JPH0230935A - Control device of engine for vehicle with automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the deterioration of operability by changing the correction quantity at the time of correction when the octane value of fuel is low smaller than when it is high in an engine correcting the engine control quantity to decrease the engine output at the time of a speed change. CONSTITUTION:A fuel detecting means D detecting the octane value of fuel is provided in an engine A provided with a speed change control quantity correcting means C correcting the engine control quantity to decrease the engine output at the time of the speed change of an automatic transmission B end using the high-octane fuel with a high octane value and the regular fuel with a low octane value. The output signal of the fuel detecting means D is inputted to a correction quantity changing means E, the correction quantity of the speed change control quantity correcting means C is changed smaller when the detected octane value of the fuel is low than when it is high. The speed change shock and the deterioration of operability due to the excessive reduction of the engine output are prevented regardless of the difference in the octane value of fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an engine for a vehicle with an automatic transmission.

(Prior Art) In recent vehicles, many vehicles have automatic transmissions. This automatic transmission generally includes a torque converter and a planetary gear type multi-speed gear mechanism. By appropriately engaging or releasing a plurality of friction elements such as brakes and clutches attached to the multi-stage gear mechanism, the power transmission path of the multi-stage gear mechanism is switched, that is, the gears are changed. .

In such a vehicle with an automatic transmission, the problem is how to reduce shock during gear shifting, that is, how to reduce gear shifting shock. It is known that in order to reduce this shift shock, it is sufficient to slowly switch the operation of the friction elements described above. However, switching the operation of the friction element too slowly increases the shift time and causes problems in terms of ensuring the durability of the friction element - especially in modern vehicles equipped with high-output engines. However, there is a limit to slow switching of the friction element due to its durability.

1. From the above point of view, no proposals have been made in which the engine output is reduced during gear shifting. In other words, Japanese Patent Publication No. 5
8-180763 discloses a system in which the ignition timing is temporarily retarded during gear shifting to reduce engine output.

-・ノ)゛, Many modern engines are designed to compensate for differences in fuel octane numbers and increase engine output as much as possible according to this octane number.1 For example, octane When using high octane fuel, the ignition timing is advanced to improve engine output compared to when using low octane regular fuel.

(Means and effects for solving the problem) As mentioned in 1j11, in an engine that can use both high-performance fuel and regular fuel, the engine output is reduced to a low drive when shifting the automatic transmission. In this case, the problem is how to set the correction amount of the engine control meter for this reduction in engine output. .

To explain this point in detail, when using low fuel, the engine output becomes harsh, so in order to prevent gear shift shock, the correction amount for reducing the engine output is 3. On the other hand, when using regular fuel, the engine output will be smaller, so in order to prevent gear shift shock, the compensation required to reduce the engine output is small. That would be enough. Therefore, if the correction I for low engine power output is set at 14 degrees assuming the use of high-power fuel, L2
G: When J-lar fuel is used, the engine output will be excessively reduced during gear shifting, resulting in deterioration of drivability. On the contrary, if the correction for low enmoji output during gear shifting is set on the premise that I/Gular fuel is used, it will be sufficient to prevent shift shifting when using I/G fuel. This becomes difficult.

Therefore, an object of the present invention is to reduce the engine output at the time of gear shifting, and while dealing with the difference in fuel octane number, it also satisfies both the requirements of gear shift shock prevention 1F and ensuring good drivability. It is an object of the present invention to provide a control device for an engine for a vehicle equipped with an automatic transmission that satisfies the needs.

(Means and operations for solving the problems) In order to achieve the objects described in 1j11, the present invention changes the degree of reduction in engine output during gear shifting in accordance with the octane number of the fuel.

Specifically, as shown in FIG. 10, in a vehicle with an automatic transmission in which the output of the engine is transmitted to the drive wheels via the automatic transmission.

A shift control 1n correction means for correcting an engine control amount so as to reduce engine output when shifting an automatic transmission; and a fuel detection means for detecting an octane number of fuel.

The present invention is configured to include a correction change means for making the amount of correction by the shift control 1 correction means smaller when the octane number of the fuel is low than when it is high.

As described above, in the present invention, the degree of reduction in engine output during gear shifting is increased when a fuel with a high octane number is used, and is decreased when a fuel with a low octane number is used.

Thereby, regardless of the difference in the octane number of the fuel, it is possible to sufficiently prevent shift shock while ensuring good drivability.

(Example) Examples of the present invention will be described below based on the attached drawings.

In FIG. 1, reference numeral 1 denotes an automatic engine, and the output of the engine 1 is transmitted via an automatic transmission 2 to drive wheels (not shown). In the embodiment, the automatic transmission 2 is composed of a torque converter 3 with a lock-up clutch and a planetary type multi-speed float mechanism 4, and the multi-speed float mechanism 4 is designed for four forward speeds.

As is known, the multi-speed shifting mechanism 4 changes gears in a range of four gears from I speed to 4th speed in accordance with the engagement and release of a plurality of friction elements such as a clutch and a brake cage. Ru. Each of these friction elements is hydraulically actuated, and by appropriately turning on or off a plurality of solenoids 5 incorporated in the hydraulic circuit, a speed change is performed in the range of 1st to 4th speeds mentioned above. . Further, the lock-up clutch is engaged and engaged by turning on and off a solenoid 6 incorporated in the hydraulic circuit for the lock-up clutch.

Since the above is well known, a detailed explanation of 84-5 will be omitted hereafter.

The ignition system of the engine 1 includes an ignition coil 8, in addition to a spark plug 7 provided for each cylinder. Equipped with a destroyer 9 and an igniter IO. That is, when the igniter 10 interrupts the primary current (low-voltage current from the battery 11) of the ignition coil 8 at a predetermined ignition timing, a high-voltage secondary current is generated in the ignition coil 8, and this secondary current is passed through the distributor 9. The spark is then supplied to a predetermined spark plug 7 and ignited.

The solenoid 5.6 is a control unit LJ for shifting.
Controlled by l. Further, the ignition timing is controlled by a control unit J2, and signals from each sensor or switch 21 to 24 are input to a speed change control unit U1 that controls a solenoid 5.6. The sensor 21 detects the throttle opening, that is, the engine load. The sensor 22 detects vehicle speed. The switch 23 is a water temperature switch that turns on when the engine cooling water temperature reaches a predetermined value (72° C. in the embodiment) or higher. The switch 24 detects the range position (for example, 1, N, R, D, 2.1) of the automatic transmission 4. On the other hand, signals from each sensor 25 to 28 are manually input to the control unit U2 that controls jg1 at the time of ignition4.This sensor 25 detects the throttle opening, and sensor 2) can be used as is. You can also do it. The sensor 26 detects the engine rotation speed. The sensor 27 detects the engine cooling water temperature in a continuously variable manner. The sensor 28 detects knocking.

The one-car control units IJI and [2] can each be constructed using a digital or analog type controller, and in the embodiment, are constructed using a microcomputer. Therefore, both control units U1 and U2 are basically CPU, ROM, R
In addition to the AM and 'CLOCK, it also has a human output interface and a Δ/D converter or D/A converter, but since these are known configurations when using a micro combiator, detailed explanations thereof will be omitted. do.

Next, each control unit U1. The outline of the control by U2 and the relationship between both Ul and U2 will be explained.

First, the shift control unit U1 controls the solenoid 5 based on the shift characteristics and lockup characteristics shown in FIG.
．． 6 is turned ON and OFF to control gear shifting and lock-up. Of course, the speed change range etc. are changed depending on the range position detected by the switch 24. When changing gears, in principle, a retardation request signal M for reducing the engine output (retarding the ignition timing in the embodiment) is output to the control unit U2 for a predetermined period of time. However, when the cooling water temperature is lower than 72° C., the retardation request signal M is not outputted because retardation will impair engine drivability. There are two other cases in which the retardation request signal M is not output: when the throttle opening is smaller than 50% (engine output is small and gear shift shock is virtually no problem), and when downshifting. is set.

On the other hand, the control of the ignition timing by the control unit U2 is as follows. First, engine speed and engine load (
The basic ignition timing IB is determined based on the throttle opening (throttle opening). At this time, the legal basic ignition time! ill I
l'l corresponds to high octane fuel (
It is assumed that engine 1 is used with either high-octane fuel or low-octane fuel).

Second, when knocking is detected by the knock sensor 28, the basic ignition timing IB is retarded until knocking no longer occurs (retard amount IN due to knocking).

Third, it is determined whether the fuel currently being used is high octane fuel or low octane fuel. This determination is made by checking whether the retardation amount IN due to knocking is north of a predetermined value (7° in the embodiment). When it is determined that the fuel is low octane fuel, the ignition timing is uniformly retarded by IR (10' in the embodiment).

Fourthly, as mentioned above, when receiving a retardation request signal for shifting from the shifting control unit Ul, as a general rule,
As shown in FIG. 3, the ignition timing is uniformly retarded by IM (10° in the embodiment). However, even if the retardation request signal M is received, the retardation in the gear shift is not performed in the following cases (1) to (2) (IM20).

■When the cooling water temperature detected by the water temperature sensor 27 is lower than 72°C.

Here, the water temperature is detected using separate controls or switches 23 and 27, and each control unit U1 determines whether or not to retard the ignition timing during gear shifting depending on the water temperature. , U2. This is to ensure reliability of control. Therefore, a decision as to whether or not to retard the ignition timing during gear shifting is made using either the control or the switches 23, 27 of either one of the control units U1. U
It can also be done with only 2.

(2) After a predetermined set time has elapsed after receiving the retardation request signal M.

This set time is set to correspond to the time required from the start to the end of the shift (it is set to be a time slightly before the end of the shift, and is 1 second in the embodiment). Therefore, the shift end signal is transmitted from the control unit U1 to the control unit U.
2, this shift end signal can be used instead of the above set time.

■When the retard angle i1N corresponding to knocking is large (4° or more in the embodiment). This is because the engine output is considerably reduced due to the large IN, and further retarding the ignition timing is not preferable in terms of ensuring good drivability of the engine 1.

■When the fuel currently being used is low octane fuel.

This is because when using low-octane fuel, the engine output is originally much lower than when using high-octane fuel, so while gear shift shock is virtually no problem, further retardation of the engine l This is because it is undesirable to ensure good drivability.

In addition, Fig. 3 shows the case where the ignition timing is retarded when using high-performance fuel, and the broken line shows the torque change without retardation, and the solid line shows the case with retardation. It shows. When regular fuel is used, the engine output is as small as shown by the solid line in FIG. 3 even without retardation.

The aforementioned control unit 1-U1. The details of the control by U2 will be explained with reference to the flowcharts of FIGS. 4 to 7. Note that in the following explanation, P or Q indicates a step.

'・Control' ・-Ll First, the system is initialized at PI, the signals from each sensor or switch 21 to 24 are input at P2, and then at P3, the retardation request signal M is being output during the current gear shift. It is determined whether or not there is. When the determination in P3 is NO, when all the determinations in P4 to P7 are YES, that is, the gear is being changed, the shift is up, the throttle opening is 50% or more, and the cooling water temperature is 72°C. When it is determined that P8
to move to. In this P8, the retard angle request signal M is output to the control unit U1.

At P9, a timer that counts the time since the retardation request signal M is output is counted up. And P
At lo, it is determined whether the count value of the timer has exceeded a set value (set time). When the determination at PIO is No, the process returns to P2, and the retard request signal M continues to be output to the control unit U1 for only the set time (YES at P3). Note that this set time can be set to the same value as the set time in the control unit Ul described above, or a slightly longer time than this. In this way, since the control unit Ul also limits the output time of the retardation request signal M, it is possible to reliably prevent a situation in which the engine output decreases due to erroneously continuing to output the retardation request signal M for a long time. be able to. When the PIO determines YES, the output of the retard request signal M is stopped at pH, and then the count value of the timer is cleared at PI2.

If the result of any of the determinations P4 to P7 is No, this means that the conditions for retarding the gear shift are not met, so the process directly shifts to pH.

Fortune 1 5th to 7th (1) Basics (Figure 5) First, the system is initialized in Ql, and after signals from sensors 25 to 28 are input in Q2, Q3
At , it is determined whether or not the engine is currently being started. When the determination in Q3 is YES, the ignition timing α for starting (generally determined using the water temperature as a parameter) is set as the final ignition timing rg in Q4.

Then, in Q5, this Ig is output to the above-mentioned igniter 10 (ignition is executed at the timing of Tg).

When the determination in Q3 is No, the basic ignition timing IQ corresponding to high octane fuel is determined in Q6 based on the engine speed and throttle opening (read from the map). After this, in Ql, it is determined whether the knock sensor 28 is normal. When the determination in Ql is YES, it is determined in Q8 whether or not the current operating state of the engine I is in a preset range (map) where knocking may occur. If YES in this Q8, Q9
~Ql+, as described later, calculates the retard angle l in response to knocking (IN setting), determines the type of fuel currently being used (octane number) (IR setting), and retards the gear shift. Determination of retard amount based on request signal M (
TM setting) is performed. After this, in Ql2, each correction ff1lN, lR
, TM are subtracted (retarded) from each other and set as the final ignition timing Tg. Then, the processing from Q12 onwards is performed.

When the determination in Q7 is No, it is difficult to detect knocking and determine the type of fuel using knocking. At this time, IN is uniformly determined to be 7° in Ql4, and IM is uniformly set to zero, and then the process moves to Ql2.

When the determination in Q8 is No, IN is set to zero in Q13, and then the process moves to Q12.

(2) Knocking control and fuel type determination (Figure 6) This control corresponds to Q9 and QIO in FIG.

First, in Q21, it is determined whether or not knocking is currently occurring. If YES in Q2+, the value obtained by adding the correction amount △I (for example, 1") per ignition timing cycle to the previous IN is set as the new I in Q22.
Set as N. After this, IN is l in Q23.
It is determined whether or not it has become larger than Oo. This Q2
If the determination in step 3 is No, the process directly proceeds to Q24, and if the determination in Q23 is YES, IN is set to the upper limit value 10° in Q25, and then the process proceeds to Q24.

In Q24, it is determined whether the flag FR is 1 or not.

This flag FR is set to 1 when the currently used fuel is low octane fuel.

If the determination in Q24 is YES, the control is immediately terminated. When the determination in Q24 is No, it is determined in Q26 whether IN is greater than 7°. If the determination in Q26 is YES, this means that the fuel currently being used is low octane fuel. At this time, Q
After setting IR to lOo in Q27, PR in Q28
Set to 1. Further, if the determination in Q26 is No, the control is terminated.

When the determination in Q2+ is No, a value obtained by subtracting a predetermined recovery amount ΔI from the previous IN is set as a new IN in Q29. After this, in the determination of Q30, it is determined whether IN is smaller than 0°. If the determination in Q30 is No, the process will proceed directly to 0.24 and the retard angle will proceed toward zero with no knocking (7,11 N), and if the determination in Q30 is YES, the IR will be set to zero. Then, the process moves to Q24 (IN return to zero is completed).

(3) Retard angle control during gear shifting (Fig. 7) This control corresponds to Qll in FIG.

First, in each determination of Q41-Q45, the water temperature is 72℃.
Thereafter, there is a retardation request signal M from the shift control unit Ul, and a predetermined period of time (
For example, 1 second) has not elapsed, the retardation amount IN according to knocking is not 4 degrees or more, and the flag FR is not 1 (when high octane fuel is used)
In Q46, the retard angle FIL I M during shifting is 10
' is set to '. Thereafter, in Q47, the retard control flag is set to 1 to indicate that the retard based on the retard request signal M is being executed.

11N, if the determination in Q42 is No, or if the determination in Q43 is YES, the process shifts to 0.48.

In Q48, it is determined whether the retard control flag FM is 1 or not. If the result of this Q48 is YES, Q
In step 49, a value obtained by subtracting the amount of return per ignition timing cycle (for example, 0.35°) from the previous IM is set as a new IM. After this, at Q50, I
It is determined whether M has become smaller than O. This Q
If the result of 50 is No, it will be returned to I.
M is gradually returned toward zero. When the determination in Q50 is YES, it means that the return of IM to zero has been completed, and the retard control flag FM is reset to O in Q51.

When the determination in Q41 is NO, and Q44, Q45
If any of the determinations is YES, in Q52 I
M is uniformly set to zero.

Figures 8 and 9 show other embodiments of the present invention. In this embodiment, even when low octane fuel is used, the ignition timing is retarded during gear shifting to reduce engine output, similar to when high octane fuel is used. However, as shown in Figure 8, when using low-octane fuel, the retard angle l (the widest retard angle view) during gear shifting is smaller than when using high-octane fuel. It is. More specifically, the retard amount is set to 6 degrees when low octane fuel is used, while it is set to 10 degrees when high octane fuel is used, as in the previous embodiment. Also, when using low octane fuel, the time for which the ignition timing is retarded is shorter than when using high octane fuel. Furthermore, in this embodiment, regardless of the octane number of the fuel, at the initial stage of retarding the ignition timing, the ignition timing is not retarded to the maximum value all at once, but is gradually retarded as in the case where the ignition timing is retarded. That's what I do.

More specifically, when using low octane fuel, the timing is retarded by △IMR for each control cycle (the same goes for recovery), and when using high octane fuel, it is retarded by △IM11 ( The same goes for return (△IMR<
△IMH). The time required to start returning to the original ignition timing after the maximum retardation is set is 0.7 seconds for low-octane fuel and 1.0 seconds for high-octane fuel after the gear shift command signal is output. By doing so, as a whole,
The ignition timing is retarded for a shorter period of time for low octane fuel than for high octane fuel.

A flowchart for carrying out the above control is shown in FIG. 9, and this FIG. 9 corresponds to that of FIG. 7 in the above embodiment.

In Fig. 9, the ignition timing retardation fI due to knocking
If N is 4 degrees or more (when the determination in Q61 is YES) or if the cooling water temperature is 72 degrees Celsius or less (when the determination in Q62 is No), in both cases, in Q80, the shift is performed in the same manner as in the above embodiment. The retard amount IM is set to 0°.

The determination in Q61 above is No, and the determination in Q62 is Y.
In the case of ES, it is determined in Q63 whether or not there is a retard angle request signal M. When the determination in Q63 is YES, it is determined in Q64 whether the flag FR is 1 or not. When the determination in Q64 is No, it means that high octane fuel is currently being used. At this time,
In Q65, it is determined whether one second or more has passed since the retardation request signal was output. With this Q65 determination, N
o, in Q66, △I is added to the previous retard amount IM.
The value obtained by adding MH is set as a new retard amount 1M. Thereafter, it is determined in Q67 whether the retard angle u TM has become 10 degrees or more, and if the determination in Q67 is No, the process directly proceeds to Q69 and the flag FM is set to 1. If the determination in Q67 is YES, the IM is set to lOo in Q68, and then the process moves to Q69.

On the other hand, when the determination in box 1 Q64 is YES, it means that low octane fuel is currently being used. At this time, Q
70, 0.7 after the retard request signal M is output.
It is determined whether or not more than a second has elapsed. When the determination in Q70 is NO, the processing in Q71 to Q73 is performed.
Since this processing corresponds to the processing of Q67 to Q69 described above, a redundant explanation thereof will be omitted. However, the retard amount added in Q71 is IMR for low octane fuel.

ii? If the determination in Q65 or Q70 of item j is YES, it is time to restore the retarded ignition timing. First, in Q74, it is determined whether the flag FM is 1 or not. If the determination in Q74 is YES, it means that the restoration of the ignition timing has not been completed, and in this case, it is determined in Q75 whether or not the flag FR is 1. If the determination in Q75 is No, this means that high octane fuel is being used, so in Q76, a predetermined return amount ΔIM)I is subtracted from the previous retard i4+M, and then the process moves to Q78. Also, the judgment of Q75 is YES.
When S, it means that low octane fuel is being used, so the predetermined return amount ΔTMR is subtracted from the previous retard amount IM in Q77, and then the process moves to Q78. In Q78,
It is determined whether the current retard angle ff11M has become smaller than 0°. If the determination in Q78 is No, the process returns directly. Further, when the determination of 0.78 is YES, it means that the restoration of the ignition timing has been completed, so the flag F)J is reset to O in Q79. And 0
．． After passing through 79, 0.7 unless the next gear shift is performed.
The determination in step 4 becomes No, and the process moves to Q and 80.

Note that when the determination in Q63 is No, the process also moves to Q74.

Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases.

(2) For 0.46, the retard amount TM at the time of shifting may be set as a value corresponding to the magnitude of the retard amount 1N corresponding to knocking, such as, for example, r1M=IO-IN.

(2) To reduce the engine output during gear shifting, in addition to adjusting the ignition timing, appropriate engine control variables such as (leaning) the air-fuel ratio and (reducing) the supercharging pressure can be used. Of course, for example, when the correction amount (decrease amount) for supercharging pressure becomes large, the ignition timing adjustment value at the time of gear shifting is reduced (or made zero), and so on. It is also possible to set the object to be controlled by the shift control amount correction means to be different from each other.

(2) Detection of the octane number of the fuel may be performed using a separate sensor for octane number detection.

However, since such sensors are quite expensive,
It is more advantageous to detect the octane number of the fuel by looking at the retardation of the ignition timing due to knocking as in the embodiment.

■The magnitude of the octane rating is detected in a continuously variable manner or in multiple stages of 3 or more, and the degree of engine output reduction during gear shifting (the size of the retard amount TM in the example) is detected in a continuously variable manner or in 3 or more stages. The change may be made in multiple stages.

(Effects of the Invention) As is clear from the above description, the present invention effectively suppresses both gear shift shock and deterioration in drivability due to excessive reduction in engine output, regardless of the difference in fuel octane number. Can defend against 1 hit.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing an example of shift characteristics and lock-up characteristics. FIG. 3 is a diagram showing how the ignition timing is retarded during gear shifting. 4 to 7 are flowcharts showing control examples of the present invention. FIGS. 8 and 9 show other embodiments of the present invention. FIG. 8 shows how the ignition timing is retarded, and FIG. 9 shows a flowchart. FIG. 1O is a block diagram showing the configuration of the present invention. 1: Engine 2: Automatic transmission 5: Solenoid (for speed change) 7: Spark plug lO: Igniter 28: Sensor (knocking - octane number) Ul: Control unit (for ignition timing control) U2: Control unit (for speed change control) No. Figure 1: Flute 3 Zu Ginmon Figure 6 Figure 7

Claims (1)

[Claims] (1) In a vehicle equipped with an automatic transmission in which engine output is transmitted to the drive wheels via an automatic transmission, when the automatic transmission shifts, the engine control amount is corrected to reduce the engine output. a control amount correction means; a fuel detection means for detecting the octane number of the fuel; and a correction amount change for making the correction amount by the shift control amount correction means smaller when the octane number of the fuel is low than when it is high. 1. A control device for an engine for a vehicle with an automatic transmission, comprising: