EP-4737703-A1 - INTERNAL COMBUSTION ENGINE SYSTEM AND COMPRESSOR

EP4737703A1EP 4737703 A1EP4737703 A1EP 4737703A1EP-4737703-A1

Abstract

An internal combustion engine system includes: a fuel gas passage that connects a fuel storing source to an internal combustion engine, the fuel storing source storing a fuel gas in a compressed state; and a compressor that pressurizes the fuel gas in the fuel gas passage. The compressor includes at least one reciprocating structure, and the reciprocating structure includes: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; and a cam that reciprocates the rod.

Inventors

IZUMI, KYOHEI
KIYOSE, HIROMITSU
SUZUKI, YUTAKA
Hattori, Tomohide
NINOMIYA, MAKOTO

Assignees

Kawasaki Motors, Ltd.

Dates

Publication Date: 20260506
Application Date: 20231222

Claims (13)

An internal combustion engine system comprising: a fuel gas passage that connects a fuel storing source to an internal combustion engine, the fuel storing source storing a fuel gas in a compressed state; and a compressor that pressurizes the fuel gas in the fuel gas passage, wherein: the compressor includes at least one reciprocating structure; and the reciprocating structure includes a cylinder including a suction port and a discharge port, a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port, a rod projecting from the piston, and a cam that reciprocates the rod.
The internal combustion engine system according to claim 1, wherein: the reciprocating structure further includes a first rod seal located between an outer peripheral surface of the rod and an inner peripheral surface of the cylinder and a recompression chamber located between the piston and the first rod seal in an axial direction of the cylinder; the recompression chamber is defined by the outer peripheral surface of the rod and the inner peripheral surface of the cylinder; a volume of the recompression chamber decreases by backward movement of the piston; and the cylinder includes an outflow port that is in fluid communication with the recompression chamber.
The internal combustion engine system according to claim 2, wherein: the reciprocating structure further includes a check valve that allows a flow from the recompression chamber through the outflow port to an outside of the recompression chamber and blocks a flow from the outside of the recompression chamber through the outflow port to the recompression chamber; and the outflow port is in fluid connection with a passage that is in fluid connection with the internal combustion engine through the check valve.
The internal combustion engine system according to claim 2 or 3, wherein: the inner peripheral surface of the cylinder includes a first inner peripheral surface defining a space in which the piston is accommodated and a second inner peripheral surface defining a space in which the rod is accommodated; an inner diameter of the second inner peripheral surface is smaller than an inner diameter of the first inner peripheral surface; the cylinder further includes an opposing surface that extends in a radial direction, connects the first inner peripheral surface to the second inner peripheral surface, and is opposed to the piston in the axial direction; and the recompression chamber is defined between the piston and the opposing surface of the cylinder.
The internal combustion engine system according to any one of claims 2 to 4, wherein: the compressor further includes a cam case defining a cam chamber in which the cam is accommodated; the reciprocating structure further includes a second rod seal located between the first rod seal and the cam chamber in the axial direction of the cylinder and interposed between the outer peripheral surface of the rod and the inner peripheral surface of the cylinder and a re-leak chamber located between the first rod seal and the second rod seal in the axial direction of the cylinder; the re-leak chamber is defined by the outer peripheral surface of the rod and the inner peripheral surface of the cylinder; a volume of the re-leak chamber decreases by backward movement of the rod; and the cylinder includes an exhaust port that is in fluid communication with the re-leak chamber.
The internal combustion engine system according to claim 5, wherein: the outflow port communicating with the recompression chamber is in fluid connection with a passage through which the fuel gas is supplied to a fuel injector of the internal combustion engine; and the exhaust port of the re-leak chamber is in fluid connection with an intake passage that is in fluid connection with the internal combustion engine.
The internal combustion engine system according to any one of claims 1 to 6, wherein: the compressor further includes a cam chamber in which the cam is accommodated; and during a stroke in which the piston moves from a top dead center to a bottom dead center, internal pressure of the cam chamber is set to be lower than internal pressure of the compression chamber.
The internal combustion engine system according to any one of claims 1 to 7, wherein: the compressor further includes a camshaft that rotates the cam; the reciprocating structure further includes a ring that covers an outer peripheral surface of the cam and is rotatable relative to the cam; the outer peripheral surface of the cam includes a true circular shape; the camshaft is eccentrically connected to the cam; and the cam pushes the rod through the ring.
The internal combustion engine system according to any one of claims 1 to 8, wherein the reciprocating structure further includes a check valve that allows a flow from the charge passage through the suction port to the compression chamber and blocks a flow from the compression chamber through the suction port to the charge passage and a check valve that allows a flow from the compression chamber through the discharge port to the charge passage and blocks a flow from the charge passage through the discharge port to the compression chamber.
The internal combustion engine system according to any one of claims 1 to 9, wherein: the at least one reciprocating structure comprises reciprocating structures; and the cams of the reciprocating structures have respective phases that are equally shifted from each other.
The internal combustion engine system according to any one of claims 1 to 10, further comprising a cooler that cools the fuel gas discharged from the discharge port of the compressor.
A compressor comprising: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; a cam that reciprocates the rod; a camshaft that rotates the cam; and a ring that covers an outer peripheral surface of the cam and is rotatable relative to the cam, wherein: the outer peripheral surface of the cam includes a true circular shape; the camshaft is eccentrically connected to the cam; and the cam pushes the rod through the ring.
A compressor comprising: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; a first rod seal located between an outer peripheral surface of the rod and an inner peripheral surface of the cylinder; and a recompression chamber located between the piston and the first rod seal in an axial direction of the cylinder, wherein: the recompression chamber is defined by the outer peripheral surface of the rod and the inner peripheral surface of the cylinder; a volume of the recompression chamber decreases by backward movement of the piston; and the cylinder includes an outflow port that is in fluid communication with the recompression chamber.

Description

Technical Field The present disclosure relates to an internal combustion engine system and a compressor. Background Art PTL 1 discloses an internal combustion engine system that generates driving force in such a manner that an internal combustion engine combusts, as fuel, a hydrogen gas supplied from a high-pressure hydrogen gas tank through a pressure reducing valve. Citation List Patent Literature PTL 1: Japanese Laid-Open Patent Application Publication No. 2021-173182 Summary of Invention Technical Problem When a fuel gas in a fuel tank is continuously consumed by the operation of an internal combustion engine, the internal pressure of the fuel tank eventually drops to less than a predetermined value. In this state, the fuel gas in the fuel tank cannot be appropriately supplied to the internal combustion engine. Thus, although the fuel gas remains in the fuel tank, the fuel tank is regarded as empty. An object of one aspect of the present disclosure is to increase the amount of fuel gas that can be supplied to the internal combustion engine while preventing an increase in the size of the system. Solution to Problem An internal combustion engine system according to one aspect of the present disclosure includes: a fuel gas passage that connects a fuel storing source to an internal combustion engine, the fuel storing source storing a fuel gas in a compressed state; and a compressor that pressurizes the fuel gas in the fuel gas passage. The compressor includes at least one reciprocating structure, and the reciprocating structure includes: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; and a cam that reciprocates the rod. A compressor according to one aspect of the present disclosure includes: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; a cam that reciprocates the rod; a camshaft that rotates the cam; and a ring that covers an outer peripheral surface of the cam and is rotatable relative to the cam. The outer peripheral surface of the cam includes a true circular shape. The camshaft is eccentrically connected to the cam. The cam pushes the rod through the ring. A compressor according to another aspect of the present disclosure includes: a cylinder including a suction port and a discharge port; a piston accommodated in the cylinder and defining a compression chamber facing the suction port and the discharge port; a rod projecting from the piston; a first rod seal located between an outer peripheral surface of the rod and an inner peripheral surface of the cylinder; and a recompression chamber located between the piston and the first rod seal in an axial direction of the cylinder. The recompression chamber is defined by the outer peripheral surface of the rod and the inner peripheral surface of the cylinder. A volume of the recompression chamber decreases by backward movement of the piston. The cylinder includes an outflow port that is in fluid communication with the recompression chamber. Advantageous Effects of Invention According to the internal combustion engine system of one aspect of the present disclosure, the amount of fuel gas that can be supplied to the internal combustion engine can be increased while preventing an increase in the size of the system. The compressor according to one aspect of the present disclosure can be made smaller than a reciprocating compressor in which a piston is caused to reciprocate by a crankshaft and a connecting rod. The compressor according to another aspect of the present disclosure can prevent the leaked fuel gas from accumulating in the cylinder. Brief Description of Drawings FIG. 1 is a schematic diagram showing a movable body on which an internal combustion engine system according to an embodiment is mounted.FIG. 2 is an enlarged schematic diagram showing a compressor assembly of FIG. 1.FIG. 3 is a perspective view showing a compressor of FIG. 2.FIG. 4 is a vertical sectional view showing the compressor of FIG. 3.FIG. 5 is a sectional view taken along line V-V of FIG. 4.FIG. 6 is a horizontal sectional view showing a recompression chamber and a re-leak chamber of the compressor of FIG. 5.FIG. 7 is a block diagram showing an example of the arrangement of a speed reducer and an electric motor.FIG. 8 is a block diagram showing another example of the arrangement of the speed reducer and the electric motor. Description of Embodiments Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a movable body on which an internal combustion engine system according to the embodiment is mounted. As shown in FIG. 1, in the present embodiment, an internal combustion engine system 1 is mounted on