12.4.6. Angles of installation of wheels
General information
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The angles of installation of back wheels are established at manufacturer and are not among under control parameters. |
The angles of installation of forward wheels define geometry of situation of the last concerning a suspension bracket of the car and a paving. Violation of adjustment of this geometry leads to decrease in controllability of the car and increase in speed of wear of tires. The angles of installation of forward wheels of the car which are subject to control are among выбег (a corner of a longitudinal inclination of an axis of turn of a wheel), disorder, a corner of a cross inclination of an axis of turn of a wheel and convergence is subject to Adjustment only one of parameters - convergence. Other parameters have to be checked on a regular basis for assessment of degree of wear of components of a suspension bracket and the steering drive.
Angles of installation of wheels of the car
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Adjustment of angles of installation of wheels is among the procedures demanding the special accuracy of measurement which high-quality implementation requires existence of special, rather bulky and expensive equipment. Performance of this work will be most correct to be charged to professional mechanics of car service. Below, for the general understanding, definitions of each of the under control angles of installation of wheels of the car which knowledge will facilitate communication of the owner of the car with personnel of car service are given.
Corner of a longitudinal inclination of an axis of turn of a wheel (vybegy) is called the projection to the vertical longitudinal plane of the car of a corner between a vertical and an awn of turn of a wheel. If the axis of turn is inclined back (the lower part of an axis is pushed forward), выбег is called positive and vice versa. Adjustment of a vybeg of forward wheels is carried out by selection of the remote washers enclosed under the pushing suspension bracket bars.
Disorder is called the tilt angle of the plane of wheels concerning a vertical. If wheels are inclined by the upper edges outside, disorder is called positive and vice versa. The size of disorder is measured in degrees. Correctness of adjustment of disorder determines the size and the provision of a spot of contact of protectors with the road and allows to compensate changes in suspension bracket geometry during commission of turns and at the movement of the car on an uneven paving. On the considered models of cars the possibility of adjustment of disorder is not provided.
Corner of a cross inclination of an axis of turn of a wheel is called the projection to the vertical cross plane of the car of a corner between a vertical and an axis of turn of a wheel.
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Thanks to disorder and a corner of a cross inclination of an axis of turn of a wheel, a point of a contact of wheels with the road settle down closer to an axis of a rotary fist, than the so-called "shoulder of a running in" the facilitating driving and reducing effect of transfer of blows of wheels about roughness of a covering on steering is supported. |
Convergence is called data size to each other of forward edges of wheels of the car. Such violation of parallelism of installation of wheels allows to minimize wear of a protector at the expense of a skid at commission of turns. At zero convergence the distance between forward edges of wheels is equal to distance between their rear edges. Normal convergence usually does not exceed two centimeters. Adjustment of convergence of forward wheels is carried out by adjustment of length of steering drafts due to change of provision of their tips. For correction of convergence of back wheels the special adjusting cam bolt screwed in the internal end of a control lever of a back suspension bracket is provided. Violation of adjustment of convergence leads to acceleration of wear of protectors of tires due to slipping them on a paving.
Conditions of check of angles of installation of wheels
PERFORMANCE ORDER |
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Adjustment of convergence of forward wheels