《汽车理论》课程教学课件（英文讲稿）第7章 汽车通过性 Passing Ability of Vehicle 7.1 Geometrical Characteristics of Vehicle（汽车几何通过特性）

Chapter 7 Passing Ability of Vehicle汽车的通过性002050220-7007202020207.1GeometricalCharacteristicsof Vehicle（汽车几何通过特性）7.2SteppingAbilityandStridingAbility（汽车越台跨沟能力）

Chapter 7 Passing Ability of Vehicle 汽车的通过性 7.1 Geometrical Characteristics of Vehicle（汽车几何 通过特性） 7.2 Stepping Ability and Striding Ability（汽车越台跨 沟能力）

GeneralizationDefinition: The passing ability of the vehicle withcertain load under both passable and impassable roadconditions.?Classification:1) The passing ability under the passable and rigid roadconditions(caused by the geometrical characteristics ofvehiclemostly).It canalsobecalledgeometricalpassingability.（几何通过特性）2) The passing ability under the passable and soft roadconditions (caused by the elastic deformation of thesoftroadmostly)

Generalization  Definition: The passing ability of the vehicle with certain load under both passable and impassable road conditions.  Classification： 1）The passing ability under the passable and rigid road conditions(caused by the geometrical characteristics of vehicle mostly) . It can also be called geometrical passing ability.（几何通过特性） 2）The passing ability under the passable and soft road conditions (caused by the elastic deformation of the soft road mostly)

7-l GeometricalCharacteristics of Vehicle1.Invalidationofclearance（间隙失效）Definition:The impassable case of the vehicle caused by theinsufficient ground clearance, i.e. being blocked or beingdragged.Classification: According to the different part causing theineffective clearance of the vehicle,the invalidation couldbe classified into three kinds:Touchingheadinvalidation（触头失效touching the ground with head,Draggingtailinvalidation（拖尾失效）touchingtheground with tail,Supportinginvalidation（顶起失效）touching theground with middle part of the bottom

7-1 Geometrical Characteristics of Vehicle 1. Invalidation of clearance（间隙失效） Definition: The impassable case of the vehicle caused by the insufficient ground clearance , i.e. being blocked or being dragged. Classification: According to the different part causing the ineffective clearance of the vehicle, the invalidation could be classified into three kinds: • Touching head invalidation（触头失效 ）—— touching the ground with head; • Dragging tail invalidation（拖尾失效）——touching the ground with tail; • Supporting invalidation（顶起失效）——touching the ground with middle part of the bottom

2.GeometricalParameter（1）Approachangle（接近角）——17The angel between the ground plane and the plane which is tangentto the front tire and passing through the lowest point of front bottomof the vehicle.（2）Departureangel（离去角）一一2 The angel between the ground plane and the plane which is tangent tothe rear tire and passing through the lowest point of rear bottom ofthe vehicle39.8037.1°纵向通过角离去角接近角(Break-OverAngle)ApproachAngle(DepartureAngle)

2. Geometrical Parameter （1）Approach angle （接近角）——  The angel between the ground plane and the plane which is tangent to the front tire and passing through the lowest point of front bottom of the vehicle. （2）Departure angel（离去角）——  The angel between the ground plane and the plane which is tangent to the rear tire and passing through the lowest point of rear bottom of the vehicle. 1  2 

2.GeometricalParameter(3)For-and-aftPassingAngel（Break-OverAngel纵向通过角）β> The angel between two panels which are tangent to the front and reartires respectively plus passing through the lowest point of middlebottom on side view23.39.8°37.10纵向通过角离去角接近角（ApproachAngle(Break-OverAngle(DepartureAngle)

（3）For-and-aft Passing Angel （Break-Over Angel纵向通过角）—— β  The angel between two panels which are tangent to the front and rear tires respectively plus passing through the lowest point of middle bottom on side view. 2. Geometrical Parameter

2.GeometricalParameter（4）Minimumgroundclearance（最小离地间隙）mir> The distance between the lowest point of the middle bottom andground panel.涉水深度(FordingDepth)610mm最小离地间隙（GroundClearance）251.5mm

（4）Minimum ground clearance （最小离地间隙）——  The distance between the lowest point of the middle bottom and ground panel. hmin 2. Geometrical Parameter

2.GeometricalParameter（5）Theminimumdiameterofturn（最小转弯直径）The diameter of the front outside wheel track circle inthe case of the maximum inner side wheel steer angle(<24m)转弯通道外圆转弯通道内圆

（5）The minimum diameter of turn （最小转弯直径）  The diameter of the front outside wheel track circle in the case of the maximum inner side wheel steer angle （≤24m）. 2. Geometrical Parameter

3.The relationship between theinvalidation ofclearance and geometrical parameters-1 ;Touching head invalidationDragging tail invalidation2 ;hmin2β 。Supporting invalidation

Touching head invalidation—— ； Dragging tail invalidation—— ； Supporting invalidation—— 。 1  2  min h , 3. The relationship between the invalidation of clearance and geometrical parameters