阅读说明：本技术 柴油机预润滑油泵控制系统及采用该控制系统的控制方法 (Control system for pre-lubricating oil pump of diesel engine and control method adopting control system ) 是由 庞立民 郁施宏 陈诚 匡云 许云秋 陈献慧 于 2021-08-09 设计创作，主要内容包括：本发明涉及柴油机预润滑油技术领域,尤其是一种柴油机预润滑油泵控制系统及采用该控制系统的控制方法,系统控制器,与温度传感器、压力传感器、预润滑油泵控制器相连,系统控制器接收温度传感器反馈数据、接收压力传感器反馈数据、接收预润滑油泵控制器反馈数据并计算输出合理的预润滑油泵控制器输出频率,并控制系统的启停操作。可减少柴油机启动前滑油预润滑时间,提高预润滑的效率,保证润滑油出口压力,优化用户体验感；同时可应用于新造机车或既有机车的改造,新造机车可由机车微机承担系统控制器的功能,既有机车可以使用独立的控制器。(The invention relates to the technical field of pre-lubrication oil of diesel engines, in particular to a control system of a pre-lubrication oil pump of a diesel engine and a control method adopting the control system. The lubricating oil pre-lubrication time before the diesel engine is started can be reduced, the pre-lubrication efficiency is improved, the lubricating oil outlet pressure is ensured, and the user experience is optimized; meanwhile, the system can be applied to the reconstruction of newly-built locomotives or existing locomotives, the functions of the system controller can be borne by the microcomputer of the newly-built locomotives, and the existing locomotives can use independent controllers.)

1. A diesel engine pre-lubrication oil pump control system is characterized in that: comprises that

The temperature sensor (2) is used for detecting the temperature T of lubricating oil at the lubricating oil inlet of the diesel engine;

a pressure sensor (3) for detecting the pressure P of the lubricating oil at the lubricating oil inlet of the diesel engine;

a pre-lubrication pump (5) for establishing a pressure-driven lubrication oil flow;

the pre-lubricating oil pump controller (4) is connected with the pre-lubricating oil pump (5) and is used for driving the pre-lubricating oil pump (5) to rotate;

the system controller (1) is connected with the temperature sensor (2), the pressure sensor (3) and the pre-lubricating oil pump controller (4), receives feedback data of the temperature sensor (2), feedback data of the pressure sensor (3) and feedback data of the pre-lubricating oil pump controller (4), calculates and outputs reasonable output frequency of the pre-lubricating oil pump controller (4), and controls start and stop operation of the system.

2. A diesel engine prelubricated oil pump control system as defined in claim 1, wherein: the pre-lubricating oil pump (5) is formed by connecting a direct current brushless motor and an oil pump part.

3. A control method for a pre-lubricating oil pump of a diesel engine is characterized by comprising the following steps: the control system of the pre-lubrication oil pump of the diesel engine as claimed in claims 1-2, the control system collects the temperature T of the inlet of the lubricating oil of the diesel engine, collects the pressure P of the inlet of the lubricating oil of the diesel engine, collects the output current I of the controller of the pre-lubrication oil pump, collects the output frequency f of the controller of the pre-lubrication oil pump, calculates the accumulated pre-lubrication time T, calculates the initial pre-lubrication time T0, calculates the minimum pre-lubrication pressure Pmin, the maximum pre-lubrication pressure Pmax, the maximum pre-lubrication time tmax, the maximum output current Imax of the controller of the pre-lubrication oil pump of the diesel engine and the maximum output frequency fmax of the controller of the pre-lubrication oil pump of the diesel engine, and comprehensively judges the starting, stopping and controlling the output frequency of the pre-lubrication oil pump according to the collected T, P, I, f and the like, thereby completing the pre-lubrication before the starting of the diesel engine.

4. A control method of a pre-lube pump of a diesel engine as set forth in claim 3, characterized in that: the system is communicated with an upper computer through a network or a switching value signal to obtain a command of starting or stopping the pre-lubricating oil pump (5), and the system comprises the following steps after receiving the starting command:

step S1: calculating pre-lubrication time t0, and the system enters a pre-lubrication time calculation step S100;

step S2: comparing t0 with 0, when t0 > 0, entering step S3, and when t0 is less than or equal to 0, entering step S15;

step S3: calculating minimum pre-lubrication pressure Pmin, and entering a pre-lubrication pressure calculation step S300 by the system;

step S4: comparing the minimum pre-lubrication pressure Pmin with 0, and when the minimum pre-lubrication pressure Pmin is more than 0, entering step S5, and when the minimum pre-lubrication pressure Pmin is less than or equal to 0, entering step S15;

step S5: starting a pre-lubricating oil pump controller (4), driving a pre-lubricating oil pump (5) to work at the lowest frequency, and entering step S6;

step S6: comparing the output current I of the pre-lubricating oil pump controller with the maximum output current Imax of the pre-lubricating controller of the diesel engine; when I is greater than Imax, the process proceeds to step S10, and when I is less than or equal to Imax, the process proceeds to step S7;

step S7: comparing the diesel engine lubricating oil inlet pressure P with the calculated pre-lubrication minimum pressure Pmax, when P is larger than Pmax, entering step S10, and when P is smaller than or equal to Pmax, entering step S8;

step S8: comparing the output frequency f of the pre-lubrication oil pump controller with the maximum output frequency fmax of the pre-lubrication oil pump controller of the diesel engine, and when f is greater than fmax, entering step S10, and when f is less than or equal to fmax, entering step S9;

step S9: increasing the output frequency f of the controller of the pre-lubricating oil pump according to a certain step length, and entering the step S11;

step S10: the output frequency f of the pre-lubricating oil pump controller is reduced according to a certain step length, and the process goes to step S11;

step S11: comparing and calculating the current accumulated pre-lubrication time t with the calculated pre-lubrication initial time t0, and when t is less than or equal to t0, entering step S6, and when t is more than t0, entering step S12;

step S12: comparing the diesel engine lubricating oil inlet pressure P with the maximum pre-lubrication pressure Pmin, and when P is larger than Pmin, entering step S14, and when P is smaller than or equal to Pmin, entering step S13;

step S13: comparing and calculating the accumulated pre-lubrication time t and the maximum pre-lubrication time tmax, and when t is less than tmax, entering step S6, and when t is more than or equal to tmax, entering step S15;

step S14: and (4) feeding back a success signal of the pre-lubrication to the upper computer, and entering the step S16.

Step S15: feeding back a failure signal of the upper computer after the pre-lubrication fails, and entering step S16;

step S16: and finishing the pre-lubrication and finishing the process.

5. A control method of a pre-lube pump of a diesel engine as set forth in claim 4, characterized in that: the pre-lubrication time t0 comprises the following calculation steps:

step S101: comparing the temperature T of the diesel engine lubricating oil inlet with T1, entering step S102 when T is more than or equal to T1, and entering step S103 when T is less than T1, wherein T1 is a preset temperature value 1;

step S102: calculating pre-lubrication initial time t0, wherein t0 is t1, and entering step S108, and t1 is set to be 1 for the pre-lubrication time;

step S103: comparing the temperature T of the diesel engine lubricating oil inlet with T2, entering step S104 when T is more than or equal to T2, and entering step S105 when T is less than T2, wherein T2 is a preset temperature value 2;

step S104: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S108, where T2 is pre-lubrication time setting 2;

step S105: comparing T with T3, when T is not less than T3, entering step S106, when T is less than T3, entering step S107, and T3 is a preset temperature value of 3;

step S106: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S108, where T3 is set to pre-lubrication time 3;

step S107: calculating t0, if t0 is 0, the process proceeds to step S108;

step S108: the sub-process is finished and returns to the inlet of the main process.

6. A control method of a pre-lube pump of a diesel engine as set forth in claim 4, characterized in that: the minimum lubrication pressure Pmin comprises the following calculation steps:

step S301: comparing the temperature T of the inlet of the diesel engine lubricating oil with T1, entering step S302 when T is more than or equal to T1, and entering step S303 when T is less than T1, wherein T1 is a preset temperature value 1;

step S302: calculating t0, and when t0 is t1, the process advances to step S308, and t1 is set to 1 for the pre-lubrication time;

step S303: comparing T with T2, when T is not less than T2, entering step S304, when T is less than T2, entering step S305, and T2 is a preset temperature value 2;

step S304: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S308, where T2 is pre-lubrication time setting 2;

step S305: comparing T with T3, when T is not less than T3, entering step S306, when T is less than T3, entering step S307, and T3 is a preset temperature value of 3;

step S306: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S308, where T3 is set to pre-lubrication time 3;

step S307: calculating t0, and if t0 is 0, the process proceeds to step S308;

step S308: the sub-process is finished and returns to the inlet of the main process.

Technical Field

The invention relates to the technical field of pre-lubrication oil of diesel engines, in particular to a control system of a pre-lubrication oil pump of a diesel engine and a control method adopting the control system.

Background

Most of the existing domestic diesel locomotives are medium and low speed diesel engines, and a pre-lubricating process is required before starting. The current mainstream method is to drive a pre-lubrication oil pump by a motor with fixed rotating speed, and start a diesel engine after a certain pre-lubrication time. The method has the disadvantages that the fixed motor rotating speed causes the pressure at the outlet of the lubricating oil pump to be too high under the condition of low temperature of the lubricating oil, the pressure at the outlet of the lubricating oil pump to be too low under the condition of high temperature of the lubricating oil, and meanwhile, the difference that the lubricating oil completes the effective pre-lubrication for the longest time under different pressures and temperatures is not considered, so that the pre-lubrication time for starting the diesel engine is too long, and the user experience is influenced.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the control system for the pre-lubricating oil pump of the diesel engine and the control method adopting the control system are provided, wherein the pre-lubricating oil pump control system can reduce the pre-lubricating time of lubricating oil before the diesel engine is started and improve the pre-lubricating efficiency.

The technical scheme adopted by the invention for solving the technical problems is as follows: a diesel engine pre-lubricating oil pump control system comprises a temperature sensor, a controller and a controller, wherein the temperature sensor is used for detecting the temperature T of lubricating oil at a lubricating oil inlet of a diesel engine; the pressure sensor is used for detecting the pressure P of lubricating oil at the lubricating oil inlet of the diesel engine; a pre-lube pump for establishing a pressure driven lube flow; the pre-lubricating oil pump controller is connected with the pre-lubricating oil pump and used for driving the pre-lubricating oil pump to rotate;

and the system controller is connected with the temperature sensor, the pressure sensor and the pre-lubricating oil pump controller, receives feedback data of the temperature sensor, feedback data of the pressure sensor and feedback data of the pre-lubricating oil pump controller, calculates and outputs reasonable output frequency of the pre-lubricating oil pump controller, and controls the start-stop operation of the system.

Furthermore, the pre-lubricating oil pump is formed by connecting a direct-current brushless motor and an oil pump part.

A control method of a pre-lubrication oil pump of a diesel engine comprises the steps of collecting temperature T of a lubricating oil inlet of the diesel engine, collecting pressure P of the lubricating oil inlet of the diesel engine, collecting output current I of a controller of the pre-lubrication oil pump, collecting output frequency f of the controller of the pre-lubrication oil pump, calculating accumulated pre-lubrication time T, calculating initial pre-lubrication time T0, calculating minimum pre-lubrication pressure Pmin, maximum pre-lubrication pressure Pmax, maximum pre-lubrication time tmax, maximum output current Imax of the controller of the diesel engine and maximum output frequency fmax of the controller of the diesel engine through the control system, comprehensively judging the starting, stopping and controlling the output frequency of the pre-lubrication oil pump according to collected T, P, I, f and the like, and finishing pre-lubrication before the diesel engine is started.

Further, the system communicates with an upper computer through a network or a switching value signal to obtain a command of starting or stopping the pre-lubricating oil pump, and the system comprises the following steps after receiving the starting command:

step S1: calculating pre-lubrication time t0, and the system enters a pre-lubrication time calculation step S100; the method mainly aims to calculate a pre-lubrication time value t0 before starting the engine according to the current temperature of the lubricating oil inlet of the diesel engine;

step S2: comparing t0 with 0, when t0 > 0, entering step S3, and when t0 is less than or equal to 0, entering step S15;

step S3: calculating minimum pre-lubrication pressure Pmin, and entering a pre-lubrication pressure calculation step S300 by the system; the main purpose of the step is to calculate the minimum value Pmin of the target pressure for starting the pre-lubrication of the diesel engine according to the current temperature of the inlet of the diesel engine lubricating oil.

Step S4: comparing the minimum pre-lubrication pressure Pmin with 0, and when the minimum pre-lubrication pressure Pmin is more than 0, entering step S5, and when the minimum pre-lubrication pressure Pmin is less than or equal to 0, entering step S15;

step S5: starting a controller of the pre-lubricating oil pump, driving the pre-lubricating oil pump to work at the lowest frequency, and entering step S6;

step S6: comparing the output current I of the pre-lubricating oil pump controller with the maximum output current Imax of the pre-lubricating controller of the diesel engine; when I is greater than Imax, the process proceeds to step S10, and when I is less than or equal to Imax, the process proceeds to step S7;

step S7: comparing the diesel engine lubricating oil inlet pressure P with the calculated pre-lubrication minimum pressure Pmax, when P is larger than Pmax, entering step S10, and when P is smaller than or equal to Pmax, entering step S8;

step S8: comparing the output frequency f of the pre-lubrication oil pump controller with the maximum output frequency fmax of the pre-lubrication oil pump controller of the diesel engine, and when f is greater than fmax, entering step S10, and when f is less than or equal to fmax, entering step S9;

step S9: increasing the output frequency f of the controller of the pre-lubricating oil pump according to a certain step length, and entering the step S11;

step S10: the output frequency f of the pre-lubricating oil pump controller is reduced according to a certain step length, and the process goes to step S11;

step S11: comparing and calculating the current accumulated pre-lubrication time t with the calculated pre-lubrication initial time t0, and when t is less than or equal to t0, entering step S6, and when t is more than t0, entering step S12;

step S12: comparing the diesel engine lubricating oil inlet pressure P with the maximum pre-lubrication pressure Pmin, and when P is larger than Pmin, entering step S14, and when P is smaller than or equal to Pmin, entering step S13;

step S13: comparing and calculating the accumulated pre-lubrication time t and the maximum pre-lubrication time tmax, and when t is less than tmax, entering step S6, and when t is more than or equal to tmax, entering step S15;

step S14: and (4) feeding back a success signal of the pre-lubrication to the upper computer, and entering the step S16.

Step S15: feeding back a failure signal of the upper computer after the pre-lubrication fails, and entering step S16;

step S16: and finishing the pre-lubrication and finishing the process.

Further, the pre-lubrication time t0 includes the following steps:

step S101: comparing the temperature T of the diesel engine lubricating oil inlet with T1, entering step S102 when T is more than or equal to T1, and entering step S103 when T is less than T1, wherein T1 is a preset temperature value 1;

step S102: calculating pre-lubrication initial time t0, wherein t0 is t1, and entering step S108, and t1 is set to be 1 for the pre-lubrication time;

step S103: comparing the temperature T of the diesel engine lubricating oil inlet with T2, entering step S104 when T is more than or equal to T2, and entering step S105 when T is less than T2, wherein T2 is a preset temperature value 2;

step S104: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S108, where T2 is pre-lubrication time setting 2;

step S105: comparing T with T3, when T is not less than T3, entering step S106, when T is less than T3, entering step S107, and T3 is a preset temperature value of 3;

step S106: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S108, where T3 is set to pre-lubrication time 3;

step S107: calculating t0, if t0 is 0, the process proceeds to step S108;

step S108: the sub-process is finished and returns to the inlet of the main process.

Further, the minimum lubrication pressure Pmin includes the following calculation steps:

step S301: comparing the temperature T of the inlet of the diesel engine lubricating oil with T1, entering step S302 when T is more than or equal to T1, and entering step S303 when T is less than T1, wherein T1 is a preset temperature value 1;

step S302: calculating t0, and when t0 is t1, the process advances to step S308, and t1 is set to 1 for the pre-lubrication time;

step S303: comparing T with T2, when T is not less than T2, entering step S304, when T is less than T2, entering step S305, and T2 is a preset temperature value 2;

step S304: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S308, where T2 is pre-lubrication time setting 2;

step S305: comparing T with T3, when T is not less than T3, entering step S306, when T is less than T3, entering step S307, and T3 is a preset temperature value of 3;

step S306: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S308, where T3 is set to pre-lubrication time 3;

step S307: calculating t0, and if t0 is 0, the process proceeds to step S308;

step S308: the sub-process is finished and returns to the inlet of the main process.

The invention has the advantages that the defects in the background technology are overcome, the lubricating oil pre-lubrication time before the diesel engine is started can be reduced, the pre-lubrication efficiency is improved, the lubricating oil outlet pressure is ensured, and the user experience is optimized; meanwhile, the system can be applied to the reconstruction of newly-built locomotives or existing locomotives, the functions of the system controller can be borne by the microcomputer of the newly-built locomotives, and the existing locomotives can use independent controllers.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a flow chart of a diesel engine prelubricated oil pump control system in accordance with the present invention;

FIG. 2 is a flow chart of a method of controlling a pre-lube pump of a diesel engine according to the present invention;

fig. 3 is a flowchart for calculating the pre-lubrication time t0 in the method for controlling the pre-lubrication oil pump of the diesel engine according to the invention;

fig. 4 is a flowchart for calculating the minimum lubrication pressure Pmin in the method for controlling the pre-lubrication pump of the diesel engine according to the present invention.

In the figure: 1. the system comprises a system controller, 2, a temperature sensor, 3, a pressure sensor, 4, a pre-lubricating oil pump controller and 5, a pre-lubricating oil pump.

Detailed Description

The invention will now be described in further detail with reference to the drawings and preferred embodiments. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

A pre-lube pump control system for diesel engines as shown in fig. 1, comprising a temperature sensor 2 for detecting the lube oil temperature T at the lube oil inlet of the diesel engine; the pressure sensor 3 is used for detecting the pressure P of lubricating oil at a lubricating oil inlet of the diesel engine; a pre-lubrication pump 5 for establishing a pressure-driven lubrication oil flow; the pre-lubricating oil pump controller 4 is connected with the pre-lubricating oil pump 5 and is used for driving the pre-lubricating oil pump 5 to rotate;

the system controller 1 is connected with the temperature sensor 2, the pressure sensor 3 and the pre-lubricating oil pump controller 4, the system controller 1 receives feedback data of the temperature sensor 2, feedback data of the pressure sensor 3 and feedback data of the pre-lubricating oil pump controller 4, calculates and outputs reasonable output frequency of the pre-lubricating oil pump controller 4, and controls starting and stopping operation of the system.

Wherein, the pre-lubricating oil pump 5 is formed by connecting a direct current brushless motor and an oil pump part.

As shown in fig. 2, a method for controlling a pre-lubrication oil pump of a diesel engine includes a control system of the pre-lubrication oil pump of the diesel engine, collecting a temperature T of an oil inlet of the diesel engine, collecting a pressure P of the oil inlet of the diesel engine, collecting an output current I of the controller of the pre-lubrication oil pump, collecting an output frequency f of the controller of the pre-lubrication oil pump, calculating an accumulated pre-lubrication time T of this time, calculating an initial pre-lubrication time T0, calculating a minimum pre-lubrication pressure Pmin, a maximum pre-lubrication pressure Pmax, a maximum pre-lubrication time tmax of the diesel engine, a maximum output current Imax of the controller of the pre-lubrication oil pump, and a maximum output frequency fmax of the controller of the diesel engine, wherein the system comprehensively judges the start, stop and control the output frequency of the pre-lubrication oil pump according to the collected T, P, I, f and the like, and completes the pre-lubrication before the start of the diesel engine.

The system obtains a command of starting or stopping the pre-lubricating oil pump 5 through communication between a network or a switching value signal and an upper computer, and the system comprises the following steps after receiving the starting command:

step S1: calculating pre-lubrication time t0, and the system enters a pre-lubrication time calculation step S100; the method mainly aims to calculate a pre-lubrication time value t0 before starting the engine according to the current temperature of the lubricating oil inlet of the diesel engine;

step S2: comparing t0 with 0, when t0 > 0, entering step S3, and when t0 is less than or equal to 0, entering step S15;

step S3: calculating minimum pre-lubrication pressure Pmin, and entering a pre-lubrication pressure calculation step S300 by the system; the main purpose of the step is to calculate the minimum value Pmin of the target pressure for starting the pre-lubrication of the diesel engine according to the current temperature of the inlet of the diesel engine lubricating oil.

Step S4: comparing the minimum pre-lubrication pressure Pmin with 0, and when the minimum pre-lubrication pressure Pmin is more than 0, entering step S5, and when the minimum pre-lubrication pressure Pmin is less than or equal to 0, entering step S15;

step S5: starting the pre-lubricating oil pump controller 4, driving the pre-lubricating oil pump 5 to work at the lowest frequency, and entering step S6;

step S6: comparing the output current I of the pre-lubricating oil pump controller with the maximum output current Imax of the pre-lubricating controller of the diesel engine; when I is greater than Imax, the process proceeds to step S10, and when I is less than or equal to Imax, the process proceeds to step S7;

step S7: comparing the diesel engine lubricating oil inlet pressure P with the calculated pre-lubrication minimum pressure Pmax, when P is larger than Pmax, entering step S10, and when P is smaller than or equal to Pmax, entering step S8;

step S8: comparing the output frequency f of the pre-lubrication oil pump controller with the maximum output frequency fmax of the pre-lubrication oil pump controller of the diesel engine, and when f is greater than fmax, entering step S10, and when f is less than or equal to fmax, entering step S9;

step S9: increasing the output frequency f of the controller of the pre-lubricating oil pump according to a certain step length, and entering the step S11;

step S10: the output frequency f of the pre-lubricating oil pump controller is reduced according to a certain step length, and the process goes to step S11;

step S11: comparing and calculating the current accumulated pre-lubrication time t with the calculated pre-lubrication initial time t0, and when t is less than or equal to t0, entering step S6, and when t is more than t0, entering step S12;

step S12: comparing the diesel engine lubricating oil inlet pressure P with the maximum pre-lubrication pressure Pmin, and when P is larger than Pmin, entering step S14, and when P is smaller than or equal to Pmin, entering step S13;

step S13: comparing and calculating the accumulated pre-lubrication time t and the maximum pre-lubrication time tmax, and when t is less than tmax, entering step S6, and when t is more than or equal to tmax, entering step S15;

step S14: and (4) feeding back a success signal of the pre-lubrication to the upper computer, and entering the step S16.

Step S15: feeding back a failure signal of the upper computer after the pre-lubrication fails, and entering step S16;

step S16: and finishing the pre-lubrication and finishing the process.

As shown in fig. 3, the pre-lubrication time t0 includes the following steps:

step S101: comparing the temperature T of the diesel engine lubricating oil inlet with T1, entering step S102 when T is more than or equal to T1, and entering step S103 when T is less than T1, wherein T1 is a preset temperature value 1;

step S102: calculating pre-lubrication initial time t0, wherein t0 is t1, and entering step S108, and t1 is set to be 1 for the pre-lubrication time;

step S103: comparing the temperature T of the diesel engine lubricating oil inlet with T2, entering step S104 when T is more than or equal to T2, and entering step S105 when T is less than T2, wherein T2 is a preset temperature value 2;

step S104: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S108, where T2 is pre-lubrication time setting 2;

step S105: comparing T with T3, when T is not less than T3, entering step S106, when T is less than T3, entering step S107, and T3 is a preset temperature value of 3;

step S106: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S108, where T3 is set to pre-lubrication time 3;

step S107: calculating t0, if t0 is 0, the process proceeds to step S108;

step S108: the sub-process is finished and returns to the inlet of the main process.

As shown in fig. 4, the minimum lubrication pressure Pmin includes the following calculation steps:

step S301: comparing T with T1, when T is not less than T1, entering step S302, when T is less than T1, entering step S303, and T1 is a preset temperature value 1;

step S302: calculating t0, and when t0 is t1, the process advances to step S308, and t1 is set to 1 for the pre-lubrication time;

step S303: comparing T with T2, when T is not less than T2, entering step S304, when T is less than T2, entering step S305, and T2 is a preset temperature value 2;

step S304: calculating T0, T0 ═ T1+ (T2-T1) × (T-T2)/(T1-T2), and proceeding to step S308, where T2 is pre-lubrication time setting 2;

step S305: comparing T with T3, when T is not less than T3, entering step S306, when T is less than T3, entering step S307, and T3 is a preset temperature value of 3;

step S306: calculating T0, T0 ═ T2+ (T3-T2) × (T-T3)/(T2-T3), and proceeding to step S308, where T3 is set to pre-lubrication time 3;

step S307: calculating t0, and if t0 is 0, the process proceeds to step S308;

step S308: the sub-process is finished and returns to the inlet of the main process.

While particular embodiments of the present invention have been described in the foregoing specification, various modifications and alterations to the previously described embodiments will become apparent to those skilled in the art from this description without departing from the spirit and scope of the invention.