JPH0763628A - Drive shaft and method for measuring output torque of the shaft - Google Patents

Abstract

PURPOSE:To make light-weight a drive shaft connected to a power transmission system via uniform speed joints at both ends. CONSTITUTION:Pulser rings 4, 5 are mounted to rims 2a, 3a of uniform speed joints 2, 3. Rotary signals generated by the pulsar rings are detected and a phase difference of the rotary signals corresponding to a twist generated at the drive shaft 1 is operated, thereby to obtain an output torque. An output of an engine is controlled based on the detected torque signal, so that the generation of an excessive torque is prevented. Since the excessive torque is prevented in this manner, the drive shaft 1 and uniform speed joints 2, 3 are reduced respectively in diameter and size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive wheel axle or drive shaft having a role of transmitting power of an automobile engine to wheels. Examples of such drive shafts include a front axle of a front-wheel drive vehicle, a rear axle of a rear-wheel drive vehicle, and all axles of an all-wheel drive vehicle.

[0002]

2. Description of the Related Art In a drive shaft of an automobile which employs an independent suspension type suspension, it is necessary to transmit the driving force while following the movement of the suspension. Therefore, one end of the drive shaft is connected to the differential through the constant velocity joint, and the other end is connected to the axle (axle) through the constant velocity joint. In this way, the drive shaft is incorporated into the drive system that transmits the power of the engine to the wheels, and the power of the engine is finally transmitted to the wheels by the drive shaft.

In recent automobiles, electronic control technology has been introduced into all parts, such as antilock brake system (ABS) and traction control system (T).
Wheel speed signals are used in traveling control such as CS) and non-slip differential (LSD). For this reason, the AB is usually installed on the outboard side (axle side) of the drive shaft.
A pulser ring for S (anti-lock brake system) control is provided, and when the gear-shaped pulser ring rotates with the rotation of the wheel, a frequency proportional to the wheel rotation speed is provided to an electromagnetic pickup installed on the vehicle body side close to the pulser ring. The pulse of is generated.

[0004]

A constant velocity joint for a drive shaft used in an automobile is required to have a strength sufficient to withstand an excessive torque generated when the automobile suddenly starts or accelerates. Therefore, the shaft diameter and the joint outer diameter are large, and the weight must be heavy.

On the other hand, the weight reduction of the vehicle body is very effective in improving the fuel consumption, and the drive shaft is also required to be reduced in weight.

Therefore, the main object of the present invention is to reduce the weight of the drive shaft.

[0007]

SUMMARY OF THE INVENTION The present invention is a drive shaft of an automobile having constant velocity joints at both ends thereof, wherein each constant velocity joint, that is, the outer ring of each of the inboard side and outboard side constant velocity joints. It features a pulsar ring.

According to a second aspect of the present invention, a pulsar ring is attached to an outer ring of each constant velocity joint of a drive shaft of an automobile which is connected to a power transmission system at both ends via constant velocity joints, and rotation generated by both pulsar rings. A method for measuring an axial torque of a drive shaft, which comprises detecting a signal and calculating a phase torque of a rotation signal corresponding to a twist generated in the drive shaft to obtain an axial torque.

According to a third aspect of the present invention, the signal of the shaft torque thus obtained is used for vehicle traveling control.

[0010]

A pulsar ring for a rotation speed detecting device (speed sensor) for detecting the rotation speed of a wheel for ABS control is provided on the drive shaft provided on the outer ring of one constant velocity joint, and further on the outer ring of the other constant velocity joint. If another pulsar ring is attached, when the drive shaft is twisted by the torque, the twist appears as a phase difference between the rotation signals generated by both pulsar rings.

A shaft torque is obtained by calculating the phase difference of the rotation signals corresponding to the twist generated in the drive shaft. The size of the constant velocity joint is reduced by controlling the output of the engine based on the obtained torque signal and suppressing the generation of excessive torque.

Further, by using the torque signal thus obtained for vehicle traveling control, optimum control becomes possible.

[0013]

EXAMPLE As shown in FIG. 1, a drive shaft (1)
Is connected to the drive system at both ends via constant velocity joints (2, 3). In the illustrated embodiment, the inboard side is connected to a differential (not shown) by a tripod type slide type constant velocity joint (2), and the outboard side is connected by a bar field type fixed type constant velocity joint (3) to the axle ( (Not shown).

The constant velocity joints at both ends of the drive shaft (1) are not limited to the combination shown in the drawing. For example, in the case of the front axle of a front-wheel drive vehicle, that is, the drive-wheel front axle, since the front wheels are steered, the wheel-side joint is required to have a large operating angle and constant velocity. In order to meet this demand, a Burfield type fixed joint (Zeppe type fixed joint), a tripod type fixed joint, etc. are used. The vehicle body side joint is required to have an operating angle that allows movement of the suspension. This operating angle is not as large as the joint on the wheel side, but it is necessary to allow the length of the vehicle body to change with the movement of the suspension. Therefore, a bar field type slide joint, a tripod type slide joint, a cross grove type joint or the like is used for the vehicle body side joint. The independent suspension type drive wheel rear axle does not require a steering function and does not require a large operating angle, so a cardan joint may be used in some cases.

A pulsar ring (5) for ABS control is attached to the outer ring (3a) of the constant velocity joint (3) on the outboard side. A pulsar ring (4) of the same kind is also attached to the outer ring (2a) of the constant velocity joint (2) on the inboard side. On the vehicle body side, electromagnetic pickups (6, 7) are installed at positions close to these pulsar rings (4, 5), and gear-shaped pulsar rings (4, 5)
When 5) rotates, a pulse having a frequency proportional to the rotation speed is generated in the electromagnetic pickup (6, 7). A pulsar ring and an electromagnetic pickup form a speed sensor.

When the vehicle is suddenly started or suddenly accelerated, the axial torque generated in the drive system is large, and the drive shaft has the lowest rigidity except the clutch portion in the drive system of the four-wheeled and two-wheeled vehicles. Therefore, the drive shaft (1) is twisted. This torsion angle is calculated based on the pulse signal from the electromagnetic pickup (6, 7) to obtain the shaft torque.

As shown in FIG. 2, when torque is not generated, there is no twist at both ends of the drive shaft (1), and pulses (FIG. 2) generated by the pulsar ring (4, 5) are generated.
The phases of (a) and (b) are also in phase. However, when torque is generated, the shaft is twisted, so that the pulse generated by the pulsar ring (5) on the outboard side is larger than the pulse generated by the pulsar ring (4) on the inboard side (FIG. 2A) (FIG. 2 ( Since c)) is delayed, a phase difference t ′ occurs. The shaft torque T can be obtained by calculating the phase difference t ′ based on the pulse signal. That is, the period t and the phase difference t ′ of the pulse (FIG. 2C) due to the pulser ring (5) on the outboard side are the clock a, and the count numbers of the clocks at the period t and the phase difference t ′, respectively. If n and n ′ are satisfied, t = na and t ′ = n′a, and therefore the axial torque T can be calculated by the equation 1.

[Equation 1] T≈Jk · 2πn '/ n where J is the moment of inertia and k is the rigidity coefficient.

Next, referring to the block diagram of FIG. 3, when the automobile is running, a pulse is generated as the pulsar rings (4, 5) rotate (FIG. 2 (a)).
(C)), this pulse is taken in by the electromagnetic pickup (6, 7) and input to the arithmetic unit (8, 9), respectively. Then, in the arithmetic unit (8), both pulse signals are input together, and the clock counter measures the cycles t and t ′ from these pulses. From this cycle t, t ′, the torque T is calculated based on the above equation (1). As in the conventional case, the pulse signal from the pulser ring (5) on the outboard side input to the arithmetic unit (9) is used for ABS control.

On the basis of the shaft torque signal thus obtained, engine control such as delaying the ignition timing of the engine is performed, and by doing so, generation of excessive torque is prevented. If the generation of excessive torque can be prevented, the size of the shaft diameter of the drive shaft (1) and the outer diameter of the constant velocity joints (2, 3) can be reduced.

Further, the shaft torque signal thus obtained can be used for engine control for traction control, control of AT transmission, traveling control of electronically controlled LSD and the like.

[0022]

As is apparent from the above description, according to the present invention, one more pulsar ring is added to the drive shaft having the ABS pulsar ring to detect the axial torque. The axial torque of the drive shaft can be detected at extremely low cost. Then, by controlling the engine based on the signal of the shaft torque, the generation of excessive torque can be suppressed. Therefore, the size of the drive shaft and the joint can be reduced, which contributes to weight reduction of the vehicle.
Further, the reduction in weight improves the fuel efficiency of the automobile.

Optimal control becomes possible by utilizing the axial torque for traveling control. For example, it can be used as a drive shaft torque signal for engine control necessary for traction control. By adding drive shaft torque control to the AT transmission, efficiency can be improved and fuel consumption can be improved. Optimal torque distribution can be obtained by adding drive shaft torque control to the electronically controlled LSD.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a drive shaft showing an embodiment.

[Fig. 2] Time chart of pulse generated by rotation of pulser ring

FIG. 3 is a block diagram of a shaft torque measuring device.

[Explanation of symbols]

 1 drive shaft 2 constant velocity joint 2a outer ring 3 constant velocity joint 3a outer ring 4 pulsar ring 5 pulsar ring 6 electromagnetic pickup 7 electromagnetic pickup 8 arithmetic unit 9 arithmetic unit

Claims (3)

[Claims] 1. A drive shaft connected at both ends to a drive system of an automobile through constant velocity joints, wherein a pulser ring is attached to an outer ring of each constant velocity joint. 2. A pulsar ring is attached to an outer ring of each constant velocity joint of a drive shaft connected to a drive system of an automobile at both ends via constant velocity joints, and a rotation signal generated by both pulsar rings is detected to drive the drive. A method for measuring the axial torque of a drive shaft, wherein the axial torque is obtained by calculating the phase difference of the rotation signals corresponding to the twist generated in the shaft. 3. A traveling control method for an automobile, wherein a signal of an axial torque obtained by the method of claim 2 is used for vehicle traveling control.