JPS59151655A - Control device for automatic transmission in vehicle - Google Patents

Abstract

PURPOSE:To prevent the side slip of a vehicle due to gear-shifting operation upon slipping, by turning off the output signal of a computing circuit for calculating the timing of gear-shifting, when the rising rate of the output shaft speed of a transmission unit is above a set value. CONSTITUTION:An acceleration detecting circuit 4 which receives a signal from a vehicle speed sensor 2 to detect the acceleration of a vehicle, determines that the detected acceleration becomes higher than a preset value and issues a high acceleration signal 4a, the detection criterion setting value being set at the degree of acceleration at which th slip of tires occurs. A gear-shift restraining circuit 5 inhibits gear-shifting operation irrespective of the condition of a gear- shifting timing computing circuit 3 when the above-mentioned acceleration detecting circuit 4 issues its output signal 4a. Accordingly, gear-shifting operation is carried out upon occurrence of a tire slip, thereby the side slip of the vehicle may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an automatic transmission for a vehicle that electrically calculates shift timing in relation to engine load and vehicle speed and automatically performs a shift operation.

Conventionally, commonly used electronically controlled automatic transmissions for automobiles electrically detect the engine load condition and vehicle speed as basic input signals, and use a shift timing calculation circuit, for example, to determine the optimum shift timing for the vehicle's driving conditions. Based on the calculation, a plurality of solenoid valves provided in the hydraulic pressure 11I control circuit of the transmission are operated in an appropriate combination according to the output, thereby switching the hydraulic control circuit and achieving a gear shifting operation.

In the case of the conventional device described above, the engine load condition is determined by a throttle opening sensor that generates a signal according to the engine throttle opening, and the speed # is provided on the output shaft of the transmission and is proportional to the rotation of the output shaft. Each is detected by a vehicle speed sensor that generates an electric signal, and the shift characteristics are such that the greater the throttle opening, the faster the shift timing shifts to a higher vehicle speed of 111+1.

Therefore, the gear ratio change of the transmission is determined by the engine throttle opening and the rotation speed of the transmission output shaft. In this case, the driving force of the tires becomes very small, so even when the accelerator pedal is depressed even slightly, the driving force of the engine exceeds the driving force of the tires, causing the tires to slip. Once slippage occurs in the tires, the coefficient of friction on the road surface generally decreases further, so the tire slippage becomes even greater, and the vehicle is hardly accelerated and becomes unable to start. On the other hand, in this state, the transmission output shaft, that is, the tires, are rotating, so the output of the above-mentioned speed sensor increases, and the above-mentioned shift timing control circuit generates a speed signal, assuming that the speed of the vehicle has increased. , performs a gear shifting operation. As a result, the rotation of the tires changes rapidly, which may cause the vehicle to move sideways.

This invention was made to eliminate the drawbacks of the conventional device as described above, and has a road surface friction coefficient of 71.
The rotational acceleration of the tires when the accelerator pedal is pressed down excessively on a road surface with a low velocity is much greater than when the vehicle normally starts. Due to the configuration that prohibits the gear shifting operation, the vehicle body may slide sideways due to the gear shifting operation when tire slip occurs.
An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes a throttle opening sensor that detects the engine load condition, and a potentiometer that is proportional to the throttle opening [K and obtains an fC voltage signal. etc. - commonly used.

2 is a vehicle speed sensor that generates an electrical signal (for example, voltage or frequency) proportional to the rotation speed of the output shaft of the transmission. Reference numeral 3 denotes a shift timing calculation circuit which compares both the signals from the throttle opening sensor 1 and the vehicle speed sensor 2 and generates a corresponding shift signal 3a'fc when a predetermined relationship is established. As mentioned in item 2 (9), the shift characteristics shift the shift timing toward higher vehicle speeds as the throttle opening increases,
In addition, the timing of shifting to a high speed gear and the timing of shifting to a low gear are designed to take care of hysteresis characteristics, respectively, in order to completely prevent hunting. Reference numeral 4 denotes an acceleration detection circuit which receives the signal from the vehicle speed sensor 2, detects the magnitude of the acceleration, and determines that this detected value exceeds a preset value to generate a high acceleration signal 4a. The detection reference setting value is set to an acceleration that causes the tire to slip, for example, lo (G is gravitational acceleration). Reference numeral 5 designates a shift suppressing circuit which, when there is no output signal 4a of the acceleration detection circuit 4, performs the shift timing calculation [output signal 3 of the o circuit 3].
The solenoid valves 6 and 7 are driven in accordance with a, but if the acceleration detection circuit 4 has an output signal 4a, the gear shift operation is prohibited regardless of the state of the shift timing calculation circuit 3. . The solenoid valves 6 and 7 are provided in a hydraulic control circuit of a transmission (not shown), and are hydraulic switching valves for switching the hydraulic control circuit.

In second speed state, solenoid pulp 61rx OFF, 7U
ON, both solenoid valves 6 and 7 are O in the 3rd gear state.
The hydraulic control circuits associated with each are in the FF state.
By turning k 0N10FF, a multi-disc clutch or brake (not shown) inside the transmission is actuated to achieve a speed change operation.

With the above configuration, the operation of an embodiment of the present invention will be described.

First, when the vehicle is stopped and the accelerator pedal (not shown) is not depressed, the transmission is in the first speed state as shown in the shift characteristics of FIG. 2.

In this state, when the driver depresses the accelerator pedal,
The engine rotation increases, the vehicle starts and is sequentially accelerated □, and when the vehicle speed reaches the speed change characteristics shown in FIG. 2 with respect to the throttle opening, the shift timing calculation circuit 3 generates a shift signal 3a'. At this time, since the road surface friction coefficient is relatively large under normal road conditions, the vehicle is accelerated according to the increase in rotation of the transmission output shaft, that is, the tires, and no abnormal speed bumps occur in the tires, and therefore, they are not detected. The magnitude of the acceleration becomes less than the detection reference setting value, and the acceleration detection circuit 4 does not output the high acceleration signal 4a. As a result, the shift suppression circuit 5 outputs the output signal 3a of the shift timing calculation circuit 3, and the solenoid pulp 6.7 is turned to 0N in accordance with this output signal 3a.
10FF' is operated, the gear ratio of the transmission (not shown) is sequentially changed to 7', and the vehicle is accelerated to the desired speed. Since the accelerator pedal is depressed excessively, the rotational acceleration of the tires becomes much larger than when starting a normal heavy-duty vehicle. (for example, IG), the acceleration detection circuit 4 outputs a high acceleration signal 4a, and the shift timing calculation circuit 3 outputs a high acceleration signal 4a.
Even when the shift signal 3a is output from the high acceleration signal 4. Since the above-mentioned shift operation is prohibited, it is possible to prevent the vehicle body from skidding due to the shift operation when tire slippage occurs, and it is possible to ensure the stability and safety of the vehicle.

As explained above, according to this '. A high acceleration discrimination means that outputs a signal, a shift suppression circuit that, when the high acceleration signal is generated, gives priority to a shift switch that causes the high acceleration signal to perform a shift operation and prohibits the shift operation, and a control device for all transmissions. By providing this, it is possible to completely prevent the vehicle body from skidding due to the gear shifting operation when tire IJ slipping occurs, and at the same time, the stability of the vehicle can be ensured.

[Brief explanation of the drawing]

No. 11 $1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing an example of the shift characteristics of the shift timing calculation circuit shown in FIG. 1... Throttle opening sensor, 2... Strain speed sensor, 3
・・Speed shift timing adjustment circuit, 4・・Acceleration detection circuit, 5・
...Speed change suppression circuit, 6,7...Solenoid knob. Agent Makoto Kuzuno - Commissioner of the Japan Patent Office 1. Indication of the case: Patent Application No. 1982-25585 2, Name of the invention: Control device for automatic transmission for vehicles 3, Person making the amendment Relationship with the case: Permit No. 19 (Representative: Hitoshi Katayama, Part 4, Agent: Address 2 Marunouchi, Chiyoda-ku, Tokyo]゛1U 12:3 >'J. 5. Scope of claims of the specification to be amended. 6. Contents of the amendment (1) Scope of claims of the specification 7. List of Attached Documents (1) Amended Patent Claims 1 or more copies 2. Claims (1) The vehicle speed is detected based on the rotational speed of the output shaft of the transmission, and A control device for an automatic transmission for a vehicle, which has an arithmetic circuit that calculates the optimum shift timing for the operating condition of the vehicle, and determines a gear position of the transmission based on a shift operation signal output from the arithmetic circuit. a high acceleration discrimination means that outputs a signal when the rate of increase in the output shaft rotational speed is equal to or higher than a predetermined set value; and a shift that prohibits gear shifting operation regardless of the output signal of the arithmetic circuit when the signal of the discrimination means is generated. 1. A control device for an automatic transmission for a vehicle, comprising a suppression circuit.
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Claims (1)

[Claims] +l) It has an arithmetic circuit that detects the CPI speed in the output shaft rotational speed of the transmission and calculates the optimum shift timing for the driving condition of the vehicle. A control device for a vehicular automatic transmission that determines a gear stage, comprising: a high acceleration determining means for outputting a signal when the rate of increase in the output shaft rotational speed of the transmission is equal to or higher than a predetermined threshold; A control device for an automatic transmission for a vehicle, characterized in that it is provided with a shift suppression circuit that turns off the output signal of the arithmetic circuit when the signal of the means is generated;