Control device for a vehicle

Abstract

The present application provides a vehicle control device capable of exhibiting a sporty performance while suppressing the occurrence of an impact in a vehicle. A vehicle control device in which a vehicle is equipped with an engine having a fuel injection valve, the vehicle control device including: a normal start control section that executes normal start control in which a fuel injection amount from the fuel injection valve is controlled to a normal start injection amount to start the engine; and a high-impact start control section that executes high-impact start control in which the fuel injection amount is controlled to a high-impact start injection amount that is greater than the normal start injection amount in such a manner that an impact speed at the time of starting the engine is increased compared to the normal start control, and the fuel injection amount is gradually changed from the high-impact start injection amount to a required injection amount corresponding to a required driving force of the engine after starting the engine.

Description

Technical Field

[0001] This invention relates to a vehicle control device. Background Technology

[0002] There is a vehicle equipped with an engine (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2024-099396 Summary of the Invention

[0004] A surge-start control could be implemented, in which the fuel injection quantity at engine start is increased compared to conventional start control, thereby increasing the engine's peak starting speed. By increasing the peak starting speed, the vehicle's handling performance can be enhanced. In this surge-start control, by gradually varying the fuel injection quantity after engine start to the required injection quantity corresponding to the required driving force of the engine, shocks to the vehicle caused by abrupt changes in fuel injection quantity can be suppressed. For example, if a surge-start control interruption request occurs during its execution, switching from surge-start control to conventional start control, a shock to the vehicle may occur depending on the timing of the switch.

[0005] Therefore, the object of the present invention is to provide a vehicle control device that can exhibit vehicle performance while suppressing vehicle impact.

[0006] The aforementioned objective can be achieved by a vehicle control device, wherein the vehicle is equipped with an engine having a fuel injection valve, and the vehicle control device includes: a conventional start control unit that performs conventional start control, wherein the fuel injection quantity from the fuel injection valve is controlled to a conventional start injection quantity to start the engine; and a surge start control unit that performs surge start control, wherein the fuel injection quantity is controlled to a surge start injection quantity greater than the conventional start injection quantity to start the engine in such a way that the surge start speed of the engine at startup is greater than that of the conventional start control, and after the engine starts, the fuel injection quantity is gradually changed from the surge start injection quantity to a required injection quantity corresponding to the required driving force of the engine. In the normal start control, after the engine starts, the start control unit gradually changes the fuel injection quantity from the normal start injection quantity to the required injection quantity. During the execution of the surge start control, if an interruption request for the surge start control occurs before the gradual change from the surge start injection quantity to the required injection quantity begins, the normal start control unit and the surge start control unit switch from the surge start control to the normal start control to switch the fuel injection quantity from the surge start injection quantity to the normal start injection quantity. During the execution of the surge start control, if an interruption request for the surge start control occurs during the gradual change from the surge start injection quantity to the required injection quantity, the surge start control unit continues the gradual change from the surge start injection quantity to the required injection quantity.

[0007] The existence of the interruption request may refer to the existence of a vehicle start request.

[0008] The existence of the interruption request may refer to a situation where the engine is diagnosed as malfunctioning.

[0009] The high-speed start control unit can perform the following control: the lower the temperature of the engine's cooling water, the greater the high-speed start injection volume.

[0010] Invention Effects

[0011] According to the present invention, a vehicle control device is provided that can exhibit vehicle performance while suppressing vehicle impact. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the engine's structure.

[0013] Figure 2 This is a flowchart illustrating engine start-up control.

[0014] Figure 3 This is a timing diagram illustrating engine start-up control.

[0015] Figure 4 This is a timing diagram illustrating the switch from high-speed start control to normal start control.

[0016] Figure 5 It is an example diagram of a mapping that specifies the initial values ​​of the surge increase and the initial values ​​of the normal increase corresponding to the temperature of the engine's coolant. Detailed Implementation

[0017] [General structure of the engine]

[0018] Figure 1 This is a schematic structural diagram of the engine 10 mounted on vehicle 1. Vehicle 1 includes: engine 10; drive wheels 13 through which power from engine 10 is transmitted via a shaft; and a starter 16 for starting engine 10. Engine 10 is a gasoline engine with multiple cylinders, but it can also be a diesel engine or a hydrogen engine. A transmission or differential (not shown) is provided in the power transmission path from engine 10 to drive wheels 13.

[0019] The engine 10 has a cylinder block 30, a cylinder head 32, a piston 33, a connecting rod 34, a crankshaft 35, an intake passage 36, an intake valve 36v, an exhaust passage 37, and an exhaust valve 37v.

[0020] A cylindrical cylinder bore 31 is provided in the cylinder block 30. The piston 33 is reciprocally accommodated within the cylinder bore 31. The combustion chamber C is defined by the wall of the cylinder bore 31, the lower surface of the cylinder head 32, and the top surface of the piston 33. The volume of the combustion chamber C increases or decreases due to the reciprocating motion of the piston 33.

[0021] A piston 33 is connected to the crankshaft 35, which serves as the output shaft of the engine 10, via a connecting rod 34. The connecting rod 34 and the crankshaft 35 convert the reciprocating motion of the piston 33 into the rotational motion of the crankshaft 35. The aforementioned crankshaft angle sensor 62 is provided in the engine 10.

[0022] The intake passage 36 is connected to the combustion chamber C via the intake valve 36v. The exhaust passage 37 is connected to the combustion chamber C via the exhaust valve 37v. The aforementioned air flow meter 63 is installed in the intake passage 36.

[0023] A cylinder injection valve 41D is provided in the cylinder block 30 for directly injecting fuel into the combustion chamber C. An intake manifold injection valve 41P is provided in the intake passage 36 for injecting fuel toward the intake port. A spark plug 42 is provided in the cylinder head 32, which ignites the air-fuel mixture introduced into the combustion chamber C. The cylinder injection valve 41D and the intake manifold injection valve 41P are examples of fuel injection valves.

[0024] A three-way catalytic converter 43 and a gasoline particulate filter (GPF) 44 are installed in the exhaust passage 37. The three-way catalytic converter 43 contains a catalyst metal and has oxygen storage capacity, which can purify NOx, HC and CO. The GPF 44 is a porous ceramic structure that captures exhaust particulate matter (hereinafter referred to as particulate matter (PM)) in the exhaust gas. The GPF 44 is an example of a filter. Alternatively, for example, in the case where the engine 10 is a diesel engine, a diesel particulate filter (DPF) is installed instead of the GPF 44.

[0025] An Electronic Control Unit (ECU) 50 is provided on vehicle 1. ECU 50 is an electronic control unit that has arithmetic processing circuits for performing various calculations related to the driving control of the vehicle and a memory storing control programs or data. ECU 50 is an example of the control device of vehicle 1, and in detail, it functionally implements the conventional start control unit and the high-speed start control unit described later.

[0026] The ECU 50 is connected to a crankshaft angle sensor 62, an air flow meter 63, a coolant temperature sensor 66, an atmospheric pressure sensor 67, a shift position sensor 68, and a throttle opening sensor 69. The crankshaft angle sensor 62 detects the rotational speed of the crankshaft of the engine 10. The air flow meter 63 detects the amount of air intake introduced into the engine 10. The coolant temperature sensor 66 detects the temperature of the coolant cooling the engine 10. The atmospheric pressure sensor 67 detects the atmospheric pressure around the vehicle 1. The shift position sensor 68 detects whether the shift lever is in the P, R, N, or D position. The throttle opening sensor 69 detects the throttle opening, which is the amount of throttle pedal operation.

[0027] In the ECU50, the opening of the throttle valve 40, the fuel injection quantity of the in-cylinder injection valve 41D or the intake manifold injection valve 41P, and the ignition timing based on the spark plug 42 are controlled based on the detection signals of the aforementioned sensors, thereby controlling the drive of the engine 10.

[0028] [Engine Start Control]

[0029] Figure 2This is a flowchart illustrating engine start control. This control is repeatedly executed during ignition on. ECU 50 determines whether there is a start request for engine 10 (step S1). A start request for engine 10 may be requested, for example, when ignition switches from off to on or when the restart condition after automatic stop is met. If "No" is received in step S1, this control ends.

[0030] If "yes" is indicated in step S1, the ECU 50 determines whether a high-speed start request exists (step S2). A high-speed start request is, for example, made when the coolant temperature of the engine 10 is above a specified temperature and the atmospheric pressure of the vehicle 1 is above a specified value. Details will be described later, because in high-speed start control, since the engine speed is high and controlled during engine start-up, it is preferable to execute the control while ensuring the engine 10's startability and suppressing exhaust emission deterioration. Furthermore, for example, a high-speed start request can also be considered to exist if the vehicle 1 can switch the driving mode to ECO mode, normal mode, or sport mode, and sport mode is selected.

[0031] If "No" is selected in step S2, the ECU 50 performs conventional start control (step S3). In conventional start control, the crankshaft of the engine 10 is started to rotate via the starter 16, and a predetermined conventional start injection amount of fuel (total fuel injection amount) is injected from at least one of the in-cylinder injection valve 41D and the intake manifold injection valve 41P, while the opening of the throttle valve 40 is controlled to the closed side. Specifically, the ratio of the in-cylinder injection amount to the total fuel injection amount (i.e., the in-cylinder injection rate) and the ratio of the intake manifold injection amount to the total fuel injection amount (i.e., the intake manifold injection rate) are adjusted based on the temperature of the engine 10's coolant and the temperature of the three-way catalytic converter 43. In conventional start control, after the engine 10 starts, the fuel injection amount gradually changes from the conventional start injection amount to the required injection amount corresponding to the required driving force of the engine 10. Here, the required injection amount is, for example, the fuel injection amount used to control the engine 10 to idle when the throttle opening is zero, and the fuel injection amount used to achieve the driving force of the engine 10 corresponding to the throttle opening when the throttle is open. Step S3 is an example of a process performed by the regular startup control unit.

[0032] If "Yes" is selected in step S2, the ECU 50 executes high-speed start control (step S4). In high-speed start control, the crankshaft of the engine 10 is started to rotate via the starter 16, and a predetermined high-speed start injection amount of fuel is injected only from the in-cylinder injection valve 41D. The opening of the throttle valve 40 is controlled to be on the open side. As a result, in high-speed start control, the high-speed start of the engine 10 is increased compared to conventional start control. This allows the vehicle 1 to exhibit improved handling performance. Furthermore, by injecting fuel from the in-cylinder injection valve 41D, the amount of fuel adhering to the intake port is suppressed, thereby suppressing the deterioration of exhaust emissions. In addition, the injection from the in-cylinder injection valve 41D occurs once per combustion cycle. Moreover, the high-speed start injection amount is greater than the conventional start injection amount. Step S4 is an example of the processing performed by the high-speed start control unit.

[0033] In the high-start control, after the engine 10 starts, the fuel injection quantity gradually changes from the high-start injection quantity to the required injection quantity corresponding to the required driving force of the engine 10. This suppresses any impact on the vehicle 1 that might occur if the fuel injection quantity changes abruptly from the high-start injection quantity to the required injection quantity.

[0034] Next, ECU 50 determines whether an interruption request exists during the execution of the surge start control and before the gradual change begins (step S5). An interruption request could be, for example, a situation where there is a start request for vehicle 1 or a diagnosis of an abnormality in engine 10. A start request could be, for example, when the automatic transmission shift position is in the D or R range and throttle operation is performed. An abnormality diagnosis for engine 10 could be, for example, an abnormality diagnosis of equipment related to fuel injection. For example, an abnormality in a sensor detecting the pressure of fuel supplied to the cylinder injection valve 41D or an abnormality in fuel leakage from the cylinder injection valve 41D. Alternatively, known abnormality diagnoses other than these may also be performed.

[0035] If "Yes" is selected in step S5, the ECU 50 switches from high-speed start control to normal start control (step S6). In the event of an interruption request, such as a start-up request, the engine speed increases due to high-speed start control, potentially causing excessive acceleration during vehicle 1's start-up. Furthermore, if an abnormality is diagnosed in engine 10, the startability of engine 10 may decrease during high-speed start control. In this embodiment, if an interruption request exists during the execution of high-speed start control and before the gradual change begins, switching from high-speed start control to normal start control can suppress excessive acceleration during vehicle 1's start-up or a decrease in engine 10's startability. Step S6 is an example of the processing performed by the normal start control unit and the high-speed start control unit.

[0036] Figure 3 This is a timing diagram illustrating engine start-up control. Figure 3 The diagram illustrates the shifts in engine speed and fuel injection quantity with the throttle closed, specifically for both conventional start control and high-speed start control. Figure 3 In the diagram, the dashed line shows the conventional increase in engine speed and fuel injection quantity as an increase in conventional start-up control, while the solid line shows the surge increase in engine speed and fuel injection quantity as an increase in surge-start control. Here, the increase refers to the injection quantity used in these start-up controls, added to the basic injection quantity. Therefore, the injection quantity obtained by adding the conventional increase to the basic injection quantity is the conventional start-up injection quantity described above. Similarly, the injection quantity obtained by adding the surge increase to the basic injection quantity is the surge-start injection quantity described above. The surge increase is greater than the conventional increase. Figure 3 The diagram shows the situation with the throttle closed, therefore the basic injection quantity is equivalent to the idle injection quantity required to maintain the idling operation of engine 10.

[0037] First, the conventional start-up control will be explained. If the crankshaft of the engine 10 is started to rotate via the starter 16, fuel injection begins at the conventional start-up injection amount, which is obtained by adding the conventional increase to the basic injection amount (time t1), and the conventional increase remains constant for a specified period. Then, if the engine speed reaches or exceeds the start-up determination speed at which the engine 10 is considered to be started, the fuel injection amount begins to gradually change from the conventional start-up injection amount to the idle speed injection amount (time t2). The idle speed injection amount here corresponds to the required injection amount corresponding to the required driving force of the engine 10 when the throttle is closed. As a result, the conventional increase gradually decreases until it reaches zero (time t3).

[0038] First, the high-intensity start control will be explained. If the crankshaft of the engine 10 is started to rotate via the starter 16, fuel injection begins at the high-intensity start injection quantity (time t1), which is obtained by adding the high-intensity increase to the basic injection quantity. During a specified period, the high-intensity increase remains constant. Then, if the engine speed reaches or exceeds the start-up determination speed, the fuel injection quantity begins to gradually change from the high-intensity start injection quantity to the idle injection quantity (time t2). As a result, the high-intensity increase gradually decreases until it reaches zero (time t3). Thus, by gradually changing from the high-intensity start injection quantity to the idle injection quantity, impact on the vehicle 1 is suppressed.

[0039] Furthermore, in reality, the engine speed for high-speed start control reaches the start-criteria threshold earlier than that for conventional start control, but... Figure 3 For ease of understanding, the speed at which the start-up determination speed is simultaneously shown is above the specified speed. Furthermore, in... Figure 3In the example, the case where the engine speed gradually changes immediately after reaching or exceeding the start-up determination speed is illustrated. However, the gradual change can also begin after a predetermined time following the engine speed reaching or exceeding the start-up determination speed. Preferably, the gradual change begins between the engine speed reaching or exceeding the start-up determination speed and the engine speed beginning to decrease.

[0040] Next, the switching from high-speed start control to normal start control will be explained. Figure 4 This is a timing diagram illustrating the switch from high-speed start control to normal start control. Figure 4 The diagram illustrates the progression of the increase in engine speed and fuel injection quantity during the execution of high-surge start control, and when an interruption request based on an abnormality diagnosis of engine 10 occurs before the gradual change begins. The crankshaft of engine 10 begins to rotate and fuel injection begins at the high-surge start injection quantity (time t1). Then, if an interruption request occurs, the injection quantity switches from the high-surge increase to a normal increase (time t12). That is, the fuel injection quantity switches from the high-surge start injection quantity to the normal start injection quantity, and the high-surge start control switches to normal start control. Then, a gradual change from the normal start injection quantity to the idle injection quantity begins (time t2), and the normal increase becomes zero (time t3). Thus, in the case of an interruption request before the gradual change begins, the switch to normal start control suppresses the decrease in engine 10's startability. Furthermore, since the injection quantity switches from the high-surge start injection quantity to the normal start injection quantity before engine 10 starts, shocks to vehicle 1 due to changes in the air-fuel ratio are also suppressed.

[0041] If an interruption request is made during the execution of the high-surge start control and after the gradual change has begun, the gradual change from the high-surge start injection quantity to the required injection quantity continues. For example, in this case, if the system switches from high-surge start control to normal start control and from the high-surge start injection quantity during the gradual change to the normal start injection quantity, the air-fuel ratio change may impact the vehicle 1 since the engine 10 has already started.

[0042] In addition, Figure 4 In the example, a case where an interruption request based on anomaly diagnosis occurs while the throttle is closed is illustrated. However, if an interruption request based on a start-up request occurs during the execution of the surge-start control but before the gradual change begins, the system switches to normal start control. After engine 10 starts, the injection quantity gradually changes from the normal start injection quantity to the required injection quantity corresponding to the throttle opening. Furthermore, if an interruption request based on a start-up request occurs during the execution of the surge-start control but after the gradual change begins, the injection quantity gradually changes from the surge-start injection quantity to the normal start injection quantity and then to the required injection quantity corresponding to the throttle opening.

[0043] Figure 5 This is an example diagram illustrating the mapping between the initial values ​​of the surge increase and the initial values ​​of the normal increase corresponding to the temperature of the engine 10's coolant. Both initial values ​​are set such that the lower the temperature of the engine 10's coolant, the larger the value. (ECU50 reference) Figure 5 These initial values ​​are set using a mapping diagram. This is because the lower the temperature of the engine coolant 10, the more fuel adheres to the inner wall of the cylinder bore 31, and the greater the amount of unburned fuel. Furthermore, these initial values ​​can vary curvilinearly or in stages depending on the coolant temperature. They can also be calculated using formulas that take the coolant temperature as a parameter. Moreover, these initial values ​​can be set based on the throttle opening. For example, a larger throttle opening allows for setting larger initial values. Additionally, the rate of decrease in the gradually changing increase can also be set based on the coolant temperature.

[0044] In addition, as mentioned above, the fuel injection quantity is also gradually changed in the normal start control, so the impact on vehicle 1 is also suppressed in this case.

[0045] While the embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments. Various modifications and alterations are possible within the scope of the spirit of the present invention as set forth in the claims.

[0046] Symbol Explanation

[0047] 1-Vehicle, 10-Engine, 41D-In-cylinder injection valve (fuel injection valve), 41P-Intake port injection valve (fuel injection valve), 50-ECU (Control unit, conventional start control unit, high-speed start control unit).

Claims

1. A vehicle control device, characterized in that, The vehicle is equipped with an engine having a fuel injection valve, and the vehicle's control device includes: A conventional start control unit performs conventional start control, in which the fuel injection quantity from the fuel injection valve is controlled to a conventional start injection quantity to start the engine; and The high-speed start control unit performs high-speed start control, in which the fuel injection quantity is controlled to be a high-speed start injection quantity greater than the conventional start injection quantity to start the engine, so that the high-speed start rotational speed of the engine at startup is greater than that of the conventional start control, and after the engine starts, the fuel injection quantity is gradually changed from the high-speed start injection quantity to the required injection quantity corresponding to the required driving force of the engine. The conventional start control unit, in the conventional start control process, gradually changes the fuel injection quantity from the conventional start injection quantity to the required injection quantity after the engine starts. If, during the execution of the surge start control, an interruption request for the surge start control exists before the gradual change from the surge start injection quantity to the required injection quantity begins, the normal start control unit and the surge start control unit switch from the surge start control to the normal start control to switch the fuel injection quantity from the surge start injection quantity to the normal start injection quantity. If an interruption request for the high-intensity start control occurs during the execution of the high-intensity start control and during the gradual change from the high-intensity start injection quantity to the required injection quantity, the high-intensity start control unit continues the gradual change from the high-intensity start injection quantity to the required injection quantity.

2. The vehicle control device according to claim 1, characterized in that, The existence of the interruption request refers to the existence of a vehicle start request.

3. The vehicle control device according to claim 1, characterized in that, The existence of the interruption request refers to a situation where the engine is diagnosed as malfunctioning.

4. The vehicle control device according to any one of claims 1 to 3, characterized in that, The high-speed start control unit performs the following control: the lower the temperature of the engine's coolant, the greater the high-speed start injection volume.

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