JPH0212241Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a housing structure for a valve mechanism provided in a vertical crankshaft type engine in which the crankshaft is vertically supported.

In a crankshaft vertically mounted engine that is equipped with a valve mechanism and supports the crankshaft vertically, the present applicant previously proposed in Utility Model Application No. 162108/1983 that the valve mechanism was installed at the bottom of a horizontally formed cylinder section. A passage for storing a push rod forming a part is provided, a guide hole for a valve lifter connected to the push rod is formed in a partition wall between the passage and the lower part of the crankcase, and the valve lifter is provided with a passage communicating with the crankcase. An engine is disclosed in which small holes are formed.

According to such an engine, a passage for housing the push rod is provided in the lower part of the horizontally formed cylinder section, so that the oil lubrication of the drive mechanism of the valve mechanism, especially the valve lifter, the cam that engages with it, and the camshaft is reduced. However, since the oil return hole is a small hole formed directly in the valve lifter, it has a sufficient effect of returning the oil in the passage into the crankcase. It is difficult to say that it will be done.

Therefore, it is conceivable to newly form an oil return hole having a certain diameter in the partition wall between the passage and the lower part of the crankcase, but the oil return hole and the passage side end surface of the guide hole of the valve lifter are on the same plane. Then, when the push rod is inserted into the passage and assembled, there is a risk that the push rod may be inserted into the oil return hole by mistake.

The present invention was developed in view of the above-mentioned circumstances and to solve these problems.The purpose of the present invention is to reduce the amount of oil in the drive mechanism of the valve train provided in a vertically mounted crankshaft engine in which the crankshaft is vertically supported. In addition to improving lubricity, it also ensures the return of oil from the storage passage of the push rod, which is a part of the valve mechanism, into the crankcase, making it easier to assemble the push rod and valve lifter, and preventing mistakes. To provide a storage part structure for a valve operating mechanism that eliminates the possibility of assembly.

In order to achieve such an objective, the present invention provides a vertical crankshaft type engine equipped with a valve mechanism, in which a passage for storing a push rod, which constitutes a part of the valve mechanism, is installed in the lower part of the horizontally formed cylinder part. In addition, an oil return hole is formed in the partition wall between the passage and the lower part of the crankcase together with a guide hole of a valve lifter connected to the push rod, and a step is provided on the end surface of the oil return hole on the side of the passage. It is said that

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings showing a longitudinal side view of the engine.

First, to explain the general structure of the engine, the engine 10 is a vertical crankshaft type engine (vertical engine) in which a crankshaft 30 is vertically supported in a cantilevered manner at the bottom. The crank case 11, the cylinder block 22 and the cylinder head 23 constituting the cylinder 21 are integrally cast to form the case. An opening 12 is formed in the upper part of the crankcase 11 and is cut diagonally from the base of the cylinder 21, and this opening 12 is removably covered with a cover 13 made of a steel plate.

A piston 51 is slidably fitted into the cylinder 21, a spark plug 55 is installed diagonally from the front upper part of the cylinder head 23, and two left and right intake/exhaust valves 41, 41 ( In the illustration, one (1) is provided due to the longitudinal section. valve 41
The valve stem 42 is engaged with the upper end of a rocker arm 43, the tip of a push rod 44 is engaged with the lower end of each rocker arm 43, and the cylinder head 23 is covered with a steel plate cover 2 from the front.
4 is removably attached.

On the other hand, a crankshaft 30 is vertically supported in the lower part of the crankcase 11 by a shaft part 31 constituting the lower part of the crankcase 11 so as to be freely rotatable with upper and lower bearing parts 14 and 15.
A gear 34 is formed on the shaft periphery between the upper and lower journals 32 and 33 of the crankcase 11, and this gear 34 is connected to the cylinder 2 between the upper and lower bearings 14 and 15 of the crankcase 11.
It faces a recess 16 formed horizontally on the first side.

Furthermore, a camshaft 60 is disposed horizontally in this recess 16, and a gear 61 formed on this camshaft 60 is orthogonally meshed with the gear 34. On both sides of the gear 61 of the camshaft 60, cams 62, 62 is formed.

The crank pin 35 of the crankshaft 30 and the piston pin 52 of the piston 51 are connected by a connecting rod 53, and a lower shaft end 31a of the crankshaft 30 that protrudes below the crank case 11 is connected to a lawn mower in the embodiment. Because of the engine used, a blade 59 is attached via a holder 58.

In the present invention, a push rod passage 25 is formed below the horizontally formed cylinder 21 and below the cylinder block 22 and the cylinder head 23, and the push rod 44 is inserted into the passage 25. A guide hole 27 for the valve lifter is formed above the partition wall 26 between the lower part of the crankcase 11 and the lower part of the crankcase 11.
A valve lifter 45 is slidably fitted in from the crankcase 11 side, and an oil return hole 28 is formed below the partition wall 26, and the oil return hole 2
A step 29 was provided on the end surface of the passageway 25 side of No. 8.

That is, a pushrod passage 25 is provided in the lower part of the cylinder 21 so as to be inclined downward toward the lower part of the crankcase 11, and a guide hole 27 having a relatively large diameter is provided above a partition wall 26 between the passage 25 and the lower part of the crankcase 11. At the same time, a step 29 recessed toward the crankcase 11 is formed below the end surface of the partition wall 26 on the passage 25 side, and an oil return hole 28 is formed in the vehicle from this recessed step 29 toward the crankcase 11. . The oil return hole 28 is smaller in diameter than the guide hole 27 and has a certain diameter, and the diameter of the opening 28a on the passage 25 side is the same as the diameter of the opening 28b on the crankcase 11 side. It forms a slightly larger taper shape. As a result, the oil returning from the inside of the passage 25 to the inside of the crankcase 11 is performed well, and the oil stored in the bottom of the crankcase 11 is prevented from flowing into the inside of the passage 25 by the oil return hole 28 in the crankcase. This is also suppressed by the orifice effect of the small diameter opening 28b on the side.

Then, from the crankcase 11 side, a valve lifter 45 whose base end forms a follower 46 is fitted into the guide hole 27, a push rod 44 is inserted into the other passage 25, and the base end of the push rod 44 and the valve lifter 45 are inserted. Connect the tip of the At this time, since a concave step 29 is provided on the end surface of the oil return hole 28 formed in the partition wall 26 on the side of the passage 25, the proximal end of the push rod 44 is inserted into the predetermined guide hole 27 avoiding the step 29. can be inserted reliably, thus eliminating the possibility of misassembly.

By the way, oil is stored at the bottom of the crankcase 11 as is known, so if the push rod passage 25 is provided at the bottom of the horizontally formed cylinder 21 as described above, the oil can be removed as a component of the drive mechanism of the valve train. The valve lifter 45, the cam 62, and the camshaft 60 can be immersed in oil, and therefore have excellent oil lubricity.

Moreover, since the oil return hole 28 having a certain diameter is formed in the partition wall 26, the passage 25
The oil returning action from the inside to the inside of the crankcase 11 can also be performed satisfactorily and reliably.

In the embodiment, the vertical engine is of a cantilevered type with a crankshaft, but of course it may be of a double-sided type.
Further, the valve mechanism is not limited to the overhead valve type as in the embodiment, but may be of the side valve type.

As is clear from the above explanation, according to the present invention,
In a vertical engine equipped with a valve mechanism,
A passage for storing the push rod is provided in the lower part of the horizontally formed cylinder part, and a guide hole for the valve lifter and an oil return hole are formed in the partition wall between the passage and the lower part of the crankcase, and the passage of the oil return hole is provided. By providing a step on the side end surface, it is possible to improve the oil lubricity of the drive mechanism of the valve train, as well as ensure the oil return action, and also facilitate the assembly of the push rod and valve lifter without the risk of incorrect assembly. , and can be done reliably.

[Brief explanation of the drawing]

The drawing is a longitudinal side view of the engine. In the drawing, 10 is the engine, 11 is the crankcase, 21 is the cylinder, 25 is the passage, 26 is the partition wall,
27 is a guide hole, 28 is an oil return hole, 29 is a step, 30 is a crankshaft, 44 is a push rod, 45 is a valve lifter, 60 is a camshaft, and 62 is a cam.

Claims (1)

[Scope of utility model registration request] In a crankshaft vertically mounted engine equipped with a valve mechanism and with a crankshaft supported vertically, a passage for storing a push rod constituting a part of the valve mechanism is provided in the lower part of a horizontally formed cylinder part. A guide hole for a valve lifter connected to the push rod is formed in the upper part of the partition wall between the passage and the lower part of the crankcase, and an oil return hole is formed below the guide hole, and an oil return hole is formed on the passage side end surface of the oil return hole. A housing structure for an engine valve mechanism characterized by having a step.