Lifting device

Abstract

The present invention provides a lifting device for driving an upper bracket to lift relative to a base. The lifting device includes: a lifting mechanism, which is in a scissor structure and includes a plurality of lifting units hinged together and a limiting member provided on at least one of the lifting units. The upper end of the lifting mechanism is used to connect the upper bracket, and the lower end of the lifting mechanism is used to connect the base; a connecting arm, which is hinged to the lifting mechanism and can abut against the limiting member. An upper supporting portion is provided at one end of the connecting arm; a driving structure, which is connected to and drives the connecting arm to rotate; wherein, the driving structure can drive the connecting arm to rotate to a first position and a second position in sequence; when in the first position, the upper supporting portion abuts against the upper bracket upward, and when in the second position, the connecting arm abuts against the limiting member to drive the lifting unit to rotate. The present invention can optimize the lifting force required in the initial stage of the lifting device rising.

Description

Technical Field

[0001] The present invention relates to the field of mechanical structures, and particularly to a lifting device. Background Art

[0002] In some prior art scissor - type lifting devices, in order to make it easier to lift in the initial stage, a power - assist arm structure is adopted in the lifting device. A roller is provided at the lower end of the power - assist arm to contact the base, and with the support force of the base, it is convenient for the lifting device to rise. In this solution, the load borne by the roller end of the power - assist arm is borne by the base. During long - term use, the local part of the base is prone to deformation under the action of the load transmitted by the power - assist arm roller, thus affecting the stability of the entire base structure and further affecting the operation of structures such as the oil cylinder and the lifting device installed on the base. And because structures such as the lifting device and the oil cylinder are all installed on the base, it is also very difficult to carry out the maintenance work of the base. Summary of the Invention

[0003] The purpose of the present invention is to provide a lifting device to optimize the lifting force required in the initial stage of the lifting device rising without relying on the base for force augmentation.

[0004] To solve the above - mentioned technical problems, the present invention adopts the following technical solution: A lifting device for driving an upper bracket to lift relative to a base, the lifting device comprising: a lifting mechanism, which is in a scissor structure, including a plurality of lifting units hinged together and a limiting member provided on at least one of the lifting units, the upper end of the lifting mechanism is used to connect the upper bracket, and the lower end of the lifting mechanism is used to connect the base; a connecting arm, which is hinged to the lifting mechanism and can abut against the limiting member, and an upper supporting portion is provided at one end of the connecting arm; a driving structure, which is connected to and drives the connecting arm to rotate; wherein, the driving structure can drive the connecting arm to rotate to a first position and a second position in sequence; in the first position, the upper supporting portion abuts against the upper bracket upwards, and in the second position, the connecting arm abuts against the limiting member to drive the lifting unit to rotate.

[0005] In some embodiments, the connecting arm includes two connecting plates arranged in parallel at intervals and a connecting shaft connecting one ends of the two connecting plates; the driving structure is hinged to the connecting shaft.

[0006] In some embodiments, the upper supporting portion is the edge of the connecting plate.

[0007] In some embodiments, the connecting arm further includes a sleeve sleeved on the connecting shaft, and the upper supporting portion is provided on the outer periphery of the sleeve.

[0008] In some embodiments, the sleeve is fixedly connected to the connecting shaft by a fastener. The outer periphery of the sleeve protrudes from the upper supporting portion, and the upper supporting portion has an upper supporting surface in a plane. The upper supporting surface extends outward beyond the edge of the connecting plate and is used for planar contact with the upper bracket.

[0009] In some embodiments, the sleeve includes a sleeve body and a gasket detachably mounted on the outer periphery of the sleeve body, and the surface of the gasket forms the upper supporting surface.

[0010] In some embodiments, the sleeve is cylindrical and rotatably sleeved on the connecting shaft. The outer periphery of the sleeve extends beyond the edge of the connecting plate, or the outer periphery of the sleeve is flush with the edge of the connecting plate; the upper supporting portion is the outer peripheral surface of the sleeve.

[0011] In some embodiments, the driving structure includes a hydraulic cylinder. The upper end of the hydraulic cylinder is hinged to the connecting shaft, and the lower end of the hydraulic cylinder is hinged to the lower end of one of the lifting units.

[0012] In some embodiments, the number of the lifting units is two. The middle parts of the two lifting units are hinged by a hinge shaft, the connecting arm is hinged on the hinge shaft, the upper ends of the two lifting units are respectively connected to the upper bracket, and the lower ends of the two lifting units are respectively connected to the base.

[0013] In some embodiments, the lifting unit includes two legs arranged at intervals, and the limiting member connects the two legs of the lifting unit where it is located; the connecting arm is located between the two legs.

[0014] As can be seen from the above technical solutions, the present invention has at least the following advantages and positive effects: Different from the prior art in which the driving structure needs to rely on the supporting force of the base on the assisting arm to provide assistance at the beginning of lifting, in the lifting device of the present invention, when the driving structure drives the connecting arm to rotate to the first position at the beginning of lifting, the upper supporting portion of the connecting arm abuts against the upper bracket upward, changing the application point of the load of the upper bracket actually acting on the hinge shaft of the lifting mechanism, shortening the acting arm of the force of the load of the upper bracket on the hinge shaft of the lifting mechanism, so reducing the torque required to lift the upper bracket, and correspondingly also reducing the lifting force required for the driving structure to lift the upper bracket. Therefore, the driving structure can more easily break through the bottleneck position at the beginning of lifting and lift the upper bracket. This lifting device does not require the base to provide additional force at the initial stage of rising, will not generate additional load on the base and cause deformation of the base structure, and improves the structural stability of the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view of the lifting device according to the first embodiment of the present invention connected to the upper bracket.

[0016] Figure 2 is Figure 1 the three-dimensional exploded view of

[0017] Figure 3 is Figure 2 the structural diagram of the connecting arm in

[0018] Figure 4 is Figure 1 the schematic diagram of the lifting mechanism in the lifting device of in the retracted state.

[0019] Figure 5 is at Figure 4 the schematic diagram of the connecting arm rotated to the first position based on

[0020] Figure 6 is Figure 5 the partial enlarged view at A in

[0021] Figure 7 is at Figure 5 the schematic diagram of the connecting arm rotated to the second position based on

[0022] Figure 8 is Figure 1 the schematic diagram of the lifting mechanism in the lifting device of in the deployed state.

[0023] Figure 9 is the three-dimensional view of the lifting device of the second embodiment of the present invention connected to the upper bracket.

[0024] Figure 10 is the three-dimensional view of the lifting device of the third embodiment of the present invention connected to the upper bracket.

[0025] Figure 11 is Figure 10 the three-dimensional exploded view of the connecting arm in

[0026] Figure 12 is Figure 10 the schematic diagram of the connecting arm in the lifting device of located at the first position.

[0027] Figure 13 is Figure 10 the schematic diagram of the connecting arm in the lifting device of located at the second position.

[0028] The description of the reference numerals is as follows:

[0029] 100, lifting device;

[0030] 1. Lifting mechanism; 11. First lifting unit; 111. First leg; 1111. First hinge hole; 112. First lower mounting shaft; 113. Upper mounting shaft; 114. Mounting seat; 115. Upper slider; 12. Second lifting unit; 121. Second leg; 1211. Second hinge hole; 1212. Third hinge hole; 122. Second lower mounting shaft; 123. Support plate; 124. Lower slider; 13. Limiting member; 131. First limiting plate; 132. Second limiting plate; 14. Hinge shaft;

[0031] 2. Connecting arm; 21. Connecting plate; 211. Mounting hole; 212. Connecting hole; 213. Edge; 214. Extension end; 22. Connecting shaft; 23. Sleeve; 231. Sleeve body; 2311. Socket hole; 2312. Upper supporting part; 2313. Receiving groove; 232. Gasket; 2321. Upper supporting surface; 233. Fastening member; 234. Screw; 25. Fixed plate;

[0032] 3. Driving structure; 31. Hydraulic cylinder; 311. Cylinder block; 312. Piston rod;

[0033] 500. Upper bracket; 501. Contact plate. Detailed implementation manner

[0034] Typical implementation manners embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different implementation manners, all of which do not depart from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes and not for limiting the present invention.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0036] The present invention provides a lifting device for driving an upper bracket to lift relative to a base. This lifting device can be applied to various devices, for example, it can be used in vehicle lifting equipment.

[0037] First Embodiment:

[0038] Figure 1 Schematically shows the structure in which the lifting device 100 of this embodiment is connected to the upper bracket 500. Figure 2 Schematically shows Figure 1 exploded view of. As Figure 1 and Figure 2 shown, the lifting device 100 of this embodiment mainly includes a lifting mechanism 1, a connecting arm 2 hinged to the lifting mechanism 1, and a driving structure 3 that connects and drives the connecting arm 2 to rotate. The upper end of the lifting mechanism 1 is connected to the upper bracket 500, and the lower end of the lifting mechanism 1 is used to connect to a base (not shown in the figure). The driving structure 3 drives the lifting mechanism 1 to lift through the connecting arm 2, so as to drive the upper bracket 500 to lift relative to the base.

[0039] Specifically, the lifting mechanism 1 is in a scissor structure, including a first lifting unit 11 and a second lifting unit 12 hinged together, and a limiting member 13 provided on the second lifting unit 12. The middle parts of the first lifting unit 11 and the second lifting unit 12 are hinged by a hinge shaft 14, so that the first lifting unit 11 and the second lifting unit 12 can be converted between a retracted state and an extended state.

[0040] The first lifting unit 11 mainly includes two first legs 111 spaced apart from each other, a first lower mounting shaft 112 connected to the lower ends of the two first legs 111, and an upper mounting shaft 113 connected to the upper ends of the two first legs 111. The first legs 111, the first lower mounting shaft 112, and the upper mounting shaft 113 make the first lifting unit 11 form a frame structure that is generally rectangular.

[0041] The first legs 111 can be made of structures such as square tubes, channel steels, or plate splicing. A through first hinge hole 1111 is provided in the middle of each first leg 111, and the axes of the first hinge holes 1111 of the two first legs 111 are on the same straight line.

[0042] The first lower mounting shaft 112 is used to be hinged to the base. The two ends of the first lower mounting shaft 112 respectively extend outwards beyond the two first legs 111. Preferably in this embodiment, an installation seat 114 for installing the driving structure 3 is further provided on the first lower mounting shaft 112, and the installation seat 114 is located between the two first legs 111.

[0043] The upper mounting shaft 113 is used to connect the upper bracket 500. Both ends of the upper mounting shaft 113 extend outwards beyond the two first legs 111 respectively. Upper sliders 115 are respectively installed at both ends of the upper mounting shaft 113 for slidably connecting with the upper bracket 500.

[0044] The second lifting unit 12 includes two spaced second legs 121, a second lower mounting shaft 122 connected to the lower ends of the two second legs 121, and a support plate 123 connected to the upper ends of the two second legs 121. The second legs 121, the second lower mounting shaft 122 and the support plate 123 also form a generally rectangular frame structure.

[0045] The second legs 121 have a similar structure to the first legs 111. A through second hinge hole 1211 is provided in the middle of the second legs 121.

[0046] In this embodiment, the support plate 123 connects the upper ends of the two second legs 121 together to form an integral body. Third hinge holes 1212 are respectively provided at the upper ends of the two second legs 121 for hinging with the upper bracket 500. In other structures not shown, the upper ends of the two second legs 121 can also be connected by a shaft and hinged to the upper bracket 500 through the shaft.

[0047] The second lower mounting shaft 122 is used to connect the base. Both ends of the second lower mounting shaft 122 extend outwards beyond the two second legs 121 respectively. Lower sliders 124 are respectively installed at both ends of the second lower mounting shaft 122 for slidably connecting with the base.

[0048] The limiting member 13 connects the two second legs 121 of the second lifting unit 12. In this embodiment, the limiting member 13 includes a first limiting plate 131 and a second limiting plate 132. The first limiting plate 131 and the second limiting plate 132 are arranged staggeredly with respect to the second hinge hole 1211. In some other embodiments, the limiting member 13 can also only include the first limiting plate 131 or only include the second limiting plate 132.

[0049] The interval between the two second legs 121 of the second lifting unit 12 is smaller than the interval between the two first legs 111 of the first lifting unit 11, so that the two second legs 121 are installed between the two first legs 111. The second hinge hole 1211 of the second leg 121 communicates with the first hinge hole 1111 of the first leg 111 and is hinged through a hinge shaft 14. In the illustrated structure, the hinge shaft 14 is divided into two, and each hinge shaft 14 hinges a first leg 111 and a second leg 121 together, which is convenient for assembly. In other structures, the hinge shaft 14 can also be an integral shaft passing through the two first legs 111 and the two second legs 121 to form a hinge.

[0050] Refer to Figure 3 The connecting arm 2 includes two connecting plates 21 arranged in parallel at intervals and a connecting shaft 22 connecting one ends of the two connecting plates 21. In this embodiment, the connecting arm 2 further includes a sleeve 23 sleeved on the connecting shaft 22.

[0051] The connecting plate 21 is provided with a mounting hole 211 for hinging on the hinge shaft 14. One end of the connecting plate 21 is provided with a connecting hole 212 for connecting the connecting shaft 22. The edge 213 of this end of the connecting plate 21 is substantially a circular arc surface, and the central axis of the circular arc surface is on the same straight line as the axis of the connecting hole 212. The other end of the connecting plate 21 is formed as an extending end 214 extending from the mounting hole 211 in a direction away from the connecting hole 212.

[0052] Both ends of the connecting shaft 22 extend into the connecting holes 212 of the two connecting plates 21 respectively, and are fixedly connected to the connecting plates 21 by bolts (not labeled in the figure) passing through the sides of the connecting plates 21.

[0053] The sleeve 23 mainly includes a sleeve body 231 and a gasket 232 detachably mounted on the outer periphery of the sleeve body 231.

[0054] The sleeve body 231 is provided with a through socket hole 2311 for sleeving on the connecting shaft 22. The sleeve body 231 is fixedly connected to the connecting shaft 22 by fasteners 233 such as bolts. The outer periphery of the sleeve body 231 is provided with a protruding upper supporting portion 2312, and the upper supporting portion 2312 extends outward beyond the edge 213 of the connecting plate 21. The upper supporting portion 2312 is used for upward abutment against the upper bracket 500. The outer shape of the upper supporting portion 2312 is substantially rectangular, and its surface is provided with a receiving groove 2313.

[0055] The gasket 232 is installed in the receiving groove 2313 and fixed to the sleeve body 231 by screws 234. The surface of the gasket 232 forms a flat upper supporting surface 2321 to form a flat contact with the upper bracket 500. In this embodiment, the gasket 232 and the sleeve body 231 form a detachable connection, and the gasket 232 can be replaced at any time according to the usage situation. In other structures not shown, the receiving groove 2313 and the gasket 232 can also be cancelled, and the surface of the upper supporting portion 2312 is used as the upper supporting surface 2321.

[0056] Combined with Figure 1 The connecting arm 2 is entirely located between the two second legs 121 of the second lifting unit 12. The two connecting plates 21 of the connecting arm 2 are respectively opposite to the two second legs 121. The connecting plates 21 are hinged to the hinge shaft 14 through the mounting holes 211 provided thereon. When the connecting plate 21 rotates relative to the second lifting unit 12, the connecting plate 21 can abut against the limiting member 13. When the connecting arm 2 abuts against the limiting member 13, the lower end of the connecting arm 2 does not extend beyond the second leg 121.

[0057] Continue to refer to Figure 1 and Figure 2 , the driving structure 3 includes a hydraulic cylinder 31 and a corresponding hydraulic control system (not shown in the figure).

[0058] The hydraulic cylinder 31 includes a cylinder block 311 and a piston rod 312 nested inside the cylinder block 311. The hydraulic cylinder 31 is connected to the hydraulic control system through a hydraulic pipeline (not shown in the figure). The hydraulic pressure inside the cylinder block 311 is controlled by the hydraulic control system to control the telescopic movement of the piston rod 312 relative to the cylinder block 311.

[0059] In this embodiment, two hydraulic cylinders 31 are arranged in parallel. The lower ends of the cylinder blocks 311 of the two hydraulic cylinders 31 are hinged to the mounting seat 114 at the lower end of the first lifting unit 11, and the upper ends of the piston rods 312 of the two hydraulic cylinders 31 are hinged to the connecting shaft 22 of the connecting arm 2. The telescopic movement of the piston rod 312 relative to the cylinder block 311 can drive the connecting arm 2 to rotate relative to the hinge shaft 14. In this embodiment, the hydraulic cylinder 31 and the first lifting unit 11 are installed together to form an integral modular unit, which is convenient for the overall installation of the lifting device 100 on the base.

[0060] Based on the above introduction, the working principle of the lifting device 100 in this embodiment is as follows:

[0061] During use, the upper end of the lifting mechanism 1 is connected to the upper bracket 500, and the lower end of the lifting mechanism 1 is connected to the base. Specifically, the first lower mounting shaft 112 of the first lifting unit 11 is hinged to the base, and the upper mounting shaft 113 of the first lifting unit 11 is movably installed on the upper bracket 500 through the upper slider 115; the second lower mounting shaft 122 of the second lifting unit 12 is movably installed on the base through the lower slider 124, and the upper ends of the two second legs 121 of the second lifting unit 12 are hinged to the upper bracket 500.

[0062] Figure 1 and Figure 2 Although the structure of the upper bracket 500 is schematically shown in, the actual structural form of the upper bracket 500 is not limited to that shown in the figure. The base and the upper bracket 500 can be set with their respective structures according to the actual application scenarios. In order to cooperate with the installation of the lifting mechanism 1, the base and the upper bracket 500 are respectively provided with adapted installation structures. The structural forms of the installation structures are not limited, as long as they can form the above-mentioned cooperation relationship with the lifting mechanism 1. It should be particularly noted that the upper bracket 500 is provided with a contact plate 501 that can abut against the boosting arm of the lifting structure.

[0063] Refer to Figure 4, when the lifting mechanism 1 is in the retracted state, the first lifting unit 11 and the second lifting unit 12 are stacked together, and the piston rod 312 of the hydraulic cylinder 31 of the driving structure 3 is retracted into the cylinder body 311. At this time, the upper bracket 500 is in the lowest position, and the connecting arm 2 is in the initial position where it does not contact the upper bracket 500 or the limiting member 13.

[0064] When it is necessary to lift the upper bracket 500, the driving structure 3 is activated, the piston rod 312 of the hydraulic cylinder 31 extends, and the driving connecting arm 2 rotates from Figure 4 the initial position shown to Figure 5 the first position shown.

[0065] As shown in Figure 5 , in the first position, the upper supporting part 2312 of the connecting arm 2 just contacts the abutting plate 501 of the upper bracket 500, and the upper supporting part 2312 abuts against the upper bracket 500 upward. However, at this time, the lifting mechanism 1 is still in the retracted state, and the upper bracket 500 is still in the lowest position.

[0066] During the process of driving the connecting arm 2 to rotate from the initial position to the first position, neither the lifting mechanism 1 nor the upper bracket 500 moves. The hydraulic cylinder 31 only needs to drive the connecting arm 2 to rotate, and the pressure requirement for the hydraulic cylinder 31 is low. When the connecting arm 2 reaches the first position, the load of the upper bracket 500 is transmitted to the hinge shaft 14 of the lifting mechanism 1 through the abutting plate 501 and the upper supporting part 2312, and the hydraulic cylinder 31 starts to be stressed.

[0067] Referring to Figure 6 , at this time, the acting force arm L0 of the load F0 of the upper bracket 500 on the hinge shaft 14 is the horizontal connection distance between the center of the upper supporting part 2312 and the center of the hinge shaft 14, and the acting force arm L1 of the lifting force F1 of the hydraulic cylinder 31 on the hinge shaft 14 is the vertical distance between the center of the hinge shaft 14 and the central axis of the hydraulic cylinder 31, F1 = F0 × L0 / L1.

[0068] If there is no upper supporting part 2312 contacting the upper bracket 500, then at the same position, the acting force arm L2 of the load of the upper bracket 500 on the hinge shaft 14 will be the horizontal connection line between the center of the hinge shaft 14 and the rotation axis where the lower end of the first lifting unit 11 is hinged to the base. For the schematic diagram of the acting force arm L2, please refer to Figure 5 .

[0069] As can be seen from the comparison, since the upper supporting portion 2312 of the connecting arm 2 abuts upward against the upper bracket 500, the application point of the load of the upper bracket 500 acting on the hinge shaft 14 of the lifting mechanism 1 is changed. As a result, the acting force arm L0 of the load F0 of the upper bracket 500 on the hinge shaft 14 of the lifting mechanism 1 is much shorter than the acting force arm L2 when the upper supporting portion 2312 does not contact the upper bracket 500. This can greatly reduce the torque required to lift the upper bracket 500. Correspondingly, it also reduces the lifting force F1 required for the driving structure 3 to lift the upper bracket 500. Therefore, the driving structure 3 can more easily break through the bottleneck position at the beginning of lifting and lift the upper bracket 500.

[0070] In this embodiment, the upper supporting portion 2312 abuts against the abutting plate 501 of the upper bracket 500 through the upper supporting surface 2321 of the gasket 232. The upper supporting surface 2321 and the abutting plate 501 form a planar contact, which has a relatively large contact area and can disperse stress. At the same time, the gasket 232 is detachable from the sleeve body 231, and the gasket 232 can be conveniently replaced after wear.

[0071] Next, refer to Figure 7 , the piston rod 312 of the hydraulic cylinder 31 of the driving structure 3 further extends on the basis of Figure 5 shown, which can drive the connecting arm 2 to rotate from the Figure 5 shown first position to the Figure 7 shown second position.

[0072] During the process of the connecting arm 2 rotating from the first position to the second position, the upper supporting portion 2312 always keeps abutting against the upper bracket 500 through the gasket 232, driving the upper bracket 500 to rise slightly. At the same time, the connecting arm 2 further rotates relative to the second lifting unit 12. At the second position, the lower end of the connecting arm 2 abuts against the limiting member 13 located on the second lifting unit 12. Specifically, in this embodiment, one side edge of the connecting plate 21 abuts against the first limiting plate 131, and at the same time, one side edge of the extending end 214 abuts against the second limiting plate 132.

[0073] Comparatively refer to Figure 7 and Figure 4 , compared with the Figure 4 state, when the connecting arm 2 is in the Figure 7 shown second position, the central axis of the hydraulic cylinder 31 already has a large angle with the horizontal plane, and the hydraulic cylinder 31 has broken through the bottleneck position at the beginning of lifting. When the piston rod 312 of the hydraulic cylinder 31 continues to extend to drive the connecting arm 2 to rotate, the upper supporting portion 2312 of the connecting arm 2 separates from the upper bracket 500. Since the connecting arm 2 abuts against the limiting member 13, the connecting arm 2 can drive the second lifting unit 12 to rotate, and then the first lifting unit 11 and the second lifting unit 12 are gradually converted intoFigure 8 in the unfolded state shown, the upper bracket 500 is continuously lifted.

[0074] During the gradual unfolding of the first lifting unit 11 and the second lifting unit 12, the upper mounting shaft 113 of the first lifting unit 11 slides along the upper bracket 500, and the second lower mounting shaft 122 of the second lifting unit 12 slides along the base accordingly. When the upper bracket 500 reaches a predetermined height position, the sliding of the upper mounting shaft 113 and / or the second lower mounting shaft 122 can be restricted by setting a limiting structure on the base and / or the upper bracket 500, or other limiting means can be adopted to keep the position of the upper bracket 500 unchanged.

[0075] When it is necessary to lower the upper bracket 500, the hydraulic cylinder 31 is depressurized, and the load of the upper bracket 500 causes the piston rod 312 of the hydraulic cylinder 31 to slowly retract into the cylinder body 311. The first lifting unit 11 and the second lifting unit 12 rotate relative to each other until they are gradually retracted until they return to Figure 4 the retracted state shown.

[0076] In this embodiment, the case where the lifting mechanism 1 includes two lifting units, namely the first lifting unit 11 and the second lifting unit 12, is exemplarily introduced. The structure of the lifting mechanism 1 is relatively simple, the number of structural parts is small, and the assembly is convenient.

[0077] In other structures not shown, the lifting mechanism 1 may also include a greater number of lifting units. A plurality of lifting units are connected to form a scissor structure. A limiting member 13 can be provided on one of the lifting units, and the driving structure 3 and the connecting arm 2 are used to drive the lifting unit to rotate. Additionally, in some embodiments, the driving structure 3 and the connecting arm 2 can be provided in multiple groups, and correspondingly, limiting members 13 are provided on a plurality of lifting units. The driving structure 3 is connected to and drives the corresponding connecting arm 2 to rotate, and the connecting arm 2 drives the corresponding lifting unit to rotate.

[0078] Second Embodiment:

[0079] Referring to Figure 9 , the difference between the lifting device 100 of this embodiment and the first embodiment is that: in this embodiment, the limiting member of the lifting mechanism only includes the first limiting plate 131. Both ends of the first limiting plate 131 are respectively connected to the two second legs 121 of the second lifting unit 12, and both ends of the first limiting plate 131 have a greater width than the middle part thereof, so that it has a better connection strength with the second legs 121. It should be noted that Figure 9 in order to clearly show the structure of the connecting arm 2, only one leg of the first lifting unit 11 and the second lifting unit 12 is shown, and the other leg is omitted.

[0080] When the connecting arm 2 is driven by the driving structure 3 to rotate, the side edges of the two connecting plates 21 can abut against the first limiting plate 131 to drive the second lifting unit 12 to rotate, and then drive the first lifting unit 11 and the second lifting unit 12 to expand relatively. The connecting arm 2 further includes a fixing plate 25, and two ends of the fixing plate 25 are respectively connected to the extending ends 214 of the two connecting plates 21, so as to make the structure of the connecting arm 2 more stable.

[0081] In this embodiment, an upper supporting portion 2312 is also provided at one end of the connecting arm 2 connected to the driving structure 3. At the beginning of the lifting of the driving structure 3, the upper supporting portion 2312 abuts upward against the upper bracket 500 to facilitate the lifting in the initial stage of the ascent. For the specific working principle, refer to the first embodiment and no further details will be given.

[0082] Third Embodiment:

[0083] Refer to Figures 10 to 13 , the difference between the lifting device 100 of this embodiment and the first embodiment lies in the different structure of the connecting arm 2.

[0084] Mainly refer to Figure 11 , in this embodiment, the connecting arm 2 includes two connecting plates 21 arranged in parallel at intervals, a connecting shaft 22 connecting one ends of the two connecting plates 21, and a sleeve 23 sleeved on the connecting shaft 22. Among them, the sleeve 23 is in a cylindrical shape and is rotatably sleeved on the connecting shaft 22. The rotation axis of the sleeve 23 is also the central axis of the connecting shaft 22.

[0085] Combined with Figure 11 and Figure 12 , in this embodiment, the outer periphery of the sleeve 23 is substantially flush with the edge 213 of the connecting plate 21. When the connecting arm 2 is driven by the driving structure 3 to rotate to the first position, that is, the position shown in Figure 12 , the outer peripheral surface of the sleeve 23 abuts upward against the upper bracket 500, that is, the outer peripheral surface of the sleeve 23 forms an upper supporting portion for abutting against the upper bracket 500. By using the contact between the sleeve 23 and the upper bracket 500, the actual acting point of the load on the upper bracket 500 on the hinge shaft 14 can also be changed, so that the lifting force required by the driving structure 3 at the beginning of the lifting can be optimized, facilitating the lifting operation.

[0086] When the connecting arm 2 is driven by the driving structure 3 to rotate from the first position shown in Figure 12 to the second position shown in Figure 13 , the contact position between the sleeve 23 and the upper bracket 500 will change. Since the sleeve 23 can rotate, a rolling contact can be formed between the sleeve 23 and the upper bracket 500 to reduce the friction force. The connecting arm 2 is in Figure 13When in the second position shown, the lower end of the connecting arm 2 abuts against the limiting member 13 on the second lifting unit 12. Thus, when the driving structure 3 further drives the connecting arm 2 to rotate, the connecting arm 2 will drive the second lifting unit 12 to rotate together, and the sleeve 23 of the connecting arm 2 will be separated from the upper bracket 500.

[0087] In this embodiment, the sleeve 23 still abuts against the upper bracket 500. When the sleeve 23 is worn, the sleeve 23 can be replaced. In some embodiments, the outer periphery of the sleeve 23 can extend beyond the edge 213 of the connecting plate 21, so that there is a gap between the connecting plate 21 and the upper bracket 500, which better avoids the wear of the connecting plate 21. In addition, in some embodiments not shown, the sleeve 23 can also be considered to be cancelled, and the edge 213 of the connecting plate 21 is used as the upper supporting part to abut against the upper bracket 500 upwards. In this case, when the connecting plate 21 is worn, the connecting plate 21 can be replaced.

[0088] According to the introduction of the above-mentioned multiple embodiments, different from the prior art in which the driving structure needs to rely on the supporting force of the base for the assisting arm to provide assistance at the beginning of lifting, in the lifting devices of the embodiments of the present invention, when the driving structure drives the connecting arm to rotate to the first position at the beginning of lifting, the upper supporting part of the connecting arm abuts against the upper bracket upwards, changing the application point of the load of the upper bracket acting on the hinge axis of the lifting mechanism, shortening the acting arm of the force of the load of the upper bracket on the hinge axis of the lifting mechanism, so as to reduce the torque required to lift the upper bracket, and correspondingly also reduce the lifting force required for the driving structure to lift the upper bracket. Therefore, the driving structure is more likely to break through the bottleneck position at the beginning of lifting and lift the upper bracket. This lifting device does not require the base to provide additional force at the initial stage of rising, will not cause additional load on the base and cause deformation of the base structure, and improves the structural stability of the base.

[0089] Although the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are descriptive and exemplary, rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A lifting device for driving an upper bracket to lift relative to a base, characterized in that, The lifting device includes: A lifting mechanism, which is in a scissor structure, includes a plurality of lifting units hinged together and a limiting member provided on at least one of the lifting units. The upper end of the lifting mechanism is used to connect the upper bracket, and the lower end of the lifting mechanism is used to connect the base; A connecting arm, which is hinged to the lifting mechanism and can abut against the limiting member. One end of the connecting arm is provided with an upper supporting portion; the connecting arm includes two connecting plates arranged in parallel at intervals and a connecting shaft connecting one ends of the two connecting plates; the driving structure is hinged to the connecting shaft; the connecting arm further includes a sleeve detachably sleeved on the connecting shaft, and the outer periphery of the sleeve is provided with the upper supporting portion; the sleeve is connected and fixed to the connecting shaft through a fastener, and the outer periphery of the sleeve protrudes out of the upper supporting portion. The upper supporting portion has an upper supporting surface in a plane, and the upper supporting surface extends outward beyond the edge of the connecting plate and is used for making a planar contact with the upper bracket; A driving structure, which connects and drives the connecting arm to rotate; the driving structure includes a hydraulic cylinder, the upper end of the hydraulic cylinder is hinged to the connecting shaft, and the lower end of the hydraulic cylinder is hinged to the lower end of one of the lifting units; Wherein, the driving structure can drive the connecting arm to rotate to a first position and a second position in sequence; in the first position, the upper supporting portion abuts against the upper bracket upward, and in the second position, the connecting arm abuts against the limiting member to drive the lifting unit to rotate.

2. A lifting device for driving an upper bracket to lift relative to a base, characterized in that, The lifting device includes: A lifting mechanism, which is in a scissor structure, includes a plurality of lifting units hinged together and a limiting member provided on at least one of the lifting units. The upper end of the lifting mechanism is used to connect the upper bracket, and the lower end of the lifting mechanism is used to connect the base; A connecting arm, which is hinged to the lifting mechanism and can abut against the limiting member. One end of the connecting arm is provided with an upper supporting portion; the connecting arm includes two connecting plates arranged in parallel at intervals and a connecting shaft connecting one ends of the two connecting plates; the driving structure is hinged to the connecting shaft; the connecting arm further includes a sleeve detachably sleeved on the connecting shaft, and the outer periphery of the sleeve is provided with the upper supporting portion; the sleeve is in a cylindrical shape and is rotatably sleeved on the connecting shaft. The outer periphery of the sleeve extends beyond the edge of the connecting plate, or the outer periphery of the sleeve is flush with the edge of the connecting plate; the upper supporting portion is the outer peripheral surface of the sleeve; A driving structure, which connects and drives the connecting arm to rotate; the driving structure includes a hydraulic cylinder, the upper end of the hydraulic cylinder is hinged to the connecting shaft, and the lower end of the hydraulic cylinder is hinged to the lower end of one of the lifting units; Wherein, the driving structure can drive the connecting arm to rotate to a first position and a second position in sequence; in the first position, the upper supporting portion abuts against the upper bracket upward, and in the second position, the connecting arm abuts against the limiting member to drive the lifting unit to rotate.

3. The lifting device according to claim 1 or 2, characterized in that, The upper supporting portion is the edge of the connecting plate.

4. The lifting device according to claim 1, characterized in that, The sleeve includes a sleeve body and a gasket detachably installed on the outer periphery of the sleeve body, and the surface of the gasket forms the upper supporting surface.

5. The lifting device according to any one of claims 1 or 2, characterized in that The number of the lifting units is two. The middle parts of the two lifting units are hinged by a hinge shaft, the connecting arm is hinged on the hinge shaft, the upper ends of the two lifting units are respectively connected to the upper bracket, and the lower ends of the two lifting units are respectively connected to the base.

6. The lifting device according to any one of claims 1 or 2, characterized in that The lifting unit includes two legs arranged at intervals, the limiting member is connected to the two legs of the lifting unit where it is located; the connecting arm is located between the two legs.

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