EP0080175A1 - Ventielantrieb einer Brennkraftmaschine mit obenliegender Nockenwelle und rotierendem Stössel zwischen Hebel und Nocke - Google Patents

Ventielantrieb einer Brennkraftmaschine mit obenliegender Nockenwelle und rotierendem Stössel zwischen Hebel und Nocke Download PDF

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Publication number
EP0080175A1
EP0080175A1 EP82110673A EP82110673A EP0080175A1 EP 0080175 A1 EP0080175 A1 EP 0080175A1 EP 82110673 A EP82110673 A EP 82110673A EP 82110673 A EP82110673 A EP 82110673A EP 0080175 A1 EP0080175 A1 EP 0080175A1
Authority
EP
European Patent Office
Prior art keywords
cam
tappet
rocker arm
oil passage
valve train
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.)
Withdrawn
Application number
EP82110673A
Other languages
English (en)
French (fr)
Inventor
Yoshimasa Hayashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Publication of EP0080175A1 publication Critical patent/EP0080175A1/de
Withdrawn legal-status Critical Current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
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/14—Tappets; Push rods
    • F01L1/16—Silencing impact; Reducing wear

Definitions

  • the present invention relates in general to valve trains of overhead camshaft engines and of the kind wherein a rocker is incorporated to transfer motion from a cam to a valve stem, and more particularly to the improvement in such valve trains for reducing the frictional sound and friction loss arising from the contact between the rocker and the cam.
  • FIGs. 1 and 2 show a prior art rocker-arm type valve train which comprises a cam 10 rotatable together with an overhead camshaft 12, a poppet valve 14 having a valve stem 14a, and a rocker arm 16 rotatable on a rocker shaft 18.
  • the rocker arm 16 has at an end 16a thereof a cam follower 20 having a part-cylindrical cam contacting surface 20a and at the opposite end 16b thereof a valve clearance adjuster 22 positioned to contact the end of the valve stem 14a for adjusting the clearance in the valve train.
  • the cam follower 20 is so made as to have a good resistance to wear and brazed or otherwise secured to the rocker arm 16.
  • the prior art valve train structured as above is encountered by a drawback in that a relatively large frictional sound and friction loss arise from the contact between the rocker arm 16 and the cam 10 since the cam contacting surface 20a and the cam surface 10a have to slide relative to each other under the bias of a valve spring 24.
  • the large friction loss not only by itself deteriorates the operation of the valve train and therefore the performance of the engine on which the valve train is mounted but also accelerates the wear of the cam 10 and the cam follower 20 to further deteriorate the same.
  • a valve train which comprises a valve stem, a valve operating cam, a rocker arm operatively engaged with the valve stem and the cam for transferring motion from the cam to the valve stem and having at a part where it is operatively engaged with the cam a hole, a rotary tappet rotatable about an axis thereof in the hole and axially supported on the rocker arm, the tappet having a cam contacting surface domed to follow the cam surface of the cam, and the cam surface being
  • a valve train is of a rocker-arm type for use in an overhead camshaft engine and comprises a rocker arm 26 rotatable on a rocker shaft 28 and having at an end 26a thereof a rotary cam follower or tappet 30 cooperating with a cam 32 rotatable together with a camshaft 34 and at the opposite end 26b thereof a valve clearance adjuster 22.
  • the tappet 30 is formed from concentric or coaxial disk and stem portions 36 and 38 and rotatably mounted at the stem portion 38 in a hole 40 provided to the end 26a of the rocker arm 26.
  • the disk portion 36 is located at the outer end of the stem portion 38 and has a bottom 36a whose outer surface is domed to follow the cam surface 32a and a top 36b formed with an annular projection 36c contacting the rocker arm 26 at a wall portion 26c thereof around the hole 40.
  • the mating surfaces of the rocker arm wall portion 26c and the annular projection 36c of the tappet disk portion 36 are finished smooth and furthermore adapted to be sufficiently lubricated as will be described hereinafter.
  • the cam surface 32a is slanted (by an angle ranging from about 1 to 5° or so) with respect to the axis of the camshaft 34 so that the cam 32 is brought into contact with the tappet 30 at a point thereon offset from the axis of the tappet 30. That is, while the outer surface of the domed bottom 36a constitutes part of a sphere whose center coincides with the axis of the tappet 30, the point of contact between the tappet 30 and the cam 32 does not coincides with the axis of the tappet 30 and spaced away from same in the axial direction of the camshaft 34. In the meantime, the axes of the camshaft 32 and the rocker shaft 28 are arranged substantially parallel to each other, and the rocker arm 26 rocks along a plane traversing the axes of the camshaft 32 and the rocker shaft 28, as is conventional.
  • the rocker shaft 28 is formed with an oil passage 28a in communication with a source of oil under pressure such as an engine oil pump.
  • the rocker arm 26 is also formed with an oil passage 26d providing communication between the oil passage 28a and the hole 40 to supply lubrication oil to the mating surfaces of the rocker arm wall portion 26c and the annular projection 36c of the tappet disk portion 36.
  • the rocker arm 26 is further formed with an oil passage 26e in the form of an extension of the oil passage 26d, which passage 26e opens adjacent the top 36b of the tappet disk portion 36 to lubricate the cam surface 32a and the bottom 36a of the tappet disk portion 36 as well as to further provide the mating surfaces in question with lubrication oil.
  • the rotation of the cam 32 causes the tappet 30 to move upwardly or downwardly together with the rocker arm end 26a and at the same time causes the tappet 30 to rotate about the axis thereof. That is, differing from the prior art valve train, the tappet 30 is successively brought into contact at different portions thereof with the cam 32 in response to the rotation of the cam 32.
  • the valve train is thus adapted to effect a rolling contact between the tappet 30 and the cam 32, considerably reducing the frictional sound and friction loss arising from the contact between the tappet 30 and the cam 32.
  • the mating surfaces of the rocker arm wall portion 26c and the annular projection 36c of the tappet disk portion 36 are finished smooth and sufficiently lubricated, making it possible to effectively prevent the frictional sound and friction loss arising from the contact between the tappet 30 and the rocker arm 26.
  • the base circle of the cam 32 may have a cylindrical cam surface to produce substantially the same effect as one having an entirely slanted cam surface as having described above.
  • Fig. 6 shows a modification of this invention wherein a steel ball 42 is utilized to further reduce the friction between the tappet 30' and the rocker arm 26.
  • the steel ball 42 is inserted into the hole 40 to interpose between the closed end of the hole 40 and the inner end of the tappet stem portion 38' so that a small gap is formed between the tappet disk portion 36' and the rocker arm 26. That is, the tappet 30' is given a flat top 36'b and adapted not to contact at the top 36'b with the rocker arm 26 but to rotate on the steel ball 42.
  • This structure makes it possible to further effectively prevent the frictional sound and friction loss arising from the contact between the tappet 30 and the rocker arm 26.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
EP82110673A 1981-11-24 1982-11-18 Ventielantrieb einer Brennkraftmaschine mit obenliegender Nockenwelle und rotierendem Stössel zwischen Hebel und Nocke Withdrawn EP0080175A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP187984/81 1981-11-24
JP18798481A JPS6059407B2 (ja) 1981-11-24 1981-11-24 内燃機関の動弁装置

Publications (1)

Publication Number Publication Date
EP0080175A1 true EP0080175A1 (de) 1983-06-01

Family

ID=16215576

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82110673A Withdrawn EP0080175A1 (de) 1981-11-24 1982-11-18 Ventielantrieb einer Brennkraftmaschine mit obenliegender Nockenwelle und rotierendem Stössel zwischen Hebel und Nocke

Country Status (2)

Country Link
EP (1) EP0080175A1 (de)
JP (1) JPS6059407B2 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2550273A1 (fr) * 1983-08-05 1985-02-08 Peugeot Dispositif d'actionnement d'une soupape, pour distribution variable d'un moteur a combustion interne
EP0376445A1 (de) * 1988-12-27 1990-07-04 Ford Motor Company Limited Ventilstösselanordnung für eine Brennkraftmaschine
GB2242952A (en) * 1990-04-11 1991-10-16 Gen Motors Corp Valve train with lash/compliance compensation
US5809842A (en) * 1995-06-26 1998-09-22 Sumitomo Electric Industries, Ltd. Ceramic sliding component
US20110209679A1 (en) * 2010-02-26 2011-09-01 Honda Motor Co., Ltd. Rocker arm structure

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BR112018067795B1 (pt) 2016-03-04 2022-12-27 Nobuto Washio Métodos de produção de um produto de solução de reidratação oral pronta para beber

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1496131A (en) * 1924-01-05 1924-06-03 Rich Steel Products Company Tappet
FR752332A (fr) * 1932-04-04 1933-09-20 Perfectionnements au mécanisme de commande des soupapes des moteurs à combustion interne
GB605242A (en) * 1945-02-09 1948-07-19 Saurer Ag Adolph Improvements in and relating to cam-actuated tappets
US4007716A (en) * 1975-08-22 1977-02-15 Allis-Chalmers Corporation Offset valve lifter effecting valve rotation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1496131A (en) * 1924-01-05 1924-06-03 Rich Steel Products Company Tappet
FR752332A (fr) * 1932-04-04 1933-09-20 Perfectionnements au mécanisme de commande des soupapes des moteurs à combustion interne
GB605242A (en) * 1945-02-09 1948-07-19 Saurer Ag Adolph Improvements in and relating to cam-actuated tappets
US4007716A (en) * 1975-08-22 1977-02-15 Allis-Chalmers Corporation Offset valve lifter effecting valve rotation

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2550273A1 (fr) * 1983-08-05 1985-02-08 Peugeot Dispositif d'actionnement d'une soupape, pour distribution variable d'un moteur a combustion interne
EP0376445A1 (de) * 1988-12-27 1990-07-04 Ford Motor Company Limited Ventilstösselanordnung für eine Brennkraftmaschine
GB2242952A (en) * 1990-04-11 1991-10-16 Gen Motors Corp Valve train with lash/compliance compensation
GB2242952B (en) * 1990-04-11 1993-11-03 Gen Motors Corp Valve train with lash/compliance compensation
US5809842A (en) * 1995-06-26 1998-09-22 Sumitomo Electric Industries, Ltd. Ceramic sliding component
US20110209679A1 (en) * 2010-02-26 2011-09-01 Honda Motor Co., Ltd. Rocker arm structure
US8689751B2 (en) * 2010-02-26 2014-04-08 Honda Motor Co., Ltd Rocker arm structure

Also Published As

Publication number Publication date
JPS5891313A (ja) 1983-05-31
JPS6059407B2 (ja) 1985-12-25

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Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19821118

AK Designated contracting states

Designated state(s): DE FR GB

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19841012

RIN1 Information on inventor provided before grant (corrected)

Inventor name: HAYASHI, YOSHIMASA