JPH0542898Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a torque distribution ratio detection device for detecting the torque distribution ratio between the front and rear wheels of a four-wheel drive vehicle.

[Conventional technology]

A four-wheel drive vehicle using the viscous coupling spring C can change the torque distribution between the front wheels 1, 2 and the rear wheels 3, 4 by creating a rotation difference between the front wheels 1, 2 and the rear wheels 3, 4. It's summery.

As a torque distribution ratio detection device for detecting the torque distribution, a device using a strain gauge sensor is conventionally known. As shown in FIG. 6, the axles 5,
Strain gauge sensors S ₁ to S ₄ are attached to the axles 5 and 6, and these strain gauge sensors S ₁ to _{S 4} detect the torsion of the axles 5 and 6 as voltages V ₁ to _{V 4} corresponding to the torsion. The torque distribution ratio between the front wheels 1, 2 and the rear wheels 3, 4 is determined from V ₄ by an arithmetic circuit (not shown). This calculation circuit calculates the torque distribution ratios of the front wheels and the rear wheels as shown below using the following equations.

(V ₁ +V ₂ ) / (V ₁ +V ₂ +V ₃ +V ₄ ) (V ₃ +V ₄ ) / (V ₁ +V ₂ +V ₃ +V ₄ ) [Problem that the invention aims to solve] However, such conventional In this torque distribution ratio detection device, strain gauge sensors S ₁ to S ₄ are attached to the axles 5 and 6, and torsion of the axles 5 and 6 is detected as strain in the strain gauge sensors S ₁ to _{S 4} . The structure is such that torque can be detected from Therefore,
Strain gauge sensors S ₁ to _{S 4} are installed on rotating axles, so slip rings are required to capture signals into the vehicle, and they generally have poor durability when used in automobiles, so the torque distribution ratio is low. There was a problem that the detection device was prone to failure. In addition, the voltage output from the strain gauge sensor varies depending on the mounting accuracy of the strain gauge sensor, and therefore there is a problem in that an accurate torque distribution ratio cannot be detected.

This invention was made by focusing on the above-mentioned problem, and provides a torque distribution ratio detection device for a four-wheel drive vehicle that can easily detect the torque distribution ratio without using a strain gauge sensor. The purpose is to

[Means for solving problems]

In order to solve the above problems, this idea installed rotation sensors that detect the rotation speed of the front and rear wheels.
The acceleration is calculated from the rotational speed of the front and rear wheels measured by this rotation sensor, and the torque distribution ratio is calculated from this acceleration.

[Effect]

With the above configuration, the torque distribution ratio between the front and rear wheels is calculated from the rotational speed of the front and rear wheels.

〔Example〕

FIG. 1 is a schematic plan view of a four-wheel drive vehicle;
In the illustration, reference numeral 11 denotes a rotor that is integrally attached to the hubs (not shown) of the front and rear wheels 1 to 4 and rotates together with the wheels.The rotor 11 is provided with a plurality of teeth 11a as shown in FIG. There is. Reference numeral 12 denotes a magneto-electric detector 12 installed at a position adjacent to the teeth 11a of the rotor 11, as shown in FIG. A sine wave voltage is generated every time the line passes near 12a. That is, the magnetoelectric detector 12 outputs a sine wave voltage having a frequency corresponding to the rotation speed of the wheel, and the magnetoelectric detector 12 and the rotor 11 constitute a rotation sensor 13.

FIG. 3 shows a block diagram of the torque distribution ratio detection device, and 13a to 13d indicate wheels 1 to 13d.
Rotation sensors are installed at each of the four locations. 14 is a waveform shaping circuit that shapes the sine waves output from each rotation sensor 13a to 13d into a rectangular wave; 15 is a waveform shaping circuit that calculates the acceleration of each wheel 1 to 4 from the rectangular wave of the waveform shaping circuit 14; This is a microcomputer (arithmetic circuit) that calculates torque distribution ratios 1 to 4.

By the way, the driving torque T is calculated by the following equation. However, M is the mass of the wheel, R is the radius of the wheel,
Let A be the acceleration of the wheel.

T=(M×A)×R...(1) ∝A(∵M, R constant) Here, A is found from A=d ² F/dt ² ...(2).

However, F is the rotation speed of the wheel.

The torque distribution ratio between the front wheels and the rear wheels is calculated using the following formula.

(T ₁ + T ₂ ) / (T ₁ + T ₂ + T ₃ + T ₄ ) ... (3) (T ₃ + T ₄ ) / (T ₁ + T ₂ + T ₃ + T ₄ ) ... (4) Here, T ₁ , T ₂ , T ₃ , and T ₄ are driving torques of each wheel 1 to 4.

Next, the operation of the above embodiment will be explained.

When each wheel 1 to 4 rotates, the rotation sensor 13s
13d outputs a sine wave voltage having a frequency corresponding to the rotational speed of the wheels 1 to 4, and this sine wave voltage is shaped into a rectangular wave by the waveform shaping circuit 14. The microcomputer 15 counts the number of rectangular waves to determine the rotational speed F ₁ to F ₄ of each wheel 1 to 4,
The accelerations A ₁ to _{A 4} of each wheel are calculated from the rotational speeds F 1 to F ₄ based on the above equation (2), and the accelerations A ₁ to A 4 of each wheel are calculated from the accelerations A ₁ to _{A 4} based on the above equation (1). 4 driving torque
Calculate T ₁ ~ _{T 4} and further calculate this driving torque T ₁ ~ _{T 4}
The torque distribution ratio between the front wheels 1 and 2 and the rear wheels 3 and 4 is calculated based on the above equations (3) and (4).

Since the torque distribution rate is calculated based on the rotational speed of the wheels 1 to 4 in this way, the torque distribution rate can be equivalently determined. Furthermore, since a strain gauge sensor is not required, the torque distribution ratio detection device does not tend to malfunction due to deterioration in the durability of the strain gauge sensor, unlike in the prior art.

FIG. 4 shows another embodiment, in which the rotor 11 is installed on the shaft H, and a magnetoelectric detector 12 is installed near the rotor 11 to reduce the number of rotation sensors 13. This is what I did.

Figure 5 shows an optical rotation sensor.
For example, a gear 21 that rotates together with the wheel is provided, a light-shielding plate 23 that rotates with the gear 22 is provided on a gear 22 that meshes with the gear 21, and a light-emitting diode 24 and a photo-optical light are placed between the teeth 23a of this light-shielding plate 23. When the transistor 25 is installed and the light shielding plate 23 is rotated, the tooth 23a and the tooth 23
The light emitted from the light emitting diode 24 is received by the phototransistor 25 between the distances a, and the number of rotations of the wheel is detected from the number of times the light is received. This means that even if the wheel rotation speed is low, the peak value output by the phototransistor will not become low.

[Effect of idea]

As explained above, according to this invention, the configuration includes a rotation sensor 13 that detects the rotation speed of the front and rear wheels 1 to 4, and a rotational acceleration of the front and rear wheels 1 to 4 based on the output of the rotation sensor 13. The front and rear wheels 1 are calculated based on the rotational acceleration.
Since the torque distribution rate detection device for a four-wheel drive vehicle is characterized in that it is equipped with an arithmetic circuit 15 for calculating the distribution rate of the drive torque generated in 4 to 4, the torque distribution rate can be easily determined. It is possible,
Further, since a strain gauge sensor is not required, the torque distribution ratio detection device does not become susceptible to failure due to deterioration in the durability of the strain gauge sensor, unlike in the conventional case.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of a four-wheel drive vehicle according to an embodiment of this invention, Fig. 2 is a schematic configuration diagram of a rotation sensor, Fig. 3 is a block diagram of a torque distribution rate detection device, and Fig. 4 is a diagram of another four-wheel drive vehicle. FIG. 5 is a schematic plan view of the embodiment, FIG. 5 is a schematic configuration diagram of an optical rotation sensor, and FIG. 6 is a schematic plan view of a conventional four-wheel drive vehicle. 1 to 4...Wheel, 13...Rotation sensor, 15...
...microcomputer.

Claims (1)

[Scope of utility model registration request] A rotation sensor 13 detects the rotational speed of the front and rear wheels 1 to 4, and calculates the rotational acceleration of the front and rear wheels 1 to 4 based on the output of the rotation sensor 13, and calculates the rotational acceleration of the front and rear wheels 1 to 4 based on the rotational acceleration. ~4
1. A torque distribution rate detection device for a four-wheel drive vehicle, comprising: an arithmetic circuit 15 for calculating a distribution rate of drive torque generated in a four-wheel drive vehicle.