CN201874632U

CN201874632U - Fully variable valve timing gear containing variable-speed swing mechanism

Info

Publication number: CN201874632U
Application number: CN2010201821277U
Authority: CN
Inventors: 朱譞晟
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-04-29
Filing date: 2010-04-29
Publication date: 2011-06-22
Anticipated expiration: 2020-04-29

Abstract

The utility model discloses a fully variable valve timing gear containing a variable-speed swing mechanism, which comprises a cam, the variable-speed swing mechanism and a valve rocker arm with a roller, wherein the crankshaft angle of the cam can reach 360 degrees to meet the requirement of continuous opening time of the valve when an internal combustion engine operates at highest rotation speed; the size of the swinging angle of the variable-speed swing mechanism can be continuously adjusted, the initial swinging position can be continuously adjusted, and the finial swinging position is constant; an adjusting cam in the variable-speed swing mechanism can be used for adjusting a power arm or a resistance arm or the fulcrum position of a lever in swinging movement, and the fixed cam displaces to generate variable-speed swinging and travel; and the valve rocker arm with the roller can convert the transverse movement of the variable-speed swing into the vertical movement of the valve. The cam drives the variable-speed swing mechanism to generate continuous swinging at variable swinging speeds, and the swinging is converted into the push action for the variable continuous opening time of the valve. The fully variable valve timing gear can meet the requirement of the continuous opening time of the valve when the internal combustion engine operates at any rotation speed.

Description

The full Variable Valve Time gear that comprises speed-changing swing mechanism

Technical field

The utility model relates to a kind of full Variable Valve Time gear that comprises speed-changing swing mechanism, and it comprises the mechanism of cam, speed-changing swing and driving valve, and the two speed-changing swing driving mechanisms of variable fulcrum knot connection are a kind of of full Variable Valve Time gear.

Background technique

Existing Variable Valve Time gear meaning with the overlapping angle that changes intake valve and exhaust valve, and the endurance of valve opening is fixed.But this kind valve timing mechanism is when improving the overlapping angle, and exhaust valve postpones to open, intake valve is closed too early, all caused the extra exhaust loss of motor, and caused air inflow to reduce, these all make output power and moment of torsion best on the internal combustion engine theory incur loss.The method that the timing of valve can be adjusted to theoretical optimal value is called full Variable Valve Time, comprises the timing and the valve overlap angle of single valve.

Publication number is the full function variable gas distribution controlling mechanism of internal combustion engine shown in the CN101408118, and the purpose of design is that valve lift, full variable timing demand are incorporated within the cam of a simple variable cross section.Difform cam is combined on the axle continuously changes, lift is too high in the time of can causing high rotating speed, and perhaps lift is too low during the slow-speed of revolution.

Continously variable valve timing valve actuating mechanism piston IC engine shown in the publication number CN1831304, show and a kind ofly attempt to adopt two valves of intake valve or exhaust valve to take the method for differential On/Off to prolong the overall unlatching endurance of valve, 70 percent when but the lift of such mechanism's valve when internal-combustion engine rotational speed is the highest has only the slow-speed of revolution obviously do not satisfied the requirement of best timing.

Publication number is the variable valve actuation of the patented technology internal-combustion engine of CN101149000, is a kind of technology of continuously variable valve lift, has the effect of additional continuous variable valve timing, promptly changes valve duration.U.S. Pat 6,659,053, being referred to as " Fully Variable Valve Train " is that the technology of full adjustable valve timing has been utilized such adjection and used as variable timing mechanism, use continuous variable valve lift mechanism simultaneously at internal combustion engine intake valve and exhaust valve, and design appropriate parameter, when valve lift is maximum with timing effect, the overlapping angle of valve is also maximum, otherwise then minimum.When but this patent was worked at needs internal-combustion engine slow-speed of revolution full throttle, the lift of valve was obviously not enough, and pumping loss is bigger, and the restriction of valve lift limited the maximum angle of valve timing on the contrary, and timing is bad when making the high rotating speed of internal-combustion engine; The compare crankshaft angles of cam, the acceleration of motion of this mechanism when high rotating speed are bigger during on the contrary than low speed, need the elastic force of valve spring bigger, and the elastic force of spring just seemed bigger than normal when internal-combustion engine was in the slow-speed of revolution, thereby the loss of the internal-combustion engine that increases; The method can not make cam angle degree be amplified to best timing angle, thereby has limited the maximum speed and the power of internal-combustion engine.

Summary of the invention

The purpose of this utility model is to make new solution at above-mentioned defective, make up a kind of new mechanism, realize better controlling valve timing, not only will regulate the overlapping angle of valve, also to regulate the time that valve continues unlatching, simultaneously the maximum lift of immutable valve.

The utility model provides a kind of so full Variable Valve Time gear that comprises speed-changing swing mechanism, drives single valve mechanism and comprises camshaft, speed-changing swing system, control cam, roller rock arm.Speed change fork one end of described speed-changing swing system has roller, and the other end is connected on the projection of another root speed change fork intermediate portion with a stationary axle, and the middle speed change fork that projection is arranged, an end is fixed on the cylinder head with stationary axle.The roller surface of contact of the speed-changing swing system of described driving valve and the described roller rock arm of its promotion is divided into two parts, promote the part and the part that keeps valve-closing of the unlatching of valve, corresponding pendulum angle scope is divided into two parts, a part keeps valve-closing, and another part promotes valve opening; The initial position of speed-changing swing system is at the angular range that keeps valve-closing, and the ultimate position is in the angular orientation that makes the valve complete opening.

Compared with prior art, the utlity model has following characteristics and beneficial effect:

(1) angle of cam can design and reach 360 crank angle degrees, and valve timing, angle can be adjusted continuously at 180 to 360 degree, can realize the continuous valve timing more desirable than timing mechanism in the past, can optimize the low speed torque and the high-speed power of internal-combustion engine; (2) in the continuous adjustment process of timing, the rotation of camshaft does not change with respect to I. C. engine crankshaft, therefore can cancel complicated huge timing mechanism in the past, simplifies corresponding structure; (3) because the rotation angle of control cam has only seldom, so its layouts is convenient, no matter be employing hydraulic driving or motoring does not have difficulties; (4) this mechanism has reached the purpose of continuous variable valve timing with minimum number of components, is the mechanism that takes into account performance and cost.

Description of drawings

Fig. 1 is the two isogonism axonometric drawings up and down of exemplary embodiments mechanism, shows the mutual alignment of concrete parts of the single valve mechanism of driving of the full Variable Valve Time gear that comprises speed-changing swing mechanism.

Fig. 2 B is the schematic representation of driving mechanism, and Fig. 2 A shows the timing effect of described mechanism valve under the internal-combustion engine slow-speed of revolution.

Fig. 3 B is the schematic representation of driving mechanism, and Fig. 3 A shows the timing effect of described mechanism valve under the high rotating speed of internal-combustion engine.

Fig. 4 is that the speed change fork is regulated schematic representation, show regulating action and the scope of control cam to speed change fork fulcrum and angle, the control cam produces the rotation of several angle and relies on its special curved surface to make point of contact is that the generation of speed change fork fulcrum is moved, and the speed change fork is rotated.

Fig. 5 is the schematic representation of maximum lift, shows the influence of the regulating action of control cam to the valve maximum lift, and described control cam can not produce appreciable impact to lift in regulation range.

Embodiment

The utility model is described further by exemplary embodiments below in conjunction with accompanying drawing.Below all suppose to use described full Variable Valve Time gear and the corresponding control of do that comprises speed-changing swing mechanism simultaneously at intake valve and exhaust valve.

Fig. 1 is the two isogonism axonometric drawings up and down that the full Variable Valve Time gear that comprises speed-changing swing mechanism drives single valve mechanism, and cam 1 contacts closely with roller 12, and roller links to each other with speed change fork 7 by axle 11.Speed change fork 7 links to each other with the boss of speed change fork 6 by axle 10, and an end of speed change fork 6 is fixed on the stationary axle 5 that rotates freely, and freely is rotated with dead axle 5 and is fixed on the cylinder head (omissions), the 6 generation oscillating motions of speed change fork 7 promotion speed change forks.Control cam 8 is fixed on the cylinder head (omissions), can not translation, thereby push speed change fork 7 itself and cam 1 are kept in touch, and maintenance speed change fork 6 has a correct initial position.Speed change fork 6 contacts with torsion spring 3, and an end of torsion spring 3 is fixed on the immovable point 4 on the cylinder head, makes it can promote speed change fork 6 and produces return motion.The slip surface of speed change fork 6 contacts closely with roller 13, and roller 13 is fixed in the intermediate portion of rocking arm 15 with axle 14.Rocking arm 15 1 end in contact hydraulic tappets 20, the top of the other end contact valve stem.Hydraulic tappet 20 supports the acquisition of rocking arm 15, makes the swing of rocking arm 15 become the to-and-fro motion of valve 19.Valve spring 17 provides the valve restoring force, and folder 16 presss from both sides 18 fixed air door springs 17 and valves 19 down with valve on the valve.

Fig. 2 B is the adjustment state of speed-changing swing mechanism under internal-combustion engine slow-speed of revolution situation.Cam 1 promotes roller 12, drives speed change fork 6, under the support of control cam 8, promote speed change fork 7, speed change fork 7 rotates around stationary axle 5, the roller 13 that speed change fork 7 promotes on the rocking arm 15, under the supporting effect of fixing hydraulic tappet 20, promote valve 19.Torsion spring 3 is used for speed change fork 7 is provided the restoring force of slip, and cylindricality spring 17 provides the restoring force of valve 19.The torsion spring is fixedly connected with engine cylinder cover on 4 position, and the valve spring links to each other with valve at punch holder 16, contacts with engine cylinder cover at die holder 18.The rotation of control cam 8 can promote speed change fork 6 and change angle, change the position of fulcrum on speed change fork 6 simultaneously, thereby change speed change fork 7 swing distances, but the angle of swing of control cam 8 is limited in the small range, make on the speed change fork 6 swing ultimate positions and offset the impetus of control cam 8, thereby the swing ultimate position is remained unchanged.Fig. 2 A is the timing effect of valve opening diagram indication mechanism, is slow-revving state among the figure.Timing shifts to an earlier date direction for left, and the timing retard direction is for to the right.The valve overlap angle has only few overlapping when rotating speed is low.

Fig. 3 B is the adjustment state of speed-changing swing mechanism under the high speed conditions of internal-combustion engine, compare with the lower-speed state of Fig. 2, the speed change fork 7 of speed-changing swing mechanism and the amplitude of fluctuation of speed change fork 6 are littler, and the time that cam 1 promotion valve opens, more early the time of valve-closing was more late.Other job descriptions are identical with Fig. 2 B.The overlapping angle of the inlet and exhaust valve among this figure is to have adopted the characteristic that is had under the situation of described full Variable Valve Time gear simultaneously at the hypothesis inlet and exhaust valve, does not need the effect of the controlling mechanism of other continuous variables.Timing shown in Fig. 3 A shifts to an earlier date direction for left, and the timing retard direction is for to the right.The valve overlap angle is maximum when high-speed state.

Fig. 4 is a control cam when being rotated counterclockwise, the variation when cam 1 does not promote speed change fork 7.When control cam 8 rotates counterclockwise, it has the surface of contact of specific arc and the contacting points position of speed change fork 7 changes, make the elongated to the length of the power arm of point of contact of speed change fork 7 by cam 1, the length of corresponding resistance arm reduces, so just change the ratio of speed change fork 7 these lever features, made the displacement of resistance spot wobble reduce.Simultaneously, what the rotation of control cam 8 had promoted speed change fork 7 is the rotation at center with cam 1, and the resistance point position of speed change fork 7 is changed, and promotes the variation that speed change fork 6 produces an initial position according to stationary axle 5.According to the principle that speed-changing swing drives, in cam period of time T regularly, valve will more early be opened more late closing.Therefore, this mechanism's working state is regulated paramount rotating speed valve timing valve timing from the slow-speed of revolution; Otherwise the control cam is when clockwise rotating, and mechanism is adjusted to the slow-speed of revolution valve timing valve timing from high rotating speed.The effect of roller 12 is frictional losss of minimizing and cam 1.Dotted line is the mechanism position that mechanism regulates valve timing when being in the high rotating speed of internal-combustion engine.

Fig. 5 is the principle that the valve maximum lift is kept.Cam is in promotion roller 12 and the maximum part of speed change fork 7 strokes 1 this moment, and speed change fork 6 is swung because of the effect of stationary axle 5.Because the curved design and the small rotation angle of control cam 8, make speed change fork 7 when the swing ultimate position, control cam 8 can not promote speed change fork 7, so the lift of valve can not change because of the swing of speed change fork 7, is to keep the constant method of valve lift.Also therefore, it is identical before and after timing is regulated that valve has the pairing cam angle degree of top lift position, thus valve to have the pairing crankshaft angles of top lift be constant.This constant be the reason that produces correct inlet and exhaust valve overlapping angle.Dotted line is the adjusted position of control cam when being in the high rotating speed of internal-combustion engine.

With regard to the utility model, the selection of appropriate mechanism parameter makes valve reach the lift maximum at same cam angle degree, the controlling mechanism state just can significantly not change the central position of curve valve timing with the behavior that adapts to rotating speed, as the timing change curve of single valve among Fig. 2,3, the variation relation of valve lift and crankshaft angles.When intake valve and exhaust valve are same when using such mechanism, the inlet and exhaust valve variation of timing has separately formed the valve overlap angle of satisfying the internal combustion engine needs naturally, just no longer needs extra controlling mechanism to adjust the valve overlap angle.The combination timing curve of the inlet and exhaust valve as shown in Fig. 2 to Fig. 3.When inlet and exhaust valve is selected the different control cam 8 of curved surface for use, can produce different timing effects in addition, help to optimize the not timing of same-action valve.With reference to figure 4 and Fig. 5, the curved surface that control cam 8 contacts with speed change fork 7 is complicated geometrical shape, and purpose is to guarantee Fig. 4 and control effect shown in Figure 5, and promptly the lasting opening time of valve changes continuously, keeps lift constant simultaneously.

Though the utility model original intention is to keep valve lift, do not repel yet and when high rotating speed, improve valve lift, reduce valve lift during the slow-speed of revolution, further to reduce pumping loss, only need the parameter designing of regulating mechanism, do not influence purport of the present utility model.

Above-mentionedly be only used for explaining exemplary embodiments of the present utility model.It is not exclusive or with the utility model restriction concrete form disclosed with it.It will be understood by those skilled in the art that in not departing from scope of the present utility model, can make various changes and element wherein can be replaced with IF-AND-ONLY-IF element.In addition, can make a lot of modifications so that particular condition or material are applicable to purport of the present utility model and do not depart from essential scope.Therefore, the utility model is not limited to realize the disclosed specific embodiment of optimal mode of the present utility model as design, but the utility model comprises all mode of executions that belong to the utility model scope.In not departing from spirit and scope of the present utility model, the utility model can be implemented in other modes beyond specific explanations and the mode of illustrating.

Claims

1. full Variable Valve Time gear that comprises speed-changing swing mechanism, this mechanism comprises:

Camshaft, this camshaft rotate with bent axle and are associated, and drive speed-changing swing mechanism urges valve and open or close;

The speed-changing swing system, this speed-changing swing system is linked together by two speed change forks, and the promotion that is subjected to described camshaft produces swing, promotes valve and opens and close;

The control cam, this control cam rotates in a scope, is the variable fulcrum of described speed-changing swing system, and rotation causes the position of the fulcrum of described speed-changing swing and angle to change;

Roller rock arm under described speed-changing swing system promotes, is converted into its oscillating motion the to-and-fro motion that promotes valve;

2. a kind of full Variable Valve Time gear that comprises speed-changing swing mechanism as claimed in claim 1, speed change fork one end that it is characterized in that described speed-changing swing system has roller, the other end is connected on the projection of another root speed change fork intermediate portion, and the middle speed change fork that projection is arranged, an end is fixed on the cylinder head to rotate freely stationary axle.

3. a kind of full Variable Valve Time gear that comprises speed-changing swing mechanism as claimed in claim 1, the roller surface of contact that it is characterized in that the described roller rock arm of the speed-changing swing system of described driving valve and its promotion is divided into two parts, promote the part and the part that keeps valve-closing of the unlatching of valve, corresponding pendulum angle scope is divided into two parts, a part keeps valve-closing, and another part promotes valve opening; The initial position of speed-changing swing system is at the angular range that keeps valve-closing, and the ultimate position is in the angular orientation that makes the valve complete opening.