A cooling device for galvanized steel strip

Abstract

This application relates to a cooling device for galvanized steel strip, and pertains to the technical field of cooling galvanized steel strip. The cooling device for galvanized steel strip includes a first cooling device and a second cooling device symmetrically arranged on both sides of the galvanized steel strip and having identical structures. The longitudinal section formed by the first and second cooling devices is trapezoidal in shape, wider at the top and narrower at the bottom. The first cooling device includes a support frame, on which multiple rows of cooling components are arranged, gradually tilting downwards towards the galvanized steel strip. Each cooling component includes a support plate, a nozzle assembly, and a drive assembly. The nozzle assembly includes multiple horizontally spaced nozzles, each nozzle being slidably connected to the support plate. The drive assembly drives the nozzles, and as the nozzles move towards the galvanized steel strip, the distance between two adjacent nozzles changes. This application has the effect of increasing the residence time of the cold air, thereby improving the cooling effect of the galvanized steel strip.

Description

Technical Field

[0001] This application relates to the field of galvanized steel strip, and more particularly to a cooling device for galvanized steel strip. Background Technology

[0002] Steel strip is a narrow and long steel plate with extremely wide applications, mainly in the automotive industry, machinery manufacturing industry, construction engineering, steel structures, and daily hardware. Steel strip can be made into cold-formed steel and welded steel pipes, etc.

[0003] Iron in steel strip readily oxidizes with oxygen in humid air and can penetrate into the interior. Zinc is chemically much more reactive than iron; therefore, by coating the surface of the steel strip with a zinc coating, zinc can remove oxygen atoms during oxidation, making it less likely for iron to oxidize. Simultaneously, a dense oxide film forms on the zinc surface, preventing further oxidation.

[0004] During hot-dip galvanizing of steel strip, the temperature of the zinc bath is generally around 460 degrees Celsius. The temperature of the galvanized steel strip is also around 460 degrees Celsius when it leaves the zinc bath, and the liquid surface needs to be cooled to solidify. After leaving the galvanizing bath, the excess zinc is usually blown off by an air knife, and then cooled by a cooling medium. However, because the galvanized steel strip is generally in a conveyor state, the contact time with the cooling medium is very short, resulting in poor cooling effect. Summary of the Invention

[0005] In order to maintain the contact time between the cooling medium and the galvanized strip and improve the cooling effect, this application provides a cooling device for galvanized strip.

[0006] This application provides a cooling device for galvanized steel strip, which adopts the following technical solution:

[0007] A cooling device for galvanized steel strip includes a first cooling device and a second cooling device symmetrically arranged on both sides of the galvanized steel strip and having the same structure. The longitudinal section formed by the first cooling device and the second cooling device is a trapezoidal shape that is wider at the top and narrower at the bottom.

[0008] The first cooling device includes a support frame, on which multiple rows of cooling components are arranged that gradually tilt from top to bottom towards the galvanized strip steel. Each cooling component includes a support plate, a nozzle assembly, and a drive assembly.

[0009] The nozzle assembly includes multiple horizontally spaced nozzles, each of which is slidably connected to the support plate. The drive assembly is used to drive the nozzles, and when the nozzles move toward the galvanized strip, the distance between two adjacent nozzles changes.

[0010] By adopting the above technical solution, the first and second cooling devices form a cone-like structure, that is, a structure that is wider at the top and narrower at the bottom. The extension of the adjacent lower nozzles is greater than that of the adjacent upper nozzles, forming layers of obstruction, which can prevent the upper cold air from going directly downwards, increase the residence time of the cold air, and thus improve the cooling effect on the galvanized strip steel;

[0011] In addition, by changing the extension between the nozzles and the distance between them, the density of the nozzles can be adjusted. This allows for cooling based on the width, thickness, and cooling requirements of the galvanized strip, making it more adaptable and providing better cooling.

[0012] Optionally, the support plate has the same number of slides as the nozzles, the gap between adjacent slides is gradually changing, the nozzles are connected to pipes, the pipe walls are fixed with connecting blocks, and connecting rods are slidably connected between the connecting blocks of two adjacent pipes. The connecting blocks are slidably disposed on the slides.

[0013] By adopting the above technical solution, the support plate provides a sliding trajectory for the extension or retraction of the nozzle, thereby enabling the distance between nozzles in the same row to change while the nozzle is extended; in addition, by setting a connecting rod, the movement of a row of nozzles can be driven by driving one of the connecting rods on the same row of nozzles.

[0014] Optionally, the drive assembly includes a push rod fixedly connected to a connecting rod located in the middle of each row.

[0015] By adopting the above technical solution, the push rod can be set up to facilitate the application of force.

[0016] Optionally, a speed-changing assembly is provided on the support frame;

[0017] The transmission assembly includes a drive source fixed to the upper end of the support frame, a driven shaft fixed to the lower end of the support frame, a plurality of transmission wheels with progressively larger diameters sleeved on the output shaft of the drive source, and a plurality of transmission wheel sets with progressively larger diameters sleeved on the driven shaft. The transmission wheels on the output shaft of the drive source and the transmission wheels on the driven shaft, which are located in the same plane, have the same diameter and are sleeved on the same transmission bar.

[0018] Each of the transmission bars is fixed with a support block, and each support block is fixedly connected to a support plate of a corresponding height.

[0019] By adopting the above technical solution, the angular velocities of multiple transmission wheels with different diameters are the same, which in turn makes the linear velocity of the transmission bar on the transmission wheel with a larger diameter greater, and makes the support block and support plate on the transmission bar with a larger linear velocity move a longer distance, thereby realizing the gradual change of the distance between different rows of nozzles and adjusting the longitudinal density of the nozzles.

[0020] Optionally, the speed change assembly consists of two sets, symmetrically distributed on both sides of the support frame.

[0021] By adopting the above technical solution, speed-changing components are simultaneously installed on both sides of the support frame, which can improve the stability of the support plate movement and thus improve the stability of the nozzle movement.

[0022] Optionally, one end of the nozzle is spherical and hinged to the tube body.

[0023] By adopting the above technical solution, the nozzle can be rotated, thereby adjusting the position of the nozzle outlet. The position of the outlet can be lower than the position of the inlet, thus forming a rotating downward airflow from top to bottom. The lower layer of gas blocks the upper layer of gas, and the lower nozzle acts as a protective air curtain for the upper nozzle, thus forming layers of protection. This helps to prolong the residence time of the purging airflow and improve the cooling effect of the galvanized strip steel.

[0024] Optionally, the nozzles located in the same row are all connected to a rotating rod.

[0025] By adopting the above technical solution, the position of the air outlet of the nozzles in the same row can be adjusted simply by rotating the rotating rod.

[0026] Optionally, all rows of push rods are connected to the same drive unit.

[0027] By adopting the above technical solution, a single driving force can push all the push rods, thereby adjusting the extension of all the nozzles and the spacing between them.

[0028] Optionally, the nozzles located in the same row form an arc shape, and the nozzles of the first cooling device and the second cooling device form a cone shape, with the galvanized strip passing through the cone, and the upper opening of the cone being larger than the lower opening.

[0029] By adopting the above technical solution, the nozzles in the same row form an arc shape, making the upper and lower openings of the cooling device for galvanized strip closer to a circle, thereby making the cooling device for galvanized strip closer to the cone, which can better surround the galvanized strip and enclose the cold air inside the cone.

[0030] Optionally, wedge-shaped push blocks are provided on both sides of the support plate, and a connecting column is fixed on the side of each support plate. Each connecting column is arranged along the wedge-shaped surface of the wedge-shaped push block and inserted into the support frame. A vertical guide groove is provided on the support frame corresponding to each connecting column.

[0031] By adopting the above technical solution and setting a wedge-shaped pusher, the position of the support plate can be raised or lowered, and the height of the nozzle can be adjusted according to the position of the galvanized strip steel.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. This application improves the cooling effect by setting the cooling space to be wider at the top and narrower at the bottom, and in an overall conical shape, thereby blocking and enveloping the upper layer of cold air, extending the residence time of the cold air in the cooling device, and improving the cooling effect.

[0034] 2. This application adjusts the position of the nozzle's air outlet so that the air inlet is higher than the air outlet and the gas flows out at an angle. This not only gathers the cold air but also creates a downward rotating airflow, forming a protective air curtain at the bottom. This reduces the speed at which the cold air passes through and increases the residence time of the cold air, thereby improving the cooling effect on the galvanized steel strip.

[0035] 3. The nozzles of the cooling device of this application can extend while the spacing between nozzles in the same row can be adjusted, as well as the spacing between different rows, so as to implement different cooling effects according to needs. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the cooling device for galvanized steel strip, which embodies Embodiment 1 of this application.

[0037] Figure 2 This is a schematic diagram of the internal structure of a cooling device for galvanized steel strip, illustrating Embodiment 1 of this application.

[0038] Figure 3 This is a schematic diagram of the internal structure of a cooling device for galvanized steel strip, illustrating Embodiment 2 of this application.

[0039] Figure 4 This is a schematic diagram of the internal structure of a cooling device for galvanized steel strip, illustrating Embodiment 3 of this application.

[0040] Figure 5 This is a schematic diagram of the overall structure of a cooling device for galvanized steel strip, which embodies Embodiment 4 of this application.

[0041] Figure 6 This is a schematic diagram of the internal structure of the rotating rod and nozzle of the cooling device for galvanized strip steel, which embodies Embodiment 4 of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Galvanized steel strip; 2. First drive wheel; 3. Second drive wheel; 4. Third drive wheel; 5. Push plate; 51. Vertical groove; 10. Wedge-shaped push block; 20. Rotating rod;

[0044] 100. First cooling device; 110. Support frame; 111. Support frame; 120. Support plate; 121. Slide rail; 130. Nozzle assembly; 131. Nozzle; 132. Pipe body; 133. Connecting block; 134. Connecting rod; 140. Drive assembly; 141. Push rod; 150. Speed ​​change assembly; 151. Drive source; 152. Driven shaft; 153. Transmission bar; 154. Support block; 155. Rotating shaft;

[0045] 200. Second cooling device. Detailed Implementation

[0046] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0047] Example 1

[0048] This application discloses a cooling device for galvanized steel strip. (Refer to...) Figure 1 and Figure 2 The cooling device for galvanized steel strip includes a first cooling device 100 and a second cooling device 200 with identical structures, and the galvanized steel strip 1 is located between the first cooling device 100 and the second cooling device 200.

[0049] The first cooling device 100 and the second cooling device 200 are arranged symmetrically, and the longitudinal section of the overall structure is a trapezoid that is narrower at the top and wider at the bottom. That is, the opening at the top is larger than the opening at the bottom, and the galvanized steel strip 1 enters from the bottom opening and exits from the top opening.

[0050] Since the galvanized steel strip 1 is cooled after being blown away by an air knife after exiting the galvanizing bath, the cooling medium in this application is air, but other gases with cooling functions can also be used.

[0051] The first cooling device 100 includes a support frame 110. The side of the support frame 110 facing the second cooling device 200 is an inclined support frame 111 that gradually approaches the galvanized strip steel 1 from top to bottom. Six rows of cooling components are fixedly arranged from bottom to top on the base plate of the support frame 110, but the arrangement is not limited to this. Each cooling component includes a support plate 120 and a nozzle assembly 130. The nozzle assembly 130 extends from the support frame 111 and faces the galvanized strip steel 1.

[0052] Each row of nozzle assemblies 130 includes multiple horizontally spaced nozzles 131. In this embodiment, there are six nozzles 131 in each row, but this is not a limitation. Each nozzle 131 is connected to a tube body 132. A connecting block 133 is fixed on the opposite wall of two adjacent tube bodies 132. The connecting block 133 has a insertion groove. A connecting rod 134 is slidably connected between the connecting blocks 133 on two adjacent tube bodies 132. The connecting blocks 133 on both sides of the middle tube body 132 have insertion grooves, and the connecting blocks 133 on one side of the edge tube body 132 have insertion grooves.

[0053] To reduce the possibility of the connecting rod 134 detaching from the insertion slot, the opening size of the insertion slot is smaller than the end size of the connecting rod 134.

[0054] Meanwhile, to ensure the stability of the connection between the connecting rod 134 and the insertion slot, a spring can be used to connect the end of the connecting rod 134 and the bottom of the insertion slot.

[0055] The support plate 120 has the same number of slides 121 as the nozzles 131, and the gap between adjacent slides 121 gradually changes. Each nozzle 131 is connected to a pipe 132 with a protrusion fixed on it. The protrusion is slidably connected to the slide 121. When the protrusion moves the nozzle 131 toward the galvanized strip steel 1, the distance between two adjacent nozzles 131 gradually increases. The end of the slide 121 is sealed to prevent the protrusion from detaching when it slides to the end.

[0056] The cooling assembly also includes a drive assembly 140 for driving each nozzle 131 toward or away from the galvanized steel strip 1. The drive assembly 140 includes a push rod 141 fixedly connected to a connecting rod 134 located in the middle of each row. The push rod 141 pushes the middle connecting rod 134, which in turn moves the remaining connecting rods 134. The connecting rods 134 then move the protrusions on the tube body 132 along the slide rail 121.

[0057] In order to better retain and surround the cold air, the nozzles 131 located in the same row form an arc shape. The nozzles 131 of the first cooling device 100 and the nozzles 131 of the second cooling device 200 together form a cone shape. The upper opening of the cone is larger than the lower opening, and the galvanized steel strip 1 passes through the cone.

[0058] To facilitate the application of force, each connecting rod 134 can be connected to a force-applying rod, and the force-applying rods can be connected to the push rod 141 together, thereby making the movement of each nozzle 131 more stable.

[0059] Different galvanized steel strips 1 have different thicknesses and widths. By pushing the corresponding layer of nozzles 131 with push rods 141 in each row, not only can the extension of the nozzles 131 be adjusted, but also the spacing between the nozzles 131 in the same row can be adjusted, thus adapting to the cooling needs of galvanized steel strips 1 with different thicknesses and widths.

[0060] When the galvanized steel strip 1 becomes thicker and narrower, the nozzles 131 can be moved backward by the push rod 141, and the density of the nozzles 131 increases. If the spray density does not need to increase, the nozzles 131 arranged at intervals in the same row can be closed to maintain a spray seal. However, if a higher spray density is required, all nozzles 131 can be opened while the nozzles 131 are retracted, thus increasing the spray density simultaneously.

[0061] When the galvanized steel strip 1 is thinner and wider, the nozzle 131 is extended by the push rod 141. At the same time, the density of the nozzle 131 decreases, thereby adjusting the density of the nozzle 131 while extending it. This makes it suitable for galvanized steel strip 1 that is thinner, wider, and requires a lower spray density.

[0062] In addition, by setting a cone structure that is narrow at the bottom and wide at the top, this application can block the cold air from going directly downwards, forming layers of obstruction, which increases the residence time of the cold air. Moreover, the first cooling device 100 and the second cooling device 200 do not need to move during the cooling process, so that the cold air will not fluctuate and the cooling is more stable.

[0063] Each row of push rods 141 can be connected to the same drive component and apply force independently. By adjusting the extension of the nozzles 131 of the corresponding layer through each row of push rods 141, the taper of the entire cone can be adjusted, thereby forming a cold air blocking structure that is more suitable for galvanized steel strip 1, better enclosing the cold air, ensuring the residence time of the cold air, and thus improving the cooling effect on galvanized steel strip 1.

[0064] Of course, a fixed taper can also be preset on the cone. In this case, all push rods 141 can be connected to the same power source, thereby achieving the effect of simultaneously adjusting the extension of all nozzles 131.

[0065] Example 2

[0066] Please refer to the above as well. Figure 3 The difference between Embodiment 2 and Embodiment 1 is that the height of each row of support plates 120 in Embodiment 2 can be adjusted, thereby adjusting the height of the nozzle 131 according to the position requirements of the galvanized strip steel 1.

[0067] Specifically, wedge-shaped push blocks 10 are provided on both sides of the support plate 120. In this embodiment, there are two wedge-shaped push blocks 10, and the height of the wedge-shaped push blocks 10 extends from the bottom support plate 120 to the top support plate 120. Connecting columns 122 are fixed on both sides of each support plate 120. Each connecting column 122 is arranged along the wedge-shaped surface of the wedge-shaped push block 10 and inserted into the support frame 110. Vertical guide grooves 112 are provided on the support frame 110 corresponding to each connecting column 122. The inclination direction of the wedge-shaped surface of the wedge-shaped push block 10 is the same as the inclination direction of the cone, that is, it gradually approaches the galvanized strip steel 1 from top to bottom.

[0068] By pushing the two wedge-shaped push blocks 10 at the same speed, the connecting columns 122 on each support plate 120 are driven to move up and down along the guide groove 112, which can raise or lower the position of the support plate 120. In this way, the height of the nozzle 131 can be adjusted according to the position of the galvanized strip steel 1 to cool the galvanized strip steel 1.

[0069] Example 3

[0070] Please refer to Figure 1 , Figure 2 and Figure 4 The difference between Embodiment 3 and Embodiment 1 is that the spacing between each row of support plates 120 in Embodiment 3 is variable, that is, the spacing between the vertically arranged nozzles 131 can be adjusted.

[0071] Specifically, a speed change assembly 150 is provided on the vertical side plates on both sides of the support frame 110. The speed change assembly 150 includes a drive source 151 fixed to the upper end of the vertical side plate of the support frame 110, and the output shaft of the drive source 151 is fixedly connected to a rotating shaft 155. The rotating shaft 155 is horizontally arranged and perpendicularly connected to the vertical side plates on both sides of the support frame 110.

[0072] The lower end of the vertical side plate of the support frame 110 is rotatably connected to a driven shaft 152. The driven shaft 152 and the rotating shaft 155 are parallel, and both ends of the driven shaft 152 and the rotating shaft 155 are fixedly fitted with multiple transmission wheel sets with progressively larger diameters. Each transmission wheel set includes a first transmission wheel 2, a second transmission wheel 3, and a third transmission wheel 4, but the number is not limited to these.

[0073] In the two sets of transmission wheel groups located on the same side of the support plate 120, the two first transmission wheels 2 share the same transmission bar 153, the two second transmission wheels 3 share the same transmission bar 153, and the two third transmission wheels 4 share the same transmission bar 153. In this embodiment, when the transmission bar 153 is a toothed belt, the transmission wheel is a gear; when the transmission bar 153 is a chain, the transmission wheel is a sprocket.

[0074] In the transmission assembly 150 on both sides of the vertical side plate of the support frame 110, one set of the drive source 151 is a motor, and the other set of power also comes from the same motor, meaning that the two sets of transmission assemblies 150 share a single drive source 151. When the motor rotates, it drives the rotating shaft 155 to rotate, which in turn drives the transmission wheel sets at both ends of the rotating shaft 155 to rotate. The rotation of the transmission wheel sets drives the transmission bar 153 to rotate, and the rotation of the transmission bar 153 drives the driven shaft 152 and the transmission wheel sets at both ends to rotate.

[0075] Each transmission bar 153 is fixed with a support block 154, and a support plate 120 is connected between two support blocks 154 located at the same horizontal position.

[0076] The first transmission wheel 2, the second transmission wheel 3, and the third transmission wheel 4 have the same angular velocity but different radii, causing the support blocks 154 driven by the transmission bars 153 on the first transmission wheel 2, the second transmission wheel 3, and the third transmission wheel 4 to move different distances. Therefore, by setting different diameters of the transmission wheels, under the drive of the drive source 151, the distance between each pair of adjacent vertically arranged support blocks 154 can be changed equidistantly. That is, to make the distance between all adjacent support plates 120 increase or decrease by the same amount simultaneously, the spacing between the vertically arranged nozzles 131 can be adjusted. Then, by pushing the push rod 141 to drive the nozzles 131 to move back and forth, the density of all nozzles 131 can be adjusted to suit the different cooling requirements of the galvanized steel strip 1.

[0077] In addition, to save power, a bevel gear can be installed on the rotating shaft 155 connected to the drive source 151. After the bevel gear is reversed, a rack is installed on the same power source connected to all push rods 141, thereby pushing all push rods 141 to move back and forth.

[0078] Appendix Figure 4 The illustration shows that all push rods 141 are connected to the push plate 5. The push plate 5 has a vertical groove 51. One end of all push rods 141 is inserted into the vertical groove 51 in the vertical direction. The opening of the groove 51 is smaller than the end of the push rod 141 to prevent the push rod 141 from separating from the vertical groove 51.

[0079] The push plate 5 can be fixedly connected to the rack mentioned above, thereby enabling all push rods 141 to move back and forth.

[0080] Example 4

[0081] Please refer to the following: Figure 5 and Figure 6The difference between this embodiment four and embodiment three is that one end of the nozzle 131 is spherical and hinged to the tube body 132, and the nozzles 131 in the same row are all connected to a rotating rod 20. By rotating the rotating rod 20, the tilt direction of the nozzle 131 can be adjusted, thereby changing the tilt of the air outlet, and the taper of the cone can also be changed to achieve different cooling effects.

[0082] The nozzles 131 are tilted downwards, meaning the air outlet is lower than the air inlet. This allows them to gather airflow. Since the nozzles 131 in the same row are arranged in an arc shape, forming a cone shape, they can create a rotating downward airflow from top to bottom. The lower layer of gas blocks the upper layer of gas, and the lower nozzles form a protective air curtain for the upper nozzles, thus creating layers of protection. This not only increases the purging force but also helps to prolong the residence time of the purging airflow, thereby improving the cooling effect on the galvanized steel strip 1.

[0083] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cooling device for galvanized steel strip, characterized in that: It includes a first cooling device (100) and a second cooling device (200) symmetrically arranged on both sides of the galvanized strip (1) and having the same structure. The longitudinal section formed by the first cooling device (100) and the second cooling device (200) is a trapezoidal shape that is wider at the top and narrower at the bottom. The first cooling device (100) includes a support frame (110), on which multiple rows of cooling components are arranged from top to bottom and gradually tilted toward the galvanized strip steel (1). Each cooling component includes a support plate (120), a nozzle assembly (130), and a drive assembly (140). The nozzle assembly (130) includes a plurality of horizontally spaced nozzles (131), each of which is slidably connected to the support plate (120). The drive assembly (140) is used to drive the nozzles (131). When the nozzles (131) move toward the galvanized strip (1), the distance between two adjacent nozzles (131) changes. The support plate (120) has the same number of slides (121) as the nozzles (131), and the gap between adjacent slides (121) is gradually changing. The nozzles (131) are connected to pipes (132), and connecting blocks (133) are fixed on the pipe walls of the pipes (132). Connecting rods (134) are slidably connected between the connecting blocks (133) of two adjacent pipes (132), and the connecting blocks (133) are slidably disposed on the slides (121). The nozzles (131) located in the same row form an arc shape. The nozzles (131) of the first cooling device (100) and the nozzles (131) of the second cooling device (200) form a cone shape. The galvanized strip steel (1) passes through the cone. The upper opening of the cone is larger than the lower opening. The support frame (110) is provided with a speed change assembly (150); The transmission assembly (150) includes a drive source (151) fixed to the upper end of the support frame (110), a driven shaft (152) fixed to the lower end of the support frame (110), a plurality of transmission wheels with successively larger diameters sleeved on the output shaft of the drive source (151), and a plurality of transmission wheels with successively larger diameters sleeved on the driven shaft (152). The transmission wheels on the output shaft of the drive source (151) and the transmission wheels on the driven shaft (152) are in the same plane and have the same diameter and are sleeved on the same transmission bar (153). Each of the transmission bars (153) is fixed with a support block (154), and each of the support blocks (154) is fixedly connected to the support plate (120) of the corresponding height.

2. The cooling device for galvanized steel strip according to claim 1, characterized in that: The drive assembly (140) includes a push rod (141) fixedly connected to a connecting rod (134) located in the middle of each row.

3. The cooling device for galvanized steel strip according to claim 1, characterized in that: The transmission components (150) are in two sets, symmetrically distributed on both sides of the support frame (110).

4. The cooling device for galvanized steel strip according to claim 1, characterized in that: The nozzles (131) located in the same row are all connected to a rotating rod (20).

5. The cooling device for galvanized steel strip according to claim 2, characterized in that: Each row of push rods (141) is connected to the same drive unit.

6. The cooling device for galvanized steel strip according to claim 1, characterized in that: The support plate (120) is provided with wedge-shaped push blocks (10) on both sides. Each support plate (120) is fixed with a connecting column (122) on its side. Each connecting column (122) is provided along the wedge-shaped surface of the wedge-shaped push block (10) and inserted into the support frame (110). Each support frame (110) is provided with a vertical guide groove (112) corresponding to each connecting column (122).

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