JPH01273736A - Kengine control device for vehicle with automatic transmission - Google Patents

Abstract

PURPOSE:To prevent drivability from deteriorating following an excessive decrease in an engine output by limiting a correction by a speed change time- control amount correcting means when a correction amount by a basic control amount correcting means is in a value of direction decreasing the engine output. CONSTITUTION:A speed change control unit U1 drives solenoids 5, 6 being based on the predetermined speed change characteristic and lockup characteristic, performing speed change and lockup controls while outputting a delay timing request signal M to a control unit U2 in the time of speed change only for a predetermined time. While the control unit U2, being based on an engine speed and a throttle opening, outputs to an ignitor 10 the basic ignition timing corresponding to high octane number fuel, performing the speed change time- delay timing in accordance with the delay timing request signal M, but when knocking is generated by a knocking sensor 28, because the delay timing control is performed in the time of low octane number fuel and low water temperature by water temperature sensors 23, 27, a correction by the delay timing request signal M is limited. Thus while preventing a speed change shock, deterioration of drivability by an excessive decrease in an output is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine control device 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 float type multi-speed gear mechanism. By appropriately engaging or releasing a plurality of frictional elements such as brakes and clutches attached to the multi-stage gear shift gear +lf mechanism, the power transmission path of the multi-stage gear shift south +1 mechanism is switched, that is, the gears are changed. ing.

On the other hand, for 1F vehicles with automatic transmissions, the problem is how to reduce the shock during gear shifting, that is, the gear shifting shock. In order to reduce this shift stain, it is known that the operation of the friction element described above may be performed slowly. However, if the friction-required operation switching is performed too slowly, the shift time becomes longer and there are problems in terms of ensuring the durability of the friction elements. Especially in recent heavy vehicles equipped with high-output engines,
Slowly switching the operation of the friction element 1) has its limits in terms of its durability. .

In view of the above, a system has been proposed in which the engine output is reduced during gear shifting. In other words, JP-A-58
Japanese Patent Application No. 80763 discloses a system in which the ignition timing is temporarily retarded during gear shifting to reduce engine output.

(Problems to be Solved by the Invention) Incidentally, engine control variables that affect ignition timing, air-fuel ratio, boost pressure, and engine output are generally corrected from various viewpoints. . For example, focusing on ignition timing, this ignition timing is generally determined as a basic ignition timing using engine speed and engine load as parameters. When knocking occurs, the basic ignition timing is retarded until knocking no longer occurs (correction of ignition timing due to knocking).

In this way, the engine control amount that affects the engine output is often corrected originally, so when the engine output is decreasing due to such correction, it is necessary to make a correction that further reduces the engine output when changing gears. If this is done, the engine output will drop excessively and drivability will deteriorate.

Therefore, an object of the present invention is to prevent an excessive drop in engine output during gear shifting, to prevent gear shift shock, and to ensure good drivability, assuming that the engine output is reduced during gear shifting. An object of the present invention is to provide an engine control device for a heavy vehicle equipped with an automatic transmission that can satisfy both of the following.

(Means and actions for solving the problem) In order to achieve the above-mentioned object, in the present invention, the engine control system has already compensated for the 1
[If it is, the engine output is low F during gear shifting.
Supplement 11: , so as to limit . Specifically, as shown in the block diagram in Figure 8, in a vehicle with an automatic transmission that transmits engine output to the drive wheels via an automatic transmission, engine control that affects engine output is performed. Basic control 1i1 supplementary 11: means for correcting M according to predetermined conditions.

At the time of gear shifting of an automatic transmission, a gear shift control t, l side city means for correcting the engine control 4; to reduce the engine output separately from the correction by the +Flf basic control M supplementary manual correction, and +jf basic control. When the correction amount by the control amount correction means is a value in the direction of lowering the engine output, the shift correction limiting means limits the correction by the 1γ1 shift control supplement 1′r1 means; .

With such a configuration, it is possible to prevent an excessive decrease in engine output and ensure good drivability, while also preventing shift shock. .

Note that the restriction on the reduction in engine output during gear shifting may be such that no correction itself is performed at all for this reduction in engine output (control during gear shifting (i)).

The amount of correction by the correction means may be zero), or the degree of reduction in engine output may be reduced (the amount of correction by the correction means may be made small).

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

・Soto - In FIG. 1, reference numeral 1 denotes a 1000-type engine, and the output of the engine 1 is transmitted to drive wheels (not shown) via an automatic transmission 2. In the embodiment, the automatic transmission 2 includes a torque converter 3 with a lock-up clutch and a freewheel. The multi-speed gear mechanism 4 is composed of an Ertun-type multi-speed gear mechanism 4, and the multi-speed gear mechanism 4 is designed for four forward speeds.

As is known, the multi-speed gear mechanism 4 is composed of Klads 1-,
Depending on the combination of engagement and disengagement of a plurality of frictional elements such as brakes, the gears are changed in a range of 4-) from 1st speed to 4th speed. Each of these friction elements is hydraulically operated and turns on a plurality of solenoids 5 incorporated in the oil 1F circuit as appropriate.
Alternatively, by turning it OFF, the gear shift is performed in the range of 1st to 4th speeds as described in 1-1. In addition, the solenoid 6 built into the hydraulic circuit for the lock-up clutch is turned ON and OFF.
By turning F, the lock-up clutch is engaged and engaged. Note that since the above is well known, further detailed explanation will be omitted.

The ignition system of the engine 1 includes an ignition coil 8, a destroyer 9, and an igniter 10 in addition to a spark plug 7 provided for each cylinder. That is, at a predetermined ignition timing, the primary current of the ignition coil 8 (
When the low-voltage current of the dispersion 11 is cut off, a high-voltage secondary current is generated in the ignition coil 8, and this secondary current is supplied to a predetermined spark plug 7 via the destroyer 9 to ignite it. 1゜njI solenoid 5 is a control unit 1- for speed change.
[Controlled by J I. Further, the ignition timing is controlled by the control unit U2.

Control unit Ut for shifting that controls solenoid 5.6
, signals from each sensor or switches 21 to 24 are input. The sensor 21 detects the throttle opening, that is, the engine load. sensor 22
is for detecting heavy speed. The switch 23 is a water temperature switch that is turned on when the engine cooling water temperature falls below a predetermined value (72° C. in the embodiment). The switch 24 selects a range position of the automatic transmission 4 (for example, P, N, It, D
, 2.1). On the other hand, signals from each of the sensors 25 to 28 are input to the control unit U2 that controls the ignition timing. This sensor 25 detects the throttle opening, and the sensor 21 can also be used as is. 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 U1 and U2 can each be constructed using a digital or analog computer, and in the embodiment, are constructed using a microcomputer. Therefore, both control units t
Jl and U2 are basically CPU and ROM, respectively.
, I<ΔM, CL, OCK, and an input/output interface as well as an A/D converter or a D/A converter, but since these are known configurations when using a microcomputer, we will not explain their details. Further explanation will be omitted.

Next, an overview of the control by each control unit U1 and [J2 and the relationship between both U1 and [J2] 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, as a general rule, the control unit jJ 2
A retardation request signal M for reducing engine output (retarding ignition timing in the embodiment) is output 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 significantly impair engine drivability. Also,
Other cases in which the retardation amount request signal M is not output are when the throttle opening is smaller than 50% (engine output is small and shift shock is actually not a problem), and when downshifting. It is set.

On the other hand, the control of the ignition timing by the control unit U2 is as follows. First, the basic ignition timing IB is determined based on the engine speed and engine load (throttle opening).
Determine. The basic ignition timing IB determined at this time is
It is assumed that the engine is compatible with high octane fuel (assuming that the engine l 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 1B is retarded until knocking no longer occurs (amount of retardation due to knocking [N).

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 1N due to knocking has exceeded 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 U1, as a general rule,
As shown in FIG. 3, the ignition timing is uniformly retarded by IM (!0° in the embodiment). However, even if the retardation request signal M is received, in the following cases (1) to (2), no retardation is performed in the gear shift (IM=0).

(2) 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. , LJ2. This is to ensure reliability of control. Therefore, the decision as to whether or not to retard the ignition timing during gear shifting is made using the control or switch 23.27.
one of the control units U1,
This can also be done using only LJ2.

(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 of the shift to the end of the shift r (it is set to be a time slightly lower than the shift line r+iJ, and is 1 second in the embodiment). Therefore, when the control unit tJ1 outputs the shift end signal to the control unit U2, this shift end signal can be used instead of the above set time.

■When the retardation amount I N corresponding to knocking is large (4° or more in the embodiment). This is 1. This is because since the engine output is considerably reduced due to the large IN, it is not preferable to further retard the ignition timing in order to ensure 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 the shift shock is not a problem, it is further delayed. This is because this is not preferable in terms of ensuring good drivability of the engine 1.

The details of the control by the control units [Jl and U2 described above 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.

'AjfU・J 41) First, the system is initialized at Pl, and the signals from each sensor or switch 21 to 24 are manually input at P2, and then at [)3, the retardation request signal M is being output during the current gear shift. It is determined whether or not. When the determination in P3 is NO, when all the determinations in P4 to P7 are YES, that is, it is during a gear change and an upshift.
Throttle opening is 50% or more and cooling water temperature is 7.
When it is determined that the temperature is 2° C. or higher, the process moves to P8. In this P8, the retardation request signal M is transmitted to the control unit LJ.
Output to 1.

At P9, the time elapsed after the retardation request signal M is output is counted up. Then, in PIO, it is determined whether the count value of the timer has exceeded a set value (set time). When the determination of this PIO is No, the process returns to I) 2, and the retard request signal M continues to be output to the control unit U1 for the set time (I) 3 becomes YES. ). Note that this set time can be set to the same value as the set time in the control unit U1 described in 11'' or a slightly longer time than this. In this way, since the output time of the retardation request signal M is limited in the control unit Ul as well, it is possible to reliably prevent the "it" situation in which the engine output decreases due to the retardation request signal M being erroneously output for a long period of time. Then, when the determination in step I) 10 is YES, the output of the retard request signal M is stopped at pH, and then the count value of the above-mentioned timer is cleared at PI3.

11", if any of the determinations from P4 to P7 is No,
5 because the conditions for retarding the gear shift are not met.
Shift directly to pH.

-1 曾]1. j:・1'・J5~・LZT (11 basics (Fig. 5) First, in Ql, system initialization is performed. In Q2, signals from sensors 25 to 28 are input manually, and then Q
In step 3, it is determined whether the engine is currently being started. When the determination in Q3 is Y/S, the ignition timing a for starting (generally determined using the water temperature as a parameter) is set as the final ignition timing 1g in Q4. Then, in Q5, this Ig is output from the above-mentioned igniter lOl\ (ignition executed at the timing of Ig) 6 If the determination in Q3 is NO, in Q6, based on the engine speed and throttle opening, A basic ignition timing I8 corresponding to high octane fuel is determined (read from map). After this, in Ql, it is determined whether the knock sensor 28 is normal. If the determination of Ql is YIES, the current engine l is determined in Q8.
It is determined whether the operating state of the engine is in a preset area (map) where knocking may occur. If the judgment of Q8 is YES,
As described later in each of Q9 to Qll,
Calculating the amount of retardation according to knocking (IN setting), determining the type of fuel currently being used (octane number) (IH
), Retard M based on Retard Requirement No. 473 M when shifting
A determination (IM setting) is made. After this, in Ql2, each correction amount IN, from the formula shown here, that is, IB,
The values obtained by subtracting (retarding) In and 1M are set as the final ignition timing 1g. And Q12
Subsequent processing is performed.

When the determination in Q7 of 1111 is NO, it is difficult to detect knocking and determine the type of fuel using knocking. At this time, after uniformly determining IN to 7° in Ql4 and uniformly setting IM to zero,
Move to Ql2.

If the determination in Q8 of 11i1 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 the determination in Q21 is YES, the ignition timing is set to the previous IN in Q22! Correction amount Δ1 per cycle (for example, l.

) is newly set as IN.

After this, it is determined in Q23 whether IN has become larger than 10". If the determination in Q23 is No, the process directly proceeds to Q24, and the determination in Q23 is YES.
In this case, IN is set to the upper limit value lO° in Q25, and then the process moves to Q24.

In Q24, it is determined whether the flag F''R is 1. 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 line r is used as is. 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 10" in 27, PR in Q28
Set to l. Furthermore, if the determination in Q26 is NO, the control is terminated.

[If No in t in Q21 of Section 111, 4+'l, which is obtained by subtracting the predetermined return amount Δ■ from 11'' IN, is set as a new IN at 0.29. After this, Q
At step 30, it is determined whether IN is smaller than 0°. If the result of this Q30 is No, continue to Q24.
If the determination in Q30 is YES, IR is set to zero and the process proceeds 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 to Q45, the water temperature is 72°C.
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 since the retardation request signal M was output, and the retardation m in response to knocking has occurred. When it is determined that I N is not 4 degrees or more and the flag FR is not 1 (when high octane fuel is used).

After the retard angle i111+4 during gear shifting is set to 10' in Q46, the retard control flag is set to 1 in Q47 to indicate that the retard angle is being executed based on the retard request signal M. Ru.

If the determination in Q42 is No, or if the determination in Q43 is YES, the process moves to Q48.

In Q48, it is determined whether the retard control flag FM is 1 or not. When the determination in Q48 is YES, a value obtained by subtracting the return voltage per ignition timing cycle (for example, 0.35°) from the previous IM is set as a new IM in Q49. After this, in Q50, it is determined whether IM has become smaller than O. If the determination in Q50 is NO, the process returns and the IM is gradually returned to zero. And Q50
If the determination is YES, it means that the return to zero of IM has been completed, and the retard control flag FM is reset to O in Q51.

l! 'J jWhen the judgment of Q41 is No, and Q4
4. If the determination of either Q45 is YES, Q52
IM is uniformly set to zero.

The L embodiment has been described above, but in Q46, the retard angle Pa I M during gear shifting is set as a value corresponding to the magnitude of the retard amount IN in response to knocking, for example, r1M=io-INJ. You can do it like this. In addition to adjusting the ignition timing, appropriate engine controls such as (leaning) the air-fuel ratio and (reducing) the supercharging pressure can be used to reduce the engine output during gear shifting. Of course, the control in the basic control amount correction means can be used, for example, when the boost pressure compensation +EFi (decreasing device) increases, the ignition timing retard device during gear shifting is made smaller (or zero). It is also possible to set the target and the target to be controlled by the shift control amount correction means as different from each other.

('9. Bright Effects) As is clear from the above description, the present invention can prevent gear shift shock and prevent deterioration in drivability due to excessive reduction in engine output. .

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing an example of shift characteristics and lock-a-tub characteristics. Figure 3 does not show how the ignition timing is retarded during gear shifting. 4 to 7 are flowcharts showing control examples of the present invention. FIG. 8 is a block diagram showing the configuration of the present invention. l: Engine 2: Automatic transmission 5: Solenoid (for speed change) 7: Spark plug 10: Igniter 28: Sensor (knocking) tJ 1: Control unit (for ignition timing control) U2: Control unit (for speed change control)

Claims (2)

[Claims] (1) In a vehicle with an automatic transmission that transmits engine output to the drive wheels via an automatic transmission, the basic control amount corrects the engine control amount that affects engine output according to predetermined conditions. correction means; a shift control amount correction means for correcting the engine control amount so as to reduce the engine output separately from the correction by the basic control amount correction means when shifting the automatic transmission; An engine for a vehicle with an automatic transmission, characterized in that the engine is equipped with a shift correction limiting means for limiting the correction by the shift control amount correction means when the correction amount is a value in the direction of reducing engine output. Control device. (2) In claim 1, the basic control amount correction means corrects the ignition timing in response to engine knocking, and the shift control amount correction means retards the ignition timing during a shift. and the shift correction limiting means causes the shift control amount correction means to retard the ignition timing when the amount of ignition timing retardation by the basic control amount correction means exceeds a predetermined value. What is prohibited.