JPH05240096A - Fuel injection quantity controller of car-mount internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] To secure sufficient power performance while preventing damage to the transmission when a low speed stage is selected. A fuel injection amount control device includes an ECU 71 that controls the fuel injection pump 1 based on a rotation speed sensor 35, a shift stage sensor 66, and the like. The ECU 71 calculates the maximum allowable injection amount on the engine side and the maximum allowable injection amount on the transmission side, and when the transmission 65 is not in the low speed stage, the fuel injection amount to the diesel engine 2 becomes an amount corresponding to the maximum allowable injection amount on the engine side. The fuel injection pump 1 is controlled so that ECU 71
Calculates the amount of change in the engine speed at the low speed stage, and if the value falls within a predetermined range, the maximum allowable injection amount on the transmission side is increased and corrected to increase the fuel injection amount to the diesel engine 2. However, the fuel injection pump 1 is controlled such that the fuel injection pump 1 has a smaller maximum allowable injection amount of the transmission-side maximum allowable injection amount and the engine-side maximum allowable injection amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection amount control device for controlling a fuel injection amount to a vehicle-mounted internal combustion engine, and more specifically, to an output torque transmitted from the internal combustion engine to a transmission. The present invention relates to a fuel injection amount control device for an on-vehicle internal combustion engine, which controls the fuel injection amount according to the operating state of the internal combustion engine so as not to exceed the torque allowed by the machine.

[0002]

2. Description of the Related Art Conventionally, a power transmission system for transmitting a driving force (torque) generated by an engine of an automobile to a wheel has a transmission (for changing (changing) the driving force according to a running state of the automobile). Transmission) is provided. This transmission has gears with various numbers of teeth,
By switching the meshing of gears by operating the shift lever in the driver's seat, the rotational speed and output torque of the engine are converted into a plurality of stages. In this transmission, the permissible torque is different for each gear stage, and among them, the permissible torque is the smallest at a low gear stage having a large gear ratio such as first gear or reverse gear. Therefore, if the low speed is selected when the engine speed is high or the output torque is high and the output torque transmitted from the engine exceeds the allowable torque of the transmission, the transmission may be damaged. There is.

Therefore, in order to solve the above-mentioned problems, for example, in Japanese Utility Model Laid-Open No. 3-56845, when the low speed stage is selected while the engine is operating in a high rotation and high torque range, the output of the engine is reduced. The amount of fuel injected into the engine is uniformly reduced so that the torque does not exceed the allowable torque of the transmission.

[0004]

However, when an automobile such as a four-wheel drive vehicle travels off-road (outside the road), it may be operated in a high rotation state while the low speed stage is selected. Therefore, even in such a case, if the fuel injection amount is constantly reduced to reduce the output torque, the power performance becomes insufficient.

That is, in this four-wheel drive vehicle or the like, it is necessary to reduce the output torque of the engine because of a sudden increase in the engine speed due to wheel idling during hopping,
This is the case when a large load is applied to the transmission due to the subsequent rapid decrease in the engine speed during landing, or when the output torque suddenly changes due to a sudden accelerator operation. Hopping here is the driving force,
This is a phenomenon in which the wheels and the vehicle body jump up and down due to the reaction force generated by the suspension with respect to the braking force and the like. It is not necessary to reduce the output torque under other operating conditions (usage conditions in which hopping does not occur). But,
In the prior art, when the low speed stage is selected, the fuel injection amount is uniformly reduced, which may impair the power performance.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to prevent damage to the transmission when a low speed stage is selected and to ensure sufficient power performance. Another object of the present invention is to provide a fuel injection amount control device for a vehicle-mounted internal combustion engine.

[0007]

In order to achieve the above object, the present invention, as shown in FIG. 1, includes a fuel adjusting means M2 for adjusting a fuel injection amount to an internal combustion engine M1 mounted on a vehicle. In order to prevent the output torque transmitted from the internal combustion engine M1 to the transmission M3 from exceeding the torque allowed by the transmission M3, the fuel injection amount by the fuel adjusting means M2 is adjusted according to the operating state of the internal combustion engine M1. Is a fuel injection amount control device for an on-vehicle internal combustion engine, which is controlled by means of an operating state detecting means M4 for detecting an operating state including the rotation speed of the internal combustion engine M1, and a shift stage of the transmission M3. Shift speed detecting means M5 for operating and the operating state detecting means M
4, the engine-side maximum allowable injection amount calculating means M6 for calculating the engine-side maximum allowable injection amount according to the operating state of the internal combustion engine M1.
A transmission-side maximum allowable injection amount calculation means M7 for calculating the transmission-side maximum allowable injection amount according to the operating state of the internal combustion engine M1 by the operating state detection means M4; and a shift stage by the shift stage detecting means M5. A first injection amount control means M8 for controlling the fuel adjusting means M2 so that the fuel injection quantity to the internal combustion engine M1 becomes an amount according to the engine-side maximum allowable injection quantity at a time other than the low speed stage. When the shift speed detected by the shift speed detecting means M5 is a low speed step, the operating state detecting means M4
The amount of change in the engine speed is calculated from the detected value by, and as the amount of change decreases, the transmission-side maximum allowable injection amount is increased and corrected, and the fuel injection amount to the internal combustion engine M1 is changed to the transmission-side maximum allowable amount. A second injection amount control means M9 for controlling the fuel adjusting means M2 so that the fuel injection amount and the engine side maximum allowable injection amount are smaller, whichever is smaller.
And are provided.

[0008]

When the vehicle is running, the operating state including the rotational speed of the internal combustion engine M1 is detected by the operating state detecting means M4, and the gear stage of the transmission M3 is the gear stage detecting means M.
Detected by 5. Further, the engine-side maximum allowable injection amount is calculated by the engine-side maximum allowable injection amount calculating means M6 according to the operating state of the internal combustion engine M1, and the transmission-side maximum allowable injection amount is calculated by the transmission-side maximum allowable injection amount calculating means M7. Is calculated.

Then, according to the operating state of the internal combustion engine M1,
The fuel adjusting means M2 is controlled using the maximum allowable injection amount on the engine side and the maximum allowable injection amount on the transmission side. Then, the fuel injection amount by the fuel adjusting means M2 is adjusted, and the output torque transmitted from the internal combustion engine M1 to the transmission M3 is adjusted.

First, when the shift stage by the shift stage detecting means M5 is other than the low shift stage, that is, when the output torque of the internal combustion engine M1 is unlikely to exceed the allowable torque of the transmission M3, fuel injection into the internal combustion engine M1 is performed. The first injection amount control means M8 controls the fuel adjusting means M2 so that the amount becomes an amount corresponding to the engine-side maximum allowable injection amount.

When the shift speed detected by the shift speed detecting means M5 is a low speed step, the second injection amount control means M9 is
The amount of change in engine speed is calculated from the value detected by the operating state detecting means M4. Then, the second injection amount control means M
Reference numeral 9 corrects the transmission-side maximum permissible injection amount calculated by the transmission-side maximum permissible injection amount calculation means M7 as the amount of change in the engine speed decreases.

Here, the reason why the maximum allowable injection amount on the transmission side is corrected according to the amount of change in the engine speed is as follows. When the shift speed detected by the shift speed detecting means M5 is a low speed, the output torque of the internal combustion engine M1 is the transmission M3.
There is a possibility that the permissible torque will not be exceeded, and a case where it will not be exceeded. Among these, there is a possibility that the permissible torque of the transmission M3 may be exceeded, for example, during off-road running in which a low speed stage is selected and is operated in a high rotation state, a sudden increase in engine speed due to wheel idling during hopping or the like. And a subsequent rapid landing of the engine speed during landing, or a sudden change in output torque due to a sudden accelerator operation. Therefore, in this case, it is necessary to reduce the output torque of the internal combustion engine M1. However, under operating conditions other than the above, the output torque of the internal combustion engine M1 does not exceed the permissible torque of the transmission M3, and even at this time, if the output torque of the internal combustion engine M1 is reduced as in the case of hopping, the power performance will be reduced. I will run out. In the present invention, it is considered that the larger the amount of change in the engine speed, the higher the possibility of occurrence of hopping and the like, and the maximum allowable injection amount is reduced.

Then, the second injection amount control means M9 causes the fuel injection amount to the internal combustion engine M1 to be the smaller one of the transmission-side maximum allowable injection amount and the engine-side maximum allowable injection amount. The fuel adjusting means M2 is controlled such that the fuel adjusting means M2 has a quantity corresponding to the quantity.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. FIG. 2 is a diagram showing a schematic configuration of an automobile diesel engine (internal combustion engine) 2 including the fuel injection amount control device of the present embodiment, and FIG. 3 is a fuel adjusting means for injecting fuel into the diesel engine 2. It is a sectional view of distribution type fuel injection pump 1. As shown in FIG. 2, the fuel injection pump 1 includes a drive pulley 3 drivingly connected to a crankshaft 40 of the diesel engine 2 via a belt or the like. Then, the fuel injection pump 1 is driven by the rotation of the drive pulley 3, and the fuel is pressure-fed to the fuel injection nozzle 4 provided for each cylinder of the diesel engine 2 to inject the fuel.

As shown in FIG. 3, a drive shaft 5 is connected to the drive pulley 3. A fuel feed pump (developed by 90 degrees in the figure) 6 which is a vane type pump, and a disc-shaped pulsar 7 having a plurality of protrusions on its outer peripheral surface are attached to the drive shaft 5.
The base end portion (right end portion in the figure) of the drive shaft 5 is connected to the cam plate 8 via a coupling (not shown). A roller ring 9 is interposed between the pulsar 7 and the cam plate 8, and a plurality of cam rollers 10 facing the cam face 8a of the cam plate 8 are attached to the roller ring 9. The cam plate 8 is constantly urged and engaged with the cam roller 10 by the spring 11.

A plunger 12 for pressurizing fuel is integrally rotatably attached to the cam plate 8, and the rotational force of the drive shaft 5 is transmitted to the cam plate 8 via a coupling, whereby the cam plate 8 is rotated. 8 and the plunger 12 are reciprocally driven in the left-right direction in the figure while rotating. 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 tip end surface (the right end surface in the drawing) of the plunger 12 and the inner bottom surface of the cylinder 14. The same number of suction grooves 16 and distribution ports 17 as the number of cylinders of the diesel engine 2 are formed on the outer periphery of the plunger 12 on the front end side. A distribution passage 18 and a suction port 19 are formed in the pump housing 13 so as to correspond to the suction groove 16 and the distribution port 17.

When the fuel feed pump 6 is driven based on the rotation of the drive shaft 5, fuel from a fuel tank (not shown) is supplied into the fuel chamber 21 through the fuel supply port 20. Further, in the intake stroke in which the plunger 12 moves (returns) in the left direction in the drawing and the high pressure chamber 15 is decompressed, one of the intake grooves 16 communicates with the intake port 19 to move from the fuel chamber 21 to the high pressure chamber 15. Fuel is introduced into. On the other hand, the plunger 12 moves to the right in the figure (forward movement).
Then, in the compression stroke in which the high pressure chamber 15 is pressurized, fuel is pressure-fed from the distribution passage 18 to the fuel injection nozzle 4 of each cylinder and injected.

The pump housing 13 has a spill passage 22 for fuel overflow that connects the high pressure chamber 15 and the fuel chamber 21.
Is formed, and an electromagnetic spill valve 23 is provided on the way. The electromagnetic spill valve 23 is a normally open type valve, and when the coil 24 is not energized (OFF), the valve body 25 is opened and the fuel in the high pressure chamber 15 overflows into the fuel chamber 21. When the coil 24 is energized (turned on), the valve body 25 is closed and the overflow of fuel from the high pressure chamber 15 to the fuel chamber 21 is stopped.

Therefore, by controlling the energization time of the electromagnetic spill valve 23, the electromagnetic spill valve 23 is controlled to be closed / opened and the overflow amount of fuel from the high pressure chamber 15 to the fuel chamber 21 is adjusted. Then, by opening the electromagnetic spill valve 23 during the compression stroke of the plunger 12, the fuel inside the high pressure chamber 15 is depressurized and the fuel injection from the fuel injection nozzle 4 is stopped. In other words, even if the plunger 12 moves forward, the high pressure chamber 15 remains open while the electromagnetic spill valve 23 is open.
The internal fuel pressure does not rise, and fuel injection from the fuel injection nozzle 4 is not performed. Also, during the forward movement of the plunger 12,
The fuel injection amount from the fuel injection nozzle 4 is controlled by controlling the closing / opening timing of the electromagnetic spill valve 23.

Below the pump housing 13, there is provided a timer device (90 degrees expanded in the figure) 26 for controlling the fuel injection timing. The timer device 26 controls the position of the roller ring 9 with respect to the rotation direction of the drive shaft 5 to control the timing when the cam face 8a engages with the cam roller 10, that is, the reciprocating timing of the cam plate 8 and the plunger 12. Is.

The timer device 26 is operated by hydraulic pressure, and includes a timer housing 27, a timer piston 28 fitted in the timer housing 27, and a low pressure chamber 29 on one side of the timer housing 27. The timer piston 28 is composed of a timer spring 31 and the like for pressing and urging the timer piston 28 toward the pressurizing chamber 30 on the other side. The timer piston 28 is connected to the roller ring 9 via the slide pin 32.

In the pressurizing chamber 30 of the timer housing 27,
The fuel pressurized by the fuel feed pump 6 is introduced. The position of the timer piston 28 is determined by the equilibrium relationship between the fuel pressure and the urging force of the timer spring 31. According to this, the position of the roller ring 9 is determined, and the reciprocating timing of the plunger 12 is determined via the cam plate 8.

In order to control the fuel pressure of the timer device 26, a timing control valve 33 is provided in the communication passage 34 connecting the pressurizing chamber 30 and the low pressure chamber 29. The timing control valve 33 is an electromagnetic valve whose opening and closing is controlled 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 timing control valve 33. Then, the lift timing of the plunger 12 is controlled by the fuel pressure adjustment, and the fuel injection timing from each fuel injection nozzle 4 is adjusted.

A rotation speed sensor 35 composed of an electromagnetic pickup coil is attached to the upper portion of the roller ring 9 so as to face the outer peripheral surface of the pulsar 7. The rotation speed sensor 35 detects passage of the protrusions of the pulsar 7 or the like when they cross each other, and outputs a timing signal (engine rotation pulse) corresponding to the engine rotation speed. Further, since the rotation speed sensor 35 is integrated with the roller ring 9,
Regardless of the control operation of the timer device 26, a reference timing signal is output to the plunger lift at a constant timing.

Next, the diesel engine 2 will be described. As shown in FIG. 2, in the diesel engine 2, the cylinder 41, the piston 42, and the cylinder head 43.
A main combustion chamber 44 is formed for each cylinder, and a sub combustion chamber 45 is connected to each main combustion chamber 44. Then, the fuel injected from each fuel injection nozzle 4 is supplied to each auxiliary combustion chamber 45. Further, a glow plug 46 as a start-up assist device is attached to each sub-combustion chamber 45.

An intake pipe 47 and an exhaust pipe 50 are connected to the diesel engine 2, respectively. A compressor 49 of a turbocharger 48 is provided in the intake pipe 47, and a turbine 5 of the turbocharger 48 is provided in the exhaust pipe 50.
1 is provided. A waste gate valve 52 for adjusting the boost pressure is attached to the exhaust pipe 50.

The exhaust pipe 50 and the intake pipe 47 are the return pipe 5.
The exhaust pipes 50 are connected to each other in a communicating state by means of 4, and a part of the exhaust gas in the exhaust pipe 50 can be returned to the intake pipe 47. An EGR valve 55 for adjusting the exhaust gas recirculation amount (EGR amount) is provided in the middle of the recirculation pipe 54. This E
The negative pressure applied to the diaphragm chamber of the GR valve 55 is
It is controlled by a vacuum switching valve (VSV) 56.

Further, in the middle of the intake pipe 47, there is provided a throttle valve 58 which is opened / closed in conjunction with an accelerator pedal 57 provided in the driver's seat. A bypass passage 59 is formed in parallel with the throttle valve 58, and a bypass throttle valve 60 is provided in the bypass passage 59 so as to be openable and closable. The bypass throttle valve 60 is opened / closed by an actuator 63. Actuator 63
Is supplied with a negative pressure generated by a negative pressure pump (not shown) via two VSVs 61 and 62.

On the output side of the diesel engine 2,
A transmission (transmission) 65 for manually changing the rotation of the crankshaft 40 is provided.
The transmission 65 is provided with gears having various numbers of teeth, and by changing the meshing of the gears by operating the shift lever in the driver's seat, the rotational speed and torque of the diesel engine 2 are converted in a plurality of stages. In the transmission 65, the gear ratio is determined by the ratio of the input rotation speed (engine rotation speed) to the output rotation speed, and in meshing the gears, reverse gear (reverse), first speed, second gear Speed, 3rd speed, 4th speed ...
And so on. A large driving force can be obtained at a low speed stage having a large gear ratio such as 1st speed or reverse.

The electromagnetic spill valve 23, the timing control valve 33, the glow plug 46 and each VSV 5
6, 61 and 62 are electronic control units (hereinafter simply “ECU”)
(Referred to as 71), and their drive timings are controlled by the ECU 71.

As a sensor for detecting the operating state of the diesel engine 2, the following sensors are provided in addition to the rotation speed sensor 35. An intake air temperature sensor 72 for detecting the intake air temperature THA of the air taken into the intake pipe 47 via the air cleaner 64, and an accelerator opening degree for detecting the accelerator opening degree ACCP corresponding to the load of the diesel engine 2 from the opening / closing position of the throttle valve 58. A sensor 73, an intake pressure sensor 74 that detects a supercharging pressure PiM in the intake port 53, a water temperature sensor 75 that detects a cooling water temperature THW of the diesel engine 2, a rotation reference position of the crankshaft 40 of the diesel engine 2, for example, a specific cylinder A crank angle sensor 76 for detecting the rotational position of the crankshaft 40 with respect to the top dead center, and a reed switch 77b by a magnet 77a rotated by the rotation of the gear of the transmission 65.
A vehicle speed sensor 77 for detecting the traveling speed (vehicle speed) by turning on / off the vehicle and a gear stage sensor 66 for detecting the gear stage of the transmission 65 are provided.

Each of the above-mentioned sensors 3 is provided in the ECU 71.
5, 66, 72 to 77 are respectively connected. Then, the ECU 71, based on the signals output from the respective sensors 35, 66, 72 to 77, the electromagnetic spill valve 23, the timing control valve 33, the glow plug 46 and the V.
SV56,61,62 etc. are controlled suitably.

Next, the structure of the above-mentioned ECU 71 will be described with reference to the block diagram of FIG. ECU 71
Is a central processing unit (CPU) 81 that constitutes an engine-side maximum allowable injection amount calculation means, a transmission-side maximum allowable injection amount calculation means, a first injection amount control means, and a second injection amount control means, and a predetermined control. A read-only memory (ROM) 82 in which programs and maps are stored in advance, and a random access memory (RAM) 8 in which the calculation results of the CPU 81 are temporarily stored
3. Backup RA that saves pre-stored data
Bus 84 for M84, input port 85 and output port 86
It is configured as a logical operation circuit connected by.

The intake port temperature sensor 7 is connected to the input port 85.
2, the accelerator opening sensor 73, the intake pressure sensor 74, and the water temperature sensor 75 are connected via the buffers 88, 89, 90, 91, the multiplexer 92, and the A / D converter 93. Further, the rotation speed sensor 35, the shift speed sensor 66, the crank angle sensor 76, and the vehicle speed sensor 77 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, 66, 72 to 77, etc., which are input via the input port 85, as input values. The output port 86 is connected to the electromagnetic spill valve 23, the timing control valve 33, the glow plug 46, the VSV 56, 61, 62, etc. via drive circuits 96, 97, 98, 99, 100, 101.

The CPU 81 uses the sensors 35, 6
Based on the input values read from 6, 72 to 77, the electromagnetic spill valve 23, the timing control valve 33, the glow plug 46, the VSV 56, 61, 62, etc. are suitably controlled.

Next, the operation and effect of this embodiment configured as described above will be described. In the present embodiment, when calculating the maximum allowable injection amount QFULL in the fuel injection amount control, a low speed stage (first speed gear or reverse gear) is selected in the transmission 65 and a shift stage other than the low speed stage is selected. Different calculation formulas are used depending on the case. That is, when the gear stage other than the low gear stage is selected, the following equation (1) is used. The maximum allowable injection amount QFULL here is an upper limit value of the fuel injection amount with respect to the intake air amount and the like.

QFULL = (α + QSP0) · KF · KNFI + QMAX + QFIX (1) Further, when the low speed stage is selected, the following formula (2) is used. QFULL = (MIN [α, β] + QSP0) · KF · KNFI + QMAX + QFIX (2) In the formula (1), α is the maximum allowable injection amount on the engine side and (K2
・ K3 ・ QSPF1) Here, K2 is an intake pressure correction coefficient for correcting the basic injection amount characteristic according to the intake pressure, and is obtained from the one-dimensional map of the supercharging pressure PiM. K3 is an intake air temperature correction coefficient for reducing and correcting the basic maximum allowable injection amount characteristic when the intake air temperature is equal to or higher than the predetermined temperature, and is obtained from the one-dimensional map of the intake air temperature THA. QSPF1 is the maximum allowable injection increase amount, and is obtained from the one-dimensional map of the engine speed NE.

In the expressions (1) and (2), QSP0 is the maximum allowable injection amount offset term, which is obtained from the one-dimensional map of the engine speed NE. KF is an injection amount temperature characteristic correction coefficient, which is calculated according to a predetermined arithmetic expression. KN
The FI is the maximum allowable injection amount QFUL according to the magnitude of the variation due to the secular change of the fuel injection pump 1 and the difference in fuel properties.
It is an integral control correction coefficient for correcting L and is obtained from the map. QMAX is a cold maximum allowable injection amount correction term. QFIX is a fixed injection amount, and is calculated according to an arithmetic expression defined using the engine speed NE.

In the equation (2), β is the maximum permissible injection amount on the final transmission side. Further, MIN [α, β] means selecting (enabling) the smaller one of the engine-side maximum allowable injection amount α and the final transmission-side maximum allowable injection amount β. ..

Next, fuel injection amount control using these equations (1) and (2) will be described with reference to the flow charts of FIGS. 5 and 6 and the timing chart of FIG. This timing chart shows changes in the engine speed NE and the maximum permissible injection amount QFULL when the transmission 65 is in the low speed stage (first gear or reverse gear), and the period from timing t3 to timing t9 in FIG. At, hopping, which consists of road grip and wheel slip, occurs.

When the processing shifts to the routine of FIG. 5, CP
First, in step 101, the U 81 determines the engine speed NE (i), the accelerator opening ACCP (i) and the supercharging pressure PiM based on the detected values from the rotation speed sensor 35, the accelerator opening sensor 73 and the intake pressure sensor 74. Read (i) respectively.

In step 102, the CPU 81 determines the basic fuel injection amount Q based on the engine speed NE (i), accelerator opening ACCP (i), etc. read in step 101.
Calculate BASE. The calculation of the basic injection amount QBASE is performed with reference to a predetermined map (not shown) having the engine speed NE and the accelerator opening ACCP as parameters. Further, for the basic injection amount QBASE, the CPU 81 performs a low temperature start increase correction, a rapid deceleration increase correction, and the like based on the values of the cooling water temperature THW, the accelerator opening ACCP, the engine speed NE, and the like as necessary.

Next, in step 103, the CPU 81 determines the intake pressure correction coefficient K2, the intake temperature correction coefficient K3, the maximum allowable injection increase QSPF1, and the maximum allowable injection amount offset term QS.
P0, injection amount temperature characteristic correction coefficient KF, integral control correction coefficient KN
FI, the cold maximum allowable injection amount correction term QMAX, the fixed injection amount QFIX, and the engine side maximum allowable injection amount α are calculated according to a map, an arithmetic expression, and the like.

In step 104, the CPU 81 fetches a signal from the gear shift stage sensor 66 and determines whether or not the low speed gear is selected in the transmission 65. When a shift speed other than the low speed (gear of 2nd speed or higher) is selected, the CPU 81 calculates the maximum allowable injection amount QFULL based on the equation (1) using the values in step 103 in step 105. To do.

Then, the CPU 81 executes step 10 in FIG.
6, the basic injection amount QBASE previously calculated in step 102 is compared with the maximum allowable injection amount QFULL in step 105, and the smaller value is set as the final injection amount QFIN. Subsequently, the CPU 81 obtains the injection amount command value TSP corresponding to the final injection amount QFIN in step 107, outputs the obtained injection amount command value TSP in step 108, and terminates this routine. The electromagnetic spill valve 23 is drive-controlled by the output of the injection amount command value TSP, and fuel injection is executed.

By the way, when the shift lever of the transmission 65 is switched from the shift speed other than the low speed to the low speed at the timing t1 in FIG.
In step 104 of FIG. 5, it is determined that the gear has been switched to the low gear based on the signal from the gear shift sensor 66, and the routine proceeds to step 109. CPU81 is step 109
At the engine speed NE (i-
1) Read out. Then, the CPU 81 proceeds to step 110.
At this time, from the engine speed NE (i) of this time read in step 101 to the previous engine speed NE (i-
1) is subtracted, and the engine speed change amount ΔNE (= N
E (i) -NE (i-1)) is calculated.

Next, in step 111, the CPU 81 sets the current engine speed NE (i) as the previous engine speed NE (i-1) in preparation for the next calculation, and sets this value in step 11
Remember in 2.

The CPU 81 then proceeds to step 11 of FIG.
3 to 115, the engine speed change amount ΔN
The final transmission-side maximum allowable injection amount β according to E is calculated.
In this calculation process, the transmission side maximum allowable injection amount QSPF2
And the correction amount ΔQSP are used. Here, the transmission-side maximum allowable injection amount QSPF2 controls the fuel injection amount by the fuel injection pump 1 so that the output torque transmitted from the diesel engine 2 to the transmission 65 does not exceed the torque allowed by the transmission 65. It is for. Maximum permissible injection amount on the transmission side QSPF2
Is preset for each engine speed NE in a map or the like. The correction amount ΔQSP is for correcting the transmission-side maximum allowable injection amount QSPF2 in accordance with the magnitude of the change amount ΔNE of the engine speed. The correction amount ΔQSP is set to an initial value when the ignition switch is turned on or when the correction coefficient KSP described later becomes “0”.

First, the CPU 81, at step 113, changes Δ in the engine speed at step 110.
A correction coefficient KSP corresponding to NE is obtained. The correction coefficient KSP here is a coefficient for setting the correction amount ΔQSP according to the change amount ΔNE. For the calculation process, a one-dimensional map in which the correction coefficient KSP for the change amount ΔNE as shown in FIG. 7 is defined is used. In this map, the change amount ΔNE is within a predetermined range (-1000 rpm <ΔNE <100
0 rpm), the correction coefficient KSP is "0", and within the predetermined range, the absolute value of the change amount ΔNE | Δ
The correction coefficient KSP increases as NE | decreases.
When the change amount ΔNE is “0”, the correction coefficient KSP
Is the maximum value (“1.5” in FIG. 7).

Therefore, if the change amount ΔNE in step 110 is less than 1000 rpm, the correction coefficient KSP is
Takes a value larger than "0". Upon obtaining the correction coefficient KSP from the map, the CPU 81 multiplies the correction amount ΔQSP by the correction coefficient KSP in step 114,
The multiplication result (ΔQSP · KSP) is used as a new correction amount ΔQ.
Update as SP.

Subsequently, in step 115, the CPU 81 adds the correction amount ΔQSP in step 114 to the transmission-side maximum allowable injection amount QSPF2, and the addition result (QSPF2 + ΔQSP) is set as the final transmission-side maximum allowable injection amount β. To do. Next, in step 116, the CPU 81 determines the engine-side maximum allowable injection amount α in step 103 and the final transmission-side maximum allowable injection amount β in step 115.
And the smaller maximum allowable injection amount, whichever is smaller. At timing t1 in FIG. 8, the final transmission side maximum allowable injection amount β is selected.

In step 117, the CPU 81 calculates the maximum allowable injection amount QFULL based on the equation (2) using each value in step 103 and the final transmission side maximum allowable injection amount β in step 116. To do. Then, the CPU 81 performs the processing of steps 106 to 108. That is, the CPU 81 compares the basic injection amount QBASE with the maximum allowable injection amount QFULL in step 106, and the smaller value is determined as the final injection amount QFIN.
Then, in step 107, the injection amount command value TSP corresponding to the final injection amount QFIN is obtained, and in step 108 the obtained injection amount command value TSP is output, and this routine is ended. This injection amount command value TSP
The electromagnetic spill valve 23 is drive-controlled by the output of, and fuel injection is executed.

By the processing in step 115, the final transmission side maximum allowable injection amount β is increased and corrected by the correction amount ΔQSP. Then, at timing t2 in FIG. 8, when the final transmission-side maximum allowable injection amount β becomes equal to or larger than the engine-side maximum allowable injection amount α, the CPU 81 selects the engine-side maximum allowable injection amount α in step 116. Therefore, in the process of step 117, the maximum allowable injection amount QFULL according to the engine-side maximum allowable injection amount α is calculated. Then, when the maximum allowable injection amount QFULL is calculated in this way, the CPU 81 performs the processing of steps 106 to 108 and ends this routine.

At timing t3 in FIG. 8, the wheels grip the road surface, and the engine speed NE begins to decrease.
At the timing t4, the engine speed NE suddenly drops,
When the absolute value | ΔNE | of the change amount becomes 1000 rpm or more, the correction coefficient KSP in step 113 becomes “0”. Therefore, the CPU 81 sets the correction amount ΔQSP to “0” in step 114, and the transmission side maximum allowable injection amount QSP.
F2 is set to the final transmission side maximum allowable injection amount β. As a result, the final transmission-side maximum allowable injection amount β becomes smaller than the engine-side maximum allowable injection amount α. Therefore, the CPU 81 selects the final transmission side maximum allowable injection amount β in the process of step 116. Therefore, in the process of step 117, the maximum allowable injection amount QFULL according to the final transmission side maximum allowable injection amount β is calculated. Then, when the maximum allowable injection amount QFULL is calculated in this way, the CPU 81 performs the processing of steps 106 to 108 and ends this routine.

When the automobile bounces off due to the suspension reaction force at the timing t5 in FIG. 8, the wheel spins idly and the engine speed NE rapidly rises. After that, at the timing t6, the vehicle lands and the wheel grips the road surface, whereby the engine speed NE is reached. Drops sharply. Further, at time t7, the engine speed NE again sharply increases due to the idling of the wheels, and thereafter, at timing t8, the wheel grips the road surface, and the engine speed NE sharply decreases. This rapid decrease in engine speed NE continues until timing t9. In the period of these timings t3 to t9, the so-called hopping phenomenon occurs due to the rapid increase in the engine rotational speed NE caused by the wheel idling and the subsequent rapid decrease in the engine rotational speed NE at the time of landing.

The absolute value | ΔNE | of the change amount of the engine speed NE at the time of hopping is 1000 rpm or more. Therefore, the CPU 81 executes the processing of step 117
The maximum allowable injection amount QFULL according to the final transmission side maximum allowable injection amount β is held. Since the correction coefficient KSP becomes “0” during this hopping, the correction amount ΔQSP is set to the initial value.

After the timing t10 at which such hopping ends, when the normal operation without the rapid change of the engine speed NE is started, the correction amount ΔQSP becomes a value other than "0" in the processing of step 114, and the timing described above is applied. Similar to t1 to t2, the maximum allowable injection amount QFULL again increases with the passage of time.

As described above, in the present embodiment, the gear position sensor 6
When the gear position according to 6 is other than the low gear position, the fuel injection pump 1 is controlled so that the fuel injection amount into the diesel engine 2 becomes an amount according to the engine-side maximum allowable injection amount α (steps 105, 106 to 108). .. When the shift speed is the low speed, the engine speed change amount ΔNE is calculated from the value detected by the rotation speed sensor 35 (step 110). The change amount ΔNE is within a predetermined range (-1000 rpm <ΔNE
<1000 rpm), the transmission side maximum allowable injection amount QSPF2 is increased and corrected as the change amount ΔNE decreases, and the final transmission side maximum allowable injection amount β is calculated. Also,
If the variation amount ΔNE is out of the predetermined range, the transmission-side maximum allowable injection amount QSPF2 is used as it is as the final transmission-side maximum allowable injection amount β without correction (steps 113 to 115). Then, the fuel injection amount into the diesel engine 2 is set to an amount corresponding to the smaller maximum allowable injection amount of the final transmission-side maximum allowable injection amount β and the engine-side maximum allowable injection amount α. , The fuel injection pump 1 is controlled (steps 116 and 11).
7, 106-108).

Here, the reason why the transmission-side maximum allowable injection amount QSPF2 is corrected according to the magnitude of the engine speed change amount ΔNE is as follows. When the shift speed by the shift speed sensor 66 is a low speed, the output torque of the diesel engine 2 may or may not exceed the allowable torque of the transmission 65. Among these, there is a possibility that the allowable torque of the transmission 65 may be exceeded when hopping occurs or when the output torque changes suddenly due to a sudden accelerator operation.
Therefore, in this case, it is necessary to reduce the output torque of the diesel engine 2. However, under operating conditions other than the above, the output torque of the diesel engine 2 does not exceed the allowable torque of the transmission 65, and at this time as well, when the output torque of the diesel engine 2 is reduced as in the case of hopping, the power performance is insufficient. Resulting in.

Therefore, in this embodiment, it is determined whether or not hopping or the like has occurred depending on whether or not the amount of change ΔNE of the engine speed is within a predetermined range. If the amount of deviation is outside the predetermined range, the transmission side maximum allowable injection amount is determined. Without correcting the QSPF2, the transmission-side maximum allowable injection amount QSPF2 is increased and corrected as the change amount ΔNE decreases within the predetermined range.

Therefore, even when the transmission 65 is in the low speed stage, only when it is necessary to reduce the output torque of the diesel engine 2 when the amount of change ΔNE of the engine speed is out of a predetermined range, that is, when the hopping is suddenly started. The fuel injection pump 1 is controlled by using the transmission-side maximum allowable injection amount QSPF2 only when an abrupt accelerator operation is performed due to sudden retreat. When the amount of change ΔNE in the engine speed other than that is small (when it is within the predetermined range), even if the transmission 65 is in the low speed stage, the final transmission side having a value larger than the transmission-side maximum allowable injection amount QSPF2. The fuel injection pump 1 is controlled using the maximum allowable injection amount β.

Therefore, unlike the prior art in which the fuel injection amount is uniformly reduced when the low speed stage is selected, in the present embodiment, the transmission 65 resulting from a sudden change in the engine speed NE during hopping or the like. It is possible to ensure power performance at low speeds while preventing damage to the vehicle.

Although the present invention has been embodied in the diesel engine 2 having the supercharger (turbocharger 48) in the above-described embodiment, the diesel engine having the supercharger as the supercharger and the supercharger It can also be embodied in a diesel engine not equipped with. Also,
It can be embodied in a gasoline engine instead of the diesel engine 2.

[0064]

As described above in detail, according to the present invention, when the transmission is not in the low speed stage, the fuel is adjusted so that the amount of fuel injected into the internal combustion engine is the amount according to the maximum allowable injection amount on the engine side. Means for controlling the means to calculate the amount of change in engine speed when the transmission is in the low speed stage, and as the amount of change decreases, the transmission side maximum allowable injection amount is increased and corrected, and fuel injection into the internal combustion engine is performed. Since the fuel adjusting means is controlled so that the amount becomes the amount corresponding to the smaller maximum allowable injection amount of the transmission-side maximum allowable injection amount and the engine-side maximum allowable injection amount, This has an excellent effect that it is possible to secure sufficient power performance while preventing the transmission from being damaged when the gear is selected.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram of the present invention.

FIG. 2 is a schematic configuration diagram showing a fuel injection amount control device of a diesel engine with a supercharger in one embodiment embodying the present invention.

FIG. 3 is a cross-sectional view of a fuel injection pump in one embodiment.

FIG. 4 is a block diagram showing an electrical configuration of an ECU in one embodiment.

FIG. 5 is a flowchart illustrating a fuel injection amount control routine executed by a CPU in one embodiment.

FIG. 6 is a flowchart illustrating a fuel injection amount control routine executed by a CPU in one embodiment.

FIG. 7 is a diagram showing a map in which a correction coefficient for an amount of change in engine speed is defined.

FIG. 8 is a timing chart showing changes in engine speed and maximum allowable injection amount.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 2 ... Diesel engine as an internal combustion engine, 35 ... Rotation speed sensor which comprises a part of operation state detection means, 65 ... Transmission (transmission), 6
6 ... Shift speed sensor as shift speed detecting means, 72 ... Intake temperature sensor forming a part of operating state detecting means, 73 ... Accelerator opening sensor forming a part of operating state detecting means,
74 ... Intake pressure sensor forming part of operating condition detecting means, 75 ... Water temperature sensor forming part of operating condition detecting means, 81 ... Engine side maximum allowable injection amount calculating means, transmission side maximum allowable injection amount calculating Means, first injection amount control means and second
Which constitutes the injection amount control means of the engine, NE (i) ... Engine speed, ΔNE ... Change in engine speed, PiM
... supercharging pressure, THA ... intake temperature, ACCP (i) ... accelerator opening, THW ... cooling water temperature, α ... engine side maximum allowable injection amount, QSPF2 ... transmission side maximum allowable injection amount, β ... final transmission side maximum Allowable injection amount

Claims (1)

[Claims] 1. A fuel adjusting means for adjusting a fuel injection amount to an internal combustion engine mounted on a vehicle, wherein an output torque transmitted from the internal combustion engine to a transmission is a torque permissible by the transmission. A fuel injection amount control device for an on-vehicle internal combustion engine, wherein the fuel injection amount by the fuel adjusting means is controlled in accordance with the operating state of the internal combustion engine so as not to exceed the limit. An operating state detecting means for detecting a state; a shift stage detecting means for detecting a shift stage in the transmission; and an engine side for calculating an engine side maximum allowable injection amount according to the operating state of the internal combustion engine by the operating state detecting means. Maximum allowable injection amount calculating means, transmission side maximum allowable injection amount calculating means for calculating the transmission side maximum allowable injection amount according to the operating state of the internal combustion engine by the operating state detecting means, and the shift stage detection When shift stage by stage other than the low speed stage,
A first injection amount control means for controlling the fuel adjusting means so that the fuel injection quantity to the internal combustion engine becomes an amount according to the engine-side maximum allowable injection quantity, and a shift speed by the shift speed detecting means. At the low speed stage, the change amount of the engine speed is calculated from the value detected by the operating state detecting means, and the transmission side maximum allowable injection amount is increased and corrected as the change amount decreases, and the fuel to the internal combustion engine is fueled. A second injection amount for controlling the fuel adjustment means so that the injection amount becomes an amount corresponding to the smaller maximum allowable injection amount of the transmission side maximum allowable injection amount and the engine side maximum allowable injection amount. A fuel injection amount control device for an on-vehicle internal combustion engine, comprising: a control means.