外文翻譯--黏性連接器用作前輪驅(qū)動(dòng)限制滑移差速器對(duì)汽車(chē)牽引和操縱的影響-汽車(chē)設(shè)計(jì)-全文預(yù)覽
【正文】 ween the two driving wheels is reduced with a viscous differential. Figure 16: Throttleoff Characteristics for a FrontWheel Drive Vehicle with an open Differential on Wet Asphalt at a Radius of 40m (Open Loop) Figure 17:Throttleoff Characteristics for a FrontWheel Drive Vehicle with Viscous Coupling on Wet Asphalt at a Radius of 40m (Open Loop) The yawing speed (yaw rate), and the relative yawing angle (in addition to the yaw angle which the vehicle would have maintained in case of continued steady state cornering) show a pronounced increase after throttleoff (Time=0 seconds in Figure 14 and 15) with the open differential. Both the sudden increase of the yaw rate after throttleoff and also the increase of the relative yaw angle are significantly reduced in the vehicle equipped with a viscous limitedslip differential. A normal driver os a frontwheel drive vehicle is usually only accustomed to neutral and understeering vehicle handing behavior, the driver can then be surprised by sudden and forceful oversteering reaction after an abrupt release of the throttle, for example in a bend with decreasing radius. This vehicle reaction is further worsened if the driver overcorrects for the situation. Accidents where cars leave the road to the inner side of the curve is proof of this occurrence. Hence the viscous coupling improves the throttleoff behavior while remaining controllable, predictable, and safer for an average driver. Although this might be considered as a negative effect and can easily be corrected when setting the YMR algorithm for a vehicle with a front viscous coupling, vehicle tests have proved that the influence is so slight that no special development of new ABS/YMR algorithms are actually needed. Some typical averaged test results are summarized in Figure 19. figure 19 : results form ABS braking tests with YMR on splitμ(Vo=50 mph, 3rd Gear, closed loop ) in figure 19 on the left a parison of the maximum speed difference which occurred in the first ABS control cycle during braking is shown. It is obvious that the viscous coupling is reducing this speed difference. As the viscous coupling counteracts the YMR, the required steering wheel angle to keep the vehicle in straight direction in the first second of braking increased from 39176。. Wheel braking force, a slightly higher vehicle deceleration was maintained(figure 19,right). 6． SUMMARY in conclusion,it can be established that the application of a viscous coupling in a frontaxle differential. It also positively influences the plete vehicle handling and stability , with only slight, but acceptable influence on torquessteer. To reduce unwanted torquesteer effects a basic set of design rules have been established: ? Toein response due to longitudinal load change must be as small as possible . ? Distance between kingpin axis and wheel center has to be as small as possible. ? Vertical bending anglerang should be centered around zero(or negative). ? vertical bending angles should be the same for both sides. ? Sideshafts should be of eq
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