JPS62160929A - Speed shift pattern change-over system in electronic control type automatic speed change gear - Google Patents

Abstract

PURPOSE:To enhance the driving function of a vehicle having a speed change gear, by detecting the opening degree of a throttle valve and acceleration to automatically change over the speed shift pattern from a normal condition into a power condition and vice versa. CONSTITUTION:For example, if a reference value with which whether the opening degree theta of a throttle valve is large or small is judges, is 20%, when theta>=20%, an acceleration calculating vehicle speed sampling timer T (which will be denoted simply as 'timer') measures the time lapse. An acceleration is calculated for every minute and is compared with a set value DELTAn/T obtained from a ROM table on which data are set for each computation, shift pattern or shift position, in accordance with the opening degree theta of the throttle valve and an initial speed N1. If DELTAN>=DELTAn, a power pattern is selected while if DELTAN<DELTAn, a normal pattern is selected. Meanwhile, if theta<20%, the time T is cleared and a change- over time T' is started. Further, if the above-mentioned condition theta<20% is still sustained, the speed shift pattern is returned into the normal pattern from the power pattern. With this arrangement, it is possible to enhance the driving function of the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shift pattern switching system for an electronically controlled automatic transmission.

[Conventional technology]

Electronically controlled automatic transmissions for automobiles automatically change gears in response to shift signals from an electronic control unit (ECU) using a microcomputer, but generally the ECU
In addition to the normal pattern, there is a shift pattern built into the program called a power pattern. The normal pattern is a fuel-efficient shift pattern that does not interfere with normal driving. On the other hand, the power pattern is a high-output shift pattern used when the rider is uphill or overweight, and has a shift point at a higher rotational speed than the normal pattern.

[Problem that the invention seeks to solve]

However, in the past, the above-mentioned shift pattern was manually switched, which had the drawback of increasing the load on the driver and degrading driving performance when the vehicle frequently went up and down on mountain roads and the like. The present invention attempts to improve this point.

[Means for solving problems]

The present invention detects the throttle opening and acceleration of a vehicle to open the swirler in a shift pattern switching system for an electronically controlled automatic transmission that has a normal shift pattern and a power pattern with a higher rotation speed as a shift point. When the acceleration falls below a set value when the throttle opening is above a certain value, the normal pattern is automatically switched to the power pattern, and when the throttle opening falls below a certain value, the power pattern is returned to the normal pattern. It is characterized by this.

[Effect]

The present invention focuses on the fact that if the throttle opening and shift gear position are the same, the acceleration when climbing a mountain (or when driving with an overweight load) is smaller than when driving on flat ground, and detects this point and automatically changes the shift pattern. I am trying to switch.

FIG. 1 is a diagram explaining the principle of the present invention, (al is an approximate linear representation of the vehicle speed characteristic when the throttle opening is constant. The solid line at is the characteristic during actual driving, and the time T The vehicle speed is increased from NI to Nt+ΔN within the same period.The dashed line al' is a reference line, and the increment Δn in vehicle speed is determined by the throttle opening, initial speed N1, shift pattern, shift position, and engine performance. This is the set value.In this case where the throttle is constant, a
When the slope of t decreases to below ai', that is, Δ
It is sufficient to switch from the normal pattern to the power pattern when N becomes equal to or less than Δn.

Figure 3) shows the time when the throttle is changed, and the vehicle speed characteristic changes from ai to ai+1 within time T. The set value Δn in this case is the set value Δn1 within the time Tl at ai,
Set value Δn2 within time (T-T+) at a,+
and compare this with ΔN. and,
When ΔN<Δn, the normal pattern is switched to the power pattern.

However, if the throttle opening is small or if the throttle opening decreases within time T, the normal pattern may be left as is even if ΔN decreases. Further, the conditions for returning from the power pattern to the normal pattern may be either (i) ΔN>Δn for a certain period of time, or (i) the throttle opening becomes small for a certain period of time.

FIG. 5 is a system configuration diagram. □, 1 is the ECU, and 2 is the automatic transmission 1i1111 (T/M). In addition to the car superstition □N, the ECUI inputs include a signal θ indicating the throttle opening degree and a range signal indicating the current gear position, and outputs a gear change signal to the transmission 2 with reference to these signals.

〔Example〕

FIG. 2 is a flowchart showing one embodiment of the present invention, in which θ
is the throttle opening, T is a vehicle speed sampling timer for acceleration calculation, and T' is a timer for determining switching from the power pattern to the normal pattern.

In this example, the throttle opening degree θ is judged based on 20'', and if θ≧20', T is measured and acceleration is calculated every minute.The acceleration is ΔN/T. This is compared with the set value Δn, > T. ΔN is calculated as the difference N - N + between the timer T started at the time when the initial speed NI is memorized, and the vehicle speed N at the time when T has elapsed. The same applies to Δn/T, but this value is calculated or determined from the ROM table recorded as the acceleration setting value Δn/T. Fig. 4 is a diagram showing an example of the ROM table, and it is calculated for each shift pattern and shift position. This ROM table sets the acceleration setting value Δn/' according to the throttle opening θ and the initial speed N1.
T is determined, and a set vehicle speed increment Δn is determined from the elapsed time T.

When the acceleration ΔN/T is less than the set value Δn/7 (ΔN<Δn), the power pattern is selected. 0
Even if it is 520%, if ΔN≧Δn, the normal pattern remains.

On the other hand, when θ<20%, the T timer is cleared and the T' timer is started. And even after 1 minute, θ<2
If it is 0%, the power pattern is returned to the normal pattern.

FIG. 3 is a flowchart showing another embodiment of the present invention,
This corresponds to the throttle change shown in FIG. 1(b).

θn is the average value of the throttle opening over one minute, and the acceleration is also the average value □ over one minute.

Further, ΔNp is a variable that changes to the power pattern, and □ΔNn is a variable that returns to the normal pattern, with the relationship ΔNn>ΔNp. In this example, the throttle opening degree is determined based on 10%, but it may be 20% as in the previous example. θn
ΔNp and ΔNn are stored in the ROM table in advance, and ΔNp and ΔNn retrieved from θn are used as the acceleration ΔNp and ΔNn.
The shift pattern is determined by comparing with N.

In this example, each time the throttle opening θ changes, the acceleration set value ΔN n /T or ΔNp/T is sequentially set from the ROM table as shown in Fig. 3 according to the throttle opening θ and initial speed NI at that time. Each set value ΔN+, 2. ..., i is determined, and the set vehicle speed increment ΔNn or ΔNp is set based on the sum of these values.

〔Effect of the invention〕

As described above, according to the present invention, the shift pattern of an electronically controlled automatic transmission can be automatically switched by detecting the throttle opening and acceleration, thereby improving the driving function of a vehicle using the transmission. There is an advantage that it can be done.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention, FIGS. 2 and 3 are flowcharts showing different embodiments of the present invention, and FIG. 4 is a diagram explaining the principle of the present invention.
FIG. 5, which is a diagram showing an example of an OM table, is a system configuration diagram of an electronically controlled automatic transmission. In the figure, 1 is an electronic control unit and 2 is an automatic transmission. Applicant Fujitsu Ten Ltd. Representative Patent Attorney Ryo Aoyagi B Implementation Row 2 System Configuration Diagram Figure 5

Claims (1)

[Claims] In the shift pattern switching method of an electronically controlled automatic transmission that has a normal shift pattern and a power pattern with a higher rotation speed as a shift point, the throttle opening and acceleration of the vehicle are detected and the throttle opening is set to a constant value. When the acceleration falls below a set value, the normal pattern is automatically switched to the power pattern, and when the throttle opening falls below a certain value, the power pattern is returned to the normal pattern. A shift pattern switching method for electronically controlled automatic transmissions.