JP7704064B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

Patent document 1 discloses a vehicle control device that cuts fuel in at least one cylinder of a multi-cylinder engine during load operation.

JP 2021-060027 A

When users drive a vehicle, there is always a demand for improved drivability and ride comfort, so measures to reduce vibration during load driving, such as when accelerating by stepping on the accelerator on an uphill slope, are important.

In addition, vibrations that occur during load operation can be caused by sudden changes in driving force, such as rotation speed and torque. One solution to this problem is to configure the vehicle so that sufficient driving force can be ensured. However, this not only increases the production costs of the vehicle, but also increases the energy required to operate the vehicle, i.e., running costs. Therefore, the above-mentioned solution cannot be said to be appropriate from either a commercial or environmental perspective.

Patent Document 1 discloses a vehicle control device that, during load operation of a multi-cylinder engine, stops the fuel supply to at least one cylinder (fuel cut) and executes a stop process to supply fuel to cylinders other than the cylinder in question, and a compensation process to compensate for the driving force shortage caused by the stop process.

However, in a vehicle equipped with an automatic transmission, when compensation processing is performed to reduce the rotation speed fluctuations caused by the stop processing, there is a risk that torque fluctuations will occur in the input shaft of the automatic transmission.

In this case, even if one of the engagement elements, such as the clutch, is shifted to the target gear position, there is a risk of an engagement shock occurring when switching from N range to D range (forward range) because the expected engagement oil pressure due to torque fluctuations differs from the actual engagement oil pressure on the transmission side.

The present invention was made to solve these problems, and aims to provide a vehicle control device that reduces engagement shock during load operation.

The vehicle control device according to the present invention is a vehicle control device applied to a vehicle equipped with a multi-cylinder internal combustion engine and an automatic transmission having at least an N range and a D range, and executes a stop process that stops the fuel supply to some cylinders of the multi-cylinder internal combustion engine, a gear setting process that sets a gear of the automatic transmission based on the vehicle speed, and a gear change process that engages a gear higher than the gear when switching from the N range to the D range during the execution of the stop process.

The present invention provides a vehicle control device that reduces engagement shock during load operation.

1 is a schematic diagram showing a configuration of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. 4 is a flowchart showing a process of the vehicle control device according to the present embodiment. 4 is a time chart showing a control state of the vehicle control device according to the present embodiment.

The following describes an embodiment of the present invention with reference to the drawings. FIG. 1 shows the configuration of a vehicle to which a vehicle control device according to this embodiment is applied. A vehicle 10 according to this embodiment includes a multi-cylinder internal combustion engine 11 having multiple cylinders, a clutch 12, an automatic transmission 13 having at least an N range and a D range, drive wheels 14, and a vehicle control device 15. The multi-cylinder internal combustion engine 11 is connected to the automatic transmission 13 via the clutch 12.

The vehicle control device 15 according to this embodiment includes a means for executing a stop process (i.e., performing a fuel cut) to stop the fuel supply to some of the cylinders of the multi-cylinder internal combustion engine 11, and a means for controlling the engagement of the clutch 12. It also includes a means for monitoring the gear operation input by the user to the automatic transmission 13. It further includes a means for executing a gear setting process to set the gear of the automatic transmission based on the vehicle speed, and a means for executing a gear change process to engage a gear higher than the gear when switching from N range to D range during the execution of the stop process.

Figure 2 shows the process executed by the vehicle control device 15 according to this embodiment. Figure 3 is a time chart showing the control state of the vehicle control device 15 according to this embodiment. Below, the control performed by the vehicle control device 15 will be explained using Figures 2 and 3.

First, in the multi-cylinder internal combustion engine 11, it is determined whether fuel cut is being implemented in at least one cylinder (S10). Hereinafter, fuel cut to at least one cylinder is referred to as "one-cylinder F/C."

If one-cylinder F/C has not been performed, the process is terminated and restarted from the beginning. If one-cylinder F/C has been performed, it is monitored whether the processing status is 0 or non-zero (S20). The processing status indicates the state of the vehicle as a result of processing performed by the vehicle control device 15 based on the user's actions during load operation. A processing status of 0 indicates that no processing has been performed. Processing statuses other than 0 will be described later.

If the processing status is 0 in S20, the vehicle control device 15 monitors the gear operation input by the user (S21). If the range has not been switched from N to D, the processing ends as no operation has occurred and the processing is restarted from the beginning. If the range has been switched from N to D, the vehicle control device 15 sets the processing status to 1 as a state of high gear engagement (S22).

If the processing status is other than 0 in S20, the vehicle control device 15 monitors the gear operation input by the user (S30). If it is in the N range, the processing status is initialized, i.e., set to 0 (S31), the processing ends, and the processing is restarted from the beginning.

If the range is D, the vehicle control device 15 monitors whether the processing status is 1, which indicates a high gear engagement state, or 2, which indicates a target gear engagement state (S40).

If the processing status is 2 in S40, the vehicle control device 15 performs the target gear engagement process (S41) and monitors the engagement state (S42). If the gear is currently engaged, the process ends and is restarted from the beginning in order to advance the engagement. If the engagement has ended, the vehicle control device 15 initializes the processing status, i.e., sets it to 0 (S43), ends the process, and restarts the process from the beginning.

If the processing status is 1 in S40, the vehicle control device 15 monitors the target gear (S50). At this time, if the target gear is 4th gear or higher, the process proceeds to step S80.

If the target gear is less than 4th gear, the vehicle control device 15 performs an engagement process for a gear higher than the target gear (S60) and monitors the engagement state (S70). If the gear is currently engaged, the process ends and is restarted from the beginning to advance the engagement. If the engagement ends, the process proceeds to step S80.

Here, regarding the process of engaging a gear stage higher than the target gear stage in S60, if the target gear stage for D range is 1st gear, for example, 3rd gear may be engaged first, followed by 1st gear. Similarly, if the target gear stage for D range is 2nd gear, for example 4th gear may be engaged first, followed by 2nd gear, and if the target gear stage is 3rd gear, for example 4th gear may be engaged first, followed by 3rd gear. In other words, the vehicle control device 15 according to this embodiment performs control to issue a shift instruction to the automatic transmission 13, with the gear stage specified by the user taking top priority.

When the target gear stage is engaged, the vehicle control device 15 sets the processing status to 2, which indicates that the target gear stage is engaged (S80), and ends the processing.

Next, the control executed by the vehicle control device 15 according to this embodiment and the state of the vehicle will be described using the time chart shown in FIG. 3. The first row in FIG. 3 indicates whether or not one-cylinder F/C is performed.

The second row of Figure 3 shows the range state. The range state here changes when the user instructs the vehicle to change its operating state, regardless of the gear. Therefore, N range can be said to be a state in which the vehicle is stopped or traveling at a constant speed, and D range is a state in which the vehicle is accelerating.

The third row in FIG. 3 shows the processing status. The fourth and fifth rows in FIG. 3 show the operating state of high gear stage engagement and the operating state of target gear stage engagement, respectively. As mentioned above, the processing status indicates the state of the vehicle according to the processing performed by the vehicle control device 15 based on the user's actions during load operation, with a no-processing state being represented as 0, a high gear stage engagement state being represented as 1, and a target gear stage engagement state being represented as 2. Furthermore, when high gear stage engagement and target gear stage engagement are completed, the processing status is initialized and represented as 0.

By controlling in this way, it is possible to reduce shock caused by engagement even when fuel is cut during load operation. In other words, it is possible to reduce fuel consumption while maintaining drivability and ride comfort.

The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit and scope of the invention.

10 Vehicle 11 Multi-cylinder internal combustion engine 12 Clutch 13 Automatic transmission 14 Drive wheels 15 Vehicle control device

Claims (1)

A vehicle control device applied to a vehicle equipped with a multi-cylinder internal combustion engine and an automatic transmission having at least an N range and a D range,
A stop process for stopping fuel supply to some cylinders of the multi-cylinder internal combustion engine during a load operation ;
A gear setting process for setting a gear of the automatic transmission based on a vehicle speed;
a gear change process for engaging a gear higher than the gear when switching from the N range to the D range during execution of the stop process ;
When the gear stage in the D range is first gear, first gear is engaged after third gear is engaged,
When the gear stage is second gear, second gear is engaged after fourth gear is engaged,
When the gear stage is third gear, the fourth gear is engaged and then the third gear is engaged .
Vehicle control device.

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