JPH04366085A - Tube fitting - Google Patents

Abstract

PURPOSE:To provide a tube fitting whose biting force into a flexible tube can be easily and adequately set and which can be used several timed. CONSTITUTION:A mounting recess part 2 is formed at an entrance of a cylindrical fitting body 1, and a ring shaped chuck 6 inserted into the mounting recess part 2. A slit 6d whose diameter can be expanded and reduced is provided at the ring shaped chuck 6. A worked face 6b is provided at the tip end of the ring shaped chuck 6, and a claw part 6c is provided at the tip end of the worked face 6b. A removable ring 3 is provided at the entrance of the mounting recess part 2, and a working face 3a is provided at the tip end of the removable ring 3 for reducing the diameter of the ring shaped chuck 6 in contact with the worked face 6a of the ring shaped chuck 6. At the rear end of the removable ring 3, a flange part 3b is provided for regulating the screwing length of the removable ring 3 for optimally setting the reduced diameter of the ring shaped chuck 6 in contact with the fitting body 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting a tube for supplying fluid to a cylinder, valve, etc. to a connection port of the cylinder, valve, etc.

0002

[Prior Art] Socket-type pipe joints have been known as this type of pipe joint, and one example is the
It is disclosed in Japanese Patent No. 38926. This pipe joint consists of a cylindrical joint body with a mounting recess on the inlet side, a cap nut that can be screwed onto the joint body, and a sleeve accommodated in the cap nut. A tapered shape is formed toward the back of the mounting recess. According to this configuration, when the cap nut is screwed in after the tip of the flexible tube is inserted to the innermost part of the attachment recess, the tip of the sleeve is gradually narrowed according to the taper. Due to this constriction action, the tip of the sleeve sinks into the outer peripheral surface of the flexible tube, and the flexible tube is securely gripped.

0003

However, the narrowing of the sleeve is a forced deformation, and even if the cap nut is loosened, the distal end of the sleeve remains deformed. Therefore, it is difficult to remove a sleeve that is strongly wedged into the flexible tube, and even if such a sleeve is forcibly removed, the deformed sleeve cannot be used again. In addition, the flexible tube is also damaged, resulting in poor sealing performance during reuse. Therefore, the flexible tube cannot be reused. Since the joint body and the cap nut do not undergo any particular deformation, they can be reused, but unless a spare sleeve is available, they will eventually have to be discarded.

[0004] The degree of penetration of the tip of the sleeve, which affects the holding power and sealing performance of the flexible tube, depends on the degree to which the cap nut is screwed in, and the degree of screwing must be determined by experience. Therefore,
In order to reliably prevent the flexible tube from coming off, there is a strong tendency to over-screw the cap nut, resulting in excessive constriction and deformation at the tip of the sleeve. With such excessive constriction deformation of the sleeve, the degree of constriction of the inner diameter of the flexible tube also increases, resulting in a problem in that the cross-sectional area of the fluid flow path of the flexible tube decreases, making it impossible to obtain the original flow rate.

The present invention has been made in view of the above problems, and its purpose is to provide a pipe joint that allows easy setting of the degree of biting into the tube and that can be used many times. The purpose is to

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a mounting recess provided on the entrance side of a cylindrical joint body, an annular chuck inserted into the mounting recess, and an annular chuck. The annular chuck has a slit that allows the diameter to be expanded and contracted, and the annular chuck has a bent part on the tip side, and a claw part at the tip of the bent part. A removable ring is provided at the entrance of the mounting recess, and the tip of the removable ring has a diameter reduction action part that contacts the bent part of the annular chuck to reduce the diameter of the annular chuck, and the diameter reduction is set optimally. The pipe joint is characterized by having a flange portion.

[0007]

[Operation] When the detachable ring is screwed in after inserting the tip of the tube to the innermost end of the attachment recess, the diameter reduction action part provided on the inner circumference of the tip of the detachable ring will come into contact with the bent part of the tip of the annular chuck. come into contact with When the detachable ring is further screwed in, the diameter reduction action portion of the detachable ring that contacts the bent portion reduces the diameter of the annular chuck, and the claw portion sinks into the outer peripheral surface of the flexible tube. The tube is gripped by this biting action. When the flange of the detachable ring comes into contact with the fitting body, both slit forming ends of the annular chuck facing each other through the slit come close to each other, making it possible to optimally set the degree of biting into the tube, and adjust the width of the slit appropriately. By setting it to , it is possible to achieve a proper embedded state. By removing the detachable ring from the joint body, the tube can be easily pulled out from the joint body. The annular chuck is bitten into the tube pulled out from the joint body, but this biting is due to elastic deformation, and it is easy to remove the annular chuck from the tube. It is therefore possible to use the annular chuck multiple times.

[0008] It is desirable that a release ring for expanding the diameter of the annular chuck is housed in the inner peripheral portion of the detachable ring. This release ring accompanies the annular chuck when the tube is pulled out, and allows the stuck annular chuck to be easily slid off from the tube.

[0009]

[Example] Hereinafter, an example embodying the present invention is shown in Figs.
This will be explained based on FIG. As shown in FIG. 1, a detachable ring 3 is screwed onto the inner periphery of the opening of a mounting recess 2 on the inlet side of a cylindrical joint body 1 that is screwed onto a connection port of a cylinder, valve, etc. A tapered working surface 3a is formed on the inner periphery of the inner end portion of 3.

A release ring 4 shown in FIG. 2 is fitted onto the inner surface of the detachable ring 3, and the inner diameter of the release ring 4 is set to be slightly larger than the outer diameter of the flexible tube 7. A tapered working surface 4 is provided on the outer periphery of the distal end of the release ring 4.
a is formed, and the working surface 4a is located on the back side from the working surface 3a. The attachment recess 2 is divided into an innermost end 2a, a small diameter part 2b, and a large diameter part 2c, and the inner diameter of the small diameter part 2b is set to be slightly larger than the outer diameter of the flexible tube 7. An annular seal ring 5 is provided on the large diameter portion 2c.
are fitted tightly together, and an annular chuck 6 having elasticity is mounted on the seal ring 5.

As shown in FIGS. 1 and 2, the annular chuck 6 is provided with a cylindrical portion 6e at its base end. The tip side of the annular chuck 6 extends toward the entrance side of the mounting recess 2 and the axis L side, and then is bent and reversed toward the back side, and the upper surface of this bent portion forms an upwardly sloped working surface 6a and a downwardly sloped surface 6a. It constitutes the operated surface 6b. At the tip of the annular chuck 6, a plurality of claws 6c are arranged circumferentially within the operated surface 6b, and the radius of the circle formed by the tip edges of these claws 6c is equal to the radius of the flexible tube 7 in the free state of FIG. It is set slightly smaller than the outer diameter of. Also, Figure 2
As shown in the figure, a slit 6d having a width W is provided in the annular chuck 6 from the base end to the distal end along the axis L, and the presence of the slit 6d allows the annular chuck 6 to expand and contract in diameter.

As shown in FIGS. 1 and 2, the lower half of the seal ring 5 has a semicircular cross section, and its outer peripheral surface is a curved surface 5e. A taper 5c is provided on the inner periphery of the upper half of the seal ring 5 in the shape of a mortar. Further, an annular protrusion 5a is provided at the upper end of the seal ring 5, and a stepped portion 5b is formed on the outer peripheral side of the base thereof. The outer diameter of the seal ring 5 is set such that its upper half outer circumferential surface 5d is in close contact with the large diameter portion 2c of the mounting recess 2. taper 5
The diameter of the circle formed by the tip periphery 5f of c is set to be slightly smaller than the outer diameter of the flexible tube 7.

In the state shown in FIG. 1, the curved surface 5e of the seal ring 5 is brought into contact with the step 2d between the large diameter portion 2c and the small diameter portion 2b. The annular chuck 6 is fitted onto the annular protrusion 5a of the seal ring 5, and the lower end of the cylindrical portion 6e is brought into contact with the stepped portion 5b. Next, the operation of this embodiment will be explained. Figure 3
As shown in the figure, when the flexible tube 7 is inserted into the detachable ring 3 and the release ring 4 and pushed in after loosening the detachable ring 3 a few times, the tip of the flexible tube 7 is exposed to the downward slope of the annular chuck 6. The annular chuck 6 comes into contact with the surface 6b and is expanded by the pushing action of the flexible tube 7. At this time, since the base end of the cylindrical portion 6e of the annular chuck 6 can slide on the stepped portion 5b, the annular chuck 6 is expanded smoothly.

When the flexible tube 7 is further pushed in, the flexible tube 7 passes through the seal ring while coming into close contact with the distal end edge 5f of the seal ring 5. Then, the tip of the flexible tube 7 fits into the small diameter portion 2b, and the tip comes into contact with the innermost end 2a. In this state, the claws 6c of the expanded annular chuck 6 are
It slightly bites into the outer peripheral surface of the flexible tube 7 due to the elastic deformation action.

That is, the biting into the flexible tube 7 in the state shown in FIG. By appropriately setting the force, the gripping force by biting into the flexible tube 7 can be appropriately and easily set. Therefore, the flexible tube 7 is smoothly inserted into the joint body 1, and the tip of the flexible tube 7 reliably reaches the innermost end 2a.

Here, let us compare this embodiment with a configuration in which the seal ring 5 is not provided with the stepped portion 5b and the annular chuck 6 is supported, for example, at the tip of the annular protrusion 5a. In either configuration, when the flexible tube 7 is inserted into the seal ring 5, the distal end periphery 5f of the seal ring 5 is pulled downward due to sliding contact between the two, and this pull causes the annular protrusion 5a to bend inward. act.

By screwing in the detachable ring 3, the upwardly sloped operated surface 6a of the annular chuck 6 becomes the operating surface 3 of the detachable ring 3.
If the seal ring is not provided with the stepped portion 5b, there is a risk that the inwardly bent annular protrusion 5a may penetrate into the uppermost part of the back side of the upwardly sloped surface 6a. In such a case, the annular protrusion 5a presses the operated surface 6a outward and prevents the annular chuck 6 from contracting in diameter. On the other hand,
According to the configuration of this embodiment, the annular protrusion 5a is
There is no room to reach the back side, and the above-mentioned adverse effects do not occur.

When the detachable ring 3 is further screwed in from the state shown in FIG. 3, the working surface 3a of the inner circumference of the tip of the detachable ring 3 comes into contact with the upwardly sloped working surface 6a of the tip of the annular chuck 6. When the detachable ring 3 continues to be screwed in after the working surface 3a comes into contact with the working surface 3a, the worked surface 6a is pressed toward the center of the flexible tube 7 by the working surface 3a of the detachable ring 3. The diameter of the annular chuck 6 is reduced by this pressing action.

When the removable ring 3 is further screwed in to reduce the diameter, both slit forming ends 6f and 6g come close to each other, increasing the screwing resistance. FIG. 6 shows a state in which both slit forming ends 6f and 6g are close to each other. The operator senses this increase in screwing resistance through the detachable ring 3, but when the detachable ring 3 is screwed in until the flange portion 3b of the detachable ring 3 contacts the joint body, the gripping force on the flexible tube 7 increases. can be obtained powerfully.

According to the above structure, by appropriately setting the width W of the slit 6d, it is possible to set the gripping force on the flexible tube 7 to an optimal setting value. The optimal setting value of the gripping force here is the annular chuck 6
This is a gripping force that can strongly grip the flexible tube 7 and prevent it from coming off while preventing excessive constriction of the flexible tube 7 due to excessive insertion. By setting the slit width W in this manner, the operator can automatically recognize that the optimum setting value has been reached by screwing the flange portion 3b of the detachable ring 3 until it contacts the joint body 1. be. Therefore, unlike conventional devices in which it is difficult to recognize when the optimum setting value has been reached, it is not necessary to rely on intuition or experience to determine the degree of screwing in of the detachable ring 3.
The flexible tube 7 can be optimally held easily and reliably.

[0021] This reliably prevents the claw portion 6c from digging into the flexible tube 7 more than necessary, thereby preventing the flexible tube from being excessively constricted and deforming, and ensuring the original flow rate. When the detachable ring 3 is loosened from the state shown in FIG. 4, the annular chuck 6
The working surface 3 that was in contact with the upward slope working surface 6a at the tip of
a is separated, and the annular chuck 6, which had been bent toward the center, returns to its original shape as shown in FIG. In this state, the gripping force of the claw portion 6c when it is inserted into the flexible tube 7 is reduced, and the claw portion 6c becomes slightly wedged into the outer circumferential surface of the flexible tube 7 due to the elastic deformation action of the annular chuck 6.

When the detachable ring 3 is removed from the joint body 1 as shown in FIG. 5 and the flexible tube 7 is pulled out from the joint body 1, the annular chuck 6 and release ring 4 are attached to the flexible tube 7 as shown in FIG. It's coming. When the release ring 4 is slid toward the distal end of the flexible tube 7, the working surface 4a of the release ring 4 comes into contact with the downward slope applied surface 6b of the annular chuck 6, and the annular chuck 6 is expanded. Due to this expansion action, the flexible tube 7
The biting of the claw portion 6c into the ring portion 6c is completely released, and the annular chuck 6 can be removed from the flexible tube 7. The flexible tube 7 can be connected by inserting the annular chuck 6, the release ring 4, and the detachable ring 3 removed from the flexible tube 7 into the joint body 1 as shown in FIG. That is, the pipe joint of this embodiment can be reused many times, unlike conventional pipe joints.

[0023] Not only the flexible tube 7 but also non-flexible tubes can be connected to such a pipe joint. Even if the flexible tube 7 is damaged due to the annular chuck 6 biting in, this damaged area will be damaged by the seal ring 5.
does not affect the sealing action of the Therefore, the flexible tube 7 can be reused.

Furthermore, if the downwardly sloped annular operated surface 6b and the peripheral edge of the tip of the flexible tube 7 are deviated in the radial direction, that is, the axis of the annular chuck 6 and the mounting recess 2
If the axis L of the flexible tube 7
When the flexible tube 7 is inserted, the peripheral edge of the distal end of the flexible tube 7 makes partial contact with the operated surface 6b. Such a one-sided contact acts as an action to tilt the annular chuck 6, and if the annular chuck 6 is tilted, only a part of the plurality of claws 6c will sink into the flexible tube 7. If pressure is applied in such a biased state, the working surface 3a and the upwardly sloped working surface 6a will come into partial contact with each other, and the working surface 6
A uniform diameter reduction effect does not occur over the entire circumference of a.

In such a state, the biting force of the claw portion 6c into the flexible tube 7 becomes weak, but in the free state before insertion of the flexible tube 7 in FIG. Because it fits on the outer peripheral surface of the annular protrusion 5a, the annular chuck 6
The axis coincides with the axis L of the mounting recess 2. As a result, the actuated surface 6b of the annular chuck 6 and the peripheral edge of the flexible tube 7 come into contact uniformly over the entire circumference, and the annular chuck 6 expands uniformly from the axis L over the entire circumference without tilting. Therefore, in the pressurized state, the operating surface 3a and the operated surface 6a do not come into partial contact with each other, and the diameter of the operated surface 6a is uniformly reduced over the entire circumference. Thereby, the plurality of claws 6c can be inserted into the flexible tube 7 evenly.

It should be noted that the present invention is not limited to the above embodiments, but can also be implemented in the following embodiments. That is,
(1) As shown in FIG. 7, the tip side of the annular chuck 8 is curved and reversed, and the length of the plurality of slits 8a for forming the plurality of claws 8b is adjusted from the tip to near the base end of the cylindrical portion 8c. shall be. Due to the presence of the slits 8a, the claws 8b are easily displaced in the radial direction of the annular chuck 8, and the diameter of the virtual circle formed by the tips of the claws 8b is reduced. (2) As shown in FIG. 8, the tip of the annular chuck 9 having the slit 9c is suddenly bent and reversed to the back side to form a downwardly sloped working surface 9b, and the bent end 9 of the annular chuck 9
It is also possible to reduce the diameter of the annular chuck 9 by bringing the ring a into contact with the working surface 3a of the detachable ring 3, and to expand the diameter of the annular chuck 9 by bringing the working surface 3a into contact with the worked surface 9b. (3) As shown in FIG. 9, the tip of the annular chuck 10 having the slit 10c is bent and reversed at right angles to the back side to form a non-slanted working surface 10b, and the bent end 10a of the annular chuck 10 is attached to a detachable ring. The diameter of the annular chuck 10 is reduced by contacting the working surface 3a of the release ring 4, and the working surface 10b of the annular chuck 10 is brought into contact with the working surface 4a of the release ring 4.
Expand the diameter of 0. Further, as shown in the drawings, the release ring in each of the above embodiments may be omitted.

[0027]

[Effects of the Invention] As detailed above, the pipe joint of the present invention has excellent effects in that it is easy to appropriately set the biting force on the tube, and it can be used many times. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a state before insertion of a flexible tube in an embodiment embodying the present invention.

FIG. 2 is an exploded perspective view of a detachable ring, a release ring, an annular chuck, and a seal ring in this embodiment.

FIG. 3 is a longitudinal sectional view showing a state in which the flexible tube is inserted and the detachable ring is loosened.

FIG. 4 is a longitudinal sectional view showing a state in which the flexible tube is inserted and the detachable ring is tightened.

FIG. 5 is a longitudinal cross-sectional view showing a state in which the detachable ring is removed while the flexible tube remains inserted.

FIG. 6 is a longitudinal sectional view showing how the annular chuck and release ring are attached to the pulled out flexible tube.

FIG. 7 is a perspective view showing another example of the annular chuck.

FIG. 8 is a vertical cross-sectional view of a main part showing another example of an annular chuck.

FIG. 9 is a longitudinal cross-sectional view of a main part showing another example of an annular chuck.

[Explanation of symbols]

1 Joint body, 2 Mounting recess, 3 Detachable ring, 3a Working surface as diameter reduction working part, 3b Flange part, 4 Release ring, 5 Seal ring, 6
Annular chuck, 6b Worked surface as a bending part,
6c claw part, 6d slit.

Claims (2)

[Claims] [Claim 1] A mounting recess (2) provided on the inlet side of a cylindrical joint body (1);
an annular chuck (6) inserted into the annular chuck (6);
) and a seal ring (5) that is inserted deeper than the
The annular chuck (6) is provided with a slit (6d) that enables diameter expansion and reduction, and a bent portion (6b) is provided on the tip side of the annular chuck (6). is provided with a claw part (6c), a detachable ring (3) is provided at the entrance of the mounting recess (2), and the tip of the detachable ring (3) is in contact with the bent part (6b) of the annular chuck (6). Diameter reduction action part (3a) for reducing the diameter of the annular chuck (6)
and a flange portion (3b) for appropriately regulating diameter reduction. 2. The pipe joint according to claim 1, wherein a release ring (4) for expanding the diameter of the annular chuck (6) is housed in the inner circumference of the detachable ring (3).