JPS63232026A - Differential device for four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To improve operating performance by variably controlling the discharge resistance per unit rotating speed of an oil pump in accordance with the operating condition of an engine in said oil pump which is operated according to the difference in rotation of front and rear wheel driving shafts in a four-wheel driving condition. CONSTITUTION:The power of an engine inputted into a transmission 8 is inputted into the ring gear 10 of a center differential gear 9 via an input gear 11. And, the inputted power is distributed by the center differential gear 9 and, after outputted from a pinion carrier 15 and a sun gear 12, drives right and left front wheel driving shafts 21, 22 and right and left rear wheel driving shafts. In this case, an electromagnetic flow control valve 65 as a discharge resistance variable means is provided on the discharge side of an oil pump 64. And, the opening of the control valve 65 is controlled by a control unit 66 in accordance with the difference ¦NF-NR¦ in rotation of the right/left front and rear wheels. Thereby, the discharge resistance per unit rotating speed of the oil pump 64 can be changed varying the distribution of driving to front and rear wheels.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a four-wheel drive system equipped with an oil pump operated by the rotational difference between a front wheel drive shaft and a rear wheel drive shaft in a four-wheel drive state.
This invention relates to a differential device for a wheel drive vehicle.

(Prior Art) Conventionally, four-wheel drive vehicles are known that are equipped with an oil pump that operates based on the rotational difference between the front wheel drive shaft and the rear wheel drive shaft in the four-wheel drive state (for example, British Patent No. 1394121 (see specification and drawings).

(Problem to be Solved by the Invention) In four-wheel drive vehicles, there is a demand for being able to change the drive distribution between the front and rear wheels by changing the rotational difference between the front and rear drive shafts. .

The present invention has been made in view of the above, and provides a differential device for a four-wheel drive vehicle that can freely change drive distribution between front wheels and rear wheels and improve driving performance. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an oil pump that operates based on a rotational difference between a front wheel drive shaft and a rear wheel drive shaft in a four-wheel drive state per unit rotation speed. and a discharge resistance variable means for changing discharge resistance.

A control means is provided which is linked to the discharge resistance variable means and controls the discharge resistance variable means during vehicle operation.

(Function) When the vehicle is operated, the variable discharge resistance means is controlled by the control means, and the discharge resistance per unit rotational speed of the oil pump is changed, so that the difference in rotation occurring between the front wheels and the rear wheel drive shaft is controlled, and the difference in rotation between the front wheels and the rear wheel drive shaft is controlled. The rear wheel drive distribution changes.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 showing the overall configuration of a differential device for a four-wheel drive vehicle, reference numeral 1 denotes an engine, which is installed horizontally so that a crankshaft 2 extends in the width direction of the vehicle body.

Further, an input shaft 4 is driven by the crankshaft 2 via a clutch 3, and an output shaft 6 has a drive gear 5 at one end.
A transmission 8 consisting of a transmission mechanism 7 and a transmission mechanism 7 provided between the two shafts 4 and 6 is also arranged laterally so that the input shaft 4 and output shaft 6 extend in the width direction of the vehicle body. A drive gear 5 provided on the output shaft 6 of the transmission 8 meshes with a large-diameter input gear 11 integrally formed on the outer periphery of a ring gear 10 in a differential device, that is, a center differential 9.

This center differential 9 includes the ring gear 10, a sun gear 12 concentric with the ring gear 10, and a plurality of binions 13 meshing with the ring gear 10 and the sun gear 12.
3 and the binion 13...13 to the bin 14...
It is constituted by a planetary gear mechanism consisting of a binion carrier 15 carried via a . . . 14.

On one side (right side in the drawing) of the center differential 9, there is a differential case 16 and a pair of binions 1 rotatably fitted in radial bins 17 whose both ends are supported by the case 16.
8.18, and a pair of left and right bevel gears 19.19 meshing with both binions [8.18], that is, a front differential 20 is disposed. A left front wheel drive shaft 21 and a right front wheel drive shaft 22 extending in the left-right direction are connected to the bevel gears 19 and 19 of the front differential 20, respectively, and the left front wheel drive shaft 21 is connected to the center differential 9.
The right front wheel drive shaft 22 reaches the right front wheel 24 through the center thereof.

The binion carrier 15 in the center differential 9 and the differential case 1 in the front differential 20 located on the side thereof
6 and is integrated as the same part. Also, the ring gear 1o and the binion carrier 15 in the center differential 9
(Differential case 16) extends beyond the front differential 20 to the right in the drawing, and is fitted with splines 35 and 36 of the same diameter formed adjacent to the outer periphery of the extended portion. A differential lock mechanism 38 that connects or separates the ring gear 10 and the binion carrier 15 in the center differential 9 is constituted by the sleeve 37 that can be slid in a fitted state across the center differential.

On the other hand, an intermediate shaft 39 is arranged parallel to and spaced apart from the axes of the center differential 9 and the front differential 20 by a certain distance. A gear 40 integrally formed with the intermediate shaft 39 meshes with a gear 41 integrally formed with the sun gear 12 of the center differential 9, and a second intermediate shaft 42 is disposed on an extension of the intermediate shaft 39. installed, rain intermediate axis 39.4
A sleeve 45 is fitted onto splines 43, 44 formed at adjacent ends of the rain shafts 39, 42, and the rain intermediate shafts 39, 42 are connected or separated by sliding of the sleeve 45. Further, an output gear 46 formed of a crown gear is provided on the second intermediate shaft 42, and a bevel gear 48 that is integrated with a propulsion shaft 47 that extends in the longitudinal direction of the vehicle body is meshed with the output gear 46. This propulsion shaft 47 reaches a rear differential device, that is, a rear differential 49, and drives left and right rear wheels 52, 53 via a left rear wheel drive shaft 50 and a right rear wheel drive shaft 51 extending left and right from the rear differential 49.

Further, an outer rotor 62 surrounding an inner rotor 61 that is provided to rotate integrally with the bevel gear 19 in the front differential 20 is fixed to the gear 41, and an oil pump that is covered with a casing 63 and supplies lubricating oil. 6
It is composed of 4It.

Therefore, the second oil pump 64 is driven by the rotation difference between the front and rear wheels, and lubricating oil is supplied to the center differential 9 and the front differential 20, thereby improving seizure resistance.

An electromagnetic flow control valve 65 as discharge resistance variable means is interposed on the discharge side of the oil pump 64, and a control unit 66 (control means) controls the opening degree of the flow control valve 65.
It is electrically controlled by.

The control unit 66 includes rotation signals NF and NR from a rotation speed sensor (not shown) that detects the rotation speed of the front wheels and rear wheels, a brake signal S1 from an anti-skid brake switch, and a steering angle signal from a steering sensor. S2 is input, and under normal conditions, the rotation signal NF is input.

The opening degree of the flow rate control valve 65 is controlled according to the rotation difference due to NR, and the rotation difference is adjusted, but when the anti-skid brake is activated, the front and rear wheels are
．． 53 needs to be rotated freely and it is necessary to prevent internal circulation torque when the steering angle is full, so the flow rate control valve 65 is opened to the maximum opening degree.

According to the above configuration, the crankshaft 2 in the engine 1
The rotation is input to the transmission 8 via the clutch 3, and after a reduction ratio is selected in the transmission 8, the rotation is input to the ring in the center differential 9 via the drive gear 5 on the output shaft 6 and the input gear 11. It is input to gear 10. The power input to the ring gear 10 is distributed at the center differential 9 and output from the binion carrier 15 and sun gear 12, respectively, and the output from the binion carrier 15 is distributed to the front differential 20.
The left and right front wheel drive shafts 21 and 22 or the left and right front wheels 23 and 24 are driven through the drive shafts. In addition, the output from the sun gear 12 is output from the gears 41, 40, the intermediate shaft 39, 42, and the output gear 4.
6 drives the propulsion shaft 47, and further drives the left and right rear wheel drive shafts 50.51 to 52.53 through the rear differential 49.
to drive. In this case, the electromagnetic flow control valve 65
The opening degree is 1 and the rotation difference between the front and rear wheels is 23, 24, 50.51 IN
Since it is controlled by the control unit 66 according to p-NRI and the discharge resistance per unit rotation speed of the oil pump 64 is changed, the drive distribution to the front and rear wheels is changed, and drivability is improved. Furthermore, when the anti-skid brake is activated or when the steering angle is at full, where it is not desirable to restrict the discharge resistance of the oil pump 64, the flow control valve 65 is not controlled and the flow control valve 65 is fully opened.

Furthermore, the splines 4 of the intermediate shaft 39 and the second intermediate shaft 42 are
If the sleeve 45 fitted across 3.44 is separated to separate the rain intermediate shaft 39.42, the engine 1
The output power will be transmitted only to the front wheels 23,24.

Furthermore, in a state in which the rain intermediate shafts 39 and 42 are coupled, that is, in a four-wheel drive state, the differential lock mechanism 3 of the center differential 9
8, slide the sleeve 37 at the ring gear 10 and the spline 35 at the pinion carrier 15.
．． 36, the ring gear 10 and the binion carrier 15 are coupled, thereby eliminating the differential function of the center differential 9. As a result, the front wheels 23, 24 and the rear wheels 52, 53 are rotated equally by the rotation of the engine 1, regardless of the resistance acting on each of them.

Although the differential lock mechanism 38 is provided in the above embodiment, it may be omitted and the differential lock may be achieved by setting the opening degree of the electromagnetic flow control valve 65 to zero.

(Effects of the Invention) Since the present invention is constructed as described above, it is possible to control the discharge resistance of the oil pump and change the drive distribution between the front and rear wheels, thereby improving driving performance.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is an overall configuration diagram of a differential device for a four-wheel drive vehicle, FIG. 2 is an explanatory diagram of a control system, and FIG. FIG. ■・・・Engine, 21.22・・・Front wheel g#h axis. 50.51... Rear wheel drive shaft, 64...
Oil pump, 65...Solenoid flow control valve, 6
6... Control unit.

Claims (1)

[Claims] (1) In a four-wheel drive vehicle equipped with an oil pump that operates based on the rotational difference between the front wheel drive shaft and the rear wheel drive shaft in a four-wheel drive state, the discharge resistance per unit rotation speed of the oil pump is changed. A differential device for a four-wheel drive vehicle, comprising: variable discharge resistance means; and control means linked to the variable discharge resistance means to control the variable discharge resistance means during vehicle operation.