JPH06117264A - Supercharging pressure control device of aircraft internal combustion engine - Google Patents

Abstract

PURPOSE:To change the opening of a waste gate valve to the opening where the target supercharging pressure is immediately obtained when the throttle opening is changed. CONSTITUTION:A waste gate valve 26 is provided in a bypass passage 24 to detour an exhaust turbine 20 of an exhaust turbocharger 10, and the supercharging pressure is controlled by this waste gate valve 26. The opening of the waste gate valve corresponding to the stored target opening is correctively controlled so that the supercharging pressure may be the target supercharging pressure, and the target opening is updated by the opening of the waste gate valve 26 where the supercharging pressure becomes the target supercharging pressure. Updating of the target opening is prohibited when the difference between the engine speed and the target speed is larger than the predetermined value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boost pressure control device for an internal combustion engine for an aircraft.

[0002]

2. Description of the Related Art An internal combustion engine for driving a propeller,
In an aircraft equipped with a turbocharger for supercharging an internal combustion engine, the turbocharger having a wastegate valve for controlling supercharging pressure, the engine speed and a target speed according to the throttle opening And the propeller pitch control device that controls the propeller pitch so that the supercharging pressure is corrected and controlled so that the supercharging pressure becomes the target supercharging pressure. The present applicant has already proposed a supercharging pressure control device that includes a supercharging pressure control device that updates the target opening amount with the opening amount of the wastegate valve that is the target supercharging pressure (Japanese Patent Application No. 4- 166192).

In this supercharging pressure control device, when the difference between the supercharging pressure and the target supercharging pressure is small and the change amount of the wastegate valve per unit time is small, the opening degree of the wastegate valve at this time is equal to the target supercharging pressure. It is determined that the opening is required to obtain the supply pressure, and the target opening is updated with this opening. If the target supercharging pressure is updated in this way, the supercharging pressure will immediately match the target supercharging pressure if the wastegate valve opening is made to match the target opening when the throttle opening changes thereafter. Will be done.

[0004]

By the way, the target engine speed of the normal engine is set so as to increase as the throttle opening increases. Therefore, as described above, the engine speed depends on the throttle opening. When the propeller pitch is controlled so that the engine speed becomes equal to the number, for example, when the throttle opening is reduced to decelerate during cruising and the target engine speed decreases, the propeller pitch increases to decrease the engine speed. To be done. However, a high-pitch stopper and a low-pitch stopper are usually provided for the propeller, and the change range of the propeller pitch is restricted by these stoppers. Therefore, if the amount of decrease in the throttle opening when the throttle opening is decreased to decelerate is large, that is, if the amount of decrease in the target speed is large, the propeller abuts the high pitch stopper and the propeller pitch becomes larger. I will not be able to. However, when the propeller is in contact with the high pitch stopper in this way, the opening of the waste gate valve becomes different from the optimum opening according to the throttle opening. Nevertheless, in the above supercharging pressure control device, the target opening of the waste gate valve is updated at this time as well, so that the stored target opening deviates from the optimum target opening. Occurs.

Next, this will be described with reference to FIG. In FIG. 16, the target supercharging pressure NET of the engine is set to increase as the throttle opening TA increases, and the target supercharging pressure is fixed to a constant value within the range of the throttle opening TA shown in FIG. The case is shown. As shown in FIG. 16, the throttle opening TA
Is rapidly decreased, the target engine speed NET of the engine is also rapidly decreased as indicated by the broken line. In this way, when the target engine speed NET is sharply reduced, the propeller pitch increases to reduce the engine speed NE,
Then, the propeller contacts the high pitch stopper, and the propeller pitch is maintained at the maximum value MAX. When the propeller pitch reaches the maximum value MAX, the engine speed NE rapidly decreases to some extent as shown by the solid line, but thereafter gradually decreases to the target speed NET. When the engine speed NE reaches the target speed NET, the control of the propeller pitch is then restarted.

On the other hand, when the throttle opening is reduced, the negative pressure downstream of the throttle valve becomes large, so that the opening of the waste gate valve is reduced in order to keep the supercharging pressure constant. At this time, the opening of the waste gate valve decreases following the decrease in the engine speed NE as shown by the solid line. During this time, the opening degree of the waste gate valve is controlled so that the supercharging pressure becomes the target supercharging pressure. Therefore, at this time, the difference between the supercharging pressure and the target supercharging pressure is small. Also,
At this time, the opening degree of the waste gate valve decreases rapidly and then gradually decreases, so that the change amount of the waste gate valve per unit time becomes small. Thus, even while the propeller is in contact with the high-pitch stopper, the difference between the supercharging pressure and the target supercharging pressure is small, and the change amount of the wastegate valve per unit time is small. The pressure control device determines that the opening of the waste gate valve at this time is the opening required to obtain the target supercharging pressure. Therefore, at this time, the target opening should be updated with this opening. become.

By the way, the opening of the waste gate valve shown by the broken line in FIG. 16 is optimum when the propeller pitch is controlled so that the engine speed NE becomes the target speed NET according to the throttle opening TA. As shown in FIG. 16, the opening indicated by the solid line when the propeller pitch is maintained at the maximum value MAX is smaller than the optimum opening indicated by the broken line when the propeller pitch is controlled. Become. That is, the propeller pitch is the maximum value MA
Since the engine speed NE is higher than the target speed NET corresponding to the actual throttle opening TA while the engine speed NE is maintained at X, the opening of the wastegate valve at this time is the optimum opening shown by the broken line. Will be smaller than. Therefore, at this time, if the target opening is updated with the opening shown by the solid line, this target opening will deviate from the optimum opening corresponding to the throttle opening shown by the broken line. Even if the opening of the waste gate valve is made to match the target opening when changed, the problem arises that the boost pressure does not immediately match the target boost pressure.

In this case, as can be seen from FIG. 16, the opening of the waste gate valve deviates from the optimum opening corresponding to the throttle opening because the target engine speed NE after the throttle opening TA is reduced. It is during the decrease to the rotation speed NET. On the contrary, when the throttle opening TA is increased, the propeller abuts against the low pitch stopper and the propeller pitch is temporarily maintained at the minimum value MIN. At this time, the engine speed NE also rises to the target speed NET. The opening of the wastegate valve deviates from the optimum opening during the period. That is, if the target opening degree is updated by the opening degree of the wastegate valve when the engine speed NE deviates from the target rotation speed NET, the above-mentioned problem occurs.

[0009]

In order to solve the above problems, according to the present invention, an internal combustion engine for driving a propeller and a turbocharger for supercharging the internal combustion engine are provided, and a turbocharger is provided. In an aircraft that has a wastegate valve for controlling boost pressure and the range of change in propeller pitch is regulated in advance, set the propeller pitch so that the engine speed becomes the target speed according to the throttle opening. A propeller pitch control device for controlling,
The waste gate valve opening corresponding to the stored target opening is corrected and controlled so that the supercharging pressure becomes the target supercharging pressure, and the supercharging pressure becomes the target supercharging pressure. A supercharging pressure control device for updating the target opening is provided, and the updating operation of the target opening is prohibited when the difference between the engine speed and the target speed is larger than a predetermined value.

[0010]

When the opening of the wastegate valve deviates from the target opening, that is, when the difference between the engine speed and the target speed is large, the updating operation of the wastegate valve is prohibited.

[0011]

1 shows diagrammatically a reciprocating internal combustion engine 1 for driving a propeller 2 of an aircraft. In the embodiment shown in FIG. 1, this internal combustion engine 1 comprises a spark ignition type V type eight cylinder internal combustion engine, and each cylinder 3a, 3b, 3c, 3d, 3e,
Spark plugs 4a, 4b, 4c, 4 on 3f, 3g, 3h, respectively
d, 4e, 4f, 4g and 4h are provided. Further, each of the cylinders 3a to 3h is connected to a common intake duct 6 via a corresponding intake branch pipe 5, and each of the intake branch pipes 5 has a fuel injection valve 7a, 7b, 7c, 7d, 7e, 7f. , 7
g and 7h are arranged. The intake duct 6 is an intercooler 8
And an exhaust turbocharger 10 via the intake duct 9
A throttle valve 11 is arranged in the intake duct 6 downstream of the intercooler 8. This throttle valve 11
Is connected to a throttle lever 12 provided in the cockpit.

The turbocharger 10 includes an air suction pipe 13,
The compressor 16 includes an impeller 14 and a compressor scroll chamber 15, and the turbine scroll chamber 17, a turbine wheel 18, and an exhaust turbine 20 including an exhaust gas outflow pipe 19. The scroll chamber 15 of the compressor 16 is connected to the intake duct 9. It On the other hand, each cylinder 3a, 3b, 3c, 3d has a common exhaust manifold 21.
The remaining cylinders 3e, 3f, 3g, 3h are connected to a common exhaust manifold 22. Each of these exhaust manifolds 21 and 22 is connected to a common exhaust pipe 23,
The exhaust pipe 23 is used for the scroll chamber 17 of the exhaust turbine 20.
Connected to. When the turbine wheel 18 is rotated by the exhaust gas discharged from each of the cylinders 3a to 3h and the impeller 14 is rotated by the exhaust gas, the air pressurized by the compressor 16 corresponds to the intake duct 9, the intercooler 8, the intake duct 6 and the corresponding air. It is supplied to each of the cylinders 3a to 3h via the intake branch pipe 5.

On the other hand, from the exhaust pipe 23, the exhaust bypass pipe 2
4 is branched, and the exhaust bypass pipe 24 is connected to the exhaust gas outflow pipe 19. A wastegate valve 26 controlled by an actuator 25 is arranged in the exhaust bypass pipe 24. The actuator 25 includes a piston 27 connected to the wastegate valve 26, and a hydraulic chamber 28 defined by the piston 27. The oil in the oil tank 29 is supplied to the hydraulic chamber 28 by an engine-driven oil pump 30, and the oil in the hydraulic chamber 28 is returned to the oil tank 29 via a flow control valve 31.

In the embodiment shown in FIG. 1, this flow control valve 31
Is a linear solenoid valve, and linear solenoid valve 3
The smaller the current supplied to 1, the smaller the opening of the linear solenoid valve 31. When the opening degree of the linear solenoid valve 31 decreases, the amount of oil returned from the hydraulic chamber 28 into the oil tank 29 decreases, so that the piston 27 moves to the left in FIG. 1, and as a result, the opening degree of the waste gate valve 26. Becomes smaller. Waste gate valve 26
When the opening degree of the turbine wheel 18 becomes smaller, the amount of exhaust gas supplied to the turbine wheel 18 increases, so that the rotation speed of the turbine wheel 18 increases, and as a result, the air pressure in the intake duct 9,
That is, the boost pressure increases. Therefore, the linear solenoid valve 31
It can be seen that the boost pressure is increased as the current supplied to is reduced.

As shown in FIG. 1, the engine body 1 is provided with a rotation speed sensor (hereinafter referred to as NE sensor) 32 for detecting the engine rotation speed NE. Further, in the intake duct 6 downstream of the throttle valve 11, the pressure P in the intake duct 6 is increased.
A pressure sensor (hereinafter referred to as PM sensor) 33 for detecting M is attached. A pressure sensor (hereinafter referred to as a PD sensor) 34 for detecting a deck pressure PD, that is, a supercharging pressure is attached in the intake duct 6 between the intercooler 8 and the throttle valve 11. Also, the throttle valve 11
An opening sensor (hereinafter referred to as a TA sensor) 35 for detecting the opening TA of the throttle valve 11 is attached to the.

As shown in FIG. 1, a casing 41 surrounding the propeller shaft 40 is attached to the front surface of the engine body 1, and FIG. 2 schematically shows the inside of the casing 41. Referring to FIG. 2, the propeller shaft 40 is rotatably supported in a casing 41, and a large diameter gear 42 is fixed to an inner end portion of the propeller shaft 40. The large-diameter gear 42 is meshed with a small-diameter gear 44 fixed to the crankshaft 43 of the engine. Therefore, the crankshaft 43 is connected to the propeller shaft 40 via the reduction gear mechanism including the gears 42 and 44. Will be.

On the other hand, a piston 45 for controlling the propeller pitch is arranged in the propeller shaft 40. The piston 45 is arranged so as to be slidable in the axial direction within the propeller shaft 40 while rotating with the propeller shaft 40. A hydraulic chamber 46 defined by the enlarged head portion 45 a of the piston 45 is formed in the tip portion of the propeller shaft 40.
A compression spring 47 that presses the piston 45 toward the hydraulic chamber 46 is arranged therein. A hydraulic conduit 48 is provided in the hydraulic chamber 46.
Oil is supplied via the hydraulic passage 49 in the piston 45. A control rod 50 is fixed on the piston 45 so as to extend toward the root portion 2a of the propeller 2 in a direction perpendicular to the axis of the piston 45, and a groove 51 is formed on the tip surface of the control rod 50. On the other hand, propeller 2
The root portion 2a of the propeller 2 is rotatably supported by a propeller shaft 40, and the root portion 2a of the propeller 2 has a root portion 2a.
5 engaging with the groove 51 at a position eccentric from the rotation axis of
2 is fixed. Therefore, when the piston 45 moves in the axial direction, the propeller 2 is rotated around the longitudinal axis of the propeller 2, and thus the piston 45 controls the pitch of the propeller 2. The amount of movement of the piston 45 is controlled by the amount of oil in the hydraulic chamber 46,
The amount of oil in 6 is controlled by a propeller pitch control actuator 53 (FIG. 1).

As shown in FIG. 2, a high pitch stopper 5 for restricting the movement of the piston 45 is provided in the propeller shaft 40.
4 and a low pitch stopper 55 are arranged. When the piston 45 contacts the high pitch stopper 54, the propeller pitch becomes maximum, and when the piston 45 contacts the low pitch stopper 55, the propeller pitch becomes minimum.

FIG. 3 shows spark plugs 4a to 4h and a fuel injection valve 7a.
~ 7h, wastegate valve control linear solenoid valve 31 and propeller pitch control actuator 53
Shows an electronic control unit 60 for controlling the.
As shown in FIG. 3, the electronic control unit 60 is composed of a digital computer, and has a read-only memory (ROM) 62, a random access memory (RAM) 63, and a microprocessor (CPU) 64 which are interconnected by a bidirectional bus 61. , An input port 65 and an output port 66.

The NE sensor 32 is the engine crankshaft 4
An output pulse is generated every time 3 rotates by a constant crank angle. The output pulse of the NE sensor 32 is input to the input port 65, and the CPU 64 calculates the engine speed NE based on this output pulse. On the other hand, the PM sensor 33 generates an output voltage proportional to the absolute pressure PM in the intake duct 6 downstream of the throttle valve 11, and the PD sensor 34 outputs the absolute pressure (deck pressure) PD in the intake duct 6 upstream of the throttle valve 11. Produces a proportional output voltage. Further, the TA sensor 35 generates an output voltage proportional to the opening degree TA of the throttle valve 11. Further, an atmospheric pressure sensor (hereinafter referred to as PA sensor) 36 is provided to detect the atmospheric pressure PA.
The sensor 36 generates an output voltage proportional to the atmospheric pressure PA. PM sensor 33, PD sensor 34, TA sensor 35
The output voltage of the PA sensor 36 is input to the input port 65 via the corresponding AD converter 67. on the other hand,
The output port 66 is connected to the spark plugs 4a to 4h, the fuel injection valves 7a to 7h, the linear solenoid valve 31 and the actuator 53 via a corresponding drive circuit 68.

By the way, in the embodiment shown in FIG. 1, the maximum output is required as in the case of takeoff, and therefore, when the throttle opening is maximized, the rich air-fuel mixture is used, whereas the throttle opening is slightly decreased. A lean mixture is used to improve fuel consumption during steady flight. However, when the air-fuel mixture suddenly changes from lean mixture to rich mixture or from rich mixture to lean mixture according to the throttle opening, a shock occurs because the engine output changes rapidly at the time of switching. Will end up. Therefore, in the embodiment according to the present invention, in order to prevent such a shock from occurring, as shown in FIG. 4, when the air-fuel ratio (A / F) changes, the target boost pressure is changed accordingly. ing.

That is, as shown in FIG. 4, when the throttle opening TA is smaller than the set opening TAH, the air-fuel ratio A /
F has a large air-fuel ratio, that is, the air-fuel mixture is made lean, and at this time the supercharging pressure PD is maintained at a relatively high target supercharging pressure TPDH. When the throttle opening TA becomes larger than the set opening TAH from such a state, the air-fuel ratio A / F is decreased, that is, the air-fuel mixture is made rich, and at the same time, the supercharging pressure PD is relatively low and the target supercharging is relatively low. The pressure is lowered to TPDL. In the embodiment according to the present invention, at this time, the increase amount of the engine output due to the reduction of the air-fuel ratio A / F and the decrease amount of the engine output due to the decrease of the supercharging pressure PD are equal to each other. Decrease (TPDH-TPD
L) is set, so that the engine output does not change even if the throttle opening TA reaches the set opening TAH, the air-fuel ratio A / F is reduced, and the boost pressure PD is decreased. Thus, as shown in FIG. 4, the engine output smoothly increases as the throttle opening TA increases.

On the other hand, as shown in FIG. 4, when the throttle opening TA is larger than the set opening TAL (<TAH), the air-fuel ratio A / F is a small air-fuel ratio, that is, the air-fuel mixture is rich and supercharged. The pressure PD is maintained at a relatively low target supercharging pressure TPDL. When the throttle opening TA becomes smaller than the set opening TAL from such a state, the air-fuel ratio A / F is increased with hysteresis as shown by the broken line in FIG. 4, that is, the air-fuel mixture is made lean, and at the same time the supercharging pressure is increased. The PD is increased to the target supercharging pressure TPDH which is relatively high.
Also at this time, the increase amount of the boost pressure PD (so that the decrease amount of the engine output due to the increase of the air-fuel ratio A / F becomes equal to the increase amount of the engine output due to the increase of the boost pressure PD ( TPDH + TPDL) is set, and therefore the throttle opening TA reaches the set opening TAL and the air-fuel ratio
Even if the A / F is increased and the boost pressure PD is increased, the engine output will not change. Thus, as shown in FIG. 4, the engine output smoothly decreases as the throttle opening TA decreases.

5 to 7 show the air-fuel ratio A / F and the boost pressure P.
7 shows an example of a routine for executing the control of D. As described above, the supercharging pressure PD is performed by controlling the current value TLS to be supplied to the linear solenoid valve 31, and in the embodiment shown in FIGS. 5 to 7, the throttle opening TA becomes large and the set opening TAH. Current value TLS to be supplied to the linear solenoid valve 31 so that the supercharging pressure PD quickly matches the target supercharging pressure TPDL when
That is, the opening of the wastegate valve 26 is proportionally integrated (P
I) When the throttle opening TA is controlled and reaches the set opening TAL under control, the supercharging pressure PD becomes the target supercharging pressure TP.
Linear solenoid valve 3 to promptly match DH
The current value TLS to be supplied to 1, that is, the opening of the waste gate valve 26 is proportional-integral (PI) controlled.

Further, in this embodiment, even if there are variations in the parts or even if the parts change over time, when the throttle opening TA becomes large and reaches the set opening TAH, the supercharging pressure PD is set to the target supercharging. Current value T to be supplied to the linear solenoid valve 31 in order to quickly match the pressure TPDL
LS, that is, the opening degree of the waste gate valve 26 is learned and controlled, and the throttle opening degree TA becomes smaller so that the set opening degree TA
When it reaches L, the current value TLS that should be supplied to the linear solenoid valve 31 in order to quickly match the supercharging pressure PD with the target supercharging pressure TPDH, that is, the waste gate valve 26.
The degree of opening is controlled to be learned.

Referring to FIGS. 5 to 7, first, at step 100, the fuel injection time TAU is calculated based on the output signal of the PM sensor 33 and the engine speed NE. This fuel injection time TAU is previously stored in the ROM 62 in the form of a map as shown in FIG. 8 as a function of the absolute pressure PM in the intake duct 6 downstream of the throttle valve 11 and the engine speed NE.
It is stored in. The fuel injection time TAU is set so as to obtain a predetermined constant air-fuel ratio at which the air-fuel mixture supplied into the engine cylinder becomes rich.

Next, at step 101, it is judged if the flag X indicating that the air-fuel mixture should be made rich is set. When the flag X is not set, that is, when the air-fuel mixture is lean, the routine proceeds to step 102, where T
Based on the output signal of the A sensor 35, it is determined whether the throttle opening TA is larger than the set opening TAH (FIG. 4). When TA ≦ TAH, the routine jumps to step 106, and when TA> TAH, the routine proceeds to step 103, the flag X is set, and then the routine proceeds to step 106.

On the other hand, when it is judged in step 101 that the flag X is set, that is, when the mixture is rich, the routine proceeds to step 104, where the throttle opening T
It is determined whether A has become smaller than the set opening TAL (FIG. 4). When TA ≧ TAL, step 106
Jump to, and if TA> TAL, step 105
And the flag X is reset. Then step 1
Proceed to 06.

At step 106, it is judged again whether or not the flag X is set. When the flag X is set, the routine jumps to step 108 and the flag X
Is reset, the routine proceeds to step 107, where 0.7 times TAU is set as the fuel injection time TAU. Then, it proceeds to step 108. Therefore, when the flag X is set, the value of the map shown in FIG. 8 becomes the fuel injection time TAU as it is, so the air-fuel mixture becomes rich at this time, and when the flag X is reset, T
Since the fuel injection time TAU is 0.7 times AU, the air-fuel mixture becomes lean.

At step 108, the target engine speed NET is calculated based on the output signal of the TA sensor 35. This target engine speed NET is a function of the throttle opening TA as shown in FIG. 9, and the relationship shown in FIG.
It is stored in M62. Next, at step 109, the propeller pitch control actuator 53 is controlled so that the engine speed NE becomes the target speed NET according to the throttle opening TA shown in FIG. That is, when the engine speed NE becomes higher than the target speed NET, the hydraulic chamber 46
Oil is supplied inside. As a result, the pitch angle of the propeller 2 becomes large, so that the engine speed NE is reduced. On the other hand, the engine speed NE is the target speed NET
When it becomes lower than this, the oil in the hydraulic chamber 46 is discharged, and therefore the pitch angle of the propeller 2 becomes small, so that the engine speed NE is increased. In this way, the engine speed NE is controlled to the target speed NET.

Next, at step 110, it is judged again whether or not the flag X is set. When the flag X is reset, the routine proceeds to step 111, where the target supercharging pressure TPDH (FIG. 4) when the air-fuel mixture is lean is calculated. Next, at step 112, TPDH is set to TPD, and the routine proceeds to step 115. On the other hand, if it is determined at step 110 that the flag X is set, then the routine proceeds to step 113, where the target supercharging pressure TPDL (FIG. 4) when the air-fuel mixture is rich is calculated. Then step 11
In 4, the TPDL is set to TPD, and the process proceeds to step 115.

In step 115, the basic control amount TLS is calculated based on the output signals of the NE sensor 32 and the PA sensor 36.
BS, that is, the basic current value TLSBS to be supplied to the linear solenoid valve 31 is calculated. This basic current value TLSB
FIG. 10 shows S for the engine speed NE and the atmospheric pressure PA.
The relationship is as shown in (A). This relationship is stored in ROM6 in advance.
It is stored in 2. This basic current value TLSBS is the supercharging pressure PD that is the target supercharging pressure TPDH when the mixture is lean.
FIG. 4 shows a current value obtained by an experiment in advance that is required to be substantially equal to (FIG. 4).

Next, at step 116, it is judged again whether or not the flag X is set. When the flag X is reset, that is, when the air-fuel mixture is lean, the routine proceeds to step 117, where the correction current value TLSOFSH for the basic current value TLSBS is calculated based on the output signals of the NE sensor 32 and the PA sensor 36. The correction current value TLSOFSH is determined by the engine speed NE and the atmospheric pressure P.
It has the relationship shown in FIG. 10B with respect to A, and this relationship is stored in the ROM 62 in advance. This correction current value TL
SOFSH is learned and controlled in the subsequent routine, and thus the correction current value TLSOFSH is hereinafter referred to as a learning correction current value. As described above, the basic current value TLSBS is the boost pressure PD that is the target boost pressure TPDH when the mixture is lean.
(Fig. 4) shows the current value required to make it almost equal, so the learning correction current value TLSOFSH is shown in Fig. 10 (B).
It becomes a relatively small value as shown in. Next, at step 118, the learning correction current value TLSOFSH is set to TLSO.
FS is set, and the process proceeds to step 121.

On the other hand, when it is judged at step 116 that the flag X is set, that is, when the air-fuel mixture is rich, the routine proceeds to step 119, where the output signals of the NE sensor 32 and the PA sensor 36 are used. A corrected current value TLSOFSL for the basic current value TLSBS is calculated. The correction current value TLSOFSL has the relationship shown in FIG. 10C with respect to the engine speed NE and the atmospheric pressure PA, and this relationship is stored in the ROM 62 in advance. This correction current value TLSOFSL is learned and controlled in the subsequent routine, and therefore, the correction current value TLSOFS is set.
SL is hereinafter referred to as a learning correction current value. As described above, the basic current value TLSBS indicates the current value required to make the supercharging pressure PD approximately equal to the target supercharging pressure TPDH (FIG. 4) when the air-fuel mixture is lean, and therefore the learning correction current value. TL
SOFSL has a relatively large value as shown in FIG. Next, at step 120, the learning correction current value T
LSOFSL is set to TLSOFS, and the routine proceeds to step 121.

Steps 121 to 123 show a routine for bringing the supercharging pressure PD closer to the target supercharging pressure by proportional-plus-integral (PI) control. That is, first, at step 121, the target supercharging pressure TPD and the PD sensor 3
The proportional term TGP of the current value is calculated from the difference from the actual supercharging pressure PD detected by No. 4 based on the following equation. In the following equation, K ₁ is a constant.

TGP = K ₁ · (TPD-PD) Next, at step 122, the proportional term TGP is used to calculate the integral term TLSFB of the current value from the following equation. In the following equation, K ₂ is a constant. TLSFB = TLSFB + K ₂ · TGP Next, at step 123, the reference current value TLSBS, the learning correction current value TLSOFS, the proportional term TGP and the integral term T.
The current value TLS to be supplied to the linear solenoid valve 31 is calculated from LSFB based on the following equation.

TLS = TLSBS + TLSOFS + TG
P + TLSFB Next, in steps 124 to 135, learning control of the learning correction current value TLSOFS is performed. That is, the difference between the engine speed NE and the target rotational speed NET first, at step 124 | NE-NET | whether is smaller than a predetermined value alpha _O is determined. | NE-NET | at the time of ≧ α _O proceeds to step 135, | NE-NET | < α
When it is _O, the process proceeds to step 125. At step 125, the difference between the target boost pressure TPD and the actual boost pressure PD | TPD
It is determined whether −PD | is smaller than the constant value α ₁ . When | TPD-PD | ≧ α ₁ , step 127
To proceed to step 135 to clear the count value CTPD. On the other hand, | TPD-PD | <α ₁
If it is, proceed to step 126 and count value CTPD
Is incremented by 1 and then step 128 is reached.

At step 128, it is judged if the count value CTPD has become larger than the constant value α ₂ . C
When TPD ≤ α ₂ , proceed to step 135, CTP
D> difference between alpha ₂ to become the currently calculated current value TLS and the previously calculated current value TLSPRE proceeds to step 129 | TLS-TLSPRE | whether less than a predetermined value alpha ₃ or not. │TLS-TLSPRE│ ≧ α
When it is _3, the routine proceeds to step 131, where the count value CTL
S is cleared, and then the routine proceeds to step 135. On the other hand, if | TLS−TLSPRE | <α ₃ , the routine proceeds to step 130, where the count value CTLS is incremented by 1, and then the routine proceeds to step 132.

At step 132, the count value CTLS is
Constant value α_FourIt is determined whether or not it has become larger than. C
TLS ≤ α_FourIf yes, go to step 135
> Α _FourThen, the process proceeds to step 133. Therefore step
In 133, the engine speed NE is almost the target speed NE.
T, and the supercharging pressure PD is almost equal to the target supercharging pressure TPD.
It is maintained for a certain period of time or more and the current value TLS is constant
When it is kept almost constant over time, that is, the waist
The opening of the gate valve 26 remains almost constant for a certain period of time
Is being done.

In step 133, the learning correction current value TLSOFSH is calculated when the air-fuel mixture is lean, and the learning correction current value TLSOFSL is calculated when the air-fuel mixture is rich. TLSOFSH or TLSOFSL = TLSOFS +
[TLS- (TLSBS + TLSOFS)] As described above, TLS = TLSBS + TLSOF.
Since S + TGP + TLSFB, the above equation [TLS-
(TLSBS + TLSOFS)] is TGP + TLSFB
Is equal to On the other hand, since TPD-PD≈0 when the routine proceeds to step 133, TGP≈0. Therefore, [TLS- (TLSBS + TL
SOFS)] ≈TLSFB. That is, the above equation becomes the following equation.

TLSOFSH or TLSOFSL≈TL
SOFTSH or TLSOFSL + TLSFB That is, the learning correction current value TLSOFSH or TLSOFS
A value obtained by adding the integral term TLSFB to L is set as a new learning correction current value TLSOFSH or TLSOFSL.

Next, at step 134, a new integral term TLSFB is calculated based on the following equation. TLSFB = TLSFB- [TLS- (TLSBS + T
LSOFS)] That is, the learning correction current value TLSOFSH or TLSOFS
A new integral term TLSFB is obtained by subtracting the integral term TLSFB by the amount added to L. Step 134
When a new integral term TLSFB is calculated at, the routine proceeds to step 135, where the current value TLS is made TLSPRE. Next, at step 136, the linear solenoid valve 31
The current value supplied to is set to TLS.

11 to 15 show another embodiment. In this embodiment, the case where the engine speed NE is controlled to the target speed by using the propeller governor 70 shown in FIGS. 11 and 12 is shown. In this embodiment, the throttle lever 11 and the propeller speed governor 70 are simultaneously controlled by the power lever 12 'provided in the cockpit, and a switch 71 for switching the air-fuel mixture is further provided.

Referring to FIG. 12, the propeller speed governor 70 has a hollow cylindrical rotating sleeve 72 which is rotated at a speed proportional to the propeller shaft 40, a spool valve 73 inserted in the rotating sleeve 72, and a spool valve 73. End plate 74 fixed to the upper end of the plate, a pair of fly weights 75 rotatably supported by a rotating sleeve 72 to urge the end plate 74 upward, and a compression spring urging the end plate 74 downward. 7
6 and a control shaft 77 screwed to the housing of the propeller speed governor 70 for controlling the spring force of the compression spring 76.

As shown in FIG. 12, three lands 78a, 78b, 78c are formed on the spool valve 73, and the first oil hole 79a and the second oil hole 79a are formed on the rotary sleeve 72.
Oil hole 79b and third oil hole 79c are formed. An annular oil groove 8 is formed around the first oil hole 79a.
0a is formed, and this oil groove 80a is connected to an oil tank via an oil return conduit 81a. An annular oil groove 80b is formed around the second oil hole 79b,
The oil groove 80b is connected to the hydraulic chamber 46 (FIG. 2) in the propeller shaft 40 via the oil conduit 81b. Also,
An annular oil groove 80c is formed around the third oil hole 79c, and the oil discharged from the oil pump is supplied into the oil groove 80c through the oil supply conduit 81c.

FIG. 12 shows when the rotation speed of the propeller 2 is maintained at the target rotation speed, that is, when the engine rotation speed NE is maintained at the target rotation speed. At this time, the second oil hole 79b is closed by the land 78b of the spool valve 73, so that the piston 45 in the propeller shaft 40 is stationary. Therefore, at this time, the propeller 2 is maintained at a constant pitch angle.

On the other hand, when the engine speed NE becomes higher than the target speed, the spool valve 73 is raised by the action of the fly weight 75. When the spool valve 73 rises, the second oil hole 79b becomes the third oil hole 79c.
Oil is supplied into the hydraulic chamber 46 of the propeller shaft 40 in order to communicate with. As a result, the pitch angle of the propeller 2 becomes large, and thus the engine speed NE is reduced.

On the other hand, when the engine speed NE becomes lower than the target speed NE, the spool valve 73 is lowered by the action of the fly weight 75. When the spool valve 73 descends, the second oil hole 79b communicates with the first oil hole 79a, so that the oil in the hydraulic chamber 46 of the propeller shaft 40 is returned to the oil tank. As a result, the pitch angle of the propeller 2 becomes small, and thus the engine speed NE is increased. In this way, the engine speed NE is maintained at the target speed.

By the way, if the pressing force of the compression spring 76 against the end plate 74 is increased, as shown in FIG.
The engine speed when 9b is closed by the land 78b of the spool valve 73, that is, the target speed becomes high. The pressing force of the end plate 74 by the compression spring 76 can be controlled by rotating the control shaft 77, and thus the target rotation speed can be controlled by rotating the control shaft 77.

Referring to FIG. 11 (A), the power lever 1
The 2'rod 82 is branched into a pair of branch rods 82a and 82b, and a pair of stators 83, 84, 85 and 86 and stators 83 and 8 are provided on the branch rods 82a and 82b, respectively.
Sliders 87, 88 arranged between 4, 85, 86 are attached. Further, a compression spring 89 is arranged between the stator 83 and the slider 87, and a compression spring 90 is also inserted between the stator 86 and the slider 88. The slider 87 is the throttle valve 11
Connected to a lever 91 attached to the throttle shaft of
The slider 88 is connected to a lever 92 fixed to the control shaft 77 of the propeller speed governor 70. Position control stoppers 93 and 94 are provided on the levers 91 and 92, respectively.
Further, the switch 71 is arranged so as to be engageable with the branch portion of the rod 82.

FIG. 11A shows the engine at low speed rotation. At this time, the opening of the throttle valve 11 is small, the target rotational speed set by the propeller speed governor 70 is low, and the air-fuel mixture is lean. Figure 1
When the power lever 12 'is pushed in from the state shown in 1 (A), the throttle valve 11 gradually opens, but the target rotational speed set by the propeller speed governor 70 is still low. The power lever 12 'is further pushed and the stator 8
When 5 contacts the slider 88, the power lever 1
As 2'is pushed in, the throttle valve 11 is opened, and the lever 92 of the propeller speed governor 70 is rotated in the direction to increase the target rotational speed. Next, the power lever 12 'is pushed further in and the throttle valve 11 is fully opened.
As shown in FIG. 11 (B), the lever 91 is attached to the stopper 93.
After that, the throttle valve 11 is held in the fully closed state, and the lever 92 of the propeller speed governor 70 is rotated in a direction to increase the target rotation speed as the power lever 12 'is pushed. Until now, the switch 71 has been off, so the mixture is lean.

Then, when the power lever 12 'is further pushed in, the branch portion of the rod 82 contacts the switch 71, and the switch 71 is turned on, as shown in FIG. 11 (C). When the switch 71 is turned on, the air-fuel mixture is switched from lean to rich. Then, when the power lever 12 'is further pushed, the lever 92 of the propeller speed governor 70 is rotated in a direction to further increase the target rotation speed.

13 to 15 show a main routine when the power lever 12 'and the propeller speed governor 70 shown in FIGS. 11 and 12 are used. Referring to FIGS. 13 to 15, first, at step 200, P
The fuel injection time TAU is calculated based on the output signal of the M sensor 33 and the engine speed NE. This fuel injection time TAU is stored in advance in the ROM 62 in the form of a map as shown in FIG. 8 as a function of the absolute pressure PM in the intake duct 6 downstream of the throttle valve 11 and the engine speed NE.
The fuel injection time TAU is set so as to obtain a predetermined constant air-fuel ratio at which the air-fuel mixture supplied into the engine cylinder becomes rich.

Next, at step 201, it is judged if the switch 71 is on, that is, if the mixture should be made rich. When the switch 71 is on, the routine jumps to step 203, and when the switch 71 is off, the routine proceeds to step 202, where the fuel injection time TAU is 0.7 times TAU. Then, it proceeds to step 203. Therefore, when the switch 71 is on, the value of the map shown in FIG. 8 becomes the fuel injection time TAU as it is, so that the mixture becomes rich at this time, and when the switch 71 is off, 0.7 times TAU is the fuel injection time. TA
Since it is set to U, the air-fuel mixture becomes lean.

Next, at step 203, the switch 7 is turned on again.
It is determined whether 1 is on. When the switch 71 is off, the routine proceeds to step 204, where the target supercharging pressure TPDH (FIG. 4) when the air-fuel mixture is lean is calculated. Next, at step 205, TPDH is set to TPD, and the routine proceeds to step 208. On the other hand, when it is determined in step 203 that the switch 71 is on, the routine proceeds to step 206, where the target supercharging pressure T when the air-fuel mixture is rich.
The PDL (Fig. 4) is calculated. Next, at step 207, TPDL is set to TPD, and the routine proceeds to step 208.

Next, at step 208, the NE sensor 32
The basic control amount TLSBS, that is, the basic current value TLSBS to be supplied to the linear solenoid valve 31 is calculated based on the output signal of the PA sensor 36. This basic current value T
The LSBS has a relationship as shown in FIG. 10 (A) with respect to the engine speed NE and the atmospheric pressure PA.
It is stored in M32. This basic current value TLSBS
Is the target boost pressure TPD when the mixture is lean
The current value obtained by an experiment necessary in advance to make it approximately equal to H (FIG. 4) is shown.

Next, at step 209, the switch 7 is turned on again.
It is determined whether 1 is on. When the switch 71 is off, that is, when the air-fuel mixture is lean, step 2
In step 10, the correction current value TLSOFSH for the basic current value TLSBS is calculated based on the output signals of the NE sensor 32 and the PA sensor 36. This correction current value TL
SOFSH has the relationship shown in FIG. 10 (B) with respect to the engine speed NE and the atmospheric pressure PA.
It is stored in 2. This correction current value TLSOFSH
Is learned and controlled in the subsequent routine, and thus the correction current value TLSOFSH is hereinafter referred to as a learning correction current value. As described above, the basic current value TLSBS is the boost pressure PD
Shows the current value required to make the target supercharging pressure TPDH (Fig. 4) when the air-fuel mixture is lean. Therefore, the learning correction current value TLSOFSH is compared as shown in Fig. 10 (B). It becomes a very small value. Next, at step 211, the learning correction current value TLSOFSH is made TLSOFS, and the routine proceeds to step 214.

On the other hand, when it is determined in step 203 that the switch 71 is on, that is, when the air-fuel mixture is rich, the routine proceeds to step 212, where the basic signals are output based on the output signals of the NE sensor 32 and the PA sensor 36. A corrected current value TLSOFSL for the current value TLSBS is calculated. This correction current value TLSOFSL has a relationship shown in FIG. 10 (C) with respect to the engine speed NE and the atmospheric pressure PA, and this relationship is stored in the ROM 32 in advance.
The correction current value TLSOFSH is learned and controlled in the subsequent routine, and therefore, the correction current value TLSOFSL is controlled.
Is hereinafter referred to as a learning correction current value. As described above, the basic current value TLSBS indicates the current value required to make the supercharging pressure PD approximately equal to the target supercharging pressure TPDH (FIG. 4) when the air-fuel mixture is lean, and therefore the learning correction current value. TLSO
The FSL has a relatively large value as shown in FIG. Next, at step 213, the learning correction current value TLS
OFSL is set to TLSOFS, and the routine proceeds to step 214.

Steps 214 to 216 show a routine for bringing the supercharging pressure PD closer to the target supercharging pressure by proportional integral (PI) control. That is, first, at step 214, the target supercharging pressure TPD and the PD sensor 3
The proportional term TGP of the current value is calculated from the difference from the actual supercharging pressure PD detected by No. 4 based on the following equation. In the following equation, K ₁ is a constant.

TGP = K ₁ · (TPD-PD) Next, at step 215, the integral term TLSFB of the current value is calculated from the following equation using the proportional term TGP. In the following equation, K ₂ is a constant. TLSFB = TLSFB + K ₂ · TGP Next, at step 216, the reference current value TLSBS, the learning correction current value TLSOFS, the proportional term TGP, and the integral term T.
The current value TLS to be supplied to the linear solenoid valve 31 is calculated from LSFB based on the following equation.

TLS = TLSBS + TLSOFS + TG
P + TLSFB Next, at step 217 to step 228, learning control of the learning correction current value TLSOFS is performed. That is, first, at step 217, it is judged if the difference | NE-NET | between the engine speed NE and the target speed NET is smaller than a constant value α ₀ . When | NE-NET | ≧ α ₀ , the routine proceeds to step 228, where | NE-NET | <α ₀
If, then the process proceeds to step 218. In step 218, the difference between the target boost pressure TPD and the actual boost pressure PD | TPD-
It is determined whether PD | is smaller than the constant value α ₁ .
When | TPD-PD | ≧ α ₁ , the routine proceeds to step 220, where the count value CTPD is cleared, and then step 22
Go to 8. On the other hand, when | TPD-PD | <α ₁ , the routine proceeds to step 219, where the count value CTPD is incremented by 1, and then the routine proceeds to step 221.

At step 221, it is judged if the count value CTPD has become larger than the constant value α ₂ . C
When TPD ≤ α ₂ , proceed to step 228, CTP
When D> α ₂ , the routine proceeds to step 222, where it is judged if the difference | TLS-TLSPRE | between the current value TLS calculated this time and the current value TLSPRE calculated last time is smaller than a constant value α ₃ . │TLS-TLSPRE│ ≧ α
When it is _3, the routine proceeds to step 224, where the count value CTL
S is cleared, and then the routine proceeds to step 228. On the other hand, if | TLS−TLSPRE | <α ₃ , the routine proceeds to step 223, where the count value CTLS is incremented by 1, and then the routine proceeds to step 225.

At step 225, the count value CTLS is
Constant value α_FourIt is determined whether or not it has become larger than. C
TLS ≤ α_FourIf it is, go to step 228, CTLS
> Α _FourThen, the process proceeds to step 226. Therefore step
The process proceeds to 226 when the engine speed NE is almost the target speed NE.
T, and the boost pressure PD is almost the target boost pressure TPD
Is maintained for a certain period of time and the current value TLS is
When it is kept almost constant for a certain period of time, that is, waste
The opening of the gate valve 26 remains constant for a certain time or longer.
It is when they are held.

At step 226, the learning correction current value TLSOFSH is calculated when the air-fuel mixture is lean, and the learning correction current value TLSOFSL is calculated when the air-fuel mixture is rich. TLSOFSH or TLSOFSL = TLSOFS +
[TLS- (TLSBS + TLSOFS)] As described above, TLS = TLSBS + TLSOF.
Since S + TGP + TLSFB, the above equation [TLS-
(TLSBS + TLSOFS)] is TGP + TLSFB
Is equal to On the other hand, when the routine proceeds to step 226, TPD-PD≈0, so TGP≈0. Therefore, [TLS- (TLSBS + TL
SOFS)] ≈TLSFB. That is, the above equation becomes the following equation.

TLSOFSH or TLSOFSL≈TL
SOFTSH or TLSOFSL + TLSFB That is, the learning correction current value TLSOFSH or TLSOFS
A value obtained by adding the integral term TLSFB to L is set as a new learning correction current value TLSOFSH or TLSOFSL.

Next, at step 227, a new integral term TLSFB is calculated based on the following equation. TLSFB = TLSFB- [TLS- (TLSBS + T
LSOFS)] That is, the learning correction current value TLSOFSH or TLSOFS
A new integral term TLSFB is obtained by subtracting the integral term TLSFB by the amount added to L. Step 227
When a new integral term TLSFB is calculated at, the routine proceeds to step 228, where the current value TLS is made TLSPRE. Next, at step 229, the linear solenoid valve 31
The current value supplied to is set to TLS.

As described above, in any of the embodiments, the basic current value TLSBS and the learning correction current value TLSOFSH
Alternatively, TLSOFSL is stored, and when the throttle opening changes, first the linear solenoid valve 31
The current value TLS supplied to the valve is the sum of the basic current value and the learning correction current value. At this time, when the supercharging pressure deviates from the target supercharging pressure, the current value TLS is the basic current value and the learning correction value. It is corrected by proportional-plus-integral (PI) control until the supercharging pressure reaches the target supercharging pressure with reference to the sum with the current value. The correction amount at this time becomes equal to the integral term TLSFB.

In this case, the sum of the basic current value and the learning correction current value represents the target opening of the wastegate valve 26, and thus this target opening is stored in advance. When the throttle opening changes, the opening of the waste gate valve 26 is first set to this target opening. At this time, when the boost pressure deviates from the target boost pressure, the opening of the waste gate valve 26 is changed. Is corrected based on the target opening degree until the supercharging pressure reaches the target supercharging pressure. Next, when the learning correction control is performed, the opening correction amount at this time is added to the target supercharging pressure. That is, when the learning correction control is performed, the target opening is updated with the opening of the waste gate valve 26 at that time.

Therefore, in any of the above-described embodiments, the target opening degree of the wastegate valve 26 is updated when the difference between the engine speed and the target speed is equal to or less than a certain value. The target opening of the valve 26 is made to match the optimum target opening corresponding to the throttle opening.

[0070]

The target opening of the wastegate valve can always be reliably updated to the opening required to obtain the target supercharging pressure.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an internal combustion engine.

FIG. 2 is a side sectional view schematically showing the vicinity of a propeller shaft.

FIG. 3 is a diagram showing an electronic control unit.

FIG. 4 is a diagram showing a relationship between an air-fuel ratio and supercharging pressure.

FIG. 5 is a flowchart of a main routine.

FIG. 6 is a flowchart of a main routine.

FIG. 7 is a flowchart of a main routine.

FIG. 8 is a diagram showing a map of fuel injection time TAU.

FIG. 9 is a diagram showing a target rotational speed NET.

FIG. 10 is a reference current value TLSBS and a correction current value TL.
It is a figure which shows SOFSH and TLSOFSL.

FIG. 11 is a diagram showing a control system using a power lever.

FIG. 12 is a side sectional view schematically showing a propeller governor.

FIG. 13 is a flowchart of a main routine.

FIG. 14 is a flowchart of a main routine.

FIG. 15 is a flowchart of a main routine.

FIG. 16 is a time chart showing changes in the degree of opening of the waste gate valve.

[Explanation of symbols]

 7a-7b ... Fuel injection valve 10 ... Turbocharger 20 ... Exhaust turbine 25 ... Actuator 26 ... Wastegate valve

Claims (1)

[Claims] 1. An internal combustion engine for driving a propeller,
In an aircraft equipped with a turbocharger for supercharging an internal combustion engine, the turbocharger having a wastegate valve for controlling the supercharging pressure, and the propeller pitch change range being regulated in advance, the engine rotation The propeller pitch control device that controls the propeller pitch so that the number becomes the target speed according to the throttle opening, and the supercharging pressure is the target supercharging pressure that corresponds to the opening of the wastegate valve that corresponds to the stored target opening. And a supercharging pressure control device that updates the target opening with the opening of the wastegate valve that makes the supercharging pressure the target supercharging pressure. Is larger than a predetermined value, the supercharging pressure control device for an internal combustion engine for an aircraft is configured to prohibit the updating action of the target opening degree.