JP2003320857A - Driving force transmission device - Google Patents
Driving force transmission deviceInfo
- Publication number
- JP2003320857A JP2003320857A JP2002126675A JP2002126675A JP2003320857A JP 2003320857 A JP2003320857 A JP 2003320857A JP 2002126675 A JP2002126675 A JP 2002126675A JP 2002126675 A JP2002126675 A JP 2002126675A JP 2003320857 A JP2003320857 A JP 2003320857A
- Authority
- JP
- Japan
- Prior art keywords
- control device
- rear wheels
- threshold value
- difference
- road surface
- 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.)
- Granted
Links
Landscapes
- Arrangement And Driving Of Transmission Devices (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、四輪駆動車におけ
る前後の車輪を連結する駆動力伝達装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force transmission device for connecting front and rear wheels in a four-wheel drive vehicle.
【０００２】[0002]
【従来の技術】四輪駆動車の前後の車輪を連結する差動
制御装置の伝達トルクは、車速、スロットル開度、旋回
半径、前後輪の差動回転数などの運転状態に応じて制御
装置により制御されるようになっている。2. Description of the Related Art The transmission torque of a differential control device that connects the front and rear wheels of a four-wheel drive vehicle depends on the operating conditions such as vehicle speed, throttle opening, turning radius, and front and rear wheel differential rotation speed. It is controlled by.
【０００３】[0003]
【発明が解決しようとする課題】道路の一部にぬかるみ
や積雪があると、その部分では車輪との間の摩擦係数が
低下するので、そのような道路は摩擦係数が正常な普通
路面と摩擦係数が低下した低μ路面が混在した状態とな
る。このような路面を四輪駆動車で走行すると、車両の
パワートレイン（駆動系）全体に大きなトルクが瞬間的
に加わるという問題がある。When there is muddy or snow on a part of the road, the friction coefficient between the road and the wheel decreases at that part, and such road frictions with a normal road surface having a normal friction coefficient. A low μ road surface with a reduced coefficient is mixed. When a four-wheel drive vehicle travels on such a road surface, there is a problem that a large torque is momentarily applied to the entire power train (drive system) of the vehicle.
【０００４】これを検討するために、先ず図２に示すよ
うに、走行している自動車Ｍの左の前輪Ｔｆ２と後輪Ｔ
ｒ２は普通路面ＧN 上にあって路面をスリップすること
なくグリップし、右の前輪Ｔｆ１と後輪Ｔｒ１は低μ路
面ＧL 上にあって路面に対し大きくスリップしている状
態（(a) 参照）から、右前輪Ｔｆ１が低μ路面ＧL から
抜けて、右後輪Ｔｒ１が低μ路面ＧL 上に残っている状
態（(b) 参照）に移った場合を考える。この図２(b) の
状態では、右前輪Ｔｆ１が低μ路面ＧL から抜けて普通
路面ＧN をグリップするので、右前輪Ｔｆ１の回転速度
は急激に減速されて左の前輪Ｔｆ２および後輪Ｔｒ２と
同じ回転速度になるが、低μ路面ＧL 上に残っている右
後輪Ｔｒ１は慣性により回り続けようとするので、駆動
系に大きなトルクが瞬間的に加わる。このようなトルク
変動が繰り返されると、駆動系が故障する原因となる問
題がある。In order to study this, first, as shown in FIG. 2, the left front wheel Tf2 and the rear wheel T of the traveling vehicle M are shown.
r2 is on the normal road surface G N and grips without slipping on the road surface, and the right front wheel Tf1 and the rear wheel Tr1 are on the low μ road surface G L and are largely slipping with respect to the road surface ((a) Consider a case where the front right wheel Tf1 passes through the low μ road surface G L and the rear right wheel Tr1 remains on the low μ road surface G L (see (b)). In the state of FIG. 2 (b), the right front wheel Tf1 passes through the low μ road surface G L and grips the normal road surface G N , so that the rotation speed of the right front wheel Tf1 is rapidly reduced to the left front wheel Tf2 and the rear wheel. Although the rotation speed becomes the same as that of Tr2, the right rear wheel Tr1 remaining on the low μ road surface G L tries to continue to rotate due to inertia, so that a large torque is momentarily applied to the drive system. If such torque fluctuations are repeated, there is a problem that causes failure of the drive system.
【０００５】本発明は、前述したような瞬間的な大きい
トルクが駆動系に加わる場合には、駆動系に設ける差動
制御装置の伝達トルクが小さくなるように制御すること
により、このような各問題を解決することを目的とす
る。According to the present invention, when a large instantaneous torque as described above is applied to the drive system, the transmission torque of the differential control device provided in the drive system is controlled to be small, so that The purpose is to solve the problem.
【０００６】[0006]
【課題を解決するための手段】このために、本発明によ
る駆動力伝達装置は、エンジンからの伝達トルクを前後
の車輪に配分して伝達し、前記前後の車輪の間の伝達ト
ルク配分率が変更可能な差動制御装置と、この差動制御
装置の伝達トルクを運転状態に応じて制御する制御装置
よりなる駆動力伝達装置において、制御装置は、前後の
各車輪の回転速度の減速度をそれぞれ演算し、各減速度
の何れか１つが所定の第１しきい値以上となれば差動制
御装置の伝達トルクを減少させるように制御することを
特徴とするものである。For this reason, the driving force transmission device according to the present invention distributes and transmits the transmission torque from the engine to the front and rear wheels, and the transmission torque distribution ratio between the front and rear wheels is increased. In a driving force transmission device including a changeable differential control device and a control device that controls a transmission torque of the differential control device according to an operating state, the control device decelerates the rotational speeds of the front and rear wheels. Each is calculated, and if any one of the decelerations is equal to or more than a predetermined first threshold value, the transmission torque of the differential control device is controlled to be reduced.
【０００７】前項に記載の駆動力伝達装置の制御装置
は、さらに左右の後輪の回転速度の平均値と左右の前輪
の回転速度の平均値との差を演算し、各車輪の回転速度
の減速度の何れか１つが第１しきい値以上で、かつ平均
値の差が所定の第２しきい値以上となった場合には差動
制御装置の伝達トルクを減少させるように制御すること
が好ましい。The control device of the driving force transmission device described in the preceding paragraph further calculates the difference between the average value of the rotational speeds of the left and right rear wheels and the average value of the rotational speeds of the left and right front wheels to calculate the rotational speed of each wheel. When any one of the decelerations is equal to or higher than the first threshold value and the difference between the average values is equal to or higher than a predetermined second threshold value, control is performed so as to reduce the transmission torque of the differential control device. Is preferred.
【０００８】また前２項に記載の駆動力伝達装置の制御
装置は、さらに各減速度の何れもが第１しきい値以上で
なくかつ平均値の差が異常に大きい場合にも差動制御装
置の伝達トルクを減少させるよう制御することが好まし
い。Further, the control device for the driving force transmission device described in the above item 2 further provides differential control even when none of the decelerations is equal to or more than the first threshold value and the difference between the average values is abnormally large. It is preferable to control to reduce the transmission torque of the device.
【０００９】[0009]
【発明の作用および効果】低μ路面でスリップしていた
１つの車輪が低μ路面から抜けて普通路面をグリップす
ればその車輪は回転速度が急激に減速され、その車輪お
よびそれと対をなす車輪の平均回転速度は減少するが、
この両車輪と駆動力伝達装置を介して連結された残る１
対の車輪で低μ路面上にあるものは慣性により回り続け
ようとするので、車両の駆動系に大きなトルクが瞬間的
に加わる。しかし本発明によれば、制御装置は、前後の
各車輪の回転速度の減速度をそれぞれ演算し、各減速度
の何れか１つが所定の第１しきい値以上となれば差動制
御装置の伝達トルクを減少させるので、低μ路面でスリ
ップしていた１つの車輪が普通路面をグリップして回転
速度が急激に減速されれば、差動制御装置の伝達トルク
は減少される。これにより駆動系にはこの減少されたト
ルク以上のトルクが加わることはないので、駆動系を保
護することができる。If one wheel slipping on a low μ road surface comes out of the low μ road surface and grips a normal road surface, the rotation speed of the wheel is rapidly reduced, and the wheel and its paired wheel. The average rotation speed of
Remaining 1 connected to both wheels via a driving force transmission device
Since the pair of wheels on the low μ road surface try to continue to rotate due to inertia, a large torque is momentarily applied to the drive system of the vehicle. However, according to the present invention, the control device calculates the deceleration of the rotation speeds of the front and rear wheels, respectively, and if any one of the decelerations becomes equal to or higher than a predetermined first threshold value, the differential control device operates. Since the transmission torque is reduced, if one wheel slipping on the low μ road surface grips the ordinary road surface and the rotation speed is rapidly reduced, the transmission torque of the differential control device is reduced. As a result, no more torque than this reduced torque is applied to the drive system, so that the drive system can be protected.
【００１０】制御装置が、さらに左右の後輪の回転速度
の平均値と左右の前輪の回転速度の平均値との差を演算
し、各車輪の回転速度の減速度の何れか１つが第１しき
い値以上で、かつ平均値の差が所定の第２しきい値以上
となった場合には差動制御装置の伝達トルクを減少させ
るように制御したものによれば、差動制御装置の伝達ト
ルクを必要以上に減少させることがないので、伝達トル
クを下げ過ぎることによる問題を回避することができ
る。The controller further calculates the difference between the average value of the rotational speeds of the left and right rear wheels and the average value of the rotational speeds of the left and right front wheels, and any one of the decelerations of the rotational speeds of the respective wheels is the first. According to the control of reducing the transmission torque of the differential control device when the difference between the threshold values is equal to or more than the predetermined second threshold value and the difference between the average values is equal to or greater than the second threshold value, Since the transmission torque is not reduced more than necessary, it is possible to avoid the problem caused by reducing the transmission torque too much.
【００１１】また制御装置が、さらに各減速度の何れも
が第１しきい値以上でなくかつ平均値の差が異常に大き
い場合にも差動制御装置の伝達トルクを減少させるよう
に制御したものによれば、各車輪の減速度の何れもが第
１しきい値以上でない場合であっても前述した平均値の
差が異常に大きい場合には差動制御装置の伝達トルクを
減少させるので、駆動系には理由の如何を問わず前述の
ように減少されたトルク以上のトルクが加わることはな
くなる。Further, the controller further controls so as to reduce the transmission torque of the differential controller even when none of the decelerations is equal to or more than the first threshold value and the difference between the average values is abnormally large. According to the above, even if none of the decelerations of the wheels is equal to or more than the first threshold value, the transmission torque of the differential control device is reduced if the difference between the average values is abnormally large. For any reason, no more torque than the torque reduced as described above is applied to the drive system.
【００１２】[0012]
【発明の実施の形態】以下に、図１〜図３に示す実施の
形態により、本発明による駆動力伝達装置の説明をす
る。この実施の形態による駆動力伝達装置は、主として
図１に示すように、エンジン１０により駆動される自動
車Ｍの前輪Ｔｆ１，Ｔｆ２と後輪Ｔｒ１，Ｔｒ２を連結
する駆動力伝達経路に設けた伝達トルクが変更可能な差
動制御装置１５と、この差動制御装置１５の伝達トルク
を制御する電子制御装置（制御装置）２０よりなるもの
である。エンジン１０からの駆動力は、トランスミッシ
ョンを備えたトランスアクスル１１を経てトランスファ
１２に伝達され、ここで前輪側に分配された駆動力はフ
ロントデファレンシャル（図示省略）を経て左右の前輪
Ｔｆ１，Ｔｆ２に伝達され、また後輪側に分配された駆
動力は、途中に差動制御装置１５が設けられたプロペラ
シャフト１３よりなる駆動力伝達経路およびリヤデファ
レンシャル１４を経て左右の後輪Ｔｒ１，Ｔｒ２に伝達
される。差動制御装置１５は電磁式または油圧式の多板
摩擦クラッチで、電子制御装置２０からの制御出力に応
じて伝達トルクが変化されるものである。左右の前輪Ｔ
ｆ１，Ｔｆ２および後輪Ｔｒ１，Ｔｒ２には、それぞれ
の回転速度を検出する車輪速センサＳ１，Ｓ２，Ｓ３，
Ｓ４が設けられている。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a driving force transmission device according to the present invention will be described with reference to the embodiments shown in FIGS. As shown in FIG. 1, the driving force transmission device according to the present embodiment mainly includes a transmission torque provided in a driving force transmission path that connects front wheels Tf1, Tf2 and rear wheels Tr1, Tr2 of an automobile M driven by an engine 10. Of the differential control device 15 and an electronic control device (control device) 20 that controls the transmission torque of the differential control device 15. The driving force from the engine 10 is transmitted to a transfer 12 via a transaxle 11 having a transmission, and the driving force distributed to the front wheels is transmitted to the left and right front wheels Tf1 and Tf2 via a front differential (not shown). The driving force distributed to the rear wheels is transmitted to the left and right rear wheels Tr1 and Tr2 via a driving force transmission path formed of a propeller shaft 13 provided with a differential control device 15 and a rear differential 14. It The differential control device 15 is an electromagnetic or hydraulic multi-disc friction clutch, and the transmission torque is changed according to the control output from the electronic control device 20. Left and right front wheels T
The wheel speed sensors S1, S2, S3 for detecting the respective rotation speeds of f1, Tf2 and the rear wheels Tr1, Tr2.
S4 is provided.
【００１３】電子制御装置２０は、自動車Ｍの走行状態
に応じて差動制御装置１５に出力する係合力の制御値を
演算するＣＰＵ２１と、この演算・出力などに必要な制
御プログラムを保存しているＲＯＭ２２と、この演算な
どのための作業領域として使用されるＲＡＭ２３と、こ
れらＣＰＵ２１、ＲＯＭ２２およびＲＡＭ２３と、差動
制御装置１５および車輪速センサＳ１，Ｓ２，Ｓ３，Ｓ
４との間の入出力を行う入出力回路２４を備えている。
電子制御装置２０のＣＰＵ２１は、各車輪速センサＳ
１，Ｓ２，Ｓ３，Ｓ４により検出された各車輪Ｔｆ１，
Ｔｆ２，Ｔｒ１，Ｔｒ２の回転速度ω1 ，ω2 ，ω3 ，
ω4 に基づいて、各車輪の減速度ψ1 ，ψ2 ，ψ3 ，ψ
4 、および後輪の回転速度ω3 ，ω4 の平均値から前輪
の回転速度ω1 ，ω2 の平均値を減じた差ΔＮを演算
し、各減速度がそれぞれ第１しきい値α以上であるか否
か、および各差ΔＮが第２しきい値β以上であるか否か
を判断し、これらの判断に基づいて差動制御装置１５の
係合力を緩めて伝達トルクを減少させるものである。The electronic control unit 20 stores a CPU 21 for calculating a control value of the engaging force output to the differential control unit 15 according to the running state of the automobile M, and a control program necessary for this calculation / output. Existing ROM 22, RAM 23 used as a work area for this calculation, these CPU 21, ROM 22 and RAM 23, differential control device 15 and wheel speed sensors S1, S2, S3, S
An input / output circuit 24 is provided for inputting / outputting data to / from the digital camera 4.
The CPU 21 of the electronic control unit 20 controls each wheel speed sensor S
1, S2, S3, S4 detected by each wheel Tf1,
Rotational speeds of Tf2, Tr1, Tr2 ω1, ω2, ω3,
Based on ω4, deceleration of each wheel ψ1, ψ2, ψ3, ψ
4 and the difference ΔN obtained by subtracting the average value of the front wheel rotational speeds ω1 and ω2 from the average value of the rear wheel rotational speeds ω3 and ω4, and whether each deceleration is equal to or greater than the first threshold value α. It is determined whether or not each difference ΔN is equal to or more than the second threshold value β, and based on these determinations, the engagement force of the differential control device 15 is loosened to reduce the transmission torque.
【００１４】次に、図２および図３により、この実施の
形態の作動の説明をする。図２(a)に示す状態では、走
行している自動車Ｍの左の前輪Ｔｆ２と後輪Ｔｒ２は普
通路面ＧN 上にあって路面をスリップすることなくグリ
ップし、右の前輪Ｔｆ１と後輪Ｔｒ１が低μ路面ＧL 上
にあって路面に対し大きくスリップしており、差動制御
装置１５の伝達トルクは、車速、スロットル開度、旋回
半径、前後輪の差動回転数などの運転状態に応じた値に
なっている。この状態から図２(b) に示すように、右前
輪Ｔｆ１が低μ路面ＧL から抜け、右後輪Ｔｒ１は低μ
路面ＧL 上に残っている状態に自動車Ｍが移った場合を
考える。Next, the operation of this embodiment will be described with reference to FIGS. 2 and 3. In the state shown in FIG. 2A, the left front wheel Tf2 and the rear wheel Tr2 of the traveling vehicle M are on the normal road surface G N and grip without slipping on the road surface, and the right front wheel Tf1 and the rear wheel Tr2 are gripped. Tr1 is on the low μ road surface G L and slips significantly with respect to the road surface, and the transmission torque of the differential control device 15 is the driving state such as the vehicle speed, the throttle opening, the turning radius, and the differential rotation speed of the front and rear wheels. It is a value according to. From this state, as shown in FIG. 2 (b), the right front wheel Tf1 comes out of the low μ road surface G L , and the right rear wheel Tr1 has a low μ.
Consider a case where the car M moves to a state where it remains on the road surface G L.
【００１５】電子制御装置２０のＣＰＵ２１は、短い所
定時間間隔Ｔ毎に図３に示すフローチャートを繰り返し
実行する。ＣＰＵ２１は先ず各車輪速センサＳ１，Ｓ
２，Ｓ３，Ｓ４から前輪Ｔｆ１，Ｔｆ２および後輪Ｔｒ
１，Ｔｒ２の回転速度ω1 ，ω2 ，ω3 ，ω4 を入力し
（ステップ１００）、各車輪の減速度ψ1 ，ψ2 ，ψ
3，ψ4 を演算し（ステップ１０１）、前述した差ΔＮ
を演算する（ステップ１０２）。ステップ１０１の減速
度ψi （ｉ＝１，２，３，４）は、前回の実行時の回転
速度ωi から今回の実行時の回転速度ωi を減じた値を
前述した所定時間間隔Ｔで除することにより演算され
る。次いでＣＰＵ２１は各減速度ψi が予め定められた
所定の第１しきい値α以上であるか否かを判断し（ステ
ップ１０３）、何れか１つの減速度ψi でも第１しきい
値α以上であれば制御動作をステップ１０４に進め、そ
うでなければ制御動作をステップ１０６に進める。The CPU 21 of the electronic control unit 20 repeatedly executes the flowchart shown in FIG. 3 at each short predetermined time interval T. First, the CPU 21 first detects the wheel speed sensors S1 and S.
2, S3, S4 to front wheels Tf1, Tf2 and rear wheels Tr
1, the rotational speeds ω 1, ω 2, ω 3, ω 4 of Tr 2 are input (step 100), and the deceleration ψ 1, ψ 2, ψ of each wheel is input.
3 and ψ4 are calculated (step 101), and the difference ΔN described above is calculated.
Is calculated (step 102). The deceleration ψi (i = 1, 2, 3, 4) in step 101 is obtained by dividing the value obtained by subtracting the rotational speed ωi of the current execution from the rotational speed ωi of the previous execution by the predetermined time interval T described above. It is calculated by Next, the CPU 21 determines whether or not each deceleration ψi is equal to or more than a predetermined first threshold value α (step 103), and any one deceleration ψi is equal to or more than the first threshold value α. If there is, the control operation proceeds to step 104, and if not, the control operation proceeds to step 106.
【００１６】図２(a) の状態では、前輪Ｔｆ１，Ｔｆ２
および後輪Ｔｒ１，Ｔｒ２の何れも回転速度が急激に減
速されることはないので、制御動作はステップ１０６に
進められる。一方、図２(b) の状態に移れば、右前輪Ｔ
ｆ１が低μ路面ＧL から抜けて普通路面ＧN をグリップ
し、その回転速度は左の前輪Ｔｆ２および後輪Ｔｒ２と
同じ回転速度になるまで急激に減速されて右前輪Ｔｆ１
の減速度ψ1 が第１しきい値α以上になるので、制御動
作はステップ１０４に進められる。第１しきい値αは、
前述のように何れか１つの車輪の急減速により、前輪Ｔ
ｆ１，Ｔｆ２と後輪Ｔｒ１，Ｔｒ２を連結する駆動力伝
達装置に瞬間的に加わる大きなトルクが定められた許容
限度を超えないように定める。In the state of FIG. 2 (a), the front wheels Tf1, Tf2
Since neither of the rear wheels Tr1 and Tr2 is rapidly decelerated in rotational speed, the control operation proceeds to step 106. On the other hand, if the state of FIG.
f1 passes through the low μ road surface G L and grips the normal road surface G N , and the rotation speed thereof is rapidly reduced until it becomes the same rotation speed as the left front wheel Tf2 and the rear wheel Tr2 and the right front wheel Tf1.
Since the deceleration ψ 1 of is greater than or equal to the first threshold value α, the control operation proceeds to step 104. The first threshold α is
As described above, due to the sudden deceleration of any one wheel, the front wheel T
The large torque that is momentarily applied to the driving force transmission device that connects f1 and Tf2 to the rear wheels Tr1 and Tr2 is determined not to exceed a predetermined allowable limit.
【００１７】制御動作がステップ１０４に進められた場
合は、ＣＰＵ２１はステップ１０２で演算した差ΔＮが
予め定められた所定の第２しきい値β以上であるか否か
を判断し、差ΔＮが第２しきい値β以上であれば差動制
御装置１５の係合力を緩めて（ステップ１０５）伝達ト
ルクを減少させ、また差ΔＮが第２しきい値β以上でな
ければ差動制御装置１５の係合力を変えることなく、制
御動作を終了する。駆動力伝達装置に加わる伝達トルク
は差ΔＮの増大に応じて増大するが、第２しきい値β
は、この伝達トルクの許容値に対応する差ΔＮに相当す
る値とする。When the control operation proceeds to step 104, the CPU 21 determines whether or not the difference ΔN calculated in step 102 is equal to or larger than a predetermined second threshold value β, which is the difference ΔN. If it is not less than the second threshold value β, the engagement force of the differential control device 15 is loosened (step 105) to reduce the transmission torque, and if the difference ΔN is not more than the second threshold value β, the differential control device 15 is made. The control operation is ended without changing the engaging force of. The transmission torque applied to the driving force transmission device increases as the difference ΔN increases, but the second threshold β
Is a value corresponding to the difference ΔN corresponding to the allowable value of the transmission torque.
【００１８】制御動作がステップ１０６に進められた場
合は、ＣＰＵ２１はステップ１０２で演算した差ΔＮが
異常に大きいか否かを判断し、差ΔＮが異常に大きい値
であれば差動制御装置１５の係合力を緩めて（ステップ
１０５）伝達トルクを減少させ、差ΔＮが異常に大きい
値でなければ差動制御装置１５の係合力を変えることな
く、制御動作を終了する。ここでいう異常に大きい値と
は、第２しきい値βよりもかなり大きい値であるが、第
２しきい値βより多少大きい程度としてもよい。すなわ
ち、各車輪毎における減速度ψi が所定の第１しきい値
α未満であっても、前後輪の回転速度差ΔＮが異常に大
きくなると、車両の駆動系に過大な負荷がかかるので、
それを回避するためである。When the control operation proceeds to step 106, the CPU 21 determines whether or not the difference ΔN calculated in step 102 is abnormally large. If the difference ΔN is an abnormally large value, the differential controller 15 Is reduced (step 105), the transmission torque is reduced, and if the difference ΔN is not an abnormally large value, the control operation is terminated without changing the engagement force of the differential control device 15. The abnormally large value mentioned here is a value considerably larger than the second threshold value β, but may be slightly larger than the second threshold value β. That is, even if the deceleration ψ i of each wheel is less than the predetermined first threshold value α, if the rotational speed difference ΔN between the front and rear wheels becomes abnormally large, an excessive load is applied to the drive system of the vehicle.
This is to avoid it.
【００１９】図２(a) に示すように、左の前後輪Ｔｆ
２，Ｔｒ２は普通路面ＧN 上にあって路面をスリップす
ることなくグリップし、右の前後輪Ｔｆ１，Ｔｒ１が低
μ路面ＧL 上にあって路面に対し大きくスリップしてい
る状態から、図２(b) に示すように、右前輪Ｔｆ１が低
μ路面ＧL から抜けて、右後輪Ｔｒ１が低μ路面ＧL 上
に残っている状態に移った場合は、低μ路面ＧL から抜
けて普通路面ＧN をグリップした右前輪Ｔｆ１の回転速
度が急激に減速され、両前輪Ｔｆ１，Ｔｆ２の平均回転
速度も急激に減少するが、低μ路面ＧL 上に残った右後
輪Ｔｒ１は慣性によりそのまま回転し続けるので両後輪
Ｔｒ１，Ｔｒ２の平均回転速度は減少しない。このため
前輪Ｔｆ１，Ｔｆ２の平均回転速度と後輪Ｔｒ１，Ｔｒ
２の平均回転速度が異なったものとなるので、前輪と後
輪を連結する駆動力伝達装置には大きなトルクが瞬間的
に加わる。しかし上述した実施の形態によれば、右前輪
Ｔｆ１の回転速度が急激に減速されれば差動制御装置１
５の係合力が緩められてその伝達トルクが減少されるの
で、前述のように瞬間的に加わろうとする大きなトルク
は差動制御装置１５の滑りにより吸収され、車両の駆動
系に加わるトルクは差動制御装置の伝達トルクと同程度
の小さいものとなる。従って、車両の駆動系を故障から
保護することができる。As shown in FIG. 2 (a), the left and right front and rear wheels Tf
2, Tr2 is on the normal road surface G N and grips without slipping on the road surface, and the front and rear wheels Tf1 and Tr1 on the right are on the low μ road surface G L and are largely slipping on the road surface. as shown in 2 (b), a right front wheel Tf1 is missing from the low μ road surface G L, when the right rear wheel Tr1 is shifted to a state remaining on the low μ road surface G L, from a low μ road surface G L The rotation speed of the right front wheel Tf1 that has slipped out and grips the normal road surface G N is sharply reduced, and the average rotation speed of both front wheels Tf1 and Tf2 also sharply decreases, but the right rear wheel Tr1 remaining on the low μ road surface G L Is continuously rotated due to inertia, the average rotation speed of both rear wheels Tr1 and Tr2 does not decrease. Therefore, the average rotational speed of the front wheels Tf1, Tf2 and the rear wheels Tr1, Tr
Since the two average rotation speeds are different, a large torque is instantaneously applied to the driving force transmission device that connects the front wheels and the rear wheels. However, according to the above-described embodiment, if the rotation speed of the right front wheel Tf1 is rapidly reduced, the differential control device 1
Since the engaging force of 5 is loosened and the transmission torque thereof is reduced, the large torque that is momentarily applied as described above is absorbed by the slip of the differential control device 15, and the torque applied to the drive system of the vehicle is different. It is as small as the transmission torque of the dynamic control device. Therefore, the drive system of the vehicle can be protected from failure.
【００２０】上述した実施の形態では、さらに左右の後
輪Ｔｒ１，Ｔｒ２の回転速度の平均値から左右の前輪Ｔ
ｆ１，Ｔｆ２の回転速度の平均値を減じた差ΔＮを演算
し、上述のように右前輪Ｔｆ１の回転速度が急激に減速
され、かつこの平均値の差ΔＮが所定の第２しきい値β
以上となった場合に差動制御装置１５の伝達トルクを減
少させるように制御しており、このようにすればそれ以
前の制御状態における差動制御装置１５の伝達トルクが
低く、それだけで右前輪Ｔｆ１の回転速度の急激な減速
により生じる大きなトルクを吸収できる場合には、伝達
トルクをそれ以上減少させることはないので、伝達トル
クの下げ過ぎによるトラクション性能の低下などの問題
を回避することができる。しかしながら本発明はこれに
限られるものではなく、前後の各車輪の回転速度の減速
度の何れか１つが所定の第１しきい値α以上となれば差
動制御装置１５の伝達トルクを減少させるようにして実
施してもよく、それだけでも前項で述べた、瞬間的に加
わる大きなトルクが車両の駆動系に加わることはなく、
従って駆動系を保護することができるという効果を得る
ことができる。In the above-described embodiment, the left and right front wheels T are further calculated from the average value of the rotational speeds of the left and right rear wheels Tr1, Tr2.
The difference ΔN obtained by subtracting the average value of the rotational speeds of f1 and Tf2 is calculated, the rotational speed of the right front wheel Tf1 is rapidly reduced as described above, and the difference ΔN between the average values is the predetermined second threshold value β.
When it becomes the above, it controls so that the transmission torque of the differential control device 15 may be reduced, and if it does in this way, the transmission torque of the differential control device 15 in the control state before that will be low, and it will be the right front wheel. When the large torque generated by the rapid deceleration of the rotation speed of Tf1 can be absorbed, the transmission torque is not further reduced, so that it is possible to avoid a problem such as deterioration of traction performance due to excessive reduction of the transmission torque. . However, the present invention is not limited to this, and the transmission torque of the differential control device 15 is reduced if any one of the decelerations of the rotation speeds of the front and rear wheels becomes equal to or higher than a predetermined first threshold value α. It may be carried out in this manner, and even by itself, the large torque that is momentarily applied as described in the previous section is not applied to the drive system of the vehicle,
Therefore, the effect that the drive system can be protected can be obtained.
【００２１】また上述した実施の形態では、各車輪Ｔｆ
１，Ｔｆ２，Ｔｒ１，Ｔｒ２の減速度の何れもが第１し
きい値α以上でない場合でも、左右の後輪Ｔｒ１，Ｔｒ
２の回転速度の平均値から左右の前輪Ｔｆ１，Ｔｆ２の
回転速度の平均値を減じた差ΔＮが異常に大きい場合に
は差動制御装置１５の伝達トルクを減少させるように制
御しており、このようにすれば各車輪の減速度の何れも
が第１しきい値α以上でない場合であっても前述した平
均値の差ΔＮが異常に大きい場合には差動制御装置１５
の伝達トルクを減少させるので、前後の車輪を連結する
駆動系には、理由の如何を問わず前述のように減少され
たトルク以上のトルクが加わることはなくなる。しかし
ながら各車輪の減速度の何れもが第１しきい値α以上で
ない場合に前述した平均値の差ΔＮが異常に大きくなる
ことはまれであるので、各車輪の減速度の何れもが第１
しきい値α以上でない場合には差動制御装置１５の係合
力を変えることなく制御動作を終了するようにして実施
しても差し支えない。Further, in the above-described embodiment, each wheel Tf.
Even if none of the decelerations of 1, Tf2, Tr1, Tr2 is equal to or greater than the first threshold value α, the left and right rear wheels Tr1, Tr
When the difference ΔN obtained by subtracting the average value of the rotational speeds of the left and right front wheels Tf1 and Tf2 from the average value of the rotational speeds of 2 is abnormally large, the transmission torque of the differential control device 15 is controlled to be reduced. In this way, even if none of the decelerations of the wheels is equal to or greater than the first threshold value α, if the difference ΔN between the average values is abnormally large, the differential controller 15
Since the transmission torque is reduced, the drive system connecting the front and rear wheels is not subjected to a torque greater than the reduced torque as described above for any reason. However, when the deceleration of each wheel is not greater than or equal to the first threshold value α, it is rare that the difference ΔN between the above-described average values becomes abnormally large, so that each of the deceleration of each wheel is equal to or less than the first threshold value α.
If the threshold value α is not exceeded, the control operation may be completed without changing the engaging force of the differential control device 15.
【００２２】上述した実施の形態では、前輪Ｔｆ１，Ｔ
ｆ２が先に低μ路面ＧL から抜ける場合について説明し
たが、普通路面ＧN と低μ路面ＧL の配置は様々であ
り、後輪Ｔｒ１，Ｔｒ２の方が前輪Ｔｆ１，Ｔｆ２より
も先に低μ路面ＧL から抜ける場合もあり、本発明はそ
のような場合にも適用可能である。その場合にも適用可
能とするには、ステップ１０４およびステップ１０６の
ΔＮを |ΔＮ| で置き換えたものとすればよい。In the above-described embodiment, the front wheels Tf1, Tf.
Although the case where f2 comes off from the low μ road surface G L has been described above, the arrangement of the normal road surface G N and the low μ road surface G L is various, and the rear wheels Tr1 and Tr2 are ahead of the front wheels Tf1 and Tf2. There is a case where the vehicle exits from the low μ road surface G L, and the present invention is applicable to such a case. In order to make it applicable also in that case, ΔN in step 104 and step 106 may be replaced with | ΔN |.
【００２３】なお差動制御装置１５の係合力を緩めるの
は各前輪の何れかが急激に減速されて駆動力伝達装置に
大きいトルクが加わる短時間だけでよいので、各減速度
ψiの何れもが第１しきい値α以上でなくなれば、所定
の小時間後に差動制御装置１５の係合力を元に戻すよう
にすればよい。Note that the engagement force of the differential control device 15 can be relaxed only for a short time in which one of the front wheels is rapidly decelerated and a large torque is applied to the driving force transmission device. If is not more than the first threshold value α, the engaging force of the differential control device 15 may be restored after a predetermined short time.
【００２４】またこの実施の形態では、センタデフを設
けない四輪駆動車につき説明したが、本発明はセンタデ
フを有する四輪駆動車にも適用可能であり、その場合に
は例えばトランスファ１２にセンタデフを組み込むよう
にして実施すればよい。In this embodiment, the four-wheel drive vehicle without the center differential has been described, but the present invention is also applicable to the four-wheel drive vehicle with the center differential. In that case, for example, the transfer 12 is provided with the center differential. It suffices to implement it by incorporating it.
【図１】 本発明による駆動力伝達装置の一実施形態の
全体構成を示す説明図である。FIG. 1 is an explanatory diagram showing an overall configuration of an embodiment of a driving force transmission device according to the present invention.
【図２】 図１に示す実施形態の作動の説明図である。FIG. 2 is an explanatory view of the operation of the embodiment shown in FIG.
【図３】 図１に示す実施形態の制御プログラムのフロ
ーチャートを示す図である。FIG. 3 is a diagram showing a flowchart of a control program of the embodiment shown in FIG.
１０…エンジン、１５…差動制御装置、２０…制御装置
（電子制御装置）、Ｍ…自動車、Ｔｆ１，Ｔｆ２…前
輪、Ｔｒ１，Ｔｒ２…後輪。10 ... Engine, 15 ... Differential control device, 20 ... Control device (electronic control device), M ... Car, Tf1, Tf2 ... Front wheel, Tr1, Tr2 ... Rear wheel.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 3D043 AA07 AB01 AB17 EA02 EA18 EA42 EE07 EE09 EF02 EF09 EF14 EF18 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 3D043 AA07 AB01 AB17 EA02 EA18 EA42 EE07 EE09 EF02 EF09 EF14 EF18
Claims (3)
に配分して伝達し、前記前後の車輪の間の伝達トルク配
分率が変更可能な差動制御装置と、この差動制御装置の
伝達トルクを運転状態に応じて制御する制御装置よりな
る駆動力伝達装置において、 前記制御装置は、前記前後の各車輪の回転速度の減速度
をそれぞれ演算し、前記各減速度の何れか１つが所定の
第１しきい値以上となれば前記差動制御装置の伝達トル
クを減少させるように制御することを特徴とする駆動力
伝達装置。1. A differential control device that distributes and transmits a transmission torque from an engine to front and rear wheels, and a transmission torque distribution ratio between the front and rear wheels can be changed, and a transmission torque of the differential control device. In the driving force transmission device including a control device for controlling the rotation speed of each of the front and rear wheels, the control device calculates a deceleration of the rotation speed of each of the front and rear wheels, and one of the decelerations is set to a predetermined value. A driving force transmission device, characterized in that the transmission torque of the differential control device is controlled to be reduced if the first threshold value or more is reached.
て、前記制御装置は、さらに左右の後輪の回転速度の平
均値と左右の前輪の回転速度の平均値との差を演算し、
前記各車輪の回転速度の減速度の何れか１つが前記第１
しきい値以上で、かつ前記平均値の差が所定の第２しき
い値以上となった場合には前記差動制御装置の伝達トル
クを減少させるように制御することを特徴とする駆動力
伝達装置。2. The driving force transmission device according to claim 1, wherein the control device further calculates a difference between an average value of rotational speeds of the left and right rear wheels and an average value of rotational speeds of the left and right front wheels,
Any one of the decelerations of the rotation speeds of the wheels is the first
When the difference is equal to or more than a threshold value and the difference between the average values is equal to or more than a predetermined second threshold value, the transmission torque of the differential control device is controlled to be reduced. apparatus.
伝達装置において、前記制御装置は、さらに前記各減速
度の何れもが前記第１しきい値以上でなくかつ前記平均
値の差が異常に大きい場合にも前記差動制御装置の伝達
トルクを減少させるよう制御することを特徴とする駆動
力伝達装置。3. The driving force transmission device according to claim 1, wherein the control device is configured such that none of the decelerations is equal to or more than the first threshold value and the difference between the average values. Is controlled to decrease the transmission torque of the differential control device even when is abnormally large.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002126675A JP3825717B2 (en) | 2002-04-26 | 2002-04-26 | Driving force transmission device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002126675A JP3825717B2 (en) | 2002-04-26 | 2002-04-26 | Driving force transmission device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003320857A true JP2003320857A (en) | 2003-11-11 |
| JP3825717B2 JP3825717B2 (en) | 2006-09-27 |
Family
ID=29541017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002126675A Expired - Fee Related JP3825717B2 (en) | 2002-04-26 | 2002-04-26 | Driving force transmission device |
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| Country | Link |
|---|---|
| JP (1) | JP3825717B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005153780A (en) * | 2003-11-27 | 2005-06-16 | Nissan Motor Co Ltd | Four-wheel drive vehicle |
| KR100698993B1 (en) | 2004-06-10 | 2007-03-26 | 닛산 지도우샤 가부시키가이샤 | Driving force control apparatus for automotive vehicles |
| CN102574465A (en) * | 2009-08-20 | 2012-07-11 | 雷诺股份公司 | Method and device for distributing engine torque between the front end and the rear end of a motor vehicle with four drive wheels |
| CN102935815A (en) * | 2012-12-04 | 2013-02-20 | 湘潭电机股份有限公司 | Electric differential control device and method for electric wheel vehicle |
| US20130304341A1 (en) * | 2011-01-27 | 2013-11-14 | Honda Motor Co., Ltd. | Driving force control device for four-wheel-drive vehicle |
| CN104129320A (en) * | 2014-08-20 | 2014-11-05 | 成都宽和科技有限责任公司 | Voltage difference control assistance system for processing speed signals and outputting signals |
-
2002
- 2002-04-26 JP JP2002126675A patent/JP3825717B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005153780A (en) * | 2003-11-27 | 2005-06-16 | Nissan Motor Co Ltd | Four-wheel drive vehicle |
| KR100698993B1 (en) | 2004-06-10 | 2007-03-26 | 닛산 지도우샤 가부시키가이샤 | Driving force control apparatus for automotive vehicles |
| CN102574465A (en) * | 2009-08-20 | 2012-07-11 | 雷诺股份公司 | Method and device for distributing engine torque between the front end and the rear end of a motor vehicle with four drive wheels |
| US20130304341A1 (en) * | 2011-01-27 | 2013-11-14 | Honda Motor Co., Ltd. | Driving force control device for four-wheel-drive vehicle |
| US8996267B2 (en) * | 2011-01-27 | 2015-03-31 | Honda Motor Co., Ltd. | Driving force control device for four-wheel-drive vehicle |
| CN102935815A (en) * | 2012-12-04 | 2013-02-20 | 湘潭电机股份有限公司 | Electric differential control device and method for electric wheel vehicle |
| CN102935815B (en) * | 2012-12-04 | 2014-11-05 | 湘潭电机股份有限公司 | Electric differential control method for electric wheel vehicle |
| CN104129320A (en) * | 2014-08-20 | 2014-11-05 | 成都宽和科技有限责任公司 | Voltage difference control assistance system for processing speed signals and outputting signals |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3825717B2 (en) | 2006-09-27 |
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