the construction, moving the machine under construction or
By connecting it, you can connect without notice
It is unlikely that the pipe is missing from the hand.

[Brief description of the drawings]

FIG. 1 is a half sectional view illustrating an embodiment of a pipe joint according to the present invention and illustrating a state before a pipe is inserted.

FIG. 2 is a half cross-sectional view illustrating a state where a holding cylinder of the pipe joint of FIG. 1 is located at a terminal end.

FIG. 3 is a half sectional view illustrating a state where a pipe is inserted into the pipe joint of FIG. 1;

FIG. 4 is a perspective view illustrating the structure of a holding cylinder of the pipe joint of FIG. 1;

FIG. 5 is a half sectional view illustrating a state before insertion of a pipe of a conventional pipe joint.

FIG. 6 is a half sectional view illustrating a state where a pipe is inserted into the pipe joint of FIG. 5;

[Explanation of symbols]

 4 advance / retreat thin tube 5 holding tube 6 piping 7 inner taper surface

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-282086 (JP, A) JP-A-4-10185 (JP, U) (58) Fields investigated (Int.Cl. ⁶ , DB name) F16L 33/23

Claims (2)

(57) [Claims] An outer peripheral surface of a holding cylinder is substantially parallel to an inner peripheral taper surface for accommodating the piping when a pipe is inserted between the reciprocating thin cylinder and the holding cylinder. When moving in the direction of the pipe insertion end in a state of being pinched by the advancing / retracting thin cylinder and the holding cylinder, almost the entire outer peripheral surface of the holding cylinder comes into contact with the inner peripheral tapered surface, so that the diameter of the pipe in the diameter reducing direction is reduced. as the pressing force is exerted substantially uniformly, the holding cylinder pipe
The inner diameter of the insertion end is slightly larger than the outer circumference of the pipe.
And the inner diameter of the end of the holding cylinder is
Characterized in that the pipe joint is also formed with a slightly smaller diameter . 2. The inner diameter of the inner peripheral taper surface at the position corresponding to the end of the holding tube at the pipe insertion port side in the axial direction when the holding tube is located at the terminal end. The pipe joint according to claim 1, wherein the diameter is set to be slightly smaller.