CN113800429B

CN113800429B - Multi-stage lifting device and lifting method for simultaneously lifting multiple turnover boxes

Info

Publication number: CN113800429B
Application number: CN202110959413.2A
Authority: CN
Inventors: 文东辉; 陈嘉琦; 胡振扬; 淦作昆
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2023-02-07
Anticipated expiration: 2041-08-20
Also published as: CN113800429A

Abstract

The invention belongs to the technical field of assembly line conveying, and particularly relates to a multi-stage lifting device and a lifting method for simultaneously lifting a plurality of turnover boxes, wherein the multi-stage lifting device comprises a lifter frame, a lifting platform and a winch, the lifter frame consists of a base, four guide posts and a top seat, and the four guide posts are parallel to each other and are vertically fixed between the base and the top seat to form a slide rail; the lifting platform comprises a platform frame, a guide mechanism, an unpowered roller set, a box blocking mechanism and a box body guide plate, wherein the box body guide plate is composed of a support plate and a plurality of convex pieces on the support plate. According to the multi-stage lifting device and the lifting method for simultaneously lifting a plurality of turnover boxes, the box body guide plate is used for shunting, the box blocking mechanism is used for blocking, shaping and orderly releasing, the platform frame and the unpowered roller set have inclination angles with the horizontal plane, and the winch is pulled up to control lifting, the guide posts and the guide wheels to guide, so that the lifting platform is adaptive to meet the requirements of simultaneously lifting, putting into a rack and descending a plurality of small and light-load turnover boxes.

Description

Multi-stage lifting device and lifting method for simultaneously lifting multiple turnover boxes

Technical Field

The invention belongs to the technical field of assembly line conveying, and particularly relates to a multi-stage lifting device and a multi-stage lifting method for simultaneous lifting of a plurality of turnover boxes.

Background

An in-line conveying apparatus is a machine that transports materials in a continuous manner. The material can be conveyed on a certain conveying line by using the in-line conveying equipment, and a material conveying flow path is formed from an initial feeding point to a final discharging point. The conveying device can be used for conveying both broken materials and finished articles. Besides pure material conveying, the device can also be matched with the requirements of the technological process in the production flow of each industrial enterprise to form a rhythmic line production conveying line. The conveying equipment is widely applied to various modern industrial enterprises.

In the field of material transfer, vertical conveyors are often used to lift material from a low level to a high level or to transfer material from a high level to a low level. For example, in the existing production line using small and light-duty turnover box transmission, a common small lifting device generally uses driving modes such as a chain, a gear and a winch to transfer objects to be lifted up and down. In the prior art, for example, patent document CN211920758U discloses a material lifting and conveying system, which comprises a lifting mechanism, a conveying hanger, a turning plate base station and a conveying box; the lifting mechanism is fixed near the material inlet and the material outlet of the spinning frame or the bobbin winder; a transportation hanging bracket is arranged at the top of the lifting mechanism; the lifting mechanism is internally connected with a liftable turning plate base platform, and a movable transport box is placed on the turning plate base platform. However, in the above-mentioned technology and prior art, the lifting efficiency of the lifting device adapted to the small-sized and light-load transfer box is slow, and the requirements for quick and continuous lifting cannot be satisfied.

In view of the above technical problems, it is desirable to improve.

Disclosure of Invention

Based on the defects in the prior art, the invention provides a multi-stage lifting device and a lifting method for simultaneously lifting a plurality of turnover boxes.

In order to achieve the purpose, the invention adopts the following technical scheme:

a multi-stage lifting device for simultaneously lifting a plurality of turnover boxes comprises a lifter frame, a lifting platform and a winch, wherein the lifter frame consists of a base, four guide posts and a top seat, the four guide posts are parallel to each other and are vertically fixed between the base and the top seat to form a slide rail; the lifting platform comprises a platform frame, a guide mechanism, an unpowered roller set, a box blocking mechanism and a box body guide plate, wherein the platform frame is connected in a sliding manner in a sliding rail through the guide mechanism, a lifting hook is arranged at the position of the platform frame, which is at the position of the center of gravity under the state of inclination with the horizontal plane, the unpowered roller set is connected and arranged in the platform frame and has an angle with the plane of the platform frame, and the box blocking mechanism is arranged at the outlet side of the platform frame and is used for blocking or releasing a turnover box which slides into the platform frame; a box body guide plate is arranged on the inlet side of the platform frame, and the box body guide plate is composed of a support plate and a plurality of convex sheets on the support plate; the winch is arranged on the top seat and connected with the lifting hook.

As preferred scheme, promote the platform still including pushing away the case mechanism, it includes pushes away case support, first cylinder, second cylinder, push pedal to push away the case mechanism, it erects on the platform frame to push away the case support, first cylinder arranges in pushing away case support bottom, the second cylinder arranges on first cylinder, receives first cylinder activity to drive up-and-down motion, the push pedal passes through the push rod and is connected with the second cylinder, receives second cylinder activity to drive seesaw.

As a preferred scheme, guide bearings are further vertically arranged on two sides of the box pushing support.

According to a preferable scheme, the box blocking mechanism comprises a blocking cross rod, three L-shaped swing rods and a third air cylinder, the blocking cross rod is transversely arranged on the outlet side of the platform frame, the L-shaped tops of the three L-shaped swing rods are connected to the two sides and the middle of the blocking cross rod in an arrayed mode, the bottoms of the L-shaped swing rods on the two sides are movably connected with the bottom side of the platform frame through shaft pins, one end of the third air cylinder is connected with the bottom of the platform frame through a connecting plate, and the other end of the third air cylinder is connected with the bottom of the L-shaped swing rod in the middle to push the L-shaped swing rods to move back and forth.

Preferably, when the third cylinder is located at the stroke end of the completion of the contraction, the blocking cross bar is driven by the L-shaped oscillating bar to descend to the position tangent to the plane formed by the upper surface of the integral roller.

As a preferred scheme, the blocking cross rod is connected with the three L-shaped swing rods in a sliding sleeve mode.

Preferably, the guide mechanism comprises two groups of guide structures arranged on two sides of the platform frame, each group of guide structures is provided with 4H-shaped guide wheels which are respectively distributed at the peripheral positions of the side surface of the platform frame and are positioned and fixed through a guide wheel mounting plate, and the guide wheel mounting plate is connected with the platform frame through bolts.

As a preferred scheme, the joints of the base, the footstock and the four guide posts are connected through positioning shaft heads in a positioning mode.

A lifting method of a multi-stage lifting device for simultaneously lifting a plurality of turnover boxes comprises the following steps:

s1, driving a lifting platform to lift by a poplarm, hovering an inlet side of a platform frame at the height of the inserted plane of a plurality of connected turnover boxes, and waiting for the plurality of turnover boxes to be inserted;

s2, enabling the multiple turnover boxes to simultaneously enter lifting platforms of respective areas through box body guide plates respectively, enabling the turnover boxes to slide in through unpowered roller sets with inclined angles by means of gravity, and simultaneously blocking and shaping the multiple turnover boxes by a box blocking mechanism;

s3, the lifting platform is driven to lift by the winding machine, the outlet side of the platform frame is suspended and supported at the height of the placed planes of the connected turnover boxes, and the turnover boxes in the platform to be lifted are placed out at the same time;

and S4, the box blocking mechanism acts to release the plurality of turnover boxes in the lifting platform, and the plurality of turnover boxes are arranged out in a sliding mode through the unpowered roller sets with the inclination angles by means of gravity to finish racking or descending.

Preferably, the lifting platform is provided with a box pushing mechanism, the box pushing mechanism is in a reset state before the plurality of turnover boxes are placed in the step S1, and the box pushing mechanism acts to push the plurality of turnover boxes while the plurality of turnover boxes are placed in a sliding manner to assist in placing the plurality of turnover boxes in the step S3.

Compared with the prior art, the invention has the beneficial effects that: according to the multi-stage lifting device and the lifting method for simultaneously lifting a plurality of turnover boxes, the box guide plates are used for shunting, the box blocking mechanism is used for blocking, shaping and orderly releasing, the platform frame and the unpowered roller set have inclination angles with the horizontal plane, the winch is pulled up to control lifting, the guide posts and the guide wheels to guide, so that the lifting platform can hover at any position in the stroke range, and the requirements of lifting, putting into a rack and descending when a plurality of small and light-load turnover boxes are used are met in a matching manner.

Drawings

Fig. 1 is a schematic overall structure diagram of a multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to a first embodiment of the invention;

fig. 2 is a schematic structural view of a lifting platform of the multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to the first embodiment of the invention;

fig. 3 is a schematic structural diagram of an unpowered roller set of the multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to the first embodiment of the invention;

fig. 4 is a schematic structural view of a box pushing mechanism of a multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to a first embodiment of the invention;

fig. 5 is a schematic structural view of a container blocking mechanism of a multi-stage lifting device for simultaneously lifting a plurality of turnover containers according to a first embodiment of the invention;

fig. 6 is a schematic diagram of a box body guide plate structure of a multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to a first embodiment of the invention;

fig. 7 is an enlarged structural schematic view of a connecting part of the top of a hoist frame of the multi-stage hoisting device for simultaneously lifting a plurality of turnover boxes according to the first embodiment of the invention;

fig. 8 is a schematic structural view of a positioning shaft head of the multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to the first embodiment of the invention;

wherein: 1. lifting the platform; 2. a guide mechanism; 3. a turnover box; 4. a hoist frame; 5. a winch; 11. a platform frame; 12. a box blocking mechanism; 13. an unpowered roller set; 14. a guide structure; 15. a box body guide plate; 16. a box pushing mechanism; 121.L-shaped oscillating bars; 122. a blocking rail; 123. a third cylinder; 151. a raised piece; 161. a guide bearing; 162. pushing the plate; 163. a first cylinder; 164. a second cylinder; 165. a box pushing bracket; 41. and positioning the shaft head.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention, the following description will explain specific embodiments of the present invention with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

The first embodiment is as follows:

as shown in fig. 1 to 8, the multi-stage lifting device for lifting a plurality of turnover boxes 3 simultaneously of the present embodiment is adapted to lifting, putting into a rack, and descending a plurality of small and light-load turnover boxes 3 simultaneously, and includes a lifter frame 4, a lifting platform 1, and a winch 5.

Specifically, the elevator frame 4 is composed of a base, four guide columns and a top seat, the base and the top seat are used as structural supports and are formed by welding a plurality of rectangular pipes, preferably, the bottom of the elevator is of an I-shaped structure and can be prevented from toppling over, all the rectangular pipes are matched with the installation direction according to the stress condition, the phenomenon that the cross beam generates excessive deflection under the stress condition is prevented to the maximum extent, the top of the elevator is of an H-shaped structure, the winch 5 is convenient to install, and the stress is stable; four guide posts are parallel to each other to vertically be fixed in and form the slide rail between base and the footstock, four guide posts act as stand again the load direction promptly, can select to use hollow steel tube welding to form, and preferably, four guide posts have the requirement of depth of parallelism when practical application, and the welding is carried out again after collocation location to location spindle nose 41 when the welding, guarantees the assembly precision so that the operation of device is more stable.

The lifting platform 1 is used for sliding in and out of the multiple turnover boxes 3 and driving the turnover boxes 3 to ascend and descend, is designed to accommodate the multiple turnover boxes 3 in parallel according to the size of the actual turnover box 3, is synchronously lifted and put in a frame, and comprises a platform frame 11, a guide mechanism 2, an unpowered roller group 13, a box blocking mechanism 12 and a box body guide plate 15.

The platform frame 11 is connected in a sliding rail formed by 4 guide posts in a sliding mode through the guide mechanism 2, so that the platform frame 11 can slide up and down in the sliding rail, the platform frame 11 is formed by integrally welding rectangular pipes, and plastic deformation is avoided and the weight is reduced as much as possible in the pulling-up process after bearing. The guide mechanism 2 comprises two groups of guide structures 14 arranged on two sides of the platform frame 11, each group of guide structures 14 is provided with 4H-shaped guide wheels, the guide wheels are respectively distributed at the positions around the side face of the platform frame 11 and are positioned and fixed through guide wheel mounting plates, the assembly precision is optimized, the guide wheel mounting plates are connected with the platform frame 11 through bolts, preferably, the H-shaped guide wheels and guide columns are in sliding fit with a preset gap, and the mechanism can be prevented from being locked due to the error of parallelism in the relative up-and-down movement process.

Platform frame 11 has arranged the lifting hook with the focus position department under the horizontal plane inclination state, links to each other with hoist engine 5 that the footstock arranged, and when the lifting hook was hung by hoist engine 5, platform frame 11 had certain inclination with the horizontal plane, does benefit to the roll-in of box, reduces the radial force that the guide post received simultaneously.

The unpowered roller set 13 is connected and arranged in the platform frame 11, the unpowered roller set 13 can be made of No. 12 channel steel and the unpowered roller set 13 with the diameter of phi 38, bearings are arranged in the rollers, the turnover box 3 makes rolling friction motion on the rollers, the unpowered roller set 13 is connected with the platform frame 11 through bolts and forms a certain angle with the horizontal plane, and the turnover box 3 can slide on the rollers by means of gravity.

A reject mechanism 12 is disposed at an outlet side of the platform frame 11 for rejecting or letting through the turnaround cases 3 slid into the platform frame 11. The structure design comprises a blocking cross rod 122, three L-shaped swing rods 121 and a third air cylinder 123, wherein the blocking cross rod 122 is transversely arranged on the outlet side of the platform frame 11 and used for blocking the box body in the lifting process to avoid dropping, and meanwhile, the box body freely rolls on the roller and then can automatically correct the direction after colliding with the blocking cross rod, so that the box body is tidy when sliding out of the platform. After the turnover box is lifted to a proper height, the blocking rod is removed, and the turnover box 3 can slide out; the top of the three L-shaped swing rods 121 are arranged and connected to two sides and the middle of the blocking cross rod 122, the bottoms of the L-shaped swing rods 121 on two sides are movably connected with the bottom side of the platform frame 11 through shaft pins for supporting the blocking cross rod 122 and the bottom of the L-shaped swing rod 122 to be rotatably movable relative to the platform frame 11, one end of the third cylinder 123 is connected with the bottom of the platform frame 11 through a connecting plate, the other end of the third cylinder is connected with the bottom of the L-shaped swing rod 121 in the middle to push the L-shaped swing rod 121 to move back and forth, when the L-shaped swing rod 121 in the middle is moved back and forth as a driving rod, the blocking cross rod 122 is transferred to the driven L-shaped swing rods 121 on two sides through the blocking cross rod 122, and further drives the blocking cross rod 122 to move up and down on the outlet side of the platform frame 11 under different telescopic strokes of the third cylinder 123, so as to block and release the turnover box 3.

The box body guide plate 15 is arranged on the inlet side of the platform frame 11 and is composed of a support plate and a plurality of convex pieces 151 on the support plate, a plurality of areas are divided by the guide plate and are adapted to the sliding-in of a plurality of small and light-load turnover boxes 3, and the guide turnover boxes 3 respectively enter the roller platforms in the respective areas to avoid the box clamping.

According to the multi-stage lifting device for simultaneously lifting the turnover boxes 3, the lifting platform 1 is lifted by the winch 5 at the top to control lifting, and is guided up and down by the four guide posts and the 8H-shaped guide wheels, so that the lifting platform can hover at any position in a stroke range, and the lifting platform is more excellent, the poplars have a power-off self-locking function, and can be locked after accidental power failure, so that the device is safer to use; the platform frame 11 and the unpowered roller group 13 have inclination angles with the horizontal plane, the box body can roll on the unpowered roller platform under the unpowered condition, the box blocking mechanism 12 is used for blocking, shaping and tidy passing, and the lifting, shelving and descending requirements of a plurality of small and light-load turnover boxes 3 can be met in a matched mode.

Further, the lifting platform 1 of the multi-stage lifting device for simultaneously lifting a plurality of turnover boxes 3 of the present embodiment is further provided with a box pushing mechanism 16 for assisting the turnover boxes 3 to be pushed away from the lifting platform 1 and put into the shelf. The box pushing mechanism 16 comprises a box pushing straight frame, a first air cylinder 163, a second air cylinder 164 and a pushing plate 162, wherein a box pushing support 165 is erected on the platform frame 11 and used for erecting the first air cylinder 163 and the second air cylinder 164 and reserving a passing space of the turnover box 3, the first air cylinder 163 is arranged at the bottom of the box pushing support 165, the second air cylinder 164 is arranged on the first air cylinder 163 and is driven by the first air cylinder 163 to move up and down, and the pushing plate 162 is connected with the second air cylinder 164 through a pushing rod and is driven by the second air cylinder 164 to move back and forth. Before the turnover box 3 enters the lifting platform 1, the first air cylinder 163 and the second air cylinder 164 are both in a contraction state, the lower space can be used for the turnover box 3 to pass through, when the turnover box 3 leaves the platform upper frame, the first air cylinder 163 is in an extension state, after the second air cylinder 164 descends, the second air cylinder 164 extends to push out the push rod, and the push plate 162 is driven to realize box pushing action. Preferably, in order to reduce the radial force applied to the push rod of the first cylinder 163 during the box pushing process, parallel guide bearings 161 are disposed on both sides for guiding and applying force, and the guide bearings 161 are designed as a set of back-to-back flange linear bearings matching with the linear optical axis. Further, the push rod of the first cylinder 163 is designed to be three-rod or multi-rod, and the first cylinder 163 is adapted to be a three-rod or multi-rod cylinder, so that the push of the push rod is more stable and durable.

s1, a lifting platform 1 is driven to lift by a winding machine 5, the inlet side of a platform frame 11 is suspended at the height of the plane where a plurality of connected turnover boxes 3 are placed, when the plurality of turnover boxes 3 are placed in the lifting platform 1 with a box pushing mechanism 16, the box pushing mechanism 16 is in a reset state, namely a first air cylinder 163 and a second air cylinder 164 are both in a contraction state, and the situation that the placement of the plurality of turnover boxes 3 is blocked is avoided;

s2, enabling a plurality of turnover boxes 3 to enter the lifting platforms 1 of respective areas through box body guide plates 15 respectively and simultaneously, enabling the turnover boxes to slide in through unpowered roller sets 13 with inclined angles by means of gravity, and simultaneously blocking and shaping the plurality of the turnover boxes 3 which slide in through a box blocking mechanism 12;

s3, the lifting platform 1 is driven to lift by the poplars 5, the outlet side of the platform frame 11 is suspended at the height of the placed planes of the connected turnover boxes 3, and the turnover boxes 3 in the platform 1 to be lifted are placed out at the same time;

and S4, the box blocking mechanism 12 acts to release the plurality of turnover boxes 3 in the lifting platform 1, the plurality of turnover boxes 3 are arranged in a sliding mode through the unpowered roller set 13 with the inclination angle by means of gravity, the lifting platform 1 with the box pushing mechanism 16 is arranged, when the plurality of turnover boxes 3 are arranged, the box pushing mechanism 16 acts to push the turnover boxes 3, namely the first air cylinder 163 and the second air cylinder 164 act, the pushing plate 162 pushes the turnover boxes 3 to assist in arranging the turnover boxes 3, and therefore the loading or descending is completed.

The multistage lifting device and the lifting method for simultaneously lifting the multiple turnover boxes of the embodiment are integrated, the multiple turnover boxes are simultaneously fed into the lifting platform, lifted/lowered and sent out of the lifting platform, the simultaneous lifting/lowering of the small-sized and light-load multiple turnover boxes of different sizes can be met, the structure is compact and efficient, the linkage is reasonable, the mechanism adaptability is strong, and the requirement that the turnover boxes need to be quickly and continuously lifted in the production line transmission process is met.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing has outlined rather broadly the preferred embodiments and principles of the present invention and it will be appreciated that those skilled in the art may devise variations of the present invention that are within the spirit and scope of the appended claims.

Claims

1. A multi-stage lifting device for simultaneously lifting a plurality of turnover boxes is characterized by comprising a lifter frame, a lifting platform and a winch, wherein the lifter frame consists of a base, four guide posts and a top seat, the four guide posts are parallel to each other and are vertically fixed between the base and the top seat to form a slide rail; the lifting platform comprises a platform frame, a guide mechanism, an unpowered roller set, a box blocking mechanism and a box body guide plate, wherein the platform frame is connected in a sliding way through the guide mechanism, a lifting hook is arranged at the position of the gravity center of the platform frame in a state of being inclined to the horizontal plane, the unpowered roller set is connected and arranged in the platform frame and is inclined to the plane of the platform frame at an angle, and the box blocking mechanism is arranged at the outlet side of the platform frame and is used for blocking or releasing a turnover box sliding into the platform frame; a box body guide plate is arranged on the inlet side of the platform frame, and the box body guide plate is composed of a support plate and a plurality of convex sheets on the support plate; the winch is arranged on the top seat and connected with the lifting hook;

the box blocking mechanism comprises a blocking cross rod, three L-shaped swing rods and a third air cylinder, the blocking cross rod is transversely arranged on the outlet side of the platform frame, the L-shaped tops of the three L-shaped swing rods are connected to the two sides and the middle of the blocking cross rod in an arrayed mode, the bottoms of the L-shaped swing rods on the two sides are movably connected with the bottom side of the platform frame through shaft pins, one end of the third air cylinder is connected with the bottom of the platform frame through a connecting plate, and the other end of the third air cylinder is connected with the bottom of the L-shaped swing rod in the middle to push the L-shaped swing rods to move back and forth.

2. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 1, wherein the lifting platform further comprises a box pushing mechanism, the box pushing mechanism comprises a box pushing support, a first air cylinder, a second air cylinder and a push plate, the box pushing support is erected on the platform frame, the first air cylinder is arranged at the bottom of the box pushing support, the second air cylinder is arranged on the first air cylinder and is driven by the movement of the first air cylinder to move up and down, and the push plate is connected with the second air cylinder through the push rod and is driven by the movement of the second air cylinder to move back and forth.

3. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 2, wherein guide bearings are further vertically arranged on two sides of the box pushing support.

4. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 1, wherein when the third cylinder is at the stroke end of completion of the shrinkage, the blocking cross bar is driven by the L-shaped swing rod to descend to a position tangent to the plane formed by the upper surface of the integral roller.

5. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 4, wherein the blocking cross bar is slidably sleeved with three L-shaped swing rods.

6. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 5, wherein the guiding mechanism comprises two sets of guiding structures disposed on both sides of the platform frame, each set of guiding structures has 4H-shaped guiding wheels, which are respectively disposed at the peripheral positions of the side surfaces of the platform frame and are fixed in position by guide wheel mounting plates, and the guide wheel mounting plates are connected with the platform frame by bolts.

7. The multi-stage lifting device for simultaneously lifting a plurality of turnover boxes according to claim 6, wherein joints of the base, the footstock and the four guide posts are connected in a positioning way through positioning shaft heads.

8. A lifting method of a multi-stage lifting device for the simultaneous lifting of a plurality of turnaround cases according to any one of claims 1 to 7, comprising the steps of:

s1, a hoisting machine drives a lifting platform to lift, the inlet side of a platform frame is suspended at the height of the plane where the connected turnover boxes are placed, and the turnover boxes are placed;

s2, enabling a plurality of turnover boxes to respectively enter lifting platforms of respective areas through box body guide plates at the same time, enabling the turnover boxes to slide in by virtue of gravity through unpowered roller sets with inclined angles, and simultaneously blocking and shaping the plurality of the turnover boxes which slide in by a box blocking mechanism;

s3, the lifting platform is driven to lift by the winch, the outlet side of the platform frame is suspended at the height of the placed planes of the connected transfer boxes, and the transfer boxes in the platform to be lifted are placed out at the same time;

9. The lifting method of the multi-stage lifting device for simultaneously lifting the multiple turnover boxes according to claim 8, wherein the lifting platform has a box pushing mechanism, in step S1, the box pushing mechanism is in a reset state before the multiple turnover boxes are put in, and in step S3, the box pushing mechanism is operated to push the multiple turnover boxes while the multiple turnover boxes are slid out, so as to assist in putting out the multiple turnover boxes.