Steering control system for a working machine and working machine

Abstract

The utility model relates to a steering control system for engineering machinery, including variable displacement pump, steering gear, steering cylinder, steering valve, shuttle valve and hydraulic oil tank, variable displacement pump input and hydraulic oil tank fluid connection, output and steering gear oil inlet and steering valve oil inlet fluid connection, the working oil port of steering gear and the working oil port of steering valve are connected with steering cylinder fluidly respectively, the first oil inlet of shuttle valve and steering gear LS mouth fluid connection, the second oil inlet and steering valve LS mouth fluid connection, the oil outlet and variable displacement pump LS control mouth fluid connection, steering control system carries out steering by first and second steering control device, when using first steering control device, hydraulic fluid is transported to steering cylinder through steering gear, steering gear LS mouth and variable displacement pump LS control mouth fluid intercommunication, when using second steering control device, hydraulic fluid is transported to steering cylinder through steering valve, steering valve LS mouth and variable displacement pump LS control mouth fluid intercommunication. The utility model relates to engineering machinery.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery, and more specifically to a steering control system for engineering machinery and an engineering machinery including the steering control system. Background Technology

[0002] In existing engineering machinery steering systems, traditional steering wheels are typically used as the steering control device. However, these systems generally suffer from the problem of requiring a large number of turns from the leftmost to the rightmost position, resulting in complex and time-consuming steering operations. This design flaw not only forces operators to perform large-amplitude, high-frequency limb movements during steering but also significantly increases their workload. Especially under prolonged continuous operation, frequent large-range steering operations can easily cause muscle fatigue, reducing operator comfort and work efficiency, and may even lead to safety hazards due to operational delays or errors. Furthermore, steering wheel steering is very unfriendly to operators when rapid steering is required, but directly reducing the number of steering turns would affect steering sensitivity.

[0003] With the increasing electrification of the machinery industry, the demand for electric steering levers is growing. However, due to regulatory constraints, steering wheels must still be retained. This necessitates an electric steering system that can be added to a steering wheel-based system. Current steering control systems that combine electric steering levers and steering wheel steering typically integrate numerous sophisticated electronic components, and the complex piping layout increases system costs.

[0004] The present invention aims to solve at least one of the above-mentioned problems in the prior art, as well as other problems. Utility Model Content

[0005] According to one aspect of this utility model, a steering control system for engineering machinery is provided, wherein the steering control system includes a variable displacement pump, a steering gear, a steering cylinder, a steering valve, a shuttle valve, and a hydraulic oil tank, wherein:

[0006] The inlet of the variable pump is fluidly connected to the hydraulic oil tank, and the outlet of the variable pump is fluidly connected to the inlet of the steering gear and the inlet of the steering valve, respectively.

[0007] The working oil port of the steering gear and the working oil port of the steering valve are respectively fluidly connected to the steering cylinder;

[0008] The first oil inlet of the shuttle valve is fluidly connected to the LS port of the steering gear, the second oil inlet of the shuttle valve is fluidly connected to the LS port of the steering valve, and the oil outlet of the shuttle valve is fluidly connected to the LS control port of the variable pump.

[0009] The steering control system can perform steering through a first steering control device and also through a second steering control device;

[0010] When steering is performed using the first steering control device, the hydraulic fluid pumped by the variable pump is delivered to the steering cylinder through the steering gear along the first oil circuit, and the LS port of the steering gear is fluidly connected to the LS control port of the variable pump through the shuttle valve.

[0011] When the first steering control device is inactive and steering is performed using the second steering control device, the hydraulic fluid pumped by the variable pump is delivered to the steering cylinder through the steering valve along the second oil circuit, and the LS port of the steering valve is fluidly connected to the LS control port of the variable pump through the shuttle valve.

[0012] The first and second oil lines are independent of each other.

[0013] Advantageously, the steering valve includes a switching valve for controlling the fluid flow between the steering valve and the steering cylinder, the switching valve having a first position and a second position, wherein:

[0014] When steering is performed using the first steering control device, the switching valve is in the first position, at which time hydraulic fluid cannot be delivered to the steering cylinder via the steering valve.

[0015] When the first steering control device is not activated, the switch valve is in the second position, at which time the second steering control device is activated, and hydraulic fluid can be delivered to the steering cylinder through the steering valve.

[0016] Advantageously, the switching valve has a control port fluidly connected to the LS port of the steering gear, wherein when steering is performed using the first steering control device, the fluid pressure from the LS port of the steering gear causes the switching valve to switch to a first position.

[0017] Advantageously, the steering valve also includes a pressure reducing valve, a first solenoid valve, a second solenoid valve, and a main valve, wherein:

[0018] The main valve is located between the oil inlet of the directional valve and the on / off valve;

[0019] The oil inlet of the pressure reducing valve is fluidly connected to the oil inlet of the steering valve, and the oil outlet of the pressure reducing valve is fluidly connected to the oil inlets of the first solenoid valve and the second solenoid valve, respectively.

[0020] The oil outlet of the first solenoid valve is fluidly connected to the first control oil port at the first end of the valve core of the main valve.

[0021] The oil outlet of the second solenoid valve is fluidly connected to the second control oil port at the second end of the valve core of the main valve.

[0022] When the first solenoid valve is energized, hydraulic fluid from the variable pump can reach the first control port of the main valve via the pressure reducing valve and the first solenoid valve;

[0023] When the second solenoid valve is energized, hydraulic fluid from the variable pump can reach the second control port of the main valve via the pressure reducing valve and the second solenoid valve.

[0024] Advantageously, the first steering control device is a steering wheel, and the second steering control device is a handle, which has two separate variable resistors built into it. These two variable resistors are electrically connected to a first solenoid valve and a second solenoid valve, respectively, wherein the resistance corresponds to the pivot angle of the handle.

[0025] Advantageously, the magnitude of the current output by the handle is linearly related to the pivot angle of the handle.

[0026] Advantageously, the pilot pressure supplied to the main valve via the first or second solenoid valve is linearly related to the current supplied by the handle to the first or second solenoid valve.

[0027] Advantageous:

[0028] The switching valve is a two-position four-way proportional valve, which is located between the main valve and the steering cylinder;

[0029] The first and second solenoid valves are two-position three-way proportional valves;

[0030] The main valve is a three-position five-way proportional valve, which has a first working position, a second working position and a neutral position. When the first solenoid valve is energized, the main valve switches to the first working position, and when the second solenoid valve is energized, the main valve switches to the second working position.

[0031] Advantageously, the pressure reducing valve, the first solenoid valve, the second solenoid valve, the main valve, and the switching valve are integrated into a single valve block.

[0032] According to another aspect of the present invention, an engineering machine is provided, wherein the engineering machine includes a steering control system according to the present invention.

[0033] The steering control system of this invention can simultaneously realize traditional steering wheel steering and handwheel steering. While ensuring steering wheel steering priority, it allows for rapid steering via handwheel control. The steering speed is linearly related to the pivot angle of the handwheel; different steering speeds can be achieved by manipulating the pivot angle. This steering control system effectively solves the problem of excessive steering rotation from the left to right limit when using a steering wheel, significantly reducing the operator's physical exertion. It also accommodates different operator habits, allowing for the most suitable steering method for both small and large angle steering operations. Attached Figure Description

[0034] The present invention will now be described in more detail with reference to the illustrative accompanying drawings. The drawings and corresponding embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Wherein:

[0035] Figure 1 A schematic diagram of the hydraulic principle of a steering control system for engineering machinery according to a preferred embodiment of the present invention is shown.

[0036] Figure 2 It shows Figure 1 An enlarged view of the steering valve.

[0037] List of reference numerals in the attached diagram:

[0038] 1. Variable displacement pump 2. Steering gear

[0039] 3. Steering cylinder 4. Steering valve

[0040] 5. Shuttle valve 6. Hydraulic oil tank

[0041] 7 Handle 41 Pressure Reducing Valve

[0042] 42 First solenoid valve 43 Second solenoid valve

[0043] 44 Main valve 45 On / off valve

[0044] 100 Steering Control System Detailed Implementation

[0045] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0046] Figure 1 This diagram schematically illustrates the hydraulic principle of a steering control system 100 for engineering machinery or other types of machinery according to a preferred embodiment of the present invention. The steering control system can be steered by a first steering actuator or a second steering actuator. In this embodiment, the first steering actuator is a steering wheel, and the second steering actuator is a handle. It should be understood that other suitable actuators can also be used as the first and second steering actuators.

[0047] like Figure 1 As shown, the steering control system 100 includes a variable pump 1, a steering gear 2, a steering cylinder 3, a steering valve 4, a shuttle valve 5, and a hydraulic oil tank 6.

[0048] The input port of variable displacement pump 1 is fluidly connected to hydraulic oil tank 6, and the output port of variable displacement pump 1 is fluidly connected to the oil inlet (or pressure port) of steering gear 2 and the oil inlet of steering valve 4, respectively. The working ports L and R of steering gear 2 and the working ports A and B of steering valve 4 are fluidly connected to steering cylinder 3, respectively. When hydraulic fluid (hydraulic oil) enters steering cylinder 3 through working port L of steering gear 2 or working port A of steering valve 4, it enables, for example, left turns of the construction machinery; when hydraulic fluid enters steering cylinder 3 through working port R of steering gear 2 or working port B of steering valve 4, it enables, for example, right turns of the construction machinery.

[0049] The first oil inlet of shuttle valve 5 is fluidly connected to the LS port of steering gear 2, the second oil inlet of shuttle valve 5 is fluidly connected to the LS port of steering valve 4, and the oil outlet of shuttle valve 5 is fluidly connected to the LS control port of variable pump 1.

[0050] According to this invention, when the operator uses the steering wheel (i.e., the first steering control device) to turn, the hydraulic fluid pumped by the variable pump 1 is delivered to the steering cylinder 3 via the steering gear 2 through the first oil circuit, and the LS port of the steering gear 2 is fluidly connected to the LS control port of the variable pump 1 through the shuttle valve 5. When the steering wheel is not in motion and the operator uses the handle (specifically, the electric handle, i.e., the second steering control device) to turn, the hydraulic fluid pumped by the variable pump 1 is delivered to the steering cylinder 3 via the steering valve 4 through the second oil circuit, and the LS port of the steering valve 4 is fluidly connected to the LS control port of the variable pump 1 through the shuttle valve 5. According to this invention, the first oil circuit and the second oil circuit are independent of each other.

[0051] During steering, by connecting the LS port of steering gear 2 or the LS port of steering valve 4 to the LS control port of variable pump 1, the load pressure of the steering system can be fed back to variable pump 1 in real time, enabling variable pump 1 to provide hydraulic fluid as needed and reduce energy loss.

[0052] like Figure 2 As shown, the steering valve 4 includes a pressure reducing valve 41, a first solenoid valve 42, a second solenoid valve 43, a main valve 44, and a switching valve 45.

[0053] The inlet of the pressure reducing valve 41 is fluidly connected to the inlet of the steering valve 4, and the outlet of the pressure reducing valve 41 is fluidly connected to the inlets of the first solenoid valve 42 and the second solenoid valve 43, respectively. The pressure reducing valve 41 is used to reduce the pressure of the hydraulic fluid from the variable pump 1 to the required pilot pressure. Figure 1 and Figure 2As shown, the pressure reducing valve 41 can be designed as a two-position three-way valve.

[0054] The oil outlet of the first solenoid valve 42 is fluidly connected to the first control oil port at the first end of the valve core of the main valve 44, and the oil outlet of the second solenoid valve 43 is fluidly connected to the second control oil port at the second end of the valve core of the main valve 44.

[0055] like Figure 1 and Figure 2 As shown, the main valve 44 can be designed as a three-position five-way proportional valve, having a first working position (left position in the figure), a second working position (right position in the figure), and a neutral position. The first solenoid valve 42 and the second solenoid valve 43 can be designed as two-position three-way proportional valves. When the first solenoid valve 42 is energized, hydraulic fluid from the variable pump 1 can reach the first control port of the main valve 44 via the pressure reducing valve 41 and the first solenoid valve 42, causing the main valve 44 to switch to the first working position. When the second solenoid valve 43 is energized, hydraulic fluid from the variable pump 1 can reach the second control port of the main valve 44 via the pressure reducing valve 41 and the second solenoid valve 43, causing the main valve 44 to switch to the second working position.

[0056] The main valve 44 and the switching valve 45 are connected in series between the oil inlet of the steering valve 4 and the steering cylinder 3. The switching valve 45 is used to control the flow of fluid between the steering valve 4 and the steering cylinder 3. Figure 1 and Figure 2 In the illustrated embodiment, the switching valve 45 is designed as a two-position four-way proportional valve, positioned between the main valve 44 and the steering cylinder 3. The switching valve 45 has a first position and a second position. When the steering wheel is in motion, the switching valve 45 is in the first position (right position in the figure). In this position, hydraulic fluid cannot be delivered to the steering cylinder 3 via the steering valve 4, and the steering function of the handle is disabled, thus preventing accidental operation of the handle. When the steering wheel is not in motion, the switching valve 45 is in the second position (left position in the figure). In this position, the steering function of the handle is enabled, and hydraulic fluid can be delivered to the steering cylinder 3 via the steering valve 4. In other words, steering wheel (i.e., the first steering control device) takes precedence over steering handle (i.e., the second steering control device).

[0057] Advantageously, the switching valve 45 has a control port that is fluidly connected to the LS port of the steering gear 2. When steering is performed using the steering wheel, the fluid pressure from the LS port of the steering gear 2 causes the switching valve 45 to switch to a first position. When steering is not performed using the steering wheel, the fluid pressure from the LS port of the steering gear 2 is zero, and the switching valve 45 returns to a second position under the action of a spring.

[0058] It is understandable that the switching valve 45 can also be located between the oil inlet of the steering valve 4 and the main valve 44. In addition, the first solenoid valve 42, the second solenoid valve 43, the main valve 44, and the switching valve 45 can be designed with other structures, as long as they can achieve the functions described above.

[0059] Advantageously, the pressure reducing valve 41, the first solenoid valve 42, the second solenoid valve 43, the main valve 44, and the switching valve 45 can be integrated into a single valve block. This reduces the piping layout of the hydraulic system.

[0060] like Figure 1 As shown, according to this invention, the steering handle 7 has two separate variable resistors built in, which are electrically connected to the first solenoid valve 42 and the second solenoid valve 43, respectively. Advantageously, the resistance corresponds to the pivot angle of the handle.

[0061] Advantageously, the magnitude of the current output by the handle is linearly related to the pivot angle of the handle, i.e., the resistance. The greater the pivot angle of the handle (e.g., in the forward / backward or left / right direction), the greater the output current.

[0062] Furthermore, the pilot pressure supplied to the main valve 44 via the first solenoid valve 42 or the second solenoid valve 43 is linearly related to the current supplied to the first solenoid valve 42 or the second solenoid valve 43 by the handle. Therefore, the steering speed is linearly related to the pivot angle of the handle. Different steering speeds can be achieved by manipulating the pivot angle of the electronically controlled handle.

[0063] Advantageously, the lever enables rapid steering of the construction machinery. More specifically, when the lever is pivoted at a certain angle, the flow rate of hydraulic fluid supplied to the steering cylinder 3 through the steering valve 4 is greater than the flow rate of hydraulic fluid supplied to the steering cylinder 3 through the steering gear 2 when the steering wheel is rotated at the same angle; for example, the former is several times the latter.

[0064] The steering control system 100 of this invention can simultaneously realize traditional steering wheel steering and lever steering. While ensuring steering wheel steering priority, it allows for rapid steering via lever control. The steering speed is linearly related to the lever's pivot angle; different steering speeds can be achieved by manipulating the lever's pivot angle. The steering control system 100 effectively solves the problem of excessive steering wheel rotation from the left to right limit when using a steering wheel, significantly reducing the operator's physical exertion. It also accommodates different operator habits, allowing for the use of the most suitable steering method for both small and large-angle steering operations.

[0065] Industrial applicability

[0066] The working principle of the steering control system 100 according to this utility model is explained in detail below.

[0067] When steering is performed using the steering wheel, hydraulic fluid pumped by variable pump 1 is delivered to steering cylinder 3 via steering gear 2, achieving steering. Fluid pressure from the LS port of steering gear 2 causes switching valve 45 to switch to its first position (right position in the diagram), disconnecting the oil circuit between steering valve 4 and steering cylinder 3 to prevent accidental operation of the steering wheel. Simultaneously, the load pressure of the steering system is fed back to variable pump 1 in real time through the LS port of steering gear 2, shuttle valve 5, and the LS control port of variable pump 1, enabling variable pump 1 to provide hydraulic fluid on demand and reduce energy loss.

[0068] When the steering wheel is stationary and the steering lever is used, hydraulic fluid from the variable pump 1 is delivered to the inlet ports of the first solenoid valve 42 and the second solenoid valve 43 via the pressure reducing valve 41. The operator supplies current to the first solenoid valve 42 or the second solenoid valve 43 by manipulating the lever (e.g., pivoting the lever in the forward / backward or left / right direction). When the first solenoid valve 42 is energized, hydraulic fluid reaches the first control port of the main valve 44 via the first solenoid valve 42, switching the main valve 44 to the first operating position (left position in the figure). At this time, the switching valve 45 is in its second position (left position in the figure), and hydraulic fluid from the variable pump 1 enters the steering cylinder 3 via the working port A of the steering valve 4, for example, to achieve a left turn. When the second solenoid valve 43 is energized, hydraulic fluid reaches the second control port of the main valve 44 via the second solenoid valve 43, switching the main valve 44 to the second operating position (right position in the figure). Hydraulic fluid from the variable pump 1 enters the steering cylinder 3 via the working port B of the steering valve 4, for example, to achieve a right turn. During this process, the load pressure of the steering system is fed back to the variable pump 1 in real time through the LS port of the steering valve 4, the shuttle valve 5 and the LS control port of the variable pump 1, so that the variable pump 1 can provide hydraulic fluid on demand and reduce energy loss.

[0069] When using the steering handle, the pivot angle of the handle is linearly related to the steering speed of the construction machinery. By controlling the pivot angle of the electronically controlled handle, different steering speeds can be achieved.

[0070] The steering control system of this utility model has been described above with reference to specific embodiments. It will be apparent to those skilled in the art that various changes and modifications can be made to the steering control system of this utility model without departing from the design principles of this utility model. For example, embodiments of this utility model may not include some of the features described, and this utility model is not limited to the specific embodiments described, but any combination of the described features and elements is conceivable. Other embodiments will be apparent to those skilled in the art in light of consideration of the specification and practice with the disclosed steering control system. The specification and examples are to be considered exemplary only, and the true scope is indicated by the appended claims and their equivalents.

Claims

1. A steering control system for engineering machinery, characterized in that, The steering control system includes a variable displacement pump (1), a steering gear (2), a steering cylinder (3), a steering valve (4), a shuttle valve (5), and a hydraulic tank (6), wherein: The inlet of the variable pump (1) is fluidly connected to the hydraulic oil tank (6), and the outlet of the variable pump (1) is fluidly connected to the oil inlet of the steering gear (2) and the oil inlet of the steering valve (4), respectively. The working port of the steering gear (2) and the working port of the steering valve (4) are respectively fluidly connected to the steering cylinder (3); The first oil inlet of the shuttle valve (5) is fluidly connected to the LS port of the steering gear (2), the second oil inlet of the shuttle valve (5) is fluidly connected to the LS port of the steering valve (4), and the oil outlet of the shuttle valve (5) is fluidly connected to the LS control port of the variable pump (1). The steering control system can perform steering through a first steering control device and also through a second steering control device; When steering is performed using the first steering control device, the hydraulic fluid pumped by the variable pump (1) is delivered to the steering cylinder (3) through the steering gear (2) along the first oil circuit, and the LS port of the steering gear (2) is fluidly connected to the LS control port of the variable pump (1) through the shuttle valve (5). When the first steering control device is inactive and the second steering control device is used to perform steering, the hydraulic fluid pumped by the variable pump (1) is delivered to the steering cylinder (3) through the steering valve (4) along the second oil circuit, and the LS port of the steering valve (4) is fluidly connected to the LS control port of the variable pump (1) through the shuttle valve (5). The first and second oil lines are independent of each other.

2. The steering control system according to claim 1, characterized in that, The steering valve (4) includes a switching valve (45) for controlling the flow between the steering valve (4) and the steering cylinder (3), the switching valve (45) having a first position and a second position, wherein: When steering is performed using the first steering control device, the switching valve (45) is in the first position, at which time hydraulic fluid cannot be delivered to the steering cylinder (3) via the steering valve (4); When the first steering control device is not activated, the switch valve (45) is in the second position. At this time, the function of the second steering control device is activated, and hydraulic fluid can be delivered to the steering cylinder (3) through the steering valve (4).

3. The steering control system according to claim 2, characterized in that, The switching valve (45) has a control port that is fluidly connected to the LS port of the steering gear (2). When steering is performed using the first steering control device, the fluid pressure from the LS port of the steering gear (2) causes the switching valve (45) to switch to the first position.

4. The steering control system according to claim 2 or 3, characterized in that, The steering valve (4) also includes a pressure reducing valve (41), a first solenoid valve (42), a second solenoid valve (43), and a main valve (44), wherein: The main valve (44) is located between the oil inlet of the steering valve (4) and the switching valve (45); The oil inlet of the pressure reducing valve (41) is fluidly connected to the oil inlet of the steering valve (4), and the oil outlet of the pressure reducing valve (41) is fluidly connected to the oil inlets of the first solenoid valve (42) and the second solenoid valve (43). The oil outlet of the first solenoid valve (42) is fluidly connected to the first control oil port at the first end of the valve core of the main valve (44); The oil outlet of the second solenoid valve (43) is fluidly connected to the second control oil port at the second end of the valve core of the main valve (44); When the first solenoid valve (42) is energized, the hydraulic fluid from the variable pump (1) can reach the first control port of the main valve (44) via the pressure reducing valve (41) and the first solenoid valve (42); When the second solenoid valve (43) is energized, the hydraulic fluid from the variable pump (1) can reach the second control port of the main valve (44) via the pressure reducing valve (41) and the second solenoid valve (43).

5. The steering control system according to claim 4, characterized in that, The first steering control device is a steering wheel, and the second steering control device is a handle. The handle has two separate variable resistors built in, which are electrically connected to the first solenoid valve (42) and the second solenoid valve (43) respectively. The resistance value corresponds to the pivot angle of the handle.

6. The steering control system according to claim 5, characterized in that, The magnitude of the current output by the handle is linearly related to the pivot angle of the handle.

7. The steering control system according to claim 6, characterized in that, The pilot pressure supplied to the main valve (44) by the first solenoid valve (42) or the second solenoid valve (43) is linearly related to the current supplied by the handle to the first solenoid valve (42) or the second solenoid valve (43).

8. The steering control system according to claim 4, characterized in that, The switching valve (45) is a two-position four-way proportional valve, which is located between the main valve (44) and the steering cylinder (3); The first solenoid valve (42) and the second solenoid valve (43) are two-position three-way proportional valves; The main valve (44) is a three-position five-way proportional valve with a first working position, a second working position and a neutral position. When the first solenoid valve (42) is energized, the main valve (44) switches to the first working position. When the second solenoid valve (43) is energized, the main valve (44) switches to the second working position.

9. The steering control system according to claim 4, characterized in that, The pressure reducing valve (41), the first solenoid valve (42), the second solenoid valve (43), the main valve (44), and the switching valve (45) are integrated into a single valve block.

10. An engineering machinery, characterized in that, The engineering machinery includes a steering control system according to any one of claims 1 to 9.

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