On the adaptability of the idea of friction circle to the tractor behavior on the slope land.

通过对拖拉机在坡地上行驶时牵引载荷的侧滑角的估算，确定了摩擦圈的概念，理清了牵引车特性与行驶面性质之间的关系。在此基础上，研究了坡地牵引特性的估计方法。侧滑角受牵引力和侧力的共同影响。将K的值定义为最大牵引力与最大侧力之比，在相同的牵引力上，一定的牵引力与最大侧滑阻力乘以K的关系为圆2。在实际应用中，在运行轮和驱动轮上，变形侧力即侧阻力除以最大侧阻力与除拖拉机纵轴滑移比外的基本侧滑移角的关系均为线性关系。在有偏航角的情况下，这一原则也适用。K在不同的跑面上有不同的值。但当变换侧力的最大系数乘以K变为1时，上述关系变为与跑面无关的形式方程。如果这个线性方程已经确定，那么只要做k值的检验，就可以估计拖拉机在坡地上的行为。对所得原理进行反算，估计了假想拖拉机在坡地上的运动特性。

On the estimation of the side slip angle of tractor running to pull the load on the slope land, the idea of friction circle was confirmed,and was cleared up the relations to both the feature of tractor and nature of running surface. Then estimation method of traction characteristics on the slope land was examined.1. The side slip angle is effected by both traction and side force. Defining a value of K as the ratio of maximum traction force to maximum side force, a certain traction force and maximum side resistance force for side slip multiplied by k on the same traction force is in the relation of a circle.2. Relation of transformed side force, that is side resistance force devided by the maximum side resistance force, to fundamental side slip angle excepted the slip ratio of longotudinal axis of tractor, is in linear within a practical use, on both running and driving wheels. On the case of having the yaw angle, this principle is also applied.3. k has each value on the different running surface. But as the maximum coefficient of transformed side force multiplied by K becomes to value of 1, this relation mentioned above becomes the formal equation not related to the running surface. Then the behavior of a tractor on the slope land can be estimated by only doing the test of value of k, if this linear equation has been decided.4. Calculating backward the principle getted here, the behavior of a supposed tractor on the slope land was estimated.