CN102242650B

CN102242650B - Can be used for the continuous variable geometry camshaft of full Variable Valve Time

Info

Publication number: CN102242650B
Application number: CN201010173177.3A
Authority: CN
Inventors: 朱譞晟
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-12
Filing date: 2010-05-12
Publication date: 2015-11-25
Anticipated expiration: 2030-05-12
Also published as: CN102242650A

Abstract

The invention discloses a kind of continuous variable geometry camshaft that can be used for full Variable Valve Time, become a cam by 3 sub-cam combination and use; Every sub-cam has a boss, and boss and respective chute closely cooperate; There is the sleeve pipe of chute to be fixed in the hole of central shaft by fixing pin, driven by central shaft and realize coaxial twitch; Along with the twitch of central shaft, drive the axial motion of sleeve pipe, utilize chute to drive the angularly direction motion of three sub-cams, the angle of the cam of combination can be regulated continuously, realize the comprehensive continuously regulating action of valve timing.

Description

Can be used for the continuous variable geometry camshaft of full Variable Valve Time

Technical field

The present invention relates to a kind of continuous variable geometry camshaft that can be used for full Variable Valve Time, common monomer cam is divided into three pages of compound cams by it, thus can realize the continuous variable of cam angle degree.

Background technique

Existing Variable Valve Time gear meaning is in the overlapping angle with change intake valve and exhaust valve, and the endurance of valve opening is fixing.But this kind of valve timing mechanism is while the overlapping angle of raising, and exhaust valve postpones to open, intake valve is closed too early, all cause the exhaust loss that motor is extra, and cause air inflow to reduce, these all make output power best in internal combustion engine theory and moment of torsion incur loss.The method timing of valve can being adjusted to theoretical optimal value is called full Variable Valve Time, comprises timing and the overlapping angle of inlet and exhaust valve of single valve.

Publication number opens the timing camshaft of duration and valve opening advance angle for continuous variable valve a kind of described in CN101173618, although cam to be divided into standing part and variable part, the unlatching endurance of valve can be changed, but the problem of the regulative mode of its coaxial rotation is the sub-cam being merely able to realize a change, therefore such result is exactly the contradiction between the base shape angle of adjustable extent and sub-cam, if namely cam angle degree adjustable extent is large, the basic angle of sub-cam must be very large, namely the situation as shown in its accompanying drawing, such method advantageously can promote power during internal-combustion engine height rotating speed, disadvantageously internal-combustion engine have lost torsion when the slow-speed of revolution.On the other hand, if increase the basic angle of sub-cam and will lift be kept, just must increase the diameter of central shaft, so not only can increase mechanism's weight, and time cam axle time border line speed high, increase frictional loss.In addition, the connection of movable device is more very thin, and in the large load operating conditions of cam, easily break down even total failure.

Summary of the invention

This patent makes new solution for above-mentioned defect, designs a kind of new continuous variable geometry camshaft mechanism, can design form that better compatible existing internal-combustion engine is current, and provides better timing effect.

Invent a kind of continuous variable geometry camshaft that can be used for full Variable Valve Time provided, become a cam use by 3 sub-cam combination, every sub-cam has contour flat-top; Every sub-cam has a boss, and boss and respective chute closely cooperate; There is the sleeve pipe of chute to be fixed in the hole of central shaft by fixing pin, driven by central shaft and realize coaxial twitch; Along with the twitch of central shaft, drive the axial motion of sleeve pipe, utilize chute to drive the angularly direction motion of three sub-cams, the angle of the cam of combination can be regulated continuously, realize the comprehensive continuously regulating action of valve timing.

Accompanying drawing explanation

Fig. 1 is exploded view, shows the component parts of camshaft.

Fig. 2 is erection drawing, shows the assembling mode of sub-cam 1 and sleeve pipe.

Fig. 3 is erection drawing, shows the assembling mode of sub-cam 3 and sleeve pipe.

Fig. 4 is erection drawing, shows the assembling mode of sub-cam 7 and sleeve pipe.

Fig. 5 is sectional view and small angle cam combination figure, shows the general assembly mode of camshaft, is now the adjustment state forming small angle cam.

Fig. 6 is wide-angle cam combination figure, shows the adjustment state that camshaft forms wide-angle cam.

Fig. 7 is general assembly drawing, shows the example of every root camshaft four cams.

Embodiment

Come below with reference to the accompanying drawings to describe an exemplary embodiments.

Fig. 1 is the decomposing schematic representation of described camshaft.Any one cam on camshaft is all be made up of three sub-cams, the numerical value of the crankshaft angles corresponding to sub-cam, meets the angle requirement that valve is opened ahead of time under internal-combustion engine minimum speed.Sub-cam 1,3,7 shown in figure, wherein 1,7 is the sub-cams on both sides, has extension, and 3 is middle sub-cams, does not have extension.Every sub-cam has contour flat-top, and the flat-top of sub-cam 1,3,7 connects and becomes a smooth entirety.Sub-cam 1 coordinates with sleeve pipe 2, and sub-cam 3 coordinates with sleeve pipe 4, and sub-cam 7 coordinates with sleeve pipe 6.Fixing pin 10,9,8 is used for sleeve pipe 2,4,6 to be fixed on hole corresponding to three of central shaft respectively, parts together with sleeve pipe being become to be completely fixed with central shaft.Rotation and the twitch along center shaft axis of central shaft all can drive together with sleeve pipe 2,4,6 moves.The angle that the contour flat-top of every sub-cam has is the upper limit that cam angle degree regulates, and determines the maximum magnitude of cam continuously adjustabe change.

Fig. 2 is that the assembling of the sleeve pipe that a work song cam of described camshaft is corresponding with it coordinates schematic diagram, the shape of the boss 11 of sub-cam 1 is identical with the chute 12 of sleeve pipe 2, can closely cooperate, sub-cam 1 is coaxially installed with sleeve pipe 2, boss 11 is corresponding with chute 12, and therefore sub-cam can be driven by sleeve pipe 2 and axially rotate.The chute 12 of sleeve pipe 2 in axial direction reverses, and when sleeve pipe 2 is twitched vertically, sub-cam 1 to have rotation relative to sleeve pipe along chute 12 in rotation angle direction.

Fig. 3 is that the assembling of the sleeve pipe that two work song cams of described camshaft are corresponding with it coordinates schematic diagram, the shape of the boss 14 of sub-cam 3 is identical with the chute 13 of sleeve pipe 4, can closely cooperate, sub-cam 3 is coaxially installed with sleeve pipe 4, boss 14 is corresponding with chute 13, and therefore sub-cam can be driven by sleeve pipe 4 and axially rotate.The chute 13 of sleeve pipe 4 in axial direction reverses, and when sleeve pipe 4 is twitched vertically, sub-cam 3 to have rotation relative to sleeve pipe along chute 13 in rotation angle direction.

Fig. 4 is that the assembling of the sleeve pipe that three work song cams of described camshaft are corresponding with it coordinates schematic diagram, the shape of the boss 16 of sub-cam 7 is identical with the chute 15 of sleeve pipe 6, can closely cooperate, sub-cam 7 is coaxially installed with sleeve pipe 6, boss 16 is corresponding with chute 15, and therefore sub-cam can be driven by sleeve pipe 6 and axially rotate.The chute 15 of sleeve pipe 6 in axial direction reverses, and when sleeve pipe 6 is twitched vertically, sub-cam 7 to have rotation relative to sleeve pipe along chute 15 in rotation angle direction.

Fig. 5 is sectional view and small angle cam combination figure.Cam on camshaft angle is now smaller angle, i.e. the angle of every sub-cam 1,3,7.B-B sectional view in figure shows the assembled relation of its each parts.Sleeve pipe 2 is fixed on central shaft 5 by fixing pin 10, and sleeve pipe 4 is fixed on central shaft 5 by fixing pin 9, and sleeve pipe 6 is fixed on central shaft 5 by fixing pin 8.The length dimension of fixing pin 8,9,10 is less than the internal diameter of sub-cam 1,3,7, and therefore sub-cam 1,3,7 can slide along chute 12,13,15.

Fig. 6 is wide-angle camshaft constitutional diagram, and visible camshaft has had axial motion relative to sub-cam 1,3,7 along with central shaft 5, and direction is moved from sub-cam 7 to sub-cam 1.This moves the axial motion driving sleeve pipe, utilize the chute band mover cam 1,3,7 of sleeve pipe, sub-cam angularly direction moves relative to described central shaft, make to produce between sub-cam differential, the angle of the cam of order combination can regulate continuously, the cam face generation notable change of the equivalence formed, defines so-called wide-angle cam.Therefore camshaft is along with the twitch of central shaft 5, and realize the comprehensive continuously regulating action of valve timing, the adjustment direction that cam angle degree increases is moved from sub-cam 7 to sub-cam 1, otherwise be then that cam angle degree reduces.

Fig. 7 is general assembly drawing, it is the example of every root camshaft 4 cams, showing sub-cam 1,3,7 is rely on mutually to extrude with the extension sleeve pipe 17,18,19 of interior outer radius with the extension of sub-cam to be close together, and two ends fix whole cam shaft system by camshaft fixture 20 and fixed cover 22 and bolt 23.Central shaft 5 shown in figure also has spline tooth 21, the moment of rotation of central shaft still can be provided when central shaft moves vertically; Hydraulic thrust dish 24 is power resources that hydraulic system promotes that central shaft 5 makes axial reciprocating adjustment movement.Shown in figure is that camshaft is in low speed small angle adjustment state, and camshaft fixture 20 and fixed cover 22 are all fixed in cylinder head, inside have suitable cavity, with the space required for the reciprocal twitch holding central shaft 5.

The angle supposing every sub-cam is 240 degree, angle corresponding to the flat-top of sub-cam is 26 degree, mutually continuous in condition with sub-cam flat-top, setting chute have adjusting angle time 24 degree, i.e. crank shaft angle 48 degree, the angle of three sub-cam cams as a whole can reach 96 degree, and namely cam can be adjusted to 336 degree continuously from 240 degree, can meet the requirement of valve timing in the great speed range from common commercial internal-combustion engine to match internal-combustion engine completely.For common civilian internal-combustion engine, the maximum angle of cam can be reduced, can be less to exchange cam minimum angles for, fully to meet the valve timing during internal-combustion engine slow-speed of revolution.The angle that the chute of sleeve pipe and the internal boss of sub-cam are reversed can adjust as required, makes the timing of valve accomplish Unsymmetrical variation.

There is the edge of the sleeve pipe of chute to be smooth in described example, also can make the pattern becoming and have tooth, so mutual meshing, play the effect of carry-over moment, improve the acrotorque that integral cam shaft can transmit.The angle of the sub-cam 3 mediated also can be slightly a little bit smaller with the sub-cam of Selection radio 1,7, to reduce profile, valve opening and close time high-stress state time born by firmer sub-cam 1,7, can further improve reliability.

Above exemplary embodiment is only the explanation carried out a kind of more general configuration, as the pattern that it highly simplifies, the sleeve pipe 2,4,6 of the chute merging that has that can be belonged to three sub-cams 1,3,7 becomes a sleeve pipe, and by the angular adjustment of the chute on the inner convex platform of different sub-cams 1,3,7 and the original sleeve pipe 2,4,6 of correspondence thereof on cross section to different directions and on the sleeve pipe being again defined in merging, thus,. sub-cam 1,3,7 does not just need an extension, all succinct as sub-cam 3.

In a word, the present invention have employed a method cam being divided into three sub-cams, making three, to do angle differential, the angle relative to bent axle of cam entirety is made to produce the change of continuously adjustabe joint, by adjusting every angle of sub-cam and the angle of chute, cam can be made can to meet any requirement to valve-opening time, endurance and shut-in time, but be only limitted to the once unlatching of valve within an operation cycle of cylinder, but not repeatedly open.But the present invention is also not limited to change the angle of cam, group cam is independent when becoming an independent cam in order to drive a valve, also can be applicable to the adjustment that common single overhead cam shaft generator does valve overlap angle.

Above-mentioned describing is only used for explaining exemplary embodiments of the present invention, and it is not exclusive or the present invention is limited and concrete form disclosed in it.It will be understood by those skilled in the art that not departing from scope of the present invention, various change can be made and element wherein can be replaced with IF-AND-ONLY-IF element.In addition, a lot of amendment can be made and not depart from essential scope to make particular condition or material be applicable to purport of the present invention.Therefore, the invention is not restricted to as conceiving the specific embodiment realized disclosed in optimal mode of the present invention, but the present invention includes all mode of executions belonging to the scope of the invention.Without departing from the spirit and scope of the present invention, the present invention can implement in other modes beyond specific explanations and the mode illustrated.

Claims

1. can be used for a continuous variable geometry camshaft for full Variable Valve Time, each cam on camshaft is made up of several sub-cam; There is a corresponding sleeve pipe every sub-cam inside, and all sub-cams and sleeve pipe are all enclosed within a central shaft, and central shaft has and rotates and move axially two degrees of freedom, and each sleeve pipe and central shaft fix with a fixing pin and be integrated;

The feature of described sub-cam is also the numerical value of the crankshaft angles corresponding to sub-cam, meets the angle requirement that valve is opened ahead of time under internal-combustion engine minimum speed, and every sub-cam has contour flat-top;

The feature of described sub-cam is also respectively there is a boss in sub-cam, the chute of boss and each self-corresponding described sleeve pipe closely cooperates, the chute of sleeve pipe in axial direction reverses, shape and the chute of boss adapt, different sleeve pipes is different with angle with the torsional direction of boss with the chute on sub-cam, and sub-cam and sleeve pipe can slide along boss or chute direction;

The feature of described central shaft is also that there are spline tooth and hydraulic thrust dish in its one end, and the other end is subject to camshaft fixture and effect of contraction and can slides axially, and is subject to the promotion of hydraulic system, and band central shaft and described sleeve pipe do axial translational movement;

The assembling mode of described camshaft is the sub-cam of each cam of camshaft is rely on sub-cam and stretched sheathed tube mutually to extrude to be close together, and two ends fix whole cam shaft system by camshaft fixture and fixed cover and bolt.