JPH07208134A - Cylinder oiling device - Google Patents

Abstract

PURPOSE:To prevent the generation of abrasion and or seizure of a cylinder, a piston, and a piston ring, by enabling oiling of a sufficient amount into the cylinder in the vicinity of the top dead point of the piston, in a reciprocating engine. CONSTITUTION:A hydraulic piston 2 is fit to the inside of a hydraulic cylinder 1 which is formed in the inside of a piston 103, an oil chamber 1a is limited, lubricating oil in the oil chamber 1a is oiled from an oil feeding port 5 which is opened to the outer circumferential surface of the piston 103 into a cylinder inner surface 102a through an outlet check valve 32 and an oil feeding passage 4 while utilizing reciprocating motion of the piston 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating engine, and more particularly to a cylinder lubricating device suitable for lubricating a cylinder inner surface of a reciprocating internal combustion engine with lubricating oil.

[0002]

2. Description of the Related Art An example of a conventional cylinder lubrication device for a large diesel engine is shown in FIGS. In FIG. 5, 101 is a combustion chamber, 102 is a cylinder, 103 is a piston, 104 is a piston ring, 105 is an exhaust valve, and 106 is an exhaust passage.

Reference numeral 107 denotes an oil injection port formed in the inner surface 102a of the cylinder 102 along the circumferential direction at intervals from each other. The oil injection port 107 is provided with a predetermined oil injection timing from an oil injection device (not shown). The lubricating oil that has been pumped is guided through the lubrication passage 110. 108 is a pressure accumulator and 109 is a check valve.

Lubricating oil pressure-fed from the lubricator at a predetermined lubrication timing is accumulated in the pressure accumulator 108 via the lubrication passage 110, and when the pressure becomes higher than the spring pressure of the check valve 109, a check is performed. The valve 109 is pushed open and discharged from the oil inlet 107 to the cylinder inner surface 102a. FIG. 6 shows an oiling timing diagram of this cylinder oiling device.

[0005]

In a large diesel engine, it is desired to inject a sufficient amount of lubricating oil into the cylinder inner surface 102a in the vicinity of the piston top dead center in the explosion and combustion strokes. However, in the conventional lubrication device, as shown in FIG. 6, a large amount of lubricating oil is lubricated near the bottom dead center of the piston, but the lubrication period near the top dead center is short, so a sufficient amount of lubrication oil is provided. Cannot inject the lubricating oil of.

Further, in the above-mentioned conventional one, the oil inlet
Since the lubricating oil is injected in the vicinity of 107, the lubricating oil is not sufficiently diffused over the entire longitudinal direction of the cylinder 102 in an engine having a long stroke. For this reason, the friction loss increases due to lack of lubricating oil, and defects such as wear and seizure of the cylinder inner surface 102a and the piston ring 104 are likely to occur.

The present invention has been made to solve the above problems, and an object of the present invention is to supply a sufficient amount of lubricating oil to the inner surface of the cylinder in the vicinity of the piston top dead center where the lubrication conditions are the most severe. In addition, the lubricating oil is sufficiently diffused along the longitudinal direction of the cylinder to prevent an increase in friction loss due to insufficient lubricating oil, and prevent wear and seizure of the inner surface of the cylinder and the piston ring.

[0008]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above problems, and its gist is to provide a cylinder lubrication device for lubricating oil on the inner surface of a cylinder which is in sliding contact with a piston. , A hydraulic cylinder is provided inside the piston along the axial direction thereof, and the hydraulic cylinder is fitted in the hydraulic cylinder so as to be slidable in an oil-tight manner to open in an oil chamber limited and the outer peripheral surface of the piston. An outlet check valve that allows only the outflow of lubricating oil from the oil chamber is installed in the oil passage that communicates with the oil inlet, and only the inflow of lubricating oil into the oil chamber occurs in the oil passage that communicates with the oil chamber. The cylinder lubrication device is characterized in that an inlet check valve that allows the above is installed.

The features of the embodiment of the present invention are the following two points. (1) A lubrication port that opens on the outer peripheral surface of the piston is provided in the lower land of the multi-stage piston ring. (2) The hydraulic cylinder, lubrication passage, oil supply passage, etc. are formed in the piston.

[0010]

Since the present invention is configured as described above, the hydraulic piston descends relative to the hydraulic cylinder due to inertial force from the descending stroke of the piston, through the bottom dead center to the first half of the ascending stroke, and enters the oil chamber. Intake lubricating oil through the oil supply passage and the inlet check valve.

The hydraulic piston relatively rises from the latter half of the upward stroke of the piston, through the top dead center, and the first half of the downward stroke.
Lubricating the inner surface of the cylinder by sending the lubricating oil in the oil chamber to the oil inlet through the outlet check valve and the oil passage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. 1 to 4, FIG. 1 is a sectional view of a main part of a cylinder oiling device for a large diesel engine, and FIGS. 2 and 3 are sectional views of a main part for explaining the operation. FIG. 4 is a diagram showing the lubrication timing.

1 to 3, 101 is a combustion chamber,
102 is a cylinder, 103 is a piston, 104 is a piston 103
A piston ring fitted in a plurality of stages (four stages in this embodiment) and an exhaust valve 105 have the same construction as the conventional one.

Reference numeral 1 denotes a hydraulic cylinder formed inside the piston 103 along the axial direction of the piston 103. By mounting the hydraulic piston 2 in the hydraulic cylinder 1 in an oil-tight manner, the oil chamber 1a is limited. Has been done. An oil supply passage 6 communicates with the chamber 1a via an inlet check valve 31.

Reference numeral 5 denotes an oil filling port opened on the outer peripheral surface of the piston 103, and these oil filling ports 5 are respectively opened to the piston land portions 103a below the piston rings 104 of the respective stages.

Reference numeral 4 denotes an oil supply passage, one end of which communicates with each oil supply port 5 and the other end of which communicates with the oil chamber 1a via an outlet check valve 32. The inlet check valve 31 is configured to allow the flow of lubricating oil flowing into the oil chamber 1a, and the outlet check valve 32 is configured to allow only the flow of lubricating oil flowing out of the oil chamber 1a. ing. Reference numeral 8 is an air supply / exhaust hole.

When operating a large diesel engine,
From the latter half of the descending stroke of the piston 103 to the first half of the ascending stroke through the bottom dead center, the piston 103 receives an upward acceleration Z, as shown in FIG.

Therefore, the hydraulic piston 2 descends relatively to the hydraulic cylinder 1 by the downward inertial force Y acting on the hydraulic piston 2. As a result, the pressure in the oil chamber 1a is lowered, so that the inlet check valve 31 is opened and the lubricating oil 10 in the oil supply passage 6 is replaced by the oil chamber 1a.
Flows in.

From the latter half of the ascending stroke of the piston 103 to the first half of the descending stroke after passing through the top dead center, the piston 103 receives downward acceleration W as shown in FIG. Rise relative to cylinder 1.

[0020] As a result, the lubricating oil in the oil chamber 1a is discharged to the outlet check valve.
32 is pushed open and flows through the oil supply passage 4 and from each oil supply port 5 to the cylinder inner surface 102a.

In this lubrication system, as shown in FIG. 4, the lubrication conditions are the most severe because the lubrication is performed from the respective lubrication ports 5 to the cylinder inner surface 102a from the latter half of the ascending stroke of the piston to the upper half of the top dead center of the piston. The lubricating oil can be reliably fed to the cylinder inner surface 102a before and after the top dead center. And since the lubrication port 5 reciprocates together with the piston 103,
The lubricating oil is sufficiently diffused over the entire cylinder inner surface 102a.

Further, since the oil injection port 5 is opened in the lower piston land 103a of each piston ring 104, the diffusion of the lubricating oil in the longitudinal direction of the cylinder is promoted also from this surface. Further, since the hydraulic cylinder 1, the lubrication passage 4, the oil supply passage 6 and the like are formed in the piston 103, the lubrication device becomes compact.

[0023]

As described above, according to the present invention, by utilizing the inertial force acting on the hydraulic piston as the piston reciprocates, the hydraulic piston is reciprocated in the hydraulic cylinder, whereby the lubricating oil is applied to the inner surface of the cylinder. Since the oil is added, the following effects are achieved.

(1) Sufficient lubrication is possible between the piston or piston ring and the inner surface of the cylinder near the top dead center where the lubrication conditions are the most severe. (2) Lubrication oil can be sufficiently diffused also in the longitudinal direction of the inner surface of the cylinder because it is lubricated from the lubrication port that opens on the outer peripheral surface of the reciprocating piston. (3) Lubrication oil consumption is reduced because oil can be injected at the most appropriate time. (4) Lubrication can be done using the reciprocating motion of the piston.
The conventional lubricator is no longer required, so the lubricator is simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a large diesel engine oiling device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of essential parts for explaining the operation of the oil supply device.

FIG. 3 is a cross-sectional view of an essential part for explaining the operation of the oil supply device.

FIG. 4 is a diagram showing an oiling timing of the oiling device.

FIG. 5 is a cross-sectional view of a main part of a conventional large diesel engine oiling device.

FIG. 6 is a diagram showing an oiling timing in the conventional oiling device.

[Explanation of symbols]

 1 Hydraulic Cylinder 2 Hydraulic Piston 1a Oil Chamber 31 Inlet Check Valve 4 Lubrication Channel 5 Lubrication Port 6 Lubrication Channel 102 Cylinder 102a Cylinder Inner Surface 103 Piston 103a Piston Land 104 Piston Ring

Claims (1)

[Claims] 1. A cylinder lubrication device for lubricating oil on an inner surface of a cylinder which is in sliding contact with a piston, wherein a hydraulic cylinder is provided inside the piston along an axial direction thereof, and a hydraulic cylinder is slidably oil-tightly slidable in the hydraulic cylinder. An outlet check valve that allows only the outflow of lubricating oil from the oil chamber is provided in the oil passage that connects the oil chamber limited by fitting the piston and the oil inlet opening on the outer peripheral surface of the piston. In addition, the cylinder lubrication device is characterized in that an inlet check valve which allows only the inflow of lubricating oil into the oil chamber is provided in an oil supply passage communicating with the oil chamber.