JPH0417806B2 - - Google Patents
Info
- Publication number
- JPH0417806B2 JPH0417806B2 JP59252178A JP25217884A JPH0417806B2 JP H0417806 B2 JPH0417806 B2 JP H0417806B2 JP 59252178 A JP59252178 A JP 59252178A JP 25217884 A JP25217884 A JP 25217884A JP H0417806 B2 JPH0417806 B2 JP H0417806B2
- Authority
- JP
- Japan
- Prior art keywords
- wheel
- slip ratio
- wheels
- driving force
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005540 biological transmission Effects 0.000 claims description 13
- 230000007423 decrease Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007562 laser obscuration time method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
- Arrangement And Driving Of Transmission Devices (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明は機関により前輪および後輪の双方が
駆動可能な前後輪駆動車の駆動力制御装置に係
り、詳しくは、クラツチ手段を介して動力伝達さ
れる車輪に対する直接的に動力伝達される車輪の
スリツプ比が目標値（目標スリツプ比）になるよ
う前輪または後輪への伝達トルクを制御して大き
な駆動力を得る駆動力制御装置に関する。Detailed Description of the Invention (Industrial Application Field) This invention relates to a drive force control device for a front and rear wheel drive vehicle in which both front and rear wheels can be driven by an engine. The present invention relates to a driving force control device that obtains a large driving force by controlling the transmission torque to a front wheel or a rear wheel so that the slip ratio of a wheel to which power is directly transmitted to a wheel to which power is directly transmitted becomes a target value (target slip ratio).
（従来の技術）
車両は、その全体として得ることができる駆動
力（全駆動力）が各駆動車輪が発揮する駆動力の
総和である。このため、前輪および後輪の双方を
機関により駆動して走行することができる作業車
あるいは４輪駆動車等の前後輪駆動車にあつて
は、発進あるいは加速時等の大きな駆動力を必要
とする場合に、前輪あるいは後輪の一方を駆動し
て走行する少数輪駆動走行から前輪および後輪の
双方を駆動して走行する多数輪駆動走行へ移行さ
せて大きな駆動力を得るものがあり、従来、この
ような前後輪駆動車の駆動力制御装置として、特
開昭55−148622号公報、特開昭58−56919号公報
および特開昭58−56921号公報等に記載されたよ
うなものが知られている。(Prior Art) The driving force (total driving force) that can be obtained as a whole of a vehicle is the sum of the driving forces exerted by each drive wheel. For this reason, front and rear wheel drive vehicles such as work vehicles or four-wheel drive vehicles that can drive both the front and rear wheels by an engine require large driving force when starting or accelerating. When doing so, there are some vehicles that obtain a large driving force by shifting from a small number wheel drive running by driving one of the front wheels or the rear wheels to a multi wheel drive running by driving both the front wheels and the rear wheels. Conventionally, as a driving force control device for such a front and rear wheel drive vehicle, devices such as those described in JP-A-55-148622, JP-A-58-56919, JP-A-58-56921, etc. It has been known.
例えば、特開昭55−148622号公報に記載された
前後輪駆動車の駆動力制御装置は、少数の車輪を
駆動して走行する小数輪駆動走行時に駆動車輪が
対地スリツプを生じると、より多数の車輪を駆動
して走行する多数輪駆動走行へ移行させて大きな
駆動力を得るものであり、また、特開昭58−
56919号公報に記載された前後輪駆動車の駆動力
制御装置は、４輪駆動車に適用されるものであつ
て、車両の停止時や発進時に所定の時間が経過す
るまで車輪および後輪を駆動する４輪駆動走行を
維持し、発進時に大きな駆動力を得るものであ
る。 For example, the driving force control device for a front and rear wheel drive vehicle described in Japanese Patent Application Laid-Open No. 55-148622 is designed to control the driving force of a front and rear wheel drive vehicle. This system obtains a large driving force by shifting to multi-wheel drive, in which the wheels of the vehicle are driven.
The driving force control device for a front and rear wheel drive vehicle described in Publication No. 56919 is applied to a four-wheel drive vehicle, and controls the wheels and rear wheels until a predetermined time elapses when the vehicle is stopped or started. It maintains four-wheel drive driving and obtains a large driving force when starting.
（この発明が解決しようとする問題点）
しかしながら、このような従来の前後輪駆動車
の駆動力制御装置にあつては、発進時等の大きな
駆動力を必要とする場合に、小数輪駆動走行から
多数輪駆動走行へ単に移行させるにすぎず、機関
の出力と駆動車輪のグリツプ力との関係を考慮し
ていないため、走行路面の摩擦係数μ等によつて
は必ずしも大きな駆動力を得ることができないと
いう問題点があつた。すなわち、車両が得ること
のできる全駆動力は当然に機関の出力トルクおよ
び駆動車輪のグリツプ力に制約されるが、例えば
一般的な４輪駆動車による乾燥コンクリート路面
等の高摩擦係数（μ＝0.8、程度）の路面上での
走行を想定して機関の出力トルクTEを２輪駆動
走行時のグリツプ力G2と４輪駆動走行時のグリ
ツプ力G4と比較すると、次式のような関係で表
される。(Problems to be Solved by the Invention) However, in the case of such a conventional driving force control device for a front and rear wheel drive vehicle, when a large driving force is required such as at the time of starting, it is difficult to control the driving force when driving in small wheel drive. It simply transitions from to multi-wheel drive driving, and does not take into account the relationship between the engine output and the grip force of the drive wheels, so it may not necessarily be possible to obtain a large driving force depending on the friction coefficient μ of the road surface, etc. There was a problem that it was not possible. In other words, the total driving force that a vehicle can obtain is naturally limited by the output torque of the engine and the grip force of the drive wheels. Assuming that the engine is running on a road surface with a speed of 0.8 , approximately It is expressed as a relationship.
G4＞TE＞G2
このため、車両は、発進あるいは加速時等の大
きな駆動力を必要とする場合に、機関を出力トル
クTEが最大となる回転数に維持しても、４輪駆
動走行へ移行する際に４輪のグリツプ力G4が機
関の過大な負荷となつて機関の出力が低下するこ
とがあり、結果的に大きな全駆動力を得ることが
できない。 G 4 > T E > G 2 Therefore, when a vehicle requires a large driving force such as when starting or accelerating, even if the engine is maintained at the rotation speed that maximizes the output torque T E , the four wheels When shifting to drive running, the grip force G4 of the four wheels may become an excessive load on the engine, resulting in a decrease in engine output, and as a result, a large total driving force cannot be obtained.
一方、上述のような場合に、車両が２輪駆動走
行を継続すれば、機関の出力トルクTEを増大さ
せると車両の全駆動力は駆動する２輪のグリツプ
力G2を超えて、駆動する２輪がスピン（高速空
転）と称せられる対地スリツプを発生してしま
う。 On the other hand, in the case described above, if the vehicle continues to run in two-wheel drive, increasing the output torque T E of the engine will cause the vehicle's total driving force to exceed the grip force G 2 of the two driving wheels. This causes the two wheels to slip on the ground, which is called spin (high-speed spinning).
（問題点を解決するための手段）
この発明にかかる前後輪駆動車の駆動力制御装
置は、上述した従来の問題点を鑑みてなされたも
ので、第１図に示すように、機関１１と前輪１２
との間の動力伝達系及び機関１１と後輪１３との
間の動力伝達系の内、一方は直接的に動力伝達
し、他方は伝達トルクを変更可能なクラツチ手段
１４を介して動力伝達する様に設定した前後輪駆
動車において、前輪１２の回転速度を検出する前
輪回転速度検知器１５と、後輪１３の回転速度を
検出する後輪回転速度検知器１６と、前輪回転速
度検知器１５と後輪回転速度検知器１６の出力信
号に基づいてクラツチ手段１４を介して動力伝達
される車輪例えば前輪１２に対する直接的に動力
伝達される車輪例えば後輪１３のスリツプ比を算
出するスリツプ比算出手段１７と、直接的に動力
伝達される車輪例えば後輪１３の駆動力係数が最
大値近辺領域となる目標スリツプ比を決定する目
標スリツプ比決定手段１８と、スリツプ比算出手
段１７と目標スリツプ比決定手段１８の出力信号
に基づいてクラツチ手段１４を制御し、クラツチ
手段１４を介して動力伝達される車輪例えば前輪
１２に対する直接的に動力伝達される車輪例えば
後輪１３のスリツプ比が目標スリツプ比になるよ
うクラツチ手段１４の伝達トルクを変更する制御
手段１９と、を有している。(Means for Solving the Problems) The driving force control device for a front and rear wheel drive vehicle according to the present invention has been made in view of the above-mentioned conventional problems, and as shown in FIG. front wheel 12
Of the power transmission system between the engine 11 and the rear wheel 13, one transmits power directly, and the other transmits power through a clutch means 14 that can change the transmission torque. In a front and rear wheel drive vehicle set as shown in FIG. and a slip ratio calculation for calculating the slip ratio of a wheel to which power is directly transmitted, for example, the rear wheel 13, to a wheel, for example, the front wheel 12, to which power is transmitted via the clutch means 14, based on the output signal of the rear wheel rotational speed detector 16. means 17, target slip ratio determining means 18 for determining a target slip ratio at which the driving force coefficient of a wheel to which power is directly transmitted, such as the rear wheel 13, is in the vicinity of the maximum value, slip ratio calculating means 17, and target slip ratio. The clutch means 14 is controlled based on the output signal of the determining means 18, and the slip ratio of the wheel to which power is directly transmitted, for example, the rear wheel 13, to the wheel, for example, the front wheel 12, to which power is transmitted via the clutch means 14 is set to the target slip ratio. control means 19 for changing the transmission torque of the clutch means 14 so that
（作用）
この発明にかかる前後輪駆動車の駆動力制御装
置によれば、伝達トルクの変更が可能な車輪例え
ば前輪１２に対する機関に直結した車輪例えば後
輪１３のスリツプ比が適正な値である目標スリツ
プ比になるよう例えば前輪１２への伝達トルクを
制御するため、前輪１２あるいは後輪１３の一方
のみを駆動して走行する場合のように、機関１１
の出力トルクが駆動する一方の前輪グリツプ力に
対して過大となつて該車輪がスピンを発生するよ
うなことも無くなり、さらに、前輪１１および後
輪１２の双方を駆動する場合にあつても、その双
方車輪のグリツプ力が機関１１に過大な負荷とし
て作用して機関１１の出力を低下させるようなこ
とも無く、大きな駆動力を得ることができる。(Function) According to the driving force control device for a front and rear wheel drive vehicle according to the present invention, the slip ratio of the wheel directly connected to the engine, such as the rear wheel 13, with respect to the wheel whose transmission torque can be changed, such as the front wheel 12, is an appropriate value. For example, in order to control the torque transmitted to the front wheels 12 so that the target slip ratio is achieved, the engine 11 is
This eliminates the possibility that the output torque of the front wheel becomes excessive with respect to the grip force of one of the front wheels and causes that wheel to spin.Furthermore, even when driving both the front wheel 11 and the rear wheel 12, The grip forces of both wheels do not act as an excessive load on the engine 11 and reduce the output of the engine 11, and a large driving force can be obtained.
（実施例）
以下、この発明の実施例を図面に基づいて説明
する。(Example) Hereinafter, an example of the present invention will be described based on the drawings.
第２図から第６図は、この発明の一実施例を輪
駆動車に適用して示す図である。 2 to 6 are diagrams showing an embodiment of the present invention applied to a wheel drive vehicle.
まず、構成を説明すると、第２図において、２
１はエンジン（機関）、２２はエンジン２１と一
体に組み付けられたトランスミツシヨンであり、
トランスミツシヨン２２の出力軸は２輪−４輪切
換用のトランスフア（クラツチ手段）２３を介し
て後輪プロペラシヤフト２４Rおよび前輪プロペ
ラシヤフト２４Fに連結されている。後輪プロペ
ラシヤフト２４Rは、後輪差動装置２５Rおよび左
右のアクスル２６RL，２６RRを介して左右の後輪
２７RL，２７RRに連結され、同様に、前輪プロペ
ラシヤフト２４Fは、前輪差動装置２５Fおよび左
右のアクスル２６FL，２６FRを介して左右の前輪
２７FL，２７FRに連結されている。 First, to explain the configuration, in Fig. 2, 2
1 is an engine (engine), 22 is a transmission assembled integrally with the engine 21,
The output shaft of the transmission 22 is connected to a rear propeller shaft 24R and a front propeller shaft 24F via a transfer (clutch means) 23 for switching between two wheels and four wheels. The rear propeller shaft 24 R is connected to left and right rear wheels 27 RL and 27 RR via a rear wheel differential 25 R and left and right axles 26 RL and 26 RR , and similarly, the front propeller shaft 24 F is connected to left and right rear wheels 27 RL and 27 RR. It is connected to left and right front wheels 27 FL and 27 FR via a front wheel differential 25 F and left and right axles 26 FL and 26 FR .
トランスフア２３は、第３図に示すように、２
つの部材２８ａ，２８ｂをボルト２９により接合
して成るトランスフアケース２８内に、トランス
ミツシヨン２２の出力軸と連結した入力軸３０が
回転自在に収納され、また、後輪プロペラシヤフ
ト２４Rと連結した後輪出力軸３１がベアリング
３２により回転自在に支持されている。これら入
力軸３０と後輪出力軸３１とは、それぞれが同軸
的に継手部材３３とスプライン結合して、該継手
部材３３により一体回転するよう接続されてい
る。継手部材３３は、入力軸３０と後輪出力軸３
１とがスプライン結合した略円筒形状のボス部３
３ａと、該ボス部３３ａから一体的に放射方向外
方へ延出したフランジ部３３ｂと、を有してい
る。継手部材３３のフランジ部３３ｂには、後述
する油圧式の摩擦多板クラツチ３４が設けられ、
また、ボス部３３ａには摩擦多板クラツチ３４へ
油圧を供給する油路３５ａが形成されている。な
お、３６はトランスフアケース２８内に嵌着され
ベアリング３７により後輪出力軸３１を回転自在
に支持するベアリングホルダであり、ベアリング
ホルダ３６には、トランスフアケース２８の部材
２８ｂに形成されて後述する制御装置に接続され
た油圧ポート３５ｃと継手部材３３のボス部３３
ａに形成された油路３５ａとを連通する油路３５
ｂが形成されている。 As shown in FIG.
An input shaft 30 connected to the output shaft of the transmission 22 is rotatably housed in a transfer case 28 formed by joining two members 28a and 28b with bolts 29, and is also connected to the rear propeller shaft 24R . A rear wheel output shaft 31 is rotatably supported by a bearing 32. The input shaft 30 and the rear wheel output shaft 31 are each coaxially spline-coupled to a joint member 33 and connected to rotate integrally through the joint member 33. The joint member 33 connects the input shaft 30 and the rear wheel output shaft 3.
1 and a substantially cylindrical boss portion 3 spline-coupled with each other.
3a, and a flange portion 33b integrally extending radially outward from the boss portion 33a. The flange portion 33b of the joint member 33 is provided with a hydraulic multi-plate friction clutch 34, which will be described later.
Further, an oil passage 35a for supplying hydraulic pressure to the friction multi-plate clutch 34 is formed in the boss portion 33a. A bearing holder 36 is fitted into the transfer case 28 and rotatably supports the rear wheel output shaft 31 by means of a bearing 37. The hydraulic port 35c connected to the control device and the boss portion 33 of the joint member 33
An oil passage 35 communicating with an oil passage 35a formed in a
b is formed.
３８は入力軸３０が同軸的かつ回転自在に挿通
された第１中空軸、同様に、３９は入力軸３０が
同軸的かつ回転自在に挿通された第２中空軸であ
り、これら第１中空軸３８と第２中空軸３９とは
一体回転するようにスプライン結合している。第
１中空軸３８は、その外周上にカウンタギア４０
ａと噛合したドライブギア３８ａが一体に形成さ
れている。カウンタギア４０ａはトランスフアケ
ース２８にベアリング４１を介し回転自在に支持
されたカウンタシヤフト４０に一体に形成され、
図示しない前輪出力軸に設けられたドリブンギア
４２と噛合している。また、第２中空軸３９は、
入力軸３０にスラストベアリング４３を介して回
転自在に係合したボス部３９ａと、該ボス部３９
ａと一体のドラム部３９ｂとを有し、該ドラム部
３９ｂと前述した継手部材３３のフランジ部３３
ｂとの間に油圧式の摩擦多板クラツチ３４が取り
付けられている。 38 is a first hollow shaft through which the input shaft 30 is coaxially and rotatably inserted; similarly, 39 is a second hollow shaft through which the input shaft 30 is coaxially and rotatably inserted; 38 and the second hollow shaft 39 are spline-coupled to rotate together. The first hollow shaft 38 has a counter gear 40 on its outer periphery.
A drive gear 38a meshing with the drive gear 38a is integrally formed with the drive gear 38a. The counter gear 40a is integrally formed with a counter shaft 40 rotatably supported by the transfer case 28 via a bearing 41.
It meshes with a driven gear 42 provided on a front wheel output shaft (not shown). Further, the second hollow shaft 39 is
A boss portion 39a rotatably engaged with the input shaft 30 via a thrust bearing 43;
a and a drum portion 39b integral with the drum portion 39b and the flange portion 33 of the aforementioned joint member 33.
A hydraulic multi-plate friction clutch 34 is installed between the clutch 34 and b.
摩擦多板クラツチ３４は、継手部材３３のフラ
ンジ部３３ｂに嵌着されたクラツチドラム４４の
内周壁にスプライン結合した複数のドライブプレ
ート４５と、第２中空軸３９のドラム部３９ｂの
外周壁にスプライン結合してドライブプレート４
５と軸方向に交互に配置された複数のドリブンプ
レート４６と、継手部材３３のボス部３３ａとフ
ランジ部３３ｂとの間の略環状空間に軸方向の移
動可能に収納されて油路３５ａと連通した油室４
７を画成する略環状のピストン４８と、ピストン
４８と継手部材３３のボス部３３ａに取り付けら
れたリテーナ４９との間に縮装されてピストン４
８を図中右方へ付勢するリターンスプリング５０
と、を備えている。この摩擦多板クラツチ３４
は、後述する制御装置から油圧ポート３５ｃおよ
び油路３５ｂ，３５ａを介し油室４７に高圧の油
圧が供給されると、ピストン４８が図中左動して
ドライブプレート４５とドリブンプレート４６と
を圧接させ、継手部材３３と第２中空軸３９との
間すなわち入力軸３０と前輪出力軸との間を供給
される油圧に応じたトルクで接続する。 The friction multi-plate clutch 34 includes a plurality of drive plates 45 spline-coupled to the inner circumferential wall of a clutch drum 44 fitted to the flange portion 33b of the joint member 33, and a plurality of drive plates 45 spline-coupled to the outer circumferential wall of the drum portion 39b of the second hollow shaft 39. Combine and drive plate 4
5 and a plurality of driven plates 46 arranged alternately in the axial direction, and a substantially annular space between the boss portion 33a and the flange portion 33b of the joint member 33 so as to be movable in the axial direction and communicate with the oil passage 35a. oil chamber 4
7 and a retainer 49 attached to the boss portion 33a of the joint member 33.
A return spring 50 that urges 8 to the right in the figure.
It is equipped with. This friction multi-plate clutch 34
When high-pressure oil pressure is supplied to the oil chamber 47 from the later-described control device through the oil pressure port 35c and oil passages 35b and 35a, the piston 48 moves to the left in the figure to press the drive plate 45 and the driven plate 46 together. and connects between the joint member 33 and the second hollow shaft 39, that is, between the input shaft 30 and the front wheel output shaft, with a torque corresponding to the supplied oil pressure.
再び第２図において、５１は制御装置であり、
制御装置５１には、トランスフア２３の後輪出力
軸３１の回転速度すなわち後輪２７RL，２７RRの
回転速度ωRを検出する後輪回転速度センサ（後
輪回転速度検知器）５２Rと前輪出力軸の回転速
度すなわち前輪２７FL，２７FRの回転速度ωFを検
出する前輪回転速度センサ（前輪回転速度検知
器）５２Fとが結線されている。これら回転速度
センサ５２R，５２Fは検出した回転速度ωR，ωF
に対応した周波数の検知信号を制御装置５１に出
力する。この制御装置５１は、後述する第４図お
よび第５図に示すように、摩擦多板クラツチ３４
の油室４７に油圧を供給する油圧駆動回路５３
と、油圧回路５３が発生する油圧を回転速度セン
サ５２R，５２Fの出力信号に基づいて制御する電
気制御回路５４と、を有している。 Referring again to FIG. 2, 51 is a control device;
The control device 51 includes a rear wheel rotation speed sensor (rear wheel rotation speed detector) 52 R that detects the rotation speed of the rear wheel output shaft 31 of the transfer shaft 23 , that is, the rotation speed ω R of the rear wheels 27 RL and 27 RR . A front wheel rotation speed sensor (front wheel rotation speed detector) 52F that detects the rotation speed of the front wheel output shaft, that is, the rotation speed ω F of the front wheels 27 FL and 27 FR , is connected. These rotational speed sensors 52 R and 52 F detect rotational speeds ω R and ω F
A detection signal with a frequency corresponding to the frequency is output to the control device 51. This control device 51 includes a friction multi-plate clutch 34, as shown in FIGS. 4 and 5, which will be described later.
Hydraulic drive circuit 53 that supplies hydraulic pressure to the oil chamber 47 of
and an electric control circuit 54 that controls the hydraulic pressure generated by the hydraulic circuit 53 based on the output signals of the rotational speed sensors 52 R and 52 F.
油圧駆動回路５３を第４図に基づいて説明する
と、同図において、３４は前述の摩擦多板クラツ
チを示し、摩擦多板クラツチ３４は、逆止弁５５
を介してポンプ５６と接続され、また、方向切換
弁５７を介してリザーバタンク５８と接続されて
いる。ポンプ５６は、制御回路５４に結線された
モータ５９により駆動され、リザーバタンク５８
内の油を加圧して吐出する。方向切換弁５７は、
制御回路５４に結線されたソレノイド５７ａを備
え、ソレノイド５７ａが通電されない時摩擦多板
クラツチ３４の油室４７をリザーバタンク５８に
開放する第１切換位置（図示位置）を採り、ソ
レノイド５７ａが通電されると油室４７をリザー
バタンク５８から遮断してポンプ５６のみに連通
する第２切換位置を採る。この方向切換弁５７
は、後述するように、制御回路５４からソレノイ
ド５７ａに断続電流が通電され（チヨツパ制御）、
この断続電流の衝撃比に応じて第１切換位置と
第２切換位置とを採る時間の割合を変化させ、
摩擦多板クラツチ３４の油室４７へ供給する油圧
を変更する。なお、６０は圧力調整弁、６１は絞
りである。 The hydraulic drive circuit 53 will be explained based on FIG.
It is connected to a pump 56 via a directional control valve 57, and is also connected to a reservoir tank 58 via a directional switching valve 57. The pump 56 is driven by a motor 59 connected to the control circuit 54, and is driven by a reservoir tank 58.
The oil inside is pressurized and discharged. The directional control valve 57 is
A solenoid 57a is connected to the control circuit 54, and when the solenoid 57a is not energized, it assumes a first switching position (position shown) in which the oil chamber 47 of the friction multi-plate clutch 34 is opened to the reservoir tank 58, and when the solenoid 57a is energized. Then, a second switching position is adopted in which the oil chamber 47 is isolated from the reservoir tank 58 and communicated only with the pump 56. This directional control valve 57
As will be described later, an intermittent current is supplied from the control circuit 54 to the solenoid 57a (chopper control),
The ratio of time spent in the first switching position and the second switching position is changed according to the impact ratio of this intermittent current,
The oil pressure supplied to the oil chamber 47 of the friction multi-plate clutch 34 is changed. Note that 60 is a pressure regulating valve, and 61 is a throttle.
制御回路５４は、第５図に示すように、前輪回
転速度センサ５２Fが出力する回転速度ωFに対応
した周波数の信号を周波数に対応した電位の信号
に変換する第1F−Ｖコンバータ６３と、後輪回
転速度センサ５２Rが出力する回転速度ωRに対応
した周波数の信号を周波数に対応した電位の信号
に変換する第2F−Ｖコンバータ６４と、第1F−
Ｖコンバータ６３および第2F−Ｖコンバータ６
４の出力信号に基づいて下式に示すスリツプ比Ｓ
を算出する演算回路（スリツプ比算出手段）６５
と、目標スリツプ比Stに対応する所定電位の基準
信号（目標スリツプ比に対応）を出力する定電圧
発生器（目標スリツプ比決定手段）６６と、演算
回路６５の出力信号と定電発生器６６の出力信号
とを比較し演算回路６５の出力信号が定電圧発生
器６６の出力信号より大きい時に駆動信号を出力
する比較器６７と、比較器６７から駆動信号が入
力すると所定衝撃比の継続電流を方向切換弁５７
のソレノイド５７ａに出力する駆動回路６８と、
を有している。 As shown in FIG. 5, the control circuit 54 includes a first F-V converter 63 that converts a signal with a frequency corresponding to the rotational speed ω F outputted by the front wheel rotational speed sensor 52 F into a signal with a potential corresponding to the frequency. , a second F-V converter 64 that converts a signal with a frequency corresponding to the rotational speed ω R outputted by the rear wheel rotational speed sensor 52 R into a signal with a potential corresponding to the frequency, and a first F-V converter 64 .
V converter 63 and second F-V converter 6
Based on the output signal of 4, the slip ratio S shown in the following formula is
Arithmetic circuit (slip ratio calculation means) 65 for calculating
, a constant voltage generator (target slip ratio determining means) 66 that outputs a reference signal of a predetermined potential (corresponding to the target slip ratio) corresponding to the target slip ratio St, and an output signal of the arithmetic circuit 65 and the constant voltage generator 66 A comparator 67 compares the output signal of the arithmetic circuit 65 with the output signal of the constant voltage generator 66 and outputs a drive signal when the output signal of the arithmetic circuit 65 is larger than the output signal of the constant voltage generator 66. Directional switching valve 57
a drive circuit 68 that outputs to the solenoid 57a;
have.
Ｓ＝（ｒ・ωF−ｒ・ωR）／ｒ・ωF
但し、ｒ：タイヤ半径
すなわち、Ｓは、伝達トルクの変更が可能な前
輪２７FL，２７FRに対するエンジン２１に直結し
た後輪２７RL，２７RRのスリツプ比を表す。 S = (r・ω F −r・ω R )/r・ω F However, r: Tire radius In other words, S is the rear wheel directly connected to the engine 21 with respect to the front wheels 27 FL and 27 FR whose transmission torque can be changed. It represents the slip ratio of 27 RL and 27 RR .
上記比較器６７は、定電圧発生器６６の出力信
号に基づいて２つの第１基準値と第２基準値とを
設定するヒステリシス回路が付加されたもので、
演算回路６５の出力信号が第１基準値より大きく
なると駆動信号を駆動回路６８へ出力し、また、
演算回路の出力信号が第２基準値より小さくなる
と駆動信号の出力を停止する。なお、定電圧発生
器６６が出力する基準信号すなわち該基準信号に
基づいて比較器６７により設定される第１基準値
と第２基準値は、大きな駆動力係数μtを得ること
ができる範囲の目標スリツプ比Stを設定する。す
なわちこの目標スリツプ比は、後輪２７RL，２７
ＲＲの駆動力係数μtが最大値近辺領域となるスリツ
プ比の値である。例えば、前述した高摩擦係数の
走行路面においては、スリツプ比Ｓと駆動力係数
μtとが第６図に示すような関係を有するため、上
記第１基準値を第６図中のスリツプ比Snaxに対応
した値に定め、また、第２基準値をスリツプSnio
に対応した値に定める。 The comparator 67 is added with a hysteresis circuit that sets two first reference values and a second reference value based on the output signal of the constant voltage generator 66.
When the output signal of the arithmetic circuit 65 becomes larger than the first reference value, a drive signal is output to the drive circuit 68, and
When the output signal of the arithmetic circuit becomes smaller than the second reference value, the output of the drive signal is stopped. Note that the reference signal output by the constant voltage generator 66, that is, the first reference value and the second reference value set by the comparator 67 based on the reference signal, are within the range in which a large driving force coefficient μ t can be obtained. Set the target slip ratio St. In other words, this target slip ratio is for the rear wheels 27 RL , 27
This is the value of the slip ratio at which the driving force coefficient μ t of RR is in the vicinity of the maximum value. For example, on the above-mentioned running road surface with a high coefficient of friction, the slip ratio S and the driving force coefficient μt have a relationship as shown in FIG. In addition, the second reference value is set to a value corresponding to the slip S nio
Set to a value corresponding to
なお、上記第１基準値および第２基準値すなわ
ち定電圧発生器６７が出力する基準信号は、走行
路面の摩擦係数等の車両の走行条件に応じて可変
としてもよい。 Note that the first reference value and the second reference value, that is, the reference signal output by the constant voltage generator 67, may be variable depending on the running conditions of the vehicle, such as the friction coefficient of the road surface.
次に、作用を説明する。 Next, the effect will be explained.
車両が大きな駆動力を必要とする場合の一例と
して加速時を説明する。 An example of a case where the vehicle requires a large driving force will be described when the vehicle is accelerating.
今、前輪２７FL，２７FRと後輪２７RL，２７RR
との間の回転数差すなわちトランスフア２３の前
輪出力軸と後輪出力軸３１との間の回転数差が零
であれば、制御回路５４は油圧回路５３の方向切
換弁５７のソレノイド５７ａに駆動電流を出力す
ることは無く、トランスフア２３の摩擦多板クラ
ツチ３４の油室４７はリザーバタンク５８と連通
されている。このため、入力軸３０と前輪出力軸
との間は遮断され、車両は後輪２７RL，２７RRの
みをエンジン２１により駆動して走行している。 Now, the front wheels are 27 FL , 27 FR and the rear wheels are 27 RL , 27 RR.
If the rotational speed difference between No driving current is output, and the oil chamber 47 of the friction multi-plate clutch 34 of the transfer 23 is communicated with the reservoir tank 58. Therefore, the input shaft 30 and the front wheel output shaft are cut off, and the vehicle runs with only the rear wheels 27 RL and 27 RR driven by the engine 21.
ここで、エンジン２１の出力トルクが後輪２７
ＲＬ，２７RRのグリツプ力を超えると、後輪２７RL，
２７RRは対地スリツプ（スピン）を発生して後輪
２７RL，２７RRと前輪２７FL，２７FRとの間すな
わち後輪出力軸３１と前輪出力軸との間に回転数
差が生じ、この時のスリツプ比Ｓは前述した式に
より示される。そして、後輪２７RL，２７RRのス
ピンが激しくなると、スリツプ比Ｓが−１に近づ
き駆動力係数μtが低下して全駆動力も低下する
が、スリツプ比Ｓが制御回路５４の比較器６７に
より設定された第１基準値に対応したSnaxを超え
ると、比較器６７が駆動信号を駆動回路６８へ出
力して駆動回路６８が所定衝撃比の断続電流を方
向切換弁５７のソレノイド５７ａへ出力する。こ
のため、方向切換弁５７は、ソレノイド５７ａへ
入力する断続電流の衝撃比に応じて第１切換位置
と第２切換位置を交互に採り、トランスフア
２３の摩擦多板クラツチ３４の油室４７に衝撃比
に応じた油圧を供給する。この結果、トランスフ
ア２３は、入力軸３０と前輪出力軸との間が接続
され、車両は、後輪２７RL，２７RRとともに前輪
２７FL，２７FRもエンジン２１により駆動して走
行する。すなわち、車両は前輪２７FL，２７FRお
よび後輪２７RL，２７RRを駆動する４輪駆動走行
へ移行してスリツプ比Ｓが低下するため、第６図
に示すように、駆動力係数μtが増大して車両の全
体としての駆動力も増大する。 Here, the output torque of the engine 21 is
RL , 27 If the grip force of the RR is exceeded, the rear wheel 27 RL ,
27 RR generates ground slip (spin) and a difference in rotational speed occurs between the rear wheels 27 RL , 27 RR and the front wheels 27 FL , 27 FR , that is, between the rear wheel output shaft 31 and the front wheel output shaft. The slip ratio S at this time is expressed by the above-mentioned formula. As the spin of the rear wheels 27 RL and 27 RR increases, the slip ratio S approaches -1, the driving force coefficient μt decreases, and the total driving force also decreases. When S nax corresponding to the set first reference value is exceeded, the comparator 67 outputs a drive signal to the drive circuit 68, and the drive circuit 68 outputs an intermittent current with a predetermined impulse ratio to the solenoid 57a of the directional control valve 57. do. For this reason, the directional switching valve 57 alternately takes the first switching position and the second switching position according to the impact ratio of the intermittent current input to the solenoid 57a, and the directional switching valve 57 alternately takes the first switching position and the second switching position according to the impact ratio of the intermittent current input to the solenoid 57a. Supplies hydraulic pressure according to the impact ratio. As a result, the input shaft 30 and the front wheel output shaft of the transfer shaft 23 are connected, and the vehicle runs with the front wheels 27 FL and 27 FR driven by the engine 21 as well as the rear wheels 27 RL and 27 RR . In other words, the slip ratio S decreases as the vehicle shifts to four-wheel drive driving the front wheels 27 FL , 27 FR and the rear wheels 27 RL , 27 RR , so the driving force coefficient μt decreases as shown in FIG. As a result, the overall driving force of the vehicle also increases.
この後、車両が加速走行から定速走行に移行す
ると、後輪２７RL，２７RRの駆動力も低下し、上
述したスピンを発生することなく走行が可能とな
り、スリツプ比Ｓが制御回路５４の比較器６７に
より設定された第２基準値に対応したSnioより低
下すると、比較器６７が駆動信号の出力を停止す
るため、駆動回路６８も方向切換弁５７のソレノ
イド５７ａへの断続電流の出力を停止する。した
がつて、摩擦多板クラツチ３４は、油室４７内の
油圧が低下して入力軸３０と前輪出力軸との間を
遮断し、車両は後輪２７RL，２７RRのみを駆動す
る２輪駆動走行へ移行する。 After this, when the vehicle shifts from acceleration running to constant speed running, the driving force of the rear wheels 27 RL and 27 RR is also reduced, and it becomes possible to run without the above-mentioned spin, and the slip ratio S increases as compared with the control circuit 54. When S nio falls below the second reference value set by the comparator 67, the comparator 67 stops outputting the drive signal, so the drive circuit 68 also stops outputting the intermittent current to the solenoid 57a of the directional control valve 57. Stop. Therefore, the friction multi-plate clutch 34 cuts off between the input shaft 30 and the front wheel output shaft due to the decrease in the oil pressure in the oil chamber 47, and the vehicle becomes a two-wheel vehicle that drives only the rear wheels 27 RL and 27 RR . Shift to drive driving.
このように、この４輪駆動車の駆動力制御装置
にあつては、前輪２７FL，２７FRに対する後輪２
７RL，２７RRのスリツプ比Ｓが目標値である目標
スリツプ比になるよう前輪２７FL，２７FRへの伝
達トルクを制御するため、２輪駆動走行時にみら
れるような過大なスピンを後輪２７RL，２７RRが
生じることもなく、また、４輪駆動走行への移行
時に４輪のクリツプ力G4がエンジン２１への過
大な負荷となつてエンジン２１の出力が低下する
ことも無くなり、車両は大きな駆動力係数μtを保
持して大きな駆動力を得ることができる。 In this way, in the driving force control device of this four-wheel drive vehicle, the rear wheels 27 FL and 27 FR are
In order to control the torque transmitted to the front wheels 27 FL and 27 FR so that the slip ratio S of 7 RL and 27 RR becomes the target slip ratio, the system prevents the rear wheels from excessive spin as seen when driving with two-wheel drive. 27 RL and 27 RR will not occur, and the output of the engine 21 will not decrease due to the clipping force G 4 of the four wheels becoming an excessive load on the engine 21 at the time of transition to four-wheel drive driving. The vehicle can maintain a large driving force coefficient μt and obtain a large driving force.
なお、上述した実施例は、後輪２７RL，２７RR
をエンジン２１に直結して前輪２７FL，２７FRへ
の伝達トルクを変更可能な４輪駆動車に本発明を
適用したものを示すが、後輪２７RL，２７RRへの
伝達トルクを変更可能な４輪駆動車、あるいはよ
り多数の車輪を駆動可能な作業車等にも本発明が
適用できることは言うまでも無い。 In addition, in the above-mentioned embodiment, the rear wheels 27 RL and 27 RR
The present invention is applied to a four-wheel drive vehicle that is directly connected to the engine 21 and can change the torque transmitted to the front wheels 27 FL and 27 FR , but it is also possible to change the torque transmitted to the rear wheels 27 RL and 27 RR . Needless to say, the present invention can also be applied to four-wheel drive vehicles or work vehicles capable of driving a larger number of wheels.
（発明の効果）
以上説明してきたように、この発明にかかる前
後輪駆動車の駆動力制御装置にあつては、クラツ
チ手段を介して動力伝達される車輪に対する直接
的に動力伝達される車輪のスリツプ比が目標スリ
ツプ比になるようクラツチ手段の伝達トルクを変
更するので、前輪あるいは後輪の一方を駆動して
走行するような場合に駆動車輪が過大な対地スリ
ツプを発生することが無くなるとともに、前輪お
よび後輪の双方を駆動して走行するような場合に
駆動車輪のグリツプ力が機関の過大な負荷となつ
て機関の出力を低下させることも無くなり、車両
は大きな駆動力係数を維持して大きな駆動力を得
ることができるようになる。(Effects of the Invention) As explained above, in the driving force control device for a front and rear wheel drive vehicle according to the present invention, the driving force control device for a front and rear wheel drive vehicle according to the present invention has the following advantages: Since the transmission torque of the clutch means is changed so that the slip ratio becomes the target slip ratio, when the vehicle is driven by driving either the front wheels or the rear wheels, the drive wheels do not generate excessive ground slip, and When driving by driving both the front and rear wheels, the grip force of the drive wheels does not become an excessive load on the engine and reduce the engine's output, and the vehicle maintains a large driving force coefficient. It becomes possible to obtain a large driving force.
第１図はこの発明にかかる前後輪駆動車の駆動
力制御装置の構成図である。第２図から第６図は
この発明の一実施例にかかる前後輪駆動車の駆動
力制御装置を示す図であり、第２図は全体概略
図、第３図は機構要部の断面図、第４図は油圧回
路図、第５図はブロツク図、第６図はスリツプ比
と駆動力係数との関係を示すグラフである。
１１，２１……機関（エンジン）、１２，２７F
Ｌ，２７FR……前輪、１３，２７RL，２７RR……後
輪、１４，２３……クラツチ手段（トランスフ
ア）、１５，５２F……前輪回転速度検知器（前輪
回転速度センサ）、１６，５２R……後輪回転速度
検知器（後輪回転速度センサ）、１７，６５……
スリツプ比算出手段（演算回路）、１８，６６…
…目標スリツプ比決定手段（定電圧発生器）、１
９，６７……制御手段（比較器）。
FIG. 1 is a configuration diagram of a driving force control device for a front and rear wheel drive vehicle according to the present invention. 2 to 6 are diagrams showing a driving force control device for a front and rear wheel drive vehicle according to an embodiment of the present invention, in which FIG. 2 is an overall schematic diagram, and FIG. 3 is a sectional view of main parts of the mechanism; FIG. 4 is a hydraulic circuit diagram, FIG. 5 is a block diagram, and FIG. 6 is a graph showing the relationship between slip ratio and driving force coefficient. 11, 21...Engine, 12, 27 F
L , 27 FR ...front wheel, 13,27 RL , 27 RR ...rear wheel, 14,23...clutch means (transfer), 15,52 F ...front wheel rotational speed detector (front wheel rotational speed sensor), 16,52 R ...Rear wheel rotation speed sensor (rear wheel rotation speed sensor), 17,65...
Slip ratio calculation means (arithmetic circuit), 18, 66...
...Target slip ratio determining means (constant voltage generator), 1
9, 67...Control means (comparator).
Claims (1)
輪との間の動力伝達系の内、一方は直接的に動力
伝達し、他方は伝達トルクを変更可能なクラツチ
手段を介して動力伝達する様に設定した前後輪駆
動車において、前輪の回転速度を検出する前輪回
転速度検知器と、後輪の回転速度を検出する後輪
回転速度検知器と、前輪回転速度検知器と後輪回
転速度検知器の出力信号に基づいて前記クラツチ
手段を介して動力伝達される車輪に対する直接的
に動力伝達される車輪のスリツプ比を算出するス
リツプ比算出手段と、前記直接的に動力伝達され
る車輪の駆動力係数が最大値近辺領域となる目標
スリツプ比を決定する目標スリツプ比決定手段
と、スリツプ比算出手段と目標スリツプ比決定手
段の出力信号に基づいてクラツチ手段を制御し、
クラツチ手段を介して動力伝達される車輪に対す
る直接的に動力伝達される車輪のスリツプ比が目
標スリツプ比になるようクラツチ手段の伝達トル
クを変更する制御手段と、を有することを特徴と
する前後輪駆動車の駆動力制御装置。1 Of the power transmission system between the engine and the front wheels and the power transmission system between the engine and the rear wheels, one transmits power directly, and the other transmits power through a clutch means that can change the transmitted torque. In front and rear wheel drive vehicles, the front wheel rotation speed detector detects the front wheel rotation speed, the rear wheel rotation speed detector detects the rear wheel rotation speed, and the slip ratio calculating means for calculating a slip ratio of a wheel to which power is directly transmitted relative to a wheel to which power is transmitted via the clutch means based on an output signal of a speed detector; and a wheel to which power is directly transmitted. controlling the clutch means based on the output signals of the slip ratio calculating means and the target slip ratio determining means;
Front and rear wheels characterized by comprising: control means for changing the transmission torque of the clutch means so that the slip ratio of the wheel to which power is directly transmitted to the wheel to which power is transmitted via the clutch means becomes a target slip ratio. Driving force control device for driving vehicles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59252178A JPS61132421A (en) | 1984-11-29 | 1984-11-29 | Drive force control device in front and rear wheel drive vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59252178A JPS61132421A (en) | 1984-11-29 | 1984-11-29 | Drive force control device in front and rear wheel drive vehicle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61132421A JPS61132421A (en) | 1986-06-19 |
| JPH0417806B2 true JPH0417806B2 (en) | 1992-03-26 |
Family
ID=17233576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59252178A Granted JPS61132421A (en) | 1984-11-29 | 1984-11-29 | Drive force control device in front and rear wheel drive vehicle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61132421A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2583910B2 (en) * | 1987-10-20 | 1997-02-19 | 本田技研工業株式会社 | Driving force distribution control method for front and rear wheel drive vehicles |
| US5132908A (en) * | 1989-04-28 | 1992-07-21 | Nissan Motor Co., Ltd. | Driving force distribution control system for a fourwheel drive vehicle |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5820521A (en) * | 1981-07-25 | 1983-02-07 | Fuji Heavy Ind Ltd | Avoiding mechanism of tight corner braking in 4-wheel driven car |
-
1984
- 1984-11-29 JP JP59252178A patent/JPS61132421A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5820521A (en) * | 1981-07-25 | 1983-02-07 | Fuji Heavy Ind Ltd | Avoiding mechanism of tight corner braking in 4-wheel driven car |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61132421A (en) | 1986-06-19 |
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