Search

EP-4484741-B1 - ENGINE SYSTEM

EP4484741B1EP 4484741 B1EP4484741 B1EP 4484741B1EP-4484741-B1

Inventors

  • MATSURA, Yoshimitsu
  • FUKUI, YOSHINORI
  • YAMAGUCHI, Eito
  • KOBAYASHI, YUKI
  • MIYAZAKI, Shinnosuke

Dates

Publication Date
20260513
Application Date
20221109

Claims (11)

  1. An engine system (1) comprising: an intake port (61) that supplies air to a combustion chamber (50), and a fuel supply unit (3) that supplies a gaseous fuel to an internal space of the intake port (61), wherein the fuel supply unit (3) has an injection unit (31) that injects the gaseous fuel, and of an internal peripheral face of the intake port (61), at least an intersection with a central axis of an injection area of the gaseous fuel from the injection unit (3) has a cooled portion (612).
  2. The engine system (1) according to claim 1, further comprising: a cylinder head (6) formed with the intake port (61), wherein the cylinder head (6) has a refrigerant passage (63) through which a refrigerant passes, and the cooled portion (612) is placed at a bulkhead portion (64) that physically separates at least the refrigerant passage (63) from the intake port (61).
  3. The engine system (1) according to claim 2, wherein the bulkhead portion (64) includes a thin wall portion (641) having a thickness between the refrigerant passage (63) and the intake port (61) smaller than a reference thickness, and a thick wall portion (642) having a thickness between the refrigerant passage (63) and the intake port (61) greater than the reference thickness, and of the thin wall portion (641) and the thick wall portion (642), only the thin wall portion (641) has the cooled portion (612).
  4. The engine system (1) according to any one of claims 1 to 3, further comprising: a refrigerant supply unit (65) that adheres an adherent refrigerant (651) to a part of the internal peripheral face of the intake port (61), wherein the cooled portion (612) is placed at at least a site to which the adherent refrigerant (651) adheres.
  5. The engine system (1) according to any one of claims 1 to 4, wherein the intake port (61) has a throttle portion (67) with a partially reduced cross sectional area perpendicular to an airflow of the air, and the cooled portion (612) includes an intersection between the internal peripheral face of the intake port (61), and a virtual line perpendicularly extending from a cross section of the throttle portion (67) in the intake port (61) toward a downstream side of the airflow.
  6. The engine system (1) according to any one of claims 1 to 5, wherein in the intake port (61), the cooled portion (612) is placed more downstream of the airflow of the air than the injection unit (31).
  7. The engine system (1) according to any one of claims 1 to 6, wherein the intake port (61) has a curved portion having a cross sectional shape that is convexed toward one direction, and the cooled portion (612) is placed on the curved portion's face on the one direction side, of the internal peripheral face of the intake port (61).
  8. The engine system (1) according to any one of claims 1 to 7, wherein a valve seat portion (66) for seating an intake valve (72) is provided at the intake port's end portion on the combustion chamber side, and the cooled portion (612) is placed at the valve seat portion (66).
  9. The engine system (1) according to any one of claims 1 to 8, wherein after satisfying a supply start condition which includes an exhaust valve's closing, and after an elapse of a cooling period, the fuel supply unit (3) starts supplying the gaseous fuel to the internal space of the intake port (61).
  10. The engine system (1) according to claim 9, wherein an end time point of the cooling period is set at and after a time point at which an opening degree of the intake valve (72) is maximized.
  11. The engine system (1) according to any one of claims 1 to 10, further comprising: a turbocharger (8) that feeds the air into the intake port (61).

Description

TECHNICAL FIELD The present disclosure relates to an engine system in which blow-by gas with a specific gravity smaller than 1 with reference to air is generatable, and to an engine system provided with a fuel supply unit that supplies a gaseous fuel to an internal space of an intake port. BACKGROUND ART As a related technology, an engine system (internal combustion engine) with countermeasure for blow-by gas leaking out from a combustion chamber to a crank chamber (crankcase) is known (see, for example, Patent Document 1). In the engine system according to the related technology, an intake port to take in the blow-by gas from the crank chamber is provided on an internal face portion of the crank chamber. The intake port is connected to a blow-by gas passage by an intake passage, and the engine system is so configured as to return, by the blow-by gas passage, the blow-by gas to the combustion chamber via the intake system. Here, the intake port (the blow-by gas intake portion) is placed in a position below a crank journal, thereby to avoid an interference between the blow-by gas intake portion and the crankshaft's crank journal. Also known is a dual-injection type engine system (internal combustion engine) provided with an in-cylinder injector and an intake passage injector (see, for example, Patent Document 2). In the engine system according to the related technology, adjusting (correcting) a fuel injection volume suppresses generation of a backfire seen during an execution of a purging process of fuel evaporated gas. Specifically, at the time of executing the purging process of the fuel evaporated gas seen when a sharing ratio of the in-cylinder injector and the intake passage injector is within a predetermined range, the fuel injection volume correction that corresponds to a to-be-introduced purged fuel volume is performed by changing only the fuel injection volume from the intake passage injector. Patent Document 3 discloses a fuel injection control system for an internal combustion engine having a fuel injection valve located near an intake port can control the timing of fuel injection in synchronism with engine revolution. Patent Document 4 discloses a fuel supply device of spark ignition type internal combustion engine comprising a fuel injection valve and an intake port. Patent Document 5 discloses an engine including a cylinder head, air intake manifold, fuel injector and fuel rail. PRIOR ART DOCUMENT PATENT DOCUMENT Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-127894Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-194197Patent Document 3: US4562817 APatent Document 4: JP H04-143456 APatent Document 5: US 6269797 B1 SUMMARY OF INVENTION TECHNICAL PROBLEM By the way, in an engine system using a gaseous fuel, such as hydrogen, with a specific gravity smaller than 1, for example, blow-by gas leaking out to a crank chamber is likely to stay above the crank chamber. Therefore, placing the intake port in a position below the crank journal, as in the above related technology may not be able to efficiently discharge the blow-by gas from the crank chamber. Further, in the engine system that uses the gaseous fuel such as hydrogen, for example, the fuel is, as the case may be, more easily ignited. Therefore, it is desirable, in the event of occurrence of the backfire, to perform a further backfire countermeasure in anticipation of a possible ignition of the fuel supplied in the intake port and a chain of backfires. An object of the present disclosure is to provide an engine system that efficiently discharges blow-by gas from a crank chamber with ease, and an engine system that is capable of providing a further backfire countermeasure. SOLUTION TO PROBLEM An engine system according to one mode of the present disclosure is an engine system as described in claims 1-11. ADVANTAGEOUS EFFECTS OF INVENTION According to the present disclosure, it is possible to provide an engine system that efficiently discharges blow-by gas from a crank chamber with ease, and an engine system that is capable of providing a further backfire countermeasure. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a system diagram showing a schematic configuration of an engine system according to a first embodiment.Fig. 2 is an explanatory view showing a schematic configuration of a ship provided with the engine system according to the first embodiment.Fig. 3 is a schematic perspective view of an engine body of the engine system according to the first embodiment.Fig. 4 is a schematic left side view of the engine body of the engine system according to the first embodiment.Fig. 5 is a schematic plan view of the engine body of the engine system according to the first embodiment.Fig. 6 is a schematic front view of the engine body of the engine system according to the first embodiment.Fig. 7 is a schematic view partially breaking an essential portion of the engine body of the engine system acco