Vehicle control system

Abstract

To provide a vehicle control device that can prevent engine exhaust system components from overheating. [Solution] The vehicle includes an engine and a control unit that performs engine revving control, which revs the engine when the accelerator pedal input exceeds a threshold TH1 in a non-driving range. When the time during which the engine revving control has been performed reaches an upper limit time TL, the control unit terminates the engine revving control and stops the engine.

Description

Technical Field

[0001] The present invention relates to a vehicle control device.

Background Art

[0002] Conventionally, Patent Document 1 has proposed a technique related to a vehicle that executes racing when an accelerator operation amount by a driver becomes equal to or greater than a threshold value when the shift range is in the parking range. Further, Patent Document 1 has proposed that when the coolant water temperature of an engine becomes equal to or higher than a predetermined temperature, the power output from the engine is restricted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology as described above, when racing (hereinafter referred to as "idling") continues within a range where the coolant water temperature of the engine does not become equal to or higher than a predetermined temperature, the power output from the engine is not restricted, so there is a problem that the exhaust system components of the engine may overheat.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle control device capable of preventing the exhaust system components of an engine from overheating.

Means for Solving the Problems

[0006] The vehicle control device according to the present invention comprises an engine and a control unit that performs engine revving control, which revs the engine when the amount of accelerator operation exceeds a threshold in a non-driving range, wherein the control unit has a configuration that terminates the engine revving control and stops the engine when the time during which the execution of the engine revving control has been continued reaches an upper limit time. [Effects of the Invention]

[0007] The present invention can provide a vehicle control device that can prevent engine exhaust system components from overheating. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of a hybrid vehicle equipped with a vehicle control device according to an embodiment of the present invention. [Figure 2] Figure 2 is a flowchart showing the idling control operation of a vehicle control device according to an embodiment of the present invention. [Figure 3] Figure 3 is a timing diagram showing an example of the state of each part when the idling control operation of the vehicle control device according to an embodiment of the present invention is performed. [Modes for carrying out the invention]

[0009] A vehicle control device according to one embodiment of the present invention comprises an engine and a control unit that performs engine revving control when the accelerator pedal input exceeds a threshold in a non-driving range, wherein the control unit terminates the engine revving control and stops the engine when the time during which the engine revving control has been performed reaches an upper limit. As a result, the vehicle control device according to one embodiment of the present invention can prevent the exhaust system components of the engine from overheating. [Examples]

[0010] Hereinafter, a vehicle equipped with a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings.

[0011] As shown in Figure 1, the vehicle 1 is composed of an engine 2, a battery 3, a first motor 4 (hereinafter also referred to as "MG1"), a first inverter 5, a second motor 6 (hereinafter also referred to as "MG2"), a second inverter 7, a boost converter 8, drive wheels 9, and a hybrid controller (hereinafter simply referred to as "HCU") 10.

[0012] Engine 2 has multiple cylinders. In this embodiment, engine 2 generates power by performing a series of four strokes for each cylinder, consisting of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.

[0013] Battery 3 is composed of a rechargeable secondary battery, such as a lithium-ion battery. Battery 3 stores the power generated by MG1 and MG2 and supplies power to drive MG1 and MG2.

[0014] The MG1 is positioned to operate in conjunction with the crankshaft of the engine 2. The MG1 is connected to the battery 3 via the first inverter 5 and the boost converter 8. The MG1 has the function of an electric motor that starts the engine 2 by rotating when power is supplied from the battery 3, and the function of a generator that converts the power generated by the engine 2 into electricity.

[0015] The MG2 is configured to be linked with the drive wheels 9 via power transmission components such as a gear mechanism. The MG2 is connected to the battery 3 via a second inverter 7 and a boost converter 8.

[0016] MG2 has the function of an electric motor that rotates the drive wheels 9 by rotating when power is supplied from battery 3 and MG1, and the function of a generator that converts the rotational force of the drive wheels 9 into electricity.

[0017] The boost converter 8 is provided between the battery 3, the first inverter 5, and the second inverter 7, boosts the voltage of the power supplied from the battery 3 to the first inverter 5 and the second inverter 7, and降压 the voltage of the power supplied from the first inverter 5 and the second inverter 7 to the battery 3.

[0018] The HCU 10 is composed of a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and an output port.

[0019] In the ROM of this computer unit, a program for causing the computer unit to function as the HCU 10 is stored together with various constants and various maps. That is, when the CPU executes the program stored in the ROM using the RAM as a work area, this computer unit functions as the HCU 10 in the present embodiment.

[0020] Various sensors including a shift position sensor 21 for detecting the shift position and an accelerator opening sensor 22 for detecting the operation amount of the accelerator pedal (hereinafter, also simply referred to as "accelerator operation amount" or "accelerator opening") are connected to the input port of the HCU 10.

[0021] Various control targets including the first inverter 5, the second inverter 7, the boost converter 8, an injector 31 for supplying fuel to the engine 2, and a spark plug 32 for igniting in the combustion chamber of the engine 2 are connected to the output port of the HCU 10. When the engine 2 is composed of an engine that does not require a spark plug, such as a diesel engine, the spark plug 32 is removed from the configuration of the vehicle 1.

[0022] Based on the information obtained from various sensors connected to the input ports, the HCU 10 controls various controlled objects connected to the output ports. In this embodiment, the HCU 10 functions as a control unit 40 that executes engine purging control to purge the engine 2 when the accelerator operation amount exceeds a threshold TH1 in a non-driving range.

[0023] In this embodiment, the non-driving range is a parking range. Therefore, when the shift position detected by the shift position sensor 21 is in the parking range, the HCU 10 executes engine purging control when the accelerator operation amount detected by the accelerator opening sensor 22 exceeds the threshold TH1. The threshold TH1 is predetermined as a value at which the accelerator operation amount is determined to be when the accelerator pedal is on.

[0024] In the engine purging control, the HCU 10 controls the first inverter 5 to drive the MG1 to rotate the crankshaft of the engine 2, and starts the fuel supply by the injector 31 and the ignition by the ignition plug 32 to start the engine 2.

[0025] When the time during which the HCU 10 continues to execute the engine purging control (hereinafter simply referred to as the "purging time") reaches the upper limit time TL, the HCU 10 ends the engine purging control and stops the engine 2. The upper limit time TL is predetermined as a value at which the exhaust system components of the engine 2 do not overheat. For example, the HCU 10 stops the engine 2 by stopping the fuel supply by the injector 31 and the ignition by the ignition plug 32.

[0026] After the HCU 10 stops the engine 2 by ending the engine purging control, when the accelerator operation amount becomes equal to or less than a predetermined value TH2 and then the accelerator operation amount exceeds the threshold TH1, the HCU 10 executes the engine purging control again. The predetermined value TH2 is predetermined as a value at which the accelerator operation amount is determined to be when the accelerator pedal is off. Therefore, the predetermined value TH2 is set lower than the threshold TH1.

[0027] The revving control operation of the HCU10 configured as described above will be explained with reference to Figure 2. Note that the revving control operation described below is repeatedly executed while the shift position is in the parking range.

[0028] First, in S1, the HCU10 determines whether the accelerator pedal input exceeds the threshold TH1. If the HCU10 determines in S1 that the accelerator pedal input exceeds the threshold TH1, it executes the process in S2. If the HCU10 determines in S1 that the accelerator pedal input does not exceed the threshold TH1, it terminates the idling control operation.

[0029] In S2, HCU10 performs engine revving control. That is, if HCU10 is not performing engine revving control, it starts engine revving control; if it is performing engine revving control, it continues engine revving control. After performing the process in S2, HCU10 performs the process in S3.

[0030] In S3, HCU10 determines whether the idling time is equal to or greater than the upper limit time TL. If HCU10 determines in S3 that the idling time is equal to or greater than the upper limit time TL, HCU10 executes the process in S4. If HCU10 determines in S3 that the idling time is not equal to or greater than the upper limit time TL, HCU10 executes the process in S1.

[0031] In S4, HCU10 terminates engine revving control and stops engine 2. After executing S4, HCU10 executes S5. In S5, HCU10 determines whether the accelerator pedal input is less than or equal to a predetermined value TH2.

[0032] In S5, if the HCU10 determines that the accelerator pedal input is less than or equal to the predetermined value TH2, the HCU10 terminates the idling control operation. In S5, if the HCU10 determines that the accelerator pedal input is not less than or equal to the predetermined value TH2, the HCU10 executes the process in S5.

[0033] In other words, if in S5 the HCU10 determines that the accelerator pedal input is not less than or equal to the predetermined value TH2, the HCU10 prohibits the execution of engine revving control until the accelerator pedal input becomes less than or equal to the predetermined value TH2.

[0034] The operation of the idling control performed by the HCU10 described above will be explained with reference to Figure 3. Figure 3 shows, from top to bottom, the relationship between the accelerator pedal input, the state of engine idling control (hereinafter also simply referred to as "engine idling control state"), and the rotational speed of engine 2 (hereinafter also simply referred to as "engine rotational speed") in chronological order.

[0035] In Figure 3, the shift position is always in the parking range. Furthermore, the engine revving control state transitions between a standby state (waiting for engine revving control to be executed), an active state (engine revving control is being executed), and a prohibited state (engine revving control is prohibited).

[0036] At time t1, if the accelerator input exceeds the threshold TH1, the engine rev control state changes from standby to active, and engine 2 is started. Once engine 2 is started, the engine speed begins to increase.

[0037] At time t2, when the engine speed reaches the speed Nr during engine revving control, the engine speed is controlled to remain constant. At time t3, when the revving time reaches the upper limit time TL, the engine revving control state changes from active to disabled, and engine 2 stops, causing the engine speed to begin to decrease.

[0038] At time t4, if the accelerator input falls below a predetermined value TH2, the engine revving control state changes from the disabled state to the standby state. At time t5, if the accelerator input exceeds the threshold TH1, the engine revving control state changes from the standby state to the activated state, and engine 2 is started.

[0039] When engine 2 is started, the engine speed begins to increase. At time t6, when the engine speed reaches the speed Nr during engine revving control, the engine speed is controlled to remain constant.

[0040] As described above, the vehicle control device according to this embodiment terminates engine idling control and stops engine 2 when the idling time reaches the upper limit time TL, thereby preventing overheating of the exhaust system components of engine 2.

[0041] Furthermore, the vehicle control device according to this embodiment can warm up the engine 2 quickly while preventing the exhaust system components of the engine 2 from overheating.

[0042] Furthermore, the vehicle control device according to this embodiment, after stopping engine 2 due to the termination of engine revving control, restarts engine revving control when the accelerator pedal input falls below a predetermined value TH2 and then exceeds a threshold TH1. Therefore, if the user wishes to continue revving engine 2, engine revving control can be restarted.

[0043] For example, the vehicle control device according to this embodiment can continue testing even when the engine 2 is revved during tests such as a proximity exhaust noise test during a vehicle inspection, while preventing the exhaust system components of the engine 2 from overheating.

[0044] Furthermore, the control device of the vehicle according to this embodiment prevents the engine revving control from being executed again shortly after the engine 2 has stopped by prohibiting engine revving control until the accelerator pedal input is below a predetermined value TH2, thereby preventing the exhaust system components of the engine 2 from overheating.

[0045] In this embodiment, the HCU10 stops the engine 2 after terminating engine revving control, and then prohibits engine revving control until the accelerator pedal input becomes less than or equal to a predetermined value TH2.

[0046] In contrast, the HCU10 may, after stopping the engine 2 due to the termination of engine revving control, prohibit engine revving control until a certain period of time has elapsed after the accelerator pedal input falls below a predetermined value TH2.

[0047] By configuring the vehicle in this way, the control device of this embodiment ensures sufficient time between the engine 2 stopping and the engine revving control being able to be executed again, thereby preventing the exhaust system components of the engine 2 from overheating.

[0048] Although embodiments of the present invention have been disclosed above, it is clear that modifications can be made to these embodiments without departing from the scope of the present invention. The embodiments of the present invention are disclosed on the premise that equivalents with such modifications are included in the invention described in the claims. [Explanation of Symbols]

[0049] 1 vehicle 2 engines 40 Control Unit

Claims

1. The engine and A vehicle control device comprising: a control unit that performs engine revving control, which revs the engine when the amount of accelerator operation exceeds a threshold in a non-driving range, The control unit is characterized in that, when the time for which the execution of the engine revving control has been continued reaches an upper limit, it terminates the engine revving control and stops the engine.

2. The control device for a vehicle according to claim 1, characterized in that, after the control unit has stopped the engine due to the termination of the engine revving control, the amount of accelerator operation becomes less than or equal to a predetermined value corresponding to accelerator off, and thereafter the amount of accelerator operation exceeds the threshold, the control unit executes the engine revving control again.

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