CN110615035A

CN110615035A - Wheeled vehicle

Info

Publication number: CN110615035A
Application number: CN201810628222.6A
Authority: CN
Inventors: 张振国; 张云雷; 梁冰; 沈勇; 张永胜
Original assignee: Technology Branch of XCMG Engineering Machinery Co Ltd
Current assignee: Technology Branch of XCMG Engineering Machinery Co Ltd
Priority date: 2018-06-19
Filing date: 2018-06-19
Publication date: 2019-12-27

Abstract

The invention discloses a wheeled vehicle having a low speed mode and a high speed mode. A wheeled vehicle includes: a first frame; a second frame hinged to the first frame; a first wheel relatively deflectably connected to the first frame; a wheel steering device for deflecting the first wheel relative to the first frame; the articulated steering device is arranged between the first frame and the second frame and is used for enabling the first frame and the second frame to rotate relatively; the hinge locking device relatively locks the first frame and the second frame in a high-speed mode; and the alignment locking device follows the deflection of the first wheel in the high-speed mode, and aligns and locks the first wheel with the first frame in the low-speed mode. The wheel type vehicle can utilize the relative rotation of the frame to steer in a low-speed mode, can stably and reliably utilize the deflection steering of the wheels in a high-speed mode, and is favorable for improving the smoothness and the operation stability of the high-speed running of the vehicle.

Description

Wheeled vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to a wheeled vehicle.

Background

In the engineering vehicle, the relative rotation radius of the frame is small, so that the maneuvering is flexible, and the relative rotation mode of the frame is widely applied. But the smoothness and the operation stability of the relative rotation high-speed running of the frame are poor. For some special requirements of users for high speed of the engineering vehicle, for example, when the users demand that the running speed of the wheel loader and the wheel bulldozer is greater than 80km/h, the current relative rotation mode of the common frame cannot meet the requirements of smoothness and steering stability when the engineering vehicle runs at high speed.

Disclosure of Invention

The invention aims to provide a wheeled vehicle which can utilize relative rotation steering of a frame in a low-speed mode and can stably and reliably switch to steering by utilizing wheel deflection in a high-speed mode, and is beneficial to improving the smoothness and the operation stability of high-speed running of the vehicle.

The present invention discloses a wheeled vehicle having a low speed mode and a high speed mode, comprising:

a first frame;

the second frame is hinged with the first frame;

a first wheel deflectably connected to the first frame;

a wheel steering device in driving connection with the first wheel for deflecting the first wheel relative to the first frame;

the articulated steering device is arranged between the first frame and the second frame and used for enabling the first frame and the second frame to rotate relatively;

an articulation lock that relatively locks the first frame and the second frame in the high speed mode and unlocks the first frame and the second frame in the low speed mode;

an alignment lock that follows the yaw of the first wheel in the high speed mode and locks the first wheel in alignment with the first frame in the low speed mode.

Further, the alignment locking device comprises an alignment locking oil cylinder and an alignment locking hydraulic circuit connected with the alignment locking oil cylinder, and the alignment locking oil cylinder is connected with the first wheel and the first frame.

Further, the alignment and locking oil cylinder comprises a cylinder barrel and a piston assembly, wherein the piston assembly comprises a piston rod and a first slide block assembly and a second slide block assembly which are connected with the piston rod; the first sliding block assembly and the second sliding block assembly divide an inner cavity of the cylinder barrel into a middle cavity between the first sliding block assembly and the second sliding block assembly, a first outer cavity outside the first sliding block assembly and a second outer cavity outside the second sliding block assembly; the first outer cavity is provided with a first oil port, the second outer cavity is provided with a second oil port, and the middle cavity is provided with a middle oil port;

the alignment locking hydraulic circuit comprises a pressure oil path and an oil return oil path, and the middle oil port is communicated with the oil return oil path;

in the high-speed mode, the alignment locking hydraulic circuit controls the first oil port and the second oil port to be communicated with the oil return oil way at the same time, and the piston rod follows the deflection of the first wheel; in the low-speed mode, the alignment locking hydraulic circuit controls the first oil port and the second oil port to be communicated with the pressure oil path at the same time, and the piston rod is locked at the alignment position of the piston rod under the action of the first sliding block assembly and the second sliding block assembly.

Further, the alignment locking hydraulic circuit comprises a first electromagnetic directional valve, a second electromagnetic directional valve, a first hydraulic control one-way valve and a second hydraulic control one-way valve; the working oil port of the first electromagnetic directional valve is connected with the hydraulic control port of the first hydraulic control one-way valve and the hydraulic control port of the second hydraulic control one-way valve; a working oil port of the second electromagnetic directional valve is connected with the first oil port and the second oil port through the first hydraulic control one-way valve and the second hydraulic control one-way valve respectively;

the pressure oil way is connected with a pressure oil port of the first electromagnetic directional valve and a pressure oil port of the second electromagnetic directional valve;

the oil return oil way is connected with an oil return port of the first electromagnetic reversing valve and an oil return port of the second electromagnetic reversing valve;

in the high-speed mode, a pressure oil port of the first electromagnetic directional valve is connected with a working oil port, and an oil return port of the second electromagnetic directional valve is connected with the working oil port; and in the low-speed mode, an oil return port of the first electromagnetic directional valve is connected with a working oil port, and an oil return port of the second electromagnetic directional valve is connected with the working oil port.

Further, the articulated locking device comprises an articulated locking oil cylinder for controlling relative locking and unlocking of the first frame and the second frame and a third electromagnetic directional valve for controlling the articulated locking oil cylinder, a pressure oil port of the third electromagnetic directional valve is connected with the pressure oil path, an oil outlet oil return port of the third electromagnetic directional valve is connected with the oil return path, and a first working oil port and a second working oil port of the third electromagnetic directional valve are respectively connected with a rod cavity and a rodless cavity of the articulated locking oil cylinder.

Further, the wheeled vehicle further comprises a controller, and the controller is coupled with the first electromagnetic directional valve, the second electromagnetic directional valve and the third electromagnetic directional valve to control the first electromagnetic directional valve, the second electromagnetic directional valve and the third electromagnetic directional valve to act.

Further, the hinge locking device comprises a hinge locking oil cylinder and a pin shaft connected with the hinge locking oil cylinder, a first pin hole and a second pin hole matched with the pin shaft are respectively formed in the first frame and the second frame, the hinge locking oil cylinder drives the pin shaft to move, so that the pin shaft can simultaneously penetrate through the first pin hole and the second pin hole to enable the first frame and the second frame to be in a relatively locked state and can be at least disengaged from one of the first pin hole and the second pin hole to enable the first frame and the second frame to be unlocked.

Further, the articulation locking device further comprises a travel switch, and the travel switch triggers the articulation steering device to be closed when the articulation locking device reaches a position for locking the first frame and the second frame relative to each other, so as to stop the action of rotating the first frame and the second frame relative to each other.

Further, the articulation locking arrangement comprises an angle sensor for detecting a relative yaw angle of the first frame and the second frame.

Further, the first wheel comprises a left wheel and a right wheel, the wheel steering device comprises a left wheel steering cylinder and a right wheel steering cylinder, the left wheel steering cylinder is connected with the left wheel and the first frame, and the right wheel steering cylinder is connected with the right wheel and the first frame; the rod cavity of the left wheel steering oil cylinder is communicated with the rodless cavity of the right wheel steering oil cylinder, and the rodless cavity of the left wheel steering oil cylinder is communicated with the rod cavity of the right wheel steering oil cylinder.

The wheeled vehicle provided by the invention can select the steering modes under two different modes, namely the low-speed mode and the high-speed mode, which are suitable for the driving state of the vehicle according to the driving state of the vehicle. Under the low-speed mode, can utilize the relative rotation to turn to between first frame and the second frame, first wheel is adjusted the locking well with first frame simultaneously, does benefit to the reliability of guaranteeing the relative rotation of frame. Under the high-speed mode, can lock first frame and second frame, then utilize the wheel deflection to turn to, it is reliable and stable, do benefit to and improve the ride comfort and the steering stability that the vehicle high-speed traveles.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a front view schematically showing a part of a structure of a wheeled vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic top view of a portion of the wheeled cart shown in FIG. 1;

figure 3 is a schematic top view of a portion of a wheeled cart in accordance with a further embodiment of the present invention;

FIG. 4 is a hydraulic schematic diagram of the alignment lock cylinder according to the embodiment of the present invention;

fig. 5 is a hydraulic schematic diagram of the articulated locking cylinder according to the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the following description, the term "front" refers to a side of the wheeled vehicle on which the head is located; "rear" refers to the side opposite to "front", and "left" and "right" refer to the left-right direction formed when facing the front.

The wheeled vehicle of the present embodiment has a low speed mode and a high speed mode. As shown in fig. 1 and 2, the wheeled vehicle includes a first frame 1, a second frame 6, a first wheel, a wheel steering device, an articulation lock device 4, and a registration lock device 17. The second frame 6 is hinged to the first frame 1. The first wheel is connected to the first frame 1 in a relatively pivotable manner. The wheel steering device is in driving connection with the first vehicle frame for deflecting the first vehicle wheel relative to the first vehicle frame 1, so that the wheeled vehicle can be turned by the deflection of the first vehicle wheel. The articulated steering device is arranged between the first frame 1 and the second frame 6 and is used for enabling the first frame 1 and the second frame 6 to rotate relatively. In the high-speed mode, the articulation lock locks the first frame 1 and the second frame 6 relative to each other, and the alignment lock 17 follows the deflection of the first wheel, i.e. in the high-speed mode, the alignment lock 17 follows only the corresponding action with the deflection of the first wheel, which does not hinder or interfere with the deflection of the first wheel. In the low speed mode the articulation lock unlocks the first frame 1 and the second frame 6 and the alignment lock 17 locks the first wheel in alignment with the first frame 1, i.e. the alignment lock 17 enables the first wheel to be rotated into alignment with the first frame 1 and simultaneously enables the first wheel to be locked in alignment with the first frame 1.

The wheeled vehicle of the present embodiment is capable of selecting a low speed mode and a high speed mode suitable for the running state of the vehicle. In the low-speed mode, the wheeled vehicle of the embodiment can utilize the relative rotation between the first frame 1 and the second frame 6 to obtain a smaller turning radius, and meanwhile, the first wheel and the first frame 1 can be aligned and locked, which is beneficial to improving the accuracy and reliability of the relative rotation of the frames. In the high-speed mode, the first frame 1 and the second frame 6 can be locked, and then the wheel deflection steering is carried out, so that the stability and the reliability are realized, and the smoothness and the operation stability of the high-speed running of the vehicle are improved.

As shown in fig. 1 and 2, the first wheel in this embodiment includes a left front wheel 14 and a right front wheel 7, and is then articulated to the axle and connected to the first frame 1 through the axle. In some embodiments, not shown, the first wheel may also be only one wheel; the first wheel can also be directly articulated to the first frame 1.

In some embodiments, the first wheel comprises a left front wheel 14 and a right front wheel 7, and the alignment locking device 17 may act on the left front wheel 14 and the right front wheel 7 respectively, or directly act on one of the left front wheel 14 and the right front wheel 7, and then drive the other wheel to be aligned and locked with the first frame 1 together through the connecting rod between the left front wheel 14 and the right front wheel 7.

In some embodiments, as shown in fig. 1, 2, 3, and 4, the alignment lock 17 includes an alignment lock cylinder connecting the first wheel and the first frame 1 and an alignment lock hydraulic circuit connected to the alignment lock cylinder. The alignment locking oil cylinder locks the alignment position of the piston rod through the extension and retraction of the piston rod and the alignment of the first wheel and the first frame 1, so that the alignment locking of the first wheel and the first frame 1 can be realized. The setting structure is simple, and the operation is convenient and reliable.

In some embodiments, as shown in FIG. 4, the alignment lock cylinder includes a cylinder barrel and a piston assembly including a piston rod and first and second slider assemblies 18 and 20 connected to the piston rod; the first slider assembly 18 and the second slider assembly 20 divide the inner cavity of the cylinder into an intermediate cavity between the first slider assembly 18 and the second slider assembly 20, a first outer cavity outside the first slider assembly 18, and a second outer cavity outside the second slider assembly 20; the first outer cavity is provided with a first oil port D1, the second outer cavity is provided with a second oil port D2, and the middle cavity is provided with a middle oil port D3; the middle oil port D3 is communicated with an oil return path T of the alignment lock-up hydraulic circuit. In the low speed mode, the alignment locking hydraulic circuit controls the first oil port D1 and the second oil port D2 to be communicated with the pressure oil path P of the alignment locking hydraulic circuit at the same time, and the piston rod is locked in the piston rod alignment position under the action of the first slide block assembly 18 and the second slide block assembly 20. In the high-speed mode, the alignment locking hydraulic circuit controls the first oil port D1 and the second oil port D2 to be simultaneously communicated with the oil return passage T, and the piston rod follows the deflection of the first wheel.

In some embodiments, as shown in fig. 4, the piston rod includes a straight piston rod extending out of the cylinder and a piston rod head located inside the cylinder and connected to the straight piston rod. The first sliding block component 18 is sleeved on the piston straight rod in a sleeved mode, is sealed with the piston straight rod and the inner wall of the cylinder barrel and can slide relatively. The second slider assembly 20 and the first slider assembly 18 are located on two sides of the piston rod head and sealed with the inner wall of the cylinder barrel and can slide relatively. The inner wall of the cylinder barrel is provided with a bulge for limiting the sliding stroke of the first sliding block component 18 and the second sliding block component 20 in the middle cavity, and the length of the bulge in the sliding direction of the piston rod is the same as that of the piston rod head. The first slider assembly 18 and the second slider assembly 20 may slide into abutment with the two ends of the protrusion, respectively, and the first slider assembly 18 may restrain the piston rod head by pushing one end face of the piston rod head and the second slider assembly 20 may restrain the piston rod head at a level with the protrusion in the sliding direction of the piston rod by pushing the other end face of the piston rod head.

In some embodiments, as shown in fig. 4, the positive lock hydraulic circuit includes a first solenoid directional valve S1, a second solenoid directional valve S2, a first pilot operated check valve, and a second pilot operated check valve. The working oil port A1 of the first electromagnetic directional valve S1 is connected with the hydraulic control port of the first hydraulic control one-way valve and the hydraulic control port of the second hydraulic control one-way valve. The working oil port a2 of the second electromagnetic directional valve S2 is connected with the first oil port D1 and the second oil port D2 through a first hydraulic control check valve and a second hydraulic control check valve, respectively. The pressure oil passage P is connected to a pressure port P1 of the first electromagnetic directional valve S1 and a pressure port P2 of the second electromagnetic directional valve S2. The oil return passage T is connected to an oil return port T1 of the first electromagnetic directional valve S1 and an oil return port T2 of the second electromagnetic directional valve S2. In the high-speed mode, the pressure port P1 of the first electromagnetic directional valve S1 is connected to the working port a1, and the return port T2 of the second electromagnetic directional valve S2 is connected to the working port a 2. At this time, the first hydraulic control one-way valve and the second hydraulic control one-way valve are opened, and the first outer cavity and the second outer cavity are both communicated with the oil return loop T, so that the piston rod can follow the deflection of the first wheel under the driving of the first wheel, and the alignment and locking device 17 has no limit effect on the deflection of the first wheel relative to the first frame. In the low speed mode, the oil return port T1 of the first electromagnetic directional valve S1 is connected to the working port a1, and the pressure port P2 of the second electromagnetic directional valve S2 is connected to the working port a 2. At this time, the first hydraulic control one-way valve and the second hydraulic control one-way valve are in one-way conduction, the first outer cavity and the second outer cavity are both communicated with the pressure oil path P, the piston rod is locked at the piston rod alignment position under the action of the first sliding block assembly 18 and the second sliding block assembly 20, and the first wheel is aligned and locked relative to the first frame by the alignment locking device 17.

The alignment locking hydraulic circuit can be matched with the alignment locking oil cylinder, and can stably and reliably realize the alignment locking function between the first wheel and the first frame 1 in the low-speed mode and the follow-up function of the alignment locking oil cylinder in the high-speed mode. Meanwhile, the stability of the control hydraulic circuit can be further improved due to the arrangement of the first hydraulic control one-way valve and the second hydraulic control one-way valve in the alignment and locking hydraulic circuit. Meanwhile, when the piston rod is aligned and locked, the pressure oil path P can be closed after the piston rod reaches the alignment position, and the first hydraulic control one-way valve and the second hydraulic control one-way valve can stably guarantee pressure oil in the first outer cavity and the second outer cavity, so that the piston rod is stably locked in the alignment position, the locking reliability is improved, and power is saved.

In some embodiments, the articulation locking device includes an articulation locking cylinder 4 and a pin connected to the articulation locking cylinder 4, the first frame 1 and the second frame 6 are respectively provided with a first pin hole and a second pin hole engaged with the pin, and the articulation locking cylinder 4 drives the pin to move so as to switch between a state in which the pin simultaneously passes through the first pin hole and the second pin hole to lock the first frame 1 and the second frame 6 relative to each other and a state in which the pin is disengaged from at least one of the first pin hole and the second pin hole to unlock the first frame 1 and the second frame 6.

As shown in fig. 1 and 5, the articulation lock device includes an articulation lock cylinder 4 and first and second pin holes provided on the first and second frames 1 and 6, respectively. And a piston rod of the hinged locking oil cylinder 4 is fixedly connected with a pin shaft of the pin hole structure. By extending and retracting the piston rod of the articulated locking cylinder 4, the pin shaft can be inserted into and withdrawn from the first and second pin holes, so that the first and second vehicle frames 1 and 6 can be locked or unlocked with respect to each other.

In some embodiments, as shown in fig. 1 and 5, the articulation locking device includes an articulation locking cylinder 4 for controlling the relative locking and unlocking of the first frame 1 and the second frame 6, and a third electromagnetic directional valve 19 for controlling the articulation locking cylinder 4. The pressure port P3 of the third electromagnetic directional valve 19 is connected to the pressure oil passage P. The oil return port T3 of the third electromagnetic directional valve 19 is connected to the oil return passage T. The first working oil port a3 and the second working oil port B3 of the third electromagnetic directional valve 19 are respectively connected with a rod cavity and a rodless cavity of the hinged locking oil cylinder 4.

In some embodiments, the wheeled vehicle further comprises a controller coupled to the first solenoid directional valve S1, the second solenoid directional valve S2, and the third solenoid directional valve 19 to control their actions. The controller controls the first electromagnetic reversing valve S1, the second electromagnetic reversing valve S2 and the third electromagnetic reversing valve 19 in a unified manner, so that the wheeled vehicle can be switched between a low-speed mode and a high-speed mode conveniently.

In some embodiments, as shown in fig. 1, the articulation locking device further comprises a travel switch 5, and the travel switch 5 triggers the articulation steering device to close when the articulation locking device reaches a position where the first frame 1 and the second frame 6 are locked relative to each other, so as to stop the action of rotating the first frame 1 and the second frame 6 relative to each other.

In some embodiments, the articulation lock comprises an angle sensor for detecting the relative angle of deflection of the first frame 1 and the second frame 6.

In some embodiments, as shown in fig. 2 and 3, the articulation lock comprises a left steering cylinder 11 and a right steering cylinder 8 between the first frame 1 and the second frame 6.

In some embodiments, as shown in fig. 1, 2, 3, the wheel steering apparatus includes a steering wheel, a steering gear 2, an angle drive 3, and a link mechanism 12. The steering wheel is connected with a steering gear 2 through an angle transmission device 3, the steering gear 2 is connected with a link mechanism 12, a pull rod 13 of the link mechanism 12 is connected with a left front wheel 14, and the left front wheel 14 is connected with a right front wheel 7 through a connecting rod.

In some embodiments, as shown in fig. 2, the first wheel comprises a left wheel 14 and a right wheel 7, the wheel steering device comprises a left wheel steering cylinder 15 and a right wheel steering cylinder 17, the left wheel steering cylinder 15 connects the left wheel 14 and the first frame 1, and the right wheel steering cylinder 17 connects the right wheel 7 and the first frame 1. The rod cavity of the left wheel steering oil cylinder 15 is communicated with the rodless cavity of the right wheel steering oil cylinder 17, and the rodless cavity of the left wheel steering oil cylinder 15 is communicated with the rod cavity of the right wheel steering oil cylinder 17. This arrangement contributes to improvement of the steering synchronism of the left and right wheels 14 and 7.

In the present embodiment, the first frame 1 and the second frame 6 are hinged by a hinge shaft 9. The articulated steering device comprises a left steering oil cylinder 11 and a right steering oil cylinder 8 which are arranged in bilateral symmetry. The left steering cylinder 11 and the right steering cylinder 8 are each connected between the first frame 1 and the second frame 6. When the first frame 1 and the second frame 6 are relatively rotated, the left steering cylinder 11 and the right steering cylinder 8 extend and retract, so that the first frame 1 and the second frame 6 are relatively rotated around the axis of the hinge shaft 9.

The working principle of the present invention is illustrated below by describing the working process of a wheeled vehicle according to an embodiment of the present invention:

a low-speed mode: as shown in fig. 3, 4 and 5, when the low-speed mode switch is pressed, the first electromagnetic directional valve S1 and the second electromagnetic directional valve S2 connected with the controller are electrically connected, and at this time, the first outer cavity and the second outer cavity of the alignment lock cylinder simultaneously enter high-pressure hydraulic oil to push the piston rod to enter an alignment position, and at this time, the first wheel is in an alignment lock state with the first frame 1. Meanwhile, JS2 of a third electromagnetic directional valve 19 connected with the controller is electrified, JS1 is electrified, oil enters a rod cavity of the hinged locking oil cylinder 4, oil returns from a rodless cavity, the hinged locking oil cylinder 4 releases hinged locking of the first frame 1 and the second frame 6, then the left wheel steering oil cylinder 15 and the right wheel steering oil cylinder 17 are closed, and finally the left steering oil cylinder 11 and the right steering oil cylinder 8 are enabled to act. When the piston rod of the left steering oil cylinder 11 retracts, the piston rod of the right steering oil cylinder 8 extends out, the first vehicle frame 1 rotates anticlockwise around the hinge mechanism 9, and the vehicle is steered to the left.

High-speed mode: as shown in fig. 3, 4 and 5, when the high-speed mode switch is pressed, it is determined that the first frame 1 and the second frame 6 are in the alignment position through the angle sensor 10, then JS1 of the third electromagnetic directional valve 19 connected with the controller is powered on, JS2 is powered off, no rod cavity of the hinged lockup cylinder 4 is powered on, oil is returned through the rod cavity, the hinged lockup cylinder 4 acts to lock the first frame 1 and the second frame 6, and at this time, after the travel switch 5 detects that the hinged lockup cylinder 4 reaches the set position, the left steering cylinder 11 and the right steering cylinder 8 act to close. And then the first electromagnetic directional valve S1 and the second electromagnetic directional valve S2 connected with the controller are de-energized, the first outer cavity and the second outer cavity of the alignment locking oil cylinder are both communicated with the oil return oil way T, the piston rod is in a floating position, the state of the alignment locking oil cylinder is changed into that the piston rod is follow-up with the first wheel, the alignment locking oil cylinder is unlocked, and the left wheel steering oil cylinder 15 and the right wheel steering oil cylinder 16 act according to the rotation of the steering wheel. When the steering wheel is turned to the left, the swing arm on the steering gear 2 swings forwards, the pull rod 13 is pushed forwards through the link mechanism 12, meanwhile, the piston rod of the left wheel steering oil cylinder 15 extends out, the piston rod of the right wheel steering oil cylinder 16 retracts, the piston rod of the alignment locking oil cylinder follows up, the left front wheel 14 rotates anticlockwise around the left hinge mechanism, and the right front wheel 7 is driven to rotate anticlockwise around the right hinge mechanism through the connecting rod, so that the left steering of the vehicle is realized. Similarly, the steering wheel is turned right, the swing arm on the steering gear 2 swings backwards, the pull rod 13 is pulled backwards through the link mechanism 12, meanwhile, the piston rod of the left wheel steering cylinder 15 retracts, the piston rod of the right wheel steering cylinder 16 extends out, the piston rod of the right wheel steering cylinder is aligned and locked to follow, the left front wheel 14 rotates clockwise around the left hinge mechanism, and the right front wheel 7 is driven to rotate clockwise around the right hinge mechanism through the connecting rod, so that the vehicle turns right.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A wheeled vehicle having a low speed mode and a high speed mode, comprising:

a first frame (1);

a second frame (6) articulated to the first frame (1);

a first wheel, which is connected to the first frame (1) in a deflectable manner;

a wheel steering device in driving connection with the first vehicle frame for deflecting the first vehicle wheel relative to the first vehicle frame (1);

the articulated steering device is arranged between the first frame (1) and the second frame (6) and is used for enabling the first frame (1) and the second frame (6) to rotate relatively;

an articulation locking device which locks the first frame (1) and the second frame (6) relative to each other in the high-speed mode and unlocks the first frame (1) and the second frame (6) in the low-speed mode;

an alignment locking device (17), wherein in the high speed mode, the alignment locking device (17) follows the deflection of the first wheel, and in the low speed mode, the alignment locking device (17) locks the first wheel in alignment with the first frame (1).

2. The wheeled vehicle of claim 1, characterized in that said alignment locking device (17) comprises an alignment locking cylinder and an alignment locking hydraulic circuit connected to said alignment locking cylinder, said alignment locking cylinder connecting said first wheel and said first frame (1).

3. The wheeled cart of claim 2,

the alignment locking oil cylinder comprises a cylinder barrel and a piston assembly, wherein the piston assembly comprises a piston rod, a first sliding block assembly (18) and a second sliding block assembly (20) which are connected with the piston rod; the first slider assembly (18) and the second slider assembly (20) divide the inner cavity of the cylinder into an intermediate cavity between the first slider assembly (18) and the second slider assembly (20), a first outer cavity outside the first slider assembly (18), and a second outer cavity outside the second slider assembly (20); the first outer cavity is provided with a first oil port (D1), the second outer cavity is provided with a second oil port (D2), and the middle cavity is provided with a middle oil port (D3);

the alignment locking hydraulic circuit comprises a pressure oil path (P) and an oil return path (T), and the middle oil port (D3) is communicated with the oil return path (T);

in the high speed mode, the alignment locking hydraulic circuit controls the first oil port (D1) and the second oil port (D2) to be simultaneously communicated with the oil return path (T), and the piston rod follows the deflection of the first wheel; in the low speed mode, the alignment locking hydraulic circuit controls the first oil port (D1) and the second oil port (D2) to be communicated with the pressure oil path (P) at the same time, and the piston rod is locked in a piston rod alignment position under the action of the first slider assembly (18) and the second slider assembly (20).

4. The wheeled cart of claim 3,

the alignment locking hydraulic circuit comprises a first electromagnetic directional valve (S1), a second electromagnetic directional valve (S2), a first hydraulic control one-way valve and a second hydraulic control one-way valve; a working oil port (A1) of the first electromagnetic directional valve (S1) is connected with a hydraulic control port of the first hydraulic control one-way valve and a hydraulic control port of the second hydraulic control one-way valve; a working oil port (A2) of the second electromagnetic directional valve (S2) is connected with the first oil port (D1) and the second oil port (D2) through the first hydraulic control one-way valve and the second hydraulic control one-way valve respectively;

the pressure oil path (P) is connected with a pressure oil port (P1) of the first electromagnetic directional valve (S1) and a pressure oil port (P2) of the second electromagnetic directional valve (S2);

the oil return oil way (T) is connected with an oil return port (T1) of the first electromagnetic reversing valve (S1) and an oil return port (T2) of the second electromagnetic reversing valve (S2);

in the high-speed mode, a pressure oil port (P1) of the first electromagnetic directional valve (S1) is connected with a working oil port (A1), and an oil return port (T2) of the second electromagnetic directional valve (S2) is connected with a working oil port (A2); in the low-speed mode, an oil return port (T1) of the first electromagnetic directional valve (S1) is connected with a working oil port (A1), and a pressure oil port (P2) of the second electromagnetic directional valve (S2) is connected with a working oil port (A2).

5. The wheeled vehicle of claim 4, characterized in that the articulation locking device comprises an articulation locking cylinder (4) for controlling the relative locking and unlocking of the first frame (1) and the second frame (6) and a third electromagnetic directional valve (19) for controlling the articulation locking cylinder (4), wherein a pressure oil port (P3) of the third electromagnetic directional valve (19) is connected with the pressure oil path (P), an oil return port (T3) of the third electromagnetic directional valve (19) is connected with the oil return path (T), and a first working oil port (A3) and a second working oil port (B3) of the third electromagnetic directional valve (19) are respectively connected with a rod chamber and a rodless chamber of the articulation locking cylinder (4).

6. The wheeled vehicle of claim 5, further comprising a controller coupled to said first solenoid directional valve (S1), said second solenoid directional valve (S2), and said third solenoid directional valve (19) to control actuation of said first solenoid directional valve (S1), said second solenoid directional valve (S2), and said third solenoid directional valve (19).

7. The wheeled vehicle of claim 1, characterized in that the articulation locking means comprises an articulation locking cylinder (4) and a pin connected to the articulation locking cylinder (4), the first frame (1) and the second frame (6) being provided with a first pin hole and a second pin hole respectively cooperating with the pin, the articulation locking cylinder (4) actuating the pin to switch between a state in which the pin simultaneously passes through the first pin hole and the second pin hole to lock the first frame (1) and the second frame (6) relative to each other and a state in which the pin is disengaged from at least one of the first pin hole and the second pin hole to unlock the first frame (1) and the second frame (6).

8. A wheeled vehicle according to claim 1, characterised in that the articulation locking means further comprises a travel switch (5), said travel switch (5) triggering the articulation steering means to close when the articulation locking means reaches a position in which the first frame (1) and the second frame (6) are locked relative to each other, to stop the action of relative rotation between the first frame (1) and the second frame (6).

9. A wheeled vehicle according to any one of claims 1 to 8, characterised in that said articulation locking means comprises an angle sensor for detecting the relative angle of deflection of said first frame (1) and said second frame (6).

10. The wheeled vehicle of claim 1, characterized in that said first wheels comprise left and right wheels, said wheel steering means comprises left and right wheel steering cylinders (15, 16), said left wheel steering cylinder (15) connecting said left wheels to said first frame (1), said right wheel steering cylinder (16) connecting said right wheels to said first frame (1); the rod cavity of the left wheel steering oil cylinder (15) is communicated with the rodless cavity of the right wheel steering oil cylinder (16), and the rodless cavity of the left wheel steering oil cylinder (15) is communicated with the rod cavity of the right wheel steering oil cylinder (16).