JP2015165139A5 - - Google Patents

Claims (8)

An exhaust valve (1) for a crosshead large two-stroke uniflow diesel engine:
Spindle bore (5);
A valve spindle (10) received in said spindle bore (5) and having a longitudinal axis (A);
A valve body (3) provided at one end of the valve spindle (10) and cooperating with the valve seat (4);
A valve actuator (109);
A pneumatic spring (123) connected to the valve spindle (10) so as to control the valve spindle (10) and urging the valve spindle (10) towards the valve seat (4);
A central bore (6) formed on the stationary housing of the valve actuator (109), the central bore forming the upper part of the spindle bore (5) and (6);
An upper portion (14) of the valve spindle (10) received in the central bore (6) and translatable in the direction of the longitudinal axis (A);
An intermediate portion (66) of said central bore (6) having an upper edge (66 ');
A variable displacement valve working chamber (60) for opening the exhaust valve (1) against the urging force of the pneumatic spring (123) ;
With
A hydraulic oil passage connecting the variable volume valve working chamber (60) to a pressurized hydraulic oil source via a port at the top of the variable volume valve working chamber (60);
It formed at the lower end of the valve spindle (10) the upper part (14), the valve spindle that form a part of the hydraulic fluid path as it passes through the intermediate portion (66), at least one axial An elongate slit (19) in which the flow of pressurized hydraulic oil from the pressurized hydraulic oil source via the hydraulic oil passage to the variable displacement valve working chamber (60) is in the upper part (14). Provided to gradually decrease as it passes through the intermediate portion (66);
At least one axially elongated slit (19);
An exhaust valve (1) characterized by the following. The exhaust valve (1) according to claim 1, wherein the depth of the at least one slit gradually increases in the direction of the extension axis (A) of the valve spindle (10). The exhaust valve (1) according to claim 1 or 2, wherein a plurality of slits (19) are provided. The exhaust valve (1) according to claim 3, wherein the plurality of slits (19) each have a different length in the direction of the extension axis (A) of the valve spindle (10). The exhaust valve (1) according to any of the preceding claims, wherein the at least one slit (19) is formed on the outer surface at the lower end (14 '') of the upper part (14) of the valve spindle (10). 1). Each of the at least one slit (19) has an upper end (19 ′) and a lower end (19 ″), and the lower end (19 ″) and the upper portion (14) of the valve spindle (10). The exhaust valve (1) according to claim 5, wherein the exhaust valve (1) increases in depth towards the downwardly facing shelf (18) and opens into the shelf (18). At least one second slit provided in the wall of the intermediate part (66) of the central bore (6) instead of or together with the at least one slit (19). and an exhaust valve according to any one of claims 1 to 6 (1), the second slit is also a part of the hydraulic fluid path when said valve spindle through said intermediate portion (66) An elongated slit formed in the axial direction, which is formed in the final stage of the exhaust valve opening process from the pressurized hydraulic oil source via the hydraulic oil passage to the variable displacement valve working chamber (60). Exhaust valve (1), wherein the flow of pressurized hydraulic oil is formed such that the upper part (14) gradually decreases as it passes through the intermediate part (66) . Each of the at least one slit (19) has an upper end (19 ′) and a lower end (19 ″), and is formed at the upper edge (19 ″) and the upper edge (66 ′) of the intermediate portion (66). headed to increasing depths, the exhaust valve according to claim 7 (1).