JP3160536B2 - Driving force left / right distribution ratio variable control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force left / right distribution ratio variable control device.

[0002]

2. Description of the Related Art Motion state quantities such as lateral acceleration, vehicle speed, steering angle, yaw rate, etc. are detected and transmitted to the left and right wheels according to these values so that the driving force to the wheels outside the turning circle becomes larger. Japanese Patent Application No. Hei 6-2518 discloses a technique for improving the responsiveness of a vehicle when turning by controlling the distribution ratio of the driving force variably.
No. 69 (JP-A-8-114255).

[0003]

However, this driving force left / right distribution ratio variable control device changes the driving force difference between left and right wheels by controlling the coupling force of two clutches incorporated in a planetary gear mechanism. The driving force difference between the left and right wheels increases according to the degree of sudden turning at high speed or sudden acceleration while turning, so the more frequently the vehicle runs under severe conditions, the more the clutch wears out. . For this reason, the durability varies greatly depending on the driving conditions of the user, but since this device cannot be replaced relatively easily like a brake pad, for example, driving under severe conditions is frequently performed. If the durability is set for the user who performs the maintenance so that the maintenance interval with other components can be balanced, there is a disadvantage that the manufacturing cost increases.

The present invention has been devised in order to solve such a problem imposed on the prior art, and its main purpose is to make the maintenance interval valid without increasing the manufacturing cost. It is an object of the present invention to provide a driving force left / right distribution ratio variable control device configured to be able to be set at a certain point.

[0005]

In order to achieve the above object, according to the present invention, a left and right driving force for generating a yawing moment in a vehicle body by distributing different driving forces to left and right wheels. In the variable ratio control device, when the integrated value indicating the degree of operation exceeds a certain value before traveling a predetermined distance, the allowable value of the driving force difference given between the left and right wheels is reduced from the initial state. Each time the vehicle travels a predetermined distance, the allowable value of the driving force difference and the integrated value are returned to the initial state.

More specifically, for example, by integrating the exciting current and the vehicle speed of a solenoid valve for controlling a clutch and the like provided in the driving force transmission path, the load conditions of the driving force left / right distribution ratio variable control device are included. If the determination value exceeds the predetermined value before traveling a certain distance, it is determined that the use load is excessive, and the allowable value of the exciting current of the clutch control solenoid valve is determined. And reduce the load on the driving force left / right distribution ratio variable control device. This allows
Even if there are many runs under severe conditions, the service life can be prevented from being extremely reduced. In this state, the vehicle is driven until the predetermined distance is reached, and when the predetermined distance is reached, the load reduction state is reset, the state is returned to the initial state, and the accumulation for obtaining the determination value of the used load is repeated. As described above, since the determination of the usage load is repeated in a certain section, even if all the values are initialized by replacing the electronic control unit in the middle, the influence thereof may be small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a driving force left / right distribution ratio variable control device to which the present invention is applied. The driving force left / right distribution ratio variable control device T (hereinafter abbreviated as distribution device) is provided between the left and right driving wheels WFL and WFR together with the differential device D connected to the output shaft 1 of the transmission to which the power of the engine is transmitted. Is provided.

The shift device D is composed of a well-known double pinion type planetary gear mechanism, in which an external gear 2ex and an internal gear 2in are integrally formed, and the external gear 2ex is attached to the shaft end of the output shaft 1 of the transmission. A driven member 2 meshed with the output gear 3 provided, a differential case 4 integrally connected to both sides of the driven member 2 in the axial direction, and left and right output shafts 5L and 5R inserted through a center hole of the differential case 4 so as to be relatively rotatable. , Left output shaft 5L
, An outer pinion 7ex meshing with the internal gear 2in to rotate and revolve, an inner pinion 7in meshing with the outer pinion 7ex and the sun gear 6 at the same time to rotate and revolve, It comprises a planetary carrier 8 rotatably supporting the outer pinions 7in and 7ex, respectively, and coupled to the shaft end of the right output pin 5R. The center of the differential case 4 is pivotally supported by the transmission housing 9. I have. The left side of the planetary carrier 8 surrounds the left output shaft 5L and is connected to the right end of the sleeve 10 inserted through the center hole of the differential case 4.

The distribution device T includes a planetary gear mechanism P, a speed-up clutch Ca and a deceleration clutch Cd, each of which is a hydraulically operated wet multi-plate clutch.

The planetary gear mechanism P of the distribution device T includes a planetary carrier 12 rotatable about a left output shaft 5L, a first pinion 13, a second pinion 14, and a third pinion 1.
5 and a plurality of (for example, four) triple pinion members 16 pivotally mounted at equal intervals on a circle concentric with the center of the planetary carrier 12 and a left output pong 5L.
A first sun gear 17 pivotally connected to the outer periphery of the first pinion 13 and a second sun gear 17 which is connected to the outer periphery of the left output pin 5L at a position adjacent to the left side of the first sun gear 17 and meshes with the second pinion 14. It comprises a sun gear 18 and a third sun gear 19 integrated with the inner plate holding member 21 of the speed increasing clutch Ca pivotally mounted on the outer periphery of the left output pong 5L and meshing with the third pinion 15.

Here, the first sun gear 17 is connected to the left end of the sleeve 10 connected to the planetary carrier 8 of the difference device D, so as to rotate integrally with the planetary carrier 8 and the right output shaft 5R of the difference device D. It has become.

The speed increasing clutch Ca includes an inner plate that is axially displaceably engaged with the inner plate holding member 21 and an outer plate that is axially displaceably engaged with the inner surface of the casing 11. And presses against each other, and exerts an action of restraining the rotation of the third sun gear 19 integrated with the inner plate holding member 21.

The deceleration clutch Cd includes an inner plate that is displaceably engaged with an inner plate holding member 25 that is integral with the planetary carrier 12, and an outer plate that is displaceably engaged with the inner surface of the casing 11. Are pressed against each other by the thrust of the hydraulic piston, and the rotation of the planetary carrier 12 is restrained, and the reciprocating motion of the triple pinion 16 pivotally supported by the planetary carrier 12 is exerted.

The pressure-increasing clutch Ca and the deceleration clutch Cd include a pressure control valve 30 controlled by an electronic control unit 29 to which the lateral acceleration GY, the vehicle speed V, the steering angle θ, and the yaw rate γ are inputted, and an opening / closing control. Valves 31 and 32
The coupling force is continuously variably controlled by the hydraulic pressure supplied via the.

According to this device, when the vehicle is traveling straight,
The deceleration clutch Cd and the speed increasing clutch Ca are both in a non-coupled state. As a result, the restraints of the planetary carrier 12 and the third sun gear 19 on the distribution device T side are both released, and the left output shaft 5L, the right output shaft 5R, the planetary carrier 8 on the differential device D side and the planetary carrier on the distribution device T side. 12, all rotate integrally. At this time,
As indicated by the shaded arrows in FIG. 1, the torque of the engine is evenly distributed from the shift device D to the left and right front wheels WFL and WFR.

When the vehicle turns right, the deceleration clutch Cd
And combine the planetary carrier 12 with the casing 11
To stop. At this time, the left output shaft 5L integral with the left front wheel WFL and the right output gear 5R integral with the right front wheel WFR (the planetary carrier 8 of the differential device D) mesh with the second sun gear 18 and the second pinion 14. , And the first pinion 13 and the first sun gear 17 are connected via meshing, so that the rotation speed NL of the left front wheel WFL is increased with respect to the rotation speed NR of the right front wheel WFR according to the following equation. You.

NL / NR = (Z4 / Z3) (Z1 / Z2) where Z1: the number of teeth of the first sun gear 17 Z2: the number of teeth of the first pinion 13 Z3: the number of teeth of the second sun gear 18 Z4: second Number of teeth of pinion 14

As described above, the rotation speed N of the left front wheel WFL
When L is increased with respect to the rotation speed NR of the right front wheel WFR, the torque of the right front wheel WFR of the turning inner wheel distributed by the differential device D is indicated by the hatched arrow in FIG. Some of the
This is transmitted to the left front wheel WFL of the turning outer wheel.

When the vehicle turns to the left, the speed increasing clutch Ca
And the third sun gear 19 integrated with the inner plate holding member 21 of the speed increasing clutch Ca is stopped. Thus, the third pinion 15 meshed with the third sun gear 19
, The three-pinion 16 revolves, and the rotation speed of the planetary carrier 12 is increased with respect to the rotation speed of the left output shaft 5L. As a result, the rotation speed NR of the right front wheel WFR becomes
Is increased by the following equation with respect to the rotation speed NL of

NR / NL = [1- (Z5 / Z6) (Z2
/ Z1)] ÷ [1- (Z5 / Z6) (Z4 / Z3)] where Z5 is the number of teeth of the third sun gear 19 Z6 is the number of teeth of the third pinion 15

As described above, the rotation speed N of the right front wheel WFR
When R is increased with respect to the rotation speed NL of the left front wheel WFL, the torque of the left front wheel WFL of the turning inner wheel distributed by the differential device D is indicated by the hatched arrow in FIG. Some of the
This is transmitted to the right front wheel WFR of the turning outer wheel. In addition,
By appropriately adjusting the coupling force between the deceleration and speed-up clutches Ca and Cd, the left front wheel W can be adjusted according to the degree of the coupling force.
The transmission amount of the driving force between FL and the front right wheel WFR can be arbitrarily changed.

In this manner, the coupling force between the deceleration clutch Cd and the speed increasing clutch Ca is adjusted to adjust the front left and right front wheels WFL.
By actively controlling the yawing moment generated in the vehicle body by changing the torque distribution ratio between the WFRs, it is possible to contribute to the improvement of the turning response.

Next, a method of reducing the control amount according to the present invention for the above embodiment will be described with reference to FIG.

In order to variably control the right / left distribution ratio of the driving force by the coupling force of the deceleration and speed-up clutches Ca and Cd, first, the lateral acceleration GY, the vehicle speed V, the steering angle θ, and the yaw rate γ are read as described above. (Step 1). The current I to be supplied to the pressure control valve 30 is determined based on these values. When the vehicle is new, the allowable current I is set as a function of a predetermined control coefficient K (step 2). In other words, the allowable value of the coupling force between the two clutches Ca and Cd is determined by the control coefficient K.

The current I flowing through the pressure control valve 30, the vehicle speed V,
An amount e corresponding to the transmitted energy during the clutch operation is obtained from the product of the operation times T (step 3), and this value is integrated (step 4).

The integrated value E is compared with a predetermined value E0 (step 5), and when the integrated value E exceeds the predetermined value E0 (point A in FIG. 5), the control coefficient K is appropriately reduced (for example, 50%). (Step 6). As a result, the current I supplied to the pressure control valve 30 is reduced, and the allowable value of the coupling force of the clutches Ca and Cd is reduced. As a result, the load on the distribution device T is reduced. In this embodiment, the coefficient is reduced by half (K ← 0.5K). However, the coefficient may be set to another reduction rate, or may be gradually reduced by setting a predetermined gradient.

The traveling distance D has reached a predetermined value D0 (see FIG. 5).
B), the integrated value E of the transmitted energy amount of the clutch
And the running distance integrated value D is reset (step 8), and the control coefficient is returned to the initial value K, and the above flow is repeated from the beginning.

[0029]

As described above, according to the present invention, when the vehicle is frequently exposed to a severe use condition, the driving force difference generated between the right and left wheels is reduced to reduce the burden on the driving force left / right distribution ratio variable control device. Is reduced, and the substantial durability of the device can be matched with other vehicle components without increasing unnecessary cost. In addition, since the integration and reset of the amount of transmitted energy of the clutch are repeated at predetermined intervals, even if all the values are initialized by replacing the electronic control unit in the middle, the effect is not affected. Is small. In addition to this, since the control amount is reduced instead of stopping the control, the dynamic characteristics of the vehicle do not need to be suddenly changed.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a power transmission system of a front engine / front drive vehicle to which the present invention is applied.

FIG. 2 is an explanatory diagram of an operation during a right turn.

FIG. 3 is an operation explanatory view at the time of turning left.

FIG. 4 is a control flowchart of the present invention.

FIG. 5 is an explanatory diagram showing a change in a control coefficient K.

[Explanation of symbols]

 Reference Signs List 1 output shaft of transmission 2 driven member 3 output gear 4 differential case 5 output shaft 6 sun gear 7 pinion 8 planetary carrier 9 transmission housing 10 sleeve 11 casing of distribution device 12 planetary carrier 13 first pinion 14 second pinion 15 third pinion 163 Continuous pinion member 17 First sun gear 18 Second sun gear 19 Third sun gear 21 Inner plate holding member of speed increasing clutch 25 Inner plate holding member of speed reducing clutch 29 Electronic control unit 30 Pressure control valve 31/32 Open / close valve T Distribution device D Differential gear P Planetary gear mechanism Ca Speed-up clutch Cd Speed-down clutch

──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Shibata 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Technical Research Institute Co., Ltd. (56) Reference JP-A-2-290722 (JP, A) JP JP-A-3-1255061 (JP, A) JP-A-5-262159 (JP, A) JP-A-7-52678 (JP, A) JP-A-8-114255 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B60K 23/04

Claims (1)

(57) [Claims] 1. A drive power left / right distribution ratio variable control device for generating a yawing moment in a vehicle body by distributing different drive powers to left and right wheels, wherein the drive power left / right distribution ratio variable control device is activated before traveling a predetermined distance. When the integrated value representing the degree exceeds a certain value, the allowable value of the driving force difference given between the left and right wheels is reduced from the initial state, and each time the vehicle travels the predetermined distance, the allowable value of the driving force difference and the integration are calculated. A drive force left / right distribution ratio variable control device, wherein the value is returned to an initial state again.