Patent ID: 8689444
Filing Date: 2014-04-08
Classification: F01L,G01B,Y10T

Abstract:
1. A valve clearance adjusting method for adjusting a valve clearance in a cylinder head comprising a valve incorporated in a cylinder head body, a rocker arm connected at one end thereof to an end of the valve, an adjustment screw screwably connected to the other end of the rocker arm and having a lower end section swingably supported by the cylinder head body, and a camshaft contacted by a camshaft contact section of a circular-shaped surface in the rocker arm and capable of rotating to open and close the valve, the method comprising: rotating the adjustment screw in one direction to tighten the adjustment screw until the valve is released to attain a certain valve opening amount; subsequently rotating the adjustment screw in a reverse direction by a certain rotation angle to loosen the adjustment screw from a position where the valve is released to attain the certain valve opening amount up to a position where the camshaft is separated from the camshaft contact section by a desired valve clearance value; when the camshaft is in contact with the camshaft contact section, rotating the rocker arm using both a center of the circular-shaped surface of the camshaft contact section and the other end of the rocker arm as a support point, and determining a first rotation angle by which the adjustment screw should be rotated to reach a position where both a valve opening amount and a valve clearance value are zero from the position where the valve is released with the certain valve opening amount, based on a relationship between an adjustment screw rotating angle and the valve opening amount during rotation of the rocker arm; when the camshaft is separated from the camshaft contact section, rotating the rocker arm using the one end of the rocker arm as the support point, and determining a second rotation angle by which the adjustment screw should be rotated to reach a position where the desired valve clearance value is obtained from the position where both the valve opening amount and a valve clearance value are zero, based on a relationship between an adjustment screw rotating angle and the valve clearance value during rotation of the rocker arm; and rotating the adjustment screw in the reverse direction by a given rotation angle which is a sum of the first and second rotation angles.