JPH0646060B2 - Car power transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for an automobile, and mainly for a part-time four-wheel drive automobile, a differential gear provided between left and right wheels to be driven wheels during two-wheel drive. This relates to improvement of the device.

2. Description of the Related Art A drive pinion is used as a differential gear unit between left and right wheels that are driven wheels for a two-wheel drive of a part-time four-wheel drive vehicle that can switch between two-wheel drive and four-wheel drive. The outer surface of the freewheel is formed by forming the inner peripheral surface of the cylindrical casing that is in mesh with the meshing gears into an uneven shape with a wavy cross section, and the left and right inner wheels splined to the left and right axles respectively The left and right rollers supported by the respective roller retainers are respectively interposed, and the left and right axles are independently driven by the free wheel mechanism composed of the outer wheel, the left and right inner wheels, and the left and right rollers, and each freely rotates. A freewheel type differential device that allows differential movement on the left and right axles so that the left and right roller retainers are held in a neutral position. In addition to providing a torral holding member, a friction clutch that connects the left and right roller retainers to the left and right inner wheels with a predetermined pressure contact when driving four wheels is provided. The rotation speed of the axle becomes high, the roller retainer on that side is in the neutral position, and the power transmission between the outer ring and the inner ring is cut off, and the outer ring on the inner side slides on the inner wheel while slipping at the pressure contact part of the friction clutch. The left and right wheels can be differentially moved by following freely and the pressure contact force of the friction clutch is released during two-wheel drive, so that the left and right roller retainers are both in the neutral position by the neutral holding member. The power transmission between the outer wheel and the inner wheel is cut off, and the power from the transfer clutch for controlling the switching between the two-wheel drive and the four-wheel drive to the outer wheel of the differential gear device is held. Reach mechanism eg propeller shear shift, which drive pinion shaft or the like has not to allow the product to be reverse driven by the rotation of the driven wheel is already developed conventionally been published in JP Sho 59-86747 JP.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional device as described above, the function of holding the driving force of the other wheel even if the grounding force of one of the left and right wheels is lost, and the differential of the left and right wheels during turning. Functions required for the differential gear device between the left and right wheels, which are the driven wheels during two-wheel drive of a part-time four-wheel drive vehicle, such as the function to allow and the function to prevent unnecessary rotation of the power transmission mechanism during two-wheel drive. Is satisfactorily satisfied, but the structure for realizing the above three functions is extremely complicated and expensive, and at the time of turning with four-wheel drive, the friction clutch plate is pressed against the inner ring on the outside of the turning center. Since the wheel rotates following the rotation of the wheel in the running state, slippage occurs between the inner ring and the clutch plate that is in pressure contact with it, and in some cases abnormal noise occurs or the maneuverability is improved. Such as things that may damage the Occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a differential device capable of solving the above problems of the conventional device.

Means for Solving the Problems The present invention is a rotational drive driven by a drive pinion for a differential gearing device provided in a power transmission system to left and right wheels which are driven wheels in a two-wheel drive of a part-time four-wheel drive vehicle. A crown gear, a casing supported by the crown gear so as to be freely rotatable with respect to each other via a bearing, and a differential pinion axially supported in the casing.
The left and right side gears that are spline-fitted to the left and right output shafts that are connected to the left and right wheel shafts and mesh with the diff pinion, the lock gear that is fixed to either the left or right output shaft, and the above-mentioned locks on the outer peripheral surface of the casing. A gear portion formed at a position axially close to the gear, a slide gear engaged with the crown gear so as to be slidable in the axial direction, and meshing with the lock gear and the gear portion of the casing; A normal wheel position that engages the gear part of the casing only, a defrost position that engages the gear part of the casing and the lock gear, and a freewheel that does not engage the gear part of the casing and the lock gear. It is characterized in that it is composed of an actuator for axially moving to three positions.

Action In the above, when the four-wheel drive is used, the actuator is operated manually or automatically to set the slide gear to the normal differential position, and the power is transmitted to the left and right wheels while allowing the differential between the left and right wheels. When it reaches a slippery road surface, the actuator is operated manually or automatically to move the slide gear to the defrost position, the left and right wheel differentials are in the locked state, and when two-wheel drive is operated manually or automatically. Specifically, the actuator is operated to set the slide gear to the freewheel position, and the power transmission between the crown gear and the casing is cut.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 is a differential gear device provided between the left and right wheels on the side that becomes driven wheels when driving a two-wheel drive vehicle of a part-time four-wheel drive vehicle. In this embodiment, a front engine. Part time 4 based on front drive
1 shows a rear differential arrangement for a wheel drive vehicle.

2 is a drive pinion shaft that is connected to a propeller shaft (not shown) through a universal joint, 4 is a crown gear that meshes with a drive pinion 3 provided on the drive pinion shaft 2, and 5 is integral or integral with the crown gear 4. The drive pinion shaft 2, the crown gear 4, the rotating member 5 and the like are fixed rotating tubular members, and are rotatably supported in the housing 12 by bearings 13 and 14.

Reference numeral 6 denotes a casing which is rotatably supported in the housing 12 by bearings 15 and 15 '. In the casing 6, left and right sides of the differential pinions 7 and 7 which are rotatably supported by the casing 6 by a shaft 7a. The left and right side gears 8 and 8 which are spline-fitted to the output shafts 9a and 9b of the casing and are engaged with the differential diffrions 7 and 7 are incorporated, and the left and right output shafts 9a and 9b are the left and right cylinders of the casing 6. Department
The output shafts 9a and 9b are connected to left and right rear wheel shafts through left and right axle shaft shafts (not shown).

The left and right cylindrical portions 61 and 62 of the casing 6 and the left and right output shafts 9a,
It goes without saying that the respective fitting portions with 9b are mutually free in the rotational direction.

One cylinder portion 61 of the casing 6 is concentrically arranged inside the cylinder of the rotating member 5 that rotates integrally with the crown gear 4, and a gear portion 61a is partially provided on the outer peripheral portion of the one cylinder portion 61. The gear portion 61a is formed on the output shaft 9a that is formed through the tubular portion 61.
A locking gear 16 having the same diameter as the above is fitted and fixed by a spline fitting or the like at a position close to the gear portion 61a, and the outer peripheral surface engages with the inner peripheral surface of the cylindrical portion of the rotating member 5 in the rotational direction. The gear portion on the inner peripheral surface of the slide gear 10 fitted so as to be slidable in the axial direction is configured to mesh with the lock gear 16 or the gear portion 61a of the casing tubular portion 61.

Reference numeral 11 is an actuator composed of, for example, a three-position stop solenoid and is attached to the housing 12.
The tip of the operating piece 11a is connected to the slide gear 10 so as to be free in the rotational direction and capable of transmitting the operating force in the axial direction. The operation of the operating piece 11a of the actuator 11 causes the slide gear 10 to move its gear portion. The normal differential position I meshed with the gear portion 61a on the outer periphery of the cylindrical portion 61 of the casing 6, the differential gear position II meshed with the lock gear 16 and the gear portion 61a, and the gear gear 16a for the gear portion 61a. It can be slid to three positions, which are free wheel positions III that do not mesh with each other.

Although illustration is omitted, the power transmission system from the output shaft of the power unit transmission such as the engine and the transmission to the rear wheel through the propeller shaft to the drive pinion shaft 2 is a transmission clutch provided in the transmission. When the transfer clutch is connected and disconnected, power is transmitted from the propeller shaft to the drive pinion shaft 2 to drive four wheels, and when the transfer clutch is disconnected, power is not transmitted to the propeller shaft and only the front wheels are connected. Power is transmitted to the rear wheels and the rear wheels are switched to two-wheel drive, which is driven wheels.

In the above, when the slide gear 10 is normally held in the differential position I in the four-wheel drive state in which the transfer clutch is in contact, the crown gear 4 and the casing 6 meshing with the drive pinion 3 are the rotary member 5, the slide member 5, and the slide member 10. It rotates integrally through a gear 10 and transmits power to the left and right output shafts 9a and 9b through a conventionally known differential gear mechanism including a diff pinion 7 and 7 and side gears 8 and 8. It is possible to smoothly absorb the difference in rotation of the rear wheels and perform a smooth turn.

In the four-wheel drive state, for example, on a slippery road surface or a rough road with unevenness, the actuator 11 is operated to slide the slide gear 10 to the defrost position II.

Then, the rotation of the crown gear 4 is simultaneously transmitted to the one output shaft 9a and the casing 6 via the rotating member 5 and the slide gear 10, and the rotation of the output shaft 9a and the casing 6 is transmitted to the other via the differential pinion 7 and the side gear 8. Output shaft 9a
As a result, the differential function is lost and a so-called defrost state occurs, so that the running performance on rough roads can be improved.

During two-wheel drive with the transfer clutch disconnected, the actuator 11 is operated to slide the slide gear 10 to the freewheel position III.

Then, the power transmission system from the casing 6 to the rear wheels is completely separated from the crown gear 4 and the rotating member 5, and the transmission gear of the transmission is connected to the propeller shaft, the drive pinion shaft 2, the crown gear 4, and the rotating member 5. The power transmission system is not driven to rotate by the rotation of the rear wheels, which are driven wheels, and it is possible to prevent an increase in vibration and noise caused by these wasted rotations and improve fuel efficiency.

The actuator 11 may be operated by a manual operation using a manual switch, but a switching signal of a drive system sensor such as a 4WD switching switch for controlling switching between two-wheel drive and four-wheel drive, and a steering operation. By switching the steering signal of the steering sensor that detects the operation of the vehicle and the signal of the road surface condition of the road surface sensor that operates by detecting the slip ratio of the wheels. When the switching signal is applied, the actuator 11 operates so as to move the slide gear 10 to the freewheel position III, and when the two-wheel drive is switched to the four-wheel drive, the actuator 11 operates the slide gear 10 normally by the switching signal. Actuator 1 is operated by the road surface condition signal from the road surface condition sensor when it is operated to move to the differential position I and the wheels reach a slippery road surface while traveling by four-wheel drive. 1 is operated to move the slide gear 10 to the defrost position II, and for other direct drive type four-wheel drive vehicles that do not have a center differential arrangement for absorbing the rotation difference between the front wheels and the rear wheels between the front and rear wheels. In this case, when a large turning is performed in the four-wheel drive state, the actuator 11 moves by moving the slide gear 10 to the freewheel position III in response to the turning signal of the turning sensor. Should be configured to operate automatically.

In the above embodiment, the front engine. Although an example in which the present invention is applied to a rear differential gear device of a part-time four-wheel drive vehicle based on a front drive is shown, other examples such as a rear engine. It can be applied to all front-wheel differential devices for part-time four-wheel drive vehicles based on the rear drive, such as day-time differential devices between left and right wheels that are driven wheels for two-wheel drive of part-time four-wheel drive vehicles. Needless to say.

EFFECTS OF THE INVENTION As described above, according to the present invention, the drive differential is rotationally driven by the drive pinion, which is provided in the power transmission system for the left and right wheels that are the two-wheel driven driven wheels of the part-time four-wheel drive vehicle. A crown gear, a casing rotatably driven by the crown gear, a diff pinion axially supported in the casing, and left and right side gears that are spline-fitted to the left and right output shafts and mesh with the diff pinion, respectively. In the gear type differential gear device, the crown gear and the casing are separated from each other so that the crown gear and the casing can freely rotate with respect to each other through a bearing, and one of the left and right output shafts for locking. The gear is fixed, and a gear portion axially close to the lock gear is provided on the outer peripheral surface of the casing.
A normal differential position in which a slide gear engaged with a crown gear so as to be slidable in the axial direction is engaged only with the gear portion of the casing, and a defrost position in which the slide gear is engaged with the gear portion for the lock and the gear portion of the casing. And a freewheel position that does not mesh with any of the lock gear and the casing gear, the actuators that move axially are provided at three positions. Need to have a function to hold the driving force of the other wheel even if the vehicle is lost, a function to accurately perform the differential between the left and right wheels during turning, and a function to prevent unnecessary rotation of the power transmission mechanism during two-wheel drive. These three functions can be reliably achieved by the axial movement of the slide gear due to the operation of the actuator, and the gear type differential gear that has been generally used from the conventional structure. The above three functions can be realized by an extremely simple modification by simply adding a slide gear that is operated by an actuator to the shear device, and the structure is simple and inexpensive, and even when steering with four-wheel drive, the conventional device can be used. There is no problem that the friction clutch wears and abnormal noise is generated at all, and it is possible to improve the maneuverability by transmitting power while allowing the differential to the left and right wheels to smoothly transmit the power. It is possible to realize a part-time four-wheel drive vehicle that is safer and allows easy driving by being configured to automatically control by the signal of the sensor, and it is possible to bring about a great effect in practical use.

[Brief description of drawings]

The accompanying drawings are cross-sectional plan views showing an embodiment of the present invention. 3 ... Drive pinion, 4 ... Crown gear, 6 ...
Casing, 7 ... Differential pinion, 8 ... Side gear,
9a, 9b ... Output shaft, 10 ... Slide gear, 11 ... Actuator, 12 ... Housing, 16 ... Lock gear, 61a ... Gear section.

Claims (2)

[Claims] 1. A crown gear rotatably driven by a drive pinion and a bearing for the crown gear, wherein a differential device provided in a power transmission system to the left and right wheels that are driven wheels when driving two wheels of a part-time four-wheel drive vehicle is used. A casing supported so as to be freely rotatable through each other, a diff pinion axially supported in the casing, and left and right output shafts connected to the left and right wheel shafts are spline-fitted to mesh with the diff pinion. Left and right side gears, a lock gear fixed to either one of the left and right output shafts, a gear portion formed axially close to the lock gear on the outer peripheral surface of the casing, and the crown gear in the axial direction. A slide gear that is engaged so as to be slidable and meshes with the locking gear and the gear portion of the casing; The normal differential position where the gear meshes only with the gear part of the casing, the differential lock position where the gear meshes with the gear part of the casing and the lock gear, and the free gear that does not mesh with the gear part of the casing and the lock gear. A power transmission device for an automobile, comprising: an actuator that axially moves to three wheel positions. 2. The actuator includes a signal from a drive system sensor that detects whether it is a two-wheel drive or a four-wheel drive, a signal from a road surface condition sensor that detects whether the road surface is slippery, and a steering sensor that detects a steering state. The power transmission of the automobile according to claim 1, wherein the power transmission of the vehicle according to claim 1 is configured to be selectively operated by a combination of signals of various sensors such as signals to automatically control the axial movement of the slide gear. apparatus.