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US3712277A - Valve actuating arrangement for internal combustion engines - Google Patents

Valve actuating arrangement for internal combustion engines Download PDF

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Publication number
US3712277A
US3712277A US00124776A US3712277DA US3712277A US 3712277 A US3712277 A US 3712277A US 00124776 A US00124776 A US 00124776A US 3712277D A US3712277D A US 3712277DA US 3712277 A US3712277 A US 3712277A
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US
United States
Prior art keywords
tappet
valves
valve
rim
cam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00124776A
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English (en)
Inventor
S Piatti
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Individual
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Individual
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Filing date
Publication date
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Publication of US3712277A publication Critical patent/US3712277A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
    • F02F1/4214—Shape or arrangement of intake or exhaust channels in cylinder heads specially adapted for four or more valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F2001/244—Arrangement of valve stems in cylinder heads
    • F02F2001/247—Arrangement of valve stems in cylinder heads the valve stems being orientated in parallel with the cylinder axis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/21—Elements
    • Y10T74/2101—Cams
    • Y10T74/2107—Follower

Definitions

  • This invention relates to a valve actuating arrangement for an internal combustion engine having plural parallel-operating poppet valves associated with the or each combustion chamber of the cylinder head of the engine, wherein said valves are actuated by a common cam via a common tappet, cooperating with, and interposed between, the cam and the valves.
  • the tappet is tubular and has a transverse wall closing one end, which is engaged by a cam. The rim, at the open end of the tubular member, engages the parallel valves.
  • the present invention relates to internal combustion engines of which the or each combustion chamber is fitted with plural inlet valves and/or plural exhaust valves.
  • valves which fulfill the same function, for example, the plural inlet valves are actuated simultaneously and in parallel, and are submitted to the same law of movement governed by the rotation of cams.
  • Each valve is opened by the opening side of the profile of the cam, and is returned to its closed position by means of a valve spring attached to the valve stem.
  • a cylindrical slidably mounted tappet of generally inverted cup shape, which is coaxial with, and surrounds the valve stem, and engages the end thereof.
  • the distance between the valve axes restricts the maximum diameter of the tappets, which, in turn, restricts the maximum valve lift for a given type of cam profile.
  • a valve actuating arrangement for an internal combustion engine having plural paralleloperating poppet valves associated with a combustion chamber thereof, wherein said valves are actuable by a common cam via a common tappet.
  • the invention also consists in an internal combustion engine, particularly an overhead valve engine, provided with one or more valve actuating arrangements as above described.
  • FIGURE is a fragmentary section of part of a cylinder head of a multicylinder overhead valve, overhead camshaft, internal combustion engine employing a valve actuating arrangement embodying the present invention.
  • the cylinder head 1 is designed to accommodate two parallel-operating poppet inlet valves 2 per combustion chamber. These valves are mounted with their axes parallel and spaced apart by a distance determined by the diameter of the valve heads. Each valve is normally urged towards its closed position shown in the drawing by a coil spring 3 which is maintained in a compressed state between the cylinder head 1 and a valve-spring retaining washer 4.
  • the washer 4 is secured to the valve stem adjacent the upper end thereof by segments 5 of an axially split, frusto-conical cotter, which are located around the valve stem in a frusto-conical cavity 6 in the washer 4.
  • each valve 2 Mounted within the cotter of each valve 2 is a replaceable cylindrical spacer 7 of predetermined length which engages the upper end of the valve stem the valve clearance being adjusted to the required value by selecting and fitting a spacer 7 of the required length.
  • the two valves 2 are actuated simultaneously and in parallel by the profile of the same cam 8 carried by a camshaft 9.
  • a common tappet l0 slidably mounted in a member 11 secured to, or integral with, the cylinder head 1.
  • This tappet 10 which is formed from a suitable metal, is cylindrical and tubular in form, and is closed at its upper end, thus resembling an inverted cup.
  • the cam 8 is co-operable with the upper face of the closed end of the tappet, whilst the spacers 7 of both valves 2 are co-operable with a thickened and accurately machined rim 12 extending around the lower open end of the tappet 10.
  • valve actuating arrangement described possess a number of advantages over prior arrangements in which individual inverted cup-shaped tappets are fitted over the end of the stern of each parallel-operating valve, with the end of the stern co-operating with the underside of the closed end of the tappet.
  • the maximum diameter of the tappet, and therefore the maximum valve lift for a given cam profile is not restricted, to the same degree, by the spacing between the valve axes.
  • the valve spring and its retaining washer do not have to be dimensioned to fit within the tappet.
  • valve clearances may be readily effected.
  • spacers 7 are employed, these may bereadily removed and replaced by spacers of different predetermined axial lengths by simply compressing the valve springs 3, without the necessity of removing the tappet and/or camshaft. This advantage will also arise if other types of adjustments are employed.
  • the weight of the arrangement may be reduced, and since only one cam is employed to actuate all the parallel-operating valves in each combustion chamber, it is possible to employ a camshaft having the same number of cams, with different cylinder heads, to actuate single, or plural parallel-operating inlet and/or exhaust valves.
  • the tappet may be non-cylindrical and/or may be perforated, relieved or otherwise formed to reduce its weight.
  • the rim 12 of the tappet need not be thickened, or may, in addition, or as an alternative, to thickening the rims to extend the rim radially inwards as shown, the rim may be thickened to extend it in a radially outward direction.
  • the or each combustion chamber may be fitted with plural parallel-operating exhaust valves, actuated in the same manner as the inlet valves 2, instead of, or in addition to plural inlet valves.
  • the plural parallel-operating valves which fulfil one function, and which may be more than two in number, may be employed with a single valve which fulfills the other function.
  • camshaft may actuate the tappet via a rocker arm
  • each of two or more parallel-operating valves per cylinder may be actuated by an individual pushrod, and a tappet, common to all the push-rods of these parallel-operating valves, and similar to the tappet illustrated, may be interposed between these push-rods and a common cam profile.
  • valve clearances are adjusted by cylindrical spacers 7 other means for adjusting the clearance may be employed.
  • the valve actuating arrangement may be employed in single or multi-cylinder two stroke or four stroke internal combustion engines.
  • the arrangement may be employed in combination with compression coil springs which surround the valve stems as shown in the drawing, or with springs which do not surround the valve stems, such as springs of the hair-pin or torsion bar type.
  • the springs may be anchored by anchoring means other than cotters as shown in the drawing.
  • a cylinder head for an internal combustion engine said cylinder head having at least one combustion chamber, a pair of parallel-operating poppet valves operatively associated with said combustion chamber, and having substantially parallel longitudinal axes, a cylindrical, tubular tappet, common to both said valves, means cooperating with the external cylindrical surface of the tappet to mount said tappet for sliding reciprocating movement relative to said head in a direction substantially parallel to the longitudinal axes of the valves, with the. longitudinal axis of the tappet substantially parallel to, and equi-spaced. from, both valve axes, said tappet having a lower open end which defines an annular valve-engaging rim of a diameter approximating the inter-axia spacing of the valve axes,
  • a cylinder head asclaimed in claim 4 including a valve clearance-adjusting spacer interposed between each valve stem and said rim, and interchangably secured to the valve stem.
  • a valve actuating arrangement for an internal combustion engine having plural parallel-operating poppetv valves associated. with the combustion chamber thereof, said valves being actuable by a common cam via a common tappet, said tappet including a crossmember extending in a direction generally transverse to the longitudinal axes of the valves and a longitudinal member connected to the cross-member and having portions disposed generally coincident with extensions of the valve axes, the cross-member being cooperable with the cam, and the ends of the generally. coincident portions of the longitudinal member remote from the cross-member being cooperable with the valves, the longitudinal member and a mounting member being provided with cooperating bearing surfaces by means of which the longitudinal member is mounted for sliding the movement relative to the mounting member,

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Valve Device For Special Equipments (AREA)
US00124776A 1970-03-24 1971-03-16 Valve actuating arrangement for internal combustion engines Expired - Lifetime US3712277A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2233870 1970-03-24

Publications (1)

Publication Number Publication Date
US3712277A true US3712277A (en) 1973-01-23

Family

ID=11194874

Family Applications (1)

Application Number Title Priority Date Filing Date
US00124776A Expired - Lifetime US3712277A (en) 1970-03-24 1971-03-16 Valve actuating arrangement for internal combustion engines

Country Status (4)

Country Link
US (1) US3712277A (de)
DE (1) DE2114477A1 (de)
FR (1) FR2085091A5 (de)
GB (1) GB1346822A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4805567A (en) * 1986-07-17 1989-02-21 General Motors Corporation Valve mechanism for at least two simultaneously actuable valves
US5184580A (en) * 1990-10-30 1993-02-09 Ferrari S.P.A. Timing system for an internal combustion engine
US6474281B1 (en) * 1998-10-30 2002-11-05 Christopher P. Walters Valve control mechanism

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3624107A1 (de) * 1986-07-17 1988-01-28 Opel Adam Ag Brennkraftmaschine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1172358A (en) * 1912-05-27 1916-02-22 Fried Krupp Germaniawerft Ag Valve-gear.
US1291264A (en) * 1916-09-16 1919-01-14 Fred I Tone Valve mechanism for internal-combustion engines.
US2309291A (en) * 1941-10-10 1943-01-26 American Locomotive Co Internal combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1172358A (en) * 1912-05-27 1916-02-22 Fried Krupp Germaniawerft Ag Valve-gear.
US1291264A (en) * 1916-09-16 1919-01-14 Fred I Tone Valve mechanism for internal-combustion engines.
US2309291A (en) * 1941-10-10 1943-01-26 American Locomotive Co Internal combustion engine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4805567A (en) * 1986-07-17 1989-02-21 General Motors Corporation Valve mechanism for at least two simultaneously actuable valves
US5184580A (en) * 1990-10-30 1993-02-09 Ferrari S.P.A. Timing system for an internal combustion engine
US6474281B1 (en) * 1998-10-30 2002-11-05 Christopher P. Walters Valve control mechanism

Also Published As

Publication number Publication date
GB1346822A (en) 1974-02-13
DE2114477A1 (de) 1971-10-14
FR2085091A5 (de) 1971-12-17

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