JP3633027B2 - Control device for automatic transmission - Google Patents

Description

[0001]
[Industrial application fields]
The present invention is intended to reduce the rattling noise caused by backlash of a differential gear or the like after a shift, in particular, an automatic transmission control device.
[0002]
[Prior art]
An automatic transmission for a vehicle or the like is a combination of a torque converter to which engine output is input and a transmission mechanism that shifts and outputs the output of the converter, and a power transmission path of the transmission mechanism is divided into a plurality of clutches, brakes, and the like. The automatic transmission according to this type of automatic transmission is configured to switch the gear position automatically according to the driving state or by the driver's selection by switching by selective engagement of the friction element. A so-called back-out shift may be performed with the release operation of the pedal. For example, the backout shift is performed by comparing a shift map set in advance with the throttle opening and the vehicle speed as parameters and the actual driving state (throttle opening and vehicle speed). For example, when the map changes from the first speed region to the second speed region, the shift stage is upshifted from the first speed to the second speed.
[0003]
By the way, during such a back-out shift, the input rotation speed (turbine rotation speed) of the speed change mechanism also decreases as the engine speed decreases, so that the power transmission state of the speed change mechanism is driven by the engine output of the vehicle. There is a problem that the vehicle changes from the forward drive state to the reverse drive state in which the vehicle travels by the inertial force of the vehicle body, and rattling noise is generated due to backlash such as a differential gear.
[0004]
For example, Japanese Patent Application Laid-Open No. 1-224754 discloses a technique for starting shift control when the turbine rotation speed is synchronized with the output rotation speed of the transmission mechanism during backout shift. . According to this, the rattling sound resulting from the said backlash can be reduced to some extent.
[0005]
[Problems to be solved by the invention]
However, in the prior art described in the above publication, since the relationship between the engine speed and the turbine speed is not particularly taken into account, there is a problem that the rattling noise generated in the differential gear cannot be effectively removed.
[0006]
That is, as shown in the time chart of FIG. 9 , when the 1-3 shift in which the target shift speed Lm is upshifted from the 1st to the 3rd speed with the sudden decrease in the throttle opening Θ is performed, the symbol (a ), The turbine rotational speed Nt decreases as the speed change operation proceeds. In this case, since the engine speed rapidly decreases as the throttle opening Θ decreases, the engine speed Ne temporarily decreases below the turbine speed Nt, as indicated by reference numeral (b). As shown in (c), it converges to a predetermined idle speed. Then, rattling noise is generated at the moment when the engine speed Ne once smaller than the turbine speed Nt becomes larger than the turbine speed Nt again before and after the end of the shift.
[0007]
An object of the present invention is to effectively reduce the rattling noise generated due to the relative rotational difference between the engine speed and the turbine speed.
[0008]
[Means for Solving the Problems]
That is, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) is a combination of a torque converter to which an engine output is input and a transmission mechanism for shifting and outputting the output of the converter. In the automatic transmission in which the gear stage is switched by switching the power transmission path of the vehicle by selective engagement of a plurality of friction elements, the running state of the vehicle is a region where the engine speed is smaller than the turbine speed by a predetermined value or more. A running state judging means for judging that the running speed of the vehicle belongs to the region by the judging means, an engine speed reduction regulating means for regulating a reduction in engine speed , and an engine An engine speed adjusting means for adjusting the engine speed to a predetermined target speed, and the engine speed reduction regulating means, Traveling state of the two is, when the engine rotational speed belongs to a predetermined value or more smaller areas than the turbine speed, by being configured to set the turbine speed as a target speed of the engine rotational speed adjusting means Features.
[ 0009 ]
Further, in the invention according to claim 2 of the present application (hereinafter referred to as the second invention), the engine speed reduction regulating means in the first invention is configured to regulate the reduction of the engine speed during the upshift. It is characterized by.
[ 0010 ]
[Action]
According to said structure, the following effects are acquired.
[ 0011 ]
In other words, in both the first and second aspects of the invention, in a traveling state where the engine speed is smaller than the turbine speed by a predetermined value or more, the decrease in the engine speed is restricted. The number does not drop more excessively than the turbine speed, thereby reducing or preventing rattling noise caused by the relative rotational difference between the engine speed and the turbine speed.
[ 0012 ]
On the other hand, according to the first aspect of the present invention, the above action is achieved by setting the turbine speed as the target speed of the engine speed adjusting means.
[ 0013 ]
According to the second aspect of the invention, the above action can be obtained during the upshift.
[ 0014 ]
【Example】
Examples of the present invention will be described below.
[ 0015 ]
As shown in FIG. 1, an intake passage 11 of an engine 10 constituting a vehicle power plant 1 is provided with a throttle valve 12 for adjusting an intake air amount or an engine output in conjunction with an accelerator pedal (not shown). In the bypass passage 13 provided by bypassing the throttle valve 12, an ISC valve 14 for adjusting the amount of bypass air during idling or the like is installed.
[ 0016 ]
On the other hand, in the automatic transmission 20 that constitutes the vehicle power plant 1 together with the engine 10, the torque converter 21 connected to the output shaft 15 of the engine 10 and the output rotation of the converter 21 are input via the turbine shaft 22. A planetary gear type transmission mechanism 23, and the output rotation of the transmission mechanism 23 is transmitted to drive wheels (not shown) via the drive shaft 2 and a differential device (not shown). The automatic transmission 20 has a plurality of shifting solenoids 24... 24, and the hydraulic circuit is switched by a combination of ON and OFF of these shifting solenoids 24. A plurality of shift stages can be obtained by selectively actuating the friction elements (not shown).
[ 0017 ]
Further, this vehicle is provided with an electronic control type control unit (hereinafter referred to as ECU) 30. The ECU 30 receives a signal from the throttle sensor 31 that detects the opening of the throttle valve 12, a signal from the engine rotation sensor 32 that detects the engine speed, a signal from the water temperature sensor 33 that detects the engine water temperature, A signal from the turbine rotation sensor 34 that detects the input rotation speed (turbine rotation speed), a signal from the output rotation sensor 35 that detects the output rotation speed of the speed change mechanism 23 that represents the vehicle speed, and the operation position (range) of the shift lever. A signal from the shift position sensor 36 to be detected is input, and based on these signals, shift control, idle speed control using the ISC valve 14 and the like are performed.
[ 0018 ]
Here, the outline of the shift control performed by the ECU 30 will be described. For example, the ECU 30 displays signals from the output rotation sensor 35 and the throttle sensor 31 in a shift map in which the vehicle speed and the throttle opening are set as parameters in advance as shown in FIG. Are applied to the actual vehicle speed V and the throttle opening Θ, and when the driving state indicated by these passes through the shift line constituting the shift map, the downshift or the upshift is determined to determine the target shift speed. Set Lm. Then, a solenoid pattern for realizing the set target shift speed Lm is determined, and a shift command signal for realizing the pattern is output to the shift solenoids 24.
[ 0019 ]
The idle speed control is specifically performed as follows in accordance with the flowchart of FIG.
[ 0020 ]
That is, after reading various signals in step S1, the ECU 30 determines in step S2 whether or not the operating state of the engine 10 is in an idle operating state. If it is determined that the engine is in an idle operating state, the ECU 30 proceeds to step S3. As shown in FIG. 4, the target engine speed Nm corresponding to the actual engine water temperature Tw is set by applying the engine water temperature Tw indicated by the water temperature signal from the water temperature sensor 33 to the target engine speed map in which the engine water temperature is set as a parameter. Further, by executing step S4, the engine water temperature Tw indicated by the water temperature signal from the water temperature sensor 33 is applied to the basic control amount map in which the engine water temperature is set as a parameter as shown in FIG. A basic control amount Gb corresponding to the engine water temperature Tw is set.
[ 0021 ]
Next, the ECU 30 calculates a rotational deviation ΔN of the engine rotational speed Ne with respect to the target rotational speed Nm, and then, on the feedback correction amount map set in advance according to the rotational deviation as shown in FIG. 6, the rotational deviation Δ By applying N, the feedback correction amount Gfb is set (steps S5 and S6). In this case, for example, when the rotation deviation ΔN is a positive value, the feedback correction amount Gfb is a negative value.
[ 0022 ]
Then, the ECU 30 executes step S7 to determine the final control amount G by adding the basic control amount Gb, the feedback correction amount Gfb, etc., and in step S8, outputs a drive signal corresponding to the final control amount G to the ISC. Output to valve 14. Therefore, the ISC valve 14 is adjusted to an opening corresponding to the final control amount G, and a part or all of the air taken in from an air cleaner (not shown) is passed from the intake passage 11 to the bypass passage 13 upstream of the throttle valve 12. And flows again into the intake passage 11 on the downstream side of the valve 12 and is then sucked into the engine 10. During idle operation of the engine 10, when the engine speed Ne is lower than the target speed Nm, the amount of bypass air that bypasses the throttle valve 12 is increased, so that the fuel supply amount is increased and the engine speed is increased. When Ne rises and the engine speed Ne rises above the target speed Nm, the amount of fuel supplied is reduced by decreasing the amount of bypass air, and the engine speed Ne is reduced. The number Ne is maintained at the target rotational speed Nm.
[ 0023 ]
In this embodiment, the engine rotation reduction suppression control at the time of backout shift is performed as follows according to the flowchart of FIG.
[ 0024 ]
That is, the ECU 30 reads various signals in step T1, determines whether the upshift flag Fup is set to 1 in step T2, and determines that the upshift flag Fup is set to 1, Proceeding to T3, it is determined whether or not the time change rate (hereinafter referred to as throttle change rate) ΔΘ of the throttle opening Θ indicated by the signal from the throttle sensor 31 is smaller than a predetermined value α (<0). That is, it is determined whether or not the throttle opening Θ has suddenly decreased.
[ 0025 ]
When it is determined that the throttle change rate ΔΘ is smaller than the predetermined value α, the ECU 30 proceeds to step T4 and the turbine speed Nt indicated by the signal from the turbine speed sensor 34 is greater than the target speed Nm for the idling speed control. If the turbine rotational speed Nt is not smaller than the target rotational speed Nm, the routine proceeds to step T5, where the turbine rotational speed Nt is set as the target rotational speed Nm, and then from the output rotational sensor 35 at step T6. Whether the calculated gear ratio Rg (= Ne / No) obtained from the output rotational speed No indicated by the above signal and the turbine rotational speed Nt is smaller than the end determination value Re set according to the type of shift. judge. When it is determined that the calculated gear ratio Rg is not smaller than the end determination value Re, the process returns to step T4 to determine again the magnitudes of the turbine speed Nt and the target speed Nm, and the calculated gear ratio Rg ends. When it is determined that it is smaller than the determination value Re, the routine proceeds to step T7, where the target engine speed Nm of the original engine 10 is set as the target engine speed Nm.
[ 0026 ]
When the ECU 30 determines that the turbine rotational speed Nt is smaller than the target rotational speed Nm in step T4, the ECU 30 skips steps T5 and T6 and proceeds to step T7 to set the target rotational speed Nm as the target rotational speed of the original engine 10. Set a number Nm.
[ 0027 ]
Therefore, according to this embodiment, the following operation can be obtained.
[ 0028 ]
That is, as shown in the time chart of FIG. 8, if the throttle change rate ΔΘ is smaller than the predetermined value α at the time t1 when the upshift flag Fup is set to 1, the target rotation of the idle speed control from that time t1. The turbine speed Nt is set as the number Nm. Therefore, as indicated by reference numeral (a) in the figure, the engine speed Ne is controlled so as to converge to the turbine speed Nt, so that the engine speed Ne does not drop excessively than the turbine speed Nt. For example, at the time t2 when the arithmetic gear ratio Rg becomes smaller than the end determination value Re, the target rotational speed Nm of the original engine 10 is set as the target rotational speed Nm of the idle rotational speed control. As shown in (a), the engine speed Ne is controlled to converge to the target speed Nm.
[ 0029 ]
Thus, at the time of backout shift, the turbine rotational speed Nt is set as the target rotational speed Nm of the idle rotational speed control, so that the engine rotational speed Ne does not drop excessively than the turbine rotational speed Nt. As a result, the rattling noise resulting from the relative rotational difference between the engine rotational speed Ne and the turbine rotational speed Nt is reduced or prevented.
[ 0030 ]
If the engine 10 is configured to adjust the idle speed of the engine 10 by controlling the ignition timing for a spark plug (not shown), the turbine speed Nt may be set as the target speed of the ignition timing control. .
[ 0031 ]
It should be noted that the engine speed Ne indicated by the signal from the engine speed sensor 32 and the turbine speed Nt indicated by the signal from the turbine speed sensor 34 indicate a traveling state in which the engine speed Ne is lower than the turbine speed Nt by a predetermined value or more. The determination may be made directly.
[ 0032 ]
【The invention's effect】
As described above, according to the present invention, in a traveling state in which the engine speed is smaller than the turbine speed by a predetermined value or more, the decrease in the engine speed is restricted. It does not drop excessively than the rotational speed, which reduces or prevents rattling noise resulting from the relative rotational difference between the engine rotational speed and the turbine rotational speed.
[Brief description of the drawings]
FIG. 1 is a control system diagram of a vehicle power plant.
FIG. 2 is an operation region diagram showing a shift map.
FIG. 3 is a flowchart showing idle speed control using an ISC valve.
FIG. 4 is an explanatory diagram of a map used in the control.
FIG. 5 is an explanatory diagram of a map that is also used in the control.
FIG. 6 is an explanatory diagram of a map that is also used in the control.
FIG. 7 is a flowchart showing an embodiment of engine rotation reduction suppression control during a backout shift.
FIG. 8 is a time chart showing the operation of the embodiment .
FIG. 9 is a time chart showing conventional problems.
[Explanation of symbols]
10 Engine 14 ISC valve 20 Automatic transmission 21 Torque converter 30 ECU
32 Engine rotation sensor 34 Turbine rotation sensor

Claims (2)

A torque converter to which engine output is input and a transmission mechanism that shifts and outputs the output of the converter are combined, and a power transmission path of the transmission mechanism is switched by selective engagement of a plurality of friction elements. Is a control device for an automatic transmission, in which the traveling state of the vehicle is determined to be a region where the engine rotational speed is smaller than the turbine rotational speed by a predetermined value or more, and the determination means When it is determined that the traveling state of the vehicle belongs to the above-described region, the engine speed reduction regulation means for regulating the engine speed reduction, and the engine speed adjustment for adjusting the engine speed to a predetermined target speed And the engine speed reduction restricting means is configured such that the vehicle running state is such that the engine speed is turbine speed. When belonging to a predetermined value or more smaller areas than the number, the control device for an automatic transmission, characterized by being configured to set the turbine speed as a target speed of the engine rotational speed adjusting means. 2. The control device for an automatic transmission according to claim 1 , wherein the engine speed reduction regulating means is configured to regulate a reduction in the engine speed at the time of upshifting.

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