(19)
(11) EP 1 207 275 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.06.2003 Bulletin 2003/26

(43) Date of publication A2:
22.05.2002 Bulletin 2002/21

(21) Application number: 01121944.1

(22) Date of filing: 12.09.2001
(51) International Patent Classification (IPC)7: F01L 1/04, F01L 1/14, F01L 1/18, F01L 1/02, F01L 1/26, F02F 1/24, F02B 75/24
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 16.11.2000 JP 2000349951

(71) Applicant: HONDA GIKEN KOGYO KABUSHIKI KAISHA
Minato-ku Tokyo (JP)

(72) Inventors:
  • Fukuzawa, Kazuto
    4-1 Chuo 1-chome, Wako-shi, Saitama-ken (JP)
  • Sanada, Makoto
    4-1 Chuo 1-chome, Wako-shi, Saitama-ken (JP)
  • Matsuda, Minoru
    4-1 Chuo 1-chome, Wako-shi, Saitama-ken (JP)

(74) Representative: Liska, Horst, Dr.-Ing. et al
Weickmann & Weickmann Patentanwälte Postfach 86 08 20
81635 München
81635 München (DE)

   


(54) Four-cycle engine


(57) The invention provides a four-cycle engine, in which a pair of intake valve ports openable/closable by respective intake valves and a pair of exhaust valve ports openable/closable by respective exhaust valves are provided in a cylinder head in such a manner as to be positioned on both sides of a first virtual plane containing the axial line of a cylinder bore and passing through an approximately central portion of a combustion chamber, and a pair of ignition plugs are mounted in the cylinder head, characterized by minimizing the degradation of a flame propagation condition even if there occurs accidental fire in either of both the ignition plugs.
A pair of ignition plugs (80), which are disposed substantially symmetrically with respect to a second virtual plane (79) passing through the center of a combustion chamber (17R) and being perpendicular to a first virtual plane(78), are mounted in a cylinder head (15R) in such a manner as to have axial lines extending substantially in parallel to the first virtual plane(78) and to be tilted with a distance therebetween becoming smaller toward the combustion chamber (17R); and end portions, projecting in the combustion chamber (17R), of the ignition plugs (80) are disposed in a region surrounded by intake valve ports (76) and exhaust valve ports (77).






Search report