CN202866918U

CN202866918U - Variable valve stroke mechanism of engine

Info

Publication number: CN202866918U
Application number: CN201220499469.0U
Authority: CN
Inventors: 李彦东; 伊丽花; 刘俊杰
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2012-09-28
Filing date: 2012-09-28
Publication date: 2013-04-10
Anticipated expiration: 2022-09-28

Abstract

The utility model provides a variable valve stroke mechanism of an engine. The variable valve stroke mechanism of the engine is used for achieving control to continuous variable valve stroke of the engine. The variable valve stroke mechanism of the engine comprises rocker arms, rocker arm shafts, air valves, cams and a cam shaft. The variable valve stroke mechanism of the engine is characterized in that pinion and rack transmission mechanisms are arranged in positions where the rocker arms are matched with the air valves. Each transmission gear is in a semicircular toothed plate structure and is located on the end portion of a driven arm of each rocker arm. Transmission racks are respectively fixed at the upper ends of air valve rods. The variable valve stroke mechanism of the engine controls the opening scope of the air valves through adjustment of the valve stroke, enables the air entering a combustion chamber of the engine to be in an optimal state, and improves dynamic performance and economic performance of the engine.

Description

A kind of engine variable valve lift mechanism

Technical field

The utility model relates to a kind of variable valve mechanism for engine, and especially a kind of engine continuous variable air valve lift range mechanism belongs to the combustion engine technical field.

Background technique

The engine variable-valve technology comprises the VVT(changing air valve phase) and the VVL(lift range variable) technology, wherein the VVT technology is by adjusting valve opening, close moment, control the valve open and close duration, be widely used on the motor car engine at present; The VVL technology is by the adjustment valve lift, controls valve and opens and closes amplitude, and this technology is also from a small amount of high-end vehicle to popular vehicle transition.

But existing VVL technology is generally the two-part variable lift, can not realize the control of continuously variable valve lift.Full changeable air valve technology (VVA) with continuous setup valve lift and gas distribution phase of engine function has solved the problems referred to above, it reaches the purpose that makes the air quantity that enters engine chamber be in the optimum state, raising engine combustion efficiency by the adjustment to engine valve opening/closing time and amplitude.At present the VVA technology is divided into mechanical type, electrolyte type and electromagnetic type, and wherein mechanical type and electrolyte type complex structure, electromagnetic type is stable not comparatively speaking; And prior art only also rests in a few manufacturer's hand that has the engine core technology, has limited applying of VVA technology.

The model utility content

The purpose of this utility model is to provide a kind of power character and Economy that can improve motor for overcoming above-mentioned prior art defective, reduces the engine variable valve lift mechanism of discharging and oil consumption.

Problem described in the utility model realizes with following technical proposals:

A kind of engine variable valve lift mechanism, it comprises rocking arm, pitman arm shaft, valve, cam and camshaft, its specialization is, at rocking arm slave arm and valve matching part rack and pinion drive mechanism is set, wherein driving gear is the semi-circular teeth plate structure, it is positioned at rocking arm slave arm end, and driving rack is fixed on the valve stem upper end.

Above-mentioned engine variable valve lift mechanism, described pitman arm shaft one end connects drive motor, and described drive motor is installed in engine cylinder and covers, and its control system is connected with Engine ECU, and its output shaft is connected with pitman arm shaft by coupling.

Above-mentioned engine variable valve lift mechanism, described rocking arm is sleeved on the pitman arm shaft, and its master arm is the arc-shaped curved surface that contacts with cam type surface, and the gear teeth with the driving rack coupling are set in its slave arm semi-circular teeth plate structure edge.

The utility model is according to the different operating conditionss of motor, under Engine ECU control, change rocking arm to the force application location of valve by drive motor driven gear rack gear, under fixing cam profile condition, the actual movement rule of rocking arm is changed, realize continuously variable valve lift; The utility model is simple in structure, and the mechanical type driving mode of camshaft and rocking arm has been inherited the reliability and stability of conventional engines distribution device; The utility model clashes into the mechanicalness noise that cause between the driving component without the valve clearance when having reduced the distribution device operation.In a word, the utility model is controlled the amplitude of valve opening by adjusting valve lift, makes the air quantity that enters engine chamber be in the optimum state, has improved power performance and the economic performance of motor.

Description of drawings

The utility model is described in further detail below in conjunction with accompanying drawing.

Fig. 1 is structural drawing of the present utility model;

Fig. 2 is the utility model camshaft and pitman arm shaft layout plan;

Fig. 3 is the utility model pitman arm shaft and driving mechanism schematic representation thereof;

Fig. 4 is the utility model valve maximum lift schematic representation when the low engine speed small load condition;

Fig. 5 is the utility model valve-closing schematic representation when the low engine speed small load condition;

Fig. 6 is the utility model valve maximum lift schematic representation when the high engine speeds high load working condition;

Fig. 7 is the utility model valve-closing schematic representation when the high engine speeds high load working condition.

Each label is among the figure: 1, cam, 2, rocking arm, 3, driving gear, 4, driving rack, 5, valve, 6, valve return springs, 7, cylinder cap, 8, camshaft, 9, pitman arm shaft, 10, drive motor, 11, coupling.

Embodiment

Referring to Fig. 1, the utility model comprises rocking arm 2, pitman arm shaft 9, valve 5, cam 1 and camshaft 8, its specialization is, at rocking arm 2 slave arms and valve 5 matching parts rack and pinion drive mechanism is set, wherein driving gear 3 is the semi-circular teeth plate structure, it is positioned at rocking arm 2 slave arm ends, and driving rack 4 is fixed on the valve stem upper end.

Referring to Fig. 2, Fig. 3, specialization of the present utility model is that also described pitman arm shaft 9 one ends connect drive motor 10, and described drive motor 10 is installed on the engine cylinder cover 7, its control system is connected with Engine ECU, and its output shaft is connected with pitman arm shaft 9 by coupling 11.

Referring to Fig. 1, its specialization of the present utility model is that also described rocking arm 2 is sleeved on the pitman arm shaft 9, and its master arm is the arc-shaped curved surface that contacts with cam 1 profile, and the gear teeth with driving rack 4 couplings are set in its slave arm semi-circular teeth plate structure edge.

Referring to Fig. 1～Fig. 7, and in conjunction with specific embodiments the utility model working principle is described: the variable air valve lift range mechanism in the utility model is connected the slave arm of valve 5 with rocking arm 2 by rack and pinion drive mechanism, the semicircle tooth plate that is positioned at rocking arm 2 slave arms one side can rotate to change contact position and the valve lift of camshaft and rocking arm master arm at the tooth bar of valve stem, thereby realizes full lift range variable control technique.When motor is in the high speed high load working condition; pitman arm shaft 9 rises to highest point by drive motor 10 controls; this moment, the top of cam 1 profile contacted with rocking arm 2 master arms; the rocking arm slave arm drives valve 5 by rack and pinion drive mechanism and moves down; valve lift is maximum, air inlet the most abundant (as shown in Figure 6).When camshaft turned to cam 1 profile basic circle and contacts with rocking arm 2 master arms, valve 5 rose under valve return springs 6 elastic force effects, and valve 5 contacts with the air valve seat ring that is positioned at the engine cylinder cover firing chamber, and valve 5 is closed (as shown in Figure 7).When motor is in the low speed small load condition; pitman arm shaft 9 drops to the appropriate position by drive motor 10 control; when the top of cam type surface 1 contact with rocking arm 2 master arms; the rocking arm slave arm drives valve 5 by rack and pinion drive mechanism and moves down; but this moment, valve 5 moved down apart from less; valve 5 unlatching amplitudes are little; air inflow minimizing (as shown in Figure 4); when the basic circle that turns to cam 1 profile when camshaft contacts with rocking arm 2 master arms; valve 5 rises under valve return springs 6 elastic force effects; valve 5 contacts with the air valve seat ring that is positioned at the engine cylinder cover firing chamber, and valve 5 is closed (as shown in Figure 5).The utility model and motor VVT technology fit applications, can realize the variable control of engine air valve lift and gas distribution phase of engine, thereby make the air quantity that enters engine chamber be in the optimum state, reach the power performance that improved motor and the purpose of economic performance.

Claims

1. engine variable valve lift mechanism, it comprises rocking arm (2), pitman arm shaft (9), valve (5), cam (1) and camshaft (8), it is characterized in that, at rocking arm (2) slave arm and valve (5) matching part rack and pinion drive mechanism is set, wherein driving gear (3) is the semi-circular teeth plate structure, it is positioned at rocking arm (2) slave arm end, and driving rack (4) is fixed on the valve stem upper end.

2. a kind of engine variable valve lift mechanism according to claim 1, it is characterized in that, described pitman arm shaft (9) one ends connect drive motor (10), described drive motor (10) is installed on the engine cylinder cover (7), its control system is connected with Engine ECU, and its output shaft is connected with pitman arm shaft (9) by coupling (11).

3. a kind of engine variable valve lift mechanism according to claim 2, it is characterized in that, described rocking arm (2) is sleeved on the pitman arm shaft (9), its master arm is the arc-shaped curved surface that contacts with cam type surface, and the gear teeth with driving rack (4) coupling are set in its slave arm semi-circular teeth plate structure edge.