JP2529537Y2 - 2 cycle engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-cycle engine in which an exhaust valve is opened and closed by a valve operating mechanism.
The present invention relates to a lubrication device for a valve train.

[0002]

2. Description of the Related Art Conventionally, there has been known a uniflow type two-stroke engine in which an exhaust port is opened in a combustion chamber and an exhaust valve for opening and closing the exhaust port is provided (for example, JP-A-56-81223). reference).

[0003] This type of two-stroke engine has an exhaust port opened in the upper part of the combustion chamber on the opposite side of the scavenging port in the lower part of the cylinder. Exhaust gas hardly remains in the upper part of the combustion chamber, and exhaust gas discharge is smooth. Therefore, there is an advantage that scavenging efficiency is improved, and output, fuel efficiency, and purification of exhaust gas are improved. In addition, by providing a dedicated exhaust valve different from the piston, the opening / closing timing of the exhaust port is arbitrarily selected, and the exhaust timing is made later than in a normal two-stroke engine, thereby increasing the effective work of the piston. be able to.

[0004]

However, since the exhaust valve is provided, a valve mechanism for driving the exhaust valve is required. Therefore, it is necessary to lubricate the valve mechanism. Therefore, in addition to the oil pump, oil filter, oil pan,
An oil cooler is required. Therefore, the advantage of the two-stroke engine, which is originally a simple structure, is impaired. Further, maintenance and inspection of the lubrication device of the valve mechanism are required, which is troublesome.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to lubricate a valve operating mechanism of an exhaust valve with a simple structure in a two-stroke engine provided with an exhaust valve.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a novel blend containing oil, fuel and air.
An intake passage for combustion that introduces aiki into the crankcase
A valve operating mechanism is provided inside .

[0007]

In a two-stroke engine, oil is contained in the new air-fuel mixture. By providing an intake passage for applying the new air-fuel mixture including the oil to the valve mechanism, the oil mist contained in the new air-fuel mixture is provided. However, by colliding with the valve operating mechanism, it is possible to lubricate the contact portions and the sliding contact portions of the valve operating mechanism.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In FIG. 1, an intake port 11 and a scavenging port 12 are opened on a side surface of a cylinder 10 of a two-cycle engine. An exhaust port 14 is open at the top of the combustion chamber 13. The exhaust port 14 communicates with the atmosphere via an exhaust passage 15 and is opened and closed by an exhaust valve 21. The exhaust valve 21 is driven to open and close by a valve operating mechanism 20 linked to the crankshaft 16 as described below.

A cam 22 is formed integrally with the crankshaft 16, and the rotation of the cam 22 causes the tappet 23 to move up and down. The tappet 23 swings the rocker arm 25 via the push rod 24 by the vertical movement. The rocker arm 25 opens the exhaust valve 21 by pushing down the upper end of the valve rod 21a of the exhaust valve 21. The valve stem 21a is a valve guide 26
And is slidably fitted to the exhaust port 14 by a valve spring 27 so as to close the exhaust port 14.

The push rod 2 of the valve train 20
4. The rocker arm 25, the valve rod 21a and the valve spring 27 are provided in the intake passage 30. The intake passage 30 communicates with an intake device 19 composed of a carburetor, an air cleaner, an intake pipe, and the like .
A new air- fuel mixture M containing air and air is introduced, and the new air-fuel mixture M is applied to the valve mechanism 20. The intake passage 30 is provided with a rocker arm chamber 18 formed above the cylinder head 10A.
, And a second intake passage 32 formed in the cylinder 10 and the cylinder head 10A. The push rod 24 penetrates through the second intake passage 32. Note that the oil of the new air-fuel mixture M is mixed by injection in the case of the separated oil supply, whereas it is contained in the fuel itself in the case of the mixed oil. 40 is a water jacket, 41 is a spark plug, 4
2 is a bearing.

Next, the flow of the new air-fuel mixture M will be briefly described. The new air-fuel mixture M is once drawn into the cylinder 10 through the intake passage 30 by the rise of the piston 43. The sucked new air-fuel mixture M is introduced from the scavenging port 12 above the piston 43 through the scavenging passage 12A by the lowering of the piston 43.

In the above configuration, the oil mist in the fresh air-fuel mixture M comes into contact with the contact portions 20a of the components of the valve mechanism 20 disposed in the intake passage 30, and also enters the sliding contact portions 20b. Therefore, the contact portion 20a and the sliding contact portion 20b of the valve train 20 are lubricated with the oil in the fresh air-fuel mixture M. Therefore,
Since complicated devices such as an oil pump, an oil filter, and an oil pan are not required, lubrication can be achieved with a simple structure. Further, since the lubricating device including the intake passage 30 does not include a driving unit such as an oil pump, maintenance and inspection thereof are facilitated.

[0013] By the way, does not need to be lubricated by applying a new air-fuel mixture M directly to all of the dynamic valve mechanism 20, for example, it may be only to collide with new air-fuel mixture M direct part in the rocker arm chamber 18.

[0014]

As described above, according to this invention, in the two-stroke engine provided with the exhaust valve, the intake passage for applying the new air-fuel mixture to the valve mechanism is provided, so that the valve mechanism has a simple structure. Lubrication can be performed. Further, since there is no drive unit such as an oil pump, maintenance and inspection become easy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a two-cycle engine showing one embodiment of the present invention.

[Explanation of symbols]

13: combustion chamber, 14: exhaust port, 17: crank chamber, 20: valve operating mechanism, 21: exhaust valve, 30: intake passage, M: new air-fuel mixture.

Claims (1)

(57) [Scope of request for utility model registration] (1) Oil, fuel and fuel supplied from an intake device.
A new air-fuel mixture containing air and air is passed through the crankcase to the combustion chamber.
A two-stroke engine that is introduced into the combustion chamber for combustion , and is provided with an exhaust valve for opening and closing an exhaust port opened to the combustion chamber.
In the intake passage for introducing the new air-fuel mixture into the crank chamber
A two-stroke engine provided with a valve mechanism for the exhaust valve .