Control device of internal combustion engine

Abstract

To provide a technology for a control device of an internal combustion engine which can shorten the time for gear change and reduce a shock due to the gear change.SOLUTION: A vehicle includes: an internal combustion engine; an automatic transmission; a first sensor that obtains the engine rotation speed as a rotation speed of the internal combustion engine; a second sensor that obtains the converter rotation speed as a rotation speed of a torque converter; and a third sensor that obtains the transmission rotation speed as a rotation speed of the automatic transmission. Upon start of the shift down of the automatic transmission, the control device controls, during the gear shift period, the torque of the internal combustion engine by instruction torque based on a target motion amount obtained based on the engine rotation speed and the transmission rotation speed. The control device controls, during the gear shift period, the torque of the internal combustion engine by the instruction torque, based on a difference between a first torque converted motion amount based on the torque of the internal combustion engine obtained based on the obtained engine rotation speed and a second torque converted motion amount based on a torque ratio of the torque converter.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] In a vehicle equipped with an automatic transmission, blipping may be performed to increase the rotation speed of the internal combustion engine when shifting gears. More specifically, in a manual shifting mode of the automatic transmission, blipping is performed as a method of reducing shock caused by shifting gears by matching the rotation speed of the internal combustion engine to the rotation speed of the transmission after downshifting. Patent Document 1 discloses a vehicle control device that controls blipping during downshifting. Hereinafter, the control of blipping during downshifting is referred to as blipping downshift control.

[0003] In an automatic transmission having a torque converter, the blipping downshift control is performed by adjusting the pressure of a multi-plate clutch of the automatic transmission using a hydraulic control device. Furthermore, the blipping downshift control increases the torque of the internal combustion engine while adjusting the pressure of the multi-plate clutch, thereby increasing the rotation speed of the internal combustion engine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-225050 A Summary of the Invention [Problem to be solved by the invention]

[0005] The torque of the internal combustion engine is determined by adjusting the throttle opening degree by feedforward control. This may result in engine racing, where the engine speed increases excessively. Furthermore, the multi-plate clutch has variations in response and transmitted torque due to the filling characteristics of the hydraulic oil and the friction coefficient of the friction material. Therefore, it is difficult to set the pressure of the multi-plate clutch to an ideal value according to the level of the torque of the internal combustion engine.

[0006] Therefore, in the blipping downshift control, it was necessary to gradually increase the torque of the internal combustion engine in order to prevent engine revving and shock caused by shifting. In other words, it was difficult to simultaneously shorten the shift time and reduce the shock caused by shifting. [Means for solving the problem]

[0007] The present disclosure can be realized in the following forms.

[0008] (1) According to one aspect of the present disclosure, there is provided a control device for an internal combustion engine mounted on a vehicle, the control device including the internal combustion engine, an automatic transmission including a torque converter, a first sensor for acquiring an engine speed as the speed of an output shaft of the internal combustion engine, a second sensor for acquiring a converter speed as the speed of an output shaft of the torque converter, and a third sensor for acquiring a transmission speed as the speed of an output shaft of the automatic transmission. The control device stores a predetermined relationship between the torque of the internal combustion engine and the engine speed, and a torque ratio between the output shaft of the internal combustion engine and the output shaft of the torque converter based on the speed ratio between the engine speed and the converter speed, and controls the torque of the internal combustion engine by an instruction torque based on a target momentum of the internal combustion engine during a shift period that is a period from the start of shifting to the end of shifting, in response to the start of a downshift by the automatic transmission, which is based on the target momentum obtained based on the engine speed and the transmission speed, and acquires the engine speed during the shift period, and controls the torque of the internal combustion engine by the instruction torque based on the difference between a first torque converted momentum based on an estimated engine torque as the torque of the internal combustion engine obtained based on the acquired engine speed, and a second torque converted momentum obtained by acquiring the converter speed and estimating the converter torque based on the estimated engine torque and the torque ratio. In this embodiment, the control device of the internal combustion engine obtains a target momentum of the internal combustion engine in response to the start of a downshift. Furthermore, after the internal combustion engine outputs an instruction torque based on the target momentum, the control device of the internal combustion engine checks the difference between a first torque converted momentum based on the estimated engine torque and a second torque converted momentum obtained by the estimated converter torque. Based on the difference, the control device of the internal combustion engine further controls the torque of the internal combustion engine based on the instruction torque. That is, the control device of the internal combustion engine can control the torque transmitted to the automatic transmission by performing feedback control of the torque of the internal combustion engine in response to the torque ratio of the torque converter after the start of the shift. Therefore, the control device of the internal combustion engine can achieve both a reduction in the time required for shifting and a reduction in the shock caused by the shift, even when the torque of the internal combustion engine is excessive or there is variation in the torque transmitted to the automatic transmission, compared to, for example, an embodiment in which the torque of the internal combustion engine is gradually increased according to a control value set in advance to reduce the shock caused by the shift. (2) In the control device for an internal combustion engine of the above form, in controlling the torque of the internal combustion engine using the command torque, the control device may reduce the torque of the internal combustion engine when the second torque converted momentum is greater than the first torque converted momentum, and maintain the torque of the internal combustion engine when the second torque converted momentum is smaller than the first torque converted momentum. With this configuration, the control device for the internal combustion engine prevents the second torque converted momentum from exceeding the first torque converted momentum. That is, the control device for the internal combustion engine can prevent the occurrence of racing in the internal combustion engine when blipping is performed. (3) In the control device for an internal combustion engine of the above-described form, the internal combustion engine may further include a combustion device that performs retarding, and the control device may control the retarding based on a difference between the first torque converted momentum and the second torque converted momentum during the shift period. With this configuration, the control device for the internal combustion engine can control the torque of the internal combustion engine by retarding the ignition timing, faster than, for example, controlling the intake of the internal combustion engine by a throttle valve. In other words, the control device for the internal combustion engine can achieve control close to real time. Therefore, the control device for the internal combustion engine is more suitable for gear changes while driving, which require fast response. (4) In the control device for an internal combustion engine of the above-described form, the internal combustion engine may further include a throttle valve, and the control device may increase the torque of the internal combustion engine by the throttle valve in controlling the torque of the internal combustion engine based on the target momentum. In this embodiment, the throttle valve increases the torque of the internal combustion engine through feedforward control. That is, the torque of the internal combustion engine may increase excessively. However, the control device of the internal combustion engine can reduce the torque of the internal combustion engine by implementing retardation, so that the torque can be easily controlled. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is an explanatory diagram showing the configuration of a vehicle. [Diagram 2] FIG. 4 is an explanatory diagram showing the relationship between engine speed and transmission speed. [Diagram 3] FIG. 4 is a diagram illustrating the relationship between the engine speed and the expected speed. [Figure 4] FIG. 4 is an explanatory diagram showing control of the torque of the internal combustion engine. [Diagram 5] 4 is a flowchart showing the processing of the control device. [Figure 6] 5 is a flowchart showing the process of the control device after the torque of the internal combustion engine is increased. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A. First embodiment: A-1. Vehicle configuration: 1 is an explanatory diagram showing the configuration of a vehicle 10. A control device 100 for an internal combustion engine 200 according to the present disclosure is mounted on the vehicle 10. The vehicle 10 includes the internal combustion engine 200, an automatic transmission 300, a first sensor 400, a second sensor 500, and a third sensor 600.

[0011] The internal combustion engine 200 outputs power of rotational motion for driving the wheels W by burning fuel. Specifically, the internal combustion engine 200 is a reciprocating engine, and is a spark-ignition type four-stroke engine that uses gasoline as fuel. In the internal combustion engine 200, an output shaft from which the power is output is connected to an automatic transmission 300, which will be described later. Thus, the power of the internal combustion engine 200 is transmitted to the automatic transmission 300. The power of the internal combustion engine 200 is determined by torque and rotation speed. In the following description, the number of revolutions per unit time of the output shaft of the internal combustion engine 200 is referred to as the engine speed Ne. Note that other revolutions in this specification will also be described as the same number of revolutions per unit time as the engine speed Ne. The internal combustion engine 200 includes a combustion device 210 and a throttle valve 220.

[0012] The throttle valve 220 changes the amount of intake air in the internal combustion engine 200. The throttle valve 220 changes the opening degree of the valve by being controlled by the control device 100 based on the amount of depression of the accelerator pedal by the driver and predetermined control conditions. In other words, the throttle valve 220 is an electronically controlled valve. In the following description, the opening degree of the valve is also referred to as the throttle opening degree. Therefore, the throttle valve 220 changes the torque of the internal combustion engine 200 by changing the throttle opening degree.

[0013] The combustion device 210 includes an injector and a spark plug. The injector injects fuel into a combustion chamber of the internal combustion engine 200. The spark plug ignites the fuel in the combustion chamber. As described above, the internal combustion engine 200 is a four-stroke engine, and therefore performs an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke. The combustion device 210 injects fuel during the intake stroke and performs ignition during the combustion stroke. Note that in FIG. 1, the injector and the spark plug are omitted in order to facilitate understanding of the technology.

[0014] The combustion device 210 has its ignition timing controlled by the control device 100. More specifically, the combustion device 210 retards the ignition timing in response to the implementation of retarding. Retarding refers to control that retards the ignition timing from the start of fuel injection to ignition compared to normal driving. A method of implementing retarding will be described in detail later. The torque of the internal combustion engine 200 decreases due to retarding. Note that the torque of the internal combustion engine 200 responds in about 20 msec from an instruction to start retarding control.

[0015] The automatic transmission 300 performs gear shifting of the vehicle 10. The automatic transmission 300 includes a torque converter 320 and a transmission 310. Furthermore, the automatic transmission 300 performs gear shifting by switching between an automatic gear shifting mode in which gear shifting is performed by automatic operation and a manual gear shifting mode in which gear shifting is performed by manual operation under the control of the control device 100. However, in this specification, gear shifting by the automatic transmission 300 refers to downshifting in the manual gear shifting mode.

[0016] Torque converter 320 transmits the torque of internal combustion engine 200 to transmission 310. More specifically, torque converter 320 is a fluid coupling, and transmits the torque of internal combustion engine 200 via a fluid between an output shaft of internal combustion engine 200 and an input shaft of transmission 310. However, torque converter 320 also transmits torque mechanically in a lockup state or a flex lockup state, which will be described later.

[0017] The torque converter 320 includes a turbine liner, a pump impeller, and a lock-up clutch. In the torque converter 320, the rotating shaft of the pump impeller is an input shaft, and the rotating shaft of the turbine liner is an output shaft. That is, the input shaft of the torque converter 320 is connected to the output shaft of the internal combustion engine 200. The output shaft of the torque converter 320 is connected to the transmission 310. In the following description, the rotation speed of the output shaft of the torque converter 320 is referred to as the converter rotation speed Nc. Furthermore, the ratio of the torque of the output shaft to the torque of the input shaft in the torque converter 320 is referred to as the torque ratio of the torque converter 320. Note that in FIG. 1, the turbine liner, the pump impeller, and the lock-up clutch are omitted in order to facilitate understanding of the technology.

[0018] The lock-up clutch engages the input shaft and output shaft of the torque converter 320 by friction. More specifically, the lock-up clutch changes the engagement state according to a torque ratio based on the ratio of the rotation speeds of the input shaft and output shaft of the torque converter 320. The engagement states of the input shaft and output shaft of the torque converter 320 include a lock-up state in which they are fully engaged, a flex lock-up state in which they are half engaged, and a torque converter state in which they are released. That is, in the lock-up state and the flex lock-up state, torque is transmitted even by mechanical engagement. In the lock-up state, the rotation speeds of the input shaft and output shaft of the torque converter 320 match. That is, the converter rotation speed Nc matches the engine rotation speed Ne.

[0019] The transmission 310 changes the gear ratio. The transmission 310 has a stepped gear mechanism including a plurality of gears, a clutch, and a hydraulic control circuit. In order to facilitate understanding of the technology, the gears, the clutch, and the hydraulic control circuit are omitted from FIG. 1. More specifically, the transmission 310 switches between a plurality of gears that determine the gear ratio by controlling the engagement of the clutch via the hydraulic control circuit under the control of the control device 100. That is, the transmission 310 changes the torque of the output shaft of the transmission 310 that is transmitted to the wheels W. The rotation speed of the output shaft of the transmission 310 is called the transmission rotation speed Nt. The transmission rotation speed Nt is also the product of the converter rotation speed Nc and the gear ratio. That is, in the lock-up state of the torque converter 320, the transmission rotation speed Nt is the product of the engine rotation speed Ne and the gear ratio.

[0020] The power transmission mechanism including the internal combustion engine 200, the torque converter 320, and the transmission 310 has inertia as a moment of inertia with respect to the power of the internal combustion engine 200. In this specification, the inertia is divided into theoretically set inertia and actual inertia. The theoretically set inertia is stored in advance in the control device 100 for determining a first command torque a1, which will be described later. That is, the theoretically set inertia is used to control the torque of the internal combustion engine 200 regardless of the shift. The actual inertia is obtained by the control device 100 during the shift period T1, which is the period from the start of the shift to the end of the shift. As described above, the torque ratio of the torque converter 320 differs depending on the engagement state. The actual inertia varies depending on the torque ratio of the torque converter 320. The determination of the actual inertia will be described in detail later.

[0021] The first sensor 400 acquires the engine speed Ne as the rotation speed of the output shaft of the internal combustion engine 200. For example, the first sensor 400 acquires the engine speed Ne by being provided on a crankshaft as the output shaft of the internal combustion engine 200. The first sensor 400 transmits a signal based on the engine speed Ne to the engine ECU 110 of the control device 100.

[0022] The second sensor 500 acquires the converter rotation speed Nc as the rotation speed of the output shaft of the torque converter 320. For example, the second sensor 500 acquires the converter rotation speed Nc by being provided on a rotating shaft of a turbine liner of the torque converter 320. The second sensor 500 transmits a signal based on the converter rotation speed Nc to the transmission ECU 120 of the control device 100.

[0023] The third sensor 600 acquires a transmission rotation speed Nt as the rotation speed of the output shaft of the transmission 310. For example, the third sensor 600 acquires the transmission rotation speed Nt by being provided on the rotating shaft of the output shaft. The third sensor 600 transmits a signal based on the transmission rotation speed Nt to the transmission ECU 120 of the control device 100.

[0024] The various sensors periodically acquire the rotation speed regardless of the shift period T1. More specifically, the various sensors acquire the rotation speed from before the shift starts to after the shift ends. Therefore, the deceleration of the transmission rotation speed Nt, which will be described later, is determined based on the rotation speed acquired before the shift starts.

[0025] The control device 100 performs control related to gear shifting of the vehicle 10. The control device 100 is composed of an engine ECU 110 as an ECU (Electronic Control Unit) that controls the internal combustion engine 200, and a transmission ECU 120 as an ECU that controls the automatic transmission 300. The engine ECU 110 and the transmission ECU 120 communicate with each other. Each ECU of the engine ECU 110 and the transmission ECU 120 includes a CPU, a ROM, and a RAM. The ROM is a read-only semiconductor memory. The ROM stores a control program for control in advance. The RAM is a main memory that is a semiconductor memory, and stores information required for control. The CPU realizes the functions of each part by executing various programs stored in the ROM. The CPU uses the RAM to store information required for processing.

[0026] A-2. How to determine momentum: The control device 100 controls the internal combustion engine 200 based on the momentum associated with the vehicle 10. The momentum associated with the vehicle 10 is divided into a first target momentum M1, a second target momentum, a first torque converted momentum, and a second torque converted momentum.

[0027] The first target momentum M1 is a momentum required of the internal combustion engine 200 at the end of the shift. The first target momentum M1 is obtained based on the engine speed Ne and the transmission speed Nt. First, the relationship between the engine speed Ne and the transmission speed Nt during the shift period T1 will be described.

[0028] FIG. 2 is an explanatory diagram showing the relationship between the engine speed Ne and the transmission speed Nt. FIG. 2 shows the relationship between the engine speed Ne and the transmission speed Nt before and after a downshift. In this specification, the transmission speed Nt is referred to as a first speed Nt1 when the gear shift starts. Furthermore, the engine speed Ne relative to the first speed Nt1 is referred to as a second speed Ne2 before the downshift and as a third speed Ne3 after the downshift. Furthermore, the difference between the second speed Ne2 and the third speed Ne3 is referred to as a differential speed Nd. That is, a difference of the differential speed Nd occurs between the engine speed Ne before and after the downshift.

[0029] FIG. 3 is an explanatory diagram showing the relationship between engine speed Ne and assumed speed Nta. FIG. 3 shows the relationship between engine speed Ne and assumed speed Nta when blipping is performed during shift period T1. Note that the shift period T1 also indicates the period from time t1 when shifting starts to time t8 when shifting ends in other drawings. The assumed speed Nta is the speed obtained by dividing the transmission speed Nt by the gear ratio. In other words, the assumed speed Nta is the converter speed Nc when the shifting is assumed to be completed, and is also the engine speed Ne when the torque converter 320 is in a lockup state.

[0030] At the time t1 when the shift starts, as described above, a difference of the engine speed Ne and the assumed speed Nta occurs by the difference speed Nd. From the time t1 when the shift starts, the output of the internal combustion engine 200 is increased by blipping, so that the assumed speed Nta and the engine speed Ne match after the shift period T1 has elapsed. That is, the shift by the automatic transmission 300 ends. In this specification, the speed at the time t8 when the shift ends is called the synchronous speed Ne4. The control device 100 determines the synchronous speed Ne4, which is the speed at the time t8 when the shift ends and at which the engine speed Ne and the assumed speed Nta match, based on the transition of the engine speed Ne and the transition of the assumed speed Nta.

[0031] The transition of the engine speed Ne is determined by the control device 100 based on the second speed Ne2 at the shift start time t1 and an acceleration determined in advance according to the second speed Ne2. The acceleration according to the second speed Ne2 is recorded in the ROM of the engine ECU 110 in advance.

[0032] The transition of the assumed rotation speed Nta is determined by the control device 100 based on the third rotation speed Ne3 at the shift start time t1 and the deceleration of the transmission rotation speed Nt. The deceleration of the transmission rotation speed Nt is determined by the second sensor 500 based on the transmission rotation speed Nt acquired before the shift start.

[0033] In response to the start of a downshift by the automatic transmission 300, the control device 100 determines a first target momentum M1 based on the synchronous rotation speed Ne4 and the theoretically set inertia.

[0034] The control device 100 controls the torque of the internal combustion engine 200 by a first command torque a1 based on a first target momentum M1. More specifically, the control device 100 controls the throttle opening by a torque value determined by dividing the first target momentum M1 by a torque-up time T2.

[0035] FIG. 4 is an explanatory diagram showing the control of the torque of the internal combustion engine 200. FIG. 4 illustrates an example of a first command torque a1 in a shift period T1. The first command torque a1 is a torque value that the control device 100 requests the internal combustion engine 200 to have. The control device 100 stores in advance in the ROM of the engine ECU 110 the relationship between the torque of the internal combustion engine 200 and the throttle opening of the throttle valve 220. For example, the predetermined relationship between the torque of the internal combustion engine 200 and the throttle opening is an experimentally determined correlation.

[0036] The torque-up time T2 is a time during which the control device 100 issues an instruction by the first instruction torque a1 to increase the torque of the internal combustion engine 200. In this specification, an increase in the torque of the internal combustion engine 200 is also called torque-up, and a decrease in the torque of the internal combustion engine 200 is also called torque-down. The control device 100 stores in advance in the ROM of the engine ECU 110 the relationship of the torque-up time T2 required depending on the engine speed Ne, the synchronous speed Ne4, the response time of the internal combustion engine 200, and the like. The response time of the internal combustion engine 200 is the time it takes for the internal combustion engine 200 to respond from the start of an instruction to control the throttle opening. The response time of the internal combustion engine 200 depends on the flow speed of the air, and therefore a delay occurs. For example, the response time of the internal combustion engine 200 is about 100 msec. That is, the response speed of the torque control of the internal combustion engine 200 by the throttle opening is slower than the response speed of the torque control of the internal combustion engine 200 by retarding the angle.

[0037] Therefore, in response to the start of a downshift, the control device 100 increases the torque of the internal combustion engine 200 by the first command torque a1 based on the first target momentum M1.

[0038] The second target momentum is obtained by replacing the theoretically set inertia in the first target momentum M1 with the actual inertia. A method for determining the actual inertia will be described in detail later.

[0039] Next, the first torque converted momentum will be described. The first torque converted momentum is a momentum determined based on the engine speed Ne acquired during the shift period T1. In determining the first torque converted momentum, the control device 100 first determines an estimated engine torque.

[0040] The control device 100 stores a predetermined relationship between the torque of the internal combustion engine 200 and the engine speed Ne in the ROM of the engine ECU 110. For example, the predetermined relationship between the torque of the internal combustion engine 200 and the engine speed Ne is a correlation determined experimentally. Therefore, the control device 100 acquires the engine speed Ne during the shifting period T1, and determines an estimated engine torque as the torque of the internal combustion engine 200 based on the acquired engine speed Ne.

[0041] Therefore, the control device 100 determines the first torque converted momentum by integrating the estimated engine torque up to the point in time when the engine speed Ne is acquired.

[0042] Next, the second torque converted momentum will be described. The second torque converted momentum is a momentum determined based on the converter rotation speed Nc acquired during the shift period T1. In determining the second torque converted momentum, the control device 100 first determines an estimated converter torque.

[0043] The control device 100 determines the estimated converter torque based on the estimated engine torque and the torque ratio of the torque converter 320. The control device 100 prestores in the ROM of the transmission ECU 120 the relationship between the torque ratio of the torque converter 320 based on the rotation speed ratio of the engine speed Ne and the converter speed Nc. Therefore, the control device 100 determines the torque ratio of the torque converter 320 based on the rotation speed ratio of the engine speed Ne and the converter speed Nc by acquiring the engine speed Ne and the converter speed Nc at the same time. Furthermore, the control device 100 determines the estimated converter torque by multiplying the estimated engine torque by the torque ratio of the torque converter 320.

[0044] Therefore, the control device 100 determines the second torque converted momentum by integrating the estimated converter torque until the converter rotation speed Nc is acquired. An example of the transition of the second torque converted momentum during the shift period T1 is illustrated in the lower part of FIG.

[0045] A-3. Control method of an internal combustion engine: Fig. 5 is a flowchart showing the processing of the control device 100. In the following description, Fig. 4 is used as an example of the processing of the control device 100 along with the flowchart. The control device 100 starts the processing of control as blipping in response to the start of a downshift by the automatic transmission 300. More specifically, the control device 100 starts the processing when the driver instructs a downshift in a state in which the automatic transmission 300 is set to the manual shift mode.

[0046] In steps S110 to S160 in FIG. 5, the control device 100 increases the torque of the internal combustion engine 200 by determining the first command torque a1 based on the first target momentum M1, as described above.

[0047] 5, the control device 100 acquires the engine speed Ne at time point t1 from the first sensor 400. That is, the control device 100 acquires the second engine speed Ne2 in FIG.

[0048] 5, the control device 100 determines the assumed rotation speed Nta at the time point t1 based on the engine rotation speed Ne and the gear ratio. That is, the control device 100 determines the third rotation speed Ne3 in FIG.

[0049] In step S130 of Fig. 5, the control device 100 determines the synchronous speed Ne4 based on the assumed speed Nta and the engine speed Ne. As described above, the control device 100 determines the deceleration of the assumed speed Nta based on the transmission speed Nt acquired before the start of the shift. Furthermore, the control device 100 acquires a predetermined acceleration according to the second speed Ne2. Therefore, as shown in Fig. 3, the control device 100 determines the synchronous speed Ne4 by calculating the speed at the time t8 at which the assumed speed Nta and the engine speed Ne match.

[0050] In step S140 of FIG. 5, the control device 100 acquires a predetermined desktop set inertia.

[0051] In step S150 of FIG. 5, the control device 100 determines the first target momentum M1 based on the synchronous rotation speed Ne4 and the theoretically set inertia, as described above.

[0052] 5, the control device 100 controls the torque of the internal combustion engine 200 by the first command torque a1 based on the first target momentum M1. That is, the control device 100 determines the first command torque a1 based on the first target momentum M1 as described above. Furthermore, in controlling the torque of the internal combustion engine 200 based on the first target momentum M1, the control device 100 increases the torque of the internal combustion engine 200 by the throttle valve 220. Therefore, the control device 100 increases the torque of the internal combustion engine 200 by controlling the throttle opening.

[0053] The upper part of Fig. 4 illustrates a transition a2 of the torque of the internal combustion engine 200 relative to the first command torque a1. As described above, the internal combustion engine 200 responds with a delay from the start of the command to control the throttle opening. That is, the period from time t1 to time t2 is a period during which the response of the internal combustion engine 200 is delayed. Next, in the period from time t2 to time t3, the internal combustion engine 200 responds, and the torque increases up to the first command torque a1. The period from time t3 onwards will be described later.

[0054] FIG. 6 is a flowchart showing the process of the control device 100 after the torque is increased.

[0055] In step S170 of FIG. 6, the control device 100 acquires the engine speed Ne from the first sensor 400.

[0056] In step S180 of FIG. 6, the control device 100 determines the first torque converted momentum based on the engine speed Ne, as described above.

[0057] In step S190 of FIG. 6, the control device 100 acquires the converter rotation speed Nc from the second sensor 500.

[0058] In step S200 of FIG. 6, the control device 100 determines the second torque converted momentum based on the converter rotation speed Nc, as described above.

[0059] In step S210 of Fig. 6, the control device 100 compares the first torque converted momentum with the second torque converted momentum. More specifically, if the second torque converted momentum is greater than the first torque converted momentum, the control device 100 advances the process to step S310. If the second torque converted momentum is less than the first torque converted momentum, the control device 100 advances the process to step S410.

[0060] In step S310 of FIG. 6, the control device 100 determines the second target momentum M2. More specifically, the control device 100 determines the second target momentum M2 by replacing the theoretically set inertia in the first target momentum M1 with the actual inertia. The control device 100 determines, as the inertia correction coefficient, the difference between the integrated value of the estimated converter torque up to the time when the converter rotation speed Nc is acquired and the product of the theoretically set inertia and the advanced converter rotation speed Nc. The advanced converter rotation speed Nc is the difference between the acquired converter rotation speed Nc and the second rotation speed Ne2. The control device 100 determines the actual inertia by the product of the inertia correction coefficient and the theoretically set inertia. Therefore, the control device 100 determines the second target momentum M2 by replacing the theoretically set inertia with the actual inertia.

[0061] In step S320 of FIG. 6, the control device 100 controls the torque of the internal combustion engine 200 by the first command torque a1 based on the second target momentum M2. More specifically, the control device 100 determines the second command torque by a method similar to that for the first command torque a1 based on the second target momentum M2. Furthermore, the control device 100 controls the retard angle based on the difference between the first command torque a1 and the second command torque. The control device 100 prestores the characteristics of the torque that is reduced by the retard angle in the ROM of the engine ECU 110. For example, the characteristics of the torque that is reduced by the retard angle are characteristics based on a correlation obtained experimentally. Therefore, the control device 100 controls the torque of the internal combustion engine 200 by reducing the torque by implementing the retard angle based on the difference between the first command torque a1 and the second command torque.

[0062] Regarding the above process, that is, the control device 100 controls the torque of the internal combustion engine 200 by the first command torque a1 based on the difference between the first torque converted momentum and the second torque converted momentum in the shifting period T1. More specifically, in controlling the torque of the internal combustion engine 200, when the second torque converted momentum is larger than the first torque converted momentum, the control device 100 reduces the torque of the internal combustion engine 200. Furthermore, in the process after step S410 described later, when the second torque converted momentum is smaller than the first torque converted momentum, the control device 100 maintains the torque of the internal combustion engine 200. That is, the control device 100 controls the internal combustion engine 200 so that the torque of the internal combustion engine 200 by the first command torque a1 is reduced by implementing retarding based on the difference between the first torque converted momentum and the second torque converted momentum in the shifting period T1.

[0063] In the torque graph of FIG. 4, an example of retarding is shown from time t4 to time t5. In FIG. 4, the dashed line indicates the decrease in torque of the internal combustion engine 200 due to retarding. After time t3, the torque of the internal combustion engine 200 is kept constant by reaching the first command torque. However, when the second torque converted momentum exceeds the first torque converted momentum, retarding is performed during that period from time t4 to time t5. As described above, the response of the internal combustion engine 200 to the retard control is faster than the response of the internal combustion engine 200 to the throttle opening control. Therefore, as shown in FIG. 4, the torque of the internal combustion engine 200 is immediately decreased by retarding.

[0064] In the momentum graph of FIG. 4, the transition of the second torque converted momentum is illustrated. The dashed line shows the transition of the second torque converted momentum when the retard is not implemented. The solid line shows the transition of the second torque converted momentum when the retard is implemented. When the retard is implemented, the second torque converted momentum decreases. Furthermore, as shown in FIG. 5, the control device 100 returns the process to step S170 after the process of step S320 is completed. Therefore, when the control device 100 determines the second torque converted momentum again, the process proceeds with the second torque converted momentum that has decreased due to the retard. Therefore, as shown in FIG. 4, after the retard is implemented from time t4 to time t5, the second torque converted momentum transitions lower than the second torque converted momentum when the retard is not implemented.

[0065] In step S410 of Fig. 6, the control device 100 determines whether to increase the torque of the internal combustion engine 200. That is, if there is an instruction based on the first command torque a1, the control device 100 advances the process to step S420. If there is no instruction based on the first command torque a1, the control device 100 ends the process. That is, the shift by the automatic transmission 300 ends.

[0066] 6, the control device 100 determines whether or not the retardation is being performed. That is, if the retardation is being performed, the control device 100 advances the process to step S430. If the retardation is not being performed, the control device 100 returns the process to step S170.

[0067] 6, the control device 100 ends the retardation. After the retardation is ended, the control device 100 returns the process to step S170.

[0068] As described above, the control device 100 of the internal combustion engine 200 controls the torque of the internal combustion engine 200 as blipping control during the shift-down shift period T1. More specifically, in this embodiment, the control device 100 of the internal combustion engine 200 obtains a first target momentum M1 of the internal combustion engine 200 in response to the start of the shift-down. Furthermore, the control device 100 of the internal combustion engine 200 checks the difference between the first torque-converted momentum based on the estimated engine torque and the second torque-converted momentum obtained by the estimated converter torque after the output of the internal combustion engine 200 by the command torque based on the first target momentum M1. The control device 100 of the internal combustion engine 200 further controls the torque of the internal combustion engine 200 by the command torque based on the difference. That is, the control device 100 of the internal combustion engine 200 can control the torque transmitted to the automatic transmission 300 by performing feedback control of the torque of the internal combustion engine 200 in response to the torque ratio of the torque converter 320 after the start of the shift. Therefore, compared to a mode in which the torque of the internal combustion engine 200 is gradually increased according to a control value that is set in advance to reduce shock caused by gear shifting, the control device 100 for the internal combustion engine 200 can achieve both a shortened gear shift time and a reduced shock caused by gear shifting even when the torque of the internal combustion engine 200 is excessive or there is variation in the torque transmitted to the automatic transmission 300.

[0069] Furthermore, by adopting such a configuration, the control device 100 of the internal combustion engine 200 prevents the second torque converted momentum from exceeding the first torque converted momentum. That is, the control device 100 of the internal combustion engine 200 can prevent the internal combustion engine 200 from racing when performing blipping.

[0070] Moreover, with this configuration, the control device 100 for the internal combustion engine 200 can control the torque of the internal combustion engine 200 by retarding the ignition timing, faster than controlling the intake of the internal combustion engine 200 by, for example, the throttle valve 220. In other words, the control device 100 for the internal combustion engine 200 can achieve control close to real time. Therefore, the control device 100 for the internal combustion engine 200 is more suitable for gear changes during driving, which require fast responsiveness.

[0071] Furthermore, in this embodiment, the throttle valve 220 increases the torque of the internal combustion engine 200 by feedforward control. That is, the torque of the internal combustion engine 200 may increase excessively. However, the control device 100 for the internal combustion engine 200 can reduce the torque of the internal combustion engine 200 by implementing retardation, and therefore the torque can be easily controlled.

[0072] B. Other embodiments: (1) In the above embodiment, the torque of the internal combustion engine 200 is controlled by determining the magnitudes of the first torque converted momentum and the second torque converted momentum. However, the torque of the internal combustion engine 200 may be controlled by other methods. For example, the torque of the internal combustion engine 200 may be controlled by determining the rate of change of the first torque converted momentum and the rate of change of the second torque converted momentum. (2) In the above embodiment, the torque of the internal combustion engine 200 is reduced by implementing retardation based on the difference between the first torque converted momentum and the second torque converted momentum. However, the torque of the internal combustion engine 200 may also be reduced by controlling the throttle opening. (3) In the above embodiment, the torque of the internal combustion engine 200 is controlled by controlling the throttle opening of the throttle valve 220, except for the retard angle. However, the internal combustion engine 200 does not have to include the throttle valve 220. For example, the internal combustion engine 200 may have a throttle valveless structure. In other words, the torque of the internal combustion engine 200 may be controlled by controlling the amount of intake air by the intake valve of the combustion chamber.

[0073] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above problems or to achieve some or all of the above effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0074] Reference Signs List 10...vehicle, 100...control device, 200...internal combustion engine, 210...combustion device, 220...throttle valve, 300...automatic transmission, 310...transmission, 320...torque converter, 400...first sensor, 500...second sensor, 600...third sensor, 110...engine ECU, 120...transmission ECU, M1...first target momentum, M2...second target momentum, Nc...converter speed, Nd...differential speed, Ne...engine speed, Ne2...second speed, Ne3...third speed, Ne4...synchronous speed, Nt...transmission speed, Nt1...first speed, Nta...expected speed, T1...shift period, T2...torque-up time, W...wheel, a1...first command torque, a2...transition of torque of internal combustion engine, t1 to t8...time points

Claims

1. A control device for an internal combustion engine mounted on a vehicle, The vehicle is The internal combustion engine; an automatic transmission having a torque converter; A first sensor that acquires an engine speed as a rotation speed of an output shaft of the internal combustion engine; a second sensor for acquiring a converter rotation speed as a rotation speed of an output shaft of the torque converter; a third sensor for acquiring a transmission rotation speed as a rotation speed of an output shaft of the automatic transmission; Equipped with The control device includes: a predetermined relationship between the torque of the internal combustion engine and the engine speed, and a torque ratio between an output shaft of the internal combustion engine and an output shaft of the torque converter based on a rotation speed ratio between the engine speed and the converter speed are stored; In response to a start of a downshift by the automatic transmission, a target momentum of the internal combustion engine during a shift period from a shift start to a shift end, the target momentum being obtained based on the engine speed and the transmission speed, and a torque of the internal combustion engine is controlled by a command torque based on the target momentum; A control device for an internal combustion engine that, during the shifting period, acquires the engine speed, and controls the torque of the internal combustion engine based on the command torque based on the difference between a first torque converted momentum based on an estimated engine torque as the torque of the internal combustion engine obtained based on the acquired engine speed, and a second torque converted momentum obtained by acquiring the converter speed and using an estimated converter torque based on the estimated engine torque and the torque ratio.

2. 2. The control device for an internal combustion engine according to claim 1, The control device, in controlling the torque of the internal combustion engine using the command torque, If the second torque equivalent momentum is greater than the first torque equivalent momentum, decreasing the torque of the internal combustion engine; A control device for an internal combustion engine that maintains a torque of the internal combustion engine when the second torque converted momentum is smaller than the first torque converted momentum.

3. The control device for an internal combustion engine according to claim 1 or 2, The internal combustion engine further includes a combustion device that performs retardation. A control device for an internal combustion engine, wherein the control device controls the retard angle based on a difference between the first torque converted momentum and the second torque converted momentum during the shift period.

4. The control device for an internal combustion engine according to claim 3, The internal combustion engine further includes a throttle valve. The control device for an internal combustion engine increases the torque of the internal combustion engine by the throttle valve in controlling the torque of the internal combustion engine based on the target momentum.

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