JPH08135424A - Lubricating oil passage structure for internal combustion engine - Google Patents

Abstract

PURPOSE: To improve strength of a case side axially supporting member in a lower case by connecting a connecting portion of the case side axially supporting member and one of side connecting members by a projected reinforcing member and forming a drop passage extended part to communicate with a lubricating oil drop passage on this reinforcing member. CONSTITUTION: A lower case 2 of an internal combustion engine connects each of its side ends by connecting members 8, 10 by arranging a plural number of case side axially supporting members 4 axially supporting a crankshaft in parallel, and a main oil gallery 12 which is a main lubricating oil passage is formed on one of these connecting members 8, 10. Additionally, a lubricating oil drop passage 16 to return lubricating oil to an oil pan is provided on the case side axially supporting members 4. Thereafter, a connecting portion of the case side axially supporting members 4 and the connecting member 8 is connected by a reinforcing member 20 projected to a position not to interfere with rotating loci 22, 24 of the crankshaft and a connecting rod, and a drop passage extended part 26 to communicate with the lubricating oil drop passage 16 is formed on this reinforcing member 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil passage structure of an internal combustion engine, and more particularly, to a lubricating oil dropping passage capable of ensuring a sufficient passage cross-sectional area while effectively utilizing a space, thereby providing a blowby gas recirculation performance. The present invention relates to a lubricating oil passage structure for an internal combustion engine, which can improve the strength of the lower case, and can improve the strength of the case side shaft support member of the lower case.

[0002]

2. Description of the Related Art In an internal combustion engine, lubricating oil is supplied in order to lubricate each part of the engine that slides and cool each part of the engine that becomes hot. Lubricating oil is stored in an oil pan and is sent by an oil pump through an oil filter or the like to a main oil gallery which is a main lubricating oil passage.

Lubricating oil in the main oil gallery is sent to a crankshaft, a piston, a camshaft, intake / exhaust valves, etc., and lubricates and cools each part. Lubricating oil that has achieved lubrication and cooling of each part is returned to the lubricating oil dropping passage (not shown).

A lubricating oil passage structure for such an internal combustion engine is shown in FIG. In FIG. 6, reference numeral 102 is a lower case that is interposed between a cylinder block and an oil pan of an internal combustion engine (not shown). Lower case 102
Crankshaft (not shown) between cylinder block and
A plurality of case-side shaft supporting members 104 for supporting the shaft are provided. The case-side shaft supporting member 104 includes the case-side shaft supporting portion 10.
6 is provided. The case side shaft supporting portion 106 pivotally supports the crank shaft between the block side shaft supporting portion of a cylinder block (not shown).

The lower case 102 has one side connecting member 208 and other members that direct the respective side ends of the plurality of case side shaft supporting members 104 in the direction intersecting the crankshaft axis A in a direction parallel to the crankshaft axis A. They are connected by side connecting members (not shown).

A main oil gallery 110, which is a main lubricating oil passage directed in the direction of the crankshaft axis A, is formed on either one of the one side connecting member 108 and the other side connecting member. In the illustrated example, the one side connecting member 10
8, a main oil gallery 110 that is oriented in the direction of the crankshaft axis A is formed and provided.

A lubricating oil introduction passage 112 for introducing lubricating oil from the main oil gallery 110 to the case side shaft supporting portion 106 is formed in the case side shaft supporting member 104. Lubricating oil of the main oil gallery 110 is sent to the bearing portion of the crankshaft by the lubricating oil introducing passage 112 to perform lubrication and cooling. Further, the lubricating oil of the main oil gallery 110 is supplied to a cylinder block, a piston of the cylinder head, a cam shaft,
It is sent to intake / exhaust valves, etc. to perform lubrication and cooling of each part.

The case side shaft supporting member 104 is provided with a lubricating oil drop passage 114 for returning the lubricating oil after lubricating and cooling the valve train such as the cam shaft to the oil pan. There is. The lubricating oil drop passage 114 is formed adjacent to the lubricating oil introduction passage 112 in the case side shaft support member 104. Lubricating oil introduction passage 112 and lubricating oil dropping passage 1
The passage 14 is isolated from the passage 14.

An example of such a lubricating oil passage structure is disclosed in Japanese Utility Model Publication No. 6-18010. In the one disclosed in this publication, an expansion chamber is provided so as to open to the crank chamber adjacent to the lower portion of the crankcase of the oil drop hole or the blow-by gas passage, and the expansion chamber is recessed from the inner surface of the crankcase. It is provided by no means.

[0010]

However, as shown in FIG.
In the lubricating oil passage structure shown in FIG.
A lubricating oil introducing passage 112 for introducing lubricating oil from the main oil gallery 110 to the case side shaft supporting portion 106 is formed at 04, and a lubricating oil dropping passage 114 is formed adjacent to the lubricating oil introducing passage 112. The passage isolation portion 116 is projected into the lubricating oil dropping passage 112, and the lubricating oil dropping passage 1
There is an inconvenience that it is difficult to reduce the cross-sectional area of the passage 12 and secure it sufficiently.

Therefore, in the conventional lubricating oil passage structure, there is an inconvenience that it becomes difficult for the lubricating oil after lubricating the valve operating system such as the cam shaft to fall into the oil pan. As a result, the recirculation performance of blow-by gas is adversely affected. In addition to this, there is the inconvenience that the air mixing ratio (air array) is increased.

On the other hand, when the lubricating oil dropping passage is formed in the one side connecting member 108 outside the main oil gallery 110 in order to secure a sufficient passage cross-sectional area of the lubricating oil dropping passage 112, the width of the lower case 102 is reduced. However, there is a problem in that the internal combustion engine is prevented from becoming compact.

[0013]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides a lower case interposed between a cylinder block and an oil pan of an internal combustion engine, and the lower case is provided between the cylinder block and the cylinder block. And a plurality of case side shaft supporting members for supporting the crank shaft are provided, and each side end of the plurality of case side shaft supporting members in a direction intersecting with the crank shaft axis is directed in a direction parallel to the crank shaft axis. A main lubricating oil passage that is oriented in the crankshaft axis direction is formed in one of the side connecting members, and the main lubricating oil passage is connected to the case side shaft support member. A lubricating oil introducing passage for introducing lubricating oil is formed in the case side shaft supporting portion, and a lubricating oil dropping passage for returning the lubricated lubricating oil to the oil pan is provided adjacent to the lubricating oil introducing passage. The crankshaft is formed on the case-side shaft supporting member, and the connecting portion between the case-side shaft supporting member forming the lubricating oil drop passage and one of the side connecting members forming the main lubricating oil passage is formed on the crankshaft. And a connecting member provided with a reinforcing member projecting to a position not interfering with the rotation locus of the connecting rod, and the reinforcing member is provided with a dropping passage expanding portion communicating with the lubricating oil dropping passage. .

[0014]

According to the structure of the present invention, the connecting portion between the case side shaft supporting member having the lubricating oil drop passage and one of the connecting members of each side having the main lubricating oil passage is connected to the rotational locus of the crankshaft and the connecting rod. It is provided by connecting with a reinforcing member that protrudes to a position that does not interfere with, and by forming a drop passage expansion part that communicates with the lubricating oil drop passage in this reinforcing member, the space in the lower case is effectively used. It is possible to secure a sufficient passage cross-sectional area for the lubricating oil drop passage,
Further, the case-side shaft supporting member can be reinforced by the reinforcing member.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show an embodiment of the present invention. In FIGS. 1 and 5, reference numeral 2 is a lower case. The lower case 2 is interposed between a cylinder block and an oil pan of an internal combustion engine (not shown). The lower case 2 is provided with a plurality of case-side shaft support members 4 that support a crank shaft (not shown) in parallel with the cylinder block. The case-side shaft supporting member 4 is provided with a case-side shaft supporting portion 6. The case-side shaft support 6 supports the crankshaft between the block-side shaft support of a cylinder block (not shown).

The lower case 2 has one side connecting member 8 and other members that direct the respective side ends of the plurality of case side shaft supporting members 4 in the direction intersecting with the crankshaft axis A in a direction parallel to the crankshaft axis A. They are connected by the side connecting member 10. A main oil gallery 12, which is a main lubricating oil passage directed in the direction of the crankshaft axis A, is formed on either one of the one side connecting member 8 and the other side connecting member 1. In this embodiment, a main oil gallery 12 is formed and provided on the one side connecting member 8.

As shown in FIG. 2, the case-side shaft supporting member 4 includes a main oil gallery 12 to a case-side shaft supporting portion 6.
A lubricating oil introducing passage 14 for introducing lubricating oil is formed and provided. Lubricating oil of the main oil gallery 12 is sent to a bearing portion of a crankshaft (not shown) by the lubricating oil introducing passage 14 to perform lubrication and cooling. Further, the lubricating oil of the main oil gallery 12 is sent to a piston of the cylinder block and the cylinder head, a cam shaft, an intake / exhaust valve, etc. through a lubricating oil passage (not shown), and lubricates and cools each part.

The case side shaft support member 4 is provided with a lubricating oil drop passage 16 for returning the lubricating oil after lubricating and cooling the various parts of the engine to the oil pan. The lubricating oil drop passage 16 is formed in the case side shaft support member 4 adjacent to the lubricating oil introduction passage 14. The lubricating oil introducing passage 14 and the lubricating oil dropping passage 16 are separated by a passage separating portion 18.

A connecting portion between the case side shaft supporting member 4 having the lubricating oil drop passage 16 and the one side connecting member 8 having the main oil gallery 12 is integrally connected by a reinforcing member 20. ing. The reinforcing member 20 is located between the case-side shaft supporting member 4 and the respective side connecting members 8 and 10 so as not to interfere with the rotation locus 22 of the crankshaft (not shown) and the rotation locus 24 of the connecting rod connected to the crankshaft. It is provided so as to protrude.

The reinforcing member 20 includes a lubricating oil drop passage 1
A drop passage expansion portion 26 communicating with 6 is formed and provided. As a result, the lubricating oil drop passage 16 is communicated with the drop passage extension portion 26 to expand the passage cross-sectional area, as shown in FIGS.

Next, the operation will be described.

Lubricating oil in an oil pan (not shown) is fed to the main oil gallery 12 by an oil pump through an oil filter or the like. Main oil gallery 12
The lubricating oil is sent to the crank shaft, piston, cam shaft, intake / exhaust valve, etc., and lubricates and cools each part.

After lubricating and cooling the valve train such as the cam shaft, the lubricating oil flows through the lubricating oil dropping passages (not shown) of the cylinder head and the cylinder block and the lubricating oil dropping passage 16 of the lower case 2. , Returned to the oil pan.

The lower case 2 is provided with a lubricating oil drop passage 16
The connecting portion between the case-side shaft supporting member 4 having the above-mentioned structure and the one-side connecting member 8 having the main oil gallery 12 is projected to a position where it does not interfere with the rotation locus 22 of the crankshaft and the rotation locus 24 of the connecting rod. It is provided integrally connected by the connecting member 20.

The reinforcing member 20 includes a lubricating oil drop passage 1
A drop passage expansion portion 26 communicating with 6 is formed and provided. As described above, the lubricating oil drop passage 16 communicates with the drop passage expansion portion 26 as shown in FIGS.
The passage cross-sectional area is expanded.

As a result, the lubricating oil passage structure has the case side shaft support member 4 and the respective side connecting members 8 in the lower case 2.
The space enclosed by 10 can be effectively used to ensure a sufficient passage cross-sectional area of the lubricating oil dropping passage 16, and the case-side shaft support member 4 can be reinforced by the reinforcing member 20.

For this reason, this lubricating oil passage structure can secure a sufficient passage cross-sectional area of the lubricating oil drop passage 16 while making effective use of the space, and perform lubrication after lubricating the valve operating system such as the cam shaft. It is possible to eliminate the inconvenience that it is difficult for oil to drop into the oil pan.

As a result, this lubricating oil passage structure can eliminate the adverse effect on the recirculation performance of blow-by gas and the inconvenience that the mixing ratio of air is increased, so that the recirculation performance of blow-by gas can be improved and The mixing ratio can be reduced.

Further, in this lubricating oil passage structure, the connecting portion between the case side shaft supporting member 4 and the one side connecting member 8 is projected to a position where it does not interfere with the crankshaft and the connecting rods 22 and 24. By integrally connecting with the member 20, the strength of the case side shaft supporting member 4 of the lower case 2 can be improved, and the connecting member 20 does not project to the outside of the lower case 2.
It does not cause an increase in the width of the lower case 2 and does not hinder the downsizing of the internal combustion engine.

[0030]

As described above, according to the present invention, the space that does not interfere with the respective rotation loci of the crankshaft and the connecting rod in the lower case is effectively utilized to ensure a sufficient passage cross-sectional area of the lubricating oil drop passage. In addition, the case-side shaft support member can be reinforced by the reinforcement member.

Therefore, in this lubricating oil passage structure, it is possible to sufficiently utilize the space while ensuring a sufficient passage cross-sectional area of the lubricating oil drop passage, and to lubricate the valve operating system such as the camshaft. Can eliminate the inconvenience that it becomes difficult to drop into the oil pan,
As a result, the adverse effect on the recirculation performance of the blow-by gas and the inconvenience that the air mixing ratio is increased can be eliminated, the recirculation performance of the blow-by gas can be improved, and the air mixing ratio can be reduced. In addition, the lubricating oil passage structure can improve the strength of the case side shaft supporting member of the lower case, does not increase the width of the lower case, and does not hinder the downsizing of the internal combustion engine.

[Brief description of drawings]

FIG. 1 is a plan view of a lower case showing an embodiment of a lubricating oil passage structure according to the present invention.

FIG. 2 is a side view of a lower case.

3 is a cross-sectional view taken along the line 〓-〓 of FIG.

FIG. 4 is a perspective view showing a relationship between a lubricating oil introducing passage, a lubricating oil dropping passage, and a dropping passage expanding portion.

FIG. 5 is a bottom view of the lower case.

FIG. 6 is a plan view of a main part of a lower case showing a conventional example of a lubricating oil passage structure.

[Explanation of symbols]

 2 Lower case 4 Case side shaft supporting member 6 Case side shaft supporting part 8 One side connecting member 10 Other side connecting member 12 Main oil gallery 14 Lubricating oil introduction passage 16 Lubricating oil dropping passage 18 Passage separating portion 20 Reinforcing member 22 Rotation locus of crankshaft 24 Rotation locus of connecting rod 26 Path extension

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[Procedure amendment]

[Submission date] December 19, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 6]

[Figure 5]

Claims (1)

[Claims] 1. A lower case provided between a cylinder block and an oil pan of an internal combustion engine is provided, and the lower case is provided with a plurality of case side shaft supporting members that pivotally support a crank shaft with the cylinder block. Each side end of the plurality of case side shaft support members in a direction intersecting with the crank shaft axis is provided by being connected by each side connecting member oriented in a direction parallel to the crank shaft axis, and one of these side connecting members is provided. A main lubricating oil passage directed in the direction of the crankshaft axis is formed, and a lubricating oil introducing passage for introducing lubricating oil from the main lubricating oil passage to the case side shaft supporting portion of the case side shaft supporting member is formed. A lubricating oil drop passage for returning the lubricated lubricating oil to the oil pan adjacent to the lubricating oil introduction passage is formed in the case side shaft support member to form the lubricating oil drop passage. The case side shaft supporting member and one of the side connecting members forming the main lubricating oil passage are connected to each other by a reinforcing member protruding to a position not interfering with the rotation loci of the crankshaft and the connecting rod. A lubricating oil passage structure for an internal combustion engine, wherein the reinforcing member is provided with a dropping passage expansion portion communicating with the lubricating oil dropping passage.