JPH01206198A - Tube joint - Google Patents

Abstract

PURPOSE:To improve durability of a tube joint by forming a holder to be a circular truncated cone cylinder which decreases toward the direction of inserting a pipe body, and providing the holder between a releasing cylinder and an elastic ring. CONSTITUTION:A holder 3 is formed to be a circular truncated cone cylinder which decreases in a diameter toward the direction of inserting a tube body T. The holder 3 is rotatably provided in the gap between a tapered face 5a of an end part of a releasing cylinder 5 and a tapered face 4a of an elastic ring 4. The stress in case of mounting/demounting the tube body T is applied to the whole holder 3 so that damage of a specified part thereof is prevented. The durability of the holder 3 is remarkably improved because it is not deformed beyond limit.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pipe joint used for a pipe body made of plastic or rubber, and more specifically, to a pipe joint that allows the pipe body to be repeatedly attached and detached, and which has particularly excellent durability. Regarding.

[Conventional technology]

In recent years, tubes made of plastic or rubber have come to be used as tubes for transferring fluids due to their weight, flexibility, chemical resistance, etc., and as a result, it has become necessary to connect these flexible tubes. Various types of pipe joints have also been developed. Among these, pipe joints, which allow pipe bodies to be easily attached and detached without using tools, are used in various types of equipment because of their ease of handling.

One type of pipe joint is a joint body that has a hollow part into which the pipe body is inserted, and a pipe that is held within the joint body by biting into the outer periphery of the pipe body to prevent the pipe body from coming off. A toothed washer-like gripping tool having a plurality of claws inclined in the body insertion direction on the inner peripheral edge side of the annular base, and the annular base of this gripping tool are held between a stepped portion provided on the inner wall surface of the joint body. For this purpose, a presser cylinder is fitted into the joint main body, and a presser cylinder is slidably fitted into the presser cylinder, and the claws of the gripping tool are pushed outward and expanded so that the claws bite into the pipe body. There is a pipe joint that is equipped with an open cylinder that releases the lock, and a seal ring that has a U-shaped cross section or the like that comes into elastic contact with the pipe body and the inner wall of the joint body when the pipe body is inserted.

With this pipe fitting, the pipe body is fixed within the joint body simply by inserting the pipe body into the joint body, and the open tube is moved in the direction in which the pipe body is inserted.
The fixed pipe body can be removed from the joint body by simply pushing it in (for example, Utility Model Application No. 60-19887 and Utility Model Application No. 61-1451 proposed by the present applicant).
(See Publication No. 88).

[Problem to be solved by the invention]

However, in such conventional pipe joints, a toothed washer is secured to the joint body at the annular base with a slight space left between the step inside the joint body and the end surface of the holding cylinder. The gripping tool has each claw piece bent in the tube insertion direction with respect to the disc-shaped annular base, so it is prone to repeated attachment and detachment of the tube or excessive tension in the tube withdrawal direction. Therefore, stress tends to concentrate on the roots when the nail pieces are attached. in this case,
Since the curvature of the annular base of the gripping tool is an important element in improving the ease of attaching and removing the tube, the gripping tool is formed with a fixed width and is weak in strength.

Therefore, these stresses may cause the annular base to deform beyond its elastic limit, resulting in a problem in that the gripping force is reduced. Furthermore, when used in industrial robots, etc., large loads such as tension, twisting, and impact are applied to the joints, so a larger stress is concentrated on the gripper, and as a result, between the weaker claw pieces. The annular base of the ring is prone to breakage, and improvements in durability have been desired.

SUMMARY OF THE INVENTION In view of the problems of the prior art, it is an object of the present invention to provide a pipe joint that can maintain a good grip on a pipe body against repeated attachment and detachment, twisting, and the like.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a joint body having a hollow portion into which a pipe body is inserted, and a plurality of joint bodies which are located in the joint body and are inclined in the pipe body insertion direction for biting into the outer periphery of the pipe body and gripping the pipe body. An annular gripping tool having a claw, an open tube located near the gripping tool, and having a tip thereof pushing down the claw toward the inner wall of the joint body to release the claw from digging into the outer periphery of the tube, and the tube. A pipe joint comprising a seal ring that comes into elastic contact with the pipe body and the inner wall of the joint body when fitted, the gripping tool having an elastic ring having a conical tapered surface provided on the outer peripheral surface side of the gripping tool, the gripping tool comprising: The tube joint is formed into a truncated conical tube shape whose diameter decreases in the direction of insertion of the tube body, and is loosely fitted between the open tube and the open tube having a tapered surface opposite to the tapered surface of the elastic ring at the distal end. do.

[Effect]

In this invention, the gripping tool is formed into a truncated conical tube shape without each of the claws being bent relative to the annular base, and as a result, the entire gripping tool deforms when subjected to external force, which may cause damage. This prevents stress from concentrating on specific parts.

Furthermore, the gripping tool is loosely fitted and held by the tip of the open cylinder and the elastic ring, and is protected by being sandwiched between these two members, so it is protected against external forces such as tension or twisting as in the conventional case. , the gripping tool does not deform beyond its elastic limit, and when the tube is attached or removed, it is pushed by the tube or open cylinder and falls toward the inner wall of the joint body. Since the ring returns quickly with the help of its elasticity, fatigue deformation is less likely to occur even when the tubular body is repeatedly attached and detached, and therefore durability is greatly improved.

〔Example〕

FIG. 1 is a partially longitudinal side view showing an embodiment of a pipe joint 1 according to the present invention. A gripping tool 3 having a biting claw piece 3a held therein, an elastic ring 4 provided on the outer peripheral surface side of the gripping tool 3, and an opening for pushing and expanding the claw pieces 3a of the gripping tool 3 in the tube insertion direction. It consists of a tube 5, a presser tube 6 that is provided on the outside of the open tube 5 and locks the open tube 5 at its stepped portion 6a, and a seal ring 7 that comes into elastic contact with the tube and the inner wall of the joint body when the tube is inserted. has been done.

The joint body 2 has two steps 2a and 2b formed on its inner wall surface, and an annular f42c for receiving the seal ring 7 between these two steps 2a and 2b. An engaging portion 2d for fitting and fixing the presser cylinder 6 is formed on the end side.

The presser cylinder 6 has the engaging portion 2 of the joint body 2 on the outer periphery of one end.
A protrusion 6b that engages with d is provided, and by press-fitting the protrusion 6b into the engaging portion 2d of the joint body 2, it is fitted and fixed within the joint body 2. This presser cylinder body 6 is a separate part to facilitate cutting of the joint body 2.
Of course, this is not necessary if the joint body 2 is processed into such a shape.

The open tube 5 has a tapered surface 5a formed at the end facing the gripping tool 3 when slidably fitted into the presser tube 6, and the open tube 5 is inserted into the joint body 2 at the other end. A flange 5b is provided which serves as a pressing part when pushing in.

The elastic ring 4 is made of an elastic material such as rubber, and has a cone-shaped tapered surface 4a at one end, as shown in detail in FIG.
is formed, and an annular shape 714b is formed on the other end side, and this annular shape 44b is latched to the stepped portion 2a of the joint main body 2 with the annular shape 44b facing in the tube insertion direction.

As shown in detail in FIG. 2, the gripping tool 3 has a truncated conical cylindrical shape, and extends from an annular base 3b formed on the large diameter side at a predetermined interval toward the small diameter side. A plurality of claw pieces 3a are provided to maintain the position.

This gripping tool 3 is attached to the tapered surface 4 of the elastic ring 4.
a and the tapered surface 5a of the open cylinder 5 so as to be rotatable. Further, the gripping tool 3 is made of an elastic material with relatively high fatigue strength, such as phosphor bronze.

The seal ring is an O-ring, and the annular i of the joint body 2
When the tube body is inserted into the joint body 2, it is curved so as to maintain airtightness by coming into elastic contact with the inner wall surface of the joint body and the outer peripheral surface of the tube body. Note that the seal ring may have other shapes, such as a U-shaped cross section, for example.

Next, the operation of the above embodiment will be explained using FIGS. 4 and 5.

To attach the tube T to the pipe joint 1, the tube T is inserted into the open tube 5. As the tubular body T is inserted, its tip portion first comes into contact with the claw piece 3a of the gripping tool 3. When the tubular body T is further pushed in, the claw pieces 3a are pushed down toward the inner wall of the joint body while resisting its elasticity, and the tapered surface 4a of the elastic ring 4 is pushed down.
The holding tool 3 is further pushed down while resisting the elasticity of the elastic ring 4, and the entire gripping tool 3 is deformed, changing from a truncated conical shape to a cylindrical shape. At this time, the elastic ring 4 has an annular i
4b, it is easily deformed, and therefore the claw piece 3a can be smoothly displaced. Next, the tube T enters the seal ring 7 while slidingly contacting the inner circumferential surface, and the stepped portion 2 in the joint body 2
It is attached to the pipe fitting 1 in a state where it comes into contact with b. That is, in this state, the claws 3a of the gripping tool 3 are in pressure contact with the tubular body T due to their elasticity, so when an attempt is made to pull out the tubular body T, the tips of the claws 3a, as shown in FIG. It bites into the tubular body T and acts freely to prevent the tubular body T from being pulled out, thereby firmly holding the tubular body T.

In addition, in order to remove the tube body T in the above state from the pipe fitting l, push the open tube 5 into the joint body 2 as shown in FIG. This is then pushed out against its elasticity and the elasticity of the elastic ring 4, and the tips of the claw pieces 3a that have bitten into the tubular body T are released from the tubular body surface.

By releasing the bite, the tubular body T can be easily pulled out from the pipe fitting l. In this case, the elastic ring 4 deforms easily due to the presence of the annular groove 4b, so that there is almost no obstacle to the pushing operation of the open cylinder 5. In addition,
Depending on the material of the elastic ring 4, the annular groove 4b may not be provided.

As described above, in the pipe joint 1 of the present invention, the gripping tool 3 is formed in a conical cylindrical shape, and the claw pieces are not bent relative to the annular base as in the conventional case, so that the pipe body T can be attached and detached. Since the gripping tool 3 as a whole deforms in response to bending stress or external forces such as tension and wrinkling, concentration of stress on a specific portion of the gripping tool 3 is prevented and damage is prevented.

Further, the gripping tool 3 has a tapered surface 5a at the tip of the open cylinder 5.
Since it is rotatably interposed in the gap between the tapered surface 4a of the elastic ring 4 and the open cylinder 5, even if external forces such as tension or twisting are applied when used in an industrial robot, for example, the open cylinder 5 and the elastic ring 4, so it will not be deformed beyond its limit, and when the tube body T is attached or detached, the grip will not be pushed by the open tube 5 or the tube body T and be pushed against the inner wall side of the joint body. Since the claw pieces 3a of the tool 3 quickly return to their original positions with the help of the elasticity of the elastic ring 4, fatigue deformation is unlikely to occur even when the tubular body T is repeatedly attached and detached, and therefore durability is greatly improved.

Furthermore, since the elastic ring 4 that the claws 3a of the gripping tool 3 abuts on is suitably elastically deformed when the tubular body T is attached or detached, there is no reduction in attachment/detachability.

〔Effect of the invention〕

As explained above, according to the present invention, the gripping tool is formed into a conical cylindrical shape whose diameter decreases as it goes in the tube insertion direction, and the gripping tool is held loosely between the tip of the open tube and the elastic ring. Since it is a pipe joint made of the same material, the service life of the pipe joint can be significantly improved compared to conventional examples without deteriorating the ease of attaching and detaching the pipe body.

It should be noted that this invention is not limited to the above-mentioned embodiments, and of course various modifications can be made within the technical idea of this invention.

[Brief explanation of the drawing]

Fig. 1 is a partially vertical side view showing an embodiment of a pipe joint according to the present invention, Fig. 2 is a partially longitudinal side view of a grip used in the embodiment shown in Fig. 1, and Fig. 3 is a similar elastic ring. Fig. 4 is a partial longitudinal side view when the pipe bodies are connected;
FIG. 5 is a partially longitudinal side view when the tubular body is removed. 2: Joint body, 2a, 2b: Stepped portion, 3: Grip,
3a: claw piece, 3b: annular base, 4: elastic ring,
5: Open tube, 4a, 5a: Tapered surface, 7: Seal ring. Patent applicant: Junko Co., Ltd. 2; Modeled after autopsy

Claims (1)

[Claims] (1) A joint body having a hollow portion into which the pipe body is inserted, and an annular gripping tool that is located inside the joint body and has a plurality of claws inclined in the pipe insertion direction for biting into the outer periphery of the pipe body and gripping the pipe body. , an open tube that is located near the gripping tool and whose tip part pushes the claw toward the inner wall of the joint body to release the claw from digging into the outer periphery of the tube; The pipe fitting has an elastic ring having a conical tapered surface provided on the outer circumferential side of the gripping tool, and the gripping tool has a diameter that decreases in the direction of insertion of the pipe body. 1. A pipe joint, which is formed into a truncated conical cylinder shape, and is loosely fitted between the open cylinder and the open cylinder, which has a tapered surface at its tip opposite to the tapered surface of the elastic ring.