CN112158776B

CN112158776B - Thrust wheel structure and tool bogie

Info

Publication number: CN112158776B
Application number: CN202011024453.XA
Authority: CN
Inventors: 李刚晖; 赵喻明; 施祖强
Original assignee: Shanhe Intelligent Special Equipment Co ltd; Sunward Intelligent Equipment Co Ltd
Current assignee: Shanhe Intelligent Special Equipment Co ltd; Sunward Intelligent Equipment Co Ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2021-10-01
Anticipated expiration: 2040-09-25
Also published as: CN112158776A

Abstract

The invention discloses a supporting wheel structure and a tool vehicle, wherein the supporting wheel structure comprises a wheel carrier, a screw rod, a swinging frame, a first supporting wheel and a second supporting wheel, one end of the wheel carrier is used for being connected with a vehicle body, and the other end of the wheel carrier is hinged with the middle part of the swinging frame; one end of the swing frame close to the vehicle body is in threaded connection with the lower end of the screw rod, one end of the swing frame far away from the vehicle body is hinged with the second supporting wheel, the upper end of the screw rod penetrates through the wheel carrier, and a limit nut which is abutted against the upper end face of the wheel carrier is fixed at the upper end of the screw rod; the first supporting wheel is hinged to a conversion frame through a first wheel shaft, the upper end of the conversion frame is detachably and fixedly connected with the swing frame through a vertically arranged rotating shaft, and the first supporting wheel is arranged between the screw rod and a hinged point in the middle of the swing frame. Therefore, the function of rotating the thrust wheel is added, the rotation of the thrust wheel of the whole vehicle under the loading condition is realized through the spiral pair, the switching from longitudinal walking to transverse walking is realized, and a larger turning space is not needed.

Description

Thrust wheel structure and tool bogie

Technical Field

The invention relates to the technical field of walking tool vehicles, in particular to a thrust wheel structure and a tool vehicle.

Background

The current market carrier vehicle is mainly driven by an electric motor or a manual motor and is lifted by hydraulic pressure. Particularly, the forklift is generally large, cannot be folded into a small space, and is inconvenient to transport and use along with the forklift.

In addition, the small carrying vehicle is mainly provided with a three-point wheel type supporting ground, the driving wheel can rotate and plays a role in turning, the thrust wheels on two sides mainly play a role in supporting, the thrust wheels adopt a single wheel type and a double wheel type, obstacle crossing is facilitated, and the turning radius of the whole vehicle is relatively large; it can not be used in narrow space.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art, provide a thrust wheel structure with a small-space internal transverse walking function and correspondingly provide a tool vehicle with the thrust wheel structure.

In order to solve the technical problems, the invention adopts the following technical scheme:

a supporting wheel structure comprises a wheel frame, a screw rod, a swinging frame, a first supporting wheel and a second supporting wheel, wherein one end of the wheel frame is used for being connected with a vehicle body, and the other end of the wheel frame is hinged with the middle part of the swinging frame; one end, close to the vehicle body, of the swinging frame is in threaded connection with the lower end of the screw rod, one end, far away from the vehicle body, of the swinging frame is hinged with the second supporting wheel, the upper end of the screw rod penetrates through the wheel carrier, and a limiting nut which is abutted against the upper end face of the wheel carrier is fixed at the upper end of the screw rod; the first supporting wheel is hinged to a conversion frame through a first wheel shaft, the upper end of the conversion frame is detachably and fixedly connected with the swing frame through a vertically arranged rotating shaft, and the first supporting wheel is arranged between the screw rod and a hinged point in the middle of the swing frame.

When the device is in an initial position, the first supporting wheel and the second supporting wheel are simultaneously contacted with the ground, and the supporting wheel structure is in a longitudinal walking state. Because the screw rod is limited by the spacing of spacing nut, only circumference rotation degree of freedom when the state of need will vertically walk is switched into the state of horizontal walking: 1) and rotating the screw rod, wherein one end of the swing frame in threaded connection with the screw rod moves upwards along the screw rod, so that the first supporting wheel is lifted off the ground, the first supporting wheel can be driven to rotate to a transverse walking state vertical to the longitudinal running direction before by releasing the fixed connection between the rotating shaft and the swing frame and then rotating the rotating shaft, and the rotating shaft is fixedly connected with the swing frame.

2) The screw rod is rotated reversely, one end of the swing frame in threaded connection with the screw rod moves downwards along the screw rod, so that the first supporting wheel contacts the ground, the second supporting wheel is off the ground, transverse walking of the supporting wheel structure in a narrow space can be achieved, and a large turning space is not needed.

And the design of double supporting wheels is adopted for longitudinal walking, compared with the conventional design of single supporting wheels, the contact area of the wheels is increased, the problem that the tool car cannot walk when falling into the ground on a soft ground is avoided, and meanwhile, the double supporting wheels can cross a trench with a certain width.

As a further improvement of the above technical solution:

the wheel carrier comprises two vertical wheel carrier plates arranged at intervals and a first hinged shaft hinged between the two wheel carrier plates, and the limiting nut is abutted to the upper end face of the first hinged shaft.

The swing frame comprises two vertical swing frame plates arranged at intervals and a second hinge shaft hinged between the two swing frame plates, and the lower end of the screw rod is in threaded connection with the second hinge shaft.

The two swing frame plates are positioned between the two wheel frame plates, and the two swing frame plates are hinged with the two wheel frame plates through a third hinge shaft.

A first connecting plate is horizontally arranged between the two swing frame plates, and the rotating shaft penetrates through the first connecting plate and then is detachably and fixedly connected with the first connecting plate through a locking nut.

And a first articulated part used for being articulated with the vehicle body is connected between the end parts of the two wheel carrier plates, which face the vehicle body.

The screw is a double-head screw.

The swing frame plate inclines downwards towards one end of the second supporting wheel to form a second hinge part hinged with the second supporting wheel; the two second hinges are hinged with the second thrust wheel through a second wheel shaft.

The hinged end of the second hinged part extends outwards horizontally along the radial direction of the second supporting wheel to form an extending part, and the extending parts of the two swing frame plates are connected through a second connecting plate.

The conversion frame is including dividing the conversion frame plate of locating first shaft axial direction both sides, connecting in the lamina tecti of two conversion frame plate upper ends to and connect in the side cap board of two conversion frame plates towards screw rod one end, the rotation axis is fixed in the upper end of lamina tecti, set up the hole of dodging the screw rod on the side cap board, two conversion frame plates are articulated through first shaft and first truckle.

As a general inventive concept, the present invention also provides a tool wagon, which comprises a wagon body, and legs hinged to left and right sides of the wagon body, wherein the legs are connected with the above-mentioned thrust wheel structure.

As a further improvement of the above technical solution:

the supporting legs are hinged with the wheel carrier through fourth hinge shafts arranged along the front-back direction of the vehicle body, so that the supporting wheel structure can rotate around the fourth hinge shafts to be arranged along the front-back direction of the vehicle body when in a folded state. Thereby the landing leg folding relatively of thrust wheel structure reduces whole car width size, realizes the transportation of depositing of tool bogie in the little space.

The supporting legs are hinged with the vehicle body through fifth hinge shafts perpendicular to corresponding side faces, the side faces are provided with working pin holes and folding pin holes, the axial center lines of the working pin holes and the fifth hinge shafts are located in the same vertical plane, the axial center lines of the folding pin holes and the fifth hinge shafts are located in the same horizontal plane, and the folding pin holes and the supporting wheel structures are respectively arranged on two sides of the fifth hinge shafts in the left and right direction of the vehicle body; the distance between the working pin hole and the fifth hinge shaft is equal to the distance between the folding pin hole and the fifth hinge shaft; be connected with the bolt pipe that a level was arranged on the landing leg, it is equipped with a bolt to insert in the bolt pipe, the bolt has the operating condition who inserts in the operating pin hole to and insert the fold condition in the folding pinhole, the landing leg is feasible around the rotatory in-process of fifth articulated shaft the switching of bolt between operating condition and fold condition.

Through the structure, the integral folding of the structure of the supporting leg and the supporting wheel can be realized, the width space of the whole vehicle can be saved, and the storage and transportation of the tool vehicle in a narrow space can be realized.

During the operating condition, thrust wheel mechanism is parallel with the rotatory landing leg of horizontal arrangement, and during folding transport state, thrust wheel structure is perpendicular with the rotatory landing leg of vertical arrangement, reduces whole car width size.

The bolt pipe is connected with the supporting leg through a connecting rod, and the connecting rod is perpendicular to the extending direction of the supporting leg.

An operating handle is arranged on the upper end face of the vehicle body, a driving wheel is arranged below the tool vehicle, and the operating handle penetrates through the vehicle body and then is fixedly connected with the driving wheel.

The lifting mechanism is arranged in the vehicle body, and one end of the lifting mechanism is connected with fork teeth extending out of the vehicle body.

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

1. the thrust wheel structure adopts a double-thrust-wheel design, realizes the rotation of the thrust wheel of the whole vehicle under the loading condition by adding the function of the rotation of one thrust wheel and the screw pair, and realizes the switching from longitudinal walking to transverse walking, thereby not needing larger turning space. In addition, the vehicle body can be carried in the longitudinal walking and transverse walking switching process, so that the practicability is improved.

2. The supporting wheel structure adopts the design of the double supporting wheels, increases the contact area of the wheels, avoids the problem that the tool car cannot walk when falling into the ground on a soft ground, and can cross a trench with a certain width by the design of the double supporting wheels.

3. The supporting legs and the supporting wheel of the tool car can be folded, so that the tool car can be stored and transported in a small space, and is particularly convenient to transport along with the transport car.

Drawings

Fig. 1 is a working state diagram of a tool wagon according to an embodiment of the present invention.

Fig. 2 is a view showing a folded state of the tool wagon according to the embodiment of the present invention.

Fig. 3 is a schematic perspective view of a track roller structure (with the small track rollers arranged longitudinally).

Fig. 4 is a cross-sectional structural view of the structure of the bogie wheel (the small bogie wheel is arranged longitudinally).

Fig. 5 is a schematic perspective view of a track roller structure (with small track rollers arranged laterally).

Fig. 6 is a view showing an initial state in which the tool wagon travels in the longitudinal direction.

Fig. 7 is a state diagram of the small track roller being lifted off the ground.

Fig. 8 is a state diagram in which the small thrust wheel is rotated to travel in the lateral direction after being lifted off the ground.

Fig. 9 is a diagram showing the state where the tool wagon is traveling in the lateral direction.

Illustration of the drawings: 1. a vehicle body; 11. folding pin holes; 12. a working pin hole; 2. an operating handle; 3. a driving wheel; 4. a tine; 5. a support leg; 51. a bolt; 52. a fourth hinge shaft; 53. a fifth hinge shaft; 54. a latch tube; 55. a connecting rod; 61. a wheel carrier; 611. a wheel frame plate; 612. a first hinge shaft; 613. a first hinge portion; 62. a screw; 63. a swing frame; 631. a swing frame plate; 6311. a second hinge portion; 6312. an extension portion; 6313. a second connecting plate; 632. a second hinge shaft; 633. a first connecting plate; 64. a first bogie wheel; 641. a first axle; 642. locking the nut; 65. a second thrust wheel; 651. a second wheel axle; 66. a limit nut; 67. a conversion frame; 671. converting the frame plate; 672. a top cover plate; 673. a side cover plate; 674. avoiding holes; 68. a rotating shaft; 69. a third hinge shaft.

Detailed Description

The invention is further described below with reference to specific preferred embodiments, without thereby limiting the scope of protection of the invention.

Example 1:

as shown in fig. 1, the tool wagon of the present embodiment, specifically, the transportation wagon, includes a wagon body 1, and a leg 5 hinged to a lateral side of the wagon body 1 in a left-right direction, wherein a supporting wheel structure 6 is connected to the leg 5.

Wherein, be equipped with operating handle 2 on the up end of automobile body 1, the below of tool bogie is equipped with action wheel 3, and operating handle 2 passes automobile body 1 after and with action wheel 3 solid link. The operating handle 2 and the driving wheel 3 are hinged with the vehicle body 1 at the same time, so that the driving wheel 3 can rotate relative to the thrust wheel structure 6 through the rotation of the operating handle 2 relative to the vehicle body 1, namely the rotation of the whole vehicle is realized.

The vehicle body 1 is internally provided with a lifting mechanism, a power unit for providing power for the lifting mechanism of the driving wheel 3 and the fork teeth 4 of the whole vehicle, a battery and the like. One end of the lifting mechanism is connected with a fork tooth 4 extending out of the vehicle body 1. Therefore, after goods are loaded on the fork teeth 4, the function of transferring the goods can be realized.

The supporting leg 5 is hinged with the vehicle body 1 through a fifth hinge shaft 53 vertical to the corresponding side surface, a working pin hole 12 and a folding pin hole 11 are formed in the side surface, the axial center line of the working pin hole 12 and the axial center line of the fifth hinge shaft 53 are located in the same vertical plane, the axial center line of the folding pin hole 11 and the axial center line of the fifth hinge shaft 53 are located in the same horizontal plane, and the folding pin hole 11 and the supporting wheel structure are respectively arranged on two sides of the fifth hinge shaft 53 in the left-right direction of the vehicle body 1; the distance between the working pin hole 12 and the fifth hinge shaft 53 is equal to the distance between the folding pin hole 11 and the fifth hinge shaft 53; the leg 5 is connected with a connecting rod 55 perpendicular to the extending direction of the leg 5, a pin tube 54 horizontally arranged and perpendicular to the side is fixed at the upper end of the connecting rod 55, a pin 51 is inserted into the pin tube 54, the pin 51 has an operating state inserted into the operating pin hole 12 and a folded state inserted into the folding pin hole 11, and the leg 5 can be switched between the operating state and the folded state by the pin 51 during rotation around the fifth hinge shaft 53.

The leg 5 is hinged with the wheel carrier 61 through a fourth hinge shaft 52 arranged along the front-rear direction of the vehicle body, so that the weight wheel structure can rotate around the fourth hinge shaft 52 to be arranged along the front-rear direction of the vehicle body 1 when in a folded state, thereby reducing the width dimension of the whole vehicle.

The rotary supporting legs 5 are hinged to the vehicle body 1, when the supporting leg bolts 51 are inserted into the working pin holes 12, the rotary supporting legs 5 are opened, the working state is achieved, when the supporting leg bolts 51 are inserted into the folding pin holes 11, the rotary supporting legs 5 are folded, and the folding working state is achieved.

The tail end of the rotating supporting leg 5 is hinged with the supporting wheel structure 6 into a whole, the switching between the working state of the supporting wheel structure 6 and the folding transportation state is realized through the fourth hinged shaft 52, during the working state, the supporting wheel structure 6 is parallel to the rotating supporting leg 5, and during the folding transportation state, the supporting wheel structure 6 is perpendicular to the rotating supporting leg 5, so that the width size of the whole vehicle is reduced.

During the operating condition, rotatory landing leg 5 is opened, and landing leg bolt 51 inserts work pinhole 12 promptly, and thrust wheel structure 6 is parallel with rotatory landing leg 5 simultaneously, and thrust wheel structure 6 constitutes three point support with action wheel 3 like this, realizes transporting of whole car. As shown in fig. 2, in the folded transportation state, the rotating leg 5 is folded, i.e. the leg pin 51 is inserted into the folding pin hole 11, and the track roller structure 6 is perpendicular to the rotating leg 5, so as to save the width space.

As shown in fig. 3 to 5, the supporting wheel structure 6 of the present embodiment includes a wheel frame 61, a screw 62, a swing frame 63, a first supporting wheel 64, and a second supporting wheel 65.

The wheel frame 61 comprises two vertical wheel frame plates 611 arranged at intervals, a first hinge shaft 612 hinged between the two wheel frame plates 611, and a first hinge part 613 connected between one ends of the two wheel frame plates 611 facing the leg 1. The first hinge portion 613 is hinged to the leg 5 by a fourth hinge shaft 52.

The swing frame 63 includes two vertical swing frame plates 631 arranged at intervals, and a second hinge shaft 632 hinged between the two swing frame plates 631, wherein the second hinge shaft 632 is disposed at one end of the swing frame 63 close to the leg 5.

The two swing frame plates 631 are positioned between the two wheel frame plates 611, and the middle portions of the two swing frame plates 631 and the end portions of the two wheel frame plates 611 opposite to the first hinge portion 613 are hinged by a third hinge shaft 69.

The screw 62 is a double-threaded screw, the screw 62 is vertically arranged and sequentially passes through the first hinge shaft 612 and the second hinge shaft 632, a gap is formed between the upper section of the double-threaded screw and the first hinge shaft 612, and the upper end of the screw 62 is fixed with a limit nut 66 abutted against the upper end face of the first hinge shaft 612. The lower section of the double-headed screw is in threaded connection with the second hinge shaft 632.

The end of the swing frame plate 631 away from the vehicle body is inclined downwards to form a second hinge part 6311 hinged with the second supporting wheel 65; the two second hinges 6311 are hinged to the second bogie wheel 65 via the second axle 651. The hinge end of the second hinge portion 6311 extends horizontally outward in the radial direction of the second supporting wheel 65 to form an extension portion 6312, and the extension portions 6312 of the two swing frame plates 631 are connected by a second connecting plate 6313.

The first supporting wheel 64 is arranged between the hinge point of the screw 62 and the middle part of the swing frame 63. The first supporting wheel 64 is hinged to a transfer frame 67 through a first wheel axle 641. The conversion frame 67 includes conversion frame plates 671 respectively disposed on two sides of the first axle 641 in the axial direction, a top cover plate 672 connected to the upper ends of the two conversion frame plates 671, and a side cover plate 673 connected to one end of the two conversion frame plates 671 facing the screw 62, a vertically arranged rotating shaft 68 is fixed at the upper end of the top cover plate 672, an avoiding hole 674 for avoiding the screw 62 is formed in the side cover plate 673, and the two conversion frame plates 671 are hinged to the first supporting wheel 64 through the first axle 641.

A first connecting plate 633 horizontally arranged is connected between the two swing frame plates 631, and the rotating shaft 68 passes through the first connecting plate 633 and is detachably and fixedly connected with the first connecting plate 633 through a lock nut 642.

The bottom of the rotating shaft 68 is provided with a groove, the swinging frame 63 is provided with a protrusion at the lower end which is matched and hinged with the rotating shaft 68, and the groove and the protrusion can be mutually matched without clearance.

Explanation of the traverse switching:

the supporting wheel frame 61 is hinged with the rotating supporting leg 5, the middle part of the double-wheel swing frame 63 is hinged with the supporting wheel frame 61, one end of the double-thread screw 62 is hinged with the supporting wheel frame 61 and limits the up-and-down movement of the screw 62 through the limit nut 66, and the other end is in threaded connection with the supporting wheel frame 61, so that the double-wheel swing frame 63 swings up and down through the rotation of the double-thread screw 62, the first supporting wheel (small supporting wheel) 64 is hinged with the double-wheel swing frame 63 and is a wheel capable of realizing transverse walking and longitudinal walking, and the second supporting wheel 65 (large supporting wheel) is hinged with the tail end of the double-wheel swing frame 63 and is a wheel capable of realizing longitudinal walking.

Before switching, the initial position is as shown in fig. 6, the small thrust wheel 64 and the large thrust wheel 65 are simultaneously contacted with the ground, the thrust wheel structure is in a longitudinal walking state, and the left and right pairs of thrust wheels and the driving wheel 3 form three-point support of the tool vehicle so as to stabilize the whole vehicle.

The screw 62 has only circumferential rotational freedom due to the position limitation of the position limiting nut 66. The process of switching from the longitudinal walking state to the transverse walking state is as follows:

1) as shown in fig. 7, the screw 62 is rotated, and one end of the swing frame 63 screwed with the screw 62 moves upward along the screw 62, so that the first weight wheel 64 is lifted off the ground, the large weight wheel 65 is continuously contacted with the ground, and by releasing the fixed connection between the rotating shaft 68 and the swing frame 63, as shown in fig. 8, the rotating shaft 68 is rotated again, so that the first weight wheel 64 is rotated to a transverse traveling state perpendicular to the longitudinal traveling direction before, and the rotating shaft 68 is fixedly connected to the swing frame 63 through a lock nut.

2) As shown in fig. 9, the screw 62 is rotated in the reverse direction, and one end of the swing frame 63 in threaded connection with the screw 62 moves downward along the screw 62, so that the small thrust wheel 64 contacts the ground, the large thrust wheel 65 moves away from the ground, and the operating handle 2 is rotated at the same time, so that the driving direction of the driving wheel 3 is consistent with the direction of the small thrust wheel 64, and the button on the operating handle 2 is operated, so that the driving wheel 3 works, and the transverse walking of the whole vehicle in a narrow space is realized without a large turning space.

In addition, the double-thrust wheel can realize partial functions through a universal single-thrust wheel, and the single-thrust wheel has mechanical limit at the transverse and longitudinal running switching positions to limit the free floating of the single-thrust wheel. But poor off-road performance and on soft ground.

Or, as above, one universal wheel is changed into two small thrust wheels, so that under the condition of the same height from the ground, the thrust wheels are smaller, the effect is not good when the ground is more vertical obstacles, and only the vertical obstacles are relatively smaller.

The above description is only for the preferred embodiment of the present application and should not be taken as limiting the present application in any way, and although the present application has been disclosed in the preferred embodiment, it is not intended to limit the present application, and those skilled in the art should understand that they can make various changes and modifications within the technical scope of the present application without departing from the scope of the present application, and therefore all the changes and modifications can be made within the technical scope of the present application.

Claims

1. A supporting wheel structure is characterized by comprising a wheel frame (61), a screw rod (62), a swinging frame (63), a first supporting wheel (64) and a second supporting wheel (65), wherein one end of the wheel frame (61) is used for being connected with a vehicle body, and the other end of the wheel frame (61) is hinged with the middle part of the swinging frame (63); one end, close to the vehicle body, of the swinging frame (63) is in threaded connection with the lower end of the screw rod (62), one end, far away from the vehicle body, of the swinging frame (63) is hinged to the second supporting wheel (65), the upper end of the screw rod (62) penetrates through the wheel frame (61), and a limiting nut (66) abutted to the upper end face of the wheel frame (61) is fixed to the upper end of the screw rod (62); the first supporting wheel (64) is hinged to a conversion frame (67) through a first wheel shaft (641), the upper end of the conversion frame (67) is detachably and fixedly connected with the swinging frame (63) through a vertically arranged rotating shaft (68), and the first supporting wheel (64) is arranged between the screw rod (62) and a hinged point in the middle of the swinging frame (63).

2. The bogie wheel structure according to claim 1, wherein the wheel carrier (61) comprises two vertical and spaced apart wheel carrier plates (611), and a first hinge shaft (612) hinged between the two wheel carrier plates (611), and the limit nut (66) abuts against an upper end surface of the first hinge shaft (612).

3. The bogie wheel structure according to claim 2, wherein the oscillating frame (63) comprises two vertically spaced oscillating frame plates (631), and a second hinge shaft (632) hinged between the two oscillating frame plates (631), and the lower end of the screw (62) is in threaded connection with the second hinge shaft (632).

4. A bogie wheel structure according to claim 3, characterized in that the two rocker plates (631) are located between the two wheel frame plates (611), the two rocker plates (631) and the two wheel frame plates (611) being hinged by means of a third hinge axis (69).

5. The bogie wheel structure according to claim 3, wherein a first connecting plate (633) horizontally arranged is connected between the two swinging frame plates (631), and the rotating shaft (68) passes through the first connecting plate (633) and is detachably and fixedly connected with the first connecting plate (633) through a locking nut (642).

6. The bogie wheel structure according to any of claims 2 to 5 wherein a first hinge portion (613) for hinging with the vehicle body is connected between the end portions of the two bogie plates (611) facing the vehicle body.

7. A track roller structure according to any of claims 1 to 5, wherein the screw (62) is a double-ended screw.

8. A tool cart comprising a cart body (1), and legs (5) hinged to left and right side surfaces of the cart body (1), wherein the legs (5) are connected with a bogie wheel structure as claimed in any one of claims 1 to 7.

9. Tool vehicle according to claim 8, characterized in that the legs (5) are hinged to the wheel carrier (61) by means of a fourth hinge axis (52) arranged in the fore-and-aft direction of the vehicle body, so that the bogie structure in folded state can be rotated about the fourth hinge axis (52) to be arranged in the fore-and-aft direction of the vehicle body (1).

10. The tool cart according to claim 8 or 9, wherein the leg (5) is hinged to the cart body (1) through a fifth hinge shaft (53) perpendicular to the corresponding side surface, the side surface is provided with a working pin hole (12) and a folding pin hole (11), the axial center line of the working pin hole (12) and the axial center line of the fifth hinge shaft (53) are located in the same vertical plane, the axial center line of the folding pin hole (11) and the axial center line of the fifth hinge shaft (53) are located in the same horizontal plane, and the folding pin hole (11) and the thrust wheel structure are respectively arranged on two sides of the fifth hinge shaft (53) along the left-right direction of the cart body (1); the distance between the working pin hole (12) and the fifth hinging shaft (53) is equal to the distance between the folding pin hole (11) and the fifth hinging shaft (53); be connected with a horizontally arranged bolt pipe (54) on landing leg (5), bolt pipe (54) interpolation is equipped with a bolt (51), bolt (51) have the operating condition who inserts in work pinhole (12) to and insert the fold condition in fold pinhole (11), landing leg (5) can be practised around the rotatory in-process of fifth articulated shaft (53) bolt (51) are between operating condition and fold condition.