Rear wheel steering system and vehicle

Abstract

The utility model relates to a rear wheel steering system and a vehicle. The rear wheel steering system comprises an oil cylinder assembly, a steering pull rod assembly and a hydraulic source. The oil cylinder assembly is connected with the steering pull rod assembly, and the steering pull rod assembly is suitable for being connected with a left rear wheel and a right rear wheel; the hydraulic source is used for supplying liquid to the oil cylinder assembly, so that the oil cylinder assembly can drive the steering pull rod assembly to move so as to drive the left rear wheel and the right rear wheel which are connected to the steering pull rod assembly to steer. According to the rear wheel steering system, a motor and a gear and rack mechanism in the prior art are replaced by the hydraulic source and the oil cylinder assembly, so that the size of the rear wheel steering system can be reduced, the situation that the rear wheel steering system occupies too much space of a vehicle is avoided, and installation and arrangement of other parts of the vehicle are facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile steering, and in particular relates to a rear wheel steering system and a vehicle. Background Art

[0002] With the development of automotive technology and market demand, more and more models are equipped with rear-wheel steering systems. The main function of rear-wheel steering systems is to reduce the vehicle's turning radius at low speeds, improving vehicle maneuverability, and enhance vehicle response and handling at high speeds.

[0003] In the prior art, rear-wheel steering systems typically consist of a motor, a rack-and-pinion mechanism, and a steering rod assembly. The motor is connected to the gears of the rack-and-pinion mechanism, which is hinged to the steering rod, which is hinged to the rear wheels. During operation, the motor drives the gears to rotate, which in turn drives the rack to move linearly left and right. The rack then applies force to the rear wheels via the steering rod, driving the rear wheels to steer.

[0004] However, this rear-wheel steering system has a large structural size, occupies a large amount of space in the vehicle, and is not conducive to the arrangement of other components of the vehicle. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a rear-wheel steering system and a vehicle in view of the problem that the existing rear-wheel steering system has a large structural size and occupies a large amount of space in the vehicle.

[0006] In order to solve the above problems, on the one hand, the utility model provides a rear-wheel steering system, including a cylinder assembly, a steering rod assembly and a hydraulic source; the cylinder assembly is connected to the steering rod assembly, and the steering rod assembly is suitable for connecting the left rear wheel and the right rear wheel; the hydraulic source is connected to the cylinder assembly to supply fluid to the cylinder assembly, so that the cylinder assembly can drive the steering rod assembly to move, thereby driving the left rear wheel and the right rear wheel connected to the steering rod assembly to steer.

[0007] Optionally, the steering rod assembly includes a first steering rod and a second steering rod; one end of the first steering rod is rotatably connected to the cylinder assembly, and the other end of the first steering rod is suitable for rotatably connecting to the left rear wheel; one end of the second steering rod is rotatably connected to the cylinder assembly, and the other end of the second steering rod is suitable for rotatably connecting to the right rear wheel.

[0008] Optionally, the cylinder assembly includes a cylinder body, a piston and a piston rod; a liquid chamber is provided in the cylinder body, and the liquid chamber completely penetrates the cylinder body along the length direction of the cylinder body; the piston rod is passed through the liquid chamber, and both ends of the piston rod extend out of the liquid chamber and are rotatably connected to the first steering rod and the second steering rod respectively; the piston is connected to the piston rod and is located in the liquid chamber; in the length direction of the cylinder body, the piston divides the liquid chamber into a first chamber and a second chamber; the first chamber and the second chamber are respectively connected to the hydraulic source, so that when the hydraulic source transports liquid to one of the first chamber and the second chamber, the liquid in the other of the first chamber and the second chamber can flow back to the hydraulic source.

[0009] Optionally, the cylinder assembly includes a first hydraulic cylinder and a second hydraulic cylinder arranged separately, and the first hydraulic cylinder and the second hydraulic cylinder are both connected to the hydraulic source; the piston rod of the first hydraulic cylinder is rotationally connected to the first steering rod; the piston rod of the second hydraulic cylinder is rotationally connected to the second steering rod.

[0010] Optionally, in the left-right direction, the first steering rod, the first hydraulic cylinder, the second hydraulic cylinder and the second steering rod are arranged in sequence.

[0011] Optionally, the first steering rod is located on the left side of the cylinder assembly, and the second steering rod is located on the right side of the cylinder assembly.

[0012] In order to solve the above problems, on the other hand, the utility model provides a vehicle, including a body, a left rear wheel, a right rear wheel and a rear-wheel steering system described in any one of the above items; the left rear wheel, the right rear wheel and the rear-wheel steering system are all connected to the body; the steering rod assembly is respectively connected to the left rear wheel and the right rear wheel.

[0013] Optionally, the vehicle also includes a left front wheel, a right front wheel and a hydraulic brake; the hydraulic brake is connected to at least one of the left rear wheel, the right rear wheel, the left front wheel and the right front wheel; the hydraulic source is connected to the hydraulic brake to supply fluid to the hydraulic brake, so that the hydraulic brake can brake and release the wheel on which it is located.

[0014] Optionally, the vehicle further includes a rear subframe, the rear subframe being connected to the vehicle body, and the oil cylinder assembly being connected to the rear subframe.

[0015] Optionally, the oil cylinder assembly is detachably connected to the rear subframe.

[0016] In the rear-wheel steering system and vehicle provided in the embodiment of the present invention, the steering rod assembly is driven by the cooperation of the hydraulic source and the cylinder assembly, which is equivalent to replacing the motor and the gear rack mechanism in the prior art with the hydraulic source and the cylinder assembly. That is, this embodiment replaces the motor drive system in the prior art with the hydraulic drive system. In this way, the volume of the rear-wheel steering system can be reduced while the external output driving force is the same, thereby avoiding the rear-wheel steering system from occupying too much space in the vehicle, which is beneficial to the installation and arrangement of other components of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the rear wheel steering system provided by one embodiment of the present utility model in cooperation with two rear wheels;

[0018] Figure 2 This is a partial structural diagram of a rear wheel steering system provided by an embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram of the hydraulic circuit of the rear wheel steering system provided by an embodiment of the present invention. Figure 1 ;

[0020] Figure 4 This is a schematic diagram of the hydraulic circuit of the rear wheel steering system provided by an embodiment of the present invention. Figure 2 ;

[0021] Figure 5 This is a schematic diagram of the hydraulic circuit of the rear wheel steering system provided by another embodiment of the utility model. Figure 1 ;

[0022] Figure 6 This is a schematic diagram of the hydraulic circuit of the rear wheel steering system provided by another embodiment of the utility model. Figure 2 .

[0023] The reference numerals in the specification are as follows:

[0024] 10. Rear wheel steering system; 20. Left rear wheel; 30. Right rear wheel;

[0025] 1. Cylinder assembly; 11. Cylinder body; 12. Piston; 13. Piston rod; 14. Fluid chamber; 141. First fluid chamber; 142. Second fluid chamber; 15. First hydraulic cylinder; 16. Second hydraulic cylinder;

[0026] 2. Steering rod assembly; 21. First steering rod; 22. Second steering rod;

[0027] 3. Hydraulic source; 31. Oil tank; 32. Oil pump; 33. First reversing valve; a1. First input interface; a2. Second input interface; b1. First output interface; b2. Second output interface;

[0028] 4. Hydraulic brake; 41. First oil chamber; 42. Second oil chamber;

[0029] 51. First connector; 52. Second connector;

[0030] 61, first control valve; 62, second control valve; c1, first inlet; c2, second inlet; c3, third inlet; c4, fourth inlet; d1, first outlet; d2, second outlet; d3, third outlet; d4, fourth outlet;

[0031] 71. First pipe joint; 72. Second pipe joint;

[0032] 81, second reversing valve; 82, third reversing valve; a3, third input interface; a4, fourth input interface; a5, fifth input interface; a6, sixth input interface; b3, third output interface; b4, fourth output interface; b5, fifth output interface; b6, sixth output interface. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] like Figure 1 As shown, in one embodiment, a vehicle includes a vehicle body, a left rear wheel 20, a right rear wheel 30, and the rear-wheel steering system 10 described in any of the above embodiments; the left rear wheel 20, the right rear wheel 30, and the rear-wheel steering system 10 are all connected to the vehicle body; the rear-wheel steering system 10 is respectively connected to the left rear wheel 20 and the right rear wheel 30 to control the steering of these two rear wheels. The left rear wheel 20 is connected to the left side of the vehicle body, and the right rear wheel 30 is connected to the right side of the vehicle body.

[0035] like Figure 1 As shown, in one embodiment, the rear-wheel steering system 10 includes a cylinder assembly 1, a steering rod assembly 2 and a hydraulic source 3; wherein the cylinder assembly 1 is connected to the steering rod assembly 2, and the steering rod assembly 2 is suitable for connecting the left rear wheel 20 and the right rear wheel 30; the hydraulic source 3 is used to supply fluid to the cylinder assembly 1, so that the cylinder assembly 1 can drive the steering rod assembly 2 to move, thereby driving the left rear wheel 20 and the right rear wheel 30 connected to the steering rod assembly 2 to steer.

[0036] In this embodiment, the hydraulic source 3 and the cylinder assembly 1 are used to replace the motor and the rack and pinion mechanism in the prior art, that is, the hydraulic drive system is used to replace the motor drive system. In this way, the volume of the rear-wheel steering system 10 can be reduced while the external output driving force is the same, thereby avoiding the rear-wheel steering system 10 occupying too much space in the vehicle, which is beneficial to the installation and arrangement of other components of the vehicle.

[0037] In addition, the hydraulic source 3 can be connected to the cylinder assembly 1 through a corresponding pipeline to supply fluid to the cylinder assembly 1. Moreover, the hydraulic source 3 can store oil, so that the hydraulic source 3 can supply oil to the cylinder assembly 1.

[0038] It should be understood that the left rear wheel 20 and the right rear wheel 30 are both connected to the vehicle body through corresponding suspension systems. The steering rod assembly 2 drives the two rear wheels to steer actually means that the steering rod assembly 2 drives the steering knuckle of the suspension system connected to the two rear wheels to steer, thereby realizing the steering of the two rear wheels.

[0039] Specifically, the left rear wheel 20 is connected to the vehicle body through a first suspension system, and the right rear wheel 30 is connected to the vehicle body through a second suspension system. The steering knuckle of the first suspension system is defined as the first steering knuckle, and the steering knuckle of the second suspension system is defined as the second steering knuckle. The left rear wheel 20 is installed on the first steering knuckle, and the right rear wheel 30 is installed on the second steering knuckle. The steering rod assembly 2 is connected to the first steering knuckle and the second steering knuckle respectively.

[0040] like Figure 1 and Figure 2 As shown, in one embodiment, the steering tie rod assembly 2 includes a first steering tie rod 21 and a second steering tie rod 22. One end of the first steering tie rod 21 is rotatably connected to the cylinder assembly 1, and the other end of the first steering tie rod 21 is adapted to be rotatably connected to the left rear wheel 20. One end of the second steering tie rod 22 is rotatably connected to the cylinder assembly 1, and the other end of the second steering tie rod 22 is adapted to be rotatably connected to the right rear wheel 30. This arrangement can simplify the structure of the steering tie rod assembly 2 and facilitate assembly of the rear-wheel steering system 10.

[0041] The first steering rod 21 being rotatably connected to the left rear wheel 20 means that the first steering rod 21 is rotatably connected to the first steering knuckle. The second steering rod 22 being rotatably connected to the right rear wheel 30 means that the second steering rod 22 is rotatably connected to the second steering knuckle.

[0042] In one embodiment, a first universal joint structure is used to achieve a universal rotation connection between the first steering rod 21 and the cylinder assembly 1, and a second universal joint structure is used to achieve a universal rotation connection between the second steering rod 22 and the cylinder assembly 1. Either the first universal joint structure or the second universal joint structure may be a universal ball joint structure.

[0043] Furthermore, a third universal joint structure provides a universal rotation connection between the first steering rod 21 and the left rear wheel 20 (i.e., the first steering knuckle). A fourth universal joint structure provides a universal rotation connection between the second steering rod 22 and the right rear wheel 30 (i.e., the second steering knuckle). Either the third or fourth universal joint structure may utilize a universal ball joint.

[0044] like Figure 1 and Figure 2 As shown, in one embodiment, the first steering rod 21 is located on the left side of the cylinder assembly 1, and the second steering rod 22 is located on the right side of the cylinder assembly 1. This can make the setting of the rear-wheel steering system 10 simpler and facilitate the installation and use of the rear-wheel steering system 10.

[0045] like Figure 2 As shown, in one embodiment, the cylinder assembly 1 includes a cylinder body 11, a piston 12 and a piston rod 13; a liquid chamber 14 is provided in the cylinder body 11, and the liquid chamber 14 completely penetrates the cylinder body 11 along the length direction of the cylinder body 11; the piston rod 13 is provided in the liquid chamber 14, and both ends of the piston rod 13 extend out of the liquid chamber 14, and the two ends of the piston rod 13 are rotatably connected to the first steering rod 21 and the second steering rod 22 respectively; the piston 12 is connected to the piston rod 13 and is located in the liquid chamber 14, and the piston 12 divides the liquid chamber 14 into a first liquid chamber 141 and a second liquid chamber 142 along the length direction of the cylinder body 11; the first liquid chamber 141 and the second liquid chamber 142 are respectively connected to the hydraulic source 3, so that when the hydraulic source 3 delivers liquid to one of the first liquid chamber 141 and the second liquid chamber 142, the liquid in the other of the first liquid chamber 141 and the second liquid chamber 142 can flow back to the hydraulic source 3.

[0046] That is, in this embodiment, the cylinder assembly 1 comprises a dual-rod hydraulic cylinder, and the two steering tie rods are driven by the two ends of the dual-rod hydraulic cylinder's piston rod 13. This arrangement simplifies the structure of the cylinder assembly 1 and reduces its size, thereby facilitating the installation of the rear-wheel steering system 10 and reducing the space occupied by the rear-wheel steering system 10 in the vehicle.

[0047] The length direction of the cylinder body 11 is the axial direction of the piston rod 13 , and the first liquid chamber 141 and the second liquid chamber 142 are arranged in sequence along the length direction of the cylinder body 11 .

[0048] like Figure 2As shown, the first liquid chamber 141 is located to the left of the second liquid chamber 142; when the hydraulic source 3 flows liquid into the first liquid chamber 141, the piston rod 13 moves to the right, which can make the two rear wheels turn left, and the liquid in the second liquid chamber 142 will flow back into the hydraulic source 3; when the hydraulic source 3 flows liquid into the second liquid chamber 142, the piston rod 13 moves to the left, which can make the two rear wheels turn right, and the liquid in the first liquid chamber 141 will flow back into the hydraulic source 3. Figure 1 In the example shown, the dotted line portion is a diagram when both rear wheels are turning to the right.

[0049] like Figure 3 As shown, in one embodiment, the hydraulic source 3 includes an oil tank 31, an oil pump 32, and a first reversing valve 33. The first reversing valve 33 has a first input port a1, a second input port a2, a first output port b1, and a second output port b2. The input port of the oil pump 32 is connected to the oil tank 31, the output port of the oil pump 32 is connected to the first input port a1, and the second input port a2 is also connected to the oil tank 31. The first output port b1 is connected to the first fluid chamber 141, and the second output port b2 is connected to the second fluid chamber 142.

[0050] In addition, the first reversing valve 33 has a switchable first working state and a second working state: when the first reversing valve 33 is in the first working state, the first input interface a1 is connected to the first output interface b1, the second input interface a2 is connected to the second output interface b2, the first input interface a1 is not connected to the second output interface b2, and the second input interface a2 is not connected to the first output interface b1; when the first reversing valve 33 is in the second working state, the first input interface a1 is connected to the second output interface b2, the second input interface a2 is connected to the first output interface b1, the first input interface a1 is not connected to the first output interface b1, and the second input interface a2 is not connected to the second output interface b2.

[0051] When the two rear wheels are controlled to turn left, the first reversing valve 33 is controlled to switch to the first working state, and the oil pump 32 is controlled to work; at this time, the liquid in the oil tank 31 will enter the oil pump 32 from the input port of the oil pump 32, and enter the first reversing valve 33 from the output port of the oil pump 32, and enter the first liquid chamber 141 through the first input interface a1 and the first output interface b1; the liquid in the second liquid chamber 142 enters the oil tank 31 through the second output interface b2 and the second input interface a2.

[0052] When the two rear wheels are controlled to turn right, the first reversing valve 33 is controlled to switch to the second working state, and the oil pump 32 is controlled to work; at this time, the liquid in the oil tank 31 will enter the oil pump 32 from the input port of the oil pump 32, and enter the first reversing valve 33 from the output port of the oil pump 32, and enter the second liquid chamber 142 through the first input interface a1 and the second output interface b2; the liquid in the first liquid chamber 141 enters the oil tank 31 through the first output interface b1 and the second input interface a2.

[0053] The first reversing valve 33 may be a three-position four-way electromagnetic first reversing valve 33 or the like.

[0054] It should be noted that the implementation method of controlling the operation of the double-rod hydraulic cylinder by the hydraulic source 3 may also adopt other existing designs, which will not be described in detail in this embodiment.

[0055] In addition, the vehicle also includes a left front wheel, a right front wheel and a hydraulic brake 4 (refer to Figure 4 ); At least one of the left rear wheel 20, the right rear wheel 30, the left front wheel and the right front wheel is connected to a hydraulic brake 4; the hydraulic source 3 is connected to the hydraulic brake 4 to supply fluid to the hydraulic brake 4, so that the hydraulic brake 4 can brake and release the wheels on which it is located.

[0056] In other words, the hydraulic source 3 of the rear-wheel steering system 10 also serves as the hydraulic source 3 of the hydraulic brake system, achieving multiple uses and reducing vehicle costs. In actual scenarios, the hydraulic source 3 is the electric hydraulic brake booster of the hydraulic brake system. In this case, the configuration of this embodiment is equivalent to extracting two pipelines from the vehicle's existing hydraulic brake system to control the operation of the cylinder assembly 1, further reducing the space occupied by the rear-wheel steering system 10 in the vehicle.

[0057] Typically, the left rear wheel 20, the right rear wheel 30, the left front wheel, and the right front wheel are all equipped with hydraulic brakes 4. In this case, the hydraulic brakes 4 on the four wheels can all be connected to the hydraulic source 3, and the hydraulic source 3 can control the hydraulic brakes 4 on the four wheels respectively.

[0058] The operation of each hydraulic brake 4 will be described using the example of the hydraulic source 3 controlling the hydraulic brake 4 on the left rear wheel 20 (this brake is defined as the first brake): the first oil port of the hydraulic source 3 is connected to the first oil chamber 41 of the first brake via a first pipe, and the second oil port of the hydraulic source 3 is connected to the second oil chamber 42 of the first brake via a second pipe. When the fluid from the hydraulic source 3 flows into the first oil chamber 41 of the first brake through the first oil port and the first pipe, the fluid in the second oil chamber 42 of the first brake flows back to the hydraulic source 3 through the second pipe and the second oil port. At this time, the first brake can be controlled to brake the left rear wheel 20, thereby achieving braking of the left rear wheel 20. When the fluid from the hydraulic source 3 flows into the second oil chamber 42 of the first brake through the second oil port and the second pipe, the fluid in the first oil chamber 41 of the first brake flows back to the hydraulic source 3 through the first pipe and the first oil port. At this time, the first brake can be controlled to release the left rear wheel 20, thereby achieving braking of the left rear wheel 20.

[0059] It should be understood that the first oil port may be the first output interface b1 of the first reversing valve 33 , and the second oil port may be the second output interface b2 of the first reversing valve 33 .

[0060] In a feasible embodiment, the pipeline for the hydraulic source 3 to supply fluid to the first brake can be divided into two routes, one of which supplies fluid to the first brake and the other supplies fluid to the cylinder assembly 1 .

[0061] At this time, the rear-wheel steering system 10 further includes a first connector 51 , a second connector 52 , a first control valve 61 and a second control valve 62 .

[0062] The first connector 51 has three interconnected channels, namely the first channel, the second channel and the third channel, and the second connector 52 has three interconnected channels, namely the fourth channel, the fifth channel and the sixth channel. In addition, both the first connector 51 and the second connector 52 can be three-way connectors.

[0063] Among them, the first control valve 61 has a first inlet c1, a second inlet c2, a first outlet d1 and a second outlet d2, and the second control valve 62 has a third inlet c3, a fourth inlet c4, a third outlet d3 and a fourth outlet d4; the first control valve 61 and the second control valve 62 both have a first state, a second state and a third state.

[0064] When the first control valve 61 is in the first state, the first inlet c1 is connected to the first outlet d1, the second inlet c2 is connected to the second outlet d2, the first inlet c1 is not connected to the second outlet d2, and the second inlet c2 is not connected to the first outlet d1; when the first control valve 61 is in the second state, the first inlet c1 is connected to the second outlet d2, the second inlet c2 is connected to the first outlet d1, the first inlet c1 is not connected to the first outlet d1, and the second inlet c2 is not connected to the second outlet d2; when the first control valve 61 is in the third state, the first inlet c1 is not connected to the first outlet d1, the first inlet c1 is not connected to the second outlet d2, the second inlet c2 is not connected to the first outlet d1, and the second inlet c2 is not connected to the second outlet d2.

[0065] When the second control valve 62 is in the first state, the third inlet c3 is connected to the third outlet d3, the fourth inlet c4 is connected to the fourth outlet d4, the third inlet c3 is not connected to the fourth outlet d4, and the fourth inlet c4 is not connected to the third outlet d3; when the second control valve 62 is in the second state, the third inlet c3 is connected to the fourth outlet d4, the fourth inlet c4 is connected to the third outlet d3, the third inlet c3 is not connected to the third outlet d3, and the fourth inlet c4 is not connected to the fourth outlet d4; when the second control valve 62 is in the third state, the third inlet c3 is not connected to the third outlet d3, the third inlet c3 is not connected to the fourth outlet d4, the fourth inlet c4 is not connected to the third outlet d3, and the fourth inlet c4 is not connected to the fourth outlet d4.

[0066] In addition, the first control valve 61 and the second control valve 62 may both be three-position four-way electromagnetic control valves.

[0067] After assembly, the first oil port is connected to the first channel, the second channel is connected to the first inlet c1, the third channel is connected to the third inlet c3, the second oil port is connected to the fourth channel, the fifth channel is connected to the second inlet c2, and the sixth channel is connected to the fourth inlet c4; the first outlet d1 is connected to the first liquid chamber 141, the second outlet d2 is connected to the second liquid chamber 142, the third outlet d3 is connected to the first oil chamber 41, and the fourth outlet d4 is connected to the second oil chamber 42.

[0068] When the hydraulic source 3 supplies oil, by controlling the states of the first control valve 61 and the second control valve 62, the flow direction of the liquid output by the hydraulic source 3 can be controlled, thereby controlling the steering of the rear wheels and the operation of the first brake valve.

[0069] For example, if the first control valve 61 is in the first state and the second control valve 62 is in the third state; the liquid flowing out of the first oil port will enter the first liquid chamber 141, and the liquid in the second liquid chamber 142 will flow back to the hydraulic source 3, and at this time, the hydraulic source 3 does not control the operation of the first brake valve.

[0070] If the first control valve 61 is in the third state and the second control valve 62 is in the first state, the liquid flowing out of the first oil port will enter the first oil chamber 41, and the liquid in the second oil chamber 42 will flow back to the hydraulic source 3. At this time, the hydraulic source 3 does not control the operation of the cylinder assembly 1.

[0071] In one embodiment, the vehicle further comprises a rear sub-frame connected to the vehicle body, and the oil cylinder assembly 1 is connected to the rear sub-frame. Specifically, the cylinder body 11 of the oil cylinder assembly 1 is connected to the rear sub-frame.

[0072] In one embodiment, the oil cylinder assembly 1 is detachably connected to the rear sub-frame. Specifically, the cylinder body 11 can be connected to the rear sub-frame by bolts or the like, thereby achieving a detachable connection with the rear sub-frame.

[0073] In addition, the axial direction of the piston rod 13 is parallel to the left-right direction.

[0074] It should be understood that the above-mentioned related designs can also be replaced by other methods, such as:

[0075] like Figure 5 and Figure 6 As shown, in other embodiments, the cylinder assembly 1 includes a first hydraulic cylinder 15 and a second hydraulic cylinder 16 that are separately arranged. The first hydraulic cylinder 15 and the second hydraulic cylinder 16 are both connected to the hydraulic source 3. The piston rod of the first hydraulic cylinder 15 is rotatably connected to the first steering rod 21; the piston rod of the second hydraulic cylinder 16 is rotatably connected to the second steering rod 22. The first hydraulic cylinder 15 and the second hydraulic cylinder 16 can both be single-rod hydraulic cylinders.

[0076] In one embodiment, the first hydraulic cylinder 15 and the second hydraulic cylinder 16 may be spaced apart in the left-right direction. In the left-right direction, the first hydraulic cylinder 15 may be located between the first steering rod 21 and the second hydraulic cylinder 16, and the second hydraulic cylinder 16 may be located between the second steering rod 22 and the first hydraulic cylinder 15. The piston rod of the first hydraulic cylinder 15 extends from the left side of the cylinder body of the first hydraulic cylinder 15, and the piston rod of the second hydraulic cylinder 16 extends from the right side of the cylinder body of the second hydraulic cylinder 16.

[0077] like Figure 5As shown, in one feasible embodiment, the first output port b1 is connected to the rod chamber of the first hydraulic cylinder 15, and the first output port b1 is connected to the rodless chamber of the second hydraulic cylinder 16. The second output port b2 is connected to the rodless chamber of the first hydraulic cylinder 15, and the second output port b2 is connected to the rod chamber of the second hydraulic cylinder 16. Thus, when the first reversing valve 33 is in the first state, both rear wheels turn left, and when the first reversing valve 33 is in the second state, both rear wheels turn right. Of course, the hydraulic source 3, the first hydraulic cylinder 15, and the second hydraulic cylinder 16 may also adopt other existing designs, and other existing connection methods may also be used to enable the hydraulic source 3 to control the extension or retraction of the piston rods of the first hydraulic cylinder 15 and the second hydraulic cylinder 16. Alternatively, there may be two hydraulic sources 3, with one hydraulic source controlling the extension or retraction of the piston rod of the first hydraulic cylinder 15 and the other hydraulic source controlling the extension or retraction of the piston rod of the second hydraulic cylinder 16.

[0078] like Figure 6 As shown, in another feasible embodiment, the hydraulic source 3 can also be capable of controlling only one hydraulic cylinder. In this case, without changing the structure of the hydraulic source 3, the rear-wheel steering system 10 further includes a first pipe joint 71, a second pipe joint 72, a second reversing valve 81, and a third reversing valve 82.

[0079] The first pipe joint 71 has three interconnected flow channels, namely the first flow channel, the second flow channel, and the third flow channel, and the second pipe joint 72 has three interconnected flow channels, namely the fourth flow channel, the fifth flow channel, and the sixth flow channel. In addition, the first pipe joint 71 and the second pipe joint 72 can both be three-way joints.

[0080] The second reversing valve 81 has a third input interface a3, a fourth input interface a4, a third output interface b3 and a fourth output interface b4, and the third reversing valve 82 has a fifth input interface a5, a sixth input interface a6, a fifth output interface b5 and a sixth output interface b6; the second reversing valve 81 and the third reversing valve 82 both have a first usage state, a second usage state and a third usage state.

[0081] When the second reversing valve 81 is in the first usage state, the third input interface a3 is connected to the third output interface b3, the fourth input interface a4 is connected to the fourth output interface b4, the third input interface a3 is not connected to the fourth output interface b4, and the fourth input interface a4 is not connected to the third output interface b3; when the second reversing valve 81 is in the second usage state, the third input interface a3 is connected to the fourth output interface b4, the fourth input interface a4 is connected to the third output interface b3, the third input interface a3 is not connected to the third output interface b3, and the fourth input interface a4 is not connected to the fourth output interface b4; when the second reversing valve 81 is in the third usage state, the third input interface a3 is not connected to the third output interface b3, the third input interface a3 is not connected to the fourth output interface b4, the fourth input interface a4 is not connected to the third output interface b3, and the fourth input interface a4 is not connected to the fourth output interface b4.

[0082] When the third reversing valve 82 is in the first usage state, the fifth input interface a5 is connected to the fifth output interface b5, the sixth input interface a6 is connected to the sixth output interface b6, the fifth input interface a5 is not connected to the sixth output interface b6, and the sixth input interface a6 is not connected to the fifth output interface b5; when the third reversing valve 82 is in the second usage state, the fifth input interface a5 is connected to the sixth output interface b6, the sixth input interface a6 is connected to the fifth output interface b5, the fifth input interface a5 is not connected to the fifth output interface b5, and the sixth input interface a6 is not connected to the sixth output interface b6; when the third reversing valve 82 is in the third usage state, the fifth input interface a5 is not connected to the fifth output interface b5, the fifth input interface a5 is not connected to the sixth output interface b6, the sixth input interface a6 is not connected to the fifth output interface b5, and the sixth input interface a6 is not connected to the sixth output interface b6.

[0083] In addition, the second reversing valve 81 and the third reversing valve 82 can both be three-position four-way electromagnetic control valves.

[0084] After assembly, the first oil port is connected to the first flow channel, the second flow channel is connected to the third input interface a3, the third flow channel is connected to the fifth input interface a5, the second oil port is connected to the fourth flow channel, the fifth flow channel is connected to the fourth input interface a4, and the sixth flow channel is connected to the sixth input interface a6; the third output interface b3 is connected to the rod chamber of the first hydraulic cylinder 15, and the fourth output interface b4 is connected to the rodless chamber of the first hydraulic cylinder 15; the fifth output interface b5 is connected to the rodless chamber of the second hydraulic cylinder 16, and the sixth output interface b6 is connected to the rod chamber of the second hydraulic cylinder 16.

[0085] When the hydraulic source 3 supplies oil, by controlling the use status of the second reversing valve 81 and the third reversing valve 82, the flow direction of the liquid output by the hydraulic source 3 can be controlled, thereby achieving steering control of the rear wheels.

[0086] For example, if the second reversing valve 81 is in the first usage state and the third reversing valve 82 is in the third usage state; the liquid flowing out of the first oil port will enter the rod chamber of the first hydraulic cylinder 15, and the liquid in the rodless chamber of the first hydraulic cylinder 15 will flow back to the hydraulic source 3, and at this time, the hydraulic source 3 does not control the operation of the second hydraulic cylinder 16.

[0087] If the second reversing valve 81 is in the third usage state and the third reversing valve 82 is in the first usage state; the liquid flowing out of the first oil port will enter the rodless chamber of the second hydraulic cylinder 16, and the liquid in the rod chamber of the second hydraulic cylinder 16 will flow back to the hydraulic source 3, and at this time, the hydraulic source 3 does not control the operation of the first hydraulic cylinder 15.

[0088] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rear wheel steering system, characterized in that: Including oil cylinder assembly, steering rod assembly and hydraulic source; The oil cylinder assembly is connected to the steering rod assembly, and the steering rod assembly is suitable for connecting the left rear wheel and the right rear wheel; The hydraulic source is used to supply fluid to the oil cylinder assembly, so that the oil cylinder assembly can drive the steering rod assembly to move, thereby driving the left rear wheel and the right rear wheel connected to the steering rod assembly to steer.

2. The rear wheel steering system according to claim 1, characterized in that: The steering tie rod assembly includes a first steering tie rod and a second steering tie rod; One end of the first steering rod is rotatably connected to the oil cylinder assembly, and the other end of the first steering rod is suitable for being rotatably connected to the left rear wheel; One end of the second steering rod is rotatably connected to the oil cylinder assembly, and the other end of the second steering rod is suitable for being rotatably connected to the right rear wheel.

3. The rear wheel steering system according to claim 2, characterized in that: The oil cylinder assembly includes a cylinder body, a piston and a piston rod; A liquid cavity is provided in the cylinder body, and the liquid cavity completely penetrates the cylinder body along the length direction of the cylinder body; The piston rod is inserted into the liquid cavity, and both ends of the piston rod extend out of the liquid cavity and are rotatably connected to the first steering rod and the second steering rod respectively; The piston is connected to the piston rod and is located in the liquid cavity; in the length direction of the cylinder body, the piston divides the liquid cavity into a first chamber and a second chamber; The first chamber and the second chamber are respectively connected to the hydraulic source, so that when the hydraulic source delivers liquid to one of the first chamber and the second chamber, the liquid in the other of the first chamber and the second chamber can flow back to the hydraulic source.

4. The rear wheel steering system according to claim 2, characterized in that: The cylinder assembly includes a first hydraulic cylinder and a second hydraulic cylinder that are separately arranged, and the first hydraulic cylinder and the second hydraulic cylinder are both connected to the hydraulic source; The piston rod of the first hydraulic cylinder is rotatably connected to the first steering rod; The piston rod of the second hydraulic cylinder is rotatably connected to the second steering rod.

5. The rear wheel steering system according to claim 4, characterized in that: In the left-right direction, the first steering rod, the first hydraulic cylinder, the second hydraulic cylinder and the second steering rod are arranged in sequence.

6. The rear wheel steering system according to claim 2, characterized in that: The first steering rod is located on the left side of the oil cylinder assembly, and the second steering rod is located on the right side of the oil cylinder assembly.

7. A vehicle, characterized in that: comprising a vehicle body, a left rear wheel, a right rear wheel, and a rear-wheel steering system according to any one of claims 1 to 6; The left rear wheel, the right rear wheel and the rear wheel steering system are all connected to the vehicle body; The steering rod assembly is connected to the left rear wheel and the right rear wheel respectively.

8. The vehicle according to claim 7, characterized in that The vehicle also includes a left front wheel, a right front wheel, and a hydraulic brake; The hydraulic brake is connected to at least one of the left rear wheel, the right rear wheel, the left front wheel, and the right front wheel; The hydraulic source is connected to the hydraulic brake to supply fluid to the hydraulic brake, so that the hydraulic brake can brake and release the wheels on which the hydraulic brake is located.

9. The vehicle according to claim 7, characterized in that The vehicle further comprises a rear sub-frame connected to the vehicle body, and the oil cylinder assembly is connected to the rear sub-frame.

10. The vehicle according to claim 9, characterized in that The oil cylinder assembly is detachably connected to the rear sub-frame.

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