Adjustable nozzle structure capable of realizing outlet closing function

Abstract

This invention discloses an adjustable nozzle structure capable of achieving outlet closure, comprising: a nozzle connecting cylinder, an adjusting ring, a nozzle convergent cylinder, two actuating cylinders, and two actuating linkages. The adjusting ring is sleeved on the nozzle connecting cylinder. The nozzle convergent cylinder includes four active adjusting plates (upper, lower, left, and right) circumferentially connected at the outlet of the nozzle connecting cylinder, and eight passive adjusting plates connected between the active adjusting plates. The two actuating cylinders are fixed to the nozzle connecting cylinder, and their telescopic ends are fixedly connected to one side of the adjusting ring. One end of each of the two actuating linkages is hinged to the other side of the adjusting ring, and the other end is slidably connected to the outer wall of the upper and lower active adjusting plates, respectively. Both actuating linkages are slidably connected to the nozzle connecting cylinder. Under the transmission of the adjusting ring and the upper and lower actuating linkages and the left and right actuating linkages, the relative positions of each adjusting plate change, and the nozzle outlet area can be adjusted to ensure the normal operation of the aero-engine under different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of aero-engine nozzle technology, and more specifically to an adjustable nozzle structure capable of achieving outlet closure. Background Technology

[0002] In view of the future development direction of high stealth and high thrust-to-weight ratio fighter jets, and considering the application requirements of submersible aircraft, there is an urgent need to develop an engine nozzle structure that can balance high thrust and high stealth and achieve nozzle exit closure.

[0003] While the widely used axisymmetric adjustable nozzles offer high thrust performance, they struggle to effectively shield rearward-rotating high-temperature components such as turbines, resulting in poor stealth capabilities. Furthermore, they cannot achieve nozzle exit closure, making them unsuitable for applications on submersible aircraft. While two-dimensional adjustable nozzles possess some stealth characteristics and can achieve nozzle exit closure under specific design conditions, their thrust performance is still relatively poor due to structural limitations.

[0004] Therefore, how to provide an adjustable nozzle structure that can improve the thrust and stealth performance of an engine, while also enabling the nozzle exit area to be closed, making it suitable for the operating environment of submersible aircraft, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides an adjustable nozzle structure with an adjustable nozzle exit area, enabling the engine to have high thrust and stealth performance, and when the nozzle is applied to a submarine aircraft, the nozzle exit can be closed to prevent external media from entering the engine and affecting its normal operation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An adjustable nozzle structure capable of achieving outlet closure includes:

[0008] A nozzle connecting sleeve, which is connected to the aircraft engine, is fitted with an adjusting ring;

[0009] The nozzle convergent tube includes an upper active adjustment plate, a lower active adjustment plate, a left active adjustment plate, a right active adjustment plate, and eight driven adjustment plates arranged opposite each other at the outlet of the nozzle connecting tube. The eight driven adjustment plates are arranged in pairs, for a total of four groups. Each group is connected between the upper active adjustment plate, the left active adjustment plate, the lower active adjustment plate, and the right active adjustment plate to form a convergent annular structure at the outlet of the nozzle connecting tube.

[0010] The actuator consists of two cylinders that are fixed vertically to each other on the outer wall of the nozzle connecting cylinder, and the telescopic ends of the two actuators are fixedly connected to one side of the adjusting ring.

[0011] An upper actuating link and a lower actuating link are arranged opposite each other. One end of the upper actuating link is hinged to the other side of the adjusting ring, and the other end is hinged to the outer wall of the upper active adjusting plate. One end of the lower actuating link is hinged to the other side of the adjusting ring, and the other end is hinged to the outer wall of the lower active adjusting plate.

[0012] The left and right actuating links are arranged opposite each other. One end of the left actuating link is hinged to the other side of the adjusting ring, and the other end is slidably connected to the outer wall of the left active adjusting plate. The left actuating link is also slidably connected to the nozzle connecting cylinder near its outlet. One end of the right actuating link is hinged to the other side of the adjusting ring, and the other end is slidably connected to the outer wall of the right active adjusting plate. The right actuating link is also slidably connected to the nozzle connecting cylinder near its outlet.

[0013] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an adjustable nozzle structure that can realize the outlet closure function, which can be used as a nozzle for an aero-engine. When used as a nozzle for an aero-engine, the inlet end of the nozzle connecting tube can be connected to the turbine or the rear of the afterburner of the engine. Initially, the actuator is positioned away from the nozzle connecting tube outlet. At this point, the nozzle convergent tube outlet has an octagonal structure, reducing airflow losses within the nozzle and improving engine thrust. As the actuator extends, the adjusting ring moves towards the nozzle outlet, driving the upper and lower actuator linkages to deflect the upper and lower active adjusting vanes inward. Simultaneously, it drives the left and right actuator linkages to deflect the left and right active adjusting vanes outward, thus changing the nozzle outlet from an octagon to a hexagon, reducing its area. This can appropriately shield high-temperature components within the engine, improving its stealth capabilities. With continued extension of the actuator, the adjusting ring moves further towards the nozzle outlet, changing the nozzle outlet from hexagonal to closed. This nozzle can then be used on submersible aircraft entering water, preventing external media from intruding and affecting normal engine operation. Therefore, through the transmission of the adjusting ring and the upper and lower actuator linkages, as well as the left and right actuator linkages, the relative positions of the adjusting vanes change, allowing for adjustment of the nozzle outlet area and ensuring normal operation of the aero-engine under different operating conditions.

[0014] Furthermore, an upper driving rod and a lower hinge rod arranged opposite to each other are fixed on the other side of the adjusting ring. An upper hinge seat is fixed on the outer wall of the upper active adjusting plate, and a lower hinge seat is fixed on the outer wall of the lower active adjusting plate. One end of the upper actuating connecting rod is hinged to the rod end of the upper driving rod away from the adjusting ring, and the other end is hinged to the upper hinge seat. One end of the lower actuating connecting rod is hinged to the rod end of the lower hinge rod away from the adjusting ring, and the other end is hinged to the lower hinge seat.

[0015] Furthermore, a left hinge seat and a right hinge seat arranged opposite to each other are fixed on the other side of the adjusting ring, a left support seat and a right support seat arranged opposite to each other are fixed on the nozzle connecting cylinder near its outlet, a left sliding block is fixed on the outer wall of the left active adjusting plate, and a right sliding block is fixed on the outer wall of the right active adjusting plate.

[0016] One end of the left actuating link is hinged to the left hinge seat, and the other end is fixed with a left sliding shaft. The left sliding shaft is slidably connected to the first left sliding groove on the left sliding block. A second left sliding groove is provided on the left actuating link near one end. The second left sliding groove is slidably connected to the sliding shaft on the left support seat.

[0017] One end of the right actuating link is hinged to the right hinge seat, and the other end is fixed with a right sliding shaft. The right sliding shaft is slidably connected to the first right sliding groove on the right sliding block. A second right sliding groove is provided on the right actuating link near one end, and the second right sliding groove is slidably connected to the sliding shaft on the right support seat.

[0018] The beneficial effects of adopting the above technical solution are as follows: as the actuator cylinder extends, the adjusting ring moves towards the nozzle outlet. Driven by the upper and lower actuator linkages, the upper and lower active adjusting plates move inward and deflect to close. At the same time, the sliding grooves on the left and right actuator linkages slide with the support seats on the nozzle connecting cylinder, and under the action of the hinge between the adjusting ring and the left and right actuator linkages, the left and right actuator linkages are pushed to open to the left and right. Then, through the interaction between the sliding shafts on the left and right actuator linkages and the sliding groove blocks on the left and right active adjusting plates, the left and right active adjusting plates are driven to deflect outward, realizing the continuous change of the nozzle outlet from a regular octagon to a convex polygon to a closed shape.

[0019] Furthermore, the two driven adjustment pieces in each group, as well as the corresponding driven adjustment pieces and the upper active adjustment piece, the left active adjustment piece, the lower active adjustment piece, and the right active adjustment piece, are all connected by hinges.

[0020] Furthermore, the upper active adjustment plate, the left active adjustment plate, the lower active adjustment plate, and the right active adjustment plate are all isosceles triangular structures, with their bases being quarter-circles of the circle at the nozzle connecting cylinder outlet. The two driven adjustment plates in each group are respectively hinged to the isosceles side of the corresponding isosceles triangular structure.

[0021] Furthermore, the nozzle connecting tube outlet has an outwardly expanding arc-shaped surface structure at the connection positions corresponding to the upper active adjustment plate, the left active adjustment plate, the lower active adjustment plate, and the right active adjustment plate.

[0022] The beneficial effects of adopting the above technical solution are: after the upper active adjustment plate, the left active adjustment plate, the lower active adjustment plate, and the right active adjustment plate are closed, they can form a sealed connection with the nozzle connecting tube outlet, avoiding the leakage of injected gas due to holes at the connection position with the nozzle connecting tube outlet, and ensuring the thrust performance of the engine. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram from a first perspective of the octagonal outlet shape of an adjustable nozzle structure that can achieve outlet closure function according to the present invention.

[0025] Figure 2 This is a schematic diagram from a second perspective of the octagonal outlet shape of an adjustable nozzle structure that can achieve outlet closure function according to the present invention.

[0026] Figure 3 This is a side view of the outlet shape of an adjustable nozzle structure with an octagonal outlet that can achieve outlet closure function according to the present invention.

[0027] Figure 4 This is a schematic diagram of the hexagonal outlet shape of an adjustable nozzle structure that can achieve outlet closure function according to the present invention.

[0028] Figure 5 This is a side view of the hexagonal outlet shape of an adjustable nozzle structure that can achieve outlet closure function according to the present invention.

[0029] Figure 6 This is a schematic diagram of the outlet closure structure of an adjustable nozzle structure that can realize the outlet closure function according to the present invention.

[0030] Figure 7 This is an outlet side view of an adjustable nozzle structure that enables outlet closure according to the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figures 1-7 As shown, this embodiment of the invention discloses an adjustable nozzle structure capable of achieving outlet closure, comprising:

[0033] Nozzle connecting sleeve 1 is connected to the aircraft engine, and an adjusting ring 2 is fitted on the nozzle connecting sleeve 1;

[0034] The nozzle convergent tube 3 includes an upper active adjustment plate 31, a lower active adjustment plate 32, a left active adjustment plate 33, a right active adjustment plate 34, and eight driven adjustment plates 35 arranged opposite each other at the outlet of the nozzle connecting tube 1. The eight driven adjustment plates 35 are arranged in pairs, for a total of four groups. Each group is connected between the upper active adjustment plate 31, the left active adjustment plate 33, the lower active adjustment plate 32, and the right active adjustment plate 34 to form a convergent annular structure at the outlet of the nozzle connecting tube 1.

[0035] The actuator cylinder 4 consists of two cylinders that are fixedly mounted on the outer wall of the nozzle connecting cylinder 1, with their telescopic ends fixedly connected to one side of the adjusting ring 2.

[0036] The upper actuating link 5 and the lower actuating link 6 are arranged opposite each other. One end of the upper actuating link 5 is hinged to the other side of the adjusting ring 2, and the other end is hinged to the outer wall of the upper active adjusting plate 31. One end of the lower actuating link 6 is hinged to the other side of the adjusting ring 2, and the other end is hinged to the outer wall of the lower active adjusting plate 32.

[0037] The left actuating link 7 and the right actuating link 8 are arranged opposite each other. One end of the left actuating link 7 is hinged to the other side of the adjusting ring 2, and the other end is slidably connected to the outer wall of the left active adjusting plate 33. The left actuating link 7 is slidably connected to the nozzle connecting cylinder 1 near its outlet. One end of the right actuating link 8 is hinged to the other side of the adjusting ring 2, and the other end is slidably connected to the outer wall of the right active adjusting plate 34. The right actuating link 8 is slidably connected to the nozzle connecting cylinder 1 near its outlet.

[0038] The nozzle of this invention can be used as a nozzle for an aero-engine. When used as an aero-engine nozzle, the inlet end of the nozzle connecting cylinder can be connected to the turbine or the rear of the afterburner of the engine. As the actuator cylinder extends, the relative positions of the adjusting plates change under the transmission of the adjusting ring and the upper and lower actuating linkages and the left and right actuating linkages, thereby adjusting the nozzle exit area and ensuring the normal operation of the aero-engine under different operating conditions.

[0039] Specifically, an upper drive rod 9 and a lower hinge rod 10 arranged opposite each other are fixed on the other side of the adjusting ring 2. An upper hinge seat 11 is fixed on the outer wall of the upper active adjusting plate 31, and a lower hinge seat 12 is fixed on the outer wall of the lower active adjusting plate 32. One end of the upper actuating link 5 is hinged to the rod end of the upper drive rod 9 away from the adjusting ring 2, and the other end is hinged to the upper hinge seat 11. One end of the lower actuating link 6 is hinged to the rod end of the lower hinge rod 10 away from the adjusting ring 2, and the other end is hinged to the lower hinge seat 12.

[0040] On the other side of the adjusting ring 2, there are left hinge seat 13 and right hinge seat 14 arranged opposite to each other. On the nozzle connecting tube 1, there are left support seat 15 and right support seat 16 arranged opposite to each other near its outlet. On the outer wall of the left active adjusting plate 33, there is left sliding block 17 and right sliding block 18.

[0041] One end of the left actuating link 7 is hinged to the left hinge seat 13, and the other end is fixed with the left sliding shaft 19. The left sliding shaft 19 is slidably connected to the first left sliding groove 171 on the left sliding block 17. A second left sliding groove 71 is opened on the left actuating link 7 near one end. The second left sliding groove 71 is slidably connected to the sliding shaft (not shown) on the left support seat 15.

[0042] One end of the right actuating link 8 is hinged to the right hinge seat 14, and the other end is fixed with a right sliding shaft 20. The right sliding shaft 20 is slidably connected to the first right sliding groove 181 on the right sliding block 18. A second right sliding groove 81 is provided on the right actuating link 8 near one end. The second right sliding groove 81 is slidably connected to the sliding shaft (not shown) on the right support seat 16.

[0043] Regarding the adjustable nozzle structure with exit closure function disclosed in the above embodiments, those skilled in the art will understand that as the actuating cylinder extends, the adjusting ring moves towards the nozzle exit direction. Under the drive of the upper and lower actuating linkages, the upper and lower active adjusting plates deflect inward and close. Simultaneously, the sliding grooves on the left and right actuating linkages slide against the support seats on the nozzle connecting cylinder, and under the action of the hinges between the adjusting ring and the left and right actuating linkages, the left and right actuating linkages are pushed to open to the left and right. Then, through the interaction between the active shaft on the left and right actuating linkages and the sliding blocks on the left and right active adjusting plates, the left and right active adjusting plates are deflected outward, realizing a continuous change in the nozzle exit from a regular octagon to a convex polygon (such as a hexagon) to closure. Therefore, the nozzle exit area decreases monotonically with the extension of the actuating cylinder, and can be adjusted from the maximum area design value to a completely closed state, i.e., zero area.

[0044] Each group of two driven adjusting vanes 35, as well as the corresponding driven adjusting vane 35 and the upper active adjusting vane 31, left active adjusting vane 33, lower active adjusting vane 32, and right active adjusting vane 34, are all connected by hinges to form a rotating pair structure. Sealing measures are employed, such as adding sealing strips to the hinge shafts, to prevent high-temperature gas leakage. Adjacent adjusting vanes can rotate within a small range relative to each other. A total of twelve adjusting vanes achieve circumferential sealing during the adjustable nozzle's movement. Therefore, the cross-sectional area of ​​the nozzle convergent tube, composed of adjusting vanes, gradually decreases from the inlet to the outlet, satisfying the basic characteristics of a nozzle and achieving acceleration of the airflow within the nozzle.

[0045] The upper active adjustment plate 31, the left active adjustment plate 33, the lower active adjustment plate 32, and the right active adjustment plate 34 are all isosceles triangular structures, with their bases being quarter-circles of the circular outlet of the nozzle connecting tube 1. The two driven adjustment plates 35 in each group are respectively hinged and sealed to the isosceles side of the corresponding isosceles triangular structure.

[0046] At the outlet of the nozzle connecting tube 1, the connection positions corresponding to the upper active adjustment plate 31, the left active adjustment plate 33, the lower active adjustment plate 32, and the right active adjustment plate 34 all have outwardly expanding arc surface structures 101. The arc surface structures 101 can be connected to the upper active adjustment plate 31, the left active adjustment plate 33, the lower active adjustment plate 32, and the right active adjustment plate 34 by hinges to realize the opening and closing actions of the upper active adjustment plate 31, the left active adjustment plate 33, the lower active adjustment plate 32, and the right active adjustment plate 34.

[0047] Specifically, regarding the adjustable nozzle structure disclosed in the above embodiments that can achieve the outlet closure function, those skilled in the art will understand that the upper and lower actuating links and the left and right actuating links are designed to match each other. Under the maximum extension condition of the actuating cylinder, the upper and lower active adjustment plates can deflect inward at the maximum angle, and the left and right active adjustment plates can deflect outward at the maximum angle, thereby ultimately achieving complete closure of the nozzle outlet.

[0048] Combination Figure 1 and Figure 3 As shown, when the engine requires high thrust performance, the nozzle exit shape is adjusted to a regular octagon to reduce flow losses. At this time, under the condition of maximum nozzle exit area, the actuator is in a contracted state, and the adjusting ring is located at the position furthest from the nozzle exit. Figure 4 and Figure 5 As shown, when the engine requires high stealth performance, the nozzle exit shape is adjusted to a hexagon to appropriately shield high-temperature components inside the engine and reduce its infrared signature. At this time, the nozzle exit area decreases, the actuator section lengthens, and the adjusting ring moves towards the nozzle exit; combined with... Figure 6 and Figure 7 As shown, when the engine nozzle outlet needs to be closed, the nozzle outlet shape is adjusted to be closed. At this time, the actuator is in the maximum extension state, and the adjusting ring is located at the position closest to the nozzle outlet.

[0049] Therefore, the nozzle of this invention utilizes four active adjusting vanes (up, down, left, and right) and eight driven adjusting vanes to form a nozzle convergent cylinder, allowing the nozzle exit shape to continuously change and freely adjust between a regular octagon, a hexagon, and a closed shape. For example, when the engine requires high thrust performance, the nozzle exit is a regular octagon to reduce airflow losses within the nozzle; when the engine requires high stealth performance, the nozzle exit can be adjusted to a hexagon or other transitional shape to appropriately shield high-temperature components within the engine; when applied to underwater aircraft, the nozzle exit is adjusted to a closed state to prevent external media from intruding into the engine and affecting its normal operation.

[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adjustable nozzle structure capable of achieving outlet closure, characterized in that, include: A nozzle connecting sleeve (1) is connected to an aero engine, and an adjusting ring (2) is fitted on the nozzle connecting sleeve (1); The nozzle convergent tube (3) includes an upper active adjustment plate (31), a lower active adjustment plate (32), a left active adjustment plate (33), a right active adjustment plate (34), and eight driven adjustment plates (35) arranged opposite each other at the outlet of the nozzle connecting tube (1). The eight driven adjustment plates (35) are arranged in pairs, for a total of four groups. Each group is connected between the upper active adjustment plate (31), the left active adjustment plate (33), the lower active adjustment plate (32), and the right active adjustment plate (34) to form a convergent annular structure at the outlet of the nozzle connecting tube (1). The actuator (4) consists of two cylinders fixed vertically to the outer wall of the nozzle connecting cylinder (1), and the telescopic ends of the two actuators (4) are fixedly connected to one side of the adjusting ring (2). An upper actuating link (5) and a lower actuating link (6) are arranged opposite each other. One end of the upper actuating link (5) is hinged to the other side of the adjusting ring (2), and the other end is hinged to the outer wall of the upper active adjusting plate (31). One end of the lower actuating link (6) is hinged to the other side of the adjusting ring (2), and the other end is hinged to the outer wall of the lower active adjusting plate (32). The left actuating link (7) and the right actuating link (8) are arranged opposite to each other. One end of the left actuating link (7) is hinged to the other side of the adjusting ring (2), and the other end is slidably connected to the outer wall of the left active adjusting plate (33). The left actuating link (7) is slidably connected to the nozzle connecting cylinder (1) near its outlet. One end of the right actuating link (8) is hinged to the other side of the adjusting ring (2), and the other end is slidably connected to the outer wall of the right active adjusting plate (34). The right actuating link (8) is slidably connected to the nozzle connecting cylinder (1) near its outlet.

2. The adjustable nozzle structure capable of achieving an exit closure function according to claim 1, wherein On the other side of the adjusting ring (2), an upper driving rod (9) and a lower hinge rod (10) are fixedly arranged opposite each other. An upper hinge seat (11) is fixed on the outer wall of the upper active adjusting plate (31), and a lower hinge seat (12) is fixed on the outer wall of the lower active adjusting plate (32). One end of the upper actuating link (5) is hinged to the rod end of the upper driving rod (9) away from the adjusting ring (2), and the other end is hinged to the upper hinge seat (11). One end of the lower actuating link (6) is hinged to the rod end of the lower hinge rod (10) away from the adjusting ring (2), and the other end is hinged to the lower hinge seat (12).

3. The adjustable nozzle structure capable of achieving an exit closure function according to claim 1 or 2, characterized in that, On the other side of the adjusting ring (2), there are left hinge seats (13) and right hinge seats (14) arranged opposite to each other. On the nozzle connecting tube (1) near its outlet, there are left support seats (15) and right support seats (16) arranged opposite to each other. On the outer wall of the left active adjusting plate (33), there is a left sliding block (17). On the outer wall of the right active adjusting plate (34), there is a right sliding block (18). One end of the left actuating link (7) is hinged to the left hinge seat (13), and the other end is fixed with a left sliding shaft (19). The left sliding shaft (19) is slidably connected to the first left sliding groove (171) on the left sliding block (17). A second left sliding groove (71) is provided on the left actuating link (7) near one end. The second left sliding groove (71) is slidably connected to the sliding shaft on the left support seat (15). One end of the right actuating link (8) is hinged to the right hinge seat (14), and the other end is fixed with a right sliding shaft (20). The right sliding shaft (20) is slidably connected to the first right sliding groove (181) on the right sliding block (18). A second right sliding groove (81) is provided on the right actuating link (8) near one end. The second right sliding groove (81) is slidably connected to the sliding shaft on the right support seat (16).

4. The adjustable nozzle structure capable of achieving an exit closure function according to claim 1 or 2, characterized in that, The two driven adjustment pieces (35) in each group, as well as the corresponding driven adjustment piece (35) and the upper active adjustment piece (31), the left active adjustment piece (33), the lower active adjustment piece (32), and the right active adjustment piece (34) are all connected by hinges.

5. An adjustable nozzle structure capable of achieving outlet closure function according to claim 4, characterized in that, The upper active adjustment plate (31), the left active adjustment plate (33), the lower active adjustment plate (32), and the right active adjustment plate (34) are all isosceles triangular structures, with their bases being quarter-circles of the circle at the outlet of the nozzle connecting cylinder (1). The two driven adjustment plates (35) of each group are respectively hinged to the isosceles side of the corresponding isosceles triangular structure.

6. The adjustable nozzle structure capable of achieving an exit closure function according to claim 4, wherein The nozzle connecting tube (1) has an outwardly expanding arc surface structure (101) at the connection position of the upper active adjustment plate (31), the left active adjustment plate (33), the lower active adjustment plate (32), and the right active adjustment plate (34).

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