JPH0234428A - Front/rear wheel drive force distribution control device - Google Patents

Abstract

PURPOSE:To enhance the head swing controllability under normal operation and the running stability at transient by introducing such a control as to increase distribution of the rear wheel drive force associating with drop of the revolution condition varying speed of the car. CONSTITUTION:A car A is equipped with a means D to transmit the drive force to the front and rear wheels B, C upon being distributed changeably. Therein the revolution condition varying speed of the car A is sensed by a means E. A means F changes distribution of the front and rear wheel drive forces so that the rear increases associating with drop of the revolution condition varying speed. The sideways acceleration varying speed of the car and the yawrate varying speed are sensed as revolution condition varying rate sensing means E. This enhances the head swing controllability due to increase in the rear wheel drive force under normal operation and also enhances the running stability due to drop of the rear wheel drive force in transient.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は車両の前後輪に対する駆動力配分を制御する装
置に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for controlling the distribution of driving force between front and rear wheels of a vehicle.

（従来の技術） 車両は今日、エンジンの高出力化にともない４輪駆動シ
ステムを採用することが多くなりつつあるが、更に進ん
で前後輪への駆動力配分を逐一最適となるようアクティ
ブに制御することも考えられている。(Prior technology) Today, vehicles are increasingly adopting four-wheel drive systems as engines become more powerful. It is also considered to do so.

そのための前後輪駆動力配分制御装置としては、従来例
えば特開昭６１−１６９３２６号公報に記載の如く、車
両の横加速度が大きくなるにつれ後輪への駆動力配分を
大きくして、大きな横加速度を発生するような車両の旋
回走行中アクセルペダル操作により後輪をパワースライ
ドさせながらのパワースライド走行を可能にするように
したものがある。Conventionally, front and rear wheel drive force distribution control devices for this purpose have been proposed, for example, as described in Japanese Patent Application Laid-open No. 169326/1982, which increases the drive force distribution to the rear wheels as the lateral acceleration of the vehicle increases. Some vehicles are capable of power sliding while power sliding the rear wheels by operating the accelerator pedal while the vehicle is turning in such a way that the vehicle is turning.

（発明が解決しようとする課題） しかしてかかる構成では、旋回走行中の定常状態で上記
の如くアクセルペダル操作による車両の転向制御性を向
上させ得るが、その反面車線変更中等の過渡状態で後輪
の駆動力増大にともなうコーナリングフォース不足によ
り走行安定性の悪化を生ずる。(Problem to be Solved by the Invention) However, with such a configuration, it is possible to improve the turning controllability of the vehicle by operating the accelerator pedal as described above in a steady state while turning, but on the other hand, in a transient state such as changing lanes, the turning controllability of the vehicle can be improved. Driving stability deteriorates due to insufficient cornering force due to increased wheel drive force.

第８図は加速しながらの同族回時における車両の旋回半
径比Ｒ／Ｒｅ　　（Ｒｏ−ｍ−初期旋回半径、Ｒ−現在
の旋回半径）特性を示し、ａが横加速度Ｇの増大によっ
てもＲ／　ＲＯ＝１を保つニュートラルステア特性、ｂ
が横加速度Ｇの増大時Ｒ／Ｒ。Figure 8 shows the turning radius ratio R/Re (Rom-initial turning radius, R-current turning radius) of the vehicle during homogeneous turning while accelerating. / Neutral steer characteristic that maintains RO=1, b
is R/R when lateral acceleration G increases.

〈１となるオーバーステア特性であるが、−ａ的にはＣ
で示す如く横加速度Ｇの増大につれＲ／　Ｒ６が大きく
なるファイナルアンダーステ特性となるよう設計するの
が普通である。このアンダーステア特性は、車線変更等
の過渡状態で安定性が増して好ましいが、旋回走行中の
定常状態では、特に高速時車両の走行軌跡が旋回方向外
側にふくらんで危険である。The oversteer characteristic is <1, but in terms of -a, C
It is normal to design the vehicle so that it has a final understeer characteristic in which R/R6 increases as the lateral acceleration G increases, as shown in FIG. This understeer characteristic is preferable because it increases stability in a transient state such as changing lanes, but in a steady state while turning, the trajectory of the vehicle bulges outward in the direction of the turn, especially at high speeds, which is dangerous.

かと言って、第８図中ｄで示す如きファイナルオーバー
ステア特性にすると、旋回走行中の定常状態で上記の危
険をなくし得るが、車線変更等の過渡状態で走行不安定
となる。On the other hand, if the final oversteer characteristic is set as shown by d in FIG. 8, the above-mentioned danger can be eliminated in a steady state during cornering, but running becomes unstable in a transient state such as when changing lanes.

これらの事実に照らして明らかなように、前記従来装置
のように横加速度の大きさのみで前後輪の駆動力配分を
＃御するのでは、定常状態と過渡状態とに夫々適した制
御が得られず、いずれか−方が犠牲にならざるおえなか
った。ちなみに、過渡状態では第８図中Ｃで示すような
ファイナルアンダーステア特性が好ましく、定常状態で
は同図中ｅで示すようにアンダーステア傾向を弱めた特
性が好ましい。In light of these facts, it is clear that if the drive force distribution between the front and rear wheels is controlled only by the magnitude of lateral acceleration as in the conventional device described above, it is not possible to achieve control that is suitable for steady states and transient states. One of them had to be sacrificed. Incidentally, in a transient state, a final understeer characteristic as shown by C in FIG. 8 is preferable, and in a steady state, a characteristic with a weakened understeer tendency as shown by e in the same figure is preferable.

本発明は、定常状態と過渡状態とを車両旋回状態の変化
速度より識別し得るとの観点から、この変化速度の遅い
定常状態では後輪駆動力配分を大きくし、上記変化速度
の速い過渡状態では後輪駆動力配分を小さくして、両状
態での要求特性を共に満足させるようにすることを目的
とする。From the viewpoint that a steady state and a transient state can be distinguished from the rate of change in the vehicle turning state, the present invention increases rear wheel drive force distribution in the steady state where the rate of change is slow, and in the transient state where the rate of change is fast. In this case, the purpose is to reduce the rear wheel drive force distribution so as to satisfy the required characteristics in both conditions.

（課題を解決するための手段） この目的のため本発明前後輪駆動力配分制御装置は第１
図に概念を示す如く、駆動力を前後輪へ可変式に分配し
て伝達する前後輪駆動力配分調整手段を具えた車両にお
いて、 車両の旋回状態変化速度を検出する旋回状態変化率検出
手段と、 旋回状態変化速度の低下につれ後輪駆動力配分を増大さ
せる前後輪駆動力配分変更手段とを設けてなるものであ
る。(Means for Solving the Problems) For this purpose, the front and rear wheel drive force distribution control device of the present invention provides the first
As conceptually shown in the figure, in a vehicle equipped with front and rear wheel drive force distribution adjusting means for variably distributing and transmitting driving force to the front and rear wheels, there is provided a turning state change rate detection means for detecting the speed at which the turning state of the vehicle changes. , front and rear wheel drive force distribution changing means for increasing the rear wheel drive force distribution as the turning state change speed decreases.

なお、旋回状態変化率検出手段としては、車両の横加速
度変化速度を検出するもの、或いは車両のヨーレイト変
化速度を検出するものがある。Note that the turning state change rate detection means includes one that detects the rate of change in the lateral acceleration of the vehicle, or one that detects the rate of change in the yaw rate of the vehicle.

（作　用） 前後輪駆動力配分調整手段は駆動力を前後輪へ逐一適切
に分゛配して伝達し、車両を好適な前後輪駆動力配分で
走行させる。(Function) The front and rear wheel drive force distribution adjusting means appropriately distributes and transmits the drive force to the front and rear wheels, one by one, and causes the vehicle to travel with a suitable front and rear wheel drive force distribution.

ここで旋回状態変化率検出手段は、車両の旋回状態変化
速度を検出し、前後輪駆動力配分変更手段は旋回状態変
化速度の低い時後輪駆動力配分を増大させ、旋回状態変
化速度の高い時後輪駆動力配分を低下させる。よって、
前者の定常旋回状態で後輪がコーナリングフォースを低
下され、アクセルペダル操作による車両の転向制御性を
向上させ得ると共に、車両の走行軌跡が旋回方向外側に
ふくらむ危険を防止することができる。又後者の過渡状
態では、後輪がコーナリングフォースを増大され、車線
変更時等での走行安定性を良好にすることができ、定常
状態の要求特性と過渡状態の要求特性を共に満足させ得
る。Here, the turning state change rate detection means detects the turning state change speed of the vehicle, and the front and rear wheel drive force distribution changing means increases the rear wheel drive force distribution when the turning state change speed is low, and increases the rear wheel drive force distribution when the turning state change speed is high. rear wheel drive force distribution is reduced. Therefore,
In the former steady turning state, the cornering force on the rear wheels is reduced, and it is possible to improve the turning controllability of the vehicle by operating the accelerator pedal, and to prevent the running trajectory of the vehicle from bulging outward in the turning direction. Furthermore, in the latter transient state, the cornering force on the rear wheels is increased, making it possible to improve running stability when changing lanes, etc., and satisfying both the required characteristics in the steady state and the required characteristics in the transient state.

（実施例） 以下、本発明の実施例を図面に基づき詳細に説明する。(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

第２図は本発明装置の一実施例を示し、ＩＬ、　ＩＲは
夫々左右前輪、２Ｌ、　２１？は夫々左右後輪、３はエ
ンジンである。前輪ＬＬ、　ＩＩ？はステアリングホイ
ール４によりステアリングギヤ５を介し転舵可能とする
。FIG. 2 shows an embodiment of the device of the present invention, where IL and IR are the left and right front wheels, respectively, and 2L and 21? are the left and right rear wheels, and 3 is the engine. Front wheel LL, II? The steering wheel 4 enables steering via the steering gear 5.

エンジン３の出力軸は変速機６を介してプロペラシャフ
ト７に結合し、このプロペラシャフトをトランスファユ
ニット８に貫通してディファレンシャルギヤ９を介し左
右後輪２Ｌ、　２Ｒに結合する。The output shaft of the engine 3 is connected to a propeller shaft 7 via a transmission 6, which passes through a transfer unit 8 and is connected to left and right rear wheels 2L, 2R via a differential gear 9.

トランスファユニット８はプロペラシャフト７の動力を
一部、プロペラシャフト１０及びディファレンシャルギ
ャ１１を経て左右前輪ＩＬ、　ＩＲに分配するもので、
第３図に明示する如く油圧式多板クラッチ８ａを内蔵す
る。このクラッチ８ａはプロペラシャフト７上に設け、
油圧作動される時その作動圧ＰＣに応じた比でプロペラ
シャフト７の動力をギヤ組８ｂ、　８ｃ、　８ｄ及びプ
ロペラシャフト１０により前輪ＩＬ。The transfer unit 8 distributes part of the power from the propeller shaft 7 to the left and right front wheels IL and IR via the propeller shaft 10 and differential gear 11.
As clearly shown in FIG. 3, a hydraulic multi-disc clutch 8a is built-in. This clutch 8a is provided on the propeller shaft 7,
When hydraulically operated, the power of the propeller shaft 7 is transferred to the front wheel IL by gear sets 8b, 8c, 8d and the propeller shaft 10 at a ratio according to the operating pressure PC.

ＩＲに伝達する。Communicate to IR.

クラッチ作動圧Ｐｃは、エンジン駆動されるオイルポン
プ１２を主たる構成要素とし、第２図の如くにアンロー
ド弁１３及びアキュムレータ１４を具える圧力源からの
一定うイン圧ＰＬを電磁減圧弁１５により調圧して造り
出す。この弁１５は駆動力配分用コントローラ１６によ
り電子制御し、このためコントローラ１６は車両重心に
設けられて横加速度Ｇを検出する横Ｇセンサ１７からの
信号を入力され、第４図の制御プログラムを実行するも
のとする。The clutch operating pressure Pc is mainly composed of an oil pump 12 driven by an engine, and a constant input pressure PL from a pressure source including an unload valve 13 and an accumulator 14 as shown in FIG. 2 is generated by an electromagnetic pressure reducing valve 15. Create by adjusting the pressure. This valve 15 is electronically controlled by a driving force distribution controller 16. Therefore, the controller 16 receives a signal from a lateral G sensor 17 installed at the center of gravity of the vehicle and detects lateral acceleration G, and executes the control program shown in FIG. shall be carried out.

第４図のプログラムは一定時間ΔＴ（例えば１００ｍ５
ｅｃ）毎に繰返し実行され、先ずセンサ１７から横加速
度を読込んでＧ、とじてメモリする。次で、横加速度前
回値（ΔＴ時間前の値）ＧＯからの変化量ΔＧ＝Ｇ＋　
　Ｇｏを演算して横加速度（旋回状態）変化速度を求め
る。その後、横加速度Ｇ、と横加速度変化速度ΔＧとか
ら第５図のテーブルデータを基に後輪駆動力配分を検索
し、これに対応する信号を電磁弁１５へ出力してクラッ
チ８ａの作動圧ＰＣ（クラッチ８ａの締結力）を上記検
索した後輪駆動力配分が得られるよう制御する。最後に
、Ｇ１をＧｏとしてメモリし、次回ΔＧの演算に資する
。The program in Fig. 4 is a fixed time ΔT (for example, 100 m5
ec), and first reads the lateral acceleration from the sensor 17 and stores it in memory. Next, the amount of change from the previous value of lateral acceleration (value before ΔT time) GO is ΔG=G+
Go is calculated to determine the rate of change in lateral acceleration (turning state). After that, the rear wheel drive force distribution is searched based on the table data of FIG. 5 from the lateral acceleration G and the lateral acceleration change rate ΔG, and a corresponding signal is output to the solenoid valve 15 to control the operating pressure of the clutch 8a. The PC (clutching force of the clutch 8a) is controlled so as to obtain the rear wheel drive force distribution searched above. Finally, G1 is stored as Go to contribute to the next calculation of ΔG.

ところで第５図は、横加速度変化速度ΔＧの低下につれ
後輪駆動力配分を増大させるものであり、ΔＧ〈ΔＧ、
の定常状態で（旋回走行中）後輪のコーナリングフォー
スを低下され、アクセルペダル操作による車両の転向制
御性を向上させ得ると共に、車両の走行軌跡が旋回方向
外側にふくらむ危険を防止することができる。その反面
、横加速度の増大につれ後輪駆動力配分が小さくなり、
ΔＧ〉ΔＧ、の過渡状態（車線変更時等）で後輪のコー
ナリングフォースを大きくして、走行安定性を向上する
ことができ、定常状態の要求特性と過渡状態の要求特性
を共に満足させ得る。By the way, FIG. 5 shows that the rear wheel drive force distribution increases as the lateral acceleration change rate ΔG decreases, and ΔG<ΔG,
In a steady state (while turning), the cornering force of the rear wheels is reduced, which improves the controllability of turning the vehicle by operating the accelerator pedal, and prevents the vehicle's travel trajectory from bulging outward in the direction of the turn. . On the other hand, as the lateral acceleration increases, the rear wheel drive force distribution becomes smaller.
It is possible to increase the cornering force of the rear wheels in a transient state of ΔG>ΔG (such as when changing lanes), improving driving stability, and satisfying both the required characteristics in a steady state and in a transient state. .

又第５図は、定常状態で横加速度Ｇｌ　（車速でもよい
）の増大に応じ後輪駆動力配分が太き（なるようにした
が、これは定常状態において横加速度の大きい時の方が
大きい転向制御性能を要求されるためである。In addition, Figure 5 shows that the rear wheel drive force distribution becomes thicker as the lateral acceleration Gl (vehicle speed may also be used) increases in a steady state, but this is larger when the lateral acceleration is large in a steady state. This is because turning control performance is required.

第６図は全輪操舵車両に対する本発明駆動力配分制御装
置の適用例で、第２図におけると同様部分を同一符号に
て示す。操舵システムを説明するに、ステアリングギヤ
５を車体に固定せず図示せざる弾性ブツシュの弾性を介
し若干長手方向へストロークして前輪ＩＬ、　ＩＲを補
助操舵可能とする。FIG. 6 shows an example of application of the driving force distribution control system of the present invention to an all-wheel steering vehicle, and the same parts as in FIG. 2 are designated by the same reference numerals. To explain the steering system, the steering gear 5 is not fixed to the vehicle body, but is slightly stroked in the longitudinal direction through the elasticity of elastic bushings (not shown) to enable auxiliary steering of the front wheels IL and IR.

この補助操舵のためにアクチュエータ１８を設け、その
作動ロンドをステアリングギヤ５のケースに結合する。An actuator 18 is provided for this auxiliary steering, and its actuating rod is coupled to the case of the steering gear 5.

又後輪２Ｌ、　２Ｒもアクチュエータ１９により補助操
舵可能とする。Further, the rear wheels 2L and 2R can also be assisted and steered by the actuator 19.

アクチュエータ１８．１９は夫々サーボ弁２０．２１に
よりストローク制御し、これらサーボ弁の圧力源を前後
輪駆動力配分制御（電磁減圧弁１５）用の圧力源と共通
にする。各サーボ弁、２０．２１は両ソレノイドのＯＦ
Ｆ時対応するアクチュエータ１８．１９を現在のストロ
ーク位置に保持し、一方のソレノイドをＯＮする時アク
チュエータ１８．１９を対応方向にストロークさせて前
後輪を対応方向へ補助操舵するものとする。サーボ弁２
０．２１のソレノイドを補助操舵制御用コントローラ２
２によりＯＮ、　ＯＦＦ制御し、これがためコントロー
ラ２２にはステアリングホイール４の操舵角θを検出す
る舵角センサ２３からの信号、車速■を検出する車速セ
ンサ２４からの信号、前輪補助舵角δ、４を検出するス
トロークセンサ２５からの信号、及び後輪補助舵角δ、
４を検出するストロークセンサ２６からの信号を夫々入
力する。The strokes of the actuators 18 and 19 are controlled by servo valves 20 and 21, respectively, and the pressure source of these servo valves is shared with the pressure source for front and rear wheel drive force distribution control (electromagnetic pressure reducing valve 15). Each servo valve, 20.21 is OF of both solenoids
At F time, the corresponding actuators 18 and 19 are held at the current stroke position, and when one solenoid is turned on, the actuators 18 and 19 are stroked in the corresponding direction to perform auxiliary steering of the front and rear wheels in the corresponding direction. Servo valve 2
0.21 solenoid as auxiliary steering control controller 2
2, the controller 22 receives a signal from the steering angle sensor 23 that detects the steering angle θ of the steering wheel 4, a signal from the vehicle speed sensor 24 that detects the vehicle speed ■, a front wheel auxiliary steering angle δ, 4, and a signal from the stroke sensor 25 that detects the rear wheel auxiliary steering angle δ,
The signals from the stroke sensors 26 that detect the strokes are respectively input.

コントローラ２２は、車速■から補助舵角演算用の比例
定数Ｋｔ　（前輪用）、Ｋ、　（後輪用）及び微分定数
（進み要素）τｆ（前輪用）、τｒ（後輪用）を求め、
これらと操舵角θとから次式により前後輪補助舵角δｔ
　（Ｓ）　、　　δ、（Ｓ）を算出する。The controller 22 calculates proportional constants Kt (for front wheels), K, (for rear wheels) and differential constants (advance factors) τf (for front wheels) and τr (for rear wheels) for calculating the auxiliary steering angle from the vehicle speed ■.
From these and the steering angle θ, the front and rear wheel auxiliary steering angle δt is calculated by the following formula:
(S), δ, and (S) are calculated.

δｒ（ｓ）　＝　ＣＫｔ＋τｔＳ）θ（Ｓ）　　　　　
　・・・（１）δ、（Ｓ）　＝　（Ｋ、−τ、Ｓ）θ（
Ｓ）　　　　　　・・・（２）但し、 ＣｆＩＶ ここでＣｆは前輪コーナリングパワー　Ｃ１は後輪コー
ナリングパワー、２はホイールベース、ａは前輪及び重
心点間距離、ｂは後輪及び重心点間距離、Ｍは車両質量
、■は車両ヨー慣性モーメント、■は車速、Ｓはラプラ
ス演算子である。δr(s) = CKt+τtS)θ(S)
...(1) δ, (S) = (K, -τ, S) θ(
S) ... (2) However, CfIV where Cf is front wheel cornering power, C1 is rear wheel cornering power, 2 is wheel base, a is the distance between the front wheels and the center of gravity, b is the distance between the rear wheels and the center of gravity, M is the vehicle mass, ■ is the vehicle yaw moment of inertia, ■ is the vehicle speed, and S is the Laplace operator.

そして、（１）式、（２）式をラプラス逆変換して前後
輪目標補助舵角δ１．δ１を算出し、サンサ２５゜２６
で検出した前後輪実測補助舵角δｆｄ＋　　δ、ｄが前
後輪目標補助舵角δ２．δ、となるようサーボ弁２０．
２１によりアクチュエータ１８．１９をストローク制御
する。Then, Equations (1) and (2) are subjected to Laplace inverse transformation to obtain the target auxiliary steering angle δ1 for the front and rear wheels. Calculate δ1, Sansa 25°26
The measured auxiliary steering angle of the front and rear wheels δfd+ δ,d detected at the front and rear wheels is the target auxiliary steering angle of the front and rear wheels δ2. δ, the servo valve 20.
21 stroke-controls the actuators 18,19.

かかる補助操舵中、補助操舵制御用コントローラ２２内
の後輪補助舵角δ、（比例定数に１でもよい）を駆動力
配分コントローラ１６に入力する。本例においてコント
ローラ１６は後輪駆動力配分を、第５図における横加速
度Ｇ１に代え第７図の如く、後輪補助舵角δ、の増大に
つれ大きくなるよう制御するものとする。ここで、後輪
の同相補助舵角δ、を大きくすることは後輪のコーナリ
ングフォース、つまり横加速度を大きくすることであり
、第５図と同様の制御が可能となる。During such auxiliary steering, the rear wheel auxiliary steering angle δ (the proportional constant may be 1) in the auxiliary steering controller 22 is input to the driving force distribution controller 16. In this example, the controller 16 controls the rear wheel drive force distribution to increase as the rear wheel auxiliary steering angle δ increases, as shown in FIG. 7, instead of the lateral acceleration G1 in FIG. 5. Here, increasing the in-phase auxiliary steering angle δ of the rear wheels means increasing the cornering force, that is, the lateral acceleration, of the rear wheels, and the same control as shown in FIG. 5 becomes possible.

なお上記の補助操舵は、車両をアンダーテスア傾向とし
て、車線変更中等の過渡状態での走行安定性を高め得る
が、逆に旋回走行中の定常状態でアクセルペダル操作に
よる転向制御性が低い。しかして後者で、コントローラ
１６により前述した如く後輪駆動力配分を大きくする場
合、転向制御性の悪さを解消することができる。The above-mentioned auxiliary steering can make the vehicle tend to undertrace and improve running stability in transient states such as changing lanes, but conversely, in a steady state during cornering, turning controllability by operating the accelerator pedal is poor. However, in the latter case, when the controller 16 increases the rear wheel drive force distribution as described above, poor turning controllability can be solved.

ところで前記各実施例では、車両の旋回状態変化速度を
横角速度の変化速度ΔＧによりチエツクし、定常状態か
、過渡状態かを判別したが、ヨーレイトの変化速度（ヨ
ー角加速度）によってもこの判別は可能である。Incidentally, in each of the embodiments described above, the rate of change in the turning state of the vehicle is checked based on the rate of change in lateral angular velocity ΔG to determine whether it is in a steady state or in a transient state, but this determination can also be made based on the rate of change in yaw rate (yaw angular acceleration). It is possible.

（発明の効果） かくして本発明装置は、車両の旋回状態変化速度の低下
につれ後輪駆動力配分を増大させる構成としたから、定
常状態で後輪駆動力の増大により転向制御性を向上させ
得ることとなり、過渡状態で後輪駆動力の低下により走
行安定性を向上させ得ることとなり、両状態での要求特
性を共に満足させることができる。(Effects of the Invention) Thus, since the device of the present invention is configured to increase rear wheel drive force distribution as the turning state change speed of the vehicle decreases, it is possible to improve turning controllability by increasing rear wheel drive force in a steady state. Therefore, driving stability can be improved by reducing the rear wheel drive force in the transient state, and the required characteristics in both states can be satisfied.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明前後輪駆動力配分制御装置の概念図、 第２図は本発明装置の一実施例を示すシステム図、 第３図は同例における変速機及びトランスファユニット
の内部模式図、 第４図は同例における駆動力配分コントローラの制御プ
ログラムを示すフローチャート、第５図は前後輪駆動力
配分の制御特性図、第６図及び第７図は夫々本発明の他
の例を示す第２図及び第５図と同様なシステム図及び特
性図、第８図は車両の加速円旋回時における旋回半径比
の変化特性図である。 ＩＬ、　ＩＲ・・・前輪 ２Ｌ、　２Ｒ・・・後輪 ３・・・エンジン ４・・・ステアリングホイール ５・・・ステアリングギヤ ６・・・変速機 ７．１０・・・プロペラシャフト ８・・・トランスファユニット ９．１１・・・ディファレンシャルギヤ１２・・・オイ
ルポンプ １３・・・アンロード弁 １５・・・電磁減圧弁 １６・・・駆動力配分コントローラ １７・・・横Ｇセンサ １８、１９・・・補助操舵アクチュエータ２０、２１・
・・サーボ弁 ２２・・・補助操舵制御用コントローラ２３・・・舵角
センサ ２４・・・車速センサ ２５゜ ２６・・・ストロークセンサFIG. 1 is a conceptual diagram of the front and rear wheel drive force distribution control device of the present invention, FIG. 2 is a system diagram showing an embodiment of the device of the present invention, and FIG. 3 is a schematic internal diagram of the transmission and transfer unit in the same example. FIG. 4 is a flowchart showing a control program of the driving force distribution controller in the same example, FIG. 5 is a control characteristic diagram of front and rear wheel driving force distribution, and FIGS. 6 and 7 are flowcharts showing other examples of the present invention. A system diagram and a characteristic diagram similar to FIGS. 2 and 5, and FIG. 8 are characteristic diagrams of changes in the turning radius ratio when the vehicle turns in an acceleration circle. IL, IR...Front wheel 2L, 2R...Rear wheel 3...Engine 4...Steering wheel 5...Steering gear 6...Transmission 7.10...Propeller shaft 8... Transfer unit 9.11...Differential gear 12...Oil pump 13...Unload valve 15...Solenoid pressure reducing valve 16...Driving force distribution controller 17...Lateral G sensor 18, 19...・Auxiliary steering actuator 20, 21・
... Servo valve 22 ... Controller for auxiliary steering control 23 ... Rudder angle sensor 24 ... Vehicle speed sensor 25° 26 ... Stroke sensor

Claims (1)

【特許請求の範囲】 １、駆動力を前後輪へ可変式に分配して伝達する前後輪
駆動力配分調整手段を具えた車両において、 車両の旋回状態変化速度を検出する旋回状態変化率検出
手段と、 旋回状態変化速度の低下につれ後輪駆動力配分を増大さ
せる前後輪駆動力配分変更手段と を設けてなることを特徴とする前後輪駆動力配分制御装
置。 ２、旋回状態変化率検出手段は車両の横加速度変化速度
を検出するよう構成した請求項１記載の前後輪駆動力配
分制御装置。 ３、旋回状態変化率検出手段は車両のヨーレイト変化速
度を検出するよう構成した請求項１記載の前後輪駆動力
配分制御装置。[Scope of Claims] 1. In a vehicle equipped with front and rear wheel drive force distribution adjusting means for variably distributing and transmitting driving force to the front and rear wheels, turning state change rate detection means for detecting the speed at which the turning state of the vehicle changes. A front and rear wheel drive force distribution control device comprising: and front and rear wheel drive force distribution changing means for increasing the rear wheel drive force distribution as the turning state change speed decreases. 2. The front and rear wheel drive force distribution control device according to claim 1, wherein the turning state change rate detection means is configured to detect a lateral acceleration change rate of the vehicle. 3. The front and rear wheel drive force distribution control device according to claim 1, wherein the turning state change rate detection means is configured to detect a yaw rate change speed of the vehicle.