In-pipe convex point pressing device, using method, double-layer bent pipe and exhaust funnel of double-layer bent pipe

Abstract

The invention discloses an in-pipe convex point pressing device, a using method, a double-layer bent pipe and an exhaust funnel of the double-layer bent pipe. The in-pipe convex point pressing device comprises a driver, a traction piece, a fixing base and at least two convex point pressing assemblies; the end, located on the fixing base, of the traction piece is provided with at least two belling point assemblies arranged in the axial direction of the traction piece, the other end of the traction piece is connected with a driver, and the driver is fixedly connected with the fixing base or the outside. The double-layer bent pipe comprises an inner bent pipe and an outer bent pipe, protruding point parts are arranged on the front portion, the rear portion and / or the middle of the bent position of the inner bent pipe, and the protruding point parts are used for making the inner bent pipe abut against and make contact with the outer bent pipe. According to the double-layer bent pipe, the inner bent pipe is tightly attached to the outer bent pipe through the protruding points which are pressed on the front portion, the rear portion and / or the middle portion of the bent position of the double-layer bent pipe through the in-pipe protruding point pressing device, so that gaps in the front portion, the rear portion and / or the middle portion of the bent position of the double-layer bent pipe are eliminated, resonance collision abnormal sounds are avoided, and the double-layer bent pipe is simple in structure, efficient and convenient to machine and low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of exhaust pipes, and in particular to a tube inner pressure convex point device and a use method thereof, a double-layer bent pipe and an exhaust pipe thereof. Background Art

[0002] The air intake pipe of some exhaust pipes is a double-layer bent pipe structure. However, due to the limitations of the structure, processing technology and method, the stress release of the inner pipe cannot ensure consistency after the inner and outer pipes are bent by sand filling, resulting in uneven gaps in the inner bend pipe or a slight fit between the inner and outer pipes.

[0003] As the vehicle is running, the power output by the engine is transmitted to the bent pipe, causing it to vibrate. However, there are parts where the inner and outer pipes of the bent pipe are not tightly fitted. The vibration can easily cause high-frequency collision noises in the tiny fitting parts inside and outside the bent pipe, causing damage to the bent pipe, affecting the quality of the exhaust pipe and the user experience.

[0004] Therefore, in order to solve the above problems, it is necessary to develop the structure, processing technology and method of the double-layer bent pipe. By using the internal tube pressure convex point device to press convex points at the front, back and / or middle of the bend position of the double-layer bent pipe, the inner bend pipe is in close contact with the outer bend pipe through the convex points, thereby eliminating the gap at the front, back and / or middle of the bend position of the double-layer bent pipe, avoiding the generation of resonance, collision and abnormal noise. In addition, the structure is simple, the processing is efficient and convenient, and the cost is low. Summary of the invention

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A device for pressing convex points in a tube, characterized in that:

[0007] It comprises a driver (5), a traction member (6), a fixing seat (7) and at least two convex point pressing components (8);

[0008] The traction member (6) is slidably sleeved with the fixing seat (7); one end of the traction member (6) located on the fixing seat (7) is provided with at least two convex point assemblies (8) arranged along the axial direction of the traction member (6); the other end of the traction member (6) is connected to the driver (5);

[0009] The driver (5) is fixedly connected to a fixing seat (7) or an external part;

[0010] The convex point pressing component (8) includes a support tube (83) sleeved with the traction member (6), a lotus head (82) and an extrusion block (81) in sequence in the direction away from the driver (5); the support tube (83) is sleeved with the traction member (6) in a sliding manner, and the support tube (83) close to the fixing seat (7) is tightly attached to the fixing seat (7);

[0011] The adjacent support tubes (83) are detachably fixedly connected;

[0012] The extrusion block (81) is adjustably fixedly connected to the traction member (6), and one end of the lotus head (82) is connected to the support tube (83);

[0013] The outer side of the extrusion block (81) is in the shape of a cone, and the small end of the cone faces the lotus head (82);

[0014] The lotus head (82) is provided with an inner hole sleeved with the cone of the extrusion block (81), and the lotus head (82) is divided into at least two equally divided clamping heads (821); one end of the clamping head (821) is movably sleeved with the support tube (83) inseparably, and the other end of the clamping head (821) is a free end; at least one free end of the clamping head (821) is provided with a convex portion (821a);

[0015] The contour of the large end of the cone of the extrusion block (81) is larger than the inner hole of the lotus head (82), and the driver (5) drives the traction member (6) to make the extrusion block (81) approach or move away from the lotus head (82);

[0016] When the extrusion block (81) is close to the lotus head (82), the convex portion (821a) of the free end of the clamping head (821) protrudes from the outer diameter profile of the support tube (83);

[0017] When the extrusion block (81) is away from the lotus head (82), the convex portion (821a) of the free end of the clamping head (821) does not protrude from the outer diameter profile of the support tube (83);

[0018] The spacing between adjacent convex point assemblies (8) is smaller than the stroke of the driver (5).

[0019] Preferably, the outer diameter profile of the extrusion block (81) is smaller than the outer diameter profile of the support tube (83).

[0020] Preferably, the lotus head (82) is split into at least three equally divided clamping heads (821), and the free ends of the clamping heads (821) are each provided with a convex portion (821a).

[0021] Preferably, the traction member (6) is a rigid pull rod, and the support tube (83) is a rigid hard tube;

[0022] A first mounting groove (83a) is provided on the inner side of one end of the support tube (83) connected to the lotus head (82); a first limiting groove (83b) is provided on the side of the first mounting groove (83a); a clamping groove (82a) is provided on the outer side of one end of the lotus head (82) connected to the first mounting groove (83a); a limiting ring (100) is provided between the clamping groove (82a) and the first limiting groove (83b); the limiting ring (100) is used to limit the lotus head (82) from detaching from the support tube (83).

[0023] Preferably, the traction member (6) is a steel wire rope, and the support tube (83) is an elastic tube;

[0024] Connecting heads (9) are provided at both ends of the support tube (83); a second mounting groove (9a) is provided on the inner side of the connecting head (9) connected to the lotus head (82); a second limiting groove (9b) is provided on the side of the second mounting groove (9a); a clamping groove (82a) is provided on the outer side of one end of the lotus head (82) connected to the second mounting groove (9a); a limiting ring (100) is provided between the clamping groove (82a) and the second limiting groove (9b); the limiting ring (100) is used to limit the lotus head (82) from being separated from the connecting head (9).

[0025] A double-layered curved pipe, which adopts the above-mentioned internal convex point pressing device to press convex points, is characterized in that it includes a double-layered curved pipe body (1), the double-layered curved pipe body (1) includes an inner curved pipe (2) and an outer curved pipe (3), and the inner curved pipe (2) is provided with a plurality of convex points (4) formed by protruding convex parts (821a) at the front, back and / or middle of the curved position, and the convex points (4) are used to make the inner curved pipe (2) and the outer curved pipe (3) fit tightly.

[0026] Preferably, the convex point portion (4) includes at least three convex points (41) arranged corresponding to the convex portion (821a), and the convex points (41) protrude from the inner wall surface of the inner bend tube (2) toward the outer wall surface, and the convex points (41) are in tight contact with the inner wall of the outer bend tube (3).

[0027] A method for processing a double-layer bent pipe, using the tube inner pressure convex point device to process the double-layer bent pipe, characterized in that it comprises the following steps:

[0028] S1: preparing an unbent inner curved pipe (2) and an outer curved pipe (3), sleeve the inner curved pipe (2) on a convex point pressing assembly (8) along a traction member (6), and then performing convex point pressing (41) on the front, rear and / or middle of a curved position (11) of the inner curved pipe (2) by a convex point pressing device;

[0029] S2: Then the inner curved pipe (2) is placed inside the outer curved pipe (3) to form a double-layer pipe, and sand is poured between the inner curved pipe (2) and the outer curved pipe (3);

[0030] S3; then put the double-layer pipe into the bending process, and after the sand is cleaned off, a double-layer bent pipe with a convex point inside the pipe is formed.

[0031] A method for processing a double-layer bent pipe, using the tube inner pressure convex point device to process the double-layer bent pipe, characterized in that it comprises the following steps:

[0032] S1: preparing an unbent inner curved pipe (2) and an outer curved pipe (3), placing the inner curved pipe (2) into the outer curved pipe (3) to form a double-layer pipe, and pouring sand between the inner curved pipe (2) and the outer curved pipe (3);

[0033] S2: Then the double-layer pipe is bent to form a double-layer bent pipe after the sand is cleaned off;

[0034] S3: Then, the traction member (6) and the convex point pressing assembly (8) of the convex point pressing device are extended into the double-layer bent pipe to perform convex points (41) on the front and back and / or middle of the bending position (11) of the inner bent pipe (2), thereby forming a double-layer bent pipe with convex points inside the pipe.

[0035] An exhaust pipe comprises the above-mentioned double-layer bent pipe, characterized in that a flange is arranged at one end of the double-layer bent pipe, and a muffler is arranged at the other end.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. By setting multiple convex points at the front, back and / or middle of the inner bend position, the inner bend pipe and the outer bend pipe can be closely fitted, thereby effectively eliminating the gap at the front, back and / or middle of the double-layer bend position, and avoiding the generation of resonance, collision and abnormal noise.

[0038] 2. The tube inner convex point pressing device adopts a structural design of at least two convex point pressing components, which can press convex points on the front, back and / or middle of the inner curved tube at one time. It has a simple structure, convenient operation, high production efficiency and low cost.

[0039] 3. By adjusting the distance between adjacent embossing components or the number of embossing components, the embossing requirements of different double-layer elbows can be met.

[0040] 4. The embossing device can be a linear embossing structure with a simple structure and convenient operation, or a more versatile bending embossing structure that is not affected by the bending position deviation and is suitable for processing double-layer bending pipes with more complex bending shapes.

[0041] 5. The double-layer bent pipe is used on motorcycle exhaust pipes to avoid abnormal noise at the air intake end of the exhaust pipe, thereby improving the quality of the exhaust pipe and the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the structure of the double-layer elbow body in the present invention;

[0043] Figure 2 It is a structural schematic diagram of the convex point pressing device in the present invention (linear convex point pressing);

[0044] Figure 3 It is a structural schematic diagram of the pressure convex point assembly of the present invention (linear pressure convex point);

[0045] Figure 4 It is a structural schematic diagram of another embodiment of the convex point pressing device in the present invention (curved convex point pressing);

[0046] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure after matching with the double-layer elbow body.

[0047] Among them: double-layer curved pipe body 1, inner curved pipe 2, outer curved pipe 3, convex point part 4, driver 5, traction part 6, fixing seat 7, convex point pressing assembly 8, connecting head 9, limiting block 10, bending position 11, limiting rod 20, convex point 41, extrusion block 81, lotus head 82, supporting pipe 83, limiting ring 100, clamping head 821, second installation groove 9a, second limiting groove 9b, convex part 821a, first installation groove 83a, first limiting groove 83b, clamping groove 82a. DETAILED DESCRIPTION

[0048] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0049] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be an element centered thereon. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon at the same time. The terms "vertical", "horizontal", "left", "right", "up", "down", "front", "rear" and similar expressions used herein are for illustrative purposes only.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0051] Below, the present invention is further described in conjunction with the accompanying drawings and specific embodiments:

[0052] like Figure 2-5 As shown, a device for pressing convex points in a pipe comprises a driver 5, a traction member 6, a fixing seat 7 and at least two pressing convex point assemblies 8;

[0053] The traction member 6 is slidably sleeved with the fixing seat 7. One end of the traction member 6 located at the fixing seat 7 is provided with at least two convex point assemblies 8 arranged along the axial direction of the traction member 6. The other end of the traction member 6 is connected to the driver 5.

[0054] The driver 5 is fixedly connected to the fixing seat 7 or the outside;

[0055] The direction of the pressing convex point assembly 8 away from the driver 5 includes a support tube 83 sleeved with the traction member 6, a lotus head 82 and an extrusion block 81 in sequence, the support tube 83 is slidably sleeved with the traction member 6, and the support tube 83 close to the fixing seat 7 is tightly attached to the fixing seat 7;

[0056] The adjacent support tubes 83 are detachably fixedly connected;

[0057] The extrusion block 81 is adjustably fixedly connected to the traction member 6, and one end of the lotus head 82 is connected to the support tube 83;

[0058] The outer side of the extrusion block 81 is in the shape of a cone, and the small end of the cone faces the lotus head 82;

[0059] The lotus head 82 is provided with an inner hole (not shown in the figure) that is sleeved with the cone of the extrusion block 81. The lotus head 82 is divided into at least two equally divided clamping heads 821. One end of the clamping head 821 is movably sleeved with the support tube 83 and cannot be separated. The other end of the clamping head 821 is a free end. At least one free end of the clamping head 821 is provided with a convex portion 821a.

[0060] The contour of the large end of the cone of the extrusion block 81 is larger than the inner hole of the lotus head 82, and the driver 5 drives the traction member 6 to make the extrusion block 81 approach or move away from the lotus head 82;

[0061] When the extrusion block 81 is close to the lotus head 82, the convex portion 821a of the free end of the clamping head 821 protrudes out of the outer diameter profile of the support tube 83;

[0062] When the extrusion block 81 is away from the lotus head 82, the convex portion 821a of the free end of the clamping head 821 does not protrude from the outer diameter profile of the support tube 83;

[0063] The spacing distance between adjacent embossing point components 8 is smaller than the stroke of the driver 5 .

[0064] In this embodiment, when working, the driver 5 is started, pulling the traction member 6 to drive the extrusion block 81 to move toward the direction close to the lotus head 82. The movement of the extrusion block 81 forces the protrusions 821a on the free ends of the multiple clamping heads 821 to be squeezed toward the direction close to the inner bend pipe 2, thereby achieving convex points on the front and back and / or middle of the bend position 11 of the inner bend pipe 2. This convex point pressing method has the characteristics of simple structure, good gap elimination effect, high efficiency and low cost.

[0065] In this embodiment, when pressing the convex point, under the action of the traction member 6 and the extrusion block 81, the moving distance of the support tube 83 and the lotus head 82 close to the fixed seat 7 is limited by the fixed seat 7, while the moving distance of the support tube 83 and the lotus head 82 away from the fixed seat 7 is limited by the adjacent extrusion block 81. Therefore, by adjusting the position of the extrusion block 81 and adapting the support tube 83 of the corresponding length, the requirements for pressing the convex point of different double-layer bent pipes can be met.

[0066] In this embodiment, the method of punching dimples on the outer bend tube 3 not only affects the appearance and easily causes corrosion of the outer bend tube 3 , but also has poor gap elimination effect and cannot achieve the effect of pressing convex points on the inner bend tube 2 .

[0067] In this embodiment, in order to prevent the squeezing block 81 from being impacted and axially moving relative to the traction member 6 , a limiting block 10 is provided on the traction member 6 at one end of the squeezing block 81 away from the lotus head 82 .

[0068] In this embodiment, the embossing requirements of different double-layer bent pipes can be met by adjusting the distance between adjacent embossing assemblies 8 or the number of embossing assemblies 8 .

[0069] Further, such as Figure 2-5 As shown, in order to achieve smooth sleeve connection of the inner bend pipe, the outer diameter profile of the extrusion block 81 is smaller than the outer diameter profile of the support pipe 83 .

[0070] Further, such as Figure 2-5 As shown, the lotus head 82 is split into at least three equally divided clamping heads 821 , and the free ends of the clamping heads 821 are each provided with a convex portion 821 a .

[0071] Further, such as Figure 2-3 As shown, the traction member 6 is a rigid pull rod, and the support tube 83 is a rigid hard tube;

[0072] A limiting rod 20 is provided between adjacent support tubes 83, and the end of the limiting rod 20 is detachably connected to the end surface of the support tube 83;

[0073] A first mounting groove 83a is provided on the inner side of one end of the support tube 83 connected to the lotus head 82, a first limiting groove 83b is provided on the side of the first mounting groove 83a, a clamping groove 82a is provided on the outer side of one end of the lotus head 82 connected to the first mounting groove 83a, a limiting ring 100 is provided between the clamping groove 82a and the first limiting groove 83b, and the limiting ring 100 is used to limit the lotus head 82 from detaching from the support tube 83.

[0074] In this embodiment, the inner bend tube 2 and the outer bend tube 3 are combined to form a bend, and then the bend-shaped convex point pressing component 8 is inserted into the inner bend tube 2 for convex point pressing. The bend-shaped convex point pressing method of the inner bend tube 2 is not affected by the deviation of the bend position 11, is suitable for double-layer bends with more complex bends, and is more universal.

[0075] In this embodiment, the limit rod 20 and the protrusion 821a are arranged alternately, and there is a movable gap between the limit rod 20 and the free end of the clamp 821. When the extrusion block 81 is close to the lotus head 82, the protrusion 821a at the free end of the clamp 821 protrudes from the outer diameter contour of the support tube 83, and the free end of the clamp 821 without the protrusion 821a moves toward the limit rod 20 through the movable gap, thereby realizing the two protrusion pressing components 8 to press the protrusion on the inner bend tube 2.

[0076] Further, such as Figure 4-5 As shown, the traction member 6 is a steel wire rope, and the support tube 83 is an elastic tube;

[0077] A limiting rod 20 is provided between adjacent support tubes 83, and the end of the limiting rod 20 is detachably connected to the end surface of the connector 9;

[0078] Connecting heads 9 are provided at both ends of the support tube 83, a second mounting groove 9a is provided on the inner side of the connecting head 9 connected to the lotus head 82, a second limiting groove 9b is provided on the side of the second mounting groove 9a, a clamping groove 82a is provided on the outer side of one end of the lotus head 82 connected to the second mounting groove 9a, a limiting ring 100 is provided between the clamping groove 82a and the second limiting groove 9b, and the limiting ring 100 is used to limit the lotus head 82 from being separated from the connecting head 9.

[0079] In this embodiment, the elastic tube is in a straight line when not under stress, and can bend along with the bent tube when under stress.

[0080] In this embodiment, in order to improve the continuous stability and reliability of the curved embossing point, the elastic tube is a high-strength spring tube, a metal braided reinforced tube or a Teflon hard rubber tube.

[0081] A double-layer elbow, such as Figure 1 As shown, the above-mentioned convex point pressing device is used to press convex points inside the tube, which is characterized in that it includes a double-layer bent tube body 1, and the double-layer bent tube body 1 includes an inner bent tube 2 and an outer bent tube 3. The front and back and / or middle of the bent position of the inner bent tube 2 are provided with multiple convex point portions 4 formed by protruding convex portions 821a, and the convex point portions 4 are used to make the inner bent tube 2 and the outer bent tube 3 fit tightly.

[0082] In this embodiment, a convex portion 4 is provided on a small gap area formed in front of and behind and / or in the middle of the bend position 11 of the inner bend pipe 2, so that the inner bend pipe 2 and the outer bend pipe 3 can be closely fitted, thereby effectively eliminating the gap in the small gap area in front of and behind and / or in the middle of the bend position 11, thereby avoiding the generation of abnormal noise caused by resonance and collision.

[0083] Further, such as Figure 1 As shown, the convex point portion 4 includes at least three convex points 41 arranged corresponding to the convex portion 821a, and the convex points 41 protrude from the inner wall surface of the inner curved tube 2 toward the outer wall surface, and the convex points 41 are in tight contact with the inner wall of the outer curved tube 3.

[0084] A method for processing a double-layer bent pipe, such as Figure 2 , 3 As shown, the method of processing the double-layer bent pipe as described above using the tube inner pressure convex point device is characterized in that it includes the following steps:

[0085] S1: preparing an unbent inner curved pipe 2 and an outer curved pipe 3, sleeve the inner curved pipe 2 on the convex point pressing assembly 8 along the traction member 6, and then use the convex point pressing device to press convex points 41 on the front and back and / or middle of the curved position 11 of the inner curved pipe 2;

[0086] S2: Then the inner curved pipe 2 is placed into the outer curved pipe 3 to form a double-layer pipe, and sand is poured between the inner curved pipe 2 and the outer curved pipe 3;

[0087] S3; then put the double-layer pipe into the bending process, and after the sand is cleaned off, a double-layer bent pipe with a convex point inside the pipe is formed.

[0088] In this embodiment, the processing method is suitable for linearly pressing convex points on the inner curved tube 2, and has the characteristics of simple structure, convenient operation, high efficiency and low cost.

[0089] A double-layer pipe bending processing method, such as Figure 4 , 5 As shown, the double-layer bent pipe as described is processed using the tube inner pressure convex point device as described, which is characterized by comprising the following steps:

[0090] S1: prepare an unbent inner curved pipe 2 and an outer curved pipe 3, place the inner curved pipe 2 into the outer curved pipe 3 to form a double-layer pipe, and pour sand between the inner curved pipe 2 and the outer curved pipe 3;

[0091] S2: Then the double-layer pipe is bent to form a double-layer bent pipe after the sand is cleaned off;

[0092] S3: Then, the traction member 6 and the convex point pressing assembly 8 of the convex point pressing device are extended into the double-layer bent pipe, and convex points 41 are pressed on the front and back and / or middle of the bending position 11 of the inner bent pipe 2 to form a double-layer bent pipe with convex points inside the pipe.

[0093] In this embodiment, the processing method is applicable to the method of pressing convex points on the bend of the inner bend pipe 2, is not affected by the deviation of the bend position 11, is applicable to double-layer bend pipes with more complex bends, and is more universal.

[0094] An exhaust pipe comprises the above-mentioned double-layer bent pipe, characterized in that a flange is arranged at one end of the double-layer bent pipe, and a muffler is arranged at the other end.

[0095] In this embodiment, by applying the double-layer bent pipe, the generation of resonance, collision and abnormal noise can be avoided, thereby improving the quality of the exhaust pipe and the user experience.

[0096] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the scope of protection of the patent claims of the present invention.

Claims

1. A device for pressing convex points in a tube, characterized in that: It comprises a driver (5), a traction member (6), a fixing seat (7) and at least two convex point pressing components (8); The traction member (6) is slidably sleeved with the fixing seat (7); one end of the traction member (6) located on the fixing seat (7) is provided with at least two convex point assemblies (8) arranged along the axial direction of the traction member (6); the other end of the traction member (6) is connected to the driver (5); The driver (5) is fixedly connected to a fixing seat (7) or an external part; The convex point pressing component (8) includes a support tube (83) sleeved with the traction member (6), a lotus head (82) and an extrusion block (81) in sequence in the direction away from the driver (5); the support tube (83) is sleeved with the traction member (6) in a sliding manner, and the support tube (83) close to the fixing seat (7) is tightly attached to the fixing seat (7); The adjacent support tubes (83) are detachably fixedly connected; The extrusion block (81) is adjustably fixedly connected to the traction member (6), and one end of the lotus head (82) is connected to the support tube (83); The outer side of the extrusion block (81) is in the shape of a cone, and the small end of the cone faces the lotus head (82); The lotus head (82) is provided with an inner hole sleeved with the cone of the extrusion block (81), and the lotus head (82) is divided into at least two equally divided clamping heads (821); one end of the clamping head (821) is movably sleeved with the support tube (83) inseparably, and the other end of the clamping head (821) is a free end; at least one free end of the clamping head (821) is provided with a convex portion (821a); The contour of the large end of the cone of the extrusion block (81) is larger than the inner hole of the lotus head (82), and the driver (5) drives the traction member (6) to make the extrusion block (81) approach or move away from the lotus head (82); When the extrusion block (81) is close to the lotus head (82), the convex portion (821a) of the free end of the clamping head (821) protrudes from the outer diameter profile of the support tube (83); When the extrusion block (81) is away from the lotus head (82), the convex portion (821a) of the free end of the clamping head (821) does not protrude from the outer diameter profile of the support tube (83); The spacing between adjacent convex point assemblies (8) is smaller than the stroke of the driver (5); The traction member (6) is a steel wire rope, and the support tube (83) is an elastic tube.

2. The device for pressing convex points in a tube according to claim 1, characterized in that: The outer diameter profile of the extrusion block (81) is smaller than the outer diameter profile of the support tube (83).

3. The device for pressing convex points in a tube according to claim 1, characterized in that: The lotus head (82) is split into at least three equally divided clamping heads (821), and free ends of the clamping heads (821) are each provided with a convex portion (821a).

4. The device for pressing convex points in a tube according to claim 1, characterized in that: Connecting heads (9) are provided at both ends of the support tube (83); a second mounting groove (9a) is provided on the inner side of the connecting head (9) connected to the lotus head (82); a second limiting groove (9b) is provided on the side of the second mounting groove (9a); a clamping groove (82a) is provided on the outer side of one end of the lotus head (82) connected to the second mounting groove (9a); a limiting ring (100) is provided between the clamping groove (82a) and the second limiting groove (9b); the limiting ring (100) is used to limit the lotus head (82) from being separated from the connecting head (9).

5. A double-layer bent pipe, which is embossed by the embossing device in the pipe as claimed in any one of claims 1 to 4, characterized in that: The invention comprises a double-layer curved pipe body (1), wherein the double-layer curved pipe body (1) comprises an inner curved pipe (2) and an outer curved pipe (3), wherein a plurality of convex points (4) formed by protruding convex parts (821a) are arranged at the front, rear and / or middle of the curved position of the inner curved pipe (2), and the convex points (4) are used to make the inner curved pipe (2) and the outer curved pipe (3) fit tightly.

6. A double-layer elbow according to claim 5, characterized in that: The convex point portion (4) comprises at least three convex points (41) arranged corresponding to the convex portion (821a), the convex points (41) protrude from the inner wall surface of the inner curved tube (2) toward the outer wall surface, and the convex points (41) are in tight contact with the inner wall of the outer curved tube (3).

7. A method for processing a double-layer bent pipe, using the tube inner pressure convex point device as described in any one of claims 1 to 4 to process the double-layer bent pipe as described in any one of claims 5 to 6, characterized in that: The following steps are involved: S1: preparing an unbent inner curved pipe (2) and an outer curved pipe (3), sleeve the inner curved pipe (2) on a convex point pressing assembly (8) along a traction member (6), and then performing convex point pressing (41) on the front, rear and / or middle of a curved position (11) of the inner curved pipe (2) by a convex point pressing device; S2: Then the inner curved pipe (2) is placed inside the outer curved pipe (3) to form a double-layer pipe, and sand is poured between the inner curved pipe (2) and the outer curved pipe (3); S3; then put the double-layer pipe into the bending process, and after the sand is cleaned off, a double-layer bent pipe with a convex point inside the pipe is formed.

8. A method for processing a double-layer bent pipe, using the tube inner pressure convex point device as described in any one of claims 1 to 4 to process the double-layer bent pipe as described in any one of claims 5 to 6, characterized in that: The following steps are involved: S1: preparing an unbent inner curved pipe (2) and an outer curved pipe (3), placing the inner curved pipe (2) into the outer curved pipe (3) to form a double-layer pipe, and pouring sand between the inner curved pipe (2) and the outer curved pipe (3); S2: Then the double-layer pipe is bent to form a double-layer bent pipe after the sand is cleaned off; S3: Then, the traction member (6) and the convex point pressing assembly (8) of the convex point pressing device are extended into the double-layer bent pipe to perform convex points (41) on the front and back and / or middle of the bending position (11) of the inner bent pipe (2), thereby forming a double-layer bent pipe with convex points inside the pipe.

9. An exhaust pipe, comprising the double-layer elbow pipe according to any one of claims 5-6, characterized in that: One end of the double-layer elbow is provided with a flange, and the other end is provided with a muffler.

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