WO2020233335A1 - Pipe joint connectable to pipe - Google Patents

Abstract

A pipe joint connectable to a pipe comprises a joint main body (1), an inner ring (2) and a nut (3). A transition section (223) is provided between an increasing-diameter conical surface (221) and a decreasing-diameter conical surface (222) of a protrusion (22) of the inner ring (2). The axial length of the transition section (223) accounts for 15% to 30% of the axial length of the protrusion (22). An included angle between a tangent at any point on an outer surface of the transition section (223) and an axial direction line of the inner ring (2) is 0° to 35°. An included angle (θ1) between an axial direction line of the inner ring (2) and the increasing-diameter conical surface (221) is greater than an included angle (θ2) between the axial direction line of the inner ring (2) and the decreasing-diameter conical surface (222).

Description

Pipe joint connected with pipe Technical field

The invention belongs to the technical field of pipe fittings, and in particular relates to a pipe joint used for fluid transport and fluid treatment processes.

Background technique

[Correct 25.05.2020 according to Rule 91]
US Patent US5743572A discloses a pipe joint commonly used in the manufacturing process of semiconductor manufacturing, pharmacy, food processing and chemical industry for fluid transportation. As shown in Figures 1 and 2, the pipe joint consists of a joint body 1, an inner ring 2 and the nut 3 are composed of three parts, and an annular groove 13 is formed between the outer tube portion 11 and the inner tube portion 12 of the joint body 1. When in use, the front end of the resin tube 4 is flared and sleeved on the outer periphery of the inner ring 2, and then inserted into the joint body 1 together with the inner ring 2. The tube 4 is fixed inside the outer cylinder part 11, and the insertion part 21 of the inner ring 2 The groove portion 13 is inserted, and the nut 3 is fastened to the outer circumference of the outer cylinder portion 11 of the joint main body 1 through a screwed portion 32. The end of the inner ring 2 in contact with the tube 4 includes a protrusion 22 in the shape of a mountain, which expands the diameter of the tube 4 sheathed on the outer circumference of the tube 4 to prevent the tube 4 from falling off the inner ring 2.

The outer surface of the protrusion 22 of the inner ring 2 includes a tapered surface 221 that gradually expands in diameter from the end and a tapered surface 222 that gradually decreases in diameter from the turning position. A circular line 220 is connected, that is, the enlarged tapered surface 221 and the reduced tapered surface 222 are directly connected. The circular line 220 corresponds to the thickest part of the protrusion 22. From the appearance, the thickest part is pointed. After the tube 4 is sleeved on the outer circumference of the inner ring 2, the outer circumference of the protrusion 22 abuts against the inner wall of the tube 4, and the thickest part of the protrusion 22 is in the closest contact with the inner wall of the tube 4, and the pressing force is the greatest. There is only a line contact between the two, the action area is small, the force is very concentrated, and the bending area 41 corresponding to the tube 4 will have a larger curvature. The superimposition of these two factors can easily cause damage to the tube 4 . In addition, because the expanded tapered surface 221 and the reduced tapered surface 222 are directly connected by only a circular line 220, the pipe 4 sleeved on its outer circumference changes suddenly from an expanded diameter to a reduced diameter. In the vicinity of the area, there is likely to be a certain gap between the inner wall of the tube 4 and the outer surface of the protrusion 22, that is, the inner wall near the bending area 41 of the tube 4 is not in close contact with the outer surface of the protrusion 22, so the sealing performance is not maximized. good.

In addition, since the inclination angles of the enlarged tapered surface 221 and the reduced tapered surface 222 of the protrusion 22 are not set properly, when the inclination angle of the enlarged tapered surface 221 is too small, the inclination angle of the reduced tapered surface 222 is relatively small. When it is large, the expanded tapered surface 221 and the reduced tapered surface 222 are directly connected by only a circular line 220, which cannot effectively prevent the sliding of the pipe 4. When the pipe joint and the pipe 4 are used in a high temperature environment, the pipe 4 After being softened by heat, it is easy to slide out along the tapered surface 222 of the reduced diameter, thereby causing leakage.

Summary of the invention

In order to solve the problem that the protruding part of the inner ring of the existing pipe joint is likely to cause damage to the pipe, the outer surface near the thickest part of the protruding part fails to make close contact with the inner wall of the pipe, and the pipe slides outward along the inner ring in a high temperature environment The present invention provides a pipe joint that is connected to a pipe. The pipe joint includes:

The joint main body has a main body cylinder part, an outer cylinder part and an inner cylinder part coaxially arranged, the outer cylinder part and the inner cylinder part are arranged protruding in the same direction from the main body cylinder part, and the inner cylinder part is arranged outside Inside the cylinder, the length of the outer cylinder protruding from the main body cylinder is greater than the length of the inner cylinder protruding from the main body cylinder, surrounded by the main body cylinder, the outer cylinder and the inner cylinder to form one Groove, the opening direction of the groove is the same as the protruding direction of the outer cylindrical portion and the inner cylindrical portion;

The inner ring has a cylindrical insertion part, a cylindrical fitting part, a cylindrical connecting part and a protruding part, and a fluid channel located in the center that are arranged coaxially and continuously in sequence, and the fitting part is detachable Fitted to the radially inner side of the outer cylinder part, the insertion part protrudes from one side of the fitting part, and is inserted into the groove part through the opening of the groove part of the joint body, the connection part and The protruding part protrudes from the other side of the fitting part, and the outer surface of the protruding part includes a tapered surface with an enlarged diameter and a tapered surface with a reduced diameter. The tapered surface with an enlarged diameter is located at the end of the protrusion, so The tapered surface with reduced diameter is located between the connecting portion and the tapered surface with enlarged diameter. The protruding portion and the connecting portion are pressed into the inside of one end of the tube, and the tube is sandwiched between it and the outer cylindrical portion, The inner ring can be connected to or disconnected from the joint body in the state of being connected to the pipe;

A nut, which is fastened to the outer cylinder part of the joint body by an internal thread, and together with the inner ring, fastens the pipe to the joint body;

Wherein, a transition section is provided between the tapered surface of the enlarged diameter and the tapered surface of the reduced diameter, and the axial length of the transition section is 15%-30% of the axial length of the protrusion. The included angle between the tangent line at any point on the outer surface of the segment and the axial direction of the inner ring is 0°～35°, and the included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is greater than that of the tapered surface of the reduced diameter The angle between.

The outer surface of the protruding portion of the inner ring of the existing pipe joint includes a tapered surface that gradually expands in diameter from the end and a tapered surface that gradually decreases in diameter from the turning position. A circular line is connected, that is, the tapered surface of the enlarged diameter and the tapered surface of the reduced diameter are directly connected. The circular line corresponds to the thickest part of the protrusion. From the appearance, the thickest part is sharp. The protrusion of the inner ring is inserted into the inside of one end of the tube, and the outer periphery of the protrusion abuts against the inner wall of the tube. The thickest part of the tip is in the closest contact with the inner wall of the tube and has the greatest pressing force, and only forms between the two. Line contact, the action area is small, the action force is very concentrated, and the tube will have a large curvature in this area. These two factors are superimposed and cause great damage to the tube.

In the existing pipe joint, the expanded tapered surface and the reduced tapered surface of the protruding part of the inner ring are directly connected by only a circular line. The pipe sleeved on the outer circumference of the pipe is suddenly changed from an expanded diameter to a reduced diameter. Near the area corresponding to the shape line, a certain gap is likely to exist between the inner wall of the tube and the outer surface of the protrusion, that is, the inner wall of the corresponding area of the tube is not in close contact with the outer surface of the thickest part of the protrusion. Therefore, the pipe joint and the pipe The tightness between the rooms is not optimal.

In addition, due to the unreasonable setting of the inclination angles of the tapered surface of the enlarged diameter and the tapered surface of the reduced diameter of the protrusion, the inclination angle of the enlarged tapered surface is too small, and the inclination angle of the reduced tapered surface is relatively large, and the diameter is enlarged The tapered surface and the reduced diameter tapered surface are directly connected by only a circular line, which cannot effectively prevent the sliding of the pipe. When the pipe joint and the pipe are used in a high temperature environment, the pipe will easily follow the reduced diameter cone after being heated and softened. Slide out facing outwards, causing leakage.

In the pipe joint provided by the present invention, a transition section is added between the enlarged tapered surface and the reduced tapered surface of the protrusion of the inner ring, and the axial length of the transition section is the axial length of the protrusion 15%-30% of the length. After the connecting part and the protruding part of the inner ring are inserted into the inside of one end of the tube, the thickest part of the protruding part is in surface contact with the inner wall of the tube through the outer surface of the transition section, the action area increases, and the squeezing force between the two It is dispersed, and the outer surface of the transition section also reduces the bending curvature of the tube. The two effects are superimposed, which greatly reduces the damage to the tube.

In addition, the angle between the tangent to any point on the outer surface of the transition section of the inner ring and the axial direction of the inner ring is 0°～35°. When the protrusion is inserted into the inside of one end of the tube, the bending curvature of the tube always falls on it. Within the tolerable range, the damage to the tube is reduced, and the inner wall of the tube is in close contact with the outer surface of the protruding part, leaving no gaps, and the sealing effect between the tube and the inner ring is improved.

In addition, the included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is greater than the included angle between the tapered surface of the reduced diameter and the axial direction of the inner ring, which makes the tapered surface of the enlarged diameter at the end form the tube outward along the tapered surface of the reduced diameter The obstacle of sliding out can prevent the pipe from sliding out along the tapered surface and transition section of the reduced diameter. When the described pipe joints and pipes are used in a high temperature environment, after the pipes are heated and softened, the pipes may slide a certain distance along the tapered surface of the reduced diameter, but due to the expansion of the tapered surface at the end and the axial direction of the inner ring The included angle between the tapered surface is greater than the included angle between the tapered surface of the reduced diameter and the axial direction of the inner ring. The tapered surface of the enlarged diameter can prevent the pipe from sliding out, which is not conducive to the sliding of the pipe, thereby ensuring the pipe joint and Reliable airtightness between tubes.

Further, the included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is 25° to 35°, and the included angle between the axial direction of the inner ring and the tapered surface of the reduced diameter is 10-20° .

The included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is 25 to 35°, and when the included angle of the tapered surface of the reduced diameter is 10 to 20°, it is ensured that the pipe will not shrink along the line under high temperature conditions. Under the premise that the tapered surface of the diameter slides out and the sealing is good, minimize the bending curvature of the tube so that the bending curvature of the tube always falls within its acceptable range, reducing the damage to the tube and extending the tube Service life.

Further, the outer surface of the transition section is a cylindrical surface of equal diameter and parallel to the axial direction of the inner ring, and the cylindrical surface has a certain axial length.

The expanded cone surface and the reduced diameter cone surface are transitionally connected by the cylindrical surface, and the cylindrical surface is not conducive to the sliding of the tube, so the tube can be prevented from slipping out of the inner ring.

Further, the outer surface of the transition section is spherical.

The expanded tapered surface and the reduced tapered surface are connected by the spherical transition. The connection is smoothly connected. The spherical surface is in closer contact with the inner wall of the pipe, and the sealing effect is better. The deformation of the pipe is gradually and can be reduced. The bending and curvature of the pipe reduce the damage to the pipe.

Further, the radial distance between the point with the largest outer diameter of the transition section and the outer surface of the fluid channel is 1.5 to 2.5 times the radial distance between the outer surface of the connecting portion and the outer surface of the fluid channel .

Further, the radial distance between the point with the largest outer diameter of the transition section and the outer surface of the fluid channel is 1.05-1.2 of the radial distance between the outer surface of the fitting portion and the outer surface of the fluid channel. Times.

When the radial distance between the point with the largest outer diameter of the transition section of the protrusion and the outer surface of the fluid channel is 1.5 to 2.5 of the radial distance between the outer surface of the connecting portion and the outer surface of the fluid channel Times, and when the radial distance between the point with the largest outer diameter of the transition section and the outer surface of the fluid channel is the radial distance between the outer surface of the fitting portion and the outer surface of the fluid channel When it is 1.05 to 1.2 times, the pipe can be firmly clamped between the inner ring and the outer cylinder, which increases the fastening force of the inner ring and the outer cylinder to the pipe, and prevents the pipe from slipping out.

Further, the inner ring further includes a cylindrical abutting portion, the abutting portion is arranged coaxially with the insertion portion, and is located radially inside the same side of the insertion portion, and the inner ring After the installation is completed, the abutting portion contacts and abuts the inner cylinder portion of the joint body. The abutting portion further improves the sealing performance between the inner ring and the joint body.

Further, the nut includes a screwed part and a pressing part, the screwed part is screwed with the thread on the outer circumference of the outer cylinder part, and the pressing part presses the tube and the inner ring toward the main body cylinder, The insertion part is pressed into the groove part to fasten the inner ring and the pipe to the joint body.

Further, the radial thickness of the insertion portion is equal to or slightly larger than the radial width of the groove portion, or the radial thickness of the insertion portion is 1.2-1.5 times the radial width of the groove portion. On the premise that the insertion part can be smoothly inserted into the groove part, the insertion part is firmly clamped in the groove part.

Further, in the direction extending from the fitting portion to the end of the insertion portion, the radial thickness of the insertion portion gradually decreases, that is, the insertion portion has a tapered shape. The tapered insertion part is easier to insert into the groove part, and the installation of the inner ring is easier.

In the pipe joint provided by the present invention, a transition section is provided between the enlarged tapered surface and the reduced tapered surface of the protrusion of the inner ring, and the axial length of the transition section is 15% to 15% of the axial length of the protrusion. 30%, the included angle between the tangent of any point on the outer surface of the transition section and the axial direction of the inner ring is 0°～35°, and the included angle between the axial direction of the inner ring and the tapered surface of the expanded diameter is greater than that of the tapered cone The angle between the faces. The outer surface of the transition section of the protrusion is in surface contact with the inner wall of the pipe, the area of action is increased, the squeezing force between the two is dispersed, and the transition section also reduces the bending and curvature of the pipe. The damage effect on the tube realizes the close contact and fastening between the expanded cone surface and the inner wall of the tube; and the included angle between the axial direction of the inner ring and the expanded cone surface is greater than the included angle between it and the reduced diameter cone surface , Even if it is used in a high temperature environment, the pipe will not slide out along the tapered surface and transition section of the reduced diameter.

Description of the drawings

The present invention will be further explained below in conjunction with the drawings:

Figure 1 is a cross-sectional view of the inner ring of a pipe joint disclosed in the prior art

Figure 2 is a cross-sectional view of a pipe joint and a pipe disclosed in the prior art after installation

Figure 3 is a cross-sectional view of the inner ring provided by the first embodiment of the present invention

4 is a cross-sectional view of the pipe joint and the pipe provided in the first embodiment of the present invention

Figure 5 is a partial cross-sectional view of the pipe joint shown in Figure 4 after sliding the inner ring out of the joint body

Figure 6 is a cross-sectional view of the inner ring provided by the second embodiment of the present invention

In Figure 1-6: 1-joint body, 10-body tube, 11-outer tube, 12-inner tube, 13-groove, 2-inner ring, 20-fitting part, 21-insertion part, 22-protrusion, 220-circular line, 221-expanded tapered surface, 222-reduced tapered surface, 223-transition section, 23-connecting part, 24-fluid channel, 25-abutting part, 3- Nut, 31-pressing part, 32-screw part, 4-pipe, 41-bending area.

Detailed ways

In order to be able to understand the above objectives, features and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other if there is no conflict.

In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described here. Therefore, the protection scope of the present invention is not limited to the specific details disclosed below. Limitations of the embodiment.

Example one

As shown in Figure 3-4, the pipe joint includes:

The joint body 1 has a main body tube portion 10, an outer tube portion 11, and an inner tube portion 12 coaxially arranged. The outer tube portion 11 and the inner tube portion 12 are arranged to protrude in the same direction from the body tube portion 10, and the inner tube portion 12 is provided On the inner side of the outer cylinder portion 11, the length of the outer cylinder portion 11 protruding from the main body cylinder portion 10 is greater than the length of the inner cylinder portion 12 protruding from the main body cylinder portion 10. The main body cylinder portion 10, the outer cylinder portion 11 and the inner cylinder portion 12 surrounds and forms a groove 13, and the opening direction of the groove 13 is the same as the protruding direction of the outer cylindrical portion 11 and the inner cylindrical portion 12.

The inner ring 2 has a cylindrical insertion portion 21, a cylindrical fitting portion 20, a cylindrical connecting portion 23 and a protruding portion 22, and a fluid channel 24 located in the center, which are successively arranged coaxially and continuously. The fitting portion 20 is It is detachably fitted to the radially inner side of the outer cylinder portion 11, and the insertion portion 21 is provided protruding from one side of the fitting portion 20, and is inserted into the groove portion 13 through the opening of the groove portion 13 of the joint body 1, and the connecting portion 23 and the protruding part 22 protrude from the other side of the fitting part 20.

The protruding part 22 and the connecting part 23 are pressed into the inside of one end of the tube 4, and the tube 4 is sandwiched between the tube 4 and the outer tube part 11. The inner ring 2 can be connected to or disconnected from the joint body 1 while being connected to the tube 4 .

The inner ring 2 further includes a cylindrical abutting portion 25 which is arranged coaxially with the insertion portion 21 and located in the radially inner part of the same side of the insertion portion 21. After the inner ring 2 is installed, the abutting portion 25 contacts and abuts the inner cylindrical portion 12 of the joint body 1. The abutting portion 25 further improves the sealing performance between the inner ring 2 and the joint body 1.

[Correct 25.05.2020 according to Rule 91]
The nut 3 is fastened to the outer cylindrical portion 11 of the joint body 1 through internal threads, and together with the inner ring 2, the pipe 4 is fastened to the joint body 1. The nut 3 includes a screwed portion 32 and a pressing portion 31. The screwed portion 32 is screwed to the thread on the outer circumference of the outer cylinder portion 11. The pressing portion 31 presses the tube 4 and the inner ring 2 in the direction of the main body cylinder portion 10. 21 is pressed into the groove 13 to fasten the inner ring 2 and the pipe 4 to the joint body 1.

As shown in FIG. 3, the outer surface of the protrusion 22 includes a tapered surface 221 with an enlarged diameter, a tapered surface 222 with a reduced diameter, and a transition section 223 between the two. The outer surface of the transition section 223 is a cylindrical surface with an equal diameter. The tapered surface 221 with an enlarged diameter is located at the extreme end of the protruding portion 22, and the tapered surface 222 with a reduced diameter is located between the connecting portion 23 and the transition section 223.

In the pipe joint provided by the present invention, a transition section 223 is added between the expanded tapered surface 221 and the reduced tapered surface 222 of the protrusion 22 of the inner ring 2, which makes the expanded tapered surface 221 and the reduced diameter The tapered surface 222 is transitionally connected by the transition section 223.

After the connecting portion 23 and the protruding portion 22 of the inner ring 2 are inserted into the inside of one end of the pipe 4, the thickest part of the protruding portion 22 is in surface contact with the inner wall of the pipe 4 through the outer surface of the transition section 223, and the effective area increases. The squeezing force between 4 and the protrusion 22 is dispersed, and the outer surface of the transition section 223 also reduces the bending curvature of the tube 4, and the two effects are superimposed, which greatly reduces the damage to the tube 4. When the axial length W2 of the transition section 223 is 15% to 30% of the axial length W1 of the protrusion 22, the transition section 223 can disperse the extrusion force of the protrusion 22 and the tube 4, and the protrusion The outer surface of 22 can be in close contact with the inner wall of the tube 4, and the bending curvature of the tube 4 is minimized. When W2/W1 is less than 15%, the increase of the extrusion area between the tube 4 and the protrusion 22 is limited, and the extrusion force between the tube 4 and the protrusion 22 is still relatively large. There is a leak as shown in Table 1. When W2/W1 is greater than 30%, the axial length W2 of the transition section 223 is too long, and the axial length W1 corresponding to the protruding portion 22 is constant, then the expanded tapered surface 221 and the reduced diameter tapered surface 222 correspond If the axial length of the tube is too short, the angle between the enlarged tapered surface 221 and the reduced tapered surface 222 and the axial direction of the inner ring 2 will be too large, and the bending curvature of the tube 4 will be relatively large. 4 has a great damage effect.

Table 1 Tightness test results of pipe joints corresponding to the corresponding ratio of W2/W1

W2/W1	Whether there is a leak in the initial connection	Is there any leakage when connecting again?
0.10	Have	Have
0.12	no	Have
0.15	no	no
0.18	no	no
0.20	no	no
0.22	no	no

0.25	no	no
0.28	no	no
0.30	no	no
0.32	no	Have
0.35	Have	Have

The outer surface of the transition section 223 is a cylindrical surface parallel to the axial direction of the inner ring 2, and the included angle between the tangent to any point on the outer surface of the transition section 223 and the axial direction of the inner ring 2 is 0°. When the protrusion 22 is inserted into the tube 4 After one end of the interior, the bending curvature of the tube 4 always falls within its acceptable range, reducing damage to the tube 4, and ensuring that the inner wall of the tube 4 is in close contact with the outer surface of the protrusion 22 without leaving any gaps. The sealing effect between the tube 4 and the inner ring 2.

In addition, the included angle θ1 between the axial direction of the inner ring 2 and the enlarged diameter tapered surface 221 is greater than the included angle θ2 between the inner ring 2 and the reduced diameter tapered surface 222, so that the enlarged diameter tapered surface 221 at the end forms the pipe 4 The obstruction of the tapered surface 222 with reduced diameter can prevent the tube 4 from sliding out along the tapered surface 222 and the transition section 223 with reduced diameter. When the pipe joint and the pipe 4 are used in a high temperature environment, after the pipe 4 is heated and softened, the pipe 4 may slide a certain distance along the reduced diameter tapered surface 222, but due to the end of the expanded tapered surface 221 and the inner ring 2 The included angle θ1 between the axial directions is greater than the included angle θ2 between the reduced-diameter tapered surface 222 and the axial direction of the inner ring 2, which is not conducive to the sliding of the pipe 4, so the enlarged tapered surface 221 can prevent the pipe 4 from sliding out, Furthermore, the reliable sealing performance between the pipe joint and the pipe 4 in a high temperature environment is ensured.

Further, the included angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 is 25 to 35°, and the included angle θ2 between the axial direction of the inner ring 2 and the reduced diameter tapered surface 222 is 10 to 20° When ensuring that the tube 4 does not slide out along the tapered surface 222 of the reduced diameter and the sealing performance is good in a high temperature environment, minimize the bending curvature of the tube 4 so that the bending curvature of the tube 4 is always If it falls within the tolerable range, the damage to the tube 4 is reduced and the service life of the tube 4 is prolonged.

When the included angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 is greater than 35°, although the inner wall of the tube 4 is in close contact with the enlarged tapered surface 221, the sealing between the pipe joint and the pipe 4 is ensured However, the bending curvature of the corresponding area of the tube 4 outside the enlarged tapered surface 221 is relatively large, and the damage effect on the tube 4 is relatively large. If the angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 is further increased, the corresponding bending curvature of the tube 4 will also be further increased, and the damage to the tube 4 will be further increased. When the included angle θ1 between the axial direction of the inner ring 2 and the expanded tapered surface 221 is less than 25°, the contact and extrusion force between the inner wall of the tube 4 and the expanded tapered surface 221 is insufficient. In the environment, the tube 4 is heated and becomes soft, and there is a possibility of slipping out of the inner ring 2, so that leakage as shown in Table 2 is likely to occur.

When the included angle θ2 between the axial direction of the inner ring 2 and the tapered surface 222 of the reduced diameter is less than 10°, the included angle θ1 between the axial direction of the inner ring 2 and the tapered surface 221 of the enlarged diameter is also greater than 35°. The inner wall cannot be in close contact with or squeezed with the tapered surface 222 of the reduced diameter. When used in a high temperature environment, the tube 4 will be heated and softened, and there may be a possibility of slipping out. The large bends are prone to leakage as shown in Table 2. Since the corresponding axial lengths of the enlarged tapered surface 221, the reduced tapered surface 222, and the outer surface of the transition section 223 and the total axial length of the protrusion 22 are constant, the axial direction of the inner ring 2 is the same as that of the enlarged tapered surface. The angle θ1 between the surfaces 221 will change with the change of the angle θ2 between the axial direction of the inner ring 2 and the tapered surface 222 of the reduced diameter. When the axial direction of the inner ring 2 and the tapered surface 222 of the reduced diameter change When the included angle θ2 is greater than 20°, the included angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 will be less than 25. As mentioned above, when the axial direction of the inner ring 2 and the enlarged tapered surface 221 When the included angle θ1 is less than 25°, the contact and squeezing force between the inner wall of the tube 4 and the enlarged tapered surface 221 is not enough. When used in a high temperature environment, the tube 4 becomes soft by heating, and there is It is possible to slip out, so it is prone to leakage as shown in Table 2.

Table 2 Corresponding values of the included angles θ1 and θ2 correspond to the tightness test results of the pipe joints

Angle θ1/°

Angle θ2/°

Whether there is a leak in the initial connection

Is there any leakage when connecting again?

twenty two	twenty three	Have	Have
twenty four	twenty one	no	Have
25	20	no	no
28	17	no	no
30	15	no	no
30	14	no	no
35	10	no	no
36	9	no	Have

Further, as shown in FIG. 5, the radial thickness of the insertion portion 21 is D1, and the radial width of the groove portion 13 is D2. The verification data table 3 shows that when the radial thickness D1 of the insertion portion 21 is 1.2-1.5 times the radial width D2 of the groove portion 13, the insertion portion 21 can be inserted into the groove portion 13 relatively easily, and can be firmly stuck in In the groove 13. When the value of D1/D2 is less than 1.2, although the insert 21 can be inserted into the groove 13 relatively smoothly, the insert 21 is not firmly stuck in the groove 13, and there is a risk of slipping out, which is easy to occur as shown in Table 2. The case of seal failure. When the value of D1/D2 is greater than 1.5, it is difficult for the insertion portion 21 to be inserted into the groove portion 13.

Table 3 Tightness test results of pipe joints corresponding to the corresponding ratio of D1/D2

D1/D2	Whether there is a leak in the initial connection	Is there any leakage when connecting again?
1.08	Have	Have
1.12	Have	Have
1.20	no	no
1.35	no	no
1.41	no	no

1.50	no	no
1.58	no	no
1.64	no	no

Further, in the direction extending from the fitting portion 20 to the end of the insertion portion 21, the radial thickness of the insertion portion 21 gradually decreases, that is, the insertion portion 21 has a tapered shape. The insertion portion 21 with a tapered tip is easier to insert into the groove portion 13, and the installation of the inner ring 2 is easier.

As shown in FIG. 3, the radial distance L1 between the point with the largest outer diameter of the transition section 223 and the outer surface of the fluid passage 24 is the radial distance L2 between the outer surface of the connecting portion 23 and the outer surface of the fluid passage 24 1.5 to 2.5 times. The result of the actual effect of this parameter is to make the thickest part of the protrusion 22 protrude from the outer surface of the connecting part 23 to a certain height, so that the tube 4 can be tightly clamped between the outer cylinder part 11 and the protrusion 22 and the connecting part 23 . When the ratio of L1/L2 is less than 1.5, the tube 4 fails to be tightly clamped by the outer cylinder portion 11 and the protrusion 22. When in a high temperature environment, the tube 4 slips out of the inner ring 2 due to heat and softens. The problem of seal failure is shown in Table 4. When the ratio of L1/L2 is greater than 2.5, it is satisfied that the pipe 4 is firmly clamped between the outer cylinder portion 11 and the protrusion 22. However, after the pipe joint and the pipe 4 are installed, due to the tightening force of the nut 3, the outer cylinder The pressing force of the portion 11 on the protrusion 22 is too large, and the protrusion 22 deforms to the inner side of the fluid channel 24 and causes the fluid channel 24 to become smaller, which is not conducive to the flow of fluid.

Table 4 Tightness test results of pipe joints corresponding to the corresponding ratio of L1/L2

L1/L2 ratio	Whether there is a leak in the initial connection	Is there any leakage when connecting again?
1.35	Have	Have
1.46	Have	Have
1.50	no	no
1.7	no	no

1.8	no	no
2.0	no	no
2.3	no	no
2.5	no	no
2.7	no	no

As shown in FIG. 3, the radial distance L1 between the point with the largest outer diameter of the transition section 223 and the outer surface of the fluid passage 24 is the radial distance between the outer surface of the fitting portion 20 and the outer surface of the fluid passage 24 1.05-1.2 times of L3. When the value of L1/L3 is 1.05～1.2, the outer circumference of the fitting portion 20 is in close contact with the inner wall of the outer tube portion 11, and the thickest part of the protrusion 22 corresponds to the transition section 223 and the outer tube portion 11 to tightly hold the tube 4 If it is stuck, the pipe 4 will not slip out of the pipe joint even in a high temperature environment. When the ratio of L1/L3 is less than 1.05, the tube 4 fails to be tightly clamped by the outer cylinder 11 and the protrusion 22. In a high temperature environment, the tube 4 slips out of the inner ring 2 due to heat and softens, as shown in the table 5 shows the problem of seal failure. When the ratio of L1/L3 is greater than 1.2, the transition section 223 corresponding to the thickest part of the outer cylinder 11 and the protrusion 22 can clamp the pipe 4 tightly. However, after the installation of the pipe joint and the pipe 4 is completed, due to the nut The tightening force of 3, the extrusion force of the outer cylinder portion 11 on the protrusion 22 is too large, and the protrusion 22 deforms to the inside of the fluid passage 24 and causes the fluid passage 24 to become smaller, which is not conducive to fluid flow.

Table 5 Tightness test results of pipe joints corresponding to the corresponding ratio of L1/L3

L1/L3	Whether there is a leak in the initial connection	Is there any leakage when connecting again?
1.00	Have	Have
1.03	Have	Have
1.05	no	no
1.10	no	no

1.12	no	no
1.16	no	no
1.20	no	no
1.25	no	no

Example two

As shown in FIG. 6, in the inner ring 2 of another structure, the outer surface of the transition section 223 of the protrusion 22 is a spherical surface, that is, the enlarged tapered surface 221 and the reduced tapered surface 222 are connected by the spherical surface transition. The connection is smooth, the spherical surface is in closer contact with the inner wall of the tube 4, and the sealing effect is better. The deformation of the tube 4 is gradual, which can reduce the bending curvature of the tube 4 and reduce the damage to the tube 4.

The included angle θ3 between the tangent line at any point on the spherical surface and the axial direction of the inner ring 2 is 0°-35°, and the spherical surface is tangentially connected with the expanded tapered surface 221 and the reduced tapered surface 222 at the intersection. At the intersection with the enlarged tapered surface 221, the angle θ3 between the tangent of the spherical surface and the axial direction of the inner ring is 35°. At the intersection with the reduced tapered surface 222, the tangent of the spherical surface is The included angle θ3 between the axial directions is 20°. At the point where the outer diameter of the spherical surface is the largest, the included angle θ3 between the tangent of the spherical surface and the axial direction of the inner ring is 0°.

The included angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 is greater than the included angle θ2 between it and the reduced tapered surface 222, so that the enlarged tapered surface 221 at the end forms the tube 4 along the reduced diameter The obstruction of the tapered surface 222 sliding outwards can prevent the tube 4 from sliding out along the tapered surface 222 and the transition section 223 of the reduced diameter. When the pipe joint and the pipe 4 are used in a high temperature environment, after the pipe 4 is heated and softened, the pipe 4 may slide a certain distance along the reduced diameter tapered surface 222, but due to the end of the expanded tapered surface 221 and the inner ring 2 The included angle θ1 between the axial directions is greater than the included angle θ2 between the reduced-diameter tapered surface 222 and the axial direction of the inner ring 2, so the enlarged tapered surface 221 can prevent the pipe 4 from sliding out, thereby ensuring that the pipe Reliable tightness between the joint and the pipe 4. The included angle θ1 is set at 25-35°, and the included angle θ2 is set at 10-20° to ensure that the pipe 4 will not slide out along the tapered surface 222 of the reduced diameter in a high temperature environment and the premise of reliable sealing Next, minimize the bending curvature of the tube 4 so that the bending curvature of the tube 4 always falls within its acceptable range, reducing damage to the tube 4 and prolonging the service life of the tube 4.

The radial distance L1 between the point with the largest outer diameter of the transition section 223 and the outer surface of the fluid passage 24 is 1.5 to 2.5 times the radial distance L2 between the outer surface of the connecting portion 23 and the outer surface of the fluid passage 24.

Further, the radial distance L1 between the point with the largest outer diameter of the transition section 223 and the outer surface of the fluid passage 24 is 1.05 to 1.2 of the radial distance L3 between the outer surface of the fitting portion 20 and the outer surface of the fluid passage 24 Times.

When the radial distance L1 between the point with the largest outer diameter of the transition section 223 of the protrusion 22 and the outer surface of the fluid passage 24 is 1.5 to the radial distance L2 between the outer surface of the connecting portion 23 and the outer surface of the fluid passage 24 2.5 times, and when the radial distance L1 between the point with the largest outer diameter of the transition section 223 and the outer surface of the fluid passage 24 is the radial distance L3 between the outer surface of the fitting portion 20 and the outer surface of the fluid passage 24 1.05～1.2 times of, the tube 4 can be firmly clamped between the inner ring 2 and the outer tube 11, which increases the tightening force of the inner ring 2 and the outer tube 11 on the tube 4 and prevents the tube 4 Slide out.

The preferred embodiments of the present invention have been described in detail above, but it should be understood that after reading the above teaching content of the present invention, those skilled in the art can make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims of this application.

Claims (10)

1. A pipe joint connected with a pipe, including:

   The joint main body has a main body cylinder part, an outer cylinder part and an inner cylinder part coaxially arranged, the outer cylinder part and the inner cylinder part are arranged protruding in the same direction from the main body cylinder part, and the inner cylinder part is arranged outside Inside the cylinder, the length of the outer cylinder protruding from the main body cylinder is greater than the length of the inner cylinder protruding from the main body cylinder, surrounded by the main body cylinder, the outer cylinder and the inner cylinder to form one Groove, the opening direction of the groove is the same as the protruding direction of the outer cylindrical portion and the inner cylindrical portion;

   The inner ring has a cylindrical insertion part, a cylindrical fitting part, a cylindrical connecting part and a protruding part, and a fluid channel located in the center, which are arranged coaxially in sequence, and the fitting part is inserted in a detachable manner. Fitted to the radially inner side of the outer cylinder, the insertion part protrudes from one side of the fitting part, and is inserted into the groove part through the opening of the groove part of the joint body, the connection part and the protrusion Portion protruding from the other side of the fitting portion, the outer surface of the protruding portion includes an enlarged diameter tapered surface and a reduced diameter tapered surface, the enlarged diameter tapered surface is located at the end of the protrusion, the The tapered surface of the reduced diameter is located between the connecting portion and the tapered surface of the enlarged diameter. The protruding portion and the connecting portion are pressed into the inside of one end of the tube, and the tube is sandwiched between it and the outer cylindrical portion. The inner ring can be connected to or disconnected from the main body of the joint while being connected to the pipe;

   The nut is fastened to the outer cylinder part of the joint body through internal threads, and together with the inner ring to fasten the pipe to the joint body; characterized in that:

   A transition section is provided between the tapered surface of the enlarged diameter and the tapered surface of the reduced diameter, and the axial length of the transition section is 15%-30% of the axial length of the protrusion. The included angle between the tangent at any point on the outer surface and the axial direction of the inner ring is 0°～35°, and the included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is greater than the angle between it and the tapered surface of the reduced diameter. Angle.
2. A pipe joint connected to a pipe according to claim 1, wherein the angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is 25° to 35°, and the inner ring The angle between the axial direction and the tapered surface of the reduced diameter is 10°-20°.
3. A pipe joint connected to a pipe according to claim 2, wherein the outer surface of the transition section is a cylindrical surface of equal diameter and parallel to the axial direction of the inner ring, and the transition section has Certain axial length.
4. The pipe joint connected with the pipe according to claim 2, wherein the outer surface of the transition section is a spherical surface.
5. A pipe joint connected to a pipe according to claim 3 or 4, wherein the radial distance between the point with the largest outer diameter of the transition section and the outer surface of the fluid channel is the connecting portion The radial distance between the outer surface and the outer surface of the fluid channel is 1.5 to 2.5 times.
6. A pipe joint connected to a pipe according to claim 3 or 4, wherein the radial distance between the point with the largest outer diameter of the transition section and the outer surface of the fluid channel is the fitting The radial distance between the outer surface of the part and the outer surface of the fluid channel is 1.05-1.2 times.
7. A pipe joint connected to a pipe according to claim 1, wherein the inner ring further comprises a cylindrical abutting portion, and the abutting portion and the insertion portion are coaxially arranged and located at the In the radial inner part of the same side of the insertion part, after the inner ring is installed, the abutting part contacts and abuts the inner cylinder part of the joint body.
8. A pipe joint connected to a pipe according to claim 1, wherein the nut includes a screw part and a pressing part, and the screw part is screwed with the thread on the outer circumference of the outer cylinder part. The pressing part presses the tube and the inner ring toward the barrel of the main body, presses the insertion part into the groove part, and fastens the inner ring and the tube to the joint body.
9. A pipe joint connected to a pipe according to claim 1, wherein the radial thickness of the insertion portion is equal to or slightly larger than the radial width of the groove portion, or the radial thickness of the insertion portion It is 1.2-1.5 times the radial width of the groove.
10. A pipe joint connected to a pipe according to claim 1, wherein the radial thickness of the insertion portion gradually decreases in the direction extending from the insertion portion to the end of the insertion portion, that is, The insertion part has a tapered shape.

Images