A method and device for controlling an oil pump, a hydraulic system and a working machine

Abstract

This invention relates to the field of engine control technology and discloses an oil pump control method, device, hydraulic system, and engineering machinery equipment. The invention matches the engine by self-calibrating the oil pump power, that is, by adjusting the oil pump control current to change the oil pump flow rate, gradually changing the oil pump control current to capture the engine's power limit, achieving optimal torque matching between the engine and the oil pump, and obtaining the oil pump control current corresponding to the engine speed of each vehicle. Subsequently, during the use of engineering vehicles, the corresponding oil pump control current can be output according to the engine speed, which not only solves the problems of engine stalling and speed drop but also improves engine power utilization.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, specifically to an oil pump control method, device, hydraulic system, and engineering machinery equipment. Background Technology

[0002] In the field of construction machinery, the common power source is a diesel engine, which drives a hydraulic pump to pump hydraulic oil. The engine generally adopts two connection methods: one is that the engine is directly connected to the oil pump through a coupling, and the other is that the engine is connected to the oil pump through a gearbox. Although the connection methods are different, the principle is the same. It is always necessary to ensure that the input power of the engine to the oil pump is greater than the power required by the oil pump. Otherwise, the engine will stall or lose speed. On the other hand, if the input power of the engine to the oil pump is much greater than the power required by the oil pump, the problem of low energy utilization will occur. Therefore, the matching between the engine and the oil pump is very important. Summary of the Invention

[0003] In view of this, the present invention provides an oil pump control method, device, hydraulic system and engineering machinery equipment to solve the problem of mismatch between engine speed and oil pump power, which leads to engine stalling or speed drop or low engine energy utilization.

[0004] In a first aspect, the present invention provides an oil pump control method, the method comprising: acquiring the current operating speed of a target vehicle engine; determining a target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed; controlling the oil pump output flow rate based on the target oil pump control current; the oil pump power corresponding to different vehicle engine speeds and the current operating speed are determined by the following steps: repeatedly performing an oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained, the oil pump power calibration operation comprising: changing the oil pump control current when the engine speed of the vehicle used for calibration is the current engine speed, and acquiring the engine speed reduction amount after changing the oil pump control current; when the engine speed reduction amount reaches a preset reduction amount threshold, determining the changed oil pump control current as the oil pump control current corresponding to the current vehicle engine speed.

[0005] The oil pump control method provided by this invention matches the engine through oil pump power self-calibration. That is, by adjusting the oil pump control current to change the oil pump flow rate, the oil pump control current is gradually changed to capture the engine's power limit and achieve optimal torque matching between the engine and the oil pump. The oil pump control current corresponding to the engine speed of each vehicle is obtained. In subsequent use of engineering vehicles, the corresponding oil pump control current can be output according to the engine speed, which can not only solve the problems of engine stalling and speed drop, but also improve the engine power utilization rate.

[0006] In one optional implementation, repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained includes: repeatedly performing the oil pump power calibration operation when the vehicle used for calibration is located in the target area until the oil pump power corresponding to different vehicle engine speeds in the target area is obtained, wherein the target area is any one of a plurality of areas, the plurality of areas including at least low-pressure areas and high-altitude areas.

[0007] This invention calibrates the corresponding relationship between engine speed and oil pump control current based on different regions where vehicles travel. During actual vehicle operation, the corresponding engine speed and oil pump current can be matched based on the environmental region, thereby accurately controlling the oil pump output and improving engine power utilization.

[0008] In one alternative implementation, before acquiring the current operating speed of the target vehicle's engine, the method further includes: controlling the oil pump to switch from a load-sensitive pump state to a constant-pressure pump state.

[0009] This invention controls the oil pump to switch from a load-sensitive pump to a constant-pressure pump before controlling the oil pump to output flow rate with the target control current, thus avoiding conflicts with the method of outputting flow rate based on load pressure.

[0010] Secondly, the present invention provides a hydraulic system comprising an oil pump and a control valve, wherein the control valve is used to control the oil pump to switch to a constant pressure pump state or a load-sensitive pump state; when the control valve controls the oil pump to switch to the constant pressure pump state, the oil pump outputs flow rate based on a target oil pump control current, the target oil pump control current being controlled by an oil pump control method according to the first aspect or any corresponding embodiment thereof.

[0011] The hydraulic system provided by this invention allows the control valve to switch the oil pump between load-sensitive pump and constant-pressure pump states. When the oil pump is in constant-pressure pump state, i.e., self-calibration condition, the target control current can be determined based on the engine speed. The oil pump outputs a constant flow rate based on the target control current to match the engine speed.

[0012] In one optional embodiment, the hydraulic system further includes damping, which represents the opening degree of the directional valve. When the control valve controls the oil pump to switch to a load-sensitive pump state, the hydraulic system pressure is fed back to the oil pump through the control valve. The oil pump outputs flow rate based on the damping opening degree. The hydraulic system pressure is related to the load.

[0013] In one optional embodiment, the hydraulic system further includes a relief valve, wherein when the oil pump is in load-sensitive pump mode, the hydraulic system pressure is the damped output load pressure, and the relief valve is used to limit the hydraulic system pressure to not exceed a preset pressure threshold; when the oil pump is in constant pressure pump mode, the relief valve is used to maintain the hydraulic system pressure at the preset pressure threshold.

[0014] This invention designs an overflow valve that plays a corresponding role when the oil pump is in different states, ensuring the safe operation of the hydraulic system.

[0015] Thirdly, the present invention provides an oil pump control device, the device comprising: a current speed acquisition module for acquiring the current operating speed of a target vehicle engine; a control current determination module for determining a target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed; and an oil pump control module for controlling the oil pump output flow rate based on the target oil pump control current; wherein the oil pump power corresponding to different vehicle engine speeds and the current operating speed are determined by the following steps: an oil pump power calibration module for repeatedly performing an oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained, the oil pump power calibration operation comprising: a control current variation module for varying the oil pump control current when the engine speed of the vehicle being calibrated is the current engine speed, and acquiring the engine speed reduction amount after varying the oil pump control current; and a control current determination module for determining the varied oil pump control current as the oil pump control current corresponding to the current vehicle engine speed when the engine speed reduction amount reaches a preset reduction amount threshold.

[0016] Fourthly, the present invention provides an engineering machinery device, the engineering machinery device including a hydraulic system and a controller according to the second aspect or any optional embodiment, the controller including: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the oil pump control method of the first aspect or any corresponding embodiment described above.

[0017] In one alternative implementation, the construction machinery equipment is a crane, excavator, concrete pump truck, grader, or road roller.

[0018] Fifthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the oil pump control method of the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of an oil pump control method according to an embodiment of the present invention;

[0021] Figure 2 This is a flowchart illustrating a power calibration operation according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic flowchart of another oil pump control method according to an embodiment of the present invention;

[0023] Figure 4 This is a structural block diagram of a hydraulic system according to an embodiment of the present invention;

[0024] Figure 5 This is a structural example diagram of a hydraulic system according to an embodiment of the present invention;

[0025] Figure 6 This is a structural block diagram of an engineering machinery equipment according to an embodiment of the present invention;

[0026] Figure 7 This is a structural block diagram of an oil pump control device according to an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the hardware structure of the controller according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] According to an embodiment of the present invention, an embodiment of an oil pump control method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0030] This embodiment provides an oil pump control method, which can be used in the aforementioned controller. Figure 1 This is a flowchart of an oil pump control method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps:

[0031] Step S101: Obtain the current operating speed of the target vehicle's engine.

[0032] During the driving process, the target vehicle of this invention can obtain the current operating speed of the engine.

[0033] Step S102: Determine the target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed.

[0034] The oil pump power corresponding to different vehicle engine speeds and the current operating speed are determined through the following steps: repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained. The oil pump power calibration operation includes: changing the oil pump control current when the engine speed of the vehicle used for calibration is the current engine speed, and obtaining the speed drop of the engine speed after changing the oil pump control current; when the speed drop of the engine speed reaches the preset speed drop threshold, determining the changed oil pump control current as the oil pump control current corresponding to the current vehicle engine speed.

[0035] According to the embodiments of the present invention, the target oil pump control current can be determined based on the oil pump power corresponding to different pre-calibrated vehicle engine speeds and the current operating speed of the engine.

[0036] The process involves entering the oil pump power self-calibration program. When the engine speed of the vehicle being calibrated is at the current engine speed (i.e., the engine speed is stable at the current set value), an initial current is given to the oil pump. The oil pump control current is then slowly changed. After changing the oil pump control current, the engine speed drop amount Δn can be obtained, and it can be determined whether the engine speed drop amount reaches a preset drop threshold. A speed drop occurs when the engine output power is insufficient. In the construction machinery industry, a drop threshold Δnmax of 100 r / min is commonly used as a standard to determine the reasonableness of the engine and oil pump matching. A drop exceeding 100 r / min indicates an unreasonable matching; this is just an example. When the engine speed drop amount reaches the preset drop threshold, the changed oil pump control current can be determined as the oil pump control current corresponding to the current vehicle engine speed.

[0037] The embodiments of the present invention do not limit the method of slowly changing the oil pump control current. It may include, but is not limited to, increasing or decreasing the control current, increasing it proportionally or decreasing it inversely. Taking an inversely proportional power control pump as an example, an initial current (maximum current, i.e., when the oil pump is at minimum torque) is given to the oil pump, and the oil pump control current is decreased inversely, while the engine speed drop is captured in real time. Alternatively, taking a direct proportional power control pump as an example, an initial current and a minimum current are given to the oil pump, and the oil pump control current is increased proportionally, while the engine speed drop is captured in real time.

[0038] Specifically, such as Figure 2 As shown, taking an inverse proportional power control pump as an example, given an initial maximum current I of the oil pump, the oil pump control current is slowly reduced, and the engine speed drop is captured in real time, as well as whether the engine speed drop reaches the preset drop threshold. If the engine speed drop reaches the preset drop threshold Δnmax, the reduced current is the calibrated oil pump control current of the current engine speed. If the engine speed drop does not reach the preset drop threshold, the oil pump control current is continuously reduced. This is just an example.

[0039] Step S103: Control the oil pump output flow rate based on the target oil pump control current.

[0040] In this embodiment of the invention, the output flow rate of the oil pump can be controlled based on a determined target oil pump control current.

[0041] The oil pump control method provided in this embodiment matches the engine through oil pump power self-calibration. That is, by adjusting the oil pump control current to change the oil pump flow rate, the oil pump control current is gradually changed to capture the engine's power limit and achieve the best torque matching between the engine and the oil pump. The oil pump control current corresponding to the engine speed of each vehicle is obtained. In subsequent use of engineering vehicles, the corresponding oil pump control current can be output according to the engine speed, which can not only solve the problems of engine stalling and speed drop, but also improve the engine power utilization rate.

[0042] This embodiment provides an oil pump control method, which can be used in the aforementioned controller. Figure 3 This is a flowchart of an oil pump control method according to an embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps:

[0043] Step S301: Control the oil pump to switch from load-sensitive pump state to constant pressure pump state.

[0044] The oil pump in this embodiment of the invention can be in two states. When the oil pump is in the load-sensitive pump state, it can automatically adjust the flow rate according to the changes in system load. It can automatically adjust the flow rate to meet the system requirements by sensing the system load pressure. When the oil pump is in the constant pressure pump state, it can maintain a constant pressure output during operation, especially in scenarios where precise pressure control is required. Therefore, the prerequisite for the oil pump of this invention to output flow rate based on the target oil pump control current is that the oil pump must be in the constant pressure pump state. Therefore, in this embodiment of the invention, the current operating speed of the target vehicle engine is obtained only after the oil pump is switched from the load-sensitive pump state to the constant pressure pump state.

[0045] This invention controls the oil pump to switch from a load-sensitive pump to a constant-pressure pump before controlling the oil pump to output flow rate with the target control current, thus avoiding conflicts with the method of outputting flow rate based on load pressure.

[0046] Step S302: Obtain the current operating speed of the target vehicle's engine. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0047] Step S303: Determine the target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed.

[0048] The oil pump power corresponding to different vehicle engine speeds and the current operating speed are determined through the following steps: repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained. The oil pump power calibration operation includes: changing the oil pump control current when the engine speed of the vehicle used for calibration is the current engine speed, and obtaining the speed drop of the engine speed after changing the oil pump control current; when the speed drop of the engine speed reaches the preset speed drop threshold, determining the changed oil pump control current as the oil pump control current corresponding to the current vehicle engine speed.

[0049] Specifically, repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained includes: when the vehicle used for calibration is located in the target area, repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds in the target area is obtained, wherein the target area is any one of multiple areas, and the multiple areas include at least low-pressure areas and high-altitude areas.

[0050] This invention takes into account the different engine power performance of vehicles in different types of areas, such as high-altitude areas and low-pressure areas, where engine power loss increases. The calibrated relationship between engine speed and oil pump control current is no longer suitable for high-altitude conditions. Therefore, corresponding oil pump power calibration operations can be performed based on different regions to obtain the corresponding relationship between engine speed and oil pump power for different environmental regions. During subsequent vehicle operation, the current driving environment of the vehicle can be determined, and the corresponding relationship between engine speed and oil pump power can be matched based on the current driving environment. Then, the target control current can be determined based on the current engine operating speed.

[0051] This invention calibrates the corresponding relationship between engine speed and oil pump control current based on different regions where vehicles travel. During actual vehicle operation, the corresponding engine speed and oil pump current can be matched based on the environmental region, thereby accurately controlling the oil pump output and improving engine power utilization.

[0052] Step S304: Control the oil pump output flow rate based on the target oil pump control current. For details, please refer to [link to relevant documentation]. Figure 1 Step S103 of the illustrated embodiment will not be described again here.

[0053] This embodiment also provides a hydraulic system, such as Figure 4 As shown, the hydraulic system includes an oil pump and a control valve. The control valve is used to control the oil pump to switch to a constant pressure pump state or a load-sensitive pump state. When the control valve controls the oil pump to switch to the constant pressure pump state, the oil pump outputs flow based on the target oil pump control current, wherein the target oil pump control current is determined through the above embodiments.

[0054] The control valve in this embodiment of the invention can control the oil source of the oil pump feedback oil, enabling the oil pump to switch between two operating states: load-sensitive pump and constant pressure pump. The type of control valve is not limited; it can be a solenoid directional valve, manual directional valve, electro-proportional directional valve, hydraulic directional valve, or other control valve that achieves LS oil circuit switching. It also includes any valve assembly used for directional valves and oil circuits that replace the directional valve function. The oil pump can also be a single pump, a dual pump, or multiple pumps connected in series, etc. When the control valve controls the oil pump to switch to constant pressure pump state, the oil pump can output flow rate based on the target oil pump control current.

[0055] The hydraulic system provided by this invention allows the control valve to switch the oil pump between load-sensitive pump and constant-pressure pump states. When the oil pump is in constant-pressure pump state, i.e., self-calibration condition, the target control current can be determined based on the engine speed. The oil pump outputs a constant flow rate based on the target control current to match the engine speed.

[0056] In one alternative embodiment, the hydraulic system further includes damping, which represents the opening degree of the directional valve. When the control valve controls the oil pump to switch to a load-sensitive pump state, the hydraulic system pressure is fed back to the oil pump through the control valve. The oil pump outputs flow rate based on the damping opening degree, wherein the hydraulic system pressure is related to the load.

[0057] like Figure 5 As shown, the hydraulic system of this embodiment of the invention also includes a damper 3. The size of the damper 3 represents the opening size of the directional valve. When the control valve 4 controls the oil pump to be in the load-sensitive pump state (the oil pump state corresponding to the control valve not switching is the load-sensitive pump state), the oil pump 1 is used as an electrically controlled power load-sensitive pump. The load pressure output by the damper 3 is used as the control pressure and output to the hydraulic system through the control valve 4, and can be fed back to the oil pump 1. The oil pump 1 can output flow rate based on the load pressure before and after the damper 3 and the flow area of ​​the damper 3 (the opening size of the damper 3).

[0058] In one optional embodiment, the hydraulic system further includes a relief valve, wherein when the oil pump is in load-sensitive pump mode, the hydraulic system pressure is the damped output load pressure, and the relief valve is used to limit the hydraulic system pressure from falling below a preset pressure threshold; when the oil pump is in constant pressure pump mode, the relief valve is used to maintain the hydraulic system pressure at the preset pressure threshold.

[0059] like Figure 5 As shown, the hydraulic system of this embodiment of the invention also includes a relief valve 2. When the control valve 4 does not switch, that is, when the oil pump 1 is in the load-sensitive pump state, the hydraulic system pressure is the load pressure output by the damper 3. The relief valve 2 acts as a safety valve to limit the hydraulic system pressure from exceeding the preset pressure threshold. When the control valve 4 switches, that is, the control valve DT01 is always energized, the oil pump operation is switched to the constant pressure pump state, and the oil pump 1 does not need to rely on the load pressure output, that is, there is no load pressure in the hydraulic system. At this time, the function of the relief valve 2 is to maintain the hydraulic system pressure constant and control the hydraulic system pressure to always be maintained at the preset pressure threshold. The oil pump 1 outputs a flow rate limited by the control power.

[0060] This invention designs an overflow valve that plays a corresponding role when the oil pump is in different states, ensuring the safe operation of the hydraulic system.

[0061] This embodiment also provides an engineering machinery device, such as Figure 6 As shown, the engineering machinery equipment includes a hydraulic system and a controller, which is used to execute the oil pump control method described above.

[0062] The engineering machinery equipment in this embodiment of the invention is not limited to single-engine (i.e., the engineering machinery equipment has only one engine), dual-engine (the engineering machinery has two engines, one in the chassis and one for onboard operation), direct connection between the engine and the oil pump, connection of the engine to the oil pump through the gearbox, or a combination of the above. All of these can be used with the oil pump control method, and are only examples.

[0063] Specifically, construction machinery and equipment can include cranes, excavators, concrete pump trucks, graders, or road rollers, etc., without limitation. The specific equipment can be updated in real time according to the actual operation. This is just an example.

[0064] This embodiment also provides an oil pump control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0065] This embodiment provides an oil pump control device, such as... Figure 7 As shown, it includes: a current speed acquisition module 701, used to acquire the current operating speed of the target vehicle's engine; a control current determination module 702, used to determine the target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed; and an oil pump control module 703, used to control the oil pump output flow based on the target oil pump control current. The oil pump power corresponding to different vehicle engine speeds and the current operating speed are determined through the following steps: an oil pump power calibration module, used to repeatedly perform an oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained. The oil pump power calibration operation includes: a control current variation module, used to vary the oil pump control current when the engine speed of the vehicle being calibrated is the current engine speed, and to acquire the engine speed reduction amount after varying the oil pump control current; and a control current determination module, used to determine the varied oil pump control current as the oil pump control current corresponding to the current vehicle engine speed when the engine speed reduction amount reaches a preset reduction amount threshold.

[0066] In some optional implementations, repeatedly performing the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained includes: repeatedly performing the oil pump power calibration operation when the vehicle used for calibration is located in the target area until the oil pump power corresponding to different vehicle engine speeds in the target area is obtained, wherein the target area is any one of multiple areas, and the multiple areas include at least low-pressure areas and high-altitude areas.

[0067] In some alternative implementations, before acquiring the current operating speed of the target vehicle's engine, the oil pump control device includes: controlling the oil pump to switch from a load-sensitive pump state to a constant-pressure pump state.

[0068] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0069] In this embodiment, the oil pump control device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0070] This invention also provides a controller having the above-described features. Figure 7 The oil pump control device shown.

[0071] Please see Figure 8 , Figure 8 This is a schematic diagram of the structure of a controller provided in an optional embodiment of the present invention, such as... Figure 8 As shown, the controller includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise as required. The processors can process instructions executed within the controller, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple controllers can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 8 Take a processor 10 as an example.

[0072] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0073] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0074] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the controller. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the controller via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0075] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0076] The controller also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0077] Input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function control of the controller, such as a touch screen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touch screen.

[0078] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0079] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for controlling an oil pump, characterized in that, The method includes: Control the oil pump to switch from load-sensitive pump mode to constant pressure pump mode; Obtain the current operating speed of the target vehicle's engine; The target oil pump control current is determined based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed. The oil pump output flow rate is controlled based on the target oil pump control current. The oil pump power corresponding to the different vehicle engine speeds is determined by the following steps: Repeatedly perform the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained. The oil pump power calibration operation includes: When the engine speed of the vehicle used for calibration is the current engine speed, the oil pump control current is changed, and after the oil pump control current is changed, the amount of engine speed drop is obtained. When the engine speed drops to a preset speed drop threshold, the changed oil pump control current is determined to be the oil pump control current corresponding to the current vehicle engine speed.

2. The method according to claim 1, characterized in that, Repeat the oil pump power calibration operation until the oil pump power corresponding to different vehicle engine speeds is obtained, including: When the vehicle used for calibration is located in the target area, the oil pump power calibration operation is repeatedly performed until the oil pump power corresponding to different vehicle engine speeds in the target area is obtained. The target area is any one of multiple areas, which includes at least low-pressure areas and high-altitude areas.

3. A hydraulic system, characterized in that, The hydraulic system includes an oil pump and a control valve, wherein the control valve is used to control the oil pump to switch to a constant pressure pump state or a load-sensitive pump state. When the control valve switches the oil pump to constant pressure pump mode, the oil pump outputs flow rate based on the target oil pump control current, which is determined by the oil pump control method according to any one of claims 1-2.

4. The hydraulic system according to claim 3, characterized in that, The hydraulic system also includes damping, which represents the opening degree of the directional valve, wherein, When the control valve switches the oil pump to the load-sensitive pump state, the hydraulic system pressure is fed back to the oil pump through the control valve. The oil pump outputs flow rate based on the damping opening. The hydraulic system pressure is related to the load.

5. The hydraulic system according to claim 4, characterized in that, The hydraulic system also includes a relief valve, wherein... When the oil pump is in load-sensitive pump mode, the hydraulic system pressure is the damped output load pressure, and the relief valve is used to limit the hydraulic system pressure to not exceed the preset pressure threshold. When the oil pump is in constant pressure pump mode, the relief valve is used to maintain the hydraulic system pressure at a preset pressure threshold.

6. An oil pump control device, characterized in that, The device includes: The current engine speed acquisition module is used to acquire the current operating speed of the engine of the target vehicle; The control current determination module is used to determine the target oil pump control current based on the oil pump power corresponding to different vehicle engine speeds and the current operating speed. The oil pump control module is used to control the oil pump output flow rate based on the target oil pump control current; The oil pump power corresponding to the different vehicle engine speeds is determined by the following steps: The oil pump power calibration module is used to repeatedly perform oil pump power calibration operations until the oil pump power corresponding to different vehicle engine speeds is obtained. The oil pump power calibration operation includes: The control current variation module is used to vary the oil pump control current when the engine speed of the vehicle being calibrated is the current engine speed, and to obtain the amount of engine speed drop after the oil pump control current is varied. The control current determination module is used to determine the changed oil pump control current as the oil pump control current corresponding to the current vehicle engine speed when the engine speed drop reaches a preset drop threshold. Before obtaining the current operating speed of the target vehicle's engine, the oil pump control device controls the oil pump to switch from load-sensitive pump mode to constant pressure pump mode.

7. An engineering machinery equipment, characterized in that, The engineering machinery equipment includes the hydraulic system and controller according to any one of claims 3-5, wherein the controller is used to execute the oil pump control method according to any one of claims 1-2.

8. The engineering machinery equipment according to claim 7, characterized in that, The engineering machinery and equipment mentioned are cranes, excavators, concrete pump trucks, graders, or road rollers.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the oil pump control method according to any one of claims 1 to 2.

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