阅读说明：本技术 一种车辆供油系统预建压方法、系统及车辆 (Pre-pressure building method and system for vehicle oil supply system and vehicle ) 是由 梅光灿 于 2021-08-19 设计创作，主要内容包括：一种车辆供油系统预建压方法、系统及车辆,包括获取车辆状态信息；根据车辆状态信息判断发动机是否处于预启动状态,以及供油系统内初始燃油压力是否小于目标燃油压力；当发动机处于预启动状态且初始燃油压力小于目标燃油压力时,对车辆供油系统进行预建压,提高初始燃油压力至目标燃油压力。可保证泄压阀设定值始终大于油泵燃油压力,避免油泵内的燃料急剧释放压力和流动而产生较大的噪音,有效改善车辆的NVH性能。(A pre-pressure building method and system for a vehicle oil supply system and a vehicle comprise the steps of obtaining vehicle state information; judging whether the engine is in a pre-starting state or not and whether the initial fuel pressure in the oil supply system is smaller than the target fuel pressure or not according to the vehicle state information; when the engine is in a pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, pre-building pressure on a vehicle oil supply system, and increasing the initial fuel pressure to the target fuel pressure. The set value of the pressure relief valve can be guaranteed to be always larger than the fuel pressure of the oil pump, the fuel in the oil pump is prevented from releasing pressure and flowing rapidly to generate large noise, and the NVH performance of a vehicle is effectively improved.)

1. A pre-pressure building method of a vehicle oil supply system is characterized by comprising the following steps: comprises that

S1: acquiring vehicle state information;

s2: judging whether the engine is in a pre-starting state or not and whether the initial fuel pressure in the oil supply system is smaller than the target fuel pressure or not according to the vehicle state information;

s3: when the engine is in the pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, pre-building pressure on a vehicle oil supply system, and increasing the initial fuel pressure to the target fuel pressure;

the target fuel pressure is greater than an engine start minimum pressure demand and less than an engine start maximum pressure demand, and the pressure relief valve pressure set value is greater than the engine start maximum pressure demand.

2. The vehicle oil supply system pre-pressurization method as claimed in claim 1, wherein: the pressure set value of the pressure relief valve is 15-18% larger than the maximum pressure requirement value for starting the engine.

3. The vehicle oil supply system pre-pressurization method as claimed in claim 1, wherein: the target fuel pressure value is 300 kPa-600 kPa.

4. The vehicle oil supply system pre-pressurization method as claimed in claim 1, wherein: the pre-pressurization method for the vehicle oil supply system further comprises the following steps: and determining an optimal duty ratio according to the initial fuel pressure, and controlling the working voltage of the oil pump according to the optimal duty ratio so as to pre-build the pressure of the oil supply system.

5. The vehicle oil supply system pre-pressurization method as set forth in claim 4, wherein: the optimal duty cycle is 18% -86%.

6. The vehicle oil supply system pre-pressurization method as claimed in claim 1, wherein: the pre-pressurization method for the vehicle oil supply system further comprises the following steps:

counting the single pre-pressure building time used by the single pre-pressure building to judge whether the time is greater than the set value of the longest working time of the allowed pre-pressure building;

and when the single pre-pressure-building time is greater than the set value of the longest working time of the allowable pre-pressure-building, the vehicle oil supply system finishes the pre-pressure-building.

7. The vehicle oil supply system pre-pressurization method as set forth in claim 6, wherein: the maximum working time set value of the allowed pre-build-up voltage is 3-5 seconds.

8. The vehicle oil supply system pre-pressurization method as set forth in claim 6, wherein: the pre-pressurization method for the vehicle oil supply system further comprises the following steps:

when the single pre-pressure building time is larger than the set value of the longest working time of the allowable pre-pressure building and the pre-pressure building is finished, counting the working times of the fuel pump due to the pre-pressure building;

and when the working times of the fuel pump are less than the set value of the maximum working times of the fuel pump, the vehicle fuel supply system carries out pre-pressure build again.

9. The vehicle oil supply system pre-pressurization method as set forth in claim 7, wherein: the maximum working times of the fuel pump are 3-5 times.

10. A pre-pressure-building system of a vehicle oil supply system, which comprises the steps of pre-building pressure on the oil supply system by adopting the pre-pressure-building method of the vehicle oil supply system according to any one of claims 1 to 9, wherein the pre-pressure-building system of the vehicle oil supply system comprises an engine control unit, a fuel pump assembly and a pressure sensor, the fuel pump control unit is respectively connected with the engine control unit and the fuel pump assembly, the engine control unit controls the fuel pump assembly by controlling the fuel pump control unit, and the pressure sensor is used for acquiring the fuel pressure in real time and sending the acquired fuel pressure to the engine control unit; when the engine control unit judges that the engine is in a pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, the engine control unit sends a pre-pressure-building signal to the fuel pump control unit, and the fuel pump control unit controls the fuel pump assembly to pre-build pressure and improve the fuel pressure; and when the fuel pressure is greater than the target fuel pressure, the engine control unit controls the fuel pump assembly to finish pre-pressure building through the fuel pump control unit.

11. A vehicle, characterized in that: the vehicle adopts the pre-pressure-building method of the vehicle oil supply system of any one of claims 1 to 9 to pre-build pressure of the oil supply system.

Technical Field

The invention relates to the field of vehicle oil supply systems, in particular to a pre-pressure building method and system for a vehicle oil supply system and a vehicle.

Background

At present, a low-pressure oil supply System is a main power supply System of an Engine and a part of hybrid electric vehicles, and since whether the fuel pressure of an oil pump of the low-pressure oil supply System reaches a target fuel pressure at the starting stage of the Engine determines whether the whole vehicle can be normally started, pre-pressurization needs to be carried out ON the vehicle oil supply System when an Engine Management System (EMS) of the vehicle is awakened or a power supply mode is switched from OFF to ON.

In the conventional pre-pressure building method of the vehicle oil supply system, when an EMS is awakened or a power supply mode is switched from OFF to ON, a fuel pump is electrified for working for a fixed time so as to build the pressure of the oil supply system. In order to ensure the safe starting of the vehicle, a pressure relief valve is arranged on the fuel pump, but the fuel pressure of the fuel pump in the fuel supply system before pressure is pre-built is different due to the influence of the ambient temperature of parts in the system and the parking time, after the fuel supply system of the vehicle adopts the pre-built pressure for a fixed time, the fuel pressure of the fuel pump possibly exceeds the pressure set value of the pressure relief valve, and the pressure relief valve of the fuel pump releases the pressure. Due to rapid release and flow of fuel, relatively large Noise is generated in a vehicle oil supply system, NVH (Noise, Vibration and Harshness) performance of a vehicle is reduced, and meanwhile, the Noise is transmitted to a passenger cabin through air and a vehicle body structure and is sensed by passengers, so that vehicle user experience is influenced.

Disclosure of Invention

The invention provides a pre-pressure building method of a vehicle oil supply system, which comprises the following steps

S1: acquiring vehicle state information;

s2: judging whether the engine is in a pre-starting state or not and whether the initial fuel pressure in the oil supply system is smaller than the target fuel pressure or not according to the vehicle state information;

s3: when the engine is in the pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, pre-building pressure on a vehicle oil supply system, and increasing the initial fuel pressure to the target fuel pressure;

the target fuel pressure is greater than an engine start minimum pressure demand and less than an engine start maximum pressure demand, and the pressure relief valve pressure set value is greater than the engine start maximum pressure demand.

Further, the pressure set value of the pressure relief valve is 15% -18% of the maximum pressure requirement for starting the engine.

Further, the target fuel pressure value is 300 kPa-600 kPa.

Further, the pre-pressurization method for the vehicle oil supply system further comprises the following steps: and determining an optimal duty ratio according to the initial fuel pressure, and controlling the working voltage of the oil pump according to the optimal duty ratio so as to pre-build the pressure of the oil supply system.

Further, the optimal duty cycle is 18% -86%.

Further, the pre-pressurization method for the vehicle oil supply system further comprises the following steps:

counting the single pre-pressure building time used by the single pre-pressure building to judge whether the time is greater than the set value of the longest working time of the allowed pre-pressure building;

and when the single pre-pressure-building time is greater than the set value of the longest working time of the allowable pre-pressure-building, the vehicle oil supply system finishes the pre-pressure-building.

Further, the maximum working time set value of the allowable pre-build-up pressure is 3-5 seconds.

Further, the pre-pressurization method for the vehicle oil supply system further comprises the following steps:

when the single pre-pressure building time is larger than the set value of the longest working time of the allowable pre-pressure building and the pre-pressure building is finished, counting the working times of the fuel pump due to the pre-pressure building;

and when the working times of the fuel pump are less than the set value of the maximum working times of the fuel pump, the vehicle fuel supply system carries out pre-pressure build again.

Further, the maximum working time of the fuel pump is 3-5 times.

In summary, in the invention, the target fuel pressure is greater than the minimum pressure requirement for starting the engine and less than the maximum pressure requirement for starting the engine, and the pressure setting value of the pressure relief valve is greater than the maximum pressure requirement for starting the engine, so that it can be ensured that the initial fuel pressure value of the oil supply system is still less than the pressure setting value of the pressure relief valve after the pre-build pressure of the vehicle is completed and the engine is started, and the pressure relief valve does not perform pressure relief work, that is, the fuel in the oil pump is not rapidly released in pressure and flows to generate large noise due to pressure relief, thereby improving the riding comfort of passengers and effectively improving the NVH performance of the vehicle. By setting a proper duty ratio, a maximum working time set value of allowed pre-pressure build-up and a maximum working time set value of the fuel pump, the vehicle fuel supply system can be ensured to quickly complete the pre-pressure build-up and the failure risk of the fuel pump can be effectively reduced.

The embodiment of the invention also provides a pre-pressure-building system of a vehicle oil supply system, which comprises an engine control unit, a fuel pump assembly and a pressure sensor, wherein the engine control unit is respectively connected with the engine control unit and the fuel pump assembly, the engine control unit controls the fuel pump assembly by controlling the fuel pump control unit, and the pressure sensor is used for acquiring the fuel pressure in real time and sending the acquired fuel pressure to the engine control unit; when the engine control unit judges that the engine is in a pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, the engine control unit sends a pre-pressure-building signal to the fuel pump control unit, and the fuel pump control unit controls the fuel pump assembly to pre-build pressure and improve the fuel pressure; and when the fuel pressure is greater than the target fuel pressure, the engine control unit controls the fuel pump assembly to finish pre-pressure building through the fuel pump control unit.

The invention further provides a vehicle, and the vehicle adopts the vehicle oil supply system pre-pressure-building method to pre-build pressure of the oil supply system.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a logic control diagram illustrating a pre-pressurization method for a vehicle oil supply system according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a pre-pressurization system of a vehicle oil supply system in another embodiment.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined objects, the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.

The invention provides a pre-pressure-building method and a system for a vehicle oil supply system and a vehicle, wherein the pre-pressure-building method for the vehicle oil supply system can ensure that the pressure value of oil pump fuel oil of the oil supply system is still smaller than the pressure set value of a pressure relief valve after the pre-pressure-building of the vehicle is finished and an engine is started, the pressure relief valve does not perform pressure relief work, namely, the pressure relief does not enable fuel in the oil pump to release pressure and flow rapidly to generate large noise, so that the riding comfort of passengers is improved, and the NVH performance of the vehicle is effectively improved.

Fig. 1 is a logic control diagram illustrating a pre-pressurization method for a vehicle oil supply system according to an embodiment of the present invention, and as shown in fig. 1, the pre-pressurization method for the vehicle oil supply system according to the embodiment of the present invention includes:

s1: acquiring vehicle state information;

s2: judging whether the engine is in a pre-starting state or not and whether the initial fuel pressure in the oil supply system is smaller than the target fuel pressure or not according to the vehicle state information;

s3: when the engine is in a pre-starting state and the initial fuel pressure is smaller than the target fuel pressure, pre-building pressure on a vehicle oil supply system, and increasing the initial fuel pressure to the target fuel pressure.

In the embodiment, when the engine is not in the pre-starting state, the vehicle oil supply system does not perform pre-pressure build-up; when the engine is in a pre-starting state, but the initial fuel pressure is greater than the target fuel pressure, the engine can be started normally, and the vehicle oil supply system does not build pressure in advance; and only when the engine is in a pre-starting state and the initial fuel pressure is less than the target fuel pressure, pre-building pressure of the vehicle fuel supply system to improve the initial fuel pressure, and finishing the pre-building pressure of the vehicle fuel supply system when the initial fuel pressure reaches the target fuel pressure in the pressure building process. Specifically, the Engine pre-start state may include a case where a vehicle EMS (Engine Management System) is awakened or a power mode is switched from OFF to ON.

Preferably, the target fuel pressure is greater than the engine start minimum pressure demand and less than the engine start maximum pressure demand. And the pressure set value of the pressure relief valve is 15-18% of the maximum pressure requirement value for starting the engine. That is, in the present embodiment, the engine start minimum pressure demand, the target fuel pressure, the engine start maximum pressure demand, and the relief valve pressure set value are set to be increased in this order.

Further, the target fuel pressure value is 300kPa to 600 kPa. In one embodiment the target fuel pressure value for the fuel supply system is 450kPa, the minimum engine start pressure requirement is 300kPa, the maximum engine start pressure requirement is 600kPa and the pressure set for the pressure relief valve is 700 kPa. Different engine models and different target fuel pressure values of the oil supply system, and for the same engine model, if the target fuel pressure value of the oil supply system is too large, the power consumption of the engine is correspondingly increased.

The target fuel pressure is greater than the minimum pressure requirement for starting the engine and less than the maximum pressure requirement for starting the engine, the pressure setting value of the pressure release valve is greater than the maximum pressure requirement for starting the engine, the pressure of the fuel supply system is still less than the pressure setting value of the pressure release valve after the pre-pressure build-up of the vehicle is completed and the engine is started, the pressure release valve does not perform pressure release work, namely, the pressure release causes the fuel in the oil pump to release pressure and flow rapidly to generate large noise, so that the riding comfort of passengers is improved, and the NVH performance of the vehicle is effectively improved.

Further, the method further comprises: and determining the optimal duty ratio according to the initial fuel pressure, and controlling the working voltage of the oil pump according to the optimal duty ratio so as to pre-build the pressure of the oil supply system. The duty ratio is the ratio of the period time occupied by the high level to the whole period time in one pulse cycle. The relationship between the initial fuel pressure and the optimum duty ratio may be preset and may be in a reverse correlation relationship, i.e., the smaller the initial fuel pressure, the larger the optimum duty ratio so that the fuel pressure rises faster. The optimal duty cycle in this embodiment is 18% to 86%. In another embodiment, the optimal duty cycle is 40% and the target fuel pressure is 300 kPa; in yet another embodiment, the optimal duty cycle is 60% and the target fuel pressure is 450 kPa; in yet another embodiment, the optimal duty cycle is 80% and the target fuel pressure is 600 kPa.

When the actual duty ratio is higher than the optimal duty ratio, the operating voltage of the oil pump is too large, and the fuel pressure easily exceeds the target fuel pressure value due to the short pre-pressure buildup process time, so that the pressure relief valve 31 can relieve the pressure. When the actual duty ratio is smaller than the optimal duty ratio, the pre-voltage-building process is lengthened due to the fact that the input voltage is smaller, the starting time of the vehicle can be prolonged, and therefore user experience of the vehicle is reduced.

Further, when pre-building pressure, the method further comprises:

counting the single pre-pressure building time used by the single pre-pressure building to judge whether the time is greater than the set value of the longest working time of the allowed pre-pressure building;

and when the single pre-pressure-building time is greater than the set value of the longest allowable pre-pressure-building working time, the vehicle oil supply system finishes the pre-pressure-building.

In the pre-pressure building process, when the pipeline connection of a vehicle is abnormal, the pipeline falls off, the pipeline is broken or no fuel is in the fuel tank, the working time of the fuel pump is limited, and the failure risk of the fuel pump assembly 30 can be reduced. In the embodiment, the longest working time of the pre-build-up voltage is allowed to be 3-5 seconds. The longest allowable pre-build-up operating time cannot be too short because the initial fuel pressure is low when the vehicle is in an extreme environment, such as when the ambient temperature is low, and the fuel pressure is difficult to reach the target fuel pressure when the fuel reaches the pre-build-up time, at which time the vehicle may have difficulty in performing the pre-build-up process; the maximum allowable pre-pressure-build-up working time cannot be too long, and when the vehicle works normally, the fuel pressure easily exceeds the target fuel pressure when the maximum allowable pre-pressure-build-up working time is reached, so that the pressure relief of the pressure relief valve 31 is caused to generate noise.

Further, the method further comprises:

when the single pre-pressure building time is larger than the set value of the longest working time of the allowed pre-pressure building and the pre-pressure building is finished, counting the working times of the fuel pump due to the pre-pressure building;

and when the working times of the fuel pump are less than the set value of the maximum working times of the fuel pump, the vehicle fuel supply system carries out pre-pressure build again.

In this embodiment, the fuel pump is registered as operating once during each pre-pressurization period. Each unsuccessful pre-build pressure increases the number of fuel pump operations by one after the engine is pre-started. In this embodiment, the maximum working time of the fuel pump is set to 3-5 times. The set value of the maximum working times of the fuel pump cannot be too large, when the pipeline connection of a vehicle is abnormal, the pipeline falls off, the pipeline is broken or no fuel exists in the fuel tank, the failure risk of the fuel pump can be reduced by limiting the working times of the fuel pump, the set value of the maximum working times of the fuel pump cannot be too small, the vehicle is in some extreme environments, for example, the environment temperature is low, the initial fuel pressure of the fuel pump is low, the time for reaching the target fuel pressure is long, and the fuel pressure can need to be pre-built for many times when reaching the target fuel pressure.

In summary, in the invention, the target fuel pressure is greater than the minimum pressure requirement for starting the engine and less than the maximum pressure requirement for starting the engine, and the pressure setting value of the pressure relief valve is greater than the maximum pressure requirement for starting the engine, so that it can be ensured that the initial fuel pressure value of the oil supply system is still less than the pressure setting value of the pressure relief valve after the pre-build pressure of the vehicle is completed and the engine is started, and the pressure relief valve does not perform pressure relief work, that is, the fuel in the oil pump is not rapidly released in pressure and flows to generate large noise due to pressure relief, thereby improving the riding comfort of passengers and effectively improving the NVH performance of the vehicle. By setting a proper duty ratio, a maximum working time set value of allowed pre-pressure build-up and a maximum working time set value of the fuel pump, the vehicle fuel supply system can be ensured to quickly complete the pre-pressure build-up and the failure risk of the fuel pump can be effectively reduced.

Fig. 2 is a schematic structural diagram of a pre-pressurization system of a vehicle oil supply system according to another embodiment of the present invention, and as shown in fig. 2, the present invention further provides a pre-pressurization system of a vehicle oil supply system, which includes an engine control unit 10, a fuel pump control unit 20, a fuel pump assembly 30, and a pressure sensor 40. The fuel pump control unit 20 is connected to the engine control unit 10 and the fuel pump assembly 30, respectively, and the engine control unit 10 controls the fuel pump assembly 30 by controlling the fuel pump control unit 20. The pressure sensor 40 is used for acquiring the fuel pressure in real time and sending the acquired fuel pressure to the engine control unit 10; when the engine control unit 10 determines that the engine 50 is in a pre-start state, specifically, when the engine control unit 10 receives a wake-up signal sent by a BCM (body control module) or receives a signal that a power supply is switched from OFF to ON, and the initial fuel pressure is less than a target fuel pressure, the engine control unit 10 sends a pre-pressure-build signal to the fuel pump control unit 20, and the fuel pump control unit 20 controls the fuel pump assembly 30 to pre-build pressure to increase the fuel pressure; when the fuel pressure is greater than the target fuel pressure, the engine control unit 10 controls the fuel pump assembly 30 to end the pre-pressure build-up through the fuel pump control unit 20.

The invention further provides a vehicle, the vehicle adopts the oil supply system pressure pre-building method to pre-build pressure for the oil supply system, and other technical characteristics of the vehicle refer to the prior art and are not repeated herein.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.