JPS63254256A - Speed change shock lightening device for vehicle equipped with automatic transmission - Google Patents

Abstract

PURPOSE:To surely reduce the speed change shock by starting the control for the engine output reduction for lightening the speed change shock when the input revolution speed of an automatic transmission becomes equal to the input revolution speed for judging the start of speed change and completing said control with the input revolution speed for judging completion. CONSTITUTION:When a speed change starting time judging means (g) detects the input revolution speed of an automatic speed change gear (b) which is detected by a detecting means (c) becomes equal to the input revolution speed for judging the start of speed change which is set on the basis of the kind of speed change and the input revolution speed in case of speed change instruction by a means (f) after speed change instruction, said means (g) operates an engine output reducing means (i). When a speed change completion timing judging means (h) detects that the input revolution speed becomes equal to the input revolution speed for judging the completion of speed change which is set similarly by the means (f) after the start of speed change, the completion of speed change is judged, and the operation of the engine output reducing means (i) is stopped. Therefore, during the time from the start of speed change to the completion, the output of an engine (a) is reduced, and the speed change shock can be surely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a shift reduction 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 (gear position), a shift shock occurs because the output shaft torque suddenly changes when changing gears15. 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 → 3 upshift). shifting), or shifting from 3rd to 4th gear (a A
In the case of "4-upshift shifting", this becomes noticeable because these shifting 1s are often carried out during power-on driving with the engine's accelerator pedal depressed greatly.

For example, as shown in FIG. 9, when there is a shift command from 2nd speed to 3rd speed at instant t0, the corresponding friction element starts operating at instant t2 after a response delay ΔT ( The friction element then completes its operation at instant t8 after an operation delay ΔT2 (speed change starts).
(end gear shifting). And the effective gear ratio of automatic transmission is Δ
As the operation of the friction element progresses during time T2, the gear ratio RL of the second speed (for example, 1,4) changes to the gear ratio RH of the third speed (for example, 1.degree. 0). Also, during this period, the input rotation speed Ni of the automatic transmission decreases in accordance with the change in the gear ratio between instants t2 and t3, and matches the output rotation speed NO of the automatic transmission (the engine rotation speed also has a similar tendency). Change). Theoretically, the input torque T1 (approximately the same as the engine output torque Te) of the automatic transmission can be input without changing the engine throttle opening! The output torque TO of the automatic transmission, which is approximately inversely proportional to the above-mentioned change in the 0 rotation speed Ni, and is expressed by multiplying this driver torque by the effective gear ratio, remains approximately constant.

However, in reality, while the input rotation speed Ni decreases during the ΔT2 period, the engine's inertia acts to prevent this rotation range from 5 to 50, and inertia mode torque is applied to the input shaft of the automatic transmission, resulting in The output torque TO changes as shown by To/ during the shift operation (during the ΔT2 period). As a result, torque Tm due to inertia force is generated during the ΔT2 period, and this has been a cause of shift shock.

Therefore, the applicant of the present application previously disclosed in Japanese Unexamined Patent Publication No. 58-207556 that the engine output is reduced at this time based on the fact that the shift shock is caused by the rapid increase in transmission output shaft torque as described above. We have already proposed a technology that slows down the ignition timing compared to normal to alleviate sudden changes in transmission output shaft torque, thereby reducing 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. '.

(Problem to be Solved by the Invention) However, the response delay from the shift command for switching the shift valve to the start of the actual shift and the operation delay from the start of shift to the end of shift are each caused by one hydraulic system. The timer control described above cannot always match the start timing of ignition timing control with the actual shift start timing, and the ignition timing The timing at which the control ends cannot be matched with the actual timing at which the gear shift ends. And ignition timing control 1
If the 0 start and end are not synchronized with the start and end of the shift, not only will it not be possible to achieve the desired effect of reducing shift shock, but additional deceleration will occur due to an unnecessary drop in engine output before or after the start of the shift. This causes shock and significantly reduces the commercial value of the vehicle.

Therefore, in Japanese Patent Application Laid-open No. 59-97350, a technique 20 was proposed in which, since the engine rotational speed causes a peculiar change during a gear shifting operation, this change is used to determine that the gear shifting operation is being performed, and the engine output is changed during this time. It was done. However, a torque converter is installed between the engine and one automatic transmission, and this causes slip, so when the change in automatic transmission input speed due to gear shifting is small, this change appears as a change in engine speed. As a result, in such a case, it is impossible to determine whether to start or end a shift.

(Means for Solving the Problems) The present invention attempts to solve the above-mentioned problems by determining the start of a shift and the end of a 10th shift based on a peculiar change in the automatic transmission input speed instead of the engine speed. As shown in FIG. 1, in a vehicle that is driven by power from an engine a through an automatic transmission, an input rotation speed detection means C for detecting the input rotation speed of the automatic transmission;
A shift command detection means d for detecting a shift command of the automatic transmission b, a shift type determination means e for determining the type of shift command, and a shift start determination according to the type of shift and the input rotation speed at the time of the shift command. an input rotation speed setting means 2°f for setting an input rotation speed for use and an input rotation speed for determining the end of shifting; A shift start timing determining means g for determining that a shift has started, and a fifth shift end timing determining means for determining that a shift has ended by detecting that the input rotation speed reaches the input rotation speed for determining the end of the shift after the start of the shift. and engine output reducing means i for reducing the output of the engine to a value required to prevent shift shock from the start of the shift until the end of the shift.

(Function) The shift start timing determining means g determines that the input rotation speed of the automatic transmission detected by means C is set based on the type of shift and the input rotation speed of the automatic transmission at the time of the shift command by means f after the shift command is issued. When it is detected that the input rotation speed for determining the start of a shift has been reached, it is assumed that the shift has started, and the output reduction means i of the engine 15 is activated.

Then, after the shift start, the shift end timing determination means determines that the input rotation speed becomes the input rotation speed for shift end determination, which is set by the means f based on the type of shift and the automatic transmission input rotation speed at the time of the shift command. It detects this and considers it to be the end of gear shifting.

The operation of the engine output reducing means i is performed at a low pressure.As a result, the output of the engine a is reduced from the start of the shift to the end of the shift, and shift shock can be prevented.

Since the timing to start and end the fifth gear shift is judged based on changes in the automatic transmission input rotational speed, the judgment can be made accurately even when the rotational change due to gear shifting is small, and the shift shock prevention effect can be applied to This can definitely be achieved under the current conditions.
10 (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 2 shows the entire system which is an embodiment of the gear shift shock reducing device of the present invention, and 1 in the figure is EN1! 2 is its intake manifold, 3 is an air flow meter that measures the amount of intake air in the engine, 4 is an air cleaner, 5 is a converter housing that houses the torque converter of the automatic transmission, and 6 is the power transmission gear train of the automatic transmission and its A transmission case that houses various friction elements that determine the power transmission path 9 (, 7), 7 a valve body that houses a shift control hydraulic circuit that selectively activates various friction elements and determines the gear stage, 8 a rear It is an extension.

The engine 1 is equipped with a distributor lO for distributing high voltage to the spark plugs 9 of each cylinder in time with the 5th rotation of the engine.
In this distributor, the ignition timing control device 11 applies the secondary side high voltage generated by intermittent primary current at predetermined timings determined by the ignition timing control signal S described later to the ignition plugs 9 individually. ° 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 fuel injection amount is increased from an injector (not shown) to increase the output, and this engine output is transferred to the torque converter in the converter housing 5 Is. The power is then input to the power transmission gear train in the transmission case 6.

The automatic transmission uses a 1-2 shift valve 18, a 2-3 shift valve 14, and a 3-4 shift valve 15 to automatically select an appropriate gear from 1st to 4th gear according to the running condition of the 20 vehicles. , the engine power is shifted at a gear ratio according to the selected gear, and is delivered to the drive wheels of the vehicle (not shown), causing the vehicle to travel.

In the ninth invention, the ignition timing control device 11 is controlled by the controller 16 to control the ignition timing s of the engine 1. For this purpose, the controller 16 is driven by the power supply +V, and responds to the signal from the throttle opening sensor 17 which detects the amount of pedal stroke (engine load) of the accelerator pedal/l/12, depending on the position of the STH7 shift valves 18-15. 1-2 shift switch 18 that opens and closes power. 2-3 shift switch 19. 3-4 Signal from shift switch 20 S, S, S, 12 28 g4 from air flow meter 3, signal qQ corresponding to intake air amount, distributor I5 signal 5 from the crank angle sensor 21 built in 10
(3-, Signal ST from engine cooling water temperature sensor 22 that detects engine cooling water temperature, and sensor 2 that detects automatic transmission input rotation speed (torque converter output rotation speed)
Output based on the calculation result of signal SN from 3 (ignition timing control signal) by S! It is assumed that the O ignition timing control device 11 is controlled.

Note that the 1-2 shift switch 18 and the 2-3 shift switch 19 are connected to the 1-2 shift valves 13 and 2-3 shift valves 13 and 2-3, respectively, as described in, for example, Japanese Patent Application Laid-Open No. 127856/1983.
When the spool of the 3-shift pulp 14 is in the downshift position, it closes to output an L level signal, and when in the upshift position, it opens to output an H level signal, and the 3-4 shift switch 20 similarly outputs a 3-4 shift valve. It is assumed that the spool 15 closes to output an L level signal when in the downshift position, and opens to output an H level signal when in the upshift position. Thus, the shift signal S engineer.

``'281 S84 has the combination of levels shown in the following table at each gear stage.

Specifically, as shown in FIG. 3, the controller 16 includes a central processing unit (CPU) 24, a random access memory (RAM) 25, and a read-only memory (ROM) 2.
6, an input interface circuit 27, an output interface circuit 28, a waveform shaping circuit 29, an A/D converter 30, a drive circuit 31, and a power supply circuit 32,
The power supply circuit 32 sets the voltage of the power supply +■ to a predetermined value to
4. The data is supplied to the RAM 25, ROM 26, circuits 27 to 29, 31, and A/D converter 30, so that they can be driven.

It is assumed that the 0PU 24 executes the control program shown in FIG. 4 stored in the ROM 26 to perform normal ignition timing control and the ignition timing control (engine output reduction control for reducing shift shock) that is the object of the present invention. This control program is repeatedly started in step 40 by a regular interrupt from a timer (not shown) when the engine is started by turning on the ignition switch. First, in step 41, a shift signal S , S or S3. It is determined whether or not there is a shift command based on whether there is a change in the rails, and if there is no shift command, the control proceeds to step 42. In this step 42, as will be described later, when the gear shift command is
The shift flag GSFLG is set to 1, set to 11 at the start of the shift, and returned to 00 at the end of the shift. GSFLG = OO as long as the shift command heat condition continues after the shift is completed.
Therefore, the control proceeds to step 43, where the retard amount θRET for the ignition timing retard (engine output reduction) control which is the object of the present invention is set to zero. In the next step 44, another routine (not shown) is performed to determine the throttle opening (signal S).
, H), crank angle signal S. Planned engine rotation speed, engine intake air amount (signal S) that can be obtained by calculating the input period of
Q), and the fuel injection pulse width (fuel supply amount) calculated based on the engine cooling water temperature (signal S, ), etc., and calculate the R
Normal ignition timing θ from table data in OMjl'6
is read using the table lookup method. In the next step 45, the ignition timing is corrected in the retard direction by the retard amount θRET, and then the control is ended in step 46.
Since θRET is now set to 0 in step 43, the ignition timing correction in step 45 is not actually executed. Therefore, the ignition timing control signal SI during non-shifting controls the ignition timing control device 11 to the normal ignition timing with respect to the crank angle signal Sc, and does not reduce the engine output 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
Set SFLG to 01 to correspond to the presence of a shift command. In the next step 55, the automatic transmission input rotation speed N□, (signal Sm) and the shift signal S12' S231834 are set for each type of shift command, which can be determined by how the level changes. By multiplying the input rotation speed change ratio β1°β2, the input rotation speed N for determining the shift start and the input rotation speed N2 for determining the shift end are determined. In the next step 48, GSFLG is checked,
Since this is now set to Ol in step 47, control proceeds to step 49. In this step, it is determined whether the automatic transmission input rotation speed Ni (signal SN) is less than or equal to the input rotation speed N2 for determining the end of the shift, that is, the input rotation speed N at the time of the shift command.
It is determined whether the ratio of the input rotational speed Ni to i is less than β, and normal ignition timing control is executed using θRET=0 in the actual variable valve 43. Note that steps 47 and 55 are executed only once when a shift command is issued, and after that, step 41 selects step 42, but since C3FLG = o o is no longer present, step 42 selects step 48. I come to do it.

After the response delay ΔT (see FIG. 9), at the start of the shift when N1≦N, step 49 selects step 50, where the output torque T shown in FIG. 15 rapidly changing molecules. l
The amount of retardation θR that causes a decrease in engine output
ET is determined by calculation or table lookup method, and in the next step 51, C3FLG is set to 11 to indicate that the shift has started, and then the control is shifted to step 4.
4, 4.5''.Thus, in step 45, the ignition timing is corrected to be delayed by θRET from the normal ignition timing θ determined in step 441, and the ignition timing control signal S is set to the ignition timing control device at the start of the shift. 11 as crank angle signal S
It is possible to control the ignition timing so that the ignition timing is delayed by θRET compared to normal with respect to c. Therefore, the engine output is reduced to T in FIG. ! It is possible to eliminate the fluctuation in the output torque shown by , and the shift shock associated with this can be reduced.

This control after starting the shift is C3FLCI as described above.

= 11, the process proceeds to step 52 via steps 41, 42, and 48, where it is determined whether the automatic transmission input rotation speed Ni is less than or equal to the input rotation speed N2 for determining the end of the shift, that is, the input rotation at the time of the shift command. It is determined whether or not the ratio of the input rotation speed Ni to the number Ni1 has become equal to or less than β2, and 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 the ignition timing is delayed from normal by the retard amount θRKT finally determined in step 50, and the period from the start of the first shift to the end of the shift is as described above. O
Ignition timing control (engine output reduction control) for reducing shift shock is continuously executed.

Then, when the gear shift is completed, step 52 is followed by step 53.
, 54 are sequentially selected, and in step 58, the retard amount θRET
is set to 0, and in step 54, the shift flag GSFLG is returned to 00. Thereafter, the control proceeds to Stella 7'44, 45, but as described above, since θRKT = 0, normal ignition timing control is executed and no reduction in engine output occurs.

To briefly explain the above control for the 2→3 shift door 10 knob shift corresponding to FIG. 9, as shown in FIG. From t2 at the start of the shift when the gear shift is N or less,
After that, until t8 at the end of the shift when Ni becomes less than the input rotation speed N2 for determining the end of the shift, the spark timing at point 13 is 0 from the normal θ.
Only RET is delayed. As a result, the engine output is reduced, so the input torque T□ becomes lower than the conventional characteristic shown by the imaginary line, as shown by the solid line, and the output torque T. The variation T. The torque due to zero inertia force can be made almost constant without l, and the torque due to zero inertia force is also shown as a solid line, and is shown as an imaginary line.

Since there is no such fluctuation Tm, shift shock can be reduced.

In the above example, the ignition timing is delayed in order to reduce the engine output to reduce the shift shock. It goes without saying that the same objective can also be achieved by reducing the turbocharger boost pressure.

FIG. 6 shows another example of the control program, in which step 56 is added between steps 47 and 55, and step 4
Steps 57 and 58 are added before step 4. Step 5
6, that is, when there is a shift command, the timer TM,
, and measure the elapsed time from the shift command IS.

In step 57, it is determined whether or not this timer has exceeded a set time as indicated by T8 in FIG. 5, for example (a set time that covers the time from the shift command to the end of the shift). 'LM□〈If T3, control step 44.45
”, the same ignition timing control l as in the previous example is executed. However, if 2I'M□≧T3, the control proceeds to step 58, where GSFLG is reset to 00 and timer TM1 is cleared. , θRET is set to O, control proceeds to step 44.45. -Thus, TM
Since the shift is originally completed when 1≧T3, the ignition timing control for reducing shift shock should have been completed, but due to a malfunction due to a signal system failure or noise, Step 5
It is possible to prevent problems such as the ignition timing control for reducing shift shock being executed indefinitely when the gear change is determined to have ended, and even when the trouble occurs, the driver is forced to drive with reduced engine output. It never happens.

FIG. 7 shows yet another example of the control program, and in this example, the first-order differential of the input rotation speed N:L shown in FIG. From the moment when the 2Va differential value Ni of the input rotation man-hours changes from negative to positive at the same time t21 as the value N-,
Gradually return the ignition timing to normal ignition timing. Therefore, in step 55, the input rotation speed N8 corresponding to the instant t21 is multiplied by the input rotation speed change ratio β8 set for each class 0 shift command and the input rotation speed Ni at the time of the first shift command. Find it by In addition, although the method for obtaining N-work in the same step is the same as in each of the above embodiments,
In this step, it is assumed that the input rotational speed N2 for determining the end of shifting is not determined. In addition, the shift flag GSFLG becomes the above-mentioned name and the retard amount θRET becomes O (the ignition timing returns to the normal ignition timing) instantaneously in FIG.
) It shall be returned to 00 at t8.

At the start of the shift when the input surface rotation number Ni after the shift command becomes equal to or less than the input rotation speed N□ for determining the shift start (instant t2 in Fig. 8), the 7th
In the figure, the control is performed in step 41j as in each of the above embodiments.
42, 48, 49, 50. 1451.57,44,4
5, and ignition timing control is performed to prevent gear shift failure. This control is continued until the instant t21 in FIG. 8 when N.times.N is reached in step 59, and the shift shock can be reduced in the same way as in the previous example.

Thereafter, in step 60, GSFLG changes at instant t2.
Since the value is set to 10 to indicate that / has been reached, step 48 selects step 61, where the retard amount θRET
A value obtained by subtracting a predetermined value α from (the value obtained in step 50 at first, and the value updated in step 61 after the 52nd time) is updated as a new retard amount.

In the next step 62, it is determined whether or not this update retard amount θRE'l' has reached 0. If it has not reached it, the control proceeds to step 57144.45, and if it has reached Ill, θRET is changed in step 63. After setting it to O and returning GSFLG to 00, the control proceeds to steps 57, 44 and 45. Thus, in this example, as shown in FIG. 8, the ignition timing is gradually controlled by α per calculation cycle after the instant t21.

The reason for controlling the ignition timing in this way is actually due to the torque fluctuation T due to the characteristics of the friction element. l (see Figures 5 and 9) does not suddenly decrease near instant t8, but gradually decreases,
In some cases, the amount of output reduction due to engine output reduction control is smaller than the torque Tm due to inertia force (see Figures 5 and 20 and Figure 9). This is to make it smoother in the vicinity and further enhance the effect of reducing shift shock.

(Effects of the Invention) Thus, as described above, the shift shock reducing device of the present invention controls the automatic transmission input rotation speed to be the input rotation speed for determining shift start when reducing the engine output in order to reduce the shift shock. Since the system is structured such that the system starts when the input rotation speed reaches the input rotation speed for determining the end of the shift, the response delay from the shift command to the start of the shift and the delay in operation from the start of the shift to the end of the shift are caused by fluctuations in the hydraulic system and friction. Even if the elements change over time or due to the temperature (viscosity) of the hydraulic oil, the start and end of the engine output reduction control can always be made to coincide with the shift start timing 15 and the shift end time, and the desired shift shock reduction effect can be achieved. This can be achieved reliably, and it is also possible to prevent new deceleration shocks from occurring due to a shift between the above two timings.

Furthermore, in the present invention, the gear shift is started with a change in the input rotation speed of the automatic transmission, rather than the engine rotation speed.

Since the start and end of the shift can be detected reliably and accurately at all times, even when the engine speed changes little due to torque converter slip, the start and end of the shift can be detected reliably and accurately. It can be achieved reliably under any conditions.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the shift shock reducing device of the present invention, Fig. 2 is a general system diagram showing one embodiment of the device of the present invention, Fig. 3 is a block diagram of the controller in the device, Fig. 4 is a flowchart showing a control program of the controller, FIG. 5 is an operation time chart of the device of the present invention, FIGS. 6 and 7 are flowcharts showing other examples of control programs, and FIG. 8 is an example of FIG. The operation time chart, Figure 9, was used to explain the cause of shift shock! This is a υ operation time chart. 1...Engine 2...Intake manifold 3
...Air flow meter 4...Air cleaner 5...
・Converter housing 6...Transmission case 7...Valve body 8・
... Rear extension 9 ... Spark plug 10 ... Distributor 11 ... Ignition timing control device 12 ... Accelerator pedal 18 ... 1-2 shift valve 14 ... 2-3 shift valve 15 ...・3-4 shift valve 16...controller 17...throttle opening sensor 18...1-2 shift switch 19...2-3 shift switch 20...3-4 shift switch 21... Crank angle sensor 22...Engine coolant temperature sensor 23...Transmission input rotation speed sensor 24...Central processing unit 25...Random access memory 26...Read-only memory 27...Input interface circuit 28 ... Output interface circuit 29 ... Waveform shaping circuit 30 ... K/Dl converter 81 ... Drive circuit 32 ... Power supply circuit Patent applicant Nissan Motor Co., Ltd. Figure 6 Figure 7

Claims (1)

[Claims] 1. In a vehicle that is driven by power from an engine via an automatic transmission, an input rotation speed detection means for detecting an input rotation speed of the automatic transmission, a shift command detection means for detecting a shift command of the automatic transmission, and a shift command detection means for detecting a shift command of the automatic transmission; A shift type discrimination means for discriminating the type of command; and an input rotation speed setting means for setting an input rotation speed for determining the shift start and an input rotation speed for determining the end of the shift according to the type of shift and the input rotation speed at the time of the shift command. a shift start timing determination means for detecting that the input rotation speed after the shift command reaches the input rotation speed for determining the shift start, and determining that the shift has started; a shift end time determining means for detecting that the input rotation speed has reached a determination input rotation speed and determining that the shift is completed; and reducing the output of the engine to a value required to prevent shift shock from the start of the shift until the end of the shift. A shift shock reducing device for a vehicle equipped with an automatic transmission, characterized in that it is provided with means for reducing engine output.