Chain case

Abstract

To provide a chain case which secures a circulation amount of an engine oil while inhibiting vibration of an engine.SOLUTION: A chain case houses a timing chain, is attached to an engine, and includes: a wall part facing the engine; a first hole which is formed at the wall part and into which a crank shaft of the engine is inserted; a second hole which is attached with an oil pump for circulating an engine oil to the engine; a third hole and a fourth hole located between the first hole and the second hole and communicating with an oil pan for recovering the engine oil; and a rib located between the third hole and the fourth hole. The rib extends along a vertical direction in a mounted state that the engine attached with the chain case is mounted on a vehicle. At least a part of the rib is located within an area, set by projecting the first hole to the vertically lower side, when viewed from an axial direction of the crank shaft in the mounted state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chain case. [Background technology]

[0002] BACKGROUND ART A chain case that houses a timing chain and is attached to an engine is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-160797 Summary of the Invention [Problem to be solved by the invention]

[0004] An oil pump may be attached to such a chain case. In such cases, the vibration of the oil pump is transmitted to the engine through the chain case, which may increase engine vibration. In addition, engine oil flows downward within the chain case, and if this flow is obstructed, the amount of engine oil circulating may decrease.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a chain case that suppresses engine vibrations while also suppressing a decrease in the amount of engine oil circulating. [Means for solving the problem]

[0006] The object is to provide a chain case that houses a timing chain and is attached to an engine, the chain case including: a wall portion that faces the engine; a first hole that is formed in the wall portion and through which a crankshaft of the engine is inserted; and an oil pump that is formed in the wall portion and that circulates engine oil in the engine. Slide bush for mountingThis can be achieved by a chain case comprising: a second hole into which a crankshaft is attached; third and fourth holes formed in the wall portion and located between the first hole and the second hole, and communicating with an oil pan of the engine that collects engine oil; and a rib formed in the wall portion and located between the third hole and the fourth hole, wherein the rib extends along the vertical direction when the engine to which the chain case is attached is mounted on a vehicle, and at least a portion of the rib is located within an area obtained by projecting the first hole vertically downward when viewed from the axial direction of the crankshaft in the mounted state.

[0007] The entire rib may be located within the region. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a chain case that ensures the amount of engine oil circulating while suppressing engine vibration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a chain case. DETAILED DESCRIPTION OF THE INVENTION

[0010] Figure 1 is an explanatory diagram of the chain case 1. Figure 1 shows the inside of the lower side of the chain case 1 when viewed from the direction of the axis A of the engine crankshaft. Figure 1 shows the vertical direction when the engine to which the chain case 1 is attached is mounted on a vehicle. In Figure 1, the engine is located at the back of the page and the chain case 1 is fixed to it.

[0011] The chain case 1 has a wall 10 and an outer edge wall 12. The wall 10 is formed in a thin plate shape and is fixed to face the side of the engine. The outer edge wall 12 is formed to rise from the wall 10 towards the front side of the page. Holes 21 to 25 are formed in the wall 10 at positions surrounded by the outer edge wall 12.

[0012] The crankshaft of the engine is inserted through the hole 21. The hole 21 is formed in a circular shape and is located approximately in the center in the horizontal direction of the wall portion 10 surrounded by the outer edge wall portion 12. The hole 21 is an example of a first hole.

[0013] Hole 22 is located vertically below hole 21 and is formed in a circular shape. An oil pump is attached to hole 22 via a slide bush, which is an attachment member. The oil pump is a mechanical oil pump that is driven in conjunction with the rotation of the crankshaft, and circulates engine oil to each sliding part of the engine. Hole 22 is formed smaller than hole 21. Hole 22 is an example of a second hole.

[0014] Holes 23 and 24 are located between holes 21 and 22; in other words, they are located vertically below hole 21 and vertically above hole 22. Holes 23 and 24 are adjacent to each other in the horizontal direction. As will be described in detail later, a rib 14 is formed between holes 23 and 24. Rib 14 is curved so as to bulge toward the front side of the paper in FIG. 1, thereby ensuring the rigidity of rib 14. Holes 23 and 24 are each formed larger than hole 21. Holes 23 and 24 are examples of third and fourth holes.

[0015] Hole 25 is located vertically lower than holes 23 and 24. Holes 23 to 25 are connected to the engine oil pan. Therefore, engine oil that splashes or flows down inside chain case 1 is collected in the oil pan via holes 23 to 25. The engine oil collected in the oil pan is circulated through the engine by being sent to each sliding part of the engine by an oil pump.

[0016] The rib 14 extends linearly between the holes 21 and 22. In other words, the rib 14 is located vertically below the hole 21 and vertically above the hole 22. By forming the rib 14 near the hole 22 in this manner, rigidity is ensured in the area around the hole 22. For example, if the holes 23 and 24 were formed as a single hole without the rib 14, the rigidity in the area around the hole 22 would decrease, and vibrations of the oil pump would be transmitted to the engine, possibly increasing engine vibrations. By forming the rib 14 near the hole 22 as in this embodiment, such engine vibrations can be suppressed.

[0017] It is possible to consider blocking holes 23 and 24 to ensure rigidity in the area surrounding hole 22. However, in this case, engine oil that splashes or flows down inside chain case 1 may accumulate inside chain case 1, reducing the amount of engine oil recovered in the oil pan and reducing the amount of engine oil circulating. By providing holes 23 and 24 as in this embodiment and providing rib 14 between holes 23 and 24, it is possible to suppress engine vibration while also preventing a decrease in the amount of engine oil circulating.

[0018] Furthermore, the ribs 14 extend in the vertical direction. "The ribs 14 extend in the vertical direction" means that the extension direction of the ribs 14 may be parallel to the vertical direction, or may be tilted at an angle of less than 45 degrees relative to the vertical direction. This allows, for example, engine oil to be encouraged to flow downward from the ribs 14 due to the action of gravity, even if it adheres to the ribs 14. From the viewpoint of encouraging the downward flow of engine oil adhered to the ribs 14, it is preferable that the extension direction of the ribs 14 be smaller than the vertical direction.

[0019] 1 also shows the direction D1 in which engine oil flows downward within the chain case 1, the direction D2 in which blow-by gas rises, and a region R when the hole 21 is projected vertically downward. Most of the engine oil flows downward to the left of region R, and most of the blow-by gas rises to the right of region R. Here, the rib 14 is located within the above-mentioned region R. In other words, the rib 14 is located approximately in the center in the horizontal direction of the wall portion 10 surrounded by the outer edge wall portion 12. Therefore, the rib 14 does not hinder either the flow of engine oil downward or the rise of blow-by gas.

[0020] For example, if the presence of the rib obstructs the flow of engine oil, the amount of engine oil recovered in the oil pan may decrease, as described above, which may result in a decrease in the amount of engine oil circulating. Furthermore, if the presence of the rib causes blow-by gas to be guided to the left of the hole 21, the flow of engine oil may be obstructed, which may result in a decrease in the amount of engine oil circulating. In this embodiment, the rib 14 is located in region R, and the extension direction of the rib 14 is aligned vertically, so that the flow of engine oil is not obstructed and a decrease in the amount of engine oil circulating can be suppressed.

[0021] From the viewpoint of suppressing a decrease in the amount of circulating engine oil without impeding the flow of engine oil downward, it is preferable, but not limited to, that the entire rib 14 be located within the region R as described above. For example, if the rib is positioned so that only a portion of it is located within the region R in order to ensure rigidity around the hole 22, it is possible to suppress engine vibration while also suppressing a decrease in the amount of circulating engine oil.

[0022] In the above embodiment, the ribs 14 extend linearly, but this is not limiting and they may extend curvedly. When the ribs 14 extend curvedly, the inclination of the tangent at any point on the center line of the curved rib 14 relative to the vertical direction should be less than 45 degrees. This is because the flow of engine oil can also be promoted in this case.

[0023] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0024] 1 chain case 10 Wall 14 Ribs 21 hole (1st hole) 22 holes (2nd hole) 23, 24 holes (3rd and 4th holes) R region

Claims

1. A chain case that houses a timing chain and is attached to an engine, a wall portion facing the engine; a first hole formed in the wall portion, through which a crankshaft of the engine is inserted; a second hole formed in the wall portion, into which a slide bush is attached for attaching an oil pump that circulates engine oil in the engine; third and fourth holes formed in the wall portion, positioned between the first hole and the second hole, and communicating with an oil pan of the engine that collects engine oil; a rib formed on the wall portion and positioned between the third hole and the fourth hole, the rib extends vertically when the engine to which the chain case is attached is mounted on a vehicle, At least a portion of the rib is located within a region obtained by projecting the first hole vertically downward when viewed from the axial direction of the crankshaft in the mounted state.

2. 2. The chain case according to claim 1, wherein the entirety of said rib is located within said region.

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