Vehicle

Abstract

To prevent deterioration of drivability.SOLUTION: A vehicle comprises: an engine with a filter collecting particulate matters installed on an exhaust system thereof; a manual transmission which transfers power from the engine to drive wheels while shifting a gear stage in response to shift operation of a driver; a clutch which can release connection between the engine and the manual transmission in response to clutch pedal operation of the driver; and a control device which prohibits a fuel cut for the engine when an accumulation amount of the particulate matters is less than a predetermined amount and a filter temperature is equal to or higher than a first predetermined temperature. The control device permits the fuel cut when the shift stage is changed even though the accumulation amount of the particulate matters is less than the predetermined amount and the filter temperature is equal to or higher than the first predetermined temperature.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to vehicles. [Background technology]

[0002] Conventionally, a vehicle of this type has been proposed that is equipped with an engine having a filter attached to the exhaust system that collects particulate matter, and that executes a fuel cut process to stop fuel injection from a fuel injection valve when a fuel cut condition is met, and stops the fuel cut process when an integrated amount of intake air becomes equal to or greater than a predetermined value while the fuel cut process is being executed (see, for example, Patent Document 1). In this vehicle, by executing the fuel cut process, oxygen is supplied to the filter, and the particulate matter accumulated on the filter is burned, thereby regenerating the filter. Also, by stopping the fuel cut process, the filter is prevented from overheating due to the burning of a large amount of particulate matter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-165564 A Summary of the Invention [Problem to be solved by the invention]

[0004] In such vehicles, if the amount of particulate matter deposited on the filter is too small, the degree of particulate matter capture by the filter decreases, so when the amount of particulate matter deposited is less than a predetermined amount and the temperature of the filter is equal to or higher than a predetermined temperature (when the particulate matter is within the temperature range in which it can be used as fuel), the engine fuel cut is prohibited. Meanwhile, in a manual transmission vehicle equipped with a manual transmission that transmits power from the engine to the driving wheels with a change in gear ratio in response to the driver's shift operation, and a clutch that can disconnect the engine and the manual transmission in response to the driver's operation of the clutch pedal, when the gear ratio of the manual transmission is changed, the clutch is basically released by depressing the clutch pedal, the gear ratio is changed in response to the shift operation, and the clutch returns to an engaged state via a slip engagement state by gradually releasing the clutch pedal. If the engine fuel cut is prohibited at this time, there is a concern that the engine will rev up and drivability will deteriorate.

[0005] The main objective of the vehicle of the present disclosure is to suppress deterioration of drivability. [Means for solving the problem]

[0006] The vehicle of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The vehicle of the present disclosure includes: A vehicle comprising: an engine having an exhaust system equipped with a filter for collecting particulate matter; a manual transmission that transmits power from the engine to drive wheels by changing gears in response to a driver's shift operation; a clutch that can disconnect the engine from the manual transmission in response to a driver's operation of a clutch pedal; and a control device that prohibits a fuel cut of the engine when an amount of accumulation of the particulate matter is less than a predetermined amount and a temperature of the filter is equal to or higher than a first predetermined temperature, The control device permits the fuel cut when changing the gear position even when the amount of accumulation of the particulate matter is less than the predetermined amount and the temperature of the filter is equal to or higher than the first predetermined temperature. The gist of the present invention is as follows.

[0008] In the vehicle of the present disclosure, when the amount of particulate matter deposition is less than a predetermined amount and the filter temperature is equal to or higher than a first predetermined temperature, the engine fuel cut is basically prohibited. However, even when the amount of particulate matter deposition is less than a predetermined amount and the filter temperature is equal to or higher than the first predetermined temperature, fuel cut is permitted when changing the gear stage. This makes it possible to suppress engine revving when changing the gear stage of the manual transmission and suppress deterioration of drivability. Here, when changing the gear stage of the manual transmission, it may be the period from when the clutch is turned off to when the gear stage is changed and the clutch is turned on, or it may be the period from when the gear stage change starts to when the change ends.

[0009] In the vehicle of the present disclosure, the control device may prohibit the fuel cut when the temperature of the filter is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature, regardless of whether the gear position is being changed or not. This makes it possible to prevent the filter from overheating due to the execution of a fuel cut of the engine. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a vehicle 20 according to an embodiment of the present disclosure. [Diagram 2] 2 is a schematic diagram of an engine 22 mounted on a vehicle 20. FIG. [Diagram 3] 4 is a flowchart showing an example of a permission / prohibition determination routine executed by an electronic control unit 50. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram of a vehicle 20 according to an embodiment of the present disclosure. Fig. 2 is a schematic configuration diagram of an engine 22 mounted on the vehicle 20. The vehicle 20 according to the embodiment is configured as a manual transmission vehicle (MT vehicle), and includes the engine 22, a manual transmission 30, a clutch 40, and an electronic control unit 50, as shown in Fig. 1.

[0012] The engine 22 is configured as a multiple cylinder internal combustion engine that uses fuel such as gasoline or diesel and outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel into an intake port and an in-cylinder injection valve 127 that injects fuel into a cylinder, and is operated in one of a port injection mode, an in-cylinder injection mode, and a common injection mode. In the port injection mode, air cleaned by an air cleaner 122 is sucked into an intake pipe 123 and passes through a throttle valve 124 and a surge tank 125, and fuel is injected from the port injection valve 126 downstream of the surge tank 125 of the intake pipe 123 to mix the air and fuel. This mixture is sucked into a combustion chamber 129 via an intake valve 128 and explosively combusted by an electric spark from an ignition plug 130, and the reciprocating motion of a piston 132 pushed down by the energy in the cylinder bore is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is drawn into the combustion chamber 129 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke or compression stroke, and is explosively combusted by an electric spark from the spark plug 130 to obtain the rotational motion of the crankshaft 23. In the shared injection mode, fuel is injected from the port injection valve 126 when air is drawn into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke or compression stroke, and is explosively combusted by an electric spark from the spark plug 130 to obtain the rotational motion of the crankshaft 23. Exhaust discharged from the combustion chamber 129 to the exhaust pipe 134 via the exhaust valve 133 is discharged to the outside air via the purification device 135 and the PM filter 136. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust. The PM filter 136 is formed as a porous filter using ceramics, stainless steel, or the like, and collects particulate matter (PM) such as soot in the exhaust gas. Instead of the PM filter 136, a four-way catalyst that combines the purification function of a three-way catalyst with the function of collecting particulate matter may be used.

[0013] 1, the manual transmission 30 is configured as a six-speed transmission, and has an input shaft connected to the crankshaft 23 of the engine 22 via a clutch 40, and an output shaft connected to a drive shaft DS connected to drive wheels DW via a differential gear DG. This manual transmission 30 establishes forward gears from 1st to 6th gears and reverse gears, and releases the connection between the input shaft and the output shaft, in response to the operation of a shift lever 32 by the driver.

[0014] The clutch 40 is provided between the engine 22 and the input shaft of the manual transmission 30, and is in an engaged state when the clutch pedal 42 is not depressed by the driver, and is in a slip-engaged state or a released state when the clutch pedal 42 is depressed depending on the amount of depression.

[0015] The electronic control unit 50 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. As shown in Figures 1 and 2, the electronic control unit 50 receives signals from various sensors via input ports.

[0016] Examples of signals input to the electronic control unit 50 include signals necessary for controlling the operation of the engine 22. Examples of signals necessary for controlling the operation of the engine 22 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22. Other examples of signals necessary for controlling the operation of the engine 22 include cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133. Other examples of the above include the throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 of the intake pipe 123, the intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and the surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples of the above include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 of the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached between the purification device 135 of the exhaust pipe 134 and the PM filter 136, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure before and after the PM filter 136 (a differential pressure between the upstream side and the downstream side).

[0017] Further, signals input to the electronic control unit 50 include an ignition signal from an ignition switch 51, an accelerator opening Acc from an accelerator pedal position sensor 54 that detects the amount of depression of an accelerator pedal 53, a brake pedal position BP from a brake pedal position sensor 56 that detects the amount of depression of a brake pedal 55, and a vehicle speed V from a vehicle speed sensor 58.

[0018] The electronic control unit 50 outputs, via an output port, various control signals for controlling the operation of the engine 22. Examples of signals output by the electronic control unit 50 include a control signal to the throttle valve 124, a control signal to the port injection valve 126, a control signal to the in-cylinder injection valve 127, and a control signal to the ignition plug 130.

[0019] The electronic control unit 50 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a load factor (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) KL based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates a PM accumulation amount Qpm as the accumulation amount of particulate matter accumulated on the PM filter 136 based on a differential pressure ΔP from the differential pressure sensor 136a, and calculates a filter temperature tf as the temperature of the PM filter 136 based on the rotation speed Ne of the engine 22 and the load factor KL.

[0020] In the vehicle 20 of the embodiment, the electronic control unit 50 sets a target load rate KL* of the engine 22 based on the accelerator opening Acc, and performs operation control of the engine 22 (intake air volume control, fuel injection control, ignition control, etc.) so that the engine 22 operates based on the target load rate KL*.

[0021] Furthermore, in the vehicle 20 of the embodiment, the electronic control unit 50 executes a fuel cut of the engine 22 when the accelerator is off. When the fuel cut of the engine 22 is executed while the filter temperature Tf is equal to or higher than the threshold value Tfref, air (oxygen) is supplied to the PM filter 136, and the particulate matter deposited in the PM filter 136 reacts with the oxygen, burning the particulate matter and regenerating the PM filter 136. Here, the threshold value Tfref is the lower limit of the temperature range in which the PM filter 136 can be regenerated (particulate matter can be burned).

[0022] Next, a description will be given of the operation of the vehicle 20 according to the embodiment, in particular, a process for determining whether or not to permit a fuel cut of the engine 22. Fig. 3 is a flowchart showing an example of a permission / prohibition determination routine executed by the electronic control unit 50. This routine is executed repeatedly.

[0023] 3 is executed, the electronic control unit 50 first determines whether the filter temperature Tf is equal to or higher than a superheat temperature Tfot that is higher than the above-mentioned threshold value Tfref (step S100). Here, the superheat temperature Tfot is determined as a temperature used to determine whether or not there is a possibility that the PM filter 136 will overheat due to the execution of a fuel cut of the engine 22. A constant value may be used as the superheat temperature Tfot, or it may be set to be lower as the PM deposition amount Qpm increases. The latter is because, when a fuel cut of the engine 22 is executed, the amount of heat generated by the combustion of particulate matter increases as the PM deposition amount Qpm increases, and the filter temperature Tf is more likely to become high.

[0024] When it is determined in step S100 that the filter temperature Tf is less than the overheat temperature Tfot, it is determined that the possibility of the PM filter 136 overheating even if fuel cut is performed for the engine 22 is sufficiently low, and it is determined whether the PM deposition amount Qpm is less than the threshold value Qpmref (step S110), and whether the filter temperature Tf is equal to or greater than the threshold value Tfref (step S120). If the PM deposition amount Qpm is too small, the particulate matter capture rate by the PM filter 136 decreases. The threshold values ​​Qpmref and Tfref are threshold values ​​used to determine whether there is a possibility that particulate matter will be burned and the PM deposition amount Qpm will become too small when fuel cut is performed for the engine 22.

[0025] When it is determined in step S110 that the PM deposition amount Qpm is equal to or greater than the threshold value Qpmref, it is determined that there is a sufficiently low possibility that the PM deposition amount Qpm will become too small even if fuel is cut off in the engine 22 and the particulate matter is burned, and fuel cut in the engine 22 is permitted (step S150), and this routine is terminated.

[0026] When it is determined in step S120 that the filter temperature Tf is less than the threshold value Tfref, it is determined that there is a sufficiently low possibility that the PM deposition amount Qpm will become too small because particulate matter is difficult to burn even if fuel is cut off to the engine 22, and fuel cut to the engine 22 is permitted (step S150), and this routine is terminated.

[0027] When it is determined in step S110 that the PM deposition amount Qpm is less than the threshold Qpmref and when it is determined in step S120 that the filter temperature Tf is equal to or greater than the threshold Tfref, it is determined that there is a possibility that the PM deposition amount Qpm becomes too small due to the combustion of particulate matter when the fuel cut of the engine 22 is executed, and it is determined whether or not it is time to change the gear stage of the manual transmission 30 (step S130). In a manual transmission vehicle, when changing the gear stage of the manual transmission 30, basically, the clutch 40 is released by depressing the clutch pedal 42, the gear stage of the manual transmission 30 is changed according to the operation of the shift lever 32, and the clutch 40 returns to the engaged state via the slip engagement state by gradually releasing the clutch pedal 42. Based on this, the time of changing the gear stage of the manual transmission 30 may be the period from the start to the end of depressing the clutch pedal 42 (from the disengagement of the clutch 40 to the return to the engaged state), or it may be the period from the start to the end of the change of the gear stage of the manual transmission 30.

[0028] When it is determined in step S130 that the gear position of the manual transmission 30 is not being changed, the fuel cut of the engine 22 is prohibited (step S140) and this routine ends. This makes it possible to prevent the PM accumulation amount Qpm from becoming too small due to the execution of the fuel cut of the engine 22.

[0029] When it is determined in step S130 that it is time to change the gear position of the manual transmission 30, fuel cut of the engine 22 is permitted (step S150), and this routine is terminated. If fuel cut of the engine 22 is prohibited when changing the gear position of the manual transmission 30, there is a concern that the engine 22 may rev up and drivability may deteriorate. In contrast, in the embodiment, fuel cut of the engine 22 is permitted when changing the gear position of the manual transmission 30, so that revving of the engine 22 and deterioration of drivability can be suppressed. Note that the inventors have confirmed through experiments and analysis that the time required to change the gear position of the manual transmission 30 is generally about several tens of msec to several hundreds of msec, the reduction in the PM accumulation amount Qpm due to fuel cut of the engine 22 is relatively small, and the reduction in the particulate matter collection rate by the PM filter 136 is also relatively small (within an acceptable range). In addition, in order to more sufficiently suppress revving of the engine 22, when changing the gear ratio of the manual transmission 30, it is preferable to do so from the period from when depression of the clutch pedal 42 begins to when it ends (from when the clutch 40 is released from the engaged state to when it returns to the engaged state) rather than from the period from when the gear ratio of the manual transmission 30 begins to when it ends.

[0030] If the filter temperature Tf is equal to or higher than the overheat temperature Tfot in step S100, it is determined that there is a possibility that the PM filter 136 will overheat due to the execution of a fuel cut of the engine 22, and the fuel cut of the engine 22 is prohibited (step S140), and this routine is terminated. This makes it possible to prevent the PM filter 136 from overheating due to the execution of a fuel cut of the engine 22.

[0031] In the vehicle 20 of the present embodiment described above, when the PM accumulation amount Qpm is less than the threshold Qpmref and the filter temperature Tf is equal to or greater than the threshold Tfref, fuel cut-off of the engine 22 is basically prohibited. However, even when the PM accumulation amount Qpm is equal to or less than the threshold Qpmref and the filter temperature Tf is equal to or greater than the threshold Tfref, fuel cut-off of the engine 22 is permitted when the gear position of the manual transmission 30 is changed. This makes it possible to suppress revving of the engine 22 when the gear position of the manual transmission 30 is changed, and to suppress deterioration of drivability.

[0032] Furthermore, in the vehicle 20 of this embodiment, when the filter temperature Tf is equal to or higher than an overheat temperature Tfot that is higher than a threshold value Tfref, fuel cut of the engine 22 is prohibited regardless of whether or not the gear position of the manual transmission 30 is being changed. This makes it possible to prevent the PM filter 136 from overheating due to the execution of fuel cut of the engine 22.

[0033] In the embodiment described above, the engine 22 has the port injection valve 126 and the in-cylinder injection valve 127. However, the engine 22 may have only one of the port injection valve 126 and the in-cylinder injection valve 127.

[0034] In the above-described embodiment, the manual transmission 30 is configured as a six-speed transmission. However, the manual transmission 30 may be configured as a four-speed transmission, a five-speed transmission, an eight-speed transmission, or the like.

[0035] 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 problem will be described below. In the embodiment, the engine 22 corresponds to the "engine", the manual transmission 30 corresponds to the "manual transmission", and the electronic control unit 50 corresponds to the "control device".

[0036] 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.

[0037] 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]

[0038] The present disclosure is applicable to the vehicle manufacturing industry and the like. [Explanation of symbols]

[0039] 20 vehicle, 22 engine, 23 crankshaft, 24 engine ECU, 30 manual transmission, 32 shift lever, 40 clutch, 42 clutch pedal, 50 electronic control unit, 51 ignition switch, 53 accelerator pedal, 54 accelerator pedal position sensor, 55 brake pedal, 56 brake pedal position sensor, 58 vehicle speed sensor, 122 air cleaner, 123 intake pipe, 123a air flow meter, 123t temperature sensor, 124 throttle valve, 124a throttle valve position sensor, 125 surge tank, 125a pressure sensor, 126 port injection valve, 127 in-cylinder injection valve, 128 intake valve, 129 combustion chamber, 130 spark plug, 132 piston, 133 exhaust valve, 134 exhaust pipe, 135 purification device, 136 PM filter, 136a differential pressure sensor, 137 front air-fuel ratio sensor, 138 rear air-fuel ratio sensor, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor.

Claims

1. A vehicle comprising: an engine having an exhaust system equipped with a filter for collecting particulate matter; a manual transmission that transmits power from the engine to drive wheels by changing gears in response to a driver's shift operation; a clutch that can disconnect the engine from the manual transmission in response to a driver's operation of a clutch pedal; and a control device that prohibits a fuel cut of the engine when an amount of accumulation of the particulate matter is less than a predetermined amount and a temperature of the filter is equal to or higher than a first predetermined temperature, the control device permits the fuel cut when changing the gear position even when the amount of accumulation of the particulate matter is less than the predetermined amount and the temperature of the filter is equal to or higher than the first predetermined temperature. vehicle.

2. 2. The vehicle of claim 1, the control device prohibits the fuel cut when the temperature of the filter is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature, regardless of whether the gear position is being changed or not. vehicle.

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