Exhaust restriction device
AssigneeDiesel Engine Retarders, Inc.
InventorNorman Schaefer
Life of this patent
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Abstract
An exhaust restriction device for an internal combustion engine is disclosed. The exhaust restriction device includes a main valve and a bypass valve for restricting the flow of exhaust gas. The main valve is located in a main passage and may be selectively closed. The bypass valve is located in a bypass passage and is biased into a position closing a port connecting the main passage and the bypass passage. Closing the main valve may cause exhaust back pressure to build against the bypass valve and an actuator therefor until the biasing force is overcome. When the biasing force is surpassed by the exhaust back pressure, the bypass valve opens to relieve the back pressure. The bypass valve closes when back pressure falls below the biasing force. A method of operating the exhaust restriction device is also disclosed.
Claims17
An exhaust restriction device located downstream of an exhaust manifold in an internal combustion engine, comprising:
- a main housing having a main passage and a bypass passage therein;
- a main exhaust valve for selectively blocking the flow of exhaust gas through the main passage;
- an upstream port providing communication between the main passage and the bypass passage at a point upstream of the main exhaust valve;
- a downstream port providing communication between the main passage and the bypass passage at a point downstream of the main exhaust valve;
- a bypass valve stopper for selectively blocking the upstream port;
- means for biasing the bypass valve stopper to block the upstream port;
- and
- means for opening the bypass valve stopper responsive to exhaust gas pressure in the device at a location upstream of the main exhaust valve.
An exhaust restriction device for providing a substantially constant level of back pressure in an engine exhaust system, comprising:
- a main housing having a main passage and a bypass passage therein;
- a main exhaust valve for selectively blocking the flow of exhaust gas through the main passage;
- an upstream port providing communication between the main passage and the bypass passage at a point upstream of the main exhaust valve;
- a downstream port providing communication between the main passage and the bypass passage at a point downstream of the main exhaust valve;
- a bypass valve stopper for selectively blocking the upstream port;
- a rod having first and second ends, said first end being connected to the bypass valve stopper and said second end extending out of the main housing;
- an actuator housing connected to the main housing and having an opening therein for receiving the second end of the rod;
- a spring biased piston located within the actuator housing, said piston being connected to and biased towards the second end of the rod such that the bypass valve stopper is biased into the upstream port from the direction of the bypass passage;
- and
- an exhaust pressure tube providing communication between an upstream side of the main passage and the actuator housing,
- wherein the bypass valve stopper is adapted to be pulled out of the upstream port responsive to the displacement of the piston in the actuator housing due to the transmission of exhaust gas pressure from the upstream side of the main passage to the actuator housing.
In an exhaust restriction device comprising a main housing containing a main exhaust passage, a main valve, a bypass passage, and a bypass valve for closing the bypass passage, the improvement comprising means for selectively opening the bypass valve responsive to the application of exhaust gas pressure to an actuator that is thermally isolated from the main exhaust housing.
An exhaust restriction device for carrying out engine warm-up, comprising:
- a main valve provided in a main passage running through the device;
- a bypass valve provided in a bypass passage running through the device, said bypass passage being connected to the main passage at a connection point upstream of the main valve;
- means for biasing the bypass valve to block the upstream connection point between the main passage and the bypass passage;
- means for opening the bypass valve responsive to a level of exhaust back pressure applied to the opening means;
- and
- means for transferring exhaust back pressure from the main passage to a chamber included in the opening means.
A method of operating an exhaust restriction device to carry out engine warm-up, the method comprising the steps of:
- providing an exhaust restriction device with a main valve and a bypass valve, said bypass valve including a bypass valve stopper and a bypass valve actuator;
- selectively biasing the bypass valve into a closed position;
- selectively closing the main valve;
- increasing exhaust back pressure in the exhaust restriction device as a result of closing the main valve;
- applying the exhaust back pressure to the bypass valve stopper and the bypass valve actuator;
- and
- opening the bypass valve responsive to the level of exhaust back pressure applied to the bypass valve stopper and the bypass valve actuator.
Dependencies are inferred from the claim text.