JPS61169623A - Engine supercharge pressure controller - Google Patents

Abstract

PURPOSE:To hold the acceleration performance at high level by correcting the highest supercharge pressure higher than a setting level for predetermined time after shift-up of speed changer upon acceleration of engine. CONSTITUTION:In supercharge pressure controller where a supercharger 4 is arranged in the intake path 2 of engine 1, highest supercharge pressure control means 53 for controlling the highest supercharge pressure of supercharger 4 to a setting level is provided. While means 51 for detecting the shift-up under engine acceleration is provided. Upon detection of acceleration shift-up, shift-up correction means 52 will correct the highest supercharge pressure to higher level than said setting level for predetermined time. Consequently, droppage of driving force due to shift-up is compensated through increase of engine output thus to hold the acceleration performance at high level.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine boost pressure control device having a maximum boost pressure control function.

(Prior art) Generally, in an engine, the engine output is taken out through a transmission, so when the transmission is shifted up while the engine is accelerating, the gear ratio of the transmission increases. Therefore, if the engine output is constant, the driving force extracted from the transmission decreases. Therefore, when re-accelerating immediately after shifting up the transmission, the acceleration performance of the engine deteriorates due to insufficient driving force.

Also, when upshifting the transmission while the engine is running, first release the accelerator, disengage the clutch, perform gear soft, and then engage the clutch again and depress the accelerator. Sometimes the amount of exhaust gas decreases temporarily. For this reason, especially in engines equipped with turbochargers, when the gear of the transmission is soft, the turbocharging pressure will temporarily drop due to the decrease in turbine rotation due to the decrease in exhaust gas, and the engine output will decrease accordingly. I will do it.

Therefore, especially in supercharged engines equipped with the maximum boost pressure control @ function that controls the maximum boost pressure to the set value, if the transmission is shifted up while the engine is accelerating, the engine output will decrease. Due to the synergistic effect of this and the increase in gear ratio, the problem arises that the driving force drops significantly immediately after the noft knob, resulting in deterioration of acceleration performance.

(Purpose of the Invention) The present invention is intended to solve the problems pointed out in the above section of the prior art, and to prevent deterioration of acceleration performance when an upshift operation is performed during acceleration in a supercharged engine. The purpose of this invention is to provide a supercharging pressure control device that prevents the above.

(Means for achieving the object) The present invention provides a first method for achieving the above object.
As shown in the figure, there is a supercharger 4 interposed in the intake passage 2 of the ennon 1, a maximum supercharging pressure control means 53 for controlling the maximum supercharging pressure of the supercharger 4 to a set value, and engine acceleration. The maximum supercharging pressure is set to a value higher than the set value for a predetermined period of time in response to the outputs of the acceleration shift-up detection means 5■, which detects a shift-up during acceleration, and the no-no-knob detection means 51 during acceleration. A shift-up correction means 52 for correcting the maximum boost pressure during acceleration is provided, and when a shift-up is performed during acceleration, the maximum boost pressure is set higher than the set value for a predetermined period of time thereafter. This is what I did.

(Function) In the uninvented system, when the transmission is shifted up while the engine is accelerating, the maximum supercharging pressure is corrected to be higher than the set value for a predetermined period of time, so that the shift-up operation is prevented. Even if engine output temporarily decreases due to a drop in boost pressure, after an upshift, the engine output is maintained at a higher level than before the upshift. Therefore, the reduction in driving force due to upshifting (increasing gear ratio) is compensated for by the increase in mechanical output, and a high level of acceleration performance is maintained.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 2 to 5.

(Structure) FIG. 2 shows an automobile engine 1 equipped with a boost pressure control device according to an embodiment of the present invention.

This engine! The intake passage 2 is provided with a blower 41 and a throttle valve 5 of the turbocharger 4, and the exhaust passage 3 is provided with a turbine 42 of the turbocharger 4.

Furthermore, a bypass passage 6 is connected to the exhaust passage 3 so as to bypass the turbine 42 . A control valve 7 is attached to the bypass passage 6 and is driven by an actuator 8, which will be described later, to control the opening and closing of the bypass passage 6.

The actuator 8 has a diaphragm 81 that is always biased in one direction by a spring 83, and an actuator 84 that has one end attached to the diaphragm 81 and the other end connected to the control valve 7 via a link lever 85. The above-mentioned control is performed by displacing the above-mentioned diaphragm 8I according to the balance between the internal pressure of the pressurizing chamber 82 formed on the surface of the diaphragm 81 and the spring force of the above-mentioned spring 83. It is configured to open and close the valve 7. In this embodiment, the pressurizing chamber 82
The operating direction of the control valve 7 is set so that the control valve 7 is opened when the internal pressure becomes greater than the spring force of the spring 83 and the diaphragm 81 is displaced toward the side opposite to the pressurizing chamber 82.

Furthermore, the pressurizing chamber 82 is connected to the blower downstream position of the intake passage 2 via a supercharging air introduction passage 10 that includes a first electromagnetic valve 12 formed of a duty valve in the middle thereof, and A second solenoid valve 13 consisting of a duty valve is installed at the end of the passage, and the passage is open to the atmosphere! ■It is open to the atmosphere through. Note that this first solenoid valve I2 and the second i
Both iE magnetic valves 13 operate in response to control signals output from the controller 14.

In FIG. 2, reference numeral 6 is a rotation speed sensor that detects the engine rotation speed, 17 is an oil level sensor that detects the lubricating oil level of the engine 1, 18 is an oil temperature sensor that detects the lubricating oil temperature, and 19 is a pro-appliance sensor. A Δ-filtration supply pressure sensor detects downstream intake pressure (i.e., supercharging pressure); 20 is a water temperature sensor that detects engine cooling water temperature; 21 is an intake air temperature sensor that detects intake air temperature; 22 is a sensor that detects the opening of throttle valve 5; This is a throttle opening sensor that detects the degree of throttle opening.

(Operation and its effects) Next, the operation and its effects of this boost pressure control device will be explained by the system diagram shown in FIG. 2, the main control routine shown in FIG. 3, and the sub-control routine shown in FIGS. 4 and 5. Explain with reference to.

First, the outline of supercharging pressure control will be explained with reference to FIG. 2. When Entsuno 1 is operated, the engine! The turbine 42 is rotated by the gas energy of the exhaust gas discharged from the engine, and further, the rotation of the turbine 42 is transmitted to the blower 41 via the rotating shaft 43, and the blower 4I performs intake air supercharging.

If this intake boost pressure becomes too high, the engine 1
The reliability of Ennon will be compromised due to damage, etc.
When the boost pressure reaches the setting @ (maximum boost pressure) determined from the viewpoint of engine reliability, the first solenoid valve 12 is activated based on a control signal from the controller 14, as will be described in detail later. The actuator 8 opens the control valve 7 to introduce supercharging air into the pressurizing chamber 82 of the actuator 8 through the supercharging air introduction passage IO, and the actuator 8 opens the control valve 7 to discharge part of the exhaust gas through the bypass passage 6. However, by suppressing the rotation of the turbine 42, the supercharging pressure is reduced to the above set value, and conversely, when the supercharging pressure falls below the above set value, the second electromagnetic valve 13 is opened to reduce the above pressurization. The chamber 82 is opened to the atmosphere and the control valve 7 is closed to accelerate the rotation of the turbine 42 and increase the boost pressure to the above set value (maximum boost pressure control).

Furthermore, in this boost pressure control device, in parallel with the maximum boost pressure control based on the level of boost pressure downstream of the turbine as described above, the two correction controls that are the gist of the present invention, namely, the engine! Acceleration correction control based on the acceleration state of Correction control is performed based on each correction element, and the above set values are adjusted based on the acceleration state of the ENON L, presence or absence of a shift-up operation, high/low engine coolant temperature, high/low temperature of intake air temperature, high/low of lubricating oil temperature, and high/low of lubricating oil level. The increase or decrease is corrected based on the following. Hereinafter, maximum boost pressure control including correction control based on each of these correction factors will be explained in detail with reference to FIGS. 3 to 5.

First, the overall control flow will be explained with reference to the main control routine shown in FIG.

After starting the engine, first check the current engine speed N, lubricating oil level LO1 lubricating oil temperature TO1, cooling water temperature Tw, and intake air temperature T.
a and throttle opening θ are read (step S).

Next, based on each of the above detected values, the target maximum boost pressure Pα (-PoxCacxCtvXC
taX'CtOXCQOXCg) is calculated (step S). Here, Po is a preset basic maximum boost pressure setting value, and Cac (≧1) is calculated based on the acceleration state of the engine in the sub-control routine shown in Fig. 4 (described in detail later). The acceleration correction coefficient Ctv (≧1) is the water temperature correction coefficient calculated based on the height of the cooling water temperature, C
ta (≧1) is an intake temperature correction coefficient calculated based on the intake temperature, Cto (≧1) is an oil temperature correction coefficient calculated based on the lubricant temperature, and Cao (≧1) is the lubrication temperature correction coefficient. The lubricating oil level correction coefficient Cg (≧1) calculated based on the level of the oil level is the shift-up correction calculated based on the presence or absence of a shift-up operation in the sub-control routine of Fig. 5 (described in detail later). It is a coefficient.

Next, the current supercharging pressure (detected supercharging pressure) Pa is read (step S), and based on the difference (Pa - PG) between the detected supercharging pressure Pa and the target maximum supercharging pressure P 1st
Control value (pulse width) t + ( by proportional system @ (P control) in duty ratio control of solenoid valve 12 and second solenoid valve 13
=PGX(Pa PG), PG.

Proportional gain) is determined (step S,). Furthermore, the current detected supercharging pressure P a(n) and the previous detected supercharging pressure P a(
Control item (=D G n) -P
a(n-l), DG differential gain) is determined (step S,).

Add these two control values 1+ and the same t (step S,)
, this sum t (=t++ty) is the actual control value.

Next, the control direction of the boost pressure is determined. That is, in step S, the detected supercharging pressure Pa and the target maximum supercharging pressure Pα are compared.
, Pa-Pa>0, it is determined that pressure reduction is necessary, and in this case, the first solenoid valve! In step S,), the control valve 7 is opened to suppress the rotation of the turbine 42 and reduce the supercharging pressure downstream of the blower. Conversely, if Pa-Pa<0, it is determined that there is a need to increase the pressure, and in this case, the second solenoid valve! In step S8), the pressurizing chamber 82 of the actuator 8 is opened to the atmosphere, and the control valve 7 is closed to accelerate the rotation of the turbine 42 and increase the supercharging pressure.

As mentioned above, the set value of the maximum boost pressure is corrected depending on the characteristics such as the acceleration state of the engine, but among these correction elements, the correction values for correction elements other than acceleration correction and pen lever knob correction It can be obtained alternatively from the map.

However, the acceleration correction coefficient and the upshift correction coefficient are set by calculation according to the driving condition of the engine. below,
The control flow of the acceleration correction control and shift-up correction control will be described in detail with reference to the sub-control routines shown in FIGS. 4 and 5.

First, the control flow of acceleration correction control will be explained with reference to FIG. Since the acceleration flag is O at the time of control start, in this case, the process proceeds from step Sa to step sb, where it is determined whether the engine is currently in an accelerating state. That is, when the current throttle opening θ and the predetermined throttle opening C+ (that is, the current boost pressure Pa exceeds the basic set value Pa, the control valve 7 is opened and the boost pressure rise suppressing action is performed). Throttle opening corresponding to the engine load such that
and the control valve 7 is always opened to some extent in the opening range equal to or greater than the predetermined throttle opening CI), and the current rate of change in throttle opening dθ/dt and a predetermined rate of change. is compared with a predetermined value C2 (i.e., the speed of change of the throttle opening when the accelerator pedal is suddenly depressed, which corresponds to the predetermined value in the claims), and θ>C, and dθ/dt. > ct, it is determined that the acceleration state is present.

If it is determined in step sb that the acceleration state is present,
Set the acceleration flag to 1 (Step Sc), and further calculate the acceleration correction coefficient C corresponding to the current engine speed N from the map.
Step S of reading out ac and the correction time (i.e., the time for continuing acceleration correction) Tac corresponding to the rotation speed N.
d) The control flow of step Se→step Sr→step Sa is repeatedly executed until the correction time Tac times up, and the acceleration correction coefficient is held as the coefficient Cac.

When the correction time Tac times up, the acceleration flag is set to 0 (step Sg), and the acceleration correction coefficient Cac is decreased by a predetermined value c every cycle to gradually converge the acceleration correction coefficient Cac to CaC=1 ( Step S
h) Acceleration correction is smoothly completed without causing torque shock.

On the other hand, as a result of the determination in step sb, if it is determined that the acceleration state is not present, the acceleration correction coefficient Cae is
Set c=1 (step Si). Therefore, no acceleration correction is performed in this case.

Next, the control flow of the upshift correction control will be explained with reference to FIG.

This shift-up correction control is basically controlled by the same control flow as the acceleration correction control described above. First, since the shift flag is 0 at the start of control, in this case, the process proceeds from step Sj to step Sk, where it is determined whether there is an upshift during acceleration (in other words, if the driver knows the intention of accelerating driving). (Whether an upshift operation was performed)
Determine. In other words, under the assumption that the accelerator pedal will not be returned too far when performing soft amplification based on the intention to accelerate, the current throttle opening θ
The throttle opening C1 corresponding to the estimated minimum depression is compared with the throttle opening C1 corresponding to the estimated minimum depression when the driver intends to shift up and returns the accelerator pedal from its maximum depression position. Immediately after an upshift, the gear ratio increases, and the rate of decrease in engine speed is greater than if the accelerator pedal was simply released temporarily to perform an upshift (i.e., during deceleration). The set value of the rate of change dN/dt of the rotational speed N and the rate of change immediately after the transmission is shifted up -
Compare with 〇.

As a result of the comparison, θ〉C4 and d N / d t <
Cs (Y), it is determined that the driver shifted up the transmission with the intention of accelerating, that is, performed an upshift operation during acceleration, and in other cases, the 7-lift up operation during acceleration is determined. FJI is determined to be the case in which it was not carried out.

If it is determined that a shift up operation has been performed during acceleration, the shift flag is set to 1 in step S.
e), furthermore, in step Sm, the shift up correction coefficient Cg corresponding to the current engine speed N is determined from the map.
(see FIG. 6(A)) and the correction time Tg (see FIG. 6(B)! IQ) corresponding to the J-nonono rotation speed are read out. After setting the shift-up correction coefficient Cg and the correction time Tg, the control flow from step Sm to step Sp to step Sj to step Sn is repeatedly executed, and during the correction time Tg, the not-up correction coefficient is set as a coefficient. Keep it at Cg.

When the correction time Tg times up, the shift flag is set to O in step SQ, and then the shift flag is set to O in step SQ.
In this step, the shift correction coefficient cg is gradually decreased by a predetermined value C1, and the shift correction is smoothly completed without causing any trouble.

On the other hand, if it is determined in step Sk that the shift-up state is not present during acceleration, the shift correction coefficient C
Set g to 1. Therefore, no soft correction is performed in this case.

In addition, this shift up correction coefficient Cg and correction time Tg are as follows:
As shown in the characteristic diagrams of FIGS. 6(A) and 6(B), the value is set so as to gradually decrease as the engine speed increases. This is because the operating conditions are more severe at high engine speeds, such as the heat load being higher than at low engine speeds, so the maximum boost pressure correction amount and correction time during upshifts are required at high engine speeds compared to at low engine speeds. This is intended to ensure engine reliability by setting a small amount.

As mentioned above, when the transmission is shifted up during acceleration, the above-mentioned acceleration correction and knot-up correction are performed simultaneously to set the maximum boost pressure to a higher pressure side than the normal setting value. Then, the supercharging pressure that temporarily drops due to the closing operation of the throttle valve during upshifting of the transmission is maintained at a higher pressure side for a predetermined period of time immediately after the upshifting than before the upshifting operation, and the engine output increases when the upshifting operation is performed. It will be even higher than before.

Therefore, even though the gear ratio is increased by upshifting the transmission, the decrease in driving force (i.e., the shaft output taken out through the transmission) due to the increase in the gear ratio is excessive. This is compensated for by an increase in engine output (that is, transmission input) due to an increase in supply pressure, so a decrease in driving force is prevented and a high level of acceleration performance is maintained.

In the above embodiment, the presence or absence of a shift-up operation of the transmission is determined based on the rate of decrease in the engine speed, but the present invention is not limited to this, and for example, the rate of decrease in the engine speed is determined. Instead of the determination, the determination may be made based on the gear position of the transmission.

(Effects of the Invention) The engine supercharging pressure control device of the present invention controls the supercharger installed in the intake passage for intake supercharging and the maximum supercharging pressure downstream of the supercharger to a set value. a maximum boost pressure control means for detecting a shift-up operation of the transmission during acceleration; a shift-up detection means for detecting a shift-up operation of the transmission during acceleration; The present invention is characterized by comprising shift-up correction means during acceleration for correcting the maximum boost pressure so as to set the maximum boost pressure to a value higher than the set value for a predetermined period of time during a lift-up operation.

Therefore, according to the engine boost pressure control device of the present invention,
If the transmission is shifted up while the engine is accelerating, the maximum boost pressure is then corrected to be higher than the set value for a predetermined period of time, so the driving force caused by the transmission upshift is controlled to be higher than the set value. The decrease in engine power is compensated for by the increase in engine output due to the increase in boost pressure, resulting in the effect that the acceleration performance of the engine is maintained at a high level.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a boost pressure control device for an engine according to the present invention, FIG. 2 is a system diagram of an engine equipped with a boost pressure control device according to an embodiment of the present invention, and FIGS. 3 to 5 2 is a control flowchart in the boost pressure control device of FIG. 2, and FIGS. 6(A) and 6(B) are characteristic diagrams of the shift-up correction coefficient and correction time. ! ...Fist engine 2 ...Intake passage 3 ...Exhaust passage 4 ...Supercharger 5 ...Throttle valve 6 ...Bypass passage 7 ... ... Control valve 8 ... Actuator 10 ... Supercharging air introduction passage It ... Atmospheric pressure introduction passage 12.13 ... Solenoid valve 14 ... Control +6...Rotation speed sensor +7...Oil level sensor 18...Oil temperature sensor 19...Supercharging pressure sensor 20...Water temperature sensor 21... ...Intake temperature sensor 22...Throttle opening sensor/...Engine 2...Intake passage 3...Exhaust passage Hiroshi...Supercharger position... ... Throttle valve B... Bypass passage 7... Suppression valve and... Actuator 10... Supercharging transmission introduction passage//... Atmospheric pressure introduction passage/ 2.73...t valve/q...controller/Otsu...rotation speed sensor/7...oil level sensor/r...oil temperature sensor/9... Boost pressure sensor〇...Mizuhata sensor 2/...Intake temperature sensor

Claims (1)

[Claims] 1. A supercharger installed in the intake passage for intake supercharging,
maximum supercharging pressure control means for controlling the maximum supercharging pressure downstream of the supercharger to a set value; and shift-up detection means during acceleration for detecting a shift-up operation of the transmission during acceleration;
During acceleration, the maximum supercharging pressure is corrected so as to set the maximum supercharging pressure to a value higher than the set value for a predetermined period of time during a shift-up operation of the transmission during acceleration in response to the output of the shift-up detecting means during acceleration. An engine supercharging pressure control device comprising shift-up correction means.