JPH035463Y2 - - Google Patents

Description

[Detailed explanation of the invention] Industrial application field Four-wheel drive has a relatively high fuel consumption. Therefore, in order to improve fuel efficiency, it is necessary to drive in two-wheel drive when it is unnecessary, and this invention automatically switches to two-wheel drive when driving in a straight line at high speed, instead of depending on the driver's judgment. This invention relates to a four-wheel drive vehicle that can be switched.

BACKGROUND OF THE INVENTION In conventional four-wheel drive vehicles, the driver judges the driving conditions and manually switches the vehicle to four-wheel drive or two-wheel drive. And there was nothing that automatically switched between them. Furthermore, there was no one that switched to two-wheel drive when driving straight at high speeds to improve fuel efficiency.

Problems the invention aims to solve Even though it is desirable to eliminate unnecessary four-wheel drive states in order to improve fuel efficiency, manual switching of drive states based on the driver's judgment is cumbersome to operate;
There were cases in which fuel efficiency could not be effectively improved due to individual differences in driver judgment.

Means for Solving the Problems The present invention solves the above-mentioned problems, and includes a vehicle speed sensor that detects vehicle speed, and a vehicle speed sensor that also outputs a first signal when the vehicle speed detected by the vehicle speed sensor exceeds a predetermined value. a determination means, a steering wheel operation angle sensor that detects the steering angle of the steering wheel, and a steering wheel steering angle determining means that outputs a second signal when the steering angle detected by the steering wheel steering angle sensor is less than or equal to a set value; a timer means for measuring the time during which the second signal is continuously output;
The four-wheel drive vehicle is characterized in that the four-wheel drive vehicle has output determining means for switching to two-wheel drive when the second signal is continuously output for a predetermined period of time or more while the second signal is being output.

Effect: According to the above-mentioned means, the vehicle speed and steering wheel operation angle are constantly detected while the vehicle is traveling, and the four-wheel drive state is activated only when the steering wheel is operated at a predetermined angle or less for a predetermined period of time while the vehicle is traveling at a predetermined vehicle speed or higher. It becomes a four-wheel drive vehicle that automatically switches from to two-wheel drive mode.

Embodiment An embodiment of a four-wheel drive vehicle according to the present invention will be described with reference to FIGS. 1 to 4. As shown in the block diagram of FIG. 1, a vehicle speed sensor 1 is provided to detect the vehicle speed V, and its pulse signal is input to the calculation means 2. The vehicle speed signal processed here is input to the vehicle speed determining means 3 and is compared with a reference value (predetermined vehicle speed) stored in advance. As a result, the vehicle speed V
is greater than or equal to the specified value. That is, when it is determined that the vehicle is running at a relatively high speed, the first signal is sent from the vehicle speed determining means 3 to the output determining means 1, which will be described later.
Output to 0. In parallel with this, a steering wheel operation angle sensor 4 is provided to detect the steering wheel operation angle θ, and the pulse signal is inputted to the calculation means 6 after the directionality thereof is identified by the operation direction identification means 5. The handle operation angle signal processed here is input to the handle operation angle determination means 7, and is compared with a predetermined reference value (set value). As a result, when the steering wheel operating angle θ is less than the set value, that is, when it is determined that the steering wheel operating angle is small and the vehicle is running almost straight, a second signal is sent from the steering wheel operating angle determining means 7 to the timer 8. It is output to duration determination means 9 which together form timer means. The duration determining means 9 measures the time during which the above-mentioned second signal is continuously output, and outputs the signal to the output determining means 10 when the time exceeds a predetermined time. In response to this, the output determining means 10 appropriately switches from four-wheel drive to two-wheel drive when it receives a signal in which the second signal continues for a predetermined period or more while the first signal is being output. It is determined that this is the case, and the solenoid 11 shown in FIGS. 2 and 3 is energized to operate the transfer actuator 12.
As a result, the four-wheel drive switching clutch 13 is automatically switched to the two-wheel drive state, and the transmission path of the drive torque that was being transmitted from the engine 14 to the rear wheels 16 via the propeller shaft 15 is now transferred to the switching clutch 13.
This results in two-wheel drive where the drive torque is exclusively transmitted to the front wheels.

In this embodiment, as shown in FIG. 2 and FIG. The means 9 and the output determining means 10 are integrated into the controller C, and 17 is a front differential;
Reference numeral 18 indicates a rear differential.

Next, the operation will be explained based on the flowchart shown in FIG. Here, we will explain the predetermined speed as 60km/h, the setting value of the steering wheel operation angle as 70deg, and the predetermined time for which the second signal continues as 10 seconds, but these may vary depending on the conditions of use of the four-wheel drive vehicle, etc. The optimum value may be set as appropriate. First, the vehicle speed V is detected by the vehicle speed sensor 1, and when it reaches 60 km/h or more, the steering angle sensor 4 detects when the steering wheel operating angle θ is a small angle that does not affect straight running, that is, when θ is 70 degrees or less. The controller automatically switches to two-wheel drive when this state is detected and continues for more than 10 seconds. However, even in four-wheel drive mode, the vehicle speed V is 60km/h.
or if the steering wheel operating angle θ is much larger than 70 degrees, or if the vehicle speed is 60 km/h or more and the steering wheel operating angle θ is 70 degrees or less, but the duration is less than 10 seconds, In both cases, switching to two-wheel drive is not performed. Therefore, in driving conditions where the advantages of four-wheel drive are not fully utilized, that is, when driving continuously straight at relatively high vehicle speeds, four-wheel drive can be automatically switched to two-wheel drive, making it easy to reduce fuel consumption. It can be implemented.

Effects of the invention As a result of the above, it is possible to reliably detect when driving in a straight line at high speed and automatically switch to two-wheel drive, making it possible to automatically improve fuel efficiency without bothering the driver. Moreover, it has the effect of providing a driving operation that does not feel strange.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is a block diagram of the configuration that realizes the function of a controller that controls the vehicle speed and steering angle, and Figure 2 shows two-wheel drive switching by the controller. FIG. 3 is a diagram showing the hardware of the controller, and FIG. 4 is a flowchart showing the software of the controller. 1...Vehicle speed sensor, 3...Vehicle speed determination means, 4...
...Handle operation angle sensor, 7...Handle operation angle determination means, 9...Duration determination means, 10...
...Output judgment means, 11...2WD switching solenoid,
12... Actuator, 13... 4WD switching clutch, 15... Propeller shaft.

Claims (1)

[Scope of utility model registration request] A vehicle speed sensor that detects the vehicle speed, a vehicle speed determination unit that outputs a first signal when the vehicle speed detected by the vehicle speed sensor exceeds a predetermined value, a steering wheel operation angle sensor that detects the operating angle of the steering wheel, and a steering wheel operation angle sensor that detects the operating angle of the steering wheel. A steering wheel operation angle determining means for outputting a second signal when the operation angle detected by the angle sensor is less than or equal to a set value; and a timer means for measuring the time period during which the second signal is continuously output. and output determining means for switching to two-wheel drive when the second signal is continuously output for a predetermined period of time or more while the first signal is being output.