JPH11218016A - Drysump lubrication type four-cycle engine unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a forming mold for forming plates to be arranged in collecting parts. SOLUTION: With this engine unit, the lubricating oil temporarily collected in collecting parts 11b... on the bottom of a crank case 11 is pumped into a lubricating oil tank by a return pump. In this case, a plate 21A for partitioning between a crankshaft and the lower oil level is arranged in the collecting parts 11b.... Then the plate 21A is divided and formed of plural divided pieces 2..., and the pieces 21 are made into the same shape, and arranged between crankshaft bearings 11a....

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement of a dry sump lubricated four-stroke engine unit.

[0002]

2. Description of the Related Art In a dry sump lubrication system, lubricating oil is supplied to each lubricating portion of an engine from a lubricating oil tank provided outside a half crankcase, and excess lubricating oil is temporarily supplied to the bottom of the half crankcase. This is a lubrication system that collects and collects the lubricating oil into a lubricating oil tank quickly with a lubricating oil pump.

[0003] As a dry sump lubricated engine unit, there is, for example, Japanese Patent Application Laid-Open No. Sho 62-23514, "Engine Lubricating Device". According to FIG. 1 of the publication, the lubricating device for the engine is provided at the bottom of the crankcase 4 (the number is quoted in the publication; the same applies hereinafter) and on both left and right sides of the crankcase 4. Oil sumps 13 and 14 extending in the direction in which the pins 10 extend are provided, and baffle plates 17 are provided above the oil sumps 13 and 14. Oil sumps 13, 14
Plays a role in temporarily collecting the lubricating oil flowing down the wall surface of the crankcase 4. Baffle plate 17 ...
It serves to prevent the lubricating oil in the oil sumps 13 and 14 from scattering. The lubricating oil collected in the oil sump 13 is
And the lubricating oil collected in the oil sump 14 is pumped into the lubricating oil tank 20 by the first scavenge pump 28.

[0004] Further, the above prior art is disclosed in the first publication of the publication.
According to the figure, a lubricating oil tank 20 is mounted on a side of the engine body 1 and on a surface parallel to the crankshaft 8. The communication between the engine body 1 and the lubricating oil tank 20 can be made without a hose.

[0005]

In the above prior art, a relatively large baffle plate 17 is provided above the oil sumps 13 and 14, and the baffle plate 1 is provided.
The molding die for molding 7 is large.

Further, in the above-mentioned conventional technique, a surface of the side of the engine body 1 parallel to the crankshaft 8 is provided with a skirt,
There are many overhangs such as ribs and bosses for attaching auxiliary equipment.
The mounting position of the lubricating oil tank 20 is limited, and the degree of freedom in design is small.

An object of the present invention is to reduce the size of a molding die for molding a plate to be disposed in a collecting section. A further object of the present invention is to allow a lubricating oil tank to be freely attached to an assembly comprising a cylinder block and a half crankcase.

[0008]

According to a first aspect of the present invention, a lubricating oil temporarily collected in a collecting portion at the bottom of a crankcase is pumped into a lubricating oil tank by a return pump. In the dry sump lubrication type four-cycle engine unit, a plate partitioning between the crankshaft and the lower oil surface is arranged in the collecting portion, and the plate is composed of a plurality of divided pieces. Further, it is characterized in that it is arranged between the crankshaft bearings.

Excessive lubricating oil after lubricating each lubricating part of the engine is temporarily collected in a collecting part at the bottom of the crankcase, and then is pumped into a lubricating oil tank by a return pump. The lubricating oil in the collecting section is prevented from being scattered by the plate. One plate is small because the plate to be arranged in the collecting unit is composed of a plurality of divided pieces.
A molding die for stamping and molding a small piece from a plate material may be small. Moreover, since a plurality of pieces have the same shape, only one type of molding die is required.

According to a second aspect of the present invention, there is provided a dry sump lubrication system having a lubricating oil tank provided outside a half crankcase.
In the cycle engine unit, a first packing surface and a second packing surface which are parallel to each other are formed in a lubricating oil tank, while, on the side of an assembly including a cylinder block and a half crankcase, and orthogonal to a crankshaft. A tank mounting packing surface is formed on the surface to be sealed, a first packing surface of a lubricating oil tank is mounted on the tank mounting packing surface, and a lid is mounted on a second packing surface of the lubricating oil tank.

[0011] Since the lubricating oil tank is mounted on a surface orthogonal to the crankshaft, which has few protruding portions such as skirts, ribs, and bosses for mounting auxiliary equipment, on the side of the assembly, There is little restriction on the mounting position, the degree of freedom in design is large, and machining of the lubricating oil tank mounting surface (packing surface) is easy. In addition, since the lubricating oil tank is mounted on the side of the assembly and on the surface orthogonal to the crankshaft, the lubricating oil tank is changed when a plurality of types of engines are produced such that the inclination of the cylinder axis is different from each other. Do not just change the assembly, or
Minimal changes are required, and design flexibility is great. Also, since there are many common parts for a plurality of types of engines, the cost of the mold can be reduced. Furthermore, since the first and second packing surfaces parallel to each other are formed on the lubricating oil tank, and the lid is attached to the second packing surface, the inside of the lubricating oil tank can be easily inspected.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a side view of a small boat equipped with a dry sump lubricated four-stroke engine unit according to the present invention. The small boat 1 indicated by imaginary lines is used for leisure or the like, and has an engine compartment of a hull 2. A dry-sump lubricated four-cycle engine unit 3 is mounted on 2a, and a jet pump 4 is driven by the engine unit 3. The jet pump 4 pressurizes water sucked from the bottom of the hull 2 and discharges the water backward as a jet stream. That will move you forward. 2d is a bulkhead, 2e is a sheet, 2f is a deck, 2g is a steering bar, 5 is a water supply port, 6 is a discharge nozzle (discharge port), and 7 is a fuel tank.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and shows an engine room 2a (formed by a lower hull 2b and an upper hull 2c).
Fig. 1 shows a state in which a dry sump lubricated four-cycle engine unit 3 is mounted. The engine unit 3 extends the crankshaft 15 in the front-rear direction of the small boat 1 (front and rear directions in the figure), inclines the cylinder axis L in the upper left direction in the figure, and shows a plurality of four front, rear, left and right mounts 8. The same shall apply hereinafter) is attached to the mounting base 2h of the lower hull 2b. Reference numeral 9 denotes a mount rubber.

FIG. 3 is a sectional view taken along line 3-3 of FIG.
2 shows a cross-sectional configuration of an engine unit 3 that takes out engine power toward the rear (left side in the figure) of the small boat 1 shown in FIG. In this figure, the area around the suction pipe 72 and the suction oil passage 24a (the range indicated by the reference numeral AA) corresponds to 3-3 in FIG.
Although it is located at a position deviated from the line, it is shown in the same cross section as other parts for convenience of explanation. The engine unit 3 is a horizontal three-cylinder engine including an engine body 10, a valve drive mechanism 40 and a flywheel unit 50 attached to the front of the engine body 10, and a lubrication unit 60 attached to the rear of the engine body 10. Engine.

The engine body 10 includes a half crankcase (crankcase) 11, a cylinder block 12 having three cylinders 12a in the front-rear direction, a cylinder head 13, a head cover 14, and a lateral crankshaft 15. A piston 16 connected to the crankshaft 15 and inserted through each cylinder 12a, a PTO shaft (power take-out shaft) 17 connected to the rear end of the crankshaft 15, a cylinder head 13 and a head cover 14. The valve train 18 and the valve train 30 housed in the valve train 18 are the main components.

The PTO shaft 17 extends rearward of the lubrication unit 60 (on the side opposite to the engine) and is connected to the drive shaft 4a of the jet pump 4 shown in FIG. A connecting portion 17a is connected to the crankshaft 15, and a connecting portion 17b is a power take-out connecting portion.
Consists of a female screw or a female spline.

The half crankcase 11 has, at its bottom, four crankshaft bearings 11a... For supporting the crankshaft 15, and a temporary lubricating oil between these bearings 11a. Three collecting sections 11b for collecting, a guide path 11c for guiding the lubricating oil collected by these collecting sections 11b, and a guide path 11c
And a return oil passage 11d for returning the lubricating oil from the lubricating unit 60 to the lubricating unit 60.

The collecting portions 11b approach the crankshaft 15 to such an extent that the accumulated lubricating oil does not contact the counterweight (wave) of the crankshaft 15, and a plurality of lubricating oils pass between the crankshaft 15 and the lower oil surface. This is a small-capacity oil reservoir partitioned by small baffle plates 21. For this reason, the half crankcase 11 can be reduced in size because the bottom can be close to the crankshaft 15. As a result, when setting the mounting position of the engine unit 3 on the small boat 1 (see FIG. 2), the influence of the interference between the bottom of the engine unit 3 and the boat bottom can be reduced. And, even though the half crankcase 11 is small, the crankshaft 15 hardly comes into contact with the lubricating oil, the friction loss at the time of rotation is suppressed, and aeration (splashing of oil) is also prevented.

The small baffle plates 21
b... plays a role in preventing the lubricating oil from scattering. Conventionally, a single baffle plate has been used to partition substantially the entire surface between the crankshaft 15 and the lower oil surface. In the present invention, one baffle plate (plate) is constituted by a plurality of divided pieces, and these pieces are formed as small baffle plates 21. That is, the small baffle plates 21 are individually arranged in the respective collecting sections 11b.

The valve drive mechanism 40 includes a crankshaft 1
5, a belt driving mechanism for driving the camshaft 31 of the valve mechanism 30. The driving pulley 41 is fixed to the crankshaft 15 projecting from the front side of the half crankcase 11.
A driven pulley 42 fixed to the camshaft 31 protruding from the front side of the cylinder head 13, and a timing belt 43 hung between the driving and driven pulleys 41, 42.
And a belt tensioner 44 for adjusting the tension of the timing belt 43. 45 is a belt cover.

The flywheel unit 50 includes a flywheel 51 bolted to the front end of the crankshaft 15, and a cylinder block 12 and a half crankcase 11 for storing the flywheel 51. Wheel case 52 bolted to
And a flat lid 53 bolted to cover the open end (front end) of the wheel case 52. That is, the cylinder block 12 and the half crankcase 11
On the side of the assembly consisting of
The flywheel unit 50 is mounted on a surface perpendicular to the plane 5, and the flywheel unit 50 is located forward of the drive pulley 41 (opposite the cylinder block 12).
It is in.

Reference numeral 54 denotes a generator, which includes a rotor 54a attached to the inner peripheral surface of the flywheel 51 and a coil 54b attached to the wheel case 52. 55 is a ring gear attached to the outer peripheral surface of the flywheel 51,
It is connected to a starter motor described later. 57 is an inspection cap for closing a hole for checking the crank angle.

The lubricating unit 60 includes the cylinder block 1
A lubricating oil tank 61 bolted to the rear side of an assembly including the crankcase 2 and the half crankcase 11; a lid 63 closing an open end (rear end) of the lubricating oil tank 61; 11 to the lubricating oil tank 61
A return pump 64 for returning the lubricating oil to the engine, a supply pump 65 for supplying the lubricating oil from the lubricating oil tank 61 to each sliding portion of the engine body 10, and a pipeline. The return pump 64 is a pump built in the lubricating oil tank 61 and a supply pump 65
Is a pump independent of the lubricating oil tank 61.

More specifically, a tank mounting packing surface (flange) 22 is formed on a side portion of an assembly including the cylinder block 12 and the half crankcase 11 and on a surface orthogonal to the crankshaft 15. On the other hand, the first packing surface (flange) 6
1a and a second packing surface (flange) 61b were formed. The second packing surface 61b is located behind the first packing surface 61a (in a direction away from the cylinder block 12 toward the PTO shaft 17). And the tank mounting packing surface 22
The lubricating oil tank 61 is attached to an assembly composed of the cylinder block 12 and the half crankcase 11 with the first packing surface 61a aligned via the packing 23 and the second packing surface 61b via the packing 62. The cover 63 is fitted and bolted. Such a lubricating oil tank 61 is a sealed tank that stores the lubricating oil by being sealed with the side wall of the assembly and the lid 63.

The return pump 64 includes a case portion 61c formed integrally with the lubricating oil tank 61, an inner cover 64a that closes the case portion 61c, an inner rotor 64b and an outer rotor 64c housed in the case portion 61c. A shaft 64f connected to the crankshaft 15 via a drive mechanism (comprising a drive gear 64d and a driven gear 64e) to drive the outer rotors 64b, 64c.
And a scavenging pump. The drive mechanism is housed in a space 66 between the lubricating oil tank 61 and the assembly. The space 66 also serves as a part of a breather passage for communicating the valve chamber 18 with the crank chamber 19. 67 is a bolt for attaching the inner cover 64a to the case 61c.

The supply pump 65 includes a case body 65a bolted to a side of an assembly including the cylinder head 13 and the head cover 14, a cover 65b closing the case body 65a, and an inner rotor 65c housed in the case body 65a. And a shaft 65e that is directly connected to the camshaft 31 of the valve mechanism 30 to drive the inner and outer rotors 65c and 65d. The shaft of the return pump 64 and the shafts 64f and 65e of the supply pump 65 are connected to the crankshaft 15
And extends parallel to the camshaft 31. An assembly composed of the cylinder block 12 and the cylinder head 13 includes a suction oil passage 24a and a discharge oil passage 24b for the supply pump 65.
(See FIG. 7). Incidentally, 58, 58 are hangers.

FIG. 4 is a sectional view of the engine body according to the present invention, and shows the engine body 10 in which the cylinder axis L is inclined in the upper left direction in the figure. The valve operating mechanism 30 includes a camshaft 31
And rocker shafts 32, 32 and rocker arms 33, 33
And an intake valve 34 and an exhaust valve 35. The cylinder head 13 includes an intake passage 13a and an exhaust passage 13b, and a floatless diaphragm carburetor 82 communicates with the intake passage 13a via an intake pipe 81.
An exhaust passage 12b of the cylinder block 12 communicates with 3b. The head cover 14 has a first breather chamber 18a for recirculating blow-by gas above the valve operating chamber 18.

Each of the small baffle plates 21 is fixed to the half crankcase 11, and partitions a range corresponding to the downstream side (left side in the figure) in the rotation direction of the crankshaft 15. Since the cylinder axis L is inclined in the upper left direction in the figure,
The half crankcase 11 has a configuration in which a guide path 11c and a return oil path 11d are arranged at the lower left, and each lubricating oil collected in each collection unit 11b flows toward the guide path 11c. This is a configuration in which a gradient is provided at the bottom of the collecting units 11b. Therefore, only one return line (the guide path 11c and the return oil path 11d) and one return pump 64 (see FIG. 3) for pumping the collected lubricating oil to the lubricating oil tank 61 are required, and the configuration is simple. . When the cylinder axis L is inclined in the upper right direction in the figure, the inclination of the collecting portions 11b and the arrangement of the guide path 11c and the return oil path 11d are opposite to the above.

Reference numeral 26 denotes a supply oil passage, which is a discharge oil passage 24b.
(See FIG. 7) and the supply pump 65 via the filter 25.
(See FIG. 7), which is an oil passage for supplying lubricating oil to each sliding portion of the engine body 10. Reference numeral 27 denotes an oil return tube for returning the lubricating oil from the valve operating chamber 18 to the crank chamber 19. In this embodiment, the oil return tube 27 is provided between the nozzle (oil return port) 13 c of the cylinder head 13 and the lower half of the half crankcase 11. By connecting with a certain nozzle (oil return port) 11e, it communicates with the collection part 11b and the guide path 11c. 28 is the valve operating chamber 1
8 is a communication passage that communicates between the crankcase 8 and the crankcase 19. 11f
Is a drain hole for extracting drain from the collecting part 11b,
.. Are cooling water passages.

FIGS. 5 (a) and 5 (b) are mounting configuration diagrams of the baffle plate according to the present invention, and FIG. 5 (a) is an exploded perspective view of the half crankcase 11 and the small baffle plates 21. b) is a plan view showing a state in which the small baffle plates 21 are assembled to the half crankcase 11;
(A) and (b) show the collecting portions 11b between the bearings 11a.
Shows that the small baffle plates 21 are individually arranged. The plurality of small baffle plates 21 form a baffle plate (plate) 21A as a whole.

The half crankcase 11 has a positioning projection 11g, a plate support 11h, and a screw hole 11i arranged on the plate support 11h at a bottom portion and at a collecting portion 11b. It is. Each of the small baffle plates 21 is a piece having the same shape as each other, and these pieces are substantially T-shaped plate members in plan view so as to partition above the collecting portion 11b and above the guide path 11c.

Since the baffle plate 21A is divided into a plurality of small baffle plates (pieces) 21, one small baffle plate 21 is small. The molding die for stamping out the small small baffle plate 21 from the plate material may be small. Moreover, a plurality of small baffle plates 2
Since... Have the same shape, only one type of molding die is required. Therefore, the mold cost can be reduced.

A small baffle plate 21 is added to the collecting portions 11b.
In order to mount the small baffle plate 21 on the plate receiving stand 11h, the engaging holes 21a of the small baffle plate 21 are fitted to the positioning protrusions 11g and aligned.
The bolt 101 is inserted into the through hole 21b of the small baffle plate 21.
And screwed into the screw hole 11i to fix it to the plate support 11h.

By the way, the small baffle plate 21
As shown in (b), it is a left-right asymmetrical piece (asymmetrical in the extension direction of the crankshaft 15 in FIG. 2). That is, this piece is asymmetrical with respect to a line So orthogonal to the axis of the crankshaft 15. For this reason, the small baffle plate 21 to be assembled upside down will hit the inner wall of the half crankcase 11 and the bearing 11a. The engaging hole 21a is located on the line So, and the through hole 21b is located at a position shifted from the line So. Therefore, even if the small baffle plate 21 is to be assembled upside down, the positioning projections 11g and the screw holes 11i do not match the corresponding engagement holes 21a and the through holes 21b. Therefore, there is no need to worry about assembling the small baffle plate 21 in the wrong direction.

FIG. 6 is an exploded plan view of the lubricating oil tank and the lid according to the present invention, and is taken along the assembly of the cylinder block 12 and the half crankcase 11 along the axis S of the crankshaft 15 shown in FIG. (Crankshaft 15
This indicates that the lubricating oil tank 61 swells in the direction in which the lubricating oil extends, and that the lubricating oil is also stored in the bulging portion 61d. In the lubricating oil tank 61, the lubricating oil can also be stored in the bulging portion 61d along the assembly. Therefore, even if the lubricating oil tank 61 has the same capacity, the front-rear dimension and the vertical dimension can be reduced. The engine unit 3 can be made small. In the figure, 61r is a lubricating oil supply port cap, 68 is a bolt for attaching the lubricating oil tank 61 to the half crankcase 11 and the cylinder block 12, and 69 is a bolt for attaching the lid 63 to the lubricating oil tank 61.

FIG. 7 shows a dry sump lubrication type 4 according to the present invention.
FIG. 3 is a rear view of the cycle engine unit with a lubricating oil tank removed, and shows a tank mounting packing surface 22 of an assembly including a cylinder block 12 and a half crankcase 11.
Indicates that it is open. .., 29A, 29B,... Are breather passages through a space surrounded by the tank mounting packing surface 22 (corresponding to the space 66 shown in FIG. 3).
The valve chamber 18 communicates with the crank chamber 19 (see FIG. 4). That is, the breather passage 29A communicates with the breather passage 29B. Reference numeral 56 denotes a starter motor, which starts the engine unit 3 by rotating the flywheel 51 via a ring gear 55 shown in FIG. By connecting the intake muffler box 83 to the carburetor 82, the intake pipe 81, the carburetor 82 and the intake muffler box 83 form an intake line of the engine body 10. 83
a is an intake port, and 84 is a bolt for mounting the intake muffler box 83 on the mount 8.

FIG. 8 shows a dry sump lubrication type 4 according to the present invention.
FIG. 5 is a rear view of the cycle engine unit with a lid for a lubricating oil tank removed, showing a second packing surface 61 of the lubricating oil tank 61;
b indicates that it is open. Lubricating oil tank 61
A suction oil passage 61e and a discharge oil passage 61f for the return pump 64, an oil reservoir 61g connected to the bulging portion 61d (see FIG. 6) for storing lubricating oil, and a second oil reservoir 61g higher than the oil reservoir 61g. The breather chamber 61h and the engine exhaust port 61i are integrally formed. Engine exhaust port 61i
Is an exhaust port communicating the exhaust passage 12b shown in FIG. 7 with an external exhaust pipe. The suction oil passage 61e and the oil reservoir 61g are located at left and right positions so as to straddle the PTO shaft 17, and the return pump 64 and the supply pump 65 are located at positions passing through the cylinder axis L. A return pump 64 is provided above the return pump 17, and a supply pump 65 is provided above the return pump 64.

A suction pipe 72 with a strainer 71 for the supply pump 65 is housed in the oil reservoir 61g, and the upper end of the suction pipe 72 communicates with the suction oil passage 24a for the supply pump 65 (see FIG. 3). In the figure, 9a is a mounting bolt, 61
m ... are baffle walls for preventing oil scattering provided in three stages in the oil reservoir 61g in the vertical direction, and 61n is a cooling water passage 1 shown in FIG.
A cooling water port communicating with the external cooling pipe 2c. Reference numeral 75 denotes a third breather tube which connects the lubricating oil tank 61 to the valve operating chamber 18 (see FIG. 3) via the gas port 61q.

FIG. 9 is a cross-sectional view of a lubricating oil tank according to the present invention. The bulging portion 61d of the lubricating oil tank 61 is an assembly comprising a cylinder block 12 (see FIG. 3) and a half crankcase 11. The shape swells along. Bulge 6
1d is disposed above the position of the intake port of the strainer 71, so that the intake port is in the oil even when the engine unit 3 is tilted due to the movement of the hull 2 (see FIG. 2). Considered. Second breather room 61
h is a labyrinth structure, the details of which are shown in FIG.
It will be explained in. In the figure, 12d is the wall of the cylinder block 12, 61s is the wall of the lubricating oil tank 61, 61t is the inclined bottom of the bulging portion 61d, 71a is the support stay of the strainer 71, and 73 is the first breather tube. 76 is an oil return tube, which extends from the second breather chamber 61h to the wall 61.
and serves to return the lubricating oil to the crankcase 19 through the s.

FIG. 10 is a perspective sectional view of a second breather chamber according to the present invention, showing three partition walls 6 of a lubricating oil tank 61.
1o and the three partition walls 63a of the lid 63 are abutted to partition the second breather chamber 61h into three chambers.
Small notches 61p, 63b alternately in 1o ..., 63a ...
.. Indicate that the second breather chamber 61h has a labyrinth structure. The second breather chamber 61h includes a gas inlet 61j and a gas outlet 61k. Gas inlet 61
j communicates with the first breather chamber 18a (see FIG. 4) via the first breather tube 73. The gas outlet 61k communicates with the upstream of the carburetor 82 (the communication pipe between the intake muffler 83 and the carburetor 82) via the second breather tube 74.

Next, the operation of the dry sump lubricated four-stroke engine unit having the above configuration will be described with reference to FIGS. 3, 4, and 8. FIG. The return pump 64 of FIG.
The lubricating oil collected in b...
d → intake oil passage 61e → return pump 64 → discharge oil passage 61f in FIG.
8 supplies the lubricating oil accumulated in the oil sump 61g to the strainer 71 → the suction pipe 72 → the suction oil passage 24a →
Supply pump 65 → discharge oil passage 24b → filter 25 in FIG.
→ The oil is supplied to each sliding portion of the engine body 10 through the supply oil passage 26. The lubricating oil remaining after lubricating each sliding part is shown in FIG.
The oil returns to the crank chamber 19 through the oil return tube 27 and is collected in the lubricating oil tank 61 through the return path.

The lubricating oil tank 61 shown in FIG.
Can be freely exchanged according to the installation condition of the device. For example, as shown in FIGS.
May be a modified example in which the direction of the cylinder axis L is changed.

FIG. 11 is a rear view of a dry sump lubricated four-stroke engine unit (modification) according to the present invention, and shows a state in which an engine body 10 having a cylinder axis L inclined in the upper right direction in the figure is mounted on a small boat 1. . In this case,
An electronically controlled fuel injection device is installed instead of the intake system including the diaphragm type carburetor 82 and the intake muffler box 83 shown in FIG. The electronic control fuel injection device includes a throttle body 91, an acceleration pump 92, an injection valve 93, a control computer (not shown), and the like. The position of the throttle body 91 can be freely set by drawing the intake pipe 81 in accordance with the space of the narrow engine room 2a.

FIG. 12 is a rear view of the dry sump lubricated four-stroke engine unit (modification) according to the present invention with the lubricating oil tank removed, showing the tank mounting packing surface 22 inclined in the upper right direction in the figure. In this case, the arrangement of the return oil passage 11d is reversed from the arrangement shown in FIG. As described above, the engine unit 3 includes a case where the cylinder axis L shown in FIG.
The engine main body 10 can be used substantially in common with the case where the cylinder axis L shown in FIG. In addition, since the cylinder axis L is inclined in the upper right direction in the figure, the communication path 28 shown in FIG. 4 is inclined obliquely downward, and serves as an oil return path for returning lubricating oil from the valve operating chamber 18 into the crank chamber 19. Fulfill. For this reason, the oil return tube 27 is unnecessary.

FIG. 13 is a rear view of the dry-sump lubricated four-stroke engine unit (modification) according to the present invention, in which a lid for a lubricating oil tank is removed. This shows a configuration in which the right and left sides are exchanged. By doing so, the minimum change of the assembly consisting of the cylinder block 12 and the half crankcase 11 shown in FIG. 12 is required, and the degree of freedom in design is increased.

FIG. 14 is a rear view of the dry sump lubricated four-cycle engine unit (a further modified example) according to the present invention, from which the lubricating oil tank is removed. This further modification shows that the tank mounting packing surface 22 is inclined in the upper right direction in the figure, but the position of the return oil passage 11d is kept as shown in FIG. In this case, the suction oil passage 61e of the lubricating oil tank 61 shown in FIG. 13 may be changed so as to communicate with the return oil passage 11d shown in FIG. By doing so, there is no need to change the assembly consisting of the cylinder block 12 and the half crankcase 11 shown in FIG. 7, and the degree of freedom in design is further increased. Further, since a relatively large mold for molding the half crankcase 11 and the cylinder block 12 can be handled only by a relatively small mold such as the lubricating oil tank 61, the mold cost can be further reduced.

As is clear from the above description, the present invention is applied to the side of the assembly comprising the half crankcase 11 and the cylinder block 12 and to the crankshaft 15.
The lubricating oil tank 61 is mounted on a surface orthogonal to the above. Therefore, when a plurality of types of engines are produced, for example, when the inclination of the cylinder axis L is different, (1)
As shown in the modified examples of FIGS. 11 to 13, only the lubricating oil tank 61 is changed and the assembly is not changed, or (2) FIG.
The minimum change is sufficient as in the further modified example. As a result, the degree of freedom in design increases. Also, since there are many common parts for a plurality of types of engines, the cost of the mold can be reduced.

In the above embodiment of the present invention,
The engine unit 3 does not limit the number of cylinders,
For example, four cylinders may be used. The lubricating oil tank 61 is provided at least on the side of the assembly including the cylinder block 12 and the half crankcase 11 and on the crankshaft 15.
What is necessary is just to be attached to the surface orthogonal to. For example, in the assembly, the valve drive mechanism 40 and the flywheel unit 50 are mounted on the side where the PTO shaft 17 projects, and the lubrication unit 60 is mounted on the side in the opposite direction (the right side in FIG. 3). In that case, the lubricating oil tank 61 is
Turn forward.

[0049]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect of the present invention, since the plate to be arranged in the collecting section is constituted by a plurality of divided pieces, one piece is small. A molding die for stamping and molding a small piece from a plate material may be small. Moreover, since a plurality of pieces have the same shape, only one type of molding die is required. For this reason, the mold cost can be reduced.

A second packing surface is formed on the lubricating oil tank in parallel with the first packing surface and the second packing surface, while the first packing surface and the second packing surface are formed on the side of the assembly comprising the cylinder block and the half crankcase, and The tank mounting packing surface is formed on a surface orthogonal to the shaft, the first packing surface of the lubricating oil tank is mounted on the tank mounting packing surface, and the lid is mounted on the second packing surface of the lubricating oil tank. Since the lubricating oil tank is mounted on the side perpendicular to the crankshaft, which has few overhangs such as skirts, ribs, and bosses for attaching auxiliary equipment, the mounting position of the lubricating oil tank is limited. There is little design freedom and the lubricating oil tank mounting surface (packing surface) is easy to machine. In addition, since the lubricating oil tank is mounted on the side of the assembly and on the surface orthogonal to the crankshaft, the lubricating oil tank is changed when a plurality of types of engines are produced such that the inclination of the cylinder axis is different from each other. It is not necessary to change the assembly by itself, or only the minimum change is required, and the degree of freedom of design is large. Also, since there are many common parts for a plurality of types of engines, the cost of the mold can be reduced. Furthermore, since the first and second packing surfaces parallel to each other were formed on the lubricating oil tank, and the lid was attached to the second packing surface,
The inside of the lubricating oil tank can be easily inspected.

[Brief description of the drawings]

FIG. 1 is a side view of a small boat equipped with a dry sump lubricated four-stroke engine unit according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view of an engine body according to the present invention.

FIG. 5 is a diagram showing a mounting configuration of a baffle plate according to the present invention.

FIG. 6 is an exploded plan view of a lubricating oil tank and a lid according to the present invention.

FIG. 7 is a rear view of the dry sump lubricated four-stroke engine unit according to the present invention with the lubricating oil tank removed.

FIG. 8 is a rear view of the dry sump lubricated four-stroke engine unit according to the present invention with a lid for a lubricating oil tank removed.

FIG. 9 is a sectional view of a lubricating oil tank according to the present invention.

FIG. 10 is a perspective plan sectional view of a second breather chamber according to the present invention.

FIG. 11 is a rear view of a dry sump lubricated four-stroke engine unit (modified example) according to the present invention.

FIG. 12 is a rear view of the dry sump lubricated four-stroke engine unit (variation example) according to the present invention with the lubricating oil tank removed.

FIG. 13 is a rear view of a dry sump lubricated four-stroke engine unit (modified example) according to the present invention with a lid for a lubricating oil tank removed.

FIG. 14 is a rear view of the dry sump lubricated four-stroke engine unit (a further modified example) according to the present invention with the lubricating oil tank removed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Small boat, 3 ... Dry sump lubrication type 4 cycle engine unit, 10 ... Engine main body, 11 ... Half crankcase (crankcase), 11a ... Bearing for crankshaft, 11b ... Collection part, 11g ... Positioning protrusion, 11
h: plate support, 11i: screw hole, 12: cylinder block, 15: crankshaft, 17: PTO shaft, 2
1A: plate (baffle plate), 21: small baffle plate, 21a: engagement hole, 22: tank mounting packing surface, 60: lubrication unit, 61: lubricating oil tank, 6
1a: first packing surface, 61b: second packing surface, 63
... lid, 64 ... return pump, 101 ... bolt.

Claims (2)

[Claims] In a dry sump lubricated four-stroke engine unit of a type in which lubricating oil temporarily collected in a collecting portion at the bottom of a crankcase is pumped to a lubricating oil tank by a return pump, a lubricating oil is provided between a crankshaft and a lower oil surface. A dry sump lubrication system characterized in that a plate partitioning the plate is arranged in the collecting portion, the plate is composed of a plurality of divided pieces, these pieces are formed in the same shape with each other, and further disposed between crankshaft bearings. 4 cycle engine unit. 2. A dry sump lubricated four-stroke engine unit having a lubricating oil tank outside a half crankcase, wherein a first packing surface and a second packing surface are formed parallel to each other on the lubricating oil tank. A tank mounting packing surface is formed on a side of an assembly including a cylinder block and a half crankcase, and on a surface orthogonal to the crankshaft, and the first packing surface of the lubricating oil tank is formed on the tank mounting packing surface. A dry sump lubricated four-stroke engine unit, wherein a lid is attached to a second packing surface of the lubricating oil tank.