JPS58177721A - 4-wheel drive electronic controller - Google Patents

Abstract

PURPOSE:To eliminate circulative torque, by providing torque sensors to driving shafts of front and rear wheels and disengaging a clutch connecting the both shafts to select operation from 4-wheel driving to 2-wheel driving when a difference of torque becomes at least a fixed value. CONSTITUTION:An engine 3 drives front wheels 7 through a transmission 4 and a differential gear 8 while also rear wheels through a clutch 5, rear wheel driving shaft 9 and a rear wheel differential gear 10. Operation between 4-wheel driving and 2-wheel driving is selected by connecting and disconnecting the clutch 5. The first torque sensor 1 is provided to a front wheel driving shaft and the second torque sensor 2 is provided to the shaft 9. A controller 6 disengages the clutch 5 when a difference between torque signals from the both torgue sensors exceeds a prescribed value. In this way, circulative torque not effective to driving of the wheels is never generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to part-time four-wheel drive, and more particularly to a control device for automatically switching between four-wheel drive and two-wheel drive.

In conventional direct-coupled 4-wheel drive vehicles, even when driving straight, the front and rear tires move in opposite directions when there is a difference in the effective diameter of the front and rear tires due to differences in air pressure, cliffs, etc., or when driving once. This causes tire wear, overloads the drive system, and in severe cases, stalls the engine. This is due to forced slip, which causes the drive shaft to have circulating torque that does not contribute to drive. This is because the above-mentioned problems can be resolved by detecting this circulating torque and switching to two-wheel drive.

The object of the present invention is to provide a part-time four-wheel IIA excitation machine with a drive IIb of the front and rear wheels based on the difference in rotational speed between the front and rear tires.
It is an object of the present invention to provide a suitable means for eliminating the torque tS that does not contribute to the drive generated in the suspension system.

The timing of this invention is front wheel A! By detecting the torque of the G-axis and the rear wheel drive shaft and finding the difference, we find the violet that corresponds to the circulating torque that does not contribute to driving, and when the torque exceeds a certain value, the clutch is disengaged and the two wheels are This is where I switched to drive mode.

An embodiment of the present invention will be described in detail below using the drawings. 1
Figure 1g1 is a system configuration diagram of an embodiment of the present invention, and d
Figure X2 is the circuit configuration diagram of the controller in Figure 1, and Figure 3 is the circuit configuration diagram of the controller in Figure 1.
The operation timing diagram in FIG. 2, 1tic4 diagram is an explanatory diagram of the operation and operation of FIG. 2, and FIG. 5 is also an explanatory diagram of the operation of FIG. 2.

In Fig. 1, l and υ2 are torque sensors that detect the torque of the drive shaft using a phase difference. - Gears are placed at two locations on one shaft, and rotation detectors are placed close to each other on the outer periphery. It has nine configurations. 3 is an engine, 4 is a transmission, 5 is a clutch that connects the drive shafts of the front and rear wheels, 6 is a controller, 7 is a front wheel, 8 is a differential gear, 9 is a rear suspension IIh cap, 10 is a dredger differential It is Range Algia. Next, excitation of the controller is performed using FIGS. 2 to 5.

The controller includes a first torque detection means 4 that detects front axle torque in response to a signal from the fAl torque sensor 1.
4, a second torque detection means 45 that detects the rear shaft torque upon receiving a signal from the torque sensor 2 of tJ42, and a first
A differential amplifier 46 that takes the difference between the outputs of the torque detection means 44 and the second torque detection means 45, and a comparator 41 that compares the output of the differential amplifier with a constant value. Monostable multi 42 that generates pulses
．． 2 and a driver for driving the clutch. 11.12 is a waveform shaping circuit, 12 is an inverter, 13 is an AND gate, 14 is a transistor,
15 is a capacitor, 16 is an operational amplifier, 18 to 28 are Teikoki, and 40 is an operational amplifier.

During operation of the system, No. 14 from torque sensor 41 is shown in FIG. 31 is led to the AND gate 13 via an inverter, and the output of the AND gate is shown at 33. Here, the pulse period is T1 and the off period is t, and the duty is D=t/'
Defining I', the duty does not change depending on the rotation speed, but changes depending on the rectangular screw size. can.

Next, the duty is converted to analog by passing it through an integrating line with approximately equal photodischarge time constants.

The output is sent to the operational amplifier 16 and the signal 34 is multiplied by tam. Here, duty D and operational amplifier 16
The relationship between the outputs 34 is proportional as shown in FIG.

Generally, the torque generated on the drive shaft can be expressed as follows.

Tr: Front-wheel torque T: Rear I Tty: Front wheel engine torque T: Rear I'r-: Circulating torque f: IjiI lost torque Here, f is the unreasonable torque that represents the loss in torque transmission. It is.

Considering the fact that the direction of the circulating torque is opposite in equations (1) and (2), and taking the difference between the front and rear drive shaft torques, TF
-'i'm = (Tar Tmm) ±2 T s-
(f (Tmy +T-)-f(T+T8)). Here, the torque distribution to the front and rear wheels is almost equal, and the difference in the torque is smaller than the circulating torque, so T-iris F! ;T*IL g2Ts>> f (
If it is assumed that Tmr+Ts) f (TxmushiTs), then TF Tmζ±2T-, and a spear corresponding to the circulating torque can be detected. That is, when the torque difference t on the front and rear axes is determined through the difference 46 between the torques on the front and rear axes, an amount corresponding to the circulation torque is detected.

In FIG. 5, the relationship between the detected torque and the clutch control signal will be described. At tl, when the front axle torque and rear axle torque run more than 100m, the switching signal 47 to 2-wheel drive is output for a certain period of time (tz - tt), the clutch is cut off, and the # rear wheel Circulating torque that is accumulated and does not contribute to drive is released.

As described above, the present embodiment has the great advantage of being able to detect torque with a simple circuit and eliminating the undesired torque that does not contribute to driving.

According to the present invention, there is a great effect that the circulating torque that does not contribute to the drive can be stopped and eliminated before it becomes large and causes a problem to the table.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram, Fig. 2 is a circuit configuration diagram of the +ig1 controller, Fig. 3 is a timing diagram of Fig. 2, Fig. 4 is a characteristic diagram of Fig. 82, and Fig. 5 is: An explanatory diagram of the second evil action. l...First torque sensor, 2...Second torque sensor, 3...Engine, 4...Tofunsumitsu 7yo/
, 5...Clutch, 6...Controller, 11...
・Modified Kanasugi circuit, 12... Waveform shaping circuit, 13...
AND gate, 14...transistor, 15...capacitor, 16...operational amplifier, 18.19,20.
21... Teikoki. 31st! I #-4th

Claims (1)

[Claims] 1. Where switching between 4-wheel drive and 2-wheel drive is required - Part-time 4-wheel drive, the first torque sensor detects the torque of the front wheel drive and detects the torque of the rear wheel drive shaft 42 torque sensors to connect the front wheel drive shaft and the pig wheel body Jttl shaft; and a clutch that receives the signals from the first torque sensor and the second torque sensor and sends control to the clutch. The controller that issues the signal is Hiroshi Hiroshi, and the front 6 controllers are the front wheels and the rear N.
- When the torque of - becomes equal to or more than a value, the control method is such that the clutch τ i'f is activated. At time t, the electronic 4-wheel drive trill +d 0 2. In the first term, the controller The torque structure of the + stage is #! with a waveform distortion circuit, gate circuit, integration circuit, and operation gamma/g! Electronic 4% formula % that has been achieved