12.5.10. Corners of installation of wheels of the car - the general information
Convergence of forward wheels is subject to adjustment only.
Possibility of restriction of vertical movings of a body and reduction of angular fluctuations round cross-section and longitudinal axes is defined by geometry of a suspension bracket and its rigidity.
Forward wheels turn round inclined axes, whose situation is defined by hinges and details of a suspension bracket of the car.
The most important is the kinematic installations of wheel assemblies listed below in relation to a steering and transfer of forces between tires and a paving. Corners of installation of wheels considerably influence stability of the car, wear of tires and fuel consumption. Nominal rates subject check and adjustment of corners of installation of wheels of cars considered in the real Management are specified in Specifications at the beginning of Head the Suspension bracket and a steering.
The projection to the horizontal plane of a corner between the plane of symmetry of the car and the plane of the wheel assembly passing through the center of the tire of the operated wheel is called as convergence (convergence); the difference of distances between lobbies and back boards of rims of wheels can be also defined. Convergence influences straightforwardness of movement of the car and on its controllability, and on front-wheel models compensates resultants kinematic changes of geometry the suspension brackets defined by influence of force of draft. At zero convergence distance between forward edges of wheels equally to distance between their back edges.
Convergence of forward wheels
The wheel tilt angle in relation to a paving in the vertical plane is called as disorder. If the top part of a wheel is inclined to an axis of symmetry of the car, disorder is called as negative, and on the contrary. Correctness of adjustment of disorder defines size and the provision of a spot of contact of protectors with a paving and allows to compensate changes in geometry the suspension brackets occurring during commission of turns and at movement of the car on a rough paving.
Corners of installation of a wheel
The kinematic length of a pin represents the shortest distance between the center of an operated wheel and an axis of its turn.
The distance between a point of contact of a wheel and a point of intersection of an axis of its turn with a paving on a side view, defining size of the stabilizing moment and influencing course stability of the car and on distribution of forces in a steering is called as a shoulder of stabilization at commission of turns.
Vybegom is called a corner of a longitudinal inclination of an axis of turn of a wheel, i.e., a corner between an axis of turn and a vertical on a side view. Together with a corner of a cross-section inclination of an axis выбег influences change of disorder of wheels at measurement of an angle of rotation of a steering wheel, and also for stabilizing moment.
The shoulder of a running in decides as distance between a point of contact of a wheel on a paving and a point of intersection of an axis of its turn with a paving on the front view. The shoulder is considered negative when the last from called above points is between the center and the top part of a wheel. The parameter influences extent of influence of forces of braking on a steering wheel and on size of the stabilizing moment, and, the negative shoulder of a running in increases the last.
The corner of a cross-section inclination of an axis of turn of a wheel represents a corner between an axis of turn of a wheel and a vertical in the plane of cross-section section of the car. Along with vybegy and size of longitudinal shift of an axis of turn influences sensitivity of a steering.
Conditions of check of corners of installation of wheels
Check of corners of installation of the car demands existence of specially equipped platform. Before the beginning of check it is necessary to make sure of performance of the following conditions:
- Pressure of air in tires corresponds to the nominal;
- Forward wheels are established rectilinearly;
- The car is not loaded, the fuel tank is completely filled;
- Elements of a suspension bracket of the car осажены with effort;
- The steering drive correctly is adjusted;
- Lyufta in wheel bearings, tips of steering drafts and spherical support of a suspension bracket do not leave out of admissible limits;
- Depth of a protector of the tires established on wheels of one axis is identical.