A self-lubricating two-stage variable vvl rocker arm

Abstract

The invention provides a self-lubricating two-stage variable VVL rocker arm, which includes a static rocker arm, a lock pin and a swing arm. A first oil inlet hole and a second oil passage are opened on the static rocker arm, and a The first oil channel and the lock pin pushing part, the lock pin oil storage cavity is formed between the lock pin pushing part and the lock pin installation hole, and the second oil inlet hole is opened on the return spring seat, and the first oil inlet Hole, the first oil passage, the second oil inlet hole, the installation groove of the return spring seat, and the second oil passage are sequentially connected to form a self-lubricating passage for the rocker arm. The first oil inlet hole is also connected to the lock pin oil storage chamber, The outlet of the second oil passage communicates with the contact R surface of the static rocker arm and the valve stem. The present invention can still lubricate the moving parts of the rocker arm when the contact R surface between the static rocker arm and the valve stem does not require an additional lubrication system, effectively reducing the friction loss and contact kinetic energy loss during the rocker arm’s working process , improving the wear durability of the rocker arm.

Description

technical field [0001] The invention relates to a VVL rocker arm, in particular to a self-lubricating two-stage variable VVL rocker arm for an internal combustion engine. Background technique [0002] The adoption of VVL (abbreviation for Variable Valve Lift in English, meaning variable valve lift) enables the engine to obtain a valve lift that meets the demand in both high-speed and low-speed areas, thereby improving the high-speed power and low-speed torque of the engine. The two-stage variable valve lift technology enables the engine to selectively match high or low valve strokes at different speeds, so as to further increase the torque output of the engine at low speeds and the power output of the engine at high speeds. When the engine is running at high speed, choosing to match a larger valve stroke can significantly increase the intake volume, thereby increasing the power output at high engine speed; when the engine is running at a low speed, choosing to match a smalle...

AI Technical Summary

Problems solved by technology

[0004] First, the roller surface of the existing two-stage variable VVL rocker arm is in direct contact with the cam surface of the camshaft. The VVL system cannot directly lubricate the roller of the rocker arm. Therefore, there is no contact between the roller of the rocker arm and the cam of the camshaft. Avoid frictional and contact kinetic energy losses

A layer of coating is usually provided on the contact R surface of the static rocker arm of the rocker arm and the valve stem, and the coating can reduce friction and improve wear durability. However, on the contact R surface, static There is still direct contact between the rocker arm and the valve stem. Therefore, during the working process of the rocker arm, this direct contact will cause the rocker arm to lose kinetic energy due to impact and friction; at the same time, because the VVL static rocker arm and the valve stem There is no lubricating design on the contact R surface, which leads to the need for an additional lubrication system in contact with the R surface of the static rocker arm and the valve stem, which increases the design and processing difficulty of the engine cylinder head

[0005] Second, in the existing two-stage variable VVL rocker arm, the diameter of the working end of the lock pin is affected by the diameter of the lock pin installation end and the reset space of the lock pin, and it is impossible to directly increase the diameter to solve the problem of the lock pin. Plastic deformation problem, therefore, the locking pin can easily fail due to plastic deformation

[0006] Third, in the existing two-stage variable VVL rocker arm, the reset device of the rocker arm generally adopts an external torsion spring, which is not conducive to the layout of the space, and increases the mass of the rocker arm

In addition, since the main body of the lock pin and the spring seat of the lock pin are integrally processed and manufactured, the processing technology is relatively complicated and the processing is difficult, resulting in high processing cost of the lock pin

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