JPH0330021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an electronically controlled automatic transmission system.

Prior Art and Problems Conventionally, an electronically controlled automatic transmission system is known that automatically and electronically performs shift switching or lock-up control in response to changes in vehicle speed and throttle opening. In other words, it detects the vehicle speed and throttle opening as the vehicle's driving condition, and when these reach a predetermined relationship, it automatically and electronically controls shifts, etc., based on road surface conditions, loaded weight, etc. No consideration is given to load conditions.

However, when accelerating under a light load such as downhill, it is better to shift up at low speed (low engine speed) than when accelerating on a flat road surface, both in terms of ride comfort and fuel efficiency. Conversely, when decelerating under a heavy load such as going uphill, it is better to downshift at high speed (high engine speed) than when the road is flat, both in terms of ride comfort and fuel efficiency. There is.

In this way, in the conventional method, shift switching control was performed without considering the negative state of the vehicle.
There were problems with ride comfort and fuel efficiency.

OBJECTS OF THE INVENTION The present invention has been made in view of the problems of the conventional systems described above, and its purpose is to provide an electronically controlled automatic transmission system that improves ride comfort and fuel efficiency.

Structure of the Invention The present invention achieves the above objects in an electronically controlled automatic transmission system that automatically and electronically performs shift switching or lock-up control according to changes in vehicle speed and throttle opening. setting a control reference value indicating the speed at which shift switching or lock-up control is to be performed, and changing the control reference value in a direction in which the deviation becomes larger when the deviation between the vehicle speed and the control reference value becomes less than a predetermined value; The shift switching or lock-up control is performed at a lower speed when the acceleration is higher during acceleration, and at a lower speed when the deceleration is lower during deceleration.

Further, it is effective to limit the change in the control reference value to within a range stored in accordance with the shift position and throttle opening.

FIG. 1 is a conceptual diagram for explaining the configuration of the present invention based on the concept of a shift line, and the horizontal axis is a vehicle speed V,
The vertical axis shows the throttle opening S, and the inclined straight line shows the gear shift line.

First, in the conventional system, the shift line is a dashed-dotted line.
Fixed as shown in To. When increasing the vehicle speed V from point A to point B while keeping the throttle opening S constant, in the conventional method, when the line segment AB intersects the fixed shift line To, regardless of the magnitude of acceleration, That is, the shift up was performed when the vehicle speed V became Lo.

On the other hand, in the present invention, when the acceleration is large, the state is equivalent to that the shift line T1 is set, and as a result, a shift up is performed at L1, which is lower than Lo. Conversely, when the acceleration is small, the state is equivalent to setting the shift line T2, and as a result, upshifting is performed at L2, which is faster than Lo.

In the case of deceleration, as shown in Figure 2, in the conventional method, a downshift is performed when the line segment AB intersects the fixed shift line To, that is, when the vehicle speed V becomes Lo, regardless of the magnitude of acceleration. It was done.

On the other hand, in the present invention, when the deceleration is large, the state is equivalent to setting the shift line T2', and as a result, downshifting is performed at L2', which is higher than Lo. Conversely, when the deceleration is small, the state is equivalent to setting the shift line T1', and as a result, downshifting is performed at L1', which is lower than Lo.

Shift points L1, L2, L in Figures 1 and 2
1'L2' depends on the magnitude of acceleration and deceleration.
It fluctuates between Lmin and Lmax, and between Lmin' and Lmax'.
The variation range Lmax-Lmin, etc. can be set to appropriate values depending on the shift speed and shift position. A preferred example is to set the shift speed to a certain percentage (for example, 30%).

The shift switching control of the present invention described above is performed by the CPU.
It may be implemented in software by providing a table of shift line groups in the table, or it may be implemented in hardware.

An example in which the process is executed mainly by hardware will be described below.

Embodiment of the Invention FIG. 3 is a block diagram of an embodiment of the invention.

1 receives the shift position signal SP, the acceleration polarity α/|α|, and the throttle opening signal S, and determines the minimum level Lmin and maximum level accordingly.
A level setting circuit that generates Lmax, 2 a vehicle speed detection circuit that detects the vehicle speed V, 3 a subtraction circuit that outputs the difference between the level L that fluctuates between Lmin and Lmax, and the vehicle speed V, and 4 the polarity of V-L. 5 is an integrator circuit that inverts and integrates the positive or negative constant current and outputs a negative or positive voltage proportional to the amount of integration; 6 is V-L; Absolute value circuit 7 outputs the absolute value of |V-L| and a predetermined reference value REF, and according to the comparison result, constant current circuit 4
8 is an addition circuit; 9 is a skip circuit that gives skip characteristics to the change in level L over time; 10 is a hold circuit that holds level L between the minimum level Lmin and the maximum level Lmax;
Reference numeral 1 denotes a comparison circuit that compares level L and vehicle speed V and generates a comparison and coincidence output, and 12 a shift switching control circuit that performs shift switching control in response to this comparison and coincidence output.

The operation of the circuit shown in FIG. 3 will be described below with reference to FIG. 4, which illustrates temporal changes in vehicle speed V and level L.

The level setting circuit 1 outputs a predetermined minimum level Lmin to the addition circuit 8 based on the input shift position signal SP, acceleration polarity, and throttle opening signal S, and also outputs the minimum level Lmin and maximum level Lmax to a hold circuit. Supply to 10. In the example of FIG. 4, the vehicle is in an accelerating state. Lmin and Lmax for shift up are output. Addition circuit 8
The minimum level Lmin supplied to the skip circuit 9,
The signal is inputted to one input terminal of the subtraction circuit 3 via the hold circuit 10. The vehicle speed V detected by the vehicle speed detection circuit 2 is input to the other input terminal of the subtraction circuit 3 . The output V-L of the subtraction circuit 3 is input to a constant current circuit 4 and an absolute value circuit 6. Output of absolute value circuit 6 |
V−L| is input to the constant current circuit 4 and the comparison circuit 7. The constant current circuit 4 receives the input V- on the condition that it is activated by the output of the comparator circuit 7.
Based on L and |V-L|, when the polarity of V-L is positive, a positive constant current is output, and when the polarity of V-L is negative, a negative constant current is output. On the other hand, the output of the absolute value circuit 6 |V
-L| is a predetermined reference value in the comparator circuit 7.
Compared to REF. As shown on the left side of Figure 4,
When the vehicle speed V is sufficiently low and Lmin-V is larger than the reference value REF, the constant current circuit 4 is not activated,
Therefore, the output of the integrating circuit 5 remains at zero. As a result, despite the increase in vehicle speed V, level L remains
It is held at Lmin.

As vehicle speed V increases, Lmin-V changes to reference value REF
When it becomes smaller than , the constant current circuit 4 is activated,
The output of the integrating circuit 5 begins to rise at a predetermined speed, and as a result, the level L starts to rise at a predetermined speed.
The rising speed of this level L is set so that level L and vehicle speed V become equal after a while after the start of rising.
The vehicle speed V is set to be smaller than the general increase speed of the vehicle speed V during acceleration. When the level L and the vehicle speed V match in this way, a shift switching control command is issued from the comparator circuit 11 to the shift switching control circuit 12. Shift switching control circuit 14 receiving this command
performs shift-up control. At the same time, the operation of the skip circuit 9 causes the level L to be skipped in the opposite direction to the previous direction of change.

The skip circuit 9 includes an integration circuit 13 that integrates the output of the constant current circuit 4 and outputs a voltage proportional to this integrated value, a delay circuit 14, and a polarity mismatch detection circuit 1.
5. It consists of a switch 16 driven by this polarity mismatch detection output and an adder circuit 17. When the polarity mismatch detection circuit 15 generates a polarity mismatch output for a predetermined delay time set in the delay circuit 14 as the vehicle speed V and the level L match, the switch 16 is driven and the integration circuit 13 is activated.
The output terminal of is released from the ground condition. The output of the integrating circuit 13 has a polarity opposite to that of the output of the integrating circuit 5, and its rate of change is also set to be a value greater than that of the integrating circuit 5. As a result, the level L rapidly decreases over a predetermined delay time set in the delay circuit 14. By providing such a skip characteristic, it is possible to prevent the output of the comparison circuit 11 from chattering.

When the predetermined delay time has elapsed, the output of the integrating circuit 13 is grounded again by the switch 16 and becomes 0.
The level L begins to rise again due to the output of the integrating circuit 5. When the level L reaches Lmax, the hold circuit 10 functions to hold it at Lmax.

Level setting circuit 1 is shift position signal SP
If the polarity of the acceleration is still positive after being incremented by 1, output Lmin and Lmax for the next shift up. On the other hand, when the polarity of acceleration becomes negative, that is, when the state changes to a deceleration state, Lmin and Lmax for downshifting are output.

Even during deceleration, downshift control is performed by the same operation as described above.

That is, the level setting circuit 1 detects the deceleration state from the polarity of acceleration and sets Lmin' and Lmin' for downshifting.
Lmax' is set and supplied to the hold circuit 10, and Lmax' is supplied to the adder circuit 8. In this example, for simplicity, Lmax'=Lmax. When the difference from Lmax becomes equal to the reference value REF as the vehicle speed V decreases, the constant current circuit 4 is activated and the integrating circuit 5 outputs a negative voltage that decreases at a predetermined speed. Note that the output of the integrating circuit 5 during the above-mentioned shift-up is discharged at an appropriate time constant after the operation of the constant current circuit 4 is prohibited.
It is 0 at the start of this downshift or the next upshift. When the vehicle speed V and the level L match, the comparison circuit 11 issues a shift change command to the shift change control circuit 12, and the skip circuit 9 operates. After the skip operation is completed,
The level L decreases at a constant speed and is held at Lmin by the hold circuit 10.

FIG. 5 illustrates the difference in shift switching control by the circuit of FIG. 3 when the vehicle accelerates and decelerates at different accelerations and decelerations. In this figure, the skip characteristic is omitted for simplicity. It is clear from the figure that during acceleration, the higher the acceleration, the lower the speed is, and during deceleration, the lower the deceleration, the later the shift change is performed.

For convenience of explanation, shift switching control is shown as an example in which the throttle opening is held constant, but the present invention is not limited to this. Lmin and
This is because even if Lmax fluctuates, it does not affect the essence of the above explanation.

Further, although an example has been shown in which the skip circuit 9 is used, it is obvious that this may be omitted.

Furthermore, although an example has been shown in which the rate of change of level L is constant, it is clear that this rate of change may be changed depending on the throttle opening and shift position, and may also be made to vary depending on the vehicle speed V. .

Furthermore, as mentioned above, the invention can also be implemented in software.

Effects of the Invention As described above in detail, the present invention has a configuration in which shift switching control is performed in consideration of load conditions, and therefore has the advantage that ride comfort and fuel efficiency can be improved.

[Brief explanation of drawings]

1 and 2 are conceptual diagrams for explaining the configuration of the present invention by replacing it with the concept of a transmission line, FIG. 3 is a configuration block diagram of an embodiment of the present invention, and FIGS.
FIG. 3 is a conceptual diagram for explaining the operation of the circuit shown in the figure. V...Vehicle speed, S...Throttle opening, To, T
1, T2...shift line, Lmin...minimum level,
Lmax...Maximum level, 1...Level setting circuit,
2... Vehicle speed detection circuit, 3... Subtraction circuit, 4... Constant current circuit, 5, 13... Integrating circuit, 6... Absolute value circuit, 7... Comparison circuit, 9... Skip circuit, 1
0...Hold circuit, 11...Comparison circuit, 12...
...Shift switching control circuit.

Claims (1)

[Claims] 1. In an electronically controlled automatic transmission system that automatically and electronically performs shift switching or lock-up control according to changes in vehicle speed and throttle opening, A control reference value indicating the speed at which lock-up control is to be performed is set, and when the deviation between the vehicle speed and the control reference value becomes less than a predetermined value, the control reference value is changed in a direction that increases the deviation, and when accelerating, the acceleration is large. At a relatively slow speed,
An electronically controlled automatic transmission system characterized in that during deceleration, the smaller the deceleration, the lower the speed becomes before performing shift change or lock-up control. 2. The electronically controlled automatic transmission system according to claim 1, wherein the change in the control reference value is limited within a stored range according to a shift position and a throttle opening.