# US 4,393,853 A · Exhaust gas recirculation type internal combustion engines and method of operating same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,393,853 A
- Document ID: US4393853A
- Status: Granted
- Kind: A
- Application number: 06/290,798
- Filed: 1981-08-06
- Granted: 1983-07-19
- Earliest claimed: 1981-08-06
- Assignees: Research Corporation
- Inventors: William N. Groves
- Web page: https://patentgrep.com/patent/US4393853A

## CPC

- F02B 17/00: Engines characterised by means for effecting stratification of charge in cylinders
- F02M 26/20: Feeding recirculated exhaust gases directly into the combustion chambers or into the intake runners
- F02M 26/40: with timing means in the recirculation passage, e.g. cyclically operating valves or regenerators; with arrangements involving pressure pulsations
- F02M 26/42: having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders
- F02M 26/63: the EGR valve being directly controlled by an operator (the EGR valve being operated together with an intake air throttle F02M26/64)
- F02B 1/04: with fuel-air mixture admission into cylinder
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF

## Abstract

A multi-cylinder internal combustion engine is disclosed in which a portion of the exhaust gas is selectively added to each cylinder. The exhaust gas is caused to swirl along the inside wall of the cylinder. Air or a fuel/air mixture is caused to swirl in a central zone in the cylinder in the same direction of swirl as the direction of swirl of the exhaust gas thereby providing a stratified exhaust gas recirculation design.

## Claims

### Claim 1

In a multi-cylinder internal combustion engine having a fuel and an air source connected to each cylinder via a substantially centrally located intake valve means in each cylinder; means for stratifying a combustible fuel/air mixture and exhaust gas in the cylinder during the intake stroke, said means for stratifying comprising:
(a) fuel/air mixture swirling means for each cylinder;
(b) at least one inlet port in each cylinder open to each cylinder from about 60.degree. BBDC to about 60.degree. ABDC;
(c) conduit means connecting each said at least one inlet port with a source of pressurized exhaust gas;
(d) said source of pressurized exhaust gas comprising the gas exhausting from the cylinder 360.degree. apart on the firing order of the engine;
(e) means for causing the exhaust gas to swirl in each cylinder in the same direction as the swirl of the air/fuel mixture.

### Claim 2 (depends on 1)

The internal combustion engine as defined in claim 1 wherein the exhaust gas swirls about the inner surface of the cylinder and the fuel/air mixture swirls in a central zone in the cylinder.

### Claim 3 (depends on 2)

The internal combustion engine as defined in claim 2 further including tangential inlet means forming the at least one exhaust gas inlet port for each cylinder.

### Claim 4 (depends on 3)

The internal combustion engine as defined in claim 3 further including a variable throttle valve means in each of the conduits connecting the at least one exhaust gas inlet port with the source of pressurized exhaust gas.

### Claim 5

In a multi-cylinder internal combustion engine having a carburetor connected to each cylinder via a substantially centered intake valve means in each cylinder during the intake stroke said means for stratifying comprising:
(a) fuel/air mixture swirling means upstream of the intake valve of each cylinder;
(b) at least one tangential inlet port in each cylinder open to each cylinder from about 60.degree. BBDC to about 60.degree. ABDC; and
(c) conduit means connecting each tangential inlet port with pressurized exhaust gas exhausting from the cylinder 360.degree. apart on the firing order of the engine.

### Claim 6

A method of operating at least a two cylinder internal combustion engine comprising the steps:
(a) directing in a swirling path air or a combustible fuel/air mixture into an engine cylinder during the intake stroke;
(b) tangentially admitting in a swirling path exhaust gas exhausting from a cylinder 360.degree. apart on the firing order of the engine, into the cylinder to provide a stratified charge of air or a fuel/air mixture and exhaust gas;
(c) compressing the stratified charge;
(d) igniting the stratified charge;
(e) expanding the charge to produce useful work; and
(f) exhausting the cylinder.