US3713428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas return means for internal combination engines
Assignee: Volkswagen AG
•
Filing: 1971-03-10
•
Granted: 1973-01-30
•
Expires: 1991-03-10
Abstract
Abstract An intake system for an internal combustion engine in which intake of air and fuel into the combustion chambers is controlled by a throttle valve. An exhaust gas passage recirculates exhaust gas from the exhaust line back into the combustion chamber together with the incoming air. The flow of exhaust gas through such passage is under the control of a shutoff valve, the operating mechanism for which is controlled in response to differences between the pressure prevailing within the intake system and the pressure in the region of the metering element or throttle valve, to open the shutoff valve only during certain predetermined load conditions of the engine.
Inventors
- 👤 J Sandhagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:43
CPC Classifications
F; F02; F02M; F02M26/00; F02M26/52; F02M26/55; F02M26/58; F02M26/13; F02M26/17; F02M26/21; F02M26/65; F02M26/66; F02M26/67
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
125 words
In an internal combustion engine with an intake manifold containing an air metering element for feeding a mixture to the combustion chambers, and an exhaust gas pipe, and means for the return of the exhaust gas to the combustion chambers, the improvement which comprises means defining an exhaust gas return passage (7, 8) for delivering exhaust gas from the exhaust gas pipe (5) to the intake manifold (4), a shutoff valve (2, 6) controlling the flow of exhaust gas through said passage (7, 8), and valve operating mechanism responsive to differences between the pressure in the intake manifold and the pressure in the region of the air metering element to open the shutoff valve (6) only in the means partial load operation of the engine.
Claim 2
Dependent Claim
125 words
In an internal combustion engine with an intake manifold containing an air metering element for feeding a mixture to the combustion chambers, and an exhaust gas pipe, and means for the return of the exhaust gas to the combustion chambers, the improvement which comprises means defining an exhaust gas return passage (7, 8) for delivering exhaust gas from the exhaust gas pipe (5) to the intake manifold (4), a shutoff valve (2, 6) controlling the flow of exhaust gas through said passage (7, 8), and valve operating mechanism responsive to differences between the pressure in the intake manifold and the pressure in the region of the air metering element to open the shutoff valve (6) only in the means partial load operation of the engine.
Claim 3
Dependent Claim
125 words
In an internal combustion engine with an intake manifold containing an air metering element for feeding a mixture to the combustion chambers, and an exhaust gas pipe, and means for the return of the exhaust gas to the combustion chambers, the improvement which comprises means defining an exhaust gas return passage (7, 8) for delivering exhaust gas from the exhaust gas pipe (5) to the intake manifold (4), a shutoff valve (2, 6) controlling the flow of exhaust gas through said passage (7, 8), and valve operating mechanism responsive to differences between the pressure in the intake manifold and the pressure in the region of the air metering element to open the shutoff valve (6) only in the means partial load operation of the engine.
Claim 4
Dependent Claim
125 words
In an internal combustion engine with an intake manifold containing an air metering element for feeding a mixture to the combustion chambers, and an exhaust gas pipe, and means for the return of the exhaust gas to the combustion chambers, the improvement which comprises means defining an exhaust gas return passage (7, 8) for delivering exhaust gas from the exhaust gas pipe (5) to the intake manifold (4), a shutoff valve (2, 6) controlling the flow of exhaust gas through said passage (7, 8), and valve operating mechanism responsive to differences between the pressure in the intake manifold and the pressure in the region of the air metering element to open the shutoff valve (6) only in the means partial load operation of the engine.
Claim 5
Dependent Claim
43 words
An internal combustion engine according to claim 1, characterized in that the air metering element is a throttle valve and the operating mechanism (2) is fed the pressure in the area of the edge of the throttle valve in its position during idling.
Claim 6
Dependent Claim
58 words
An internal combustion engine according to claim 1, characterized in that the operating mechanism (2) comprises two diaphragms (12, 13) supporting a tappet valve (6) for operative movement, said diaphragms respectively cooperating with pressure chambers (19, 20) in one of which the pressure of the intake manifold (4) prevails and in the other of which another pressure prevails.
Claim 7
Dependent Claim
75 words
An internal combustion engine according to claim 3, characterized in that a spring (22) forcing the shut-off valve (6) in the direction of the valve seat (10), has been disposed in one (20) of the two pressure chambers (13, 20), the strength of said spring and the relative areas of the respective diaphragms bEing such that only in the event of equality of the two pressures in the said chambers is the valve (6) opened.
Claim 8
Dependent Claim
34 words
An internal combustion engine according to claim 4, characterized in that the valve (6) is suspended movably by means of diaphragms (12, 13), and is formed for self-centering engagement with a valve seat (10).
Claim 9
Dependent Claim
28 words
An internal combustion engine according to claim 5, characterized in that said valve (6) is formed with a convex end (11) and the valve seat (10) is concave.
Claim 10
Dependent Claim
91 words
An internal combustion engine according to claim 3, characterized in that the return passage comprises two parts (7, 8), the first of which (7) extends from the exhaust pipe (5) up to the first pressure chamber (19) in which the pressure of the induction system (4) prevails and the second part (8) extends from this pressure chamber (19) to the induction system (4), and in that the valve seat (10) is formed at the junction (9) of the first part (7) of the return passage with the first pressure chamber (19).
Claim 11
Dependent Claim
36 words
An internal combustion engine according to claim 7, characterized in that the first part (7) of the return pipe contains a restrictor in the form of a valve part 9 adjacent to the valve seat (10).
Claim 12
Dependent Claim
60 words
An internal combustion engine according to claim 7, characterized in that the pressure chambers (19, 20), the valve (6), the intake manifold (4), and the exhaust gas pipe (5) are disposed in a common plane (1) and that the first part (7) of the return pipe encirlces the cross-section of the intake manifold (4) in the form of an arc.
Claim 13
Dependent Claim
68 words
An internal combustion engine according to claim 9, characterized in that the junction (9) of the first part (7) of the return pipe comprises a valve part defined by a connecting block (3) between the pressure chambers (19, 20) and the intake system (4), said block (3) being formed with a channel (8) for transferring the pressure in the intake system 4 to the adjoining pressure chamber (19).
Claim 14
Dependent Claim
27 words
An internal combustion engine according to claim 10, characterized in that the valve operating mechanism (2) including the valve (6) is releasably associated with the block (3).
Claim 15
Dependent Claim
34 words
An internal combustion engine according to claim 11, characterized in that said valve operating mechanism is connected to the block (3) by way of screw connections (17) shielded against contact with the exhaust gas.
Claim 16
Dependent Claim
110 words
In an internal combustion engine having an intake manifold delivering air from the atmosphere into its combustion chamber, a throttle valve in said manifold for controlling the flow of air therethrough, an exhaust pipe for discharging exhaust gases from the combustion chambers, and means defining an exhaust gas return passage for establishing communication between the exhaust pipe and said intake manifold, a shutoff valve controlling the flow of exhaust gases through said return passage and means for operating said valve in response to varying differences between the pressure prevailing within said manifold in the region of said throttle valve and the pressure within said manifold remote from said throttle valve.
Claim 17
Dependent Claim
110 words
In an internal combustion engine having an intake manifold delivering air from the atmosphere into its combustion chamber, a throttle valve in said manifold for controlling the flow of air therethrough, an exhaust pipe for discharging exhaust gases from the combustion chambers, and means defining an exhaust gas return passage for establishing communication between the exhaust pipe and said intake manifold, a shutoff valve controlling the flow of exhaust gases through said return passage and means for operating said valve in response to varying differences between the pressure prevailing within said manifold in the region of said throttle valve and the pressure within said manifold remote from said throttle valve.
Claim 18
Dependent Claim
18 words
The combination defined in claim 13, including resilient means constantly urging the said shutoff valve toward closed position.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |