JPH02176114A - Control device for engine - Google Patents

Abstract

PURPOSE:To concurrently obtain high responsiveness and the output characteristic with higher efficiency by switching a valve operational state switching device while keeping the change rate of the supercharging pressure by a variable- capacity supercharger at the preset value or above. CONSTITUTION:An electronic control circuit 21 controls the switching action of a valve system 14 changing the valve timing in stages and the supercharging capacity changing action of a variable-capacity turbo-charger 7 in response to the operational state of an engine 1 containing at least the engine rotating speed. The intercept point of the turbo-charger 7 is correctly grasped based on the engine rotating speed and the change rate of the supercharging pressure, and the engine is operated at the low-speed valve timing set to generate the peak torque in this region at the rotating speed area lower than the intercept point. The engine is switched to the ordinary valve timing operation at the rotating speed area higher than the intercept point, the supercharging pressure control is performed after the switching, thereby the output can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an engine control device including a valve operation state switching device and a variable capacity supercharger.

<Prior art> A/D in the exhaust gas passage flowing into the turbine wheel
A variable capacity supercharger that changes R using a flap or multiple vanes and is able to obtain optimal supercharging pressure with high responsiveness over a wider operating range was published in Japanese Patent Laid-Open No. 1983-
Various proposals have been made, such as in Japanese Patent No. 282128.

By the way, no matter how variable capacity a turbocharger is, there is a limit to the boost pressure output in the extremely low rotational speed range, and the response may be insufficient, especially when starting or when suddenly accelerating from low-speed cruising. It may happen.

On the other hand, by changing at least one of the operating angle and lift of the intake valve or exhaust valve provided for each cylinder mainly in response to the engine rotation speed, the mixture into the combustion chamber can be improved over a wider operating range. A valve operating mechanism equipped with a valve operating state switching device that improves air filling efficiency has been proposed, for example, in Japanese Patent Application Laid-open No. 16111/1983. And in the low speed valve timing operation area,
It is known that by setting at least one of the opening angle and lift of the valve relatively small, the speed of intake air flowing into the combustion chamber can be increased, and the output torque in a low speed range can be suitably increased. Therefore, if this valve operating state switching device is applied to a supercharged engine, it is believed that a dramatic improvement in engine performance can be expected.

<Problems to be Solved by the Invention> In view of such knowledge, the main purpose of the present invention is to further improve performance by combining a valve operation state switching device and a variable capacity supercharger. The purpose of the present invention is to provide an engine control device that obtains the desired results.

[Structure of the Invention] Means for Solving the Problems According to the present invention, the present invention provides a switching device for varying the valve operating state of at least one of an intake valve and an exhaust valve; a variable capacity supercharger; and a control means for controlling a switching operation of the switching device and a variable supercharging capacity operation of the supercharger in response to an operating state of the engine including at least an engine rotation speed. This is achieved by providing an engine control device, characterized in that the switching operation of the switching device is performed by the control means in a state where the rate of change of supercharging pressure in the engine is equal to or higher than a predetermined value. . Particularly, at least the intake valves include a plurality of valves for each cylinder, and the switching device causes the control means to deactivate some of the plurality of valves in an operating range below a predetermined engine speed. It is good to say.

<Operation> In this way, the output torque in the operating range before reaching the set supercharging pressure can be compensated for by increasing the low-speed output by optimal setting corresponding to the low-speed range of the valve operating state. .

Embodiments The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

FIG. 1 shows the overall configuration of an intake system and an exhaust system of an engine to which the present invention is applied. For example, an intake manifold 3 connected to the intake port 2 of each cylinder in an engine body 1 consisting of an in-line four-cylinder engine includes an intake pipe 4, a throttle body 5, an intercooler 6, and a compressor section of a variable displacement turbocharger 7. 8 and air cleaner 9 are connected in this order. In addition, the exhaust manifold 11 connected to the exhaust port 10 of each cylinder has
A turbine section 12 and a catalytic converter 13 of a variable capacity turbocharger 7 are connected.

A valve mechanism 14 for controlling the intake of air-fuel mixture into the combustion chamber of each cylinder and the discharge of combustion gas is configured to transfer hydraulic pressure generated by an oil pump 15 driven by the engine body 1 to a solenoid valve 16.
The valve timing can be varied step by step by controlling the switching control valve 17 and the switching control valve 17.

The variable capacity turbocharger 7 uses supercharging pressure P2 directly downstream of the compressor or intake negative pressure P2 directly downstream of the throttle valve.
The actuator 1.8 driven by the actuator B continuously changes the cross-sectional area of the exhaust gas flow path to the turbine section 12, thereby continuously varying the supercharging capacity of the compressor. The turbocharger 7 is cooled together with the intercooler 6 by a water pump 19 driven by the engine body 1 with cooling water that is recirculated through a radiator 20 that is separate from the engine cooling water.

On the other hand, this engine 1 is configured to variably control the fuel injection amount, valve timing, and supercharging pressure by an electronic control circuit 21.

The electronic control circuit 21 receives an oil pressure signal 01 from a normally closed oil pressure switch 22 provided on the switching control valve 17, a 0□ signal from an oxygen concentration sensor 23 provided on the exhaust manifold 11, and an engine rotation sensor 24. rotational speed signal N5, water temperature signal Tw from the cooling water temperature sensor 25 provided in the water jacket of the engine body 1, parking and 221 tral signal P-N at the shift position of the automatic transmission 26, throttle body 5 The intake temperature signal TA from the intake temperature sensor 27 provided in the intake passage 4a on the downstream side, the intake pressure signal PR from the intake pressure sensor 28, the valve opening signal θTll from the throttle valve opening sensor 29, and the intake temperature signal θTll from the throttle valve opening sensor 29, A boost pressure signal P2 from the boost pressure sensor 30 provided in the intake passage 4b, an intake passage 4C between the air cleaner 9 and the compressor 8 of the turbocharger 7
An atmospheric pressure signal PA from an atmospheric pressure sensor 31 and a traveling speed signal V from a vehicle speed sensor 32 are respectively input. Based on each of these input signals, a solenoid valve 16 and an intake boat 2 for switching valve timing are operated.
a fuel injection valve 33 for injecting fuel into the engine, and a solenoid valve 34 for controlling supercharging pressure P2 and intake negative pressure P for driving the actuator 18 that changes the supercharging capacity, respectively.
- The operations of 35 are respectively controlled by output signals from the electronic control circuit 21.

Next, the valve train 14 will be explained with reference to FIG.

The engine to which the present invention is applied is a so-called DOHC engine in which the intake valve and exhaust valve are driven by separate camshafts, and each cylinder is provided with two intake valves and two exhaust valves. Since both valves have basically the same configuration, only the valve operating mechanism on the intake side will be described below.

The rocker shaft 40 fixed to the cylinder head has
For each cylinder, three rocker arms 41, 42, and 43 are pivotably supported adjacent to each other so as to be swingable and relative to each other in angular displacement. A camshaft 45 is rotatably supported above the rocker arms 41, 42, 43 by a cam journal 44 formed in the cylinder head.

The camshaft 45 includes a low-speed cam 46 with a small operating angle and lift amount, a single high-speed cam 47 with a large operating angle and lift amount, and a perfect circular contour that is approximately equal to the base circle of both of these cams 46 and 47. The raised portion 45a is integrally formed. Two oil supply pipes 48 and 49 are arranged above the camshaft 45 to lubricate the sliding surfaces of the camshaft 45 and the cam and the rocker arm. In addition, a pair of intake valves 50a and 50, which are normally elastically biased in the valve-closing direction, are provided at the free ends of the first and 20th lever arms 41 and 42, which are in sliding contact with the low-speed cam 46 and the raised portion 45a, respectively.
The upper end of the valve stem at point b is in contact. On the other hand,
Arranged between the first and 20th arm arms 41 and 42,
The 30th lever arm 43, which is in sliding contact with the high-speed cam 47, has a lost motion spring (not shown) in contact with the lower end of the 30th lever arm 43, so that it is constantly biased upward.

A connection switching device 51 is built inside the first to thirtieth lever arms 41 to 43 that are adjacent to each other. This connection switching device 51 consists of guide holes provided inside each rocker arm and a switching pin that slides into these guide holes.

The 10th claw arm 41 has a first guide hole 52 with a bottom that opens on the 30th claw arm 43 side.
0, and in this first guide hole 52,
The first switching pin 53 is slidingly engaged. A hydraulic chamber 54 is defined at the bottom of the first guide hole 52.
4 communicates with an oil supply passage 57 provided inside the rocker shaft 40 via an oil passage 55 provided inside the tenth lever arm 41 and an oil supply hole 56 opened on the circumference of the hollow rocker shaft 40. There is.

The 30th lever arm 43 has a second guide hole 58 which is parallel to the rocker shaft 40 and has the same diameter and is concentric with the first guide hole 52 in the rest position where the cam slipper is in sliding contact with the base circle of the high-speed cam 47. A second switching pin 59, which extends through and has one end in contact with the first switching pin 53, slides therein.

Similarly, a third guide hole 60 with a bottom is bored in the 20th hook arm 42, and a stopper pin 61 whose one end is in contact with the other end of the second switching pin 59 is slidably fitted inside the third guide hole 60. .

The stopper pin 61 has its shaft portion 63 fitted into a guide sleeve 62 fitted to the bottom of the third guide hole 60, and is always resiliently biased toward the 30th hook arm 43 by a return spring 64.

By moving these first and second switching pins 53 and 59 in the left-right direction in FIG. 2 by the action of the hydraulic pressure introduced into the hydraulic chamber 54 and the biasing force of the return spring 64, The state in which each of the rocker arms 41 to 43 can swing independently, that is, the 10th rocker arm is in sliding contact with the low speed cam 46.
The rocker arms 41 to 43 are integrally connected by driving only one of the air supply valves 50a to open via the lever arm 41, and by having the switching bins 53 and 59 straddle between adjacent rocker arms. The high-speed cam 47 can selectively switch between a state in which the valves 50a and 50b are driven to open simultaneously by the high-speed cam 47.

Four of the aforementioned oil supply pipes for high-speed lubricating oil are connected downstream of the oil supply passage 57 provided inside the rocker shaft 40 . This high-speed lubricating oil supply pipe 49 is provided with an ejection hole 65 at a position corresponding to the high-speed cam 47 for injecting lubricating oil in a shower style.

Further, the other low-speed lubricating oil supply pipe 48 is connected to a lubricating oil path 66 branched from the oil gear gallery. This low-speed lubricating oil supply pipe 48 has respective cams 45a and 46-4.
A jet hole 67 for spraying lubricating oil in a shower-like manner is provided at a position corresponding to 7, and the lubricating oil is also supplied to the cam journal 44 via an oil passage 68.

On the other hand, the switching control valve 17 described above is attached to the cylinder head, and is driven to open by the oil pressure supplied via the electromagnetic valve 16 which is controlled to open and close by the control signal described above. It has a built-in spool valve 70 which is resiliently biased to a normally closed position.

When the spool valve 70 is in the upper closed position (the state shown in FIG. 2), an inlet port 72 is connected to the lubricating oil passage 66 via the oil filter 71, and an outflow is connected to the oil supply passage 57 in the rocker shaft 40. The port 73 communicates only through the orifice hole 74. At the same time, the outflow port 73 communicates with a drain port 75 that opens into the upper space of the cylinder head, and the oil pressure in the oil supply path 57 becomes low.

Therefore, oil pressure is not supplied to the oil supply path 57, and each pin 53 and
59 is in a position where it is urged toward the hydraulic chamber 54 by a return spring 64, and each rocker arm is driven separately by a corresponding cam and is angularly displaced relative to each other. In this case, the oil supplied from the oil pan 76 to the oil gear gallery by the oil pump 15 is supplied to the low-speed lubricating oil supply pipe 48 via the lubricating oil passage 66, and as described above, the oil is supplied to the oil supply pipe 48 for low-speed lubricating oil, and as described above, the oil is Lubricate the contact surfaces and cam journal 44.

When the spool valve 70 is switched to the lower open position, the inflow port 72 and the outflow port 73 are connected to the spool valve 70.
The outflow boat 73 communicates with the annular groove 77 of the
The communication between the lubricating oil passage 66 and the drain port 75 is cut off, and oil is force-fed from the lubricating oil passage 66 to the oil supply passage 57. This results in the 10th
When hydraulic pressure is supplied to the hydraulic chamber 54 of the lever arm 41, the first and second switching pins 53 and 59 fit into the second guide hole 58 and the third guide hole 60, respectively, against the urging force of the return spring 64. and each rocker arm 41 to 43
are integrally connected. At this time, the oil supplied to the oil supply passage 57 operates the connection switching device 51 of each cylinder, and passes through the downstream end of the oil supply passage 57 to the oil supply pipe 49 for high-speed lubricating oil.
The high-speed cam 47 and the 30th latch arm 43
Lubricate the sliding surface.

The spool valve 70 described above is switched to the open position against the biasing force of the return spring 69 by pilot pressure manually applied to the upper end side of the spool valve 70 via a pilot oil passage 78 branched from the inflow port 72. The normally-closed solenoid valve 16 described above is interposed in the pilot oil passage 78, and energization of the solenoid of the solenoid valve 16 is controlled by an output signal from the electronic control circuit 21 to open the solenoid valve 16. When the valve is opened, the spool valve 70 is switched to the open position and the valve timing is adjusted as described above for both intake valves 50a.
50b are simultaneously driven, and when the solenoid valve 16 is closed, the spool valve 70 is switched to the closed position, and the valve timing is changed to one of the intake valves 5.
The valve timing is switched to a low speed valve timing in which 0a is stopped.

The switching operation of the spool valve 70 is performed by a hydraulic switch 22 provided in the housing of the switching control valve 17 that detects the hydraulic pressure of the outflow port 73 and turns on when the pressure is low and turns off when the pressure is high.
Confirmed by.

Next, the variable capacity turbocharger 7 will be explained with reference to FIG. Since the compressor section 8 of this turbocharger 7 is basically the same as any known type of turbocharger, only the turbine section 12 will be specifically explained.

The turbine casing 80 of the turbocharger 7 has an annular scroll passage 8 whose cross-sectional area gradually decreases toward the downstream.
1, and an exhaust gas inlet 82 is opened in the tangential direction thereof. And at the center position of the scroll passage 81,
A turbine wheel 83 is disposed integrally attached to the shaft end of a turbine shaft coaxial with the compressor shaft.

Inside the scroll passage 81, four fixed vanes 84 having a partially arcuate shape are formed integrally with the turbine casing 80 on a circumference concentric with the turbine wheel 83, with equal widths and equal intervals. These fixed vanes 84 divide the scroll passage 81 into an outer circumferential path 85 and an inner circumferential path 86 .

Between the fixed vanes 84 adjacent to each other, the fixed vanes 84
Four movable vanes 87 having a partial arc shape with approximately the same curvature as
are arranged on the same circumference as the fixed vane 84. These movable vanes 87 are each pivoted at a position adjacent to one circumferential end of the corresponding fixed vane 84 so as to be able to tilt only inward of the aforementioned circumference, and when in the fully open state. Both vanes 84 and 87 form a continuous airfoil. The inclination angle of the movable vane 87 is continuously variably controlled by a movable vane drive control device to be described later.

The movable vane drive control device controls the pivot shaft 88 of the movable vane 87.
A lever member 89 integrally extends from the lever member 89, and a pair of lever members 89 having slits 90 cut at both ends thereof to engage with the free ends of the two lever members 89, and pivotally supported to be able to swing freely. One end is connected to the pivot shaft 92 of each seesaw member 91, and the other end is connected to one link rod 9.
3 and an actuator 18 as a drive source for the movable vane 87. This actuator 18 has a drive shaft 95 that reciprocates in the axial direction with fluid pressure.
It is connected to the link rod 93 via a connecting shaft 96.

In the link mechanism, a drive shaft 95 and a connecting shaft 96 are connected through a ball joint 97, and a connecting shaft 96 and a link rod 93 are connected through a clevis joint 98, and the driving force from the actuator 18 is can be smoothly transmitted to the link arm 94. Additionally, a bracket 99 is provided integrally with the turbine casing 80 in order to define the fully open position of the movable vane 87 by regulating the stroke of the drive shaft 95.
A stopper 10 that comes into contact with an adjustment bolt 100 screwed into the
1 is fixed to the connecting shaft 96.

The actuator 18 includes a diaphragm 104 sandwiched between a bottomed cylindrical casing 102 and a cover 103 caulked to the open end of the casing 102.
4 defines a negative pressure chamber 105 and a positive pressure chamber 106 therein.

At the center of the diaphragm 104 is a retainer 107.1.
The other end of the drive shaft 95 is fixed via the pin 08. And the retainer 107 and casing 102 on the negative pressure chamber 105 side
A compression coil spring 109 is sandwiched between the bottom wall and the diaphragm 104 and the drive shaft 95 at all times.
03 side, that is, to the right in FIG. 3.

The drive shaft 95 is slidably supported at the center of the bottom wall of the casing 102 . The protruding portion of the drive shaft 95 from the bottom wall of the casing 102 is a bellows made of a flexible but friction-free material formed by cutting a cylindrical member made of fluororesin into an annular shape from the inside and outside. It is sealed at 110. In addition, the negative pressure chamber 10
5 and the inside of the bellows 110 communicate with each other via a through hole 111.

A negative pressure inlet 112 is formed in the casing 102 to communicate the negative pressure chamber 105 with the outside. Further, the cover 103 is formed with a positive pressure inlet 113 for communicating the positive pressure chamber 106 with the outside.

In this actuator 18, the positive pressure inlet 113
When positive pressure is introduced toward the positive pressure chamber 106, the diaphragm 104 is pressed leftward in FIG. 3 against the biasing force of the compression coil spring 109, and the drive shaft 9
5 is driven to the left. Further, when negative pressure is introduced into the negative pressure chamber 105 from the negative pressure inlet 112, the drive shaft 95 is similarly driven to the left via the diaphragm 104. That is, in the low opening range of the throttle valve where the intake negative pressure P is high,
The actuator 18 operates in a direction to push out the drive shaft 95. As a result, the link rod 93 is displaced to the left in FIG. 3, the link arm 94 rotates the seesaw member 91 clockwise about the pivot shaft 92, and the lever member 89 engages with the slits 90 at both ends. The movable vane 87 is driven inward about the pivot shaft 88 via the movable vane 87 . By opening the movable vane 87, a so-called large capacity state is formed in which the nozzle gap GN defined by the lap between the front edge of the fixed vane 84 and the rear edge of the movable vane 87 is maximized (
(state shown by imaginary lines in Figure 3).

When the above-mentioned negative pressure control solenoid valve 35 is controlled to cut off the intake negative pressure PB to the negative pressure chamber 105, the negative pressure in the negative pressure chamber 105 decreases, and the coil spring 109 is driven by the biasing force of the coil spring 109. The shaft 95 is retracted. Then, the link rod 93 is displaced to the right in FIG. 3, the link arm 94 rotates the seesaw member 91 counterclockwise about the pivot shaft 92, and the lever member 89 engages with the slits 90 at both ends. The movable vane 87 is driven outward about the pivot 88 via the movable vane 87 (the state shown by the solid line in FIG. 3). By closing the movable vane 87, the front edge of the fixed vane 84 and the movable vane 87
Gap GN of the nozzle defined in the lap part with the trailing edge
A so-called small capacitance state is formed in which . Therefore, the exhaust gas flow is throttled to the maximum extent and accelerated, becoming a swirling flow within the inner circumferential passage 86 and driving the turbine wheel 83.
The supercharging effect is ensured in the low engine speed range.

When the engine speed increases and the supercharging effect becomes sufficient,
The positive pressure control solenoid valve 34 is controlled to introduce supercharging pressure P2 into the positive pressure chamber 106. As a result, the actuator 18 operates in the direction of pushing out the drive shaft 95, and the link arm 94
tilts in the opposite direction to the above, rotates the seesaw member 91 clockwise, and moves the movable vane 81 via the lever member 89.
tilt inward. By widening the nozzle gap GN in this way, the speed of the exhaust flow is not increased and the flow path resistance is reduced, making it possible to reduce the exhaust back pressure against the engine.

In this embodiment, the opening of the movable vane 81 is mainly controlled by the positive pressure control solenoid valve 34, but in some cases, the negative pressure control solenoid valve 35 may also be used. good.

(Left below) Next, a control program incorporated into the electronic control circuit 21 to control the valve timing switching solenoid valve 6 will be described with reference mainly to FIG.

In a first step 201, it is determined whether the engine is in the starting mode, that is, whether the engine is cranking.

If cranking is in progress, then in a second step 202, the elapsed time T, .

Next, in a third step 203, a valve closing command is issued to the solenoid valve 16, and low speed valve timing operation is selected. Then, in a fourth step 204, a time period TDIIV (for example, 0.1 seconds) is set to elapse after the switching operation to high-speed valve timing operation, and preparations are made for a delay time measurement operation after the switching operation.

On the other hand, if cranking is not in progress in the first step 201,
That is, if it is determined that the engine is already in operation, in a fifth step 205, it is determined whether signals from various sensors are normally input to the electronic control circuit 21, that is, whether failsafe should be performed. Determine whether or not. If it is determined that the system is not in failsafe mode, that is, that it is in a normal state, the process proceeds to the second step 206 in the sixth step 206.
The remaining time of the elapsed time TD and T after startup set in step 02 is determined. If the remaining time is not 0, proceed to the third step 203; if the remaining time is 0, proceed to the seventh step 207.
At , it is determined whether the cooling water temperature Tw is lower than the set temperature Tw1 (for example, 60° C.), that is, whether or not warming has been completed.

If it is determined that Tw is Twl, the process proceeds to the third step 203, and if Tw≧Tw1, the process proceeds to the eighth step 208, where the vehicle speed V is set to an extremely low set vehicle speed V't (including hysteresis, for example, 8 ~5km/h) or less. Here, if V<V, proceed to the third step 203, and if V≧V1, proceed to the ninth step 203.
At step 09, it is determined whether or not the tank is a manual transmission tank MT.

To summarize the operations up to this point, before starting, during cranking, immediately after starting, before completion of warm-up, and when the engine is stopped or running slowly, low-speed valve timing operation is unconditionally set. In other words, this is a measure to prevent malfunction of the connection switching device 51 or occurrence of irregular combustion due to the viscosity of the lubricating oil when the engine is cold.

If it is determined at the ninth step 209 that the tank is not a manual transmission tank, that is, it is an automatic transmission tank AT, it is determined at a tenth step 210 whether the shift position is in the parking P or neutral N range. P-N
If it is in the range, the process advances to the third step 203. On the other hand, in the case of a manual transmission tank MT, in the 11th step 211, the lower limit rotational speed N (for example, 101000RP and the current The engine rotation speed NE is compared with the engine rotation speed NE.If it is determined that N8 is NO, the process advances to the third step 203.

From the flow up to this point, it can be seen that if the valve is in a stopped state or is rotating at a low speed, the low speed valve timing operation is set.

On the other hand, if it is determined in the eleventh step 211 that NE≧NEL, the output in the normal valve timing operation always exceeds the output in the low speed valve timing operation. Rotational speed N.

Compare with. Here, NEKUNI! If it is determined that the current supercharging pressure P2 is
The rate of change ΔP2 and the set rate of change ΔP2S are compared. However, the setting change rate ΔP2. is a rate of change that corresponds to the rate of change in supercharging pressure ΔP2 and is set in advance as a rate of change that produces sufficient supercharging efficiency when the supercharging pressure P2 passes a so-called intercept point where it immediately starts to rise. . Here, if it is determined that ΔP2 is less than ΔP2S, a valve closing command is issued to the solenoid valve 16 in a fourteenth step 214, that is,
Select low speed valve timing operation, ΔP2≧ΔP2S
If it is determined that this is the case, a valve opening command is issued to the solenoid valve 16 in a fifteenth step 215, that is, normal valve timing operation is selected. The main routine shown in FIG.
The boost pressure change rate ΔP2 is updated by the DC signal, but since the boost pressure change rate ΔP2 is too small with just one TDC signal, in order to accurately read the boost pressure behavior, that is, the boost pressure change rate ΔP2, the boost pressure 6 times before The difference from P2N-6 is calculated.

From the flow up to this point, it can be seen that the so-called intercept point of the supercharger is accurately grasped from the engine rotational speed NE and the boost pressure change rate ΔP2, and the valve timing is switched at the intercept point.

After selecting the regular valve timing operation, in a sixteenth step 216, a signal from the oil pressure switch 22 for checking the operating status of the switching control valve 17 is determined. If it is determined that the oil pressure switch 22 is off, that is, that the oil pressure is acting on the connection switching device 51, the delay after the connection switching device is activated, which is set in the fourth step 204, is determined to be OFF. The remaining time of time TDHVT is determined in a seventeenth step 217. T here. If it is determined that HVT-0, an 18th step 218 sets the elapsed time TDLVT (for example, 0°2 seconds) after switching to low-speed valve timing operation, and prepares for delay time measurement operation after switching. Let's do it.

On the other hand, after a valve closing command is issued to the electromagnetic valve 16 in the 14th step 214, the oil pressure switch signal O1 is determined in the 19th step 219. If it is determined that the oil pressure switch 22 is on, that is, that the oil pressure is not acting on the connection switching device 51, the remaining time of the delay timer TDLvT set in the 18th step 218 is
It is read in step 220, and if TDLVT=O, the process proceeds to the fourth step 204.

If the oil pressure switch signal OP is not turned off at the 16th step 216 even though the low-speed valve timing operation has been switched to the normal valve timing operation in this way, the process proceeds to the 20th step 220, where the oil pressure switch signal OP is turned off. The operating condition was maintained at low speed valve timing until the valve was turned off, and even though the normal valve timing operation was switched to low speed valve timing operation, the oil pressure switch signal OP was turned on at the 19th step 219. If not, the process proceeds to step 17 217, and the operating condition at the regular valve timing is maintained until the oil pressure switch signal OP is turned off.

In addition, the setting time T DH of the dual switching delay timer set in the above-mentioned 4th and 18th steps 204 and 218
VT ” T LIIVT is the response time from when the solenoid valve 16 operates and the spool valve 70 of the switching control valve 17 moves to when the oil pressure of the oil supply passage 57 changes and the switching operation of the switching pin of the gold cylinder is completed. Even if the start of switching operation is confirmed from the oil pressure switch signal 0., when switching from high speed to low speed, T DLVT-0,
When switching from low speed to high speed, until T HLVT reaches 0, it is assumed that the valve timing of all cylinders has not been changed yet, and operation is maintained using the fuel injection amount control before the valve timing change command. .

Note that if NE≧N80 is not established in the 11th step 211, that is, immediately after the start of travel, low-speed valve timing operation is set without checking the oil pressure switch signal O1. This measure is taken in consideration of the adverse effects that may occur if the signal remains off due to a defect in the switch 22 or the like.

Next, a control program for the solenoid valve 34 for changing the supercharging capacity, that is, the supercharging pressure, of the turbocharger 7 will be explained with reference mainly to FIGS. 5a and 5b. however,
The positive pressure control solenoid valve 34 used in this system is a duty control solenoid valve. In addition, this boost pressure control
Open loop control that performs boost pressure control based on the basic boost pressure control amount (hereinafter referred to as basic duty DM), and basic duty D according to the deviation between the actual boost pressure and the preset target boost pressure. This is a control system that also has feedback control that performs boost pressure control by modifying .

In the first step 301, it is determined whether or not the engine is in the starting mode, that is, whether the engine is cranking. If the engine is in the starting mode, the start of the feedback control is delayed in the second step 302. After resetting the timer TDFB, the duty D0tJT for the solenoid valve 34 is set to 0 in a third step 303, and the duty Dou'r is outputted in a fourth step 304. However, duty D in this main routine. In the U method, the duty ratio of the solenoid in the solenoid valve 34 decreases as the value increases, and the DO
UT'''O is a state in which the duty ratio is 100%, that is, the movable vane 87 is driven inward to the maximum extent, that is, the solenoid valve 34 is fully opened, and the air gap circulation area between the fixed vane 84 and the movable vane 87 is maximum. Corresponding to the state where DOUT −1
00 corresponds to a duty ratio of 0%, that is, a state in which the movable vane 87 is driven outward to the maximum extent, that is, a state in which the air gap circulation area is minimized.

Incidentally, the feedback delay timer TDPB in the second step 302 is selected according to the subroutine shown in FIG. Here, depending on the rate of change ΔP2 of boost pressure P2, three timers TDFBI, TD'B2, T DPB
3 is selected, but the supercharging pressure change rate ΔP2 is the current supercharging pressure P2N and the six previous supercharging pressure P2N-6
(ΔP2 = P2N P2N-6). That is, the main routine shown in FIGS. 5a and 5b is updated by the TDC signal, but since the boost pressure change rate ΔP2 is too small with only one TDC signal, the boost pressure behavior, that is, the boost pressure change rate In order to read ΔP2 accurately, the difference between it and the six previous supercharging pressure P2N-6 is calculated. In addition, the setting lowering rate ΔP22. and the set high rate of change ΔP2PI+ is a predetermined value depending on the engine rotational speed N, and in the case of ΔP2≦ΔP2PL, TD.

B1 is set, TDFB□ is set when ΔP2PL<ΔP2≦Δpzpu, and TDFB3 is set when ΔP2P□<ΔP2. Moreover, TD, B engineering<T
When the relationship DF8□<TD, B3 exists and the boost pressure change rate ΔP2 is small, that is, when the boost pressure P2 is changing slowly, the delay time TDFB is set small and the boost pressure change rate ΔP2 When TDFB is large, that is, when the boost pressure is changing rapidly, the delay time TDFB is set large. In this way, when transitioning from open-loop control to feedback control, the optimum delay time TOFB is set according to the speed and speed of the load change, and the hunting phenomenon does not occur during the transition. becomes possible.

If it is determined in the first step 301 that the engine is not in the starting mode, it is determined in the fifth step 305 whether or not fail-safe mode is to be performed. This checks the self-diagnosis of the ECUφCPU and the input signals from each sensor including the oil pressure switch signal O2 to indicate the operating state of the valve timing connection switching device 51. If there is an abnormality, the process proceeds to the second step 302. , if normal, the sixth step 306
Proceed to.

Next, in a sixth step 306, the intake air temperature TA is compared with the set low air temperature TAL, and if TA<TA, the process proceeds to the second step 302, and if TA≧TAL, the process proceeds to the seventh step 307. In a seventh step 307, the cooling water temperature Tw and the set high cooling water temperature TwL are compared, and if Tw<Tw, the process proceeds to the second step 302, and Tw≧TwL.
If so, proceed to the eighth step 308. In an eighth step 308, the intake air temperature TA and the set high intake air temperature TAH are compared, and if TA>TAH, the process proceeds to the second step 302, and if TA≦TA11, the process proceeds to the ninth step 309. In the ninth step 309, the cooling water temperature Tw and the set high cooling water temperature TwH are compared, and if Tw>Twl, the process proceeds to the second step 302, and if Tw≦Tw□, the process proceeds to the first step 302.
Proceed to step 310. At the tenth step 310, the current supercharging pressure P2 and the predetermined supercharging pressure judgment card value P2HG are determined.
If B2>P2□1G, the process proceeds to the second step 302, and if P2≦P2++G, the process proceeds to the eleventh step 311. However, high boost pressure judgment guard value P2
．． ．． . is a preset value corresponding to the engine rotational speed NE, and is set so as to obtain the maximum output after considering the durability of the engine.

To summarize the flow up to this point, if the engine is not running, or if there is some kind of abnormality in the control system, or if the intake temperature T
A and cooling water temperature Tw are outside the predetermined ranges, or if the supercharging pressure P2 is above the predetermined value, the fixed vanes 84 and movable vanes 87 in the turbocharger 7 are removed regardless of other factors. The cross-sectional area of the flow path between the two is controlled to be maximized. This is because it can be concluded that the conditions for stable operation of the engine are not satisfied in any of the above steps, so it is rather undesirable to introduce supercharging pressure P2 into the combustion chamber in such a state. This is because it clearly promotes stability.

If it has been determined in the steps up to this point that the engine is in stable operating condition and is in running condition,
At the eleventh step 311, the basic duty DM is searched. By the way, this basic duty DM is the engine rotation speed Nl! and the throttle opening θTl+, and a basic duty DM suitable for the current load situation is searched from the setting table.

Next, in the twelfth step 312, the shift position is changed to the first
Determine whether the speed is high or not. If it is determined that the engine is in the first speed position, in a thirteenth step 313, the basic duty DM as the basic boost pressure control amount is subtracted.

Incidentally, in the thirteenth step 313, the DM value is subtracted according to the subroutine shown in FIG. That is, a determination zone that requires a reduction in the DM value is set in advance in accordance with the operating conditions determined by the engine rotational speed NE and the intake negative pressure PB, and whether or not the DM value is within this determination zone is determined.
Alternatively, it is determined whether or not to subtract the DM value depending on whether the DM value is outside the determination zone. Here, engine rotation speed N
6 and intake negative pressure P8, the engine output torque can be determined from
This is to prevent the force acting on the gear shaft in the high speed position from becoming overloaded. Here, if it is outside the discrimination zone, that is, the allowable torque is not exceeded, the searched DM value is left as is and the process proceeds to the next step, but if it is within the discrimination zone, that is, in the area exceeding the allowable torque. In this case, it is determined whether the flag indicating the feedback control state is Fopc=0 or not, and when the open loop control state is in effect, the subtraction is performed as follows: DM=search DM DF, and the duty D for the solenoid valve 34 is determined.

When the UT tends to be reduced somewhat and the feedback control state is in effect, the following subtraction is performed: P2R-Search P2R-ΔP2+1, and the target supercharging pressure P2R is set somewhat lower. However, D is a preset subtraction value, P2R
is the target boost pressure set according to the engine rotational speed NI and the intake air temperature TA used when the feedback control state is in effect, and ΔP2R is a preset subtraction value.

Through the processing up to this point, the supercharging pressure is set to a low level in order to prevent overtorque due to a sudden start in the first gear position. If it is determined at the twelfth step 312 that the position is not the first speed position, the process proceeds to the fourteenth step 314 without subtracting the basic duty DM.

Next, in the fourteenth step 314, the duty correction coefficient KMOD, the duty atmospheric pressure correction coefficient KPAD (
0.8 to 1.0), and duty intake temperature correction coefficient K
Search for each TAD (0,8 to 1.3). However, the duty correction coefficient KMoD is searched from a map determined by the engine speed NF and the intake air temperature TA, and is learned when the optimum boost pressure P2 (described later) falls within a predetermined deviation. Updated from time to time based on learning. Further, the duty atmospheric pressure correction coefficient K PAD is determined in accordance with the intake pressure PA, and the duty intake temperature correction coefficient KTAD is determined in accordance with the intake air temperature TA.

Through these controls, it is possible to adapt to changes in external factors at any time.

Next, in a fifteenth step 315, a correction coefficient KDN is searched according to the subroutine shown in FIG.

This subroutine interrupts the main routine of FIGS. 5a and 5b every time the TDC signal is sent, and the duty is D. When UT is 0, reset timer TDN and set duty D. The correction coefficient KDN is set to the initial value KDNO(
For example, set it to 0.5).

Then, after the timer TDN has passed a certain set time TDND (for example, 5 seconds), a predetermined addition value ΔKDN (for example, 0.01) is added for each TDC signal to obtain a new correction coefficient KON. The correction coefficient KDN is 1
．． After it exceeds 0, it is set to 1.0.

The correction coefficient KDN determined in this manner is used in the correction formula for the duty D 01lT described later, and is used when the engine is operating in a certain operating range, that is, when the intake air temperature TA is abnormally high or low, or when the cooling water temperature Tw is Duty D in a specific operating range where the temperature is abnormally high or low, or where the supercharging pressure P2 is abnormally high. When the state in which LIT is forced to 0, that is, the gap between the fixed vane 84 and the movable vane 87 is maximized, the duty DOIJ
This is for stable control of T. In other words, if the duty D OUT immediately returns to the normal value when returning to the normal operating state from the specified operating state where I) = 0, the boundary between the specific operating range and the normal operating range will be Irregular control may occur. Therefore, after, for example, 5 seconds have elapsed since returning to the normal operating range, the correction coefficient KDN is increased by, for example, 0.1 for each TDC signal cycle, and the duty D is set. The occurrence of such irregular control is avoided by gradually returning the UT to the normal control value.

Next, in the 16th step 316, the current throttle opening θ1H and the preset reference throttle opening θTHP are determined.
Compare with B. This set throttle opening θt(F
E corresponds to the medium/high load operation region, and is set to determine whether to shift from open loop control to feedback control. By employing the throttle opening degree θTH as a determination parameter in this manner, it is possible to accurately determine whether or not the driving situation at that time requires supercharging. Here, θTl+≦
θa, 1. If it is determined as B, that is, if the open loop control is to be continued, the feedback delay timer TDFB shown in FIG. 31
Proceed to step 8. Also, in the 16th step 316, θ18. 〉
If it is determined that θ□, B, the 22nd step 322
Proceed to.

In the eighteenth step 318, the set subtraction duty DT and the set addition duty DTRB are searched. The set subtraction duty D corresponds to the rate of change ΔP2 of the supercharging pressure P2, and is determined according to the subroutine shown in FIG. Here, θ engineering 9. 〉In the case of θTIIFB, that is, in the medium/high load operation region where open loop control shifts to feedback control, the preset subtraction duty is set based on the relationship between boost pressure change rate ΔP2 and engine rotation speed NE. DT is selected, θ engineering, I≦θTIIF
If it is B, it is set as DT-0, and the basic duty DM
No correction will be made.

By the way, the set subtraction duty D1 is set to increase in stages according to an increase in the rate of change in supercharging pressure ΔP2, and is changed to three stages, for example, depending on the range of the engine rotational speed NB. . As a result, the larger the boost pressure change rate ΔP2 and the larger the engine rotational speed N5, the larger the subtraction value is set. This process is started before the actual supercharging pressure P2 reaches the target supercharging pressure P2R, so that the transition from open loop control to feedback control can be made smoothly.

Further, the set addition duty DTRE is determined according to the subroutine shown in FIG. Here, in the open loop control state (Fopc=1) and when the boost pressure change rate ΔP2 is in a negative state, the set addition duty D TRB determined by -ΔP2 and the engine rotation speed NE is selected. , furthermore, the set subtraction duty DT is set to 0.

In addition, if the feedback control state (FOPC=O) or the boost pressure change rate ΔP2 is positive,
The set addition duty DTRB is set to 0. This setting addition duty D TRB is also the setting subtraction duty D
Similarly to T, it is assumed that the holding is changed according to the engine rotation speed N8 and the negative charge pressure change rate -ΔP2, and the larger the engine rotation speed N, the negative charge pressure change rate -ΔP2.
The larger P2 is, the larger the added value is. Thereby, the reaction of the set subtraction duty DT can also be corrected, and stable supercharging pressure control can be performed.

In this way, each correction coefficient KMoD- has a 1. ADKT
After AD-KDN, the set subtraction duty D and the set addition duty DTRI3 are determined, the duty DOut is corrected in the 19th step 319 using the following equation.

DOυT=KMoDxKPADxKTADxKDNX
(DM + DTRB DT) Therefore, the output duty D output from the fourth step 304. U-engineering is set by comprehensively taking into account the operating conditions of the engine, taking into account the above-mentioned contents and external factors, and is able to automatically perform optimal boost pressure control corresponding to the load situation at that time. can.

Next, in the 20th step 320, a flag is set to F'op to indicate that the current state is open loop control.

After setting the value to 1, the process proceeds to the 21st step 321. At the 21st step 321, it is checked whether the duty DOUT exceeds a limit value preset according to the engine rotational speed N, and if it is within the limit value, at the 4th step 304, the duty DOUT is checked. OUT is output.

On the other hand, in the 16th step 316, θT11 > θworkHFB
If it is determined that this is the case, the previous flag is determined in the 22nd step 322, and if it is determined that Fopc=1, that is, the previous open loop control was performed, the current error is determined in the 23rd step 323. Supply pressure P2 and duty control start determination supercharging pressure P in open loop control state
Compare with 2ST.

This duty control start determination supercharging pressure P2ST is P2S
It is obtained by T""P2R-ΔP2ST. However, ΔP 2ST is
This is a subtraction value that is preset based on the boost pressure change rate ΔP2 and the engine rotation speed N8, and is set to increase as the engine rotation speed increases and the boost pressure change rate ΔP2 increases.

If it is determined at the 23rd step 323 that P2>P2ST, then at the 24th step 324 the supercharging pressure P2 and the feedback control start determination supercharging pressure P2 are compared. This feedback control start determination supercharging pressure P 2FB is obtained by P2FB"P2R-ΔP 2FB. However, ΔP 2FB is
Similar to ΔP2S mentioned above, this is a subtraction value that is preset according to the boost pressure change rate ΔP2 and the engine rotational speed NE.

Here, if it is determined that P2>P2FB, the 25th
At step 325, the feedback delay timer T is
It is determined whether or not the opa has elapsed, and if it has elapsed, the process proceeds to the twenty-sixth step 326.

Also, in the 22nd step 322, the flag is set to Fopc-.
0, that is, if it is determined that it was feedback control last time, the process proceeds to the 26th step 326, and if it is determined that P2≦P2ST in the 23rd step 323,
Go to the 27th step 327, P in the 24th step 324
If it is determined that 2≦P2FB, the 17th step 31
If the feedback delay timers TD and B have not elapsed in the 25th step 325, the process proceeds to the 18th step 318, respectively.

At the 27th step 327, the engine rotation speed N is determined. The set duty Ds as the auxiliary basic boost pressure control amount that is set in advance according to the
Duty D according to the following formula. UT is calculated.

DoUT=D,×1AD×KPAD Next, in the 29th step 329, the feedback delay timer T, . . . is reset, and then the process proceeds to the 21st step 321.

The process leading to the 28th step 328 described in "1" is intended to obtain stable supercharging pressure control in the operating range until the supercharging pressure P2 reaches the target supercharging pressure P2R,
The output duty D is based on the duty D5 that is preset according to the engine rotational speed NF. By determining UT, it is possible to suitably prevent overshoot from occurring regardless of the boost pressure change rate ΔP2.

On the other hand, at the 26th step 326, the supercharging pressure change rate ΔP2
The absolute value of is compared with the feedback control determination supercharging differential pressure G6,2. This G and P2 are set to, for example, 30 mmHg, and in the case of IΔP21>GaF2, the 18th
The process proceeds to step 318, and if 1ΔP21≦G6,2, the process proceeds to the 30th step 330. In other words, 1ΔP2
1> If feedback control is started in a state where GA, 2, that is, the boost pressure change rate ΔP2 exceeds the limit and is steep, it will cause hunting, so the process returns to the 18th step 318 and performs open loop control. There is.

At the next 30th step 330, the engine rotation speed N8
and target supercharging pressure P2 preset based on intake temperature TA.
R is searched, and then in a 31st step 331, it is determined whether the shift position of the automatic transmission is in the first gear position. If it is determined that the vehicle is in the first speed position, the subroutine shown in FIG.
After performing the subtraction 2R-search P2R-ΔP2R, the process proceeds to the thirty-third step 333.

However, this ΔP2F+ is a subtraction value that is set when the shift position is at the first speed position. If it is determined at the 31st step 331 that the shift position is at a position other than the first speed position, the process proceeds to the 33rd step 333 without subtracting the target supercharging pressure P2H.

In the 33rd step 333, 2 is searched for using the atmospheric pressure correction coefficient for boost pressure set in advance according to the atmospheric pressure PA, and then in the 34th step 334, the following calculation is performed to calculate the target boost pressure P2R. Make corrections.

Correction P 2R””Search P2RxK, A, 2×KRTB However, KRTB is a correction coefficient set corresponding to the engine knock state.

At the 35th step 335, it is determined whether the absolute value of the deviation between the target supercharging pressure P2R and the current supercharging pressure P2 is greater than or equal to a predetermined set value G,2. However, this 02□ is the dead zone defining pressure during feedback control, for example, 20 mmHg.
It is set to a certain degree. Here, P2RP2 l≧GP2
In this case, the process proceeds to the 36th step 336, and the proportional control term DP of the duty is calculated using the following equation.

Dp = Kp In this FIG. 11, when the engine rotation speed N8 is less than the first switching rotation speed NFB, K, 1
Also, 11 is selected as the feedback coefficient related to the integral control term to be described later, and the engine rotation speed NF! , exceeds the first switching rotational speed N, B1 and is less than or equal to the second switching rotational speed NPB□, selects KP□・K,□, and further sets the engine rotational speed N, M second switching rotational speed NFB2. When exceeding the limit, select KP3/KI3.

Then, in the 37th step 337, the engine rotation progress N6
and the correction coefficient KMOD corresponding to the intake air temperature TA, and in the 38th step 338, the previous flag is F. P,=1
In other words, it is determined whether this is the first feedback control state. F here. ,. =1, that is, when open loop control was performed last time, the previous integral control term DI (N-11) is calculated in the 39th step 339 according to the following equation.

D,,N-,,=KTAD XK,^DXDMX (K
MoD-1) After completing this calculation, the 40th step 34
0, but at the 38th step 338 Fopc”O1
That is, if it is not open loop control, the process bypasses the 39th step 339 and proceeds to the 40th step 340, where the current integral control term DIN is calculated according to the following equation.

DIN-DI(N-1)+KI+(P211
P2) Thereafter, in the 41st step 341, the duty D ou'r is calculated. That is, DOUT=KTADxKPADxKDNxDM+DP+
Operations D and N are performed, and the flag is set to FOPC-0 at the 42nd step 342, after which the process proceeds to the 21st step 321.

On the other hand, in the 35th step 335, I P2 + <G,
If it is determined to be 2, at the 43rd step 343, the proportional control term is set to -0, and the integral control term is set to N=D.

N-1). Next, in the 44th step 344, the atmospheric pressure PA is set to the set atmospheric pressure PAM (for example, 650 mmHg).
In step 345, it is determined whether or not the water temperature Tw is within a certain range.
At the 6th step 346, it is determined whether the retard amount T2R is 0 or not, that is, whether or not the knock state is removed. At the 47th step 347, it is determined whether the shift position is other than the 1st speed position. If all of these conditions are met, the process proceeds to the 48th step 348, and if even one of these conditions is not met, the process proceeds to the 41st step 341.

At the 48th step 348, the duty correction coefficient KMo
A coefficient KR for learning D is calculated according to the following equation.

KR= (KTAD X DM + D IN)/ (
KTAD X DM) Next, in the 49th step 349, the correction coefficient KM is calculated.

In order to search and learn ゎ, (1 line margin) KMOD = (CMOD XKR) / 6553
6+ (65536-CI.D)
Then, the process proceeds to the 41st step 341.

The 46th to 51st steps 346 to 351 store the learning control result as a correction coefficient KMoD when the boost pressure P2 is stably feedback-controlled in the dead band GP2, and in special operating conditions. This is to prevent the storage of KMor from adversely affecting the operating condition.

Now, as is well known, in a turbocharger with a fixed A/R, there is a lack of responsiveness in the low speed range due to insufficient boost pressure in the low speed/low load operating range where the exhaust pressure is low. (so-called turbo lag) has been pointed out. Various variable superchargers have been proposed to correct this problem, but as long as the absolute energy of exhaust pressure is low, there is a limit to how much supercharging efficiency can be improved.

Therefore, in the present invention, as detailed in the above embodiment, the intercept point of the supercharger is accurately grasped from the engine rotation speed NE and the boost pressure change rate ΔP2, and in the rotation speed range lower than the intercept point, It operates with low-speed valve timing set to generate peak torque in this region, and switches to normal valve timing operation in the rotation speed range higher than the intercept point.
After switching, the output is increased by controlling the boost pressure.

In addition, acceleration is detected by the throttle valve opening, and when accelerating from a low speed range, the operation is fixed at low speed valve timing for a certain period of time, and when accelerating from a medium speed range, the fixed vane 84 and the movable vane are used. 87 may be fixed at a narrowed position for a certain period of time to improve responsiveness.

[Effects of the Invention] As described above, according to the present invention, the valve timing is set so that the output torque in the extremely low rotational speed region is generated at a peak torque at a rotational speed before the required boost pressure is reached. By doing so, the required output characteristics can be obtained by controlling the boost pressure in the normal operating speed range. Therefore, a great effect can be achieved in achieving both high responsiveness and highly efficient output characteristics.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an engine control system based on the present invention. FIG. 2 is a configuration diagram around the valve train mechanism. FIG. 3 is an explanatory diagram of the mechanism of the variable displacement turbocharger. FIG. 4 is a flowchart of a control program related to valve timing switching. Figures 5a and 5b are flowcharts of a control program related to varying the supercharging pressure. 6 to 11 are flowcharts of each subroutine related to the program. 1...Engine body 2...Intake port 3...
Intake manifold 4...Intake pipe 5...Throttle body 6...Intercooler 7...Variable displacement turbocharger 8...Compressor section 9...Air cleaner 10.
・・Exhaust port 11・・Exhaust manifold 12・
...Turbine part 13...Catalytic converter 14...
・Valve mechanism 15...Oil pump 16...Solenoid valve 17...Switching control valve 18...One actuator...Water pump 20...Radiator 21...Electronic control circuit 22...・Oil pressure switch
23...Oxygen concentration sensor 24...Engine rotation sensor 25...Cooling water temperature sensor 26...Automatic transmission 27...
...Intake temperature sensor 28...Intake pressure sensor 29...
Throttle valve opening sensor 30...Supercharging pressure sensor 31...Intake pressure sensor 32
...Vehicle speed sensor 33...Fuel injection valves 34, 35
...Solenoid valve 40...Rocker shaft 41, ~43
...Rocker arm 45...Camshaft 45a...Protuberance 46...
・Low speed cam 47...High speed cam 50a, 50b
... Intake valve 51 ... Connection switching device 83 ... Turbine wheel 84 ... Fixed vane 87 ... Movable vane 104
...Diaphragm 105...Negative pressure chamber 106...Positive pressure chamber 0,...Hydraulic pressure signal 02...Oxygen concentration NE...
・Engine speed Tw...Cooling water temperature P...Parking range signal N...Neutral range signal TA...Intake temperature P,...Intake negative pressure θTIE
...Throttle valve opening P2...Supercharging pressure PA...Atmospheric pressure■...Traveling speed DM...Basic duty PHI□G・
...High boost pressure judgment guard value DT...Setting subtraction duty DTRI]...Setting addition duty P2R...Target supercharging pressure Δ, 2...Supercharging pressure change rate ΔP2S...Setting supercharging Pressure change rate patent applicant Honda Motor Co., Ltd.
Attorney Patent Attorney Akira Oshima - H3 Figure 6 Figure 8 Figure 7 Figure 9 Figure 10 Procedural amendment (method) % formula %] Display of case 1985 Patent Application No. 330432 2゜Invention Name: Engine control device Location: 1-8-6 Iidabashi, Chiyo IJI-ku, Tokyo 102 6゜7゜8゜Number of inventions increased by the amendment Column for detailed explanation of the invention in the specification subject to the amendment Description of the contents of the amendment Page 2, line 1, after ``Control device.'', insert r3, ``Detailed description of the invention.'' Figure 11

Claims (2)

[Claims] (1) A switching device for varying the operating state of at least one of an intake valve and an exhaust valve, a variable capacity supercharger, a switching operation of the switching device, and a variable supercharging capacity of the supercharger. and control means for controlling the operation in accordance with the operating state of the engine including at least the engine rotational speed, and the switching device is configured to control the switching device in a state where the rate of change of the boost pressure in the engine is equal to or higher than a predetermined value. An engine control device characterized in that the switching operation is performed by the control means. (2) At least the intake valves include a plurality of valves for each cylinder, and the switching device causes the control means to deactivate some of the plurality of valves in an operating range below a predetermined engine speed. The first characterized by being
An engine control device according to the claims.