JPS632726A - Part time four-wheel drive car - Google Patents

Abstract

PURPOSE:To prevent members of a driving system from being free-run due to wheels by providing a means which judges as to whether two-wheel drive or four-wheel drive is in operation, whereby controlling NO.2 shaft connected to a driven means not to be rotated when two-wheel drive is judged to be in operation. CONSTITUTION:When it is judged by a judging means 64 that two-wheel drive is in operation, the revolving speed of a wheel 16 and a case 34 is calculated by a control device 70. Then, a ring gear 52 is made zero in revolving speed by controlling the revolving speed of an electric motor in an adjusting means. As a result, a driving force transmitted from a transmission 10 to a propeller shaft 12 is transmitted to a right and a left rear wheel 20 via a differential gear 20 in the rear section. In this case, the revolving speed of the ring gear 52 is zero whereby no free running due to the rotation of front wheels is produced.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a four-wheel drive vehicle, and in particular, to a four-wheel drive vehicle in which rolling by wheels does not occur in drive system components on the non-drive side during two-wheel drive. , concerning part-time four-wheel drive vehicles.

(Prior art) In part-time four-wheel drive vehicles, during two-wheel drive, wheel drag occurs in drive system parts such as propeller shafts, differential gears, and drive shafts that are connected to the non-drive side by VC, reducing fuel efficiency. There is a problem that is getting worse.

(Problems to be Solved by the Invention) In order to eliminate the above-mentioned problems, a freewheel equipped with a drive force transmission switching mechanism is used as a knob that supports the wheels that are not driven during two-wheel drive. Sometimes,
This freewheel/\pu changes from four-wheel drive to two-wheel drive,
When switching to the opposite direction, the driver has to step out of the vehicle and perform the operation, which is troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide a part-time four-wheel-drive vehicle that can prevent wheel-induced rotation of drive system components on the non-drive side during two-wheel drive.

(Means for Solving the Problems) The present invention uses the driving force transmitted from the transmission to the propeller shaft to drive the left and right wheels on the front side via the drive shaft on the front side on one side, and the left and right wheels on the front side on the other side through the drive shaft on the front side. This is a part-time four-wheel drive vehicle that drives left and right rear wheels via a drive shaft, and is incorporated into one of the front and rear drive shafts. a first differential device that receives driving force from the propeller shaft; a driven means that receives driving force from the propeller shaft that is incorporated in the other of the front and rear drive shafts; a second differential device disposed on the right side of the driven means and engaged with the right wheel; the number of revolutions of a first shaft extending from the differential to the left wheel; and
and a first means incorporated in the second differential for adjusting the rotational speed of a second shaft to which the driven means is coupled and which is between the differential and the third differential. ,
second means incorporated in the third differential for adjusting the rotational speed of a third shaft extending from the third differential to the right wheel and the rotational speed of the second shaft; , including means for determining whether the vehicle is a four-wheel drive or a two-wheel drive, and a control device into which signals from a steering angle sensor and a vehicle speed sensor are input, and the control device is coupled to the first shaft based on the signals. In addition to calculating the difference in rotational speed between the wheels and the wheels connected to the third shaft, when the determining means determines that the drive is two-wheel drive, the first adjusting means and the third shaft are adjusted so that the second shaft does not rotate. the first yA adjusting means and the second adjusting means so that when the determining means determines four-wheel drive, the left and right wheels have the rotational speed difference. and control.

According to a preferred embodiment of the invention, the first and second adjusting means each include an electric motor, a worm attached to the output shaft of the electric motor, and a worm wheel meshing with the worm.

(Operation and Effect) When the determining means determines two-wheel drive, the control device controls the first and second adjusting means so as not to rotate the second shaft. In this way, the portions of the second shaft, the driven means, and the propeller shaft that are connected to the second and third differential gears are prevented from rotating.

When the determining means determines four-wheel drive, when the vehicle turns, the control device selects a wheel located on the outside of the turn among the wheels connected to the drive shaft in which the second and third differential m are installed. The difference between the rotational speed of the wheel located on the inside and the rotational speed of the wheel located on the inside is calculated from the steering angle and the vehicle speed, and the rotational speed of the wheel located on the outside and the inside is controlled respectively through adjustment means during a turn.

When the vehicle is traveling straight, one of the two wheels connected to the drive shaft in which the second and third differentials are installed may run onto snow, etc., causing that wheel to rotate at a speed commensurate with the vehicle speed. If the wheel attempts to rotate at a higher rotation speed, the control device maintains the rotation speed of the relevant wheel at a rotation speed commensurate with the vehicle speed.
The rotational speed of the adjusting means of the differential device that engages the wheels is controlled so that the rotational speed difference between the two wheels becomes zero.

2 on one of the front and rear drive shafts.
In addition to incorporating two differential devices, each differential device is equipped with an adjustment means, and the rA adjustment means rotation speed is controlled by the control bag, so even if one of the wheels tries to spin, the other wheels will be reliably adjusted. I can offer help. Further, even during normal driving, steering stability can be improved by appropriately adjusting the difference in rotational speed between the left and right wheels.

(Embodiment) As shown in FIGS. 1 to 3, a four-wheel drive vehicle uses the driving force transmitted from the transmission 10 to the propeller shaft 12 to drive the front side through the front drive shaft 14 on the front side. The first differential device 22 drives the left and right wheels 16 on the left side, and the left and right wheels 20 on the rear side via the drive shaft 18 on the rear side.
, a second differential device 24 , and a third differential device 26 .

In the illustrated case, the first differential device 22 has the same structure as the conventional one, and is incorporated into the rear drive shaft 18. That is, within the differential case 28, the binion 30 is rotatably supported by the binion shaft 29, and the two side gears 31 are connected to the pinion 30.
They are engaged. A shaft 19a extends from one side gear 31 to the left wheel 20, and a shaft 19b extends from the other side gear 31 to the right wheel 20, and is connected to each wheel via a constant velocity joint (not shown).

The rear drive shaft 18 is composed of a shaft 19a and a shaft 19b.
8 receives the driving force of the propeller shaft 12 through a ring gear 32 fixed to the differential case 28 and a pinion 33 fixed to the propeller shaft 12 and meshed with the ring gear 32.

The second differential device 24 and the third differential bag 26 are incorporated into the front drive shaft 14, and each differential device includes a case 34 and a binion 36 disposed inside the case 34. , a side gear 3B disposed within the case 34
Equipped with.

The case 34 is a so-called differential case, and the two cases 34 are the differential carriers 4.
axially spaced within 0.0. Differential bag m
The case 34 of the differential gear 24 is connected to the differential carrier 4 by a pair of rolling bearings 42 mounted on the differential carrier 40, and the case 34 of the differential gear 26 is connected to the differential carrier 4 by a pair of rolling bearings 42 mounted on the differential carrier 40.
The case 34 is rotatably supported by a pair of rolling bearings 44 mounted on the case 34, and the case 34 is rotatable about a common axis.

A pinion shaft 46 is attached to each case 34. In the embodiment shown in FIG.
6 are arranged perpendicularly to each other. These pinion shafts 46 are arranged so that their respective axes are perpendicular to the rotational axis of the case 34. A pair of pinions 36 are attached to each pinion shaft 46 at intervals in the axial direction, and these pinions 36 are rotatably supported by the pinion shaft 46. Binion shaft 46 is 1
In the case of a book, the two pinions 36 are connected to the pinion shaft 46
is rotatably supported by.

Two side gears 38 are arranged in each case 34 at intervals, and each side gear 38 meshes with four pinions 36.

The first shirt) 15a is engaged with the left side gear 38 in the case 34 of the differential device 24, extends leftward from the case 34, and is connected to the differential carrier 40.
stands out from The shaft 15a is supported by a rolling bearing (not shown) and is rotatable about the axis of the case 34. J2) 15a is a constant velocity joint (
(not shown) to the left wheel 16.

The second shaft 15b is serrated connected to the right side gear 38 inside the case 34 of the differential bag fi24, extends to the left side gear 38 inside the case 34 of the differential device 26, and is connected to this side gear 38 through serrations. The shirt L5b is supported by a pair of rolling bearings 48 mounted on the differential carrier 40, and is rotatable about the axis of the case 34.

The third shirt) 15c is connected to the right side gear 38 in the case 34 of the differential bag 26 through serrations, and the case 3
4 to the right and protrudes from the differential carrier 40. The shaft 15c is supported by a rolling bearing (not shown) and is rotatable about the axis of the case 34. The shaft 15c is connected to the right wheel 16 via a constant velocity joint (not shown).

The front drive shaft 14 has three shafts 1
5a, 15b, and 15c, this drive shaft 14 includes a pinion 50 fixed to the propeller shaft 12, and a pinion 50 fixed to the shaft 15b.
A driving force is received from the propeller shaft 12 through a ring gear 52 which is a driven means that meshes with the propeller shaft 12.

A first adjustment means 54 is located between the second differential 24 and the third differential 126 and the rotational speed of the gear 2) 15a extending to the left wheel 16. Ja 2
) second differential device 24 to adjust the rotation speed of 15b.
is incorporated into. Also, a second adjusting means 56 extends from the third differential bag 2126 to the right wheel 16 (2).
15c and shirt 15c) is incorporated into the third differential device 26 to adjust the rotation speed of 15b.

The readjustment means have the same configuration, and both are equipped with electric! It includes a Jl1 machine 58, a worm 60 rotatably supported by a differential carrier 40 and connected to an output shaft 59 of an electric motor 58 through serrations, and a worm wheel 62 attached to a case 34 and meshing with the worm 60.

A means 64 for determining whether it is a four-wheel drive or a two-wheel drive is provided in the transformer 77 of the Bubelashaf) 12.
When the unit is connected, a four-wheel drive signal is sent to the control device, and when it is disconnected, a two-wheel drive signal is sent to the control device.

The control device 70 is a CPU or a computer, and based on signals from a steering angle sensor 72 that detects a steering direction and a steering angle, and a vehicle speed sensor 74,
Left wheel 16 and third jar 2) connected to 5a
The rotational speed difference of the right wheel 16 connected to wheel 5c is calculated.

The control device 70 controls the first adjusting means 54 and the second adjusting means 56 so that the second shaft 15b does not rotate when the determining means 64 determines that the drive is two-wheel drive. When the drive is determined, the first wheel is set so that the left wheel 16 connected to the shirt 15a and the right wheel 16 connected to the shirt 15c have the rotational speed difference obtained as a result of the vt calculation. Adjustment means 54 and second adjustment means 5
6.

(Operations of the Embodiment) When the vehicle is running, a signal is input from the first determining means 64 to the control device 70, and the control device 70 determines whether the vehicle is two-wheel drive or four-wheel drive, as shown in FIG. 4 (80). If it is two-wheel drive,
The control device 70 includes a vehicle speed sensor 74 and a steering angle sensor 72.
The rotational speed of the left and right wheels 16 is calculated based on the signal from 82), and then the rotational speed of the case 34 is calculated.

The rotational speed of the wheel 16 connected to the shirt) 15a or the jacket 2) 15c is set to N1. Assume that the rotational speed of the ring gear 52 attached to the shirt (shirt) 15b is N2, and the rotational speed of the case 34 is NO.

The relationship No - (Nl + N2) holds true. Therefore, the rotation speed of the case 34 is calculated so that No = N, /2 (84), and the control device 70 controls the rotation speed of the electric motor 58 of the adjustment means 54 and the electric motor 58 of the adjustment means 56. Then, the rotational speed of the ring gear 52 is set to zero (86), and as a result, the driving force transmitted from the transmission 1° to the propeller shaft 12 is transmitted to the left and right rear wheels 20 via the rear differential device 22, The vehicle has two-wheel drive. At this time, since the rotational speed of the ring gear 52 is zero, no drag occurs due to the rotation of the front wheel 16.

When the vehicle turns during four-wheel drive, the determining means 64 determines four-wheel drive, and the control device 70 calculates the turning radius and vehicle speed based on the signals from the vehicle speed sensor 74 and steering angle sensor 72, and the left and right wheels 16 (88), and calculates the rotation speed of the case 34 which gives the calculated rotation speeds to the left and right wheels respectively (90), and adjusts the adjustment means 54.
and the motor 58 of the adjusting means 56 to give a predetermined rotational speed to the left and right wheels (92).
Thus, during four-wheel drive, smooth turning is ensured while transmitting driving force to the four wheels.

When the vehicle is running, if either of the left or right front wheels 16 runs onto snow or the like and attempts to spin, the control device 70 adjusts the rotation speed difference between the two wheels to zero based on the signal from the vehicle speed sensor 74. , controls the rotational speed of the electric motor 58 of the adjustment means that engages the wheel that is about to spin.

The first and second adjustment means are electric motors of 58° and 60° worms.
and a worm wheel 62, so the worm 60
Although it is possible to rotate the worm wheel 62 by
The reverse operation, that is, rotating the worm 6o by the worm wheel 62 is not possible due to the characteristics of the worm, so each shaft is reliably rotationally controlled by the electric motor a58.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the two differentials taken along the axis of rotation of the case, Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1, and Figure 3 is a four-wheel drive A diagram schematically showing a car,
FIG. 4 is a control flowchart. 10 Nidoran transmission, 12 Nipro propeller shaft, 14.18: Drive shaft. 16.20: Wheel, 22.24.26: Differential unit, 34: Case, 36: Pinion, 38: Side gear, 54.56: Adjustment means, 60: Worm. 62: Worm wheel, 64: Discrimination means, 70: Control device. Agent: Yoshiyuki Matsunaga, Patent Attorney Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) The driving force transmitted from the transmission to the propeller shaft drives the front left and right wheels via the front drive shaft on the one hand, and the rear left and right wheels via the rear drive shaft on the other hand. The part-time four-wheel drive vehicle includes: a first differential device that is incorporated in one of the front and rear drive shafts and receives driving force from the propeller shaft; and a first differential device that receives driving force from the propeller shaft; a driven means that receives driving force from the propeller shaft and is incorporated in the other shaft; a second differential device that is disposed to the left of the driven means and engages the left wheel; and a right side of the driven means. a third wheel located at the right wheel and engaged with the right wheel;
a differential device, a rotational speed of a first shaft extending from the second differential device to the left wheel, and the driven means between the second differential device and the third differential device; a first means incorporated in said second differential for adjusting the rotational speed of a second shaft coupled to said third differential;
a second means incorporated in the third differential for adjusting the rotational speed of a third shaft extending from the differential to the right wheel and the rotational speed of the second shaft; The control device includes means for determining whether the drive is drive or two-wheel drive, and a control device into which signals from a steering angle sensor and a vehicle speed sensor are input, and the control device is configured to control the wheels connected to the first shaft and the In addition to calculating the rotational speed difference between wheels connected to the third shaft, when the determining means determines two-wheel drive, the first adjusting means and the second shaft are adjusted so that the second shaft does not rotate. and controlling the first adjusting means and the second adjusting means so that when the determining means determines four-wheel drive, the left and right wheels have the rotational speed difference. , part-time four-wheel drive. (2) The first adjusting means and the second adjusting means each include an electric motor, a worm connected to the electric motor, and a worm wheel meshing with the worm. Part-time four-wheel drive vehicles as described in section.