Hydrogen engine

Patent metadata

Field	Value
Publication number	US-12546248-B2
Application number	US-202318856359-A
Country	US
Kind code	B2
Filing date	Apr 13, 2023
Priority date	Apr 25, 2022
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A hydrogen engine using fuel gas containing hydrogen, including: a cylinder; a piston movable within the cylinder; a cylinder head forming a combustion chamber with the piston, and including an intake port connected to the combustion chamber and a fuel supply port connected to the combustion chamber; an intake valve for opening and closing the intake port; a fuel supply valve for opening and closing the fuel supply port; and a valve train commonly provided for the intake valve and the fuel supply valve, and configured to open and close the intake valve and the fuel supply valve in conjunction with each other. The hydrogen engine is configured such that a valve opening timing of the fuel supply valve is more retarded than a valve opening timing of the intake valve.

First claim

The invention claimed is:

1 . A hydrogen engine using fuel gas containing hydrogen, comprising:
a cylinder; a piston movable within the cylinder; a cylinder head forming a combustion chamber with the piston, and including an intake port connected to the combustion chamber and a fuel supply port connected to the combustion chamber; an intake valve for opening and closing the intake port; a fuel supply valve for opening and closing the fuel supply port; and a valve train commonly provided for the intake valve and the fuel supply valve, and configured to open and close the intake valve and the fuel supply valve in conjunction with each other, wherein the hydrogen engine is configured such that a valve opening timing of the fuel supply valve is more retarded than a valve opening timing of the intake valve.

2 . The hydrogen engine according to claim 1 ,
wherein the valve train includes:
an intake rocker arm configured to rotate around a predetermined rotational axis and to press the intake valve; and
a fuel supply valve arm configured to rotate around the rotational axis together with the intake rocker arm and to press the fuel supply valve, and
wherein a maximum value of a distance between the fuel supply valve arm and the fuel supply valve in one combustion cycle of the engine is greater than a maximum value of a distance between the intake rocker arm and the intake valve in the one combustion cycle of the engine.

3 . The hydrogen engine according to claim 2 ,
wherein the distance between the fuel supply valve arm and the fuel supply valve at a valve closing timing of an exhaust valve of the engine is greater than 0.

4 . The hydrogen engine according to claim 1 ,
wherein the fuel supply valve includes:
a valve stem;
a valve body portion disposed on one end side of the valve stem and abuttable against a valve seat surface of the fuel supply port in an axial direction of the valve stem; and
a collar portion disposed between the valve stem and the valve body portion, and located upstream of a flow of the fuel gas in an axial direction of the fuel supply valve relative to the valve seat surface of the fuel supply port in a state in which the valve body portion abuts against the valve seat surface.

5 . The hydrogen engine according to claim 4 ,
wherein H1>0.7L is satisfied, where L is a lift amount of the fuel supply valve at a valve closing timing of an exhaust valve of the engine and H1 is a height of the collar portion.

6 . The hydrogen engine according to claim 1 ,
wherein the fuel supply port includes:
a first flow passage portion disposed along an axial direction of the fuel supply valve;
a valve seat surface disposed downstream of the first flow passage portion; and
a second flow passage portion disposed downstream of the valve seat surface and having a flow passage width greater than a flow passage width of the first flow passage portion, and
wherein an outer peripheral surface of a valve body portion of the fuel supply valve is configured to slide on a flow passage wall of the second flow passage portion.

7 . The hydrogen engine according to claim 6 ,
wherein H2>0.7L is satisfied, where L is a lift amount of the fuel supply valve at a valve closing timing of an exhaust valve of the engine and H2 is a length of the second flow passage portion in an axial direction of the fuel supply valve.

8 . A hydrogen engine using fuel gas containing hydrogen, comprising:
a cylinder; a piston movable within the cylinder; a cylinder head forming a combustion chamber with the piston, and including an intake port connected to the combustion chamber, a fuel supply port connected to the combustion chamber, and an exhaust port connected to the combustion chamber; an intake valve for opening and closing the intake port; a fuel supply valve for opening and closing the fuel supply port; a valve train commonly provided for the intake valve and the fuel supply valve, and configured to open and close the intake valve and the fuel supply valve in conjunction with each other; and a cover portion configured to cover at least a part of an outlet portion of the fuel supply port on a side of the exhaust port in at least a part of a valve opening period of the fuel supply valve.

9 . The hydrogen engine according to claim 8 ,
wherein the cover portion is a collar portion disposed between a valve stem of the fuel supply valve and a valve body portion, and wherein the collar portion is formed in a disk or columnar shape, is located upstream of a flow of the fuel gas in an axial direction of the fuel supply valve relative to a valve seat surface of the fuel supply port in a state in which a valve body portion of the fuel supply valve abuts against the valve seat surface, and has an outer diameter greater than an outer diameter of the valve stem.

10 . The hydrogen engine according to claim 8 ,
wherein the cylinder head includes:
a cylinder head body;
a valve seat member forming a valve seat surface of the fuel supply port and configured separately from the cylinder head body; and
a mask plate interposed between the cylinder head body and the valve seat member,
wherein the mask plate includes a protruding portion protruding from a flow passage wall of the fuel supply port toward a valve stem of the fuel supply valve, and wherein the cover portion is the protruding portion.

11 . The hydrogen engine according to claim 8 ,
wherein the cylinder head includes:
a cylinder head body; and
a valve seat member forming a valve seat surface of the fuel supply port and configured separately from the cylinder head body,
wherein the valve seat member includes a protruding portion protruding from a flow passage wall of the fuel supply port toward a valve stem of the fuel supply valve, and wherein the cover portion is the protruding portion.

12 . The hydrogen engine according to claim 8 ,
wherein, where a strength S of a swirling flow of intake air flowing into the combustion chamber from the intake port is a dimensionless number indicating how many times the swirling flow rotates about the combustion chamber during one rotation of the engine, an angular width OL is a width of a crank angle, which corresponds to, of one combustion cycle of the engine, a period of overlap between a valve opening period of an exhaust valve of the engine and a valve opening period of the fuel supply valve, and an angle θ is a product of the strength S of the swirling flow and the angular width OL, and where S1 is a range on a side of the exhaust port and S2 is a range of the angle θ from an upstream end in a rotational direction of the swirling flow in the range S1 to an upstream side in the rotational direction of the swirling flow, in a circumferential direction around an axis of the fuel supply valve, the cover portion is disposed in a range including the range S1 and the range S2 in the circumferential direction.

13 . A hydrogen engine using fuel gas containing hydrogen, comprising:
a cylinder; a piston movable within the cylinder; a cylinder head forming a combustion chamber with the piston, and including an intake port connected to the combustion chamber, a fuel supply port connected to the combustion chamber, and an exhaust port connected to the combustion chamber; an intake valve for opening and closing the intake port; a fuel supply valve for opening and closing the fuel supply port; and a valve train commonly provided for the intake valve and the fuel supply valve, and configured to open and close the intake valve and the fuel supply valve in conjunction with each other, wherein a lower surface of the cylinde

Assignees

• Mitsubishi Heavy Ind Engine & Turbocharger Ltd

Inventors

• Endo Hiroyuki
• Toda Masaki
• Watanabe Sota
• Noguchi Tomohiro

Classifications

• F02D19/024 Primary

  by controlling fuel injectors · CPC title

• F02B2275/14

  Direct injection into combustion chamber · CPC title

• F02B2201/04

  Gas · CPC title

• F02B1/08

  with separate admission of air and fuel into cylinder · CPC title

• F01L1/181

  Centre pivot rocking arms · CPC title