Chassis steering hydraulic system and work machine

Abstract

This invention belongs to the field of work machinery technology and provides a chassis-controlled hydraulic system and work machinery. The system includes a pump unit and a steering unit. The steering unit includes a steering gear, a proportional electronically controlled valve assembly, and a steering actuator cylinder. The inlet and outlet ports of the steering gear and the proportional electronically controlled valve assembly are connected to the pump unit and the oil tank, while the other side has left and right steering oil circuits, which are connected to the steering actuator cylinder. The steering gear responds to steering wheel operations, and the proportional electronically controlled valve assembly responds to electronic control commands. Both control the hydraulic oil flow according to the hydraulic direction corresponding to the current steering direction, entering and exiting the steering actuator cylinder through their respective left and right steering oil circuits. This system can achieve both manual and remote steering.

Description

Technical Field

[0001] This invention belongs to the field of construction machinery technology, specifically relating to a chassis control hydraulic system and construction machinery. Background Technology

[0002] With the continuous development of vehicle electrification and intelligent technology, the demand for remote control functionality is increasingly evident in the field of special vehicles in closed environments such as airports and ports, in addition to traditional manual driving. Currently, the steering of these vehicles still uses a hydraulic drive system. The reason for this is that they need to bear loads of tens or even hundreds of tons during operation, resulting in extremely high resistance torque. Hydraulics, with its inherent advantages of high power density, large output torque, and strong impact resistance, can well adapt to the demands of such heavy-duty working conditions. However, these types of operational machinery have not yet integrated any form of remote steering functionality. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies, the present invention provides a chassis control hydraulic system and working machinery, which aims to solve the technical problem that existing working machinery does not integrate both manual steering control and remote steering modes.

[0004] To achieve the above objectives, the present invention also provides a chassis control hydraulic system, which includes a pump unit and a steering unit. The steering unit includes a steering gear, a proportional electronically controlled valve assembly, and a steering actuation cylinder. The inlet and outlet ports of the steering gear and the proportional electronically controlled valve assembly are connected to the pump unit and the oil tank, and the other side is provided with a left steering oil circuit and a right steering oil circuit, which are connected to the steering actuation cylinder. The steering gear is used to respond to steering wheel operations, and the proportional electronically controlled valve assembly is used to respond to electronic control commands. Both are used to control the hydraulic oil to flow in and out of the steering actuation cylinder through their respective left and right steering oil circuits according to the hydraulic flow direction corresponding to the current steering direction.

[0005] In this embodiment, there are multiple steering actuator cylinders, and the steering unit also includes a steering switching valve group. The left steering oil circuit and the right steering oil circuit of the steering gear and the proportional electronic control valve group are respectively connected to each steering actuator cylinder through the steering switching valve group. The steering switching valve group is used to select some steering actuator cylinders and control the selected steering actuator cylinders to enter and exit oil according to the hydraulic flow direction corresponding to the current steering.

[0006] In this embodiment, the multiple steering cylinders include a front steering cylinder and a rear steering cylinder, and the steering switching valve group includes a first switching valve and a second switching valve. The first switching valve connects the left-turn working chamber and the right-turn working chamber of the front steering cylinder, and the second switching valve connects the left-turn working chamber and the right-turn working chamber of the rear steering cylinder. The two valves are also connected to the left steering oil circuit and the right steering oil circuit, respectively. The first switching valve and the second switching valve are used to control whether the front steering cylinder and the rear steering cylinder participate in steering, respectively or in concert.

[0007] In this embodiment, the first switching valve has a first oil port and a second oil port, and the second switching valve has a third oil port and a fourth oil port. The first oil port is connected to the left steering oil circuit, and a connecting channel is formed between the second oil port and the third oil port. The fourth oil port is connected to the right steering oil circuit. The first switching valve and the second switching valve have a conducting position and a cut-off position, respectively. In the conducting position, the first switching valve controls the first oil port and the second oil port to respectively connect the left-turn working chamber and the right-turn working chamber of the front steering cylinder, and the second switching valve controls the third oil port and the fourth oil port to respectively connect the left-turn working chamber and the right-turn working chamber of the rear steering cylinder. In the cut-off position, the first oil port and the second oil port are connected, the third oil port and the fourth oil port are connected, and the two working chambers of the front steering cylinder and the rear steering cylinder are cut off.

[0008] In this embodiment, the first switching valve is further provided with a four-wheel axial working position. In the four-wheel axial working position, the oil inlet and return direction of the front steering cylinder is opposite to the oil inlet and return direction when the first switching valve is in the open position; or the second switching valve is further provided with a four-wheel axial working position. In the four-wheel axial working position, the oil inlet and return direction of the rear steering cylinder is opposite to the oil inlet and return direction when the second switching valve is in the open position.

[0009] In this embodiment, the steering switching valve group has multiple sets of working ports, which are configured one-to-one with multiple steering actuator cylinders. Each set of working ports includes a left-turn working port and a right-turn working port for connecting the left-turn working chamber and the right-turn working chamber of the corresponding steering actuator cylinder, respectively. The steering switching valve group also includes a floating control valve connected between the left-turn working port and the right-turn working port for controlling the opening or closing of the two.

[0010] In this embodiment, the steering switching valve group also includes a replenishing oil port, and the floating control valve is also connected to the replenishing oil port. When the left turn working oil port and the right turn working oil port are connected, the replenishing oil port is controlled to be connected to the left turn working oil port and the right turn working oil port simultaneously.

[0011] In this embodiment, the chassis control hydraulic system further includes a braking unit, which includes a brake control valve, a brake actuator, and a brake accumulator. The brake control valve is connected between the pump unit and the brake actuator via a check valve, and the brake accumulator is connected in the oil line between the brake control valve and the check valve.

[0012] In this embodiment, the brake actuator is located near the service brake and the parking brake. The brake control valve includes a service brake valve and a parking brake valve. The parking brake valve is used to receive parking commands from the driver's cab and remote parking commands to control the parking brake to operate. The service brake valve is provided with a proportional control terminal, which is linked to the brake pedal. The proportional control terminal is also connected to the brake accumulator through a brake electro-proportional valve. The brake electro-proportional valve is used to open to the corresponding opening degree according to the remote braking command of the vehicle.

[0013] To achieve the above objectives, the present invention also provides a working machine, wherein the working machine includes a chassis-operated hydraulic system as described above.

[0014] Through the above technical solutions, the chassis control hydraulic system provided by the embodiments of the present invention has the following beneficial effects: By connecting a proportional electronically controlled valve assembly in parallel to the existing manual hydraulic steering system, an electronically controlled remote steering channel is added to the vehicle without altering the original steering gear and steering cylinder structure. This achieves compatibility between manual and remote control modes. Simultaneously, the steering gear and the proportional electronically controlled valve assembly respond independently to different control commands without interference. When one control mode is active, the other is in standby mode. This retains the reliability of the original manual control while adding the flexibility of remote steering, effectively solving the problem of existing work machinery being unable to be remotely controlled. It significantly improves the vehicle's operational convenience and intelligence in enclosed environments.

[0015] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a hydraulic schematic diagram of the chassis control hydraulic system according to an embodiment of the present invention; Figure 2 This is a hydraulic schematic diagram of the steering switching valve group according to an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures 1. Pump unit; 2. Steering unit; 21. Steering gear; 22. Proportional electronic valve assembly; L, Left steering circuit; R, Right steering circuit; 23. Steering actuator cylinder; 231. Front steering cylinder; 232. Rear steering cylinder; 24. Steering switching valve assembly; 241. First switching valve; 241a. First port; 241b. Second port; A1. First left chamber connection port; B1. First right chamber connection port; 242. Second switching valve; 2 42a, Third oil port; 242b, Fourth oil port; A2, Second left chamber connection oil port; B2, Second right chamber connection oil port; 243, Floating control valve; 24C, Oil replenishment port; 3, Braking unit; 31, Service brake valve; 32, Parking brake valve; 33a, Front axle service brake accumulator; 33b, Rear axle service brake accumulator; 33c, Parking brake accumulator; 33d, Remote control accumulator; 4, Manual pump; 5, Brake proportional valve. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] The chassis control hydraulic system of the present invention will now be described with reference to the accompanying drawings.

[0020] The chassis control of construction machinery typically encompasses two core functions: steering and braking. Among these, steering, as a key action to ensure that the machinery runs along a predetermined trajectory during operation, directly affects operational safety and efficiency in terms of its precision and flexibility.

[0021] Taking airport aircraft towing vehicles as an example, this type of vehicle plays a crucial role in towing commercial airliners into and out of parking positions, taxiing, and other operations. Sometimes, the driver's cab's visibility is limited in certain scenarios, such as when towing an aircraft in reverse, or at night or in inclement weather, resulting in significant blind spots. These factors increase the difficulty and safety risks of steering operations from the cab. If a remote steering function could be added while retaining the original manual control mode, the driver could step out of the cab and choose a better observation position outside the vehicle to remotely operate the vehicle, thus compensating for the control hazards caused by limited visibility.

[0022] To integrate manual and remote steering functions for this type of work machinery, this invention provides a chassis control hydraulic system, such as... Figure 1 As shown, the system mainly includes a pump unit 1 and a steering unit 2.

[0023] Pump unit 1 is connected to the oil tank and provides the power oil source for the entire hydraulic system.

[0024] The steering unit 2 includes a steering gear 21, a proportional electronic control valve assembly 22, and a steering actuation cylinder 23. The steering gear 21 and the proportional electronic control valve assembly 22 are arranged in parallel between the pump unit 1 and the steering actuation cylinder 23. Specifically, the inlet and outlet ports of the steering gear 21 and the proportional electronic control valve assembly 22 are connected to the pump unit 1 and the oil tank, and the other side is provided with a left steering oil passage L and a right steering oil passage R. The left steering oil passage L and the right steering oil passage R are directly or indirectly connected to the two working chambers of the steering actuation cylinder 23.

[0025] The steering gear 21 responds to the driver's steering wheel operation and contains a rotary valve. When the steering wheel is turned, the rotary valve actuates, guiding hydraulic oil to the corresponding steering oil circuit and actuating the steering cylinder 23. The proportional electronic valve assembly 22 responds to electronic control commands issued by a remote controller or controller. It integrates a proportional solenoid valve, which can adjust the flow direction and flow rate of hydraulic oil according to the magnitude and direction of the control signal. It also drives the steering cylinder 23 to move in the specified direction. According to the indicated steering direction, the steering gear 21 and the proportional electronic valve assembly 22 control the hydraulic oil to flow in and out of the steering cylinder 23 through their respective left steering oil circuit L and right steering oil circuit R, thereby realizing steering functions in both manual and remote control modes.

[0026] By connecting a proportional electronic control valve group 22 in parallel to the existing manual hydraulic steering system, an electronic remote steering channel is added to the vehicle without altering the main structure of the original steering gear 21 and steering actuator cylinder 23, achieving compatibility between manual and remote control modes. Simultaneously, the steering gear 21 and the proportional electronic control valve group 22 respond independently to different control commands without interference. When one control mode is operating, the other is in standby mode. This retains the reliability of the original manual control while adding the flexibility of remote steering, effectively solving the problem of existing work machinery being unable to be remotely controlled, and significantly improving the vehicle's operational convenience and intelligence level in enclosed environments.

[0027] like Figure 1 and Figure 2 As shown, in this embodiment, there can be multiple steering cylinders 23, each corresponding to a different axle or a different wheel. The steering unit 2 may further include a steering switching valve group 24, with the left steering oil circuit L and the right steering oil circuit R of the steering gear 21 and the proportional electronic control valve group 22 respectively connected to each steering cylinder 23 through the steering switching valve group 24.

[0028] The steering switching valve assembly 24 can integrate multiple directional valves. Each directional valve can individually control a steering actuation cylinder 23, or multiple directional valves can be linked to control the steering actuation cylinders 23. Each directional valve is used to selectively control the corresponding directional valve to switch its valve position according to an externally input mode selection signal (such as a mode selection switch in the driver's cab or a mode switching command on the remote control). This allows the two working chambers of some steering actuation cylinders 23 to be connected to the left steering circuit L and the right steering circuit R, respectively. The selected cylinder participates in steering, while the unselected cylinder remains locked or does not participate in steering.

[0029] By selecting and controlling the steering switching valve group 24, the working machinery can quickly switch between multiple steering modes according to the actual working conditions, such as realizing individual steering of a certain axle and coordinated steering of multiple axles, thereby significantly improving the working machinery's adaptability to working conditions and operational flexibility.

[0030] For example, such as Figure 1 and Figure 2 As shown, the multiple steering cylinders 23 may include a front steering cylinder 231 and a rear steering cylinder 232, which correspond to the front axle and rear axle of the vehicle, respectively. The steering switching valve assembly 24 includes a first switching valve 241 and a second switching valve 242. The first switching valve 241 connects the left-turn working chamber and the right-turn working chamber of the front steering cylinder 231, and the second switching valve 242 connects the left-turn working chamber and the right-turn working chamber of the rear steering cylinder 232. Simultaneously, the first switching valve 241 and the second switching valve 242 are also connected to the left steering circuit L and the right steering circuit R, respectively. The first switching valve 241 and the second switching valve 242 are used to control whether the connected cylinders participate in the steering action, that is, to control the on / off state between the left steering circuit L and the right steering circuit R and the front steering cylinder 231 and the rear steering cylinder 232.

[0031] The first switching valve 241 and the second switching valve 242 are respectively connected to the left steering oil circuit L and the right steering oil circuit R. The connection here can be direct or indirect.

[0032] Direct connection refers to a direct connection between the oil port of the switching valve and the left steering oil circuit L or the right steering oil circuit R via an oil circuit. In this connection configuration, when the first switching valve 241 is in the open position, the left-turn working chamber of the front steering cylinder 231 is connected to the left steering oil circuit L, and the right-turn working chamber is connected to the right steering oil circuit R, allowing the front axle to participate in steering. When the first switching valve 241 is in the closed position, the two working chambers of the front steering cylinder 231 are disconnected from the steering oil circuit, the cylinder is locked, and the front axle does not participate in steering. Similarly, the second switching valve 242 operates on a similar principle to the first switching valve 241. The second switching valve 242 controls whether the rear steering cylinder 232 is connected to the steering oil circuit, thereby determining whether the rear axle participates in steering.

[0033] Indirect connection means that there is a connection between the oil ports of the first switching valve 241 and the second switching valve 242. They are not independently connected to the left steering oil circuit L and the right steering oil circuit R, but are connected in series through their respective oil circuits, so that one switching valve is indirectly connected to the main steering oil circuit through the other switching valve.

[0034] For example, the first switching valve 241 has a first oil port 241a, a second oil port 241b, a first left chamber connected to oil port A1, and a second left chamber connected to oil port A2; the second switching valve 242 has a third oil port 242a, a fourth oil port 242b, a second left chamber connected to oil port A2, and a second right chamber connected to oil port B2.

[0035] The first oil port 241a can be connected to the left turn oil circuit L, the second oil port 241b and the third oil port 242a form a connecting channel, and the fourth oil port 242b can be connected to the right turn oil circuit R.

[0036] The first left cavity connecting port A1 and the first right cavity connecting port B1 are respectively connected to the left-turn working chamber and the right-turn working chamber of the front steering cylinder; the second left cavity connecting port A2 and the second right cavity connecting port B2 are respectively connected to the left-turn working chamber and the right-turn working chamber of the rear steering cylinder.

[0037] Furthermore, the first switching valve 241 and the second switching valve 242 have an on position and an off position, respectively.

[0038] In the conducting position, the first switching valve 241 controls the first oil port 241a to be connected to the first left cavity connecting oil port A1 and the second oil port 241b to be connected to the first right cavity connecting oil port B1, so that the left steering oil circuit L is connected to the left steering working chamber of the front steering cylinder through the first oil port 241a and the first left cavity connecting oil port A1 in sequence, and the right steering working chamber of the front steering cylinder flows to the connecting channel through the first right cavity connecting oil port B1 and the second oil port 241b.

[0039] The second switching valve 242 controls the third oil port 242a to be connected to the second left chamber connection port A2 and the fourth oil port 242b to be connected to the second right chamber connection port B2, so that the hydraulic oil from the connecting channel enters the left turning working chamber of the rear steering cylinder through the third oil port 242a and the second left chamber connection port A2, and the right turning working chamber of the rear steering cylinder flows to the right steering oil circuit R through the second right chamber connection port B2 and the fourth oil port 242b and returns to the oil tank.

[0040] In the cut-off position, the first switching valve 241 controls the first oil port 241a to be connected to the second oil port 241b, and the second switching valve 242 controls the third oil port 242a to be connected to the fourth oil port 242b.

[0041] Based on the above connection relationship, the following three operating modes can be achieved by controlling the valve position combination of the first switching valve 241 and the second switching valve 242: When the first switching valve 241 is in the open position and the second switching valve 242 is in the closed position (i.e. Figure 2When solenoid valve Y3 is energized, while Y4 and Y5 are de-energized, the left steering oil circuit L connects to the left-turn working chamber of the front steering cylinder 231 via the first oil port 241a and the internal passage of the first switching valve 241. The hydraulic oil in the right-turn working chamber of the front steering cylinder 231 flows through the first switching valve 241 to the second oil port 241b, and then through the connecting passage to the third oil port 242a. Since the second switching valve 242 is in the off position, the third oil port 242a and the fourth oil port 242b are connected. Therefore, the return oil flows through the fourth oil port 242b to the right steering oil circuit R and directly back to the oil tank. At this time, only the front steering cylinder 231 is working, and the vehicle operates in front-wheel steering mode.

[0042] When the first switching valve 241 is in the off position and the second switching valve 242 is in the on position (i.e.) Figure 2 When the Y3 solenoid valve is de-energized, the Y4 valve is energized, and the Y5 valve is de-energized, the left steering oil circuit L enters the second switching valve 242 via the first oil port 241a, the second oil port 241b, the connecting channel, and the third oil port 242a. The oil then flows through the internal channel of the second switching valve 242 to the left-turn working chamber of the rear steering cylinder 232. The hydraulic oil in the right-turn working chamber of the rear steering cylinder 232 flows through the second switching valve 242 to the fourth oil port 242b, then to the right steering oil circuit R and returns to the oil tank. At this time, only the rear steering cylinder 232 is engaged, and the vehicle operates in rear-wheel steering mode.

[0043] When both the first switching valve 241 and the second switching valve 242 are in the on position (i.e.) Figure 2 When solenoid valves Y3, Y4, and Y5 are energized, the left steering oil circuit L is connected to the left-turn working chamber of the front steering cylinder 231 via the first switching valve 241. The hydraulic oil in the right-turn working chamber of the front steering cylinder 231 flows to the second port 241b via the first switching valve 241, and then enters the left-turn working chamber of the rear steering cylinder 232 via the connecting channel, the third port 242a, and the second switching valve 242. The hydraulic oil in the right-turn working chamber of the rear steering cylinder 232 flows to the right steering oil circuit R via the fourth port 242b via the second switching valve 242 and returns to the oil tank. At this time, the two steering cylinders 23 form a series connection in the hydraulic circuit, the front and rear axles participate in steering simultaneously, and their steering is the same, and the vehicle is in crab mode.

[0044] In this mode, because the hydraulic oil flows through the two cylinders in sequence, the piston movements of the two cylinders are forced to remain synchronized at the hydraulic circuit level. In other words, in crab mode, the deflection angles of the front and rear axle wheels can always be consistent without relying on additional electrical synchronization control algorithms or angle sensor feedback, thus avoiding abnormal tire wear or vehicle deviation.

[0045] In this embodiment, the first switching valve 241 is also provided with a four-wheel axial working position. In the four-wheel axial working position, the oil inlet and outlet directions of the front steering cylinder 231 are opposite to the oil inlet and outlet directions when the first switching valve 241 is in the open position.

[0046] Alternatively, the second switching valve 242 may also be provided with a four-wheel radial working position (i.e. Figure 2 (The valve position corresponding to the energized Y5) is in the four-wheel axial working position, and the oil inlet and return direction of the rear steering cylinder 232 is opposite to the oil inlet and return direction when the second switching valve 242 is in the conducting position.

[0047] Taking the second switching valve 242 having a four-wheel axial working position as an example, when the first switching valve 241 remains in the conducting position and the second switching valve 242 switches to the four-wheel axial working position (i.e. Figure 2 When the Y3 solenoid valve is energized, Y4 is not energized, and Y5 is energized, the oil inlet and outlet directions of the front steering cylinder 231 remain unchanged, while the oil inlet and outlet directions of the rear steering cylinder 232 are opposite to those of the front steering cylinder 231. At this time, the deflection directions of the front axle wheels and the rear axle wheels are opposite, and each wheel makes a centripetal motion around the same instantaneous steering center, significantly reducing the turning radius of the entire vehicle.

[0048] Furthermore, in conjunction with the reversing control of the first switching valve 241 or the second switching valve 242, the wheels of the corresponding axle can actively correct themselves and return to the center position. For example, the system sends a corresponding control signal to the electro-proportional multi-way valve based on the current wheel deflection angle position detected by the angle sensor located at the front axle or steering cylinder 23. The electro-proportional multi-way valve controls the flow of hydraulic oil into the first switching valve 241 based on the signal, thereby controlling the time when the first switching valve 241 is in the conducting position to achieve wheel centering correction.

[0049] In summary, by combining different valve positions of the first and second directional control valves, flexible switching of multiple steering modes can be achieved. Furthermore, the first and second directional control valves can be configured as solenoid valves, making the aforementioned multiple steering modes compatible with both manual and remote control operation modes. This provides a simple and highly reliable technical solution for the intelligent upgrading of machinery.

[0050] like Figure 1 and Figure 2 As shown, in this embodiment, the steering switching valve assembly 24 has multiple sets of working ports, each set corresponding to a plurality of steering actuator cylinders 23. Each set of working ports includes a left-turn working port and a right-turn working port for connecting the left-turn working chamber and the right-turn working chamber of the corresponding steering actuator cylinder 23, respectively. Figure 2 The first left cavity is connected to oil port A1, and the first right cavity is connected to oil port B1, which constitute two working oil ports in a set of working oil ports.

[0051] The steering switching valve assembly 24 also includes a floating control valve 243, which is connected between the left turn working port and the right turn working port and has an on position and an off position. The two valve positions are used to control the left turn working port and the right turn working port to be on and off, respectively.

[0052] The floating control valve 243 is typically switched to the on position when the entire machine is stopped. When the floating control valve 243 is in the on position, the left-turn working chamber and the right-turn working chamber of the corresponding steering cylinder 23 are interconnected through the floating control valve 243. The pressure in the two chambers of the cylinder is balanced, and the piston can slide freely under the action of external force. The wheel corresponding to the steering cylinder 23 is in a floating state. Thus, when the vehicle is stopped and needs to be towed or transported, in this floating state, each wheel can adaptively deflect according to the actual driving direction during the traction process based on the ground friction and lateral force, without generating rigid resistance due to the closure of the two chambers of the steering cylinder 23. This effectively avoids damage to the steering cylinder 23 and steering transmission mechanism caused by the inability of the front and rear axle wheels to deflect during the traction process, ensuring the safety and towing capability of the vehicle under power-off transport conditions.

[0053] When the machine is started, the floating control valve 243 can be switched to the cut-off position. At this time, the passage between the left-turn working chamber and the right-turn working chamber is cut off, the two chambers of the oil cylinder are closed, and the steering control function of the axle is restored to normal.

[0054] like Figure 1 and Figure 2 As shown, in this embodiment, the steering switching valve group 24 also includes a replenishing oil port 24C, and the floating control valve 243 is also connected to the replenishing oil port 24C. When the left turn working oil port and the right turn working oil port are connected, the replenishing oil port is controlled to be connected to both the left turn working oil port and the right turn working oil port.

[0055] By controlling the oil supply port 24C to be simultaneously connected to the left turn working oil port and the right turn working oil port, each steering actuator cylinder 23 can maintain a floating state and have a certain floating steering damping when the vehicle is powered off, thus preventing the wheels from turning randomly.

[0056] In this embodiment, since the floating function mainly occurs when the vehicle is stopped, the hydraulic oil in the oil replenishment port 24C is preferably from the accumulator. The accumulator connected to the oil replenishment port 24C can be the brake accumulator in the brake unit 3, or it can be a separately set accumulator.

[0057] like Figure 1 and Figure 2As shown, in this embodiment, there can be multiple floating control valves 243, and each floating control valve 243 is configured in a one-to-one correspondence with a steering actuation cylinder 23. By independently configuring a floating control valve 243 for each steering actuation cylinder 23, the floating state of each axle or each wheel can be achieved when the vehicle is stopped.

[0058] like Figure 1 and Figure 2 As shown, in this embodiment, hydraulic control check valve groups can be provided on the left steering oil circuit L and the right steering oil circuit R of the proportional electronic control valve group 22. By setting hydraulic control check valve groups at the oil outlet of the proportional electronic control valve group 22, the backflow of hydraulic oil from the steering gear 21 to the proportional electronic control valve group 22 can be effectively prevented.

[0059] like Figure 1 and Figure 2 As shown, in this embodiment, the chassis control hydraulic system also includes a braking unit 3. The braking unit 3 includes a brake control valve, a brake actuator, and a brake accumulator. The brake control valve is connected between the pump unit 1 and the brake actuator through a check valve, and the brake accumulator is connected in the oil line between the brake control valve and the check valve.

[0060] By setting a brake accumulator in the brake unit 3, the system can store some hydraulic energy in the accumulator when the pump unit 1 is working normally. When the brake control valve is activated, the accumulator can quickly release the pressure oil to provide instantaneous hydraulic energy replenishment to the main brake circuit, thereby ensuring that the brake actuator can establish sufficient braking force in a very short time and significantly improving the braking response speed.

[0061] like Figure 1 and Figure 2 As shown, in this embodiment, the brake actuator includes a service brake and a parking brake, and the brake control valve includes a service brake valve 31 and a parking brake valve 32. The parking brake valve 32 is used to receive parking commands from the driver's cab and remote parking commands to control the parking brake to lock and release the vehicle. The parking brake valve 32 adopts an on / off control method. When a parking command is received, the parking brake valve 32 switches to the braking position, supplies oil to the parking brake to engage it, and the vehicle enters the parking locked state. When a release command is received, the parking brake valve 32 switches to the release position, the parking brake releases oil, and the vehicle is released from the parking lock.

[0062] The service brake valve 31 is equipped with a proportional control terminal, which is linked to the brake pedal. Specifically, the proportional control terminal is connected to the displacement output terminal of the brake pedal. When the driver depresses the brake pedal, the pedal travel is transmitted to the proportional control terminal through mechanical linkage or hydraulic pilot, driving the valve core of the service brake valve 31 to move. This controls the output oil pressure of the service brake valve 31 to change proportionally with the pedal travel, thereby realizing continuous proportional adjustment of the service braking force.

[0063] In addition, the proportional control terminal is also connected to a brake accumulator via a brake proportional valve 5. The brake proportional valve 5 is used to open to the corresponding degree according to the remote braking command. When the remote controller issues a driving brake command, the controller outputs a corresponding current signal to the brake proportional valve 5 according to the braking intensity signal carried in the command. The brake proportional valve 5 opens to the corresponding degree according to the current magnitude, introducing the pressurized oil in the brake accumulator into the proportional control terminal of the driving brake valve 31 in a proportional manner, pushing the valve core to move, thereby controlling the output oil pressure of the driving brake valve 31 to change proportionally with the braking command intensity, realizing the proportional adjustment of driving braking force in remote control mode.

[0064] With the above settings, cab control and remote control of service brake and parking brake can be achieved.

[0065] For ease of understanding, the following example uses a two-axle vehicle. In this example, the number of brake accumulators can be four sets, which can include a front axle service brake accumulator 33a, a rear axle service brake accumulator 33b, a parking brake accumulator 33c, and a remote control accumulator 33d.

[0066] The front axle service brake accumulator 33a is connected between the oil port in the service brake valve 31 that controls the front axle service brake and the corresponding check valve, and is used to provide an independent pressure oil source for the front axle service brake.

[0067] The rear axle service brake accumulator 33b is connected between the oil port in the service brake valve 31 that controls the rear axle service brake and the corresponding check valve, and is used to provide an independent pressure oil source for the rear axle service brake.

[0068] The parking brake accumulator 33c is connected between the oil inlet of the parking brake valve 32 and the corresponding check valve, and is used to provide an independent pressure oil source for the parking brake valve 32.

[0069] The remote control accumulator 33d stores energy through the pump unit 1 and is connected to the proportional control terminal of the service brake valve 31 via the brake proportional valve 5. When the remote control issues a service brake command, the controller outputs a corresponding current signal to the brake proportional valve 5 according to the braking intensity signal indicated by the handle. The brake proportional valve opens to the corresponding degree according to the current magnitude, introducing the pressurized oil in the remote control accumulator 33d proportionally into the proportional control terminal of the service brake valve 31, pushing the valve core to move, thereby controlling the output oil pressure of the service brake valve 31 to change proportionally with the braking command intensity, realizing the proportional adjustment of the service braking force in remote control mode.

[0070] By equipping the front axle service brake, rear axle service brake, parking brake, and remote braking with independent accumulators, physical isolation of the oil supply for each braking function is achieved, avoiding the risk of simultaneous failure of braking functions due to pressure fluctuations in a single oil source, and significantly improving the safety redundancy and overall reliability of the braking system.

[0071] In this embodiment, the hydraulic oil at the oil replenishment port 24C can be supplied via the remote-controlled accumulator 33d.

[0072] like Figure 1 As shown, in this embodiment, the chassis control hydraulic system further includes a steering brake switching valve. The steering brake switching valve is connected to the pump unit 1, the steering gear 21, the proportional electronic control valve group 22, and the brake control valve. The steering brake switching valve has a steering working position and a brake working position. In the steering working position, the pump unit 1 supplies oil to the steering gear 21 and the proportional control valve group. In the brake working valve position, the pump unit 1 supplies oil to the brake control valve and the brake accumulator. The brake working valve position is the normally occupied valve position of the steering brake switching valve.

[0073] Since the brake working position is a stationary valve position, in most operating conditions after the vehicle is started and there is no steering operation, the hydraulic oil output by pump unit 1 always flows preferentially to the brake accumulator to charge it. This design ensures that the braking system has sufficient reserve pressure at all times.

[0074] In this embodiment, the braking unit 3 also includes a manual pump 4, which can control the brake actuator to unlock in the event of a vehicle power failure and brake lockup, thereby facilitating vehicle relocation operations in the event of a failure.

[0075] In this embodiment, the pump in pump unit 1 may include a load-sensitive variable pump. The displacement control terminal of the load-sensitive variable pump can be connected to the steering actuator cylinder 23 or the brake controller through a shuttle valve. When the pump unit 1 is in standby mode during the two execution periods, it can maintain the minimum flow rate, thereby effectively reducing the energy consumption of the whole machine.

[0076] In this embodiment, the pump unit 1 can be driven by a servo motor. By controlling the speed of the motor, the pump displacement can be matched with the load.

[0077] In this embodiment, pump unit 1 may also include a standby pump.

[0078] To achieve the above objectives, the present invention also provides a working machine, wherein the working machine includes a chassis-controlled hydraulic system as described above. The working machine can be a heavy-duty working vehicle such as a locomotive tractor, baggage tractor, passenger boarding bridge, port tractor, or container handling vehicle that requires remote-controlled driving and multi-mode steering in enclosed or specific environments. Since the working machine adopts all the solutions described in the above embodiments, it possesses at least the beneficial effects brought by the above embodiments, and will not be repeated here.

[0079] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of the present invention have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A chassis control hydraulic system, characterized in that, include: Pump unit (1); The steering unit (2) includes a steering gear (21), a proportional electronic control valve group (22), and a steering actuator cylinder (23). The steering gear (21) and the proportional electronic control valve group (22) are connected to the pump unit (1) and the oil tank on the inlet and outlet sides. The other side is provided with a left steering oil circuit (L) and a right steering oil circuit (R). The left steering oil circuit (L) and the right steering oil circuit (R) are connected to the steering actuator cylinder (23). The steering gear (21) is used to respond to steering wheel operation, and the proportional electronic control valve group (22) is used to respond to electronic control commands. Both are used to control the hydraulic oil to enter and exit the steering actuator cylinder (23) through their respective left steering oil circuit (L) and right steering oil circuit (R) according to the hydraulic flow direction corresponding to the current steering.

2. The chassis control hydraulic system according to claim 1, characterized in that, The number of steering actuator cylinders (23) is multiple. The steering unit (2) also includes a steering switching valve group (24). The left steering oil circuit (L) and the right steering oil circuit (R) of the steering gear (21) and the proportional electronic control valve group (22) are respectively connected to each of the steering actuator cylinders (23) through the steering switching valve group (24). The steering switching valve group (24) is used to select some of the steering actuator cylinders (23) and control the selected steering actuator cylinders (23) to enter and exit oil according to the hydraulic flow direction corresponding to the current steering.

3. The chassis control hydraulic system according to claim 2, characterized in that, The plurality of steering cylinders (23) include a front steering cylinder (231) and a rear steering cylinder (232). The steering switching valve group (24) includes a first switching valve (241) and a second switching valve (242). The first switching valve (241) is connected to the left-turn working chamber and the right-turn working chamber of the front steering cylinder (231). The second switching valve (242) is connected to the left-turn working chamber and the right-turn working chamber of the rear steering cylinder (232). They are also connected to the left steering circuit (L) and the right steering circuit (R) respectively. The first switching valve (241) and the second switching valve (242) are used to control whether the front steering cylinder (231) and the rear steering cylinder (232) participate in steering, respectively or in coordination.

4. The chassis control hydraulic system according to claim 3, characterized in that, The first switching valve (241) has a first oil port (241a) and a second oil port (241b), and the second switching valve (242) has a third oil port (242a) and a fourth oil port (242b). The first oil port (241a) is connected to the left turn oil circuit (L), and a connecting channel is formed between the second oil port (241b) and the third oil port (242a). The fourth oil port (242b) is connected to the right turn oil circuit (R). The first switching valve (241) and the second switching valve (242) have an on position and an off position, respectively. In the on position, the first switching valve (241) controls the first oil port (241a) and the second oil port (241b) to respectively connect the left-turn working chamber and the right-turn working chamber of the front steering cylinder (231), and the second switching valve (242) controls the third oil port (242a) and the fourth oil port (242b) to respectively connect the left-turn working chamber and the right-turn working chamber of the rear steering cylinder (232). In the off position, the first oil port (241a) and the second oil port (241b) are connected, the third oil port (242a) and the fourth oil port (242b) are connected, and the two working chambers of the front steering cylinder (231) and the rear steering cylinder (232) are cut off.

5. The chassis control hydraulic system according to claim 4, characterized in that, The first switching valve (241) is also provided with a four-wheel axial working position. In the four-wheel axial working position, the oil inlet and outlet directions of the front steering cylinder (231) are opposite to the oil inlet and outlet directions when the first switching valve (241) is in the open position; or The second switching valve (242) is also provided with a four-wheel axial working position. In the four-wheel axial working position, the oil inlet and outlet direction of the rear steering cylinder (232) is opposite to the oil inlet and outlet direction when the second switching valve (242) is in the open position.

6. The chassis control hydraulic system according to claim 2, characterized in that, The steering switching valve group (24) has multiple sets of working ports, and the multiple sets of working ports are configured one-to-one with multiple steering actuation cylinders (23). Each set of working ports includes a left-turn working port and a right-turn working port for connecting the left-turn working chamber and the right-turn working chamber of the corresponding steering actuation cylinder (23) respectively. The steering switching valve group (24) also includes a floating control valve (243), which is connected between the left-turn working port and the right-turn working port and is used to control the opening or closing of the two.

7. The chassis control hydraulic system according to claim 6, characterized in that, The steering switching valve group (24) also includes a replenishing oil port (24C), and the floating control valve (243) is also connected to the replenishing oil port (24C). When the left turn working oil port and the right turn working oil port are connected, the replenishing oil port (24C) is controlled to be connected to the left turn working oil port and the right turn working oil port simultaneously.

8. The chassis control hydraulic system according to any one of claims 1 to 7, characterized in that, The chassis control hydraulic system also includes a braking unit (3), which includes a braking control valve, a braking actuator, and a braking accumulator. The braking control valve is connected between the pump unit (1) and the braking actuator via a check valve, and the braking accumulator is connected to the oil line between the braking control valve and the check valve.

9. The chassis control hydraulic system according to claim 8, characterized in that, The brake actuator is located near the service brake and the parking brake. The brake control valve includes a service brake valve (31) and a parking brake valve (32). The parking brake valve (32) is used to receive parking commands from the driver's cab and remote parking commands to control the parking brake. The service brake valve (31) is provided with a proportional control terminal. The proportional control terminal is linked to the brake pedal and is also connected to the brake accumulator through a brake electric proportional valve (5). The brake electric proportional valve (5) is used to open to the corresponding opening degree according to the remote braking command of the vehicle.

10. A type of operating machinery, characterized in that, Includes the chassis control hydraulic system as described in any one of claims 1 to 9.

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