Torque control method for internal combustion engine and torque control device for internal combustion engine

Abstract

To provide a torque control method of an internal combustion engine and a torque control device of the internal combustion engine, capable of improving uphill starting performance in a highland, while restraining damage of a driving system by double correction in the highland.SOLUTION: In the torque control method for an internal-combustion engine and the torque control device for an internal-combustion engine according to the present invention, in an engine speed region where the engine speed is equal to or less than the first threshold value Rx1, the drive protection required torque T p is corrected in accordance with the atmospheric pressure to obtain a highland drive protection required torque T h, and the driver required torque T d (engine torque T e) is limited to the drive protection required torque T p without performing highland correction of the drive protection required torque T p in a region where the engine speed exceeds the first threshold value Rx1. As a result, it is possible to improve the uphill starting performance at high altitude while suppressing damage to the drive system due to double correction at high altitude.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a torque control method for an internal combustion engine and a torque control device for an internal combustion engine. [Background technology]

[0002] A conventional torque control method for an internal combustion engine is known, for example, from Patent Document 1 below.

[0003] In conventional torque control devices for internal combustion engines, the actual torque is calculated by adding the throttle opening area corresponding to the basic required torque calculated from the accelerator opening to the throttle opening area corresponding to the idle torque, and the actual torque is calculated based on this opening area, and a correction (drive system protection correction) is made to limit the actual torque to a drive system protection required torque that is set to prevent excessive torque from being generated in order to protect the drive system, thereby limiting the engine torque to protect the drive system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-150388 Summary of the Invention [Problem to be solved by the invention]

[0005] It is generally known that actual torque decreases at high altitudes due to a decrease in intake air density. Therefore, in internal combustion engines equipped with a supercharger, the supercharging pressure is corrected to compensate for the decrease in actual torque caused by the decrease in intake air density.

[0006] Furthermore, as mentioned above, since the actual torque decreases due to a decrease in intake density at high altitudes, in order to ensure good uphill starting performance at high altitudes, it is desirable to perform a high altitude correction that increases the drive protection required torque by the amount of the decrease in actual torque.

[0007] However, with the conventional torque control device for an internal combustion engine, when the supercharging pressure correction of the supercharger is performed in addition to the driveline protection correction at high altitudes, such double corrections may cause the engine torque to exceed the driveline protection required torque, and there is a risk that the driveline may not be sufficiently protected, and therefore there is still room for improvement.

[0008] Therefore, the present invention has been devised in consideration of the technical problems of the conventional torque control methods, and aims to provide a torque control method for an internal combustion engine and a torque control device for an internal combustion engine that can improve uphill starting performance at high altitudes while suppressing damage to the drive system due to double correction at high altitudes. [Means for solving the problem]

[0009] One aspect of the present invention is a torque control method for an internal combustion engine equipped with a supercharger, which calculates a driver requested torque in accordance with an operation amount by a driver, calculates a target torque for the internal combustion engine based on the driver requested torque, corrects a supercharging pressure of the supercharger in accordance with air pressure that varies with altitude based on the target torque, calculates a high altitude driving protection requested torque by correcting a drive protection requested torque that is set so as not to generate excessive torque to protect the drive system in accordance with air pressure that varies with altitude in a region where the engine speed is equal to or less than a first threshold, and sets the smaller of the driver requested torque and the high altitude driving protection requested torque as the target torque, while in a region where the engine speed is greater than the first threshold, does not correct the drive protection requested torque and sets the smaller of the driver requested torque and the drive protection requested torque as the target torque. [Effects of the Invention]

[0010] According to the present invention, in a range where the engine speed exceeds a first threshold at high altitudes, it is possible to suppress double corrections, in which corrections of the drive protection request torque and the boost pressure are overlapped, thereby improving uphill starting performance at high altitudes while suppressing damage to the drive train due to the double corrections at high altitudes. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of an internal combustion engine to which the present invention is applied; [Figure 2] 1 is a functional block diagram of torque control of an internal combustion engine according to the present invention; [Figure 3] FIG. 3 is a functional block diagram showing details of a target torque calculation unit shown in FIG. 2. [Figure 4] 10 is a time chart of torque control at high altitudes. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a torque control method and a torque control device for an internal combustion engine according to the present invention will be described below in detail with reference to the accompanying drawings.

[0013] (Configuration of internal combustion engine) FIG. 1 shows a schematic diagram of an internal combustion engine 1 according to this embodiment.

[0014] For example, as shown in FIG. 1, an internal combustion engine 1 according to this embodiment is a four-stroke, spark-ignition internal combustion engine equipped with a turbocharger 2, which is a supercharger. Specifically, in the internal combustion engine 1, a pair of intake valves 4 and a pair of exhaust valves 5 are arranged on the ceiling wall of each cylinder 3, and an ignition plug 6 is arranged in the center surrounded by the intake valves 4 and the exhaust valve 5. A fuel injection valve 7 that supplies fuel to the inside of the cylinder 3 is provided below the intake valve 4. The ignition timing of the spark plug 6 and the injection timing and injection amount of the fuel injection valve 7 are controlled by a control device 9 serving as an engine controller (ECU) that constitutes a control unit according to the present invention. The type of fuel injection device is not limited to a direct injection type, and may be a port injection type.

[0015] The intake valve 4 and the exhaust valve 5 are equipped with well-known variable valve timing mechanisms VT1 and VT2 that can change the opening and closing timings of the intake valve 4 and the exhaust valve 5. The variable valve timing mechanisms VT1 and VT2 change the opening and closing timings of the intake valve 4 and the exhaust valve 5, for example, by retarding or advancing the phase of a camshaft relative to the phase of the crankshaft. Note that the type of the variable valve timing mechanisms VT1 and VT2 is an example and can be changed as desired depending on the specifications of the internal combustion engine 1, etc. The variable valve timing mechanisms VT1 and VT2 are not essential components of the present invention and can be omitted depending on the specifications of the internal combustion engine 1, etc.

[0016] An intake passage 11 connected to a combustion chamber 10 via an intake valve 4 has an intake collector 12. An electronically controlled throttle valve 13, the opening of which is controlled by a control signal from a control device 9, is provided upstream of the intake collector 12. A compressor 2a of the turbocharger 2 is provided upstream of the throttle valve 13, and an air flow meter 14 for detecting the amount of intake air and an air cleaner 15 are provided upstream of the compressor 2a. An intercooler 16, such as a water-cooled type, is provided between the compressor 2a and the throttle valve 13. A well-known recirculation valve 17 is provided to communicate the discharge side and intake side of the compressor 2a. When the throttle valve 13 is closed during deceleration, the recirculation valve 17 opens, preventing the compressed air from being released to the atmosphere and allowing it to be recirculated to the intake side.

[0017] A turbine 2b of the turbocharger 2 is provided in an exhaust passage 21 connected to the combustion chamber 10 via an exhaust valve 5. A catalytic device 22 made of a three-way catalyst and an exhaust particulate filter (GPF) 23 coated with the three-way catalyst are provided downstream of the turbine 2b in the exhaust passage 21. An air-fuel ratio sensor 24 for detecting the air-fuel ratio is disposed upstream of the exhaust passage 21. The turbine 2b is also provided with a wastegate valve 25 that bypasses part of the exhaust gas in accordance with the boost pressure in order to control the boost pressure. The wastegate valve 25 is, for example, an electric type whose opening is controlled by a control signal from the control device 9.

[0018] The internal combustion engine 1 is also provided with an exhaust gas recirculation passage 26, which is a so-called EGR passage, that recirculates a portion of the exhaust gas from the exhaust passage 21 to the intake passage 11. One end of the exhaust gas recirculation passage 26 is connected, for example, between the catalytic device 22 and the exhaust particulate filter 23 in the exhaust passage 21, and the other end of the exhaust gas recirculation passage 26 is connected to the intake passage 11 upstream of the compressor 2a. The exhaust gas recirculation passage 26 is also provided with, for example, a water-cooled EGR cooler 27 that cools the EGR gas, which is the recirculated exhaust gas, and an EGR valve 28 that controls the amount of exhaust gas recirculated. The opening degree of the EGR valve 28 is controlled by the control device 9.

[0019] In addition to the air flow meter 14 and the air-fuel ratio sensor 24, detection signals from various sensors are input to the control device 9, such as a crank angle sensor 31 for detecting engine speed, a water temperature sensor 32 for detecting coolant temperature, an accelerator pedal position sensor 33 for detecting the amount of depression of an accelerator pedal operated by the driver, a vehicle speed sensor 34 for directly or indirectly detecting vehicle speed, an atmospheric pressure sensor 35 for detecting atmospheric pressure, an intake air temperature sensor 36 for detecting intake air temperature (outside air temperature), and a boost pressure sensor 37 for detecting boost pressure. Based on the detection signals from the above sensors input from outside, the control device 9 optimally controls, for example, the fuel injection amount and fuel injection timing, ignition timing, the opening of the throttle valve 13, the opening of the wastegate valve 25, the valve timing of the variable valve timing mechanisms VT1 and VT2, and the opening of the EGR valve 28.

[0020] (Control device description) FIG. 2 shows a functional block diagram of the torque control of the internal combustion engine according to this embodiment.

[0021] 2, the control device 9 that realizes torque control of the internal combustion engine mainly includes a target torque calculation unit B1, a highland supercharging pressure correction unit B2, and a final torque calculation unit B3. The target torque calculation unit B1 includes a driver request torque calculation unit B11 that calculates a driver request torque, a drive protection request torque calculation unit B12 that calculates a drive protection request torque, and a highland drive protection torque correction unit B13 that corrects the drive protection request torque at high altitudes. In this way, the control device 9 performs two corrections at high altitudes: correction of the drive protection request torque by the highland drive protection torque correction unit B13, and correction of the supercharging pressure by the highland supercharging pressure correction unit B2.

[0022] The driver-requested torque calculation unit B11 determines the driver-requested torque based on the amount of depression of the accelerator pedal by the driver. The driver-requested torque includes not only the basic required torque calculated from the amount of depression of the accelerator pedal, but also torques determined based on required torques requested by other controllers of the vehicle and required torques requested by automatic driving functions such as cruise control.

[0023] The drive protection request torque calculation unit B12 determines a drive protection request torque that is set so that excessive torque for protecting the drive train is not generated relative to the driver's request torque. This drive protection request torque is an engine upper limit torque that prevents excessive engine torque from being input to the vehicle drive train, thereby damaging the durability of the drive train, and is calculated and determined based on, for example, a control map set for drive train protection. That is, the drive protection request torque calculation unit B12 limits the driver's request torque by setting the drive protection request torque calculated based on the control map as the maximum engine torque.

[0024] The highland driving protection torque correction unit B13 corrects the driving protection request torque in accordance with the atmospheric pressure that changes with altitude, because at high altitudes where the intake air density is low, if the driver request torque is limited by the same driving protection request torque as at low altitudes, the engine torque (actual torque) desired by the driver cannot be ensured. Specifically, the highland driving protection torque correction unit B13 calculates the highland driving protection request torque by multiplying the driving protection request torque by a correction coefficient that corresponds to the atmospheric pressure, for example.

[0025] With the above-described configuration, the target torque calculation unit B1 determines the target engine torque by limiting the driver-requested torque by the driving protection requested torque at low altitudes. On the other hand, the target torque calculation unit B1 determines the target engine torque by limiting the driver-requested torque by the high altitude driving protection requested torque, which is the driving protection requested torque corrected by the high altitude driving protection torque correction unit B13.

[0026] The highland supercharging pressure corrector B2 corrects the supercharging pressure of the turbocharger 2 with respect to the target torque in order to obtain the target engine torque at high altitudes. That is, at high altitudes where the intake air density is low, the same supercharging pressure as at low altitudes cannot ensure engine torque (actual torque) corresponding to the target torque, so the highland supercharging pressure corrector B2 corrects the supercharging pressure of the turbocharger 2 with respect to the target torque in accordance with the atmospheric pressure which changes with altitude.

[0027] The final torque calculation unit B3 calculates the final torque based on the target torque calculated in the target torque calculation unit B1 and the supercharging pressure of the turbocharger 2 corrected for this target torque in the high altitude supercharging pressure correction unit B2.

[0028] (Details of the target torque calculation section) FIG. 3 is a functional block diagram showing details of the target torque calculation unit shown in FIG.

[0029] 3, the target torque calculation unit B1 has a target torque determination unit 41 that determines the target torque Tt based on the driver required torque Td and the driving protection required torque Tp. The target torque determination unit 41 compares the driver required torque Td and the driving protection required torque Tp input to the target torque determination unit 41, and outputs the smaller one as the target torque Tt.

[0030] Here, the drive protection request torque Tp input to the target torque determination unit 41 is a torque value selected by a drive protection request torque switching unit 52, which is output to the target torque determination unit 41. Based on the determination result input from a switching condition determination unit 53, the drive protection request torque switching unit 52 switches between the drive protection request torque Tp obtained from, for example, a control map stored in the control device 9, and the high altitude drive protection request torque Th obtained by multiplying the drive protection request torque Tp by an atmospheric pressure correction coefficient Cf. Note that the atmospheric pressure correction coefficient Cf is a value greater than "1", and the high altitude drive protection request torque Th is greater than the drive protection request torque Tp.

[0031] The switching condition determination unit 53 outputs a switching signal to the driving protection request torque switching unit 52 when the vehicle speed is equal to or lower than a predetermined vehicle speed Vx (e.g., 8 km / h) and the engine speed is equal to or lower than a first threshold value Rx1 (e.g., 2000 rpm). In this embodiment, by adding a vehicle speed parameter in addition to the engine speed parameter as a switching condition for the high altitude correction of the driving protection request torque Tp, there is an advantage that the torque control according to the present invention can be adapted to a wider range of vehicle models. In other words, in the present invention, only the engine speed parameter is sufficient as the switching condition, and the vehicle speed is not an essential parameter.

[0032] On the other hand, if the parameter for the switching condition is set only based on the vehicle speed parameter, there is a risk that the engine torque Te will exceed the drive protection torque Tp when the engine speed increases significantly even at an extremely low vehicle speed, for example in a continuously variable transmission. For this reason, in the torque control according to the present invention, setting only the vehicle speed parameter as the parameter for the switching condition is not appropriate in terms of ensuring driveline protection.

[0033] In this way, when the vehicle speed is equal to or lower than the predetermined vehicle speed Vx and the engine rotational speed is equal to or lower than the first threshold value Rx1, the driving protection request torque switching unit 52 outputs the high altitude driving protection request torque Th obtained by multiplying the driving protection request torque Tp by the atmospheric pressure correction coefficient Cf. On the other hand, when the vehicle speed is higher than the predetermined vehicle speed Vx or the engine rotational speed is higher than the first threshold value Rx1, the driving protection request torque switching unit 52 outputs the driving protection request torque Tp obtained from the control map as is.

[0034] Furthermore, the torque value (driving protection request torque Tp or high altitude driving protection request torque Th) output from the driving protection request torque switching unit 52 is subjected to damper processing in the damper processing unit 54 and then input to the target torque determination unit 41. When switching from the high altitude driving protection request torque Th to the driving protection request torque Tp, the damper processing unit 54 gradually reduces the high altitude driving protection request torque Th. This reduces the gap between the high altitude driving protection request torque Th and the driving protection request torque Tp, making it possible to suppress any discomfort felt by the driver.

[0035] (Torque control method at high altitudes) FIG. 4 is a time chart showing engine torque control at high altitudes, with column (a) showing the engine torque control status and column (b) showing the correction control status. The time chart shown in FIG. 4 shows the acceleration state when the vehicle starts at high altitudes. In the time chart in column (a) of FIG. 4, the target torque is shown by a dashed line indicated by symbol Tt, the drive protection request torque is shown by a thick solid line indicated by symbol Tp, and the actual torque, i.e., the engine torque, is shown by a thin solid line indicated by symbol Te. In the time chart in column (b) of FIG. 4, a correction signal for high altitude correction of the drive protection request torque Tp is shown by a thick solid line indicated by symbol Cp, and a correction signal for correcting the boost pressure of the turbocharger 2 is shown by a thin solid line indicated by symbol Cb.

[0036] As shown in FIG. 4(a), when the vehicle is stopped at a high altitude and the engine speed is Ri, the driver depresses the accelerator pedal to start the vehicle. Then, when the vehicle starts, the vehicle speed is equal to or lower than a predetermined vehicle speed Vx and the engine speed is equal to or lower than a first threshold value Rx1. Therefore, as shown in FIG. 4(b), a correction signal Cp for high altitude correction of the drive protection request torque Tp is output. As a result, when the vehicle starts, high altitude correction of the drive protection request torque Tp is performed, as shown in FIG. 4(a). The high altitude drive protection request torque Th obtained by this high altitude correction is compared with the driver request torque Td, and the smaller torque value is output as the target torque Tt. This allows a higher target torque Tt to be permitted at high altitudes than at low altitudes. By raising the target torque Tt in this way, the engine torque Te rises more quickly even at high altitudes where the intake air density is low, thereby improving uphill starting performance, particularly at high altitudes.

[0037] 4(b), when the engine speed reaches the second threshold value Rx2, high altitude boost pressure correction of the turbocharger 2 is executed, and when the engine speed reaches the first threshold value Rx1, high altitude correction of the drive protection request torque Tp is canceled. In this embodiment, high altitude boost pressure correction of the turbocharger 2 is started at the second threshold value Rx2 that is smaller than the first threshold value Rx1 so that the high altitude boost pressure correction of the turbocharger 2 is maximized at the first threshold value Rx1. However, from the viewpoint of avoiding double correction together with the high altitude correction of the drive protection request torque Tp, it is preferable that the second threshold value Rx2 is set to be equal to or greater than the first threshold value Rx1, and that the high altitude boost pressure correction of the turbocharger 2 is executed at an engine speed equal to or greater than the second threshold value Rx2 that is equal to or greater than the first threshold value Rx1. Furthermore, the correction of the drive protection request torque Tp is canceled together with a damper process that gradually decreases the high altitude drive protection request torque Th, thereby alleviating the gap between the high altitude drive protection request torque Th and the drive protection request torque Tp.

[0038] In the engine speed range from the second threshold value Rx2 to the first threshold value Rx1, the high altitude boost pressure correction of the turbocharger 2 and the high altitude correction of the drive protection request torque Tp overlap, resulting in a so-called double correction state. However, as shown in FIG. 4(a), in the engine speed range from the second threshold value Rx2 to the first threshold value Rx1, the engine speed is low and the output engine torque Te is also small. Therefore, there is no risk that the deviation of the engine torque Te from the drive protection request torque Tp becomes large and the engine torque Te exceeds the drive protection request torque Tp. This makes it possible to appropriately protect the drive system, such as the transmission.

[0039] As described above, when the engine speed exceeds the first threshold value Rx1 and the engine torque Te approaches the target torque Tt, the high altitude correction of the drive protection request torque Tp is completely canceled through damper processing, as shown in Fig. 4(b). On the other hand, when the engine speed reaches the second threshold value Rx2, a correction signal Cb for correcting the boost pressure of the turbocharger 2 is output, as shown in Fig. 4(b). This starts the high altitude boost pressure correction of the turbocharger 2, and when the engine speed reaches the first threshold value Rx1, the high altitude boost pressure correction of the turbocharger 2 reaches its maximum.

[0040] In this way, in a region where the engine speed is equal to or less than the first threshold value Rx1, high altitude correction of the driving protection request torque Tp is performed, and in a region where the engine speed is greater than the first threshold value Rx1, high altitude correction of the driving protection request torque Tp is canceled and switched to high altitude supercharging pressure correction of the turbocharger 2. In other words, in the torque control of the internal combustion engine according to this embodiment, the first threshold value Rx1 and the second threshold value Rx2 are made to roughly coincide as a predetermined engine speed, and at this predetermined engine speed, the high altitude correction of the driving protection request torque Tp is canceled and high altitude supercharging pressure correction of the turbocharger 2 is started, thereby preventing the high altitude correction of the driving protection request torque Tp and the high altitude supercharging pressure correction of the turbocharger 2 from overlapping.

[0041] Thereafter, when the engine speed increases and the engine torque Te reaches the target torque Tt, the engine torque Te exhibits torque characteristics in accordance with the target torque Tt limited by the driving protection request torque Tp.

[0042] (Effects of this embodiment) Here, as in the conventional torque control described above, if a double correction occurs in which the overlap between the high altitude correction of the drive protection request torque Tp and the high altitude boost pressure correction of the turbocharger 2 is not taken into consideration, the drive protection request torque Tp is raised to the high altitude drive protection request torque Th by the high altitude correction of the drive protection request torque Tp, and when the engine speed increases as a result of the high altitude boost pressure correction of the turbocharger 2, there is a risk that the engine torque Te will exceed the drive protection request torque Tp, as shown by the dashed line in Figure 4(a).

[0043] In contrast, in this embodiment, in an engine speed range where the engine speed is equal to or less than the first threshold value Rx1, the drive protection request torque Tp is subjected to high-altitude correction in accordance with the atmospheric pressure, and the driver request torque Td is limited to the high-altitude drive protection request torque Th obtained by the high-altitude correction. Meanwhile, in an engine speed range where the engine speed exceeds the first threshold value Rx1, the drive protection request torque Tp is not subjected to high-altitude correction, and the driver request torque Td is limited to the drive protection request torque Tp. Therefore, in an engine speed range where the engine speed exceeds the first threshold value Rx1, it is possible to suppress double correction, in which the high-altitude correction of the drive protection request torque Tp and the high-altitude boost pressure correction of the turbocharger 2 overlap. This prevents damage to the drive train that would otherwise occur if the engine torque Te exceeded the drive protection request torque Tp due to the double correction, while improving uphill starting performance at high altitudes. In other words, it is possible to achieve both protection of the drive train and improved uphill starting performance at high altitudes.

[0044] Furthermore, in the torque control of this embodiment, high altitude correction is performed on the drive protection request torque Tp in a relatively low rotation speed range where supercharging by the turbocharger 2 is not required, and high altitude supercharging pressure correction is performed on the turbocharger 2 in accordance with the air pressure in an engine rotation speed range where supercharging by the turbocharger 2 is required. This makes it possible to effectively correct the drive protection request torque Tp at high altitudes in accordance with the operating state of the internal combustion engine.

[0045] Furthermore, in the torque control according to this embodiment, the timing for canceling the high altitude correction of the drive protection request torque Tp (first threshold value Rx1) and the timing for starting the high altitude boost pressure correction of the turbocharger 2 (second threshold value Rx2) are roughly matched, so that at high altitudes, the target torque Tt can be increased in accordance with the air pressure over the entire range of engine speeds, thereby providing torque performance that meets the driver's demands.

[0046] Furthermore, in the torque control according to this embodiment, after the engine speed reaches the first threshold value Rx1, damper processing is performed to gradually decrease the high altitude driving protection request torque Th, thereby making it possible to suppress a torque gap that occurs when switching from high altitude correction of the driving protection request torque Tp to high altitude boost pressure correction of the turbocharger 2 at high altitudes. This suppresses any discomfort felt by the driver and makes it possible to achieve smooth torque control at high altitudes.

[0047] Furthermore, the torque control according to this embodiment is configured to perform high altitude correction of the drive protection request torque Tp when the engine speed is in a range equal to or less than the first threshold value Rx1 and the vehicle speed is equal to or less than a predetermined vehicle speed Vx. In this way, by adding a vehicle speed parameter in addition to the engine speed parameter as a condition for performing high altitude correction of the drive protection request torque Tp, the torque control according to the present invention can be adapted to a wide range of vehicle models with different durability of the drive train.

[0048] The present invention is not limited to the configuration exemplified in the above embodiment, and for example, the specific values ​​of the first threshold value Rx1 and the second threshold value Rx2, the switching conditions of the switching condition determination unit 53, etc. can be freely changed depending on the specifications of the automobile (internal combustion engine) to which the present invention is applied, etc. [Explanation of symbols]

[0049] 1...Internal combustion engine 2...Turbocharger 9...Control device (control unit) Td: Driver requested torque Tp: Drive protection required torque Th…High altitude driving protection required torque Tt: Target torque Rx1: First threshold Rx2: Second threshold Vx…Predetermined vehicle speed

Claims

1. A torque control method for an internal combustion engine equipped with a supercharger, comprising: Calculating the driver's requested torque according to the driver's operation amount, calculating a target torque of the internal combustion engine based on the driver requested torque; correcting the supercharging pressure of the supercharger in accordance with atmospheric pressure that varies with altitude based on the target torque; In an area where the engine speed is equal to or less than a first threshold value, a drive protection request torque is set so as not to generate excessive torque for protecting the drive system, and is corrected in accordance with atmospheric pressure that changes with altitude to calculate a high altitude drive protection request torque, and the smaller of the driver request torque and the high altitude drive protection request torque is set as the target torque, In a region where the engine rotation speed is greater than the first threshold value, the drive protection request torque is not corrected, and the smaller of the driver request torque and the drive protection request torque is set as the target torque. A method for controlling torque in an internal combustion engine.

2. 2. A torque control method for an internal combustion engine according to claim 1, The correction of the boost pressure is performed in a region where the engine speed is equal to or greater than a second threshold value, and the engine speed is equal to or greater than the first threshold value. A method for controlling torque in an internal combustion engine.

3. 3. A torque control method for an internal combustion engine according to claim 2, The first threshold value and the second threshold value are approximately equal. A method for controlling torque in an internal combustion engine.

4. 4. The torque control method for an internal combustion engine according to claim 3, After the engine rotation speed reaches the first threshold value, a damper process is performed to gradually reduce the high altitude driving protection required torque. A method for controlling torque in an internal combustion engine.

5. A torque control method for an internal combustion engine according to any one of claims 1 to 4, When the engine speed is in a region equal to or less than the first threshold value and the vehicle speed is equal to or less than a predetermined vehicle speed, the driving protection required torque is corrected in accordance with the air pressure to calculate the high altitude driving protection required torque. A method for controlling torque in an internal combustion engine.

6. A torque control device for an internal combustion engine equipped with a supercharger, a control unit that controls torque control and boost pressure control of the internal combustion engine, The control unit Calculating the driver's requested torque according to the driver's operation amount, calculating a target torque of the internal combustion engine based on the driver requested torque; correcting the supercharging pressure of the supercharger in accordance with atmospheric pressure that varies with altitude based on the target torque; In an area where the engine speed is equal to or less than a first threshold value, a drive protection request torque is set so as not to generate excessive torque for protecting the drive system, and is corrected in accordance with atmospheric pressure that changes with altitude to calculate a high altitude drive protection request torque, and the smaller of the driver request torque and the high altitude drive protection request torque is set as the target torque, In a region where the engine rotation speed is greater than the first threshold value, the drive protection request torque is not corrected, and the smaller of the driver request torque and the drive protection request torque is set as the target torque. Torque control device for internal combustion engines.

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