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EP-4739897-A1 - CYLINDER HEAD, CYLINDER HEAD COVER, CYLINDER HEAD ASSEMBLY AND PISTON ENGINE

EP4739897A1EP 4739897 A1EP4739897 A1EP 4739897A1EP-4739897-A1

Abstract

The cylinder head (1) for a piston engine comprises an inlet port (9), a fuel injector hole (7), an oil supply channel (11) having an inlet end (11A) and an outlet end (11B) opening onto a top surface (1B) of the cylinder head (1), a first injector cooling channel (13) for supplying cooling oil to the fuel injector hole (7), arranged in fluid communication with the oil supply channel (11) and having an outlet end (13B) opening into the fuel injector hole (7), and a second injector cooling channel (14) for discharging cooling oil from the fuel injector hole (7) and having an inlet end (15A) opening into the fuel injector hole (7) and an outlet end (16B) opening onto the top surface (1B) of the cylinder head (1), the outlet ends (11B, 16B) of the oil supply channel (11) and the second injector cooling channel (14) being located in an area that is configured to be covered by the cylinder head cover (4).

Inventors

  • SUNDSTEN, MAGNUS
  • NIINIKANGAS, SAKU
  • MÄKINEN, Katri

Assignees

  • Wärtsilä Finland Oy

Dates

Publication Date
20260513
Application Date
20230704

Claims (20)

  1. 1. A cylinder head (1 ) for a piston engine, the cylinder head (1 ) having a bottom surface (1 A) configured to delimit an upper end of a main combustion chamber (2) of a cylinder (3) of a piston engine, and a top surface (1 B) facing an opposite direction than the bottom surface (1 A), the top surface (1 B) being configured to receive a cylinder head cover (4) that is attachable to the cylinder head (1 ), the cylinder head (1 ) comprising - an inlet port (9) extending from a side surface of the cylinder head (1 ) to the bottom surface (1A) of the cylinder head (1 ) and having an inlet opening (9a) on said side surface, - a fuel injector hole (7) configured to receive a fuel injector (8), - an oil supply channel (11 ) having an inlet end (11 A) and an outlet end (11 B), the outlet end (11 B) opening onto the top surface (1 B) of the cylinder head (1 ), - a first injector cooling channel (13) for supplying cooling oil to the fuel injector hole (7), the first injector cooling channel (13) being arranged in fluid communication with the oil supply channel (11 ) and having an outlet end (13B) opening into the fuel injector hole (7), and - a second injector cooling channel (14) for discharging cooling oil from the fuel injector hole (7), the second injector cooling channel (14) having an inlet end (15A) opening into the fuel injector hole (7) and an outlet end (16B) opening onto the top surface (1 B) of the cylinder head (1 ), wherein the outlet end (11 B) of the oil supply channel (11 ) and the outlet end (16B) of the second injector cooling channel (14) are located in an area that is configured to be covered by the cylinder head cover (4).
  2. 2. A cylinder head (1 ) according to claim 1 , wherein the inlet end (11 A) of the oil supply channel (11 ) opens onto an outer surface of the cylinder head (1 ) below the level of the inlet opening (9A) of the inlet port (9) of the cylinder head (1 ).
  3. 3. A cylinder head (1 ) according to claim 2, wherein the cylinder head (1 ) comprises a lateral extension (18) and the inlet opening (9a) of the inlet port (9) and the inlet end (11 A) of the oil supply channel (11 ) are located in said extension (18).
  4. 4. A cylinder head (1 ) according to claim 3, wherein the inlet end (11 A) of the oil supply channel (11 ) opens onto a bottom surface (18A) of said extension (18) of the cylinder head (1 ).
  5. 5. A cylinder head (1 ) according to any of the preceding claims, wherein the outlet end (11 B) of the oil supply channel (11 ) is located in an area that is configured to be covered by a wall of the cylinder head cover (4).
  6. 6. A cylinder head (1 ) according to any of the preceding claims, wherein the outlet end (16B) of the second injector cooling channel (14) is located in an area that is configured to open into the interior of the cylinder head cover (4).
  7. 7. A cylinder head (1 ) according to any of the preceding claims, wherein the cylinder head (1 ) comprises a second oil supply channel (12) having an inlet end (12A) and an outlet end (12B), the outlet end (12B) opening onto the top surface (1 B) of the cylinder head (1 ) and being located in an area that is configured to be covered by the cylinder head cover (4).
  8. 8. A cylinder head (1 ) according to claim 7, wherein the inlet end (12A) of the second oil supply channel (12) opens onto an outer surface of the cylinder head (1 ) below the level of the inlet opening (9A) of the inlet port (9) of the cylinder head (1 ).
  9. 9. A cylinder head (1 ) according to claim 8, wherein the cylinder head (1 ) comprises a lateral extension (18) and the inlet opening (9a) of the inlet port (9) and the inlet end (12A) of the second oil supply channel (12) are located in said extension (18).
  10. 10. A cylinder head (1 ) according to claim 9, wherein the inlet end (12A) of the second oil supply channel (12) opens onto a bottom surface (18A) of said extension (18) of the cylinder head (1 ).
  11. 11. A cylinder head (1 ) according to any of claims 7-10, wherein the oil supply channel (11 ) and the second oil supply channel (12) are arranged on opposite sides of the inlet port (9) of the cylinder head (1 ).
  12. 12. A cylinder head cover (4) that is configured to be attached to a cylinder head (1 ) according to any of the preceding claims, wherein the cylinder head cover (4) has a bottom surface (4A) that is configured to face the top surface (1 B) of the cylinder head (1 ) and the cylinder head cover (4) comprises an oil supply channel (21 ) having an inlet end (21 A), which is configured to be aligned with the outlet end (11 B) of the oil supply channel (11 ) of the cylinder head (1 ) in a mounted position of the cylinder head cover (4).
  13. 13. A cylinder head cover (4) according to claim 12, wherein the oil supply channel (21 ) of the cylinder head cover (4) is configured to conduct pressurized oil to hydraulic means for variable exhaust valve timing.
  14. 14. A cylinder head cover (4) according to claim 12 or 13, wherein the oil supply channel (21 ) is integrated into a wall of the cylinder head cover (4).
  15. 15. A cylinder head cover (4) according to any of claims 12-14, wherein the cylinder head cover (4) is configured to be attached to a cylinder head (1 ) according to any of claims 7-11 and the cylinder head cover (4) comprises a second oil supply channel (22) having an inlet end (22A), which is configured to be aligned with the outlet end (12B) of the second oil supply channel (12) of the cylinder head (1 ) in a mounted position of the cylinder head cover (4).
  16. 16. A cylinder head cover (4) according to claim 15, wherein the second oil supply channel (22) of the cylinder head cover (4) is configured to conduct pressurized oil to hydraulic means for variable intake valve timing.
  17. 17. A cylinder head cover (4) according to claim 15 or 16, wherein the second oil supply channel (22) is integrated into a wall of the cylinder head cover (4).
  18. 18. A cylinder head cover (4) according to claim any of claims 15-17, wherein the cylinder head cover (4) comprises a fuel injector hole (23) configured to receive a fuel injector (8), and the oil supply channel (21 ) and the second oil supply channel (22) of the cylinder head cover (4) are arranged on opposite sides of the fuel injector hole (23).
  19. 19. A cylinder head assembly for a piston engine, the cylinder head assembly comprising a cylinder head (1 ) according to any of claims 1-11 and a cylinder head cover (4) according to any of claims 12-18 attached to the cylinder head (1 ).
  20. 20. A piston engine comprising a cylinder head assembly according to claim 19.

Description

Cylinder head, cylinder head cover, cylinder head assembly and piston engine Technical field of the invention The present invention concerns a cylinder head for a piston engine, as defined in claim 1. The invention also concerns a cylinder head cover, as defined in another independent claim. The invention further concerns a cylinder head assembly and a piston engine. Background of the invention Each cylinder of a four-stroke piston engine is typically provided with two intake valves and two exhaust valves. A conventional way of operating the intake and exhaust valves of a piston engine is using one or more camshafts. The intake and exhaust valves are mechanically coupled to the cams of the camshafts. Mechanical, cam-operated actuating mechanisms are reliable. However, the opening and closing crank angles of the intake and exhaust valves are usually fixed. Variable valve timing has many benefits for example in terms of engine performance, emissions and fuel consumption. Therefore, valve actuating systems allowing variable valve timing are becoming more and more common. Variable valve timing can be implemented in many different ways. Typically, hydraulic and/or electrical components are utilized, but also purely mechanical systems exist. A valve timing system utilizing both a camshaft and hydraulic components can combine the benefits of both mechanical and hydraulic systems. A drawback of such a system is that the oil supply lines needed for the operation of the valve timing system are often complex, increase the manufacturing cost of the engine and increase the number of locations where oil leakages can occur. Summary of the invention An object of the present invention is to provide an improved cylinder head for a piston engine. Another object of the invention is to provide an improved cylinder head cover. Further objects of the invention are to provide an improved cylinder head assembly and an improved piston engine. The cylinder head according to the invention has a bottom surface configured to delimit an upper end of a main combustion chamber of a cylinder of a piston engine, and a top surface facing an opposite direction than the bottom surface, the top surface being configured to receive a cylinder head cover that is attachable to the cylinder head. The cylinder head comprises - an inlet port extending from a side surface of the cylinder head to the bottom surface of the cylinder head and having an inlet opening on said side surface, - a fuel injector hole configured to receive a fuel injector, - an oil supply channel having an inlet end and an outlet end, the outlet end opening onto the top surface of the cylinder head, - a first injector cooling channel for supplying cooling oil to the fuel injector hole, the first injector cooling channel being arranged in fluid communication with the oil supply channel and having an outlet end opening into the fuel injector hole, and - a second injector cooling channel for discharging cooling oil from the fuel injector hole, the second injector cooling channel having an inlet end opening into the fuel injector hole and an outlet end opening onto the top surface of the cylinder head, wherein the outlet end of the oil supply channel and the outlet end of the second cooling channel are located in an area that is configured to be covered by the cylinder head cover. The cylinder head according to the invention allows conducting pressurized oil through the cylinder head to a cylinder head cover. The pressurized oil can be used for controlling the exhaust or intake valve timing. By connecting the injector cooling channel to the oil supply channel, the number of external oil channels can be reduced, thus reducing the risk of oil leakages. According to an embodiment of the invention, the inlet end of the oil supply channel opens onto an outer surface of the cylinder head below the level of the inlet opening of the inlet port of the cylinder head. This allows arranging an oil supply rail below the inlet ports of the engine to supply oil to the cylinder heads. According to an embodiment of the invention, the cylinder head comprises a lateral extension and the inlet opening of the inlet port and the inlet end of the oil supply channel are located in said extension. According to an embodiment of the invention, the inlet end of the oil supply channel opens onto a bottom surface of said extension of the cylinder head. The extension and the oil supply channel opening onto the bottom surface of the extension facilitate connection of the oil supply channel to an oil supply rail. According to an embodiment of the invention, the outlet end of the oil supply channel is located in an area that is configured to be covered by a wall of the cylinder head cover. That allows supplying oil from the oil supply channel directly into a channel integrated into a wall of the cylinder head cover without external piping. According to an embodiment of the invention, the outlet end of the second in