Hydraulic steering system for a construction machine and control method

Abstract

This invention discloses a hydraulic steering system and control method for engineering machinery. The system includes a hydraulic oil tank, a steering pump, an emergency steering pump, a controller, a steering operating device, a steering valve, a hydraulic lock, a displacement sensor, a pressure sensor, an emergency steering valve, and a steering cylinder. The invention receives signals from the steering operating device, displacement sensor, and pressure sensor through the controller, processes these signals logically, and then outputs different commands to the steering pump, emergency steering pump, steering valve, and emergency steering valve, respectively controlling their corresponding actions to meet the overall steering function requirements of the machine. When the engine, steering pump, or steering valve malfunctions, the controller, upon receiving an abnormal pressure feedback signal from the pressure sensor or an abnormal displacement feedback signal from the displacement sensor, immediately issues commands to the emergency steering pump and emergency steering valve, causing them to immediately intervene and ensure normal steering function.

Description

Technical Field

[0001] This invention relates to a hydraulic steering system and control method for engineering machinery, belonging to the field of engineering machinery technology. Background Technology

[0002] The application of construction machinery is becoming increasingly widespread, and a large proportion of products use hydraulic steering systems. If the engine or steering pump fails during the operation of the construction machinery, causing the steering pump to fail to output hydraulic oil normally, or if the steering valve fails to switch directions normally, steering failure will occur, posing a major safety hazard and endangering the personal safety of the driver and personnel in the work area. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hydraulic steering system and control method for engineering machinery. By monitoring the outlet pressure of the steering pump and the displacement of the steering valve core, the emergency steering pump and emergency steering valve can immediately intervene to ensure normal steering function when engine failure, steering pump failure, or steering valve failure occurs.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides a hydraulic steering system for engineering machinery, comprising: a hydraulic oil tank, a steering pump, an emergency steering pump, a controller, a steering operating device, a steering valve, a hydraulic lock, a displacement sensor, a pressure sensor, an emergency steering valve, and a steering cylinder; the inlet O1 and leakage port T1 of the steering pump are connected to the hydraulic oil tank, the outlet P1 of the steering pump is connected to the inlet P2 of the steering valve, and a pressure sensor is connected to the outlet P1 of the steering pump; the T2 port of the steering valve is connected to the hydraulic oil tank; the inlet O2 and leakage port T3 of the emergency steering pump are connected to the hydraulic oil tank, the outlet P3 of the emergency steering pump is connected to the inlet P4 of the emergency steering valve, and the T4 port of the emergency steering valve is connected to the hydraulic oil tank; the outlet A1 of the steering valve is connected to the inlet B1 of the hydraulic lock, and the outlet A2 of the steering valve is connected to the inlet B2 of the hydraulic lock; the outlet B3 of the hydraulic lock is connected to the steering cylinder and also to the outlet A3 of the emergency steering valve, and the outlet B4 of the hydraulic lock is connected to the steering cylinder and also to the outlet A4 of the emergency steering valve.

[0006] Furthermore, the controller is connected to the steering operation device and to the displacement sensor and pressure sensor; at the same time, the controller is connected to the steering pump, emergency steering pump, steering valve, and emergency steering valve; the controller is used to perform logical processing on the different signals received from the steering operation device, displacement sensor, and pressure sensor, and then send corresponding instructions to the steering pump, emergency steering pump, steering valve, and emergency steering valve to control them to perform different actions, thereby realizing the steering requirements.

[0007] Furthermore, the displacement sensor is installed on the steering valve, and the displacement sensor is used to monitor the displacement change of the main valve core of the steering valve to determine whether the steering valve can switch directions normally.

[0008] Furthermore, the pressure sensor is installed at the outlet of the steering pump, and the pressure sensor is used to monitor the outlet pressure of the steering pump to determine whether the steering pump can output hydraulic oil normally.

[0009] Secondly, the present invention provides a control method for a hydraulic steering system of engineering machinery according to any one of the foregoing claims, comprising:

[0010] When the engine or steering pump fails, the pressure sensor detects an abnormality in the steering pump outlet pressure. After receiving the abnormal feedback signal, the controller immediately sends a command to the emergency steering pump, which then outputs a large displacement. The controller then sends a command to the emergency steering valve, which switches its main valve core to the left or right position. The hydraulic oil output by the emergency steering pump goes through the internal channel of the emergency steering valve to the steering cylinder, enabling the machine to turn left or right.

[0011] Furthermore, including:

[0012] When the steering valve malfunctions, the displacement sensor detects an abnormal change in the displacement of the steering valve core. After receiving the abnormal feedback signal, the controller immediately sends a command to the emergency steering pump. The emergency steering pump outputs a large displacement, and the controller sends a command to the emergency steering valve. The main valve core of the emergency steering valve switches to the left or right position. The hydraulic oil output by the emergency steering pump goes to the steering cylinder through the internal channel of the emergency steering valve, enabling the machine to turn left or right.

[0013] Furthermore, including:

[0014] When the engine, steering pump, and steering valve fail, the controller immediately sends a command to the emergency steering pump after receiving both the abnormal pressure feedback signal from the pressure sensor and the abnormal displacement feedback signal from the displacement sensor. The emergency steering pump outputs a large displacement, and the controller sends a command to the emergency steering valve. The main valve core of the emergency steering valve switches to the left or right position. The hydraulic oil output by the emergency steering pump goes to the steering cylinder through the internal channel of the emergency steering valve, enabling the machine to turn left or right.

[0015] Furthermore, including:

[0016] When the steering mechanism is activated, the controller receives a command from the steering mechanism and determines that the machine needs to turn left or right. The controller sends a command to the steering pump, which outputs a large displacement. The controller also sends a command to the steering valve, which switches the main valve core to the left or right position. At the same time, the pressure sensor monitors the outlet pressure of the steering pump and transmits the pressure signal to the controller. The displacement sensor monitors the displacement change of the steering valve core and transmits the main valve core position signal to the controller. After receiving the pressure and displacement signals, the controller sends a command to the emergency steering pump. The emergency steering pump stops outputting and sends a command to the emergency steering valve. The main valve core of the emergency steering valve remains in the neutral position and does not switch directions. The hydraulic oil output by the steering pump flows through the internal channel of the steering valve, passes through the hydraulic lock, and goes to the steering cylinder, thus enabling the machine to turn left or right.

[0017] Furthermore, including:

[0018] When the steering mechanism is inactive, the controller determines that there is no steering requirement and sends a command to the steering pump to output the minimum displacement. The emergency steering pump does not output, and the steering valve and emergency steering valve are in the neutral position. No hydraulic oil enters the steering cylinder, and the entire machine does not steer.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0020] This invention provides a hydraulic steering system and control method for engineering machinery. The system receives signals from the steering operating device, displacement sensor, and pressure sensor via a controller. It processes these signals logically and then outputs different commands to the steering pump, emergency steering pump, steering valve, and emergency steering valve, respectively controlling their corresponding actions to meet the overall steering function requirements of the machine. When the engine, steering pump, or steering valve malfunctions, the controller receives abnormal pressure feedback signals from the pressure sensor or abnormal displacement feedback signals from the displacement sensor and immediately issues commands to the emergency steering pump and emergency steering valve, causing them to intervene immediately and ensure normal steering function. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the working principle of a hydraulic steering system for engineering machinery provided in an embodiment of the present invention.

[0022] In the diagram: 1. Hydraulic oil tank; 2. Steering pump; 3. Emergency steering pump; 4. Controller; 5. Steering operating device; 6. Steering valve; 7. Hydraulic lock; 8. Displacement sensor; 9. Pressure sensor; 10. Emergency steering valve; 11. Steering cylinder. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., 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 with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example 1

[0027] See Figure 1This embodiment describes a hydraulic steering system for engineering machinery, including: a hydraulic oil tank 1, a steering pump 2, an emergency steering pump 3, a controller 4, a steering operating device 5, a steering valve 6, a hydraulic lock 7, a displacement sensor 8, a pressure sensor 9, an emergency steering valve 10, and a steering cylinder 11; the oil inlet O1 and leakage port T1 of the steering pump 2 are connected to the hydraulic oil tank 1, and the oil outlet P1 of the steering pump 2 is connected to the oil inlet P2 of the steering valve 6. Simultaneously, the oil outlet P1 of the steering pump 2 is connected to the pressure sensor 9, and the T2 port of the steering valve 6 is connected to the hydraulic oil tank 1; the oil inlet O2 and leakage port T3 of the emergency steering pump 3 are connected to the hydraulic oil tank 1, and the oil outlet P3 of the emergency steering pump 3 is connected to the oil inlet P4 of the emergency steering valve 10. The T4 port of the emergency steering valve 10 is connected to the hydraulic oil tank 1; the oil outlet of the steering valve 6... Port A1 is connected to the inlet B1 of the hydraulic lock 7, and outlet A2 is connected to the inlet B2 of the hydraulic lock 7. The outlet B3 of the hydraulic lock 7 is connected to the steering cylinder 11 and also to the outlet A3 of the emergency steering valve 10. The outlet B4 of the hydraulic lock 7 is connected to the steering cylinder 11 and also to the outlet A4 of the emergency steering valve 10. The controller 4 is connected to the steering operating device 5, and also to the displacement sensor 8 and the pressure sensor 9. The controller 4 is also connected to the steering pump 2, the emergency steering pump 3, the steering valve 6, and the emergency steering valve 10. The controller 4 processes the different signals received from the steering operating device 5, the displacement sensor 8, and the pressure sensor 9, and then sends corresponding commands to the steering pump 2, the emergency steering pump 3, the steering valve 6, and the emergency steering valve 10 to control them to perform different actions, thereby achieving the steering requirements. When the steering pump 2 and steering valve 6 are working normally, different steering actions can be achieved by operating the steering operation device 5. At this time, the emergency steering pump 3 does not output hydraulic oil. When the engine or steering pump 2 fails, causing the steering pump 2 to fail to output hydraulic oil normally, or when the steering valve 6 fails and cannot switch directions normally, the emergency steering pump 3 and emergency steering valve 10 will immediately intervene. The hydraulic oil output by the emergency steering pump 3 enters the steering cylinder 11 to ensure normal steering and safe driving.

[0028] The working principle of the above technical solution in the embodiments of the present invention is as follows:

[0029] See Figure 1When the system starts up, if the steering operating device 5 is inactive, the controller 4 determines that there is no steering demand and sends a command to the steering pump 2 to output at minimum displacement. The emergency steering pump 3 does not output, and the steering valve 6 and emergency steering valve 10 are in the neutral position. No hydraulic oil enters the steering cylinder 11, and the entire machine does not steer. When the steering operating device 5 is activated, the controller 4 receives a command from the steering operating device 5 and determines that the entire machine has a left or right turn demand. The controller 4 sends a command to the steering pump 2, and the steering pump 2 outputs at high displacement. The controller 4 also sends a command to the steering valve 6, and the main valve core of the steering valve 6 switches to the left or right position. At the same time, the pressure sensor 9 monitors the outlet pressure of the steering pump 2. The pressure signal is transmitted to the controller 4. The displacement sensor 8 detects the displacement change of the valve core of the steering valve 6 and transmits the main valve core position signal to the controller 4. After receiving the pressure and displacement signals, the controller 4 issues a command to the emergency steering pump 3. The emergency steering pump 3 does not output and issues a command to the emergency steering valve 10. The main valve core of the emergency steering valve 10 is in the neutral position and does not switch directions. The hydraulic oil output by the steering pump 2 flows through the internal channel of the steering valve 6, passes through the hydraulic lock 7, and goes to the steering cylinder 11, enabling the machine to turn left or right. If the engine or steering pump 2 fails, the pressure sensor 9 detects an abnormal outlet pressure of the steering pump 2. After receiving the abnormal feedback signal, the controller 4... The controller immediately issues a command to the emergency steering pump 3, which outputs a large displacement. The controller then issues a command to the emergency steering valve 10, causing the main valve core of the emergency steering valve 10 to switch to the left or right position. The hydraulic oil output from the emergency steering pump 3 flows through the internal passage of the emergency steering valve 10 to the steering cylinder 11, enabling the machine to turn left or right. If the steering valve 6 malfunctions, the displacement sensor 8 detects an abnormal change in the valve core displacement. Upon receiving the abnormal feedback signal, the controller 4 immediately issues a command to the emergency steering pump 3, which outputs a large displacement. The controller 4 then issues a command to the emergency steering valve 10, causing the main valve core of the emergency steering valve 10 to switch to the left or right position. The hydraulic oil output by the emergency steering pump 3 goes to the steering cylinder 11 through the internal channel of the emergency steering valve 10, enabling the machine to turn left or right. If the engine or steering pump 2 fails, and the steering valve 6 also fails, the controller 4 will immediately send a command to the emergency steering pump 3 after receiving the abnormal pressure feedback signal from the pressure sensor 9 and the abnormal displacement feedback signal from the displacement sensor 8. The emergency steering pump 3 will then output a large displacement, and the controller 4 will send a command to the emergency steering valve 10. The main valve core of the emergency steering valve 10 will switch to the left or right position, and the hydraulic oil output by the emergency steering pump 3 will go to the steering cylinder 11 through the internal channel of the emergency steering valve 10, enabling the machine to turn left or right.

[0030] This embodiment provides a hydraulic steering system for engineering machinery. The controller 4 receives signals from the steering operating device 5, displacement sensor 8, and pressure sensor 9. It processes these signals logically and then outputs different commands to the steering pump 2, emergency steering pump 3, steering valve 6, and emergency steering valve 10, controlling their respective actions to meet the overall steering function requirements. When the engine, steering pump 2, or steering valve 6 malfunctions, the controller 4 receives an abnormal pressure feedback signal from pressure sensor 9 or an abnormal displacement feedback signal from displacement sensor 8. Immediately upon receiving these signals, the controller sends commands to the emergency steering pump 3 and emergency steering valve 10, causing them to intervene immediately and ensure normal steering function.

[0031] Example 2

[0032] This embodiment provides a control method for a hydraulic steering system of engineering machinery according to any one of Embodiment 1, including:

[0033] When the engine or steering pump 2 fails, the pressure sensor 9 detects an abnormal outlet pressure of steering pump 2. After receiving the abnormal feedback signal, the controller 4 immediately sends a command to the emergency steering pump 3, which outputs a large displacement. The controller 4 then sends a command to the emergency steering valve 10, which switches the main valve core of the emergency steering valve 10 to the left or right position. The hydraulic oil output by the emergency steering pump 3 goes to the steering cylinder 11 through the internal channel of the emergency steering valve 10, enabling the machine to turn left or right.

[0034] When the steering valve 6 malfunctions, the displacement sensor 8 detects an abnormal change in the displacement of the steering valve 6 spool. After receiving the abnormal feedback signal, the controller 4 immediately sends a command to the emergency steering pump 3, which outputs a large displacement. The controller 4 then sends a command to the emergency steering valve 10, which switches the main spool of the emergency steering valve 10 to the left or right position. The hydraulic oil output by the emergency steering pump 3 goes to the steering cylinder 11 through the internal channel of the emergency steering valve 10, enabling the machine to turn left or right.

[0035] When the engine or steering pump 2 fails, and steering valve 6 fails, controller 4 receives both the abnormal pressure feedback signal from pressure sensor 9 and the abnormal displacement feedback signal from displacement sensor 8. Controller 4 then immediately issues a command to emergency steering pump 3, which outputs a large displacement. Controller 4 then issues a command to emergency steering valve 10, which switches its main valve core to the left or right position. The hydraulic oil output by emergency steering pump 3 flows through the internal channel of emergency steering valve 10 to steering cylinder 11, enabling the machine to turn left or right.

[0036] When the steering operating device 5 is activated, the controller 4 receives the command from the steering operating device 5 and determines that the whole machine has a left or right turn steering requirement. The controller 4 sends a command to the steering pump 2, the steering pump 2 outputs a large displacement, and the controller 4 sends a command to the steering valve 6. The main valve core of the steering valve 6 switches to the left or right position to work. At the same time, the pressure sensor 9 monitors the outlet pressure of the steering pump 2 and transmits the pressure signal to the controller 4. The displacement sensor 8 monitors the displacement change of the valve core of the steering valve 6 and transmits the main valve core position signal to the controller 4. After receiving the pressure signal and the displacement signal, the controller 4 sends a command to the emergency steering pump 3. The emergency steering pump 3 does not output and sends a command to the emergency steering valve 10. The main valve core of the emergency steering valve 10 is in the neutral position and does not switch. The hydraulic oil output by the steering pump 2 flows through the internal channel of the steering valve 6, passes through the hydraulic lock 7, and goes to the steering cylinder 11. The whole machine realizes the left or right turn action.

[0037] When the steering operation device 5 is not activated, the controller 4 determines that there is no steering requirement and issues a command to the steering pump 2 to output the minimum displacement. The emergency steering pump 3 does not output, the steering valve 6 and the emergency steering valve 10 are in the neutral position, no hydraulic oil enters the steering cylinder 11, and the whole machine does not turn.

[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hydraulic steering system for engineering machinery, characterized in that, include: The hydraulic oil tank (1), steering pump (2), emergency steering pump (3), controller (4), steering operating device (5), steering valve (6), hydraulic lock (7), displacement sensor (8), pressure sensor (9), emergency steering valve (10), and steering cylinder (11) are all included. The oil inlet O1 and leakage port T1 of the steering pump (2) are connected to the hydraulic oil tank (1), and the oil outlet P1 of the steering pump (2) is connected to the oil inlet P2 of the steering valve (6). At the same time, the oil outlet P1 of the steering pump (2) is connected to the pressure sensor (9), and the T2 port of the steering valve (6) is connected to the hydraulic oil tank (1). The emergency steering pump (3) is also included. The oil inlet O2 and the leakage port T3 are connected to the hydraulic oil tank (1). The oil outlet P3 of the emergency steering pump (3) is connected to the oil inlet P4 of the emergency steering valve (10). The T4 port of the emergency steering valve (10) is connected to the hydraulic oil tank (1). The oil outlet A1 of the steering valve (6) is connected to the inlet B1 of the hydraulic lock (7), and the oil outlet A2 is connected to the inlet B2 of the hydraulic lock (7). The oil outlet B3 of the hydraulic lock (7) is connected to the steering cylinder (11) and also to the outlet A3 of the emergency steering valve (10). The oil outlet B4 of the hydraulic lock (7) is connected to the steering cylinder (11) and also to the outlet A4 of the emergency steering valve (10). The controller (4) is connected to the steering operation device (5) and to the displacement sensor (8) and pressure sensor (9); at the same time, the controller (4) is connected to the steering pump (2), the emergency steering pump (3), the steering valve (6), and the emergency steering valve (10); the controller (4) is used to perform logical processing on the different signals received from the steering operation device (5), the displacement sensor (8), and the pressure sensor (9), and then send corresponding instructions to the steering pump (2), the emergency steering pump (3), the steering valve (6), and the emergency steering valve (10) to control them to make different actions, thereby realizing the steering requirements; The displacement sensor (8) is installed on the steering valve (6). The displacement sensor (8) is used to monitor the displacement change of the main valve core of the steering valve (6) and to determine whether the steering valve (6) can switch directions normally. The pressure sensor (9) is installed at the outlet of the steering pump (2). The pressure sensor (9) is used to monitor the outlet pressure of the steering pump (2) and determine whether the steering pump (2) can output hydraulic oil normally.

2. A control method for a hydraulic steering system of engineering machinery according to claim 1, characterized in that, include: When the engine or steering pump (2) fails, the pressure sensor (9) detects that the outlet pressure of the steering pump (2) is abnormal. After receiving the abnormal feedback signal, the controller (4) immediately issues an instruction to the emergency steering pump (3). The emergency steering pump (3) outputs a large displacement. The controller (4) issues an instruction to the emergency steering valve (10). The main valve core of the emergency steering valve (10) switches to the left or right position. The hydraulic oil output by the emergency steering pump (3) goes to the steering cylinder (11) through the internal channel of the emergency steering valve (10). The whole machine realizes the left or right turning action.

3. The control method for the hydraulic steering system of engineering machinery according to claim 2, characterized in that, include: When the steering valve (6) fails, the displacement sensor (8) detects an abnormal change in the valve core displacement of the steering valve (6). After receiving the abnormal feedback signal, the controller (4) immediately issues a command to the emergency steering pump (3). The emergency steering pump (3) outputs a large displacement, and the controller (4) issues a command to the emergency steering valve (10). The main valve core of the emergency steering valve (10) switches to the left or right position. The hydraulic oil output by the emergency steering pump (3) goes to the steering cylinder (11) through the internal channel of the emergency steering valve (10), and the whole machine realizes the left or right turning action.

4. The control method for the hydraulic steering system of engineering machinery according to claim 2, characterized in that, include: When the engine fails or the steering pump (2) fails, and the steering valve (6) fails, the controller (4) immediately sends a command to the emergency steering pump (3) after receiving the pressure abnormality feedback signal from the pressure sensor (9) and the displacement abnormality feedback signal from the displacement sensor (8). The emergency steering pump (3) outputs a large displacement, and the controller (4) sends a command to the emergency steering valve (10). The main valve core of the emergency steering valve (10) switches to the left or right position. The hydraulic oil output by the emergency steering pump (3) goes to the steering cylinder (11) through the internal channel of the emergency steering valve (10), and the whole machine realizes the left or right turning action.

5. The control method for the hydraulic steering system of engineering machinery according to claim 2, characterized in that, include: When the steering operation device (5) is activated, the controller (4) receives the instruction from the steering operation device (5), determines that the whole machine has a left or right turn steering requirement, the controller (4) sends an instruction to the steering pump (2), the steering pump (2) outputs a large displacement, the controller (4) sends an instruction to the steering valve (6), the main valve core of the steering valve (6) switches to the left or right position to work, at the same time the pressure sensor (9) monitors the outlet pressure of the steering pump (2) and transmits the pressure signal to the controller (4), the displacement sensor (8) monitors the displacement change of the valve core of the steering valve (6) and transmits the main valve core position signal to the controller (4), after receiving the pressure signal and displacement signal, the controller (4) sends an instruction to the emergency steering pump (3), the emergency steering pump (3) does not output, sends an instruction to the emergency steering valve (10), the main valve core of the emergency steering valve (10) is in the middle position and does not switch, the hydraulic oil output by the steering pump (2) flows through the internal channel of the steering valve (6) through the hydraulic lock (7) and then to the steering cylinder (11), the whole machine realizes the left or right turn action.

6. The control method for the hydraulic steering system of engineering machinery according to claim 2, characterized in that, include: When the steering operation device (5) does not move, the controller (4) determines that there is no steering requirement and issues a command to the steering pump (2) to output the minimum displacement. The emergency steering pump (3) does not output, the steering valve (6) and the emergency steering valve (10) are in the neutral position, no hydraulic oil enters the steering cylinder (11), and the whole machine does not turn.

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