CN110843960A

CN110843960A - Heavy-load AGV flat car

Info

Publication number: CN110843960A
Application number: CN201911294662.3A
Authority: CN
Inventors: 赵国忠; 郁延松
Original assignee: TIANJIN LANGYU TECHNOLOGY DEVELOPMENT Co Ltd
Current assignee: TIANJIN LANGYU TECHNOLOGY DEVELOPMENT Co Ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-02-28

Abstract

The invention belongs to the field of AGV production, and particularly relates to a heavy-load AGV flat car which comprises a car frame, wherein a plurality of rolling units are detachably mounted below the car frame, and each rolling unit comprises a top mounting plate, a turntable bearing, a chassis, a base and two wheels; the chassis is rotatably supported and arranged below the top mounting plate through a turntable bearing, the top mounting plate is detachably and fixedly connected with a bearing inner ring of the turntable bearing, and the chassis is detachably and fixedly connected with a bearing outer ring; a steering structure limit and a steering induction limit are arranged between the top mounting plate and the chassis; a plurality of guide posts are fixedly connected below the chassis and can be movably inserted in the base up and down; two wheels are respectively and independently matched with a driving element, a clutch structure is arranged between the wheels and the driving element, and the two wheels are independently and coaxially rotatably arranged on two sides of the base. The invention can solve the problem of steering limitation caused by poor driving when the bearing capacity of the existing truck is large.

Description

Heavy-load AGV flat car

Technical Field

The invention belongs to the field of AGV production, and particularly relates to a heavy-load AGV flat car.

Background

In industrial production, the AGV car can realize unmanned driving, can ensure that the system can automatically travel along the predetermined route under the condition that does not need manual piloting, transport goods or material from the initial point to the destination automatically, and the good flexibility of AGV, characteristics such as degree of automation height and intelligent level are obtained wide application, current heavily loaded AGV car operation mode is fairly simple, generally adopt front wheel or rear wheel drive, can only realize simple gos forward, retreat, turn to, when the load is great, its ability of turning to receives very big restriction, consequently, need improve its drive performance, with the conversion of the AGV car direction of travel when satisfying big bearing capacity, improve its self capacity.

Disclosure of Invention

In view of this, the present invention provides a heavy-duty AGV flatbed to solve the problem of steering limitation caused by poor driving when the loading capacity of the existing truck is large.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the heavy-load AGV flat car comprises a frame, wherein a plurality of rolling units are detachably mounted below the frame, and each rolling unit comprises a top mounting plate, a turntable bearing, a chassis, a base and two wheels; the rolling unit is detachably arranged below the frame through a top mounting plate;

the chassis is rotatably supported and arranged below the top mounting plate through a turntable bearing, the top mounting plate is detachably and fixedly connected with a bearing inner ring of the turntable bearing, and the chassis is detachably and fixedly connected with a bearing outer ring; a steering structure limit and a steering induction limit are arranged between the top mounting plate and the chassis;

a plurality of guide posts are fixedly connected below the chassis and can be movably inserted in the base up and down;

two wheels are respectively and independently matched with a driving element, a clutch structure is arranged between the wheels and the driving element, and the two wheels are independently and coaxially rotatably arranged on two sides of the base.

Furthermore, the steering structure between the top mounting plate and the chassis is limited by a limiting column fixedly connected to the lower surface of the top mounting plate and a limiting stop fixedly connected to the upper surface of the chassis, the lower surface of the limiting column is lower than the upper surface of the limiting stop, and the limiting column is located on the running track of the limiting stop when the limiting stop rotates along with the chassis.

Furthermore, a rotation limit position marking point is arranged on the outer ring of the bearing, a proximity sensor corresponding to the rotation limit position marking point is installed on the lower surface of the top mounting plate, and the proximity sensor is used for sensing and limiting the steering between the top mounting plate and the chassis.

Further, the base comprises an inner seat and an outer seat which are sleeved together, the inner seat and the outer seat are connected through two half shafts, the two half shafts are coaxial, and the axis connecting line of the two half shafts is vertical to the central axis of the wheel; the inner seat is provided with a plurality of guide holes corresponding to the guide posts one by one, the lower parts of the guide posts penetrate through the guide holes, and the lower ends of the guide posts are fixedly connected with limiting baffle plates.

Furthermore, a buffering and limiting structure is arranged between the chassis and the base; the buffering limiting structure comprises a buffering supporting column and a spring;

the inner seat is provided with an accommodating groove, and the spring is positioned in the accommodating groove and is extruded between the lower surface of the chassis and the bottom plate of the accommodating groove; the buffer support columns are arranged between the lower surface of the chassis and the upper surface of the outer seat at intervals.

Furthermore, a vertical wire passing column is fixedly connected in the base, the wire passing column is of a hollow tubular structure, and penetrates through the base plate.

Furthermore, the driving element is a servo motor, and the servo motor is in transmission connection with the corresponding wheel through a chain transmission mechanism.

Furthermore, the clutch structure is arranged between an output shaft of the servo motor and a driving chain wheel in the chain transmission mechanism;

the clutch structure comprises a clutch shaft sleeve detachably and fixedly connected to an output shaft of the servo motor, and the driving sprocket is sleeved on the clutch shaft sleeve and connected with the clutch shaft sleeve through a clutch bolt; the clutch shaft sleeve is a section of stepped shaft sleeve, the middle part of the clutch shaft sleeve is provided with a step surface for the driving sprocket to axially limit on the clutch shaft sleeve, the front section of the clutch shaft sleeve is an installation section, and the installation section is provided with a plurality of half screw holes I which are circumferentially distributed; the hole wall of the central hole of the driving sprocket is provided with a plurality of half screw holes II which correspond to the half screw holes I one to one; the driving chain wheel is sleeved on the mounting section of the clutch shaft sleeve, the half screw hole I and the half screw hole II are spliced to form a complete screw hole, and the clutch bolt is screwed in the complete screw hole.

Furthermore, an encoder for detecting the rotation angle of the outer ring of the bearing is arranged below the top mounting plate; the bearing outer ring transmits the angle information to the encoder through a meshing gear and a synchronous belt which are meshed with the bearing outer ring.

Further, a circle of induction anti-collision strip is arranged on the periphery of the frame; a plurality of safety baffles which are in one-to-one correspondence with the positions of the rolling units are arranged on the lower edge of the frame; a plurality of tracking sensors are arranged below the frame, and laser sensors are respectively arranged at the front end and the rear end of the frame.

Compared with the prior art, the invention has the following advantages:

the flat car can meet the driving requirements of forward movement, backward movement, in-situ rotation, steering and the like, and meets the requirements of forward movement, backward movement, steering and 90-degree translation of the AGV.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic perspective view of a scrolling unit according to the present invention;

FIG. 2 is a front view of the scrolling unit of the present invention;

FIG. 3 is a left side view of FIG. 2;

FIG. 4 is a bottom view of FIG. 2;

FIG. 5 is a top view of FIG. 2;

FIG. 6 is a cross-sectional view at section A of FIG. 5;

FIG. 7 is a cross-sectional view at section B of FIG. 5;

FIG. 8 is a schematic view of the installation position of the bump stopper;

FIG. 9 is a schematic view of the construction of the top mounting plate;

FIG. 10 is a schematic view showing the installation position of the encoder;

FIG. 11 is a schematic structural view of the inner seat;

FIG. 12 is a cross-sectional view of the inner housing;

FIG. 13 is a schematic structural view of the outer seat;

FIG. 14 is a schematic view of the connection structure of the inner seat and the outer seat in the direction of FIG. 6;

FIG. 15 is a schematic view of the connection structure of the inner seat and the outer seat in the direction of FIG. 7;

FIG. 16 is a schematic structural view of the chain tensioning mechanism;

FIG. 17 is a schematic view of a mounting structure of a clutch sleeve on an output shaft of a servo motor;

FIG. 18 is a schematic view of a mounting structure for the drive sprocket;

FIG. 19 is a schematic structural view of a clutch collar;

FIG. 20 is a schematic structural view of the drive sprocket;

FIG. 21 is a schematic view of the structure of the flat car of the present invention;

FIG. 22 is a bottom view of the flat car of the present invention;

fig. 23 is a schematic view of the mounting position of the rolling unit under the vehicle frame.

Description of reference numerals:

1-a top mounting plate; 11-a limiting column; 12-a proximity sensor; 2-a turntable bearing; 21-bearing outer race; 22-bearing inner race; 3-a chassis; 31-buffer support columns; 32-limit stops; 4-a guide post; 41-limiting baffle plates; 5-a base; 51-an inner seat; 511-a receiving groove; 512-a pilot hole; 513-a first shaft mounting hole; 514-bottom plate; 52-outer seat; 521-shaft mounting hole II; 522-connecting plate; 5221-oblong hole; 53-half shaft; 54-wire passing post; 55-a spring; 61-a servo motor; 610-clutch bolt; 611-clutch shaft sleeve; 6111-mounting section; 6112-half screw hole I; 6113-step surface; 62-a wheel; 621-axle; 63-chain drive; 631-a drive sprocket; 6311-half screw hole two; 641-a movable plate; 642-swing spindle; 643-scalloped holes; 6431-fastening bolts; 644-adjusting bolt; 645-a detent bump; 646-lock nuts; 7-an encoder; 71-meshing gears; 72-a synchronous belt; 8-a frame; 80-a scrolling unit; 81-induction bumper strips; 82-a safety barrier; 83-laser sensor.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

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 meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1-23, a heavy-duty AGV flatbed comprises a frame 8, a plurality of rolling units 80 detachably mounted below the frame 8, each rolling unit 80 comprising a top mounting plate 1, a turntable bearing 2, a chassis 3, a base 5 and two wheels 62; the rolling unit 80 is detachably mounted below the frame 8 through the top mounting plate 1;

the chassis 3 is rotatably supported and installed below the top mounting plate 1 through the turntable bearing 2, the top mounting plate 1 and a bearing inner ring 22 of the turntable bearing 2 are detachably and fixedly connected together, and the chassis 3 and a bearing outer ring 21 are detachably and fixedly connected together; a steering structure limit and a steering induction limit are arranged between the top mounting plate 1 and the chassis 3;

a plurality of guide posts 4 are fixedly connected below the chassis 3, and the guide posts 4 can be movably inserted in the base 5 up and down;

the two wheels 62 are respectively and independently matched with a driving element, a clutch structure is arranged between the wheels 62 and the driving element, and the two wheels 62 are independently and coaxially rotatably arranged on two sides of the base 5.

Specifically, the steering structure limit between the top mounting plate 1 and the chassis 3 comprises a limit column 11 fixedly connected to the lower surface of the top mounting plate 1 and a limit stop 32 fixedly connected to the upper surface of the chassis 3, the lower surface of the limit column 11 is lower than the upper surface of the limit stop 32, and the limit column 11 is located on the operation track of the limit stop 32 when the limit stop 32 rotates along with the chassis 3. Furthermore, a rotation limit position marking point is arranged on the bearing outer ring 21, a proximity sensor 12 corresponding to the rotation limit position marking point is arranged on the lower surface of the top mounting plate 1, and the proximity sensor 12 is used for steering sensing limiting between the top mounting plate 1 and the chassis 3. The chassis 3 can rotate for top mounting panel 1 at the turn in-process of marcing of flatbed, sets up proximity sensor 12 response spacing, and when the chassis 3 rotated and is close extreme position, proximity sensor 12 sent the control system of car with position signal transmission, sent the suggestion of reporting to the police. If the flatbed cannot be controlled to correct the steering at this moment, the limiting column 11 and the limiting stop 32 are arranged, when the chassis 3 rotates to the limiting position, the limiting column 11 can stop the flatbed, the flatbed is prevented from rotating over the limit, and the electric wire can be prevented from being damaged due to excessive torsion.

Preferably, the base 5 comprises an inner seat 51 and an outer seat 52 which are sleeved together, the inner seat 51 and the outer seat 52 are connected through two half shafts 53, the two half shafts 53 are coaxial, and the connecting line of the two shaft centers is vertical to the central axis of the wheel 62; two opposite side walls of the inner seat 51 are respectively provided with a first shaft mounting hole 513, two corresponding side walls of the outer seat 52 are respectively provided with a second shaft mounting hole 521, the inner seat 51 is sleeved inside the outer seat 52, a movable space is reserved between the inner seat and the outer seat 52, the first shaft mounting holes 513 correspond to the second shaft mounting holes 521 in a one-to-one mode, the half shafts 53 penetrate through the first shaft mounting holes 513 and the second shaft mounting holes 521 simultaneously, the half shafts 53 are fixedly connected with the outer seat 52, and meanwhile the half shafts 53 are in clearance fit with the first shaft mounting holes 513. Flatbed is at the ground unevenness in the in-process of marcing, two wheels 62 are uneven because of the different atress of difference in height, it can be to the automobile body part damage to have lasted for a long time, set up this structure, when meetting this condition, two wheels 62 difference in height are different, can self-adaptation adjustment, two wheels 62 produce slight swing around the axis of semi-axis 53, can drive outer seat 52 and slightly swing, consequently, need satisfy outer seat 52 wobbling demand through structural design, consequently can realize both can produce the effect of relatively stable relative motion with half swing joint of inner seat 51 and outer seat 52 through this semi-axis 53, can not transmit the atress inequality that leads to because the ground unevenness to the automobile body.

Preferably, the inner seat 51 is provided with a plurality of guide holes 512 corresponding to the guide posts 4 one to one, the lower parts of the guide posts 4 penetrate through the guide holes 512, and the lower ends of the guide posts 4 are fixedly connected with the limiting baffle plates 41. The guide post 4 moving up and down is limited by the limit baffle 41 and is prevented from falling out of the guide hole 512.

Preferably, a buffering and limiting structure is arranged between the chassis 3 and the base 5; the buffering limiting structure comprises a buffering supporting column 31 and a spring 55; the inner seat 51 is provided with a containing groove 511, and the spring 55 is positioned in the containing groove 511 and is pressed between the lower surface of the chassis 3 and the bottom plate 514 of the containing groove 511; the cushioning support posts 31 are spaced between the lower surface of the chassis 3 and the upper surface of the outer seat 52. The buffer support column 31 can be made of polyurethane elastic column. The buffer limiting structure can prevent the chassis 3 from being in hard contact with the base 5 in the process of up-and-down movement.

Preferably, a vertical wire passing column 54 is fixedly connected to the base 5, the wire passing column 54 is a hollow tubular structure, and the wire passing column 54 penetrates through the chassis 3. The chassis 3 moves up and down along the wire passing column 54 in the up-and-down movement process, the wire passing column 54 can play an auxiliary guiding role on one hand, and on the other hand, the hollow structure can accommodate electric wires of electric appliances such as a motor and the like to pass through the hollow structure, so that the wire passing column plays a protection role, and the phenomenon that the wheel 62 turns to cause winding in the vehicle moving process is prevented.

Preferably, the driving element is a servo motor 61, and the servo motor 61 and the corresponding wheel 62 are in transmission connection through a chain transmission mechanism 63; a chain tensioning mechanism is further arranged, a connecting plate 522 is fixedly connected to the base 5, and a long round hole 5221 is formed in the connecting plate 522; a movable plate 641 is fixedly connected to one side of the output shaft of the servo motor 61, a sector hole 643 is formed in the upper portion of the movable plate 641, the output shaft of the servo motor 61 penetrates through the oblong hole 5221, the movable plate 641 is attached to the connecting plate 522, the lower ends of the movable plate 641 and the connecting plate 522 are connected through a swinging rotating shaft 642, the upper ends of the movable plate 641 and the connecting plate 522 are detachably connected together through a fastening bolt 6431, the fastening bolt 6431 penetrates through the sector hole 643 and is screwed into the connecting plate 522, and a nut of the fastening bolt 6431 is pressed against the hole edge of the sector hole 643; a locking protrusion 645 is further fixed to the side of the movable plate 641; the device also comprises an adjusting bolt 644, and a locking nut 646 is screwed on the adjusting bolt 644; the adjusting bolt 644 is screwed in the blocking protrusion 645, and the end of the adjusting bolt 644 is against the side of the base 5, and the locking nut 646 is pressed on one side of the blocking protrusion 645.

The tightness of the chain can be adjusted through the chain tensioning mechanism, the chain is prevented from loosening in the transmission process, when the chain is loosened and needs to be tensioned, only by loosening the fastening bolt 6431, the movable plate 641 can swing around the swing rotating shaft 642 at the lower end of the connecting plate 522, the adjusting bolt 644 is screwed, the adjusting bolt 644 abuts against the side surface of the base 5, and the locking protrusion 645 reversely drives the movable plate 641 and the servo motor 61 thereon to swing outwards by a small angle, so that the output shaft of the servo motor 61 and the driving sprocket 631 thereon also move outwards, the driving sprocket 631 gradually tensions the chain in the process of moving, when the chain is tightly tightened, the fastening bolt 6431 is tightened to fixedly connect the movable plate 641 and the connecting plate 522, and then the locking nut 646 is tightened, so that the locking nut 646 plays a role in strengthening locking and preventing the threaded connection between the adjusting bolt 644 and the locking protrusion 645 from loosening.

Further, a clutch structure is provided between the output shaft of the servo motor 61 and the drive sprocket 631; the clutch structure comprises a clutch shaft sleeve 611 which is detachably and fixedly connected with the output shaft of the servo motor 61, and a driving chain wheel 631 is sleeved on the clutch shaft sleeve 611 and is connected with the clutch shaft sleeve 611 through a clutch bolt 610; the clutch shaft sleeve 611 is a section of stepped shaft sleeve, the middle part of the clutch shaft sleeve is provided with a stepped surface 6113 for the driving sprocket 631 to axially limit on the clutch shaft sleeve 611, the front section of the clutch shaft sleeve 611 is an installation section 6111, and the installation section 6111 is provided with a plurality of half screw holes 6112 which are distributed circumferentially; the hole wall of the central hole of the driving sprocket 631 is provided with a plurality of half-screw holes II 6311 which correspond to the half-screw holes I6112 one by one; the driving sprocket 631 is sleeved on the mounting section 6111 of the clutch shaft sleeve 611, the first half screw hole 6112 and the second half screw hole 6311 are spliced to form a complete screw hole, and the clutch bolt 610 is screwed in the complete screw hole.

The clutch structure is used for disconnecting the output shaft of the servo motor 61 and the driving sprocket 631, when one servo motor 61 of the flat car is damaged in the advancing process, in order to prevent the other servo motor 61 and the wheels 62 from working normally, the servo motor 61 and the corresponding driving sprocket 631 need to be disconnected, only the clutch bolt 610 needs to be detached, the connection between the clutch shaft sleeve 611 and the driving sprocket 631 is disconnected, at the moment, the abnormal action of the servo motor 61 cannot be transmitted to the driving sprocket 631 and the wheels 62, and at this moment, the flat car can be temporarily driven to a maintenance place for maintenance by the normal operation of the other wheels 62.

Preferably, an encoder 7 for detecting the rotation angle of the bearing outer ring 21 is arranged below the top mounting plate 1; the bearing outer race 21 transmits the angle information to the encoder 7 through a meshing gear 71 and a timing belt 72 which mesh therewith. Encoder 7 is used for detecting the turned angle of wheel 62 relative frame 8, the real time monitoring of being convenient for, the action wheel of meshing gear 71 and hold-in range 72 is coaxial, hold-in range 72's driven wheel is installed at the transmission of encoder 7 epaxially, hold-in range 72 has certain flexibility, transmit the moment of torsion through hold-in range 72, hard contact causes encoder 7 to damage when can avoiding directly adopting the gear transmission moment of torsion.

Preferably, a circle of sensing bumper strips 81 are mounted on the periphery of the frame 8.

Preferably, a plurality of safety barriers 82 are installed on the lower edge of the frame 8 in one-to-one correspondence with the positions of the rolling units 80. In the vehicle operation process, operating personnel stands and sometimes carelessly can stretch into frame 8 below with the foot when the car is other, sets up safety shield 82 and can play effectively and stop, prevents that operating personnel from stretching into frame 8 below with the foot mistake and being rolled by wheel 62.

Preferably, a plurality of tracking sensors are installed below the frame 8 for tracking the running track of the wheels 62, and laser sensors 83 are respectively installed at the front and rear ends of the frame 8. When the vehicle runs and encounters an obstacle, the obstacle enters a sensing area of the laser sensor 83, and the laser sensor 83 feeds a signal back to the control system, so that the control system can make direction adjustment in time.

According to the flat car, a plurality of independent rolling units 80 are arranged below a car frame 8, each rolling unit 80 is provided with two wheels 62, the rotating speed of a servo motor 61 corresponding to the wheels 62 is respectively controlled by a car control system, so that the running of the car is realized, the running requirements of forward movement, backward movement, in-situ rotation, steering and the like can be realized, the requirements of forward movement, backward movement, steering and 90-degree translation of an AGV are met, the steering of the wheels 62 is mainly realized through the differential speed of the two wheels 62 in each rolling unit 80, when the rotating speeds of the two wheels 62 are inconsistent, the torque of the wheels 62 is transmitted to a base 5, the base 5 transmits the torque to a bearing outer ring 21 through a guide column 4, the bearing outer ring 21 rotates, an encoder 7 records the rotating angle and feeds the rotating angle back to the car control system, an operator adjusts the rotating angle of the wheels 62 in real time according to information recorded, to achieve accurate steering. To this AGV car, each rolling unit 80 independent operation, two wheels 62 in each rolling unit 80 independent design separately, through motor drive separately, AGV car driving direction's when being convenient for realize big bearing capacity conversion improves its self carrying capacity, can solve the current load-carrying capacity when great the bad steering limited problem that leads to of drive.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. Heavy load AGV flatbed, its characterized in that: the device comprises a frame (8), wherein a plurality of rolling units (80) are detachably mounted below the frame (8), and each rolling unit (80) comprises a top mounting plate (1), a turntable bearing (2), a chassis (3), a base (5) and two wheels (62); the rolling unit (80) is detachably arranged below the frame (8) through the top mounting plate (1);

the chassis (3) is rotatably supported and installed below the top mounting plate (1) through the turntable bearing (2), the top mounting plate (1) is detachably and fixedly connected with a bearing inner ring (22) of the turntable bearing (2), and the chassis (3) is detachably and fixedly connected with a bearing outer ring (21); a steering structure limit and a steering induction limit are arranged between the top mounting plate (1) and the chassis (3);

a plurality of guide posts (4) are fixedly connected below the chassis (3), and the guide posts (4) can be movably inserted in the base (5) up and down;

the two wheels (62) are respectively and independently matched with a driving element, a clutch structure is arranged between the wheels (62) and the driving element, and the two wheels (62) are independently and coaxially and rotatably arranged on two sides of the base (5).

2. The heavy loaded AGV pallet of claim 1 wherein: the steering structure between the top mounting plate (1) and the chassis (3) is limited by a limiting column (11) fixedly connected to the lower surface of the top mounting plate (1) and a limiting stop (32) fixedly connected to the upper surface of the chassis (3), the lower surface of the limiting column (11) is shorter than the upper surface of the limiting stop (32), and the limiting column (11) is located on the running track of the limiting stop (32) when the limiting stop (32) rotates along with the chassis (3).

3. The heavy loaded AGV pallet of claim 1 wherein: the bearing outer ring (21) is provided with a rotation limit position marking point, the lower surface of the top mounting plate (1) is provided with a proximity sensor (12) corresponding to the rotation limit position marking point, and the proximity sensor (12) is used for steering induction spacing between the top mounting plate (1) and the chassis (3).

4. The heavy loaded AGV pallet of claim 1 wherein: the base (5) comprises an inner seat (51) and an outer seat (52) which are sleeved together, the inner seat (51) and the outer seat (52) are connected through two sections of half shafts (53), the two half shafts (53) are coaxial, and the axis connecting line of the two half shafts is vertical to the central axis of the wheel (62); the inner seat (51) is provided with a plurality of guide holes (512) which correspond to the guide columns (4) one by one, the lower parts of the guide columns (4) penetrate through the guide holes (512), and the lower ends of the guide columns (4) are fixedly connected with limiting baffle plates (41).

5. The heavy loaded AGV pallet of claim 4, wherein: a buffering and limiting structure is arranged between the chassis (3) and the base (5); the buffering limiting structure comprises a buffering supporting column (31) and a spring (55);

the inner seat (51) is provided with an accommodating groove (511), and the spring (55) is positioned in the accommodating groove (511) and is extruded between the lower surface of the chassis (3) and the bottom plate (514) of the accommodating groove (511); the buffer supporting columns (31) are arranged between the lower surface of the chassis (3) and the upper surface of the outer seat (52) at intervals.

6. The heavy loaded AGV pallet of claim 1 wherein: a vertical wire passing column (54) is fixedly connected in the base (5), the wire passing column (54) is of a hollow tubular structure, and the wire passing column (54) penetrates through the base plate (3).

7. The heavy loaded AGV pallet of claim 1 wherein: the driving element is a servo motor (61), and the servo motor (61) is in transmission connection with the corresponding wheel (62) through a chain transmission mechanism (63).

8. The heavy loaded AGV pallet of claim 7 wherein: the clutch structure is arranged between the output shaft of the servo motor (61) and a driving chain wheel (631) in the chain transmission mechanism (63);

the clutch structure comprises a clutch shaft sleeve (611) detachably and fixedly connected to an output shaft of the servo motor (61), a driving chain wheel (631) is sleeved on the clutch shaft sleeve (611) and connected with the clutch shaft sleeve through a clutch bolt (610); the clutch shaft sleeve (611) is a stepped shaft sleeve, the middle part of the clutch shaft sleeve is provided with a stepped surface (6113) for axially limiting the driving sprocket (631) on the clutch shaft sleeve (611), the front section of the clutch shaft sleeve (611) is an installation section (6111), and the installation section (6111) is provided with a plurality of half screw holes I (6112) distributed in the circumferential direction; the hole wall of the central hole of the driving chain wheel (631) is provided with a plurality of half screw holes II (6311) which correspond to the half screw holes I (6112) one by one; the driving chain wheel (631) is sleeved on the mounting section (6111) of the clutch shaft sleeve (611), the first half screw hole (6112) and the second half screw hole (6311) are spliced and enclosed to form a complete screw hole, and the clutch bolt (610) is screwed in the complete screw hole.

9. The heavy loaded AGV pallet of claim 1 wherein: an encoder (7) for detecting the rotation angle of the bearing outer ring (21) is arranged below the top mounting plate (1); the bearing outer ring (21) transmits the angle information to the encoder (7) through a meshing gear (71) and a synchronous belt (72) which are meshed with the bearing outer ring.

10. The heavy loaded AGV pallet of claim 1 wherein: a circle of induction anti-collision strip (81) is arranged on the periphery of the frame (8); a plurality of safety baffles (82) which are in one-to-one correspondence with the rolling units (80) are arranged on the lower edge of the frame (8); a plurality of tracking sensors are arranged below the frame (8), and laser sensors (83) are respectively arranged at the front end and the rear end of the frame (8).