Blade push-and-pull positioning device used during tool changing of double-side shears

Abstract

The invention relates to the field of blade push-and-pull positioning, in particular to a blade push-and-pull positioning device during blade replacement of double-side shears, which comprises a fixed table, two groups of fixed sleeve shells detachably mounted on the outer side surface of the top of the fixed table, and an extended sleeve shell fixedly mounted on the surface of one side of the fixed table, the attaching swing arm plate is movably connected to the outer side surface of the outward-extending sleeve shell in a threaded and sleeving mode, the threaded lifter is fixedly installed on the surface of one side of the outward-extending sleeve shell, and the crowbar is movably connected to the outer side surface of the threaded lifter in a sleeving mode. After the position of the crowbar needs to be positioned, a second hydraulic rod is matched to push a semi-arc plate, the semi-arc plate is tightly attached to the outer side surface of the crowbar, and friction force and clamping force between the semi-arc plate and the surface of the crowbar are increased through an anti-skid pad on the inner side wall face of the semi-arc plate; excessive shaking force cannot occur, and the crowbar cannot slide on the surface of the second limiting sleeve shell along with pulling of the attaching sleeve.

Description

Technical Field

[0001] The invention belongs to the technical field of blade push-pull positioning, in particular to a blade push-pull positioning device for double-sided shears when changing blades. Background Art

[0002] The double-sided shearing of wide and thick plates in metallurgical enterprises consists of a fixed shear and a mobile shear. The two shears are installed relatively on the same base. Each shear has a longitudinal shear for cutting edges and a scrap shear for cutting waste edges. They are driven by the main motor through a gear transmission device and three parallel crankshafts.

[0003] In the current existing technology, the existing double-sided shearing process requires blade replacement every 30,000 blades, which is an average of twice a week. When replacing the old blade with the new one, the operator generally uses a pry bar or directly pushes and pulls the blade with his hands. Using a pry bar with a free stick as a fulcrum can easily cause the pry bar to slip, which may cause the person to lose balance and fall. When it is necessary to pry the blade with the crowbar as a support point, in order to prevent the blade from resetting due to its own gravity, the employee needs to keep pulling the crowbar to keep the crowbar in an upturned state, and there will be a certain clamping locking force between the blade and the equipment. It takes more force to pry the blade manually to remove the blade from the equipment. If the blade is pushed directly by hand, it is very difficult for one person to push the blade and it is easy to cause hand squeezing.

[0004] To this end, the present invention provides a blade push-pull positioning device for double-sided shears when changing blades. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a blade push-pull positioning device for changing blades of a double-sided shear described in the present invention comprises a fixed platform and two groups of fixed shells detachably mounted on the outer surface of the top of the fixed platform, an outward expansion shell fixedly mounted on one side surface of the fixed platform, a fitting swing arm plate threadedly movably sleeved on the outer surface of the outward expansion shell, a threaded lifter fixedly mounted on one side surface of the outward expansion shell, a crowbar movably sleeved on the outer surface of the threaded lifter, and a limiting slider movably sleeved on the outer surface of the two groups of the fixed shells, a motor 2 is fixedly mounted on the top surface of one group of the fixed shells, a threaded rod 2 movably sleeved on the inner wall surface of the fixed shell is fixedly mounted on the output end of the motor 2, and a limiting rod 2 is fixedly mounted on the inner wall surface of the other group of the fixed shells, a limiting shell 1 is movably sleeved on the outer surface of the limiting shell 1, a hydraulic rod 1 is detachably mounted on the inner wall surface of the limiting shell 1, a binding band is fixedly connected to the output end of the hydraulic rod 1, and a fitting sleeve movably sleeved on the outer surface of the crowbar is fixedly connected on the outer surface of the binding band.

[0007] Preferably, a slider is movably sleeved on the inner wall surface of the threaded lifter, a rotating shaft is movably sleeved on the outer surface of the slider, and a limiting sleeve shell 2 movably sleeved on the outer surface of the crowbar is fixedly connected to the outer surface of the rotating shaft.

[0008] Preferably, a trapezoidal overlapping platform is fixedly installed on the inner surface of the threaded lifter and located at the bottom edge, and a clamping groove is provided on the top surface of the trapezoidal overlapping platform.

[0009] Preferably, a second hydraulic rod is symmetrically fixedly installed on the inner wall surface of the second limiting sleeve shell, and a semicircular arc plate is fixedly connected to the output end of the second hydraulic rod.

[0010] Preferably, an anti-slip pad is provided on the outer surface of the semi-circular arc plate and is movably sleeved on the outer surface of the crowbar. An anti-sway sleeve is fixedly connected to the inner wall of the limiting sleeve 2 and at the upper and lower edge positions of the hydraulic rod 2 and the semi-circular arc plate.

[0011] Preferably, a fitting anti-skid soft plate is provided on the outer surface of the fitting swing arm plate, a universal wheel is provided on the bottom surface of the fitting swing arm plate, and a double-hole slider is fixedly installed on one side surface of the fitting swing arm plate.

[0012] Preferably, a motor is fixedly mounted on one side surface of the expansion sleeve, a limiting rod is arranged on the inner wall surface of the expansion sleeve, a threaded rod arranged on the inner wall surface of the expansion sleeve is fixedly connected to the output end of the motor, and the outer surfaces of the threaded rod and the limiting rod are movably sleeved on the inner wall surface of the double-hole slider.

[0013] Preferably, a hollow groove is opened on the outer surface of the fixed sleeve, the outer surface of the limit slider is movably sleeved on the inner wall of the hollow groove, and the outer surfaces of the threaded rod 2 and the limit rod 2 are movably sleeved on the outer surface of the limit slider.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The blade push-pull positioning device for changing the blade of a double-sided shear described in the present invention, when the blade is removed from the surface of the equipment, the new blade is placed at the interface of the cutting equipment, and the pair of threaded rods 1 on both sides are rotated in cooperation with the motor, and the double-hole sliders on the outer surfaces of the threaded rods 1 on both sides and the limiting rod 1 move toward the middle position of the pry bar, and the fitting non-slip soft plate on the surface of the fitting swing arm plate fits on the two side surfaces of the new blade, and the new blade and the equipment interface are at the same height and angle, and then one end of the pry bar is clamped in the positioning slot of the new blade, and the pair of fitting sleeves of the hydraulic rod are pushed in the opposite direction, so that the pry bar rotates with the limiting sleeve shell 2 as the fulcrum, and the new blade is pushed into the docking slot of the equipment to perform blade clamping, so that the interface of the new blade and the equipment forms a horizontal intersection angle by using the two clamping plates, and the new blade can be reinstalled without human support and positioning;

[0016] 2. The blade push-pull positioning device for changing blades of a double-sided shear described in the present invention cooperates with employees to move the fixed platform and the fitting swing arm plate to the edge positions of both sides of the blade, and uses the positioning slots with a diameter of 30 mm on both ends of the blade to clamp one end of the crowbar, and uses the limiting sleeve shell 2 and the threaded lifter on the outer surface of the crowbar to form a support point, and cooperates with the hydraulic rod to pull the fitting sleeve on the outer surface of the strap. The crowbar rotates with the limiting sleeve shell 2 as the support point to push the blade on one end of the crowbar and push the blade off the surface of the cutting device. While the hydraulic rod 1 is pulling, it cooperates with the strap to deform the bending between the fitting sleeve and the output end of the hydraulic rod 1;

[0017] 3. The blade push-pull positioning device for changing blades of a double-sided shear described in the present invention, after the crowbar slides inside the second limiting sleeve shell, it is necessary to position the position of the crowbar, and then the semi-circular arc plate is pushed in cooperation with the second hydraulic rod, and the semi-circular arc plate is tightly fitted on the outer surface of the crowbar. At this time, the friction and clamping force between the semi-circular arc plate and the surface of the crowbar are increased by the anti-skid pad on the inner wall of the semi-circular arc plate. When the crowbar is pulled and rotated, there will be no excessive shaking force, and the crowbar will not slide on the surface of the second limiting sleeve shell as the fitting sleeve is pulled;

[0018] 4. The blade push-pull positioning device for changing the blade of a double-sided shear described in the present invention, if the friction between the blade and the equipment component is too large or the blade interface is slightly bent, making it difficult to remove the blade, the second threaded rod is rotated in cooperation with the second motor, and the limit slider moves upward on the surface of the second limit rod and the second threaded rod, and one end of the fitting sleeve is fitted with the edge position of the other end of the crowbar, thereby increasing the pulling force of the lever arm and generating a greater pushing force on the other end of the crowbar, thereby achieving the effect of utilizing the force applied by the long arm end to be transmitted to the fulcrum through a longer lever arm, so as to pry heavier objects and push the blade out of the equipment. In addition, by changing the height of the hydraulic rod one, one end of the crowbar will not be too large due to the bending force and the bending angle, thereby improving the effect of the hydraulic rod one generating a greater pulling force. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 is a stereogram of the present invention;

[0021] Figure 2 It is a three-dimensional diagram of the fitted swing arm plate in the present invention when closed;

[0022] Figure 3 is a cutaway stereogram of a fixed platform in the present invention;

[0023] Figure 4 It is a two-section stereogram of the limiting sleeve in the present invention;

[0024] Figure 5 It is a perspective view of the expansion of the fitted swing arm plate in the present invention;

[0025] Figure 6 is a three-dimensional diagram of the fixed housing in the present invention;

[0026] Figure 7 It is a three-dimensional diagram of the thread lifter in the present invention.

[0027] In the figure: 11, fixed platform; 12, extension shell; 121, limit rod 1; 122, threaded rod 1; 123, motor 1; 13, fixed shell; 131, empty slot; 132, limit slider; 133, limit rod 2; 134, threaded rod 2; 135, motor 2; 136, limit shell 1; 137, hydraulic rod 1; 138, strap; 139, fitting sleeve; 14, fitting swing arm plate; 141, universal wheel; 142, fitting anti-skid soft board; 143, double-hole slider; 15, threaded lifter; 151, slider; 152, rotating shaft; 153, limit shell 2; a1, anti-sway sleeve; a2, hydraulic rod 2; a3, semi-circular arc plate; a4, anti-skid pad; 154, trapezoidal lap platform; 155, clamping groove; 16, pry bar. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0029] like Figures 1 to 3 and Figure 5 - Figure 7 As shown, a blade push-pull positioning device for changing blades of a double-sided shear according to an embodiment of the present invention comprises a fixed platform 11 and two groups of fixed shells 13 detachably mounted on the outer surface of the top of the fixed platform 11, an extension shell 12 fixedly mounted on one side surface of the fixed platform 11, a fitting swing arm plate 14 threadedly movably sleeved on the outer surface of the extension shell 12, a threaded lifter 15 fixedly mounted on one side surface of the extension shell 12, a crowbar 16 movably sleeved on the outer surface of the threaded lifter 15, a limiting slider 132 movably sleeved on the outer surfaces of the two groups of fixed shells 13, and a top of one group of fixed shells 13. A motor 2 135 is fixedly installed on the surface, and a threaded rod 2 134 movably sleeved on the inner wall of the fixed sleeve 13 is fixedly installed on the output end of the motor 2 135, and a limiting rod 2 133 is fixedly installed on the inner wall of another group of fixed sleeves 13, and a limiting sleeve 136 is movably sleeved on the outer surface of the limiting slider 132, and a hydraulic rod 137 is detachably installed on the inner wall of the limiting sleeve 136, and a strap 138 is fixedly connected to the output end of the hydraulic rod 137, and a fitting sleeve 139 movably sleeved on the outer surface of the crowbar 16 is fixedly connected to the outer surface of the strap 138.

[0030] Cooperate with the staff to move the fixed platform 11 and the fitting swing arm plate 14 to the edge positions on both sides of the blade. At this time, the positioning slots with a diameter of 30 mm on both ends of the blade are used to clamp one end of the crowbar 16. At this time, the limiting sleeve 153 and the threaded lifter 15 on the outer surface of the crowbar 16 form a support point. At this time, cooperate with the hydraulic rod 137 to pull the fitting sleeve 139 on the outer surface of the strap 138. The crowbar 16 rotates with the limiting sleeve 153 as the support point to push the blade on one end of the crowbar 16 and push the blade off the surface of the cutting device. While the hydraulic rod 137 is pulling, it cooperates with the strap 138 to deform the bending between the fitting sleeve 139 and the output end of the hydraulic rod 137;

[0031] If the friction between the blade and the equipment component is too great or the blade interface is slightly bent, making it difficult to remove the blade, the motor 135 is used to rotate the threaded rod 134, and the limit slider 132 moves upward on the surface of the limit rod 133 and the threaded rod 134, and one end of the fitting sleeve 139 fits with the edge of the other end of the crowbar 16, thereby increasing the pulling force of the lever arm and generating a greater pushing force on the other end of the crowbar 16, thereby achieving the goal of using the force applied by the long arm end to be transmitted to the fulcrum through a longer lever arm, thereby being able to pry heavier objects and push the blade out of the equipment. In addition, by changing the height of the hydraulic rod 137, one end of the crowbar 16 will not be too large due to the bending force and the bending angle, thereby increasing the effect of the hydraulic rod 137 generating a greater pulling force. This avoids the situation where the blade and the equipment are slightly deformed and the friction is too great, which makes it impossible for employees to use the crowbar to squeeze and push the blade off the surface of the cutting equipment to replace the blade.

[0032] like Figure 1 - Figure 3 and Figure 5 - Figure 6 As shown, a non-slip soft plate 142 is provided on the outer surface of the fitting swing arm plate 14, a universal wheel 141 is provided on the bottom surface of the fitting swing arm plate 14, a double-hole slider 143 is fixedly installed on one side surface of the fitting swing arm plate 14, a motor 123 is fixedly installed on one side surface of the expansion sleeve 12, a limiting rod 121 is provided on the inner wall of the expansion sleeve 12, and a threaded rod 122 arranged on the inner wall of the expansion sleeve 12 is fixedly connected to the output end of the motor 123, the outer surfaces of the threaded rod 122 and the limiting rod 121 are movably sleeved on the inner wall of the double-hole slider 143, an empty groove 131 is opened on the outer surface of the fixed sleeve 13, the outer surface of the limiting slider 132 is movably sleeved on the inner wall of the empty groove 131, and the outer surfaces of the threaded rod 134 and the limiting rod 133 are movably sleeved on the outer surface of the limiting slider 132.

[0033] When the blade is removed from the surface of the equipment, the new blade is placed on the interface of the cutting equipment, and the motor 123 is used to rotate the threaded rod 122. The threaded rod 122 on both sides and the double-hole slider 143 on the outer surface of the limit rod 121 move to the middle position of the pry bar 16, and the non-slip soft plate 142 on the surface of the swing arm plate 14 is attached to the two side surfaces of the new blade. The new blade and the equipment interface are at the same height and angle, and then one end of the pry bar 16 is clamped in the positioning slot of the new blade, and the hydraulic rod 137 is used to push the fitting sleeve 139 in the opposite direction, and the pry bar 16 is limited. The second sleeve shell 153 is rotated as a fulcrum to push the new blade into the docking slot of the equipment for blade clamping, thereby achieving the effect of using two clamping plates to make the interface of the new blade and the equipment form a horizontal intersection angle, and the new blade can be reinstalled without human support and positioning; this avoids the need for an employee to straighten the new blade and then have another employee push the new blade for blade clamping for effective installation when installing the new blade, which would waste manpower and require a high degree of tacit understanding between the two employees, otherwise it would cause a lot of useless effort, resulting in the inability to effectively install the new blade.

[0034] like Figures 1 to 5 and Figure 7 As shown, a hydraulic rod a2 is symmetrically fixedly installed on the inner wall of the limiting sleeve 153, a semi-circular plate a3 is fixedly connected to the output end of the hydraulic rod a2, and an anti-skid pad a4 that is movably sleeved on the outer surface of the crowbar 16 is arranged on the outer surface of the semi-circular plate a3, an anti-slip sleeve a1 is fixedly connected to the inner wall of the limiting sleeve 153 and at the upper and lower edge positions of the hydraulic rod a2 and the semi-circular plate a3, a slider 151 is movably sleeved on the inner wall of the threaded lifter 15, a rotating shaft 152 is movably sleeved on the outer surface of the slider 151, and a limiting sleeve 153 that is movably sleeved on the outer surface of the crowbar 16 is fixedly connected to the outer surface of the rotating shaft 152, a trapezoidal overlapping platform 154 is fixedly installed on the inner surface of the threaded lifter 15 and at the bottom edge position, and a clamping groove 155 is provided on the top surface of the trapezoidal overlapping platform 154.

[0035] After the crowbar 16 slides inside the limiting sleeve 153, when the position of the crowbar 16 needs to be positioned, the semi-circular plate a3 is pushed in cooperation with the hydraulic rod a2, and the semi-circular plate a3 fits tightly on the outer surface of the crowbar 16. At this time, the anti-slip pad a4 on the inner wall of the semi-circular plate a3 increases the friction and clamping force between the surface of the crowbar 16, and the crowbar 16 will not have excessive shaking force when being pulled and rotated, and the crowbar 16 will not slide on the surface of the limiting sleeve 153 as the fitting sleeve 139 is pulled.

[0036] Working principle: Cooperate with employees to move the fixed platform 11 and the fitting swing arm plate 14 to the edge positions on both sides of the blade. At this time, the positioning slots with a diameter of 30 mm on both ends of the blade are used to clamp one end of the crowbar 16. At this time, the limiting sleeve 153 and the threaded lifter 15 on the outer surface of the crowbar 16 form a support point. At this time, cooperate with the hydraulic rod 137 to pull the fitting sleeve 139 on the outer surface of the strap 138. The crowbar 16 rotates with the limiting sleeve 153 as the support point to push the blade on one end of the crowbar 16 and push the blade off the surface of the cutting equipment. While the hydraulic rod 137 is pulling, it cooperates with the strap 138 to deform the bending between the fitting sleeve 139 and the output end of the hydraulic rod 137;

[0037] If the friction between the blade and the equipment component is too great or the blade interface is slightly bent, making it difficult to remove the blade, the motor 135 is used to rotate the threaded rod 134, and the limit slider 132 moves upward on the surface of the limit rod 133 and the threaded rod 134, so that one end of the fitting sleeve 139 fits with the edge of the other end of the crowbar 16, thereby increasing the pulling force of the lever arm, and generating a greater pushing force on the other end of the crowbar 16, so that the force applied by the long arm end is transmitted to the fulcrum through a longer lever arm, so that heavier objects can be pried, thereby pushing the blade out of the equipment. By changing the height of the hydraulic rod 137, one end of the crowbar 16 will not be too large due to the bending force and bending angle, thereby increasing the effect of the hydraulic rod 137 generating a greater pulling force;

[0038] After the blade is removed from the surface of the equipment, the new blade is placed at the interface of the cutting equipment, and the motor 123 is used to rotate the threaded rod 122, and the threaded rod 122 on both sides and the double-hole slider 143 on the outer surface of the limit rod 121 move to the middle position of the crowbar 16, and the non-slip soft plate 142 on the surface of the swing arm plate 14 is attached to the two side surfaces of the new blade, and the new blade and the equipment interface are at the same height and angle, and then one end of the crowbar 16 is clamped into the positioning slot of the new blade, and the hydraulic rod 137 is used to push the fitting sleeve 139 in the opposite direction, and the crowbar 16 is rotated with the limit sleeve shell 153 as the fulcrum, and the new blade is pushed into the docking slot of the equipment to clamp the blade, so that the interface of the new blade and the equipment forms a horizontal intersection angle using the two clamping plates, and the new blade can be reinstalled without human support and positioning;

[0039] When the crowbar 16 slides inside the limiting sleeve 153, when the position of the crowbar 16 needs to be positioned, the semi-circular plate a3 is pushed by the hydraulic rod a2, and the semi-circular plate a3 fits tightly on the outer surface of the crowbar 16. At this time, the anti-slip pad a4 on the inner wall of the semi-circular plate a3 increases the friction and clamping force between the surface of the crowbar 16. When the crowbar 16 is pulled and rotated, there will be no excessive shaking force, and the crowbar 16 will not slide on the surface of the limiting sleeve 153 as the fitting sleeve 139 is pulled.

[0040] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A blade push-pull positioning device for changing blades of a double-sided shear, comprising a fixed platform (11) and two sets of fixed shells (13) detachably mounted on the outer surface of the top of the fixed platform (11), an extension shell (12) fixedly mounted on one side surface of the fixed platform (11), a fitting swing arm plate (14) threadedly movably sleeved on the outer surface of the extension shell (12), a threaded lifter (15) fixedly mounted on one side surface of the extension shell (12), and a pry bar (16) movably sleeved on the outer surface of the threaded lifter (15), characterized in that: A limiting slider (132) is movably sleeved on the outer surfaces of the two groups of the fixed sleeves (13); a second motor (135) is fixedly installed on the top surface of one group of the fixed sleeves (13); a second threaded rod (134) movably sleeved on the inner wall surface of the fixed sleeve (13) is fixedly installed on the output end of the second motor (135); a second limiting rod (133) is fixedly installed on the inner wall surface of the other group of the fixed sleeves (13); a limiting sleeve (136) is movably sleeved on the outer surface of the limiting slider (132); a hydraulic rod (137) is detachably installed on the inner wall surface of the limiting sleeve (136); a binding belt (138) is fixedly connected to the output end of the hydraulic rod (137); a fitting sleeve (139) movably sleeved on the outer surface of the crowbar (16) is fixedly connected to the outer surface of the binding belt (138).

2. The blade push-pull positioning device for double-sided shears when changing blades according to claim 1, characterized in that: A slider (151) is movably sleeved on the inner wall surface of the threaded lifter (15), a rotating shaft (152) is movably sleeved on the outer surface of the slider (151), and a limiting sleeve shell (153) movably sleeved on the outer surface of the crowbar (16) is fixedly connected to the outer surface of the rotating shaft (152).

3. The blade push-pull positioning device for double-sided shears when changing blades according to claim 2, characterized in that: A trapezoidal lap platform (154) is fixedly mounted on the inner side surface of the thread lifter (15) and located at the bottom edge, and a clamping groove (155) is provided on the top surface of the trapezoidal lap platform (154).

4. The blade push-pull positioning device for double-sided shears when changing blades according to claim 2, characterized in that: A second hydraulic rod (a2) is symmetrically fixedly installed on the inner wall surface of the second limiting sleeve shell (153), and a semicircular arc plate (a3) ​​is fixedly connected to the output end of the second hydraulic rod (a2).

5. The blade push-pull positioning device for double-sided shears when changing blades according to claim 4, characterized in that: The outer surface of the semicircular plate (a3) ​​is provided with an anti-skid pad (a4) which is movably sleeved on the outer surface of the crowbar (16); the inner wall surface of the second limiting sleeve (153) and the upper and lower edge positions of the second hydraulic rod (a2) and the semicircular plate (a3) ​​are fixedly connected with an anti-sway sleeve (a1).

6. The blade push-pull positioning device for double-sided shears when changing blades according to claim 1, characterized in that: A fitting anti-skid soft plate (142) is provided on the outer surface of the fitting swing arm plate (14), a universal wheel (141) is provided on the bottom surface of the fitting swing arm plate (14), and a double-hole slider (143) is fixedly mounted on one side surface of the fitting swing arm plate (14).

7. The blade push-pull positioning device for double-sided shears when changing blades according to claim 1, characterized in that: A motor (123) is fixedly mounted on one side surface of the expansion housing (12), a limit rod (121) is arranged on the inner wall surface of the expansion housing (12), a threaded rod (122) arranged on the inner wall surface of the expansion housing (12) is fixedly connected to the output end of the motor (123), and the outer surfaces of the threaded rod (122) and the limit rod (121) are movably sleeved on the inner wall surface of the double-hole slider (143).

8. The blade push-pull positioning device for double-sided shears when changing blades according to claim 1, characterized in that: The outer surface of the fixed housing (13) is provided with a hollow groove (131), the outer surface of the limiting slider (132) is movably sleeved on the inner wall of the hollow groove (131), and the outer surfaces of the second threaded rod (134) and the second limiting rod (133) are movably sleeved on the outer surface of the limiting slider (132).

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