JPH06241014A - Engine oil return passage - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an oil return passage for an engine that does not affect the oil that returns from the engine's cylinder head to the oil pan and is not affected by gears, etc. is there. [Structure] Oil returning from a cylinder head to an oil pan 26 is supplied to an oil passage 44 provided in a cylinder block and an oil passage 45 provided in a crankcase 25.
In the four-cycle engine passing through the inside of the clutch cover 37 and the inside of the clutch cover 37, the partition wall 48 is provided inside the clutch cover 37 and the oil return passage 51 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil return passage of an engine, and more particularly to an oil return passage of a four-cycle engine in which oil returns from a cylinder head to an oil pan.

[0002]

2. Description of the Related Art Since an engine has many sliding parts and rotating parts inside, oil is supplied to each part by using a lubrication device, and the frictional resistance of each part is reduced by the action of the oil so that the engine functions sufficiently. It is designed to demonstrate.

For example, as shown in FIG. 4, the oil flow of the lubrication system adopting the wet sump system is such that the oil stored in the oil pan 3 provided under the crankcase 2 of the engine 1 is stored in the strainer 4 first. Is sucked up by the oil pump 5.

The sucked oil is filtered by an oil filter 6 and sent to each lubrication section in the engine 1 via an oil pipe, an oil passage 7 and the like.

After lubricating the various parts inside the engine 1, the oil falls naturally or returns to the oil pan 3 again via the oil pipe, the oil passage 8 and the like.

For the oil supplied to the cylinder head 9 of the engine 1, for example, as shown in FIG. 5A, an oil pipe 10 is piped outside the engine 1a, and the oil flows from the cylinder head 9a to the oil pipe 10. Some return to the oil pan 3a via. Further, as shown in FIG. 5 (b), the oil is the cylinder head 9b of the engine 1b.
To the oil passage 12b provided in the cylinder block 11b or the crankcase 2b, and the oil outlet 13b provided above the crankcase 2b to the clutch cover 14
There is also one that passes through the inside of b, passes around the oil pump gear 15, and returns to the oil pan 3b from the oil inlet 16b provided at the lower rear part of the crankcase 2b.

Further, as shown in FIG. 5 (c), oil flows from the cylinder head 9c of the engine 1c to an oil passage 12c provided in the cylinder block 11c and the crankcase 2c, and an oil outlet provided above the crankcase 2c. 13c through the inside of the clutch cover 14c, the oil inlet 16 provided at the lower front of the crankcase 2c
Some return from c to the oil pan 3c immediately below the crank 17.

[0008]

However, as shown in FIG.
As shown in (a), the oil pipe 10 is attached to the engine 1a.
If the exterior is used, the structure becomes complicated, the number of parts increases, and the cost increases, which is not preferable. Further, the appearance of the oil pipe 10 is inferior due to layout restrictions.

On the other hand, as shown in FIG. 5B, oil flows from the oil passage 12b provided in the cylinder block 11b and the crankcase 2b and the oil outlet 13b provided above the crankcase 2b into the clutch cover 14b. When the oil is passed through the oil pump gear 15 and returned to the oil pan 3b from the oil inlet 16b provided at the lower rear portion of the crankcase 2b, the oil passing therethrough is agitated by the oil pump gear 15 and the oil The temperature may rise and the oil may deteriorate.
Therefore, it is necessary to expand the clutch cover 14b downward to secure an oil passage space, which complicates the formation of the crankcase 2b and the clutch cover 14b, which is not preferable in terms of cost and appearance.

Further, as shown in FIG. 5 (c), oil passes through an oil passage 12c provided in the cylinder 11c and the crankcase 2c and an oil outlet 13c provided above the crankcase 2c from the inside of the clutch cover 14c. Then, when the oil inlet 16c provided at the lower front of the crankcase 2c is returned to the oil pan 3c immediately below the crank 17, it is necessary to provide the oil inlet 16c communicating with the oil pan 3c so as not to interfere with the crank 17. After all, the crankcase 2c and the clutch cover 1
The formation of 4c becomes complicated, and it is not preferable in terms of cost and appearance.

The present invention has been made in consideration of the above-mentioned circumstances, and the oil returning from the cylinder head of the engine to the oil pan is not affected by gears or the like, and it is not necessary to change the shape of each part of the engine. It is intended to provide an oil return passage for an engine.

[0012]

In order to solve the above-mentioned problems, the oil return passage of the engine according to the present invention is such that the oil returning from the cylinder head to the oil pan is transferred to the cylinder block. In a four-cycle engine that passes through the oil passage provided in the engine, the oil passage provided in the crankcase, and the inside of the clutch cover, a partition wall is provided inside the clutch cover to form an oil return passage.

[0013]

In the present invention having the above structure, the oil returning from the cylinder head to the oil pan passes through the oil passage provided in the cylinder block, the oil passage provided in the crankcase, and the inside of the clutch cover. In the cycle engine, since the partition wall is provided in the clutch cover and the oil return passage is formed, the oil returning from the cylinder head to the oil pan is not affected by gears and the shape of each engine part needs to be changed. Can provide a no engine oil return passage.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic right side view showing an example of an engine to which the present invention is applied. Further, FIG. 2 shows A- of FIG.
It is sectional drawing which follows the A line, and FIG. 3 is a staircase sectional view which follows the BB line of FIG.

In FIG. 1, the engine 21 is, for example, a 4-cycle DOHC type engine, and employs a wet sump system as a lubricating method.

The engine 21 mainly comprises a cylinder head cover 22, a cylinder head 23, a cylinder block 24,
It is composed of a crankcase 25 that can be divided vertically and horizontally, and an oil pan 26.

Above the cylinder head 23, camshafts 27a, 2 which are a part of an intake / exhaust valve opening / closing mechanism.
7b is provided, and an intake / exhaust valve mechanism 28 is provided in the cylinder head 23. The cylinder head 23 is closed by the cylinder head cover 22.

In the cylinder block 24, the piston 2
9 is held in the cylinder block 24 so as to be slidable in the vertical direction, and the piston 29 has a crankshaft 31 provided in the crankcase 25 via a connecting rod 30.
Are linked to.

The vertical movement of the piston 29 is converted into rotational movement by the crankshaft 31, and this rotational movement is transmitted from a primary gear (drive) 32 provided at the end of the crankshaft 31 via a plurality of gears (not shown) to an oil pump. It is transmitted to the driven gear 33, the primary gear (driven) 34, the counter shaft 35, the drive shaft 36, and the like.

The above-mentioned gears are covered with a clutch cover 37.

The oil pan 26 has a role of storing oil for lubricating the engine 21. A strainer 38 is provided inside the oil pan 26.
Is an oil pump 39 provided in the crankcase 25.
Connected to.

The oil pump 39 is driven by the oil pump driven gear 33 and has a function of pumping the oil in the oil pan 26 to each part in the engine 21. An oil filter 40 is provided in the crankcase 25 and is connected to the oil pump 39.

The oil filter 40 includes a plurality of oil feed pipes 4.
1, 42, 43 are connected to the oil feeding pipes 41, 42, 4
The oil is supplied to each part in the engine 21 through 3.

As shown in FIG. 2, the cylinder block 24
An oil passage 44 is provided in the. Similarly, an oil passage 45 is provided in the crankcase 25, while an oil outlet 46 is provided above the surface of the crankcase 25 with respect to the clutch cover 37 and at the lower end of the oil passage 45. The oil passages 44 and 45 and the oil outlet 4
6, the cylinder head 23 and the clutch cover 37 communicate with each other.

On the other hand, an oil inlet 47 is provided below the surface of the crankcase 25 with respect to the clutch cover 37, and the inside of the clutch cover 37 and the oil pan 26 are communicated with each other.

As shown in FIG. 3, at the inner bottom of the clutch cover 37, a partition wall 48 formed of a metal plate or the like serves as a fixing means via a spacer 49 on the inner surface of the clutch cover 37 so as to hide the oil pump driven gear 33. Screw 50
The oil return passage 51 is formed between the partition wall 48 and the clutch cover 37.

Further, one end of the partition wall 48 is in contact with a rib 52 protruding from the crankcase 25.

Next, the operation of this embodiment will be described.

Since many sliding parts and rotating parts exist inside the engine 21, oil is applied to each part in the engine 21 so that frictional resistance and frictional heat of each part are reduced and the function of the engine 21 is fully exerted. Supply and circulate.

As shown by the arrow in FIG. 1, the oil flow of the lubricating device adopting the wet sump system is as shown in FIG.
Oil pan 2 provided under the crankcase 25 of No. 1
The oil stored in 6 is first sucked up by the oil pump 39 after the relatively large foreign matter is removed by the strainer 38, and is further filtered by the oil filter 40.

A part of the oil filtered by the oil filter 40 lubricates the bearing (not shown) of the crankshaft 31 via the oil feed pipe 41, and then is discharged to the lower portion of the piston 29 to lubricate the inside of the cylinder block 24. , The oil falls naturally and returns to the oil pan 26.

Further, a part of the oil filtered by the oil filter 40 is passed through the oil feed pipe 42 to the counter shaft 3
After lubricating the bearing 5 (not shown) of the drive shaft 36 and the drive shaft 36, the oil naturally drops and returns to the oil pan 26.

Further, a part of the oil filtered by the oil filter 40 is guided to the cylinder head cover 22 via the oil feed pipe 43 to lubricate the camshafts 27a and 27b in the cylinder head 23, the intake / exhaust valve mechanism 28 and the like. After that, the oil passage 44 provided in the cylinder block 24
The oil is discharged into the clutch cover 37 from an oil outlet 46 provided in the crankcase 25 through an oil passage 45 provided in the crankcase 25.

As shown in FIG. 3, the oil discharged into the clutch cover 37 passes through the bottom of the clutch cover 37, and the oil inlet 47 provided in the lower portion of the crankcase 25.
Return to the oil pan 26. At this time, the oil is the oil return passage 51 formed between the partition wall 48 attached inside the clutch cover 37 and the inner surface of the clutch cover 37.
Via.

The partition wall 48 shields the oil pump driven gear 33 from the oil together with the rib 52 projecting from the crankcase 25, so that the oil in the clutch cover 37 is not agitated by the oil pump driven gear 33 and is discharged from the oil inlet 47. It returns to the oil pan 26.

As described above, the oil returning from the cylinder head 23 is returned to the oil pan 26 in the clutch cover 37 without being agitated by the oil pump driven gear 33, so that the temperature of the oil rises due to the agitation of the oil. And prevent the oil from deteriorating.

Further, since the above effect can be obtained only by attaching the partition wall 48 to the inner surface of the clutch cover 37, the cost increase can be suppressed to a low level without changing the shapes of the crankcase 25 and the clutch cover 37.

[0039]

As described above, according to the oil return passage of the engine of the present invention, the oil returning from the cylinder head to the oil pan is provided in the oil passage provided in the cylinder block and the oil provided in the crankcase. In the four-cycle engine passing through the passage and the inside of the clutch cover, the partition wall is provided in the clutch cover to form the oil return passage, so that the oil returning from the cylinder head to the oil pan is not affected by gears or the like. Further, it is possible to provide an oil return passage of the engine which does not require changing the shape of each part of the engine.

[Brief description of drawings]

FIG. 1 is a schematic right side view showing an embodiment of an engine to which an oil return passage of the engine according to the present invention is applied.

FIG. 2 is a sectional view taken along the line AA of FIG.

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

FIG. 4 is a diagram showing a flow of oil in a wet sump type lubricating device.

5A, 5B and 5C are views showing an example of a conventional oil return passage.

[Explanation of symbols]

 21 Engine 23 Cylinder Head 24 Cylinder Block 25 Crank Case 26 Oil Pan 31 Crank Shaft 33 Oil Pump Driven Gear 37 Clutch Cover 38 Strainer 39 Oil Pump 40 Oil Filter 41, 42, 43 Oil Pipe 44, 45 Oil Passage 46 Oil Outlet 47 Oil Inlet 48 Partition wall 51 Oil return passage 52 Rib

Claims (1)

[Claims] 1. A four-cycle engine in which oil returning from a cylinder head to an oil pan passes through an oil passage provided in a cylinder block, an oil passage provided in a crankcase, and an inside of the clutch cover. An oil return passage for an engine, characterized in that a partition is provided on the oil passage to form an oil return passage.