JPS60260749A - Speed change shock reducing device of car with automatic speed change gear - Google Patents

Abstract

PURPOSE:To obtain a sure speed change shock reducing effect by starting the control for lowering an engine output to lessen a speed change shock when the time change rate of an engine revolution number to above a preset valve and ending the control when it comes to below the preset value. CONSTITUTION:In case of controlling an ignition time control device 11 by means of a controller 16 to control an engine output and lessen a speed change chock caused by operation of an automatic speed change gear 6, the time change rate of an engine revolution number found from an output of a rev count sensor 23 is first detected. At the time of detecting a speed change command of the automatic speed change gear 6, if the above time change rate comes to above a preset value, it is regarded as the start of speed change operation and the ignition time control device 11 is controlled to correct the ignition time on the lag angle side, so that an engine output is lowered. After the start of speed change operation, if the time change rate comes to below the preset value, it is regarded as end of speed charge operation, so that the correction of the above ignition time to the lag angle side is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a shift shock reducing device for a vehicle equipped with an automatic transmission that is driven by power from an engine via the automatic transmission.

(Prior art) Automatic transmissions use internal friction elements (
Clutches, brakes, etc.) are selectively operated, and the optimum gear position (
Although the engine power is increased/decelerated to match the driving condition by automatically selecting the gear position (1 to 1), a shift shock occurs because the output shaft torque suddenly changes when changing gears. This shift shock occurs when changing from a low gear to a high gear, that is, when changing from 1st gear to 2nd gear (1→2 upshift), and from 2nd gear to 8th gear (2-→8 upshift). shift) or #! Shifting from 8th gear to 4th gear (8-→
4 upshifts), this becomes noticeable because these shifts are often performed during power-on driving with the engine's accelerator pedal depressed greatly.

For example, as shown in Fig. 10, when there is a shift command from 2nd speed to 8th speed at instant t, the corresponding friction element starts operating (shifting) at instant t2 after response delay ΔT0. The friction element then completes its operation (ends the gear shift) at an instant t8 after an operation delay ΔT2. And the effective gear ratio of the automatic transmission is ΔT
As the operation of the friction element progresses during the two-hour period, the gear ratio RL of the second speed (for example, 1,4) changes to the gear ratio RH of the eighth speed (for example, 1.0). Also, during this period, the input rotation speed N4 of the automatic transmission decreases in accordance with the change in the gear ratio between W4 time t2 and t8, and matches the output rotation speed No of the automatic transmission (the engine rotation speed also shows a similar tendency). Theoretically, the input torque Tj-(
(approximately the same as the engine output torque) is approximately inversely proportional to the above change in the input rotation speed Ni unless the engine throttle opening is changed, and the automatic transmission output is expressed by multiplying this torque by the effective gear ratio. Torque Tom remains approximately constant.

However, in reality, while the engine speed N decreases during the ΔT2 period, the engine inertia acts to prevent this decrease in rotation, and the inertia mode torque is stored in the input shaft of the automatic transmission, resulting in As a result, the output torque To has a change as shown by To' during the shift operation (during the ΔT2 period). As a result, during the ΔT8 period, a torque Tm that increases due to inertia is generated, which causes a shift shock.

Therefore, the applicant of the present application previously disclosed in Japanese Unexamined Patent Application Publication No. 58-207556 that based on the recognition of the fact (4) that the shift shock is caused by a sudden change in the transmission output shaft torque as described above, the engine output at this time is reduced. The proposed method is a technique to reduce sudden changes in transmission output shaft torque by retarding the ignition timing from normal to reduce gear shift shock.

The same publication also introduced the technical idea of matching the start timing of the ignition timing control with the actual shift start timing using timer control.

However, the response delay from the shift command that switches the shift valve to when the automatic transmission starts the actual shift, and the operation delay from the start of the shift to the end of the shift are caused by variations in the hydraulic system, wear and tear over time of friction elements, and operational delays. It varies depending on the oil temperature (viscosity), and with the above-mentioned timer control, the start time of ignition timing control cannot always match the actual shift start time, and the end time of ignition timing control also does not match the actual shift end time. Unable to match. If the start and end of ignition timing control are not synchronized with the start and end of gear shifting, not only will the intended effect of reducing shift shock not be achieved, but
Before or after shifting, a new deceleration shock occurs due to an unnecessary reduction in engine output, which greatly reduces the commercial value of the vehicle.

(Object of the Invention) The present invention is designed to reduce the speed at which the engine speed or the automatic transmission input speed starts to change suddenly at a larger rate of change than after the speed change command until the start of the speed change when the actual speed change starts. By determining the speed change rate, it is possible to determine whether or not the speed change has started. Also, when the speed change is completed, the rotation speed changes at a smaller rate than from the start of the speed change until the end of the speed change, which indicates that the speed change has ended. Based on the recognition of the fact that it is possible to say whether or not this is the case, the above-mentioned problem is solved by fully starting and ending the engine output reduction control for reducing shift shock at the shift start time and shift end time determined based on the above. With the goal.

By the way, in this case, if it becomes impossible to determine the end of the gear shift due to some kind of failure, there is a concern that the above-mentioned engine output reduction control will not be able to end, and the vehicle will be forced to drive at a constantly reduced engine output. The purpose of the invention is to make it possible to solve such troubles as well.

(Structure of the Invention) For the former purpose, as shown in FIG. a speed change rate detection means for detecting a time change rate of the speed; a shift command detection means for detecting a shift command of the automatic transmission; and a speed change command detection means for detecting a speed change command of the automatic transmission; a shift start timing determining means for detecting the shift start time and determining that the shift has started; an engine output reducing means for reducing the engine output to a value required for preventing shift shock from the shift start time; and a temporal change in the rotation speed after the shift start. The present invention is characterized in that it is provided with shift end timing determining means for detecting that the ratio becomes less than a set value, determining that the shift has ended, and stopping the operation of the engine output reducing means.

Moreover, for the latter purpose, the gear shift shock reducing device of the present invention has a second purpose.
As shown in the figure, in a vehicle that is driven by power from an engine via an automatic transmission, a rotation speed change rate detection means for detecting a time (?) rate of change in engine rotation speed or automatic transmission input rotation speed; a shift command detecting means for detecting a shift command of the automatic transmission; a shift start timing determining means for determining that a shift has started by detecting that the time rate of change in the rotational speed after the shift command has exceeded a set value; An engine output reducing means for reducing the engine output to a value required for preventing shift shock from the shift start time, and an engine output reducing means for reducing the engine output to a value required for preventing shift shock, and detecting that the time rate of change of the rotation speed becomes equal to or less than a set value after the shift start, and detecting that the shift is completed. a shift end time determining means for stopping the operation of the engine output reducing means; a timer for measuring the elapsed time from the shift command; and a timer for measuring the time elapsed since the shift command; The present invention is characterized in that it is provided with fail-safe means for stopping the operation of the engine output reducing means when the end timing determining means does not determine that the shift has ended.

(Example〕 Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 8 shows the entire system (8) of the gear shift shock reducing device of the present invention, in which 1 is the engine, 2 is its intake manifold, 8 is a 70-meter for measuring the engine intake air amount, 4 is an air cleaner, and 5 is an air cleaner. 6 is a converter housing that houses the torque converter of the automatic transmission; 6 is a transmission case that houses the power transmission gear train of the automatic transmission and various friction elements that determine its power transmission path; and 7 is a transmission case that selectively operates the various friction elements. 8 is a rear extension/valve body housing a shift control hydraulic circuit that determines the gear position.

The engine 1 is equipped with an IJ fuser 1 (Nice) for distributing high voltage to the spark plugs 9 of each cylinder in time with engine operation.
0, and this distributor applies the secondary side high voltage generated by intermittent primary current to the spark plugs 9 individually by the ignition timing control device 11 at predetermined timings determined by the ignition timing control signal S described later. to enable engine 1 to operate. Then, as the accelerator pedal 12 is depressed, the intake air amount of the engine 1 is increased, and the injector (
Fuel injection i: (not shown) is increased to increase output, and the output of the engine is inputted to a power transmission gear train in a transmission case 6 via a torque converter in a converter housing 5.

The automatic transmission uses a 1-2 shift valve 18, a 2-8 shift valve 14, and a 3-4 shift pulse 7-15 to automatically select an appropriate gear from 1st to 4th gear according to the vehicle running condition. The engine power is shifted at a gear ratio according to the gear position and transmitted to the drive wheels of the vehicle (not shown) to drive the vehicle.

In the present invention, the controller 1flK controls the ignition timing control device 11 to control the ignition timing of the engine l. For this purpose, the roller 16 is driven by the power supply +V, and the amount of depression of the accelerator pedal 12 (
Signal sTH' from throttle opening sensor 17 that detects engine load) Opens and closes according to the spool position of shift valves 13 to 15] -2 shift switch 18.2-8 shift switch 19.8-4 shift switch 2o Signal S111 "'28 * S84, signal SQ corresponding to the intake air amount from the flow meter 8 - tvM number S from the crank angle sensor 21 built in the distributor 10
o, calculation of the signal ST from the engine cooling water temperature sensor 22 that detects the engine cooling water temperature, and the signal SN from the engine rotation speed sensor 23 that detects the engine rotation speed (a sensor that detects the automatic transmission input rotation speed may also be used); It is assumed that the ignition timing control device 11 is controlled by the output (ignition timing control signal) S based on the result.

Note that the 1-2 shift switch 8 and the 2-3 shift switch 19 are used to downshift the spools of the 1-2 shift pulse 718 and the 2-8 shift valve 14, respectively, as described in, for example, Japanese Patent Application Laid-Open No. 56-127856. The 8-4 shift switch 2 shall be closed to output an L level signal when in the upshift position, and open to output an H level signal when in the upshift position.
Similarly, the spool of the 8-4 shift valve 5 is closed to output an L level signal when it is in the downshift position, and is opened to output an H level signal when it is in the upshift position. Thus, the shift signals S, 51228 and 884 have the combination of levels shown in the following table at each gear stage.

(11) Specifically, as shown in FIG. 4, the controller 16 includes a central processing unit (CPU) 24, a random access memory (RAM) 25, and a read-only memory (ROM) 26.
, an input interface circuit 27, an output interface circuit 28, a waveform shaping circuit 29, an A/D converter 80, a drive circuit 81, and a power supply circuit 82. The power supply circuit 82 receives the voltage of the power supply +V. 0PU24 with predetermined value
, RAM25, ROW 26, circuits 27 to 29.81
and the power converter 80 to enable them to be driven.

0PtJ14 executes the control program shown in FIG. 5 stored in the ROM 26 to perform normal ignition timing control () and ignition timing control (engine output reduction control for reducing shift shock) which is the object of the present invention. This control program is started when the engine is started by turning on the ignition switch, and is repeatedly executed in step 40 by a regular interrupt from a timer (not shown).First, in step 41, the shift signal s1.
It is determined whether or not there is a shift command based on whether there is a level change in 5fA8 or S,84, and if there is no shift command, the control proceeds to step 411. In this step 42, as will be described later, a shift flag G is set to O1 when a shift command is issued, set to 11 when a shift is started, and returned to 00 when a shift is completed.
Check out SFLG. Since the limit for which the shift command heat state continues after the shift is completed is 5GSFLG=00, the control proceeds to step 48 after passing through step 41.42 ft. Here, the control proceeds to step 48 for ignition timing retardation (engine output reduction) control which is the objective of the present invention. The retard amount θRIiT is set to O. Next step 4
4, in another routine (not shown), the throttle opening (signal 5TH), engine speed (signal SN), engine intake air amount (signal SQ), and engine cooling water temperature (signal S
Fuel injection pulse width (fuel supply amount) calculated based on T), etc.
At the same time, the normal ignition timing is read out from the table data in the ROM 26 based on the fuel injection pulse width and engine speed using a table lookup method. In the next step 45, this ignition timing is corrected in the retard direction by the retard amount θRET, and then the control is terminated in step 46. However, since θRET has been set to 0 in step 48, it is essentially the step 45. Ignition timing correction will not be performed. Therefore, the non-shifting ignition timing control signal S□ causes the ignition timing control device 11 to output the crank angle signal S. The ignition timing is controlled to be at the normal ignition timing, and the engine output is not reduced during non-shifting.

By the way, if it is determined in step 41 that there is a shift command,
Control proceeds to step 47, where the shift flag G
SFLGffi Set to 01 to correspond to the presence of a gear change command. In the next step 48, GSFLGt is checked, but since this has been set to Ol in step 47, the control advances to steps 44 and 46 while the shift has not started in step 49, and θRET = θRET in step 48.
0" is used to execute normal ignition timing control. Note that step 47 is executed only once when a shift command is issued, and thereafter step 41 selects step 42, but GSFLG is no longer 00. Then step 42 selects step 48.

49ilc step 50 is selected, and here the retard amount θ that causes a decrease in engine output to be eliminated in the sudden change numerator o' of the output torque To shown in FIG. 11 is determined by calculation ET or table lookup method, and the following After GSFLGffi is set to 11 in step 51 to indicate that the shift has started, control proceeds to steps 44 and 45. Thus, in step 45, the ignition timing is corrected to be delayed by θRET from the normal ignition timing determined in step 44, and the ignition timing correction signal (15) is sent.At the start of the shift, the ignition timing controller]l is set to the crank angle. It is possible to control the ignition timing to be delayed by θRET with respect to the signal So. Therefore, the engine output is reduced to T in FIG. It is possible to eliminate fluctuations in the output torque shown by ′,
The shift shock associated with this can be reduced.

This control after the start of the shift is performed as described above with GSFLG=11
41.4'a and 48, it is determined whether or not the shift has been completed. If the shift has not been completed, the control proceeds to steps 44 and 45, so that the ignition timing is delayed from normal by the retard amount θRET finally achieved in step 5o, and the period from the start of the shift to the end of the shift is as described above. Ignition timing control (engine output reduction control) for reducing shift shock is continuously executed.

When the gear shift is completed, step 52 is followed by step l1.
zl, 54 are selected in sequence, the retard amount θRET is set to 0 in step 58, and the shift fluff GS is set in step 54.
Return FLG to 00. Control then proceeds to step 44.45.
However, as described above, since θRET=0, normal ignition timing control is executed and no reduction in engine output occurs.

The above control will be briefly explained for the 2→8 upshift corresponding to FIG. 1.Then, as shown in FIG. 6, the ignition timing is delayed by .theta.RET from normal until the end of the water speed. This reduces engine output, so
The input torque Ti, as shown by the solid line, is lower than the conventional custom-made one shown by the imaginary line, and the output torque Tok can be kept almost constant without fluctuations To', and the torque due to inertial force also has no fluctuations as shown by the phantom line. This reduces gear shift shock.

In the above example, the ignition timing is delayed in order to reduce engine output to reduce shift shock, but in addition to or in place of this, it is also possible to reduce the amount of fuel supplied to the engine or increase the amount of exhaust gas recirculation. It is also possible to achieve the same objective by reducing the turbocharger supercharging pressure.

FIG. 7 shows another example of the control program, in which step 55 is added between steps 47 and 48, and step 4
Add step 56.5'7' before step 4. In step 55, that is, when there is a shift command, the timer T
Activate M1' and measure the elapsed time from the shift command. In step 56, it is determined whether or not this timer has exceeded a set time as shown, for example, at T8 in FIG. 6 (a set time that covers the time from the shift command to the end of the shift). TM, (If T8, control step 44.4
In order to proceed to step 5, ignition timing control similar to the example described above is executed. However, if TM□≧T8, control proceeds to step 57, where GSFLG' is reset to 00,
After clearing the timer TM0 and setting θRR to 1'''', control 7 advances to step 4141.45.

Therefore, since the shift is originally completed at TM, ≧T8, the ignition timing control for reducing the shift shock should have been completed, but due to a malfunction due to a failure or noise in the signal system, the shift is not performed in step 52. It is possible to prevent problems such as the ignition timing control for reducing shift shock being executed indefinitely, and even when the nuclear trouble occurs, the driver is not forced to drive with reduced engine output. .

FIG. 8 shows still another example of the control program, and in this example, in step 49, it is determined whether or not to start shifting. This determination is made based on whether or not the change has become negative, and the amount of change NE is shown in Fig. 9 for a 2 to 8 upshift. It can be determined that the shift has started.Also, in step 58 instead of step 52 in FIGS. 5 and 7, depending on whether or not the change i cage has turned positive, the shift can be determined from t8 at the end of the shift in FIG. Instant t2' slightly before
(19) If not, the control proceeds to steps 56, 44, and 45, and the ignition timing is delayed by θRET from normal as shown in FIG. A similar engine output reduction control for preventing shift shock is executed. In addition, Ne is Ne
It may be determined as #ΔHe = No −He.

At the instant t,' in FIG. 9, where it is determined in step 58 that NE ) 0, control passes to step 59, which replaces steps 58 and 54 in FIGS.
After setting IO to indicate that G'i instant sl has been reached, control passes to step 56°44.45. This GSFLG = 10 is not set on each side, so in this example, when checking this shift flag in steps 42 and 48, check whether GSFLG = 10. If it is determined that = 10, step 60 is selected and the retard amount θRKT (initial (20
) is the value determined in step 50, and from the second time onwards, the value updated in step 60] is updated by subtracting the predetermined value α from the value as the new retard amount. In the next step 61, this update delay amount θ
It is determined whether RET has reached 0 or not. If it has not reached 0, the control proceeds to step 56.44.45. If it has reached 0, θRET is set to 0 and GSFLG
After returning to 00, control proceeds to steps 56, 44, and 45.

Thus, in this example, the ignition timing is instantaneous 1 as shown in Figure 9.
, / Thereafter, the normal ignition timing is gradually controlled by α per 1 calculation cycle.

The reason for controlling the ignition timing in this way is actually the torque fluctuation T. This is because, as shown in FIG. 10, the curve does not become rectangular near t8 at the end of the shift, but is absorbed and reduced by the interference of the corresponding friction elements in the automatic transmission. In order to match the actual situation of such torque fluctuation T0', the ignition timing is changed to 1 instant as in this example. /If the engine output is gradually returned to the normal value, the resulting decrease in engine output will be the actual torque fluctuation T. ′, and the instant t,′
It is possible to eliminate the problem of a new deceleration shock occurring due to excessive reduction in engine output thereafter.

(Effects of the Invention) Thus, as described above, the gear shift shock reducing device of the present invention, when reducing engine output in order to reduce gear shift shock, controls the engine speed or automatic transmission input rotation speed by adjusting the rate of change over time to the set value. Since the configuration is configured to start when the shift is above the set value and end when the shift is below the set value, the response delay from the shift command to the start of the shift and the operation delay from the start of the shift to the end of the shift are caused by variations in the hydraulic system and friction elements over time. Even if changes occur due to wear or hydraulic oil temperature (viscosity), the start and end of the engine output reduction control can always be made to coincide with the shift start and end timings, and the desired shift shock reduction effect can be reliably achieved. At the same time, it is possible to prevent new deceleration shock from occurring due to the difference between the two timings.

In addition, since the system is configured to stop the engine output reduction control after the set time has elapsed from the shift command, even if it becomes impossible to determine the end of the shift due to a malfunction or the introduction of noise,
The engine output reduction control does not become impossible to stop, and troubles such as being forced to constantly drive with reduced engine output can be completely prevented.

[Brief explanation of the drawing]

1 and 2 are conceptual diagrams of the shift shock reducing device of the present invention, respectively. FIG. 8 is an overall system diagram showing an embodiment of the device of the present invention. FIG. 4 is a block diagram of the controller in the device. 5 is a flowchart showing the control program of the controller, FIG. 6 is an operation time chart by the device of the present invention, FIGS. 7 and 8 are flowcharts showing other examples of the control program, respectively, and FIG. 9 is the flowchart shown in FIG. Operation time chart according to the example, No. 10
The figure is a 1311 production time chart used to explain the cause of shift shock occurrence. 1... Engine 2... Intake manifold 8... Flow meter 4... Air cleaner 5... Converter housing 6... Transmission case 7... Valve body 8...
Rear extension 9... Spark plug IO... Distributor 11.
...Ignition timing control device]2...Accelerator pedal 13.
...1-2 shift valve 14...2-8 shift valve]5...8-4 shift valve 16...controller 17...throttle opening sensor 18...]-2 shift switch 19 ...2-8 shift switch 20...8-4 shift switch 2]...Crank angle sensor 22...Engine coolant temperature sensor 28...Engine speed sensor 24...Central processing unit 25... - Random access memory (24) 26... Read-only memory 27... Input interface circuit 28... Output interface circuit 29... Waveform shaping circuit 30 - A/D converter 81...
Drive circuit 82...Power supply circuit. Patent applicant Nissan Motor Co., Ltd.

Claims (1)

[Scope of Claims] In a vehicle that is driven by power from an engine via an automatic transmission, there is provided a rotation speed change rate detection means for detecting a time change rate of the engine rotation speed or the input rotation speed of the automatic transmission; a shift command detecting means for detecting a shift command of the machine; a shift start timing determining means for detecting that the time rate of change in the rotational speed after the shift command becomes equal to or higher than a set value and determining that the shift has started; An engine output reducing means for reducing the engine output to a value required to prevent shift shock from a timing, and detecting that the time rate of change of the rotation speed becomes less than a set value after the shift is started, and determining that the shift has ended. Shift shock reduction device for a vehicle equipped with an automatic transmission, characterized in that the device further comprises a shift end timing determining means for stopping the operation of the engine output reducing means. Shift shock reduction device for a vehicle equipped with an automatic transmission according to claim 1, which gradually reduces the amount of engine output reduction from the front and makes the engine output reduction amount zero at the end of shifting & by power from the engine In a vehicle running via an automatic transmission, a rotation speed change rate detection means for detecting a time change rate of an engine rotation speed or an automatic transmission input rotation speed, and a shift command detection means for detecting a shift command of the automatic transmission. , a shift start timing determining means for detecting that the time rate of change of the rotation speed becomes equal to or higher than a set value after the shift command, and determining that the shift has started; a speed change means for reducing the engine output to a value equal to or less than a predetermined value; and a speed change for detecting that the time rate of change in the rotational speed becomes equal to or less than a set value after the start of the speed change, determining that the speed change has ended, and stopping the operation of the engine power reduction means. a timer for measuring the elapsed time from the shift command; and a timer for measuring the elapsed time from the shift command; and a timer for measuring the time elapsed since the shift command; Shift shock reduction device for a vehicle equipped with an automatic transmission, characterized in that it is provided with a fail-safe means for stopping the operation of an engine output reduction means. 9. The shift shock reducing device for a vehicle equipped with an automatic transmission according to claim 8, which gradually reduces the amount of decrease in engine output and makes the amount of decrease in engine output zero at the end of the shift.