JPH02173330A - Engine controller at vehicle with automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the worsening of an operation feeling at what changes and engine generation output at a speed shift process, by detecting a revolution number change rate on an automatic transmission input shaft side at the speed shift process, and setting the change time of the generation output of the engine according to its value. CONSTITUTION:At an engine controller for a vehicle with an automatic transmission, when it is detected by means of a speed shift start detecting means A that the automatic transmission is in the process of speed shifting, an arrangement is so made that the generation output of an engine is changed by means of an engine generation output changing means B, and as a result, a speed shift shock is lowered. In this instance, a change rate detecting means C which detects the change rate of a revolution number on the input shaft side of the automatic transmission at a speed shift process, is provided, and the change time of the engine generation output is arranged to be set by means of a time setting means D according to the revolution number change rate thus detected. As a result, a timing precision between a speed shift period and the change of the engine generation output is heightened, and the worsening of an operation feeling is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an engine control device for a vehicle with an automatic transmission, and more specifically, the present invention relates to an engine control device for a vehicle with an automatic transmission, and more specifically, it changes the output generated by the engine during a gear shift process in order to reduce shift shock. related to things.

(Prior Art and its Problems) Vehicles equipped with automatic transmissions have a built-in problem of torque shock that accompanies gear shifting, that is, gear shift shock. That is, during the gear shifting process, the inertia of the rotating members of the automatic transmission gives a temporary peak to the drive torque, and this temporal peak appears as a gear shifting shock. Therefore, in order to reduce the shift shock, it is sufficient to suppress the occurrence of the above-mentioned temporary peak of the drive torque.

Conventionally, a common method of reducing shift shock is to engage a friction element with the rotating member of the transmission to dissipate part of the energy held by the transmission as frictional heat, thereby reducing the proportion of energy flowing to the drive torque side. Efforts are being made to suppress this.

However, as engines are becoming more powerful these days, it is becoming increasingly difficult to balance the reliability of friction elements with shift shock. That is, the greater the output generated by the engine, the greater the amount of energy that must be dissipated as frictional heat, which poses a problem in the durability of the friction element.

Japanese Unexamined Patent Publication No. 59-97350 discloses a technique for suppressing the temporary peak of drive torque that appears during the gear shifting process by adjusting the engine output itself. Although this has the advantage of reducing the load on the friction elements and making it easier to achieve both reliability of the friction elements and reduction of shift shock, there is no technique for adjusting the output generated by the engine to match the shift timing. f+kr is required. In other words, since the output of the engine is forcibly adjusted in order to suppress the temporal peak of drive l/lux that appears during the gear shift process, this forced adjustment continues even after the gear shift is completed. If this were done, the result would be contrary to Nagisa's intention and the driving feeling would deteriorate.

From this point of view, the above-mentioned publication discloses a method of detecting a period based on a rate of change in engine speed. That is, the shift period is found by focusing on the change in the rotational speed accompanying the start or end of the shift and evaluating the change in the rotational speed.

However, when using this method, there is a problem in that it is difficult to set a determination value for determining the shift path γ timing. This point will be explained in detail below.

For example, when considering a shift amplifier, the shift end point appears as a minimum point in the change in rotational speed. In other words, the rate of change in the rotational speed has a negative sign before the shift end point, and a positive sign after the shift end point. In the vicinity of the shift end point, the rate of change in rotational speed continues to have no value, that is, to remain at approximately zero. Therefore, in order to detect the shift end point, it is necessary to set an extremely small value as the determination value.

Of course, in this case, the detection accuracy of the rotational speed also becomes a problem. In other words, if the rotation speed detection accuracy is poor, a rate of change due to the rotation speed detection error will appear, making it difficult to distinguish between the rate of change based on this detection error and the rate of change based on the end of gear shifting, resulting in malfunctions. It becomes easier to wake up.

Another possible method is to use a timer. In other words, if changes in the output of the engine are supervised by time, the above-mentioned malfunctions can be avoided in a simple manner. However, the time required for shifting varies depending on the responsiveness of the oil and is not necessarily constant. For this reason, when timer supervision is used, it becomes difficult to make the change and stop of the engine generated output coincide with the end of the shift.

Therefore, the object of the present invention is to control the engine in a vehicle with an automatic transmission by increasing the timing viscosity between the shift period and the change in the engine output when the change in the engine output is supervised by time. The goal is to provide equipment.

(Means and effects for solving the problem) The present invention is based on the point that there is a constant relationship between the time required for shifting and the rate of change of engine speed during the shifting process. ] It is structured as follows. In other words, if the rate of change in the engine speed is large during the gear shifting process, the gear shifting ends abruptly. On the other hand, when the rate of change in the rotational speed is small, the gear shift ends late.

Therefore, by looking at the rate of change in the engine speed during the shift process, it is possible to predict the time required to reach the shift path r from this rate of change. Based on this idea, the present invention, as shown in FIG. 1, is equipped with an automatic transmission, and when the automatic transmission is in the process of changing gears, the output generated by the engine is changed. The engine control device for a vehicle with an automatic transmission is provided with a rate of change detection means for detecting a rate of change in rotational speed on the input shaft side of the automatic transmission during a gear shifting process, and a signal from the rate of change detection means. and time setting means for setting a change time of the output generated by the engine according to the rate of change of the rotational speed.

(Example) Hereinafter, an example of the present invention will be described based on the attached drawings.

In FIG. 2, reference numeral 1 denotes an Otto-type engine body of a cycle reciprocating type, and as is known, this engine body 1 has a - bank 2 and another bank 3 arranged in a V-shape with each other. It is a so-called V-type engine, and three cylinders 4 are provided in each of the negative bank 2 and the other bank 3, making it a V-type six-cylinder engine with six cylinders in total.

Each cylinder 4 has a combustion chamber 6 defined by a piston 5, a spark plug (not shown) is disposed in the combustion chamber 6, and an intake port 7 and an exhaust port 8 are opened. The ports 7.8 are opened and closed by the intake valve 9 or the exhaust valve 10 at known timings in synchronization with an engine output shaft (not shown).

The intake ports 7 are opened at opposite sides of the negative bank 2 and the other bank 3, and each intake port 7 is provided with a fuel injection valve 11. The independent intake passage 12 connected to each intake port 7 has a passage shape that extends in a direction away from the side surface of each bank 2.3 and then reverses approximately 180 degrees.

That is, in the V-bank central space 13 sandwiched between the bank 2 and the other bank 3, long independent intake pipes 14 forming the independent intake passage 12 are arranged to intersect with each other. . A surge tank 15 forming an intake expansion chamber is disposed in the V-bank central space 13, and the independent intake pipe 14 is connected to the surge tank 15. In addition, the intake passage 1 on the upstream side of the surge tank 15
6, from the upstream side to the downstream side, an air cleaner 17, an intake temperature sensor 18 that detects the intake air temperature, an air flow meter 19 that detects the amount of intake air, a throttle valve 20, and the opening degree of the throttle valve 20. A throttle position sensor 21 is provided to detect.

The internal space of the surge tank 15 is divided into two chambers by a partition wall 22, an expansion chamber 15a for the negative bank 2 and an expansion chamber 15b for the other bank 3. Communication hole 22 between chamber 15a and other enlarged chamber 15b
A is provided in the communication hole 22a, and an on-off valve 24 that is opened and closed by a diaphragm 23 as an actuator is provided in the communication hole 22a. This on-off valve 24 forms intake resonance tuning conditions according to the engine speed, as will be described later. In addition, the above-mentioned - enlargement chamber 15a and other enlargement chambers 1
5b communicates with the upstream intake passage 16 via a bypass passage 25 that bypasses the throttle valve 20, and a solenoid valve 26 is disposed in this bypass passage 25, and the opening degree of the solenoid valve 26 is controlled. By adjusting this, the engine speed during idling operation can be adjusted.

On the other hand, in the exhaust passage 28 connected to the exhaust port 8, from the upstream side to the downstream side, an air-fuel ratio sensor 29, a three-way catalyst 30 as an exhaust gas purification device, and a temperature of the three-way catalyst 30 are detected. A so-called caterpillar sensor 31 is arranged. The air-fuel ratio sensor 29 is a so-called lean sensor that outputs a signal corresponding to the air-fuel ratio (oxygen surplus rate) of exhaust gas (there is already a sensor that outputs a signal approximately proportional to the air-fuel ratio). has been put into practical use).

An automatic transmission 32 is connected to the output shaft of the engine main body 1, and a torque converter 33 is interposed between the engine output shaft and the automatic transmission 32 here. The automatic transmission 32 is composed of a multi-stage transmission consisting of a planetary gear mechanism and a hydraulic control circuit (not shown), and its gear shifting operation is based on the on/off combination of a plurality of solenoid valves 34. This is done by appropriately operating friction elements such as clutches and brakes. A lock-up clutch (not shown) is attached to the torque converter 33, and this lock-up clutch is controlled based on whether a solenoid valve 35 is turned on or off.

In FIG. 2, reference numerals 40 and 41 indicate a control unit constituted by a microcomputer, and as is known, the CPU
, RAM, and ROM, the - control unit 40 is used for engine control, and the other control unit 41 is used for speed change control of the automatic transmission 32 (+=including lock-up control of the torque converter 33). ing.

The signals from each of the sensors 18, 19, 21, 29, 31 are input to the engine control unit 40, which also includes sensors 42
Signals from ~49 are input. The sensor 42 is a stop lamp switch attached to the precipetal 51. Further, the sensor 44 is attached to the distributor 54 and detects the crank angle, that is, the engine rotation speed, and the sensor 49 detects the engine cooling water temperature. The engine control unit 40 outputs control signals to the fuel injection valve 11, the solenoid valve 26, and the igniter 53. For example, when a predetermined ignition timing signal is output from the control unit 40 to the igniter 53, the primary current of the ignition coil 54 is cut off and a high voltage is generated on its secondary side. Destripitor 52
It is supplied to a spark plug (not shown) via.

Signals from sensors 60 to 62 are input to the surface speed change control unit 41. The sensor 60 is the accelerator pedal 6
4 is a kick-down switch coated with a sensor 6.
1 is an inhibitor switch attached to the select lever unit 65.

The engine control unit 40 performs ignition timing control, air-fuel ratio control, idle rotation speed control, and intake inertia supercharging control. For example, in controlling the air-fuel ratio, as in the past, the basic fuel injection amount is determined based on the intake air amount and the engine speed, and this basic fuel injection amount is determined based on the intake air temperature, engine cooling water temperature, acceleration/deceleration, etc. Correct,
While receiving the output from the air-fuel ratio sensor 29, feedback control is performed to achieve a desired air-fuel ratio.

In addition, the intake inertial supercharging control is to open and close the opening/closing valve 24 according to the engine speed, thereby creating a resonance synchronization condition between a low-speed operating range and a high-speed operating range. That is, the tire flam 23 as an actuator of the on-off valve 24 uses the intake negative pressure as its operating source, and controls a renoid valve (not shown) attached to the air guide pipe 63 to control the tire flam 23 in the low rotation range. In this case, the on-off valve 22 is closed, and in the high rotation range, the on-off valve 22 is opened. Other ignition timing control and idle speed control are basically the same as before, so
A detailed explanation thereof will be omitted, and only parts related to the present invention will be described later.

The gear change control unit 41 basically selects a predetermined gear stage based on the control map shown in FIG. 3 in accordance with the throttle/nottle opening and the vehicle speed. In the figure, solid lines u1 to u3 indicate shift change lines for upshifts, and broken lines d1 to d3 indicate shift change lines for downshifts. More specifically, the upshift switching line u1 is for shifting from 1st to 2nd gear, U2 is for shifting from 2nd to 3rd gear, and U3 is for shifting from 3rd to 4th gear. belongs to. The downshift switching line d1 is for shifting from 2nd speed to 1st speed, d2 is for shifting from 3rd speed to 2nd speed, and d3 is for shifting from 4th speed to 3rd speed. The control unit 41 also controls the torque converter 33 based on the control map shown in FIG.
This long-amp control is the same as the switching lines u3 and d3 in the shift map (Fig. 3), except when the throttle opening is small, and the shift from 3rd gear to 4th gear is performed. upshift, 4th to 3rd gear
Mouth 1 in sync with the town shift to speed. turn on the backup,
Off control is performed.

In addition, during the above-mentioned amplifier shift or downshift, the ignition timing is changed during the gear shifting operation to change the torque generated by the engine, thereby reducing gear shifting. . In this embodiment, the ignition timing is changed only during upshifts, and therefore, during the gear shifting process, the ignition timing is retarded by a predetermined amount to lower the torque generated by the engine. ing. The ignition timing is changed by detecting the rate of change in the engine speed Nt, that is, the shift start point.
Retard control is performed only after a predetermined time tl from the detected shift start point. This prevents the above-mentioned retard control from being started due to a detection error in the engine speed Nt, etc., in which it is determined that a gear shift has started even though it has not actually started. This is to prevent this, and for this reason, if the engine speed Nt increases during the predetermined time t1, the start of the retard control is prohibited.

On the other hand, the end of the retard control is managed by a timer Te, and the set time of the timer Te is adjusted as appropriate in accordance with the rate of change DNt of the engine speed Nt during the gear shifting process.

Based on the above-mentioned premise, a detailed explanation will be given based on the flowcharts from FIG. 5 onwards.

FIG. 5 shows the details of ignition timing control.

The ignition timing is determined by adding, to the basic ignition timing IB, correction amounts Ic such as water temperature correction, intake temperature correction, acceleration correction, etc., and retardation correction I ret associated with gear shifting (see step S6). . Therefore, first in step S1, the intake air amount, engine rotational speed, etc. are detected, and in the next step S2, the basic ignition timing IB is calculated. The correction amount Ic is determined in step S3, and then in step S4 it is determined whether the flag F is set. As will be described later, this flag F indicates whether or not retard control is required during gear shifting. When flag F=1, it is determined that retard control is necessary, and the process proceeds to step S5 to determine the amount of retard. A calculation of I ret is performed. In this embodiment, the retardation amount I ret is set to a predetermined constant value S. On the other hand, when this flag F is reset, the process moves from step S7 to step S8, and the retard amount I ret is gradually decreased until it reaches "01." When expressed over time, it becomes as shown in FIG.

FIG. 6 shows a routine for starting the retard angle control, that is, setting the flag F. First, in step SIO, it is determined whether flag F is set. Since the flag F is initially in the reset state (flag F=0), the answer is NO and the process proceeds to step Sll, where it is determined whether or not the shift has started. Here, the start of the shift is detected by assuming that the shift has started when the rate of change DNt of the engine speed Nt exceeds a predetermined negative value. In other words, to explain with reference to FIG. 8, suppose that a shift signal from 1st gear to 2nd gear is output across the upshift switching line u1 in FIG. 3 (8th point, point PI) . Then, when the gear shift actually starts after that, the engine rotational speed Nt should decrease, and it is determined that the gearshift has started by looking at this decrease in the rotational speed Nt. Therefore, point P2 in FIG. 8 is the shift start determination point. If the determination in step Sll is YES (speed change start), the process advances to step S12, where timer T1 is set. Then, in the next step S13, it is determined whether or not a predetermined time t1 has elapsed, and until the predetermined time t1 has elapsed, the process proceeds to step S14, where a change in the engine speed Nt is determined. Here, immediately after the shift actually starts, it must be in a deceleration state, and the fact that it is in an acceleration state or a constant speed state means that the shift start determination in step S11 above was an erroneous determination. There is no other way than that. Therefore, until the predetermined time t1 has elapsed, it is confirmed in this step S14 that the vehicle is in a deceleration state, and only after that is the flag F set (step S15). By setting this flag F, the ignition timing retard control is started. On the other hand, if it is determined in step S14 that the acceleration state is present, for example, step 31
6, the timer T1 is reset. In other words, the start of the ignition timing retard control is prohibited. In this way, after thoroughly confirming the start of gear shifting,
Since the ignition timing retard control is started for the first time, it is possible to reliably prevent a malfunction in which the retard control is started even though a shift has not actually started.

FIG. 7 shows a routine for resetting the flag F, that is, terminating the retard control. First, in step S20, it is determined whether flag F is set. Here, assuming that flag F is set in step S15, the answer is YES.
Proceeding to step S21, it is determined whether the torque down timer Te is in the set state. This timer Te
-1- defines the end of the retard control. Therefore, immediately after the flag F is set, the answer is No, and the process advances to step S22, where the I-lookdown timer Te is set. After the timer Te is set, the process moves from step S21 to step S23, where it is determined whether or not the point f shown in FIG. 8 has been passed j7. This point f is determined based on the engine rotation speed Ntf that is intermediate between the engine rotation speed Nta at the shift start point P2 and the engine rotation speed Ntb at the shift end point P4, and between this rotation speed Ntf and the actual rotation speed. This is determined by comparison with Nt. Incidentally, the engine rotation speed Ntb at the shift end point P4 is determined as follows.

Now, if the gear is to be shifted from 1st gear to 2nd gear, the rotational speed Nts at point e shown in FIG. It will be done. That is, it is calculated based on the following formula.

In this embodiment, the shift end point P4, that is, the point at which the flag F should be reset, is such that the retard amount Iret is gradually reduced to zero after the flag F is reset as described above. Regarding the relationship (step S7 in Fig. 5,
S8) It is necessary to reset the flag F at point P5 (C) shown in FIG. 8, which is before the shift end point P4.

The rotation speed Ntc of this point P5 can be determined by the following formula based on the rotation speed Nts of the point e.

Nt c=Nt 5-DNt f+ JN, t
Here, DNtf is the rate of change in the engine speed at point f. Further, ΔN is defined by the following formula.

ΔNtx = PemeDNtf σ; Coefficient And if the engine speed at point P3 (d) where flag F is set is Ntd, then the time Te from point P3 to point P5 can be found by the following formula. Become.

Based on the above considerations, when the "biped point f" is determined in step S24, the process proceeds to step S25, where the
After determining the rate of change DNt f of the engine speed at the point, in step 326, the time during which the 2-lag F should be set, that is, the above Te, is determined, and in the next step S27, from this set time Te to the point f. The set time Te is adjusted by subtracting the elapsed time. As a result, as shown in FIG. 8, when the rate of change DNtf is large, a short time is set as the time for setting the flag F. Conversely, as shown by the virtual line in the same figure,
When the rate of change DNtf is small, a long time is set as the time for setting the flag F.

After passing point f, the process advances to step S28, and after waiting for the set time adjusted in step S27 to elapse, the process advances to step S30. In this step S30, the flag F is reset. It is done.

By resetting this flag F, the retard control is canceled (FIG. 5, steps S7 and S8).

The above control can be expressed in a block diagram as shown in FIG. 9. In this figure, the basic ignition timing calculation section 70 corresponds to step S2 in FIG. Also, the final ignition timing calculation section 71
corresponds to step S6 in FIG.
2 corresponds to step S3 in FIG. Further, the retard start determination unit 73 corresponds to step 311 in FIG. 6, the timer TI activation unit 74 corresponds to step SI2 in FIG. 6, and the engine rotation speed deceleration determination unit 75 corresponds to step S1 in FIG.
Corresponds to 4. The comparator 76 corresponds to step SL3 in FIG. 6, and the flag F is set after a predetermined time t1 has elapsed since the timer T1 was started. In response to this flag F being set, the timer Te77 starts counting, and a predetermined retard amount Iret is set in the retard amount calculation section 82, and this retard amount Iret is equal to the final ignition timing. This will be reflected in the timing calculation. The time Te during which the flag F is set is calculated by the set time calculation section 80. This set time calculation section 80 corresponds to steps 326 and 327 in FIG. 7 above. And the northern time T
e is a comparator 7 corresponding to step S24 in FIG.
8, the above-mentioned point f is found, and the rate of change DNtf of the engine rotational speed at this point f is calculated by the rate of change calculating section 79.

The change rate calculating section 79 performs step S in FIG.
25.

Although the present invention has been described in detail above, the present invention is not limited thereto and includes the following modifications.

(1) In setting the retard control time Te, as shown in FIG. 10, a map may be created in advance according to the shift mode, and the time may be determined from this map. In this case, between the power mode that emphasizes output and the economy mode that emphasizes fuel efficiency, a shorter time is set in the economy mode because the engine output during gear shifting is smaller. Then, the mapped control time Te may be corrected depending on the magnitude of the rate of change in the engine speed during the gear shifting process.

(2) Instead of the rate of change in the engine speed, the retard control time Te may be adjusted based on the rate of change in the turbine speed of the torque converter 33.

(3) The ignition timing may be adjusted not only during upshifts but also during downshifts to prevent shift shock. Of course, even in this case, the ignition timing adjustment time may be appropriately adjusted as described above.

(Effects of the Invention) As is clear from the above description, according to the present invention, even though the change time of the engine generated output performed to prevent a shift shock is managed by a simple means called a timer, the shift period is It is possible to cancel the change in the engine output at the optimum time in response to the variation in the engine output.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the present invention. Figure 2 shows the overall system diagram of the system. Figure 3 is a map used for speed change control. Figure 4 is a map used for shift amplifier control. FIG. 5 to FIG. 7 are flowcharts showing an example of control. FIG. 8 is a timing chart showing control details of the embodiment. FIG. 9 is a functional block diagram of the embodiment. FIG. 10 is a map showing a modification of the engine output change time setting. 1: Engine body 32: Automatic transmission 33: Torque converter 44, engine rotation speed sensor 53: Igniter 62: Turbine rotation speed sensor DNt: Engine rotation speed Te: Torque down setting time interval L→■1 rotation speed sensor t- CD”=J→Director Shiihi

Claims (1)

[Claims] (1) An engine control device for a vehicle equipped with an automatic transmission, which is equipped with an automatic transmission and is configured to change the output generated by the engine when the automatic transmission is in the process of changing gears, comprising: an input to the automatic transmission during the process of changing gears; a rate-of-change detection means for detecting a rate of change in the rotational speed on the shaft side; and a time for receiving a signal from the rate-of-change detection means and setting a change time for the output generated by the engine according to the rate of change in the rotational speed. An engine control device for a vehicle with an automatic transmission, comprising: a setting means.