Control device of internal combustion engine

Abstract

To inhibit overheating of a fuel pump.SOLUTION: An internal combustion engine device includes: an internal combustion engine; and a fuel supply device including a saddle shaped fuel tank, having first and second storage parts capable of storing a fuel to be used in the internal combustion engine and a saddle part connecting the first storage part with the second storage part and including a bottom part which is curved so as to form a raised bottom, a first fuel pump disposed at the first storage part, and a second fuel pump disposed at the second storage part. A control device of the internal combustion engine is used in the internal combustion engine device and controls the internal combustion engine. When the internal combustion engine device inclines relative to a horizontal direction, an idle rotation number which is a rotation number set during idle operation of the internal combustion engine is lowered compared to a case where the internal combustion engine device does not incline relative to the horizontal direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control device for an internal combustion engine. [Background technology]

[0002] Conventionally, as this type of internal combustion engine control device, one that is used in an internal combustion engine system that includes an internal combustion engine and a fuel tank and controls the internal combustion engine has been proposed (see, for example, Patent Document 1). The fuel tank is formed into an egg-shaped overall, and stores therein fuel to be supplied to the internal combustion engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-67237 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, a fuel tank has been proposed that is saddle-shaped with a first and second storage section capable of storing fuel used in an internal combustion engine, a saddle section that connects the first storage section and the second storage section and is curved to form a raised bottom, and that includes a first fuel pump disposed in the first storage section and a second fuel pump disposed in the second storage section. In this internal combustion engine device, when the device is tilted relative to the horizontal direction, fuel may be unevenly stored in one of the first storage section and the second storage section. In this case, the fuel pump runs idle and overheats because there is little fuel stored in the other storage section.

[0005] The main object of the internal combustion engine control device disclosed herein is to prevent the fuel pump from overheating. [Means for solving the problem]

[0006] The internal combustion engine control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The control device for an internal combustion engine according to the present disclosure includes: An internal combustion engine; a saddle-shaped fuel tank having first and second storage sections capable of storing fuel used in the internal combustion engine, a saddle section connecting the first storage section and the second storage section and including a curved bottom section to form a raised bottom, a first fuel pump disposed in the first storage section, and a second fuel pump disposed in the second storage section, and a fuel supply device supplying fuel to the internal combustion engine, the control device being used in an internal combustion engine system and controlling the internal combustion engine, the control device comprising: When the internal combustion engine device is inclined with respect to the horizontal direction, the idle speed, which is the speed at which the internal combustion engine is idled, is made lower than when the internal combustion engine device is not inclined with respect to the horizontal direction. The gist of the present invention is as follows. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of a fuel supply device 23. [Diagram 3] 10 is a flowchart showing an example of a setting routine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with a control device for an internal combustion engine according to the present embodiment. The hybrid vehicle 20 of the embodiment includes an engine (internal combustion engine) 22, a fuel supply device 23, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a planetary gear 30, motors MG1 and MG2, a motor electronic control unit (hereinafter referred to as "motor ECU") 40, a battery 50, a battery electronic control unit (hereinafter referred to as "battery ECU") 52, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0010] The engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel, etc. as fuel. The operation of the engine 22 is controlled by an engine ECU 24.

[0011] The fuel supply device 23 is configured as a device that supplies gasoline, diesel, or the like as fuel to the engine 22. FIG. 2 is a schematic diagram showing the configuration of the fuel supply device 23. As shown in the figure, the fuel supply device 23 includes a fuel tank 100, first and second feed pumps 102 and 104, and a delivery pipe 106. In addition, the fuel supply device 23 includes a release valve and an oil filter attached to the delivery pipe 106, which are not shown. The fuel tank 100 is formed into a saddle shape as a whole, and includes first and second storage sections 100a and 100b that store fuel, and a saddle section 100c that connects the first storage section 100a and the second storage section 100b and includes a curved bottom section 100d that forms a raised bottom. The fuel tank 100 is disposed on the vehicle such that the first storage section 100a is on the front side of the vehicle, and the second storage section 100b is on the rear side of the vehicle. The first feed pump 102 is disposed in the first storage section 100a, and pumps fuel to a delivery pipe 106. The second feed pump 104 is disposed in the second storage section 100b, and pumps fuel to the delivery pipe 106. The delivery pipe 106 supplies fuel to a fuel injection valve (not shown) of the engine 22.

[0012] The engine ECU 24 is configured as a microprocessor centered on a CPU. The engine ECU 24 receives signals from various sensors required for controlling the operation of the engine 22, such as a crank angle θ from a crank position sensor (not shown) attached to a crankshaft 26 of the engine 22. The engine ECU 24 outputs various control signals for controlling the operation of the engine 22, such as a pump control signal for controlling the first and second feed pumps 102, 104. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θ from the crank position sensor (not shown).

[0013] The planetary gear 30 is configured as a single-pinion planetary gear mechanism, with a carrier connected to the crankshaft 26 of the engine 22 and a ring gear connected to a drive shaft 36 which is connected via a differential gear 37 to drive wheels 38a, 38b.

[0014] The motors MG1 and MG2 are configured as, for example, synchronous generator motors. The motor MG1 has a rotor (rotating shaft) connected to a sun gear of the planetary gear 30. The motor MG2 has a rotor (rotating shaft) connected to a drive shaft 36. The motors MG1 and MG2 are controlled by inverters 41 and 42.

[0015] The motor ECU 40 is configured as a microprocessor centered on a CPU. Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40. The motor ECU 40 outputs switching control signals and the like to switching elements (not shown) of the inverters 41 and 42. The motor ECU 40 calculates the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from rotation position detection sensors that detect the rotation positions of the rotors of the motors MG1 and MG2.

[0016] The battery 50 is configured as, for example, a lithium ion secondary battery, and exchanges electric power with the motors MG1, MG2 via inverters 41, 42. The battery 50 is managed by a battery ECU 52.

[0017] The battery ECU 52 is configured as a microprocessor centered on a CPU. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52. In order to manage the battery 50, the battery ECU 52 calculates a power storage ratio SOC, which is a ratio of the capacity of power that can be discharged from the battery 50 at that time to the total capacity, based on an integrated value of the charge / discharge current Ib of the battery 50 detected by a current sensor (not shown), and calculates input / output limits Win, Wout, which are allowable input / output power that may be charged / discharged to the battery 50, based on the calculated power storage ratio SOC and a battery temperature Tb.

[0018] Inputted to the HVECU 70 are a start switch signal ST from a start switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the depression amount of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the depression amount of a brake pedal 85, a vehicle speed V from a vehicle speed sensor 88, a gradient θr from a gradient sensor 90 that detects the gradient of the road surface relative to the horizontal direction, and a remaining fuel amount Vf from a remaining amount sensor 92 that detects the volume (remaining amount) of fuel stored in a fuel tank 100. The shift position SP includes a parking position (P position) used when parking, a reverse position (R position) for reverse driving, a neutral position (N position), a forward position (D position) for forward driving, and the like. The HVECU 70 is communicably connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

[0019] In the hybrid vehicle 20 of this embodiment configured in this manner, the engine 22 and the motors MG1 and MG2 are controlled by cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 40 so that the vehicle runs in a motor driving mode in which the operation of the engine 22 is stopped, or in a hybrid driving mode in which the vehicle runs with the engine 22 operating.

[0020] In addition, in the hybrid vehicle 20 of the embodiment, when the engine 22 is operated at idle, for example when the required power of the engine 22 is a value of 0, ignition control, intake air amount control, fuel injection control, etc. of the engine 22 are performed so that the engine 22 idles (operates independently) at the target idle speed Nidl* through cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 40.

[0021] Next, the operation of the hybrid vehicle 20 of this embodiment, particularly the operation when setting the target idle speed Nidl*, will be described. Fig. 3 is a flowchart showing an example of a speed setting routine executed by the HVECU 70. This routine is repeatedly executed at predetermined time intervals (e.g., every few msec) when the engine 22 is operating at idle.

[0022] When this routine is executed, the CPU of the HVECU 70 executes a process of inputting the gradient θr from the gradient sensor 90, the shift position SP from the shift position sensor 82, the remaining fuel amount Vf from the remaining amount sensor 92, and the charge storage ratio SOC calculated by the battery ECU 52 (step S100). Next, it is determined whether the vehicle is stopped and the shift position SP is the P position (step S110), and whether the remaining fuel amount Vf is less than a threshold value Vfref and the gradient θr exceeds a threshold value θref (step S120). The threshold value Vfref is a threshold value for determining whether the fuel in the fuel tank 100 is low or not, and may be, for example, an upper limit value of the remaining amount at which a fuel remaining amount warning light is turned on. The threshold value θref is a threshold value for determining whether or not the fuel tank 100 is tilted relative to the horizontal direction due to the road surface gradient, causing fuel to be concentrated in one of the first storage section 100a and the second storage section 100b, resulting in a decrease in the remaining amount of fuel in the other section, and is set to, for example, 7 degrees, 8 degrees, 9 degrees, etc.

[0023] When the vehicle is running in step S110, the shift position SP is not the P position, or when the remaining fuel amount Vf is equal to or greater than the threshold Vfref in step S120, or the gradient θr is equal to or less than the threshold θref, the target idle speed Nidl* is set to a basic idle speed Nib that is determined in advance as a basic value for idling the engine 22 (independent operation) (step S130). The basic idle speed Nib is set to, for example, 800 rpm, 1000 rpm, 1200 rpm, etc. When the target idle speed Nidl* is set in this manner, ignition control, intake air amount control, fuel injection control, etc. of the engine 22, and control of the motor MG1, etc. are performed by cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 40 so that the engine 22 idles (independent operation) at the target idle speed Nidl* (=Nib). With such control, the engine 22 can be idled at the idle speed Nidl (=Nib).

[0024] When the vehicle is stopped in step S110 and the shift position SP is in the P position, and when the remaining fuel amount Vf is less than the threshold value Vfref and the gradient θr exceeds the threshold value θref in step S120, it is determined that there is a very high possibility that the first or second feed pump 102, 104, whichever has the less remaining fuel amount, will spin, and the target idle speed Nidl* is set to a speed obtained by subtracting a predetermined speed Nref from the basic idle speed Nib (step S140). The predetermined speed Nref is set to, for example, 50 rpm, 100 rpm, 150 rpm, etc. When the target idle speed Nidl* is set in this manner, the HVECU 70, the engine ECU 24, and the motor ECU 40 perform cooperative control of the engine 22 to idle (operate autonomously) at the target idle speed Nidl* (=Nib), and control of the motor MG1, etc. With this control, engine 22 can be idled at idle speed Nidl (=Nib-Nref), and since idle speed Nidl is lower than when the vehicle is moving or the shift position SP is not in the P position in step S110, or when the remaining fuel amount Vf is equal to or greater than threshold value Vfref or gradient θr is equal to or less than threshold value θref in step S120, fuel consumption can be suppressed. Therefore, idling of first and second feed pumps 102, 104 can be suppressed, and thus heating of first and second feed pumps 102, 104 can be suppressed.

[0025] Next, it is determined whether the power storage ratio SOC is greater than the threshold value SOCref (step S150). The threshold value SOCref is a lower limit value of the power storage ratio SOC permitted for the battery 50 or a value slightly higher than the lower limit value. When the power storage ratio SOC is equal to or less than the threshold value SOCref, the load operation of the engine 22 for charging the battery 50 is permitted (step S160), and when the power storage ratio SOC is greater than the threshold value SOCref, the load operation of the engine 22 for charging the battery 50 is prohibited (step S170), and this routine is terminated. When the power storage ratio SOC is greater than the threshold value SOCref, the load operation of the engine 22 for charging the battery 50 is prohibited, so that fuel consumption due to the load operation can be suppressed. This makes it possible to suppress idling of the first and second feed pumps 102, 104, and thus to suppress heating of the first and second feed pumps 102, 104.

[0026] According to the hybrid vehicle 20 equipped with the internal combustion engine control device of the present embodiment described above, when the vehicle is stopped, the shift position SP is in the P position, the remaining fuel amount Vf is less than the threshold value Vfref, and the gradient θr exceeds the threshold value θref, the target idle speed Nidl* is set lower than when the vehicle is moving, the shift position SP is not in the P position, the remaining fuel amount Vf is equal to or greater than the threshold value Vfref, or the gradient θr is equal to or less than the threshold value θref, thereby suppressing heating of the first and second feed pumps 102, 104.

[0027] In the above embodiment, when the vehicle is stopped, the shift position SP is in the P position, the remaining fuel amount Vf is less than the threshold Vfref, and the gradient θr exceeds the threshold θref, the idle speed Nidl is reduced. However, regardless of whether the vehicle is stopped, whether the shift position SP is in the P position, or whether the remaining fuel amount Vf is less than the threshold Vfref, when the gradient θr exceeds the threshold θref, the target idle speed Nidl* may be reduced.

[0028] In the above-described embodiment, steps S150 to S170 are executed. However, when the present disclosure is used in an internal combustion engine device mounted on an automobile that does not have a motor that outputs power for running and runs only on power from the engine, steps S150 to S170 do not need to be executed.

[0029] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described below. In the embodiment, the engine 22 corresponds to the "internal combustion engine", the fuel tank 100 corresponds to the "fuel tank", the first feed pump 102 corresponds to the "first fuel pump", the second feed pump 104 corresponds to the "second fuel pump", and the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to the "control device for the internal combustion engine".

[0030] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0031] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0032] The present disclosure is applicable to a control device for an internal combustion engine. [Explanation of symbols]

[0033] 22 engine, 24 engine electronic control unit (engine ECU), 70 hybrid electronic control unit (HVECU), 90 gradient sensor, 92 fuel level sensor, 100 fuel tank, 100a first storage section, 100b second storage section, 100c saddle section, 102 first feed pump, 104 second feed pump.

Claims

[Claim 1] An internal combustion engine; a saddle-shaped fuel tank having first and second storage sections capable of storing fuel used in the internal combustion engine, and a saddle section connecting the first storage section and the second storage section and including a curved bottom section to form a raised bottom, a first fuel pump disposed in the first storage section, and a second fuel pump disposed in the second storage section, and a fuel supply device supplying fuel to the internal combustion engine; A control device for an internal combustion engine, which is used in an internal combustion engine device and controls the internal combustion engine, When the internal combustion engine device is inclined with respect to the horizontal direction, the idle speed, which is the speed at which the internal combustion engine is idled, is made lower than when the internal combustion engine device is not inclined with respect to the horizontal direction. A control device for an internal combustion engine.

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