The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 1992
Filed:
May. 16, 1991
Mazda Motor Corporation, Hiroshima, JP;
Abstract
A multiple-cylinder engine has first and second groups of cylinders, the firing order being set so that the cylinders in each group do not fire one after another. An intake system for the engine has first and second groups of discrete intake passages which communicate with the respective cylinders in the first and second groups at their downstream ends and with first and second branch intake passage at their upstream ends. A circular passage communicates with the discrete intake passages at their intermediate portions so that all the discrete intake passages communicate with each other through the circular passage, and an on-off valve opens the circular passage when the engine speed is higher than a predetermined value and closes the same when the engine speed is not higher than the predetermined value. The length of each discrete intake passage is such that a first inertia tuning is obtained at a first engine speed lower than a maximum allowable engine so long as the discrete intake passages are not communicated with the circular passage, and the length of the part of each discrete intake passage downstream of the circular passage is such that a second inertia tuning is obtained at a second engine speed higher than the maximum allowable engine so long as the discrete intake passages are communicated with the circular passage.