JPH0425168B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field) The present invention relates to a shift shock 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 selectively activate internal friction elements (clutches, brakes, etc.) depending on the vehicle state while the vehicle is running, and automatically select the optimum gear position to match the engine power to the driving state. However, when changing gears, the output shaft torque suddenly changes, causing a shift shock. This shift shock is used 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 3rd gear (2 → 3 upshift). Shifting) or shifting from 3rd to 4th gear (3→4 upshift), these shifts are often performed during power-on driving with the engine's accelerator pedal fully depressed. Become. Therefore, the applicant of the present application previously disclosed in Japanese Patent Application Laid-Open No. 58-207556, based on the fact that the transmission shock is based on sudden changes in the transmission output shaft torque.
At this time, we have already proposed a technology that delays the ignition timing from normal in order to reduce the engine output, thereby alleviating sudden changes in transmission output shaft torque and 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. However, the response delay between an automatic transmission's shift command to switch the shift valve and the start of the actual shift varies depending on variations in the hydraulic system, wear over time of friction elements, and hydraulic fluid temperature (viscosity). However, with the above-mentioned timer control, it is not possible to always make the start timing of the ignition timing control coincide with the actual shift start timing. If the timing of the two is different, not only will the desired reduction effect of the shift shock not be obtained, but a new deceleration shock will occur due to a decrease in engine output before or after shifting, which will greatly impair the commercial value of the vehicle. . (Object of the Invention) The present invention has the following advantages: When an actual gear shift is started, the engine speed or the automatic transmission input rotation speed starts to change suddenly at a larger rate of change than after the gear change command and before the start of the gear shift. Based on the fact that it is possible to determine whether or not a shift has started by judging this rotational speed change rate, the above-mentioned ignition timing control is started from the time when it is determined that a shift has started based on this, thereby solving the above-mentioned problem. The purpose is to solve the problem. (Structure of the Invention) For this purpose, the shift shock reducing device of the present invention, as shown in the concept in FIG. a rotation speed change rate detection means for detecting a time change rate of a machine input rotation speed; a shift command detection means for detecting a shift command of an automatic transmission; A gear shift start timing determining means detects the shift start time and determines that the shift has started, and an ignition timing control means delays the ignition timing so that the engine output decreases to a value required for preventing shift shock from the shift start time. It is characterized by being (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. Fig. 2 shows the entire system of the shift shock reducing device of the present invention, in which 1 is the engine, 2 is its intake manifold, 3 is a flow meter that measures the amount of intake air in the engine, 4 is an air cleaner, and 5 is the automatic transmission. A converter housing that houses a torque converter; 6 a transmission case that houses a power transmission gear train of an automatic transmission and various friction elements that determine its power transmission path; 7 a transmission case that houses various friction elements that determine the gear position by selectively operating the various friction elements; 8 is the rear extension. The engine 1 includes a distributor 10 for distributing high voltage to the spark plugs 9 of each cylinder in time with the operation of the engine _. The secondary side high voltage generated by temporarily intermittent current is applied to the spark plugs 9 at predetermined timings determined by the above, thereby enabling the engine 1 to operate. 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.
The power is input to the power transmission gear train in the transmission case 6 via the torque converter in the transmission case 6. Automatic transmission has 1-2 shift valves 13, 2-3
The shift valve 14 and the 3-4 shift valve 15 automatically select an appropriate gear from 1st to 4th gear according to the vehicle running condition, and change the engine power at a gear ratio corresponding to the selected gear. The information is transmitted to the drive wheels of the vehicle (not shown) and the vehicle is driven. In the present invention, the ignition device 11 is controlled by the controller 16 to control the ignition timing of the engine 1. For this purpose, the controller 16 is driven by the power supply +V, and opens and closes according to the signal S _TH from the throttle opening sensor 17 that detects the amount of depression of the accelerator pedal 12 (engine load), and the spool position of the shift valves 13 to 15.
Signals S ₁₂ from -2 shift switch 18, 2-3 shift switch 19, 3-4 shift switch 20,
S ₂₃ , S ₃₄ , a signal S _Q corresponding to the intake air amount from the flow meter 3, a signal S _C from the crank angle sensor 21 built into the distributor 10, an engine cooling water temperature sensor 22 that detects the engine cooling water temperature.
The ignition device 11 is controlled by an output (ignition timing control signal) S _I based on the calculation result of the signal S _T from the engine and the signal S _N from the engine rotation speed sensor 23 that detects the engine rotation speed. Note that the 1-2 shift switch 18 and the 2-3 shift switch 19 are each disclosed in, for example, Japanese Patent Application Laid-Open No. 56-127856.
As described in the publication, the 1-2 shift valve 13
When the spool of the 2-3 shift valve 14 is in the downshift position, it closes and outputs an L level signal, and when in the upshift position, it opens and outputs an H level signal, and the 3-4 shift switch 20 similarly outputs a 3-4 shift valve 14.
It is assumed that the spool of the 4-shift valve 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 signals S ₁₂ , S ₂₃ , and S ₃₄ have the combinations of levels shown in the following table at each gear stage.

[Table] Specifically, as shown in FIG. 3, the controller 16 includes a central processing unit (CPU) 24, a random access memory (RAM) 25, a read-only memory (ROM) 26, and an input interface circuit 27. and an output interface circuit 28,
It is composed of a waveform shaping circuit 29, an A/D converter 30, a drive circuit 31, and a power supply circuit 32, and the power supply circuit 32 sets the voltage of the power supply +V to a predetermined value and controls the CPU 24,
RAM25, ROM26, circuits 27-29, 31
and the A/D converter 30 to enable them to be driven. It is assumed that the CPU 24 executes the control program shown in FIG. 4 stored in the ROM 26 to perform normal ignition timing control and ignition timing control that 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 by a regular interrupt from a timer (not shown). First, in step 41,
It is determined whether the ignition timing control flag TFLG is set to 1, which indicates that the ignition timing control (ignition timing control for reducing shift shock during gear shifting) which is the object of the present invention is being executed. If TFLG=1 and the ignition timing control is not being executed, step 42 is selected, during which the ignition timing control according to the invention is to be executed during a gear change (in this example, from 1→2, 2→3 or 3→ It is determined whether a shift flag SFTFLG is set to 1, which indicates a 4-upshift shift, but may also include a 2->1, 3->2, or 4->3 downshift. If SFTFLG is not 1 and the shift-up is not in progress, the control proceeds to step 43, where the current gear position G, which can be determined based on the table above based on the combination of the levels of the shift signals S ₁₂ , S ₂₃ , and S ₃₄ , is determined.
(NEW) is the same as the previous gear position G (OLD). If G (NEW) = G (OLD), the spool position of any of the shift valves 13 to 15 has not been changed and there is no shift command, so the control proceeds to steps 44 to 46 in sequence and returns to normal. The ignition timing control is executed, and the control is ended in step 47. In step 44, a separate routine (not shown) determines the throttle opening (signal S _TH ), engine speed (signal S _N ), engine intake air amount (signal S _Q ),
and the fuel injection pulse width T _P (fuel supply amount) calculated based on the engine cooling water temperature (signal S _T ), etc., and the engine rotation speed used for this calculation.
Load N _E. In the next step 45, the normal ignition timing R _ij is read out from the following table data based on the fuel injection pulse width T _P and the engine speed N _E using a table lookup method.

[Table] After that, set this ignition timing R _ij to the corresponding address of the output register. In this way, the output S _I can control the non-shift timing ignition device 11 to the normal ignition timing R _ij with respect to the crank angle signal S _C. If it is determined in step 43 that G (NEW) is not equal to G (OLD), that is, if it is determined that a shift command has been received, the shift signal S ₁₂ , S ₂₃ or
It is determined whether or not _S34 has changed in level indicating an upshift. If it is not an upshift shift, this is a downshift shift in which ignition timing control for reducing shift shock is not performed in this example, so the control proceeds to steps 44 to 47 and normal ignition timing control similar to that described above is performed. By the way, if it is an upshift shift, step 48 should select step 49,
Here, the throttle opening TH (engine load) is read from the signal S _TH , and the shift signal is set at the next step 50.
The type of upshift is determined based on which of S ₁₂ , S ₂₃ , and S ₃₄ changes from L level to H level. For 1→2 shifting, step 51 is selected, for 2→3 shifting, step 52 is selected, and for 3→4 shifting, step 53 is selected. In these steps, the cable data shown in the table below is selected for each type of shifting. Based on the throttle opening TH, the engine speed change rate setting value is used to determine when the actual gear shift has started.
X ₁ , X ₂ , X ₃ , corrected ignition timings Y ₁ , Y ₂ , Y ₃ for reducing shift shock, and shift times T ₁ , T ₂ , T ₃ to maintain these corrected ignition timings, respectively, are table-picked up. Read by.

[Table] From step 51, 52, or 53, control proceeds to step 54, where the shift flag SFTFLG is set to 1 to indicate that there is an upshift shift command for performing ignition timing control for reducing shift shock. . In the next step 55, the engine speed N _E is calculated based on the signal S _N , and in the next step 56, the engine speed N _E is calculated based on the signal S N.
is differentiated with time to find the rate of change in engine speed over time.
Calculate dN _E /dt. In the next step 57, it is determined whether or not the actual speed change has started, depending on whether or not this rate conversion ratio dN _E /dt is greater than or equal to the set value X _ij read out in steps 51, 52, or 53. If dN _E /dt<X _ij , it is assumed that the rate of change in the engine speed after the shift command is still below the set value X _ij and the actual shift has not yet started, and in this case, the control is stepped. Proceed to steps 44 to 47 to continue normal ignition timing control. Note that the control then proceeds to step 41.
When step 42 is reached, step 54 sets SFTFLG to 1, so step 42 is replaced by steps 43, 48 to 48.
As a result of skipping step 54 and selecting step 55, information _X1 to
Ignition timing control for reducing shift shock is executed based on X ₃ , Y ₁ to Y ₃ , and T ₁ to T ₃ . That is, when it is determined in step 57 that dN _E /dt≧X _ij , that is, at the start of the shift when the rate of change in engine speed after the shift command reaches the set value X _ij , step 57 selects step 58. Step 58
The corrected ignition timing Y _ij for shifting shock reduction read in 51, 52 or 53 is set in the corresponding address of the output register. In the next step 59, step 51,
The ignition timing control time T _ij for shifting shock reduction read out in step 52 or 53 is set to the corresponding address of the output register, and then in step 60 the above-mentioned flag TFLG is set to indicate that the ignition timing control aimed at by the present invention is being executed. Set to 1. Next, step 61
starts a counter that functions as a timer to measure the execution time of the ignition timing control,
Control ends at step 47. As described above, after it is determined in step 57 that the gear shift has started, the output S _I controls the ignition system 11 to the corrected ignition timing Y _ij which is delayed from the normal ignition timing R _ij with respect to the crank angle signal S _C. As a result, the output of the engine is reduced after the shift starts, and the shift shock can be reduced. This ignition timing control is executed by the following timer control until the shift is completed. In other words, since TFLG is set to 1 in step 60 when the ignition timing control for reducing shift shock is started, step 41 selects step 62.
Here, the counter started in step 61 is set to the set time set in step 59.
It is determined whether T _ij or more is indicated. If the counter is not ≧T _ij , the counter is incremented in step 63, and then the control proceeds to step 47, during which time the ignition timing control for reducing the shift shock is continued. By the way, when the counter that is repeatedly incremented in step 63 indicates the set time T _{ij or} more,
In other words, when the ignition timing control for reducing shift shock is executed for the set time _Tij , step 62 selects step 64, where the counters, TFLG and SFTFLG are respectively cleared, and the control then proceeds to steps 44 to 47. Proceed to return to normal ignition timing control.
In this way, the ignition timing control for reducing shift shock is executed from the start of the shift until the end of the shift when the set time T _ij has elapsed, and is performed in synchronization with the actual shift period. (Effects of the Invention) Thus, as described above, the shift shock reducing device of the present invention delays the ignition timing to reduce the engine output torque in order to reduce the shift shock at the time of gear shifting. When the rate of change dN _E /dt (the rate of change in the torque converter output rotation speed, that is, the rate of change in the automatic transmission input rotation speed) exceeds the set value X _ij (the rotation speed suddenly changes due to the start of gear shifting) Even if the response delay from the shift command to the start of shift changes due to variations in the hydraulic system, wear of friction elements over time, or hydraulic oil temperature (viscosity), the ignition timing control can be started at It is possible to always match the shift start timing, thereby reliably achieving the desired shift shock reduction effect, and preventing new deceleration shocks from occurring due to a shift between the above two timings. (Effects of the Example) As shown in the illustrated example, the set value X _ij of the rotation speed change rate, which is the criterion for starting a shift, is set to the optimum value for each engine load (throttle opening in the illustrated example) and type of shift. If it is changed, the shift start timing can always be accurately detected even if the engine load or the type of shift is different, and the above-mentioned effects can be more pronounced.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the shift shock reducing device of the present invention, Fig. 2 is an overall system diagram showing an embodiment of the device of the present invention, Fig. 3 is a block diagram of the controller in the device, and Fig. 4 is the controller. 2 is a flowchart showing a control program. 1...Engine, 2...Intake manifold, 3...
...Flow meter, 4...Air cleaner, 5...Converter housing, 6...Transmission case, 7...
...Valve body, 8...Rear extension,
9...Spark plug, 10...Distributor, 1
1...Ignition device, 12...Accelerator pedal, 13
...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...Engine speed sensor, 24...Central processing unit, 25...Random access memory, 26 ...read-only memory, 2
7... Input interface circuit, 28... Output interface circuit, 29... Waveform shaping circuit,
30... A/D converter, 31... Drive circuit, 32
...Power circuit.

Claims (1)

[Claims] 1. 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 change rate of the engine rotation speed or the automatic transmission input rotation speed; A shift command detecting means for detecting a shift command of the machine; a shift start timing determining means for determining that a shift has started by detecting that the time rate of change of the rotational speed after the shift command has exceeded a set value; 1. A shift shock mitigation device for a vehicle equipped with an automatic transmission, comprising ignition timing control means for retarding ignition timing so that the engine output decreases to a value required for preventing shift shock. 2. The shift shock reduction device for a vehicle equipped with an automatic transmission according to claim 1, wherein the set value of the rotational speed change rate changes depending on the engine load. 3. The shift shock reduction device for a vehicle equipped with an automatic transmission according to claim 1, wherein the set value of the rotational speed change rate changes depending on the type of shift.