Self-resetting single-valve double-piston hydraulic driving device and method for overhead cam engine

Abstract

The invention relates to a self-resetting single-valve double-piston hydraulic driving device and method for an overhead cam engine. The self-resetting single-valve double-piston hydraulic driving method comprises the steps that a driving main piston and a driving auxiliary piston are correspondingly arranged on a rocker arm body and a valve bridge body, the driving auxiliary piston is connected with an exhaust valve, and a driving oil way communicates with the driving main piston, the driving auxiliary piston and a driving control valve; when the driving control valve opens the driving oil way, the driving main piston and the driving auxiliary piston achieve hydraulic linkage, the rocker arm body and the valve bridge do not move during lift driving, and the driving auxiliary piston opensthe exhaust valve; when the main lift starts, a main piston body oil way and an auxiliary piston oil way are disconnected, and the driving auxiliary piston automatically resets; and when the driving oil way is disconnected, in the integrated cam driving lift process, the driving main piston absorbs the driving lift of an integrated cam assembly to the rocker arm body, the rocker arm body does notmove, and the integrated cam driving lift is not transmitted to one side of the exhaust valve. The self-resetting single-valve double-piston hydraulic driving method is simple in principle and compactin structure, and the reliability and durability of engine driving operation are improved.

Description

technical field

[0001] The invention relates to the technical field of overhead cam engines, in particular to an overhead cam engine self-resetting single-valve double-piston hydraulic drive device and method. Background technique

[0002] The concept and operation of compression release engine brakes is well known in the heavy commercial vehicle industry. Cost, power, reliability and engine change requirements are often factors in determining whether engine braking will be employed. Several different types of compression-release engine brakes exist in practical applications, among which the valve train integrated engine brake system has become more popular due to its low cost, high performance and reliability, and compact structure.

[0003] One approach to engine braking system integration is to incorporate actuated valve lift into positive power cams and include "loose" devices in the valvetrain to hide or inhibit the braking lift of the valves from actuated valves when ...

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