11.5. Suspension bracket geometry
Corners of installation of wheels considerably influence stability of the car, wear of tires and fuel consumption. Nominal rates of corners are specified in Specifications.
The tilt angle of the plane of a wheel concerning a vertical is called as disorder. If wheels are inclined by the upper edges outside, disorder is called as positive, and on the contrary. The size of disorder is measured in degrees. 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.
The data size to each other forward edges of wheels of the car is called as convergence (convergence). Such violation of parallelism of installation of wheels allows to minimize wear of a protector at the expense of prevention юза at commission of turns. At zero convergence distance between forward edges of wheels equally to distance between their back edges. Normal convergence usually does not exceed inch shares (1 inch = 2.54 cm). Violation of adjustment of convergence conducts to acceleration of wear of protectors of tires at the expense of a proskalzyvaniye them on a paving.
Vybegom is called a corner of a longitudinal inclination шкворня / axes of turn of a wheel, i.e., a corner of a deviation of this axis from a vertical in the rim plane. If the turn axis / шкворень is inclined back, выбег is called as positive, and on the contrary.
By analogy, a corner of a cross-section inclination of an axis of turn of a wheel call a corner of a deviation imagined шкворня from a vertical in the plane, the perpendicular plane of symmetry of the car.
The size of limiting angles of rotation of forward wheels of the car should be lowered at increase in the size of the last. Distance from edge of the tire of the wheel turned against the stop to the longitudinal lever of a suspension bracket should make about 2 cm, otherwise it is necessary the corresponding adjustment (see. Section Check and adjustment of limiting angles of rotation of forward wheels).
The general check of geometry of a suspension bracket is made at the special stand in the conditions of a specialized workshop.
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 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.