Engine control device

Abstract

The present invention addresses the problem of suppressing vibrations that may occur in a traveling vehicle due to driving a compressor that compresses an air-conditioning refrigerant. In a vehicle that is provided with an engine and a compressor that compresses an air-conditioning refrigerant using the engine as a drive source and that is in a traveling state, a control device according to the present invention executes air-conditioning load torque correction control. A change in an air-conditioning load torque caused by a change in a driving state of a compressor is reflected in a request torque based on an operation by a driver. The air-conditioning load torque correction control includes: a first torque correction control for increasing the intake air amount and increasing the actual air amount torque when the compressor transitions from the drive-released state to the drive state, and decreasing the intake air amount and decreasing the actual air amount torque when the compressor transitions from the drive state to the drive-released state; and a second torque correction control.

Description

Technical Field

[0001] This invention relates to a control device for an engine. Background Technology

[0002] Previously, a technique was known to control the target engine speed during idling by taking into account changes in engine load caused by the driving of the compressor that compresses the refrigerant for air conditioning (see, for example, Patent Document 1). According to Patent Document 1, it is possible to appropriately suppress engine speed fluctuations.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2015-203334 Summary of the Invention

[0004] However, Patent Document 1 is designed for control during idling. Therefore, there is room for improvement in suppressing vibrations generated in a moving vehicle due to the compressor's operation.

[0005] The purpose of this invention is to suppress vibrations that may occur in a moving vehicle due to changes in the driving state of the compressor that compresses the refrigerant for air conditioning.

[0006] The above objective can be achieved by an engine control device as follows: an engine control device, in a vehicle having an engine and a compressor for compressing air conditioning refrigerant driven by the engine, and in a driving state, wherein the engine control device performs air conditioning load torque correction control to reflect changes in air conditioning load torque caused by changes in the driving state of the compressor in a requested torque calculated based on driver operation, wherein the air conditioning load torque correction control in the engine control device includes: a first torque correction control that increases the intake air volume to increase the actual air volume torque when the compressor transitions from a driving disengagement state to a driving state, and decreases the intake air volume to decrease the actual air volume torque when the compressor transitions from a driving state to a driving disengagement state; and a second torque correction control that delays the ignition timing to decrease the actual air volume torque when the compressor transitions from a driving disengagement state to a driving state and when the compressor transitions from a driving state to a driving disengagement state, thereby setting a torque target value corresponding to the air conditioning load torque.

[0007] Invention Effects

[0008] It can suppress vibrations that may occur in a moving vehicle due to changes in the driving state of the compressor that compresses the refrigerant for air conditioning. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the engine control device of the engine according to the applicable implementation method.

[0010] Figure 2 This is an example of a timeline showing the content of the air conditioning load torque correction control performed by the engine control device of the embodiment.

[0011] Figure 3 This is a block diagram illustrating the processing flow of the air conditioning load torque correction control implemented in the embodiment.

[0012] Figure 4 This is a flowchart illustrating an example of air conditioning load torque correction control performed by the engine control device in an embodiment.

[0013] Figure 5 A is an example of a time-sharing diagram illustrating the control state when changes in the compressor's drive state occur continuously. Figure 5 B is an example of a time-sharing diagram representing the control state when a change in the compressor's drive state occurs within a short period of time. Detailed Implementation

[0014] (Implementation Method)

[0015] Hereinafter, this embodiment will be described with reference to the accompanying drawings.

[0016] [Engine Components]

[0017] refer to Figure 1 The general configuration of the engine 100 according to the embodiment will be described. Various controls of the engine 100 are performed by an electronic control unit (ECU) 50, which is a control device.

[0018] Engine 100 has multiple cylinders 2 in the cylinder block (in Figure 1 Only one cylinder 2 is shown in the diagram. A piston 3 is slidably housed within each cylinder 2. A combustion chamber 2a is formed between the piston 3 and the cylinder head, which is located on the upper side of the cylinder block. The piston 3 is connected to the crankshaft 5 via a connecting rod 4. An injector 6 and a spark plug 7 are provided in the combustion chamber 2a to inject fuel into the cylinder. The fuel injected from the injector 6 forms a mixture in the combustion chamber 2a and is ignited by the spark plug 7. If the ignited mixture burns and explodes, the piston 3 is pressed down. The pressed piston 3 transmits the explosive force to the crankshaft 5 via the connecting rod 4, causing the crankshaft 5 to rotate. A crankshaft angle sensor 15 for detecting the crankshaft angle is provided in the engine 100.

[0019] The engine 100 has an air intake 8 and an exhaust port 9 arranged facing the combustion chamber 2a. An intake pipe 10 is connected to the air intake 8. An exhaust pipe 11 is connected to the exhaust port 9.

[0020] On the intake manifold 10, an air filter 12, an air flow meter 13, a throttle valve 17, and an intake manifold 18 are sequentially arranged from the upstream side of the intake air flow. The air flow meter 13 detects the amount of air flowing in the intake manifold 10. The throttle valve 17 adjusts the amount of air supplied to the combustion chamber 2a. The intake manifold 10 is branched by the intake manifold 18 and connected to the intake ports 8 of each cylinder.

[0021] On the exhaust pipe 11, an exhaust manifold 20 and a catalyst 21 are sequentially arranged from the upstream side of the exhaust flow. The catalyst 21 purifies the exhaust.

[0022] The engine 100 has an intake valve 23 for opening and closing the intake port 8 and an exhaust valve 24 for opening and closing the exhaust port 9. The intake valve 23 is opened and closed by a valve mechanism 25. The exhaust valve 24 is opened and closed by a valve mechanism 26.

[0023] Engine 100 is connected to compressor 31, which compresses refrigerant for air conditioning unit (hereinafter referred to as AC) 30. Compressor 31 is connected to crankshaft 5 via clutch 31a. The drive state of compressor 31 changes depending on the engagement state of clutch 31a. In the following description, the torque of the drive load portion of compressor 31 is referred to as air conditioning load torque. AC 30 includes refrigerant pressure sensor 32a for measuring refrigerant pressure and refrigerant temperature sensor 32b for measuring refrigerant temperature. Furthermore, AC 30 includes air conditioning control unit 33. In this embodiment, AC 30 is a fixed capacity AC.

[0024] The ECU 50 includes a Central Processing Unit (CPU), Random Access Memory (RAM), Read Only Memory (ROM), and storage devices. The ECU 50 controls the engine 100 by executing programs stored in the ROM or storage devices. The storage devices contain programs or maps used for control.

[0025] The ECU 50 functions as a request torque calculation unit 51 and an air conditioning load torque correction unit 52 by executing programs. The air conditioning load torque correction unit 52 includes a timing unit 53, an ignition timing control unit 54, and a throttle control unit 55. The ignition timing control unit 54 includes a difference calculation unit 56.

[0026] The ECU 50 is electrically connected to the air flow meter 13 and the crankshaft angle sensor 15. The ECU 50 is also electrically connected to the throttle opening sensor 58, which measures the amount of pressure applied to the accelerator pedal 57. The ECU 50 is further electrically connected to the shift position sensor 60, which detects the shift position in the shift mechanism 59, and the vehicle speed sensor 61, which detects the speed of the vehicle 80. The ECU 50 includes a gear information acquisition unit 62 that acquires information about the gear position in the transmission 81 of the vehicle 80. The ECU 50 selects the gear position in the transmission 81 based on the driving status of the vehicle 80 and the amount of pressure applied to the accelerator pedal 57 by the driver. The gear information acquisition unit 62 acquires information about which gear is selected.

[0027] The requested torque calculation unit 51 calculates the requested torque required by the engine 100 based on the driver's operation. The requested torque is calculated based on the engine speed obtained by the crankshaft angle sensor 15, the vehicle speed obtained by the vehicle speed sensor 61, and the throttle pedal pressure obtained by the throttle opening sensor 58.

[0028] The air conditioning load torque correction unit 52 performs air conditioning load torque correction control. The air conditioning load torque correction control is a control that makes the requested torque reflect the change in air conditioning load torque that accompanies the change in the driving state of the compressor 31.

[0029] The timing unit 53 measures the period used to terminate the air conditioning load torque correction control. The termination of the air conditioning load torque correction control will be explained later. The ignition timing control unit 54 controls the ignition timing of the engine 100. The throttle control unit 55 controls the intake air volume by adjusting the opening of the throttle valve 17.

[0030] The throttle control unit 55 also adjusts the opening of the throttle valve 17 in various controls of the engine 100, except for the air conditioning load torque correction control. In the air conditioning load torque control, the throttle control unit 55 performs a first torque correction control that changes the intake air volume. The first torque correction control adjusts the throttle valve opening to make the engine torque a future torque target value. The future torque is the engine torque obtained by adjusting the intake air volume within a responsive range. Since the future torque originates from the intake air volume, there is a response delay. In the following description, the torque corresponding to the intake air volume controlled by the first torque correction control is referred to as the actual air volume torque. The actual air volume torque can be determined based on the intake air volume detected by the airflow meter 13.

[0031] The ignition timing control unit 54 adjusts the ignition timing of the spark plug 7 in various controls of the engine 100, except for the air conditioning load torque correction control. The ignition timing control unit 54 performs a second torque correction control that changes the ignition timing in the air conditioning load torque control. The second torque correction control controls the ignition timing to make the engine torque the most recent torque target value. The most recent torque is the engine torque compensated for by adjusting the ignition timing within a range that allows adjustment of the deviation between the actual air volume torque and the air conditioning load torque, which is subject to the effect of the response delay in adjusting the intake air volume. Since the most recent torque originates from the ignition timing, it has high responsiveness and can instantly obtain the targeted torque. The most recent torque is reduced by delaying the ignition timing. In the following description, the torque corresponding to the ignition timing controlled by the second torque correction control is referred to as the actual generated torque.

[0032] In this embodiment, firstly, the actual air volume torque is obtained through a first torque correction control. Then, the actual air volume torque is reduced through a second torque correction control, thereby aligning with the air conditioning load torque that is the target actual generated torque. In this embodiment, the actual air volume torque is not actually output; instead, the actual generated torque obtained by correcting the actual air volume torque is output.

[0033] The difference calculation unit 56 calculates the difference between the actual air volume torque and the most recent torque target value in the second torque correction control. If this difference is below a specified value, the second torque correction control ends. The termination of the second torque correction control will be explained later.

[0034] <Air Conditioning Load Torque Correction Control>

[0035] Next, refer to Figures 2 to 4 This paper explains the torque correction control for air conditioning load.

[0036] In this embodiment, the execution conditions for air conditioning load torque correction control are set (see reference). Figure 4 (Step S1 in the flowchart shown). In this embodiment, the following three conditions are specified as prerequisites for performing air conditioning load torque correction control.

[0037] The first condition is to select a shift position other than the stop position using the shift device 59. Specifically, this means selecting a position other than the Parking (P) or Neutral (N) position on the shift device 59. This condition stipulates that the vehicle 80 is in a drivable state.

[0038] The second condition is selecting a low gear or reverse gear via the transmission 81. For example, if the low gear and second gear are set as low gears, then the low gear is selected. This condition specifies a state where the driver can easily perceive the vibration of the vehicle 80 while it is in motion.

[0039] The third condition is that the accelerator pedal pressure is below a preset threshold. For example, if the accelerator pedal pressure exceeds the threshold, in conjunction with the acceleration of the vehicle 80, the driver will find it difficult to perceive the vibration caused by the change in the driving state of the compressor 31. The third condition also specifies a state in which the driver can easily perceive the vibration of the vehicle 80 while it is in motion.

[0040] Next, a general overview of the air conditioning load torque correction control will be provided. Based on Figure 4 A detailed explanation of the flowchart shown will follow.

[0041] The air conditioning load torque correction control is executed when the drive state of AC30 changes. Specifically, in Figure 2 When there is an AC connection request at time t1 and at Figure 2 Execution occurs when an AC disconnection request is received at time t3. Figure 2 The diagram shows the future torque target value, the most recent torque target value, the actual air volume torque, and the actual generated torque. The future torque target value is depicted with a thick solid line. The most recent torque target value is depicted with a thin solid line. The actual air volume torque is depicted with a dashed line. The actual generated torque is obtained by executing ignition timing control to obtain the most recent torque target value. Due to the good responsiveness of the ignition timing control, the most recent target torque and the actual generated torque largely overlap.

[0042] The AC 30's driving state changes under the control of the air conditioning control unit 33. After an AC on request is received at time t1, the AC 30 engages the clutch 31a at time t2. That is, after an AC on request is received, a delay period is set from time t1 to time t2 until the clutch 31a is engaged. Furthermore, after an AC off request is received at time t3, the AC 30 disengages the clutch 31a at time t4. That is, after an AC off request is received, a delay period is set from time t3 to time t4 until the clutch 31a is disengaged.

[0043] refer to Figure 3 To set the target ignition timing and target throttle opening, the requested torque is first calculated based on driver input. The requested torque varies depending on engine speed, vehicle speed, and throttle input, all based on driver input. The requested torque is calculated using these parameters. It is obtained by controlling the intake air volume. This requested torque becomes the future torque target value at that point in time. In the air conditioning load torque correction control, this future torque target value is corrected for changes in the AC30's drive state. Setting the target throttle opening and changing the intake air volume is equivalent to the first torque correction control. Furthermore, changing the target ignition timing is equivalent to the second torque correction control.

[0044] <<First Torque Correction Control>> in Figure 2 The time graph shown only depicts the change in torque corresponding to the air conditioning load torque. That is, in Figure 2 This does not include the requested torque calculated based on the driver's operation. The torque required for engine 100 is the value reflected by adding the air conditioning load torque to the requested torque.

[0045] First, the case where there is an AC turn-on request at time t1 will be explained. The future torque target value when there is an AC turn-on request includes the stable air conditioning load torque and the inertia compensation torque.

[0046] The stable air conditioning load torque is the torque required to maintain the stable rotation of compressor 31. The inertia compensation torque is the torque used to compensate for the inertia of compressor 31 when it transitions to a stable rotation state. In the air conditioning load torque correction, the stable air conditioning load torque and the inertia compensation torque are added to the future load torque target value. The value obtained by adding the stable air conditioning load torque and the inertia compensation torque is taken as the future torque target value at that point in time. Here, the inertia compensation torque in the first torque correction control is estimated to be large enough to fully compensate for the envisioned inertia.

[0047] In the first torque correction control, the stabilizing air conditioning load torque and the inertia compensation torque are added together. These torque sums are obtained by increasing the intake air volume.

[0048] Therefore, the target air volume is calculated, and the corresponding target throttle opening is calculated. The target throttle opening is indicated to the throttle valve 17. There is a response delay in the torque obtained based on the intake air volume. The actual air volume torque is obtained by using the throttle valve 17 to achieve the target throttle opening. The effect on the engine 100 caused by the actuation of AC30 occurs after the moment t2 when the clutch 31a is engaged. In this embodiment, by setting a delay period from moment t1 to moment t2, the change in actual air volume torque occurs approximately around moment t2. Figure 2 In the example shown, the actual air volume torque begins to rise in a phase slightly earlier than time t2.

[0049] The inertial compensation torque causes its rising and falling portions to change slowly. Therefore, the actual air volume torque changes slowly.

[0050] Next, the case where there is an AC disconnection request at time t3 will be explained. When there is an AC disconnection request, the inertia component does not need to be considered. Therefore, the future torque target value when there is an AC disconnection request is set as the torque component of the stable air conditioning load at time t3.

[0051] When an AC disconnection request is received, the air conditioning load torque becomes unnecessary by disengaging clutch 31a. However, even if the requested torque, which is the value minus the stable air conditioning load torque, is set as the future torque target value at time t3, the actual air volume torque will still exhibit a response delay. That is, even if the future torque target value is reduced along with the AC disconnection request, the state where the actual air volume torque is higher than the requested torque will persist for a period of time.

[0052] This first torque correction control is a feedforward control with a pre-set future torque target value corresponding to the characteristics of AC30.

[0053] <<Second Torque Correction Control>>

[0054] The second torque correction control delays ignition timing. By delaying ignition timing, the actual air volume torque is reduced. This reduced torque becomes the actual generated torque. Figure 2 The recent torque target value is shown instead of the ignition delay. The recent torque target value is the torque calculated as the output of the engine 100, reflecting the driving state of the compressor 31, i.e., the engagement state of the clutch 31a.

[0055] refer to Figure 3 In the air conditioning load torque correction, torque efficiency is calculated by considering the set future torque target value and the most recent torque target value. Ignition delay is then calculated based on this torque efficiency. Furthermore, the target ignition timing is calculated based on this ignition delay and the minimum advance for best torque (MBT) at that point in time.

[0056] First, the case where there is an AC turn-on request at time t1 is explained. The most recent torque target value at the time of the AC turn-on request also includes the stable air conditioning load torque and the inertia compensation torque. The meanings of the stable air conditioning load torque and the inertia compensation torque are the same as those in the future torque target value. Specifically, the inertia compensation torque in the first torque correction control is estimated to be sufficient to fully fill the envisioned inertia component. In contrast, the inertia compensation torque in the second torque correction control is smaller than the inertia compensation torque in the first torque correction control.

[0057] The recent torque target value is set to rise at a time approximately coinciding with the moment t2 when clutch 31a is engaged. Therefore, during the period prior to t2, when the actual air volume torque is greater than the recent target torque, the second torque correction control delays the ignition timing to bring the actual air volume torque closer to the recent target torque.

[0058] Furthermore, during the period when the actual air volume torque is equivalent to the inertia compensation torque, the ignition timing is also delayed to make the actual air volume torque closer to the nearest target torque.

[0059] Therefore, vibrations that accompany torque fluctuations caused by the driving of the compressor 31 can be suppressed.

[0060] Next, the case where an AC disconnection request is made at time t3 will be explained. When an AC disconnection request is made, the inertia component does not need to be considered. Therefore, the nearest torque target value when an AC disconnection request is made is set to the torque component of the stable air conditioning load after time t3. In this case, the nearest torque target value changes slowly.

[0061] When an AC disconnection request is received, the air conditioning load torque becomes unnecessary by disengaging clutch 31a at time t4. As mentioned above, after time t3, there is a period when the actual air volume torque is higher than the requested torque. In the second torque correction control, by delaying the ignition timing, the actual generated torque is corrected to be close to the requested torque.

[0062] Therefore, it is possible to suppress vibrations caused by torque fluctuations resulting from the release of the compressor 31's drive.

[0063] Furthermore, the actual generated torque remains approximately stable under air conditioning load after the AC disconnection request at time t3 until around time t4 when the clutch 31a is disengaged. This prevents a decrease in engine 100 rotation speed caused by the compressor 31 connected to the engine 100.

[0064] This second torque correction control is a feedforward control with a future torque target value set to correspond to the characteristics of AC30.

[0065] <<Control Example>>

[0066] Here, for reference Figure 4 The flowchart shown illustrates an example of air conditioning load torque correction control performed by the ECU 50, including the air conditioning load torque correction unit 52.

[0067] In step S1, the ECU 50 determines whether the preconditions for control are met. The preconditions for control are the three conditions mentioned above used to determine that the vehicle 80 is in a driving state. If the determination in step S1 is "yes", the process proceeds to step S2. On the other hand, if the determination in step S1 is "no" ("no" determination), the ECU 50 ends the process.

[0068] In step S2, ECU 50 determines whether the request to turn AC 30 on or off has changed. If the determination in step S2 is "no", ECU 50 ends the process. If the determination in step S2 is "yes", the method of change of the request is further determined. Specifically, it determines whether the change of the request is from off to on or from on to off. If the change of the request is from off to on, the process proceeds to step S3. On the other hand, if the change of the request is from on to off, the process proceeds to step S8. In addition, ECU 50 obtains information related to the change of the request to turn AC 30 on and off from the air conditioning control unit 33. Furthermore, in step S2, when either request changes, the timing unit 53 starts counting.

[0069] In step S3, ECU 50 calculates the target future torque value. ECU 50 incorporates the target future torque value calculated in step S3 into the requested torque calculated based on the driver's input. Furthermore, the throttle control unit 55 of ECU 50 performs throttle control. After processing in step S3, ECU 50 proceeds to step S4.

[0070] In step S4, ECU50 determines whether a predetermined time has elapsed since AC30 was switched on. Here, the predetermined time is... Figure 2 The delay period in step S4 is used to determine whether time t2 has elapsed. If the determination in step S4 is "yes", the process proceeds to step S5. On the other hand, if the determination in step S4 is "no", the process proceeds to step S7.

[0071] In step S5, ECU 50 calculates the most recent torque target value. Furthermore, ECU 50 calculates the ignition timing corresponding to the most recent torque target value. The most recent torque target value includes the torque for stabilizing the air conditioning load and the torque for inertia compensation. ECU 50 incorporates the most recent torque target value calculated in step S5 into the requested torque calculated based on the driver's operation. The ignition timing control unit 54 controls the ignition timing to eliminate the deviation between the actual air volume torque and the most recent torque target value. When the actual air volume torque is greater than the most recent torque target value, the ignition timing is delayed. After processing in step S5, ECU 50 proceeds to step S6.

[0072] In step S6, ECU50 determines whether the termination condition for the air conditioning load torque correction control is met. In this embodiment, three conditions are set as termination conditions for the air conditioning load torque correction control. If any one of these three conditions is met, the air conditioning load torque correction control ends. Furthermore, the air conditioning load torque correction control ends by ending the ignition timing control in the second torque correction control. The three conditions serving as termination conditions for the air conditioning load torque correction control will be explained later.

[0073] If the determination in step S6 is "yes", the ECU 50 ends the processing of air conditioning load torque correction control. On the other hand, if the determination in step S6 is "no", the ECU 50 repeats the processing of step S3.

[0074] Next, step S7 will be explained. In step S7, the ECU 50 calculates the most recent torque target value. Furthermore, the ignition timing control unit 54 calculates the ignition timing corresponding to the most recent torque target value. The ECU 50 reflects the most recent torque target value calculated in step S7 into the requested torque calculated based on the driver's operation. The most recent torque target value in step S7 differs from that in step S5 and is set to 0 Nm. Therefore, the most recent torque target value from time t1 to time t2 is consistent with the requested torque calculated based on the driver's operation. The ignition timing control unit 54 controls the ignition timing to eliminate the deviation between the actual air volume torque and the most recent torque target value. There is a response delay in the increase of the actual air volume torque. Therefore, the ignition timing is maintained at MBT until the actual air volume torque increases. Moreover, after the actual air volume increases, the ignition timing is delayed. After the processing in step S7, the ECU 50 repeats the processing in step S3.

[0075] Next, step S8 will be explained. The processing after step S8 becomes the processing when there is an AC disconnection request. In step S8, ECU 50 calculates a future torque target value. ECU 50 reflects the future torque target value calculated in step S8 into the requested torque calculated based on the driver's operation. Furthermore, the throttle control unit 55 of ECU 50 performs throttle control. The future torque target value in step S8 is set to 0 Nm. This is because, based on the AC disconnection request, the future air conditioning load torque becomes unnecessary. Therefore, the future torque target value after time t3 is consistent with the requested torque calculated based on the driver's operation. After the processing in step S8, ECU 50 proceeds to step S9.

[0076] In step S9, ECU50 determines whether a predetermined time has elapsed since AC30 was switched off. Here, the predetermined time is... Figure 2 The delay period in step S9 is determined by ECU50. Specifically, ECU50 determines whether time t4 has elapsed. If the determination in step S9 is "yes," the process proceeds to step S10. Conversely, if the determination in step S9 is "no," the process proceeds to step S12.

[0077] In step S10, the ECU 50 calculates the most recent torque target value. Furthermore, the ECU 50 calculates the ignition timing corresponding to the most recent torque target value. The ECU 50 incorporates the most recent torque target value calculated in step S10 into the requested torque calculated based on the driver's operation. The ignition timing control unit 54 controls the ignition timing to eliminate the deviation between the actual air volume torque and the most recent torque target value. When the actual air volume torque is greater than the most recent torque target value, the ignition timing is delayed. After processing in step S10, the ECU 50 proceeds to step S11.

[0078] In step S11, ECU50 determines whether the termination condition for the air conditioning load torque correction control is met. The process in step S11 is largely the same as that in step S6. Therefore, a detailed description of step S11 is omitted here.

[0079] In step S11, if the determination is "yes", the ECU 50 ends the air conditioning load torque correction control process. On the other hand, if the determination is "no" in step S11, the ECU 50 repeats the process of step S8.

[0080] Here, the setting of the most recent torque target value when performing step S10 again is explained by repeating step S8. In the initial step S10, a value equivalent to the stable air conditioning load torque is set as the most recent torque target value. In subsequent steps S10, the value obtained by subtracting a predetermined amount from the most recent torque target value set in the previous step S10 is set as the new most recent torque target value. That is, the most recent torque target value decreases slowly. This smooths out the change in the actual generated torque and effectively suppresses the generation of vibration.

[0081] Next, step S12 will be explained. In step S12, the ECU 50 calculates the most recent torque target value. Furthermore, the ignition timing control unit 54 calculates the ignition timing corresponding to the most recent torque target value. The ECU 50 incorporates the most recent torque target value calculated in step S12 into the requested torque calculated based on the driver's operation. After the processing in step S12, the ECU 50 repeats the processing in step S8.

[0082] Here, the setting of the nearest torque target value when performing step S12 again is explained by repeating step S8. In step S12, unlike step S10, the nearest torque target value set in the previous step S12 is maintained.

[0083] Additionally, refer to Figure 2 The recent target torque value and the actual generated torque began to decrease slightly earlier than time t4. The decrease in the recent target torque value can be roughly targeted to begin at time t4. For example... Figure 2As shown, by disengaging the clutch 31a after the actual generated torque begins to decrease, the actual generated torque can be changed more smoothly, thereby effectively suppressing the generation of vibration.

[0084] Here, we will explain in detail the three conditions that serve as the termination conditions for the air conditioning load torque correction control in steps S6 and S11.

[0085] The first termination condition is that the difference between the actual air volume torque and the most recent torque target value, which is the target torque value in the second torque correction control, is below a preset predetermined value. The actual air volume torque can be calculated based on the detection value of the airflow meter 13. The difference between the actual air volume torque and the most recent target torque is calculated by the difference calculation unit 56. If the difference between the actual air volume torque and the most recent torque target value becomes smaller, it is difficult to generate vibration caused by the air conditioning load torque even if the ignition timing delay is stopped. Therefore, a condition related to the difference between the actual air volume torque and the most recent torque target value is set.

[0086] The second termination condition is that a predetermined time has elapsed after the instruction to change the drive state of compressor 31. If the air conditioning load torque correction control continues, the ignition timing correction continues, and MBT ignition will not be performed. If MBT ignition is not performed, it will affect the output or fuel consumption of engine 100. Therefore, if the first condition is not met within the predetermined time, the ECU forcibly terminates the air conditioning load torque correction control.

[0087] The third termination condition is a change in the AC30 request during air conditioning load torque correction control. For example, if an AC disconnection request is received while air conditioning load torque correction control based on an AC on request is being executed, the control ends. In this case, the control is re-executed based on the AC disconnection request. Similarly, if an AC on request is received while air conditioning load torque correction control based on an AC disconnection request is being executed, the control ends. And the control is re-executed based on the AC on request.

[0088] For example, such as Figure 5As shown in Figure A, suppose air conditioning load torque correction control is executed based on an AC turn-on request at time t1, and an AC turn-off request is received at time t3. In this case, at time t3, air conditioning load torque correction control based on the AC turn-on request continues. Thus, while continuously executing the previously executed air conditioning load torque correction control, when an AC turn-off request is received, the air conditioning load torque correction control temporarily ends. Furthermore, the process of step S1 is executed again. This example is equivalent to the case in step S2 where the AC 30 request changes from turn-on to turn-off. Therefore, the process proceeds to step S8, and air conditioning load torque correction control is re-executed. In this way, by continuously executing air conditioning load torque correction control, vibration can be effectively suppressed. The case where the AC 30 request changes from turn-off to turn-on is also handled in the same manner.

[0089] Furthermore, when the switching interval between AC30's on and off is short, the previously executed air conditioning load torque correction control temporarily ends. Instead, a new air conditioning load torque correction control is executed. For example, as... Figure 5 As shown in (B), suppose that after the AC turn-on request is issued at time t1, the AC turn-off request is issued at time t3' and the clutch 31a is disengaged at time t4' within a short period of time. Even in this case, the previously executed air conditioning load torque correction control ends and a new air conditioning load torque correction control is executed.

[0090] In this embodiment, the air conditioning load torque correction control ends when one of these three conditions is met.

[0091] [Effect]

[0092] When the vehicle 80 is in a predetermined driving state and the driving state of the compressor 31 changes, the control device in this embodiment adjusts the requested torque calculated based on the driver's operation to reflect the change in the air conditioning load torque accompanying the change in the driving state of the compressor 31. At this time, a first torque correction control that changes the intake air volume and a second torque correction control that changes the ignition timing in the engine 100 are executed. As a result, vibrations that may occur in the vehicle 80 while it is in motion due to the driving of the compressor 31 can be suppressed.

[0093] The embodiments of the present invention have been described in detail above, but the present invention is not limited to this specific embodiment. Various modifications and alterations can be made within the scope of the spirit of the present invention as set forth in the claims.

[0094] Symbol Explanation

[0095] 1-Internal combustion engine, 7-Spark plug, 30-Air conditioning unit (AC), 31-Compressor, 31a-Clutch, 33-Air conditioning control unit, 50-ECU, 51-Requested torque calculation unit, 52-Air conditioning load torque correction unit, 53-Timing unit, 54-Ignition timing control unit, 55-Throttle control unit, 56-Differential calculation unit, 58-Throttle opening sensor, 59-Shift device, 60-Shift position sensor, 61-Vehicle speed sensor, 62-Gear information acquisition unit, 80-Vehicle, 81-Transmission device, 100-Engine.

Claims

1. An engine control device, in a vehicle having an engine and a compressor for compressing air conditioning refrigerant driven by the engine, and in a driving state, wherein the engine control device performs air conditioning load torque correction control to reflect changes in air conditioning load torque caused by changes in the driving state of the compressor in a requested torque calculated based on driver operation, characterized in that... The air conditioning load torque correction control includes: The first torque correction control increases the intake air volume and thus increases the actual air volume torque when the compressor switches from the drive disengagement state to the drive state, and decreases the intake air volume and thus decreases the actual air volume torque when the compressor switches from the drive state to the drive disengagement state. and The second torque correction control delays the ignition timing to reduce the actual air volume torque when the compressor transitions from the drive disengagement state to the drive state, and when the compressor transitions from the drive state to the drive disengagement state, thereby setting a torque target value corresponding to the air conditioning load torque.

2. The engine control device according to claim 1, characterized in that, The vehicle is equipped with: a shifting device; and a transmission device capable of selecting at least a low gear, a high gear, and a reverse gear. When the shifting device selects a shifting position other than the stop position, the transmission device selects a low gear or reverse gear, and the accelerator pedal pressure is below a preset threshold, the control device determines that the vehicle is in a driving state.

3. The engine control device according to claim 1, characterized in that, If the difference between the actual air volume torque and the torque target value in the second torque correction control is below a predetermined value, the control device terminates the second torque correction control.

4. The engine control device according to claim 1, characterized in that, After a predetermined time has elapsed following the issuance of an instruction to change the drive state of the compressor, the control device terminates the second torque correction control.

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