JP3904681B2 - Dry sump lubrication type 4-cycle engine unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a dry sump lubricated four-cycle engine unit.
[0002]
[Prior art]
The dry sump lubrication type supplies lubricating oil to the lubricating parts of the engine from a lubricating oil tank provided outside the half crankcase, and temporarily collects excess lubricating oil at the bottom of the half crankcase and collects the lubrication. This is a lubrication system in which oil is quickly pumped into a lubricant tank with a lubricant pump.
As a dry sump lubrication type engine unit, for example, there is JP-A-62-23514 “engine lubrication device”, and according to FIG. 1 of the publication, the engine body 1 (the number is cited in the publication) The same applies to the following), and a lubricating oil tank 20 is attached to a surface parallel to the crankshaft 8.
According to this device, the engine body 1 and the lubricating oil tank 20 can communicate with each other without a hose.
[0003]
[Problems to be solved by the invention]
In the above prior art, the side parallel to the crankshaft 8 of the side part of the engine body 1 has many overhanging parts such as skirts, ribs, auxiliary equipment mounting bosses, etc., so the mounting position of the lubricating oil tank 20 is limited. The degree of design freedom is small.
[0004]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to attach a lubricating oil tank freely to an assembly composed of a cylinder block and a half crankcase.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a dry sump lubrication type four-cycle engine unit provided with a lubricating oil tank outside the half crankcase, and a first packing surface parallel to the lubricating oil tank, and A second packing surface is formed. On the other hand, a tank mounting packing surface is formed on the side of the assembly composed of the cylinder block and the half crankcase and on a surface orthogonal to the crankshaft. A first packing surface of the lubricating oil tank is attached, and a lid is attached to the second packing surface of the lubricating oil tank.
[0006]
  Since the lubricating oil tank is mounted on the side of the assembly that has few overhanging parts such as skirts, ribs, and auxiliary equipment mounting bosses and is perpendicular to the crankshaft, the mounting position of the lubricating oil tank must be There are few restrictions, the freedom of design is large, and the processing 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 a surface orthogonal to the crankshaft, the lubricating oil tank is changed when a plurality of types of engines are produced such as different cylinder axis inclinations. As a result, the assembly is not changed, or minimal changes are required, and the degree of freedom in design is great. In addition, since there are many common parts for multiple types of engines, the mold cost 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.
The invention according to claim 2 is characterized in that a lubricating oil tank is attached to the half crankcase and the cylinder block with a first bolt, and a lid is attached to the lubricating oil tank with a second bolt. As a result, when the second bolt is removed, only the lid can be removed, and the internal inspection of the lubricating oil tank is facilitated.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a small boat equipped with a dry sump lubrication type four-cycle engine unit according to the present invention. A small boat 1 indicated by an imaginary line is used for leisure purposes and includes an engine room of a hull 2. A dry sump lubrication type 4-cycle engine unit 3 is mounted on 2a, and the jet pump 4 is driven by the engine unit 3, and the water sucked from the bottom of the hull 2 is pressurized by the jet pump 4 and discharged backward as a jet water flow. That is something that moves forward.
2d is a bulkhead, 2e is a seat, 2f is a deck, 2g is a steering bar, 5 is a water supply port, 6 is a discharge nozzle, and 7 is a fuel tank.
[0008]
FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, and shows a state where the dry sump lubrication type four-cycle engine unit 3 is mounted in the engine chamber 2a (formed by the lower hull 2b and the upper hull 2c).
The engine unit 3 extends the crankshaft 15 in the front-rear direction (the front-rear direction) of the small boat 1, inclines the cylinder axis L in the upper left direction in the figure, and indicates four front, rear, left, and right mounts 8. The same applies hereinafter)) to a mounting base 2h of the lower hull 2b. 9 is a mount rubber.
[0009]
FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2 and shows a cross-sectional configuration of the engine unit 3 in which engine power is extracted toward the rear (left side in the figure) of the small boat 1.
In this figure, the suction pipe 72 and the suction oil passage 24a (the range indicated by reference AA) are located at a position deviated from the line 3-3 in FIG. Is shown.
The engine unit 3 includes a horizontal three-cylinder system including an engine body 10, a valve drive mechanism 40 and a flywheel unit 50 attached to the front part of the engine body 10, and a lubrication unit 60 attached to the rear part of the engine body 10. It is an engine.
[0010]
The engine body 10 is connected to a half crankcase 11, a cylinder block 12 having three cylinders 12 a in the front-rear direction, a cylinder head 13, a head cover 14, a lateral crankshaft 15, and the crankshaft 15. A piston 16 inserted into each cylinder 12a, a PTO shaft (power take-off shaft) 17 connected to the rear end of the crankshaft 15, a valve operating chamber 18 formed by the cylinder head 13 and the head cover 14, The valve mechanism 30 housed in the valve chamber 18 is the main component.
The PTO shaft 17 extends rearward (opposite the engine side) from the lubrication unit 60 and is connected to the drive shaft 4a of the jet pump 4 shown in FIG. Reference numeral 17a denotes a connecting part connected to the crankshaft 15, and 17b denotes a power take-out connecting part. These connecting parts 17a and 17b are formed by female screws or female splines.
[0011]
The half crankcase 11 is provided with three collecting parts 11a for lubricating the sliding parts and collecting excess lubricating oil at the bottom, and the lubricating oil collected by these collecting parts 11a. A guiding path 11b for guiding and a return oil path 11c for returning the lubricating oil from the guiding path 11b to the lubricating unit 60 are provided.
The collecting portions 11a are so close to the crankshaft 15 that the accumulated lubricating oil does not come into contact with the counterweight (web) of the crankshaft 15, and the baffle plate 21 between the crankshaft 15 and the lower oil surface. A small-capacity oil reservoir that is partitioned. For this reason, the half crankcase 11 can be made compact because the bottom can be brought close to the crankshaft 15. As a result, when setting the mounting position of the engine unit 2 on the small boat 1 (see FIG. 2), the influence of interference between the bottom of the engine unit 2 and the ship bottom can be reduced. In spite of the small size of the half crankcase 11, the crankshaft 15 is difficult to come into contact with the lubricating oil, the friction loss during rotation is suppressed, and aeration (scattering of oil) is also prevented.
[0012]
The valve drive mechanism 40 is a mechanism that belt drives the camshaft 31 of the valve drive mechanism 30 with the crankshaft 15, and includes a drive pulley 41 fixed to the crankshaft 15 protruding from the front side portion of the half crankcase 11, and a cylinder A driven pulley 42 fixed to the camshaft 31 protruding from the front side portion of the head 13, 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. Become. 45 is a belt cover.
[0013]
The flywheel unit 50 is bolted to the front side of an assembly including a flywheel 51 bolted to the front end of the crankshaft 15 and the cylinder block 12 and the half crankcase 11 for housing the flywheel 51. Wheel case 52 and a flat lid 53 bolted to cover the open end (front end) of the wheel case 52.
That is, the flywheel unit 50 is attached to the side portion of the assembly composed of the cylinder block 12 and the half crankcase 11 and to the surface orthogonal to the crankshaft 15, and the flywheel unit 50 is driven. It is in front of the pulley 41 (on the side opposite to the cylinder block 12).
[0014]
A generator 54 includes a rotor 54 a attached to the inner peripheral surface of the flywheel 51 and a coil 54 b attached to the wheel case 52. A ring gear 55 is attached to the outer peripheral surface of the flywheel 51 and is connected to a starter motor described later. An inspection cap 57 closes a hole for confirming the crank angle.
[0015]
The lubricating unit 60 includes a lubricating oil tank 61 that is bolted to the rear side of the assembly including the cylinder block 12 and the half crankcase 11, and a lid that closes the open end (rear end) of the lubricating oil tank 61. 63, a return pump 64 for returning the lubricating oil from the collecting portion 11a of the half crankcase 11 to the lubricating oil tank 61, and 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 pipe line.
The return pump 64 is a pump built in the lubricating oil tank 61, and the supply pump 65 is a pump independent of the lubricating oil tank 61.
[0016]
Specifically, a tank mounting packing surface (flange) 22 is formed on the side portion of the assembly including the cylinder block 12 and the half crankcase 11 and on a surface orthogonal to the crankshaft 15. On the other hand, a first packing surface (flange) 61a and a second packing surface (flange) 61b parallel to each other were formed in the lubricating oil tank 61. The second packing surface 61b is behind the first packing surface 61a (in the direction away from the cylinder block 12 toward the PTO shaft 17).
The first packing surface 61a is aligned with the tank mounting packing surface 22 via the packing 23, and the lubricating oil tank 61 is mounted on the assembly composed of the cylinder block 12 and the half crankcase 11, and the second packing surface. 61b is fitted with a lid 63 via a packing 62 and bolted. Such a lubricating oil tank 61 is a sealed tank that is sealed by the side wall of the assembly and the lid 63 and accumulates lubricating oil.
[0017]
The return pump 64 includes a case portion 61c formed integrally with the lubricating oil tank 61, an inner cover 64a closing the case portion 61c, an inner rotor 64b and an outer rotor 64c housed in the case portion 61c, and the inner and outer rotors 64b, This is a scavenging pump comprising a shaft 64f connected to the crankshaft 15 via a drive mechanism (comprising a drive gear 64d and a driven gear 64e) to drive 64c. 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 operating chamber 18 and the crank chamber 19. Reference numeral 67 denotes a bolt for attaching the inner cover 64a to the case portion 61c.
[0018]
The supply pump 65 includes a case main body 65a bolted to the side of the assembly composed of the cylinder head 13 and the head cover 14, a cover 65b closing the case main body 65a, an inner rotor 65c and an outer rotor 65d housed in the case main body 65a. And a shaft 65e directly connected to the camshaft 31 of the valve operating mechanism 30 to drive the inner and outer rotors 65c and 65d.
Note that the shaft of the return pump 64 and the shafts 64 f and 65 e of the supply pump 65 extend parallel to the crankshaft 15 and the camshaft 31.
The assembly including the cylinder block 12 and the cylinder head 13 includes a suction oil passage 24a and a discharge oil passage 24b (see FIG. 7) for the supply pump 65.
Reference numerals 58 and 58 denote hangers.
[0019]
FIG. 4 is a cross-sectional view of the engine body according to the present invention, showing the engine body 10 with the cylinder axis L inclined in the upper left direction in the figure.
The valve mechanism 30 includes a camshaft 31, rocker shafts 32 and 32, rocker arms 33 and 33, an intake valve 34, and an exhaust valve 35.
The cylinder head 13 includes an intake passage 13a and an exhaust passage 13b. A floatless diaphragm carburetor 82 communicates with the intake passage 13a via an intake pipe 81, and an exhaust passage 12b of the cylinder block 12 communicates with the exhaust passage 13b.
The head cover 14 includes a first breather chamber 18a for blow-by gas recirculation at the upper part of the valve operating chamber 18.
[0020]
Each baffle plate 21 is fixed to the half crankcase 11 and partitions a range corresponding to the downstream side (left side in the figure) in the rotational direction of the crankshaft 15. In the present embodiment, the half crankcase 11 is divided. It is fixed to the bottom portion of the base plate by locking one place with a locking projection 11d for preventing rotation and bolting the other one place. In addition, you may partition the whole required range with one baffle plate.
Reference numeral 26 denotes a supply oil passage which is connected to a supply pump 65 (see FIG. 7) via a discharge oil passage 24b (see FIG. 7) and a filter 25 and supplies lubricating oil to each sliding portion of the engine body 10. Road.
An oil return tube 27 returns lubricating oil from the valve operating chamber 18 to the crank chamber 19. In this embodiment, the nozzle 13 c of the cylinder head 13 and the nozzle 11 e in the lower half of the half crankcase 11 By connecting between them, it connects with the collection part 11a and the guidance | induction part 11b.
A communication passage 28 communicates the valve operating chamber 18 and the crank chamber 19.
11f is a drain hole for extracting drain from the collection part 11a, 12c ... is a cooling water passage.
[0021]
FIG. 5 is an exploded plan view of the lubricating oil tank and the lid according to the present invention, and is along the axis S direction of the crankshaft 15 (extension of the crankshaft 15) along the assembly composed of the cylinder block 12 and the half crankcase 11. It is shown that the lubricating oil tank 61 is swollen in the direction) and the lubricating oil is also stored in the swollen portion 61d.
Of the lubricating oil tank 61, the lubricating oil can also be stored in the bulging portion 61d along the assembly, so that the front and rear dimensions and the vertical dimension can be reduced even with the lubricating oil tank 61 of the same capacity. The engine unit 3 can be reduced in size.
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.
[0022]
FIG. 6 is a rear view of the dry sump lubrication type four-cycle engine unit according to the present invention with the lubricant tank removed, and the tank mounting packing surface 22 of the assembly comprising the cylinder block 12 and the half crankcase 11 is opened. Indicates that
29A, 29B ... are breather passages that communicate the valve operating chamber 18 and the crank chamber 19 via a space surrounded by the tank mounting packing surface 22 (corresponding to the space 66 shown in FIG. 3). is there. 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 the ring gear 55 shown in FIG.
By connecting the intake silencer box 83 to the carburetor 82, the intake pipe 81, the carburetor 82, and the intake silencer box 83 form an intake line of the engine body 10.
Reference numeral 83 a denotes an intake port, and 84 denotes a bolt for attaching the intake silencer 83 to the mount 8.
[0023]
FIG. 7 is a rear view of the dry sump lubrication type four-cycle engine unit according to the present invention, with the lid for the lubricating oil tank removed, showing that the second packing surface 61b of the lubricating oil tank 61 is open.
The lubricating oil tank 61 includes a suction oil passage 61e and a discharge oil passage 61f for the return pump 64, an oil reservoir 61g that is connected to the bulging portion 61d (see FIG. 5), and stores the lubricating oil, and the oil reservoir 61g. The upper second breather chamber 61h and the engine exhaust port 61i are integrally formed. The engine exhaust port 61i is an exhaust port that communicates the exhaust passage 12b and the external exhaust pipe shown in FIG.
The intake oil passage 61e and the oil reservoir 61g are located at positions separated left and right 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, and the PTO shaft A return pump 64 is provided above 17, and a supply pump 65 is provided above the return pump 64.
[0024]
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, 61m... Is an oil scattering prevention baffle wall provided in three stages in the oil reservoir 61g, 61n is in communication with the cooling water passage 12c and the external cooling pipe shown in FIG. Cooling water port. 75 is a 3rd breather tube, and is a tube which connects the lubricating oil tank 61 to the valve operating chamber 18 (refer FIG. 3) via the gas port 61q.
[0025]
FIG. 8 is a cross-sectional view of the lubricating oil tank according to the present invention, and shows a shape in which the bulging portion 61 d of the lubricating oil tank 61 bulges along the assembly composed of the cylinder block 12 and the half crankcase 11. .
The bulging portion 61d is disposed above the suction port position of the strainer 71, so that the suction port is in the oil even when the engine unit 3 is inclined due to the movement of the hull 2 (see FIG. 2). It is considered to be.
The second breather chamber 61h has a labyrinth structure, and details thereof will be described with reference to FIG.
In the figure, 12d is a wall portion of the cylinder block 12, 61s is a wall portion of the lubricating oil tank 61, 61t is an inclined bottom portion of the bulging portion 61d, 71a is a support stay for the strainer 71, and 73 is a first breather tube. An oil return tube 76 serves to return the lubricating oil from the second breather chamber 61h to the crank chamber 19 through the wall 61s.
[0026]
FIG. 9 is a plan sectional perspective view of the second breather chamber according to the present invention, in which the three partition walls 61o of the lubricating oil tank 61 and the three partition walls 63a of the lid 63 are abutted to form the second breather chamber 61h. It is shown that the second breather chamber 61h has a labyrinth structure by partitioning into three chambers and further providing small notches 61p, 63b... In each partition wall 61o.
The second breather chamber 61h includes a gas inlet 61j and a gas outlet 61k. The gas inlet 61j 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 silencer 83 and the carburetor 82) via the second breather tube 74.
[0027]
Next, the operation of the dry sump lubrication type 4-cycle engine unit having the above configuration will be described with reference to FIGS. 3, 4 and 7. FIG.
3 returns the lubricating oil collected in the collecting portions 11a... (Guide path 11b → return oil path 11c → suction oil path 61e in FIG. 7 → return pump 64 → discharge oil path 61f (return path). ) To return to the oil sump 61g.
7 supplies the lubricating oil accumulated in the oil reservoir 61g to the strainer 71 → the suction pipe 72 → the suction oil passage 24a → the supply pump 65 → the discharge oil passage 24b → the filter 25 in FIG. 4 → the supply oil passage 26. The fuel is supplied to each sliding portion of the engine main body 10 through a route.
The surplus lubricating oil after lubricating each sliding portion returns to the crank chamber 19 through the oil return tube 27 of FIG. 4 and is collected in the lubricating oil tank 61 through the return path.
[0028]
The lubricating oil tank 61 shown in FIG. 3 can be attached to and detached from the engine body 10 and can be freely replaced in accordance with the installation condition of the engine unit 3 and the like. For example, a modified example in which the direction of the cylinder axis L of the engine unit 3 is changed as shown in FIGS.
[0029]
FIG. 10 is a rear view of a dry sump lubrication type four-cycle 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 FIG.
In this case, an electronically controlled fuel injection device is installed in place of the intake system comprising the diaphragm type carburetor 82 and the intake silencer box 83 of FIG. The electronically controlled 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.
[0030]
FIG. 11 is a rear view of the dry sump lubrication type four-cycle engine unit (modified example) according to the present invention with the lubricating oil tank removed, and shows a state in which the tank mounting packing surface 22 is inclined in the upper right direction of the figure.
As described above, the engine unit 3 shares the engine body 10 when the cylinder axis L shown in FIG. 2 is inclined in the upper left direction in the figure and when the cylinder axis L shown in FIG. 12 is inclined in the upper right direction in the figure. it can.
4 is inclined downward, and the role of the oil return passage for returning the lubricating oil from the valve operating chamber 18 into the crank chamber 19 is achieved. Fulfill. For this reason, the oil return tube 27 is unnecessary.
[0031]
FIG. 12 is a rear view of the dry sump lubrication type four-cycle engine unit (modified example) according to the present invention with the lid for the lubricating oil tank removed, and the bulging portion of the lubricating oil tank 61 is left and right with respect to the cylinder axis L. Shown in the state of being replaced with the opposite one.
In this way, there is no need to change the assembly composed of the cylinder block 12 and the half crankcase 11 shown in FIG.
In addition, since relatively large molds for molding the half crankcase 11 and the cylinder block 12 can be handled on the relatively small mold side such as the lubricating oil tank 61, the mold cost can be reduced.
[0032]
In the above-described embodiment of the present invention, the engine unit 3 does not limit the number of cylinders, and may be, for example, four cylinders.
The lubricating oil tank 61 may be attached to a side portion of the assembly including at least the cylinder block 12 and the half crankcase 11 and to a surface orthogonal to the crankshaft 15. For example, in the assembly, the valve drive mechanism 40 and the flywheel unit 50 are attached to the side portion from which the PTO shaft 17 protrudes, and the lubrication unit 60 is attached to the side portion in the opposite direction (right side in FIG. 3). In that case, the lubricating oil tank 61 faces the front of the small boat 1.
[0033]
【The invention's effect】
  The present invention exhibits the following effects by the above configuration.
  The invention according to claim 1 is a dry sump lubrication type four-cycle engine unit having a lubricating oil tank outside the half crankcase.A wall part is formed between the half crankcase and the edge of this wall part.First packing surfaceAnd is parallel to the first packing surface and becomes an open end.A second packing surface is formed. On the other hand, a tank mounting packing surface is formed on the side of the assembly composed of the cylinder block and the half crankcase and on a surface orthogonal to the crankshaft. The first packing surface of the lubricating oil tank is attached, and a lid is attached to the second packing surface of the lubricating oil tank.
[0034]
  Since the lubricating oil tank is mounted on the side of the assembly that has few overhanging parts such as skirts, ribs, and auxiliary equipment mounting bosses and is perpendicular to the crankshaft, the mounting position of the lubricating oil tank must be There are few restrictions, the freedom of design is large, and the processing 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 a surface orthogonal to the crankshaft, the lubricating oil tank is changed when a plurality of types of engines are produced such as different cylinder axis inclinations. As a result, the assembly is not changed, or minimal changes are required, and the degree of freedom in design is great. In addition, since there are many common parts for multiple types of engines, the mold cost 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.
In the invention of claim 2, since the lubricating oil tank is attached to the half crankcase and the cylinder block with the first bolt, and the lid is attached to the lubricating oil tank with the second bolt, only the lid is removed when the second bolt is removed. It can be removed and internal inspection of the lubricating oil tank becomes easy.
[Brief description of the drawings]
FIG. 1 is a side view of a small boat equipped with a dry sump lubricated four-cycle engine unit according to the present invention.
2 is a sectional view taken along line 2-2 of FIG.
3 is a sectional view taken along line 3-3 in FIG.
FIG. 4 is a sectional view of an engine body according to the present invention.
FIG. 5 is an exploded plan view of a lubricating oil tank and lid according to the present invention.
FIG. 6 is a rear view of a dry sump lubrication type four-cycle engine unit according to the present invention with a lubricating oil tank removed.
FIG. 7 is a rear view of the dry sump lubrication type four-cycle engine unit according to the present invention with the lid for the lubricating oil tank removed
FIG. 8 is a sectional view of a lubricating oil tank according to the present invention.
FIG. 9 is a perspective sectional view of a second breather chamber according to the present invention.
FIG. 10 is a rear view of a dry sump lubrication type four-cycle engine unit (modification) according to the present invention.
FIG. 11 is a rear view of the dry sump lubrication type four-cycle engine unit (modified example) according to the present invention with the lubricant tank removed
FIG. 12 is a rear view of the dry sump lubrication type four-cycle engine unit (modified example) according to the present invention with the lid for the lubricating oil tank removed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Small ship, 3 ... 4 cycle engine unit, 10 ... Engine main body, 11 ... Half crankcase, 12 ... Cylinder block, 15 ... Crankshaft, 17 ... PTO shaft, 22 ... Tank mounting packing surface, 60 ... Lubrication unit 61 ... Lubricating oil tank, 61a ... First packing surface, 61b ... Second packing surface, 63 ... Lid.

Claims (2)

In a dry sump lubrication type four-cycle engine unit provided with a lubricant tank outside the half crankcase, a wall portion is formed in the lubricant tank between the half crankcase and the wall portion. together form a first packing surface edge, the first parallel to the packing surface, the second packing surface comprising an open end formed, whereas the side of the assembly consisting of the cylinder block and half crankcase And a tank mounting packing surface is formed on a surface orthogonal to the crankshaft, the first packing surface of the lubricating oil tank is mounted on the tank mounting packing surface, and a lid is attached to the second packing surface of the lubricating oil tank. A dry sump lubrication type 4-cycle engine unit that is mounted. The dry sump lubrication type four cycle according to claim 1, wherein the lubricating oil tank is attached to the half crankcase and the cylinder block with a first bolt, and the lid is attached to the lubricating oil tank with a second bolt. Engine unit.

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