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US4671233A Expired / Lapsed US ⏱️ 0.0 years remaining

Cylinder head variable swirl siamese type intake port structure including biasing means diverting mixture flow towards diverting means which bypasses straight intake passage control valve

Assignee: Toyota Motor Corp
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Filing: 1986-08-11
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Granted: 1987-06-09
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Expires: 2006-08-11
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Abstract

Abstract A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A means is provided to the generally straight intake passage on the side thereof towards the generally helical intake passage, for, when the control valve is in its position to maximize the flow resistance of the generally straight intake passage, diverting a relatively minor proportion of air-fuel mixture sucked into the intake port structure from a point upstream of the control valve to a point near the downstream end of the first generally straight intake passage, thus bypassing the control valve. Further, there is provided a means for biasing flow of air-fuel mixture sucked into the intake port structure towards the diverting means. This diverting means may include an auxiliary passage formed from upstream of the control valve to a portion of the generally straight intake passage near the downstream end thereof, or alternatively a notch portion formed in said control valve, preferably in the edge thereof which is on the side thereof towards said generally helical intake passage.

Inventors

  • 👤 Yoshihiro Iwashita
  • 👤 Takeshi Okumura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 11:00
CPC Classifications
F; F02; F02F; F02F1/00; F02F1/24; F02F1/42; F02F1/4214; F02F1/4228; F02B; F02B1/00; F02B1/02; F02B1/04; F02F2001/244; F02F2001/245; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 197 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head formed with a combustion chamber to which a spark plug having an ignition point is provided, comprising: a first generally straight intake passage which leads to a first intake port opening to said combustion chamber; a second generally helical intake passage which leads to a second intake port, also opening to said combustion chamber, formed with a helical end vortex portion; a control valve fitted in said first generally straight intake passage at an upstream portion thereof so as to control its flow resistance; a means, provided to said generally straight intake passage on the side thereof towards said generally helical intake passage, for, when said control valve is in its position to maximize the flow resistance of said generally straight intake passage, diverting a relatively minor proportion of air-fuel mixture sucked into said intake port structure from a point upstream of said control valve to a point near the downstream end of said first generally straight intake passage, bypassing said control valve; and: a means for biasing flow of air-fuel mixture sucked into said intake port structure towards said diverting means.
Claim 2
Dependent Claim 197 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head formed with a combustion chamber to which a spark plug having an ignition point is provided, comprising: a first generally straight intake passage which leads to a first intake port opening to said combustion chamber; a second generally helical intake passage which leads to a second intake port, also opening to said combustion chamber, formed with a helical end vortex portion; a control valve fitted in said first generally straight intake passage at an upstream portion thereof so as to control its flow resistance; a means, provided to said generally straight intake passage on the side thereof towards said generally helical intake passage, for, when said control valve is in its position to maximize the flow resistance of said generally straight intake passage, diverting a relatively minor proportion of air-fuel mixture sucked into said intake port structure from a point upstream of said control valve to a point near the downstream end of said first generally straight intake passage, bypassing said control valve; and: a means for biasing flow of air-fuel mixture sucked into said intake port structure towards said diverting means.
Claim 3
Dependent Claim 67 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein the flow resistance of said diverting means both is substantially greater than the flow resistance of said first generally straight intake passage and said first intake port, and is substantially greater than the flow resistance of said second generally helical intake passage and said second intake port.
Claim 4
Dependent Claim 60 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, said spark plug being provided in the generally central portion of said combustion chamber, wherein the flow of air-fuel mixture through said diverting means points through said first intake port, when open, generally in the radial direction of said combustion chamber.
Claim 5
Dependent Claim 70 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein the flow of air-fuel mixture through said diverting means points through said first intake port, when open, into said combustion chamber in a direction somewhat to tend to cancel large scale turbulence induced in said combustion chamber by flow through said generally helical intake passage and said second intake port.
Claim 6
Dependent Claim 84 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein the flow of air-fuel mixture through said diverting means points through said first intake port, when open, into said combustion chamber in a direction somewhat to that side of said ignition point of said spark plug in the direction to tend to cancel large scale turbulence induced in said combustion chamber by flow through said generally helical intake passage and said second intake port.
Claim 7
Dependent Claim 79 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 3, wherein the flow of air-fuel mixture through said diverting means points through said first intake port, when open, into said combustion chamber in a direction somewhat inclined to the radial direction thereof in the sense to tend to cancel large scale turbulence induced in said combustion chamber by flow through said generally helical intake passage and said second intake port.
Claim 8
Dependent Claim 32 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein said diverting means comprises a notch portion formed in said control valve.
Claim 9
Dependent Claim 48 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein said diverting means comprises an auxiliary passage formed from upstream of said control valve to a portion of said generally straight intake passage near the downstream end thereof.
Claim 10
Dependent Claim 49 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 7, wherein the edge of said control valve in which said notch portion is formed is that edge thereof which is on the side thereof towards said generally helical intake passage.
Claim 11
Dependent Claim 61 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 7, wherein the edge of said control valve in which said notch portion is formed is that edge thereof which is its downstream edge when said control valve is in its position to maximize the flow resistance of said generally straight intake passage.
Claim 12
Dependent Claim 26 words
A variable swirl siamese type intake port structure for an internal combustion engine cylinder head according to claim 1, wherein said biasing means is a bulge.

References Cited (Backward Citations)

JPS54151718A Cited
US4548175A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-06-08 1990-12-08 1991-06-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-06-08 1994-12-08 1995-06-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-06-08 1998-12-08 1999-06-09 $7700.00 Window Closed / Lapsed

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