WO2023238178A1

WO2023238178A1 - Internal combustion engine

Info

Publication number: WO2023238178A1
Application number: PCT/JP2022/022739
Authority: WO
Inventors: 正矢部
Original assignee: 日産自動車株式会社
Priority date: 2022-06-06
Filing date: 2022-06-06
Publication date: 2023-12-14

Abstract

In the present invention, a front cover (7) has, on an inner surface (7a) thereof, a guide rib (31) which forms a ridge. The guide rib (31) guides an oil level gauge inserted through a gauge insertion port (19). The guide rib (31) constitutes, together with the inner surface (7a) of the front cover (7) and the end surface on one end side in the direction of a cylindrical column of an internal combustion engine body (8), an oil level gauge passage (32), which is a tunnel-like passage through which an oil level gauge passes. The guide rib (31) improves the rigidity of the front cover (7), thereby suppressing front cover (7) film vibration.

Description

internal combustion engine

The present invention relates to an internal combustion engine.

For example, Patent Document 1 discloses a case member that is attached to one side of an engine body and has a protrusion that forms a gauge passage. The oil level gauge is inserted into the gauge passage.

Further, Patent Document 2 discloses a chain case of an internal combustion engine in which a rib-shaped band guide forming an oil level gauge passage is formed.

However, in these

Patent Documents

1 and 2, no special consideration is given to improving the rigidity of the case member or the chain case to reduce membrane vibration. In other words, in an internal combustion engine having a cover member such as the case member or chain case described above, there is room for further improvement in reducing the membrane vibration of these cover members.

JP2015-34528A JP2015-63906A

The internal combustion engine of the present invention has a front cover made of resin, the inner surface of which faces the end face of the internal combustion engine main body on one end side in the cylinder row direction, and covers the end face of the internal combustion engine main body on the one end side in the cylinder row direction. There is. The front cover has a gauge insertion port into which an oil level gauge is inserted, and a protruding guide rib that guides the oil level gauge inserted from the gauge insertion port. The guide rib is formed on the inner surface of the front cover. An oil level gauge passage through which the oil level gauge passes is formed by the inner surface of the front cover, the guide rib, and the end face of the internal combustion engine main body on one end side in the cylinder row direction.

According to the present invention, the guide rib contributes to improving the rigidity of the front cover while forming a part of the oil level gauge passage. In internal combustion engines, the guide ribs improve the rigidity of the front cover, so that membrane vibration of the front cover can be suppressed.

1 is an explanatory diagram schematically showing a schematic configuration of an internal combustion engine to which the present invention is applied. FIG. 1 is an explanatory diagram schematically showing one end side in a cylinder row direction of an internal combustion engine to which the present invention is applied. Front view of the front cover. Rear view of the front cover. A perspective view of the front cover.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. In each figure, the X axis is an axis along the longitudinal direction of the internal combustion engine 1 (an axis parallel to the central axis of the crankshaft of the internal combustion engine 1), and the Y axis is the horizontal direction of the internal combustion engine 1 (internal combustion engine width direction). The axis along the axis A and the Z axis respectively indicate an axis along the vertical direction of the internal combustion engine 1 (an axis parallel to the cylinder axis A of the internal combustion engine 1). That is, the X-axis is an axis along the cylinder row direction of the internal combustion engine 1 or the internal combustion engine main body 8 (described later). Further, the Y-axis is an axis along the width direction of the internal combustion engine main body 8.

FIG. 1 is an explanatory diagram schematically showing a schematic configuration of an internal combustion engine 1 to which the present invention is applied.

The internal combustion engine 1 is, for example, an in-line multi-cylinder internal combustion engine, and includes a cylinder head 2, a cylinder block 3 attached to the lower part of the cylinder head 2, a cam bracket 4 attached to the upper part of the cylinder head 2, and cylinders. The engine has an upper oil pan 5 attached to the lower part of the block 3, an oil pan lower 6 attached to the lower part of the upper oil pan 5, and a front cover 7 that covers the front surface of the internal combustion engine main body 8. Note that the cylinder head 2, cylinder block 3, cam bracket 4, and oil pan upper 5 constitute an internal combustion engine main body 8. Therefore, the inner surface 7a of the front cover 7 faces the end surface 8a of the internal combustion engine main body 8 at one end in the cylinder row direction, and the inner surface 7a covers the end surface 8a. The outer surface 7b of the front cover 7 faces outward. Further, the front cover 7 has a vertical wall 7c that is continuous along the entire outer periphery. The vertical wall 7c is formed to extend in the direction along the X-axis.

The cylinder head 2 is a cast product made of a metal material such as an aluminum alloy, and has an intake port (not shown) that supplies intake air to a combustion chamber (not shown) and exhaust air from the combustion chamber (not shown). An exhaust port (not shown) is formed for exhaust.

The cylinder block 3 is a cast product made of a metal material such as an aluminum alloy, and is formed with a number of cylinders (not shown) corresponding to the number of cylinders.

The cam bracket 4 is made of a metal material such as aluminum alloy, and supports the camshaft 10 (see FIG. 2) rotatably together with the cylinder head 2.

The oil pan upper 5 is made of a metal material such as an aluminum alloy, and together with the cylinder block 3 constitutes a crankcase (not shown) in which a crankshaft (not shown) is housed.

The oil pan lower 6 is made of a synthetic resin material such as polyamide, and stores lubricating oil.

The front cover 7 is made of a synthetic resin material such as polyamide, and is attached to the internal combustion engine main body 8 in a liquid-tight manner so as to cover the front surface of the internal combustion engine main body 8. More specifically, the front cover 7 is attached to the front surface of the cylinder block 3, the front surface of the cylinder head 2, the front surface of the cam bracket 4, and the front surface of the oil pan upper 5 by bolts (not shown). In other words, the front cover 7 is attached to the internal combustion engine main body 8 so as to cover one end surface of the cylinder block 3 and the cylinder head 2 in the crankshaft axial direction, that is, one end surface 8a of the internal combustion engine main body 8 in the cylinder row direction. It is attached.

As shown in FIG. 2, the front cover 7 has a shallow dish shape, and is connected to the front surface of the internal combustion engine main body 8, which is an end surface 8a on one end side of the internal combustion engine main body 8 in the cylinder row direction. A space 9 communicating with the oil storage space is formed. FIG. 2 is an explanatory diagram schematically showing one end side of the internal combustion engine 1 in the cylinder row direction in a plan view. The space 9 accommodates a cam sprocket 11 fixed to the front end of the camshaft 10 and a crank sprocket 12 fixed to the crankshaft (see FIG. 3). A timing chain (not shown) for transmitting rotational power is wound around the cam sprocket 11 and crank sprocket 12.

An intake cam sprocket 11a and a variable phase mechanism (variable valve mechanism) 13 are attached to the front end of the intake camshaft 10a. The phase variable mechanism 13 changes the valve timing of the intake valve by changing the phase of the lift center angle of the intake valve. An exhaust cam sprocket 11b is attached to the front end of the exhaust camshaft 10b.

As shown in FIGS. 3 to 5, the front cover 7 is continuous with the crankshaft through hole 14, the first bolt through hole 15, the second bolt through hole 16, the through

holes

17 and 18, and the space 9. It has a gauge insertion port 19 formed as follows. FIG. 3 is a front view of the front cover 7. FIG. 4 is a rear view of the front cover 7. FIG. 5 is a perspective view of the front cover 7.

The crankshaft through hole 14 is a hole through which a crankshaft (not shown) passes. The periphery of the crankshaft through hole 14 is a flat crank pulley facing portion 21 sandwiched between the crank sprocket 12 and a crank pulley 20 fixed to the front end of the crankshaft. A plurality of protruding ribs 22 are formed on the outer periphery of the outer surface of the crank pulley facing portion 21 so as to intersect with guide ribs 31, which will be described later. In other words, a plurality of ribs 22 are formed on the outer surface 7b of the front cover 7 so as to be vertically aligned along an oil level gauge passage 32, which will be described later.

The first bolt through holes 15 are through which bolts (not shown) that fix the front cover 7 to the internal combustion engine main body 8 pass, and a plurality of first bolt through holes 15 are formed on the outer peripheral edge of the front cover 7.

A plurality of second bolt through holes 16 are formed in the front cover 7 (at five locations) through which bolts (not shown) that fix parts other than the outer peripheral edge of the front cover 7 to the internal combustion engine main body 8 pass. ing.

The through

holes

17 and 18 are holes through which a part of a mount bracket (not shown) for fixing the internal combustion engine 1 to the vehicle body passes.

The gauge insertion port 19 is a hole formed through the upper part of the front cover 7.

Further, as shown in FIG. 4, the front cover 7 has a protruding guide rib 31 rising from the inner surface 7a. The guide rib 31 guides (the tip side of) an oil level gauge (not shown) inserted from the gauge insertion port 19 to an oil reservoir (oil reservoir) at the lower part of the internal combustion engine 1 . The guide rib 31 includes an oil level gauge passage 32 (indicated by the thick broken line in FIG. 4), which is a tunnel-shaped passage through which the oil level gauge passes, together with the inner surface 7a of the front cover 7 and the end face 8a of the internal combustion engine main body 8 on one end side in the cylinder row direction. ) is formed in space 9.

The guide ribs 31 include a first guide rib row 33 extending in the vertical direction of the front cover 7 (direction along the Z axis), and a first guide rib row 33 extending in the width direction of the front cover 7 (direction along the Y axis). It consists of second guide rib rows 34 facing each other at a predetermined distance apart. The first guide rib row 33 and the second guide rib row 34 face each other with an interval such that an oil level gauge can be inserted therein. The second guide rib row 34 is located closer to the inner circumference of the front cover 7 than the first guide rib row 33 when viewed in the X-axis direction as shown in FIG. 3 or 4 .

The first guide rib row 33 has a plurality of first ribs 35 arranged in series along the vertical direction of the front cover 7 (direction along the Z axis). The front cover 7 has first guide rib rows 33, which are arranged in order from above in the vertical direction of the front cover 7, such as a first rib 35a, a first rib 35b, a first rib 35c, a first rib 35d, a first rib 35e, and a first rib 35a. 1 rib 35f is formed. These first ribs 35 are formed along the outer peripheral edge of the front cover 7 so as to be spaced apart from each other in the vertical direction of the front cover 7 (direction along the Z axis).

The second guide rib row 34 has a plurality of second ribs 36 arranged in series along the vertical direction of the front cover 7 (direction along the Z axis). On the front cover 7, a second rib 36a, a second rib 36b, a second rib 36c, a second rib 36d, and a second rib 36e are formed as a second guide rib row 34 in order from above in the vertical direction of the front cover 7. has been done. The plurality of second ribs 36 are spaced apart from each other along the vertical direction of the front cover 7 (direction along the Z-axis).

A portion of the guide rib 31 is connected to a bolt boss portion 37 in which the first bolt through hole 15 is formed. Specifically, the lower end of the first rib 35e and the upper end of the first rib 35f are connected to the bolt boss portion 37a. The lower end of the first rib 35f and the lower end of the second rib 36e are connected to the bolt boss portion 37b. The bolt boss portion 37a is located below the front cover 7. The bolt boss portion 37b is located at the lower end of the front cover 7.

The guide rib 31 is formed on the outer peripheral edge of the crank pulley facing portion 21. In other words, the guide rib 31 is formed at a position adjacent to the outer peripheral edge of the crank sprocket 12. In detail, the front cover 7 has a lower part of the first rib 35d, a first rib 35e, an upper part of the first rib 35f, a lower part of the second rib 36c, and an upper part of the second rib 36d and the second rib 36e facing the crank pulley. It is formed so as to be located at the outer peripheral edge of the portion 21.

Further, the guide rib 31 is formed at a position adjacent to the outer peripheral edge of the intake cam sprocket 11a. In other words, the guide rib 31 is formed on the outer peripheral edge of the cam sprocket facing portion 41 of the front cover 7 . The cam sprocket opposing portion 41 is a flat portion of the front cover 7 that covers the intake cam sprocket 11a. Specifically, in the front cover 7, the upper ends of the first rib 35a and the first rib 35b, and the upper ends of the second rib 36a and the second rib 36b are formed at positions adjacent to the outer peripheral edge of the intake cam sprocket 11a.

In the internal combustion engine 1 of the embodiment described above, a tunnel-shaped oil level gauge passage 32 is formed by the inner surface 7a of the front cover 7, the guide rib 31, and the end surface 8a of the internal combustion engine main body 8 on one end side in the cylinder row direction. There is.

Therefore, the guide rib 31 contributes to improving the rigidity of the front cover 7 while forming a part of the tunnel-shaped oil level gauge passage 32.

In the internal combustion engine 1, since the guide ribs 31 improve the rigidity of the front cover 7, membrane vibration of the front cover 7 can be suppressed.

The guide rib 31 is formed along the outer peripheral edge of the front cover 7. This allows the guide rib 31 to face the outer peripheral edge of the front cover 7. Specifically, a portion of the second guide rib row 34 that does not face the first guide rib row 33 can be made to face the vertical wall 7c of the outer peripheral edge of the front cover 7. The distance between the first rib 35d and the first rib 35e in the vertical direction is increased, but during this time, the outer peripheral edge of the front cover 7 is replaced by the first guide rib row 33 as a tunnel-shaped oil level gauge passage 32. It forms part of the wall. That is, the oil level gauge passage 32 is formed between the guide rib 31 and the vertical wall 7c on the outer peripheral edge of the front cover 7.

That is, the oil level gauge passage 32 can be constructed using the vertical wall 7c on the outer periphery that was originally formed on the front cover 7.

Therefore, the internal combustion engine 1 can configure the tunnel-shaped oil level gauge passage 32 while suppressing increases in materials and weight.

Further, in the internal combustion engine 1, the outer peripheral edge (outer edge) of the front cover 7, which is relatively susceptible to external force, can be reinforced by using the guide ribs 31 forming the oil level gauge passage 32.

The crank pulley facing portion 21 of the front cover 7 is formed into a flat plate shape, which makes it difficult to increase the rigidity due to its structure.

However, in the internal combustion engine 1, the rigidity of the crank pulley facing part 21 around the crankshaft through hole 14 is reduced by providing the guide rib 31 adjacent to the outer peripheral edge of the crank pulley facing part 21 of the front cover 7. It is possible to improve this and suppress membrane vibration.

In the internal combustion engine 1, since the plurality of ribs 22 are formed on the outer surface of the crank pulley facing portion 21, the rigidity of the vicinity of the crankshaft through hole 14 of the front cover 7 (crank pulley facing portion 21) can be improved. .

The cam sprocket facing portion 41 of the front cover 7 is formed into a flat plate shape, and structurally, it is difficult to increase the rigidity.

However, in the internal combustion engine 1, by providing the guide rib 31 adjacent to the outer peripheral edge of the cam sprocket facing part 41 of the front cover 7, the rigidity of the cam sprocket facing part 41 is improved and membrane vibration is suppressed. can be achieved.

In the internal combustion engine 1, the guide rib 31 is connected to the bolt boss portion 37. Therefore, in the internal combustion engine 1, the rigidity of the front cover 7 can be improved by making the guide ribs 31 and the bolt boss portions 37 work together.

Although specific embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit thereof.

Furthermore, for example, the number of first ribs 35 in the first guide rib row 33 is not limited to six, and may be other than six. Further, the number of second ribs 36 in the second guide rib row 34 is not limited to five, and may be other than five.

Claims

a resin front cover whose inner surface faces an end face on one end side in the cylinder row direction of the internal combustion engine main body and covers the end face on the one end side in the cylinder row direction of the internal combustion engine main body,
The front cover has a gauge insertion port into which an oil level gauge is inserted, and a protruding guide rib that guides the oil level gauge inserted from the gauge insertion port,
The guide rib is formed on the inner surface of the front cover,
An internal combustion engine, wherein an oil level gauge passage through which the oil level gauge passes is formed by the inner surface, the guide rib, and an end face of the internal combustion engine main body on one end side in a cylinder row direction.
The internal combustion engine according to claim 1, wherein the guide rib is formed along an outer peripheral edge of the front cover.
The front cover has a crankshaft through hole through which the crankshaft passes,
Claim 1: The guide rib is formed on an outer peripheral edge of a crank pulley facing portion that is a portion on the outer peripheral side of the crankshaft through hole that is sandwiched between a crank pulley attached to the crankshaft and the internal combustion engine main body. or the internal combustion engine described in 2.
The internal combustion engine according to claim 3, wherein a plurality of protruding ribs are formed on the outer surface of the crank pulley facing portion so as to intersect with the guide ribs.
The front cover covers a cam sprocket attached to an end of a camshaft protruding from an end face of the internal combustion engine main body on one end side in the cylinder row direction,
The internal combustion engine according to claim 1 or 2, wherein the guide rib is formed on the outer peripheral edge of the cam sprocket.
The internal combustion engine according to claim 1 or 2, wherein the guide rib is connected to a bolt boss through which a bolt for fastening the front cover to the internal combustion engine main body passes.