Machine provided with pulsating oil pressure reducing device

Abstract

A pulsating oil pressure reducing device 40 for an internal combustion engine has an oil chamber 41 for reducing pulsating oil pressure in a discharge passage 30 for carrying oil discharged from an oil pump 20. The oil chamber 41 communicates with the discharge passage 30 by way of a connecting port 41a1 and makes the oil stagnate therein. The oil chamber 41 is connected to the discharge passage 30 by an air vent passage 45 through which air is discharged from the oil chamber 41 into the discharge passage 30. The air vent passage 45 has an inlet port 45a opening into a top part 41a of the oil chamber 41 and a discharge port 45b opening into the oil passage 30 at a level above the inlet port 45a. Since the pulsating oil pressure reducing device 40 having the air vent passage separately from the connecting port, air can be efficiently discharged from the oil chamber and the degree of freedom of placement of the oil passage and the oil chamber is increased.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary view, partly in section, of an internal combustion engine to which the present invention is applied;

FIG. 2 is a view of a balancer and an oil pump included in the internal combustion engine shown in FIG. 1, taken in the direction of the arrow II in FIG. 1;

FIG. 3 is a sectional view taken on the line III-III in FIG. 2;

FIG. 4 is a sectional view taken on the line IV-IV in FIG. 2;

FIG. 5 is a sectional view taken on the line V-V in FIG. 2;

FIG. 6 is a sectional view taken on the line VI-VI in FIG. 2;

FIG. 7 is a sectional view taken on the line VII-VII in FIG. 6;

FIG. 8 is a sectional view taken on the line VIII-VIII in FIG. 6;

FIG. 9 is a graph comparatively showing variation of pulsating oil pressure with engine speed in a part of an oil passage near an oil filter on an internal engine according to the present invention provided with a pulsating oil pressure reducing device and variation of pulsating oil pressure with engine speed in a part of an oil passage near an oil filter on an internal combustion engine in a comparative example not provided with any pulsating oil pressure reducing device; and

FIG. 10 is a graph comparatively showing variation of noise level of noise generated by an oil filter included in an internal engine according to the present invention provided with a pulsating oil pressure reducing device, with engine speed, and variation of noise level of noise generated by a filter included in an internal combustion engine in a comparative example not provided with any pulsating oil pressure reducing device, with engine speed.

Claims

1. A machine provided with a pulsating oil pressure reducing device, for reducing pulsating oil pressure in an oil passage, including an oil chamber communicating with the oil passage by way of a connecting port in a manner to make oil stagnate in the oil chamber; wherein the oil chamber is connected to the oil passage by an air vent passage through which air is discharged from the oil chamber into the oil passage, the air vent passage is provided separately from the connecting port and has an inlet port opening into a top part of the oil chamber and an outlet port opening into the oil passage at a level above the inlet port.

2. The machine according to claim 1, wherein the oil passage and the oil chamber are horizontally arranged in side-by-side relation.

3. The machine according to claim 2, wherein the oil passage and the oil chamber extend horizontally.

4. The machine according to claim 1, wherein the air vent passage has an upper ceiling surface sloping upward from the oil chamber toward the oil passage.

5. The machine according to claim 1, wherein the oil passage and the pulsating oil pressure reducing device are formed in a structure dividable along a parting line into an upper member and a lower member, the oil passage is defined by both the upper and the lower member, the oil chamber is formed only in the lower member, and the air vent passage is formed only in the upper member.

6. The machine according to claim 5, wherein the oil chamber has a groove formed in the lower member and is a cavity having an expanded part in a depth thereof remote from the connecting port opening into the oil passage.

7. The machine according to claim 6, wherein the inlet port of the air vent passage is positioned nearer to the connecting port than the expanded part of the oil chamber.

8. The machine according to claim 5, wherein the air vent passage is a narrow groove formed in the upper member.

9. The machine according to claim 1, wherein the oil passage has an upstream end connected to an oil pump, and the outlet port of the air vent passage is nearer to the oil pump than the connecting port.