Two stroke opposed-piston engines with compression release for engine braking
In a two-stroke opposed-piston engine, a ported cylinder with a pair of opposed pistons is equipped with a decompression port including a valve and a passage with an opening through the cylinder wall that is located between the cylinder's intake and exhaust ports. The decompression port enables the release of compressed air from the cylinder after the intake and exhaust ports are closed. The valve controls airflow through the passage, and is opened to permit compressed air to be released from the cylinder through the passage, and closed to retain compressed air in the cylinder. Engine braking is supported by release of compressed air through the decompression port into an exhaust channel when the pistons are at or near top dead center positions as the cycle transitions from the intake/compression stroke to the power/exhaust stroke. Compression release from the cylinder via the decompression port after intake and exhaust, port closure can also support other engine operations. 1. A two-stroke opposed piston engine, which comprises: at least one cylinder, the at least one cylinder comprises a piston control the gas outlet and the air inlet; the charge air channel, for providing pressurized air to at least one of the engine air inlet; and the exhaust passage, it is used for the exhaust gas of the engine from the at least one exhaust outlet, wherein the inside of the cylinder including the pressure reduction port is in fluid communication with the exhaust channel is coupled to the output in order to be used for when the piston is close to the corresponding top dead center position (TDC) when the release of compressed air from the cylinder. 2. Two-stroke opposed piston engine according to Claim 1, wherein the opening comprises a states the reduced pressure with the cylinder passage is communicated with inside of the, valve, the valve can be set up to close the passageway and the closed state can be set up as to be arranged in said passageway in fluid communication with the output of the open-state. 3. Two-stroke opposed piston engine according to Claim 2, wherein the valve is a poppet valve. 4. Two-stroke opposed piston engine according to Claim 1, wherein the opening comprises a states the reduced pressure is communicated with the interior of the cylinder is connected with the passage, and the exhaust channel is coupled to the output; and a valve, which can be arranged to close the passageway and the closed state can be set up as to be arranged in said passageway in fluid communication with the output of the open-state. 5. Two-stroke opposed piston engine according to Claim 4, wherein the valve is a poppet valve. 6. A two-stroke opposed piston engine, which comprises: at least one cylinder, the at least one cylinder comprises a piston control the gas outlet and the air inlet; the charge air channel, for providing the same mechanical supercharging air to at least one of the engine air inlet; and an exhaust channel, which is used for the exhaust gas of the engine from the at least one exhaust outlet, wherein the inside of the cylinder including the pressure reduction port is in fluid communication with the exhaust channel is coupled to the output in order to be used for when the piston is close to the corresponding top dead center (TDC) position of the cylinder release from the mechanical supercharging air. 7. Two-stroke opposed piston engine according to Claim 6, wherein the opening comprises a states the reduced pressure is communicated with the interior of the cylinder is connected with the passage, coupled to the output of the exhaust passage; and a valve, which can be arranged to close the passageway and the closed state can be set up as to be arranged in the passage and coupled to the exhaust passage is in fluid communication with the output of the open-state. 8. Two-stroke opposed piston engine according to Claim 7, wherein the valve is a poppet valve. 9. A two-stroke opposed piston engine, which comprises: at least one cylinder, the at least one cylinder comprises a piston control the gas outlet and the air inlet; the charge air channel, for providing pressurized air to at least one of the engine air inlet; and an exhaust channel, which is used for the exhaust gas of the engine from the at least one exhaust outlet, wherein the inside of the cylinder including the pressure reduction port is in fluid communication with the exhaust channel is coupled to the output in order to be used for when the opening is closed and the piston is close to the corresponding top dead center position (TDC) when the compressed air is removed from the cylinder. 10. Two-stroke opposed piston engine according to Claim 9, wherein the opening comprises a states the reduced pressure with the passage is communicated with the interior of the cylinder, compression release valve, the compression release valve may be provided to close the passageway and the closed state can be set up as to be arranged in the passage and coupled to the exhaust passage is in fluid communication with the output of the open-state. 11. Two-stroke opposed piston engine according to Claim 10, wherein the exhaust channel comprises a turbo-supercharger and the decompression port is coupled to the output of the turbine of the turbocharger between the input and the exhaust port of the exhaust passage. 12. Two-stroke opposed piston engine according to Claim 10, wherein the exhaust channel comprises a turbo-supercharger and the decompression port is coupled to the output of the with the the output of the turbocharger is communicated with the exhaust passage. 13. Two-stroke opposed piston engine according to Claim 10, it further includes device, including the device with said air pressure channel is connected to the input and the output, wherein the by-pass valve may be provided in order to make said output and the exhaust channel is connected to the 1st state and can be set up as the output with the device is communicated with the input of the 2nd state. 14. Two-stroke opposed piston engine according to Claim 13, wherein the device comprises a one-way valve and the input of the release device for the valve can be set up for the output device with said air pressure channel is connected to the 1st state and can be arranged to output the 2nd state blocks said device. 15. A kind of operation has at least one with a valve cylinder and a pair of opposed in the cylinder of the piston is two-stroke opposed piston engine method, wherein during the intake/compression stroke, the air inlet and air outlet of the cylinder is closed, with the cylinder of the associated reduced pressure mouth , from the cylinder release in the opposed piston between the compressed charge air, the engine is used for braking. 16. With at least one operation with valve cylinder and a pair of opposed in the cylinder of the piston is two-stroke opposed piston engine method according to Claim 13, wherein the compressed charge air in the air intake/compression stroke next after the power/exhaust stroke before a released into the exhaust passage of the engine. 17. A kind of braking two-stroke fuel injection opposed piston engine method, the engine comprising an exhaust passage, at least one cylinder and with a valve of a pair is in the cylinder the piston of the opposed, wherein during the intake/compression stroke, the pressurized air is compressed between the opposed pistons in the cylinder, in the intake/compression stroke, with the piston near top dead center (TDC) position, is located near the longitudinal center of the cylinder of the pressure-reducing hole is is opened in order to release compressed air from the cylinder, prevent the fuel injection into the compressed air in, on and after the intake/compression stroke in the next power/exhaust stroke begins, with the piston toward the bottom dead center (BDC) position, the pressure relief opening is closed.