JPH11240349A - Vihicular starting assist device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lubrication failure from occurring in a differential gear even in any state happening, in this starting assist device which is equipped with an electric motor and this differential gear having those of first, second and third rotational elements, connecting this motor to the first rotational element via a reduction gear train and simultaneously connecting a driven wheel to the second rotational element, and in time of starting a vehicle, braking the third rotation element by a braking means, and then making an output torque in the motor so as to be transmitted to the driven wheel via the reduction gear train and the differential gear. SOLUTION: A first lubricating oil passage 191 feeding each lubricating spot of two differential gears 9L and 9R with oil raked up by rotation of a gear 10f of a reduction gear train and a second lubricating oil passage 192 feeding the lubricating spot with oil raked up by rotation of a third rotational element 9b both are installed in a gear case 18 housing the reduction gear train and both these differential gears 9L and 9R. In time of starting, oil is supplied via the lubricating oil passage 191 and thereby the differential gears are lubricated, and after the starting, the oil is supplied by a braking release of the rotational element 9b via the lubricating oil passage 192 and thus the differential gears are lubricated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start assist device mounted on a vehicle having one of a front wheel and a rear wheel as a drive wheel driven by an engine and the other as a driven wheel.

[0002]

2. Description of the Related Art Conventionally, an electric motor and a differential having first, second and third rotating elements are provided as this kind of starting assist device, and the first rotating element of the differential is provided with an electric motor. Are connected via a reduction gear train, and a driven wheel is connected to a second rotating element of the differential device, and brake means for braking the third rotating element of the differential device is provided. It is known that the output torque of an electric motor is transmitted to driven wheels via a reduction gear train and a differential device by operating the driven motor, and the driven wheels are driven by the electric motor to assist starting (Japanese Patent Laid-Open No. Hei 9 (1994)). -79348).

In this vehicle, the braking of the third rotating element by the braking means is released after the vehicle starts, and the driving of the electric motor is stopped. In this case, the third rotating element idles with the rotation of the second rotating element connected to the driven wheel,
The reverse driving force from the driven wheel is no longer transmitted to the first rotating element, and the rotation of the reduction gear train is stopped.

[0004]

By the way, lubrication of a rotating member in a gear case accommodating a reduction gear train is generally performed by:
This is done by supplying the oil scraped up by the gears of the reduction gear train to the lubrication points.
After the start, the rotation of the reduction gear train is stopped, so that the oil supplied to the lubrication points of the differential device cannot be scraped up by the gears of the reduction gear train.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a start assist device capable of supplying oil to lubricating portions of a differential gear even if rotation of a reduction gear train is stopped after the start. I have.

[0006]

Means for Solving the Problems In order to solve the above problems,
According to the present invention, there is provided a start assist device mounted on a vehicle having one of a front wheel and a rear wheel as a drive wheel driven by an engine and the other as a driven wheel, comprising: an electric motor, first, second, and third electric motors. A differential having a rotating element, wherein an electric motor is connected to a first rotating element of the differential via a reduction gear train, and a driven wheel is connected to a second rotating element of the differential, Brake means for braking the third rotating element of the device is provided, and the output means of the electric motor is transmitted to the driven wheels via a reduction gear train and a differential device by operating the brake means when the vehicle starts. A first lubricating oil passage for supplying oil scooped up by the rotation of the gears of the reduction gear train to a lubrication point of the differential gear, in a gear case accommodating the reduction gear train and the differential; Oy which was picked up by the rotation of the third rotating element Forming a second lubricating oil passage for supplying the lubrication points of the differential device.

At the time of starting when the third rotating element of the differential device is braked by the brake means, the oil scooped up by the rotation of the gears of the reduction gear train passes through the first lubricating oil passage to the lubrication point of the differential device. On the other hand, when the rotation of the reduction gear train is stopped by the braking release of the third rotation element by the braking means after the start and the driving stop of the electric motor, the rotation of the second rotation element connected to the driven wheel is stopped. As a result, the oil swept up by the idling of the third rotating element is supplied to the lubricating portion of the differential via the second lubricating oil passage. Thus, poor lubrication of the differential after starting can be prevented.

[0008]

FIG. 1 shows a front wheel drive vehicle in which right and left front wheels 3L and 3R are driven by an engine 1 via a transmission 2. Each front wheel 3L and 3R has a constant velocity joint 4a at both ends. Connected to the transmission 2 via the drive shafts 4L and 4R.

Connecting shafts 6L and 6R having constant velocity joints 6a at both ends are connected to the left and right rear wheels 5L and 5R, which are driven wheels, respectively, and a start assist device 7 is interposed between the two connecting shafts 6L and 6R. Have been.

[0010] As shown in FIG.
A pair of left and right electric motors 8L and 8R and a pair of right and left differential devices 9L and 9R are provided. Each differential 9L, 9R
Is a sun gear 9a, a ring gear 9b, and both gears 9
and a carrier 9d carrying a planetary pinion 9c meshing with the a and 9b. The electric motors 8L, 8R are connected to sun gears 9a, which are the first rotating elements of the differentials 9L, 9R, via reduction gear trains 10L, 10R, respectively, and the second rotation of the differentials 9L, 9R is performed. The element carrier 9d is connected to the constant velocity joints 6a of the connection shafts 6L and 6R.
Further, the ring gear 9b, which is the third rotating element of the two differentials 9L, 9R, is connected to each other so that the ring gear 9b can be braked by the dog clutch 11, which is a braking means.

The dog clutch 11 is turned on and off by a solenoid 11a as described later in detail. A controller 12 for controlling the electric motors 8L and 8R and the solenoid 11a is provided.
A front wheel speed sensor 13 that detects the rotation speed VF of the front wheels 3L and 3R, a rear wheel speed sensor 14 that detects the rotation speed VR of the rear wheels 5L and 5R, a brake switch 15, an accelerator switch 16, and the transmission 2 A signal from the neutral sensor 17 for detecting whether or not the vehicle is in a neutral state is input,
Start assist control and turning assist control are performed.

Details of the start assist control are as shown in FIG. 3, in which the brake switch 15 is off (S1), the accelerator switch 16 is on (S2), the transmission 2 is in the non-neutral state (S3), and the rear wheel speed VR Is determined to be a start when the four conditions of less than a predetermined start determination reference value VS (for example, 10 km / h) (S4) are satisfied, and when it is determined to be a start, the start assist flag F is set to “1”. It is determined whether or not it is set (S5). If F = 0, the difference ΔV between the front wheel speed VF and the rear wheel speed VR is equal to a predetermined reference value ΔV.
It is determined whether it is equal to or more than S (S6). If ΔV ≧ △ VS, it is determined that the front wheels 3L and 3R are slipping, the start assist flag F is set to 1 (S7), and then the solenoid 11a is energized to turn on the dog clutch 11 and (S8), drive the electric motors 8L and 8R (S8)
9). According to this, the sun gear 9a of each differential 9L, 9R is rotated via each reduction gear train 10L, 10R,
The planetary pinion 9c of each of the differentials 9L and 9R revolves while rotating by using the ring gear 9b braked by the dog clutch 11 as a reaction force receiver, and the carrier 9d of each of the differentials 9L and 9R rotates, and each of the electric motors The output torque of 8L, 8R is transmitted to each rear wheel 5L, 5R, and the starting is assisted by driving the rear wheels 5L, 5R, which are driven wheels.

When VR ≧ VS1 after the start, the start assist flag F is reset to “0” (S10), and then the energization of the solenoid 11a is stopped to turn off the dog clutch 11 (S11), and the electric motor 8L , 8R are stopped (S12). According to this, each rear wheel 5L, 5
The rotation of the carrier 9d of each of the differentials 9L and 9R due to the rotation of R causes the ring gear 9b to idle, and the reverse driving force from the rear wheels 5L and 5R is not transmitted to the sun gear 9a, and the reduction gear trains 10L and 10L. And the rotation of the electric motors 8L and 8R is stopped.

The turning assist control is performed by turning the left and right electric motors 8L,
Of the 8Rs, the electric motor on the outer ring side is rotated forward and the electric motor on the inner ring side is rotated reversely. For example, when turning right,
The left electric motor 8L is rotated forward and the right electric motor 8R is rotated reversely. According to this, the sun gear 9a of the left differential 9L is rotated forward and the carrier 9d is rotated forward with respect to the ring gear 9b, and the sun gear 9a of the right differential 9R is rotated backward and the carrier 9d is rotated. Is reversed with respect to the ring gear 9b. In this case, a reverse reaction force acts on the ring gear 9b of the left differential 9L, and a forward reaction acts on the ring gear 9b of the right differential 9R. Since 9b and 9b are connected to each other, both reaction forces are canceled. Therefore, based on the rotation speed of the ring gear 9b, the left differential 9
The speed of the carrier 9d of L, that is, the left rear wheel 5L is increased, and the speed of the carrier 9d of the right differential 9R, that is, the right rear wheel 5R is reduced. As a result, a driving force is applied to the left rear wheel 5L, which is the outer wheel, and a braking force is applied to the right rear wheel 5R, which is the inner wheel, to generate yaw moment in the right turning direction, thereby assisting turning.

The specific structure of the start assist device 7 is shown in FIG.
As shown below, a rotor 8a, a stator 8b, and a brush 8c are provided on both left and right outer sides of an upper portion of a gear case 18 that accommodates the differentials 9L, 9R and the reduction gear trains 10L, 10R.
An electric motor 8L comprising a DC brush motor having
8R, and differential devices 9L, 9R are arranged between left and right shaft support walls 180, 180 provided at a lower portion in the gear case 18. The ring gear 9b of the differential devices 9L and 9R is supported on the shaft support wall 180 via a bearing 9e, and a hollow sun gear shaft 9f extending axially outward from the sun gear 9a of each of the differential devices 9L and 9R. Are supported on the bearing walls 180 and the left and right end walls 181 of the gear case 18 via bearings 9g and 9h, respectively.
A carrier shaft 9i extending axially outward from the carrier 9d of the 9R is inserted through the sun gear shaft 9f with a gap therebetween, and is axially supported on each end wall portion 181 via a bearing 9j.
The constant velocity joint 6a is connected to the outer end of i.

Each of the reduction gear trains 10L, 10R includes a first gear 10a on an output shaft 8d of each electric motor 8L, 8R, a second gear 10b meshing with the first gear 10a, and a second gear 1R.
0b, a fourth gear 10d meshing with the third gear 10c, a fifth gear 10e coaxial with the fourth gear 10d, and a sun gear shaft 9e meshing with the fifth gear 10e. And a sixth gear 10f.

As shown in FIG. 6, the dog clutch 11 is a movable dog 1 which is spline-engaged with the outer periphery of a ring gear 9b.
1b and a fixed dog 11c fixed to the left pivot wall 180
And a shift sleeve 11e engaged with the movable dog 11b via a ball 11d is provided.
A rod 11f interlocking with a solenoid 11a attached to the left outer side of the gear case 18 is provided, a fork 11g engaging with a shift sleeve 11e is attached to the rod 11f, and when the solenoid 11a is energized, the rod 11f
move left to oppose h, fork 11g and shift sleeve 1
1e, the movable dog 11b moves leftward and the fixed dog 11
c, the dog clutch 11 is turned on and the ring gear 9
b is braked.

The planetary pinion 9c of each of the differentials 9L and 9R is supported by a pinion shaft 9k mounted on a carrier 9d via a needle bearing 91. An oil guide plate 9m is mounted on the carrier 9d. The oil collected by the oil guide plate 9m is supplied to the needle bearing 91 via an oil hole 9n formed in the pinion shaft 9k.

Here, oil is injected into the gear case 18 to a level indicated by L in FIG.
The oil is scraped up by the rotation of the sixth gear 10f of the left and right gears 10R, and the movable dog 11b and the shift sleeve 11e on the outer periphery thereof are rotated by the rotation of the ring gear 9b of the differential gears 9L and 9R.
The oil is stirred up. And gear case 1
8 is partially cut out in each end wall portion 181 so that the mounting portions of the bearings 9h and 9j are cut off, and an oil groove 182 facing the sixth gear 10f is formed.
Is formed, and the oil scraped up by the sixth gear 10f is
A gap between the oil groove 182, the sun gear shaft 9f and the carrier shaft 9i, and a radial oil hole 90 formed in the sun gear shaft 9f.
And each differential 9 via an oil guide plate 9m.
L, constitute the first lubricating oil passage 19 ₁ is supplied to 9R lubricating points of serving needle bearing 9l.

A ring gear 9 is provided on the inner surface of the gear case 18 located on the rear side of the portion where the differentials 9L and 9R are disposed.
An oil hole 184 is formed in the shaft support wall 180 to receive the oil scooped up by the rotation of the b. The oil hole 184 communicates with the oil sump 183 as shown in FIG. Is formed and the oil scraped up by the rotation of the ring gear 9b is transferred to the oil sump 183 and the oil hole 18
4, a second oil guide plate 185 attached to each shaft support wall 180, and a second lubricating oil passage 19 to be supplied to the needle bearing 91 via the oil guide plate 9m.
_Make up _two . In this embodiment, the gear case 1 is used.
An oil hole 186 is formed in each end wall portion 181 for guiding the oil from the oil sump 183 to the gap between the sun gear shaft 9f and the carrier shaft 9i, and the oil scraped up by the rotation of the ring gear 9b is used for the oil. as can be supplied to the needle bearing 9l a path via the holes 186, it is provided two paths of a path via a path and oil hole 186 through the oil hole 184 as the ₂ second lubricating oil passage 19 .

The dog clutch 11 is turned on and the ring gear 8 is turned on.
b, the speed reduction gear train 10L,
The oil scraped up by the sixth gear 10f of the 10R is the first oil.
The lubricating oil passage 19 ₁ through to the differential device 9 L, is supplied to 9R needle bearing 9l, starting after the dog clutch 1
1 is turned off to release the braking of the ring gear 8b, the oil scraped up by the rotation of the ring gear 8b is supplied to the needle bearings 9l of the differentials 9L, 9R via the _second lubricating oil passage 192. Is done. Also, when turning assist,
The oil is scraped up by the rotation of the ring gear 8b, and the oil is also scraped up by the sixth gear 10f of each of the reduction gear trains 10L, 10R by driving the electric motors 8L, 8R. Oil is supplied to the needle bearing 9l via the first and second lubricating oil passages 19 ₁ and 19 ₂ . Thus, the needle bearing 91 is well lubricated in any state.

Although the embodiment in which the present invention is applied to the start assist device mounted on the front wheel drive vehicle has been described above, the present invention is similarly applied to the start assist device for driving the front wheel which is the driven wheel of the rear wheel drive vehicle. it can.

[0023]

As is clear from the above description, according to the present invention, even if the rotation of the reduction gear train is stopped after starting and oil cannot be scraped up by the gears of the reduction gear train,
The oil scooped up by the rotation of the third rotating element of the differential can be supplied to the lubrication points of the differential, and the differential can be lubricated well in any state.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of use of the apparatus of the present invention.

FIG. 2 is a skeleton diagram showing an example of the apparatus of the present invention.

FIG. 3 is a flowchart showing a start assist control program.

FIG. 4 is a side view showing a specific configuration of the second device.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 4;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 5;

8 is a sectional view taken along line VIII-VIII in FIG.

[Explanation of symbols]

1 Engine 3L, 3R Front wheel (drive wheel) 5L, 5R Rear wheel (follower wheel) 8L, 8R
Electric motor 9L, 9R Differential gear 9a Sun gear (first rotating element) 9b Ring gear (third rotating element) 9d Carrier (second rotating element) 10L, 10R Reduction gear train 11 Dog clutch (brake means) 18 Gear case 19 ₁ First
Lubricating oil passage 19 ₂ Second lubricating oil passage

Claims (1)

[Claims] 1. A start assist device mounted on a vehicle having one of a front wheel and a rear wheel as a drive wheel driven by an engine and the other as a driven wheel, comprising: an electric motor, first, second, and third motors. And an electric motor connected to a first rotating element of the differential device via a reduction gear train, and a second rotating element of the differential device.
Brake means for connecting a driven wheel to a rotating element and braking a third rotating element of the differential device are provided, and when the vehicle starts moving, the brake means is operated to reduce the output torque of the electric motor to the reduction gear train and the differential device. And transmitting the oil scooped up by the rotation of the gears of the reduction gear train to a lubrication point of the differential gear in a gear case accommodating the reduction gear train and the differential gear. A first lubricating oil passage, and a second lubricating oil passage for supplying oil scooped up by rotation of a third rotating element of the differential to a lubricating point of the differential. Start assist device.