JPH01121527A - Supercharge pressure control device of electronically controlled engine - Google Patents

Abstract

PURPOSE:To eliminate necessity for use of any barometric sensor by comparing the fundamental fuel injection amount calculated from the suction air amount and the number of revolutions with the reference value calculated from the degree of throttle valve opening and the number of revolutions, determining the altitude constant, and controlling the degree of weight gate opening from the altitude correction value. CONSTITUTION:Detection values from a throttle sensor 5, suction air amount sensor 8, number-of-revolutions sensor 16, etc., are fed into a control means 17, and the fundamental fuel injection amount is set on a data map from the suction air amount and the number of revolutions. From the degree of throttle valve opening and the number of revolutions, the reference fuel injection amount is set on the data map, and the altitude constant is calculated from comparison of the normal operation reference fuel injection amount with the fundamental fuel injection amount to correct the fundamental fuel injection amount. The target fuel injection amount after correction is compared with the fundamental fuel injection amount, and if the former is greater than the latter, it is judged that the supercharge pressure based on the absolute pressure, and weight gate 31d is controlled through a weight gate control drive part 30.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is an electronically controlled engine supercharging pressure control method that determines the waste gate opening of a supercharger from the throttle opening, intake air amount, and engine speed. Regarding equipment.

[Problems to be solved by the prior art and the invention] Generally, the boost pressure of the supercharger installed in an electronically controlled engine increases in proportion to the engine rotation, so sufficient supercharging is not achieved in the low speed range. In addition, the supercharging pressure becomes excessive in the high speed rotation range.

Therefore, as shown in FIG. 6 (schematic diagram), a wastegate 53 that bypasses the turbine 51a is formed in the turbine housing 52 of the supercharger 51, and the opening foot (or By adjusting the opening time) with the actuator 54, the turbine output is reduced, supercharging is not performed in the low speed rotation range, and the supercharging pressure P2 is maintained constant after the interset point. many.

That is, when the rotation speed of the compressor 51b increases and the supercharging pressure P2 reaches the set pressure, the diaphragm of the actuator 54 that takes in this supercharging pressure P2 opens the control valve 53a of the waste gate 53. The opening degree of the waste gate 53 is controlled according to the height of the supercharging pressure P2.

As a result, the exhaust pressure corresponding to the opening degree of the control valve 53a is wasted, the turbine output is reduced, and the supercharging pressure P2 is maintained at a constant state.

By the way, the diaphragm of the actuator 54 is
Control operation is performed based on the difference between supercharging pressure P2 and atmospheric pressure P1 (P2-
P1=const).

The supercharging pressure P2 and the atmospheric pressure P1 gradually decrease as the altitude increases. Therefore, with conventional boost pressure control devices that perform supercharging control based on the difference between boost pressure P2 and atmospheric pressure P1, the boost pressure P2 becomes relatively low as the altitude increases, making it impossible to obtain a sufficient supercharging effect. .

To deal with this, for example, a waste gate control solenoid is interposed in the middle of the supercharging pressure passage 54a that introduces the supercharging pressure P2 into the actuator 54, as disclosed in Japanese Patent Laid-Open No. 57-913338. The waste gate control solenoid is operated using the absolute pressure detected by the atmospheric pressure detection device, and the supercharging pressure applied to the actuator 54 is controlled equally, so that sufficient supercharging effect can be obtained even at high altitudes. Various techniques have been devised and adopted.

However, it is difficult to newly assemble the above-mentioned atmospheric pressure detection device and the like in an engine room equipped with various auxiliary equipment due to severe restrictions on Iia installation. In addition, the need for the above-mentioned barometric pressure detection device increases the equipment cost and the structure becomes complicated, resulting in increased cost! 10 ri.

[Purpose of the Invention] The present invention has been made in view of the above circumstances, and has a simple structure, is easy to handle, and provides sufficient supercharging effect not only on flatlands but also on highlands without using an air pressure detection device. The purpose of the present invention is to provide a boost pressure control device for an electronically controlled engine.

[Means and effects for solving the problem] The boost pressure control device for an electronically controlled engine according to the present invention controls the boost pressure by adjusting the waste gate opening of the supercharger.
As a means, the reference fuel injection amount is calculated from the throttle opening detected by the throttle sensor and the engine rotation speed detected by the rotation speed sensor. A basic fuel injection amount calculation section that calculates the basic fuel injection rJA spear from the intake air amount and the engine speed, and the reference fuel 104 foot calculation section
A comparison calculation section that compares the calculated reference fuel injection amount with the basic fuel injection amount 9 calculated by the basic fuel injection amount calculation section, and calculates an altitude constant based on the comparison ratio calculated by this comparison calculation section. An altitude constant calculation section, an altitude correction coefficient calculation section that calculates an altitude correction coefficient from the 'tS degree constant obtained by this altitude constant calculation section, and the above reference fuel injection! a target fuel injection amount calculation section that calculates a target fuel injection amount by correcting the standard fuel injection period calculated by the 11M calculation section with the altitude correction coefficient calculated by the altitude correction coefficient calculation section; and the basic fuel injection amount. A gate opening degree that compares the basic fuel injection distance calculated by the calculation unit and the target fuel injection a calculated by the target fuel injection 7 calculation part, and calculates the waste gate opening degree m based on the comparison value. A calculation section is provided.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 5 show one embodiment of the present invention, FIG. 1 is a schematic diagram of the engine control system, FIG. 2 is a block diagram of the boost pressure control device, and FIG. 3 is the throttle opening (Trθ Fig. 4 is a comparison f! i(A> and engine speed (N
) and throttle opening (TrO), and FIG. 5 is a patterned chart showing the relationship between the altitude constant (KALT) and the altitude correction coefficient (1<2).

Reference numeral 1 in the figure is an engine body, and the figure shows a horizontally opposed engine. Further, a throttle chamber 3 is communicated with the upstream side of an intake manifold 2 that communicates with intake boats (not shown) provided in both banks (LH, RH) of the engine body 1. Additionally, three throttle sensors 5 are attached to the throttle valve 4 provided in the throttle chamber 3. Further, a single point injector (SPI) 6 is provided on the upstream side of the throttle chamber 3.

Further, an intake pipe 7 is connected to the upstream side of the throttle chamber 3, and a compressor 31a of the supercharger 31 is interposed on the upstream side of the intake pipe 7. The main passage 8a of the hot-wire air 70 meter 8, which is an example of a sensor for air conditioning, is communicated with the AC cleaner 9. Furthermore, a hot wire V8C and a temperature compensating resistor 8d, which constitute a part of the bridge circuit, are exposed in the sub passage 8b of the hot wire air flow meter 8.

On the other hand, an 02 sensor 13 is placed in the middle of the exhaust manifold 12 that communicates with an exhaust boat (not shown) of the supercharger 1, and a turbine 31b of the supercharger 4131 is located downstream of the 02 sensor 13.
is interposed. J3, numeral 14 is a catalytic converter.

Furthermore, a waste gate 31d that bypasses the turbine 31b is formed in the turbine housing 31c that covers the coupin 31b of the supercharger 1. Also,
A control valve 31e is provided on the diaphragm of the actuator 32.

Further, an atmospheric chamber 32a of the actuator 32 is communicated with the atmosphere, and an operating chamber 32b is communicated with a valve chamber 33a of the wastegate control solenoid 33. This valve chamber 33a has a supercharging pressure introduction passage 3 communicating with the outflow side of the compressor 31a of the supercharger 31.
4 and an atmospheric air introduction passage 35 communicating directly downstream of the hot wire air flow meter 8.

In addition, the above waste gate control solenoid 3
A switching valve 33c that selectively opens and closes both the passages 34 and 35 according to the excitation force of the coil 33b is installed in the valve chamber 33a of No. 3.

In addition, the camshaft of the engine body 1 (not shown)
A rotational speed sensor 16 that also serves as a crank angle sensor is attached to a distributor 15 that is connected to the engine.

On the other hand, reference numeral 17 is a control means for controlling the boost pressure, and one input terminal of this control means 17 is connected to the throttle sensor 5.
, rotational speed sensor 16, hot wire air flow meter 8.02 sensor 13 are in contact with G'jS.

Further, the coil 33b of the waste gate control solenoid 33 is connected to the output side of the control 211 means 17.
is connected. This coil 33b is connected to the control means 1.
When a duty signal is input from 7, the switching valve 33C moves forward and backward to selectively close one of the boost pressure passage 34 and the atmospheric air introduction passage 35.

In addition, the above 11J 111 means 17 includes a throttle n
degree detection section 18, engine rotation speed detection section 19, intake air amount detection section 20, lean ridge determination section 21, basic fuel injection amount (Tp) calculation section 22, reference fuel injection amount (T pl) calculation section 23, comparison sieve section 24, steady state determination section 25, altitude constant calculation section 26, altitude correction coefficient (K2) calculation section 27, target fuel injection amount (Tp'') calculation section 28, gate opening degree calculation section 29, and waste gate control The drive unit 30 and the like are depicted as 1'.

(effect) Next, the wJ control operation of the control means 17 will be explained.

During steady operation, the throttle opening detection section 18 detects the throttle opening TrO from the output signal of the throttle sensor 5. Further, the engine rotation speed detection section 19 detects the engine rotation speed N from the rotation speed sensor 16. Further, the intake air amount detection section 20 detects the mass flow rate, that is, the intake air ff1Q from the output of the hot wire air meter 8. Further, the lean ridge determination section 21 determines from the output signal of the 02 sensor 13 whether the air-fuel ratio during current operation is lean (λ10n) or rich (λric) with respect to the stoichiometric air-fuel ratio.

Then, the Tp calculation unit 22 calculates the parking fuel injection amount ( Pulse width) Tp is calculated (Tp = -Q/NK... constant).

Further, in the Tpl calculation unit 23, the throttle It'd
From the throttle opening degree Trθ detected by the degree detection unit 18 and the engine rotation speed N, the basic fuel injection interval (pulse width) Tp
Calculate l.

That is, in this Tp1 calculating section 23, as shown in FIG.
(Trθ lattice) and a two-dimensional map (T p1
MAP) Read the standard fuel injection coefficient KTp1 from M'P1, and based on it read the standard fuel injection coefficient KTp1 during the current operation.
E) Determine 1.

This reference fuel injection coefficient K Tpl is determined by the above N grid ↑r
The reference fuel injection coefficient K Tpl between each grid point is written at the grid points with the θ grid, and the reference fuel injection coefficient K Tpl between the grid points is determined by area setting or interpolation calculation. Note that the reference fuel injection coefficient K Tp included in each grid point of this Tp1 map MPI
l is determined in advance through experiments and the like.

Then, a comparison section n section 24 compares the reference fuel injection aT111 obtained in the Tpl calculation section 23 with the basic fuel injection faTp obtained in the To operation P,'> section 22, and calculates a comparison value A. (A=Tp1-Tp'').

On the other hand, the steady state determination unit 25 determines the lean (λfan)/rich (λ fan) determined by the lean-rich determination unit 21.
ric) and count this lean rich (λfen
/λric) is repeated three times, for example (n≧
3) Determine steady operation and instruct the comparison calculation section 24 to output the calculation result.

Then, in the advanced constant calculation unit 26, 'the comparison calculation unit 24
Calculate the high surface constant KALT based on the lt' comparison value calculated in ? A? ;'J.

That is, the ts degree constant calculation unit 26 calculates a three-point map (ig degree map) M, which is composed of the engine speed N, throttle opening Trθ, and comparison value A, as shown in FIG.
Determine the altitude coefficient from P2, and calculate the altitude constant KALT based on that value. And this altitude constant KAL
T is stored in a storage means (for example, RAM) not shown.

'It should be noted that the altitude constant KALT stored in this storage means is sequentially changed every time the operating conditions change.'

“For example, when driving at a high altitude, the air density is lower than that on a flat land, so the throttle opening ff1 (Trθ) at a constant rotation speed under a constant load state becomes larger than that on a flat land. A reference fuel injection Oi1 to Tp1 is calculated as an absolute interval according to the opening degree Trθ.

On the other hand, the Tp calculating section 22 calculates the U main fuel injection Q4 V-T F+ from the substantial intake air ff1Q detected based on the mass flow age of the hot wire airflow meter 8, so that the quasi-1 (This fuel injection boat Tp shows a substantial value depending on the altitude change.

Therefore, both the above fuel injection '()JAtTpl, Tf)
The altitude can be calculated by comparing.

Therefore, the storage means stores an altitude constant KALT having a corresponding value for highlands, and an altitude constant KALT having a corresponding value for flatlands.

Then, the K2 calculating section 27 reads the altitude constant KALT stored in the storage means, and calculates 2 as the altitude correction coefficient for the target fuel injection 01 m To'' based on the value.

In addition, this all! The correction factor 2 is the altitude constant K
Patterned as a function of ALT-. That is, K2 = f (KALT) (see Figure 5).

Also, in the p1 calculation section 28, the reference fuel injection ff1Tl)1 calculated in the Tp1 calculation section 23 is corrected by 2 to the altitude correction coefficient calculated in the 2 calculation section 27, and the target fuel injection ff1TE1'' is calculated. (Tp = TD
IXK2).

Further, in the gate opening calculation section 29, the Tp calculation section 2
Compare the basic fuel injection amount Tp calculated in step 2 with the target fuel injection amount ■p* calculated by the Tp main calculation section 28 (T
p: Tp”).

TI)<TD'', it is determined that the supercharging pressure based on absolute pressure is low, and a valve close signal (DUTY=100%) is output to the wastegate control drive unit 30.

On the other hand, if Tp>Tp'', it is determined that the supercharging pressure based on absolute pressure is high, and the wastegate control drive unit 30
Outputs a valve close signal (DUTY=0%).

The wastegate control drive section 30 outputs a duty signal to the coil 33b of the wastegate control solenoid 33 in response to the signal from the gate opening calculation section 29.

This wastegate control solenoid 33 (7
): t<Rtl open signal (DUTY=
100%) is input, the switching valve 33c
Open the atmosphere introduction passage 35 side, and open the supercharging pressure introduction passage 34.
Open the side valve (as shown in Figure 1).

Then, a pressure almost equal to atmospheric pressure immediately downstream of the hot wire air meter 8 is applied to the supercharging pressure η input passage 34 and the valve 933 of the waste gate control solenoid 33.
a, and flows into the operating chamber 32b of the actuator 32. This actuator 32 is operated by the difference between the atmospheric pressure P1 flowing into the atmospheric chamber 32a and the pressure flowing into the operating chamber 32b. Supply pressure P2
Lower pressure is being injected.

Therefore, the die X7 phragm of this actuator 32 is bent toward the operation chamber 32b, and the control valve 31e connected to this diaphragm is connected to the ist gate 31d.
Open the door.

As a result, the full exhaust pressure is applied to the turbine 31b of the supercharger 31, the turbine output increases, and the compressor 3'1a
The supercharging pressure P2 gradually increases. - On the other hand, when the supercharging pressure P2 increases, the intake air amount (Q) measured by the hot wire air flow meter 8 increases, and the basic fuel injection (8 mTp) calculated by the Tp calculation section 22 increases, and the above target fuel injection fi
It gradually approaches tTp.

Further, when a valve close signal (DUTY=0%) is input from the start control device 17 to the coil 33b of the waste gate control solenoid 33, the switching valve 33G closes the air introduction passage 35 side, and Open the boost pressure introduction passage 34 side.

Then, the supercharging pressure P2 of the supercharger 31 flows into the operating chamber 32b of the actuator 32, and the diaphragm
The difference between this supercharging pressure P2 and the above atmospheric pressure P1 is (P2-Pl
=const), which controls the opening degree of the waste gate 31d.

In this way, the difference between supercharging pressure P2 and atmospheric pressure P1 (p2-p
At high altitudes where the pressure (l = const) is set low, the wastegate control solenoid 33 controls the supercharging pressure P2 to perform supercharging pressure control based on absolute pressure, making it possible to obtain excellent supercharging performance. .

[Effects of the Invention] As explained above, according to the present invention, it is possible to control the boost pressure by determining the altitude using software from existing equipment (without adding an atmospheric pressure detection device, etc.). It not only has a simple structure, is easy to handle, and can reduce costs, but also has excellent effects such as being able to obtain a sufficient supercharging effect not only on flatlands but also on highlands.

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention, FIG. 1 is a schematic diagram of the engine control system, FIG. 2 is a block diagram of the boost pressure control device, and FIG. 3 is the throttle opening (Trθ The reference fuel injection Q [map, Figure 4 is a three-dimensional map consisting of the comparison value (A), the engine speed a (N), and the throttle opening (TrO) The constructed altitude map, FIG. 5, is a patterned chart showing the relationship between the altitude constant (KALT) and the altitude correction coefficient (K2), and FIG. 6 is a schematic diagram of a conventional supercharger. 5... Throttle sensor, 8... Intake air M sensor (air 70 meter), 16... Rotation speed sensor, 17...
. . . Control means, 22 . . . Basic fuel injection amount calculation unit, 23
. . . Reference fuel slanted injection Q4 performance port, 24 . . . Comparison calculation section, 26 . . . Arithmetic unit, 29...
Inter-gate degree calculation section, 31...Supercharger, 31d...Wastegate, A...Comparison value, K2...Altitude correction coefficient, KALT...Altitude constant, N...Engine Rotation speed, P2...supercharging pressure, Q...intake air surroundings, Tp・
...Basic fuel injection amount, Tpl...Reference fuel injection port, T
p9...Target fuel injection interval, TrO...Throttle opening degree. Figure 3: Nen Te (9m) Figure 4 Figure 5

Claims (1)

[Claims] A control means for controlling the supercharging pressure by adjusting the waste gate opening of the supercharger, based on the throttle opening detected by a throttle sensor and the engine rotation speed detected by a rotation speed sensor. a reference fuel injection amount calculation section that calculates a reference fuel injection amount; a basic fuel injection amount calculation section that calculates a basic fuel injection amount from the intake air amount detected by the intake air amount sensor and the engine rotational speed; and the above-mentioned standard. a comparison calculation section that compares the reference fuel injection amount calculated by the fuel injection amount calculation section and the basic fuel injection amount calculated by the basic fuel injection amount calculation section, and a comparison calculation section based on the comparison value calculated by the comparison calculation section. an altitude constant calculation unit that calculates an altitude constant based on the altitude constant calculation unit; an altitude correction coefficient calculation unit that calculates an altitude correction coefficient from the altitude constant calculated by the altitude constant calculation unit; and a reference fuel injection amount calculated by the reference fuel injection amount calculation unit. a target fuel injection amount calculation section that calculates a target fuel injection amount by correcting the above with the altitude correction coefficient calculated by the altitude correction coefficient calculation section; and a basic fuel injection amount calculated by the basic fuel injection amount calculation section and the above. An electronic device comprising: a gate opening calculation section that compares the target fuel injection amount with the target fuel injection amount calculated by the target fuel injection amount calculation section and calculates the waste gate opening amount based on the comparison value. Control engine boost pressure control device.