Flow control method and device for engineering machinery and engineering machinery

Abstract

The invention provides a flow control method and device of engineering machinery and the engineering machinery, and relates to the field of engineering machinery. The method comprises the following steps: acquiring a real-time pressure value of an outlet of a main pump of the engineering machinery; whether the real-time pressure value is smaller than a preset pressure starting value or not is judged, and the pressure starting value is smaller than or equal to the opening pressure value of the overflow valve; if not, determining a target pressure compensation value corresponding to the real-time pressure value according to a preset pressure compensation curve; and according to the real-time pressure value and the target pressure compensation value, the real-time flow value of the main pump is determined. According to the method, the overflow loss is effectively reduced, hydraulic impact is avoided, and the system stability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, and in particular to a flow control method and device for engineering machinery and engineering machinery. BACKGROUND

[0002] The hydraulic system is the core power transmission and control part of engineering machinery (such as excavators, loaders, cranes, etc.), which converts mechanical energy into hydraulic energy through a hydraulic pump, and then converts the hydraulic energy into mechanical energy through a hydraulic cylinder or a hydraulic motor to drive the mechanical action.

[0003] Under high pressure working conditions, the hydraulic system needs to prevent component damage or energy waste caused by excessively high pressure, and therefore usually adopts a pressure cut-off function. When the system pressure reaches a preset value, the hydraulic pump automatically reduces or stops oil supply to prevent component damage or energy waste caused by excessively high system pressure. In the related art, pressure cut-off is mainly achieved by a mechanical overflow valve, which opens to guide excess oil back to the oil tank when the main pump pressure reaches the set value. However, the pressure cut-off of the overflow valve has a response lag effect, and starts to overflow before the main pump pressure reaches the set value, resulting in large overflow loss; and the pressure cut-off of the mechanical overflow valve is instantaneous cut-off, which is easy to cause hydraulic impact and affect system stability.

[0004] Therefore, there is a need for a flow control scheme for engineering machinery that can effectively reduce overflow loss and improve system stability. SUMMARY

[0005] The embodiments of the present application provide a flow control method and device for engineering machinery and engineering machinery, which can effectively reduce overflow loss and improve system stability.

[0006] In a first aspect, the embodiments of the present application provide a flow control method for engineering machinery, comprising:

[0007] obtaining a real-time pressure value of a main pump outlet of the engineering machinery;

[0008] determining whether the real-time pressure value is less than a preset pressure setting value, the pressure setting value being less than or equal to an opening pressure value of an overflow valve;

[0009] if not, determining a target pressure compensation value corresponding to the real-time pressure value according to a pressure compensation curve;

[0010] determining a real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value.

[0011] In a possible implementation, the pressure compensation curve is obtained by the following way:

[0012] determining a target cylinder flow corresponding to the relief valve pressure being the set pressure value, the set pressure value being greater than the pressure pickup value;

[0013] determining a second pressure compensation value according to the set pressure value and the target cylinder flow, the second pressure compensation value being a pressure compensation value when the relief valve pressure is the set pressure value;

[0014] performing curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve, the first pressure compensation value being a pressure compensation value when the relief valve pressure is the pressure pickup value.

[0015] In a possible implementation, the determining of the target cylinder flow corresponding to the relief valve pressure being the set pressure value comprises:

[0016] obtaining a hydraulic cylinder speed when the relief valve pressure is the set pressure value;

[0017] determining the target cylinder flow corresponding to the relief valve pressure being the set pressure value according to the hydraulic cylinder speed and a cylinder area.

[0018] In a possible implementation, the determining of the second pressure compensation value according to the set pressure value and the target cylinder flow comprises:

[0019] determining a current gear of the engineering machinery and determining a target power corresponding to the current gear;

[0020] determining a calculated pressure value of the main pump outlet according to the target power and the target cylinder flow;

[0021] determining the second pressure compensation value according to a difference between the calculated pressure value and the set pressure value.

[0022] In a possible implementation, the performing of the curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve comprises:

[0023] establishing a two-dimensional coordinate system with a main pump outlet pressure value as an abscissa and a pressure compensation value as an ordinate;

[0024] generating a first coordinate point according to the pressure pickup value and a first pressure compensation value corresponding to the pressure pickup value;

[0025] generating a second coordinate point according to the set pressure value and the second pressure compensation value;

[0026] performing curve fitting according to the first coordinate point and the second coordinate point to obtain the pressure compensation curve.

[0027] In a possible implementation, the curve fitting of the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve comprises:

[0028] acquiring one or more intermediate pressure values between the pressure starting value and the set pressure value of the overflow valve;

[0029] determining a third pressure compensation value corresponding to the intermediate pressure value;

[0030] establishing a two-dimensional coordinate system with a main pump outlet pressure value as an abscissa and a pressure compensation value as an ordinate;

[0031] generating a first coordinate point according to the pressure starting value and a first pressure compensation value corresponding to the pressure starting value;

[0032] generating a second coordinate point according to the set pressure value and the second pressure compensation value;

[0033] generating a third coordinate point according to the intermediate pressure value and the third pressure compensation value;

[0034] curve fitting of the first coordinate point, the second coordinate point and the third coordinate point to obtain the pressure compensation curve.

[0035] In a possible implementation, the determination of the real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value comprises:

[0036] determining a corrected pressure value of the main pump according to the real-time pressure value and the target pressure compensation value;

[0037] determining the real-time flow value of the main pump according to the target power corresponding to the current gear of the engineering machinery and the corrected pressure value of the main pump.

[0038] In a second aspect, the embodiments of the present application provide a flow control device of an engineering machinery, comprising:

[0039] an acquisition module configured to acquire a real-time pressure value of a main pump outlet of the engineering machinery;

[0040] a processing module configured to determine a target pressure compensation value corresponding to the real-time pressure value according to a preset pressure compensation curve if the real-time pressure value is not less than a preset pressure starting value, the pressure starting value being less than or equal to an opening pressure value of an overflow valve; and determine a real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value.

[0041] In a third aspect, the embodiments of the present application provide another flow control device of an engineering machinery, comprising:

[0042] The processor, and the memory that is in communication with the processor;

[0043] Memory is used to store instructions that the computer executes;

[0044] The processor is configured to execute computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0045] Fourthly, embodiments of this application provide a piece of construction machinery, including: a flow control device for construction machinery as described in the third aspect above.

[0046] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect described above.

[0047] In a sixth aspect, embodiments of this application provide a computer program product, including a computer program, which, when executed by a processor, is used to implement the first aspect and / or various possible implementations of the first aspect as described above.

[0048] This application provides a flow control method, device, and machinery for construction machinery. A pressure compensation curve can be pre-designed based on the pressure set-off value of the relief valve. After detecting that the real-time pressure value at the main pump outlet is greater than or equal to the pressure set-off value, the corresponding target pressure compensation value can be determined based on the pressure compensation curve. After dynamically compensating the real-time pressure value based on the target pressure compensation value, the real-time flow value of the main pump can be determined. The pressure compensation curve can cover the entire adjustment range of the relief valve. Dynamic compensation of the main pump pressure using the pressure compensation curve can minimize overflow losses under high-pressure conditions, essentially allowing the relief valve to be used only as a safety valve. Furthermore, the dynamic compensation of the pressure compensation curve is a smooth and controllable gradual process, effectively avoiding hydraulic shocks caused by instantaneous cut-off, thereby improving system stability. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0050] Figure 1 This is a schematic diagram of the structure of an engineering machinery according to an embodiment of this application;

[0051] Figure 2 This is a flowchart of a flow control method for construction machinery according to an embodiment of this application;

[0052] Figure 3A pressure-flow dynamic compensation diagram for an embodiment of the present application;

[0053] Figure 4 A pressure compensation curve diagram for an embodiment of the present application;

[0054] Figure 5 A structure diagram of a flow control device of a construction machine for an embodiment of the present application;

[0055] Figure 6 A structure diagram of a flow control device of a construction machine for another embodiment of the present application.

[0056] The specific embodiments of the present application have been shown through the above-described drawings, and will be described in more detail hereinafter. The drawings and the written description are not intended to restrict the scope of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is made with reference to the accompanying drawings in which like reference numerals represent like elements, unless the context of use indicates otherwise. The following description of exemplary embodiments is not representative of all embodiments consistent with the present application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims.

[0058] The terms "first", "second", "third", "fourth" and the like in the description and the claims of the present application and the above-described drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of these terms herein is to be construed to cover the recurrence of a process, procedure, operation, concept, method, product or device in different embodiments of the application, unless the context of use indicates otherwise. Further, the terms "comprise" and "include", and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, product or device that comprises a list of steps or elements is not necessarily limited to those steps or elements, but can include additional steps or elements not expressly listed or inherent to such process, method, product or device.

[0059] In the technical solution of the present application, the collection, storage, use, processing, transmission, provision and disclosure of information such as financial data or user data comply with relevant laws and regulations and do not violate public order and good customs.

[0060] It should be noted that in the embodiments of the present application, some industry existing solutions of software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility in the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solutions.

[0061] It should also be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards, and provide corresponding operation portal for user to choose authorization or refusal.

[0062] The flow control method and device of the engineering machinery and the engineering machinery of the present application can be used in the field of engineering machinery, and can also be used in any field other than the field of engineering machinery, such as the field of flow control, etc. The application field of the flow control method and device of the engineering machinery and the engineering machinery of the present application is not limited.

[0063] The flow control method and device of the engineering machinery and the engineering machinery of the present application can be applied to the scene of flow control of engineering machinery with hydraulic system. The engineering machinery can be excavators, loaders, cranes, etc. As long as the engineering machinery has a hydraulic system, the flow control method and device of the engineering machinery and the engineering machinery of the present application can be applied.

[0064] The hydraulic system is the core power transmission and control part of the engineering machinery (such as excavators, loaders, cranes, etc.), which converts mechanical energy into hydraulic energy through a hydraulic pump, and then converts the hydraulic energy into mechanical energy through a hydraulic cylinder or a hydraulic motor to drive the mechanical action.

[0065] Under high pressure working conditions, the hydraulic system needs to prevent component damage or energy waste caused by excessive pressure, so the pressure cut-off function is usually used. When the system pressure reaches the preset value, the hydraulic pump will automatically reduce or stop oil supply to prevent component damage or energy waste caused by excessive system pressure. In the related art, the pressure cut-off is mainly realized by a mechanical overflow valve. When the main pump pressure reaches the set value, the overflow valve is opened to guide the excess oil back to the oil tank.

[0066] However, since the set pressure value of the overflow valve (the pressure set value for opening the overflow valve) is the stable pressure value when the overflow valve is fully open, it is generally greater than the opening pressure value of the overflow valve, resulting in a response lag effect of the pressure cut-off of the overflow valve. The overflow starts before the main pump pressure reaches the set value, and the overflow loss is large.

[0067] For example, a certain overflow valve has a set pressure value of 34 MPa and an opening pressure value of 30 MPa. Therefore, before the pressure cut-off is detected when the pressure is greater than 34 MPa, the overflow valve will start to overflow when the pressure reaches 30 MPa, resulting in energy loss.

[0068] In addition, the pressure cut-off of the mechanical overflow valve is instantaneous cut-off, which is easy to cause hydraulic impact and affect the stability of the system, and the cut-off pressure adjustment is complex and requires professional tools to accurately calibrate.

[0069] For example, during the excavator bucket excavation process, the main pump flow is instantaneously cut off to the minimum when a certain pressure is reached. The oil in the pipeline between the pump outlet and the load cannot stop immediately due to inertia, and the kinetic energy will be converted into pressure energy, resulting in a sharp increase in local pressure, affecting the life of the components and the pipeline.

[0070] Based on the above technical problems, the technical concept of the present application is to provide a flow control scheme for engineering machinery that can effectively reduce overflow loss and improve system stability.

[0071] The embodiments of the present application provide a flow control method and device for engineering machinery and engineering machinery, which can dynamically compensate the main pump pressure by using a pressure compensation curve. Since the pressure compensation curve can cover the entire adjustment range of the overflow valve, the dynamic compensation can reduce the overflow loss as much as possible under high pressure working conditions, and basically make the overflow valve only serve as a safety valve. In addition, the dynamic compensation of the pressure compensation curve is a smooth and controllable gradual change process, which can effectively avoid the hydraulic impact caused by instantaneous cut-off, thereby improving the stability of the system.

[0072] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0073] Figure 1 The structural schematic diagram of the engineering machinery of an embodiment of the present application is shown in FIG. 1. Figure 1As shown, the engineering machine can include a pressure sensor arranged at the main pump outlet position, a flow control device of the engineering machine connected with the pressure sensor, the main pump being an electric proportional control main pump, and the flow control device further connected with the main pump. The flow control device of the engineering machine can acquire a real-time pressure value of the main pump outlet by using the pressure sensor; determine whether the real-time pressure value is less than a preset pressure setting value, the pressure setting value being less than or equal to an opening pressure value of the overflow valve; if not, determine a target pressure compensation value corresponding to the real-time pressure value according to a preset pressure compensation curve; determine a real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value, and control the flow of the main pump according to the real-time flow value.

[0074] Figure 2 The flow chart of the flow control method of the engineering machine of an embodiment of the present application, the embodiment is described with respect to the flow control method of the engineering machine by the flow control device of the engineering machine as the execution subject. As shown in the figure, Figure 2 The flow control method of the engineering machine can include the following steps:

[0075] S201: Acquire a real-time pressure value of the main pump outlet of the engineering machine.

[0076] In the embodiment, the engineering machine can be a excavator, a loader, a crane, etc., and is not limited herein as long as the engineering machine has a hydraulic system.

[0077] In the embodiment, the flow control device of the engineering machine can be a vehicle controller of the engineering machine, or other structure on the engineering machine with flow control function. Of course, the flow control device can also be an additional device with flow control function on the engineering machine.

[0078] In the embodiment, the main pump can be various specifications of electric proportional control main pumps.

[0079] In the embodiment, the main pump outlet position of the engineering machine can be provided with a pressure sensor, and the pressure sensor can be connected with the flow control device of the engineering machine through a CAN bus, or wirelessly communicate with the flow control device of the engineering machine, so that the flow control device acquires the real-time pressure value of the main pump outlet through the pressure sensor.

[0080] In the embodiment, the pressure sensor can reuse the existing sensors in the electrical system of the engineering machine, without the need for additional increase.

[0081] S202: Determine whether the real-time pressure value is less than a preset pressure setting value.

[0082] In the embodiment, the pressure setting value is less than or equal to the opening pressure value of the overflow valve.

[0083] In the embodiment, the opening pressure value of the overflow valve can be the pressure when the overflow valve is just opened (critical pressure when not opened and opened), and the opening pressure value of the overflow valve can be obtained through factory data (overflow valve characteristic curve) of the overflow valve. Of course, in order to improve the accuracy of the opening pressure value, the overflow valve can also be calibrated.

[0084] In the embodiment, in order to cover the entire adjustment range of the overflow valve and reduce the overflow loss as much as possible, the pressure setting value can be set to be less than or equal to the opening pressure value of the overflow valve, and the pressure compensation is performed before the overflow valve is opened (the pressure setting value less than the opening pressure value of the overflow valve expands the adjustment range).

[0085] In the embodiment, the difference between the opening pressure value and the pressure setting value is less than or equal to the preset pressure difference threshold, that is, the pressure setting value and the opening pressure value cannot be too different, and the pressure difference threshold can be 3 MPa or 3 MPa, which is not limited herein.

[0086] For example, the opening pressure value of a certain overflow valve is 30 MPa, and the pressure setting value is 27 MPa.

[0087] S203: If not, the target pressure compensation value corresponding to the real-time pressure value is determined according to the pressure compensation curve.

[0088] In the embodiment, the pressure compensation curve can be a curve in which the pressure compensation value changes with the main pump outlet pressure value, and the pressure compensation curve can be pre-constructed and stored in the flow control device.

[0089] In the embodiment, the working machine can correspond to different pressure compensation curves in different working gears, and if the real-time pressure value is greater than or equal to the pressure setting value, the target pressure compensation value corresponding to the real-time pressure value can be determined according to the pressure compensation curve corresponding to the current gear.

[0090] In the embodiment, after the real-time pressure value is obtained, the corresponding target pressure compensation value can be determined by interpolation from the pressure compensation curve.

[0091] S204: The real-time flow value of the main pump is determined according to the real-time pressure value and the target pressure compensation value.

[0092] In the embodiment, the following formula (1) is a power formula of the working machine:

[0093] N=P×Q / 60 (1)

[0094] Wherein, N is the set power corresponding to the current gear, P is the main pump pressure, and Q is the main pump flow.

[0095] Since the set power N is constant when the gear is fixed, the main pump flow Q decreases when the main pump pressure P increases, thereby correcting the main pump output flow and achieving the pressure cut-off effect.

[0096] In this embodiment, the pressure units involved in the present application are MPa, and the flow units are L / min. The 60 in the above formula (1) is a unit conversion coefficient, which is calculated based on the above units. If the pressure unit and the flow unit change, the unit conversion coefficient in formula (1) also changes accordingly.

[0097] In this embodiment, if the real-time pressure value is greater than or equal to the pressure setting value, it indicates that the main pump outlet pressure is too high, and the main pump flow needs to be reduced to avoid overflow. In order to reduce the main pump flow, the target pressure compensation value corresponding to the real-time pressure value can be determined according to the preset pressure compensation curve, and the real-time pressure value is compensated by using the target pressure compensation value. The main pump flow is smoothly reduced by dynamically increasing the pressure.

[0098] In this embodiment, the main pump is an electric proportional control main pump, and after the real-time flow value is determined, the flow control device can control the flow of the main pump according to the real-time flow value.

[0099] S205: Determine the real-time flow value of the main pump according to the real-time pressure value.

[0100] In this embodiment, if the real-time pressure value is less than the pressure setting value, it indicates that the main pump outlet pressure is not high, and there is no risk of overflow. The flow can be adjusted only according to the real-time pressure value.

[0101] In this embodiment, the above flow adjustment process can be applied to various electric proportional control main pumps, and the pressure cut-off can be achieved without built-in pressure cut-off valve groups or additional devices. While avoiding overflow loss, the pressure cut-off process is smooth and controllable, the pressure regulation is accurate and efficient, no additional cost is required, and the compatibility is strong.

[0102] In this embodiment, the pressure compensation curve can be designed in advance according to the pressure setting value of the overflow valve. After detecting that the real-time pressure value of the main pump outlet is greater than or equal to the pressure setting value, the corresponding target pressure compensation value can be determined according to the pressure compensation curve. After dynamically compensating the real-time pressure value according to the target pressure compensation value, the real-time flow value of the main pump can be determined. The pressure compensation curve can cover the entire adjustment range of the overflow valve. The dynamic compensation of the pressure compensation curve for the main pump pressure can reduce the overflow loss as much as possible under high pressure conditions, and basically make the overflow valve only used as a safety valve. In addition, the dynamic compensation of the pressure compensation curve is a smooth and controllable gradual change process, which can effectively avoid hydraulic impact caused by instantaneous cut-off, thereby improving the system stability.

[0103] In a possible implementation, the pressure compensation curve in step S203 can be obtained by the following method:

[0104] S11: determining the target cylinder flow corresponding to the set pressure value of the overflow valve pressure.

[0105] S12: determining the second pressure compensation value according to the set pressure value and the target cylinder flow, the second pressure compensation value being the pressure compensation value when the overflow valve pressure is the set pressure value.

[0106] S13: performing curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve, the first pressure compensation value being the pressure compensation value when the overflow valve pressure is the pressure starting value.

[0107] In the embodiment, in order to cover the entire adjustment range of the overflow valve and reduce the overflow loss as much as possible, the compensation range of the pressure compensation curve can be from the pressure starting value of the overflow valve to the set pressure value of the overflow valve.

[0108] In the embodiment, the set pressure value of the overflow valve pressure (when the overflow valve is in a fully open stable state) can be obtained by the factory data (overflow valve characteristic curve) of the overflow valve, and the set pressure value is greater than the pressure starting value.

[0109] In the embodiment, when the overflow valve is in the overflow state, the main pump outlet pressure value is equal to the overflow valve pressure, that is, when the overflow valve pressure is the set pressure value, the overflow valve is in the overflow state, and the main pump outlet pressure value is also the set pressure value.

[0110] In the embodiment, the target cylinder flow when the overflow valve pressure is the set pressure value can be considered as the main pump flow, the second pressure compensation value when the overflow valve pressure is the set pressure value can be calculated according to the set pressure value and the target cylinder flow, and the pressure compensation curve between the pressure starting value and the set pressure value can be obtained by performing curve fitting on the first pressure compensation value corresponding to the pressure starting value and the second pressure compensation value.

[0111] In a possible implementation, step S11 of determining the target cylinder flow corresponding to the set pressure value of the overflow valve pressure can include:

[0112] S21: obtaining the hydraulic cylinder speed when the overflow valve pressure is the set pressure value.

[0113] S22: determining the target cylinder flow corresponding to the set pressure value of the overflow valve pressure according to the hydraulic cylinder speed and the cylinder area.

[0114] In the embodiment, the hydraulic cylinder speed when the relief valve pressure is the set pressure value can be obtained by using the sensor, and of course, the relief valve can be calibrated in advance to obtain the hydraulic cylinder speed when the relief valve pressure is the set pressure value.

[0115] In the embodiment, the following formula (2) is the hydraulic cylinder speed formula:

[0116] V = Q / A (2)

[0117] wherein V is the hydraulic cylinder speed, in units of m / min; Q is the hydraulic cylinder flow, in units of L / min; and A is the hydraulic cylinder area, in units of m2.

[0118] In the embodiment, the hydraulic cylinder area is fixed and known, and can be obtained according to the hydraulic cylinder factory data.

[0119] In the embodiment, after obtaining the hydraulic cylinder speed when the relief valve pressure is the set pressure value, since the hydraulic cylinder area is fixed and known, the target hydraulic cylinder flow corresponding to the relief valve pressure being the set pressure value can be simply and accurately determined according to the above formula (2).

[0120] In one possible embodiment, the step S12 of determining the second pressure compensation value according to the set pressure value and the target hydraulic cylinder flow can include:

[0121] S31: determining the current gear of the engineering machinery and determining the target power corresponding to the current gear.

[0122] S32: determining the calculated pressure value of the main pump outlet according to the target power and the target hydraulic cylinder flow.

[0123] S33: determining the second pressure compensation value according to the difference between the calculated pressure value and the set pressure value.

[0124] In the embodiment, different gears of the engineering machinery correspond to different powers, and the power corresponding to each gear can be stored in the flow control device of the engineering machinery. After determining the current gear, the target power corresponding to the current gear can be determined, and the target power is a fixed value.

[0125] In the embodiment, the pressure compensation values under different gears can be determined according to the powers corresponding to different gears of the engineering machinery, and then the pressure compensation curves corresponding to different gears can be generated.

[0126] For example, according to the target cylinder flow (main pump flow) Q2 when the relief valve pressure is the set pressure value and the above formula (1), the calculation pressure value P2' when the flow Q2 can be deduced, and according to the calculation pressure value P2' and the set pressure value P2, the second pressure compensation value AP2 = P2'-P2 when the relief valve pressure is the set pressure value can be determined.

[0127] For example, Figure 3 The pressure-flow dynamic compensation schematic diagram of an embodiment of the present application is shown in FIG. 1. Figure 3 As shown in FIG. 1, the horizontal coordinate is the main pump outlet pressure value, and the vertical coordinate is the pressure compensation value. When the main pump outlet pressure value is the pressure starting value P1, pressure compensation is not needed, the main pump flow is Q1, and the pressure compensation value AP1 = 0. When the main pump outlet pressure value is the set pressure value P2, pressure cut-off is needed due to the high pressure. If pressure compensation is not performed, the main pump flow before compensation is Q2, and there is a risk of overflow. If pressure compensation is performed according to the main pump calculation pressure value P2', AP2 = P2'-P2, the main pump flow after compensation is Q2', and at this time, the main pump flow is low, and there is no risk of overflow.

[0128] In the present embodiment, the target cylinder flow can be considered as the main pump flow Q. After the target power corresponding to the current gear is determined, the calculation pressure value of the relief valve (main pump outlet) when the relief valve pressure is the set pressure value can be accurately determined according to the above formula (1), and the second pressure compensation value when the relief valve pressure is the set pressure value can be accurately determined according to the difference between the calculation pressure value and the set pressure value.

[0129] In a possible embodiment, the step S13 of curve fitting the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve can include:

[0130] S41: establishing a two-dimensional coordinate system with the main pump outlet pressure value as the horizontal coordinate and the pressure compensation value as the vertical coordinate.

[0131] S42: generating a first coordinate point according to the pressure starting value and the first pressure compensation value corresponding to the pressure starting value.

[0132] S43: generating a second coordinate point according to the set pressure value and the second pressure compensation value.

[0133] S44: curve fitting according to the first coordinate point and the second coordinate point to obtain the pressure compensation curve.

[0134] In the present embodiment, since the pressure starting value is less than or equal to the opening pressure value of the relief valve, pressure compensation is not needed when the main pump pressure reaches the pressure starting value P1, and therefore, the first pressure compensation value AP1 corresponding to the pressure starting value is 0.

[0135] For example, the first coordinate point is (P1, 0), and the second coordinate point is (P2, △P2). Figure 4 A pressure compensation curve diagram for an embodiment of the present application is shown in FIG. 2. As shown in FIG. 2, the pressure compensation curve is a straight line. Figure 4

[0136] In the present embodiment, after the first coordinate point and the second coordinate point are determined, curve fitting is performed according to the first coordinate point and the second coordinate point, and thus the pressure compensation curve of the pressure compensation value changing with the main pump outlet pressure value can be obtained.

[0137] In another possible embodiment, the step S13 of performing curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve can include:

[0138] S51: obtaining one or more intermediate pressure values between the pressure pickup value and the set pressure value of the overflow valve.

[0139] S51: determining a third pressure compensation value corresponding to the intermediate pressure value.

[0140] S52: establishing a two-dimensional coordinate system with the main pump outlet pressure value as the horizontal coordinate and the pressure compensation value as the vertical coordinate.

[0141] S53: generating a first coordinate point according to the pressure pickup value and the first pressure compensation value corresponding to the pressure pickup value.

[0142] S54: generating a second coordinate point according to the set pressure value and the second pressure compensation value.

[0143] S55: generating a third coordinate point according to the intermediate pressure value and the third pressure compensation value.

[0144] S56: performing curve fitting according to the first coordinate point, the second coordinate point, and the third coordinate point to obtain the pressure compensation curve.

[0145] In the present embodiment, the number of intermediate pressure values can be flexibly set by those skilled in the art according to actual conditions, and no limitation is made herein.

[0146] In the present embodiment, the determination of the third pressure compensation value corresponding to the intermediate pressure value can refer to the above steps S11-S12, S21-S22, and S31-S33, that is, the hydraulic cylinder speed (obtained by a sensor or calibration) when the pressure of the overflow valve is the intermediate pressure value is obtained; the corresponding cylinder flow is determined according to the above formula (2); the calculation pressure value corresponding to the cylinder flow is back calculated according to the above formula (1), and the third pressure compensation value corresponding to the difference between the calculation pressure value and the intermediate pressure value is determined.

[0147] ​In the embodiment, the intermediate pressure value corresponds to the third coordinate point, for example, the intermediate pressure value is P3, the third pressure compensation value is ΔP3, and the third coordinate point is (P3, ΔP3).

[0148] In the embodiment, the pressure compensation curve can be a straight line, a convex curve, or a concave curve, and the shape of the curve can be determined by the coordinate points for curve fitting.

[0149] In the embodiment, the accuracy of curve fitting using only the first coordinate point and the second coordinate point can not be high, therefore, one or more intermediate pressure values can be set between the pressure setting value and the set pressure value, and corresponding third coordinate points can be generated, and curve fitting is performed according to the first coordinate point, the second coordinate point, and the third coordinate point, thereby improving the accuracy of the pressure compensation curve, and further improving the accuracy of the dynamic pressure compensation.

[0150] In one possible embodiment, the step S204 of determining the real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value can include:

[0151] S61: determining a corrected pressure value of the main pump according to the real-time pressure value and the target pressure compensation value.

[0152] S62: determining the real-time flow value of the main pump according to the target power corresponding to the current gear of the engineering machinery and the corrected pressure value of the main pump.

[0153] In the embodiment, the corrected pressure value of the main pump = the real-time pressure value + the target pressure compensation value.

[0154] In the embodiment, after the target power and the corrected pressure value of the main pump are determined, the corresponding real-time flow value of the main pump can be determined according to the above formula (1), and since the corrected pressure value is dynamically compensated, the real-time flow value of the main pump is reduced, the overflow valve does not overflow, and can only be used as a safety valve, thereby reducing the overflow loss as much as possible.

[0155] The flow control method of the engineering machinery of the present application is described below with reference to a specific embodiment.

[0156] In one specific embodiment, the flow control process of a certain excavator is as follows:

[0157] (I) The excavator is calibrated in advance to obtain a pressure compensation curve:

[0158] First, the operator determines the opening pressure value when the overflow valve just opens and the set pressure value P2 when the overflow valve is fully open according to the overflow valve characteristic curve of the overflow valve when the excavator is shipped, and sets the pressure setting value P1 according to the opening pressure value.

[0159] Second step, the operator will open the pressure value, set pressure value P2 and pressure start value P1 into the flow control device of the excavator, calibration in different working gear of the excavator, generate and store each gear corresponding pressure compensation curve, take gear A as an example, the specific process is:

[0160] ①The flow control device of the excavator obtains the hydraulic cylinder speed when the relief valve pressure is the set pressure value P2 through the sensor, and determines the target cylinder flow Q2 corresponding to the relief valve pressure being the set pressure value P2 according to the hydraulic cylinder speed and the cylinder area.

[0161] ②The flow control device of the excavator determines the target power N corresponding to gear A, and determines the calculated pressure value P2' of the main pump outlet according to the target power N and the target cylinder flow Q2.

[0162] ③The flow control device of the excavator determines the second pressure compensation value △P2=P2'-P2 when the relief valve pressure is the set pressure value according to the difference between the calculated pressure value P2' and the set pressure value P2.

[0163] ④The flow control device of the excavator establishes a two-dimensional coordinate system with the main pump outlet pressure value as the abscissa and the pressure compensation value as the ordinate, generates the first coordinate point (P1, 0) according to the pressure start value and the first pressure compensation value △P1=0 corresponding to the pressure start value, and generates the second coordinate point (P2, △P2) according to the set pressure value and the second pressure compensation value.

[0164] ⑤The flow control device of the excavator performs curve fitting according to the first coordinate point (P1, 0) and the second coordinate point (P2, △P2) to obtain the pressure compensation curve corresponding to gear A.

[0165] (II) The flow control process of the excavator in the actual operation process is as follows:

[0166] First step, the flow control device of the excavator obtains the real-time pressure value of the main pump outlet of the engineering machinery, and before time B, the real-time pressure value is less than the preset pressure start value P1, then according to the real-time pressure value, the real-time flow value of the main pump is determined.

[0167] Second step, the flow control device of the excavator detects that the real-time pressure value is greater than the pressure start value at time B, then the pressure compensation curve corresponding to the current gear A is determined, and the target pressure compensation value corresponding to the real-time pressure value is determined according to the pressure compensation curve.

[0168] Third step, the flow control device of the excavator determines the corrected pressure value of the main pump according to the sum of the real-time pressure value and the target pressure compensation value, and determines the real-time flow value of the main pump according to the target power corresponding to the current gear of the engineering machinery and the corrected pressure value of the main pump.

[0169] Figure 5 Fig. 1 is a structural schematic diagram of a flow control device of an engineering machine according to an embodiment of the present application, as shown, the flow control device of the engineering machine comprises: an acquisition module 51, configured to acquire a real-time pressure value of an outlet of a main pump of the engineering machine; a processing module 52, configured to determine whether the real-time pressure value is less than a preset pressure starting value, the pressure starting value being less than or equal to an opening pressure value of an overflow valve; if not, determine a target pressure compensation value corresponding to the real-time pressure value according to a preset pressure compensation curve; and determine a real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value. Figure 5

[0170] The flow control device of the engineering machine provided by the embodiment of the present application can execute the technical solutions shown in the method embodiments, and the implementation principles and beneficial effects are similar, which will not be repeated here.

[0171] Figure 6 Fig. 2 is a structural schematic diagram of a flow control device of an engineering machine according to another embodiment of the present application, as shown, the flow control device of the engineering machine comprises: a processor 601, and a memory 602 in communication connection with the processor 601; the memory 602 stores computer execution instructions; the processor 601 executes the computer execution instructions stored in the memory 602, and realizes the steps of the flow control method of the engineering machine in the above-mentioned method embodiments. Figure 6

[0172] In the flow control device of the engineering machine, the memory 602 and the processor 601 are directly or indirectly electrically connected to realize the transmission or interaction of data. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines, such as through bus connection. The memory 602 stores computer execution instructions for realizing the data access control method, including at least one software function module stored in the memory 602 in the form of software or firmware, and the processor 601 executes various functional applications and data processing by running the software program and the module stored in the memory 602.

[0173] ​​The memory 602 can be, but is not limited to, a Random Access Memory (RAM), a Read Only Memory (ROM), a Programmable Read-Only memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electric Erasable Programmable Read-Only Memory (EEPROM), etc. The memory 602 is configured to store programs, and the processor 601 executes the programs upon receiving an execution instruction. Further, the software programs and modules in the memory 602 can further include an operating system, which can include various software components and / or drivers for managing system tasks (such as memory management, storage device control, power management, etc.), and can communicate with various hardware or software components to provide an operating environment for other software components.

[0174] The processor 601 can be an integrated circuit chip with a processing capability. The processor 601 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. The processor 601 can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0175] An embodiment of the present application further provides an engineering machine, including: Figure 6 A flow control device of the engineering machine as shown.

[0176] An embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores computer execution instructions. When the computer execution instructions are executed by a processor, the steps of the method embodiments of the present application are implemented.

[0177] An embodiment of the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method embodiments of the present application are implemented.

[0178] It should be noted that, for the foregoing method embodiments, the sequences of the described actions are merely illustrative, and the present application is not limited to the sequences of the described actions. In some embodiments, the sequences of the described actions can be changed or reordered. In some embodiments, some of the actions can be performed simultaneously. In some embodiments, some of the actions can be performed in different sequences or at different times.

[0179] It should be noted that, for the foregoing method embodiments, the sequences of the described actions are merely illustrative, and the present application is not limited to the sequences of the described actions. In some embodiments, the sequences of the described actions can be changed or reordered. In some embodiments, some of the actions can be performed simultaneously. In some embodiments, some of the actions can be performed in different sequences or at different times.

[0180] It should be understood that the above-described apparatus embodiments are merely illustrative, and the apparatus of the present application can also be implemented in other manners. For example, the division of the units / modules in the above-described embodiments is merely a logical function division, and actual implementation can be in another manner. For example, a plurality of units / modules or components can be combined, or can be integrated into another system, or some features can be omitted or not implemented.

[0181] In addition, unless specifically stated otherwise, each functional unit / module in each embodiment of the present application can be integrated in one unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated together. The above-mentioned integrated unit / module can be realized in the form of hardware or in the form of a software program module.

[0182] In the above-described embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments. Each technical feature of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but it should be considered that any combination of the technical features is within the scope of the present application as long as the combination does not exist contradictory.

[0183] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0184] It is to be understood that the application is not limited to the precise construction herein disclosed and shown in the drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A flow control method for engineering machinery, characterized in that, include: Obtain the real-time pressure value at the outlet of the main pump of the construction machinery; Determine whether the real-time pressure value is less than the preset pressure adjustment value, wherein the pressure adjustment value is less than or equal to the opening pressure value of the relief valve; If not, then determine the target pressure compensation value corresponding to the real-time pressure value based on the pressure compensation curve; The real-time flow rate of the main pump is determined based on the real-time pressure value and the target pressure compensation value.

2. The flow control method for engineering machinery according to claim 1, characterized in that, The pressure compensation curve was obtained in the following way: The target cylinder flow rate is determined when the overflow valve pressure is the set pressure value, wherein the set pressure value is greater than the pressure adjustment value. Based on the set pressure value and the target cylinder flow rate, a second pressure compensation value is determined. The second pressure compensation value is the pressure compensation value when the overflow valve pressure is the set pressure value. The pressure compensation curve is obtained by curve fitting the first pressure compensation value and the second pressure compensation value, wherein the first pressure compensation value is the pressure compensation value when the overflow valve pressure is the pressure adjustment value.

3. The flow control method for engineering machinery according to claim 2, characterized in that, The determination of the target cylinder flow rate corresponding to the overflow valve pressure being the set pressure value includes: The speed of the hydraulic cylinder is obtained when the pressure of the relief valve is the set pressure value. Based on the hydraulic cylinder speed and cylinder area, the target cylinder flow rate corresponding to the set pressure value of the relief valve is determined.

4. The flow control method for engineering machinery according to claim 2, characterized in that, The step of determining the second pressure compensation value based on the set pressure value and the target cylinder flow rate includes: Determine the current gear of the construction machinery and the target power corresponding to the current gear; The calculated pressure value of the main pump outlet is determined based on the target power and the target cylinder flow rate. A second pressure compensation value is determined based on the difference between the calculated pressure value and the set pressure value.

5. The flow control method for engineering machinery according to claim 4, characterized in that, The step of performing curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve includes: A two-dimensional coordinate system is established with the main pump outlet pressure value as the horizontal axis and the pressure compensation value as the vertical axis. A first coordinate point is generated based on the pressure start-up value and the first pressure compensation value corresponding to the pressure start-up value. A second coordinate point is generated based on the set pressure value and the second pressure compensation value. The pressure compensation curve is obtained by curve fitting based on the first coordinate point and the second coordinate point.

6. The flow control method for engineering machinery according to claim 4, characterized in that, The step of performing curve fitting on the first pressure compensation value and the second pressure compensation value to obtain the pressure compensation curve includes: Obtain one or more intermediate pressure values ​​of the relief valve between the pressure adjustment value and the set pressure value; Determine the third pressure compensation value corresponding to the intermediate pressure value; A two-dimensional coordinate system is established with the main pump outlet pressure value as the horizontal axis and the pressure compensation value as the vertical axis. A first coordinate point is generated based on the pressure start-up value and the first pressure compensation value corresponding to the pressure start-up value. A second coordinate point is generated based on the set pressure value and the second pressure compensation value. A third coordinate point is generated based on the intermediate pressure value and the third pressure compensation value; The pressure compensation curve is obtained by performing curve fitting based on the first coordinate point, the second coordinate point, and the third coordinate point.

7. The flow control method for engineering machinery according to any one of claims 1-6, characterized in that, Determining the real-time flow rate of the main pump based on the real-time pressure value and the target pressure compensation value includes: The corrected pressure value of the main pump is determined based on the real-time pressure value and the target pressure compensation value. The real-time flow rate of the main pump is determined based on the target power corresponding to the current gear of the construction machinery and the corrected pressure value of the main pump.

8. A flow control device for engineering machinery, comprising: The acquisition module is used to acquire the real-time pressure value at the outlet of the main pump of the construction machinery; The processing module is used to determine whether the real-time pressure value is less than a preset pressure adjustment value, wherein the pressure adjustment value is less than or equal to the opening pressure value of the relief valve; if not, it determines the target pressure compensation value corresponding to the real-time pressure value according to a preset pressure compensation curve; and determines the real-time flow value of the main pump according to the real-time pressure value and the target pressure compensation value.

9. A flow control device for engineering machinery, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory is used to store computer-executed instructions; The processor is used to execute computer execution instructions stored in the memory, causing the processor to perform the flow control method for engineering machinery as described in any one of claims 1-7.

10. An engineering machinery, characterized in that, include: The flow control device for engineering machinery as described in claim 9.

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