TWI734475B - A pipe joint connected with a pipe - Google Patents

Abstract

The present invention provides a pipe joint connected with a pipe, which comprises a joint body, an inner ring and a nut. A transition section is provided between the diameter-expanded tapered surface and the reduced-diameter tapered surface of the protruding part of the inner ring. The axial length of the protrusion is 15%~30% of the axial length of the protrusion. The angle between the tangent to any point on the outer surface of the transition section and the axial direction of the inner ring is 0°~35°. The axial and enlarged diameter of the inner ring The included angle between the tapered surface is greater than the included angle between the tapered surface and the tapered surface. The outer surface of the transition section of the protruding part is in surface contact with the inner wall of the pipe, the action area is increased, the squeezing force between the two is dispersed, and the transition section also reduces the bending and curvature of the pipe. Small damage to the tube, to achieve 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 It is to prevent the tube from sliding out along the tapered surface of the reduced diameter in a high temperature environment.

Description

A pipe joint connected with a pipe

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.

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 It is composed of three parts with the nut 3, 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 circumference 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 11, and the insertion part 21 of the inner ring 2 Inserted into the groove portion 13, the nut 3 is fastened to the outer circumference of the outer cylinder portion 11 of the joint 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, and 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 periphery of the inner ring 2, the outer periphery of the protrusion 22 abuts against the inner wall of the tube 4, and the thickest part of the tip of the protrusion 22 is the same as that of the tube 4 The inner wall is in the tightest contact and the squeezing force is the largest, and there is only a line contact between the two, the action area is small, the force is very concentrated, and the bending area 41 of the corresponding tube 4 will have a larger curvature. , The superposition of these two factors can easily cause damage to the tube 4. In addition, since 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, a certain gap is likely to exist 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 good. Reach the best.

In addition, because the inclination angles of the enlarged diameter tapered surface 221 and the reduced diameter tapered surface 222 of the protrusion 22 are set unreasonably, when the inclination angle of the enlarged diameter tapered surface 221 is too small, the inclination angle of the reduced diameter tapered surface 222 is relatively large. However, 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 is heated After being softened, it is easy to slide out along the tapered surface 222 of the reduced diameter, thereby causing leakage.

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 out along the inner ring in a high temperature environment. The problem of sealing failure caused by the present invention provides a pipe joint connected with a pipe. The pipe joint includes: a joint main body, which has a main body cylinder part, an outer cylinder part and an inner cylinder part coaxially arranged. The part is arranged on the inner side of the outer tube part, and the length of the outer tube part protruding from the main body tube part is longer than that of the inner tube part protruding from the main body. The length of the body cylinder is surrounded by the main cylinder, the outer cylinder and the inner cylinder to form a groove, and the opening direction of the groove is the same as the protrusion direction of the outer cylinder and the inner cylinder; the inner ring , It 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 and continuously in sequence, and the fitting part is detachably fitted in On 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, and the connecting part and the protruding part are from The other side of the fitting portion is protrudingly arranged, and the outer surface of the protruding portion includes a tapered surface with an enlarged diameter and a tapered surface with a reduced diameter. The tapered surface of the diameter is located between the connecting portion and the enlarged tapered surface. The protruding portion and the connecting portion are pressed into the inside of one end of the tube, and the tube is clamped between it and the outer tube. The inner ring It can be connected to or disconnected from the main body of the joint while being connected to the pipe; a nut, which is fastened to the outer cylinder of the main body of the joint through internal threads, and together with the inner ring to fasten the pipe to the The main body of the joint; 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% to 30% of the axial length of the protrusion, 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 enlarged diameter is greater than the angle between the axial direction of the inner ring and the tapered surface of the reduced diameter. The angle between the cones.

The outer surface of the protruding part 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. The circular line is connected, that is, the tapered surface of the enlarged diameter is directly connected to the tapered surface of the reduced diameter. The circular line corresponds to the thickest part of the protrusion. From the appearance, the thickest part is sharp. The protruding part of the inner ring is inserted into the inside of one end of the tube, and the outer periphery of the protruding part abuts against the inner wall of the tube. The maximum force is exerted, and only a line contact is formed between the two here, the action area is small, the action force is very concentrated, and the tube will have a larger curvature in this area. The superposition of these two factors will cause great damage to the tube. damage.

In the existing pipe joints, 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. Near the area corresponding to the 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 outer surface of the protrusion The tightness between the tubes is not optimal.

In addition, due to the unreasonable setting of the inclination angles of the enlarged tapered surface and the reduced tapered surface of the protruding part, the inclination angle of the enlarged tapered surface is too small, and the inclination angle of the reduced tapered surface is relatively large. The tapered surface and the tapered surface of the reduced diameter 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 tapered surface of the reduced diameter after being heated and softened. Slide out, causing leakage.

In the pipe joint provided by the present invention, a transition section is added between the expanded tapered surface and the reduced diameter 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 length. After the connecting part and the protrusion of the inner ring are inserted into the inside of one end of the tube, the thickest part of the protrusion is in surface contact with the inner wall of the tube through the outer surface of the transition section. The force 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 at 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 Within the range that it can bear, the damage to the tube is reduced, and the inner wall of the tube is in close contact with the outer surface of the protrusion without leaving any gap, 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 enlarged diameter and the tapered surface of the reduced diameter. The obstruction 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. The included angle 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 out of the pipe, thereby ensuring the connection between the pipe joint and the pipe in a high temperature environment. The reliable sealing performance.

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

The angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is 25~35°, and when the angle between the tapered surface of the reduced diameter is 10-20°, it is ensured that the pipe will not follow the tapered surface of the reduced diameter in a high temperature environment. On the premise that the cone surface slides out and the sealing is good, try to reduce the bending curvature of the tube, so that the bending curvature of the tube always falls within its tolerable range, reducing the damage to the tube and prolonging the service life of the tube .

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 tapered surface and the reduced tapered 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 tapered surface of the enlarged diameter and the tapered surface of the reduced diameter are connected by the spherical transition, and 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 gradual and can be reduced. The bending and curvature of the small tube reduces the damage to the tube.

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 1.05 of the radial distance between the outer surface of the fitting portion and the outer surface of the fluid channel When ~1.2 times, the tube can be firmly clamped between the inner ring and the outer tube, which increases the fastening force of the inner ring and the outer tube to the tube and prevents the tube 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 is installed After completion, the abutting part contacts and abuts the inner cylinder part 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 inserting portion to the end of the inserting portion, the radial thickness of the inserting portion gradually decreases, that is, the inserting 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% 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 enlarged diameter is greater than the angle between it and the tapered surface of the reduced diameter的角。 The included angle. The outer surface of the transition section of the protruding part is in surface contact with the inner wall of the pipe, the action area is increased, the squeezing force between the two is dispersed, and the transition section also reduces the bending and curvature of the pipe. Small damage to the tube, to achieve 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 tube will not slide out along the tapered surface and transition section of the reduced diameter.

1: Connector body

10: The main body tube

11: Outer cylinder

12: Inner cylinder

13: Groove

2: inner ring

20: Fitting part

21: Insertion part

22: protrusion

220: round wire

221: Expanded cone

222: reduced cone

223: Transition section

23: Connection

24: fluid channel

25: Buttress

3: nut

31: Pressing part

32: Screw part

4: tube

41: bending area

D1: Radial thickness

D2: Radial width

L1: Radial distance

L2: Radial distance

L3: Radial distance

W1: axial length

W2: axial length

θ1: included angle

θ2: included angle

θ3: included angle

The present invention will be further described below with reference to the accompanying drawings: [Figure 1] is a cross-sectional view of the inner ring of the pipe joint disclosed in the prior art

[Figure 2] is a cross-sectional view of the pipe joints and pipes disclosed in the prior art after the installation is completed

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

[Figure 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 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 with reference to 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 Figures 3-4, the pipe joint includes: a joint body 1, which has a main body tube portion 10, an outer tube portion 11, and an inner tube portion 12 that are coaxially arranged. Protruding in the same direction, the inner tube 12 is provided on the inner side of the outer tube 11, and the length of the outer tube 11 protruding from the main body tube 10 is greater than the length of the inner tube 12 protruding from the main body tube 10. The cylindrical portion 10, the outer cylindrical portion 11 and the inner cylindrical portion 12 surround and form 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 passage 24 located in the center, which are successively arranged coaxially and continuously. The fitting portion 20 can be It is fitted on the radially inner side of the outer cylinder portion 11 in a detachable manner, 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 protrudes from the other side of the fitting part 20.

The protruding portion 22 and the connecting portion 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 portion 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.

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 located 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, the 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 surfaces 222 are 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 tube 4, the thickest part of the protruding portion 22 is in surface contact with the inner wall of the tube 4 through the outer surface of the transition section 223, and the effective area is increased. The squeezing force between the tube 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 transition When the axial length W2 of 223 is 15% to 30% of the axial length W1 of the protrusion 22, the transition section 223 generates the squeezing force of the protrusion 22 and the tube 4, and the outer surface of the protrusion 22 It 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 to The axial length of the tube 4 is too short, which will cause the angle between the expanded tapered surface 221 and the reduced tapered surface 222 and the axial direction of the inner ring 2 to be too large, and the bending curvature of the tube 4 will be relatively large. The damage effect is great.

The outer surface of the transition section 223 is a cylindrical surface parallel to the axial direction of the inner ring 2, and the 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 one end of the tube 4 After the inside of the tube 4, the bending curvature of the tube 4 always falls within its acceptable range, reducing the 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, leaving no gaps, improving 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 tube 4 along the contraction. The obstruction of the tapered surface 222 of the diameter from sliding out 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 tapered surface 222 of reduced diameter, but due to the end of the 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, thereby ensuring This improves the reliable sealing performance between the pipe joint and the pipe 4 in a high temperature environment.

Further, when the included angle θ1 between the axial direction of the inner ring 2 and the enlarged diameter 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°, To ensure that the tube 4 will not slide out along the tapered surface 222 of the reduced diameter under the condition of good sealing performance in a high temperature environment, minimize the bending curvature of the tube 4 so that the bending curvature of the tube 4 always falls on Within the tolerable range, 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 pipe 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 cone surface 221 is less than 25°, the contact and extrusion force between the inner wall of the tube 4 and the expanded cone surface 221 is insufficient. In the environment, the tube 4 is heated and softened, and there is a possibility of slipping out of the inner ring 2, so that leakage as shown in Table 2 is prone to occur.

When the 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 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°, and the inner wall of the pipe 4 It 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. Because of the bending of the amplitude, the leakage as shown in Table 2 is prone to occur. 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 included angle θ1 between the surfaces 221 will change with the change of the included angle θ2 between the axial direction of the inner ring 2 and the reduced diameter tapered surface 222, when the included angle θ2 between the axial direction of the inner ring 2 and the reduced diameter tapered surface 222 When it 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 included angle θ1 between the axial direction of the inner ring 2 and the enlarged tapered surface 221 When it 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 will be heated and softened, and there is a possibility of slipping out of the inner ring 2 , So it is prone to leakage as shown in Table 2.

Further, as shown in FIG. 5, the radial thickness of the insertion portion 21 is D1, and the radial width of the groove 13 is D2. The verification data table 3 shows that when the radial thickness D1 of the insertion part 21 is 1.2-1.5 times the radial width D2 of the groove part 13, the insertion part 21 can be inserted into the groove part 13 relatively easily, and can be firmly stuck in槽部13内。 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.

Further, in the direction extending from the fitting portion 20 to the distal 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 part 21 with a tapered tip is easier to insert into the groove part 13, and the installation of the inner ring 2 is easier.

As shown in FIG. 3, the radial distance L1 between the point of 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 1.5~2.5 times. The actual effect of this parameter results in that the thickest part of the protrusion 22 protrudes 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, 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.

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 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 that. 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 tighten the tube 4 The ground is stuck, even in a high temperature environment, the pipe 4 will not slip out of the pipe joint. When the ratio of L1/L3 is less than 1.05, the tube 4 fails to be tightly clamped by the outer cylinder portion 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 portion 11 and the protrusion 22 can clamp the pipe 4 tightly. However, after the pipe joint and the pipe 4 are installed, 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 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 5 Tightness test results of pipe joints corresponding to the corresponding ratio of L1/L3

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 expanded tapered surface 221 and the reduced diameter 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 of 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 enlarged diameter tapered surface 221 and the reduced diameter 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 angle θ3 between the two directions is 20°. At the point where the outer diameter of the spherical surface is the largest, the 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 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 a cone along the reduced diameter of the pipe 4 Face 222 The obstacle of sliding out 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 tapered surface 222 of reduced diameter, but due to the end of the tapered surface 221 and the inner ring 2 The included axial angle θ1 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 diameter tapered surface 221 can prevent the pipe 4 from sliding out, thereby ensuring the pipe joint and Reliable airtightness between the pipes 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 under the premise of reliable sealing performance in a high temperature environment. 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 channel 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 channel 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 1.05~1.2 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, the tube 4 can be firmly clamped between the inner ring 2 and the outer tube 11, which increases the fastening force of the inner ring 2 and the outer tube 11 on the tube 4 and prevents the tube 4 from slipping. 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 with ordinary knowledge in the technical field to which the present invention belongs can Various changes or modifications were made to the invention. These equal forms also fall within the scope defined by the scope of the patent application attached to this application.

2: inner ring

20: Fitting part

21: Insertion part

22: protrusion

221: Expanded cone

222: reduced cone

223: Transition section

23: Connection

24: fluid channel

25: Buttress

L1: Radial distance

L2: Radial distance

L3: Radial distance

W1: axial length

W2: axial length

θ1: included angle

θ2: included angle

Claims (9)

A pipe joint connected with a pipe includes a joint main body with a main body cylinder part, an outer cylinder part and an inner cylinder part arranged coaxially, and the outer cylinder part and the inner cylinder part are arranged protruding in the same direction from the main body cylinder part, The inner tube part is arranged inside the outer tube part, and the length of the outer tube part protruding from the main body tube part is greater than the length of the inner tube part protruding from the main body tube part. The cylindrical portion and the inner cylindrical portion are surrounded to form a groove, and the opening direction of the groove is the same as the protruding direction of the outer cylindrical portion and the inner cylindrical portion; The fitting part, the cylindrical connecting part and the protruding part and the fluid channel located in the center, the fitting part is detachably fitted into the radial inner side of the outer cylinder part, and the insertion part is inserted from the fitting One side of the part protruding, and the groove part is inserted into the groove part through the opening of the groove part of the joint body, the connecting part and the protruding part protruding from the other side of the fitting part, the protruding part The outer surface includes an enlarged tapered surface and a reduced tapered surface, the enlarged tapered surface is located at the end of the protrusion, and the reduced tapered surface is located between the connecting portion and the enlarged tapered surface, The protruding part and the connecting part are pressed into the inside of one end of the tube, and the tube is clamped between the tube and the outer cylinder part, and the inner ring can be connected to or disconnected from the joint body in the state of being connected to the tube; Cap, which is fastened to the outer cylinder part of the joint body by internal threads, and together with the inner ring to fasten the pipe to the joint body; characterized in that: the enlarged tapered surface A transition section is provided between the tapered surface and the tapered surface. The axial length of the transition section is 15% to 30% of the axial length of the protrusion. The tangent to any point on the outer surface of the transition section and the inner The included angle between the axial direction of the 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 included angle between the axial direction of the inner ring and the tapered surface of the reduced diameter; The included angle between the axial direction of the inner ring and the tapered surface of the enlarged diameter is 25°-35°, and the included angle between the axial direction of the inner ring and the tapered surface of the reduced diameter is 10°-20°. A pipe joint connected to a pipe according to claim 1, wherein the outer surface of the transition section is a cylindrical surface of equal diameter and is parallel to the axial direction of the inner ring, and the transition section has a certain axial length . The pipe joint connected with the pipe according to claim 1, wherein the outer surface of the transition section is a spherical surface. A pipe joint connected to a pipe as described in claim 2 or 3, 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 outer surface of the connecting portion and the outer surface of the fluid channel. The radial distance between the outer surfaces of the fluid channels is 1.5 to 2.5 times. A pipe joint connected to a pipe according to claim 2 or 3, 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 outer surface of the fitting portion The radial distance from the outer surface of the fluid channel is 1.05~1.2 times. According to claim 1, a pipe joint connected to a pipe, wherein the inner ring further includes a cylindrical abutting portion, and the abutting portion is arranged coaxially with the insertion portion and is located at the end of the insertion portion. In the radial inner part of the same side, after the inner ring is installed, the abutting portion contacts and abuts the inner cylinder portion of the joint body. According to claim 1, a pipe joint connected to a pipe, wherein the nut includes a screwed portion and a pressing portion, the screwed portion is screwed with the thread on the outer circumference of the outer cylinder, and the pressing portion The tube and the inner ring are pressed in the direction of the main body cylinder, and the insertion part is pressed into the groove part, so that the inner ring and the tube are fastened to the joint body. A pipe joint connected to a pipe according to claim 1, wherein the radial thickness of the insertion part is equal to or slightly larger than the radial width of the groove part, or the radial thickness of the insertion part is the same as that of the groove part. 1.2-1.5 times the radial width. 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 portion The tip is tapered.

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