JP3709644B2 - Torque control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a torque control device that suppresses torsional vibration generated in a drive system of a vehicle such as an automobile.
[0002]
[Prior art]
In general, when a vehicle such as an automobile is accelerated or decelerated rapidly, the output torque of the engine changes abruptly and a torsional vibration is generated in a drive system for transmitting the engine output to drive wheels. As a result, so-called squealing in which the acceleration of the vehicle fluctuates in a wavy manner may be given to the occupant.
[0003]
Therefore, conventionally, a technique for suppressing the torsional vibration has been taken, and for example, one disclosed in Japanese Patent Application Laid-Open No. 7-324644 is known. In the device described in this publication, in a diesel engine having a manual transmission, the amount of change in engine speed during a predetermined period is detected, and the amount of change is used as the amount of torsional vibration of the drive system. In this apparatus, the torsional vibration is suppressed by controlling the engine torque for a certain period by correcting the increase or decrease in the fuel injection amount in accordance with the vibration amount. That is, when the change amount of the engine rotation speed is large on the plus side (during rapid acceleration), the fuel injection amount is reduced for a certain period to reduce the torque. On the other hand, when the change amount of the engine rotation speed is large on the negative side (at the time of rapid deceleration), the fuel injection amount is increased for a certain period to increase the torque. By such torque control, torque fluctuation due to torsional vibration is reduced, thereby suppressing the vehicle vibration.
[0004]
[Problems to be solved by the invention]
By the way, in the above-described conventional apparatus, torque control is performed based on the amount of change in the engine rotation speed. Therefore, the torque control can be performed even in an operating state where the vehicle does not vibrate except during sudden acceleration or sudden deceleration. It was sometimes implemented. For example, the same torque control is performed when a so-called double clutch operation is performed in which the gear is shifted after increasing the engine rotation speed when the gear is neutral.
[0005]
Normally, this double clutch operation is performed in order to reduce a shift shock that occurs during downshifting. Therefore, during this operation, the driver depresses the accelerator pedal in order to rapidly increase the rotation speed when the engine is not loaded. However, in the conventional apparatus, the torque control is performed according to the amount of change in the engine rotation speed, so that the fuel injection amount is reduced, and consequently the engine rotation speed increases to the rotation speed intended by the driver. As a result, there will be a delay in drivability.
[0006]
The present invention has been made in view of such circumstances, and the object of the present invention is an internal combustion engine capable of further improving drivability by combining torsional vibration suppression and engine rotational speed tracking. The object is to provide a torque control device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a detection means for detecting a change amount of the engine rotational speed in a predetermined period corresponding to a vibration amount of a vehicle on which the internal combustion engine is mounted. For detecting torsional vibration based on vehicle acceleration / deceleration In a second period longer than the first period, torque control means for controlling the torque of the engine in a direction in which the amount of vibration of the vehicle is reduced based on the amount of change in engine rotation speed detected in the first period When the detected amount of change in engine speed is greater than or equal to a predetermined value, it is determined that the double clutch operation is being performed, and torque control by the torque control means is During ~ Torque control to stop During ~ And a stopping means.
[0008]
According to the above configuration, the change amount of the engine rotation speed corresponding to the vibration amount of the vehicle is detected by the detection means, For detecting torsional vibration based on vehicle acceleration / deceleration The torque of the internal combustion engine is controlled by the torque control means so that the vibration amount of the vehicle is reduced based on the amount of change detected in the first period. The torque control means reduces the torque of the engine, for example, when the engine rotational speed changes to the positive side, and increases the torque of the engine when the rotational speed changes to the negative side.
[0009]
Where For detecting torsional vibration based on vehicle acceleration / deceleration When the amount of change in the engine rotational speed detected in the second period longer than the first period is equal to or greater than a predetermined value, that is, when the rotational speed increases rapidly in a no-load state due to a double clutch operation. The torque control by the torque control means is stopped through the torque control. Incidentally, when the engine rotational speed changes to the plus side, the torque control means performs control so as to reduce the fuel injection amount, for example, to reduce the engine torque, but the amount of change in the engine rotational speed in the second period is When it exceeds the predetermined value, torque control During ~ By stopping, the engine speed increases quickly. As a result, in addition to the suppression of the torsional vibration, the followability of the engine speed during double clutch operation is also improved.
[0011]
In addition, torque control During ~ The stopping means refers to the amount of change in engine speed over a relatively long period of time. During ~ Judgment is based on long-term fluctuations in the rotation speed. Therefore, temporary fluctuations in the engine speed are not taken into account, and torque control is performed at an appropriate time. During ~ Stopped.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a torque control device for a diesel engine will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a schematic configuration diagram showing a torque control device for a diesel engine mounted on a vehicle, and FIG. 2 is an enlarged cross-sectional view showing the distributed fuel injection pump 1 of FIG.
[0014]
As shown in FIG. 1, the diesel engine 2 includes a fuel injection pump 1 for supplying fuel to the engine 2. The fuel injection pump 1 has a drive pulley 3 and a drive shaft 5 that are drivingly connected to a crankshaft 40 of the engine 2 via a belt or the like. The fuel injection pump 1 is driven by the rotation of the drive pulley 3, and fuel is injected from the fuel injection nozzle 4 provided in each cylinder (in this case, 4 cylinders) of the diesel engine 2.
[0015]
In this embodiment, the diesel engine 2 is drivingly connected to a manual transmission (not shown), and a drive system is configured by the crankshaft 40 and the like.
[0016]
In the diesel engine 2, a main combustion chamber 44 corresponding to each cylinder is formed by a cylinder bore 41, a piston 42 and a cylinder head 43. A sub-combustion chamber 45 communicating with each main combustion chamber 44 is provided corresponding to each cylinder. The sub-combustion chambers 45 are supplied with fuel injected from the fuel injection nozzle 4. Each sub-combustion chamber 45 is provided with a known glow plug 46 as a starting assist device.
[0017]
The diesel engine 2 is provided with an intake passage 47 and an exhaust passage 48, respectively. The intake passage 47 is provided with a compressor 50 of a turbocharger 49 constituting a supercharger, and the exhaust passage 48 is provided with a turbine 51 of the turbocharger 49. The exhaust passage 48 is provided with a waste gate valve 52 for adjusting the supercharging pressure. As is well known, the turbocharger 49 rotates the turbine 51 using the energy of the exhaust gas, and rotates the compressor 50 on the same axis to boost the intake air. By this action, a high-density air-fuel mixture is sent to the main combustion chamber 44 to burn a large amount of fuel, and the output of the diesel engine 2 is increased.
[0018]
Further, the diesel engine 2 is provided with an exhaust gas recirculation device (EGR). The apparatus includes an EGR passage 54 for returning a part of the exhaust gas in the exhaust passage 48 to the intake port 53 of the intake passage 47 and a diaphragm type EGR valve 55 provided in the middle of the EGR passage 54. Furthermore, in order to adjust the opening of the EGR valve 55 by adjusting the introduction of negative pressure, an electric vacuum regulating valve (EVRV) 56 whose opening is adjusted by a duty-controlled electric signal is provided. The opening of the EGR valve 55 is adjusted by the operation of the EVRV 56, and the EGR amount guided from the exhaust passage 48 to the intake passage 47 through the EGR passage 54 is adjusted by this adjustment.
[0019]
Further, a throttle valve 58 that is opened and closed in conjunction with the amount of depression of the accelerator pedal 57 is provided in the intake passage 47. A bypass passage 59 is provided in parallel with the throttle valve 58, and a bypass throttle valve 60 is provided in the bypass passage 59. The bypass throttle valve 60 is controlled to be opened and closed by an actuator 63 having a two-stage diaphragm chamber driven by control of two VSVs (vacuum switching valves) 61 and 62. The bypass throttle valve 60 is controlled to open and close according to various operating conditions. For example, during idle operation, it is controlled to a half-open state in order to reduce noise vibration, etc., controlled to a full-open state during normal operation, and further controlled to a fully-closed state for smooth stop when operation is stopped.
[0020]
As shown in FIG. 2, the drive shaft 5 provided in the fuel injection pump 1 has a drive pulley 3 at its distal end and a disk-like pulsar 7 at its proximal end. The number of cylinders of the diesel engine 2 (FIG. 1), that is, four incisors are formed at equiangular intervals on the outer peripheral surface of the pulsar 7, and there are 14 (in total 56 in total) between each incisor. Projections are formed at equiangular intervals. In the middle of the drive shaft 5 is provided a fuel feed pump 6 (developed 90 degrees in this figure) comprising a vane pump. A roller ring 9 is provided at the base end of the drive shaft 5 so as to be rotatable relative to the shaft 5, and the roller ring 9 has a cam roller 10 along its circumference.
[0021]
The fuel injection pump 1 includes a plunger 12 that is provided coaxially with the drive shaft 5. A cam plate 8 is attached to the base end of the plunger 12. The cam plate 8 has the same number of cam faces 8 a as the number of cylinders of the engine 2. Here, a coupling (not shown) is accommodated in the roller ring 9, and the coupling connects the drive shaft 5 and the cam plate 8 so as to be integrally rotatable, and the cam plate 8 and the plunger 12 move in the axial direction. Is acceptable. The cam plate 8 is always urged and engaged toward the cam roller 10 by a spring 11.
[0022]
Here, when the drive shaft 5 is rotated, the cam plate 8 is rotated integrally with the shaft 5 via the coupling, and is reciprocated in the axial direction by the same number as the number of cylinders by engagement with the cam roller 10. Moved. As the cam plate 8 reciprocates, the plunger 12 reciprocates in the axial direction while rotating. That is, the plunger 12 is moved forward (lifted) when the cam face 8a of the cam plate 8 rides on the cam roller 10 of the roller ring 9, and conversely, the plunger 12 is moved back when the cam face 8a rides down the cam roller 10. The
[0023]
The plunger 12 is fitted into a cylinder 14 formed in the pump housing 13, and a high-pressure chamber 15 is formed between the distal end surface of the plunger 12 and the bottom surface of the cylinder 14. Further, the same number of intake grooves 16 and distribution ports 17 as the number of cylinders of the diesel engine 2 are formed on the outer periphery on the tip end side of the plunger 12. The pump housing 13 is formed with a distribution passage 18 and a suction port 19 corresponding to the suction groove 16 and the distribution port 17.
[0024]
In such a fuel injection pump 1, the fuel is supplied from the fuel tank (not shown) into the fuel chamber 21 through the fuel supply port 20 by driving the fuel feed pump 6 by rotating the drive shaft 5. Is done. In addition, during the suction stroke in which the plunger 12 is moved backward to decompress the high pressure chamber 15, one of the suction grooves 16 communicates with the suction port 19, whereby fuel is introduced from the fuel chamber 21 to the high pressure chamber 15. . On the other hand, during the compression stroke in which the plunger 12 is moved forward and the high pressure chamber 15 is pressurized, fuel is pumped from the distribution passage 18 to the fuel injection nozzle 4 (FIG. 1) of each cylinder and injected.
[0025]
On the other hand, the pump housing 13 is formed with a spill passage 22 for fuel overflow (spill) that allows the high pressure chamber 15 and the fuel chamber 21 to communicate with each other. An electromagnetic spill valve 23 for adjusting a fuel spill from the high pressure chamber 15 is provided in the middle of the spill passage 22. The electromagnetic spill valve 23 is a normally open valve. When the coil 24 is not energized (off), the valve body 25 is opened and the fuel in the high pressure chamber 15 is spilled into the fuel chamber 21. Further, when the coil 24 is energized (turned on), the valve body 25 is closed and the fuel spill from the high pressure chamber 15 to the fuel chamber 21 is stopped.
[0026]
Therefore, by controlling the energization time of the electromagnetic spill valve 23, the valve 23 is controlled to open and close, and fuel spill adjustment from the high pressure chamber 15 to the fuel chamber 21 is performed. Then, by opening the electromagnetic spill valve 23 during the compression stroke of the plunger 12, the fuel in the high pressure chamber 15 is depressurized and the fuel injection from the fuel injection nozzle 4 is stopped. That is, even if the plunger 12 moves forward, the fuel pressure in the high pressure chamber 15 does not increase while the electromagnetic spill valve 23 is open, and fuel injection from the fuel injection nozzle 4 is not performed. Further, during the forward movement of the plunger 12, the timing of closing / opening the electromagnetic spill valve 23 is controlled, thereby adjusting the end of injection from the fuel injection nozzle 4 and controlling the fuel injection amount.
[0027]
On the other hand, on the lower side of the pump housing 13, a timer device (developed 90 degrees in this figure) 26 for controlling the fuel injection timing is provided. The timer device 26 changes the timing at which the cam face 8 a engages the cam roller 10, that is, the reciprocating timing of the cam plate 8 and the plunger 12 by changing the position of the roller ring 9 with respect to the rotational direction of the drive shaft 5. Is for.
[0028]
The timer device 26 is driven by control oil pressure. The timer piston 27 is fitted in a timer housing 27, a timer piston 28 fitted in the housing 27, and a low-pressure chamber 29 on one side of the timer housing 27. It comprises a timer spring 31 and the like that urges the pressurizing chamber 30 on the other side. The timer piston 28 is connected to the roller ring 9 via the slide pin 32.
[0029]
Fuel pressurized by the fuel feed pump 6 is introduced into the pressurizing chamber 30 of the timer housing 27. The position of the timer piston 28 (hereinafter referred to as “timer piston position”) is determined by the balance between the fuel pressure and the urging force of the timer spring 31. Further, by determining the timer piston position, the position of the roller ring 9 is determined, and the reciprocating timing of the plunger 12 is determined via the cam plate 8.
[0030]
In order to adjust the fuel pressure acting as the control hydraulic pressure of the timer device 26, the timer device 26 is provided with a timer control valve (TCV) 33. That is, the pressurizing chamber 30 and the low pressure chamber 29 of the timer housing 27 are communicated with each other by the communication passage 34, and the TCV 33 is provided in the middle of the communication passage 34. The TCV 33 is an electromagnetic valve that is controlled to open and close by a duty-controlled energization signal, and the fuel pressure in the pressurizing chamber 30 is adjusted by the opening and closing control of the TCV 33. The lift timing of the plunger 12 is controlled by adjusting the fuel pressure, and the fuel injection timing from each fuel injection nozzle 4 is controlled.
[0031]
On the other hand, a rotational speed sensor 35 made of an electromagnetic pickup coil is attached to the upper part of the roller ring 9 so as to face the outer peripheral surface of the pulsar 7. The rotational speed sensor 35 detects the passage of the projection of the pulsar 7 and passes a timing signal corresponding to the engine rotational speed NE, that is, an engine rotational pulse at a constant crank angle (11.25 ° CA). Output. The rotation speed sensor 35 detects an instantaneous rotation speed for each engine rotation pulse. Further, since the rotation speed sensor 35 is integrated with the roller ring 9, the rotation speed sensor 35 outputs a reference timing signal at a constant timing to the plunger lift regardless of the control operation of the timer device 26.
[0032]
The diesel engine 2 is provided with various sensors for detecting the operating state of the engine 2 in addition to the rotation speed sensor 35.
As shown in FIG. 1, an intake air temperature sensor 72 for detecting the intake air temperature THA is provided in the vicinity of the air cleaner 64 provided at the inlet of the intake passage 47. Further, an accelerator sensor 73 is provided in the vicinity of the throttle valve 58 for detecting an accelerator opening ACCP corresponding to the load of the diesel engine 2 from the opening / closing position of the throttle valve 58. In the vicinity of the intake port 53, an intake pressure sensor 74 for detecting an intake air pressure after being supercharged by the turbocharger 49, that is, an intake pressure PM, is provided. Further, the water jacket of the engine 2 is provided with a water temperature sensor 75 that detects the cooling water temperature THW of the engine 2. Further, the engine 2 is provided with a crank angle sensor 76 that detects an engine rotation re-reference position of the crankshaft 40. In addition, the transmission is provided with a vehicle speed sensor 77 that detects the vehicle speed (vehicle speed) SPD by turning on and off the reed switch 77b by a magnet 77a rotated by the rotation of the gear.
[0033]
As described above, the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the VSVs 56, 61, 62, and the various sensors 35, 72 to 77 provided in the fuel injection pump 1 and the diesel engine 2 are electronic control units (hereinafter referred to as “ECU”). ”) 71). The ECU 71 suitably controls the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 56, the VSVs 61, 62, and the like based on the detection signals output from the sensors 35, 72 to 77.
[0034]
Next, the configuration of the ECU 71 will be described with reference to FIG.
As shown in the figure, the ECU 71 stores data such as a central processing unit (CPU) 81, a read-only memory (ROM) 82 in which predetermined control programs and function data are stored in advance, calculation results of the CPU 81, engine rotational speed NE, and the like. A random access memory (RAM) 83 that temporarily stores data, a backup RAM 84 that can store stored data, and the like are provided. The ECU 71 is configured as a logical operation circuit in which these units are connected to the input port 85, the output port 86, and the like through a bus 87.
[0035]
The input port 85 is connected to the intake air temperature sensor 72, the accelerator sensor 73, the intake pressure sensor 74, and the water temperature sensor 75 described above via the buffers 88, 89, 90, 91, the multiplexer 93, and the A / D converter 94. Has been. Similarly, the rotational speed sensor 35, the crank angle sensor 76, and the vehicle speed sensor 77 described above are connected to the input port 85 via a waveform shaping circuit 95. Then, the CPU 81 reads the detection signals of the sensors 35, 72 to 77 and the like input via the input port 85 as input values. Further, the electromagnetic spill valve 23, the TCV 33, the glow plug 46, the EVRV 56, the VSV 61, 62, and the like are connected to the output port 86 through the respective drive circuits 96, 97, 98, 99, 100, 101.
[0036]
Next, processing operations relating to torque control (actually fuel injection amount control) executed by the ECU 71 will be described with reference to FIGS.
FIG. 4 is a “final injection amount calculation routine” for calculating and determining the final injection amount QFIN, and this processing is executed by angle interruption for each predetermined crank angle.
[0037]
When the process proceeds to this routine, first in step 101, the ECU 71 reads the values of the current engine speed NE, the rotational position signal CNIRQ of the crankshaft 40, the accelerator opening ACCP, and the intake pressure PM from the RAM 83, and also the RAM 83. The engine speed change amount DLNE, engine speed rising speed determination value SNE, and torque control execution flag F are stored in the RAM 83.
[0038]
Where These The torque control execution flag F, the rotational speed change amount DLNE, and the determination value SNE are set or calculated by a separate routine and stored in a predetermined area of the RAM 83.
[0039]
Incidentally, the torque control execution flag F is a flag indicating whether or not it is necessary to perform torque control for suppressing the above-described vehicle vibration (sucking). The torque control execution flag F is set to “1” when it is determined that torque control needs to be performed, and is set to “0” otherwise. In this embodiment,
(1) The vehicle is a manual transmission vehicle,
(2) Being other than at the start,
(3) The engine speed NE is within a predetermined range (for example, 500 rpm or more and less than 4000 rpm),
(4) The cooling water temperature THW is a predetermined value (for example, −20 ° C.) or more,
(5) The engine 2 is operating normally,
(6) Currently running,
When all the six conditions are satisfied, the torque control execution flag F is set to “1”. In other words, the condition (5) is a state in which no failure has occurred in the engine 2. The above conditions are merely examples, and conditions under which it can be determined that vibrations can occur in the vehicle, or other conditions may be employed.
[0040]
The rotational speed change amount DLNE is a parameter used to calculate the correction amount of the torque control. Specifically, a value obtained by subtracting the previously detected rotational speed NE1 from the current rotational speed NE value is obtained. Calculated as the rotational speed change amount DLNE. The rotational speed NE is detected every very short first period T1, and the rotational speed change amount DLNE represents the change amount of the rotational speed NE changed during the period T1. When the value of the rotational speed change amount DLNE is positive, it indicates that the engine rotational speed NE has increased instantaneously. When the value of the rotational speed change amount DLNE is negative, the engine rotational speed NE is Indicates a momentary decrease. Therefore, according to the explosion timing of each cylinder of the engine 2, a temporary fluctuation of the rotational speed NE generated between the cylinders is also reflected in the rotational speed change amount DLNE. In this embodiment, torque control is executed on the assumption that the rotational speed change amount DLNE is proportional to the vibration amount of the vehicle.
[0041]
On the other hand, the determination value SNE performs the torque control. During ~ A parameter used to determine whether or not to stop, specifically, subtracting the rotational speed NE2 before the second period T2 that is relatively longer than the first period T1 from the current rotational speed NE The obtained value is calculated as the determination value SNE. However, since this determination value SNE is a parameter indicating the rising speed of the rotational speed NE, when the subtraction value is positive (when the rotational speed NE is increasing), the determination value SNE is the above value. However, when the subtraction value is negative (when the rotational speed NE is decreasing), the determination value SNE is set to zero. Accordingly, the determination value SNE does not reflect the temporary fluctuation of the rotational speed NE, and reflects only the increasing tendency of the rotational speed NE.
[0042]
The ECU 71 that has finished reading each value next determines whether or not the final fuel injection calculation time has come in step 102 based on the value of the rotational position signal CNIRQ. In this embodiment, as an example, it is determined whether or not the value of the rotational position signal CNIRQ is “6”. Based on this determination, the subsequent processing is performed at a rate of twice per one rotation of the crankshaft 40. If the value of the rotational position signal CNIRQ is not “6”, the ECU 71 determines that it is not necessary to perform the subsequent processing, and once terminates the subsequent processing. On the other hand, if the value of the rotational position signal CNIRQ is “6”, the ECU 71 proceeds to step 103. The numerical value “6” may be arbitrarily changed according to the calculation timing of the final injection amount.
[0043]
In step 103, the ECU 71 refers to the function data stored in the ROM 64 to calculate the basic injection amount QBASE based on the values of the engine speed NE and the accelerator opening ACCP. In calculating the basic injection amount QBASE, predetermined function data is referred to using the basic injection amount QBASE, the engine speed NE, and the accelerator opening ACCP as parameters.
[0044]
Further, at step 104, the ECU 71 refers to the function data stored in the ROM 64 to calculate the maximum injection amount QFULL corresponding to the values of the engine speed NE and the intake pressure PM. Here, the maximum injection amount QFULL means the upper limit value of the amount of fuel to be supplied to each combustion chamber 12, and when the fuel is supplied exceeding this upper limit value, the smoke discharged from the combustion chamber 12 is reduced. It will increase rapidly.
[0045]
In step 105, the ECU 71 sets the smaller one of the calculated basic injection amount QBASE and maximum injection amount QFULL as the pre-correction injection amount QFINA. The ECU 71 stores the calculated pre-correction injection amount QFINA in the RAM 83.
[0046]
On the other hand, in step 106, the ECU 71 determines whether or not the torque control execution flag F is “1”. As described above, when the value of the flag F is “1”, it is determined that torque control needs to be executed, and the routine proceeds to step 107. On the other hand, when the value of the torque control execution flag F is not “1”, that is, “0”, the ECU 71 determines that it is not necessary to execute the torque control, and the normal fuel injection amount. The process proceeds to step 112 in order to calculate.
[0047]
In step 107, the ECU 71 determines whether or not the pre-correction injection amount QFINA calculated in step 105 is equal to the basic injection amount QBASE. That is, in step 107, it is determined whether or not the basic injection amount BASE calculated in step 103 is smaller than the maximum injection amount QFULL calculated in step 104. When the basic injection amount BASE is equal to or greater than the maximum injection amount QFULL, it is determined that the rotational speed NE is rapidly increasing because the fuel injection amount required by the engine 2 is large. In this case, the ECU 71 shifts the process to step 111. On the other hand, when the basic injection amount BASE is less than the maximum injection amount QFULL, the fuel injection amount required by the engine 2 is relatively small, so it is determined that the rotational speed NE has not increased rapidly. Then, the ECU 71 shifts the process to step 108.
[0048]
Next, in step 108, the ECU 71 calculates a correction amount QACC2 related to the fuel injection amount based on the rotational speed change amount DLNE read in step 101. The correction amount QACC2 is calculated based on function data corresponding to the graph of FIG.
[0049]
FIG. 6 is a graph showing the relationship between the rotational speed change amount DLNE and the correction amount QACC2. As shown in the figure, the correction amount QACC2 is inversely proportional to the rotational speed change amount DLNE, and as the rotational speed change amount DLNE increases to the positive side, the correction amount QACC2 is set to a negative side. Further, as the value of the rotational speed change amount DLNE increases toward the minus side, the correction amount QACC2 is set larger toward the plus side. The correction amount QACC2 has an upper limit value and a lower limit value. When the rotation speed change amount DLNE is equal to or greater than the predetermined value DLNE1, the correction amount QACC2 is set to the lower limit value QACC21. Further, when the rotational speed change amount DLNE is equal to or smaller than the predetermined value DLNE2, the correction amount QACC2 is set to the upper limit value QACC22.
[0050]
In the next step 109, the ECU 71 that has calculated the correction amount in this way sets a value obtained by adding the correction amount QACC2 to the uncorrected injection amount QFINA as the corrected injection amount QFINK. That is, the fuel injection amount is corrected to increase or decrease according to the value of the correction amount QACC2.
[0051]
In step 110, the ECU 71 sets the smaller one of the calculated corrected injection amount QFINK and maximum injection amount QFULL as the final injection amount QFIN. The pre-correction injection amount QFINA set in step 105 is equal to or less than the maximum injection amount QFULL. However, depending on the value of the correction amount QACC2, the value of the correction injection amount QFINK may exceed the maximum injection amount QFULL. This process is performed. The ECU 71 stores the final injection amount QFIN obtained in this way in the RAM 83, and then temporarily terminates the subsequent processing. Thus, the torque of the engine 2 is adjusted so as to reduce the amount of vibration of the vehicle by correcting the final injection amount QFIN to increase or decrease according to the correction value QACC2. Incidentally, in this embodiment, torque control for reducing the amount of vibration of the vehicle is performed through the processing of steps 101, 108, and 109.
[0052]
On the other hand, in step 111 after shifting from step 107, the ECU 71 determines whether or not the value of the determination value SNE read in step 101 is equal to or greater than a predetermined value α. Incidentally, before entering this step 111, it is determined in step 107 that the rotational speed NE has been rapidly increased. That is, it is determined whether or not an operation is performed so that the driver depresses the accelerator pedal 57 in the no-load state of the engine (when the gear is neutral). And only when such an operation is performed, the value of α is set so that the value of the determination value SNE is equal to or greater than the predetermined value α.
[0053]
Accordingly, in step 111, if the value of the determination value SNE is less than the predetermined value α, the ECU 71 determines that the engine 2 is in a normal acceleration state, and shifts the process to step 108 described above. The correction amount QACC2 for the torque control is calculated. On the other hand, when the value of the determination value SNE is equal to or greater than the predetermined value α, the ECU 71 determines that the increase in the rotational speed NE is due to the double clutch operation, and proceeds to step 112.
[0054]
In step 112 after shifting from step 111 or step 106, the ECU 71 sets the value of the correction amount QACC2 to “0”, and the subsequent processing shifts to step 109. That is, since the value of the correction amount QACC2 is “0”, torque control for reducing the vibration amount of the vehicle in the subsequent processing is performed. During ~ A normal fuel injection amount that is stopped and not corrected for increase / decrease is calculated as the final injection amount QFIN.
[0055]
Thus, in the “final injection amount calculation routine”, when calculating the final injection amount QFIN, the fuel injection amount is corrected by the correction amount QACC2 corresponding to the rotational speed change amount DLNE during normal vehicle acceleration / deceleration. When using the double clutch, the correction using the correction amount QACC2 During ~ Stopped.
[0056]
Next, based on FIG. 5, the operation | movement concerning the torque control of the apparatus of this embodiment is further explained in full detail.
FIG. 5 is a timing chart showing changes in the accelerator opening ACCP, the determination value SNE, the final injection amount QFIN, and the engine rotational speed NE when the rotational speed NE is increased by a double clutch operation. Here, it is assumed that all the conditions for setting the value of the torque control execution flag F to “1” are satisfied in the operation state of the engine 2 over the entire time axis t of the timing chart. At timing t0, it is assumed that the engine 2 is in a no-load state (a gear is in a neutral state) and a clutch (not shown) is in a connected state.
[0057]
As shown in the figure, since the accelerator opening ACCP is fully closed before the timing t1, the rotational speed NE decreases with time. By performing torque control according to the amount of decrease in the rotational speed NE, a correction amount QACC2 having a positive value is calculated. At this time, the basic injection amount QBASE takes a negative value, and its absolute value is larger than the correction amount QACC2. As a result, while the accelerator opening ACCP is fully closed, the final injection amount QFIN is set to zero even if the increase is corrected by the correction amount QACC2.
[0058]
Here, when the accelerator opening ACCP is fully opened (timing t1), the value of the final injection amount QFIN is rapidly increased. Based on the increase in the final injection amount QFIN, the rotational speed NE begins to increase slightly later than the fully open timing of the accelerator opening ACCP (timing t2). At this time, since the engine 2 is in a no-load state, the rotational speed NE increases more rapidly than during normal vehicle acceleration.
[0059]
Based on this rapid increase in rotational speed NE, torque control for suppressing vehicle vibration based on torsional vibration of the drive system is performed after timing t2. In this case, the correction amount QACC2 is set to a negative value, and the final injection amount QFIN is reduced and corrected accordingly. However, in the current state where the driving force of the engine 2 is not transmitted to the transmission, such vibration does not occur even if the rotational speed NE increases rapidly. Therefore, unnecessary torque control is performed after timing t2.
[0060]
On the other hand, the determination value SNE starts to increase simultaneously with the increase of the rotational speed NE, and at timing t3, the value becomes equal to or greater than the predetermined value α. As a result, it is determined that the sudden increase in the rotational speed NE is caused by the double clutch operation, and the torque control is performed as described above. During ~ Stopped (timing t3). As a result, after the timing t3, unnecessary torque control is performed. During ~ Each parameter changes as shown by the solid line because it is stopped. That is, after timing t3, the value of the correction amount QACC2 is set to “0”, and the reduction correction of the final injection amount QFIN is stopped. Note that when the torque control is continuously executed after the timing t3, each parameter changes as indicated by a two-dot chain line. Therefore, torque control like this During ~ By stopping, the rotational speed NE is increased by an amount corresponding to the area indicated by the oblique lines, and the rotational speed NE can be quickly increased as intended by the driver.
[0061]
As described above, according to the torque control device of this embodiment, many excellent effects shown below can be achieved.
-The drivability can be improved by improving the rising speed of the rotational speed NE when the double clutch is operated.
[0062]
・ Torque control During ~ Since the determination value SNE, which is the amount of change in the rotational speed NE over a relatively long period, is used as a parameter for determining when to stop, it is not affected by instantaneous rotational speed changes caused by variations between cylinders, etc. Proper torque control During ~ Can be stopped.
[0063]
・ Torque control is performed in normal operating conditions other than during double clutch operation, so the amount of torsional vibration based on vehicle acceleration / deceleration is reduced, thereby suppressing vibrations before and after the vehicle (acceleration / deceleration shock, shackle, etc.) as much as possible. can do.
[0064]
Since the torque control is performed by adjusting the fuel injection amount of the engine 2, the torque control can be executed accurately and reliably.
Since the torsional vibration amount is authorized based on the rotational speed change amount DLNE of the diesel engine 2, the torsional vibration amount is accurately grasped, and as a result, controllability can be improved.
[0065]
In addition, the torque control apparatus of the said embodiment can also be changed as follows.
In the above embodiment, it is determined whether or not the double clutch operation is performed based on the determination value SNE that is the amount of change in the rotational speed NE during a predetermined period. On the other hand, a double clutch sensor may be provided in the engine 2 to determine whether or not a double clutch operation is being performed based on a signal from the sensor.
[0067]
In the above embodiment, the torque control is performed by controlling the fuel injection amount of the diesel engine 2. However, the torque control may be performed by controlling the fuel injection timing. Further, it can be applied to a gasoline engine instead of the diesel engine 2. When a gasoline engine is employed as the internal combustion engine, torque control can be performed by controlling ignition timing, air-fuel ratio, intake air amount, and the like.
[0068]
The relationship of the correction amount QACC2 with respect to the rotational speed change amount DLNE in the embodiment does not necessarily have to be linear as shown in FIG.
[0069]
The technical ideas other than the claims that can be grasped from the above embodiment will be described together with the effects thereof.
Detecting means for detecting a change amount of the engine rotational speed in a predetermined period corresponding to a vibration amount of the vehicle on which the internal combustion engine is mounted, and a vibration amount of the vehicle is reduced based on the detected change amount of the engine rotational speed; Torque control means for controlling the torque of the engine in the direction, a sensor for detecting double clutch operation, and when the double clutch operation is detected by the sensor, torque control by the torque control means is performed. During ~ Torque control to stop During ~ A torque control device for an internal combustion engine.
[0070]
According to the above configuration, during double clutch operation where the engine power is not transmitted to the drive system, torque control is performed. During ~ Therefore, the startability of the engine speed can be improved.
[0071]
【The invention's effect】
According to the first aspect of the present invention, in addition to the suppression of torsional vibration, for example, the followability of the engine speed during double clutch operation is also improved. Therefore, in a vehicle equipped with an internal combustion engine that is torque controlled, the drivability can be further improved.
[0072]
Furthermore, torque control During ~ With regard to the stop timing, torque control is performed at an appropriate time without taking into account temporary fluctuations in the engine speed. During ~ The follow-up performance of the engine speed can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a torque control device for a diesel engine according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a fuel injection pump of the diesel engine.
FIG. 3 is a block diagram showing a circuit configuration of an ECU.
FIG. 4 is a flowchart showing a torque control procedure according to the embodiment.
FIG. 5 is a timing chart showing a torque control mode of the same embodiment.
FIG. 6 is a graph showing the relationship between the rotational speed change amount and the fuel injection correction amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 2 ... Diesel engine as an internal combustion engine, 35 ... Rotational speed sensor, 40 ... Crankshaft, 71 ... Electronic control unit (ECU).

Claims (1)

Detecting means for detecting a change amount of the engine rotational speed in a predetermined period corresponding to a vibration amount of a vehicle in which the internal combustion engine is mounted;
Torque control means for controlling the torque of the engine in a direction in which the amount of vibration of the vehicle is reduced based on the amount of change in the engine rotational speed detected in the first period for detecting the amount of torsional vibration based on the acceleration / deceleration of the vehicle When,
When the change amount of the engine speed detected in the second period longer than the first period is equal to or greater than a predetermined value, it is determined that the double clutch operation is being performed, and torque control by the torque control unit is performed. the torque control device for an internal combustion engine, characterized in that it comprises a torque control during stop means for abort.

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