CN111760259A

CN111760259A - Special training ware of tennis

Info

Publication number: CN111760259A
Application number: CN202010609858.3A
Authority: CN
Inventors: 林玉凯
Original assignee: Dezhou Vocational and Technical College
Current assignee: Dezhou Vocational and Technical College
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2020-10-13

Abstract

The invention provides a tennis special trainer, which relates to the technical field of sports training articles and comprises a rack, a power device, an energy storage device and a launching device, wherein the power device, the energy storage device and the launching device are all arranged on the rack, the end part of the rack is fixedly provided with the power device, the power device is in transmission connection with the energy storage device, the energy storage device is fixedly connected with the launching device, the rack comprises a support, a fixed platform and a handle, the power device is arranged at one end of the fixed platform, the other end of the fixed platform is provided with the handle, and the bottom of the fixed platform is movably inserted with the support. When the tennis ball launching device is used, an operator holds the handle, moves the fixing platform to aim at the position under the feet of a trainer, absorbs air through the power device, extrudes the air into the energy storage device, and when the air pressure reaches a certain degree, the energy storage device is opened, and tennis balls in the launching device are ejected out by utilizing high-pressure air. The tennis ball serving device is high in tennis ball serving efficiency, the tennis ball serving route and the tennis ball serving force can be freely adjusted, and the tennis ball training level is effectively improved.

Description

Special training ware of tennis

Technical Field

The invention relates to the technical field of sports training articles, in particular to a special training device for tennis.

Background

The physical education course is an important link for promoting the development of students as an important content of a teaching system of a college and universities of professorship. However, the maintenance of the enthusiasm and interest in learning of college students on physical education is limited by the factors of site facilities, subject setting, and the number and quality of tennis professional teachers. Especially in the aspect of tennis training, teachers train students in a two-by-two sparring mode, the efficiency is low, and expected training effect is difficult to achieve quickly, the existing tennis ball serving machines in the market are mainly divided into a double-wheel type, a pneumatic type and an ejection type, wherein the double-wheel type easily damages tennis balls, the pneumatic type launching efficiency is low, the ejection type launching speed is slightly insufficient, the existing tennis ball serving machines are expensive, the serving mode and the serving route are single, the serving strength is difficult to adjust, and real competition situations are difficult to simulate, so that the skill and tactical level of training players is difficult to further improve, and the training teaching level of tennis is limited.

Novel content

Therefore, the tennis special trainer provided by the embodiment of the invention can improve the service efficiency, change the service route and force and effectively improve the tennis training level.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention discloses a tennis special trainer which comprises a rack, a power device, an energy storage device and a transmitting device, wherein the power device, the energy storage device and the transmitting device are all arranged on the rack;

the rack comprises a support, a fixed platform and a handle, the power device is arranged at one end of the fixed platform, the handle is arranged at the other end of the fixed platform, and the support is inserted into the bottom of the fixed platform.

Furthermore, the power device comprises a rotary table, a power machine, a connecting rod, a piston rod and a piston, wherein the power machine is fixedly arranged at one end of the fixed platform and is in transmission connection with the rotary table, the rotary table is hinged with one end of the connecting rod, the other end of the connecting rod is hinged with one end of the piston rod, the piston is sleeved at the other end of the piston rod, and the piston is slidably arranged in the energy storage device.

Furthermore, the energy storage device comprises an acquisition cylinder barrel, an energy storage gas tank and a gas transmission pipeline, the piston is arranged in the acquisition cylinder barrel in a sliding mode, the acquisition cylinder barrel is communicated with one end of the gas transmission pipeline, the other end of the gas transmission pipeline is communicated with the energy storage gas tank, and the energy storage gas tank is fixedly connected with the launching device.

Furthermore, the gas collection cylinder barrel comprises a cylinder barrel and a first one-way valve, the piston is arranged in an inner cavity of the cylinder barrel in a sliding mode, the first one-way valve is installed on the outer wall of the cylinder barrel, and the inner cavity of the cylinder barrel is communicated with the energy storage gas tank through a gas transmission pipeline.

Further, the energy storage gas tank comprises a second one-way valve and a gas storage tank, the other end of the gas transmission pipeline is communicated with one end of the second one-way valve, and the other end of the second one-way valve is communicated with one end of the gas storage tank.

Furthermore, the launching device comprises an adjusting mechanism and a ball storage mechanism, the other end of the gas storage tank is fixedly communicated with one end of the ball storage mechanism, and the other end of the ball storage mechanism is provided with the adjusting mechanism.

Furthermore, the ball storage mechanism comprises an electromagnetic pressure release valve, a ball storage bin and a transmitting three-way pipe, the other end of the gas storage tank is communicated with one end of the electromagnetic pressure release valve, an air inlet of the transmitting three-way pipe is communicated with the other end of the electromagnetic pressure release valve, a ball inlet of the transmitting three-way pipe is connected with the ball storage bin, and a ball outlet of the transmitting three-way pipe is provided with an adjusting mechanism.

Furthermore, the adjusting mechanism comprises a threaded pipe, a expansion and contraction pipe and a launching cap, a ball outlet of the launching three-way pipe is communicated with one end of the threaded pipe, the expansion and contraction pipe is arranged at the other end of the threaded pipe, a plurality of gaps are formed in the side wall of the expansion and contraction pipe, the launching cap is in threaded connection with the threaded pipe, and the inner wall of the launching cap abuts against the expansion and contraction pipe.

Furthermore, the support comprises a lifting screw, a support frame and a guide rod, the bottom of the fixed platform is movably inserted with the top end of the guide rod, the guide rod is movably inserted into the support frame, the bottom of the guide rod is in threaded connection with the lifting screw, and the lifting screw abuts against the support frame.

Further, the guide bar includes hinge, stand pipe, guide way and screw hole, fixed platform's bottom activity is inserted and is equipped with the hinge, the hinge is articulated with the one end of stand pipe, the other end of stand pipe is provided with the screw hole, screw hole and lifting screw spiro union, the side of stand pipe is provided with the guide way, the guide way offsets with the support frame.

The embodiment of the invention has the following advantages:

1. the existing service robot can not adjust the route of service at will, so in ordinary training, a player can easily receive a ball as long as the player grasps the launching rule of the service robot, and thus the on-site reaction capability of the player cannot be well trained.

2. The most mainstream tennis ball serving machine at present extrudes the tennis ball by means of relative rotation of the two wheels, and the tennis ball is shot by utilizing elastic deformation of the tennis ball, however, the tennis ball serving machine is easy to damage when launching the tennis ball.

3. The power device provided by the invention adopts the connecting rod sliding block mechanism, air can be compressed in a short time, so that the launching efficiency is greatly improved, the pressure for launching the tennis ball can be freely adjusted through the electromagnetic pressure release valve, the inner diameter of the tennis ball launching port can be freely adjusted through the adjusting mechanism, the launching force is larger when the inner diameter is smaller, so that the launching force can be freely adjusted, corresponding adjustment can be carried out according to the specific conditions of a trainer, and compared with the tennis ball pitching machine in the prior art, the tennis ball pitching machine has no free adjusting capability, so that the tennis ball launching machine provided by the invention can achieve a better training effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the specification are only used for matching with the contents disclosed in the specification to be understood and read by those skilled in the art, and are not used for limiting the conditions of the present invention, so they have no technical essence, and any modifications of the structures, changes of the ratio relationships, or adjustments of the sizes should still fall within the scope of the present invention without affecting the functions and the achievable purposes of the present invention.

FIG. 1 is a perspective view of a tennis training device provided in the present invention;

FIG. 2 is a perspective view of a launching device of a training device for tennis according to the present invention;

FIG. 3 is a perspective view of an energy storage device of the training device for tennis according to the present invention;

FIG. 4 is a perspective view of a power device of a training device for tennis provided by the present invention;

FIG. 5 is a perspective view of a tennis training device frame according to the present invention;

FIG. 6 is a perspective view of a tennis training device stand according to the present invention

FIG. 7 is a perspective view of a guide rod of a training device for tennis according to the present invention

In the figure: 1, a frame; 11 a support; 111 lifting screw rods; 112 supporting frame; 113 a guide bar; 1131, a hinge joint; 1132 a guide tube; 1133, a guide groove; 1134, a thread inner hole; a fixed platform; 13 a handle; 2, a power device; 21 a turntable; 22, a power machine; 23 connecting rods; 25 a piston rod; 26 a piston; 3 an energy storage device; 31, collecting a cylinder barrel; 311 a cylinder barrel; 312 a first one-way valve; 32 an energy storage gas tank; 321 a second one-way valve; 322 an air reservoir; 33 gas transmission pipelines; 4 a transmitting device; 41 an adjustment mechanism; 411 a threaded pipe; 412 a pipe expanding and contracting; 413 a launch cap; 42 a ball storage mechanism; 421 electromagnetic pressure relief valves; 422 ball storage bin; 423 launch the tee.

Detailed Description

The present invention is described in terms of particular embodiments, and other advantages and benefits of the present invention will become apparent to those skilled in the art from the following disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-7, an embodiment of the invention provides a training device special for tennis, which includes a frame 1, a power device 2, an energy storage device 3 and a launching device 4, wherein the power device 2, the energy storage device 3 and the launching device 4 are all mounted on the frame 1, the power device 2 is fixedly arranged at an end of the frame 1, and the power device 2 is in transmission connection with the energy storage device 3 so as to provide power for the energy storage device 3, thereby compressing air. The energy storage device 3 is fixedly connected with the launching device 4, and when the energy storage device 3 releases energy, tennis balls in the launching device 4 can be launched out;

according to a specific embodiment provided by the invention, the frame 1 comprises a support 11, a fixed platform 12 and a handle 13, the power device 2 is arranged at one end of the fixed platform 12, the other end of the fixed platform 12 is provided with the handle 13, a coach can manually hold the handle 13 to change the position of the fixed platform 12 and then control the launching track of tennis balls, so that the coach or teacher can exercise pertinently aiming at the weakness of the player and further improve the exercise effect. A bracket 11 is movably inserted into the bottom of the fixed platform 12. The height of the support 11 can be freely adjusted, so that the tennis launching accuracy is improved, and the tennis over-top buckling and killing technology demonstration can be simulated.

According to a specific embodiment provided by the present invention, the power device 2 includes a rotary table 21, a power machine 22, a connecting rod 23, a piston rod 25 and a piston 26, the power machine 22 is fixedly disposed at one end of the fixed platform 12, the power machine 22 can be a gasoline engine or an electric motor, the power machine 22 is in transmission connection with the rotary table 21, so that the rotary table 21 rotates, the rotary table 21 is hinged to one end of the connecting rod 23, the other end of the connecting rod 23 is hinged to one end of the piston rod 25, the piston 26 is sleeved at the other end of the piston rod 25, the piston 26 is slidably disposed in the energy storage device 3, so as to form a crank-slider mechanism, the connecting rod 23 is driven by the rotation of the rotary table 21 to drive the piston rod 25 to push the piston, so that the piston 26 makes reciprocating motion in the collecting cylinder 31, and then external air is pressed into, to power tennis ball launching.

According to a specific embodiment provided by the present invention, the energy storage device 3 includes an acquisition cylinder barrel 31, an energy storage tank 32 and a gas transmission pipeline 33, the piston 26 is slidably disposed in the acquisition cylinder barrel 31, the acquisition cylinder barrel 31 is communicated with one end of the gas transmission pipeline 33, and the other end of the gas transmission pipeline 33 is communicated with the energy storage tank 32, so as to compress air into the energy storage tank 32. Energy storage gas pitcher 32 and emitter 4 fixed connection, be provided with electromagnetism relief valve 421 between energy storage gas pitcher 32 and the emitter 4, when the pressure value of energy storage gas pitcher 32 reached the critical value of electromagnetism relief valve 421, electromagnetism relief valve 421 was automatic to open in leading-in emitter 4 of high-pressure air, thereby launch the tennis.

According to an embodiment of the present invention, the gas collection cylinder 31 includes a cylinder 311 and a first check valve 312, the piston 26 is slidably disposed in the inner cavity of the cylinder 311, and the piston 26 can freely slide in the inner cavity of the cylinder 311 and is ensured to have good contact with the inner cavity of the cylinder 311, so as to avoid gas leakage. The outer wall of the cylinder 311 is provided with a first one-way valve 312, the inner cavity of the cylinder 311 is communicated with the energy storage air tank 32 through an air transmission pipeline 33, when the piston 26 moves backwards and backwards, outside air flows into the inner cavity of the cylinder 311 through the first one-way valve 312, when the piston 26 feeds, the air enters the energy storage air tank 32 along the air transmission pipeline 33, and the piston 26 repeatedly moves back and forth in the inner cavity of the cylinder 311, so that the air can be continuously pressed into the energy storage air tank 32, the air compression is realized, and power is provided for launching tennis balls.

According to an embodiment of the present invention, the energy storage tank 32 includes a second check valve 321 and a gas storage tank 322, the other end of the gas transmission pipeline 33 is communicated with one end of the second check valve 321, the gas storage tank 322 mainly plays a role of pressure storage, and the other end of the second check valve 321 is communicated with one end of the gas storage tank 322. The cylinder 311 presses air into the air storage tank 322 through the second check valve 321, and the second check valve 321 plays a role in preventing the pressure in the air storage tank 322 from flowing out reversely, so that the air collection cylinder 31 can continuously compress air.

According to an embodiment of the present invention, the launching device 4 includes an adjusting mechanism 41 and a ball storage mechanism 42, the other end of the air storage 322 is fixedly connected to one end of the ball storage mechanism 42, and the ball storage mechanism 42 is used for storing tennis balls and providing the tennis balls to be launched for the launching device. The other end of the ball storage mechanism 42 is provided with an adjusting mechanism 41. The adjusting mechanism 41 can control the tennis ball launching speed by adjusting the inner diameter of the launching port.

According to a specific embodiment provided by the present invention, the ball storage mechanism 42 includes an electromagnetic pressure release valve 421, a ball storage bin 422 and a launching three-way pipe 423, the other end of the air storage tank 322 is communicated with one end of the electromagnetic pressure release valve 421, an air inlet of the launching three-way pipe 423 is communicated with the other end of the electromagnetic pressure release valve 421, the electromagnetic pressure release valve 421 can set a critical value of pressure release, and when the pressure exceeds the critical value, the pressure release valve is opened, or the electromagnetic pressure release valve 421 can be opened through electric signal control. The ball inlet of the launching three-way pipe 423 is connected with the ball storage bin 422, tennis balls are stored in the ball storage bin 422, and the tennis balls in the ball storage bin 422 can enter the launching three-way pipe 423 from the bottom of the ball storage bin, and then the tennis balls are launched by utilizing compressed air.

According to an embodiment of the present invention, the adjusting mechanism 41 includes a threaded pipe 411, an expansion and contraction pipe 412 and a launching cap 413, a ball outlet of the launching three-way pipe 423 is communicated with one end of the threaded pipe 411, the other end of the threaded pipe 411 is provided with an expansion and contraction pipe 412, the launching cap 413 is screwed with the threaded pipe 411, since the interior of the launching cap 413 is a conical surface, when the launching cap 413 is screwed on the threaded pipe 411, the inner wall of the launching cap 413 abuts against the expansion and contraction pipe 412, and then since the side wall of the expansion and contraction pipe 412 is provided with a plurality of gaps, the width of the gaps on the expansion and contraction pipe 412 will be gradually narrowed, and simultaneously the inner diameter of the expansion and contraction pipe 412 will be reduced, when a tennis ball is launched from the launching cap 413, the smaller the inner diameter of the expansion and contraction pipe 412 is, the larger the deformation amount of the tennis ball is, and the tennis ball has better elasticity, and therefore the launching force of the, therefore, the technical effect of adjusting the tennis ball launching speed can be achieved.

According to a specific embodiment provided by the invention, the device has two launching modes, wherein in one time running mode, a fixed critical value is set on the electromagnetic pressure release valve 421, when the pressure borne by the electromagnetic pressure release valve 421 reaches the critical value, the electromagnetic pressure release valve 421 is automatically opened, so that the compressed air in the air storage tank 322 is released into the launching three-way pipe 423, tennis is further pushed to be launched, and a large number of tennis balls can be launched in a short time through the running mode, so that the physical ability of athletes is improved; the other mode is a spot shooting mode, namely, the critical value of the electromagnetic pressure release valve 421 is increased, the air storage tank 322 is continuously inflated through the energy storage air tank 32, when the pressure in the air storage tank 322 is enough, the power machine stops running, the electromagnetic pressure release valve 421 is manually opened, tennis balls are emitted, and through the spot shooting mode, a ball path can be controlled, the tennis balls are shot at dead angles on a football court, and therefore the reaction capacity and the technical and tactical level are improved.

In an embodiment of the present invention, the support 11 includes a lifting screw 111, a support frame 112 and a guide rod 113, a top end of the guide rod 113 is movably inserted into the bottom of the fixed platform 12, the guide rod 113 is movably inserted into the support frame 112, the bottom of the guide rod 113 is screwed with the lifting screw 111, and the lifting screw 111 abuts against the support frame 112. When the height of the fixed platform 12 needs to be raised, the rocking handle is shaken to rotate the lifting screw 111, so that the guide rod 113 can move up and down along the guide groove 1133 by utilizing the screw pair formed by the lifting screw 111 and the guide rod 113, and therefore, the tennis shooting device can shoot tennis balls from a high position to simulate the tennis killing state, and the training level of athletes is improved.

In an embodiment of the present invention, the guide rod 113 includes a hinge 1131, a guide tube 1132, a guide groove 1133 and a threaded inner hole 1134, the hinge 1131 is movably inserted at the bottom of the fixed platform 12, the hinge 1131 is hinged to one end of the guide tube 1132, the threaded inner hole 1134 is disposed at the other end of the guide tube 1132, the threaded inner hole 1134 is screwed to the lifting screw 111, the guide groove 1133 is disposed on the side surface of the guide tube 1132, and the guide groove abuts against the support frame 112. By using the hinge joint 1131 disposed on the guide tube 1132, not only the fixed platform 12 can rotate left and right, but also the fixed platform 12 can tilt back and forth, so that tennis balls with various motion paths can be launched by the tennis training device, thereby improving the ability of athletes to judge the tennis motion trajectories.

The application process of the embodiment of the invention is as follows:

the power machine 22 drives the rotary table 21 to rotate, the connecting rod 23 is hinged on the rotary table 21, and then the connecting rod 23 drives the piston rod 25 to move, so that the piston 26 reciprocates in the cylinder 311, and in the process of the movement of the piston 26, outside air can continuously enter an inner cavity of the cylinder 311 and then is compressed into the air storage tank 322.

When the equipment enters a point shooting mode, the air storage tank 322 is continuously inflated through the energy storage air tank 32, when the pressure in the air storage tank 322 is enough, the power machine 22 stops running, the position of the fixed platform 12 is adjusted to aim at a dead angle of the player position, and then the electromagnetic pressure release valve 421 is opened, so that tennis balls are shot out;

when the equipment is in a continuous launching mode, a fixed critical value is set on the electromagnetic pressure release valve 421, and when the pressure borne by the electromagnetic pressure release valve 421 reaches the critical value, the electromagnetic pressure release valve 421 is automatically opened, so that the compressed air in the air storage tank 322 is released into the launching three-way pipe 423, and then tennis ball launching is pushed.

Compared with the prior art, the tennis special trainer provided by the invention avoids the problem that tennis balls are damaged due to extrusion deformation under the condition of ensuring higher launching efficiency, and simultaneously improves the flexibility of tennis ball launching. The device provided by the invention can be used for training tennis lovers or professional athletes by assisting in matching with two launching modes. Not only improves the training level of tennis, but also is beneficial to improving the quality of tennis training teaching and improving the love of trainees on tennis.

Although the present invention has been described in detail hereinabove with reference to specific embodiments thereof, it will be apparent to those skilled in the art that modifications and improvements can be made thereto without departing from the spirit and scope of the invention. Therefore, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. The training device special for tennis is characterized by comprising a rack (1), a power device (2), an energy storage device (3) and a transmitting device (4), wherein the power device (2), the energy storage device (3) and the transmitting device (4) are all arranged on the rack (1), the power device (2) is fixedly arranged at the end part of the rack (1), the power device (2) is in transmission connection with the energy storage device (3), and the energy storage device (3) is fixedly connected with the transmitting device (4);

frame (1) includes support (11), fixed platform (12) and handle (13), power device (2) set up the one end at fixed platform (12), the other end of fixed platform (12) is provided with handle (13), support (11) are inserted to the bottom of fixed platform (12).

2. The training device special for tennis as claimed in claim 1, wherein the power device (2) comprises a turntable (21), a power machine (22), a connecting rod (23), a piston rod (25) and a piston (26), the power machine (22) is fixedly arranged at one end of the fixed platform (12), the power machine (22) is in transmission connection with the turntable (21), the turntable (21) is hinged to one end of the connecting rod (23), the other end of the connecting rod (23) is hinged to one end of the piston rod (25), the piston (26) is sleeved at the other end of the piston rod (25), and the piston (26) is slidably arranged in the energy storage device (3).

3. The training device special for tennis as recited in claim 2, wherein said energy storage device (3) comprises a collection cylinder (31), an energy storage gas tank (32) and a gas transmission pipeline (33), said piston (26) is slidably disposed in said collection cylinder (31), said collection cylinder (31) is communicated with one end of said gas transmission pipeline (33), the other end of said gas transmission pipeline (33) is communicated with said energy storage gas tank (32), and said energy storage gas tank (32) is fixedly connected with said launching device (4).

4. A training device special for tennis as recited in claim 3, wherein said gas collecting cylinder (31) comprises a cylinder (311) and a first check valve (312), said piston (26) is slidably disposed in the inner cavity of the cylinder (311), said first check valve (312) is mounted on the outer wall of the cylinder (311), the inner cavity of the cylinder (311) is communicated with the energy storage gas tank (32) through the gas transmission pipeline (33).

5. The training device special for tennis as claimed in claim 4, wherein the energy storage tank (32) comprises a second one-way valve (321) and an air storage tank (322), the other end of the air transmission pipeline (33) is communicated with one end of the second one-way valve (321), and the other end of the second one-way valve (321) is communicated with one end of the air storage tank (322).

6. The training device special for tennis as claimed in claim 5, wherein said launching device (4) comprises an adjusting mechanism (41) and a ball storage mechanism (42), the other end of said air storage tank (322) is fixedly communicated with one end of the ball storage mechanism (42), and the other end of said ball storage mechanism (42) is provided with the adjusting mechanism (41).

7. The tennis special training device as claimed in claim 6, wherein the ball storage mechanism (42) comprises an electromagnetic pressure release valve (421), a ball storage bin (422) and a launching tee pipe (423), the other end of the air storage tank (322) is communicated with one end of the electromagnetic pressure release valve (421), the air inlet of the launching tee pipe (423) is communicated with the other end of the electromagnetic pressure release valve (421), the ball inlet of the launching tee pipe (423) is connected with the ball storage bin (422), and the ball outlet of the launching tee pipe (423) is provided with a regulating mechanism (41).

8. The training device special for tennis as claimed in claim 7, wherein the adjusting mechanism (41) comprises a threaded pipe (411), a collapsible pipe (412) and a launching cap (413), the ball outlet of the launching tee pipe (423) is communicated with one end of the threaded pipe (411), the other end of the threaded pipe (411) is provided with the collapsible pipe (412), the side wall of the collapsible pipe (412) is provided with a plurality of slits, the launching cap (413) is in threaded connection with the threaded pipe (411), and the inner wall of the launching cap (413) abuts against the collapsible pipe (412).

9. The training device special for tennis as claimed in claim 8, wherein said support (11) comprises a lifting screw (111), a support frame (112) and a guide rod (113), the bottom of said fixed platform (12) is movably inserted with the top end of the guide rod (113), said guide rod (113) is movably inserted into the support frame (112), and the bottom of said guide rod (113) is screwed with the lifting screw (111), said lifting screw (111) is abutted with the support frame (112).

10. The training aid special for tennis as claimed in claim 8, wherein the guide rod (113) comprises a hinged joint (1131), a guide tube (1132), a guide slot (1133) and a threaded inner hole (1134), the hinged joint (1131) is movably inserted into the bottom of the fixed platform (12), the hinged joint (1131) is hinged to one end of the guide tube (1132), the threaded inner hole (1134) is formed in the other end of the guide tube (1132), the threaded inner hole (1134) is in threaded connection with the lifting screw (111), the guide slot (1133) is formed in the side surface of the guide tube (1132), and the guide slot abuts against the support frame (112).