A buffer device for assembling a pressure vessel

Abstract

The present invention discloses a buffer device for assembling a pressure vessel, comprising a bracket, a positioning pin, a guide pin, a locking hook, and a handle. The bracket is the main part of the buffer device, the upper part of the bracket is a T-shaped structure, the right side of the T-shaped structure is a strip structure, the middle part of the bracket is a flat strip structure extending downward, and the lower right corner of the bracket is a pointed corner; the lower end of the handle is a fork-shaped structure and a pin hole is provided on the upper edge of the end, and the pin hole is used to fix the roller on the handle through the B pin; the positioning pin is installed in the positioning pin hole of the bracket for connection with the pressure vessel A; the guide pin is installed in the guide pin hole of the bracket, and the guide pin is used for connection and positioning with the pressure vessel A; the upper part of the locking hook is provided with a pin hole, and the locking hook is installed and connected to the handle through the pin hole and the first A pin. The present invention not only solves the instability problem existing in assembly using a pneumatic manipulator alone, but also solves the problem that the guide pin cannot be installed in the smooth hole on the flange of the pressure vessel.

Description

Technical Field

[0001] The present invention relates to a buffer device, in particular to a buffer device for assembling a pressure vessel. Background Art

[0002] Sealing performance is the most important performance of a pressure vessel, and the fitting accuracy of the pressure vessel docking parts is relatively high. Therefore, assembly process and technical methods are one of the important factors affecting the sealing performance of pressure vessels. The inner liner of some special-purpose pressure vessels is made of brittle materials such as graphite and ceramics, and they are also equipped with flammable and explosive materials. The assembly process must ensure smooth and slow docking. Otherwise, the brittle materials such as graphite and ceramics will be damaged, affecting product reliability. Product quality problems may cause major safety accidents, resulting in damage to the environment or casualties. To accommodate the assembly of pressure vessels with brittle materials such as graphite and ceramics, a manual winch-type robotic arm lifting method is currently used.

[0003] Pressure vessels are generally assembled using a crane vertical lifting method, a vehicle-mounted horizontal assembly method, and a manual winch-type mechanical arm vertical lifting method. For pressure vessels whose liner materials are brittle materials such as graphite and ceramics and which contain flammable and explosive materials, it is necessary to use equipment that meets explosion-proof requirements for assembly and the assembly process should be slow and stable. The crane vertical lifting method and the vehicle-mounted horizontal assembly method cannot meet the assembly needs. For pressure vessels whose liner materials are brittle materials such as graphite and ceramics and which contain flammable and explosive materials, a manual winch-type mechanical arm (see Figure 1 ) Vertical hoisting method assembly, the manual hoisting robot arm requires 5 people to operate simultaneously to complete product assembly.

[0004] Before assembling the pressure vessel, it is necessary to install a special lifting device on the pressure vessel and connect the lifting device to the hook of the manual winch arm. When the manual winch arm lifts the pressure vessel, it is necessary to use human power to shake the handle to drive the drum to rotate. When the drum rotates, the length of the wire rope wound on the drum is changed to achieve pitching and lifting. Pitching, lifting and rotation are completed by independent mechanisms, so three people are required to be respectively at A, B and C of the manual winch arm (see Figure 1 ) operates the pitch, lift, and slewing mechanisms, while two others are responsible for docking the pressure vessel. A total of five people are required to assemble the pressure vessel. Manual operation is inefficient, making the assembly process time-consuming. Furthermore, the coordination of five people operating the robotic arm is difficult, posing a safety hazard.

[0005] Certain special-purpose pressure vessels contain flammable or explosive materials and cannot be assembled using non-explosion-proof assembly equipment. Pressure vessels are generally made of composite materials, and some contain brittle materials such as graphite and ceramics. Therefore, the assembly process requires appropriate equipment to ensure smooth and slow docking. Due to these special characteristics of pressure vessels, manual winch arms are currently used for assembly. However, manual winch arms require three people to operate, which is difficult and poses safety risks. They also suffer from low assembly efficiency and are time-consuming. To address the low efficiency and difficulty of multiple people working together when lifting pressure vessels using manual winch arms, and to avoid the drawbacks of manual winch arms, pneumatic arms are being used instead. Pneumatic arms offer the advantages of explosion resistance and ease of operation. Their explosion-proof properties make them suitable for use in explosion-proof environments. However, they suffer from poor stability, resulting in the workpiece vibrating during assembly, making them unsuitable for assembling pressure vessels containing brittle materials such as graphite and ceramics. The unstable nature of pneumatic manipulators stems from the elasticity of the compressed gas within the cylinder, which can either compress or expand further under certain conditions. When subject to subtle external uncertainties, the pneumatic manipulator can vibrate up and down during descent or ascent. Addressing the stability of the pneumatic manipulator requires addressing the impact of vertical vibration during the lifting process on assembly safety and reliability.

[0006] Furthermore, most pressure vessels utilize flanged connections with high precision, requiring the use of guides, typically installed in the threaded holes of the pressure vessel flanges. Some pressure vessels are already loaded with flammable or explosive materials prior to assembly, requiring assembly to be performed in an explosion-proof environment and using explosion-proof equipment. When both pressure vessel flanges have bare holes, conventional guides cannot be installed during assembly. The lack of threaded holes in some pressure vessel flanges precludes the installation of guide pins, leading to quality issues such as damage to the sealing ring and mating surface materials during the docking process. Without the use of guides, the first-time assembly success rate is low, and damage to the sealing surface can easily occur during assembly, leading to seal failure. To improve assembly pass rates, the problem of installing guides in the bare holes of pressure vessel flanges needs to be addressed. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a buffer device for assembling pressure vessels to solve the problems of low pressure vessel assembly efficiency and safety hazards in the assembly process, and the inability to install guide pins in the smooth holes on the flange.

[0008] In order to solve the existing technical problems, the technical solution adopted by the present invention is: a buffer device for assembling a pressure vessel, comprising a bracket, a positioning pin, a guide pin, a lock hook and a handle, the bracket being the main part of the buffer device, the upper part of the bracket being a T-shaped structure, the left side of the T-shaped structure having two circular holes, which are respectively a positioning pin hole and a guide pin hole, for installing the positioning pin and the guide pin, and the right side of the T-shaped structure is a strip structure; the middle part of the bracket is a flat strip structure extending downward; the lower right side of the bracket is further extended to the lower right by the flat strip structure, and the flat strip structure extending from the lower right is an inclined plane, and the inclined plane is used to allow the lock hook to slide downward on the inclined plane when the handle is rotated clockwise with the first A pin; the lower right corner of the bracket is a sharp corner, and the sharp corner is used to cooperate with the lock hook and fix the lock hook when the lock hook moves into place; a pin hole is provided in the middle of the bracket for installing the second A pin; the handle is a lever structure, and a notch is provided at the right-angled bend of the lower end of the handle, and the notch is used to prevent the handle from interfering with the pressure vessel B during assembly. interference occurs in the flange; the lower end of the handle is a fork-shaped structure and a pin hole is provided on the upper edge of the end, and the pin hole is used to fix the roller to the handle through the B pin; two equal-sized circular holes are provided in the middle section of the handle, the upper circular hole is used to install the lock hook on the handle through the first A pin, and the lower circular hole is used to install and connect the handle and the bracket together through the second A pin; the positioning pin is a cylindrical structure, which is installed in the positioning pin hole of the bracket for connecting with the pressure vessel A; one end of the guide pin is a cylindrical structure and the other end is a conical structure, the end of the cone is a spherical structure, and the guide pin is installed in the guide pin hole of the bracket, and the guide pin is used to connect and position with the pressure vessel A; the lock hook is a hook-shaped structure, and a pin hole is provided on the upper part of the lock hook, and the lock hook is installed and connected to the handle through the pin hole and the first A pin; a cylindrical protrusion is provided on the back of the lock hook, and a small annular groove is provided on the protrusion. The annular groove is used to install and fix one end of the tension spring, and the other end of the tension spring is connected and fixed with the second A pin installed on the bracket.

[0009] Furthermore, a recess is provided on the strip structure on the right side of the T-shaped structure on the upper portion of the bracket of the present invention.

[0010] Furthermore, the upper end of the handle of the present invention is also provided with an upward raised structure to prevent the handle from slipping when being pressed down.

[0011] Furthermore, the right edge of the lock hook of the present invention is also provided with a raised thin sheet structure for pushing the lock hook away when the lock hook is separated from the bracket.

[0012] When two workpieces are spaced a certain distance apart, the present invention employs a buffer device to pull the upper workpiece downward at a constant speed, allowing the pneumatic manipulator's hook and the suspended workpiece to simultaneously move downward at a constant speed. This buffering method prevents the pneumatic manipulator's hook and suspended workpiece from vibrating during descent. This buffering method is of great significance for assembling pressure vessels containing brittle materials such as graphite and ceramics.

[0013] The buffer device and pneumatic manipulator of the present invention are both lever structures. A small downward pressure on the buffer device handle can cause a large downward displacement of the pneumatic manipulator hook. This feature makes the operation process more labor-saving and also makes the buffer device's buffering process more stable.

[0014] When the buffer device is used to dock the pressure vessel flange into place, the pneumatic manipulator hook exerts a pulling force on the upper pressure vessel that is greater than the pressure vessel's weight. If the hand pressing on the buffer device handle is released, the upper pressure vessel will rise to its original position. Because the locking hook on the buffer device automatically hooks onto the sharp corner at the lower right corner of the bracket when the flange is docked, the buffer device has a self-locking function. This reduces operational difficulty and prevents operational accidents caused by the sudden rise of the upper pressure vessel.

[0015] In the present invention, when both pressure vessel flanges being assembled have blank holes, guide pins cannot be installed during assembly, resulting in unreliable coaxiality during pressure vessel docking and negatively impacting pressure vessel assembly quality. The guide pins of the buffer device serve as both positioning pins and guide pins. As the buffer device pulls the upper pressure vessel downward, the guide pins on the buffer device also move downward in sync. Thus, the buffer device also functions as a guide pin, resolving the issue of blank holes in pressure vessel flanges being unable to accommodate guide pins.

[0016] Beneficial effects

[0017] The present invention utilizes an assembly method that uses a buffer device in conjunction with a pneumatic manipulator to assemble a pressure vessel. The pneumatic manipulator is easy to operate and can avoid the safety hazards associated with multiple people working together. Simultaneously using the pneumatic manipulator can reduce the number of operators and improve assembly efficiency. The guide pins on the buffer device serve as both positioning pins and guide pins, simultaneously performing the positioning function and the guiding function required for pressure vessel docking. This solves both the instability problem associated with assembly using a pneumatic manipulator alone and the problem of guide pins being unable to be installed in the smooth holes on the pressure vessel flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a manual winch type robotic arm;

[0019] Figure 2 Schematic diagram of a pneumatic robotic arm;

[0020] Figure 3 This is the main view of the buffer device;

[0021] Markings in the figure: 1- bracket, 2- positioning pin, 3- guide pin, 4- roller;

[0022] Figure 4 It is a top view of the buffer device;

[0023] Figure 5 It is the left view of the buffer device;

[0024] Figure 6 It is the A-direction view of the left side of the buffer device;

[0025] Markings in the figure: 5-first A pin, 6-second A pin, 7-B pin, 8-lock hook, 9-tension spring, 10-handle;

[0026] Figure 7 A schematic diagram showing the state where the buffer device is installed on the flange for ease of installation;

[0027] Figure 8 This is a schematic diagram of the state where the buffer device starts working after being assembled in place;

[0028] Figure 9 Schematic diagram of the state where the pressure vessel is assembled in place for the buffer device;

[0029] Figure 10 This is the main view of the bracket;

[0030] Markings in the figure: 11-round hole, 12-strip structure, 13-flat strip structure, 14-pointed corner;

[0031] Figure 11 This is the right side view of the bracket;

[0032] Figure 12 It is a top view of the bracket;

[0033] Markings in the figure: 15-guide pin hole, 16-positioning pin hole;

[0034] Figure 13 AA section view of the bracket;

[0035] Figure 14 This is the main view of the handle;

[0036] Figure 15 This is a top view of the handle;

[0037] Figure 16 This is a schematic diagram of pin A;

[0038] Figure 17 This is a schematic diagram of pin B;

[0039] Figure 18 Schematic diagram of the guide pin;

[0040] Figure 19 Schematic diagram of the positioning pin;

[0041] Figure 20 This is the main view of the lock hook;

[0042] Figure 21 This is the left view of the lock hook;

[0043] Figure 22 This is the right side view of the lock hook. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0045] A buffer device for assembling a pressure vessel according to the present invention, as shown in the attached Figure 3-Figure 6 As shown, it consists of a bracket 1, a positioning pin 2, a guide pin 3, a roller 4, a first A pin 5, a second A pin 6, a B pin 7, a locking hook 8, a tension spring 9, and a handle 10.

[0046] Bracket 1, as attached Figure 10-13 The main part of the buffer device is shown in FIG. The main parts of the buffer device work together with the bracket 1. The upper part of the bracket 1 is a T-shaped structure. Figure 12 As shown, there are two circular holes 11 on the left side of the T-shaped structure, which are respectively a positioning pin hole 16 and a guide pin hole 15, for installing the positioning pin 2 and the guide pin 3. The right side of the T-shaped structure is a strip structure 12, and there is a recessed portion on the strip structure 12. This recessed strip structure 12 is convenient for pinching by hand when installing the buffer device, and the recessed structure has an anti-slip effect when pinched by hand. The middle part of the bracket 1 is a flat strip structure 13 extending downward. The lower right side of the bracket 1 is a flat strip structure 13 extending to the lower right. The inclined plane on the flat strip structure 13 is used to allow the lock hook 8 to slide downward on the inclined plane when the handle 10 rotates clockwise with the first A pin 5. The sharp corner 14 at the lower right corner of the bracket 1 is used to cooperate with the lock hook 8 and fix the lock hook 8 when the lock hook 8 moves into place. The circular hole in the middle of the bracket 1 is a pin hole, which cooperates with the second A pin 6.

[0047] Handle 10, as attached Figure 14-15 As shown, the lever structure has a notch formed at the right-angled bend at the lower end. This notch prevents the handle 10 from interfering with the flange of pressure vessel B during assembly. The lower end of the handle 10 is forked, with a smaller pinhole at the upper edge for mounting the B pin 7 and roller 4. The middle section of the handle 10 has two equal-sized circular holes for mounting the first A pin 5 and the second A pin 6. The upper end of the handle 10 has an upturned protrusion to prevent it from slipping when pressed down by hand.

[0048] The roller 4 is a bearing and is connected to the pin hole at the lower end of the handle 10 through the B pin 7. During the assembly of the pressure vessel, the handle 10 needs to rotate clockwise with the second A pin 6 as the axis. Figure 3 As shown, during the rotation process, the roller 4 at the lower end of the handle 10 is slightly displaced to the left relative to the flange of the pressure vessel B, so the roller 4 helps the lower end of the handle 10 to move to the left and prevents the handle 10 from scratching the flange of the pressure vessel B.

[0049] Positioning pin 2, as attached Figure 19 As shown, it is a cylindrical structure, installed in the positioning pin hole 16 of the bracket 1, as shown in the attached Figure 12 As shown, the buffer device can be connected to the pressure vessel A, and the positioning pin 2 and the positioning pin hole 16 are interference fit.

[0050] One end of the guide pin 3 is a cylindrical structure, and the other end is a conical structure, and the end of the cone is a spherical structure. Figure 18 The guide pin 3 is installed in the guide pin hole 15 of the bracket 1, as shown in the attached Figure 12 The guide pin 3 can connect the buffer device to the pressure vessel A. The guide pin 3 and the guide pin hole 15 are interference fit. The guide pin 3 has the function of a positioning pin and also serves as a guide pin during assembly.

[0051] The first A pin 5 and the second A pin 6 have the same structure. Figure 16 As shown, the main structure is cylindrical. One end of the first A pin 5 and the second A pin 6 has a short cylindrical structure with a slightly larger diameter. A small annular groove is provided on the short cylinder for mounting a tension spring. The first A pin 5 connects the handle 10 to the lock hook 8 and then rivets them together. The second A pin 6 connects the handle 10 to the bracket 1 and then rivets them together.

[0052] The main structure of the B pin 7 is cylindrical, with a short cylindrical structure with a slightly larger diameter at one end. Figure 17 As shown, the handle 10 and the roller 4 are connected by pin B 7 and then riveted.

[0053] Lock hook 8, as attached Figure 20-22 As shown, it is a hook-shaped structure connected to the handle 10 through the first A pin 5. When the handle 10 is pressed down during the assembly process, the lower end of the lock hook 8 slides downward along the lower right side of the bracket 1 and gradually opens to the right. Figure 9In this state, the hook 8, under the tension of the tension spring, hooks onto the sharp corner below the bracket 1. This maintains the relative position of pressure vessel A to pressure vessel B. A raised tab is located on the right edge of the hook 8, allowing it to be pushed open with a finger when separated from the bracket 1. The back of the hook 8 has a cylindrical protrusion with a small annular groove for connection to the tension spring.

[0054] When assembling pressure vessels using a pneumatic robotic arm, first lift pressure vessel A and connect the two pressure vessels to the flanges with a distance of about 40mm-50mm. Figure 7 As shown in the figure, two sets of buffer devices are installed symmetrically on the flange of pressure vessel A. Figure 3-Figure 6 As shown, pinch the buffer device with your hands and put the positioning pin 2 and guide pin 3 of the buffer device into the two adjacent light holes on the flange of the pressure vessel A, as shown in the attached Figure 7 After releasing the buffer device, the handle 10 of the buffer device turns downward under the action of gravity until the roller 4 on the handle 10 presses against the lower end face of the flange of the pressure vessel B below. Figure 8 As shown. Since the handle 10 is a lever structure and the bearing at the lower end of the handle 10 has already pressed against the lower section of the pressure vessel B, when the handles 10 of the two buffer devices are pressed down slowly with both hands, during the process of pressing the handle 10 down, the bracket 1, the positioning pin 2, the guide pin 3 and the pressure vessel A move slowly downward at the same time under the traction of the first A pin 5, that is, the flange of the pressure vessel A slowly moves towards the pressure vessel B, and the two flanges are connected. As shown in the attached figure Figure 9 As shown, when the buffer device pulls the pressure vessel A downward to dock, the pressure vessel A can be ensured to move downward smoothly.

[0055] When two pressure vessels are docked Figure 9 In the state, the lock hook on the buffer device is hooked to the sharp corner of the lower end of the bracket under the action of the spring. Since the pulling force of the pneumatic robot arm hook on the pressure vessel is greater than the gravity of the pressure vessel, the lock hook is hooked to the bracket to prevent the pressure vessel A from rebounding to the initial state after the buffer device handle is released. Figure 7 As shown, the self-locking function of the locking hook can avoid a collision accident caused by the pressure vessel A rebounding to the initial state.

[0056] When the flanges of two pressure vessels are butted to a distance of about 40mm-50mm and buffer devices are installed, as shown in the attached Figure 8 As shown, the guide pin passes through the upper pressure vessel flange and aligns with the light hole in the lower pressure vessel flange. As the buffer device actively applies tension to gradually bring the two pressure vessel flanges closer together, the guide pin gradually enters the light hole in the lower pressure vessel flange, completing its guiding function during the docking process.

[0057] Since the handle 10 of the buffer device is a 4:1 lever structure, as shown in the attached Figure 2 As shown, the cantilever beam of the pneumatic manipulator arm utilizes a 5:1 lever structure. When a pair of buffers are used to simultaneously pull pressure vessel A downward, the pressure applied to the buffer handles is amplified by the levers, transforming it into a downward pull on the pneumatic manipulator's hook. This pull is further amplified and converted into an upward pull on the pneumatic manipulator's piston rod. Therefore, even a small pull applied to the buffer handles is amplified 20-fold by the two-stage lever action, becoming pressure on the gas within the cylinder. This pressure reduces the volume of the gas within the cylinder, causing the cylinder piston to move slightly upward. This displacement causes the hook at the end of the pneumatic manipulator arm's cantilever beam and the pressure vessel A it is hanging to move downward by a factor of five. In other words, a small downward pressure on the buffer handles can produce a significant downward displacement of the pneumatic manipulator arm's hook.

[0058] During pressure vessel assembly, a buffer device is used to mitigate the instability of the pneumatic manipulator arm. This mitigation exploits the fact that pneumatic manipulator arms are prone to up and down movement under external forces. This instability arises from the fact that the cantilever beam of the pneumatic manipulator arm maintains a stable relative position under the influence of the gas within the cylinder. When the pressure of the gas within the cylinder changes, its volume changes accordingly, causing a slight displacement of the cylinder piston. This slight displacement of the cylinder, amplified five times by a lever, results in a noticeable displacement of the end of the cantilever beam of the pneumatic manipulator arm.

[0059] When a buffer device is used to cause a significant displacement of the pneumatic manipulator's cantilever beam, the pressure acting on the cylinder causes a slight change in the volume of the gas within the cylinder. The flexible nature of the gas within the cylinder enables significant up and down displacement of the cantilever beam under the influence of external forces. When a small pulling force is actively applied to the buffer device, it pulls pressure vessel A slowly downward until the two pressure vessels are smoothly docked. As the buffer device pulls pressure vessel A, the cantilever beam of the pneumatic manipulator also gradually and smoothly moves downward.

[0060] This pressure vessel assembly buffer device has been successfully applied in the assembly of a pressure vessel made of graphite and with smooth flanges. The device ensures smooth docking and eliminates the vibrations associated with the pneumatic robotic arm during the lifting process. Furthermore, the buffer device's guide pins provide excellent guidance during assembly, achieving a 100% first-pass assembly yield and resolving the issue of guide pins being unable to fit through the smooth flanges. This assembly method, combining this buffer device with the pneumatic robotic arm, improves efficiency by 40% compared to the existing manual winch assembly method.

Claims

1. A buffer device for assembling a pressure vessel, comprising a bracket (1), a positioning pin (2), a guide pin (3), a locking hook (8) and a handle (10), characterized in that: The bracket (1) is the main body of the buffer device. The upper part of the bracket (1) is a T-shaped structure. The left side of the T-shaped structure has two round holes (11), which are respectively a positioning pin hole (16) and a guide pin hole (15) for installing the positioning pin (2) and the guide pin (3). The right side of the T-shaped structure is a strip structure (12); the middle part of the bracket (1) is a flat strip structure extending downward; the lower right side of the bracket (1) further extends to the lower right is also a flat strip structure (13), and the flat strip structure extending from the lower right is The structure (13) is provided with an inclined plane, and the inclined plane is used for the lock hook (8) to slide downward on the inclined plane when the handle (10) rotates clockwise with the first A pin (5); the lower right corner of the bracket (1) is a sharp corner (14), and the sharp corner (14) is used to cooperate with the lock hook (8) and fix the lock hook (8) when the lock hook (8) moves into place; a pin hole is provided in the middle of the bracket (1) for installing the second A pin (6); a recess is provided on the strip structure (12) on the right side of the T-shaped structure on the upper part of the bracket (1); The handle (10) is a lever structure, and a notch is provided at the right-angled bend of the lower end of the handle (10), and the notch is used to prevent the handle (10) from interfering with the flange of the pressure vessel B during assembly; the lower end of the handle (10) is a fork-shaped structure and a pin hole is provided on the upper edge of the end, and the pin hole is used to fix the roller (4) on the handle (10) through the B pin (7); the middle section of the handle (10) is provided with two equal-sized circular holes, the upper circular hole is used to install and connect the lock hook (8) to the handle (10) through the first A pin (5), and the lower circular hole is used to install and connect the handle (10) and the bracket (1) together through the second A pin (6); The positioning pin (2) is a cylindrical structure, installed in the positioning pin hole (16) of the bracket (1), and is used to connect with the pressure vessel A; One end of the guide pin (3) is a cylindrical structure, and the other end is a conical structure, the end of the cone is a spherical structure, the guide pin (3) is installed in the guide pin hole (15) of the bracket (1), and the guide pin (3) is used for connection and positioning with the pressure vessel A; The lock hook (8) is a hook-shaped structure, and a pin hole is provided on the upper part of the lock hook (8). The lock hook (8) is installed and connected with the handle (10) through the pin hole and the first A pin (5); a cylindrical protrusion is provided on the back of the lock hook (8), and a small annular groove is provided on the protrusion. The annular groove is used to install and fix one end of the tension spring (9), and the other end of the tension spring (9) is connected and fixed with the second A pin (6) installed on the bracket (1); a raised thin plate structure is provided on the right edge of the lock hook (8), which is used to push the lock hook (8) away when the lock hook (8) is separated from the bracket (1).

2. The buffer device according to claim 1, characterized in that: The upper end of the handle (10) is provided with an upward raised structure for preventing the handle (10) from slipping when being pressed down.

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