CN113200080A

CN113200080A - Caster folding structure of flat-plate trolley

Info

Publication number: CN113200080A
Application number: CN202110661235.5A
Authority: CN
Inventors: 叶青松; 容卓
Original assignee: Dongguan Heyi Electronics Co ltd
Current assignee: Dongguan Heyi Electronics Co ltd
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-08-03

Abstract

The invention discloses a caster folding structure of a flat-plate trolley, which comprises a supporting plate; the device also comprises at least two caster wheel folding components; two fixing pipes extending forwards and backwards are symmetrically arranged at the bottom of the supporting plate, and a sliding pipe capable of sliding along the length direction of the fixing pipes is respectively arranged in the two fixing pipes; the trundle folding assemblies are correspondingly arranged on the two fixed pipes and the two sliding pipes; each trundle folding assembly comprises a trundle fixing seat which is rotatably sleeved on the fixed pipe, a trundle which is connected to one side of the trundle fixing seat and a bolt which is fixed on the outer wall of the sliding pipe; a first strip-shaped hole for the bolt to move back and forth is formed in the fixed pipe; an arc-shaped track used for guiding the caster fixing seat is arranged inside the caster fixing seat, and the bolt is inserted into the arc-shaped track; the two ends of the arc-shaped track are respectively provided with an opening positioning groove and a folding positioning groove. The foldable trundles are arranged, so that the volume of the trolley can be effectively reduced, and the trolley is favorable for storage and transportation.

Description

Caster folding structure of flat-plate trolley

Technical Field

The invention relates to the technical field of transportation equipment, in particular to a caster folding structure of a flat-plate cart.

Background

The folding structure of the caster wheel of the flat-plate cart is a small material transporting device, is widely applied in production and life, has low manufacturing cost, simple maintenance, convenient operation and light dead weight, can work in places where motor vehicles are inconvenient to use, and is very convenient when carrying articles in short distance. Due to its convenience, it is widely used for short-distance transportation in warehouses, manufacturing plants, department stores, logistics centers, freight stations or distribution.

The conventional flat-bed cart generally comprises a support plate and casters connected to the support plate. However, the existing caster wheels are generally fixed at the bottom of the supporting plate and cannot be folded, so that the whole size of the flat-plate cart is large, and the flat-plate cart is not beneficial to storage and transportation.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a caster folding structure of a flat-plate cart, which has simple and reasonable structure and convenient use, and can effectively reduce the volume of the flat-plate cart and facilitate storage and transportation by arranging the foldable caster; meanwhile, the folding structure is stable and effective, and the operation is very convenient.

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

a caster wheel folding structure of a flat-plate cart comprises a supporting plate; the device also comprises at least two caster wheel folding components; two fixing pipes extending forwards and backwards are symmetrically arranged at the bottom of the supporting plate, and a sliding pipe capable of sliding along the length direction of the fixing pipes is respectively arranged in the two fixing pipes; the caster wheel folding assemblies are correspondingly arranged on the two fixed tubes and the two sliding tubes; each caster folding assembly comprises a caster fixing seat which is rotatably sleeved on the fixed pipe, a caster which is connected to one side of the caster fixing seat and a bolt which is fixed on the outer wall of the sliding pipe; a first strip-shaped hole for the bolt to move back and forth is formed in the fixed pipe; an arc-shaped track used for guiding the caster fixing seat is arranged inside the caster fixing seat, and the bolt is inserted into the arc-shaped track; an opening positioning groove and a folding positioning groove are respectively arranged at the two ends of the arc-shaped track; the bolt is matched with the arc-shaped rail in the front and back moving process to realize the conversion of the caster between the folding state and the opening state.

For the additional structure of the above technical scheme, the following scheme is also included:

as a specific embodiment, the caster fixing seat comprises an inner fixing seat and an outer fixing seat; the inner fixed seat is sleeved on the outer wall of the fixed pipe; the front end of the inner fixed seat is provided with a first arc-shaped surface extending from back to front, and the rear end of the first arc-shaped surface is connected with the folding positioning groove; the outer fixing seat is sleeved on the inner fixing seat and the fixing pipe in a matching manner, and the caster wheel is connected to one side of the outer fixing seat; a second arc-shaped surface which is matched with the first arc-shaped surface and extends from back to front is arranged in the outer fixed seat, and the front end of the second arc-shaped surface is connected with the opening positioning groove; the arc-shaped track is formed between the first arc-shaped surface and the second arc-shaped surface.

Furthermore, each caster folding assembly also comprises a guide locking assembly which is arranged behind the caster fixing seat and matched with the caster fixing seat; the outer walls of the two sides of the inner fixed seat are respectively provided with a locking block, and each locking block is respectively provided with a locking groove with an opening at the rear end; the guide locking assembly comprises a guide rod arranged on the sliding pipe and a guide piece fixedly sleeved on the fixed pipe; two ends of the guide rod respectively penetrate through the sliding pipe, and a second strip-shaped hole for the two ends of the guide rod to move back and forth is formed in the fixed pipe; a guide strip-shaped hole penetrating through the front end and the rear end of the guide piece is formed in the guide piece, and the two ends of the guide rod are positioned in the guide strip-shaped hole; when the caster is in an open state, two ends of the guide rod are correspondingly embedded into the two locking grooves.

Further, the side surface of the guide rod facing the locking groove is a convex arc-shaped surface.

Furthermore, a spring sleeved on the fixed pipe is further installed at the front end of the outer fixed seat; one end of the spring abuts against a fixing piece fixedly arranged on the fixing pipe, and the other end of the spring abuts against the outer fixing seat.

As a specific embodiment, a positioning block is further mounted at the front end of each sliding tube; a front positioning frame strip is arranged on the front side of the supporting plate; the front positioning frame strip is provided with a positioning strip hole and is used for blocking the positioning block tightly.

Furthermore, a left positioning frame strip, a right positioning frame strip and a rear positioning frame strip are respectively arranged on the left side, the right side and the rear side of the supporting plate; the front positioning frame strip, the left positioning frame strip, the right positioning frame strip and the rear positioning frame strip are sequentially connected to form a structural reinforcing frame.

Furthermore, two sides of the front end of each positioning block are respectively provided with a step; the front end of the positioning block can be inserted into the positioning strip-shaped hole, and the positioning block can be clamped with the front positioning frame strip through the two steps.

As a specific embodiment, the caster wheel folding assemblies are four, and four caster wheel folding assemblies are uniformly arranged.

As a specific embodiment, the two pins are symmetrically arranged, and the two arc-shaped tracks, the two opening positioning grooves and the two folding positioning grooves are respectively provided with two pins which are correspondingly matched with the two pins.

The invention has the beneficial effects that:

the foldable flat plate trolley is simple and reasonable in structure and convenient to use, and the size of the flat plate trolley can be effectively reduced by arranging the foldable trundles, so that the flat plate trolley is favorable for storage and transportation; meanwhile, the folding structure is stable and effective, and the operation is very convenient. When the caster is used, the sliding pipe moves back and forth to synchronously drive the bolt to move back and forth, and the caster is promoted to be switched between a folded state and an unfolded state, so that the process is simple.

Drawings

FIG. 1 is a first schematic view of the overall structure of the present invention in a folded state;

FIG. 2 is a second schematic view of the overall structure of the present invention in a folded state;

FIG. 3 is a partial schematic view of the first embodiment of the present invention;

FIG. 4 is a second partial schematic view of the present invention;

FIG. 5 is a third schematic view of a portion of the present invention;

FIG. 6 is a schematic view of the caster mount and the latch of the present invention in use;

FIG. 7 is a schematic structural view of the caster mount of the present invention;

FIG. 8 is a schematic structural view of the guide lock assembly of the present invention;

FIG. 9 is a first schematic view of the overall structure of the present invention in the open state;

fig. 10 is a schematic view of the overall structure of the present invention in an open state.

Reference numerals:

1. a support plate; 101. a front positioning frame strip; 1011. positioning the strip-shaped holes; 102. a left positioning frame strip; 103. a right positioning frame strip; 104. a rear positioning frame strip; 2. a pushing handle; 21. a pushing part; 211. inserting a block; 22. a fixed part; 221. a slot; 222. positioning pins; 23. a limiting groove; 3. a guide rail; 31. a connecting portion; 32. a limiting part; 4. positioning blocks; 41. a step; 42. clamping the positioning groove; 43. a positioning bead; 5. a fixed tube; 51. a first bar-shaped hole; 52. a second bar-shaped hole; 6. a sliding tube; 7. a caster fixing seat; 71. an arc-shaped track; 72. opening the positioning groove; 73. folding the positioning groove; 74. an inner fixed seat; 741. a first arc-shaped surface; 742. a locking block; 743. a locking groove; 75. an outer fixed seat; 751. a second arcuate surface; 752. a bayonet; 8. a guide locking assembly; 81. a guide bar; 82. a guide member; 821. a guide strip-shaped hole; 9. a bolt; 10. a caster wheel; 11. a spring.

Detailed Description

The invention will be further elucidated with reference to the drawings and the embodiments, which are exemplary only and do not limit the scope of the invention.

As shown in fig. 1-10, a caster folding structure of a flat-bed cart comprises a support plate 1; the device also comprises at least two caster wheel folding components; two fixing tubes 5 extending back and forth are symmetrically arranged at the bottom of the supporting plate 1, and a sliding tube 6 capable of sliding along the length direction of the fixing tubes 5 is respectively arranged in the two fixing tubes 5; the caster wheel folding components are correspondingly arranged on the two fixed tubes 5 and the two sliding tubes 6; each caster folding assembly comprises a caster fixing seat 7 which is rotatably sleeved on the fixed tube 5, a caster 10 connected to one side of the caster fixing seat 7 and a bolt 9 fixed on the outer wall of the sliding tube 6; a first strip-shaped hole 51 for the bolt 9 to move back and forth is arranged on the fixed pipe 5; an arc-shaped track 71 for guiding the caster fixing seat 7 is arranged inside the caster fixing seat 7, and the bolt 9 is inserted into the arc-shaped track 71; an opening positioning groove 72 and a folding positioning groove 73 are respectively arranged at the two ends of the arc-shaped track 71; the bolt 9 is matched with the arc-shaped track 71 during the back and forth movement process to realize the conversion of the caster 10 between the folding state and the opening state, in particular, when the sliding tube 6 moves back and forth, the bolt 9 is synchronously driven to move back and forth. In this embodiment, the bolt 9 is provided with two symmetrically arranged bolts, and the arc-shaped rail 71, the opening positioning groove 72 and the folding positioning groove 73 are also respectively provided with two bolts 9 corresponding to the two bolts, so that the rotation stability of the caster fixing seat 7 can be improved, and the caster fixing seat 7 is not easily damaged. The foldable flat plate trolley is simple and reasonable in structure and convenient to use, and the size of the flat plate trolley can be effectively reduced by arranging the foldable trundles 10, so that the flat plate trolley is favorable for storage and transportation; meanwhile, the folding structure is stable and effective, and the operation is very convenient.

As shown in fig. 5-7, the caster mount 7 includes an inner mount 74 and an outer mount 75; the inner fixed seat 74 is sleeved on the outer wall of the fixed pipe 5; a first arc-shaped surface 741 extending from back to front is arranged at the front end of the inner fixed seat 74, and the rear end of the first arc-shaped surface 741 is connected with a folding positioning groove 73; the outer fixing seat 75 is fittingly sleeved on the inner fixing seat 74 and the fixing tube 5, the caster 10 is connected to one side of the outer fixing seat 75, and specifically, the outer fixing seat 75 and the inner fixing seat 74 are mutually clamped through a clamping block and a clamping groove so as to move synchronously; a second arc-shaped surface 751 which is matched with the first arc-shaped surface 741 and extends from back to front is arranged inside the outer fixed seat 75, and the front end of the second arc-shaped surface 751 is connected with the opening positioning groove 72; the first arc-shaped surface 741 and the second arc-shaped surface 751 form an arc-shaped rail 71 therebetween. Can make things convenient for production and dismouting truckle fixing base 7 and bolt 9 through above setting, also can let bolt 9 conveniently remove.

As shown in fig. 5, in order to facilitate the connection between the inner fixing seat 74 and the outer fixing seat 75, a bayonet 752 engaged with the locking block 742 is disposed at the lower end of the outer fixing seat 75, and the bayonet 752 is engaged with the locking block 742 to improve the stability between the inner fixing seat 74 and the outer fixing seat 75.

As shown in fig. 4, 5 and 8, each caster folding assembly further includes a guiding locking assembly 8 disposed behind the caster fixing base 7 and engaged with the caster fixing base 7; the outer walls of the two sides of the inner fixed seat 74 are respectively provided with a locking block 742, and each locking block 742 is respectively provided with a locking groove 743 with an opening at the rear end; the guiding locking assembly 8 comprises a guiding rod 81 arranged on the sliding pipe 6 and a guiding piece 82 fixedly sleeved on the fixed pipe 5; two ends of the guide rod 81 respectively penetrate outside the sliding tube 6, and a second strip-shaped hole 52 for the two ends of the guide rod 81 to move back and forth is arranged on the fixed tube 5; a guide strip hole 821 penetrating through the front end and the rear end of the guide 82 is arranged in the guide 82, and the two ends of the guide rod 81 are positioned in the guide strip hole 821; when the caster 10 is in the open state, the two ends of the guide rod 81 are correspondingly inserted into the two locking grooves 743. The caster 10 can be conveniently kept in an open state by arranging the guide locking assembly 8, and the caster 10 is prevented from loosening.

Preferably, in order to allow the guide rod 81 to be more smoothly inserted into the locking slot 743, the side surface of the guide rod 81 facing the locking slot 743 is a convex arc surface, that is, the guide rod 81 is a D-shaped rod.

As shown in fig. 4 and 5, a spring 11 sleeved on the fixed pipe 5 is further installed at the front end of the outer fixed seat 75, one end of the spring 11 abuts against a fixed member fixedly installed on the fixed pipe 5, and the other end abuts against the outer fixed seat 75. Can let truckle 10 utilize spring 11 to support tight truckle fixing base 7 and utilize spring 11's extension power and make truckle fixing base 7 comparatively stable when using through setting up spring 11 to improve truckle 10's stability, simultaneously, spring 11 also can play partial cushioning effect to a certain extent.

As shown in fig. 1-4, a positioning block 4 is further installed at the front end of each sliding tube 6; a front positioning frame strip 101 is arranged on the front side of the support plate 1; a positioning strip hole 1011 is formed in the front positioning frame strip 101, and the front positioning frame strip 101 is used for blocking the positioning block 4. Through the arrangement, the positioning block 4 can be conveniently utilized to drive the sliding pipe 6 to move back and forth, the bolt 9 is synchronously driven to move back and forth, and the front positioning frame strip 101 can be used for preventing the sliding pipe 6 from exceeding the preset stroke and damaging the bolt 9.

As shown in fig. 1, a left positioning frame strip 102, a right positioning frame strip 103 and a rear positioning frame strip 104 are respectively arranged on the left side, the right side and the rear side of the support plate 1; the front positioning frame strip 101, the left positioning frame strip 102, the right positioning frame strip 103 and the rear positioning frame strip 104 are connected in sequence to form a structural reinforcing frame. The structure of the support plate 1 can be reinforced by the above arrangement, making it more durable.

As shown in fig. 4, two sides of the front end of each positioning block 4 are respectively provided with a step 41; the front end of the positioning block 4 can be inserted into the positioning strip-shaped hole 1011, and the positioning block 4 can be fastened with the front positioning frame strip 101 through two steps 41. Through above setting up can conveniently keep off tight locating piece 4, when using, after, locating piece 41's front end was worn to establish in location bar hole 1011, two steps 41 also supported tightly on preceding locating frame strip 101 correspondingly to accomplish the screens.

In this embodiment, the truckle folding assembly is equipped with four and four truckle folding assemblies and evenly sets up.

In this embodiment, two springs 11 are provided, and the two springs 11 are respectively installed at the front ends of the two outer fixing seats 75 near the two positioning blocks 4.

As shown in fig. 1-3, in order to facilitate the movement of the two positioning blocks 4, a pushing handle 2 is further disposed on the supporting plate 1; two sides of the bottom of the supporting plate 1 are symmetrically provided with a guide rail 3 respectively; the pushing handle 2 comprises a pushing part 21 and two fixing parts 22 respectively hinged at two ends of the pushing part 21; two ends of the pushing part 21 and the two fixing parts 22 are respectively and correspondingly arranged on the two guide rails 3 in a front-back sliding manner; the two positioning blocks 4 are used for limiting the two fixing parts 22; when the pushing portion 21 is pulled outward until the positioning block 4 limits the fixing portion 22, the pushing portion 21 extends out of the supporting plate 1. Preferably, the pushing portion 21 has a shape of "". When using, the both ends of promotion portion 21 and two fixed parts 22 are installed respectively on two guide rails 3, when needs pulling the pallet truck, only need outwards stimulate pushing hands 2, make promotion portion 21 outwards break away from guide rail 3 and stretch out backup pad 1, and locating piece 4 is spacing to fixed part 22, just so can utilize the articulated of promotion portion 21 and fixed part 22 and make promotion portion 21 can overturn from top to bottom outside backup pad 1, make things convenient for people according to use custom angle of adjustment.

As shown in fig. 3, each guide rail 3 includes a connecting portion 31 for connecting with the support plate 1 and a T-shaped limiting portion 32 disposed at a lower end of the connecting portion 31; two ends of the pushing portion 21 and the two fixing portions 22 are respectively provided with a T-shaped limiting groove 23 which is correspondingly sleeved on the limiting portion 32. Through the arrangement, the pushing handle 2 can stably slide on the guide rail 3, and the pushing handle 2 and the guide rail 3 are prevented from loosening. Of course, the shape of the limiting portion 32 and the limiting groove 23 may be set to other shapes, for example, an arch portion may be set on the limiting portion 32 and the limiting groove 23, so as to further increase the stability of the pushing handle 2 when sliding.

As shown in fig. 3, an insertion block 211 is respectively provided at both ends of the pushing portion 21; the front ends of the two fixing parts 22 are respectively provided with a slot 221 matched with the inserting block 211; insertion holes corresponding to each other are respectively formed at both sides of the insertion block 211 and the insertion groove 221, and bolts are horizontally installed in the insertion holes to hinge the insertion block 211 to the fixing portion 22. Through the arrangement, the pushing part 21 and the fixing part 22 can be stably hinged, and the structure is stable. However, it should be understood by those skilled in the art that the pushing portion 21 and the fixing portion 22 may be hinged by a hinge, such as a hinge.

As shown in fig. 1 and 4, a positioning pin 222 is provided on an inner side edge of each fixing portion 22; a clamping positioning groove 42 matched with the positioning pin 222 is arranged on the outer side edge of each positioning block 4; two sides of each clamping positioning groove 42 are respectively provided with a positioning bead 43 which is arranged oppositely, and a gap for the positioning pin 222 to pass through is reserved between the two positioning beads 43; the positioning block 4 can be clamped or separated from the positioning pin 222 by pulling or pushing the push handle 2. The fixing part 22 can conveniently drive the positioning block 4 to move through the arrangement, and the arrangement mode can conveniently realize the clamping or separating of the positioning block 4 and the positioning pin 222; meanwhile, the two positioning beads 43 can limit the position of the positioning pin 222 to prevent the position from being separated. Since the positioning beads 43 are prior art, they will not be described in detail herein.

The principle of use of the invention is described below in connection with fig. 9 and 10 in order to understand the invention:

first, the flatbed cart is folded as shown in fig. 1 and 2. When the door needs to be opened, the pushing part 21 is pulled, so that the pushing part 21 penetrates through the positioning strip-shaped hole 1011 outwards; when the positioning pins 222 on the two fixing portions 22 move to the preset positions and penetrate through the two positioning beads 43 to be inserted into the two clamping positioning grooves 42, the two positioning blocks 4 move forwards along with the fixing portions 22; when the two positioning blocks 4 move, the two sliding pipes 6, the bolts 9 on the sliding pipes 6 and the guide rods 81 are driven to move forwards, the bolts 9 move forwards along the arc-shaped rails 71 after being separated from the folding positioning grooves 73, and the bolts 9 can only move in the front-back direction, so that the caster fixing seats 7 can be driven to be changed from a horizontal state to a vertical state when moving, and the caster 10 is synchronously driven to be changed from a folding state to an opening state; when the plug 9 is inserted into the opening positioning groove 72, the opening of the caster 10 is completed, one side of the guide rod 81 just penetrates through the guide strip-shaped hole 821 and is inserted into the locking groove 743, meanwhile, the front end of the positioning block 4 is just inserted into the positioning strip-shaped hole 1011 and abuts against the front positioning frame strip 101 by using the step 41, the pushing part 21 is just separated from the guide rail 3 and extends out of the supporting plate 1, and people can freely turn over the pushing part 21 for use; the opening of the flat bed cart is completed through the above steps, and the opened state of the flat bed cart is shown in fig. 9 and 10.

When the folding is needed, the pushing part 21 is turned over to be horizontal to the fixing part 22, then the pushing handle 2 is pushed backwards into the positioning strip-shaped hole 1011, and in the moving process, the positioning pin 222 penetrates out of the two positioning beads 43 and then is separated from the clamping positioning groove 42; when the front end of the pushing part 21 enters the positioning strip-shaped hole 1011, the pushing part contacts the two positioning blocks 4 and pushes the two positioning blocks 4 to move backwards, so that the two sliding tubes 6 and the bolts 9 and the guide rods 81 on the sliding tubes 6 are driven to move backwards, the bolts 9 are separated from the opening positioning grooves 72, the guide rods 81 are separated from the clamping positioning grooves 42 and then move along the guiding strip-shaped holes 821, the bolts 9 move backwards along the arc-shaped rails 71, so that the caster fixing seat 7 is enabled to be changed from a vertical state to a horizontal state, and the caster 10 is synchronously driven to be changed from an opening state to a folding state; when the plug 9 is inserted into the folding positioning groove 73, the caster 10 is folded, the positioning block 4 is separated from the front positioning frame strip 101, and the front end of the pushing part 21 is correspondingly embedded into the positioning strip-shaped hole 1011; the folding of the flat-bed cart is completed through the above steps, and the folding state of the flat-bed cart is shown in fig. 1 and 2.

In summary, the invention is provided with the push handle capable of being stored at the bottom of the supporting plate 1 and the caster 10 capable of being folded, so that the volume of the caster folding structure of the flat-bed cart can be greatly reduced, and the storage and transportation are facilitated; meanwhile, the operation mode of the invention is very simple and convenient, and is beneficial to use.

The present invention is not limited to the above-described embodiments, and various modifications and variations of the present invention are intended to be included within the scope of the claims and the equivalent technology of the present invention if they do not depart from the spirit and scope of the present invention.

Claims

1. The utility model provides a truckle beta structure of dull and stereotyped shallow, including the backup pad, its characterized in that:

the device also comprises at least two caster wheel folding components; two fixing pipes extending forwards and backwards are symmetrically arranged at the bottom of the supporting plate, and a sliding pipe capable of sliding along the length direction of the fixing pipes is respectively arranged in the two fixing pipes; the caster wheel folding assemblies are correspondingly arranged on the two fixed tubes and the two sliding tubes; each caster folding assembly comprises a caster fixing seat which is rotatably sleeved on the fixed pipe, a caster which is connected to one side of the caster fixing seat and a bolt which is fixed on the outer wall of the sliding pipe; a first strip-shaped hole for the bolt to move back and forth is formed in the fixed pipe; an arc-shaped track used for guiding the caster fixing seat is arranged inside the caster fixing seat, and the bolt is inserted into the arc-shaped track; an opening positioning groove and a folding positioning groove are respectively arranged at the two ends of the arc-shaped track; the bolt is matched with the arc-shaped rail in the front and back moving process to realize the conversion of the caster between the folding state and the opening state.

2. The caster folding structure of a flatbed cart according to claim 1, characterized in that:

the caster fixing seat comprises an inner fixing seat and an outer fixing seat; the inner fixed seat is sleeved on the outer wall of the fixed pipe; the front end of the inner fixed seat is provided with a first arc-shaped surface extending from back to front, and the rear end of the first arc-shaped surface is connected with the folding positioning groove; the outer fixing seat is sleeved on the inner fixing seat and the fixing pipe in a matching manner, and the caster wheel is connected to one side of the outer fixing seat; a second arc-shaped surface which is matched with the first arc-shaped surface and extends from back to front is arranged in the outer fixed seat, and the front end of the second arc-shaped surface is connected with the opening positioning groove; the arc-shaped track is formed between the first arc-shaped surface and the second arc-shaped surface.

3. The caster folding structure of a flatbed cart according to claim 2, characterized in that:

each caster folding assembly also comprises a guide locking assembly which is arranged behind the caster fixing seat and matched with the caster fixing seat; the outer walls of the two sides of the inner fixed seat are respectively provided with a locking block, and each locking block is respectively provided with a locking groove with an opening at the rear end; the guide locking assembly comprises a guide rod arranged on the sliding pipe and a guide piece fixedly sleeved on the fixed pipe; two ends of the guide rod respectively penetrate through the sliding pipe, and a second strip-shaped hole for the two ends of the guide rod to move back and forth is formed in the fixed pipe; a guide strip-shaped hole penetrating through the front end and the rear end of the guide piece is formed in the guide piece, and the two ends of the guide rod are positioned in the guide strip-shaped hole; when the caster is in an open state, two ends of the guide rod are correspondingly embedded into the two locking grooves.

4. The caster folding structure of a flatbed cart as claimed in claim 3, characterized in that:

the side surface of the guide rod facing the locking groove is an outward convex arc-shaped surface.

5. The caster folding structure of a flatbed cart according to claim 2, characterized in that:

the front end of the outer fixed seat is also provided with a spring sleeved on the fixed pipe; one end of the spring abuts against a fixing piece fixedly arranged on the fixing pipe, and the other end of the spring abuts against the outer fixing seat.

6. The caster folding structure of a flatbed cart according to claim 1, characterized in that:

the front end of each sliding tube is also provided with a positioning block; a front positioning frame strip is arranged on the front side of the supporting plate; the front positioning frame strip is provided with a positioning strip hole and is used for blocking the positioning block tightly.

7. The caster folding structure of a flatbed cart as claimed in claim 6, characterized in that:

a left positioning frame strip, a right positioning frame strip and a rear positioning frame strip are respectively arranged on the left side, the right side and the rear side of the supporting plate; the front positioning frame strip, the left positioning frame strip, the right positioning frame strip and the rear positioning frame strip are sequentially connected to form a structural reinforcing frame.

8. The caster folding structure of a flatbed cart as claimed in claim 6, characterized in that:

two sides of the front end of each positioning block are respectively provided with a step; the front end of the positioning block can be inserted into the positioning strip-shaped hole, and the positioning block can be clamped with the front positioning frame strip through the two steps.

9. The caster folding structure of a flatbed cart according to claim 1, characterized in that:

the truckle folding assembly is equipped with four and four truckle folding assembly evenly sets up.

10. The caster folding structure of a flatbed cart according to claim 1, characterized in that:

the bolt is provided with two symmetrically arranged bolts, and the arc-shaped track, the opening positioning groove and the folding positioning groove are respectively provided with two bolts correspondingly matched with the two bolts.