A stretch sealing device

Abstract

The present invention discloses a stretching and sealing device, comprising a mounting bracket, a stretching bracket, a sealing mechanism, a linear guide rail and a stretching mechanism; the stretching mechanism comprises a first mounting seat arranged on the linear guide rail, a stretching rod arranged on the first mounting seat; the sealing mechanism comprises a sealing cylinder arranged on the mounting bracket, a lifting rod inserted in the sealing cylinder, a sealing member arranged at the bottom end of the lifting rod, a first connecting rod whose lower end is rotatably connected to the top end of the lifting rod through a first shaft, a second connecting rod whose one end is rotatably connected to the stretching bracket through a second shaft, and the other end of the second connecting rod is rotatably connected to the upper end of the first connecting rod through a third shaft; the stretching mechanism also comprises a first cam surface arranged on the first mounting seat, an outer cam arranged on the first mounting seat and having a second cam surface, and a first roller arranged on the third shaft; the first cam surface and the second cam surface are respectively used to drive the first roller to rise and fall. The stretching and sealing device of the present invention has a simple structure and stable and reliable operation.

Description

Technical Field

[0001] The invention relates to the technical field of bottle blowing, and in particular to a stretch sealing device. Background Art

[0002] As the bottle blowing machine develops towards high speed and low noise, the requirements for the motion accuracy of each mechanism of the bottle blowing machine are getting higher and higher. During the execution of a bottle blowing action, the lifting and lowering actions of the sealing cylinder and the stretching rod need to be completed continuously. The lifting and lowering action of the sealing cylinder of the existing equipment is powered by a cylinder or a cam, and the lifting and lowering action of the stretching rod is powered by a cylinder or a servo motor. The two actions have two different powers, the structure is complex, and the installation accuracy is poor, which has a certain impact on the high-speed and stable operation of the equipment.

[0003] The Chinese patent application number 202010362182.2 discloses a stretching and sealing linkage device for a bottle blowing machine. When sealing, the first mounting seat is driven downward, and the roller and the lifting rod move downward synchronously by gravity until the sealing member contacts the mouth of the preform to seal. The first mounting seat continues to move downward and disengages from the roller, and the stretching rod completes the stretching action on the preform. This structure can realize the linkage between sealing and stretching, but has the following problems:

[0004] The acceleration of the downward movement of the first mounting seat cannot be greater than the acceleration of gravity, otherwise the first mounting seat will be disengaged from the roller, and the stretching rod will stretch before the sealing, resulting in the problem that the stretching cannot be coordinated with the blowing;

[0005] The speed at which the roller descends is determined by the acceleration of gravity. Not only is the speed slow, resulting in low sealing efficiency, but there is also an uncontrollable problem;

[0006] The mechanical structure below has a certain resistance, which will cause the roller to descend more slowly or even fail to descend. Summary of the invention

[0007] The object of the present invention is to provide a stretching and sealing device with a simple structure, stable and reliable operation, controllable linkage movement of stretching and sealing, and relatively high processing efficiency.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A stretching and sealing device, comprising a mounting bracket, a stretching bracket and a sealing mechanism arranged on the mounting bracket, and a linear guide rail and a stretching mechanism arranged on the stretching bracket;

[0010] The stretching mechanism comprises a first mounting seat slidably arranged on the linear guide rail, a stretching rod connected to the first mounting seat, and a driving component arranged on the stretching bracket for driving the first mounting seat to slide;

[0011] The sealing mechanism comprises a sealing cylinder connected to the mounting bracket, a lifting rod which is lifted and lowered in the sealing cylinder along the length extension direction thereof, a sealing member arranged at the bottom end of the lifting rod, a first connecting rod whose lower end is rotatably connected to the top end of the lifting rod via a first axis, a second connecting rod whose one end is rotatably connected to the stretching bracket via a second axis, and the other end of the second connecting rod is rotatably connected to the upper end of the first connecting rod via a third axis; the stretching rod is inserted in the sealing member;

[0012] The stretching mechanism further comprises a first cam surface provided on the first mounting seat, an outer cam provided on the mounting seat and having a second cam surface, and a first roller provided on the third shaft and capable of rolling along the first cam surface or the second cam surface, wherein the first cam surface and the second cam surface extend obliquely in the up-down direction respectively;

[0013] The second cam surface has a first position:

[0014] In the first position, the first cam surface and the second cam surface form a conjugate cam, the first cam surface is used to drive the first roller to rise, and the second cam surface is used to drive the first roller to descend;

[0015] When the second link rotates away from the outer cam, the first roller can escape upward from the gap between the first cam surface and the second cam surface.

[0016] Preferably, the sealing mechanism further comprises a second mounting seat slidably disposed on the linear guide rail, the lifting rod is fixedly connected to the second mounting seat via the first shaft, and the second mounting seat is disposed below the first mounting seat.

[0017] More preferably, the outer cam is rotatably connected to the first mounting seat around a rotation axis, and the stretching mechanism further comprises an elastic member connected between the first mounting seat and the outer cam, and a limiting member provided on the first mounting seat and used to limit one end of the outer cam, and the elastic member and the limiting member are used to cooperate with each other to make the second cam surface be in the first position;

[0018] The elastic member is also used for providing an elastic restoring force for driving the outer cam to return to its original position when the upper end of the outer cam rotates outwardly relative to the first cam surface.

[0019] More preferably, the elastic member is a compression spring and two ends thereof are respectively connected to the first mounting seat and the lower end of the outer cam, and the limiting member is located outside the lower end of the outer cam.

[0020] Still more preferably, the compression spring and the first connecting rod are staggered with each other along the axial centerline direction of the third axis.

[0021] More preferably, the elastic member is a tension spring and two ends thereof are respectively connected to the first mounting seat and the upper end of the outer cam, and the limiting member is located on the inner side of the upper end of the outer cam.

[0022] Still more preferably, the tension spring and the second connecting rod are staggered with each other along the axis direction of the third axis.

[0023] More preferably, the sealing mechanism further comprises a second roller disposed on the second mounting seat, and when the first mounting seat fails to drive the first roller to rise as expected, the second roller is used to drive the first roller to rise under the drive of a driving cam.

[0024] More preferably, the stretching rod passes downward through the second mounting seat, the lifting rod and the sealing member.

[0025] More preferably, both ends of the first shaft pass through the second mounting seat respectively, and both ends of the first shaft are connected to symmetrically arranged connecting rod mechanisms respectively, and the connecting rod mechanism includes the first connecting rod, the third shaft, the second connecting rod and the second shaft connected in sequence.

[0026] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the stretch sealing device of the present invention is provided with a pair of first cam surface and second cam surface which can form a conjugate cam on the first mounting seat, the first cam surface is used to drive the first roller to rise, and the second cam surface is used to drive the first roller to descend; during the descending process of the first roller, the second connecting rod rotates away from the outer cam, and the first roller can be disengaged upward from the gap between the first cam surface and the second cam surface, so as to realize the separate descent and stretching of the stretching rod after the sealing is completed. The stretch sealing device has a simple structure, stable and reliable operation, controllable linkage movement of stretching and sealing, and relatively high processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Attached Figure 1 The structure of the stretch sealing device according to the specific embodiment of the present invention is shown in FIG. Figure 1 (Unsealed state);

[0028] Attached Figure 2 For attachment Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0029] Attached Figure 3 The structure of the stretch sealing device according to the specific embodiment of the present invention is shown in FIG. Figure 2 (sealed state);

[0030] Attached Figure 4It is a schematic side structural diagram of a stretch sealing device according to a specific embodiment of the present invention (unsealed state).

[0031] Among them: 1. mounting bracket; 2. stretching bracket; 3. linear guide rail; 4. first mounting seat; 41. first cam surface; 5. stretching rod; 6. driving assembly; 7. sealing cylinder; 8. lifting rod; 9. sealing member; 10. first axis; 11. first connecting rod; 12. second axis; 13. second connecting rod; 14. third axis; 15. outer cam; 151. second cam surface; 16. first roller; 17. second mounting seat; 18. elastic member; 19. second roller; 20. first slider; 21. second slider; 22. rotation axis. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below in conjunction with specific embodiments and drawings.

[0033] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0034] In the description of the embodiments of the present invention, it should be understood that the terms "length", "inside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0037] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] The disclosure below provides many different embodiments or examples to implement different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present invention. In addition, the embodiments of the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0039] See also Figure 1 As shown, this embodiment provides a stretching and sealing device, including a mounting bracket 1, a stretching bracket 2 and a sealing mechanism arranged on the mounting bracket 1, and a linear guide rail 3 and a stretching mechanism arranged on the stretching bracket 2. The mounting bracket 1 is rotatably arranged on a bottle blowing machine frame (not shown in the figure) in a circumferential direction.

[0040] In this embodiment, the linear guide rail 3 is parallel to the vertical direction. The stretching mechanism includes a first slider 20 and a second slider 21 slidably disposed on the linear guide rail 3, a first mounting seat 4 connected to the first slider 20, and a second mounting seat 17 connected to the second slider 21, wherein the second mounting seat 17 is located directly below the first mounting seat 4.

[0041] A stretching rod 5 is provided on the first mounting seat 4, and a driving assembly 6 for driving the first mounting seat 4 to move up and down is also provided on the stretching bracket 2. In this embodiment, the stretching rod 5 extends in a vertical direction, and is used to penetrate into the preform downward, and cooperate to stretch the preform downward when blowing.

[0042] The sealing mechanism comprises a sealing cylinder 7 connected to the mounting bracket 1, a lifting rod 8 which is inserted into the sealing cylinder 7 and can be lifted and lowered along the direction of its own length, and a sealing member 9 which is provided at the bottom end of the lifting rod 8 and is used to seal the mouth of the bottle blank. In this embodiment, the sealing cylinder 7, the lifting rod 8 and the sealing member 9 are arranged coaxially, and their axes all extend in the vertical direction. The sealing cylinder 7 is located above the mounting bracket 1, and the sealing member 9 is located below the mounting bracket 1, and the upper and lower ends of the lifting rod 8 respectively pass through the sealing cylinder 7.

[0043] See also Figure 1 As shown, the sealing mechanism also includes a first connecting rod 11 whose lower end is rotatably connected to the top of the lifting rod 8 through a first shaft 10, a second connecting rod 13 whose one end is rotatably connected to the stretching bracket 2 through a second shaft 12, and the other end of the second connecting rod 13 is rotatably connected to the upper end of the first connecting rod 11 through a third shaft 14. In this embodiment, the first shaft 10 is fixed to the top of the lifting rod 8, the second shaft 12 is fixed to the stretching bracket 2, the left end of the second connecting rod 13 is hinged to the second shaft 12, and the right end of the second connecting rod 13 is hinged to the upper end of the first connecting rod 11 through the third shaft 14, and the third shaft 14 has flexible freedom. The first shaft 10, the second shaft 12 and the third shaft 14 are parallel to each other and perpendicular to the linear guide 3. The first mounting seat 4 is located below the second connecting rod 13 and between the linear guide 3 and the first connecting rod 11.

[0044] The first shaft 10 is also fixedly connected to the second mounting seat 17. The second mounting seat 17 is provided to stabilize and guide the lifting movement of the lifting rod 8. In this embodiment, the stretching rod 5 passes downward through the second mounting seat 17, the lifting rod 8 and the sealing member 9 to enter the preform.

[0045] See also Figure 4 As shown, in this embodiment, both ends of the first shaft 10 pass through the second mounting seat 17, and both ends of the first shaft 10 are connected with symmetrically distributed connecting rod mechanisms, and the linear guide 3 is located between the two connecting rod mechanisms. The connecting rod mechanism includes a first connecting rod 11, a third shaft 14, a second connecting rod 13 and a second shaft 12 connected in sequence. The two connecting rod mechanisms act synchronously, and this setting ensures the stability of the linkage action.

[0046] The stretching mechanism further includes a first cam surface 41 disposed on the first mounting seat 4, an outer cam 15 disposed on the mounting seat and having a second cam surface 151, and a first roller 16 disposed on the third shaft 14 and rotatable around its own axis. The first roller 16 can roll along the first cam surface 41 or the second cam surface 151 while rotating, and the first cam surface 41 and the second cam surface 151 extend obliquely in the up-down direction, respectively.

[0047] The second cam surface 151 has a first position. Figure 2As shown, the first cam surface 41 is tilted from the upper left to the lower right as a whole; the second cam surface 151 is in the first position, and the second cam surface 151 is also tilted from the upper left to the lower right as a whole. At this time, the first cam surface 41 and the second cam surface 151 form a conjugate cam.

[0048] The first cam surface 41 and the second cam surface 151 are cam curves respectively. By specifically setting their shapes, the first cam surface 41 is used to drive the first roller 16 to rise, and the second cam surface 151 is used to drive the first roller 16 to descend.

[0049] When the first mounting seat 4 descends, the second cam surface 151 first contacts the first roller 16 through its lower part, driving the first roller 16 to roll along the second cam surface 151. At this time, the second connecting rod 13 rotates clockwise (i.e., rotates away from the outer cam 15) until the first roller 16 escapes upward from the gap between the first cam surface 41 and the second cam surface 151. At this time, the lifting rod 8 descends a distance that can complete the sealing of the bottle blank by the sealing member 9, i.e., the sealing member 9 is Figure 1 Move down to Figure 3 The position in.

[0050] When the first mounting seat 4 rises, the first cam surface 41 first contacts the first roller 16 through its upper part, driving the first roller 16 to roll along the first cam surface 41. At this time, the second connecting rod 13 rotates counterclockwise (i.e., rotates toward the outer cam 15) to make the lifting rod 8 rise and reset, thereby preventing the sealing member 9 from colliding with other mechanisms of the bottle blowing machine.

[0051] See also Figure 1 As shown, the sealing mechanism also includes a second roller 19 disposed on the second mounting seat 17. When the first mounting seat 4 fails to drive the first roller 16 to rise as expected, in order to avoid the sealing member 9 from colliding with other mechanisms of the bottle blowing machine, the second roller 19 is used to drive the first roller 16 to rise under the drive of a driving cam (not shown in the figure). Specifically, the driving cam can be an arc shape, and its center is located on the rotation center line of the mounting bracket 1. The driving cam is located below the second roller 19, and its cam curve is the trajectory of the second roller 19 during normal movement. When the first mounting seat 4 is raised and lowered normally, the driving cam and the second roller 19 always maintain a certain distance from each other and do not conflict with each other. When the first mounting seat 4 fails to rise as expected, the second roller 19 can rise under the drive of the driving cam.

[0052] See also Figure 2As shown, the outer cam 15 is rotatably connected to the first mounting seat 4 around a rotation axis 22, and the rotation axis 22 is parallel to the third axis 14 and extends in the horizontal direction. The stretching mechanism further includes an elastic member 18 connected between the first mounting seat 4 and the outer cam 15, and a stopper provided on the first mounting seat 4 and used to stop one end of the outer cam 15. The elastic member 18 and the stopper are used to cooperate with each other to keep the second cam surface 151 in the first position.

[0053] Through this arrangement, when the first roller 16 rises before the first mounting seat 4 and is located above the first mounting seat 4, if the first mounting seat 4 rises and resets at this time, the first roller 16 will collide with the top of the outer cam 15; because the outer cam 15 is rotatably connected to the first mounting seat 4 and elastically tensioned by the elastic member 18, when the first roller 16 and the outer cam 15 abut, the outer cam 15 can rotate clockwise under the action of the first roller 16 (that is, the upper end of the outer cam 15 rotates outward relative to the first cam surface 41) to allow the roller to enter between the first cam surface 41 and the second cam surface 151 to avoid damaging the mechanism. After the first roller 16 enters, under the action of the elastic member 18, the outer cam 15 rotates counterclockwise to reset, and stops rotating after abutting against the limiter, so that the second cam surface 151 can be in the first position again.

[0054] In this embodiment, see Figure 2 As shown, the elastic member 18 is a compression spring and its two ends are respectively connected to the first mounting seat 4 and the inner side of the lower end of the outer cam 15, and the stopper is located outside the lower end of the outer cam 15. In order to avoid interference during movement, the compression spring and the first connecting rod 11 are staggered along the axis direction of the third shaft 14.

[0055] In another embodiment, the elastic member 18 is a tension spring and its two ends are respectively connected to the first mounting seat 4 and the inner side of the upper end of the outer cam 15, and the stopper is also located on the inner side of the upper end of the outer cam 15. In order to avoid interference during movement, the tension spring and the second connecting rod 13 are staggered along the axis of the third shaft 14.

[0056] The working process of this embodiment is described in detail below:

[0057] First, the driving assembly 6 drives the first mounting seat 4 to move downward, and the outer cam 15 presses the first roller 16 downward through the second cam surface 151, driving the first roller 16 to roll along the second cam surface 151. At this time, the second connecting rod 13 rotates clockwise relative to the stretching bracket 2, that is, rotates away from the outer cam 15, so as to drive the first connecting rod 11 to descend until the first roller 16 escapes upward from the gap between the first cam surface 41 and the second cam surface 151. At this time, the lifting rod 8 drives the sealing member 9 to descend to a distance that can complete the sealing of the preform.

[0058] Next, the driving assembly 6 continues to drive the first mounting seat 4 to move downward, stretching the preform through the stretching rod 5, and simultaneously blowing the preform with pressurized gas until the stretching rod 5 stops descending and the blowing of the preform is completed;

[0059] Finally, the driving assembly 6 drives the first mounting seat 4 to move upward. After the first mounting seat 4 moves upward for a certain distance, the first cam surface 41 presses the first roller 16 upward, driving the first roller 16 to roll along the first cam surface 41. At this time, the second connecting rod 13 rotates counterclockwise relative to the stretching bracket 2, that is, rotates toward the outer cam 15 to drive the first connecting rod 11 to rise until the sealing member 9 rises to the set position. At this time, the stretching rod 5 is also completely withdrawn from the bottle body;

[0060] When the driving assembly 6 fails and causes the first mounting seat 4 to fail to rise as expected, in order to avoid the sealing member 9 and the stretching rod 5 from colliding with other mechanisms of the bottle blowing machine, the second roller 19 is driven to rise by the driving cam, so that the lifting rod 8 and the stretching rod 5 rise synchronously, and then when the first mounting seat 4 is reset, since the outer cam 15 is rotatably connected to the first mounting seat 4 and elastically tensioned by the elastic member 18, when the first roller 16 and the top of the outer cam 15 abut, the outer cam 15 can rotate clockwise under the action of the first roller 16 (that is, the upper end of the outer cam 15 rotates outward relative to the first cam surface 41 and opens), so as to allow the roller to enter between the first cam surface 41 and the second cam surface 151 to avoid damaging the mechanism; after the first roller 16 enters, under the action of the elastic member 18, the outer cam 15 rotates counterclockwise to reset, and stops rotating after abutting against the limit member, so that the second cam surface 151 can be in the first position again.

[0061] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A stretching and sealing device, comprising a mounting bracket, a stretching bracket and a sealing mechanism arranged on the mounting bracket, and a linear guide rail and a stretching mechanism arranged on the stretching bracket; The stretching mechanism comprises a first mounting seat slidably arranged on the linear guide rail, a stretching rod connected to the first mounting seat, and a driving component arranged on the stretching bracket for driving the first mounting seat to slide; The sealing mechanism comprises a sealing cylinder connected to the mounting bracket, a lifting rod lifted and lowered in the sealing cylinder along its length extension direction, a sealing member arranged at the bottom end of the lifting rod, a first connecting rod rotatably connected to the top end of the lifting rod via a first axis at the lower end, a second connecting rod rotatably connected to the stretching bracket via a second axis at one end, the other end of the second connecting rod being rotatably connected to the upper end of the first connecting rod via a third axis; the stretching rod is inserted in the sealing member; Features: The stretching mechanism further includes a first cam surface provided on the first mounting seat, an outer cam provided on the mounting seat and having a second cam surface, and a first roller provided on the third shaft and rolling along the first cam surface or the second cam surface, wherein the first cam surface and the second cam surface extend obliquely in the up-down direction respectively; The second cam surface has a first position: In the first position, the first cam surface and the second cam surface form a conjugate cam, the first cam surface is used to drive the first roller to rise, and the second cam surface is used to drive the first roller to descend; When the second connecting rod rotates away from the outer cam, the first roller escapes upward from the gap between the first cam surface and the second cam surface; The sealing mechanism further comprises a second mounting seat slidably arranged on the linear guide rail, the lifting rod is fixedly connected to the second mounting seat via the first shaft, and the second mounting seat is arranged below the first mounting seat; The outer cam is rotatably connected to the first mounting seat around the rotation axis, and the stretching mechanism further includes an elastic member connected between the first mounting seat and the outer cam, and a limiting member provided on the first mounting seat and used to limit one end of the outer cam, and the elastic member and the limiting member are used to cooperate with each other to make the second cam surface be in the first position; The elastic member is also used to provide an elastic restoring force for driving the outer cam to return to its original position when the upper end of the outer cam rotates outward relative to the first cam surface; The sealing mechanism further comprises a second roller arranged on the second mounting seat. When the first mounting seat fails to drive the first roller to rise as expected, the second roller is used to drive the first roller to rise under the drive of a driving cam.

2. The stretch sealing device according to claim 1, characterized in that: The elastic member is a compression spring, and two ends of the elastic member are respectively connected to the first mounting seat and the lower end of the outer cam, and the limiting member is located outside the lower end of the outer cam.

3. The stretch sealing device according to claim 2, characterized in that: The compression spring and the first connecting rod are staggered with each other along the axis direction of the third axis.

4. The stretch sealing device according to claim 1, characterized in that: The elastic member is a tension spring, and two ends of the elastic member are respectively connected to the first mounting seat and the upper end of the outer cam, and the limiting member is located on the inner side of the upper end of the outer cam.

5. The stretch sealing device according to claim 4, characterized in that: The tension spring and the second connecting rod are staggered with each other along the axis direction of the third axis.

6. The stretch sealing device according to claim 1, characterized in that: The stretching rod passes downward through the second mounting seat, the lifting rod and the sealing member.

7. The stretch sealing device according to claim 1, characterized in that: Both ends of the first shaft pass through the second mounting seat respectively, and both ends of the first shaft are connected with symmetrically arranged connecting rod mechanisms respectively, and the connecting rod mechanism includes the first connecting rod, the third shaft, the second connecting rod and the second shaft connected in sequence.

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