Anti-flameout control method and device for heat engine process of excavator

Abstract

The invention discloses an anti-flameout control method and device in the heat-up process of an excavator, and relates to the technical field of anti-flameout control. The current environment pressure of the excavator is obtained, if the current environment pressure meets the starting condition, an engine of the excavator is started, the water temperature of the engine is obtained, and if the water temperature meets the heat-up condition of the engine, the excavator is started; and executing the engine heating process flameout prevention control strategy to keep the rotating speed of the engine constant at the preset rotating speed, and executing the hydraulic system heating flameout prevention control strategy when the rotating speed of the engine is at the preset rotating speed and a hydraulic lock switching instruction is received.

Description

Technical Field

[0001] The present application relates to the technical field of flameout prevention control, and more specifically, to a flameout prevention control method and device for a thermal engine process of an excavator. Background Art

[0002] In high altitude and low temperature environments, the excavator engine needs to be warmed up. Warming up is done by operating the hydraulic system to raise the hydraulic oil temperature. If the machine is not operated, the oil temperature will not rise.

[0003] After the engine is cold started, during the engine warm-up process, due to factors such as low oxygen content in the plateau, high viscosity of low-temperature hydraulic oil, and high friction resistance, the performance deteriorates significantly, and even flameout occurs. As a result, the basic warm-up process cannot be carried out smoothly, which is not conducive to the rapid warm-up and rapid commissioning of the machine. Moreover, once the engine is turned off, restarting it will have a greater impact on the loss of the starter and battery.

[0004] Therefore, how to prevent the excavator from stalling during the warm-up process is an urgent problem to be solved in this application. Summary of the invention

[0005] In view of this, the present application discloses a flameout prevention control method and device for an excavator during a heat-up process, aiming to prevent the excavator from flameout during the heat-up process.

[0006] In order to achieve the above purpose, the disclosed technical solution is as follows:

[0007] The first aspect of the present application discloses a flameout prevention control method for a heat engine process of an excavator, the method comprising:

[0008] Get the current environmental pressure of the excavator;

[0009] If the current ambient pressure meets the starting condition, start the engine of the excavator and obtain the engine water temperature;

[0010] If the water temperature meets the engine warm-up condition, the engine warm-up process anti-stall control strategy is executed to keep the engine speed constant at a preset speed;

[0011] When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic system thermal engine anti-stall control strategy is executed.

[0012] Preferably, if the current ambient pressure meets the starting condition, starting the engine of the excavator and obtaining the engine water temperature includes:

[0013] Comparing the current ambient pressure with a set value;

[0014] If the current ambient pressure is less than the set value, determining that the current ambient pressure meets the start condition;

[0015] When the current ambient pressure meets the starting condition, the engine of the excavator is started and the engine water temperature is obtained.

[0016] Preferably, if the water temperature meets the engine warm-up condition, executing the engine warm-up process anti-stall control strategy to keep the engine speed constant at a preset speed includes:

[0017] comparing the engine water temperature with a preset water temperature;

[0018] If the engine water temperature is less than or equal to the preset water temperature, the engine is heated up by an engine heating program;

[0019] During the engine warm-up process, if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid, the engine idle speed is increased according to the preset time interval and preset speed increase until the highest speed is reached;

[0020] During the process of the engine idling speed reaching the highest speed, if the engine water temperature is greater than the preset water temperature, it is determined that the engine warm-up is completed;

[0021] After the engine warm-up is completed, the engine speed is kept constant at the preset speed.

[0022] Preferably, the hydraulic system thermal engine flameout prevention control strategy includes at least an engine power boost strategy and a hydraulic loading speed reduction prevention strategy. When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic system thermal engine flameout prevention control strategy is executed, including:

[0023] When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic control system is heated up through a hydraulic system heating program;

[0024] During the process of the hydraulic control system warming up, the engine power boosting strategy and the hydraulic loading anti-speed drop strategy are respectively executed to complete the process of executing the hydraulic system warming up anti-stalling control strategy.

[0025] Preferably, the process of executing the engine power enhancement strategy includes:

[0026] The target torque is obtained by checking the torque curve based on the feedforward torque of the pilot pressure and different pilot pressures; wherein the target torque is the maximum value of each final torque obtained under multiple pilot pressures during the operation of the excavator;

[0027] Get the actual speed of the excavator during operation;

[0028] Correcting the actual speed by setting the speed;

[0029] The engine of the excavator is adjusted by the target torque and the corrected actual speed to complete the process of executing the hydraulic system thermal engine anti-stall control strategy.

[0030] Preferably, the process of executing the hydraulic loading anti-speed drop strategy includes:

[0031] Obtain the real-time air intake volume of the excavator's engine, the real-time hydraulic oil temperature of the hydraulic system, and the hydraulic loading rate of the hydraulic system;

[0032] Determine an air intake correction parameter according to the real-time air intake volume, and determine an oil temperature correction parameter according to the real-time hydraulic oil temperature;

[0033] The hydraulic loading rate is corrected in real time through the air intake correction parameter;

[0034] The oil temperature correction parameter is used to correct the hydraulic loading rate after the intake volume is corrected, so as to complete the process of the hydraulic loading anti-speed drop strategy.

[0035] Preferably, during the process in which the engine speed is at the preset speed, when a hydraulic lock switch command is received, after executing the hydraulic system thermal engine anti-stall control strategy, the method further includes:

[0036] If the engine water temperature is detected to be greater than the preset water temperature and the hydraulic oil temperature is greater than the preset oil temperature, the vehicle control program is executed.

[0037] The second aspect of the present application discloses an anti-stall control device for a heat engine process of an excavator, the device comprising:

[0038] An acquisition unit, used for acquiring the current environmental pressure of the excavator;

[0039] A starting unit, used to start the engine of the excavator and obtain the engine water temperature if the current ambient pressure meets the starting condition;

[0040] A first execution unit is used to execute an anti-stall control strategy during the engine warm-up process if the water temperature meets the engine warm-up condition, so as to keep the engine speed constant at a preset speed;

[0041] The second execution unit is used to execute the hydraulic system thermal engine anti-stall control strategy when receiving a hydraulic lock switch command during the process in which the engine speed is at the preset speed.

[0042] Preferably, the starting unit comprises:

[0043] A first comparison module, used for comparing the current ambient pressure with a set value;

[0044] A first determination module, configured to determine that the current environmental pressure meets a start condition if the current environmental pressure is less than the set value;

[0045] The starting module is used to start the engine of the excavator and obtain the engine water temperature when the current ambient pressure meets the starting condition.

[0046] Preferably, the first execution unit includes:

[0047] A second comparison module, used for comparing the engine water temperature with a preset water temperature;

[0048] A first execution module, configured to perform engine warm-up through an engine warm-up program if the engine water temperature is less than or equal to a preset water temperature;

[0049] The speed increasing module is used to increase the engine idle speed according to a preset time interval and a preset speed increase until the highest speed is reached during the engine warm-up process if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid;

[0050] The second determination module is used to determine that the engine warm-up is completed if the engine water temperature is greater than a preset water temperature during the process of the engine idle speed reaching the highest speed;

[0051] The constant module is used to keep the engine speed constant at a preset speed after the engine warm-up is completed.

[0052] It can be known from the above technical scheme that the present application discloses an anti-stall control method and device for the hot engine process of an excavator, which obtains the current ambient pressure of the excavator. If the current ambient pressure meets the starting conditions, the engine of the excavator is started and the engine water temperature is obtained. If the water temperature meets the engine hot engine conditions, the anti-stall control strategy for the engine hot engine process is executed to keep the engine speed constant at a preset speed. When the hydraulic lock switch command is received during the process of the engine speed being at the preset speed, the hydraulic system hot engine anti-stall control strategy is executed.

[0053] Through the above scheme, in high altitude, low temperature and other environments, the excavator engine is first warmed up. The engine warm-up process is achieved by alternating the speed to achieve rapid warm-up, and then the hydraulic system is warmed up to prevent damage to the engine caused by direct operation of the vehicle at low engine temperatures. The hydraulic system anti-stall strategy uses the coordinated control of the engine and hydraulic system, and through measures such as increasing the speed, increasing the injection, and accelerating the injection of the engine's main power to maximize the engine's capacity, effectively avoiding the excavator from stalling due to sudden load increases caused by operations during the warm-up process, and achieving the purpose of preventing the excavator from stalling during the warm-up process. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0055] Figure 1 A schematic flow chart of an anti-stall control method for a heat engine process of an excavator disclosed in an embodiment of the present application;

[0056] Figure 2 This is an example diagram of the rotation speed performance during the heat engine process disclosed in the embodiment of the present application;

[0057] Figure 3 A schematic diagram of the framework of the engine thermal process anti-stall control strategy disclosed in the embodiment of the present application;

[0058] Figure 4 A schematic diagram of an engine power enhancement strategy disclosed in an embodiment of the present application;

[0059] Figure 5 A curve diagram of the hydraulic loading anti-speed drop strategy disclosed in the embodiment of the present application;

[0060] Figure 6 A flow chart of another method for preventing flameout during a heat engine process of an excavator disclosed in an embodiment of the present application;

[0061] Figure 7 It is a structural schematic diagram of an anti-stallation control device for the thermal engine process of an excavator disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0064] As can be seen from the background technology, after the engine is cold-started, during the engine warm-up process, due to factors such as low oxygen content in the plateau, high viscosity of low-temperature hydraulic oil, and high friction resistance, the performance deteriorates significantly, and even flameout problems may occur. As a result, the basic warm-up process cannot be carried out smoothly, which is not conducive to the rapid warm-up and rapid commissioning of the machine. Moreover, once the engine is turned off, restarting it will have a greater impact on the loss of the starter and battery. Therefore, how to prevent the excavator from stalling during the warm-up process is a problem that urgently needs to be solved in this application.

[0065] In order to solve the above problems, the present application discloses a flameout prevention control method and device for the excavator heat-up process. In high altitude, low temperature and other environments, the excavator engine is first heated up. The engine heat-up process achieves rapid heat-up by alternating the speed. Then the hydraulic system is heated up to prevent damage to the engine caused by direct operation of the vehicle at low engine temperatures. The hydraulic system flameout prevention strategy uses coordinated control of the engine and the hydraulic system, and measures such as increasing the speed, increasing the injection, and accelerating the injection of the engine's main power to maximize the engine's capacity, effectively avoiding the excavator from stalling due to sudden load increases caused by operations during the heat-up process, thereby achieving the purpose of preventing the excavator from stalling during the heat-up process. The specific implementation method is described in detail through the following embodiments.

[0066] refer to Figure 1 As shown, an anti-stall control method for an excavator thermal engine process disclosed in an embodiment of the present application is shown, and the anti-stall control method for an excavator thermal engine process mainly includes the following steps:

[0067] S101: Obtain the current environmental pressure of the excavator.

[0068] The current ambient pressure of the excavator can be obtained by using a vehicle-mounted pressure sensor, or by using an intake control module to calculate the current ambient pressure of the engine in an intake control algorithm. The method of obtaining the current ambient pressure of the excavator is not specifically limited in this application.

[0069] S102: If the current ambient pressure meets the start condition, start the excavator engine and obtain the engine water temperature.

[0070] The starting condition is determined by the current ambient pressure and the set value.

[0071] Specifically, if the current ambient pressure meets the starting condition, the process of starting the excavator engine and obtaining the engine water temperature is as shown in A1-A3.

[0072] A1: Compare the current ambient pressure with the set value.

[0073] The setting value is set according to the actual situation and is not specifically limited in this application.

[0074] A2: If the current ambient pressure is less than the set value, it is determined that the current ambient pressure meets the start-up conditions.

[0075] A3: When the current ambient pressure meets the starting conditions, start the excavator engine and obtain the engine water temperature.

[0076] S103: If the water temperature meets the engine warm-up condition, execute the engine warm-up process anti-stall control strategy to keep the engine speed constant at a preset speed.

[0077] In S103, if the water temperature meets the engine warm-up condition, the engine warm-up process anti-stall control strategy is executed through the engine warm-up program. The engine warm-up program is used to automatically lock and prohibit speed increase and operate the hydraulic system.

[0078] The speed performance during the specific heat engine process is as follows Figure 2 shown. Figure 2 Just an example.

[0079] Figure 2 The speed performance of the warm-up process at an altitude of 4700m and an ambient temperature of -20 degrees Celsius. The horizontal axis is time and the vertical axis is speed.

[0080] In plateau and low-temperature environments, after a cold start, the excavator engine will experience significant performance deterioration during the vehicle warm-up process (operating the hydraulic system raises the hydraulic oil temperature, and not operating the machine will cause the oil temperature to not rise). This is due to factors such as low oxygen content in the plateau, high viscosity of low-temperature hydraulic oil, and high friction resistance. It may even cause flameout problems. This prevents the basic warm-up process from proceeding smoothly, which is not conducive to the rapid warm-up and rapid commissioning of the machine. Moreover, once it is turned off, restarting it will cause relatively large losses to the starter and battery. Therefore, through this solution's control method for preventing flameout during the excavator warm-up process specifically for plateau and low-temperature environments, this solution can effectively avoid flameouts that may occur during the warm-up process due to sudden increases in load caused by operations.

[0081] Specifically, if the water temperature meets the engine warm-up condition, the engine warm-up process anti-stall control strategy is executed to keep the engine speed constant at a preset speed, as shown in B1-B5.

[0082] B1: Compare the engine water temperature with the preset water temperature.

[0083] Among them, the preset water temperature can be 40°C, 45°C, etc. The preset water temperature is set according to actual conditions and this application does not make any specific limitations.

[0084] B2: If the engine water temperature is less than or equal to the preset water temperature, the engine is warmed up through the engine warm-up procedure.

[0085] Warming up the engine means that in a low-temperature environment, after the vehicle is started, in order to quickly heat up the engine and hydraulic system, the driver usually operates the machine to load the system and let the machine warm up quickly. The operation can be slow or fast.

[0086] B3: During the engine warm-up process, if it is detected that the speed increase command is invalid and the hydraulic lock switch is invalid, the engine idle speed is increased according to the preset time interval and preset speed increase until the highest speed is reached.

[0087] Among them, the preset time interval can be an interval of 30 seconds (s), an interval of 40s, etc. The preset time interval is set according to actual conditions and this application does not make any specific limitations.

[0088] The preset speed increase may be an interval of 100 revolutions per minute (RPM), an interval of 110 RPM, etc. The preset speed increase is set according to the actual situation and is not specifically limited in this application. The preset speed increase of this application is preferably an interval of 100 RPM.

[0089] B4: When the engine idle speed reaches the highest speed, if the engine water temperature is greater than the preset water temperature, it is determined that the engine warm-up is complete.

[0090] In order to facilitate understanding of the process of executing the engine warm-up process anti-stall control strategy if the water temperature meets the engine warm-up conditions to keep the engine speed constant at the preset speed, an example is given here to illustrate:

[0091] For example, when the excavator starts successfully in plateau, low temperature and other environments, if the engine water temperature is lower than 40°C at this time, the engine warm-up program will be entered first. At this time, the engine warm-up program will automatically lock and prohibit speed increase and operation of the hydraulic system. The engine warm-up program will run automatically, and the speed will increase from idle speed by 100RPM intervals. Each speed will be maintained for 30s until the water temperature exceeds 40°C, indicating that the engine warm-up is completed.

[0092] B5: After the engine warm-up is completed, the engine speed is kept constant at the preset speed.

[0093] The preset speed may be 1400RPM, 1500RPM, etc. The preset speed is set according to the actual situation, and this application does not make specific restrictions. The preset speed of this application is preferably 1400RPM. For example, after the engine heats up, the vehicle speed is automatically constant at 1400RPM.

[0094] S104: When the engine speed is at a preset speed and a hydraulic lock switch command is received, a hydraulic system hot engine anti-stall control strategy is executed.

[0095] In S104, when the engine speed is at the preset speed, when the hydraulic lock switch command is received, the hydraulic control system is heated up through the hydraulic system heating program. During the hydraulic control system heating process, the engine power boost strategy and the hydraulic loading anti-speed drop strategy are respectively executed to complete the process of executing the hydraulic system heating anti-stall control strategy.

[0096] Among them, the hydraulic system thermal engine anti-stall control strategy at least includes an engine power boost strategy and a hydraulic loading anti-speed drop strategy.

[0097] The specific process of implementing the engine power enhancement strategy is shown in C1-C4.

[0098] C1: The target torque is obtained by checking the torque curve based on the feedforward torque of the pilot pressure and different pilot pressures; wherein the target torque is the maximum value of each final torque under multiple pilot pressures during the operation of the excavator.

[0099] Among them, different pilot pressure sizes include the boom retraction pilot pressure value, the boom swing pilot pressure value, the boom lifting pilot pressure value, etc.

[0100] C2: Get the actual speed of the excavator during operation.

[0101] C3: Correct the actual speed by setting the speed.

[0102] This solution adds a load-based speed correction value (a positive value) on the basis of the set speed, and the greater the load, the greater the speed correction value.

[0103] The set speed is determined by the speed correction value of the load, the calibration value, the total required torque of the engine during the action process, and the gear speed.

[0104] C4: The excavator engine is adjusted through the target torque and the corrected actual speed to complete the process of executing the hydraulic system thermal engine anti-stall control strategy.

[0105] The strategy for improving engine power is mainly to increase engine speed and increase fuel injection volume. Increasing fuel injection volume can be achieved by increasing torque and shielding all fuel injection restrictions, such as smoke restrictions. Figure 3 shown. Figure 3 The schematic diagram of the framework of the engine thermal process anti-stall control strategy is shown.

[0106] Figure 3 In the process, the feedforward torque based on the pilot pressure is added to the traditional engine proportional and integral control (Proportional Integral) PI torque calculation. The feedforward torque obtains the target torque by checking the torque curve (the X-axis of the torque curve is the pilot pressure value, and the Z-axis is the torque setting value) with different pilot pressures (pilot pressure value for bucket arm retraction, bucket arm swing outward, boom lifting pilot pressure value, etc.). Since the excavator operation process involves multiple pilot pressure conditions, the final torque takes the maximum value, that is, the target torque. In this way, in the engine control process, the actual torque is greater than the traditional torque, and the fuel injection is more and faster.

[0107] Figure 3 In, K p For proportional control; K i is integral control; Trq i Calculate the torque for integration; Trq pi The sum of proportional torque and integral torque; Trq piolt The feedforward torque value is obtained by checking the curve for the pilot pressure; the sum of the torque values ​​calculated by PI is the control torque, which is used to eliminate the speed deviation and make the actual speed close to the set speed. On this basis, the feedforward control is introduced. The feedforward control is mainly based on the operating pilot handle signal of the excavator, which is obtained by checking the built-in torque curve. The torque value obtained in this way is greater than the traditional PI torque value. The greater the torque, the more oil is injected. The better the responsiveness.

[0108] The working speed of a traditional excavator is the set speed. The actual speed will be greater or less than the set speed as the load changes (for example, the speed is lower than the gear speed when loaded, and higher than the gear speed when unloaded). This solution adds a load-based speed correction value (a positive value) on the basis of the set speed, and the greater the load, the greater the speed correction value. Specifically, as shown in formula (1):

[0109] Set speed = gear speed + factor*(Trq 总 -Trq 起掉 )(1)

[0110] Among them, factor is the calibration value; Trq 总 The total torque required by the engine during the action process; set Trq 起掉 The purpose is to ensure that the set speed is equal to the gear speed when the vehicle is not being operated.

[0111] The speed of a traditional excavator during loading will gradually decrease, but this solution can gradually increase the speed during loading, further improving the engine's load resistance. Figure 4 shown. Figure 4 A schematic diagram of the engine power boost strategy is shown.

[0112] Figure 4 In the figure, the red speed curve shows that the speed of the traditional excavator will gradually decrease during the loading process. The black speed curve shows the engine power improvement strategy of this solution. The engine power improvement strategy of this solution improves the engine power during the hot engine process by increasing the engine speed and the engine injection torque during the operation process.

[0113] After the engine is warmed up, if the driver's command to turn on the hydraulic lock switch is received, the system will automatically enter the hydraulic system warm-up program in response to the command of the hydraulic lock switch to warm up the hydraulic system. The hydraulic lock switch is the enabling switch for the excavator operation. When the hydraulic lock switch is turned on, the hydraulic circuit is connected. At this time, when the machine is operated, the working device will act according to the command; when the hydraulic lock switch is turned off, the hydraulic circuit is cut off. At this time, when the machine is operated, the working device will not respond.

[0114] When the working device is moving according to the instructions, the hydraulic operating handle is operated, and the hydraulic controller TCU sends a pressure signal (0-40bar). The pilot pressure drives the corresponding valve core of the main valve to open and close, thereby realizing the action of the working device.

[0115] The specific process of implementing the hydraulic loading anti-speed drop strategy is shown in E1-E4.

[0116] E1: Obtain the real-time air intake volume of the current engine of the excavator, the real-time hydraulic oil temperature of the hydraulic system, and the hydraulic loading rate of the hydraulic system.

[0117] Among them, the curve of the hydraulic loading rate of the hydraulic system (ie, the hydraulic loading power curve) is determined by the correction coefficient of the engine intake volume and the gear setting power.

[0118] E2: Determine the air intake correction parameter according to the real-time air intake volume, and determine the oil temperature correction parameter according to the real-time hydraulic oil temperature.

[0119] The correction factor is built-in based on two curves of intake air volume and hydraulic oil temperature.

[0120] An intake volume curve is obtained according to the real-time intake volume, and the K1 coefficient (i.e., intake volume correction coefficient) is found through the intake volume curve. An oil temperature curve is obtained according to the real-time hydraulic oil temperature, and the K2 coefficient (i.e., oil temperature correction coefficient) is found through the oil temperature curve.

[0121] E3: The hydraulic loading rate is corrected in real time through the intake volume correction parameter.

[0122] E4: The oil temperature correction parameter is used to correct the hydraulic loading rate after the intake volume is corrected, so as to complete the process of the hydraulic loading anti-speed drop strategy.

[0123] The correction process is to multiply the hydraulic loading rate by the K1 coefficient and the K2 coefficient. The purpose of the correction is to reduce the hydraulic loading rate.

[0124] The hydraulic loading anti-speed drop strategy mainly takes into account the current engine intake volume and the current hydraulic oil temperature in the current loading rate, and adjusts the hydraulic loading rate in real time according to the intake volume correction parameters, and makes certain corrections to the hydraulic loading rate after the intake volume correction based on the oil temperature correction parameters.

[0125] It should be noted that the purpose of the heat engine is to quickly raise the temperature by operating the machine, so the machine's control performance is not required to be high. In order to maximize the effectiveness of the hydraulic loading anti-speed drop strategy and ensure that it does not stall as much as possible, the above power ramp curve can be calibrated very slowly (the slower the load on the pump end, the slower the loading, and the less likely it is to stall).

[0126] The hydraulic loading speed drop prevention strategy mainly increases the distributed mapping structure (Rmap) function of the pump power loading. The Rmap function is used to ramp the pump power control and reduce the pump power loading speed. The hydraulic loading speed drop prevention strategy is a pump power loading strategy based on the circulating air intake and hydraulic oil temperature. The pump power loading strategy of circulating air intake and hydraulic oil temperature controls the pump power loading slope based on the circulating air intake and hydraulic oil temperature. The lower the oil temperature, the slower the loading and the greater the ramp slope.

[0127] The detailed description of the hydraulic loading anti-speed drop strategy is as follows Figure 5 shown. Figure 5 A curve diagram of the hydraulic loading anti-speed drop strategy is shown.

[0128] Figure 5 In the figure, the X-axis is the engine intake volume, in grams per second (g / h); the Y-axis is the correction coefficient of the gear setting power.

[0129] Traditionally, pump loading is mainly done by the hydraulic system controller TCU calculating the flow demand based on the control demand (pilot signal size), combining the current pump pressure and power settings, calculating the displacement change required at this time, and then inputting it into the pump regulator to change the pump displacement. Traditionally, considering the action speed, the displacement loading instruction (current) of the pump is usually relatively fast, and the speed drop in plain conditions can be guaranteed to be within a certain range. However, in plateau areas, performance deterioration causes fast current loading instructions to cause huge speed drops or even stalling. Therefore, this problem is solved through the hydraulic loading anti-speed drop strategy of this solution.

[0130] When the engine speed is at the preset speed, when the hydraulic lock switch command is received, after the hydraulic system thermal engine anti-stall control strategy is executed, if the engine water temperature is monitored to be greater than the preset water temperature and the hydraulic oil temperature is greater than the preset oil temperature, the vehicle control program is executed.

[0131] For example, during the warm-up process of the hydraulic control system, the water temperature and oil temperature are monitored. If the water temperature exceeds 80°C and the hydraulic oil temperature exceeds 30°C, it means that the vehicle warm-up is complete, then the warm-up program is exited and the normal vehicle control program is entered. The vehicle control program is developed for excavators and is a program used for operations that comes with the product sold.

[0132] In order to facilitate the understanding of the anti-stall control process of the excavator thermal engine process, combined with Figure 6 Let's take an example:

[0133] For example, the current environmental pressure of the excavator is obtained. If the current environmental pressure is less than the set value, the excavator is started. If the start is successful, the engine water temperature is obtained.

[0134] Determine whether the engine water temperature is less than or equal to 40°C;

[0135] If not, the fixed speed is kept constant at the preset speed (such as 1400RPM);

[0136] If yes, warm up the engine through the engine warm-up procedure;

[0137] During the engine warm-up process, if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid, that is, SpdEnc_st=0, the speed will be automatically increased by 100RPM every 30s from the idle speed to the highest speed, and the engine water temperature at this time will be obtained;

[0138] Determine whether the engine water temperature is greater than 40°C, and keep the fixed speed constant at the preset speed (such as 1400RPM);

[0139] Determine whether the hydraulic switch is open;

[0140] If not, return to the step of setting the fixed speed constant at the preset speed (such as 1400RPM);

[0141] If yes, execute the hydraulic system thermal engine anti-stall control strategy;

[0142] Determine whether the engine water temperature exceeds 80°C and the hydraulic oil temperature is greater than 30°C;

[0143] If so, enter the normal vehicle control procedure;

[0144] If not, return to the step of executing the hydraulic system thermal engine anti-stall control strategy.

[0145] This application can ensure that no matter how the user operates the machine or what load is encountered during the excavator heat-up process under plateau and low-temperature conditions, there will be no risk of flameout, etc., and the heat-up process can be completed quickly and smoothly to the greatest extent possible. The anti-stall strategy of this application (anti-stall control strategy for engine heat-up process and anti-stall control strategy for hydraulic system heat-up process) maximizes the maximum capacity of the engine through the coordinated control of the hydraulic system and the engine system, ensuring that no matter how the user operates the machine or what load is encountered during the excavator heat-up process under plateau and low-temperature conditions, there will be no risk of flameout, etc.

[0146] The heat-up process of this application is divided into two stages: first, the engine is heated, then the hydraulic system is heated, and finally the whole vehicle operation is performed through the vehicle control program. Prevent damage to the engine caused by direct operation of the whole vehicle at low engine temperatures. The engine heat-up process achieves rapid heat-up through alternating speeds. The hydraulic system anti-stall strategy uses coordinated control of the engine and hydraulics, and through measures such as increasing the speed, increasing fuel injection, and accelerating fuel injection to increase the engine's main power enhancement measures, to maximize the engine's capacity and ensure that it will not stall.

[0147] The beneficial effects of the embodiments of the present application are as follows: In high altitude, low temperature and other environments, the excavator engine is first warmed up, and the engine warm-up process is achieved by alternating the speed to achieve rapid warm-up, and then the hydraulic system is warmed up to prevent damage to the engine caused by direct operation of the vehicle at low engine temperatures. The hydraulic system anti-stall strategy uses the coordinated control of the engine and the hydraulic system, and through measures such as increasing the speed, increasing the injection, and accelerating the injection of the engine's main power to maximize the engine's capacity, effectively avoiding the excavator from stalling due to sudden load increases caused by operations during the warm-up process, thereby achieving the purpose of preventing the excavator from stalling during the warm-up process.

[0148] Based on the above embodiments Figure 1 The disclosed method for preventing flameout during the heat engine process of an excavator is disclosed. The embodiment of the present application also discloses a device for preventing flameout during the heat engine process of an excavator. Figure 7As shown, the anti-stall control device of the excavator thermal engine process includes:

[0149] An acquisition unit 701 is used to acquire the current environmental pressure of the excavator;

[0150] A starting unit 702 is used to start the engine of the excavator and obtain the engine water temperature if the current environmental pressure meets the starting condition;

[0151] The first execution unit 703 is used to execute the engine heat-up process anti-stall control strategy if the water temperature meets the engine heat-up condition, so as to keep the engine speed constant at a preset speed;

[0152] The second execution unit 704 is used to execute the hydraulic system thermal engine anti-stall control strategy when receiving a hydraulic lock switch command during the process in which the engine speed is at a preset speed.

[0153] Furthermore, the starting unit 702 includes:

[0154] A first comparison module, used to compare the current environmental pressure with a set value;

[0155] A first determination module, configured to determine that the current ambient pressure meets the start condition if the current ambient pressure is less than the set value;

[0156] The starting module is used to start the excavator engine and obtain the engine water temperature when the current ambient pressure meets the starting conditions.

[0157] Furthermore, the first execution unit 703 includes:

[0158] A second comparison module is used to compare the engine water temperature with a preset water temperature;

[0159] A first execution module, configured to heat up the engine through an engine heat-up program if the engine water temperature is less than or equal to a preset water temperature;

[0160] The speed increasing module is used to increase the engine idle speed according to a preset time interval and a preset speed increase until the highest speed is reached during the engine warm-up process if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid;

[0161] The second determination module is used to determine that the engine warm-up is completed if the engine water temperature is greater than a preset water temperature during the process of the engine idle speed reaching the highest speed;

[0162] The constant module is used to keep the engine speed constant at a preset speed after the engine warm-up is completed.

[0163] Furthermore, the hydraulic system thermal engine flameout prevention control strategy includes at least an engine power boost strategy and a hydraulic loading speed reduction prevention strategy. The second execution unit 704 includes:

[0164] The second execution module is used to perform a hydraulic control system warm-up through a hydraulic system warm-up program when a hydraulic lock switch command is received during the process in which the engine speed is at a preset speed;

[0165] The third execution module is used to respectively execute the engine power enhancement strategy and the hydraulic loading anti-speed drop strategy during the hydraulic control system hot engine process to complete the process of executing the hydraulic system hot engine anti-stall control strategy.

[0166] Furthermore, the third execution module for executing the engine power enhancement strategy includes:

[0167] The first acquisition submodule is used to obtain the target torque by checking the torque curve based on the feedforward torque of the pilot pressure and different pilot pressures; wherein the target torque is the maximum value of each final torque obtained under multiple pilot pressures during the operation of the excavator;

[0168] The second acquisition submodule is used to acquire the actual rotation speed of the excavator during operation;

[0169] A first correction submodule, used to correct the actual speed by setting the speed;

[0170] The adjustment submodule is used to adjust the excavator engine through the target torque and the corrected actual speed to complete the process of executing the hydraulic system thermal engine anti-stall control strategy.

[0171] Furthermore, the third execution module for executing the hydraulic loading anti-speed drop strategy includes:

[0172] The third acquisition submodule is used to acquire the real-time air intake volume of the excavator's engine, the real-time hydraulic oil temperature of the hydraulic system, and the loading rate of the hydraulic system;

[0173] A determination submodule, used to determine an air intake correction parameter according to the real-time air intake volume, and to determine an oil temperature correction parameter according to the real-time hydraulic oil temperature;

[0174] A second correction submodule is used to correct the hydraulic loading rate in real time through an intake air volume correction parameter;

[0175] The third correction submodule is used to perform oil temperature correction on the hydraulic loading rate after the intake amount correction through the oil temperature correction parameter, so as to complete the process of the hydraulic loading anti-speed drop strategy.

[0176] Furthermore, the anti-stall control device for the excavator thermal engine process also includes:

[0177] The third execution unit is used to execute the vehicle control program if it is monitored that the water temperature of the engine is greater than a preset water temperature and the hydraulic oil temperature is greater than a preset oil temperature.

[0178] The beneficial effects of the embodiments of the present application are as follows: In high altitude, low temperature and other environments, the excavator engine is first warmed up, and the engine warm-up process is achieved by alternating the speed to achieve rapid warm-up, and then the hydraulic system is warmed up to prevent damage to the engine caused by direct operation of the vehicle at low engine temperatures. The hydraulic system anti-stall strategy uses the coordinated control of the engine and the hydraulic system, and through measures such as increasing the speed, increasing the injection, and accelerating the injection of the engine's main power to maximize the engine's capacity, effectively avoiding the excavator from stalling due to sudden load increases caused by operations during the warm-up process, thereby achieving the purpose of preventing the excavator from stalling during the warm-up process.

[0179] For the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0180] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0181] The steps in the methods of the embodiments of the present application can be adjusted in order, combined, and deleted according to actual needs.

[0182] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0183] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

[0184] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A flameout prevention control method for an excavator thermal engine process, characterized in that: The method comprises: Get the current environmental pressure of the excavator; If the current ambient pressure meets the starting condition, start the engine of the excavator and obtain the engine water temperature; If the water temperature meets the engine warm-up condition, the engine warm-up process anti-stall control strategy is executed to keep the engine speed constant at a preset speed; When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic system thermal engine anti-stall control strategy is executed.

2. The method according to claim 1, characterized in that If the current ambient pressure meets the starting condition, starting the engine of the excavator and obtaining the engine water temperature includes: Comparing the current ambient pressure with a set value; If the current ambient pressure is less than the set value, determining that the current ambient pressure meets the start condition; When the current ambient pressure meets the starting condition, the engine of the excavator is started and the engine water temperature is obtained.

3. The method according to claim 1, characterized in that: If the water temperature meets the engine warm-up condition, executing the engine warm-up process anti-stall control strategy to keep the engine speed constant at a preset speed, including: comparing the engine water temperature with a preset water temperature; If the engine water temperature is less than or equal to the preset water temperature, the engine is heated up by an engine heating program; During the engine warm-up process, if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid, the engine idle speed is increased according to the preset time interval and preset speed increase until the highest speed is reached; During the process of the engine idling speed reaching the highest speed, if the engine water temperature is greater than the preset water temperature, it is determined that the engine warm-up is completed; After the engine warm-up is completed, the engine speed is kept constant at the preset speed.

4. The method according to claim 1, characterized in that: The hydraulic system thermal engine flameout prevention control strategy at least includes an engine power boost strategy and a hydraulic loading speed reduction prevention strategy. When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic system thermal engine flameout prevention control strategy is executed, including: When the engine speed is at the preset speed, when a hydraulic lock switch command is received, the hydraulic control system is heated up through a hydraulic system heating program; During the process of the hydraulic control system warming up, the engine power boosting strategy and the hydraulic loading anti-speed drop strategy are respectively executed to complete the process of executing the hydraulic system warming up anti-stalling control strategy.

5. The method according to claim 4, characterized in that The process of implementing an engine power improvement strategy includes: The target torque is obtained by checking the torque curve based on the feedforward torque of the pilot pressure and different pilot pressures; wherein the target torque is the maximum value of each final torque obtained under multiple pilot pressures during the operation of the excavator; Get the actual speed of the excavator during operation; Correcting the actual speed by setting the speed; The engine of the excavator is adjusted by the target torque and the corrected actual speed to complete the process of executing the hydraulic system thermal engine anti-stall control strategy.

6. The method according to claim 4, characterized in that The process of implementing the hydraulic loading anti-speed drop strategy includes: Obtain the real-time air intake volume of the excavator's engine, the real-time hydraulic oil temperature of the hydraulic system, and the hydraulic loading rate of the hydraulic system; Determine an air intake correction parameter according to the real-time air intake volume, and determine an oil temperature correction parameter according to the real-time hydraulic oil temperature; The hydraulic loading rate is corrected in real time through the air intake correction parameter; The oil temperature correction parameter is used to correct the hydraulic loading rate after the intake volume is corrected, so as to complete the process of the hydraulic loading anti-speed drop strategy.

7. The method according to claim 1, characterized in that In the process that the engine speed is at the preset speed, when a hydraulic lock switch command is received, after executing the hydraulic system thermal engine anti-stall control strategy, the method further includes: If the engine water temperature is detected to be greater than the preset water temperature and the hydraulic oil temperature is greater than the preset oil temperature, the vehicle control program is executed. 8.An anti-stall control device for the thermal engine process of an excavator, characterized in that: The device comprises: An acquisition unit, used for acquiring the current environmental pressure of the excavator; A starting unit, used to start the engine of the excavator and obtain the engine water temperature if the current ambient pressure meets the starting condition; A first execution unit is used to execute an anti-stall control strategy during the engine warm-up process if the water temperature meets the engine warm-up condition, so as to keep the engine speed constant at a preset speed; The second execution unit is used to execute the hydraulic system thermal engine anti-stall control strategy when receiving a hydraulic lock switch command during the process in which the engine speed is at the preset speed.

9. The device according to claim 8, characterized in that The startup unit comprises: A first comparison module, used for comparing the current ambient pressure with a set value; A first determination module, configured to determine that the current environmental pressure meets a start condition if the current environmental pressure is less than the set value; The starting module is used to start the engine of the excavator and obtain the engine water temperature when the current ambient pressure meets the starting condition.

10. The device according to claim 8, characterized in that The first execution unit includes: A second comparison module, used for comparing the engine water temperature with a preset water temperature; A first execution module, configured to perform engine warm-up through an engine warm-up program if the engine water temperature is less than or equal to a preset water temperature; The speed increasing module is used to increase the engine idle speed according to a preset time interval and a preset speed increase until the highest speed is reached during the engine warm-up process if the speed increase command is detected to be invalid and the hydraulic lock switch is invalid; The second determination module is used to determine that the engine warm-up is completed if the engine water temperature is greater than a preset water temperature during the process of the engine idle speed reaching the highest speed; The constant module is used to keep the engine speed constant at a preset speed after the engine warm-up is completed.

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