Tray stacking and unstacking method
Technical Field
The invention relates to the field of tray stacking equipment, in particular to a tray stacking and unstacking method.
Background
Pallets are horizontal platform devices used for containerization, stacking, handling and transportation to place goods and articles as unit loads. The pallet is used as important loading, unloading, storing and transporting equipment in the logistics operation process, and plays a great role in modern logistics in cooperation with a forklift.
At present, the tray is widely applied in the conveying line field. The trays must be stacked after being used, otherwise, the conveying line is messy on site, the working efficiency is influenced, and safety accidents are easily caused. And when in use, the piled trays must be unstacked. And present pile up neatly and break a jam all rely on fork truck to accomplish, break a jam with the tray of fork truck on with the tray frame or pile up the tray on the tray frame, produced the factory building that is used for parking fork truck again like this, purchase fork truck moreover and be expensive, maintain also inconvenient.
A device for stacking and unstacking trays, which is disclosed by the patent No. CN104129653B, comprises a tray conveying line arranged in a frame, mounting bottom plates are fixed on the frames at two sides of the tray conveying line, mounting upright columns are fixed on the mounting bottom plates, mounting top plates are fixed at the top ends of the mounting upright columns, guide columns are fixed on the mounting bottom plates and the mounting top plates, lifting plates are slidably mounted on the guide columns, driven chain wheels are rotatably mounted on the lower surfaces of the mounting top plates, lifting motors are fixed on the frame, driving chain wheels are fixed on output shafts of the lifting motors, lifting chains are arranged on the driving chain wheels and the driven chain wheels, connecting pieces are fixed on the lifting chains, and the connecting pieces are fixed with the lifting plates; an inserting plate cylinder is fixed on the lifting plate, and an inserting plate is fixed at the end part of a piston rod of the inserting plate cylinder. The invention can realize the unstacking and stacking of the trays, but only can unstack and stack the trays of one size. The invention can move the tray in the vertical direction, but still needs workers to manually move the lowest shelf out, and the automation rate is not high.
Disclosure of Invention
The invention aims to provide a tray stacking and unstacking method to solve the problems in the background technology.
The invention provides a method for stacking and unstacking trays, which is realized based on an unstacking device, the unstacking device comprises a tray conveying mechanism, a tray stacking mechanism and a tray lifting mechanism, wherein the tray conveying mechanism is provided with a plurality of positioning mechanisms which are arranged at equal intervals, a first limiting mechanism is arranged at the blanking end of the tray conveying mechanism, a U-shaped bracket is arranged right below the center of the tray conveying mechanism, the U-shaped bracket is provided with a second limiting mechanism, the tray lifting mechanism is positioned below the top of the tray conveying mechanism, the tray stacking mechanism comprises a portal frame, two lifting components and two tray fixing components, the portal frame is erected on the tray conveying mechanism, the two lifting components are symmetrically installed on the portal frame, the two tray fixing components are respectively fixed on the two lifting components, and the side of the tray conveying mechanism is further provided with a tray transferring conveyor belt butted with the tray conveying conveyor belt.
The unstacking method comprises the following steps:
(1) the pallets are sequentially placed on a pallet conveying mechanism, and the pallet conveying mechanism can sequentially convey the pallets to the position right below the portal frame;
(2) in the conveying process, all the first electric push rods can drive the positioning plates to drive the positioning frames and the positioning wheels to move, so that the positioning wheels can position two sides of the tray, and the first limiting mechanism and the second limiting mechanism can limit the position of the tray being conveyed so as to avoid disorder of the tray;
(3) the lifting cylinder can drive the lifting cylinder to drive the lifting plate to lift, the lifting plate can lift the trays on the tray conveying mechanism to lift and lift all the trays right above the trays, then the two tray fixing assemblies fix all the trays so as to complete stacking, and the stacked trays are conveyed onto the transfer conveyor belt from the tray conveying mechanism, so that a forklift can conveniently carry the stacked trays away, and the portal frame is prevented from being damaged by the forklift;
(3) the lifting cylinder drives the lifting plate to support all the trays, then the two tray fixing assemblies support the penultimate tray from bottom to top, the tray at the bottom can be supported by the lifting plate, then the lifting cylinder drives the tray to abut against the tray conveying mechanism, and the tray conveying mechanism conveys the tray out.
Further, tray conveying mechanism includes carriage, servo motor, first sprocket, second sprocket and two conveyer belts, the last rotation of carriage is installed a plurality of and is the rotation roller that equidistant setting, two the conveyer belt symmetry cover is established on all rotation rollers, the second sprocket is installed on one of them rotation roller, servo motor is located the second sprocket under, first sprocket is installed on servo motor's output, first sprocket and second sprocket pass through chain drive and connect.
Furthermore, the positioning mechanism comprises a U-shaped first mounting plate and two positioning components symmetrically arranged on the first mounting plate, the first mounting plate is arranged on the conveying bracket, the positioning assembly comprises a first electric push rod, a mounting frame and an L-shaped positioning plate, the mounting frame is arranged on the side wall of the positioning plate close to the top, two symmetrically arranged rotating shafts are rotatably arranged in the mounting frame, each rotating shaft is provided with a positioning wheel which is in rotating fit with the rotating shaft, the first electric push rod is arranged on the first mounting plate, the output end of the first electric push rod penetrates through the first mounting plate, the positioning plate is mounted on the output end of the first electric push rod, the positioning plate is provided with two first guide rods which are symmetrically arranged, and the first mounting plate is provided with two first guide seats which are in one-to-one sliding fit with the two first guide rods.
Further, first stop gear is the same with second stop gear's structure, first stop gear includes second electric putter, limiting plate and the second mounting panel that is the T type, first stop gear's second mounting panel is installed on the carriage, second stop gear's second mounting panel is installed on U type support, second electric putter is the vertical one end of installing at the second mounting panel to second electric putter's output sets up, and the other end of second mounting panel is equipped with the slide rail that two symmetries set up, set up two and two slide rail one-to-one sliding fit's spout on the limiting plate, be equipped with the connecting plate that is the level setting on the limiting plate, second electric putter's output is connected with the bottom of connecting plate.
Furthermore, the lifting assembly comprises a lifting component and a driving component, the lifting component is installed on the side wall of the portal frame, the driving component is installed at the top of the portal frame, and the driving component is in transmission connection with the lifting component.
Further, the lifting component includes two gears and two draw bars, be equipped with two symmetries on the inner wall of portal frame and set up and all with draw bar sliding fit's slide, two draw bars are installed respectively on two slides, two square holes with two draw bar one-to-ones are seted up at the top of portal frame, be equipped with the rotation seat that two symmetries set up on the outer wall of portal frame to two rotate the seat and be located between two slides, all be equipped with in every rotation seat rather than normal running fit's drive shaft, every drive shaft all runs through the portal frame lateral wall, and two gears are installed respectively in two drive shafts, and two gears mesh mutually, set up the window that supplies the gear to pass on every slide is close to the one end lateral wall at its top, and the one end of every draw bar is all seted up and is equidistant setting and with gear engagement's tooth's socket.
Furthermore, the driving part comprises a driving motor and a third chain wheel, the driving motor is installed at the top of the portal frame, the third chain wheel is installed at the output end of the driving motor, a fourth chain wheel is installed on one of the driving shafts, and the third chain wheel is in transmission connection with the fourth chain wheel through a chain.
Further, the tray fixing assembly comprises an installation block, a third electric push rod and a pressing and aligning plate, the installation block is horizontally installed on the two sliding strips, the third electric push rod is installed at the top of the installation block, the pressing and aligning plate is vertically installed at the output end of the third electric push rod, two second guide rods symmetrically arranged are arranged on the rear side wall of the pressing and aligning plate, two guide grooves which are in one-to-one sliding fit with the two second guide rods are formed in the installation block, and two inserting plates which are symmetrically arranged and are horizontally arranged are arranged on the front side wall of the pressing and aligning plate.
Further, the tray lifting mechanism comprises a lifting cylinder and a lifting plate, the lifting cylinder is vertically installed on the ground, the lifting plate is horizontally installed at the output end of the lifting cylinder, four third guide rods which are distributed in a rectangular shape are arranged at the bottom of the lifting plate, and four second guide seats which are in one-to-one sliding fit with the four third guide rods are arranged on the ground.
Compared with the prior art, the invention has the beneficial effects that:
firstly, the trays can be sequentially conveyed to the position under the portal frame through the tray conveying mechanism, the two sides of the trays can be positioned through all the positioning mechanisms, the trays are prevented from inclining, the positions of the trays can be limited through the first limiting mechanism and the second limiting mechanism, the trays on the tray conveying mechanism can be lifted through the tray lifting mechanism, and then the trays are stacked or unstacked through the matching of the two lifting assemblies and the two tray fixing assemblies.
Secondly, the positioning plate can be driven to move through the first electric push rod, and the positioning plate drives the positioning frame and the positioning wheels to move, so that the positioning wheels can position one side of the tray, and the tray positioning device can be suitable for positioning trays with various sizes.
Thirdly, the two driving motors respectively drive the corresponding fourth chain wheels to rotate, the fourth chain wheels drive the corresponding driving shafts and the corresponding gears to rotate together around the axes of the driving shafts, the gears drive the other gears to rotate reversely, the two gears respectively drive the corresponding racks to lift, then the third electric push rods on the two tray fixing assemblies drive the pressing and aligning plates to move, the pressing and aligning plates can press and align the edges of the trays at the lowest end, the two inserting plates on the pressing and aligning plates can be just inserted into the trays at the lowest end, and one end of each tray can be synchronously lifted with the two inserting plates.
Fourthly, the lifting plate can be driven to lift through the lifting cylinder, the lifting plate can lift the trays on the tray conveying mechanism and lift all the trays right above the trays, then the two tray fixing assemblies fix all the trays so as to complete stacking, when unstacking is carried out, the lifting cylinder drives the lifting plate to support all the trays, then the two tray fixing assemblies support the penultimate tray from bottom to top, the tray at the bottommost end can be supported by the lifting plate, then the lifting cylinder drives the tray to abut against the tray conveying mechanism, and the tray conveying mechanism conveys the tray without moving out of a worker.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic view of a first angular perspective structure of the present invention;
FIG. 2 is a schematic view of a second angular perspective structure according to the present invention;
FIG. 3 is a third perspective view of the present invention;
FIG. 4 is an enlarged view taken at A in FIG. 3;
FIG. 5 is a schematic view of a first angular perspective of the tray palletizer mechanism;
FIG. 6 is an enlarged view at B in FIG. 5;
FIG. 7 is an enlarged view at C of FIG. 5;
FIG. 8 is a second angular perspective view of the tray stacking mechanism;
FIG. 9 is an enlarged view at D of FIG. 8;
FIG. 10 is a partial schematic view of the present invention;
reference numerals: a tray conveying mechanism 1, a conveying bracket 1a, a servo motor 1b, a first chain wheel 1c, a second chain wheel 1d, a conveying belt 1e, a rotating roller shaft 1f, a tray stacking mechanism 2, a portal frame 2a, a sliding seat 2a1, a window 2a2, a square hole 2a3, a rotating seat 2a4, a driving shaft 2a5, a fourth chain wheel 2a6, a lifting component 2b1, a gear 2b1a, a sliding bar 2b1b, a tooth groove 2b1c, a driving component 2b2, a driving motor 2b2a, a third chain wheel 2b2b, a tray fixing component 2c, a mounting block 2c1, a third electric push rod 2c2, a pressing alignment plate 2c 8, a second guide rod 2c4, an insertion plate 2c5, a tray lifting mechanism 3, a lifting cylinder 3a, a lifting plate 3b, a third guide rod 3b, a second guide rod 364, a first electric push rod 6864, a first positioning seat 364 and a positioning mechanism, installing frame 4c, locating wheel 4c1, locating plate 4d, first guide bar 4d1, first stop gear 5, second electric putter 5a, limiting plate 5b, spout 5b1, connecting plate 5b2, second mounting panel 5c, slide rail 5c1, U type support 6, second stop gear 7, tray transfer conveyer 8.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.
The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
As shown in fig. 1 to 10, an embodiment of the present invention provides a method for stacking and unstacking trays, which is implemented based on an unstacking device, and the device includes a tray conveying mechanism 1, a tray stacking mechanism 2 and a tray lifting mechanism 3, wherein the tray conveying mechanism 1 is provided with a plurality of positioning mechanisms 4 arranged at equal intervals, a first limiting mechanism 5 is arranged at a blanking end of the tray conveying mechanism 1, a U-shaped bracket 6 is arranged right below a center of the tray conveying mechanism 1, the U-shaped bracket 6 is provided with a second limiting mechanism 7, the tray lifting mechanism 3 is located below a top of the tray conveying mechanism 1, the tray stacking mechanism 2 includes a portal frame 2a, two lifting assemblies 2b and two tray fixing assemblies 2c, the portal frame 2a is erected on the tray conveying mechanism 1, the two lifting assemblies 2b are symmetrically installed on the portal frame 2a, two the fixed subassembly of tray 2c is fixed respectively on two elevating system 2b, the side of tray conveying mechanism 1 still is equipped with rather than the tray transfer conveyer belt 8 of butt joint.
Specifically, as shown in fig. 2 and 3, fig. 2 is a schematic diagram of a second angle solid structure of the present invention, and fig. 3 is a schematic diagram of a third angle solid structure of the present invention; the tray conveying mechanism 1 comprises a conveying support 1a, a servo motor 1b, a first chain wheel 1c, a second chain wheel 1d and two conveying belts 1e, wherein a plurality of rotating roller shafts 1f which are arranged at equal intervals are rotatably arranged on the conveying support 1a, the two conveying belts 1e are symmetrically sleeved on all the rotating roller shafts 1f, the second chain wheel 1d is arranged on one rotating roller shaft 1f, the servo motor 1b is positioned right below the second chain wheel 1d, the first chain wheel 1c is arranged at the output end of the servo motor 1b, and the first chain wheel 1c is in chain transmission connection with the second chain wheel 1 d; servo motor 1b drives first sprocket 1c and rotates, and first sprocket 1c drives second sprocket 1d through the chain and rotates, and second sprocket 1d drives corresponding live-rollers 1f and rotates singly, and live-rollers 1f drives two conveyer belts 1e and rotates in step, and two conveyer belts 1e can carry the tray and remove.
Specifically, as shown in fig. 2 and 3, fig. 2 is a schematic diagram of a second angle solid structure of the present invention, and fig. 3 is a schematic diagram of a third angle solid structure of the present invention; the positioning mechanism 4 comprises a first mounting plate 4a in a U shape and two positioning components symmetrically arranged on the first mounting plate 4a, the first mounting plate 4a is mounted on the conveying support 1a, the positioning components comprise a first electric push rod 4b, a mounting frame 4c and a positioning plate 4d in an L shape, the mounting frame 4c is mounted on the side wall of the positioning plate 4d close to the top, two rotating shafts symmetrically arranged are rotatably mounted in the mounting frame 4c, a positioning wheel 4c1 in rotating fit with each rotating shaft is arranged on each rotating shaft, the first electric push rod 4b is mounted on the first mounting plate 4a, the output end of the first electric push rod 4b penetrates through the first mounting plate 4a, the positioning plate 4d is mounted on the output end of the first electric push rod 4b, and two first guide rods 4d1 symmetrically arranged are arranged on the positioning plate 4d, the first mounting plate 4a is provided with two first guide seats 4a1 which are in one-to-one sliding fit with the two first guide rods 4d 1; first electric putter 4b can drive the removal of locating plate 4d, and locating plate 4d drives locating frame and locating wheel 4c1 and moves to let locating wheel 4c1 can fix a position one side of tray, and can be applicable to the tray of multiple type size and fix a position, locating plate 4d can be guaranteed throughout to the cooperation of first guide bar 4d1 with first guide holder 4a 1.
Specifically, as shown in fig. 4 and 10, fig. 4 is an enlarged view of a portion a in fig. 3, and fig. 10 is a partial schematic view of the present invention; the first limiting mechanism 5 and the second limiting mechanism 7 have the same structure, the first limiting mechanism 5 comprises a second electric push rod 5a, a limiting plate 5b and a T-shaped second mounting plate 5c, the second mounting plate 5c of the first limiting mechanism 5 is arranged on the conveying bracket 1a, the second mounting plate 5c of the second limiting mechanism 7 is arranged on the U-shaped bracket 6, the second electric push rod 5a is vertically arranged at one end of the second mounting plate 5c, the output end of the second electric push rod 5a is arranged upwards, the other end of the second mounting plate 5c is provided with two symmetrically arranged slide rails 5c1, the limiting plate 5b is provided with two sliding grooves 5b1 which are in one-to-one sliding fit with the two sliding rails 5c1, the limiting plate 5b is provided with a connecting plate 5b2 which is horizontally arranged, and the output end of the second electric push rod 5a is connected with the bottom of the connecting plate 5b 2; second electric putter 5a drive connecting plate 5b2 goes up and down, and connecting plate 5b2 drives limiting plate 5b and goes up and down, and limiting plate 5b can be outstanding two conveyer belts 1e and carry on spacingly to the tray on it, and the cooperation of spout 5b1 and slide rail 5c1 can guarantee that limiting plate 5b keeps vertical state and goes up and down.
Specifically, as shown in fig. 5 and 6, fig. 5 is a schematic view of a first angular perspective structure of the tray palletizing mechanism, and fig. 6 is an enlarged view at B in fig. 5; the lifting assembly 2b comprises a lifting part 2b1 and a driving part 2b2, the lifting part 2b1 is installed on the side wall of the gantry 2a, the driving part 2b2 is installed at the top of the gantry 2a, and the driving part 2b2 is in transmission connection with the lifting part 2b 1; the driving component 2b2 can drive the lifting component 2b1 to lift, and the lifting component 2b1 drives the tray fixing component 2c to lift synchronously.
Specifically, as shown in fig. 5 to 9, fig. 5 is a schematic view of a first angular perspective structure of the tray palletizing mechanism, fig. 6 is an enlarged view at B in fig. 5, fig. 7 is an enlarged view at C in fig. 5, fig. 8 is a schematic view of a second angular perspective structure of the tray palletizing mechanism, and fig. 9 is an enlarged view at D in fig. 8; the lifting component 2b1 comprises two gears 2b1a and two sliding bars 2b1b, two sliding seats 2a1 which are symmetrically arranged and are in sliding fit with the sliding bars 2b1b are arranged on the inner wall of the portal frame 2a, the two sliding bars 2b1b are respectively installed on the two sliding seats 2a1, two square holes 2a3 corresponding to the two sliding bars 2b1b one by one are formed in the top of the portal frame 2a, two rotating seats 2a4 which are symmetrically arranged are arranged on the outer wall of the portal frame 2a, the two rotating seats 2a4 are positioned between the two sliding seats 2a1, a driving shaft 2a5 which is in rotating fit with the driving seats is arranged in each rotating seat 2a4, each driving shaft 2a5 penetrates through the side wall of the portal frame 2a, the two gears 2b1a are respectively installed on the two driving shafts 2a5, the two gears 2b1a are meshed, a window 462 a2 for the gear 2a a to pass through is formed in one side wall of one end of each sliding seat 2a1 close to the top of the sliding seat, one end of each sliding strip 2b1b is provided with tooth grooves 2b1c which are arranged at equal intervals and meshed with the gear 2b1 a; the driving part 2b2 drives a driving shaft 2a5 to rotate around the axis of the driving shaft 2a5, the gear 2b1a on the driving shaft 2a5 rotates along with the driving shaft, the gear 2b1a drives another gear 2b1a and the driving shaft 2a5 to rotate reversely, the two gears 2b1a respectively drive the two sliding bars 2b1b to lift in the corresponding sliding seat 2a1, and the window 2a2 can facilitate the gear 2b1a to enter the sliding seat 2a1 to be meshed with the toothed groove 2b1 c.
Specifically, as shown in fig. 5 to 9, fig. 5 is a schematic view of a first angular perspective structure of the tray palletizing mechanism, fig. 6 is an enlarged view at B in fig. 5, fig. 7 is an enlarged view at C in fig. 5, fig. 8 is a schematic view of a second angular perspective structure of the tray palletizing mechanism, and fig. 9 is an enlarged view at D in fig. 8; the driving part 2b2 comprises a driving motor 2b2a and a third chain wheel 2b2b, the driving motor 2b2a is installed at the top of the portal frame 2a, the third chain wheel 2b2b is installed at the output end of the driving motor 2b2a, a fourth chain wheel 2a6 is installed on one driving shaft 2a5, and the third chain wheel 2b2b is connected with the fourth chain wheel 2a6 through chain transmission; the driving motor 2b2a drives the third chain wheel 2b2b to rotate, the third chain wheel 2b2b drives the fourth chain wheel 2a6 to rotate through a chain, and the fourth chain wheel 2a6 drives a driving shaft 2a5 to rotate around the axis of the driving shaft 2a 5.
Specifically, as shown in fig. 5 and 7, fig. 5 is a schematic view of a first angular perspective structure of the tray palletizing mechanism, and fig. 7 is an enlarged view at C in fig. 5; the tray fixing assembly 2c comprises a mounting block 2c1, a third electric push rod 2c2 and a leveling plate 2c3, the mounting block 2c1 is horizontally mounted on two sliding bars 2b1b, the third electric push rod 2c2 is mounted at the top of the mounting block 2c1, the leveling plate 2c3 is vertically mounted at the output end of the third electric push rod 2c2, two symmetrically-arranged second guide rods 2c4 are arranged on the rear side wall of the leveling plate 2c3, two guide grooves which are in one-to-one sliding fit with the two second guide rods 2c4 are formed in the mounting block 2c1, and two symmetrically-arranged insertion plates 2c5 which are both horizontally arranged are arranged on the front side wall of the leveling plate 2c 3; the third electric push rod 2c2 drives the pressing and aligning plate 2c3 to move, the pressing and aligning plate 2c3 can press and align the edges of the lowest trays, the two inserting plates 2c5 on the pressing and aligning plate 2c3 can be just inserted into the lowest tray, and one end of the tray can be lifted and lowered synchronously with the two inserting plates 2c 5.
Specifically, as shown in fig. 3 and 4, fig. 3 is a schematic diagram of a third angle solid structure of the present invention, and fig. 4 is an enlarged view of a point a in fig. 3; the tray lifting mechanism 3 comprises a lifting cylinder 3a and a lifting plate 3b, the lifting cylinder 3a is vertically arranged on the ground, the lifting plate 3b is horizontally arranged at the output end of the lifting cylinder 3a, the bottom of the lifting plate 3b is provided with four third guide rods 3b1 which are distributed in a rectangular shape, and the ground is provided with four second guide seats 3c which are in one-to-one sliding fit with the four third guide rods 3b 1; the lifting cylinder 3a drives the lifting plate 3b to lift, the lifting plate 3b can support all trays and can drive the trays to lift, and the third guide rod 3b1 and the second guide seat 3c can ensure that the lifting plate 3b keeps a horizontal state.
The unstacking method comprises the following steps:
(1) the pallets are sequentially placed on the pallet conveying mechanism 1, and the pallet conveying mechanism 1 can sequentially convey the pallets to the position right below the portal frame 2 a;
(2) in the conveying process, all the first electric push rods 4b can drive the positioning plate 4d to drive the positioning frame and the positioning wheels 4c1 to move, so that the positioning wheels 4c1 can position two sides of the tray, and the first limiting mechanism 5 and the second limiting mechanism 7 can limit the position of the tray being conveyed so as to avoid disorder of the tray;
(3) the lifting cylinder 3a can drive the lifting cylinder 3a to drive the lifting plate 3b to lift, the lifting plate 3b can lift the tray on the tray conveying mechanism 1 to lift and lift all trays right above the tray, then the two tray fixing assemblies 2c fix all trays so as to complete stacking, and the stacked trays are conveyed from the tray conveying mechanism 1 onto the transfer conveyor belt, so that a forklift can conveniently move the stacked trays away, and the forklift is prevented from damaging the portal frame 2 a;
(3) the lifting cylinder 3a drives the lifting plate 3b to support all the trays, then the two tray fixing assemblies 2c support the penultimate tray from bottom to top, the tray at the bottommost end can be supported by the lifting plate 3b, then the lifting cylinder 3a drives the tray to abut against the tray conveying mechanism 1, and the tray conveying mechanism 1 conveys the tray out.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.