JPS59550A - Twin cylinder engine - Google Patents

Abstract

PURPOSE:To make an engine compact, and to increase the area of a valve opening, by forming the cross section of a cylinder normal to the direction of the reciprocation of a piston into such a shape that two semicircles are combined together, whose longer axis extends in parallel to the axis of a crank shaft. CONSTITUTION:The piston 1 has such a configuration that parts of two cylindrical pistons are cut and the cut pistons are combined, and the marged sections are provided with notches 5 so that friction of the concentrated contact pressure between the piston and edges of the inner wall of the cylinder can be avoided. Thus adopting a twin cylinder, a compact engine can be designed, even if it is made into multicylinder construction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cross-sectional shape of a cylinder of a reciprocating engine.

With the miniaturization of automobiles and rationalization of their comfort, the miniaturization of engines has become an important issue in automobile design.

The cross-sectional shape of the cylinder of conventional reciprocating engines was simply circular, so in order to narrow the cylinder width without changing the displacement, K reduced the inner diameter of the cylinder.
The method used was to lengthen the piston stroke.

However, it is difficult to avoid the negative impact of this method on the demands for combustion efficiency and high engine speed, so reducing the width of the cylinder and improving the performance of the engine are contradictory issues. , there were limits.

The present invention has been made in order to overcome this limitation and obtain effective effects for automobiles.

In other words, by adopting a cylinder with a bicircular cross-sectional shape, the cylinder width can be narrowed without lengthening the piston stroke, or by further shortening the piston stroke, the engine height can be reduced by one degree. By doing so, the engine itself is made smaller, with the aim of reducing the size of the engine compartment of the car and making more effective use of space, while at the same time aiming to improve the performance of the engine.

The shape of the bicircular cross section is the first one if we explain the drawings.
As shown in the figure, the respective radii are R1 and RL (R+≧R
, ) with a constant center-to-center distance L (Rt+-R
t,>r,). The width of this cross section is the cylinder width, which is clearly smaller than the inner diameter of a cylindrical cylinder with the same cross-sectional area.

Embodiments of specialized pistons and piston rings that are applied to cylinders with a bicircular cross-sectional shape include the following.

To explain the drawings, the piston is as shown in Figure 2.
It is shaped like two parts of a cylindrical piston cut out and glued together, and has a cutout to avoid friction caused by concentrated contact pressure with the corners of the inner wall of the cylinder. It is a feature. As shown in Figure 3, one piece of the piston ring has a C-shape, which is divided into two pieces.
A feature is that by combining the pieces, one bicircular ring is constructed. As shown in FIG. 4, the end of the piston ring base piece has an abutting part with an L-shaped cross section to prevent compression leakage and oil leakage.

One of the advantages of an engine using a bicircular cylinder is the problem of pulp opening area in a four-stroke overhead valve system.

Conventional 4-stroke overhead valve engines use complicated mechanisms such as four pulps per cylinder in order to increase the opening area of the valves, but this engine uses a double-circle structure in the cylinder head. By effectively arranging two valves for intake and exhaust in each of the nata, the opening area for the pulp can be made sufficiently large.

Regarding the inner surface processing of the cylinder, since the bicircular cross section is basically composed of two circles, the inner surface processing of the cylinder can be completed satisfactorily using conventional cylinder inner surface processing techniques.

As described above, by adopting a bi-circular cylinder, it is possible to design an engine with a relatively compact width and height even with multiple cylinders, which breaks the conventional common sense concept.
It is possible to produce small, comfortable, high-performance, and inexpensive cars.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a bicircular cylinder Fig. 2 is a three-dimensional view of a piston Fig. 3 is a plan view of a piston ring Fig. 4 is a side view of a butt part of a piston ring Pressure ring, 3 is oil ring, 4
263- is the piston pin, 5 is the cutaway view, Figure 1, Figure 2, Figure 3.

Claims (1)

[Claims] A reciprocating engine in which the cross section of the cylinder perpendicular to the direction of the reciprocating movement of the piston is in the shape of two overlapping circles with a constant center distance in the direction perpendicular to the direction of the crankshaft.