JPS6026187Y2 - Multi-cylinder engine for models - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a model engine used for model airplanes and the like, and particularly relates to a sequential explosion type multi-cylinder engine in which each cylinder is arranged radially.

This type of engine generally has a relatively low torque despite its high rotational speed.

For example, if we look at the performance diagram of a model multi-cylinder engine shown in FIG. 1, the maximum horsepower is achieved in the high rotation range of 17,000 rpm, and the torque in this vicinity is quite small.

This shows that the engine's horsepower can be utilized by rotating the small-diameter propeller, which has a light load, at high speed.

From the above, it is impossible to rotate a large diameter propeller that requires high torque in a model airplane equipped with this type of model engine, and the diameter of the propeller compared to the actual aircraft (real aircraft) is Only small-diameter propellers, which were considerably unbalanced compared to the previous model, could be installed.

Nowadays, there are an increasing number of model airplane enthusiasts who demand a realistic feel (feel similar to the real aircraft), and it is now possible to install propellers that match the size of the aircraft, and also to rotate the propellers at a low rotation speed close to the actual aircraft. The demand for rotation has increased.

Conventionally, the above problems were solved by equipping the existing model engine with a gear mechanism reducer, but the structure was complicated and the weight of the reducer itself was added to the engine, causing the engine and aircraft to be damaged. This went against the trend of weight reduction.

In view of the above-mentioned drawbacks, this invention aims to provide a multi-cylinder engine for models that has a simple structure and has high torque without increasing weight.

The gist of this invention to achieve the above purpose is as stated in the claims for utility model registration above.

Preferred embodiments of this invention will be described below with reference to the drawings.

The crankcase indicated by the reference numeral 1 in FIGS. 2 and 3 is separated from the main body 1a and the rear cover 1b, and has a plurality of cylinders (in this example, five cylinders are indicated by the numbers 2A, 2B, 2c, 2D, and 2E). has been done.

) and a carburetor 3 for mixing fuel and air at a predetermined ratio.

Further, a housing 4 is attached to the front surface of the crankcase 1, and a main shaft 5 passing through the housing 4 projects into the crankcase 1.

Each cylinder 2 is arranged radially at equal intervals around the axis of the main shaft 5, and a connecting rod 7 connected to a piston 6 inside the cylinder 2 is connected to five mutually independent crank chambers provided in the crankcase 1. It has entered one of the 8.

A disk 10 provided at one end of the crankshaft 9 supported by the main body 1a and the housing 4 is accommodated in each crank chamber, and a connecting rod 7 is attached to a pin 11 implanted in the disk 10 at a distance from the center. The big ends of are connected.

Further, each crankshaft 9 has a crankshaft side gear 13 in a gear chamber 12 formed in the housing 4.
is attached, and this crankshaft side gear 13 meshes with a main shaft side gear 14 attached to the main shaft 5.

Further, as shown in FIG. 5, the number of teeth of the main shaft side gear 14 is twice the number of teeth of the crankshaft side gear 13, so that the main shaft 5 rotates once per 9.2 revolutions of the crankshaft.
It is configured to rotate.

A drive washer 15, which is a component for fixing a propeller (not shown), is fixed by a screw 16 to the front end portion of the main shaft 5 that passes through the housing 4.

Further, a recess 17 formed in the center of the rear cover 1b communicates with a mixer supply port of the carburetor 3 and also with an intake chamber 18 formed at the rear end of the main shaft 5.

Furthermore, the main shaft 5 has two intake holes 19 formed by cutting the peripheral wall of the intake chamber 18 at two symmetrical positions.

These two intake holes 19 sequentially fit into ports 20 formed in the peripheral wall of each crank chamber 8 while rotating relative to the crankcase 1 as the main shaft 5 rotates.

That is, when the main shaft 5 rotates, the intake chamber 18 communicates with the five crank chambers 8 sequentially through the intake holes 19 and ports 20.

An example of the relative relationship between the intake hole 19 and the port 20 is shown in the fourth example.
As shown in the figure.

Therefore, while the main shaft 5 rotates in one direction, the two intake holes 19 always have at least two ports 20.
In the positional relationship shown in the figure, it communicates with three ports 20 at the same time.

In addition, the order in which the intake hole 19 and the port 20 are completely communicated with each other is that if the main shaft 5 rotates in the direction of the arrow (in the direction opposite to the clock hands) in FIG.
2E, 2C, and so on, and when the main shaft 5 rotates 180', the cycle ends.

Note that the communication period of each port 20 and its timing are appropriately selected depending on conditions such as the maximum rotational speed of the engine or the stroke of the piston.

In the engine configured in this manner, when each piston 6 rises within the cylinder 2, the pressure inside the crank chamber 8 provided corresponding to this cylinder 2 decreases.

Here, the relative positional relationship between the crankshaft 9 and the main shaft 5 is determined such that the port 20 of the crank chamber 8 communicates with the intake chamber 18 via the intake hole 19.

Therefore, in the crank chamber 8, there is a recess 1 from the carburetor 3.
7, the mixer is inhaled through the intake chamber 18, the intake hole 19 and the port 20.

In the process of the piston 6 descending, the air-fuel mixture sucked into the crank chamber 8 is compressed, and the upper end of a side passage (not shown) formed in the peripheral wall of the cylinder 2 opens into the combustion chamber of the cylinder 2. When the piston 6 is lowered to this position, it is sent into the combustion chamber through this side passage.

Further, this air-fuel mixture sends exhaust gas (combustion gas) existing in the combustion chamber to the outside from an exhaust port 21 formed in the peripheral wall of the cylinder 2.

As a result, a fresh air-fuel mixture is accommodated in the combustion chamber in place of the exhaust gas, and this air-fuel mixture is compressed by the upward movement of the piston 6, and the glow plug 2 is placed near the top dead center of the air-fuel mixture.
It is ignited by the action of 2.

A similar cycle is 2A, 2D,
2B, 2E, and 2G are performed in this order, and each crankshaft 9 rotates in the same direction.

In addition, the crankshaft 9 is connected to the crankshaft side gear 1.
3 and the main shaft side gear 14, the torque from each crankshaft 9 is sequentially transmitted to the main shaft 5, and the crankshaft side gear 13 and the main shaft side gear 14 are Teeth ratio is 1
:2, so the rotation of the crankshaft 9 is 1.
72 and is transmitted to the main shaft 5.

As described in detail above, according to this invention, the number of teeth of the main shaft side gear 14 is made twice the number of teeth of the crankshaft side gear 13, and the main shaft 5 is provided with two intake holes 19, so that the crankshaft The rotation of 9 is decelerated to 1/2, and at the same time, the torque is doubled and output to the main shaft 5.

This makes it possible to attach propellers to model airplanes that are large enough to maintain the feel of a real aircraft, and to rotate at speeds close to those of the actual aircraft.

Furthermore, since there is no need to provide a reduction gear separate from the engine, the weight of the engine can be reduced, and furthermore, conventional multi-cylinder engines can be easily and inexpensively improved.

In this embodiment, regarding a five-cylinder engine, the number of teeth of the main shaft side gear 14 is twice the number of teeth of the crankshaft side gear 13, and two intake holes 19 are provided. The number of teeth and the number of intake holes are appropriately selected depending on the number of cylinders (number of cylinders) and desired torque.

[Brief explanation of drawings]

Figure 1 is a performance curve diagram of a conventional multi-cylinder model engine.
Fig. 2 is a front view of a model engine according to an embodiment of this invention, Fig. 3 is a vertical sectional view of the main part of the same engine in Fig.
The figure is an explanatory diagram showing the relationship between the intake hole and the boat, and Figure 5 is
FIG. 3 is an explanatory diagram showing the relationship between a crankshaft side gear and a main shaft side gear. 1... Crankcase, 2... Schilling, 3... Carburetor, 5... Main shaft, 6... Zeston, 9... ... Crankshaft, 12 ... Gear chamber, 13 ... Crankshaft side gear, 14 ... Main shaft side gear, 18 ... Intake chamber , 19...Intake hole, 20...Port.

Claims (1)

[Scope of utility model registration request] A main shaft pivotally supported on the crankcase, a plurality of cylinders attached to the crankcase in a radial arrangement centered on the axis of the main shaft, and a plurality of cylinders provided on the crankcase adjacent to each cylinder. mutually independent crank chambers, a crankshaft connected to a piston in each cylinder in each crank chamber via a connecting rod, a crankshaft side gear and a main shaft side gear that connect each crankshaft to the main shaft; A chamber formed in the main shaft so that the air-fuel mixture is introduced from the carburetor, and an intake hole provided in the main shaft so that this chamber sequentially communicates with each crank chamber via a port. In the multi-cylinder engine for models, the number of teeth of the gear on the main shaft side is twice the number of teeth on the gear on the crankshaft side, or an integral multiple of twice or more, and the intake port is
A multi-cylinder engine for models, characterized by having one or more cylinders.