Hydraulic system for steering mechanism, steering mechanism and engineering machine

Abstract

A hydraulic system for a steering mechanism, the hydraulic system being configured to control the steering of a vehicle during forward travel and reverse travel. The hydraulic system for a steering mechanism comprises: a hydraulic pump (1); an unloading valve group (2), which is disposed in an oil supply circuit of the hydraulic pump (1), the unloading valve group (2) being configured to relieve the pressure of hydraulic oil; a proportional control valve group (3), which is disposed in an operating oil circuit of the unloading valve group (2), the proportional control valve group (3) being configured to control the steering direction and steering angle of a first steering axle (10) and a second steering axle (20); and a flow amplification valve group (4), which is disposed between the proportional control valve group (3) and a steering oil cylinder (5), wherein both the flow amplification valve group (4) and the steering oil cylinder (5) are located in an operating oil circuit of the proportional control valve group (3), and the flow amplification valve group (4) is configured to amplify the flow of the hydraulic oil entering the steering oil cylinder (5). A steering mechanism, comprising the hydraulic system for a steering mechanism. An engineering machine, comprising the hydraulic system for a steering mechanism, and the steering mechanism. With such an arrangement, the steering direction and angle of front and rear steering axles of a vehicle can be precisely controlled, thereby enabling the bidirectional travel of the vehicle, reducing the control difficulty during the bidirectional travel of the vehicle, and increasing the steering response speed, and thus improving the vehicle control performance.

Description

Steering mechanism hydraulic system, steering mechanism and engineering machinery

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese application No. 202411614237.9, filed on November 12, 2024, the disclosure of which is hereby incorporated by reference in its entirety into the present disclosure. TECHNICAL FIELD

[0003] The present disclosure relates to a steering mechanism hydraulic system, a steering mechanism and an engineering machinery. BACKGROUND

[0004] The open-pit mining capacity is increasing year by year, and the earthwork stripping and transportation demand is large. Combined with the requirements of open-pit mine development towards intelligence, green and information, and the open road of open-pit mine area has strong closure, the site partition and transportation route are relatively fixed, and the transportation vehicle drives at low speed, the application demand of large-tonnage unmanned electric mine dump truck is also increasingly strong.

[0005] In the process of open-pit coal mining and earthwork stripping and transportation, the reverse parking control in the unmanned mine car loading and unloading area is an important difficulty. Sometimes it needs to be adjusted back and forth several times to reach the qualified position, which occupies time and affects the transportation efficiency and equipment utilization. SUMMARY

[0006] Embodiments of the present disclosure provide a steering mechanism hydraulic system, a steering mechanism and an engineering machinery, which can drive a vehicle to realize bidirectional driving.

[0007] According to a first aspect of the present disclosure, a steering mechanism hydraulic system is provided for controlling forward driving steering and reverse driving steering of a vehicle, the vehicle comprising a first steering axle and a second steering axle, the first steering axle being a frontmost axle and the second steering axle being a rearmost axle, the first steering axle and the second steering axle each comprising a steering cylinder, the steering mechanism hydraulic system comprising:

[0008] a hydraulic pump, which is drivingly connected to the steering motor;

[0009] an unloading valve group, which is arranged on an oil supply oil path of the hydraulic pump, the unloading valve group being configured to unload pressure of the hydraulic oil;

[0010] a proportional control valve group, which is arranged on a working oil path of the unloading valve group, the proportional control valve group being configured to control steering direction and steering angle of the first steering axle and the second steering axle; and

[0011] a flow amplification valve group, which is arranged between the proportional control valve group and the steering cylinder, the flow amplification valve group and the steering cylinder being located on the working oil path of the proportional control valve group, the flow amplification valve group being configured to amplify hydraulic oil flow entering the steering cylinder.

[0012] In some embodiments, the proportional control valve group comprises:

[0013] a reversing valve configured to control an outlet fluid path of the proportional control valve group to control a steering direction of the first and second steering bridges; and

[0014] a proportional valve configured to control an outlet fluid flow of the proportional control valve group to control a steering angle of the first and second steering bridges.

[0015] In some embodiments, the proportional control valve group further comprises:

[0016] a normally open on-off valve disposed between the reversing valve and the proportional valve, the normally open on-off valve being configured to be closed when a spool of the proportional valve moves to a preset position, so that the outlet fluid flow of the proportional valve is maintained at a preset flow.

[0017] In some embodiments, the spool movement amount of the proportional valve is negatively related to a vehicle speed of the vehicle.

[0018] In some embodiments, the proportional control valve group comprises a same main control valve group and a secondary control valve group, the secondary control valve group being disconnected in a case where the main control valve group does not fail, and the secondary control valve group being enabled in a case where the main control valve group fails.

[0019] In some embodiments, the proportional control valve group further comprises a normally open on-off valve disposed between the reversing valve and the proportional valve, and in a case where the reversing valve and the normally open on-off valve of the main control valve group are both in an on state, if the spool of the proportional valve does not move, it is determined that the main control valve group fails.

[0020] In some embodiments, the reversing valve comprises a three-position four-way reversing valve, and in a case where the main control valve group does not fail, the reversing valve of the secondary control valve group is in a neutral position, so that the secondary control valve group is disconnected.

[0021] In some embodiments, the proportional control valve group comprises a same first control valve group and a second control valve group, the first control valve group and the second control valve group are both disposed on a working oil path of the unloading valve group, the first control valve group is configured to control a steering direction and a steering angle of the first steering bridge, and the second control valve group is configured to control a steering direction and a steering angle of the second steering bridge; the flow amplification valve group comprises a first amplification valve group and a second amplification valve group, the first amplification valve group is disposed between the first control valve group and a steering cylinder of the first steering bridge, and the second amplification valve group is disposed between the second control valve group and a steering cylinder of the second steering bridge.

[0022] In some embodiments, the flow amplification valve group comprises:

[0023] a first overflow valve disposed between a control oil path of the proportional valve and an oil tank;

[0024] a flow amplifier connected between the working oil passage of the proportional control valve group and the steering oil cylinder; and

[0025] a priority valve configured to introduce hydraulic oil from a hydraulic pump to amplify the flow of hydraulic oil from the proportional control valve group.

[0026] In some embodiments, the steering oil cylinder comprises a first oil cylinder and a second oil cylinder, and the flow amplification valve group further comprises:

[0027] two oil cylinder safety valves, each having one end connected to the first oil cylinder and the second oil cylinder respectively, and each having the other end connected to the oil tank, the oil cylinder safety valve comprising a check valve and a second overflow valve arranged in parallel, the check valve allowing oil flow only from the oil tank to the first oil cylinder or the second oil cylinder.

[0028] In some embodiments, the first outlet of the flow amplification valve group is connected to the large cavity of the first oil cylinder and the small cavity of the second oil cylinder, and the second outlet of the flow amplification valve group is connected to the small cavity of the first oil cylinder and the large cavity of the second oil cylinder, the oil cylinder being elongated when hydraulic oil enters the large cavity and being shortened when hydraulic oil enters the small cavity.

[0029] In some embodiments, the vehicle further comprises a third steering bridge, the third steering bridge being arranged between the first steering bridge and the second steering bridge, the third steering bridge being located at the center of the first steering bridge and the second steering bridge, or a plurality of third steering bridges being arranged symmetrically about the center of the first steering bridge and the second steering bridge.

[0030] In some embodiments, the steering mechanism hydraulic system further comprises:

[0031] a steering shut-off valve arranged between the flow amplification valve group and the steering oil cylinder of the third steering bridge, the steering shut-off valve being configured to switch the third steering bridge between a non-steering state and a steering state.

[0032] In some embodiments, the steering shut-off valve comprises a normally closed on-off valve, the normally closed on-off valve disconnecting the flow amplification valve group and the steering oil cylinder of the third steering bridge in the absence of electricity, and the normally closed on-off valve connecting the flow amplification valve group and the steering oil cylinder of the third steering bridge in the presence of electricity.

[0033] In some embodiments, the first steering bridge and the second steering bridge are arranged rotationally symmetrically about the center of both.

[0034] In some embodiments, the steering mechanism hydraulic system further comprises an accumulator arranged on the oil supply passage of the hydraulic pump, the accumulator being connected to the unloading valve group, the unloading valve group comprising:

[0035] a first unloading valve arranged on the working oil passage of the hydraulic pump and configured to unload the hydraulic oil pressure supplied by the hydraulic pump;

[0036] a second unloading valve provided on the working oil line of the accumulator and configured to unload the hydraulic oil pressure supplied to the accumulator; and

[0037] a third overflow valve provided on the working oil line between the hydraulic pump and the accumulator.

[0038] In some embodiments, the steering mechanism hydraulic system further comprises:

[0039] a first pressure sensor connected to the unloading valve group and configured to detect the hydraulic oil pressure supplied to the accumulator;

[0040] a second pressure sensor connected to the unloading valve group and configured to detect the hydraulic oil pressure supplied to the accumulator in case of failure of the first pressure sensor;

[0041] a third pressure sensor connected to the unloading valve group and configured to detect the hydraulic oil pressure supplied to the hydraulic pump; and

[0042] a fourth pressure sensor connected to the unloading valve group and configured to detect the hydraulic oil pressure supplied to the hydraulic pump in case of failure of the third pressure sensor.

[0043] In some embodiments, the vehicle performs an immediate stop operation when the hydraulic oil pressure supplied to the hydraulic pump is less than a preset pressure and the hydraulic oil pressure supplied to the accumulator is less than the preset pressure, and performs an emergency steering operation when the hydraulic oil pressure supplied to the hydraulic pump is less than the preset pressure and the hydraulic oil pressure supplied to the accumulator is not less than the preset pressure.

[0044] In some embodiments, the steering cylinder comprises a first cylinder and a second cylinder, and a displacement sensor is provided in the first cylinder and / or the second cylinder, the displacement sensor being configured to detect the displacement of the cylinder piston rod to obtain the steering angle of the steering axle.

[0045] According to a second aspect of the present disclosure, a steering mechanism is provided, comprising a first steering axle and a second steering axle, for realizing forward driving steering and reverse driving steering of a vehicle, the first steering axle being a frontmost axle and the second steering axle being a rearmost axle, and each of the first steering axle and the second steering axle comprising:

[0046] a first steering knuckle and a second steering knuckle, each for mounting a tire;

[0047] a first support and a second support, each for being connected to a side of a vehicle frame;

[0048] a steering cylinder comprising a first cylinder and a second cylinder, the first cylinder being hinged between the first support and the first steering knuckle, and the second cylinder being hinged between the first support and the second steering knuckle;

[0049] The steering mechanism further comprises a steering arm, a first pull rod and a second pull rod, a first end of the steering arm is hinged to the second support, the first pull rod is hinged between the first steering knuckle and a second end of the steering arm, and the second pull rod is hinged between the second steering knuckle and a third end of the steering arm.

[0050] The steering mechanism hydraulic system of the above embodiment is configured to drive the steering cylinder to extend and retract.

[0051] In some embodiments, the steering mechanism further comprises:

[0052] An angle sensor is arranged in the steering arm and configured to detect a rotation angle of the steering arm.

[0053] According to a third aspect of the present disclosure, an engineering machine chassis is provided, comprising:

[0054] A vehicle frame; and

[0055] The steering mechanism of the above embodiment, the first steering knuckle and the second steering knuckle are connected to the vehicle frame through the suspension cylinders respectively, and the first support and the second support are connected to two sides of the vehicle frame respectively.

[0056] According to a fourth aspect of the present disclosure, an engineering machine is provided, comprising the steering mechanism hydraulic system of the above embodiment, or the steering mechanism of the above embodiment, or the engineering machine chassis of the above embodiment.

[0057] In some embodiments, the engineering machine comprises an unmanned mine dump truck.

[0058] Based on the above technical solutions, the steering mechanism hydraulic system of the embodiment of the present disclosure can realize accurate control of the steering direction and angle of the front and rear steering axles of the vehicle, thereby driving the vehicle to realize bidirectional driving, reduce the control difficulty of bidirectional driving of the vehicle, realize loading and unloading actions in a direct drive mode, and improve production efficiency; the hydraulic pump is driven by the steering motor, can realize unmanned driving, and can provide the required pressure oil for the hydraulic system; the unloading valve group can ensure safe operation of the hydraulic system, stabilize the oil supply pressure of the hydraulic pump, avoid damage to components due to excessively high pressure, and ensure safety during maintenance and repair; the proportional control valve group adjusts the flow direction and size of the hydraulic oil, and can accurately control the steering direction and angle; and the flow amplification valve group can amplify the flow of the hydraulic oil, speed up the steering response speed, and enhance the vehicle control performance. BRIEF DESCRIPTION OF DRAWINGS

[0059] The accompanying drawings, which are included to provide a further understanding of the present disclosure and constitute a part of this application, illustrate certain illustrative embodiments of the present disclosure and are used to explain the present disclosure, but do not limit the present disclosure. In the drawings:

[0060] FIG. 1 is a schematic diagram of some embodiments of a hydraulic system of a steering mechanism of the present disclosure.

[0061] FIG. 2 is a schematic diagram of some embodiments of a unloader valve group of the hydraulic system of the steering mechanism of the present disclosure.

[0062] FIG. 3 is a schematic diagram of some embodiments of a proportional control valve group of the hydraulic system of the steering mechanism of the present disclosure.

[0063] FIG. 4 is a schematic diagram of some embodiments of a flow amplification valve group of the hydraulic system of the steering mechanism of the present disclosure.

[0064] FIG. 5 is a partial structural schematic diagram of some embodiments of a steering mechanism of the present disclosure.

[0065] FIG. 6 is a structural schematic diagram of some embodiments of a work machine chassis of the present disclosure. DETAILED DESCRIPTION

[0066] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative in nature and is in no way intended to limit the disclosure, its application or uses. The disclosure can be implemented in numerous different forms, as will be apparent to one of ordinary skill in the art. The embodiments provided are in the nature of a best mode of the disclosure and are provided to fully and entirely disclose the disclosure to those skilled in the art. It is to be noted that the relative arrangement of the components and steps set forth in the embodiments, the components of the materials, numerical expressions, and numerical values are to be interpreted as merely exemplary and not as a limitation unless specifically stated otherwise.

[0067] The terms "first", "second", and similar terms in the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different parts. The terms "include", "comprise", and similar terms mean that the elements before the terms encompass the elements listed after the terms, and do not exclude the possibility of also encompassing other elements. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0068] In the present disclosure, when it is described that a certain device is located between a first device and a second device, there can be an intervening device between the certain device and the first device or the second device, or there can be no intervening device. When it is described that a certain device is connected to other devices, the certain device can be directly connected to the other devices without an intervening device, or can not be directly connected to the other devices with an intervening device.

[0069] All terms used in the present disclosure, including technical or scientific terms, have the same meanings as those understood by those having ordinary knowledge in the art to which the present disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0070] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0071] Based on the above embodiments of the present disclosure, the technical features of one embodiment can be beneficially combined with one or more other embodiments without explicit negation or conflict.

[0072] The inventor found in the research process that the front axle of the traditional mine dump truck is a steering axle, only with one-way driving and front axle steering capability, the vehicle position control of the open-pit mine unmanned mine dump truck loading and unloading area is difficult, and the production efficiency is low.

[0073] To solve the above problems, first, the present disclosure provides a steering mechanism hydraulic system for controlling the forward driving steering and reverse driving steering of a vehicle, the vehicle of the present disclosure can be any vehicle, and some of the following embodiments are described with the example of an "unmanned mine dump truck". As shown in FIGS. 1-6, the vehicle includes a first steering axle 10 and a second steering axle 20, the first steering axle 10 is the frontmost axle, and the second steering axle 20 is the rearmost axle, the first steering axle 10 and the second steering axle 20 each include a steering cylinder 5, and the steering mechanism hydraulic system includes:

[0074] A hydraulic pump 1 is drivingly connected to a steering motor 11;

[0075] An unloading valve group 2 is provided on the oil supply circuit of the hydraulic pump 1, and the unloading valve group 2 is configured to unload the pressure of the hydraulic oil;

[0076] A proportional control valve group 3 is provided on the working oil circuit of the unloading valve group 2, and the proportional control valve group 3 is configured to control the steering direction and steering angle of the first steering axle 10 and the second steering axle 20; and

[0077] A flow amplification valve group 4 is provided between the proportional control valve group 3 and the steering cylinder 5, and the flow amplification valve group 4 and the steering cylinder 5 are both located on the working oil circuit of the proportional control valve group 3, and the flow amplification valve group 4 is configured to amplify the flow of hydraulic oil entering the steering cylinder 5.

[0078] Specifically, the steering motor 11 and the hydraulic pump 1 cooperate to convert mechanical energy into hydraulic energy, and the rotation input of the steering motor instead of the steering wheel can realize the drive-by-wire of the steering system. The hydraulic pump is also called a steering pump. Specifically, the unloading valve group 2 can protect the hydraulic system from high pressure and avoid the risk of pressure impact on personnel during inspection and maintenance.

[0079] Specifically, the steering directions include forward driving left steering, forward driving right steering, reverse driving left steering, and reverse driving right steering, and the steering mechanism hydraulic system of the present disclosure enables the unmanned mine dump truck to have bidirectional driving capability. Specifically, the proportional control valve group 3 controls the steering direction of the steering axle through the outflow path of the hydraulic oil, for example, in the forward driving working condition, the hydraulic oil flows out from the L port of the proportional control valve group 3, then the first steering axle 10 steers left, and the hydraulic right flows out from the R port of the proportional control valve group 3, then the first steering axle 10 steers right.

[0080] Specifically, the flow amplification valve group 4 amplifies the hydraulic oil from the proportional control valve group 3, which can accelerate the steering speed, improve the responsiveness, and improve the hydraulic control precision and control stability. The hydraulic oil from the proportional control valve group 3 and the additional hydraulic oil from the hydraulic pump 1 flow into the steering cylinder 5, and the hydraulic oil received by the steering cylinder 5 pushes the piston to move, thereby causing the steering knuckle of the steering axle and the wheel to produce corresponding steering actions.

[0081] Optionally, the steering axle can adopt a whole steering trapezoidal structure, or a disconnected steering trapezoidal structure. Optionally, the first steering axle 10 and the second steering axle 20 can be arranged in rotational symmetry about the center of the two, or can be arranged side by side in the same direction.

[0082] Optionally, the first steering axle 10 and the second steering axle 20 can be controlled simultaneously, for example, one proportional control valve group 3 controls the steering of the first steering axle 10 and the second steering axle 20; the first steering axle 10 and the second steering axle 20 can also be controlled separately, which improves the flexibility of steering driving, for example, one proportional control valve group 3 controls the steering of the first steering axle 10, and another proportional control valve group 3 controls the steering of the second steering axle 20.

[0083] The steering mechanism hydraulic system of the embodiment can realize accurate control of the steering direction and angle of the front and rear steering axles of the vehicle, thereby driving the vehicle to realize bidirectional driving, reducing the control difficulty of bidirectional driving of the vehicle, and realizing loading and unloading actions in a direct drive manner, thereby improving production efficiency. The hydraulic pump 1 is driven by the steering motor 11, can realize unmanned driving, and can provide the pressure oil required by the hydraulic system. The unloading valve group 2 can ensure safe operation of the hydraulic system, stabilize the oil supply pressure of the hydraulic pump 1, avoid damage to components caused by excessively high pressure, and ensure safety during maintenance. The proportional control valve group 3 adjusts the flow direction and flow rate of the hydraulic oil, and can accurately control the steering direction and steering angle. The flow amplification valve group 4 can amplify the flow rate of the hydraulic oil, accelerate the steering response speed, and enhance the vehicle control performance.

[0084] In some embodiments, as shown in FIGS. 1 and 3, the proportional control valve group 3 includes:

[0085] The reversing valve 31 is configured to control the liquid outlet path of the proportional control valve group 3 to control the steering direction of the first steering axle 10 and the second steering axle 20; and

[0086] The proportional valve 32 is configured to control the liquid outlet flow rate of the proportional control valve group 3 to control the steering angle of the first steering axle 10 and the second steering axle 20.

[0087] Specifically, the reversing valve 31 changes the hydraulic oil outflow path of the proportional control valve group 3 by switching the flow direction of the hydraulic oil, for example, outflowing from the R port or outflowing from the L port, thereby ensuring that the hydraulic oil flows into the steering cylinder 5 according to the predetermined path, and further changing the steering direction of the steering axle. Alternatively, the reversing valve 31 can be a two-position four-way electromagnetic reversing valve, or a three-position four-way electromagnetic reversing valve, etc.

[0088] Specifically, different valve core displacements of the proportional valve 32 correspond to different opening degrees, thereby controlling the flow rate of the hydraulic oil, further controlling the change speed of the extension and retraction amount of the steering cylinder, controlling the extension and retraction amount of the steering cylinder per unit time, and further controlling the steering angle of the steering axle. The proportional valve 32 can adjust the oil amount flowing into the steering cylinder 5 from the hydraulic oil of the reversing valve 31 according to the rotation angle of the steering wheel or the expected steering angle of the controller, thereby realizing smooth and accurate steering action. Alternatively, the valve core displacement of the proportional valve 32 can be detected in real time.

[0089] Specifically, the PE port of the proportional control valve group 3 is connected to the P1 port of the unloading valve group 2 through a hydraulic pipeline, and the L port, R port, and LS port of the proportional control valve group 3 are respectively connected to the L port, R port, and LS port of the flow amplification valve group 4 through a hydraulic pipeline.

[0090] For example, when the vehicle is driving forward and turning left, the controller gives a forward driving left turning instruction, for the hydraulic flow path corresponding to the first steering axle 10, the reversing valve 31 is in the right position, the oil enters the right control oil chamber of the proportional valve 32 through the PE port of the proportional control valve group 3 to push it to move left to work in the right position, and the output oil enters the L port of the flow amplification valve group 4 through the L port of the proportional control valve group 3.

[0091] The proportional control valve group 3 of this embodiment can realize accurate control of the steering direction and angle of the steering axle through the cooperation of the reversing valve 31 and the proportional valve 32; the reversing valve 31 is responsible for switching the flow direction of the hydraulic oil, which can ensure that the steering axle rotates left or right as needed; the proportional valve 32 controls the change speed of the extension and retraction amount of the steering cylinder by adjusting the flow of the hydraulic oil, thereby controlling the change speed of the steering angle, and further controlling the steering angle of the steering axle, which can realize smooth steering action, improve the steering performance of the vehicle, and optimize the controllability and stability.

[0092] In some embodiments, as shown in FIGS. 1 and 3, the proportional control valve group 3 further comprises:

[0093] The normally open on-off valve 33 is arranged between the reversing valve 31 and the proportional valve 32, and the normally open on-off valve 33 is configured to be closed when the spool of the proportional valve 32 moves to the preset position, so as to keep the liquid flow of the proportional valve 32 at the preset flow.

[0094] Specifically, the proportional control valve group 3 includes two normally open on-off valves 33, which are respectively communicated with the left position and the right position of the reversing valve 31. Before the spool of the proportional valve 32 moves to the preset position, the normally open on-off valve 33 remains open; after the normally open on-off valve 33 is closed, the liquid flow of the proportional valve 32 is locked at the preset flow, and the steering axle continuously changes the steering angle at a preset steering angle change speed. Optionally, the normally open on-off valve 33 can be a normally open high-frequency electromagnetic on-off valve, which keeps the hydraulic flow path connected when there is no electricity, and cuts off the hydraulic flow path when there is electricity.

[0095] Specifically, the controller monitors the displacement of the spool of the proportional valve 32 in real time, and when the spool of the proportional valve reaches the preset flow control position, the normally open on-off valve 33 is closed, for example, the high-frequency electromagnetic on-off valve is electrified to be in the left position cut-off state, the control oil way of the proportional valve 32 is cut off, and the spool of the proportional valve 32 is kept at a specific position so that the steering mechanism hydraulic system continuously performs steering action at a specific flow (corresponding to a specific steering angle of the steering axle).

[0096] Optionally, the preset displacement or preset opening degree of the spool of the proportional valve 32 can be determined according to the current vehicle speed information of the vehicle, for example, the vehicle speed is negatively correlated with the opening degree of the spool, so as to improve the safety and stability of the vehicle steering.

[0097] The normally open on-off valve 33 of the embodiment can lock the flow when the spool of the proportional valve 32 reaches the preset position, ensuring the consistency of the steering angle; by locking the flow, the influence of external interference on the steering mechanism can be reduced, and the stability of vehicle steering can be improved; stable flow control can help to avoid over-steering or under-steering, improve the steering control accuracy of the hydraulic system, and improve the safety of the vehicle.

[0098] In some embodiments, the spool movement of the proportional valve 32 is negatively related to the speed of the vehicle.

[0099] In this embodiment, the spool movement of the proportional valve 32 is negatively related to the speed of the vehicle, the higher the speed, the smaller the spool movement, and the smaller the flow and steering angle change speed is locked, the steering action is more gentle and stable, which can improve the stability of high-speed driving; the lower the speed, the greater the spool movement, and the greater the flow and steering angle change speed is locked, the steering is more sensitive, which can improve the maneuverability of low-speed driving; it can reduce the risk of vehicle out of control caused by over-steering, and improve the safety of the vehicle.

[0100] In some embodiments, as shown in FIG. 1, the proportional control valve group 3 includes the same main control valve group and auxiliary control valve group, the auxiliary control valve group is disconnected in the case that the main control valve does not fail, and the auxiliary control valve group is enabled in the case that the main control valve fails.

[0101] Specifically, in the case of separate control of multiple steering axles, the proportional control valve group 3 of each steering axle includes the same main control valve group and auxiliary control valve group, for example, for the first steering axle 10, the first control valve group 301 includes the first main control valve group and the first auxiliary control valve group, for the second steering axle 20, the second control valve group 302 includes the second main control valve group and the second auxiliary control valve group, and for the third steering axle 30, the third control valve group 303 includes the third main control valve group and the third auxiliary control valve group.

[0102] Specifically, the main control valve group works under normal circumstances, and the auxiliary control valve group is disconnected; when the main control valve group fails, the auxiliary control valve group is automatically enabled. The double control valve group can ensure that even if the main control valve group fails, the auxiliary control valve group can immediately take over, maintain the normal operation of the steering system, and avoid the failure of the hydraulic system steering caused by the failure of the main control valve group.

[0103] This embodiment can improve the reliability and stability of the hydraulic system by redundantly designing the proportional control valve group 3, and can ensure the steering function of the vehicle is not affected when the main control valve group fails, which significantly improves the safety of the vehicle; the standby of the auxiliary control valve group can reduce the downtime caused by the failure of the main control valve group, improve the availability and working efficiency of the vehicle, which is particularly important for automatic driving engineering vehicles that need to run continuously for a long time.

[0104] In some embodiments, as shown in FIG. 1 and FIG. 3, the proportional control valve group 3 further comprises a normally open on-off valve 33 arranged between the reversing valve 31 and the proportional valve 32, in the case that the reversing valve 31 and the normally open on-off valve 33 of the main control valve group are both in the on state, if the proportional valve 32 has no spool displacement data feedback, it is determined that the main control valve group has a fault.

[0105] Specifically, in the case that the reversing valve 31 is in the left position or the right position, and the two normally open on-off valves 33 are always open, if the proportional valve 32 has no spool displacement data feedback, it is determined that the main control valve group has a fault, and the auxiliary control valve group needs to be automatically started.

[0106] This embodiment can improve the timeliness and accuracy of fault diagnosis by monitoring the state of the reversing valve 31, the normally open on-off valve 33 and the proportional valve 32 to determine whether the main control valve group has a fault. In the case that the main control valve group has a fault, switching to the auxiliary control valve group to control steering can ensure that the steering function of the vehicle is not affected, and significantly improves the safety of the vehicle. The standby of the auxiliary control valve group can reduce the downtime caused by the failure of the main control valve group, and improve the availability and work efficiency of the vehicle.

[0107] In some embodiments, as shown in FIG. 1 and FIG. 3, the reversing valve 31 comprises a three-position four-way reversing valve, in the case that the main control valve group has no fault, the reversing valve 31 of the auxiliary control valve group is in the center position, so that the auxiliary control valve group is disconnected. In the case that the main control valve group has a fault, the auxiliary control valve group is enabled.

[0108] Specifically, in the normal working state, the reversing valve 31 of the main control valve group is in the left position or the right position, and the main control valve group participates in steering control; the reversing valve 31 of the auxiliary control valve group is in the center position, so that the auxiliary control valve group is disconnected, and the auxiliary control valve group does not participate in steering control, and the reversing valve 31 of the auxiliary control valve group is not switched to the left position or the right position. Once it is detected that the main control valve group has a fault, the auxiliary control valve group is enabled, and the reversing valve 31 of the auxiliary control valve group can be switched to the left position, the right position or the center position according to the control logic, to continue to stably control the steering direction and the steering angle of the vehicle.

[0109] This embodiment can improve the reliability of the main and auxiliary control valve group settings and the timeliness of the main and auxiliary control valve group switching by using a three-position four-way reversing valve for the reversing valve 31, which can ensure the continuous operation of the steering mechanism and improve the safety of the vehicle and the availability of the vehicle.

[0110] In some embodiments, as shown in FIG. 1, the proportional control valve group 3 includes the same first control valve group 301 and second control valve group 302, both of which are arranged on the working oil circuit of the unloading valve group 2, the first control valve group 301 is configured to control the steering direction and steering angle of the first steering axle 10, and the second control valve group 302 is configured to control the steering direction and steering angle of the second steering axle 20; the flow amplification valve group 4 includes the same first amplification valve group 401 and second amplification valve group 402, the first amplification valve group 401 is arranged between the first control valve group 301 and the steering cylinder 5 of the first steering axle 10, and the second amplification valve group 402 is arranged between the second control valve group 302 and the steering cylinder 5 of the second steering axle 20.

[0111] Optionally, the proportional control valve group 3 further includes a third control valve group 303 configured to control the steering direction and steering angle of the third steering axle 30; and the flow amplification valve group 4 further includes a third amplification valve group 403 arranged between the third control valve group 303 and the steering cylinder 5 of the third steering axle 30.

[0112] This embodiment can improve the accuracy and flexibility of steering by independently controlling the steering direction and angle of the front and rear steering axles through the first control valve group 301 and the second control valve group 302 respectively; and can accelerate the steering response speed by amplifying the hydraulic oil flow entering the steering cylinder 5 through the first amplification valve group 401 and the second amplification valve group 402 respectively.

[0113] In some embodiments, as shown in FIG. 1 and FIG. 4, the flow amplification valve group 4 includes:

[0114] a first overflow valve 41 arranged between the control oil circuit of the proportional valve 32 and the oil tank;

[0115] a flow amplifier 42 connected between the working oil circuit of the proportional control valve group 3 and the steering cylinder 5; and

[0116] a priority valve 43 configured to introduce hydraulic oil from the hydraulic pump 1 to amplify the hydraulic oil flow from the proportional control valve group 3.

[0117] Specifically, the first overflow valve 41 can limit the maximum pressure of the hydraulic oil circuit to ensure the safety of the hydraulic system; the flow amplifier 42 connected between the working oil circuit of the proportional control valve group 3 and the steering cylinder 5 can amplify the hydraulic oil flow entering the steering cylinder 5 to improve the steering response speed; and the priority valve 43 introduces hydraulic oil from the hydraulic pump 1 (or the accumulator 7) to ensure that the steering cylinder obtains sufficient hydraulic oil flow, thereby improving the reliability and stability of the system.

[0118] Specifically, the PF port of the flow amplification valve group 4 is connected to the P port and the P2 port of the unloading valve group 2 through a hydraulic pipeline, the CL port of the flow amplification valve group 4 is connected to the large cavity of the first oil cylinder 51 and the small cavity of the second oil cylinder 52 through a hydraulic pipeline, and the CR port of the flow amplification valve group 4 is connected to the large cavity of the second oil cylinder 52 and the small cavity of the first oil cylinder 51 through a hydraulic pipeline.

[0119] For example, when the vehicle is driving forward and the left steering is turned, for the hydraulic flow path corresponding to the first steering axle 10, the oil output from the L port of the proportional control valve group 3 enters the L port of the flow amplification valve group 4, and the LS port of the proportional control valve group 3 communicates with the LS port of the flow amplification valve group 4 to reach the left control oil port of the priority valve 43, the right control oil port of the priority valve 43 communicates with the PF port of the flow amplification valve group 4, and because the left control oil pressure of the priority valve 43 plus the left spring thrust is greater than the right control oil thrust of the priority valve 43, the priority valve 43 is in the left position and works, and the oil supplied by the hydraulic pump 1 (or the accumulator 7) enters the flow amplifier 42 through the PF port and merges with the oil entering the L port to flow out from the CL port, enters the large cavity of the first oil cylinder 51 and the small cavity of the second oil cylinder 52 of the first steering axle 10, so that the first oil cylinder 51 is elongated, the second oil cylinder 52 is shortened, and the wheels of the first steering axle 10 are turned left.

[0120] The flow amplification valve group 4 of this embodiment cooperates with the first overflow valve 41, the flow amplifier 42 and the priority valve 43 to limit the maximum pressure of the hydraulic oil path, ensure the safety of the hydraulic system, amplify the hydraulic oil flow, improve the steering response speed, enhance the vehicle handling performance, and improve the reliability and stability of the hydraulic system.

[0121] In some embodiments, as shown in FIGS. 1-6, the steering oil cylinder 5 includes a first oil cylinder 51 and a second oil cylinder 52, and the flow amplification valve group 4 further includes:

[0122] Two oil cylinder safety valves 44, each end of which respectively communicates with the first oil cylinder 51 and the second oil cylinder 52, and the other end of each of which communicates with the oil tank, the oil cylinder safety valve 44 includes a check valve 441 and a second overflow valve 442 arranged in parallel, and the check valve 441 only allows oil to flow from the oil tank to the first oil cylinder 51 or the second oil cylinder 52.

[0123] The oil cylinder safety valve 44 in this embodiment can function to supplement oil and protect against overload for the first oil cylinder 51 and the second oil cylinder 52. When the steering oil cylinder 5 stops extending and retracting, a vacuum will be generated at the inlet of the steering oil cylinder due to inertia, at which time the hydraulic oil in the oil tank can supplement the inlet of the steering oil cylinder 5 in time through the check valve 441 in the oil cylinder safety valve 44 to prevent the phenomenon of air suction, and the second overflow valve 442 can limit the maximum allowable pressure of the steering oil cylinder to prevent it from being damaged by overload.

[0124] In some embodiments, as shown in FIG. 1 and FIG. 4, the first outlet CL of the flow amplification valve group 4 is connected to the large cavity of the first oil cylinder 51 and the small cavity of the second oil cylinder 52, and the second outlet CR of the flow amplification valve group 4 is connected to the small cavity of the first oil cylinder 51 and the large cavity of the second oil cylinder 52. When hydraulic oil enters the large cavity, the oil cylinder extends, and when hydraulic oil enters the small cavity, the oil cylinder shortens.

[0125] Specifically, when the vehicle is driving forward, for the hydraulic flow path corresponding to the first steering axle 10, the first oil cylinder 51 is an oil cylinder arranged on the left side of the vehicle, and the second oil cylinder 52 is an oil cylinder arranged on the right side of the vehicle. If the second steering axle 20 is arranged side by side with the first steering axle 10 in the same direction, the first oil cylinder 51 of the second steering axle 20 is also an oil cylinder arranged on the left side of the vehicle, and the second oil cylinder 52 is an oil cylinder arranged on the right side of the vehicle.

[0126] In this embodiment, the first outlet CL is connected to the large cavity of the first oil cylinder 51 and the small cavity of the second oil cylinder 52, and the second outlet CR is connected to the small cavity of the first oil cylinder 51 and the large cavity of the second oil cylinder 52. When hydraulic oil enters the large cavity, the oil cylinder extends, and when hydraulic oil enters the small cavity, the oil cylinder shortens. The distribution of hydraulic oil can be accurately controlled, the steering direction and angle can be accurately controlled, and the response speed of vehicle steering can be improved.

[0127] In some embodiments, as shown in FIG. 1 and FIG. 6, the vehicle further comprises a third steering axle 30, which is arranged between the first steering axle 10 and the second steering axle 20, and the third steering axle 30 is located at the center of the first steering axle 10 and the second steering axle 20, or a plurality of third steering axles 30 are symmetrically arranged about the center of the first steering axle 10 and the second steering axle 20.

[0128] Optionally, in addition to the frontmost axle and the rearmost axle ensuring bidirectional driving steering, the vehicle can be provided with one or more third steering axles 30. In the case of one third steering axle 30, the third steering axle 30 is arranged at the center of the first steering axle 10 and the second steering axle 20 in the direction of extension of the vehicle body. In the case of multiple third steering axles 30, the multiple third steering axles 30 are symmetrically arranged about the center of the first steering axle 10 and the second steering axle 20 in the direction of extension of the vehicle body. Optionally, the third steering axle 30 can participate in steering, or it can not participate in steering by being provided with a steering cutoff valve.

[0129] This embodiment can finely control the overall steering of the vehicle by arranging the third steering axle 30. In particular, in a multi-axle vehicle, the multiple steering axles can be ensured to coordinate with each other, the accuracy and stability of steering control can be improved, and the maneuverability of the vehicle under different speeds and road conditions can be improved. The arrangement of the third steering axle 30 helps to evenly distribute the weight of the vehicle, reduces the load of the front and rear steering axles, and improves the service life of the tires and the overall performance of the vehicle.

[0130] In some embodiments, as shown in FIG. 1, the steering mechanism hydraulic system further comprises:

[0131] The steering cut-off valve 6 is arranged between the flow amplification valve group 4 and the steering cylinder 5 of the third steering axle 30, and is configured to switch the third steering axle 30 between the non-steering state and the steering state.

[0132] Specifically, for the steering axle that does not need to participate in steering frequently, the steering cut-off valve 6 is added in the connection of the CL port and the CR port of the flow amplification valve group 4 and the first cylinder 51 and the second cylinder 52, which can cut off the steering in the working condition that the steering does not need to occur.

[0133] The steering cut-off valve 6 of this embodiment is arranged between the flow amplification valve group 4 and the steering cylinder 5 of the third steering axle 30, and can switch the third steering axle 30 between the non-steering state and the steering state; the steering cut-off valve 6 allows the vehicle to select whether to enable the third steering axle 30 as needed, which can improve the flexibility and adaptability of the vehicle; in the case where additional steering precision is not needed, closing the third steering axle 30 can reduce system complexity and energy consumption, and in the case where high-precision steering is needed, opening the third steering axle 30 can improve steering precision and enhance the controllability and safety of the vehicle.

[0134] In some embodiments, as shown in FIG. 1, the steering cut-off valve 6 comprises a normally closed on-off valve, which disconnects the flow amplification valve group 4 and the steering cylinder 5 of the third steering axle 30 in the case where no electricity is obtained, and connects the flow amplification valve group 4 and the steering cylinder 5 of the third steering axle 30 in the case where electricity is obtained. Specifically, the steering cut-off valve 6 comprises a normally closed electromagnetic on-off valve.

[0135] The steering cut-off valve 6 of this embodiment comprises a normally closed on-off valve, which disconnects the flow amplification valve group 4 and the steering cylinder 5 of the third steering axle 30 in the default state, ensuring that the third steering axle 30 does not participate in steering when it is not needed, which can reduce system complexity and energy consumption; when high-precision steering is needed, the flow path is connected by electricity of the normally closed on-off valve to open the third steering axle 30 to participate in steering, which can improve steering precision and enhance the controllability and safety of the vehicle.

[0136] In some embodiments, as shown in FIG. 6, the first steering axle 10 and the second steering axle 20 are arranged rotationally symmetrically about the center of both.

[0137] The first steering axle 10 and the second steering axle 20 of the embodiment are arranged symmetrically about the center of rotation of both, which can ensure that the movements of the front and rear steering axles are synchronized and balanced when the vehicle is steering, improve the accuracy and stability of steering, and help to evenly distribute the weight and steering force of the vehicle, reduce the phenomenon of tilting and instability during steering, and improve the safety of the vehicle. The symmetric arrangement can also simplify the structure of the vehicle, facilitate manufacturing and maintenance, and reduce production costs.

[0138] In some embodiments, as shown in FIG. 1, the steering mechanism hydraulic system further comprises an accumulator 7 arranged on the oil supply oil circuit of the hydraulic pump 1, and the accumulator 7 is connected to the unloading valve group 2, which comprises:

[0139] a first unloading valve 21 arranged on the working oil circuit of the hydraulic pump 1 and configured to unload the hydraulic oil pressure supplied by the hydraulic pump 1;

[0140] a second unloading valve 22 arranged on the working oil circuit of the accumulator 7 and configured to unload the hydraulic oil pressure supplied by the accumulator 7; and

[0141] a third overflow valve 23 arranged on the working oil circuits of the hydraulic pump 1 and the accumulator 7.

[0142] Specifically, the accumulator 7 can store and release hydraulic energy to ensure that the system can quickly provide stable hydraulic oil pressure when needed. The third overflow valve 23 is arranged on the working oil circuits of the hydraulic pump 1 and the accumulator 7, which can prevent the pressure of the entire hydraulic system from exceeding the safe range.

[0143] Specifically, the hydraulic pump 1 is connected to the P port of the unloading valve group 2 through a hydraulic pipeline, the accumulator 7 is connected to the AC port of the unloading valve group 2 through a hydraulic pipeline, the PE port of the proportional control valve group 3 is connected to the P1 port of the unloading valve group 2 through a hydraulic pipeline, the oil tank is connected to the T port of the unloading valve group 2, and a one-way valve is arranged between the P port and the AC port of the unloading valve group 2 to avoid the hydraulic oil of the accumulator 7 impacting the hydraulic pump 1.

[0144] Optionally, to meet the huge hydraulic oil demand of the mine dump truck steering, multiple accumulators 7 can be arranged to accommodate a large amount of hydraulic oil, for example, three accumulators 7 are arranged, and the three accumulators 7 are connected to the AC1 port, the AC2 port and the AC3 port of the unloading valve group 2 respectively.

[0145] Optionally, the first unloading valve 21 can be a unloading valve composed of a normally closed electromagnetic on-off valve and an overflow valve, which unloads the pressure of the hydraulic pump 1 when the normally closed electromagnetic on-off valve is powered; the second unloading valve 22 can be a two-position three-way electromagnetic on-off valve, which connects the accumulator 7 and the P2 port when it is not powered, and connects the accumulator 7 and the T port when it is powered, to unload the pressure of the accumulator 7.

[0146] The accumulator 7 of the embodiment can store and release hydraulic energy, ensuring that stable emergency hydraulic oil is quickly provided when the hydraulic pump 1 fails; the first unloading valve 21 can selectively unload the hydraulic oil pressure supplied by the hydraulic pump 1, the second unloading valve 22 can selectively unload the hydraulic oil pressure supplied by the accumulator 7, and the third overflow valve 23 can prevent system overpressure. The unloading valve group can protect the hydraulic system components and prolong the service life of the hydraulic system; when the vehicle steering system needs to be maintained, the first unloading valve 21 and the second unloading valve 22 cooperate to completely unload the steering pump pressure and the accumulator pressure, which can avoid the risk of pressure impact causing harm to personnel.

[0147] In some embodiments, as shown in FIG. 1, the steering mechanism hydraulic system further comprises:

[0148] A first pressure sensor connected to the unloading valve group 2, the first pressure sensor being configured to detect the hydraulic oil pressure supplied by the accumulator 7;

[0149] A second pressure sensor connected to the unloading valve group 2, the second pressure sensor being configured to detect the hydraulic oil pressure supplied by the accumulator 7 in the event of failure of the first pressure sensor;

[0150] A third pressure sensor connected to the unloading valve group 2, the third pressure sensor being configured to detect the hydraulic oil pressure supplied by the hydraulic pump 1; and

[0151] A fourth pressure sensor connected to the unloading valve group 2, the fourth pressure sensor being configured to detect the hydraulic oil pressure supplied by the hydraulic pump 1 in the event of failure of the third pressure sensor.

[0152] Specifically, the AP port of the unloading valve group 2 is connected to a pressure sensor, the AP1 port and the AP2 port of the unloading valve group 2 are used to detect the hydraulic oil pressure supplied by the accumulator 7, and the two are backup redundant, one of which fails and the other functions, for example, the first pressure sensor is connected to the AP1 port, and the second pressure sensor is connected to the AP2 port; the AP3 port and the AP4 port of the unloading valve group 2 are used to detect the hydraulic oil pressure supplied by the hydraulic pump 1, and the two are backup redundant, one of which fails and the other functions, for example, the third pressure sensor is connected to the AP3 port, and the fourth pressure sensor is connected to the AP4 port.

[0153] The sensors of the embodiment can detect the hydraulic oil pressure supplied by the accumulator 7 and the hydraulic oil pressure supplied by the hydraulic pump 1 in real time, can timely find the pressure abnormalities of the hydraulic system, prevent the hydraulic system from being overpressured or underpressured, and prolong the service life of the hydraulic system; both pressure sensors are provided with redundant backup, which can ensure that the system can continue to monitor the pressure in real time even if a sensor fails, and can improve the reliability and safety of the steering mechanism hydraulic system.

[0154] In some embodiments, when the hydraulic oil pressure supplied by the hydraulic pump 1 is less than the preset pressure and the hydraulic oil pressure supplied by the accumulator 7 is less than the preset pressure, the vehicle performs an immediate stop operation; when the hydraulic oil pressure supplied by the hydraulic pump 1 is less than the preset pressure and the hydraulic oil pressure supplied by the accumulator 7 is not less than the preset pressure, the vehicle performs an emergency steering operation.

[0155] Specifically, when the pressure sensors detect that the hydraulic oil pressure supplied by the accumulator 7 and the hydraulic oil pressure supplied by the hydraulic pump 1 are both lower than the allowable working pressure, the vehicle performs an immediate stop operation at this time to avoid safety accidents; when the hydraulic oil pressure supplied by the hydraulic pump 1 is lower than the allowable working pressure and the hydraulic oil pressure supplied by the accumulator 7 is higher than the allowable working pressure, the vehicle performs an emergency steering operation at this time, and both the first steering axle 10 and the second steering axle 20 can complete one full steering action.

[0156] This embodiment can avoid dangerous situations caused by steering failure and ensure vehicle safety when the hydraulic system fails (i.e., the hydraulic pump 1 and the accumulator 7 cannot provide sufficient pressure), the vehicle immediately stops; when the hydraulic pump 1 fails but the accumulator 7 can still provide sufficient pressure, the vehicle performs an emergency steering operation, uses the reserve energy of the accumulator 7 to complete the necessary steering action, and can ensure that the vehicle can still perform basic steering control in an emergency.

[0157] In some embodiments, as shown in FIGS. 1-6, the steering oil cylinder 5 includes a first oil cylinder 51 and a second oil cylinder 52, and a displacement sensor is arranged in the first oil cylinder 51 and / or the second oil cylinder 52, which is configured to detect the displacement of the oil cylinder piston rod to obtain the steering angle of the steering axle.

[0158] Specifically, the extension and retraction of the piston rods of the first oil cylinder 51 and the second oil cylinder 52 cause the wheels to steer. The determination of the release of the steering working condition is based on the detection of the steering angle of the wheels by the geometric conversion of the extension and retraction positions of the steering oil cylinder through the built-in position sensor, and when the steering angle of the wheels reaches a specified position, the controller issues a steering working condition release instruction.

[0159] This embodiment can obtain the steering angle of the steering axle by real-time monitoring of the displacement of the oil cylinder piston rod through the displacement sensor, and can adjust the steering action in a targeted manner through real-time feedback of the steering angle, thereby improving the control accuracy of the hydraulic system and the steering stability of the vehicle; real-time monitoring of the steering angle can also timely discover and correct steering errors, thereby improving the safety of the vehicle.

[0160] In some specific embodiments, the first steering axle 10 and the second steering axle 20 are arranged rotationally symmetrically about the center of both, i.e. the first oil cylinder 51 of the first steering axle 10 and the second oil cylinder 52 of the second steering axle 20 are located on the same side of the vehicle, and the second oil cylinder 52 of the first steering axle 10 and the first oil cylinder 51 of the second steering axle 20 are located on the other side of the vehicle. The steering axle steering steps of the steering mechanism hydraulic system will be described in detail below in combination with FIGS. 1-6:

[0161] The steering motor 11 is powered to charge the accumulator 7 with oil;

[0162] In the case where the first pressure sensor or the second pressure sensor detects that the pressure of the accumulator 7 reaches the set working pressure, the controller can give a driving instruction; in the case where the first pressure sensor or the second pressure sensor detects that the pressure of the accumulator 7 does not reach the set working pressure, the controller cannot give a driving instruction;

[0163] When the vehicle is going to the open-pit loading area, the controller gives a forward driving instruction;

[0164] When the vehicle is driving forward and turning left, the controller gives a forward driving left turning instruction. For the hydraulic flow path corresponding to the first steering axle 10, the reversing valve 31 is in the right position, the normally open on-off valve 33 is in the normally open state, and the oil enters the right side control oil chamber of the proportional valve 32 through the PE port of the proportional control valve group 3 to push it to move left to work in the right position. Different valve core displacements correspond to different opening degrees, so as to control the flow rate of the output, and the output oil enters the L port of the flow amplification valve group 4 through the L port of the proportional control valve group 3, and the LS port of the proportional control valve group 3 and the LS port of the flow amplification valve group 4 are communicated to reach the left side control oil port of the priority valve 43. The right side control oil port of the priority valve 43 is communicated with the PF port of the flow amplification valve group 4. Since the left side control oil pressure of the priority valve 43 plus the left side spring thrust is greater than the right side control oil thrust of the priority valve 43, the priority valve 43 works in the left position. The oil supplied by the hydraulic pump 1 or the accumulator 7 enters the flow amplifier 42 through the PF port, and is combined with the oil entering through the L port to flow out from the CL port, enters the large cavity of the first oil cylinder 51 and the small cavity of the second oil cylinder 52 of the first steering axle 10, so that the first oil cylinder 51 is elongated, the second oil cylinder 52 is shortened, and the wheels of the first steering axle 10 turn left;

[0165] For the hydraulic flow path corresponding to the second steering axle 20, the reversing valve 31 is in the left position, the normally open on-off valve 33 is in the normally open state without electricity, and the oil enters the left control oil chamber of the proportional valve 32 through the PE port of the proportional control valve group 3 to push it to move to the right to work in the left position. Different valve core displacements correspond to different opening degrees, thereby controlling the flow rate of the output, and the output oil enters the R port of the flow amplification valve group 4 through the R port of the proportional control valve group 3. At the same time, the LS port of the proportional control valve group 3 and the LS port of the flow amplification valve group 4 are connected to the left control oil port of the priority valve 43, and the right control oil port of the priority valve 43 is connected to the PF port of the flow amplification valve group 4. Since the left control oil pressure of the priority valve 43 plus the left spring thrust is greater than the right control oil thrust of the priority valve 43, the priority valve 43 works in the left position. The oil supplied by the hydraulic pump 1 or the accumulator 7 enters the flow amplifier 42 through the PF port and flows out from the CR port together with the oil entering through the R port, and enters the large cavity of the second oil cylinder 52 and the small cavity of the first oil cylinder 51 of the second steering axle 20, so that the second oil cylinder 52 of the second steering axle 20 is elongated, the first oil cylinder 51 is shortened, and the wheels of the second steering axle 20 turn left;

[0166] For the hydraulic flow path corresponding to the third steering axle 30, the steering stop valve 6 of the third steering axle 30 cannot be electrified, so that the oil cannot enter the first oil cylinder 51 or the second oil cylinder 52 of the third steering axle 30. The wheels of the third steering axle 30 are always in the neutral state and do not steer, so that the vehicle performs forward driving left steering;

[0167] The controller monitors the valve core displacement of the proportional valve 32 of the first steering axle 10 and the second steering axle 20 in real time. When the valve core displacement of the proportional valve 32 reaches the specified flow control position, the normally open on-off valve 33 is electrified to be in the left position and cut off state, the left and right control oil paths of the proportional valve 32 are cut off, and the valve core of the proportional valve 32 is kept in a specific position to make the steering system continuously perform steering action at a specific flow rate;

[0168] When the forward driving left steering working condition is released, the normally open on-off valve 33 of the first steering axle 10 and the second steering axle 20 is not electrified to be in the normally open state, the reversing valve 31 returns to the neutral position, the left and right control oil paths of the proportional valve 32 return to the tank through the TE port, and the proportional valve 32 returns to the neutral working state. At this time, there is no steering action.

[0169] When the vehicle is forward driving and right turning, the controller gives forward driving right turning instruction, for the hydraulic flow path corresponding to the first steering axle 10, the reversing valve 31 is in left position, the normally open on-off valve 33 is in normally open state without electricity, the oil enters the left control oil chamber of the proportional valve 32 through the PE port of the proportional control valve group 3 to push it to move right to work in left position, different valve core displacements correspond to different opening degrees to control the output flow, the output oil enters the R port of the flow amplification valve group 4 through the R port of the proportional control valve group 3, at the same time, the LS port of the proportional control valve group 3 and the LS port of the flow amplification valve group 4 are communicated to reach the left control oil port of the priority valve 43, the right control oil port of the priority valve 43 is communicated with the PF port of the flow amplification valve group 4, because the left control oil pressure of the priority valve 43 plus the left spring thrust is greater than the right control oil thrust of the priority valve 43, so the priority valve 43 is in left position, the oil supplied by the hydraulic pump 1 or the accumulator 7 enters the flow amplifier 42 through the PF port, and is combined with the oil entering through the R port to flow out from the CR port, and enters the second oil cylinder 52 large cavity and the first oil cylinder 51 small cavity of the first steering axle 10, so that the second oil cylinder 52 is elongated, the first oil cylinder 51 is shortened, and the wheels of the first steering axle 10 turn right;

[0170] For the hydraulic flow path corresponding to the second steering axle 20, the reversing valve 31 is in right position, the normally open on-off valve 33 is in normally open state without electricity, the oil enters the right control oil chamber of the proportional valve 32 through the PE port of the proportional control valve group 3 to push it to move left to work in right position, different valve core displacements correspond to different opening degrees to control the output flow, the output oil enters the L port of the flow amplification valve group 4 through the L port of the proportional control valve group 3, at the same time, the LS port of the proportional control valve group 3 and the LS port of the flow amplification valve group 4 are communicated to reach the left control oil port of the priority valve 43, the right control oil port of the priority valve 43 is communicated with the PF port of the flow amplification valve group 4, because the left control oil pressure of the priority valve 43 plus the left spring thrust is greater than the right control oil thrust of the priority valve 43, so the priority valve 43 is in left position, the oil supplied by the hydraulic pump 1 or the accumulator 7 enters the flow amplifier 42 through the PF port, and is combined with the oil entering through the L port to flow out from the CL port, and enters the first oil cylinder 51 large cavity and the second oil cylinder 52 small cavity of the second steering axle 20, so that the first oil cylinder 51 of the second steering axle 20 is elongated, the second oil cylinder 52 is shortened, and the wheels of the second steering axle 20 turn right;

[0171] For the hydraulic flow path corresponding to the third steering axle 30, the steering cut-off valve 6 of the third steering axle 30 is without electricity, so that the oil cannot enter the first oil cylinder 51 or the second oil cylinder 52 of the third steering axle 30, and the wheels of the third steering axle 30 are always in neutral state without turning, so that the vehicle is forward driving right turning;

[0172] The controller monitors the spool displacement of the proportional valve 32 of the first steering axle 10 and the second steering axle 20 in real time, when the spool displacement of the proportional valve 32 reaches the specified flow control position, the normally open on-off valve 33 is powered to the left position to cut off the state, the proportional valve 32 left and right control oil circuit is cut off, the spool of the proportional valve 32 is kept at a certain position so that the steering system continues to steer at a certain flow;

[0173] When the forward driving right steering condition is released, the normally open on-off valve 33 of the first steering axle 10 and the second steering axle 20 is not powered to the always-on state, the reversing valve 31 returns to the neutral position, the proportional valve 32 left and right control oil circuit returns to the tank through the TE port, and the proportional valve 32 returns to the neutral working state, at this time, there is no steering action.

[0174] After the vehicle is loaded, it goes to the unloading area, the controller gives the reverse driving instruction, the vehicle reverse driving left steering control steps are the same as the vehicle forward driving right steering, and the vehicle reverse driving right steering is the same as the vehicle forward driving left steering. The steering action and the steering angle are given by the path planning and control decision system of the unmanned system.

[0175] Secondly, the disclosure also provides a steering mechanism, as shown in FIGS. 5 and 6, comprising a first steering axle 10 and a second steering axle 20, for realizing forward driving steering and reverse driving steering of a vehicle, the first steering axle 10 is the frontmost axle, and the second steering axle 20 is the rearmost axle, the first steering axle 10 and the second steering axle 20 each comprise:

[0176] A first steering knuckle 81 and a second steering knuckle 82, each for mounting a tire 80;

[0177] A first support 83 and a second support 84, respectively connected to two sides of a vehicle frame 40;

[0178] A steering cylinder 5, comprising a first cylinder 51 and a second cylinder 52, the first cylinder 51 is hinged between the first support 83 and the first steering knuckle 81, and the second cylinder 52 is hinged between the first support 83 and the second steering knuckle 82;

[0179] A steering rocker arm 85, a first pull rod 86 and a second pull rod 87, a first end of the steering rocker arm 85 is hinged to the second support 84, the first pull rod 86 is hinged between the first steering knuckle 81 and a second end of the steering rocker arm 85, and the second pull rod 87 is hinged between the second steering knuckle 82 and a third end of the steering rocker arm 85; and

[0180] The steering mechanism hydraulic system of the above embodiment is configured to drive the steering cylinder 5 to extend and retract.

[0181] Specifically, the steering mechanism further comprises a first connecting piece 801, a second connecting piece 802, a third connecting piece 803 and a fourth connecting piece 804, the first connecting piece 801 and the fourth connecting piece 804 are fixed to the first steering knuckle 81, and the second connecting piece 802 and the third connecting piece 803 are fixed to the second steering knuckle 82. The first connecting piece 801, the second connecting piece 802, the third connecting piece 803 and the fourth connecting piece 804 are also called steering knuckle arms or steering trapezoidal arms, which are fixedly connected to the steering knuckles through bolts.

[0182] The first oil cylinder 51 is hinged between the first support 83 and the first connecting piece 801, the first pull rod 86 is hinged between the fourth connecting piece 804 and the steering rocker arm 85, the second oil cylinder 52 is hinged between the first support 83 and the second connecting piece 802, and the second pull rod 87 is hinged between the third connecting piece 803 and the steering rocker arm 85.

[0183] The first support 83 is bolted to the vehicle frame 40, the steering rocker arm 85 is hinged to the vehicle frame 40 through a pin shaft, the first oil cylinder 51 and the second oil cylinder 52 are hinged to the connecting pieces and the first support 83 through pin shafts and joint bearings, and the first pull rod 86 and the second pull rod 87 are hinged to the connecting pieces and the steering rocker arm 85 through pin shafts and joint bearings.

[0184] The steering mechanism of this embodiment drives the steering knuckles to rotate through the first oil cylinder 51 and the second oil cylinder 52 of the hydraulic system, can realize precise control of the steering direction and angle of the front and rear steering axles of the vehicle, thereby driving the vehicle to realize bidirectional driving, reduces the control difficulty of bidirectional driving of the vehicle, realizes loading and unloading actions in a straight driving manner, and improves production efficiency.

[0185] In some embodiments, as shown in FIG. 5, the steering mechanism further comprises:

[0186] An angle sensor 88 is arranged in the steering rocker arm 85 and is configured to detect the rotation angle of the steering rocker arm 85.

[0187] Specifically, the angle sensor 88 is embedded in the steering rocker arm 85 and is used to detect the swing angle value of the steering rocker arm 85, thereby indirectly obtaining the current wheel rotation angle value. The steering rocker arm 85 embeds the angle sensor as a redundant detection means for the steering angle, and the displacement sensor built in the steering cylinder is the first detection means for the wheel steering angle detection. When the displacement sensor built in the steering cylinder fails, the angle sensor 88 serves as the second detection means to replace the detection of the current wheel steering angle. The detection method of the displacement sensor built in the steering cylinder failure is that the controller cannot receive the displacement sensor data built in the steering cylinder.

[0188] The embodiment redundantly designs the steering cylinder built-in displacement sensor through the angle sensor 88, can switch to the angle sensor 88 to detect the steering angle of the wheel when the steering cylinder built-in displacement sensor fails, and then adjusts the steering action through the real-time feedback of the steering angle, improves the control accuracy of the hydraulic system and the steering stability of the vehicle; the real-time monitoring of the angle sensor 88 can further improve the safety of the vehicle.

[0189] Again, as shown in FIG. 6, the present disclosure also provides an engineering machinery chassis, comprising:

[0190] The frame 40; and

[0191] The steering mechanism of the above embodiment, the first steering knuckle 81 and the second steering knuckle 82 are connected to the frame 40 through the suspension oil cylinder respectively, and the first support 83 and the second support 84 are connected to the two sides of the frame 40 respectively.

[0192] Specifically, the first support 83 and the second support 84 are fixedly connected to the two sides of the frame 40 respectively.

[0193] The engineering machinery chassis of the embodiment drives the steering knuckle to rotate through the steering cylinder of the hydraulic system, can realize accurate control of the steering direction and angle of the front and rear steering axles of the vehicle, thereby driving the vehicle to realize bidirectional driving, reduces the control difficulty of bidirectional driving of the vehicle, realizes loading and unloading action in a straight drive manner, and improves production efficiency.

[0194] In addition, the present disclosure also provides an engineering machinery, comprising the steering mechanism hydraulic system of the above embodiment, or the steering mechanism of the above embodiment, or the engineering machinery chassis of the above embodiment.

[0195] The engineering machinery of the embodiment drives the steering knuckle to rotate through the steering cylinder of the hydraulic system, can realize accurate control of the steering direction and angle of the front and rear steering axles of the vehicle, thereby driving the vehicle to realize bidirectional driving, reduces the control difficulty of bidirectional driving of the vehicle, realizes loading and unloading action in a straight drive manner, and improves production efficiency.

[0196] In some embodiments, the engineering machinery comprises an unmanned mine dump truck.

[0197] The above describes in detail the steering mechanism hydraulic system, the steering mechanism and the engineering machinery provided by the present disclosure. The principles and implementation modes of the present disclosure are described by applying specific embodiments, and the above embodiment description is only used to help understand the method and core idea of the present disclosure. It should be noted that, for those skilled in the art, without departing from the principles of the present disclosure, the present disclosure can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the present disclosure.

Claims

1. A steering mechanism hydraulic system for controlling forward and reverse steering of a vehicle, the vehicle including a first steering axle (10) and a second steering axle (20), the first steering axle (10) being the foremost axle and the second steering axle (20) being the rearmost axle, both the first steering axle (10) and the second steering axle (20) including steering cylinders (5), the steering mechanism hydraulic system comprising: A hydraulic pump (1) is connected to a steering motor (11) via a transmission. An unloading valve assembly (2) is provided on the oil supply line of the hydraulic pump (1), and the unloading valve assembly (2) is configured to unload the pressure of the hydraulic oil; A proportional control valve assembly (3) is provided in the working oil circuit of the unloading valve assembly (2). The proportional control valve assembly (3) is configured to control the steering direction and steering angle of the first steering axle (10) and the second steering axle (20). and A flow amplification valve assembly (4) is provided between the proportional control valve assembly (3) and the steering cylinder (5). Both the flow amplification valve assembly (4) and the steering cylinder (5) are located in the working oil circuit of the proportional control valve assembly (3). The flow amplification valve assembly (4) is configured to amplify the flow rate of hydraulic oil entering the steering cylinder (5).

2. The steering mechanism hydraulic system according to claim 1, wherein, The proportional control valve assembly (3) includes: A reversing valve (31) is configured to control the outlet path of the proportional control valve assembly (3) to control the steering direction of the first steering axle (10) and the second steering axle (20); and A proportional valve (32) is configured to control the outflow rate of the proportional control valve assembly (3) to control the steering angle of the first steering axle (10) and the second steering axle (20).

3. The steering mechanism hydraulic system according to claim 2, wherein, The proportional control valve assembly (3) also includes: A normally open switch valve (33) is provided between the reversing valve (31) and the proportional valve (32). The normally open switch valve (33) is configured to close when the valve core of the proportional valve (32) moves to a preset position, so that the liquid flow rate of the proportional valve (32) is maintained at a preset flow rate.

4. The steering mechanism hydraulic system according to claim 2 or 3, wherein, The valve core movement of the proportional valve (32) is negatively correlated with the vehicle speed.

5. The steering mechanism hydraulic system according to any one of claims 2 to 4, wherein, The proportional control valve group (3) includes the same main control valve group and auxiliary control valve group. When the main control valve does not fail, the auxiliary control valve group is disconnected. When the main control valve group fails, the auxiliary control valve group is activated.

6. The steering mechanism hydraulic system according to claim 5, wherein, The proportional control valve group (3) also includes a normally open switch valve (33) located between the reversing valve (31) and the proportional valve (32). If the valve core of the proportional valve (32) does not move when both the reversing valve (31) and the normally open switch valve (33) of the main control valve group are in the on state, it is determined that the main control valve group has malfunctioned.

7. The steering mechanism hydraulic system according to claim 5 or 6, wherein, The reversing valve (31) includes a three-position four-way reversing valve. When the main control valve group is not malfunctioning, the reversing valve (31) of the secondary control valve group is in the neutral position so that the secondary control valve group is disconnected.

8. The steering mechanism hydraulic system according to any one of claims 1 to 7, wherein, The proportional control valve group (3) includes the same first control valve group (301) and second control valve group (302). The first control valve group (301) and the second control valve group (302) are both located in the working oil circuit of the unloading valve group (2). The first control valve group (301) is configured to control the steering direction and steering angle of the first steering axle (10), and the second control valve group (302) is configured to control the steering direction and steering angle of the second steering axle (20). The flow amplification valve group (4) includes the same first amplification valve group (401) and second amplification valve group (402). The first amplification valve group (401) is located between the first control valve group (301) and the steering cylinder (5) of the first steering axle (10), and the second amplification valve group (402) is located between the second control valve group (302) and the steering cylinder (5) of the second steering axle (20).

9. The steering mechanism hydraulic system according to any one of claims 1 to 8, wherein, The flow amplification valve assembly (4) includes: The first relief valve (41) is located between the control oil circuit of the proportional valve (32) and the oil tank; A flow amplifier (42) is connected between the working oil circuit of the proportional control valve assembly (3) and the steering cylinder (5); and Priority valve (43) is configured to introduce hydraulic oil from the hydraulic pump (1) to amplify the flow rate of hydraulic oil from the proportional control valve assembly (3).

10. The steering mechanism hydraulic system according to claim 9, wherein, The steering cylinder (5) includes a first cylinder (51) and a second cylinder (52), and the flow amplification valve assembly (4) further includes: Two cylinder safety valves (44) are connected at one end to the first cylinder (51) and the second cylinder (52) respectively, and at the other end to the oil tank. The cylinder safety valve (44) includes a one-way valve (441) and a second relief valve (442) arranged in parallel. The one-way valve (441) only allows oil to flow from the oil tank to the first cylinder (51) or the second cylinder (52).

11. The steering mechanism hydraulic system according to claim 10, wherein, The first outlet (CL) of the flow amplification valve assembly (4) is connected to the large chamber of the first cylinder (51) and the small chamber of the second cylinder (52). The second outlet (CR) of the flow amplification valve assembly (4) is connected to the small chamber of the first cylinder (51) and the large chamber of the second cylinder (52). When the hydraulic oil enters the large chamber, the cylinder extends and when the hydraulic oil enters the small chamber, the cylinder shortens.

12. The steering mechanism hydraulic system according to any one of claims 1 to 11, wherein, The vehicle also includes a third steering axle (30), which is disposed between the first steering axle (10) and the second steering axle (20). The third steering axle (30) is located at the center of the first steering axle (10) and the second steering axle (20), or a plurality of the third steering axles (30) are symmetrically arranged about the center of the first steering axle (10) and the second steering axle (20).

13. The steering mechanism hydraulic system according to claim 12, further comprising: A steering shut-off valve (6) is provided between the flow amplification valve group (4) and the steering cylinder (5) of the third steering axle (30), and the steering shut-off valve (6) is configured to enable the third steering axle (30) to switch between a non-steering state and a steering state.

14. The steering mechanism hydraulic system according to claim 13, wherein, The steering shut-off valve (6) includes a normally closed switch valve. When the normally closed switch valve is not energized, it disconnects the flow amplification valve group (4) and the steering cylinder (5) of the third steering axle (30). When the normally closed switch valve is energized, it connects the flow amplification valve group (4) and the steering cylinder (5) of the third steering axle (30).

15. The steering mechanism hydraulic system according to any one of claims 1 to 14, wherein, The first steering axle (10) and the second steering axle (20) are arranged rotationally symmetrically about their centers.

16. The steering mechanism hydraulic system according to any one of claims 1 to 15, further comprising an accumulator (7), the accumulator (7) being disposed in the oil supply line of the hydraulic pump (1), the accumulator (7) being connected to the unloading valve assembly (2), the unloading valve assembly (2) comprising: The first unloading valve (21) is provided in the working oil circuit of the hydraulic pump (1) and is configured to unload the hydraulic oil pressure supplied by the hydraulic pump (1); The second unloading valve (22) is provided in the working oil circuit of the accumulator (7) and is configured to unload the hydraulic oil pressure supplied by the accumulator (7); and The third relief valve (23) is located in the working oil circuit of the hydraulic pump (1) and the accumulator (7).

17. The steering mechanism hydraulic system according to claim 16, further comprising: A first pressure sensor is connected to the unloading valve assembly (2), and the first pressure sensor is configured to detect the hydraulic oil pressure supplied by the accumulator (7); A second pressure sensor is connected to the unloading valve assembly (2), and the second pressure sensor is configured to detect the hydraulic oil pressure supplied by the accumulator (7) in the event of failure of the first pressure sensor. A third pressure sensor is connected to the unloading valve assembly (2), and the third pressure sensor is configured to detect the pressure of the hydraulic oil supplied by the hydraulic pump (1); and A fourth pressure sensor is connected to the unloading valve assembly (2) and is configured to detect the hydraulic oil pressure supplied by the hydraulic pump (1) in the event of failure of the third pressure sensor.

18. The steering mechanism hydraulic system according to claim 16 or 17, wherein, When the hydraulic oil pressure supplied by the hydraulic pump (1) is less than the preset pressure and the hydraulic oil pressure supplied by the accumulator (7) is less than the preset pressure, the vehicle performs an immediate stop operation. When the hydraulic oil pressure supplied by the hydraulic pump (1) is less than the preset pressure and the hydraulic oil pressure supplied by the accumulator (7) is not less than the preset pressure, the vehicle performs an emergency steering operation.

19. The hydraulic system for the steering mechanism according to any one of claims 1 to 18, wherein, The steering cylinder (5) includes a first cylinder (51) and a second cylinder (52). The first cylinder (51) and / or the second cylinder (52) are provided with a displacement sensor, which is configured to detect the displacement of the cylinder piston rod to obtain the steering angle of the steering axle.

20. A steering mechanism, comprising a first steering axle (10) and a second steering axle (20), for realizing forward steering and reverse steering of a vehicle, wherein the first steering axle (10) is the foremost axle and the second steering axle (20) is the rearmost axle, and both the first steering axle (10) and the second steering axle (20) include: The first steering knuckle (81) and the second steering knuckle (82) are both used to mount the tire (80); The first support (83) and the second support (84) are used to connect to both sides of the frame (40); The steering cylinder (5) includes a first cylinder (51) and a second cylinder (52). The first cylinder (51) is hinged between the first support (83) and the first steering knuckle (81), and the second cylinder (52) is hinged between the first support (83) and the second steering knuckle (82). The steering rocker arm (85), the first tie rod (86), and the second tie rod (87) are provided. The first end of the steering rocker arm (85) is hinged to the second support (84). The first tie rod (86) is hinged between the first steering knuckle (81) and the second end of the steering rocker arm (85). The second tie rod (87) is hinged between the second steering knuckle (82) and the third end of the steering rocker arm (85). and The steering mechanism hydraulic system according to any one of claims 1 to 19 is configured to drive the steering cylinder (5) to extend or retract.

21. The steering mechanism according to claim 20, further comprising: An angle sensor (88) is provided in the steering rocker arm (85) and is configured to detect the rotation angle of the steering rocker arm (85).

22. A chassis for engineering machinery, comprising: Frame (40); and The steering mechanism according to claim 20 or 21, wherein the first steering knuckle (81) and the second steering knuckle (82) are respectively connected to the frame (40) via suspension cylinders, and the first support (83) and the second support (84) are respectively connected to both sides of the frame (40).

23. An engineering machinery, comprising a steering mechanism hydraulic system as described in any one of claims 1 to 19, or a steering mechanism as described in claim 20 or 21, or an engineering machinery chassis as described in claim 22.

24. The engineering machinery according to claim 23 includes an unmanned mining dump truck.

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