Pipe expanding mechanism and pipe expanding equipment

Abstract

The utility model discloses a pipe expansion mechanism and pipe expansion equipment, when the pipe expansion mechanism works, an expansion rod pushes a push expansion head and a pull expansion head to forwards penetrate into a refrigerant pipe to a specified position, and the diameter of a second pipe expansion part is not greater than that of a first pipe expansion part during the period, so that the first pipe expansion part of the push expansion head performs primary pipe diameter expansion on the refrigerant pipe; then the expansion rod backwards pulls the push expansion head and the pull expansion head, the pull expansion part is matched with the pull expansion head and expands the pull expansion head during the period, so that the diameter of the second pipe expansion part is larger than that of the first pipe expansion part, the second pipe expansion part of the pull expansion head plays a role in secondary pipe diameter expansion on the refrigerant pipe, and multi-time pipe expansion is achieved through a single pipe expansion mechanism; and the heat exchanger tube expansion production process is simplified.

Description

TECHNICAL FIELD

[0001] The utility model relates to heat exchanger expansion, especially a kind of expansion mechanism and expansion equipment. BACKGROUND

[0002] Heat exchanger includes fin group and refrigerant pipe, refrigerant pipe is assembled and is inserted into fin group, and it needs to be expanded by the expansion mechanism of expansion equipment to the refrigerant pipe, so that the pipe diameter of refrigerant pipe increases, so that the contact between refrigerant pipe and fin group is more closely.Some expansion equipment, its expansion mechanism includes expansion rod and expansion head, expansion head is connected to the front of expansion rod.When expansion operation is carried out, expansion head is placed into refrigerant pipe, expansion head is pushed to predetermined position by expansion rod, and then it is pulled back, and the pipe diameter of refrigerant pipe is expanded by pushing expansion or pulling expansion.For some refrigerant pipe, for example steel refrigerant pipe, in order to avoid refrigerant pipe breakage, refrigerant pipe is usually expanded in several times to reach the required pipe diameter size, and the common way is to use expansion mechanism with different expansion head specifications to implement expansion respectively, and the overall production process is relatively troublesome. SUMMARY

[0003] The utility model aims at at least one of the technical problems existing in prior art is solved.For this purpose, the utility model provides an expansion mechanism, which can realize expansion in several times by single expansion mechanism, so as to simplify the production process of heat exchanger expansion.

[0004] The utility model further provides an expansion equipment with the above-mentioned expansion mechanism.

[0005] According to the expansion mechanism of the first aspect of the utility model, expansion rod is arranged along front-back direction, expansion rod is provided with pulling expansion part, pushing expansion head is connected to the front of expansion rod and can move with expansion rod, the outer periphery of pushing expansion head is provided with first expansion part, pulling expansion head is connected to the front of expansion rod and can move with expansion rod, pulling expansion head has elasticity, pushing expansion head and pulling expansion head are arranged along the length direction of expansion rod, the outer periphery of pulling expansion head is provided with second expansion part, wherein when expansion rod moves forward, pulling expansion head is separated from pulling expansion part, the diameter of second expansion part is not greater than the diameter of first expansion part, when expansion rod is pulled back, pulling expansion part cooperates with pulling expansion head and expands pulling expansion head, so that the diameter of second expansion part is greater than the diameter of first expansion part.

[0006] According to the pipe expanding mechanism, the following beneficial effects are achieved: when the pipe expanding mechanism works, the expansion rod pushes the pushing expansion head and the pulling expansion head to penetrate into the refrigerant pipe forward until the specified position, the diameter of the second pipe expanding part is not greater than the diameter of the first pipe expanding part during the process, so that the first pipe expanding part of the pushing expansion head plays a role of one-time pipe expanding diameter on the refrigerant pipe; then the expansion rod pulls the pushing expansion head and the pulling expansion head back, the pulling expansion part cooperates with the pulling expansion head and expands the pulling expansion head during the process, so that the diameter of the second pipe expanding part is greater than the diameter of the first pipe expanding part, the second pipe expanding part of the pulling expansion head plays a role of two-time pipe expanding diameter on the refrigerant pipe, and the single pipe expanding mechanism is used to realize pipe expanding in batches, and the heat exchanger pipe expanding production process is simplified.

[0007] According to some embodiments of the utility model, first stop part, first rod section, second rod section and second stop part are sequentially arranged in the direction from back to front along the expansion rod, the diameter of the second rod section is greater than the diameter of the first rod section, the first rod section and the second rod section are coaxially arranged, the expansion rod is movably arranged in the pulling expansion head, the pulling expansion head is located between the first stop part and the second stop part and can move between the first rod section and the second rod section, the first stop part and the second stop part can limit the position of the pulling expansion head, the second rod section forms the pulling expansion part, when the expansion rod moves forward, the pulling expansion head is located in the first rod section, when the expansion rod pulls back, the pulling expansion head is at least partially located in the second rod section.

[0008] According to some embodiments of the utility model, the pulling expansion head comprises a connecting ring and at least two elastic arms, the first rod section is arranged in the connecting ring, the elastic arms extend along the length direction of the expansion rod, one end of the elastic arm is connected with the connecting ring, all the elastic arms are arranged around the central axis of the expansion rod, the elastic arms are located on the side of the connecting ring close to the second rod section, and the side of all the elastic arms away from the expansion rod forms the second pipe expanding part.

[0009] According to some embodiments of the utility model, the expansion rod comprises a main rod body and a mounting rod coaxially arranged, one end of the mounting rod is mounted on the main rod body, the first rod section and the second rod section are arranged on the mounting rod, the other end of the mounting rod forms the second stop part, the pushing expansion head and the pulling expansion head are connected to the mounting rod, and the end of the main rod body close to the mounting rod forms the first stop part.

[0010] According to some embodiments of the utility model, the end of the second rod section close to the first rod section is provided with a chamfered surface.

[0011] According to some embodiments of the present application, the second rod section is movably arranged in the push-expanding head, the push-expanding head is located between the pull-expanding head and the second stop part, and the first stop part and the second stop part can limit the position of the push-expanding head.

[0012] According to some embodiments of the present application, the push-expanding head is provided with a gas-permeable groove on the side close to the second stop part, and a gas-permeable gap is arranged between the push-expanding head and the expanding rod, and the gas-permeable groove and the gas-permeable gap are in communication.

[0013] According to some embodiments of the present application, the first tube-expanding part is located at one end of the push-expanding head close to the pull-expanding head, and the second tube-expanding part is located at one end of the pull-expanding head close to the push-expanding head.

[0014] According to some embodiments of the present application, the first tube-expanding part is a first tube-expanding surface, and the second tube-expanding part is a second tube-expanding surface.

[0015] According to the tube-expanding device of the second aspect of the present application, the above-mentioned tube-expanding mechanism is adopted.

[0016] According to the tube-expanding device of the second aspect of the present application, at least the following beneficial effects are achieved: the adoption of the above-mentioned tube-expanding mechanism can simplify the tube-expanding production process of the heat exchanger.

[0017] The additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:

[0019] Figure 1 It is a schematic view of the tube-expanding mechanism of the present application when moving forward;

[0020] Figure 2 It is a schematic view of the tube-expanding mechanism of the present application when moving forward;

[0021] Figure 3 It is a schematic view of the tube-expanding mechanism of the present application when moving backward;

[0022] Figure 4 It is a schematic view of the tube-expanding mechanism of the present application when moving backward;

[0023] Figure 5 It is an exploded schematic view of the tube-expanding mechanism of the present application.

[0024] Reference signs:

[0025] expansion rod 100, main rod body 110, first stop portion 111, mounting rod 120, first rod segment 121, second rod segment 122, second stop portion 123, chamfer surface 124;

[0026] expansion head 200, first expansion tube portion 210, air permeable groove 220;

[0027] expansion head 300, second expansion tube portion 310, elastic arm 320, connecting ring 330. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0029] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0030] In the description of the present application, the plural refers to two or more. If there is a description of first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0031] In the description of the present application, unless otherwise explicitly limited, the words such as setting, mounting, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0032] Reference Figures 1 to 5The utility model discloses an expand mechanism of heat exchanger pipe, including expansion rod 100, push expansion head 200 and pull expansion head 300. Expansion rod 100 sets up along the front -back direction, and expansion rod 100 is provided with pull expansion part, push expansion head 200 is connected to the front of expansion rod 100 and can move with expansion rod 100, and the periphery of push expansion head 200 is provided with first expansion pipe part 210, pull expansion head 300 is connected to the front of expansion rod 100 and can move with expansion rod 100, and pull expansion head 300 has elasticity, and push expansion head 200 and pull expansion head 300 are arranged along the length direction of expansion rod 100, and the periphery of pull expansion head 300 is provided with second expansion pipe part 310, wherein when expansion rod 100 moves forward, pull expansion head 300 separates with pull expansion part, and the diameter of second expansion pipe part 310 is not greater than the diameter of first expansion pipe part 210, when expansion rod 100 is pulled back, pull expansion part cooperates with pull expansion head 300 and expands pull expansion head 300 to make the diameter of second expansion pipe part 310 greater than the diameter of first expansion pipe part 210.

[0033] When the expand mechanism works, expansion rod 100 pushes push expansion head 200 and pull expansion head 300 to enter the refrigerant pipe forward until the specified position, and during the period, the diameter of second expansion pipe part 310 is not greater than the diameter of first expansion pipe part 210, so that first expansion pipe part 210 of push expansion head 200 plays a role of primary expansion pipe diameter on the refrigerant pipe, then expansion rod 100 pulls back push expansion head 200 and pull expansion head 300, during the period, pull expansion part cooperates with pull expansion head 300 and expands pull expansion head 300, so that the diameter of second expansion pipe part 310 is greater than the diameter of first expansion pipe part 210, and second expansion pipe part 310 of pull expansion head 300 plays a role of secondary expansion pipe diameter on the refrigerant pipe, so that the single expand mechanism realizes the expansion pipe in batches, and the heat exchanger expansion pipe production process is simplified.

[0034] Specifically, the length direction of expansion rod 100 is the front-back direction. Expansion rod 100 and push expansion head 200 are rigid structures.

[0035] In the embodiment, expansion rod 100 is sequentially arranged and provided with first stop part 111, first rod segment 121, second rod segment 122 and second stop part 123 along the direction from back to front, the diameter of second rod segment 122 is greater than the diameter of first rod segment 121, first rod segment 121 and second rod segment 122 are coaxially arranged, expansion rod 100 is movably arranged in pull expansion head 300, pull expansion head 300 is located between first stop part 111 and second stop part 123 and can move between first rod segment 121 and second rod segment 122, first stop part 111 and second stop part 123 can limit the position of pull expansion head 300, second rod segment 122 forms pull expansion part, when expansion rod 100 moves forward, pull expansion head 300 is located in first rod segment 121, when expansion rod 100 is pulled back, pull expansion head 300 is at least partially located in second rod segment 122.

[0036] When the expansion rod 100 pushes the push expansion head 200 and the pull expansion head 300 forward to penetrate into the refrigerant pipe, the outer periphery of the pull expansion head 300 is in frictional contact with the inner hole of the refrigerant pipe, so that the pull expansion head 300 is entirely moved to the first rod section 121 to allow elastic reduction, that is, the second pipe expansion section 310 is also reduced, and then is pushed to move by the first stop portion 111, at this time, the diameter of the second pipe expansion section 310 is less than or equal to the diameter of the first pipe expansion section 210, so that the push expansion head 200 plays a role of a first pipe expansion diameter, and the pull expansion head 300 basically does not play a role; when the expansion rod 100 pulls the push expansion head 200 and the pull expansion head 300 backward, since the outer periphery of the pull expansion head 300 is in frictional contact with the outer periphery of the refrigerant pipe, the pull expansion head 300 is partially moved to the second rod section 122 relative to the expansion rod 100, and is driven to move by the second stop portion 123, since the diameter of the second rod section 122 is greater than the diameter of the first rod section 121, the second rod section 122 can expand the pull expansion head 300, so that the diameter of the second pipe expansion section 310 is greater than the diameter of the first pipe expansion section 210. Therefore, the pull expansion head 300 plays a role of a second pipe expansion diameter during the backward pulling of the expansion rod 100, and the push expansion head 200 basically does not play a role, so that the two pipe expansion diameters can respectively expand the refrigerant pipe to a relatively appropriate size.

[0037] It can be understood that the pull expansion head 300 can also be entirely moved to the second rod section 122 during the backward pulling.

[0038] In the embodiment, the pull expansion head 300 includes a connecting ring 330 and four elastic arms 320, the first rod section 121 is arranged in the connecting ring 330, the elastic arms 320 extend along the length direction of the expansion rod 100, one end of the elastic arm 320 is connected with the connecting ring 330, all the elastic arms 320 are arranged around the central axis of the expansion rod 100, the elastic arms 320 are located on the side of the connecting ring 330 close to the second rod section 122, all the elastic arms 320 form an elastic deformation section, and the side of all the elastic arms 320 away from the expansion rod 100 forms the second pipe expansion section 310. When the elastic arms 320 of the pull expansion head 300 enter the second rod section 122, since the diameter of the second rod section 122 is increased, the elastic arms 320 are elastically deformed to be separated from each other, so that the diameter of the second pipe expansion section 310 is increased; when the elastic arms 320 of the pull expansion head 300 are separated from the second rod section 122, the elastic arms 320 can be reduced under the elastic action of the elastic arms 320 themselves, or are pressed to be reduced in contact with the pipe hole of the refrigerant pipe, so that the diameter of the second pipe expansion section 310 can be reduced, thereby realizing the function of the pull expansion head 300, the structure is relatively simple, and an additional driving mechanism is not needed to drive the pull expansion head 300 to expand or reduce, and the use effect is good.

[0039] Specifically, the dilatation head 300 has four elastic arms 320, and a gap groove is formed between adjacent elastic arms 320 for elastic deformation of the elastic arms 320. It can be imagined that in other embodiments, the dilatation head 300 can also have two, three or more elastic arms 320, which are not limited here.

[0040] It can be imagined that in other embodiments, the dilatation head 300 can also be expanded or reduced by other means, for example, a movable conical block is arranged at the front end of the dilatation rod 100, the conical block is pulled to move by a pulling rope, and then the elastic arms 320 of the dilatation head 300 are pushed by the conical block to expand. Similarly, the structure of the dilatation head 300 can also be other structures, for example, the dilatation head 300 includes a plurality of connecting arms and an elastic ring, all the connecting arms are arranged around the central axis of the dilatation rod 100, all the connecting arms are connected to the elastic ring, and the outer periphery of all the connecting arms forms the second dilatation tube part 310. When the dilatation head 300 is in the first rod section 121, the elastic ring is elastically reduced, so that the second dilatation tube part 310 is reduced; when the dilatation head 300 is in the second rod section 122, the elastic ring is elastically expanded, so that the second dilatation tube part 310 is increased.

[0041] In the embodiment, the dilatation rod 100 includes a main rod body 110 and a mounting rod 120 arranged coaxially, one end of the mounting rod 120 is mounted to the main rod body 110, the first rod section 121 and the second rod section 122 are arranged on the mounting rod 120, the other end of the mounting rod 120 forms a second stop part 123, the dilatation head 200 and the dilatation head 300 are connected to the mounting rod 120, and the end of the main rod body 110 close to the mounting rod 120 forms a first stop part 111. The main rod body 110 and the mounting rod 120 are assembled and connected to form the dilatation rod 100, which facilitates the installation of the dilatation head 300 and the dilatation head 200 to the main rod body 110, and facilitates production and assembly.

[0042] Specifically, the main rod body 110 is provided with a threaded hole in the direction of the central axis, and the mounting rod 120 is provided with a threaded column section which is threadedly connected to the threaded hole, so that the main rod body 110 and the mounting rod 120 are assembled relatively firmly. It can be imagined that in other embodiments, one end of the mounting rod 120 can also be mounted to the main rod body 110 by other means, for example, one end of the mounting rod 120 is assembled and connected to the main rod body 110 by welding or riveting.

[0043] In the embodiment, the second rod section 122 is provided with a chamfered surface 124 at the end close to the first rod section 121, which facilitates the elastic arms 320 of the dilatation head 300 to slide from the first rod section 121 to the second rod section 122, and reduces the risk that the dilatation head 300 cannot slide to the second rod section 122.

[0044] In the embodiment, the second rod section 122 is movably arranged in the push inflation head 200, the push inflation head 200 is located between the pull inflation head 300 and the second stop 123, and the first stop 111 and the second stop 123 can limit the position of the push inflation head 200. The push inflation head 200 can also move along the second rod section 122, facilitating the inflation rod 100 to pass the push inflation head 200 and the pull inflation head 300 into the refrigerant pipe, the push inflation head 200 can slide towards the first rod section 121, push the pull inflation head 300 to separate from the second rod section 122, reduce the risk that the pull inflation head 300 cannot separate from the second rod section 122, and make the production mode of the split inflation pipe diameter relatively stable.

[0045] It can be imagined that in other embodiments, the push inflation head 200 can also be fixed on the inflation rod 100.

[0046] In the embodiment, the side of the push inflation head 200 close to the second stop 123 is provided with an air permeation groove 220, an air permeation gap is arranged between the push inflation head 200 and the inflation rod 100, and the air permeation groove 220 is in communication with the air permeation gap. The air permeation groove 220 is arranged to allow air flow on both sides of the push inflation head 200 when the inflation rod 100 and the push inflation head 200 and the pull inflation head 300 move back and forth in the refrigerant pipe, avoiding the risk of excessive or insufficient local air pressure in the refrigerant pipe, and improving the safety of the inflation pipe.

[0047] In the embodiment, the first inflation pipe portion 210 is located at the end of the push inflation head 200 close to the pull inflation head 300, and the second inflation pipe portion 310 is located at the end of the pull inflation head 300 close to the push inflation head 200. The first inflation pipe portion 210 and the second inflation pipe portion 310 are arranged in a relatively reasonable position, which is beneficial to fully inflate the refrigerant pipe in multiple steps.

[0048] In the embodiment, the first inflation pipe portion 210 is a first inflation pipe surface, and the second inflation pipe portion 310 is a second inflation pipe surface. The first inflation pipe surface and the second inflation pipe surface are adopted, the push inflation head 200 contacts the inner hole surface of the refrigerant pipe when the push inflation head 200 inflates the pipe, the inflation effect is good, and the risk of wear of the push inflation head 200 is reduced; the pull inflation head 300 also contacts the inner hole surface of the refrigerant pipe when the pull inflation head 300 inflates the pipe, the inflation effect is good, and the risk of wear of the pull inflation head 300 is reduced.

[0049] It can be imagined that in other embodiments, the first inflation pipe portion 210 can also be, for example, an annular line, that is, the push inflation head 200 contacts the inner hole line of the refrigerant pipe to inflate the pipe; and the second inflation pipe portion 310 can also be, for example, an annular line, that is, the pull inflation head 300 contacts the inner hole line of the refrigerant pipe to inflate the pipe.

[0050] Specifically, during the process of pushing the tube expanding mechanism forward into the refrigerant pipe, the expansion rod 100 drives the pulling expansion head 300 and the pushing expansion head 200 to move by the first stop portion 111; during the process of pulling the tube expanding mechanism backward from the refrigerant pipe, the expansion rod 100 drives the pushing expansion head 200 and the pulling expansion head 300 to move by the second stop portion 123.

[0051] The utility model discloses still a kind of tube expanding equipment using the above tube expanding mechanism. Since the above tube expanding mechanism is used, the heat exchanger tube expanding production process can be simplified.

[0052] Specifically, the tube expanding mechanism of the utility model is particularly suitable for the tube expanding of steel refrigerant pipe. It can be understood that the tube expanding mechanism of the utility model can also be used for other material refrigerant pipe.

[0053] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] Although the embodiments of the utility model have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the utility model, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A tube expansion mechanism, characterized in that, include: An expansion rod (100) is provided along the front-to-back direction, and the expansion rod (100) is provided with a tensioning part; An expansion head (200) is connected to the front of the expansion rod (100) and can move with the expansion rod (100). A first expansion tube (210) is provided on the outer periphery of the expansion head (200). A tension head (300) is connected to the front of the expansion rod (100) and can move with the expansion rod (100). The tension head (300) is elastic. The push head (200) and the tension head (300) are arranged along the length direction of the expansion rod (100). A second expansion tube (310) is provided on the outer periphery of the tension head (300). When the expansion rod (100) moves forward, the expansion head (300) separates from the expansion part, and the diameter of the second expansion tube (310) is not greater than the diameter of the first expansion tube (210); when the expansion rod (100) is pulled back, the expansion part cooperates with the expansion head (300) and expands the expansion head (300) so that the diameter of the second expansion tube (310) is greater than the diameter of the first expansion tube (210).

2. The tube expansion mechanism according to claim 1, characterized in that: The expansion rod (100) is arranged sequentially from back to front, including a first stop (111), a first rod segment (121), a second rod segment (122), and a second stop (123). The diameter of the second rod segment (122) is larger than the diameter of the first rod segment (121). The first rod segment (121) and the second rod segment (122) are coaxially arranged. The expansion rod (100) is movably inserted through the expansion head (300), which is located between the first stop (111) and the second stop. The expansion rod (100) is movable between the first rod segment (121) and the second rod segment (122), and the first stop (111) and the second stop (123) can restrict the position of the expansion head (300). The second rod segment (122) forms the expansion part. When the expansion rod (100) moves forward, the expansion head (300) is located in the first rod segment (121); when the expansion rod (100) is pulled back, the expansion head (300) is at least partially located in the second rod segment (122).

3. The tube expansion mechanism according to claim 2, characterized in that: The expansion head (300) includes a connecting ring (330) and at least two elastic arms (320). The first rod segment (121) passes through the connecting ring (330). The elastic arms (320) extend along the length direction of the expansion rod (100). One end of the elastic arm (320) is connected to the connecting ring (330). All the elastic arms (320) are arranged around the central axis of the expansion rod (100). The elastic arms (320) are located on the side of the connecting ring (330) closer to the second rod segment (122). The side of all the elastic arms (320) away from the expansion rod (100) forms the second expansion tube (310).

4. The tube expansion mechanism according to claim 2, characterized in that: The expansion rod (100) includes a main rod body (110) and a mounting rod (120) arranged coaxially. One end of the mounting rod (120) is installed on the main rod body (110). The first rod segment (121) and the second rod segment (122) are both disposed on the mounting rod (120). The other end of the mounting rod (120) forms the second stop portion (123). The push expansion head (200) and the pull expansion head (300) are both connected to the mounting rod (120). The first stop portion (111) is formed at the end of the main rod body (110) near the mounting rod (120).

5. The tube expansion mechanism according to claim 2, characterized in that: The second segment (122) has a chamfered surface (124) at one end near the first segment (121).

6. The tube expansion mechanism according to claim 2, characterized in that: The second rod segment (122) is movably inserted through the push head (200), which is located between the pull head (300) and the second stop (123). The first stop (111) and the second stop (123) can restrict the position of the push head (200).

7. The tube expansion mechanism according to claim 6, characterized in that: The push-up head (200) is provided with a vent groove (220) on the side near the second stop (123), and a vent gap is provided between the push-up head (200) and the expansion rod (100), and the vent groove (220) communicates with the vent gap.

8. The tube expansion mechanism according to claim 1, characterized in that: The first expansion tube (210) is located at the end of the push expansion head (200) near the pull expansion head (300), and the second expansion tube (310) is located at the end of the pull expansion head (300) near the push expansion head (200).

9. The tube expansion mechanism according to claim 1, characterized in that: The first expansion tube section (210) is the first expansion tube surface, and the second expansion tube section (310) is the second expansion tube surface.

10. A tube expansion device, characterized in that, Includes the tube expansion mechanism as described in any one of claims 1 to 9.

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