JPH0425169B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an upshift control device for an automatic transmission for a vehicle, and particularly includes means for detecting vehicle running conditions including a vehicle speed suitable for use in shift control during manual upshifting, and a manual operation mechanism. The present invention relates to an improvement in an upshift control device for an automatic transmission for a vehicle, which is capable of upshifting automatically based on vehicle running conditions and upshifting based on manual operation.

[Conventional technology]

A gear transmission mechanism and a plurality of frictional engagement devices are provided, and engagement of the frictional engagement devices is selectively switched by operating a hydraulic control device, and any one of the plurality of gears is set. Automatic transmissions for vehicles configured to achieve this are already widely known. Such automatic transmissions for vehicles generally include a shift lever operated by the driver, a vehicle speed sensor that detects the vehicle speed, and a throttle that detects the throttle opening, which is considered to reflect the engine load. The frictional engagement device is equipped with a sensor so that the engagement state of the frictional engagement device can be automatically switched in accordance with the range of the shift lever and at least in relation to the vehicle speed and the throttle opening.

[Problems to be solved by the invention]

However, in the case of the above-mentioned automatic transmission, manual upshifting is particularly important when the engine torque is positive (hereinafter referred to as the power ON state), that is, from running in the 2nd gear range to driving in the drive range, or overshifting in the drive range. When an upshift is performed based on a manual operation such as turning on a drive switch, generally speaking, such a manual shift can be performed by the driver's will as long as the vehicle speed is above the shift point when driving in the drive range, no matter how high the vehicle speed is. Since gears can now be changed freely, there was a problem that problems could occur unless appropriate countermeasures were taken. In other words, the amount of work performed by the frictional engagement device during upshifting is divided into engine torque absorption and inertia torque absorption. Of these, inertia torque absorption increases by the square of the vehicle speed, so at high speeds When shifting in this state, the amount of work (energy absorption) performed by the frictional engagement device increases, which may place an unexpected burden on the frictional engagement device. For example, when the throttle opening is around 60%, the working oil pressure of the frictional engagement device is set lower than when the throttle is fully opened. This is a dry range,
This is because since the shift point is lower than when the engine is fully open, the absorption of the inertia torque is expected to be small even if the engine torque is not significantly lower than when the engine is fully open. However, when the shifting vehicle speed is high, the frictional engagement device may absorb almost the same energy as when the gear is fully opened due to an increase in inertia torque. Therefore, if the manual shift is performed in a high-speed state, the amount of work of the frictional engagement device becomes large, and there is a risk that the durability will deteriorate. In particular, drivers who prefer power driving tend to always drive in second gear or with overdrive OFF, and then shift to drive range driving or turn on the overdrive switch when the vehicle speed reaches a high speed. This problem will become more serious as it becomes stronger. As a countermeasure to this problem, it is conceivable to set the working oil pressure of the frictional engagement device to a slightly higher level in advance from the viewpoint of durability. However, in this case, another problem arises in that the working oil pressure during automatic shifting, which accounts for most of the shifting, becomes unnecessarily high and the shift shock increases. By the way, several technologies have been proposed in which the load on the friction engagement device is reduced by changing the engine torque during gear shifting, and the gear shifting can be performed in a short time and with a small gear shifting shock (for example, Kai 55-69738, Kai 56-96129, Kai 58-
28536, 58-77138). In particular, Japanese Patent Laid-Open No. 55-69738 proposes a method in which the amount of engine torque reduction at that time is determined depending on the engine rotational speed in claim 9 thereof. However, for example, in Japanese Patent Laid-Open No. 55-69738, the engine torque control amount is determined depending on the engine rotation speed, as is clear from the purpose of this invention. (to start engine torque control from a certain engine speed)'', and did not take into account the relationship between vehicle speed and the amount of work of the frictional engagement device as described above. . That is, this Japanese Patent Application Publication No. 1983-
The technologies proposed in the above-mentioned publications, including 69738, all focus only on automatic gear shifting, and therefore focus on the "shift point (vehicle speed)" at which gear shifting occurs.
was assumed to be determined in advance within a specific narrow range. However, manual upshifts, such as upshifts caused by manual operation to D range after pulling the vehicle to high speed while driving in 2nd gear,
In the case of upshifting due to manual operation to enable overdrive after pulling the vehicle to a high speed with overdrive not permitted, the "shift point (vehicle speed)" itself is not determined at all, and therefore, for the reason mentioned above, the "shift point"'' may vary greatly, and accordingly, the energy (work amount) to be absorbed by the frictional engagement device, particularly the work amount due to inertia torque, will vary greatly. Therefore, in order to ensure the durability of the friction engagement device, it becomes necessary to make the amount of change in engine torque itself dependent on the vehicle speed, but the conventional technology has not anticipated this problem at all. It was.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and provides an automatic transmission for a vehicle that can prevent an increase in the amount of work of a friction engagement device and reduce a shift shock when performing a manual upshift. The object of the present invention is to provide an upshift control device.

[Means to solve the problem]

The present invention includes means for detecting vehicle running conditions including vehicle speed, and a manual operation mechanism,
In an upshift control device for an automatic transmission that has both cases of upshifting automatically based on vehicle driving conditions and cases of upshifting based on manual operation, a command to upshift based on manual operation is received. When upshifting based on manual operation, the engine torque increases as the actual vehicle speed is higher than the vehicle speed that is the shift point when upshifting is automatically performed based on the vehicle running condition. The above object is achieved by providing means for greatly reducing the Further, in an embodiment of the present invention, the reduction amount of the engine torque is determined based on a predetermined map that takes into account not only the vehicle speed but also the type of gear change or the throttle opening. can be set to the optimum amount. Further, in another embodiment of the present invention, the amount of reduction in the engine torque is determined based on the degree of work of the friction engagement device determined by taking into account the type of gear change or the throttle opening in addition to the vehicle speed. In particular, it is possible to accurately prevent an increase in the load on the frictional engagement device. Furthermore, in another embodiment of the present invention, the engine torque reduction amount is based on an engine torque reduction amount that is determined corresponding to when an upshift is executed by automatic gear shifting in the drive range, and By correcting the basic engine torque reduction amount according to the vehicle speed at the time of manual upshifting, it is possible to perform manual upshifting with fewer design changes if engine torque is controlled during drive range driving. This allows us to respond accurately even at times. As described above, the present invention does not depend on whether or not torque down control is performed during drive range driving, but rather reduces the workload of the friction engagement device when a manual upshift is performed in a high-speed state. , and from the viewpoint of improving the transmission shock, this is independently established regardless of the presence or absence of engine torque reduction control during drive range driving.

[Effect]

In the present invention, since the amount of torque of the engine is changed by an amount dependent on the vehicle speed during a manual upshift, the amount of torque transmitted from the engine during the shift can be appropriately changed, and therefore each part of the automatic transmission can be changed. By controlling the amount of energy absorbed by the members or the frictional engagement devices that brake them, gear shifts can be completed in a short time and with a small shift shock. Durability can be improved.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 4 is an overall schematic diagram of an automatic transmission combined with an intake air amount sensing type automobile electronic fuel injection engine to which the present invention is applied. Air taken in from the air cleaner 10 is sent to an air flow meter 12, a throttle valve 14, a surge tank 16, and an intake manifold 18 in sequence. This air is mixed with fuel injected from the injector 22 near the intake port 20, and
Further, the combustion chamber 26A of the engine body 26 via 4
sent to. Exhaust gas generated as a result of combustion of the air-fuel mixture in the fuel chamber 26A passes through the exhaust valve 2.
8, exhaust port 30, exhaust manifold 32 and exhaust pipe 34 to the atmosphere. The air flow meter 12 is provided with an intake temperature sensor 100 for detecting intake temperature. The throttle valve 14 rotates in conjunction with an accelerator pedal (not shown) provided at the driver's seat.
This throttle valve 14 is provided with a throttle sensor 102 for detecting its opening degree. Further, a water temperature sensor 104 for detecting the engine cooling water temperature is disposed in the cylinder block 26B of the engine main body 26, and a water temperature sensor 104 for detecting the oxygen concentration in the collecting part of the exhaust manifold 32 is disposed in the collecting part of the exhaust manifold 32. An O ₂ sensor 106 is provided. Further, the distributor 38 having a shaft rotated by the crankshaft of the engine body 26 is provided with a crank angle sensor 108 for detecting a crank angle from the rotation of the shaft. The automatic transmission A/T also includes a vehicle speed sensor 100 for detecting vehicle speed from the rotational speed of its output shaft, and a shift position sensor for detecting shift positions such as a drive range and a 2nd speed travel range. A sensor 112 is provided. Each of these sensors 100, 102, 104, 1
The outputs of 06, 108, 110, and 112 are input to an engine computer (hereinafter referred to as ECU) 40. The ECU 40 calculates the fuel injection amount using input signals from each sensor as parameters, and controls the injector 22 to inject fuel for a predetermined time corresponding to the fuel injection amount. Note that an idle rotation control valve (ISCV) 42 is provided in the circuit that communicates the upstream side of the throttle valve 14 and the surge tank 16, and the ECU 40
The idle speed is controlled by a signal from the engine. As shown in detail in FIG. 5, the ECU 40 includes:
A central processing unit (CPU) 40A consisting of a microprocessor, a memory 40B for storing control programs and various data, and converting analog signals from the intake temperature sensor 100, water temperature sensor 104, etc. into digital signals. In order to incorporate
An analog-to-digital converter (A/D converter) 40C having a multiplexer function and outputs from the throttle sensor 102, O ₂ sensor 106, crank angle sensor 108, vehicle speed sensor 110, shift position sensor 112, etc. are directly transmitted. An input interface circuit 40D for inputting the ignition signal to the ignition coil 44 and an ignition signal to the injector 2 according to the arithmetic processing results of the CPU 40A.
Combustion injection signal to ISCV 2, idle rotation control signal to ISCV 42, and ECT for automatic transmission A/T
and an output interface circuit 40E for outputting signals to the computer 50. On the other hand, the ECT computer 50 includes a central processing unit (CPU) 5 consisting of a microprocessor.
0A, a memory 50B for storing control programs and various data, etc., and a throttle sensor 10.
2. Vehicle speed sensor 110, shift position sensor 1
12. An input interface circuit 50D for inputting outputs from the pattern select switch 120, brake lamp switch 122, cruise control switch 124, and overdrive switch 126, and an automatic transmission according to the arithmetic processing results of the CPU 50A. It is comprised of an output interface circuit 50E for outputting control signals to solenoids S ₁ , S ₂ , and S ₃ of the A/T. The automatic transmission A/T includes a 2-3 shift valve 61 driven by the solenoid _S1 , a 1-2 shift valve 62 and a 3-4 shift valve 63 driven by the solenoid _S2 , and a 3-4 shift valve 63 driven by the solenoid S2. A lock-up crunch control valve 64 driven by a solenoid S ₃ and a shift valve 6
1 and 62 control a third speed section unit for obtaining a gear ratio configuration of first to third speeds, and a shift valve 63 controls an overdrive unit for obtaining an overdrive gear ratio. ,
A lock-up clutch control valve 64 controls a lock-up clutch that mechanically directly connects the input and output sides of the torque converter. Also, in this ECU40, crank angle sensor 1
Using the fact that the reciprocal of the time interval of the signal for each 30° crank angle output from the crank angle sensor 108 is proportional to the engine rotation speed, the engine rotation speed is calculated based on the output signal from the crank angle sensor 108. I'm looking for. Furthermore, this ECU 40 is an ECT computer 5
0 shift information (shift judgment, shift command, lock-up clutch engagement permission, etc.), executes engine torque down control and uses this control information.
Output to the ECT computer 50. Based on this information, the ECT computer 50 issues a lock-up crunch release command and checks whether the above control is being performed reliably. In this embodiment, the ECU 40 and the ECT computer 50 are separate units, and are set to reduce engine torque during both automatic gear shifting and manual shifting during drive range driving, and the amount of engine torque reduction and The ECU 40 determines and executes the timing. Next, the operation of this embodiment will be explained using FIG. First, in step 200, a manual upshift is determined based on the output of the shift position sensor 112 or overdrive switch 126, etc., and after a time corresponding to timer _T1 has elapsed in step 202, a shift command is output in step 204. be done. Note that the timer
The reason for having a grace period of T ₁ is that 2 or more within a short period of time,
Alternatively, this is to issue a shift command based on the last shift decision made when a shift decision of two or more gears is made. After that, in step 206, the engine speed Ne is monitored to detect the inertia phase (rotational speed change section of each member of the automatic transmission), the throttle opening θ is monitored to detect the engine load, and , the vehicle speed (rotational speed of the output shaft of the automatic transmission) No. is monitored to detect inertia torque during gear shifting. This monitor first detects in step 208 when a member of the automatic transmission enters the inertia phase. This inertia phase is detected by determining whether or not the current engine rotational speed Nei has become smaller than the previous engine rotational speed _Nei-1 for ni consecutive times. When the inertia phase is detected in step 208, the process proceeds to step 210, where it is determined whether No≧Nc+Na holds true. Here, Nc is the upshift shift point in drive range driving, Na is,
This is a constant determined by the type of gear change and throttle opening. When No≧Nc+Na is established in step 210, it is determined that the vehicle speed is very high compared to the upshift shift point in the drive range, and the
At 212, a command is issued to reduce the engine torque by 50%, and the lock-up clutch is turned off.
A command is issued. If No≧Nc+Na is not established in step 210, it is determined that the vehicle speed is not very high compared to the upshift shift point in the drive range, and in step 214, a 30% reduction command for engine torque and a lock-up clutch are issued.
An OFF command is issued. Next, in step 216, Nei<No×I _H −N ₁
The end timing of the inertia phase is detected by determining whether or not _n times have occurred consecutively. Here, _IH is the gear ratio after shifting, and _N1 is a constant determined according to the type of shifting and the throttle opening θ. When the end timing of the inertia phase is detected in step 216, an engine torque return command is output in step 218, and in step 220, it is determined whether or not the period after the gear change is within the lock-up clutch engagement permission range, and the lock-up clutch is engaged. If it is within the lock-up permission area, a lock-up clutch engagement permission command is issued in step 222. In FIG. 1, F _T and F _P are time flags or phase flags for controlling the time or success/failure of conditions in steps 202, 208, and 216, respectively. That is, step 202 is a step for setting a timer _T1 between when a manual upshift is determined and when a gear change command is _issued . Step 300 while still small
After setting the timer flag F _T to 1, it is reset. In this case, in step 301
Since the determination is YES, the process directly advances to step 202, where it is again determined whether or not the time t has become larger than the timer _T1 .
The process proceeds to step 302, where the timer flag F _T is reset to 0, and then a gear shift command is issued. Further, step 208 is a step for determining whether or not the automatic transmission has entered the inertia phase, but unless the automatic transmission has entered the inertia phase yet, the phase flag F _P is set to 1 in step 400 and then reset. In this case, the process proceeds from step 401 to step 402 and then to step 206, so each monitor in step 206, until entering the inertia phase,
The determination in step 208 is repeated, and when the inertia phase is entered, the process proceeds to step 210. Further, step 216 is a step for detecting the completion of the inertia phase, but while it is still in the inertia phase, the phase flag F _P is set to 2 in step 403 and then reset.
In this case, after proceeding to step 401 and step 402, the process proceeds to step 216 again, so that the determination corresponding to step 216 is repeated until the inertia phase is completed, and the determination at step 216 is repeated.
Only when the answer is YES will the process proceed to step 218. Note that the phase flag F _P is
It is reset to 0 at 404. Next, FIG. 2 shows a speed change transient characteristic diagram. In the figure, the solid line shows the drive range, the broken line shows the transient characteristics during the conventional manual shift in the high speed state, and the one-dot chain line shows the transient characteristics during the manual shift in the high speed state according to this embodiment. In the drive range, as in the past, after a shift command is issued, the engine rotational speed Ne and throttle opening θ are monitored, engine torque down control is started when the engine torque down start conditions are met, and an appropriate time is set after the return conditions are met. The torque is being restored. In this case, if the shift control is performed during manual shift at high speed under the same conditions as when driving in the drive range (in this example, the ignition retard amount ΔT is the same), the inertia torque of the friction engagement device is absorbed. As the number of minutes increases, the shift time also increases. The increase in the shift time means an increase in the load on the frictional engagement device. According to this embodiment, after a shift command, not only the engine rotation speed Ne and the throttle opening θ but also the vehicle speed (output shaft rotation speed of the automatic transmission) No are monitored,
Even if the throttle opening θ is the same, the amount of engine torque reduction is increased (the ignition retard amount is increased to ΔT') depending on the value of the vehicle speed No, and frictional engagement is achieved with the shift time being approximately the same as during automatic shifting in the drive range. The durability of the equipment is ensured. In the above embodiment, the vehicle speed No. is the upshift shift point Nc during drive range driving.
The amount of torque reduction of the engine was divided into two types, 50% and 30%, based on whether or not the amount of torque reduction was greater than a constant Na determined by the type of gear shift and throttle opening. The method for determining the amount of engine torque reduction in the present invention is not limited to this, but may be determined based on a map consisting of the type of shift, throttle opening, and vehicle speed, for example. According to this method, highly accurate engine torque down control can be performed in response to fluctuations in each element. Alternatively, the determination may be made based on the degree of thermal load on the frictional engagement device determined from the type of gear change, throttle opening, and vehicle speed. In this case, the degree of the heat load may be calculated from a theoretical formula, or may be approximated by a function in advance from experimentally measured data.
According to this method, control can be performed more directly and with high precision in terms of reducing the load on the frictional engagement device. Furthermore, the engine torque control amount is determined based on the engine torque control amount that has been determined in response to power-on upshift automatic gear shifting in the drive range, and is determined by changing the basic engine torque control amount in accordance with the vehicle speed at the time of manual upshifting. You may.
In other words, this method is a more accurate version of the method in the embodiment described above, and as an example of this method, as shown in FIG. It is conceivable to divide the torque into two cases depending on how high the throttle opening is, and further change the amount of engine torque reduction depending on the throttle opening. In addition,
In the example shown in Figure 3, when the throttle opening is high, the vehicle speed is
As No increases, the inertia equivalent term of the absorbed energy of the frictional engagement device increases rapidly during gear shifting, and this exceeds the amount of engine torque absorbed due to the decrease in engine torque, so the amount of engine torque reduction is increased. At medium and low throttle openings, the amount of absorption is originally low and the amount of reduction in engine torque is large, so the amount of torque reduction is not particularly changed. Further, in the above embodiment, the rotational speed No. of the automatic transmission output shaft is used to detect the vehicle speed, but the present invention is not limited to this, and the rotational speed of the engine rotational speed and the rotational speed of the automatic transmission rotating member is used to detect the vehicle speed. may be substituted for this. In this case, it goes without saying that the value No that determines the amount of torque reduction can also be replaced with this value. In addition, in the above embodiment, the engine rotation speed
Although the engine torque reduction control is performed after monitoring Ne and recognizing the completion of the start of the inertia phase, the present invention is not limited to the timing of starting and returning the engine torque reduction. Further, in the above embodiment, a means for increasing or decreasing the amount of retardation of the ignition timing was adopted as a control means for reducing the engine torque, but the present invention is not limited to the means for reducing the engine torque itself. For example, means for increasing or decreasing the amount of fuel injection, means for controlling the opening/closing timing of intake and exhaust valves, means for controlling the amount of intake air, etc. may be used.

【Effect of the invention】

As explained above, according to the present invention, when a manual upshift is performed, it is possible to prevent an excessive load on the friction engagement device and also to reduce the shift shock, which is an excellent effect. .

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an embodiment of an upshift control device for a vehicle automatic transmission according to the present invention, and FIG.
3 is a graph showing an example of a map for limiting the amount of torque reduction. FIG. 4 is a graph showing the intake air to which the above embodiment is applied. FIG. 5 is an overall schematic diagram of an automatic converter combined with a volume sensing electronic fuel injection engine for an automobile, and is a block diagram extracting the input/output relationship of the engine and automatic transmission. 102...Throttle sensor, 110...Vehicle speed sensor, 112...Shift position sensor, 1
26...Overdrive switch, θ...Throttle opening, No...Vehicle speed (output shaft rotational speed of automatic transmission), Nc...Power ON in D range
Upshift gear point, Ne...Engine rotation speed.

Claims (1)

[Claims] 1. Means for detecting vehicle running conditions including vehicle speed;
In an upshift control device for an automatic transmission for a vehicle, which is equipped with a manual operation mechanism and has both automatic upshifting based on vehicle running conditions and upshifting based on manual operation, means for detecting whether or not a command to upshift has been received based on a manual operation; An upshift control device for an automatic transmission for a vehicle, comprising: means for reducing engine torque to a greater extent as the vehicle speed is higher than the corresponding vehicle speed. 2. The vehicle according to claim 1, wherein the reduction amount of the engine torque is determined based on a predetermined map that takes into consideration not only the vehicle speed but also the type of gear change or the throttle opening. Upshift control device for automatic transmission. 3. Claims characterized in that the amount of reduction in the engine torque is determined based on the degree of work of the frictional engagement device determined in consideration of the vehicle speed, the type of gear change, or the throttle opening. 2. An upshift control device for a vehicle automatic transmission according to item 1. 4. The engine torque reduction amount is based on the engine torque reduction amount that is determined in response to when an upshift is automatically executed in the drive range based on the vehicle running condition, and the basic engine torque reduction amount is determined. The upshift control device for an automatic transmission for a vehicle according to claim 1, wherein the upshift control device for an automatic transmission for a vehicle is determined by correcting according to the actual vehicle speed at the time of manual upshifting.