JP2530848Y2 - Lubrication structure for vertical engine - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The invention relates to a lubrication structure for a vertical shaft type engine.

(Prior Art) In various general-purpose engines and the like, as shown in a cross section in FIG.
The crankshaft 2 is vertically supported by 3, 4
The large end of the connecting rod 8 of the piston 7 in the horizontal cylinder 6 is fitted to the crank 5 of the horizontal cylinder 6, and the rotation is taken out from the gear 9 on the crankshaft 2 to the outside through a gear system (not shown). Type engines are known.

An intake valve 11 and an exhaust valve 12 are provided at upper and lower portions of a head portion 10 of a cylinder 6 of the vertical shaft type engine. Valve stem portions 13 and 14 of the intake valve 11 and the exhaust valve 12 are provided with bearing portions 15 and 16. And slidably supported by spring retainers 17a, 18a provided at the ends of the valve stems 13, 14.
Valve springs 19 and 20 elastically mounted between the spring receiving portions 17b and 18b of the bearing portions 15 and 16 constantly bias the springs in the valve closing direction. The lower part of the crankcase 1 has an oil reservoir.
The oil in the oil sump 21 is formed into a mist by pressure pulsation waves generated in the crank chamber 1a of the crankcase 1, and the oil passages 22, Oil is supplied to the rocker arm chamber 24 through 23 to lubricate the sliding portions of the valve stems 13 and 14 and the sliding portions of the rocker arms 25 and 26 with oil. The lubricated oil is returned to the oil reservoir 21 through the lower oil passage 23.

(Problems to be Solved by the Invention) In the conventional vertical shaft type engine, the oil in the oil reservoir 21 becomes mist due to the pressure pulsation wave generated in the crankcase 1 by the rotation of the crankshaft 2, and the upper and lower oil passages 22, It is supplied into the rocker arm chamber 24 through 23,
The valve stems 13, 14 of the intake valve 11 and the exhaust valve 12 are lubricated.

At this time, the mist oil entering the rocker arm chamber 24 from the lower oil passage 23 directly lubricates the sliding portion of the exhaust valve 12, or the mist oil disturbs the lubricating oil accumulated in the rocker arm chamber 24. Part of the oil stored in the lower bottom portion of the rocker arm chamber 24 becomes mist-like due to splashing or the influence of the pressure pulsation wave in the crank chamber, and is supplied to the lower valve stem portion 14 immediately above and oil lubrication. Is made. Both the conventional upper and lower oil passages 22 and 23 are provided with holes 27 and 28 in the cylinder joint wall of the cylinder head portion 10 to communicate with each other.
There has been a problem that the oil lubrication to the valve stem 14 becomes excessive, the amount of oil flowing down from the valve stem 14 increases, and the consumption of oil increases.

The present invention focuses on the problems of the prior art described above and aims to improve the problems. The oil in the operating portions of the intake valve and the exhaust valve can be obtained without a large change in the structure or using ancillary equipment. An object of the present invention is to provide a lubricating structure for a vertical shaft type engine that can optimize lubrication and reduce oil consumption.

[Structure of device]

(Means for Solving the Problems) In order to solve the above-mentioned problems of the prior art, the lubricating structure of the vertical shaft type engine according to the present invention includes a rocker arm chamber formed by a cylinder head cover in a cylinder head portion and an oil reservoir above a crankcase oil reservoir. The crank chamber is directly communicated with upper and lower cylinders through upper and lower oil passages extending horizontally in the upper and lower portions of the cylinder, and is configured to oil-lubricate operating portions of an intake valve and an exhaust valve driven by a rocker arm. In the vertical shaft type engine, an extended cylindrical passage formed integrally with the cylinder head portion in the lower oil passage and extending toward the cylinder head cover in parallel with the valve stem portion is formed. The extended cylindrical passage extends from the bearing of the valve stem of the intake valve or exhaust valve, while also serving as the outer wall of the cylinder head. The oil extending to the vicinity of the valve spring on the rocker arm side spring receiving portion and opening to the rocker arm chamber, the oil lower than the lower bottom of the extended cylindrical passage at the rocker arm chamber lower bottom between the rocker arm chamber side opening and the cylinder head cover. This is one in which a reservoir is formed.

(Operation) The oil mist-formed by the pressure pulsation wave generated in the crank chamber in the crankcase from the upper oil passage is supplied to the upper valve stem, the rocker arm sliding portion, the lower valve stem, The sliding portion of the rocker arm is lubricated with oil, and the remaining oil accumulates in an oil reservoir at the lower bottom of the rocker arm chamber. In addition, the mist-like oil that is pressure-fed through the lower oil passage has its oil passage extending from the bearing portion of the valve stem beyond the rocker arm chamber-side spring receiving portion of the valve spring by the extended cylindrical passage, and The mist oil is rebounded by the inner surface of the cylinder head cover (outer wall of the rocker arm chamber) while the lower valve stem is hardly directly lubricated. It collects in the oil reservoir at the bottom of the rocker arm chamber. Part of the accumulated oil is mist-like and scatters due to the influence of the pressure pulsation wave in the crank chamber. However, since the lower valve stem is not located immediately above the oil reservoir, the oil in the oil reservoir is Part of the oil becomes a mist due to the pressure pulsation wave in the crank chamber, and it can be prevented from being applied too much to the lower valve stem immediately above, and the rest of the oil accumulated in the oil sump is extended from the extended cylindrical passage. The oil is returned into the crankcase through the lower oil passage, and is stored in an oil reservoir below the crankcase. As a result, the amount of oil flowing down from the lower valve stem to the lower bottom of the rocker arm chamber is reduced, and the amount of oil consumption is reduced.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows an enlarged cross section of a main part of the present invention. As shown in FIG. 1, of the upper and lower oil passages 22 and 23 provided in the upper and lower portions of the cylinder 6, the lower oil passage 23 is Is communicated with an extended tubular passage 29 provided inside. The extended cylindrical passage 29 is formed by integral molding of the cylinder head 10, and one side of the extended cylindrical passage 29 also serves as an outer wall of the cylinder head 10. The extended cylindrical passage 29 extends toward the cylinder head cover 24 in parallel with the valve stem 1. The extended cylindrical passage 29 is a bearing portion of the valve stem portion 14.
The length of the rocker arm extends beyond the dimension A up to at least the spring receiving portion 18b of the valve spring 20 and extends beyond the retainer 18a as a spring receiving portion formed at the end of the valve spring 20 on the rocker arm 26 side. It is open to the chamber 24.

The rocker arm chamber 24 is formed so as to be covered by the cylinder head unit 10 with a cylinder head cover 24a.

In the illustrated embodiment, the extended cylindrical passage 29 is formed integrally with the cylinder head portion 10 at the stage of forming the cylinder head portion 10, and its longitudinal cross-sectional shape is, as shown in FIG. In addition to a straight hole having the same diameter as that of the cylinder and a circular hole, an extended cylindrical passage 29 provided in the cylinder head portion 10 is made slightly thicker than the oil passage 23 of the cylinder 6 as shown in FIG. As shown in a cross-sectional example in FIG. 5, the diameter may be gradually increased in the direction of the open end by a rectangular hole, and the cross-sectional shape is arbitrarily selected. The other components are the sixth
Since it is the same as the conventional example shown in the figure, the corresponding members are denoted by the same reference numerals, and detailed description thereof will be omitted.

 Next, the operation will be described.

The oil which is pumped in a mist form by the pressure pulsation wave generated in the crank chamber 1a of the crankcase 1 from the upper oil passage 22 is supplied to the upper valve stem 13, the sliding portion of the rocker arm 25, and the lower valve. The sliding portion of the stem portion 14 and the sliding portion of the rocker arm 26 are each lubricated with oil, and the remaining oil is formed in the lower bottom of the rocker arm chamber 24 and accumulates in the oil reservoir 30 lower than the lower bottom of the extended tubular passage 29.

Further, the mist-like oil fed from the lower oil passage 23 is supplied to the bearing portion 16 of the valve stem portion 14 of the rocker arm chamber 34 by the presence of the extended cylindrical passage 29.
Extends to a position beyond the retainer 18 which is a rocker arm side spring bearing portion, and opens to the rocker arm chamber 34, so that the lower valve stem portion 14 hardly lubricates, and the outer wall of the rocker arm chamber 24 (cylinder head cover) ) It is rebounded by the inner surface of 24a and flows down, and accumulates in the oil reservoir 30 at the lower bottom in the rocker arm chamber 24.

The oil that has accumulated in the oil sump 30 at the lower bottom of the rocker arm chamber 24 becomes partly mist-like due to the action of the pressure pulsation wave in the crankcase 1 and the lower valve stem 14
However, since the oil sump 30 is narrow, the amount of mist generated is small, and most of the oil stored in the oil sump 30 passes through the lower cylindrical oil passage 23 from the extended cylindrical passage 29 and cranks. It is returned into the case 1 and stored in the oil reservoir 21 at the lower part of the crankcase 1.

As a result, excess mist-like oil is less likely to be supplied to the lower valve stem portion 14, and therefore the amount of oil flowing down from the lower valve stem portion 14 in the rocker arm chamber 24 is reduced, and the intake valve 11 and the exhaust The amount of oil lubrication in the operating portion of the valve 12 is optimized, and the amount of oil consumption is reduced.

[Effect of the invention]

As described above, the present invention provides a rocker arm chamber formed by a cylinder head cover in a cylinder head portion and a crank chamber above an oil reservoir of a crankcase.
In a vertical shaft type engine configured to directly communicate with upper and lower oil passages extending horizontally in the upper and lower portions of a cylinder and to oil-lubricate operating portions of an intake valve and an exhaust valve driven by a rocker arm. The lower oil passage communicates with an extended cylindrical passage formed integrally with the cylinder head portion and extending parallel to the valve stem portion toward the cylinder head cover. One side of the extended cylindrical passage is connected to an outer wall of the cylinder head portion. On the other hand, the extended cylindrical passage is
The rocker arm chamber extends from the bearing of the valve stem portion of the intake valve or the exhaust valve to a position beyond the rocker arm-side spring receiving portion of the valve spring, and opens to the rocker arm chamber. Since the oil reservoir portion is formed at the lower bottom and lower than the lower bottom of the extended cylindrical passage, the mist-like oil generated by the pressure pulsation wave in the crank chamber passes through the upper and lower oil passages and the oil in the rocker arm chamber. Efficiently supplied to the upper and lower intake and exhaust valves for efficient oil lubrication, while the rocker arm chamber side opening of the extended tubular passage exceeded the rocker arm side spring receiving part of the valve spring from the valve stem bearing part. Mist oil that has passed through the lower oil passage extends directly to the vicinity of the lower valve stem to open it. While preventing the supplied, narrow oil reservoir portion formed in the rocker arm chamber under the bottom,
In addition, since the valve spring is not located directly above the oil reservoir, the oil accumulated in the oil reservoir becomes mist-like due to the pressure pulsation wave in the crank chamber, and is excessively applied to the lower valve stem immediately above. Mist-like oil can be effectively prevented from being excessively supplied to the lower valve stem, and the amount of oil supplied to the oil lubrication can be optimized to reduce the oil consumption. Can be greatly reduced, and the performance can be improved.

In addition, the lower oil passage is constituted by an extended cylindrical passage integrally formed with the cylinder head portion, and one side of the extended cylindrical passage is also used as the outer wall of the cylinder head portion. The material can be saved even if the annular passage is formed, and since there is no need to separately provide a seal member such as a stem seal in the lower valve stem portion, it is structurally simple and advantageous in cost. is there.

Further, since the extended cylindrical passage can be integrally formed with the cylinder head portion, it is advantageous in terms of maintenance, and furthermore, the extended cylindrical passage can be formed into an arbitrary cross-sectional shape without forming a perfect circular hole. Therefore, there are various effects such as being able to be constituted only by die molding, not requiring machining, and being able to be carried out without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing one embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view taken along the line PP of FIG. 1, FIG. 3 is a partial cross-sectional view showing a modification of the extended cylindrical passage in FIG. 1, and FIGS. 4 and 5 are QQs in FIG. Sectional drawing showing an example of a sectional shape, FIG.
FIG. 1 is a sectional view showing a conventional vertical shaft type engine. DESCRIPTION OF SYMBOLS 1 ... Crankcase, 1a ... Crank chamber, 2 ... Crankshaft, 6 ... Cylinder, 10 ... Cylinder head part, 11 ... Intake valve, 12 ... Exhaust valve, 13,14 ... Valve stem part … 15,16 …… Bearing part, 17a, 18a …… Retainer (spring receiving part), 17b, 18b …… Spring receiving part, 19,20… Valve spring, 21 …… Oil sump, 22,23 …… Oil Aisle, 24 ...
Rocker arm chamber, 24a ... Cylinder head cover (outer wall of rocker arm chamber), 25, 26 ... Rocker arm, 29 ...
Extended cylindrical passage, 30 ... Oil reservoir.

Claims (1)

(57) [Scope of request for utility model registration] A rocker arm chamber formed by a cylinder head cover in a cylinder head portion and a crank chamber above an oil sump of a crankcase are connected to upper and lower cylinders by upper and lower oil passages extending horizontally. In a vertical shaft engine configured to directly communicate and oil-lubricate operating portions of an intake valve and an exhaust valve driven by a rocker arm, a lower oil passage is integrally formed with a cylinder head portion, and a valve stem portion. An extended tubular passage extending in parallel to the cylinder head cover side is formed, and one side of the extended tubular passage is also used as an outer wall of the cylinder head portion, while the extended tubular passage is a valve stem of an intake valve or an exhaust valve. Extending from the bearing of the section to a position beyond the rocker arm side spring receiving portion of the valve spring and opening to the rocker arm chamber, Lubricating structure for vertical shaft type engine, characterized in that the formation of the lower oil reservoir portion than the lower base of the extended tubular passageway rocker arm chamber under the bottom between the rocker arm chamber side opening and the cylinder head cover.