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Suspension bracket geometry
Corners of installation of wheels of the car - the general information
The geometry of a suspension bracket and its rigidity define possibility of restriction of vertical movings of a body and reduction of angular fluctuations round cross-section and longitudinal axes.
Forward wheels turn round inclined axes, whose position is defined by hinges and details of a suspension bracket of the car.
The most important are the kinematic installations of wheel assemblages listed more low in relation to a steering and transfer of forces between tyres and a road covering. It is necessary to remember that corners of installation of wheels appreciably influence stability of the car, deterioration of tyres and the fuel expense. Rating values subject check and adjustment of corners of installation of wheels of cars considered in the present Management are resulted in Specifications of the Head the Suspension bracket and a steering.
As convergence (convergence) is called the corner between the lines formed at section by a horizontal plane of following planes:
Plane of symmetry of the car;
Plane of a wheel disk.
Convergence of forward wheels
Convergence can be defined also as a difference of distances between extreme forward and back edges of wheel assemblages. 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 draught. At zero convergence distance between forward edges of wheels to equally distance between their back edges. Normal convergence usually does not exceed inch shares (1 inch = 2.54 sm).
As disorder is called the corner between the lines formed at section by a vertical plane, a perpendicular plane of symmetry of the car of following planes:
Plane of symmetry of the car;
Plane of a wheel disk.
Corners of installation of a wheel
If the top part of a wheel is rejected from an axis of symmetry of the car outside, disorder is called as negative, and on the contrary. Correctness of adjustment of disorder defines size and position of a stain of contact of protectors with a road covering and allows to compensate changes in geometry the suspension brackets occurring during fulfilment of turns and at movement of the car on a rough road covering.
The kinematic length of a pin represents the shortest distance between the centre of an operated wheel and an axis of its turn. For all-wheel drive cars the given parametre characterises influence of forces of draught and forces of resistance качению on controllability of a vehicle.
As stabilisation shoulder is called the distance between a point of contact of a wheel and a point of intersection of an axis of its turn with a road covering on a side view, defining size of the stabilising moment and influencing course stability of the car and on distribution of forces in a steering at fulfilment of turns.
Выбегом the 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 is called. Together with a corner of a cross-section inclination of an axis выбег influences change of disorder of wheels at change of an angle of rotation of a steering wheel, and also influences stabilising moment.
The shoulder обкатки is defined as distance between a point of contact of a wheel with a road covering and a point of intersection of an axis of its turn with a road covering on the front view. The shoulder is considered negative when last from named above points is between the centre and the top part of a wheel. The parametre influences degree of influence of forces of braking on a steering wheel and on size of the stabilising moment, and, the negative shoulder обкатки increases 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 a plane of cross-section section of the car. Along with выбегом and size of longitudinal displacement of an axis of turn influences sensitivity of a steering.
The general check of geometry of a suspension bracket is made at the special stand in the conditions of a specialised workshop.
Back wheels of the car have the suspension brackets defined by geometry which are not giving in to adjustment zero corners of disorder and выбега. The description of procedures of check and adjustment of corners of installation of forward wheels of the car is resulted in Section Check and adjustment of corners of installation of forward wheels.
Conditions of check of corners of installation of wheels
Check of corners of installation of the car demands presence of specially equipped platform. Before the check beginning it is necessary to make sure of performance of following conditions:
Pressure of air in tyres 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 are besieged with effort;
The steering drive is adjusted in the correct image;
Люфты in wheel bearings, tips of steering draughts and spherical support of a suspension bracket do not leave for admissible limits;
Depth of a protector of the tyres established on wheels of one axis is identical.