WO2010001498A1

WO2010001498A1 - Two-crank type internal-combustion engine

Info

Publication number: WO2010001498A1
Application number: PCT/JP2008/068835
Authority: WO
Inventors: 久直丸山
Original assignee: Maruyama Hisanao
Priority date: 2008-07-02
Filing date: 2008-10-17
Publication date: 2010-01-07
Also published as: JP2010013960A

Abstract

A two-crank type internal-combustion engine increases the geometric compression rate within a cylinder twice or more in an angle at which a moment arm of a crank becomes maximum to improve the rotation torque and output of an engine compared with conventional engines. An auxiliary piston is added to a main piston contained heretofore in the engine, and combustion chambers are made to be in communication with each other. Further, the main piston and the auxiliary piston are controlled in phase such that the auxiliary piston is positioned approximately at a top dead center in an angle at which a moment arm of a main crank for the main piston becomes maximum to constrain reduction in pressure within the combustion chambers in communication. Such an arrangement improves the rotation torque of the crank.

Description

2-crank type internal combustion engine

The present invention relates to an internal combustion engine with improved torque and power.

For example, in a so-called reciprocating type internal combustion engine (engine) in which a piston and a crank are connected by a link as shown in Patent Document 1, a state in which a moment arm for generating a rotational torque of the crank becomes the largest At approximately the center of the stroke, the compression ratio in the geometric cylinder is less than doubled, and not only the torque does not occur effectively, but also the low efficiency and low power of the engine There is.
JP 2007-92693 A

The problem to be solved is that at the angle where the moment arm of the crank is the largest, the geometrical compression ratio in the cylinder is more than doubled and the rotational torque and output of the engine are improved compared to the conventional engine. It is.

The present invention adds an auxiliary cylinder in addition to the main cylinder conventionally contained in an engine and communicates the respective combustion chambers, and the moment arm of the main crank for the main cylinder is at the largest angle, and the auxiliary cylinder is substantially The rotational torque of the crank is improved by controlling the phases of each other so as to be positioned at the top dead center and suppressing the pressure drop in the communicated cylinders.

In the present invention, it is expected that the torque of the engine can be greatly improved by simply combining the auxiliary cylinder and the crank.

Furthermore, in the present invention, when it is not necessary to increase the torque and output of the engine, the displacement of the engine can be reduced, and the fuel consumption and the weight of the engine can be reduced.

The present invention is an internal combustion engine that explodes and burns vaporized fuel in a cylinder to move a piston, and rotates a crankshaft via a link connected to the piston, wherein an auxiliary piston and a rotation less than half of the piston are rotated. It consists of an auxiliary crank whose speed is twice that of the crank, and when the previous piston is at top dead center, each crank shaft is a gear or the like so that the auxiliary piston is between the bottom dead center and half the stroke. This two-stroke internal combustion engine is characterized in that it is connected via a transmission and the internal spaces of the cylinder heads are communicated with each other.

As shown in FIG. 1, two large and

small pistons

31 and 41 and

cranks

32 and 42 are prepared, and the rotation speed of the small crankshaft 42 is doubled that of the large crankshaft 31 with gears or the like (not shown). Link.

At this time, the small pistons 41 are in phase such that the large pistons 31 are at the bottom dead center or at a position elevated from within the point by half or less of the stroke when the large pistons 31 are at the top dead center.

When the large piston 31 is at the top dead center and the small piston 41 is at the bottom dead center and the large and

small cylinder heads

34 and 44 are communicated, the compression ratio of the combined cylinder is large as shown in FIG. The compression ratio at a crank angle of 270 degrees at which the moment arm of the piston 31 is maximized as the bore ratio increases as the bore ratio increases, as the bore ratio changes with the bore ratio to the piston 31 and the bore ratio is larger, i.e. It can be expected to increase and increase torque.

However, if the bore ratio becomes too large, the maximum compression rate decreases, and there is a risk that the temperature of the air in the cylinder will not rise sufficiently in the compression stroke.

Therefore, when the large piston 31 is at the top dead center, the small piston 41 is raised as much as half of the stroke. FIG. 3 shows a graph in which the large and small phases when the bore ratio is 0.3 are represented by the angle of the large crank 32. The minus of the phase difference indicates that the large piston 31 is at the top dead center while the small piston 41 is descending, and the plus of the phase difference is that it is ascending. It can be seen that the maximum compression ratio increases as the phase difference increases regardless of plus or minus. By setting the phase difference to 30 degrees, the maximum compression ratio can be increased from 4.5 to nearly 9 practical.

On the other hand, FIG. 4 shows the relationship between the above-described phase and the torque index addition obtained by multiplying the ratio of the geometric compression ratio in the cylinder 20 and the moment radius of the crank and the turning radius of the crank. Since the influence of the auxiliary crank is influenced not only by the crank rotation radius but also by the cylinder area ratio and the rotation speed ratio of the crank even at the same pressure, the value obtained by multiplying the bore ratio by 2 is considered. At the maximum compression rate in Fig. 3 there was no difference due to the sign of the phase difference, but when it comes to torque index it is better that the phase difference is plus, ie when the large piston 31 is at top dead center, it is better for the small piston 41 to ascend I understand. This torque index corresponds to about 1.5 times that in the absence of a phase difference and about 2 times that in the conventional engine.

FIG. 5 is a cross-sectional view showing each process of the present embodiment. The respective strokes of intake, compression, explosion and exhaust are shown in order from (a) of the left figure.

Although FIG. 5 shows the case of a four-stroke gasoline engine, the present invention is not limited to this, and can be applied to a diesel engine, a two-stroke engine, and the like.

It is a perspective view showing the engine of this example. It is a graph which shows the size of an auxiliary cylinder, and the relation of compression ratio. It is a graph which shows the relationship between the phase of an auxiliary cylinder, and a compression ratio. It is a graph which shows the phase of an auxiliary cylinder, and the relationship of a torque. Sectional drawing which shows each process of a present Example.

Explanation of sign

10 Engine 20 Cylinder Block 31 Main Piston 41 Auxiliary Piston 32, 42 Crank 34, 44 Cylinder Head

Claims

In an internal combustion engine that explodes and burns fuel vaporized in a cylinder to move a piston and rotate a crankshaft via a link connected to the piston, the auxiliary piston having a displacement equal to or less than half of the piston and the rotational speed The cranks are gear-shifted with each other such that the auxiliary piston is between the position where the auxiliary piston is raised from the bottom dead center to a half stroke when the piston is at the top dead center. A two-crank type internal combustion engine, which is connected via a cylinder and allows the internal spaces of the cylinder heads to communicate with each other.