EP0265960A2
Expired / Lapsed
EP
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Intake system for multiple-cylinder engine
Assignee: Mazda Motor Corp
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Filing: 1987-10-30
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Granted: —
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Expires: 2007-10-30
Abstract
Abstract An intake system for a multiple-cylinder engine (E) has a main intake passage open to the atmosphere at its upstream end, a plurality of discrete intake passages (12a-f) which communicate the respective cylinders (2a-f) with the main intake passage by way of intake ports, and a circular (11L, 14, 11R, 15) passage which is communicated with the cylinders. The circular passage is adapted to propagate pressure waves generated by the intake strokes without reflecting the pressure waves, and is provided with a valve (14b, 15b) which opens the circular passage to permit propagation of the pressure waves in a predetermined high engine speed range. The length of the circular passage is selected so that the pressure waves resonate in the predetermined high engine speed range.
Inventors
- 👤 Mitsuo Hitomi
- 👤 Katsumi Okazaki
- 👤 Junso Sasaki
- 👤 Yasuhiro Yuzuriha
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 08:51
CPC Classifications
F; F02; F02B; F02B75/00; F02B75/16; F02B75/18; F02B75/22; F02B27/00; F02B27/02; F02B27/0205; F02B27/021; F02B27/0226; F02B27/0242; F02B27/0247; F02B27/0252; F02B2075/1804; F02B2075/1824; F02F; F02F2200/00; F02F2200/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
An intake system for a multiple-cylinder engine having a plurality of cylinders comprising a common intake passage open to the atmosphere at its upstream end, a plurality of discrete intake passages which communicate the respective cylinders with the common intake passage by way of intake ports, a circular passage which is communicated with the cylinders and is adapted to propagate pressure waves generated by the intake strokes without reflecting the pressure waves, and a valve means which opens the circular passage to permit propagation of the pressure waves in a predetermined high engine speed range, the length of said circular passage being selected so that the pressure waves resonate in said predetermined high engine speed range.
Claim 2
Dependent Claim
116 words
An intake system for a multiple-cylinder engine having a plurality of cylinders comprising a common intake passage open to the atmosphere at its upstream end, a plurality of discrete intake passages which communicate the respective cylinders with the common intake passage by way of intake ports, a circular passage which is communicated with the cylinders and is adapted to propagate pressure waves generated by the intake strokes without reflecting the pressure waves, and a valve means which opens the circular passage to permit propagation of the pressure waves in a predetermined high engine speed range, the length of said circular passage being selected so that the pressure waves resonate in said predetermined high engine speed range.
Claim 3
Dependent Claim
103 words
An intake system as defined in Claim l in which said multiple-cylinder engine is a V-type engine having first and second cylinder banks set at an angle to each other, and the cylinders in each bank do not fire one after another, said discrete intake passages for the cylinders in the first cylinder bank being connected to the common intake passage by way of a first branch intake passage, said discrete intake passages for the cylinders in the second cylinder bank being connected to the common intake passage by way of a second branch intake passage separated from the first branch intake passage.
Claim 4
Dependent Claim
77 words
An intake system as defined in Claim 2 in which said first and second branch intake passages are connected together at the respective downstream ends and at upstream side portions to form said circular passage, the circular passage running through the first branch intake passage, the junction of the downstream ends of the first and second branch intake passages, the second branch intake passage and the upstream side junction of the first and second branch intake passages.
Claim 5
Dependent Claim
80 words
An intake system as defined in Claim 3 in which said junction of the downstream ends of the first and second branch intake passages forms a first pressure reflecting portion, and said upstream side junction of the first and second branch intake passages forms a second pressure reflecting portion, the first and second pressure reflecting portions being respectively provided with first and second on-off valves which are both opened to open the circular passage in said high engine speed range.
Claim 6
Dependent Claim
47 words
An intake system as defined in Claim 4 in which said first and second branch intake passages are converged at the upstream ends thereof and connected to the common intake passage, the junction of the first and second branch intake passages forming a third pressure reflecting portion.
Claim 7
Dependent Claim
120 words
An intake system as defined in Claim 5 in which said first and second on-off valves are both closed in a low engine speed range, and the first on-off valve is closed with the second on-off valve being opened in the intermediate engine speed range between said low engine speed range and the high engine speed range, the length of the first and second branch intake passages being selected so that the pressure waves resonate in the low engine speed range, and the distance between the cylinders and the second pressure reflecting portions being selected so that the pressure waves resonate in the intermediate engine speed range when the second on-off valve is opened with the first on-off valve closed.
Claim 8
Dependent Claim
67 words
An intake system as defined in Claim 6 in which said circular passage is provided with a shortcut passage communicating the first and second branch intake passages with each other at a portion upstream of the first pressure reflecting portion, and the shortcut passage is provided with an on-off valve which is opened when the engine speed exceeds a predetermined value in said high engine speed range.
Claim 9
Dependent Claim
45 words
An intake system as defined in Claim 6 in which said intake valves in the respective cylinders open toward the space between the first and second cylinder banks and said first and second branch intake passages extend in the longitudinal direction of the cylinder banks.
Claim 10
Dependent Claim
31 words
An intake system as defined in Claim 3 in which the length and the diameter of each of the discrete intake passages are selected so that inertia effect cannot occur therein.
Claim 11
Dependent Claim
110 words
l0. An intake system as defined in Claim 3 in which each of the distance between the discrete intake passage for the upstream-most cylinder in the first cylinder bank and the discrete intake passage for the upstream-most cylinder in the second cylinder bank as measured along the upstream side portion of said circular passage and the distance between the discrete intake passage for the downstream-most cylinder in the first cylinder bank and the discrete intake passage for the downstream-most cylinder in the second cylinder bank as measured along the downstream side portion of said circular passage is sufficiently larger than the distance between two adjacent cylinders in either cylinder bank.
Claim 12
Dependent Claim
99 words
An intake system as defined in Claim l0 in which the distance between the discrete intake passage for the upstream-most cylinder in the first cylinder bank and the discrete intake passage for the upstream-most cylinder in the second cylinder bank as measured along the upstream side portion of said circular passage and the distance between the discrete intake passage for the downstream-most cylinder in the first cylinder bank and the discrete intake passage for the downstream-most cylinder in the second cylinder bank as measured along the downstream side portion of said circular passage are substantially equal to each other.
Claim 13
Dependent Claim
194 words
An intake system as defined in Claim l in which said multiple-cylinder engine is an in-line engine having a plurality of cylinders arranged in a single line, and the cylinders are divided into first and second cylinder groups so that the cylinders in each cylinder group do not fire one after another, the discrete intake passages for the cylinders of the first cylinder group being connected to said common intake passage by way of a first branch intake passage and the discrete intake passages for the cylinders of the second cylinder group being connected to the said common intake passage by way of a second branch intake passage, said first and second branch intake passages being connected together at the respective downstream ends to form said circular passage, the circular passage running through the first branch intake passage, the junction of the downstream ends of the first and second branch intake passages, the second branch intake passage and the junction of the first and second branch intake passages to the common intake passage, and said valve means being provided at the junction of the downstream ends of the first and second branch intake passages.
Claim 14
Dependent Claim
92 words
An intake system as defined in Claim l in which said multiple-cylinder engine is an in-line engine having a plurality of cylinders arranged in a single line, and said discrete intake passages are connected to the common intake passage in parallel, said circular passage being formed by providing the common intake passage with an extension passage which connects the downstream end of the common intake passage with a portion of the common intake passage upstream of the junction of the discrete intake passage for the upstream-most cylinder to the common intake passage.
Claim 15
Dependent Claim
94 words
An intake system as defined in Claim l in which said multiple-cylinder engine is an in-line engine having a plurality of cylinders arranged in a single line, and said discrete intake passages are merged together and connected to the common intake passage by way of a single passage, said circular passage being formed by providing the common intake passage with an extension passage which connects the downstream end of the common intake passage with a portion of the common intake passage upstream of the junction of the single passage to the common intake passage.
Claim 16
Dependent Claim
28 words
An intake system as defined in Claim l4 in which the cross-sectional area of said extension passage is smaller than the cross-sectional area of the common intake passage.
References Cited (Backward Citations)
No citation records indexed.
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