JP2001073731A - Lubrication device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize supply of oil, and make oil pump compact in dry sump type oil pump. SOLUTION: This oil pump 30 consists of feed pump 31 and two scavenge pumps, that is, main scavenge pump 32 and sub-scavenge pump 33, incorporated by rotors fitted on common driving shaft. Feed pump 31 supplies every part needing lubrication with oil and lubricate it from oil tank 34 via oil filter 36. Oil after lubrication collects at oil sumps at bottom of engine, but these oil sumps are divided into oil sump 37 and oil sumps 38, which are put at places with different conditions, front or rear, left or right, and high or low. Main scavenge pump 32 and sub-scavenge pump 33 suction oil independently from oil sump 37 and oil sump 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry sump lubrication system for an internal combustion engine having a feed pump and a scavenge pump.

[0002]

2. Description of the Related Art A dry sump lubricating apparatus is known which includes a feed pump for sending oil from an oil tank to various parts of an engine for lubrication and a scavenge pump for sending oil remaining at the bottom of the engine to the oil tank after lubrication. (For example, JP-A-2-9904).

[0003]

Vehicles that run on rough terrain or steep roads, such as buggies, must have a minimum ground height and a low center of gravity.
The structure of the oil pool such as an oil pan is limited, and large unevenness cannot be formed. For this reason, dry sump lubrication is adopted to cope with the problem. However, in this case, the structure of the oil reservoir must be determined in consideration of the inclination of the vehicle body, and the shape determination is greatly restricted.

[0004]

In order to solve the above problems, a lubricating device for an internal combustion engine according to the present invention includes a feed pump for supplying lubricating oil in an oil tank to each lubricating portion of the internal combustion engine; In a lubricating device for an internal combustion engine having a scavenge pump for returning lubricating oil accumulated in an oil reservoir to the oil tank, the oil reservoir of the internal combustion engine is divided into a plurality of sections, and each of the partitioned oil pools is And a plurality of scavenge pumps are provided.

[0005]

According to the present invention, a plurality of recesses or sections for storing oil are provided as oil pools, and a plurality of scavenge pumps are provided in correspondence with the plurality of recesses or sections. Even if there is a large change, it is easier to maintain the oil suction by combining any of the oil sump and the scavenge pump, so that the effect of the oil level due to the tilt of the vehicle body can be minimized and the stable lubrication oil can be supplied. Become.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment applied to a four-wheel buggy will be described below with reference to the drawings. 1 is a lubrication system diagram according to the embodiment, FIG. 2 is a side view of a main part of a vehicle body of a four-wheel buggy vehicle to which the embodiment is applied, and FIG.
FIG. 2 is a sectional view showing an oil pump and an oil passage structure thereof.

First, the overall structure of a four-wheel buggy will be outlined with reference to FIG. This four-wheel buggy vehicle includes a pair of left and right front wheels 2 and a pair of rear wheels 3 on the front and rear sides of a body frame 1, and a power unit 4 integrally provided with an engine and a transmission is supported at the center of the body frame 1. . The power unit 4 is of a vertical type in which the crankshaft 5 is arranged in the front-rear direction of the vehicle body.

The four-wheel buggy is of a four-wheel drive type. The front wheel 2 is driven via a front wheel propeller shaft 7 by an output shaft 6 provided below the power unit 4 in parallel with the crankshaft 5. The rear wheel 3 is driven via the wheel propeller shaft 8.

The front side of the crankcase 10 constituting the power unit 4 is covered with a front case cover 11 and the rear side is covered with a rear case cover 12, which constitutes a power unit case. The crankcase 10 is further divided into a front case 10a and a rear case 10b. A cylinder block 13, a cylinder head 14, and a cylinder head cover 15 are attached to an upper portion of the crankcase 10, and a carburetor 16 is connected to an intake port of the cylinder head 14, and an air cleaner is connected to the carburetor 16 from behind. 17 are connected. An exhaust pipe 18 is connected to an exhaust port of the cylinder head 14.

An oil cooler 20 is disposed in front of the power unit 4, communicates with an oil pump provided in the crankcase 10 via a feed hose 21, and is provided in the crankcase 10 via a return hose 22. Communicates with the oil pump. In the figure, reference numeral 23 denotes a cooling fan, 24 denotes a handle, 25 denotes a fuel tank, and 26 denotes a saddle type seat.

Next, a dry sump lubrication system in the power unit 4 will be described. As shown in FIG. 1, an oil pump 30 provided in the power unit 4
It has one feed pump 31 and two scavenge pumps, namely a main scavenge pump 32 and a sub-scavenge pump 33.

The feed pump 31 sucks oil from an oil tank 34 via a strainer 35 and discharges the oil to an oil filter 36. The oil discharged from the oil filter 36 is sent to lubricating parts of various parts of the engine to be lubricated.

The lubricated oil is collected in an oil sump or an oil sump 37 or 38 at the bottom of the crankcase 10 or the like.
Drops on and accumulates. The oil sumps 37 and 38 are provided so as to have different heights, front-rear, left-right arrangements in the crankcase 10, and the like, so that oil can be sucked from any of the scavenge pumps regardless of how the vehicle body posture changes. Is set.

The oil accumulated in these oil sumps 37 and 38 is sucked through strainers 39 and 40 by a main scavenge pump 32 and a sub-scavenge pump 33, respectively, and is discharged from a discharge side to a feed side hose 2 from a discharge side.
1, the oil is sent to the oil cooler 20, and the cooled oil is returned to the oil tank 34 via the return hose 22. The oil tank may be provided outside the power unit 4 or may be built therein.

A relief valve 41 is provided between the discharge-side passage of the feed pump 31 and the discharge-side passages of the main scavenge pump 32 and the sub-scavenge pump 33, so that the hydraulic pressure in the discharge-side passage of the feed pump 31 is reduced to a predetermined value. When the pressure is exceeded, the relief valve 41 is opened to release the excess, and is sent to the oil cooler 20 together with the oil discharged from the main scavenge pump 32 and the sub-scavenge pump 33.

Next, the oil pump will be described. As shown in FIGS. 3 and 4, the oil pump 30 is provided between the front case 10 a and the rear case 10 b of the crankcase 10 and is built in the crankcase 10. The oil pump 30 includes an integrated feed pump 31, a sub-scavenge pump 33, and a main scavenge pump 3.
2 are driven together by a drive shaft 43 provided at one end with a sprocket 42 that rotates synchronously with the crankshaft via a chain (not shown).

That is, a feed pump rotor 44, a sub-scavenge pump rotor 45, and a main scavenge pump rotor 46 are arranged on the drive shaft 43 in the axial direction, and each of them is integrally rotatable. The three rotors are arranged side by side, and each rotor part constitutes an individual pump provided in an independent pump chamber. These individual pumps constitute a feed pump 31, a sub-scavenge pump 33 and a main scavenge pump 32.

The pump housing of the oil pump 30 has a first block 4 divided into four parts in the direction orthogonal to the axis of the drive shaft 43.
7, a second block 48, a third block 49, and a fourth block 50, which are mutually connected and integrated by a through bolt 51. The third block 49 also functions as a partition wall for the sub-scavenge pump 33 and the main scavenge pump 32.

The sub-scavenge pump 33 is provided with the oil accumulated on the oil sump 38 above the sub-scavenge pump 33, and is formed in the fourth block 50 through the sub-scavenge pump suction port 52 formed in the rear case 10b from the strainer 40. A sub passage 53 and a sub passage 54 formed between the second block 48 and the third block 49 so as to communicate therewith.
The air is further sucked and discharged to the sub-scavenge pump discharge port 55 formed in the second block 48.

The main scavenge pump 32 sucks up the oil accumulated on the oil sump 37 at the center bottom of the crankcase 10 lower than the oil sump 38 from the strainer 39, and pumps the oil through the main scavenge pump suction port 56 provided in the rear case 10b. The liquid is sucked from the main passage 57 formed in the fourth block 50 and discharged to the main scavenge pump discharge port 58 formed in the fourth block 50.

The sub-scavenge pump discharge port 55 and the main scavenge pump discharge port 58 are respectively connected to the collective discharge passage 5.
9, the oil discharged from each scavenge pump is sent to the scavenge pump discharge passage 60 formed on the front case 10 a side through the collective discharge passage 59, and further to the oil tank 20 through the feed side hose 21. Sent out to

The feed pump 31 is connected to the first block 47 and the second block 47 through an oil inlet (not shown) of the front case 10a.
Feed pump suction port 6 formed between blocks 48
Suction from the first block 47 and the second block 48
And is sent to the oil filter 36 through a feed pump discharge port 62 and an oil filter communication passage 63 provided in the front case 10a in communication with the feed pump discharge port 62.

As is apparent from FIG.
The oil reservoir 38 is separated from the oil reservoir 38 in the front-rear direction at the bottom of the crankcase 10, and is partitioned by the partition wall 28. The main scavenge pump 32 and the sub-scavenge pump 33 separately pump oil from the oil reservoir 37 and the oil reservoir 38, respectively. The oil sump 37 is almost at the center of the bottom of the crankcase 10 and there is a place where oil is most likely to accumulate when the vehicle body posture is normal, whereas the oil sump 38 is located on the rear side and in the left-right direction, although not clear in the drawing. It is located at a shifted position, and is a position where oil can easily move when the vehicle body posture is increased in the front-back or left-right direction.

As is apparent from FIGS. 3 and 4, a relief chamber 64 communicating with the feed pump discharge port 62 is formed in the upper part of the oil pump 30 from the first block 47 to the fourth block 50. The second block 48 portion, which is a portion, forms a small-diameter cylindrical portion 65 that is a narrow passage,
The relief valve 41 drives the drive shaft 43 in the small-diameter cylindrical portion 65.
Liquid-slidable in a direction parallel to.

The relief valve 41 has a cylindrical shape, and a flange 66 is provided at an intermediate portion thereof.
7, the sheet portion 6 being one end of the small-diameter cylindrical portion 65
It is pressed against 8. The through-hole 6 is formed at a portion of the relief valve 41 closer to the feed pump discharge port 62 than the flange 66.
9 are provided. However, as long as the flange 66 is pressed against the seat portion 68, the through hole 69 is closed by the inner wall of the small-diameter cylindrical portion 65 so that the oil in the relief valve 41 does not escape from the through hole 69. .

An intermediate portion of the relief valve 41 where the flange 66 is provided is provided with a partition wall 70 for partitioning the inside of the relief valve 41 into right and left, and a pilot hole 71 is formed to communicate left and right. The end of the relief valve 41 on the side opposite to the feed pump discharge port 62 fits on the outer periphery of a guide 72 also serving as a spring receiver for one end of a relief spring 67, and the opening at the right end of the relief valve 41 in the figure is closed by the guide 72. Have been.

The oil pressure of the oil discharged to the feed pump discharge port 62 is the relief pressure, that is, the relief spring 6.
7, the relief valve 41 moves in the direction of compressing the relief spring 67, the flange 66 separates from the seat portion 68, and when the through-hole 69 comes out of the small-diameter cylindrical portion 65, the fourth block 50 is released. The discharge pressure of the feed pump 31 is reduced to a certain level by allowing a part of the oil to escape from the feed pump discharge port 62 side to the relief chamber 64 by communicating with the relief chamber 64 on the side.

The outlet 73 at the end of the relief chamber 64 communicates directly with the discharge port 58 of the main scavenge pump, and the oil released to the relief chamber 64 is returned to the discharge port 58 of the main scavenge pump. In the collective discharge passage 59, the oil is discharged to the oil tank 20 together with the discharge oil from the sub-scavenge pump discharge port 55 and the main scavenge pump discharge port 58. The discharge port 73, the main scavenge pump discharge port 58, the sub-scavenge pump discharge port 55, and the collective discharge path 59 are all formed directly in a member that is integral with the oil pump 30 as a housing.

Next, the operation of this embodiment will be described. The oil pump 30 has three pumps, ie, a feed pump 31, a feed pump rotor 44, a sub-scavenge pump rotor 45, and a main scavenge pump rotor 46 arranged side by side on a common drive shaft 43. The sub-scavenge pump 33 and the main scavenge pump 32 are integrated.

Therefore, as compared with the case where these three pumps are separately provided, the number of parts can be reduced, piping can be omitted, and the arrangement in the crankcase 10 can be assembled, so that the necessary arrangement space can be reduced. The capacity of the scavenge pump can be increased. In addition, the overall capacity of the oil pump 30 is reduced in size and weight, and the structure of the oil pump 30 is simplified to facilitate manufacture.

The two main scavenge pumps 32
And the sub-scavenge pump 33, the oil is separately pumped from different positions to the oil sump 37 at the center in the front-rear direction and the oil sump 38 at the rear of the bottom of the crankcase 10, so that it is possible to cope with a change in the posture of the vehicle body. Thus, oil can be constantly sucked up from the oil reservoirs 37 and 38 of each part, and stable lubrication can be performed.

In particular, the sub-scavenge pump 3 is moved from the oil sump 38 located on the rear side separate from the oil sump 37.
Since the oil was sucked up at 3, even when the front part of the vehicle body was raised, such as when climbing a steep hill, the oil sump 38 side was not easily pumped up by the main scavenge pump 32 due to fluctuations in the oil level. The sub-scavenge pump 33 can be effectively lubricated even in such a state because the oil which has moved to the portion is easily accumulated. Therefore, the arrangement of the main scavenge pump 32 and the sub-scavenge pump 33 can be easily sucked up without applying a special device for easily collecting oil by applying the bottom of the crankcase 10 to changes in the posture of the vehicle body. Can be optimized, the degree of freedom in designing the bottom of the crankcase 10 increases, and the crankcase 10
It is easy to reduce the center of gravity while maintaining the required minimum ground clearance with respect to the bottom of the vehicle. Therefore, the present invention is suitable for an all-terrain vehicle such as a four-wheel buggy employing a dry sump lubrication structure.

Further, since the discharge port 73 of the relief valve 41 can be directly connected and connected in the same fourth block 50 as the main scavenge pump discharge port 58, there is no need for piping and the structure can be simplified.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously applied and modified. For example, the feed pump 31 can be provided with a plurality of rotors, and both the feed pump and the scavenge pump are provided with a plurality of rotors. Can be provided one by one. In addition, the dry sump type can be used not only for four-wheel buggy vehicles but also for other vehicles.

[Brief description of the drawings]

FIG. 1 is a diagram of a lubrication system according to an embodiment.

FIG. 2 is a side view of a main part of a vehicle body of a four-wheel buggy vehicle to which the embodiment is applied.

FIG. 3 is a sectional view of an oil pump according to the embodiment.

FIG. 4 is a sectional view showing an oil pump and an oil passage structure thereof.

[Explanation of symbols]

Power unit 4, oil cooler 20, oil tank 34, crankcase 10, oil pump 30, drive shaft 43, feed pump rotor 44, sub-scavenge pump rotor 45, main scavenge pump rotor 46, feed pump 31, sub-scavenge pump 33, main Scavenge pump 32, oil sump 38, oil sump 37, main scavenge pump suction port 56, sub scavenge pump discharge port 55, main scavenge pump discharge port 58, main passage 57, feed pump suction port 61,
Feed pump discharge port 62, relief valve 41, discharge port 73

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobutaka Yagigaya 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G013 AA02 AA16 AB00 BB04 BB19 BB25 BD46 3G015 AA02 AA16 AB00 BB01 BB07 CA06 CA07 DA10 EA14

Claims (2)

[Claims] An internal combustion engine having a feed pump for supplying lubricating oil in an oil tank to each lubricating portion of the internal combustion engine and a scavenge pump for returning lubricating oil accumulated in an oil reservoir of the internal combustion engine to the oil tank. A lubricating device for an internal combustion engine, wherein the oil sump of the internal combustion engine is divided into a plurality of sections, and a plurality of scavenge pumps are provided corresponding to each of the divided oil sumps. 2. The lubricating device for an internal combustion engine according to claim 1, wherein the plurality of scavenge pumps include a plurality of rotors arranged in parallel on a drive shaft of one oil pump. .