JPS5925097B2 - Internal combustion engine rotary valve device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary valve device that controls the timing of exhaust air, intake air, or scavenging air of an internal combustion engine.

Conventionally, when a rotary valve driven by a crankshaft is used as a device for controlling the timing of exhaust, intake, or scavenging air in an internal combustion engine, the rotary valve comes into direct contact with the combustion gas, so it reaches a high temperature. As a result, the gas sealing performance of the rotary valve deteriorates, resulting in problems such as a decrease in horsepower and fuel efficiency, making it impractical.

In view of these points, the present invention solves the above-mentioned thermal problem by actively cooling the rotary valve and makes it practical, and also provides an internal combustion engine in which the rotary valve functions as a water pump for a water-cooled engine. The present invention provides a rotary valve device for an engine.

Embodiments of the present invention will be described below based on the drawings. 1st
The figure shows an example in which the rotary valve device of the present invention is used as an exhaust valve for a two-cylinder, two-stroke engine.

Reference numeral 1 denotes an engine case, in which two-cycle engines 2, 2 are installed with two cylinders arranged in parallel.

3 is a crankcase disposed at the lower part of an engine case 1, and a crankshaft 4 is disposed horizontally inside the crankcase.

Each cylinder of the 2-cycle engine 2 and 2 is connected to the crankcase 3.
It is fixed against.

A bevel gear 5 is fixed to this crankshaft 4, and this bevel gear 5
has a bevel gear 6 at its lower end that meshes with the engine; a rotary valve shaft T is disposed perpendicularly above the crankshaft 4 and passes through the inside of the engine case 1 between the two-stroke engines 2; It rotates at the same rotation speed relative to the crankshaft 4. A disk-shaped rotary valve 8 is fixedly installed at the upper end of this rotary box shaft 1, and the combustion chambers 2a, 2 of both two-cycle engines 2, 2
It is provided so as to be horizontally rotatable within the cylinder head 10 across the exhaust holes 9, 9 provided above a. This rotary valve 8
As shown in FIG. 2, there is one exhaust timing control hole 11 that penetrates vertically near the periphery of the disk, and this hole 11
Exhaust is achieved by matching the exhaust hole 9 with the exhaust hole 9. Further, the rotary valve 8VC is provided with an internal cavity communicating from the center of the disc to its outer circumferential side, and has impellers 12, 12, . . .
Impeller-shaped cooling water passages 13, 13, . . . are partitioned into approximately equal parts by . 14 to a radiator (not shown),
On the other hand, the leaf exits 13b, 13b, . . . on the outer peripheral side surface
The coolant is circulated to the radiator through cooling water discharge holes 15 provided in the cylinder head 10 facing each other. However, a closing wall 16 is provided around the cooling water passage 13 to prevent it from opening into the exhaust timing control hole 11. 17
Reference numeral 18 indicates a seal ring for gas sealing provided on the bottom end and outer peripheral side of the rotary valve 8, and 18 indicates a sealing ring for cooling water seal provided at the upper center of the rotary valve 8.

The rotary valve shaft 7 and the crankshaft 4 are interlocked by a bevel gear 5.
, 6, or a belt or the like may be used as long as they are synchronously interlocked.

Further, the rotation ratio between the crankshaft 4 and the rotary valve shaft 7 is determined by the number of control holes 11 provided in the rotary valve, the engine type (number of cycles), the number of cylinders, and the phase difference between each cylinder. In the case of a two-stroke, two-cylinder engine with one control hole 11 and a phase difference between cylinders of 18d) as in this example, it is necessary to set the ratio to 1:1. Further, in the case of a four-stroke engine, it is necessary to make the rotational speed of the rotary valve shaft 7 the same as compared to a two-stroke engine. The rotary valve device of the present invention has the following features:
Of course, in addition to the above exhaust valve use, it can also be used for scavenging boxes or intake valves.

Since the present invention has the above configuration, it is possible to control the timing of exhaust, intake, or scavenging air in two cylinders with one rotary valve without providing a large protrusion above the cylinder head, and Since the cylinder is fixed and only the rotary valve is rotated, and the cooling water passage of the rotary valve is shaped like an impeller, the cooling water flowing from the center of the rotary valve flows through the impeller-shaped cooling water passage as the rotary valve rotates. While actively and uniformly cooling the entire rotary valve, it flows smoothly and is discharged from the discharge port on the outer periphery, making it possible to forcibly cool the high-temperature rotary valve as the timing control valve. Moreover, by connecting it to a radiator, it can suck and discharge cooling water, so it can function as a water pump for a water-cooled engine, and the amount of cooling water increases as the engine speed increases. This has the advantage that the rotary valve can be sufficiently cooled and the water pump function can be performed, and a conventional water pump is not required.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the invention, FIG. 1 being a partially cut-away side view and FIG. 2 being a partially cut-away top view of a rotary valve. DESCRIPTION OF SYMBOLS 1... Engine case, 2... 2-stroke engine, 2a... Combustion chamber, 3... Crank case, 4...
・Crankshaft, 5, 6...Bevel gear, 7...Rotary valve shaft, 8...Rotary valve, 9...Exhaust hole, 10...Cylinder head, 11...For exhaust timing control Hole, 12・
...Impeller, 13...Cooling water passage, 13'...Intake port, 13b...Discharge port, 14...Cooling water inlet,
15...Cooling water discharge hole, 16...Closing wall, 17,1
8... Seal ring.

Claims (1)

[Claims] 1 Two cylinders are fixed in parallel to the crankcase, and a rotary valve shaft that is driven synchronously with the crankshaft is provided between the two cylinders in parallel with the cylinders. The rotary valve is located above the combustion chambers of the two cylinders, and is provided with a control hole penetrating in the vertical direction for controlling the timing of exhaust, intake, or scavenging in both cylinders. A cooling water inlet is provided at the center of the rotary valve, and a cooling water outlet is provided at the outer periphery of the rotary valve, and the cooling water inlet and the cooling water outlet are communicated through an impeller-shaped cooling water passage. A rotary valve device for an internal combustion engine, characterized in that the impeller-shaped cooling water passage sucks and discharges cooling water from a radiator.