US3380440A - Oil-damped valve-seating compensator - Google Patents

Description

April 68 c. THUESEN 3,380,440

OIL-DAMPED VALVE- SEATING COMPENSATOR Filed June 5, 1967 INVENTOR.

gV/EL c THUESE/V ATTORNEY United States Patent 3,380,440 OIL-DAMPED VALVE-SEATING COMPENSATOR Niel C. Thueseu, 6021 Compton Ave, Los Angeles, Calif. 90001 Filed June 5, 1967, Ser. No. 643,732 7 Claims. (Cl. 123-90) ABSTRACT OF THE DISCLOSURE In a poppet valve mechanism, means connecting a poppet valve and a tappet, the latter incorporating piston means for bypassing oil conducted to the interior of the tappet to provide oil-damped compensation to allow the poppet valve to properly seat under conditions in which the disc valve is warped out of its true flat shape due to an uneven heating of said disc valve.

BACKGROUND OF THE INVENTION Particularly in poppet valve mechanisms, as in U.S. Patent No. 3,211,138, in which the valves are reciprocated positively in both directions, as by complementary cam means, it is necessary to provide means effecting positive closing of the valves. Such means, both mechanical, are disclosed in the mentioned patent and also in US. Patent No. 3,183,901. The present oil-damping compensating means provides improvements over such mechanical devices for the important reasons that the same compensates, also, for warp due to unequal expansion of the seat-engaging discs of a poppet valve and reduces the damping effect by automatic increase of bypass of the oil according to the degree of valve warp.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description, which is based on the accompanying drawing. However, said drawing merely shows, and the following description merely describes, one embodiment of the present invention, which is given by way of illustration or example only.

SUMMARY OF THE INVENTION The oil-damped, valve-seating compensator S of the present invention is incorporated in poppet valve mechanism 6 ordinarily mounted on the cylinder block 7 of an internal combustion engine or the like, and having valve seats 8 for communicating, when open, the cylinder chambers 9 and their respective flow passages 10 which may be either intake or exhaust passages.

BRIEF DESCRIPTION OF THE DRAWING In the drawing, like reference characters designate similar parts in the several views.

FIG. 1 is a vertical sectional view of poppet valve mechanism and incorporating oil-damped, valve-seating compensator means according to the present invention.

FIG. 2 is an enlarged vertical sectional view of said compensator means.

FIG. 3 is a cross-sectional view taken on the plane of line 3-3 of FIG. 2, portions being successively broken away for clearer illustration.

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DESCRIPTION OF THE PREFERRED EMBODIMENT The poppet valve mechanism 6 is enclosed in a housing 15 that is mounted on the cylinder block 5, a cam shaft 16 extending longitudinally through said housing. For each cylinder 9 there is provided a poppet valve 17 which has a disc 18 that is adapted to control flow past the valve seat 8 and the connecting passage 10, whether of a charge of carbureted air to be fed to the cylinder for ignition therein, or of exhaust gases resulting from such ignition and exiting through said passage. The compensator 5, hereinafter more fully detaiied, is connected to the stem 19 of the valve 17 and is mounted in a tappet 20 on the lower end of a cage 21, the upper end of which is provided with a cam follower-provided yoke part 22 that is guided for vertical sliding movement in guides 23 provided on the inner sides of the housing 15. A set of rods 24 connects the portions 20 and 22 of the cage 21 and complementary or reciprocal cams 25 and 26 on the cam shaft 16 and operative in the space between said portions 20 and 22, effect positive reciprocative movement in both directions. The cam 26 is located to have operative contact with an arcuately curved surface 27 to move the tappet 20 in a valve-opening direction, and the cam 25 (actually two similar cams, one on each side of the cam 26) is located to have operative engagement with the followers 28 of the cage member 22 to move the tappet 20 in a valve-closing direction. The present compensator means 5, due to the fixed travel of the valve disc 18 under control of the cam 25, provides for oildamped seating of the valve disc 18, under the various conditions hereinbefore explained.

Said compensator 5 is shown as a cylinder 2? formed on the tappet 20 below the surface 27 which is on a top wall 30 which has an oil-bleeding orifice 31 therein. In this case, a recess 32 is formed in the inside of the wall 30. Adjacent its lower edge, said cylinder 29 is provided with an outer annular groove 33 with one or more ports 34 opening said groove to the inside of the cylinder. An oil line 35 terminates at one of two opposite faces 36 of the housing 15 and is in register with said groove 33 when the tappet is in valve-closing position, as in FIG. 1. The cylinder slidingly fits between said faces. Therefore, the inside of the cylinder will receive oil under pressure from said line.

An oil ring 37 is fitted into said cylinder and is held against downward displacement by a snap ring 38. A channel 39 in said ring receives oil passing inwardly through the ports 34, said oil then passing through a plurality of ports 40 into an annular well 41 interiorly of the channel 39. A check ring 42 fits within the oil ring 37 and is provided with an upper outwardly directed flange 43 A ring 44 fits in an outer groove in the check ring 42 and is provided with spring fingers 45 that bear against the bottom face of said oil ring, thereby biasing the flange 43 into fiow-stopping engagement with the upper face of the channel portion of the oil ring. Oil under pressure in the well can lift the check ring so the same may enter the annular space 46 above the flange 43, said flange 43 preventing or checking against return flow from the chamber 46- back to the well 41.

A hollow piston 47 is fitted in the check ring 42, the same extending upwardly above said ring and partly and freely into the recess 32 in the wall 30; a flange 48 on said piston above the space 46 extends into clearance relationship, as at 49, with the cylinder 29. At its lower end, said piston is provided with an internal hub 50 which is grooved for an O-ring 51 that has sealing engagement with the inner surface of the check ring 42. An axial bore 52 extends through said hub.

An oil bleeder ring 53 is slidingly fitted on the piston 47, the same having a flange 54 spaced above the flange 49 and also in clearance relationship, at 55, with the cylinder 29. An annular space 56 is enclosed between the flange 48 of the piston 47 and the flange 54 of the oil bleeder ring 53, and a third annular space 56a is enclosed between the latter flange and the wall 30 of cylinder 39. The top edge of the oil bleeder ring is provided with slotted ports 57 which communicate said space 56 with the recess 32 in wall 30 when said ring is in its topmost position as limited by said wall.

The hub 50 serves as a mounting portion for a fitting 58 having a flange 59 engaged with the under face of said hub, a portion extending freely through the bore 52 of said hub, and an axial thread 60; a flanged nut 61 connects with said thread and is engaged with the upper face of the hub, thereby connecting said fitting to the hub 50 and the piston 47 on which the hub is provided. The threaded upper end 62 of the valve stem 19 is locked in the thread 60 by endwise engagement with the nut 61.

While the present mechanism is shown vertically, the same may be disposed at an angle, as in V-type engines.

OPERATION A constant supply of oil, under pressure from the engine, is provided in the line 35. When the valve 17 closes the valve seat 8, as in FIG. 1, such oil, the pressure of which may vary but may be in the area of sixty-five p.s.i., will enter the oil ring 37. When the valve is open or is moving, in either direction, between closed and fully opened positions, the outer face of the cylinder 29 arrests such flow. In any case, during the normal reciprocations of the valve 17 under control of the poppet valve mechanism 6, the oil from line 35 will pass from the well 41 to the space 46, bypassing between the ring 37 and the check flange 43, then bleed through clearance space 49 into space 56, then through clearance space 55 into space 56 and through bleeder slots 57, recess 32 and orifice 31 into the interior of the housing for lubrication of the mechanism 6. Return flow from said housing interior to the oil source is effected in a normal manner.

It will be seen that the slow movement or bleeding of oil through the above-described system of spaces, small clearances and bleed holes, causes a dash pot or damping action which allows the cage 21 and tappet to have positive movement imparted by the complementary earns and 26 while allowing the valve 18 to close softly under the compensating flow of oil past the check flange 43, thence through the successive spaces 46, 56 and 56a and thence outwardly into the interior of the housing 15 through the recess 32 and orifice 31. Since the clearance spaces 49 and 55 and the slotted ports 57 are small, the non-compressible oil in said spaces will allow the above movement of the oil, thereby damping the connection between the cage and tappet on the one hand, and the valve 17 on the other.

Under abnormal conditions which may prevent the proper closing of the valve 17 as, for instance, carbon particles in the exhaust from cylinder 9, or impurities in the charge of carbureted fuel being supplied through passage 19, return of the valve 17 is prevented from being fully effected, and full valve closing does not result. Such conditions may occur only from time to time. When an engine is operating over long periods of time and also under load, the valve disc 18, whether of an intake or an exhaust valve, is subjected on one side to the extremely high heat generated in the combustion chamber 9 of the engine cylinder, and on the opposite side to a much lower temperature, as can readily be understood. Such heat differential is substantially constant, due to the high speeds of internal combustion engines, especially under load.

The warping of the valve disc 18 under the expansion that is caused by such differential temperatures, may vary from a few thousandths of an inch to several thousandths. Moreover, such expansion due to its being on the face of the disc that is open to the combustion chamber 9, causes the disc to assume a dished form in which the seat-contacting face of the disc 18 makes contact with the valve seat 8 before the valve can move its full amount.

The present oil-damped compensating means automatically reacts to such a condition. At the instant that the face 18a seats, the valve stem 19, due to its direct connection with the piston 47, stops its upward movement. Since the earns 25 continue to carry out their function of raising the cage, the oil in space 46 is placed under compression between the ring 37 and the flange 48, causing increase of bypass of oil from said space 46 to the space 56. The latter space then, being also under compression, causes increase of oil bypass from space 56 to space 56a. Thus, the damping action is varied to the extent that permits full operative movement of the tappet 20 when the valve stem, for whatever reason, is prevented from effecting its full movement.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention. the construction is, of course, subject to modification without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a mechanism having complementary cams for reciprocating a tappet positively in both directions, and having a valve movable between open position and valve seat-engaging, closed position to control flow between a combustion cylinder and a passage for carbureted fuel into, or gases of combustion out of, said cylinder,

(a) a cylinder formed on and extending downwardly from said tappet,

(b) piston means connected to the valve and disposed within the cylinder,

(c) a line to conduct oil to the interior of the cylinder and around the piston when the valve is in closed position, and

((1) means partly carried by the cylinder and partly by the piston cooperating to form oil-containing spaces for said oil with oil-bypassing clearances between said spaces and constituting damping compensator means and acting to allow the tappet and cylinder to continue their operative movement in the valve-closing direction under the positive control of the complementary cams after the movement of the valve and the piston means has stopped due to seating of the valve seat.

2. In a mechanism according to claim 1, a housing enclosing the complementary cams and tappet, and the cylinder having a top wall with an orifice therein for discharging bypassed oil into said housing for lubrication of the mechanism within the housing.

3. In a mechanism according to claim 1 and in which the piston means is provided with a portion annularly spaced from the cylinder,

(a) means comprising one ring carried on the inside of the cylinder, and a check ring slidingly engaged with the outside of said piston portion, and

(b) a flange on the latter ring resiliently biased to engage said one ring to check against return flow from the oil-containing spaces in a direction toward the oil line.

4. In a mechanism according to claim 3, said one ring being provided with an oil well receptive of oil from said oil line, the pressure in said line being manifest in said well to raise the check ring and its flange against the mentioned resilient bias.

5 6 5. In a mechanism according to claim 4, said bias References Cited being applied by aspring ring engaged with both the UNITED STATES PATENTS check ring and said one nng, the ring busing the two n'ngs in opposite directions. 1,074,121 9/1913 Kelly 123-90 6. In a mechanism according to claim 3, an annular 5 1,232,35 7/1917 MacVicar 123-90 flange on the piston and an oil bleeder ring slidingly 1,516,310 11/ 1924 y n 1 -90 mounted on the piston, the latter ring and said flange 2,878,796 3/1959 Mannerstedt 12390 having oil-bypassing engagement with the inner face 3,183,901 5/1965 Thuesen 123-90 of the cylinder 3,185,139 5/1965 Thuesen 123-90 7. In a mechanism according to claim 6, bleeder 10 3211138 10/1965 Colhns et 123 90 ports in the upper end .of the oil bleeder ring. AL LAWRENCE SMITH, Primary Examiner

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