Small size universal petrol engine valve swing arm directional working mechanism
Technical field
The present invention relates to a kind of petrol engine accessory, especially a kind of small size universal petrol engine valve swing arm directional working mechanism.
Prior art
At present, the valve rocker operation mechanism of domestic use on small utility gasoline engine is that Japanese honda company produces.On structure, this mechanism by the valve clearance of 1. hypomere band nut adjust screw rod, 2. the upper end is a nut, the lower end be the cylindrical adjustment nut body of spherical shape, 3. the bottom for groove, both wings by the valve rocker of recess or convex closure, 4. locking nut etc. is formed.Wherein adjusting screw rod passes valve rocker successively, adjusts nut body, locking nut.The sphere end of adjusting nut body inserts in the groove of valve rocker, and the bottom surface of valve rocker contacts with nut on the adjustment screw rod hypomere.Because designed valve rocker bottom groove is spherical shape, the columniform adjustment nut body bottom of inserting in the valve rocker bottom groove also is a spherical shape, therefore, can do spherical motion around adjusting the nut body bottom during valve rocker work, and its degrees of freedom is big.Because of valve rocker at work, both can move axially, can do circumferentially swing around adjusting nut body bottom sphere again, so it can not guarantee that valve rocker does orientation movement according to need of work.When valve rocker occurs when adjusting the circumferential swing of nut body bottom sphere do, the valve actuating push rod that is positioned at the valve rocker below can break away from the sphere recess of valve rocker one wing, the convex closure of another wing of valve rocker can break away from the petrol engine valve thereupon, causes petrol engine to quit work.In order to prevent that valve rocker is because of circumferentially swing is excessive around adjusting nut body bottom sphere, and the phenomenon that the valve actuating push rod that occurs is deviate from from the valve rocker recess, Japanese honda company has added valve actuating push rod support (this erects the effect of valve actuating push rod guide and limit), and the swing of rocking arm is controlled in attempt by the swing of pusher bar support control valve actuating push rod.Yet, circumferentially swing can occur because of former carrying on as before such as vibrations during valve rocker work, will inevitably cause valve actuating push rod to rub with pusher bar support, form the switching time of drag effects valve with the rocking arm swing, cause the power instability of motor, also can produce friction noise simultaneously.And valve actuating push rod and pusher bar support rub for a long time, also pusher bar support can be worn and torn, when pusher bar support may wear to a certain degree, valve actuating push rod is with regard to the swing of uncontrollable rocking arm, and valve actuating push rod still can be deviate from from the rocking arm recess, causes engine operation to stop.
Summary of the invention
Order of the present invention provides a kind of small size universal petrol engine valve swing arm directional working mechanism, and solving the valve rocker and the cylindrical adjustment nut body that exist in the prior art can circumferentially swing around adjusting screw rod, influences the problem of engine power; Solve apneustic pusher bar support simultaneously, valve actuating push rod will be deviate from valve rocker sphere recess, influences the switching time of valve, and valve actuating push rod and support wear and tear because of friction and produce the problem of noise.
The object of the present invention is achieved like this: a kind of small size universal petrol engine valve swing arm directional working mechanism, adjusting screw rod passes the valve rocker that recess or convex closure are arranged for groove, both wings at the bottom, the bottom surface of valve rocker contacts with the adjustment nut of adjusting screw rod hypomere, upper end at adjusting screw rod is equipped with locking nut, its main points are: A. is equipped with the cuboid guide block at the adjusting screw rod middle part, insert in the groove of valve rocker the bottom of this guide block, is set with the valve clearance and adjusts nut between guide block and locking nut; The bottom of B. described guide block and valve rocker is an arc surface, the both sides of arc surface are the plane, the arc surface of guide block inserts in the arc surface groove of valve rocker Spielpassung with it, and arc surface two side planes of valve rocker groove lean against the outside of guide block arc surface two side planes; Described guide block arc surface two side planes are meant and the frontal plane and the back plane of guide block bottom arc surface vertical connection that the bottom line on this two plane is the outer camber line of arc surface.C. be provided with position structure on the top of adjusting screw rod; D. adjust the hypomere that nut thread is connected adjusting screw rod.
The present invention substitutes original bottom cylindrical adjustment nut body spherical in shape with cuboid guide block and valve clearance adjusting nut, not only has the valve clearance of adjusting function, and the guide block that is provided with between valve rocker and the clearance adjusting nut can circumferentially not rotated guide block around adjusting screw rod by circumferentially spacing on adjusting screw rod.And the guide block bottom design become the circular arc working surface that matches with the valve rocker groove, valve rocker groove arc surface two side planes are simultaneously near the two side plane work of valve guide block arc surface, the degrees of freedom that valve rocker is circumferentially swung is restricted, valve rocker can circumferentially not swung around adjusting screw rod, can only do orientation movement along the arc surface of guide block lower end, valve actuating push rod just can not break away from from the recess of valve rocker one wing, thereby cancelled the pusher bar support of original structure, fretting wear and noise between pusher bar support and the valve actuating push rod have been eliminated, guarantee engine power, reached purpose of the present invention.
Adopt the advantage of such scheme to be: after cancellation valve actuating push rod support, can guarantee effectively that valve rocker does directional swing (making the inlet and outlet door by the punctual switching of port timing requirements) by its characteristics of motion, petrol engine power is protected.Simultaneously, noise and the wearing and tearing that produce because of friction between valve actuating push rod and the support have been eliminated.Reliable operation is worked well through the installation test run in this mechanism.
Description of drawings
Fig. 1 is a plan view of the present invention;
Fig. 2 is the plan view of Fig. 1;
Fig. 3 is the plan view of valve rocker 3 among Fig. 1;
Fig. 4 is the structural drawing of adjusting screw rod 1 among Fig. 1;
Fig. 5 is that the present invention is installed in the user mode figure in the petrol engine.
Embodiment
Please see Figure 1, Fig. 2, the present invention is mainly by adjusting screw rod 1, adjust nut 2, valve rocker 3, guide block 4, nut 5 is adjusted in the valve clearance, locking nut 6, feather key 7 is formed, be groove bottom wherein adjusting screw rod 1 passes, both wings have the valve rocker 3 of recess or convex closure, the bottom surface of valve rocker 3 contacts with the adjustment nut 2 of adjusting screw rod 1 hypomere, in the upper end of adjusting screw rod 1 locking nut 6 is installed, invention main points of the present invention are: A. is equipped with cuboid guide block 4 at adjusting screw rod 1 middle part, insert in the groove of valve rocker 3 bottom of this guide block 4, is set with the valve clearance and adjusts nut 5 between guide block 4 and locking nut 6; The bottom of B. described guide block 4 and valve rocker 3 is an arc surface, the both sides of arc surface are the plane, the arc surface of guide block 4 inserts in the arc surface groove of valve rocker 3 Spielpassung with it, and arc surface two side planes of valve rocker 3 grooves lean against the outside of guide block 4 arc surfaces two side planes; Described guide block arc surface two side planes are meant and the frontal plane and the back plane of guide block bottom arc surface vertical connection that the bottom line on this two plane is the outer camber line (as a plane among Fig. 2 and b plane) of arc surface.C. be provided with position structure on the top of adjusting screw rod 1; D. adjust the hypomere that nut 2 is threaded in adjusting screw rod 1.
As shown in Figure 1: adjusting screw rod 1 of the present invention is divided into the upper, middle and lower section, and wherein epimere and hypomere are screw rod, and the stage casing is smooth round column structure; Be provided with feather key 7 at cylindrical section; Described guide block 4 through-hole walls have guiding groove, and this guiding groove cooperates installation with feather key 7 on the adjusting screw rod 1.Feather key 7 has positioning action, makes feather key 7 consistent with the operative orientation of rocking arm.Guide block 4 can only be endwisely slipped along screw rod 1 by circumferentially spacing on screw rod 1 like this.
Can further see from Fig. 1: the lower end that nut 5 is adjusted in valve clearance of the present invention is the internal thread cylinder, the upper end is orthohexagonal nut, the cylinder bottom plane that nut 5 lower ends are adjusted in the valve clearance contacts with guide pad 4, thus the axial position that restriction guide block 4 makes progress on adjusting screw rod 1.Can avoid simultaneously the valve clearance to adjust nut 5 lower ends and valve rocker 3 generation interference.
As Fig. 1, shown in Figure 3: the bottom of valve rocker 3 grooves is an arc surface, and the bottom has flat hole, is convenient to adjust screw rod 1 and passes, and can laterally slide in flat hole.
As shown in Figure 4: the position structure on described adjusting screw rod 1 top is to be provided with opening slot 15 in screw tip, location when being convenient to install.Hexagonal or outer-hexagonal is cubic or structure such as flat side in also the position structure on the top of adjusting screw rod 1 can being designed to.
Can further understand the present invention from Fig. 5 and be installed in working condition on the petrol engine: earlier adjusting screw rod 1 hypomere is threaded on the cylinder head 9 of petrol engine, the opening slot according on the valve Height Adjustment screw rod 1 makes its accurate positioning, tightens up with adjustment nut 2 again.Then, valve rocker 3 and guide block 4 are enclosed within the stage casing of adjusting screw rod 1 successively, the epimere that nut 5 is threaded in screw rod 1 is adjusted in the valve clearance.Adjust the valve clearance and adjust nut 5, make valve rocker 3 be fit to the requirement of distribution gap again along the arc surface flexible motion of guide block 4, last, with valve clearance locking nut 6 locking and positioning.Since at the bottom of the groove ends of valve rocker 3 with adjusting screw rod 1 hypomere on adjustment nut 2 approaching, the circular arc at the bottom of the groove ends of valve rocker 3 can be shaken above the plane of adjusting nut 2 flexibly.When the external diameter of adjusting nut 2 during, adjust nut 2 and also limited valve rocker 3 downward axial position on adjusting screw rod 1 greater than the minor axis diameter of valve rocker 3.Because guide block 4 bottoms are arc surface, and insert in the groove of rocking arm 3 arc surface Spielpassung with groove, therefore, valve rocker 3 can only be moved along the arc surface of guide block 4.The arc surface of guide block 4 is provided with through hole and connects guide block 4 upper and lower end, the hole wall of its through hole is provided with a keyway, the feather key 7 on the adjusting screw rod 1 and the keyway Spielpassung of guide block 4 hole walls make guide block 4 by circumferentially spacing on adjusting screw rod 1, can only endwisely slip along screw rod 1.Because guide block 4 is by circumferentially spacing on screw rod 1, and the arc surface of guide block 4 inserts in the arc surface groove of rocking arm 3 Spielpassung with it, the groove arc surface both sides that cause valve rocker 3 are simultaneously near the two side plane work of guide block 4 arc surfaces, and the valve rocker 3 circumferentially degrees of freedom of swing is restricted.Because of the plane at the bottom of the cylinder of adjustment nut 5 bottoms, valve clearance contacts with guide block 4, so limited the axial position that guide block 4 makes progress on screw rod 1.Valve clearance locking nut 6 is installed in screw rod 1 epimere, and nut 5 locking and positioning are adjusted in the valve clearance.The present invention is after installing on the cylinder head, the sphere of petrol engine valve actuating push rod 8 upper ends withstands in the sphere recess of valve rocker 3 one ends, the sphere of valve actuating push rod 8 lower ends is against in the sphere recess of petrol engine tappet 10 upper ends, and the lower end of tappet 10 contacts with the curved surface periphery of camshaft 11; The sphere convex closure of the other end of valve rocker 3 is pressed on the petrol engine valve 14.During petrol engine work, crankshaft gear 13 drives camshaft 11 by camshaft gear wheel 12 and rotates, and the curved surface periphery of camshaft 11 drives valve actuating push rod 8 by tappet 10 and moves up and down, thereby makes valve rocker 3 do regular motion by the port timing requirement.When valve actuating push rod 8 upwards promotes, valve rocker 3 the other ends calm the anger downwards the door 14 afterbodys, open valve; When valve actuating push rod 8 moved down, valve rocker 3 the other ends were tilted upward, and valve 14 is closed under the valve spring effect.The present invention is owing to adopted the bottom to be the cuboid guide block 4 of arc surface, effectively avoided valve rocker 3 and guide block 4 around adjusting screw rod 1 circumferential movement, the original degrees of freedom of rocking arm is restricted, and guarantee that valve actuating push rod 8 can not come off because of vibrations from the sphere recess of valve rocker 3, thereby guarantee that petrol engine inlet and outlet door opens and closes on request on time, so the power stability of petrol engine is reliable.