JP2000038912A - Lubricating device for four-cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively supply oil stored in an oil sump and scattered by an oil-scattering impeller to a valve train, a crank shaft, and around a piston even in any service mode of a four-cycle engine, a horizontal mode or a vertical mode. SOLUTION: A horizontal mode forms the bottom of a crank case 3 into an oil sump 17. A vertical mode forms the bottom of a valve chamber 15 into an oil sump. Part of an oil-scattering impeller 35 driven by a crank shaft 2 is dipped in the oil sump 17 associated with any mode and is placed to approach the center line Y of a cylinder bore 5a as its plane of rotation is kept away from the crank shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine body including a crankcase for supporting a crankshaft and a cylinder barrel having a cylinder bore. A valve mechanism driven by the crankshaft is provided. In a horizontal mode in which the crankshaft is horizontal, the bottom in the crankcase serves as an oil reservoir, and in a vertical mode in which the crankshaft is vertical, the valve mechanism is not movable. The present invention relates to a lubricating device for a four-stroke engine in which the bottom of a valve chamber serves as an oil reservoir.

[0002]

2. Description of the Related Art Conventionally, in such an engine lubrication system, in a horizontal mode, an impeller driven by a crankshaft by immersing a part in an oil sump is rotated in a direction in which a valve train mechanism extends. So that oil in the oil sump scattered by the impeller is supplied to the valve operating mechanism. In the vertical mode, a part of the oil is immersed in the oil sump and driven by the crankshaft. The oil scattering impeller is arranged so that its rotating surface is parallel to the axis of the crankshaft, so that oil in the oil reservoir scattered by the impeller is supplied around the crankshaft and to the valve mechanism. A known example is known (for example, see Japanese Patent Application Laid-Open No. 10-131733).

[0003]

SUMMARY OF THE INVENTION In the above conventional device,
It is necessary to change the direction of the oil scattering impeller between the horizontal mode and the vertical mode and attach it to the engine body to control the oil scattering direction. Is necessary,
The number of parts is large and cost reduction is difficult.

The present invention has been made in view of such circumstances, and in any of the horizontal mode and the vertical mode, if only a valve mechanism is provided by the oil in the oil reservoir scattered by the same oil scatter blade. It is another object of the present invention to provide a lubricating device for the engine that can lubricate around a crankshaft and around a piston.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a dynamic engine which communicates with the inside of the crankcase on one side of an engine body including a crankcase supporting a crankshaft and a cylinder barrel having a cylinder bore. A valve mechanism is formed in the valve chamber, and a valve mechanism driven by the crankshaft is disposed in the valve chamber. In a horizontal mode in which the crankshaft is horizontal, the bottom in the crankcase serves as an oil sump, In an engine in which the bottom of the valve operating chamber becomes an oil reservoir in the vertical mode in which the shaft is vertical, a part of the crankshaft is immersed in both the horizontal mode and the vertical mode in the oil chamber. The oil-spattering impeller driven by the cylinder is moved to the center line of the cylinder bore as its rotating surface moves away from the crankshaft. That it has axially supported on the engine body so that brute the first feature.

According to the first feature, in both the horizontal mode and the vertical mode, the oil scattering impeller scatters oil in the oil reservoir, and the direction of the oil scatters from the crankshaft. The oil scattered by the same oil-spraying impeller in both the horizontal mode and the vertical mode is displaced along the rotating surface of the impeller that is inclined so as to approach the center line of the cylinder bore as the distance increases. As well as reflected around the crankshaft and around the piston, reflecting on the inner wall of the crankcase and lubricating them.

According to a second aspect of the present invention, in addition to the above-described features, the impeller is configured such that a blade is protruded from an outer periphery of a rotary disk of a governing centrifugal governor driven by the crankshaft. Features.

According to the second feature, since the rotating disk of the centrifugal governor for speed control also serves as the impeller for oil scattering, it is not necessary to provide a special impeller for oil scattering.

[0009]

Embodiments of the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional front view of a four-stroke engine used in a horizontal mode, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 of FIG. 1, and FIG. It is a vertical front view of the engine used in an aspect.

First, a four-stroke engine used in a horizontal mode will be described with reference to FIGS.

In FIGS. 1 and 2, reference symbol E denotes a four-stroke engine. The engine body 1 has a crankcase 3 for horizontally supporting a crankshaft 2 and a cylinder bore in which a piston 4 is slidably fitted. A cylinder barrel 5 having a cylinder 5a and a cylinder head 18 defining a combustion chamber 6 between a top surface of the piston 4 and a crank portion 2c of the crankshaft 2 are connected to the piston 4 via a connecting rod 7. Connected. The cylinder head 18 is provided with intake and exhaust valves 8 and 9 and a spark plug 10.

[0013] crankcase 3 is composed of a first case half 3 ₁ and the second case half 3 ₂ which are joined by split plane P intersecting the axis and oblique crankshaft 2, the first case half Body 3 ₁ , cylinder barrel 5 and cylinder head 1
The three members 8 are integrally formed by casting to form the engine block 1a. First and second case halves 3 ₁ , 3
₂ are detachably joined by a plurality of bolts 11, 11,... (See FIG. 2).

The crankshaft 2 is provided on both sides of the crank portion 2c.
Adjacent first and second journal sections 2j₁, 2j_TwoIs shaped
And the first and second journals 2j₁,
2j _TwoThe ball bearing 12₁, 12_TwoSupported through
First and second bearing portions 13 ₁, 13_TwoAre the first and second
Case half 3₁, 3_TwoAre integrally formed.

A side cover 14 defining a valve chamber 15 is joined to an outer surface of the engine block 1a opposite to the dividing surface P by a plurality of bolts (not shown). The second case half 3 ₂ and the side cover 14
The oil seal 1 is in close contact with the outer peripheral surface of the crankshaft 2.
6 ₁ and 16 ₂ are respectively mounted.

[0016] The first case half 3 _1, the first bearing portion 13
An opening 30 is provided below ₁ to communicate the valve train 15 and the inside of the crankcase 3 with each other, and from the inside of the crankcase 3 to the valve train 15, an oil reservoir 17 for storing lubricating oil at the bottom thereof. Is formed.

The upper portion of the valve operating chamber 15 extends through the side wall of the cylinder barrel 5 to above the cylinder head 18. The upper portion of the valve operating chamber 15 has a head cover joined to the upper surface of the cylinder head 18. It is closed by 18a. A valve operating mechanism 19 that opens and closes the intake and exhaust valves 8 and 9 by rotation of the crankshaft 2 is disposed in the valve operating chamber 15.

As shown in FIGS. 1 and 3, the valve mechanism 19
It includes a drive timing gear 20 which is fixed to the crank shaft 2 in a first outer bearing part 13 _1, driven timing gear which is driven by a reduction ratio which is supported on the intermediate shaft 21 to 2 minutes from the driving timing gear 20 22, a cam 23 connected to one end of the driven timing gear 22, a pair of cam followers 25 and 25 supported by a cam follower shaft 24, and a rocker shaft 26 to be swung by the cam 23. And a pair of rocker arms 27, 27, one ends of which contact the valve heads of the intake and exhaust valves 8, 9, and the cam follower 2 is mounted on the other end of the rocker arms 27, 27.
A pair of push rods 2 for connecting 5, 25 respectively
8, 28 and valve springs 29, 29 for urging the intake and exhaust valves 8, 9 in the valve closing direction, respectively.
When the lift surface of No. 3 pushes up the push rods 28, 28 via the cam followers 25, 25, the intake valve 8 or the exhaust valve 9 opens, and the base surface of the cam 23 becomes the cam follower 25, 25.
25, the intake valve 8 or the exhaust valve 9 is closed by the urging force of the valve springs 29, 29.

The intermediate shaft 21 and the cam follower shaft 2
4 are supported at both ends by the engine block 1a and the side cover 14.

A speed control centrifugal governor 33 driven by the drive timing gear 20 below the crankshaft 2 is attached to the side cover 14. The centrifugal governor 33 includes a support shaft 3 fixed to the inner wall of the side cover 14.
A rotating disk 35 supported by the rotary shaft 4, a cylindrical slider 36 slidably fitted on a support shaft 34, and a slider 36.
And a plurality of pendulum-type centrifugal weights 37 that are pivotally supported on a rotating disk 35 with the centrifugal force therebetween. When each centrifugal weight 37 swings radially outward due to centrifugal force, a slider 36 is provided. Is provided with an operating arm 37a that slides in one direction. When the slider 36 slides in the one direction, the throttle valve (not shown) of the carburetor is operated to the closed side via the link mechanism 38 to control the engine speed to the set value, as is conventionally done. It has become.

The rotating surface of the rotating disk 35 is the crankshaft 2.
From the center of the cylinder bore 5a as the distance from the cylinder bore 5a increases. A driven gear 4 meshing with the drive timing gear 20 is provided on the outer periphery of the rotary disc 35.
0 and a plurality of oil scattering blades 41 adjacent to the driven gear 40 are integrally formed, and the lower part of the driven gear 40 and the oil scattering blades 41 is immersed in the oil of the oil reservoir 17 so as to be immersed in the oil. 35 is arranged. Thus, the rotating disk 35 is also used as an oil scattering impeller.

The crank shaft 2, the one end portion protruding to the second case half 3 ₂ outside the cooling fan 44 is fixed flywheel 45 which is formed integrally, projecting in the crankshaft 2, the outer side cover 14 Working equipment A used in a horizontal state, for example, a rotor of a water pump, is connected to the other end.

Therefore, when assembling the engine E,
First and second journals 2j ₁ and 2j ₂ of the crankshaft ₂
Ball bearings 12 ₁ and 12 ₂ are mounted on the first and second case halves 3 ₁ and 3 ₂ , and these ball bearings 12 ₁ and 12 ₂ are fitted into the first and second bearing portions 13 ₁ and 13 ₂ of the first and second case halves 31 and 32. and instrumentation, the two case halves 3 _1, 3 ₂ mutually bolted to. Thereafter, assembled valve operating mechanism 19 in the first bearing portion 13 ₁ outside of the valve chamber 15, the end side cover 14 and the head cover 18a is bolted to the engine block 1a. Thus, the first and second case halves 3 ₁ ,
3 ₂ bonded to the, while securely supporting the crankshaft 2. Thus assemble the valve operating mechanism 19, there is no need to provisional-assembly as in the prior art, the assembling property is improved.

During operation of the engine E, when a load is applied from the piston 4 to the crank portion 2c of the crankshaft 2 via the connecting rod 7 during the expansion stroke and the compression stroke, the load is applied to the first and second case halves 3 _1. , 3 ₂ , the first and second bearings 13 ₁ , 13 ₂ are supported.
3 _1, 13 but moments bending the crank shaft 2 between ₂ occurs, the bending moment, bearing portions 13 _1, 13 ₂
Are smaller as the interval L between the two is smaller. Incidentally, as described above, the valve mechanism 19 the first bearing portion 13 ₁ outside of the valve chamber 15
And the two bearings 13 ₁ and 13 ₂ are connected to the valve mechanism 19.
The bending moment can be suppressed to a minimum because it is adjacent to both ends of the crank portion 2c without any hindrance, and the distance L between them is minimized, which can contribute to the improvement of the durability of the crankshaft 2.

During operation of the engine E, the crankshaft 2
Drives the centrifugal governor 33, the driven gear 40 and the scattering blades 41 of the rotating disk 35 scatter the oil in the oil reservoir 17 while stirring, and the oil scatters away from the crankshaft 2. Rotating plate 3 inclined so as to approach the center line Y of the cylinder bore 5a
5 and is directly supplied to the valve operating mechanism 19 and reflected on the inner wall of the crankcase 2 to be reflected by the crank portion 2c and the journal portion 2j of the crankshaft 2.
₁ , 2j ₂ , the connecting rod 7 and the piston 4 are also supplied to the periphery thereof to lubricate them.

When the amount of oil scattered around the crankshaft 2 and the piston 4 becomes insufficient, as shown by the chain line in FIG. It is preferable to provide an oil dipper 42 for scattering the oil in the oil reservoir 17.

Next, a case where the four-stroke engine E is used in a vertical mode in which the crankshaft 2 is arranged vertically will be described with reference to FIG.

In this case, the four-cycle engine E is configured for lawn mowing by changing the side cover 14. That is,
A plurality of housing mounting bosses 59 are integrally formed on the outer surface of the side cover 14. And side cover 1
The engine E is mounted on a mowing blade housing 60 of the lawn mower with the 4 facing downward, and the mowing blade housing 60 is fixed to the housing mounting boss 59 by bolts 61.
The cutting blade 62 is attached to the crankshaft 2 in the cutting blade housing 60.
And a drive pulley 63 for driving a drive wheel (not shown) by a belt. The configuration and arrangement of the centrifugal governor 33 are the same as those in the above-mentioned horizontal mode.

As described above, in the vertical mode of the four-stroke engine E, since the side cover 14 is turned downward, the bottom of the valve operating chamber 15 becomes a new oil reservoir 17 '.
The lower portion of the drive gear 20 and the lower part of the blades 41 of the rotating disk 35 of the centrifugal governor 33 will be immersed in a new oil reservoir 17 '.

Therefore, also in this vertical mode, the centrifugal governor 33 is driven by the crankshaft 2 during the operation of the engine E, and the driven gear 40 of the rotating disk 35 is driven.
And the scattering blades 41 scatter the oil in the oil reservoir 17 'while stirring, and the direction of the oil scatters on the rotating surface of the rotating disk 35 inclined so as to approach the center line Y of the cylinder bore 5a as the distance from the crankshaft 2 increases. Therefore, the oil is supplied directly to the valve mechanism 19, is also reflected on the inner wall of the crankcase 2, and is also supplied around the crankshaft 2 and around the piston 4 to lubricate them.

As described above, the valve operating mechanism 19 and the crankshaft are scattered by the scattered oil of the rotary disk 35 irrespective of the mode of use, such as the horizontal and vertical of the engine, by the scattered oil from the rotary disk 35 of the same centrifugal governor 33. Since the periphery of the piston 2 and the periphery of the piston 4 can be lubricated, the centrifugal governor 33 can be used in common, and the number of parts can be reduced, and the cost can be reduced.

Further, as in the above embodiment, when the rotary disk 35 of the centrifugal governor is used also as an oil scattering impeller,
There is no need to provide a special impeller for oil scattering, and the configuration can be simplified accordingly.

The present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the gist of the present invention.

[0034]

As described above, according to the first aspect of the present invention, a valve train communicating with the inside of the crankcase on one side of an engine body including a crankcase supporting a crankshaft and a cylinder barrel having a cylinder bore. In the valve operating chamber, a valve operating mechanism driven by the crankshaft is provided, and in a horizontal mode in which the crankshaft is horizontal, the bottom in the crankcase serves as an oil sump.
In the vertical mode in which the crankshaft is vertical, in an engine in which the bottom of the valve operating chamber becomes an oil sump, a part is immersed in both the horizontal mode and the vertical mode oil sump. The oil scattering impeller driven by the crankshaft is supported by the engine main body such that the rotation surface thereof approaches the center line of the cylinder bore as the rotation surface moves away from the crankshaft, so that the impeller can be used in any of the horizontal mode and the vertical mode. ,
The valve operating mechanism, the circumference of the crankshaft, and the circumference of the piston can be lubricated with the oil scattered by the same oil scattering impeller, thereby reducing the number of parts and reducing the cost.

According to the second feature of the present invention, the impeller is configured by protruding the blade on the outer periphery of the rotating disk of the centrifugal governor driven by the crankshaft.
The rotating disk of the governing centrifugal governor also serves as an oil scattering impeller, and there is no need to provide a special oil scattering impeller, and the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal front view of a four-stroke engine used in a horizontal mode.

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. 1;

FIG. 4 is a vertical front view of a four-stroke engine used in a vertical mode.

[Explanation of symbols]

E: 4 cycle engine Y: Center line of cylinder bore 1 ... Engine body 2 ... Crank shaft 3 ... Crank case 5 ... Cylinder barrel 15 ... Moving Valve chamber 17 ・ ・ ・ Oil reservoir in horizontal mode 17 ′ ・ ・ Oil reservoir in vertical mode 19 ・ ・ ・ Valve mechanism 33 ・ ・ ・ Centrifugal governor for speed regulation 35 ・ ・ ・ Also used as impeller for oil scattering Centrifugal governor rotating plate 41

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keita Ito 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G013 AA01 AA03 AA04 AB03 BA04 BB04 BB11 BB31 BD46 EA02 3G024 AA46 AA69 AA74 BA23 DA03 DA04 DA08 DA16 DA21 DA23 EA00 EA14 FA07

Claims (2)

[Claims] 1. A side of an engine body (1) including a crankcase (3) supporting a crankshaft (2) and a cylinder barrel (5) having a cylinder bore (5a) communicates with the inside of the crankcase (3). A valve operating mechanism (19) driven by the crankshaft (2) is disposed in the valve operating chamber (15), and the crankshaft (2) is leveled. In the horizontal mode, the bottom of the crankcase (3) becomes an oil sump (17), and in the vertical mode in which the crankshaft (2) is vertical, the bottom of the valve chamber (15) is an oil sump (17 '). In the four-cycle engine, the oil sump (1) in the horizontal mode and the vertical mode is used.
7, 17 ') and a part is immersed in the crankshaft (2).
The oil scattering impeller (35) driven by the engine body (1) is pivotally supported on the engine body (1) so that the rotation surface thereof approaches the center line (Y) of the cylinder bore (5a) as the rotation surface moves away from the crankshaft (2). A four-stroke engine lubrication system. 2. The lubricating device for an engine according to claim 1, wherein the oil scattering impeller is connected to an outer periphery of a rotating disk (35) of a governing centrifugal governor (33) driven by the crankshaft (2). A lubricating device for a four-stroke engine, characterized in that a blade (41) is protruded from the lubrication device.