WO2023082848A1

WO2023082848A1 - Starting system and control method

Info

Publication number: WO2023082848A1
Application number: PCT/CN2022/120319
Authority: WO
Inventors: 祝浩; 刘元治; 徐家良; 刘加明; 盛振兴
Original assignee: 中国第一汽车股份有限公司
Priority date: 2021-11-15
Filing date: 2022-09-21
Publication date: 2023-05-19
Also published as: CN113982804B; CN113982804A

Abstract

A starting system. The starting system comprises an engine (1), an electric generator, a control unit (5), an air storage tank (2), a suction pipeline (3) and a solenoid valve (4), wherein the electric generator can drive the engine to rotate; the engine comprises an air cylinder (11), a piston (13) and a throttle valve (12), the air cylinder having an air intake manifold (111), and the throttle valve being arranged on the air intake manifold; two ends of the suction pipeline can be respectively in communication with the air storage tank and the air intake manifold, and the throttle valve and the suction pipeline are sequentially arranged in a flow direction of a gas in the air intake manifold; and the solenoid valve is arranged on the suction pipeline. Further disclosed is a control method for a starting system.

Description

Starting system and control method

This application claims priority to a Chinese patent application with application number 202111345370.5 filed with the China Patent Office on November 15, 2021, the entire contents of which are incorporated herein by reference.

technical field

The present application belongs to the technical field of automobiles, and for example relates to a starting system and a control method.

Background technique

The hybrid vehicle has a series configuration hybrid, and the engine and generator are directly connected together through torsional shock absorbers. During the starting process, the output torque of the generator drags the engine to a certain speed and then the engine ignites, then the torque of the generator turns from positive torque to negative torque for power generation, and the power output by the generator is transmitted to the drive motor to complete the drive of the vehicle .

During the start-up dragging process, the dragging resistance torque comes from the moment of inertia of the crankshaft, torsional shock absorber, reduction gear and generator rotor on the one hand, and from the compression reaction force of the piston in the engine on the other hand. The actual intake air volume in the cylinder during the dragging process can be reduced to a certain extent through the coordinated control of the intake and exhaust variable valve timing and the throttle valve, thereby reducing the compression reaction force of the piston. Since the intake and exhaust variable valve timing of the current engine is mostly in the form of hydraulic drive, the variable valve timing can hardly be controlled during the starting process, so it is difficult to effectively reduce the actual progress in the cylinder during the dragging process only through throttle control. capacity.

Contents of the invention

The present application provides a starting system to reduce the compression reaction force of the piston of the engine and the drag torque of the generator, and improve the starting speed and vibration and harshness (Noise, Vibration, Harshness, NVH) performance of the engine.

A starting system comprising an engine, a generator and a control unit, the generator being configured to drive the engine to rotate; the engine comprising a cylinder, a throttle valve and a piston, the piston being slidably disposed in the cylinder, The cylinder has an intake manifold, and the throttle valve is arranged on the intake manifold; the starting system also includes:

gas tank;

A suction pipeline, the two ends of the suction pipeline communicate with the gas storage tank and the intake manifold respectively, and the throttle valve and the suction pipeline communicate with the gas in the intake manifold The flow directions of are arranged in sequence; and

A solenoid valve is arranged on the suction pipeline; the solenoid valve is configured to open when the engine is stopped and the throttle valve is closed, and when the opening time of the solenoid valve reaches a preset opening time or the engine is closed when the rotational speed of the engine is zero; or, when the engine starts, the throttle valve is closed and the rotational speed of the engine reaches the first preset rotational speed, it is opened when the control unit issues a fuel injection command or the engine’s Turns off when the speed reaches the second preset speed.

In one embodiment, the starting system further includes:

A rotational speed sensor is arranged on the cylinder, and the rotational speed sensor is configured to measure the rotational speed of the engine.

In one embodiment, the starting system further includes:

A pressure sensor is arranged on the intake manifold, and the throttle valve and the pressure sensor are sequentially arranged along the flow direction of gas in the intake manifold.

In one embodiment, twice the sum of the volume of the intake manifold between the throttle valve and the cylinder and the displacement of the engine is the volume of the air storage tank.

In one embodiment, when the pressure of the gas storage tank is 1000HPa, the pressure at the end of the solenoid valve far away from the gas storage tank is always maintained at 300HPa, and the suction pipeline is configured such that when the solenoid valve is opened , so that the pressure of the gas storage tank can drop from 1000HPa to 500HPa within 0.4s.

In one embodiment, the first preset speed of the engine is 20r/min-50r/min, and the second preset speed is 900r/min-1100r/min.

In one embodiment, when the engine is stopped, 1.5 times the time for the engine speed to drop from 1200r/min to 800r/min is the preset opening time of the solenoid valve.

The present application provides a control method for a starting system, so as to reduce the compression reaction force of the piston of the engine and the drag torque of the generator, and improve the starting speed and NVH performance of the engine.

A control method for a starting system, applied to the above-mentioned starting system, the control method for the starting system comprising:

When the engine starts, the generator starts and drives the engine to rotate, and at the same time, the control unit issues a fuel cut command, and the throttle valve is closed;

judging whether the rotational speed of the engine reaches the first preset rotational speed;

In response to the rotational speed of the engine reaching the first preset rotational speed, the solenoid valve is opened, and the intake manifold communicates with the air storage tank so that the air storage tank and the piston jointly pump air within the intake manifold;

judging whether the control unit issues a fuel injection command; and/or judging whether the rotational speed of the engine reaches the second preset rotational speed;

If the control unit issues an oil injection command and/or the engine speed reaches the second preset speed, the solenoid valve is closed.

In an embodiment, the control method of the starting system further includes:

When the engine is shut down, the control unit issues a fuel cut command, and the throttle valve is closed to reduce the pressure of the intake manifold;

The solenoid valve is opened, and the intake manifold communicates with the air storage tank, so that the intake manifold sucks the air in the air storage tank until the intake manifold is connected to the air storage tank. The pressure of the gas tank is the same;

Judging whether the opening time of the solenoid valve reaches the preset opening time; or, judging whether the rotational speed of the engine is zero;

If the opening time of the electromagnetic valve reaches the preset opening time; or, when the rotational speed of the engine is zero, the electromagnetic valve is closed.

In one embodiment, the opening and closing of the throttle valve and the solenoid valve are controlled by the control unit.

Description of drawings

Fig. 1 is a schematic structural diagram of a starting system provided by an embodiment of the present application;

Fig. 2 is a flow chart of a method for controlling the start-up system during the start-up process provided by the embodiment of the present application;

Fig. 3 is a flow chart of a method for controlling the starting system during the shutdown process provided by the embodiment of the present application.

In the picture:

1. Engine; 11. Cylinder; 111. Intake manifold; 112. Outlet manifold; 12. Throttle; 13. Piston; 14. Crankshaft; 15. Flywheel; 16. Speed sensor; 17. Pressure sensor; 18. Turbocharger; 19. Three-way catalytic converter;

2. Gas storage tank; 3. Suction pipeline; 4. Solenoid valve; 5. Control unit; 51. Engine controller; 52. Vehicle controller.

Detailed ways

The technical solution of the present application will be described below in conjunction with the accompanying drawings and through specific implementation methods. The specific embodiments described herein are for illustration of the application only. For ease of description, only parts relevant to the present application are shown in the drawings.

In the description of this application, unless otherwise stipulated and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the meanings of the above terms in this application according to the situation.

In this application, unless otherwise specified and limited, a first feature being "on" or "under" a second feature may include that the first and second features are in direct contact, and may also include that the first and second features are not in direct contact. contact but through additional feature contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this embodiment, the terms "up", "down", "right", and other orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operations, rather than indicating Or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the application. In addition, the terms "first" and "second" are only used to distinguish in description, and have no special meaning.

The technical solution of the present application will be described below in conjunction with the accompanying drawings and through specific implementation methods.

As shown in FIG. 1 , this embodiment discloses a starting system, which includes an engine 1 , a generator and a control unit 5 . The starting system is a starting system of a hybrid vehicle, for example, may be a starting system of a hybrid vehicle, or may be a starting system of a hybrid passenger vehicle.

The engine 1 includes a cylinder 11, a throttle valve 12, a piston 13, a crankshaft 14, and a flywheel 15. The cylinder 11 has an intake manifold 111 and an exhaust manifold 112 communicating with the inner cavity of the cylinder 11. The throttle valve 12 is mounted on the intake manifold. On the pipe 111 , it is configured to control the amount of air entering the intake manifold 111 . The turbocharger 18 and the three-way catalytic converter 19 are sequentially installed on the outlet manifold 112 along the flow direction of the air in the outlet manifold 112 . The piston 13 is slidably arranged in the cylinder 11, and the piston 13 performs work through the compressed air, thereby driving the crankshaft 14 and the flywheel 15 to rotate.

The control unit 5 of this embodiment includes an engine controller 51 and a vehicle controller 52, and the vehicle controller 52 is connected to the engine controller 51 through a controller area network (ontroller Area Network, CAN) bus. The engine controller 51 can send the speed signal of the engine 1 , the pressure signal of the intake manifold 111 , the opening degree signal of the throttle valve 12 and the like to the vehicle controller 52 through the CAN bus. The vehicle controller 52 can transmit the fuel injection enabling signal of the engine 1 , the generator output torque signal, etc. to the engine controller 51 through the CAN bus.

As shown in FIG. 1 , the starting system further includes a rotational speed sensor 16 and a pressure sensor 17 , and the rotational speed sensor 16 is arranged on the cylinder 11 . The rotational speed sensor 16 is configured to measure the rotational speed of the engine 1 . The rotational speed of the crankshaft 14 of the engine 1 is the rotational speed of the engine 1 . The pressure sensor 17 is arranged on the intake manifold 111 to measure the pressure value in the intake manifold 111 after the throttle valve 12 is closed. The throttle valve 12 and the pressure sensor 17 are arranged in sequence along the gas flow direction in the intake manifold 111 .

Both the rotational speed sensor 16 and the pressure sensor 17 are in communication connection with the engine controller 51 to transmit the pressure value in the intake manifold 111 and the rotational speed of the engine 1 to the engine controller 51 .

In this embodiment, the opening and closing of the throttle valve 12 and the electromagnetic valve 4 are controlled by the control unit 5 . The engine controller 51 controls the opening degree of the throttle valve 12 and can transmit the opening degree signal of the throttle valve 12 to the vehicle controller 52 . The vehicle controller 52 controls the opening and closing of the solenoid valve 4 .

In addition, the vehicle controller 52 can send a fuel injection enabling signal to the engine controller 51 . When the fuel injection enable signal is 0, it means a fuel cut command. When the fuel injection enable signal is 1, it means a fuel injection command.

The normal starting process of the engine is as follows: the vehicle controller 52 controls the generator to output positive torque to drive the crankshaft 14 of the engine 1 to rotate. When the engine 1 reaches a certain speed, the torque of the generator changes from positive torque to negative torque. Power generation, the power output by the generator is transmitted to the drive motor to complete the drive of the vehicle. The throttle valve 12 in the engine 1 is opened, and the piston 13 sucks the air in the intake manifold 111 and compresses it in the cylinder 11 to do work to drive the crankshaft 14 and the flywheel 15 to rotate. Then the exhaust gas is discharged into the exhaust manifold 112 , and after passing through the turbocharger 18 , the exhaust gas is finally purified by the three-way catalytic converter 19 and discharged to the outside of the engine 1 .

The drag torque of the engine 1 comes from the moment of inertia of the crankshaft 14 and other related structures on the one hand, and from the compression reaction force of the piston 13 on the other hand. Although, the actual intake air volume of the cylinder 11 during the dragging process can be reduced to a certain extent through the coordinated control of the intake and exhaust variable valve timing and the throttle valve 12, thereby reducing the compression reaction force of the piston 13. However, the intake and exhaust variable valve timing of the engine 1 is mostly driven by hydraulic pressure, and effective control cannot be realized during the starting process. Therefore, it is difficult to effectively reduce the actual intake air volume in the cylinder 11 during dragging only by controlling the throttle valve 12 .

In addition, the compression reaction force of the piston 13 is the main cause of vibration and noise of the engine 1 , and excessive compression reaction force also affects the NVH performance of the engine 1 .

As shown in FIG. 1 , the starting system of this embodiment further includes an air storage tank 2 , a suction pipeline 3 and a solenoid valve 4 . Both ends of the suction pipeline 3 can communicate with the gas storage tank 2 and the intake manifold 111 respectively, and the throttle valve 12 and the suction pipeline 3 are sequentially arranged along the flow direction of the gas in the intake manifold 111 . The solenoid valve 4 is arranged on the suction pipeline 3 to control the on-off of the suction pipeline 3 .

This embodiment also discloses a control method for the start-up system. During the start-up process of the engine 1, the control method for the start-up system can enable the air storage tank 2 to extract air from the intake manifold 111 to reduce the pressure of the piston 13. The air extraction amount is reduced, thereby reducing the compression reaction force of the piston 13 and improving the NVH performance of the engine 1 .

As shown in Figure 2, the steps in the shutdown process of the control method of the starting system are as follows:

When the engine 1 is stopped, the control unit 5 issues a fuel cut command, and the throttle valve 12 is closed, so that the pressure of the intake manifold 111 drops.

The solenoid valve 4 is opened, and the intake manifold 111 communicates with the air storage tank 2, so that the intake manifold 111 sucks the air in the air storage tank 2 until the pressure of the intake manifold 111 and the air storage tank 2 are the same.

It is judged whether the opening time of the solenoid valve 4 reaches the preset opening time. Alternatively, it is judged whether the rotational speed of the engine 1 is zero.

If the opening time of the electromagnetic valve 4 reaches the preset opening time; or, when the rotational speed of the engine 1 is zero, the electromagnetic valve 4 is closed.

As shown in Figure 3, the steps of the control method of the starting system in the starting process are as follows:

When the engine 1 starts, the generator starts and drives the engine 1 to rotate, and at the same time the control unit 5 issues a fuel cut command, and the throttle valve 12 is closed.

It is judged whether the rotational speed of the engine 1 reaches the first preset rotational speed.

If the rotational speed of the engine 1 reaches the first preset rotational speed, the solenoid valve 4 is opened, and the intake manifold 111 communicates with the air storage tank 2 , so that the air storage tank 2 and the piston 13 suck air in the intake manifold 111 together.

It is judged whether the control unit 5 issues a fuel injection instruction. And/or, it is judged whether the rotation speed of the engine 1 reaches the second preset rotation speed.

If the control unit 5 issues an oil injection command and/or the rotational speed of the engine 1 reaches the second preset rotational speed, the solenoid valve 4 is closed.

The control method of the starting system of the present embodiment is as follows:

During the shutdown process of the engine 1, the fuel injection enable signal sent by the vehicle controller 52 to the engine controller 51 is set to 0, that is, a fuel cut-off command. The engine controller 52 controls the throttle valve 12 to close, and since the engine 1 is still rotating, the piston 13 will draw air from the intake manifold 111 . After the engine control 51 sends the closing signal of the throttle valve 12 to the vehicle controller 52, the vehicle controller 52 controls the solenoid valve 4 to open, the gas storage tank 2 communicates with the intake manifold 111, and the piston 13 passes through the intake manifold. 111 extracts the air in the air storage tank 2, so that the pressure of the air storage tank 2 decreases rapidly and has a certain degree of vacuum. When the opening time of the electromagnetic valve 4 reaches the preset opening time or the rotational speed of the engine 1 is zero, the electromagnetic valve 4 is closed. Keep the lower pressure before the solenoid valve 4 is closed in the air storage tank 2, and prepare for starting next time.

When the engine 1 is stopped, the vehicle controller 52 sends a fuel injection enable signal 0 to the engine controller 51, that is, a fuel cut command. The engine controller 51 controls the throttle valve 12 to close. At this time, record the time when the rotational speed of the engine 1 drops from 1200r/min to 800r/min, and use 1.5 times of this time as the preset opening time of the solenoid valve 4 .

During engine 1 start-up process, vehicle controller 52 controls generator to start, and drag engine 1 to rotate. At the same time, the vehicle controller 52 sends a fuel injection enable signal 0 to the engine controller 51, that is, a fuel cut-off command. The engine controller 51 closes the throttle valve 12 after receiving the fuel cut command. When the rotational speed of the engine 1 reaches a first preset rotational speed, the piston 13 starts to extract air from the intake manifold 111 . The electromagnetic valve 4 is opened, and the pressure in the air storage tank 2 is relatively low at this moment, so that the air storage tank 2 and the piston 13 jointly extract the air of the intake manifold 111 , reducing the amount of air drawn by the piston 13 . When the vehicle controller 52 sends the fuel injection enable signal 1 (fuel injection command) to the engine controller 51 or the speed of the engine 1 reaches the second preset speed, the engine 1 is started and the solenoid valve 4 is closed.

The first preset speed of the engine 1 is 20r/min˜50r/m/in, and the second preset speed is 900r/min˜1100r/min. For example, the first preset rotation speed may be 20r/min, 30r/min, 40r/min or 50r/min and so on. The second preset rotation speed may be 900r/min, 1000r/min or 1100r/min, etc. In this embodiment, the first preset rotation speed is 20r/min, and the second preset rotation speed is 1000r/min.

When the engine 1 is stopped, the throttle valve 12 is closed, and the piston 13 draws air from the intake manifold 111 , so that the pressure of the intake manifold 111 decreases. Electromagnetic valve 4 is opened, so that gas storage tank 2 communicates with intake manifold 111, piston 13 sucks the air of gas storage tank 2 through intake manifold 111, and the pressure of gas storage tank 2 decreases, so that gas storage tank 2 has a certain of vacuum. When the engine 1 is started, the throttle valve 12 is closed, and when the rotational speed of the engine 1 reaches the first preset rotational speed, the electromagnetic valve 4 is opened, so that the gas storage tank 2 is communicated with the intake manifold 111, and the gas storage tank 2 is connected with the piston. 13 jointly extract the air of the intake manifold 111, which reduces the amount of air drawn by the piston 13, thereby reducing the compression reaction force of the piston 13, which is conducive to reducing the drag torque of the generator and improving the starting efficiency of the engine 1.

At the same time, by reducing the compression reaction force of the piston 13 , the starting vibration of the engine 1 can be reduced, and the NVH performance of the engine 1 can be improved.

During each starting process, the pressure in the air storage tank 2 will increase, and during the shutdown process, the pressure of the air storage tank 2 will decrease to suck the air in the intake manifold 111 during the next starting process , so as to achieve the purpose of reducing the compression reaction force of the piston 13 . Therefore, each start must be successful, before the start is successful, stop control is not allowed during the start process.

During the start-up process of the engine 1 , the air storage tank 2 can draw air in the intake manifold 111 . At the same time, since the intake valve of the engine 1 is opened, the air storage tank 2 may also extract a part of the air in the cylinder 11 . Therefore, the volume of the air storage tank 2 is related to the volume of the intake manifold 111 and the displacement of the engine 1 .

The volume of the air storage tank 2 is twice the sum of the volume of the intake manifold 111 between the throttle valve 12 and the cylinder 11 and the displacement of the engine 1 . The displacement of the engine 1 refers to the sum of the volumes of all the cylinders 11 . For example, the intake manifold 111 of the present embodiment has a volume of 3L between the throttle valve 12 and the intake valve of the cylinder 11, the engine 1 has four cylinders 11, and the volume of each cylinder 11 is 0.5L. The displacement of 1 is 2L, and the volume of the gas storage tank 2 is 10L.

In order to improve the starting efficiency, during the starting process of the engine 1 , after the solenoid valve 4 is opened, it is necessary to suck the air in the intake manifold 111 into the air storage tank 2 as soon as possible. Therefore, it is necessary to select the solenoid valve 4 and the suction pipeline 3 of specific specifications so that the flow cross-sectional area of the two can meet the requirements of use.

The selection principle is: when the volume of the gas storage tank 2 is determined, the pressure of the gas storage tank 2 is set to 1000HPa, and the pressure at the end of the solenoid valve 4 away from the gas storage tank 2 is always kept at 300HPa. When the electromagnetic valve 4 is opened, the air in the air storage tank 2 can flow out through the electromagnetic valve 4 and the suction line 3, so that the pressure of the air storage tank 2 can drop from 1000HPa to 500HPa within 0.4s. The minimum pipeline cross-sectional area that satisfies the pumping speed is taken as the flow cross-sectional area of the suction pipeline 3 and the solenoid valve 4 .

Claims

A starting system, including an engine (1), a generator and a control unit (5), the generator is configured to drive the engine (1) to rotate; the engine (1) includes a cylinder (11), a valve (12) and piston (13), the piston (13) is slidingly arranged in the cylinder (11), the cylinder (11) has an intake manifold (111), and the throttle valve (12) is set On the intake manifold (111); the starting system also includes:

Gas storage tank (2);

A suction pipeline (3), the two ends of the suction pipeline (3) communicate with the gas storage tank (2) and the intake manifold (111) respectively, the throttle valve (12) and The suction pipelines (3) are sequentially arranged along the gas flow direction in the intake manifold (111); and

A solenoid valve (4), arranged on the suction line (3); the solenoid valve (4) is configured to open when the engine (1) is stopped and the throttle valve (12) is closed , close when the opening time of the electromagnetic valve (4) reaches the preset opening time or the rotational speed of the engine (1) is zero; or, when the engine (1) starts, the throttle valve ( 12) When it is closed and the speed of the engine (1) reaches the first preset speed, it is turned on, when the control unit (5) issues an injection command or the speed of the engine (1) reaches the second preset speed closed in case of
The starting system according to claim 1, further comprising:

A rotational speed sensor (16) is arranged on the cylinder (11), and the rotational speed sensor (16) is configured to measure the rotational speed of the engine (1).
The starting system according to claim 1, further comprising:

The pressure sensor (17) is arranged on the intake manifold (111), and the throttle valve (12) and the pressure sensor (17) are along the gas flow direction in the intake manifold (111) Arranged sequentially.
The starting system according to claim 1, wherein the volume of the intake manifold (111) between the throttle valve (12) and the cylinder (11) and the displacement of the engine (1) Twice of the sum of the amounts is the volume of the gas storage tank (2).
The starting system according to claim 4, wherein, when the pressure of the gas storage tank (2) is 1000HPa, the pressure at the end of the solenoid valve (4) away from the gas storage tank (2) 300HPa is always maintained, and the suction line (3) is configured to reduce the pressure of the gas storage tank (2) from 1000HPa to 500HPa within 0.4s when the solenoid valve (4) is opened.
The starting system according to claim 1, wherein the first preset speed of the engine (1) is 20r/min-50r/min, and the second preset speed is 900r/min-1100r/min min.
The starting system according to claim 1, wherein, when the engine (1) is stopped, 1.5 times of the time for the engine (1) to drop from 1200r/min to 800r/min is the The preset opening time of the solenoid valve (4).
A control method for a starting system, applied to the starting system according to any one of claims 1-7, comprising:

When the engine starts, the generator starts and drives the engine to rotate, and at the same time, the control unit issues a fuel cut command, and the throttle valve is closed;

judging whether the rotational speed of the engine reaches a first preset rotational speed;

In response to the rotational speed of the engine reaching the first preset rotational speed, the solenoid valve is opened, and the intake manifold communicates with the air storage tank so that the air storage tank and the piston jointly pump air within the intake manifold;

Judging at least one of the following: whether the control unit issues a fuel injection command; judging whether the speed of the engine reaches the second preset speed;

The solenoid valve is closed in response to at least one of the following: the control unit sends out the fuel injection command; the speed of the engine reaches the second preset speed.
The control method of the starting system according to claim 8, further comprising:

When the engine is shut down, the control unit issues a fuel cut command, and the throttle valve is closed to reduce the pressure of the intake manifold;

The solenoid valve is opened, and the intake manifold communicates with the air storage tank, so that the intake manifold sucks the air in the air storage tank until the intake manifold is connected to the air storage tank. The pressure of the gas tank is the same;

Judging whether the opening time of the solenoid valve reaches the preset opening time; or, judging whether the rotational speed of the engine is zero;

In response to the opening time of the electromagnetic valve reaching the preset opening time; or, when the rotational speed of the engine is zero, the electromagnetic valve is closed.
The control method of the starter system according to claim 8, wherein the opening and closing of the throttle valve and the solenoid valve are controlled by the control unit.