Scissor fork with mechanical limit

Abstract

The application discloses a scissor fork with mechanical limiting, which comprises a platform, a jacking platform is arranged on the upper side of the platform, a second support and a first support are arranged between the jacking platform and the platform and are cross-rotatingly connected with each other, one of the second support and the first support is arranged at the front and the rear respectively, a rotating seat is rotatably connected to the left side of the first support and the second support, the rotating seat is fixedly connected with the jacking platform and the platform, the right side of the second support and the first support is rollingly connected with the platform and the jacking platform through a roller sliding rail assembly, a hydraulic cylinder assembly is connected between the second support and the first support, a sensor assembly for limiting and controlling the lifting height of the jacking platform is arranged between the platform and the second support, a locking frame is further arranged in the external space, a telescopic rod assembly is fixed to the bottom of the jacking platform, and the telescopic rod assembly is clamped and fixed with the locking frame after the jacking platform is lifted to the position of the locking frame.

Description

Technical Field

[0001] This invention relates to the field of hydraulic scissor fork technology, specifically a scissor fork with mechanical limiting. Background Technology

[0002] Existing AGV-mounted scissor lift platforms primarily rely on sliding friction contact between the cross brackets and the platform, resulting in high movement resistance and severe wear after prolonged use, impacting lifting efficiency and lifespan. The rotating connections of existing scissor lifts lack effective lubrication structures; the shafts and brackets often have rigid direct contact, leading to high frictional resistance, noise, and wear. Furthermore, lubrication is inconvenient and difficult to maintain consistently. Current scissor lift height control largely depends on open-loop hydraulic control or simple limit switches, making precise height detection and adjustment difficult. Height deviations are prone to occur when docking with external work platforms, affecting the smoothness of cargo transfer. After reaching the target height, existing scissor lifts typically rely on hydraulic cylinder pressure to maintain the platform height, lacking mechanical limit locking structures. The hydraulic cylinders are constantly under stress, resulting in high energy consumption and susceptibility to uneven pressure during cargo handling, causing platform swaying, tilting, or even overturning, posing safety hazards. In addition, the existing scissor fork shaft connection structure is simple and lacks reliable axial limiting and anti-loosening measures. Under high load and frequent lifting conditions, the shaft is prone to axial movement and loosening, which affects the structural stability and operational reliability. Summary of the Invention

[0003] This invention addresses the problems of existing scissor forks, such as high frictional resistance in lifting, poor lubrication of rotating parts leading to wear and abnormal noise, low precision in lifting height control, high energy consumption and risk of tipping during long-term hydraulic pressure holding, and easy axial movement and loosening of the rotating shaft. It provides a scissor fork with mechanical limit.

[0004] This invention is achieved through the following technical solution: A scissor fork with mechanical limiting includes a platform, a lifting platform on the upper side of the platform, a second bracket and a first bracket rotatably connected to each other between the lifting platform and the platform, one of each of the second and first brackets being arranged at the front and rear, a rotating seat rotatably connected to the left side of the first and second brackets, the rotating seat being fixedly connected to the lifting platform and the platform, the right side of the second and first brackets being rotatably connected to the platform and the lifting platform through a roller slide rail assembly, a hydraulic cylinder assembly connecting the second and first brackets, a sensor assembly for limiting and controlling the lifting height of the lifting platform being arranged between the platform and the second bracket, a locking frame being arranged in the external space, and a telescopic rod assembly being fixed to the bottom of the lifting platform, the telescopic rod assembly engaging and fixing with the locking frame after the lifting platform is lifted to the position of the locking frame.

[0005] A further technical solution includes a roller slide rail assembly comprising a guide rail fixed within the platform and the lifting platform, with one guide rail at each end. A roller is rotatably mounted on one side of the second support and the first support, and the roller is in rolling engagement with the guide rail. The roller is mounted on one side of the second support and the first support via a rotating shaft spacer structure.

[0006] A further technical solution includes a rotating shaft spacer structure comprising a first shaft, a first boss fixed on one side of the first shaft, a first bushing fitted on the outer surface of the first shaft, a roller rotatably mounted on the outer surface of the first bushing, the first boss abutting against the first bushing and the roller, a ball embedded at the end of the first shaft, a first spacer fitted on the outer surface of the first shaft, the first spacer being located within the second bracket and the first bracket, a washer further provided between the first spacer, the first bushing, and the roller, the washer fitted on the outer surface of the first shaft, a first grooved nut threadedly connected to the outer surface of the first shaft, a first through hole provided inside the first shaft, and a first pin inserted through the first grooved nut and then inserted into the first through hole for fixation, thereby fixing the first shaft within the second bracket and the first bracket.

[0007] A further technical solution includes a hydraulic cylinder assembly comprising a first circular tube fixed between the second supports and a second circular tube fixed between the first supports. A plurality of first cam plates are fixed on the first circular tube. A hydraulic cylinder is rotatably mounted on one side of the first cam plate. A telescopic rod is mounted inside the hydraulic cylinder. A connecting block is fixed to the end of the telescopic rod. A second cam plate is fixed on one side of the second circular tube. The second cam plate is rotatably connected to the connecting block.

[0008] A further technical solution also includes a lubrication shaft assembly, which is disposed between the rotating seat and the first bracket, between the second bracket and the first bracket, between the second cam plate and the connecting block, and between the first cam plate and the hydraulic cylinder.

[0009] A further technical solution includes a lubrication shaft assembly comprising a second shaft, a second boss fixed on one side of the second shaft, a second through hole inside the second shaft, a second grooved nut threadedly connected to the end of the second shaft, and a second pin inserted and fixed into the second through hole after passing through the second grooved nut. A first oil hole is provided inside the second shaft, and a plurality of second oil holes communicating with the outer surface of the second shaft are provided on one side of the first oil hole. An oil plug is provided at the end of the first oil hole.

[0010] A further technical solution includes a sensor assembly comprising a first infrared sensor for transmitting a signal indicating the left extreme position of the second support, and a pull-wire encoder fixed to the bottom of the platform. The pull-wire end of the pull-wire encoder is fixed with a pull-wire fixing bracket, and the pull-wire fixing bracket is fixedly connected to the lifting platform.

[0011] A further technical solution includes a telescopic rod assembly comprising a sliding sleeve frame fixed to the bottom of the lifting platform, a telescopic sliding rod disposed within the sliding sleeve frame, an electronic limiting structure for electronically limiting the telescopic range of the sliding rod disposed on one side of the sliding sleeve frame, a slider linkage structure for simultaneously driving the telescopic extension and retraction of the sliding rod disposed at the bottom of the lifting platform, and the sliding rod being inserted and fixed into a semi-circular hole in the locking frame.

[0012] A further technical solution includes an electronic limiting structure comprising a slide groove formed within the slide sleeve frame, a nut fixed to one side of the slide rod, the nut slidingly abutting against the slide groove, a mounting bracket fixed to one side of the mounting plate, and a second infrared sensor disposed within the mounting bracket.

[0013] A further technical solution includes a slider-link structure comprising a frame, within which a double-threaded screw is rotatably mounted. The double-threaded screw has threads with opposite directions of rotation, and internal thread blocks are threadedly connected to these threads. Each internal thread block has a rotatably mounted upper and lower connecting rod, which is rotatably connected to a fixed block. A reduction motor for driving the double-threaded screw is mounted on one side of the frame. Guide grooves are formed on the upper and lower end faces of the frame. Guide posts are fixed to the upper and lower sides of the internal thread blocks, and the guide posts slide against the guide grooves.

[0014] The beneficial effects of the present invention are as follows: First, the scissor fork with mechanical limit of the present invention achieves rolling cooperation between the support and the platform through the roller slide rail assembly, continuous lubrication of each rotating part through the lubrication shaft assembly, high-precision detection and control of the height through the sensor assembly, and mechanical locking through the cooperation of the telescopic rod assembly and the locking frame. This achieves the technical effects of smooth and stable lifting, precise height control, and reliable and safe locking, and effectively overcomes the defects of existing scissor forks such as high sliding friction resistance, insufficient lubrication, rough height control, and easy overturning due to hydraulic pressure holding.

[0015] Second, the roller slide rail assembly transforms the sliding friction between the cross support and the platform into rolling friction through the rolling cooperation of the guide rail and the roller, which significantly reduces the moving resistance and improves the lifting efficiency; the ball at the end of the first shaft rolls against the end wall of the platform and the lifting platform, avoiding hard contact, thus reducing wear and impact and extending the service life.

[0016] 3. The lubricating shaft assembly has an oil hole inside the shaft, through which lubricating oil is directly distributed between the shaft and the bushing, providing continuous lubrication to all rotating connection parts. This avoids hard rotational friction between the shaft and the bracket, reduces rotational resistance, and eliminates abnormal noise. The oil plug design facilitates the replenishment of lubricating oil later, making maintenance simple. The two-way locking structure formed by the second boss and the second groove nut ensures that the shaft is firmly installed, preventing axial movement and loosening.

[0017] Fourth, the sensor assembly detects the extreme position of the bracket through the first infrared sensor to achieve a safe limit on the upper limit of the lifting. In conjunction with the pull-wire encoder, it reads the lifting height of the lifting platform in real time and feeds it back to the controller to achieve precise height control. This enables the lifting platform to accurately dock with the external working platform, improving the smoothness and automation of cargo transfer.

[0018] 5. The telescopic rod assembly drives the sliding rod to extend through the slider linkage structure and engage with the semi-circular hole of the locking frame to fix it. After the lifting platform reaches the target height, a reliable mechanical lock is formed, which replaces the traditional hydraulic pressure holding method. This eliminates the need for the hydraulic cylinder to maintain a stressed state for a long time, reducing energy consumption. At the same time, it effectively avoids the shaking, tilting and overturning of the platform caused by uneven pressure during cargo handling, improving alignment accuracy and operational safety.

[0019] VI. The slider linkage structure adopts a double-threaded screw to drive the internal threaded blocks on both sides to move synchronously closer or further away. The linkage drives the front and rear sliders to extend and retract synchronously, resulting in good consistency and smooth extension and retraction. The slider is physically limited by the slide groove, and electronically limited by the second infrared sensor, forming a double protection to ensure the accuracy and safety of the slider extension and retraction range.

[0020] 7. The top of the support is fixed with pads to support the lifting platform when it is at its lowest position, which avoids structural deformation caused by the platform being suspended for a long time and improves the stability and durability of the equipment. Attached Figure Description

[0021] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the overall structure of a scissor fork with mechanical limiting according to the present invention; Figure 2 for Figure 1 A schematic diagram at point A in the middle; Figure 3 for Figure 1 A schematic diagram at point B in the middle; Figure 4 for Figure 1 A schematic diagram of the other side of the equipment; Figure 5 for Figure 4 A schematic diagram at point C in the middle; Figure 6 for Figure 4 A schematic diagram at point D in the middle; Figure 7 for Figure 1 A schematic diagram of the structure of the equipment from below; Figure 8 for Figure 7 A schematic diagram at point E in the middle; Figure 9 for Figure 8 A schematic diagram at point F in the middle; Figure 10 for Figure 8 A schematic diagram at point G in the middle; Figure 11 for Figure 1 A schematic diagram of the cutting device using the second support as a reference. Figure 12 This is a schematic diagram of point H in the lifting platform; Figure 13 This is a schematic diagram of point I in the lifting platform; Figure 14 for Figure 1 A schematic diagram of the cutting device with the first support as the reference. Figure 15 This is a schematic diagram of point J in the second support; Figure 16 for Figure 4 A schematic diagram of a transverse cutting device based on a telescopic rod and a hydraulic cylinder; Figure 17 This is a schematic diagram of point K in the first support; Figure 18 This is a schematic diagram of point L in the first support; In the diagram, the components are: lifting platform 11, locking frame 12, guide rail 13, second bracket 14, platform 15, first bracket 16, rotating seat 17, upright seat 18, pad block 19, wire encoder 21, wire fixing bracket 22, side plate 23, first infrared sensor 24, second round tube 31, connecting block 32, second cam plate 33, telescopic rod 34, hydraulic cylinder 35, first round tube 37, first cam plate 38, roller 39, sliding sleeve bracket 41, sliding rod 42, card seat 43, nut 44, bolt 45, base plate 46, semi-circular hole 47, mounting plate 51, nut 52, slide groove 54, and fixing block 56. 57. Mounting bracket; 58. Second infrared sensor; 59. Side bracket; 62. Connecting rod; 63. Gear motor; 65. Frame; 66. Guide groove; 67. Guide post; 71. Double threaded screw; 72. Internal threaded block; 73. Stop block; 74. First boss; 75. Ball bearing; 76. First bushing; 78. Washer; 79. First shaft; 81. First slotted nut; 82. First through hole; 83. First pin; 84. Second pin; 85. Second through hole; 86. Second slotted nut; 87. Second shaft; 88. Second bushing; 89. Second spacer; 91. First oil hole; 92. Oil plug; 93. Second oil hole; 94. Second boss; 95. Detailed Implementation

[0023] like Figures 1-18 As shown, the present invention will be described in detail. For ease of description, the directions mentioned below are defined as follows: the directions of up, down, left, right, front, and back mentioned below are the same as... Figure 1 The directions of the projection relationship are consistent in all directions: up, down, left, right, front, and back.

[0024] In Embodiment 1, a scissor fork with mechanical limiting according to the present invention includes a platform 15, a lifting platform 11 is provided on the upper side of the platform 15, a second bracket 14 and a first bracket 16 are provided between the lifting platform 11 and the platform 15 and are rotatably connected to each other, one of the second bracket 14 and one of the first bracket 16 are provided at the front and rear, a rotating seat 17 is rotatably connected to the left side of the first bracket 16 and the second bracket 14, and the rotating seat 17 is fixedly connected to the lifting platform 11 and the platform 15, the right side of the second bracket 14 and the first bracket 16 are rotatably connected to the platform 15 and the lifting platform 11 through a roller slide rail assembly, a hydraulic cylinder assembly is connected between the second bracket 14 and the first bracket 16, a sensor assembly for limiting and controlling the lifting height of the lifting platform 11 is provided between the platform 15 and the second bracket 14, a locking frame 12 is also provided in the external space, and a telescopic rod assembly is fixed to the bottom of the lifting platform 11 and is engaged and fixed with the locking frame 12 after the lifting platform 11 is lifted to one side of the locking frame 12.

[0025] The device uses a roller slide rail assembly to connect the bottom right side of the second support 14 to the platform 15, and the upper right side of the first support 16 to the lifting platform 11. Under the operation of the hydraulic cylinder assembly, the bottom right side of the second support 14 and the upper right side of the first support 16 move to the left, thereby lifting the lifting platform 11 relative to the platform 15. A sensor assembly is used to limit the maximum lifting height of the lifting platform 11 and precisely control the specific lifting height, enabling the lifting platform 11 to dock with the external work platform. If the external work platform is equipped with a locking frame 12, the telescopic rod assembly can be used to lock and fix the lifting platform 11 to the locking frame 12, maintaining a constant height between the lifting platform 11 and the platform 15, thus forming a locking structure and preventing tilting, overturning, or misalignment of the equipment during cargo handling.

[0026] Advantageously, a support 18 is fixed to the top of the platform 15, and a pad 19 is fixed to the top of the support 18. When the lifting platform 11 is in the lowest position, the pad 19 abuts against the lower end face of the lifting platform 11 to support the lifting platform 11.

[0027] Example 2, based on Example 1, further defines the following: The roller slide rail assembly includes a guide rail 13 fixed in the platform 15 and the lifting platform 11, with one guide rail 13 at the front and one at the rear. Rollers 39 are rotatably mounted on one side of the second support 14 and the first support 16. The rollers 39 are in rolling engagement with the guide rail 13. The rollers 39 are mounted on one side of the second support 14 and the first support 16 through a rotating shaft spacer structure.

[0028] By installing guide rails 13 in both platform 15 and lifting platform 11, and connecting the rollers 39 on one side of the second support 14 and the first support 16 with the guide rails 13 in a rolling engagement, a rolling support structure is formed. When the second support 14 and the first support 16 move closer to each other, the rollers 39 roll to the left on the guide rails 13. A stop block 73 is fixed on one side of the guide rails 13 to physically limit the rollers 39.

[0029] Advantageously, the rotating shaft spacer structure includes a first shaft 79, a first boss 74 fixed on one side of the first shaft 79, a first bushing 76 sleeved on the outer surface of the first shaft 79, a roller 39 rotatably disposed on the outer surface of the first bushing 76, the first boss 74 abutting against the first bushing 76 and the roller 39, a ball 75 embedded at the end of the first shaft 79, a first spacer 81 sleeved on the outer surface of the first shaft 79, the first spacer 81 being located within the second bracket 14 and the first bracket 16, a washer 78 being provided between the first spacer 81, the first bushing 76, and the roller 39, the washer 78 being sleeved on the outer surface of the first shaft 79, a first grooved nut 82 being threadedly connected to the outer surface of the first shaft 79, a first through hole 83 being provided inside the first shaft 79, and a first pin 84 being inserted and fixed into the first through hole 83 after passing through the first grooved nut 82, thereby fixing the first shaft 79 within the second bracket 14 and the first bracket 16.

[0030] The ball bearing 75 is used to roll against the front and rear end walls of the platform 15 and the lifting platform 11, avoiding hard contact. The first shaft 79 is separated from the second support 14 and the first support 16 by the first spacer 81, and is limited and fixed within the second support 14 and the first support 16 by a limiting structure formed by the first groove nut 82, the first through hole 83, the first pin 84, the first bushing 76, the roller 39 and the first boss 74, preventing loosening. Furthermore, the roller 39 has a first bushing 76 on its inner side, and a washer 78 is provided between it and the first spacer 81, so that the resistance of the roller 39 during rolling is small, avoiding hard friction and improving the moving efficiency of the second support 14 and the first support 16.

[0031] Example 3, based on any one of Examples 1 to 2, further defines the following: The hydraulic cylinder assembly includes a first circular tube 37 fixed between the second supports 14, and a second circular tube 31 fixed between the first supports 16. A plurality of first cam plates 38 are fixed on the first circular tube 37. A hydraulic cylinder 35 is rotatably mounted on one side of the first cam plate 38. A telescopic rod 34 is provided inside the hydraulic cylinder 35. A connecting block 32 is fixed at the end of the telescopic rod 34. A second cam plate 33 is fixed on one side of the second circular tube 31. The second cam plate 33 is rotatably connected to the connecting block 32.

[0032] Advantageously, it also includes a lubrication shaft assembly, which is disposed between the rotating seat 17 and the first bracket 16, between the second bracket 14 and the first bracket 16, between the second cam plate 33 and the connecting block 32, and between the first cam plate 38 and the hydraulic cylinder 35.

[0033] Advantageously, the lubrication shaft assembly includes a second shaft 88, a second boss 95 fixed on one side of the second shaft 88, a second through hole 86 opened inside the second shaft 88, a second groove nut 87 threaded to the end of the second shaft 88, and a second pin 85 inserted and fixed into the second through hole 86 after passing through the second groove nut 87. A first oil hole 92 is opened inside the second shaft 88, and a plurality of second oil holes 94 communicating with the outer surface of the second shaft 88 are provided on one side of the first oil hole 92. An oil plug 93 is provided at the end of the first oil hole 92.

[0034] Lubricating oil is injected into the first oil hole 92 and the second oil hole 94, and then sealed by the oil plug 93 to maintain the lubrication of the outer surface of the second shaft 88. After the oil plug 93 is rotated to separate the second shaft 88, lubricating oil is added to the first oil hole 92 and the second oil hole 94 to replenish the lubrication. The two-way locking structure formed by the second boss 95 and the second groove nut 87 allows the lubrication shaft assembly to be stably installed in the corresponding structural component.

[0035] Advantageously, when the lubrication shaft assembly is connected to the first bracket 16 and the second bracket 14, the second shaft 88 passes through the first bracket 16 and the second bracket 14, and the outer surface of the second shaft 88 is rotatably fitted with the second bushing 89 and the second spacer 91 from the inside to the outside, and the second spacer 91 is fixed inside the first bracket 16 and the second bracket 14.

[0036] By fixing the second spacer 91 inside the first bracket 16 and the second bracket 14, and then fitting a second bushing 89 on the outer surface of the second shaft 88, the second bushing 89 is rotatably connected to the second spacer 91, and the second oil hole 94 is opposite to the second bushing 89. Lubricating oil is distributed between the second shaft 88 and the second bushing 89, which avoids the second shaft 88 from being directly and rigidly rotatably connected to the first bracket 16 and the second bracket 14, thus avoiding wear and providing good lubrication, making the relative rotation between the second bracket 14 and the first bracket 16 smoother.

[0037] Advantageously, when the lubrication shaft assembly is connected to the first bracket 16 and the rotating seat 17, the second shaft 88 passes through the first bracket 16 and the rotating seat 17, and the outer surface of the second shaft 88 is rotatably fitted with a second bushing 89 and a second spacer 91 from the inside to the outside, and the second spacer 91 is fixed inside the first bracket 16.

[0038] A similar structure allows for smoother rotation between the first support 16 and the rotating seat 17.

[0039] Advantageously, when the lubrication shaft assembly is connected to the first cam plate 38 and the hydraulic cylinder 35, the second shaft 88 passes through the first cam plate 38 and the hydraulic cylinder 35, the second boss 95 abuts against one side of the first cam plate 38, the second groove nut 87 is tightened and pressed against one side of the first cam plate 38, the hydraulic cylinder 35 is rotatably disposed on the outer surface of the second shaft 88, and the outlet of the second oil hole 94 is disposed inside the hydraulic cylinder 35.

[0040] By fixing the second shaft 88, the second boss 95, and the second groove nut 87 to the first cam plate 38 to form an integral structure, the hydraulic cylinder 35 is rotated and set on the outer surface of the second shaft 88. The lubricating oil flowing out of the second oil hole 94 directly lubricates the outer surfaces of the hydraulic cylinder 35 and the second shaft 88, reducing the friction between them.

[0041] Advantageously, when the lubrication shaft assembly is connected to the second cam plate 33 and the connecting block 32, the second shaft 88 passes through the second cam plate 33 and the connecting block 32, the second boss 95 abuts against one side of the second cam plate 33, the second groove nut 87 is tightened and pressed against one side of the second cam plate 33, the connecting block 32 is rotatably disposed on the outer surface of the second shaft 88, and the outlet of the second oil hole 94 is disposed in the connecting block 32.

[0042] By fixing the second shaft 88, the second boss 95, and the second groove nut 87 to the second cam plate 33 to form an integral structure, the connecting block 32 is rotatably set on the outer surface of the second shaft 88, and the lubricating oil flowing out of the second oil hole 94 directly lubricates the connecting block 32 and the outer surface of the second shaft 88, reducing the friction between them.

[0043] Example 4, based on any one of Examples 1 to 3, further defines the following: The sensor assembly includes a first infrared sensor 24 for transmitting the left extreme position signal of the second bracket 14, and also includes a pull-wire encoder 21 fixed to the bottom of the platform 15. The pull-wire end of the pull-wire encoder 21 is fixed with a pull-wire fixing frame 22, and the pull-wire fixing frame 22 is fixedly connected to the lifting platform 11.

[0044] After the second bracket 14 aligns with the first infrared sensor 24, it transmits a positioning signal to the controller, which then stops the hydraulic cylinder assembly. The cable fixing bracket 22 is installed and fixed to the lifting platform 11. After the lifting platform 11 moves up and down relative to the platform 15, the cable encoder 21 reads the length of the cable pulled out to determine the lifting height of the lifting platform 11 and the platform 15, and then feeds this information back to the controller. When the preset height is reached, the controller stops the hydraulic cylinder assembly, thus achieving the function of accurately lifting to different heights.

[0045] Advantageously, a side plate 23 is fixed to one side of the second bracket 14, and a vertical plate is provided on the top of the platform 15. A first infrared sensor 24 is fixed on the vertical plate. When the side plate 23 is opposite to the first infrared sensor 24, the first infrared sensor 24 triggers an electrical signal.

[0046] Advantageously, the bottom of the lifting platform 11 is fixed with a side support 59, and the guy wire fixing bracket 22 is fixedly connected to the side support 59.

[0047] Example 5, based on any one of Examples 1 to 4, further defines the following: the telescopic rod assembly includes a sliding sleeve frame 41 fixed to the bottom of the lifting platform 11, with one sliding sleeve frame 41 at the front and one at the rear, and a telescopic sliding rod 42 inside the sliding sleeve frame 41. An electronic limiting structure for electronically limiting the telescopic range of the sliding rod 42 is provided on one side of the sliding sleeve frame 41, and a slider connecting rod structure that simultaneously drives the telescopic extension of the sliding rod 42 is provided at the bottom of the lifting platform 11.

[0048] Advantageously, the outer surface of the sliding sleeve frame 41 is fixed with a front and a rear mounting plate 51, and the mounting plate 51 is fixedly connected to the lifting platform 11.

[0049] Advantageously, the electronic limiting structure includes a slide groove 54 opened in the slide sleeve 41, a nut 52 fixed on one side of the slide rod 42, the nut 52 slidingly abutting against the slide groove 54, and a mounting bracket 57 fixed on one side of the mounting plate 51, with a second infrared sensor 58 at the front and rear respectively installed in the mounting bracket 57.

[0050] The sliding groove 54 physically limits the extension range of the sliding rod 42, and a second infrared sensor 58 is provided to electronically limit the movement range of the sliding rod 42 and the nut 52. The inner second infrared sensor 58 is the initial point, and the outer second infrared sensor 58 is the end point. When the locking signal is issued, the slider linkage structure moves, the nut 52 moves from the initial point to the end point, and then the slider linkage structure stops working, and the sliding rod 42 remains inserted and fixed to the locking frame 12. When the unlocking signal is issued, the slider linkage structure moves, the nut 52 moves from the end point to the initial point, and then the slider linkage structure stops working, and the sliding rod 42 disengages from the locking frame 12.

[0051] Advantageously, the slider connecting rod structure includes a frame 65, within which a double-threaded screw 71 is rotatably mounted. The double-threaded screw 71 has threads with opposite directions of rotation, and internal thread blocks 72 are threadedly connected to these threads. Each internal thread block 72 has a connecting rod 62 rotatably mounted at the top and bottom. A fixing block 56 is fixed to one side of the slider 42, and the connecting rods 62 are rotatably connected to the fixing block 56. A reduction motor 63 for driving the double-threaded screw 71 is mounted on one side of the frame 65. Guide grooves 66 are formed in the upper and lower end faces of the frame 65, and guide posts 67 are fixed to the upper and lower sides of the internal thread blocks 72, with the guide posts 67 slidingly abutting against the guide grooves 66.

[0052] When the telescopic rod assembly's working command is triggered, the reduction motor 63 drives the double-threaded screw 71 to rotate, which in turn causes the internal threaded blocks 72 on both sides to move closer or further apart. Since the connecting rod 62 is rotatably connected between the internal threaded blocks 72 and the fixing block 56, it also causes the fixing block 56 and the slide rod 42 to move, allowing the slide rod 42 to extend and retract within the sliding sleeve frame 41. The guide post 67 and the guide groove 66 are slidably connected, allowing the internal threaded blocks 72 to slide by the double-threaded screw 71. When the slide rod 42 is locked to the locking frame 12, the internal threaded blocks 72 move closer to each other. Through the structural design of the connecting rod 62, the fixing block 56, and the slide rod 42, the slide rod 42 extends out of the sliding sleeve frame 41 and is inserted and fixed to the locking frame 12. When the slide rod 42 is unlocked from the locking frame 12, the internal threaded blocks 72 move further apart.

[0053] Example 6, based on any one of Examples 1 to 5, further defines the following: the locking frame 12 includes a card seat 43, a semi-circular hole 47 is provided in the card seat 43, two bolts 45 are fixed on the top of the base plate 46, a plurality of nuts 44 are threaded on the outer surface of the bolts 45, the card seat 43 is sleeved on the bolts 45, the nuts 44 are pressed and fixed with the card seat 43, the semi-circular hole 47 is provided in the card seat 43, and the slide rod 42 extends into the semi-circular hole 47 and abuts against the lower end wall of the semi-circular hole 47.

[0054] By adjusting the height of the nut 44, the height of the card holder 43 can be changed so that after the locking bracket 12 is installed on the external space work platform, the semi-circular hole 47 is aligned with the slide rod 42.

[0055] The base plate 46 is installed on the workbench in the external space. The AGV trolley is equipped with the scissor fork. After the AGV trolley moves between the workbench and the workbench, the scissor fork operates, driving the lifting platform 11 upward. When the sliding rod 42 is aligned with the semi-circular hole 47, the sliding rod 42 extends out of the sliding sleeve frame 41 and abuts against the semi-circular hole 47, allowing the lifting platform 11 to be relatively fixed relative to the locking frame 12 and the workbench. This prevents the hydraulic cylinder assembly of the scissor fork from being under constant force, keeping the lifting platform 11 and the platform 15 locked together. This is more conducive to the loading and unloading of goods, avoiding uneven pressure on the hydraulic cylinder assembly during loading and preventing overturning. Generally, a track is set on the lifting platform 11, and another AGV trolley that moves laterally is specified. After loading goods in the cargo transport area, the other AGV trolley returns to the lifting platform 11. Then, the sliding rod 42 disengages from the semi-circular hole 47, and the hydraulic cylinder assembly operates, driving the lifting platform 11 downward to reset. Afterward, the AGV trolley can move to other workstations.

[0056] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived without creative effort should be included within the scope of protection of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A scissor fork with mechanical limiting, comprising a platform (15) and a lifting platform (11), and further comprising a second bracket (14) and a first bracket (16) rotatably connected to each other, wherein a rotating seat (17) is rotatably connected to the left side of the first bracket (16) and the second bracket (14), and the rotating seat (17) is fixedly connected to the lifting platform (11) and the platform (15), characterized in that, The second bracket (14) and the first bracket (16) are connected to the platform (15) and the lifting platform (11) on the right side by a roller slide rail assembly. A hydraulic cylinder assembly is connected between the second bracket (14) and the first bracket (16). A sensor assembly for limiting and controlling the lifting height of the lifting platform (11) is provided between the platform (15) and the second bracket (14). A locking frame (12) is also included. A telescopic rod assembly that is locked and fixed to the locking frame (12) is fixed at the bottom of the lifting platform (11).

2. A scissor fork with mechanical limiting according to claim 1, characterized in that: The roller slide rail assembly includes a guide rail (13) fixed in the platform (15) and the lifting platform (11). There is one guide rail (13) at the front and one at the back. Rollers (39) are rotatably provided on one side of the second bracket (14) and the first bracket (16). The rollers (39) are in rolling engagement with the guide rail (13). The rollers (39) are provided on one side of the second bracket (14) and the first bracket (16) through a rotating shaft spacer structure.

3. A scissor fork with mechanical limiting according to claim 2, characterized in that: The rotating shaft spacer structure includes a first shaft (79), a first boss (74) fixed on one side of the first shaft (79), a first bushing (76) sleeved on the outer surface of the first shaft (79), a roller (39) rotatably disposed on the outer surface of the first bushing (76), the first boss (74) abutting against the first bushing (76) and the roller (39), a ball bearing (75) embedded at the end of the first shaft (79), and a first spacer (81) sleeved on the outer surface of the first shaft (79). Located within the second bracket (14) and the first bracket (16), a washer (78) is provided between the first spacer (81), the first bushing (76), and the roller (39). The washer (78) is sleeved on the outer surface of the first shaft (79). A first groove nut (82) is threaded onto the outer surface of the first shaft (79). A first through hole (83) is provided inside the first shaft (79). A first pin (84) is provided inside the first groove nut (82) and is inserted and fixed to the first through hole (83).

4. A scissor fork with mechanical limiting according to claim 1, characterized in that: The hydraulic cylinder assembly includes a first round tube (37) fixed between the second brackets (14) and a second round tube (31) fixed between the first brackets (16). A plurality of first cam plates (38) are fixed on the first round tube (37). A hydraulic cylinder (35) is rotatably mounted on one side of the first cam plate (38). A telescopic rod (34) is provided inside the hydraulic cylinder (35). A connecting block (32) is fixed at the end of the telescopic rod (34). A second cam plate (33) is fixed on one side of the second round tube (31). The second cam plate (33) is rotatably connected to the connecting block (32).

5. A scissor fork with mechanical limiting according to claim 4, characterized in that: It also includes a lubrication shaft assembly, which is disposed between the rotating seat (17) and the first bracket (16), between the second bracket (14) and the first bracket (16), between the second cam plate (33) and the connecting block (32), and between the first cam plate (38) and the hydraulic cylinder (35).

6. A scissor fork with mechanical limiting according to claim 5, characterized in that: The lubrication shaft assembly includes a second shaft (88), a second boss (95) fixed on one side of the second shaft (88), a second through hole (86) inside the second shaft (88), a second groove nut (87) threadedly connected to the end of the second shaft (88), a second pin (85) provided inside the second groove nut (87) and inserted and fixed to the second through hole (86), a first oil hole (92) inside the second shaft (88), a plurality of second oil holes (94) communicating with the outer surface of the second shaft (88) on one side of the first oil hole (92), and an oil plug (93) provided at the end of the first oil hole (92).

7. A scissor fork with mechanical limiting according to any one of claims 1-6, characterized in that: The sensor assembly includes a first infrared sensor (24) for transmitting the left extreme position signal of the second bracket (14), and also includes a pull-wire encoder (21) fixed to the bottom of the platform (15). The pull-wire encoder (21) has a pull-wire fixing bracket (22) fixed to its pull-wire end, and the pull-wire fixing bracket (22) is fixedly connected to the lifting platform (11).

8. A scissor fork with mechanical limiting according to any one of claims 1-6, characterized in that: The telescopic rod assembly includes a sliding sleeve frame (41) fixed to the bottom of the lifting platform (11). A telescopic sliding rod (42) is provided inside the sliding sleeve frame (41). An electronic limiting structure for electronically limiting the telescopic range of the sliding rod (42) is provided on one side of the sliding sleeve frame (41). A slider connecting rod structure that simultaneously drives the telescopic movement of the sliding rod (42) is provided at the bottom of the lifting platform (11). The sliding rod (42) is inserted and fixed into the semi-circular hole (47) in the locking frame (12).

9. A scissor fork with mechanical limiting according to claim 8, characterized in that: The electronic limiting structure includes a slide groove (54) opened in the slide sleeve frame (41), a nut (52) fixed on one side of the slide rod (42), the nut (52) slidingly abutting against the slide groove (54), a mounting plate (51) fixed on one side of the lifting platform (11), a mounting bracket (57) fixed on one side of the mounting plate (51), and a second infrared sensor (58) is provided in the mounting bracket (57) at the front and back.

10. A scissor fork with mechanical limiting according to claim 8, characterized in that: The slider-link structure includes a frame (65), within which a double-threaded screw (71) is rotatably mounted. The double-threaded screw (71) has threads with opposite directions of rotation, and internal thread blocks (72) are threadedly connected to the threads. Each internal thread block (72) has a connecting rod (62) rotatably mounted at the top and bottom. A fixing block (56) is fixed to one side of the slider (42), and the connecting rod (62) is rotatably connected to the fixing block (56). A reduction motor (63) for driving the double-threaded screw (71) to rotate is mounted on one side of the frame (65). Guide grooves (66) are provided on the upper and lower end faces of the frame (65), and guide posts (67) are fixed to the upper and lower sides of the internal thread block (72). The guide posts (67) slide against the guide grooves (66).

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