Welding mechanism for inner oven wall of oven

Abstract

The invention discloses an oven inner oven wall welding mechanism which comprises a fixing frame, and a lower oven is arranged in the fixing frame. The cylinder is matched with the lower oven, the welding assembly is used for welding the cylinder to the lower oven, a limiting assembly is arranged outside the welding assembly, and when the welding assembly moves downwards, the limiting assembly is driven to move to limit the inner wall of the cylinder. According to the welding mechanism for the inner oven wall of the oven, the lower oven is placed on the fixing frame, then the cylinder is placed on the lower oven, the cylinder is passively clamped through the clamping assembly, and the welding assembly is moved to the joint of the lower oven and the cylinder; in the downward moving process of the welding assembly, the limiting assembly is unlocked so that the limiting assembly can limit the inner wall of the cylinder, after limiting, welding is conducted through the welding assembly, and the limiting assembly drives the driving assembly to rotate during welding, so that the driving assembly drives the welding assembly to rotate and drives the cylinder and the lower oven to rotate, and comprehensive welding of the inner oven wall is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of baking oven welding equipment, and in particular to a welding mechanism for a furnace wall in a baking oven. Background Art

[0002] An oven is a device used to bake and cook food, usually in a closed or semi-closed structure. It can be heated by burning wood, coal, or using electricity, natural gas, etc. to form hot air to bake food. Modern ovens are usually multifunctional, can independently control the temperature of each layer, and are equipped with an automatic constant temperature system to ensure the consistency of the baking effect.

[0003] In the production process of cylindrical ovens, it is necessary to weld the joints of the two parts of the oven wall. Since the welding is inside the oven, it is impossible to effectively observe and operate simply through manual welding, which increases the difficulty of welding and easily leads to instability of the joints, reducing the strength of the joints. Welding by instruments increases the cost investment, and when welding by instruments, it is necessary to ensure that the two parts of the oven are completely overlapped before welding can be carried out, which increases the early debugging time and reduces the efficiency of oven welding. Summary of the invention

[0004] The purpose of the present invention is to provide a furnace wall welding mechanism in a baking oven to solve the above-mentioned deficiencies in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solution: comprising a fixing frame, wherein a lower oven is arranged in the fixing frame;

[0006] It also includes a cylinder adapted to the lower oven and a welding assembly for welding the cylinder to the lower oven, wherein a limiting assembly is arranged outside the welding assembly, and when the welding assembly moves downward, the limiting assembly is driven to move to limit the inner wall of the cylinder;

[0007] It also includes a driving component, which passively drives the welding component to rotate after the limiting component clamps the cylinder, and drives the cylinder to rotate when the welding component welds the lower oven and the cylinder, so as to fully weld the connection.

[0008] As a further description of the above technical solution:

[0009] The welding assembly includes a hydraulic cylinder, the output end of the hydraulic cylinder is rotatably connected to a limit tube, a limit rod is slidably arranged inside the limit tube, a welding head is arranged outside the limit rod, a limit spring is fixedly connected inside the limit tube, and the limit spring is rotatably connected to the limit rod.

[0010] As a further description of the above technical solution:

[0011] The limiting assembly includes a fixed tube fixed to the outside of the limiting tube, a clamping rod is slidably arranged in the fixing tube, and a worm is rotatably connected in the fixing tube, one end of the worm is provided with a thread, and the thread is threadedly connected to the clamping rod, the other end of the worm extends into the limiting tube and is fixedly connected to a first gear, a rack matched with the first gear is fixedly connected in the limiting rod, and an abutment spring is arranged in the fixing tube.

[0012] As a further description of the above technical solution:

[0013] A rope winding wheel is rotatably arranged on the fixed tube, a pull rope is wound around the rope winding wheel, and the pull rope extends into the fixed tube and is fixedly connected to the clamping rod.

[0014] As a further description of the above technical solution:

[0015] It also includes a connecting piece for connecting the rope winding wheel and the worm gear, the connecting piece includes a rotating rod rotating in the fixed tube, a worm wheel matched with the worm gear is fixedly connected to the outside of the rotating rod, an active ratchet is fixedly connected to the top of the rotating rod, a rectangular rod is slidably arranged in the rope winding wheel, and a driven ratchet matched with the active ratchet is fixedly connected to the bottom end of the rectangular rod.

[0016] As a further description of the above technical solution:

[0017] The outer sleeve of the rectangular rod is provided with a return spring, and the two ends of the return spring are respectively fixedly connected to the driven ratchet disk and the rope winding wheel.

[0018] As a further description of the above technical solution:

[0019] The driving assembly includes a second gear fixed outside the limiting tube, the bottom end of the rotating rod extends outside the fixing tube and is sleeved with a pull tube, and the bottom end of the pull tube is fixedly connected with a third gear matched with the second gear.

[0020] As a further description of the above technical solution:

[0021] A guide block is fixedly connected to the outside of the rotating rod, and a guide groove matched with the guide block is provided in the pull tube.

[0022] As a further description of the above technical solution:

[0023] It also includes a plurality of clamping assemblies, which passively clamp the cylinder when the lower oven and the cylinder are placed on a fixed frame. The clamping assembly includes a telescopic rod rotatably arranged on the fixed frame, and both ends of the telescopic rod are rotatably connected to a sliding rod and a connecting rod respectively. The sliding rod is slidably arranged in the fixed frame, and the end of the connecting rod is fixedly connected to a clamping plate.

[0024] As a further description of the above technical solution:

[0025] A fixing plate is fixedly connected to the fixing frame, the connecting rod is slidably arranged in the fixing plate, and a tension spring is arranged on the outer sleeve of the connecting rod, and two ends of the tension spring are respectively fixedly connected to the connecting rod and the fixing plate.

[0026] In the above technical solution, the invention provides a furnace wall welding mechanism in a baking oven with the following beneficial effects:

[0027] The present invention places the lower oven on a fixed frame, and then places the cylinder on the lower oven; the cylinder is passively clamped by a clamping assembly to achieve automatic docking of the lower oven and the cylinder; the welding assembly is then moved to the connection between the lower oven and the cylinder; during the downward movement of the welding assembly, the limiting assembly is unlocked so that the limiting assembly limits the inner wall of the cylinder to achieve clamping of the cylinder; after limiting, welding is performed by the welding assembly; during welding, the limiting assembly drives the driving assembly to rotate, so that the driving assembly drives the welding assembly to rotate, thereby causing the limiting assembly to rotate, driving the cylinder and the lower oven to rotate, thereby achieving comprehensive welding of the inner furnace wall; there is no need to manually align the cylinder and the lower oven, and the efficiency of oven welding is improved.

[0028] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0029] This application document provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0031] Figure 1 A schematic diagram of a three-dimensional structure provided by an embodiment of the present invention;

[0032] Figure 2 The embodiment of the present invention provides Figure 1 An enlarged view of point A is shown;

[0033] Figure 3 A schematic diagram of the longitudinal section structure of the lower oven and the cylinder provided in an embodiment of the present invention;

[0034] Figure 4 The embodiment of the present invention provides Figure 3 An enlarged view of point B is shown;

[0035] Figure 5 A schematic diagram of a partial longitudinal section structure of a limiting tube and a fixing tube provided in an embodiment of the present invention;

[0036] Figure 6 The embodiment of the present invention provides Figure 5 An enlarged view of point C is shown;

[0037] Figure 7 The embodiment of the present invention provides Figure 5 An enlarged view of D is shown.

[0038] Description of reference numerals:

[0039] 1. Fixed frame; 2. Lower oven; 21. Cylinder; 31. Hydraulic cylinder; 32. Limiting tube; 33. Limiting rod; 34. Welding head; 35. Limiting spring; 41. Fixed tube; 42. Clamping rod; 43. Worm; 44. First gear; 45. Rack; 46. Rope wheel; 47. Pull rope; 48. Thread; 49. Abutment spring; 51. Rotating rod; 52. Worm wheel; 53. Active ratchet; 54. Rectangular rod; 55. Driven ratchet; 56. Return spring; 61. Pulling tube; 62. Third gear; 63. Second gear; 64. Guide block; 65. Guide groove; 71. Telescopic rod; 72. Sliding rod; 73. Connecting rod; 74. Clamping plate; 75. Fixed plate; 76. Tension spring. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0041] See also Figure 1-Figure 7The present embodiment provides a furnace wall welding mechanism, comprising a fixing frame 1, in which a lower furnace 2 is arranged; a cylinder 21 adapted to the lower furnace 2 and a welding assembly for welding the cylinder 21 to the lower furnace 2; a limiting assembly is arranged outside the welding assembly, and when the welding assembly moves downward, the limiting assembly is driven to move to limit the inner wall of the cylinder 21; and a driving assembly is further provided, which passively drives the welding assembly to rotate after the limiting assembly clamps the cylinder 21, and drives the cylinder 21 to rotate when the welding assembly welds the lower furnace 2 and the cylinder 21, so as to fully adjust the connection. Perform welding; place the lower oven 2 on the fixed frame 1, and then place the cylinder 21 on the lower oven 2, passively clamp the cylinder 21 through the clamping assembly, move the welding assembly to the connection between the lower oven 2 and the cylinder 21, unlock the limit assembly during the downward movement of the welding assembly so that the limit assembly limits the inner wall of the cylinder 21, and after limiting, weld through the welding assembly. During welding, the limit assembly drives the driving assembly to rotate, so that the driving assembly drives the welding assembly to rotate, thereby causing the limit assembly to rotate, driving the cylinder 21 and the lower oven 2 to rotate, and realizing comprehensive welding of the inner furnace wall.

[0042] In an embodiment further provided by the present invention, the welding assembly includes a hydraulic cylinder 31, the output end of the hydraulic cylinder 31 is rotatably connected to a limiting tube 32, a limiting rod 33 is slidably arranged inside the limiting tube 32, a welding head 34 is arranged outside the limiting rod 33, a limiting spring 35 is fixedly connected inside the limiting tube 32, the limiting spring 35 is rotatably connected to the limiting rod 33, the height of the welding head 34 on the limiting rod 33 is adjustable, and the position of the welding head 34 is adjusted according to the depth of the lower oven 2, and after the bottom end of the limiting rod 33 contacts the inner wall of the lower oven 2, the welding table moves to the connection between the lower oven 2 and the cylinder 21.

[0043] In an embodiment further provided by the present invention, the limiting assembly includes a fixed tube 41 fixed to the outside of the limiting tube 32, a clamping rod 42 is slidably arranged in the fixed tube 41, a rubber wheel is arranged at the end of the clamping rod 42, and the rubber wheel rotates only in one direction. When the limiting tube 32 moves up and down, the friction of the clamping rod 42 moving up and down can be reduced by the rubber wheel. When the limiting tube 32 is rotated, the rubber wheel can increase the friction with the cylinder 21, so that when the clamping rod 42 rotates, the cylinder 21 can be driven to rotate synchronously, and a worm 43 is rotatably connected in the fixed tube 41, and the worm 43 is rotatably connected in the fixed tube 41. 3 is provided with a thread 48, and the thread 48 is connected with the thread 48 of the clamping rod 42. The other end of the worm 43 extends into the limiting tube 32 and is fixedly connected with the first gear 44. The limiting rod 33 is fixedly connected with a rack 45 adapted to the first gear 44. An abutment spring 49 is provided in the fixing tube 41. When the limiting tube 32 moves downward, the first gear 44 is driven to rotate by the rack 45, so that the worm 43 rotates, and the driving thread 48 is separated from the clamping rod 42 after rotation, and then the clamping rod 42 is pushed to move and abut against the inner wall of the cylinder 21 by the abutment spring 49.

[0044] Furthermore, a rope winding wheel 46 is rotatably provided on the fixed tube 41 , and a pull rope 47 is wound around the rope winding wheel 46 . The pull rope 47 extends into the fixed tube 41 and is fixedly connected to the clamping rod 42 .

[0045] Furthermore, it also includes a connecting piece for connecting the rope winding wheel 46 and the worm 43, the connecting piece includes a rotating rod 51 that rotates in the fixed tube 41, the rotating rod 51 is fixedly connected to a worm wheel 52 that matches the worm 43, the top of the rotating rod 51 is fixedly connected to an active ratchet 53, a rectangular rod 54 is slidably arranged in the rope winding wheel 46, and the bottom end of the rectangular rod 54 is fixedly connected to a driven ratchet 55 that matches the active ratchet 53. When the rack 45 moves downward to drive the first gear 44 to rotate, the contact surface between the active ratchet 53 and the driven ratchet 55 is a wedge-shaped surface, so the rotation of the active ratchet 53 will not drive the driven ratchet 55 to rotate, and when the thread 48 is unscrewed out of the clamping rod 42, the clamping rod 42 moves out to pull out the rope, driving the driven ratchet 55 and the active ratchet 53 to rotate relative to each other, so that the rotation of the driven ratchet 55 does not interfere with the active ratchet 53.

[0046] Specifically, a return spring 56 is disposed on the outer sleeve of the rectangular rod 54 , and two ends of the return spring 56 are respectively fixedly connected to the driven ratchet 55 and the rope winding wheel 46 .

[0047] In the embodiment provided by the present invention, the driving assembly includes a second gear 63 fixed outside the limiting tube 32, the bottom end of the rotating rod 51 extends to the outside of the fixed tube 41 and is sleeved with a pull tube 61, and the bottom end of the pull tube 61 is fixedly connected to a third gear 62 adapted to the second gear 63.

[0048] In the solution further provided by the present invention, a guide block 64 is fixedly connected to the outside of the rotating rod 51, and a guide groove 65 matched with the guide block 64 is opened in the pull tube 61. When the rack 45 drives the first gear 44 to rotate downward, the worm 43 drives the worm wheel 52 to rotate, so that the rotating rod 51 rotates, and the guide block 64 rotates in the spiral groove, so that the pull tube 61 moves downward, driving the second gear 63 and the third gear 62 to engage with each other. After the clamping rod 42 moves out of the clamping of the cylinder 21, the limit tube 32 is driven to rotate, so that the cylinder 21 rotates.

[0049] The present invention also includes a plurality of clamping assemblies. When the lower oven 2 and the cylinder 21 are placed on the fixed frame 1, the cylinder 21 is passively clamped. When the welding assembly moves downward, the bottom end of the limiting rod 33 contacts and squeezes the inner wall of the lower oven 2, increasing the downward force on the lower oven 2, thereby increasing the stability of the clamping assembly clamping the cylinder 21. The clamping assembly includes a telescopic rod 71 rotatably set on the fixed frame 1. The two ends of the telescopic rod 71 are rotatably connected with a sliding rod 72 and a connecting rod 73 respectively. The sliding rod 72 is slidably set in the fixed frame 1. The end of the connecting rod 73 is fixedly connected with a clamping plate 74. A ball is set on the clamping plate 74. The ball is in contact with the cylinder 21, so that when the clamping plate 74 limits the cylinder 21, it does not affect the rotation of the cylinder 21.

[0050] In the present invention, a fixing plate 75 is fixedly connected to the fixing frame 1, a connecting rod 73 is slidably disposed in the fixing plate 75, and a tension spring 76 is disposed on the outer sleeve of the connecting rod 73, and two ends of the tension spring 76 are respectively fixedly connected to the connecting rod 73 and the fixing plate 75.

[0051] During welding, the lower oven 2 is placed on the fixing frame 1, and then the cylinder 21 is connected to the lower oven 2. The gravity of the lower oven 2 and the cylinder 21 pushes the sliding rod 72 to move into the fixing frame 1, so that the telescopic rod 71 rotates, thereby pushing the connecting rod 73 to push the clamping plate 74 on the fixing plate 75 to limit the cylinder 21, and at the same time, the tension spring 76 is stretched. The cylinder 21 is limited by setting a plurality of clamping plates 74.

[0052] Then, the hydraulic cylinder 31 drives the limiting tube 32 to move downward into the cylinder 21. When the limiting rod 33 contacts the inner wall of the lower oven 2, the welding head 34 moves to the connection between the lower oven 2 and the cylinder 21, and the limiting tube 32 continues to move downward. Since the limiting rod 33 is limited, the limiting spring 35 is compressed, thereby generating a downward force on the limiting rod 33, pushing the lower oven 2 to move downward, thereby increasing the clamping force of the clamping plate 74 on the cylinder 21, and ensuring stable clamping of the cylinder 21.

[0053] After the welding table moves to the connection point, the limiting tube 32 moves downward, driving the fixing tube 41 to move synchronously, thereby driving the first gear 44 to mesh with the rack 45, and continuing to move downward to rotate the first gear 44, thereby driving the worm 43 to rotate, so that the thread 48 rotates in the clamping rod 42, thereby screwing the clamping rod 42 out of the screw, and then pushing the clamping rod 42 through the abutment spring 49, so that the clamping rod 42 moves to contact the inner wall of the cylinder 21;

[0054] When the clamping rod 42 moves outward from the fixed tube 41, the pull rope 47 is pulled to move, so that the rope wheel 46 rotates, and the driven ratchet 55 is driven to rotate from right to left through the rectangular rod 54 (such as Figure 6As shown in FIG. 1 , the worm 43 rotates to drive the worm wheel 52 to rotate, so that the rotating rod 51 rotates synchronously, thereby causing the active ratchet 53 to rotate from left to right (as shown in FIG. 1 ). Figure 6 As shown), when moving downward, the rotation of the rope wheel 46 and the rotation of the worm 43 will not cause motion interference;

[0055] When moving downward, the rotating rod 51 rotates to drive the guide block 64 to move, and the pull tube 61 moves downward through the spiral groove, driving the third gear 62 to mesh with the second gear 63, so that the third gear 62 rotates to drive the second gear 63 to rotate, thereby causing the limit tube 32 to rotate synchronously, driving the welding head 34 to rotate synchronously, and when the welding head 34 starts to rotate, the connection between the lower oven 2 and the cylinder 21 is welded through the welding head 34, and after the clamping rod 42 clamps the cylinder 21, the cylinder 21 starts to rotate;

[0056] When the limiting tube 32 moves to the lowest position, the limiting tube 32 rotates one circle at the same time, so that the welding head 34 completes the welding of the lower oven 2 and the cylinder 21. After the welding is completed, the limiting tube 32 is driven by the hydraulic cylinder 31 to move upward. At this time, the first gear 44 rotates in the opposite direction on the rack 45, so that the rotating rod 51 rotates in the opposite direction, and the guide block 64 rotates in the spiral groove, so that the tension spring 76 moves upward, so that the second gear 63 is separated from the third gear 62, and the rotation of the cylinder 21 is stopped;

[0057] Then, by reversing the rotating rod 51, the active ratchet 53 is driven to rotate from right to left. At this time, the contact surface between the active ratchet 53 and the driven ratchet 55 is a plane, so it will drive the driven ratchet 55 to rotate synchronously, thereby driving the rope wheel 46 to rotate to reel in the pull rope 47, thereby driving the clamping rod 42 to move into the fixed tube 41. When the clamping rod 42 moves to the thread 48, the thread 48 rotates through the rotation of the worm 43 to limit the clamping rod 42. Then the first gear 44 moves out of the rack 45, and the hydraulic cylinder 31 continues to move until the limit rod 33 moves out of the cylinder 21, so as to achieve welding of the inner wall of the oven.

[0058] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A furnace wall welding mechanism in a baking oven, comprising a fixing frame (1), characterized in that: A lower oven (2) is arranged in the fixed frame (1); It also includes a cylinder (21) adapted to the lower oven (2) and a welding assembly for welding the cylinder (21) to the lower oven (2); a limiting assembly is arranged outside the welding assembly, and when the welding assembly moves downward, the limiting assembly is driven to move to limit the inner wall of the cylinder (21); It also comprises a driving assembly, which passively drives the welding assembly to rotate after the limiting assembly clamps the cylinder (21), and drives the cylinder (21) to rotate when the welding assembly welds the lower oven (2) and the cylinder (21), so as to fully weld the connection.

2. The furnace wall welding mechanism of the oven according to claim 1, characterized in that: The welding assembly comprises a hydraulic cylinder (31), the output end of the hydraulic cylinder (31) is rotatably connected to a limit tube (32), a limit rod (33) is slidably arranged inside the limit tube (32), a welding head (34) is arranged outside the limit rod (33), a limit spring (35) is fixedly connected inside the limit tube (32), and the limit spring (35) is rotatably connected to the limit rod (33).

3. The furnace wall welding mechanism of the oven according to claim 2, characterized in that: The limiting assembly comprises a fixed tube (41) fixed to the outside of the limiting tube (32), a clamping rod (42) is slidably arranged in the fixed tube (41), and a worm (43) is rotatably connected in the fixed tube (41), one end of the worm (43) is provided with a thread (48), and the thread (48) is connected to the thread (48) of the clamping rod (42), the other end of the worm (43) extends into the limiting tube (32) and is fixedly connected to a first gear (44), the limiting rod (33) is fixedly connected to a rack (45) matched with the first gear (44), and an abutment spring (49) is arranged in the fixed tube (41).

4. The furnace wall welding mechanism of the oven according to claim 3, characterized in that: A rope winding wheel (46) is rotatably arranged on the fixed tube (41), a pull rope (47) is wound around the rope winding wheel (46), and the pull rope (47) extends into the fixed tube (41) and is fixedly connected to the clamping rod (42).

5. The furnace wall welding mechanism of the oven according to claim 4, characterized in that: The invention also comprises a connecting member for connecting the rope winding wheel (46) and the worm (43), wherein the connecting member comprises a rotating rod (51) rotating in the fixed tube (41), a worm wheel (52) matched with the worm (43) being fixedly connected to the outside of the rotating rod (51), an active ratchet (53) being fixedly connected to the top end of the rotating rod (51), a rectangular rod (54) being slidably arranged in the rope winding wheel (46), and a driven ratchet (55) matched with the active ratchet (53) being fixedly connected to the bottom end of the rectangular rod (54).

6. The furnace wall welding mechanism of the oven according to claim 5, characterized in that: The outer sleeve of the rectangular rod (54) is provided with a return spring (56), and the two ends of the return spring (56) are respectively fixedly connected to the driven ratchet disk (55) and the rope winding wheel (46).

7. The furnace wall welding mechanism of the oven according to claim 5, characterized in that: The driving assembly comprises a second gear (63) fixed outside the limiting tube (32); the bottom end of the rotating rod (51) extends to the outside of the fixing tube (41) and is sleeved with a pull tube (61); the bottom end of the pull tube (61) is fixedly connected with a third gear (62) matched with the second gear (63).

8. The furnace wall welding mechanism of claim 7, characterized in that: A guide block (64) is fixedly connected to the outside of the rotating rod (51), and a guide groove (65) adapted to the guide block (64) is provided in the pull tube (61).

9. The furnace wall welding mechanism of a baking oven according to claim 1, characterized in that: It also includes a plurality of clamping assemblies, which passively clamp the cylinder (21) when the lower oven (2) and the cylinder (21) are placed on the fixed frame (1), and the clamping assembly includes a telescopic rod (71) rotatably arranged on the fixed frame (1), and the two ends of the telescopic rod (71) are respectively rotatably connected to a sliding rod (72) and a connecting rod (73), and the sliding rod (72) is slidably arranged in the fixed frame (1), and the end of the connecting rod (73) is fixedly connected to a clamping plate (74).

10. The furnace wall welding mechanism of the oven according to claim 9, characterized in that: A fixing plate (75) is fixedly connected to the fixing frame (1), the connecting rod (73) is slidably arranged in the fixing plate (75), and a tension spring (76) is arranged on the outer sleeve of the connecting rod (73), and the two ends of the tension spring (76) are respectively fixedly connected to the connecting rod (73) and the fixing plate (75).

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