JPH065011B2 - Gasoline engine cylinder-mechanism - Google Patents

Description

Description: [Industrial field of use] The present invention relates to a cylinder mechanism of a gasoline engine.

[Prior Art] Conventionally, a large number of air intake holes communicating with the inside of the cylinder are provided at the lower limit position of the piston, and a fuel supply pipe with an injection valve is provided diagonally above the cylinder. In a cylinder of a gasoline engine, an exhaust valve and a spark plug are separately provided for the cylinder, and the upper end surface of the piston is flat.

[Problems to be Solved by the Invention] As described above, providing the exhaust valve and the spark plug separately to the cylinder increases the layout of the cylinder itself and increases the mounting holes for the two members. Therefore, there is a problem in that it requires at least twice as much labor to manufacture the cylinder and ensure the airtightness.

Moreover, since the upper end surface of the piston is flat, the explosion pressure at the time of compression ignition is directly and strongly applied to the circumferential wall of the cylinder, which easily damages the circumferential wall of the cylinder and shortens the life of the cylinder. There was a point.

It is an object of the present invention to provide a cylinder mechanism for a gasoline engine that solves the above conventional problems.

[Means for Solving the Problems] The present invention provides an exhaust valve from the center of the upper end wall of a cylinder of a gasoline engine into the cylinder, and exposes the exhaust valve at the center of the exhaust valve into the cylinder to fix the spark plug therethrough. The gist is that the upper end surface of the piston is formed into a bowl-shaped concave surface.

[Operation] The exhaust valve and the spark plug can be mounted at the same location at the same time only by forming a mounting hole for the exhaust valve in the center of the upper end wall of the cylinder of the gasoline engine.

Further, by forming the upper end surface of the piston into a bowl-shaped concave surface, the explosion pressure at the time of compression ignition can be first applied to the central portion of the bowl-shaped concave surface and diffused sequentially along the bowl-shaped concave surface.

The operation of each part of the cylinder mechanism is the same as the conventional one.

[Embodiment] An embodiment of a cylinder mechanism of a gasoline engine according to the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 1 is a cylinder of a gasoline engine, and an air intake hole 1b communicating with the inside of the cylinder 1 at a lower limit position of a piston 2 is formed on a peripheral wall 1a of the cylinder 1.
Are provided in large numbers.

It is recommended that the air entering the cylinder 1 from each of the air intake holes 1b is supplied so as to swirl along the inner surface of the peripheral wall 1a of the cylinder 1.

A central guide vertical hole 1d is formed in an upper end wall (cylinder head) 1c of the cylinder 1, and a supporting guide pipe 3a having an exhaust valve 3 fixed to a lower end thereof is penetrated through the central guide vertical hole 1d. ing. The support guide pipe 3a has coil springs 3b fixed at both ends to the upper surface of the upper end wall 1c of the cylinder 1 and the upper flange 3c of the support guide pipe 3a and fitted around the outer periphery of the support guide pipe 3a. The guide pipe 3a is elastically supported via a cam 4, which is rotationally controlled via a synchronous control mechanism (not shown), and descends against the coil spring 3b. It is designed to repeat the vertical movement in which the ball blasts and rises.

The cam 4 compresses and repels the coil spring 3b to vertically move the supporting guide pipe 3a, so that the exhaust valve 3 fixed to the supporting guide pipe 3a extends from the lower portion of the central guide vertical hole 1d of the cylinder 1 to the upper end of the cylinder 1. The lower surface of the opening 1f, which is the base end of the exhaust passage 1e extending in one direction of the wall 1c and opening, is continuously opened and closed in a predetermined cycle.

At the center of the exhaust valve 3, a spark plug 5 is exposed and fixed in the cylinder 1, and an ignition cable 6 is connected to the upper end of the spark plug 5. A fuel supply pipe 7 with an injection valve is provided at an obliquely upper position of the peripheral wall 1a of the above, and the upper end surface of the piston 2 is provided with a bowl-shaped concave surface 2a.

[Effects of the Invention] As described above, according to the cylinder of the gasoline engine of the present invention, the exhaust valve and the spark plug can be provided only by forming the mounting hole for the exhaust valve in the center of the upper end wall of the cylinder. Since they can be mounted at the same location at the same time, the cylinder can be downsized, and the labor for manufacturing the cylinder and ensuring airtightness can be significantly reduced, which contributes to cost reduction.

However, by forming the upper end surface of the piston into a bowl-shaped concave surface, the explosion pressure at the time of compression ignition can be first applied to the central portion of the bowl-shaped concave surface, and can be sequentially diffused along the bowl-shaped concave surface. Therefore, the explosion pressure is not directly and strongly applied to the peripheral wall of the cylinder, so that the peripheral wall of the cylinder can be prevented from being damaged and the life of the cylinder can be extended.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional front view of a cylinder mechanism of a gasoline engine according to the present invention. In the figure, 1 is a cylinder, 1a is a peripheral wall, 1b is an air intake hole, 1c is an upper end wall, 1d is a central guide vertical hole, 1e is an exhaust passage, 1f is an opening portion, 2 is a piston, 2a is a bowl-shaped concave surface, 3 is an exhaust valve, 3a is a supporting guide pipe, 3b is a coil spring, 4 is a cam, 5 is a spark plug, 6 is an ignition cable, and 7 is a fuel supply pipe with an injection valve.

Claims (1)

[Claims] 1. A cylinder mechanism for a gasoline engine having a large number of air intake holes in the cylinder peripheral wall which communicate with the inside of the cylinder at the lower limit position of the piston, and having a fuel supply pipe with an injection valve diagonally above the cylinder peripheral wall. An exhaust valve supporting guide pipe penetrates through the center guide vertical hole in the upper end wall of the cylinder and is vertically controllable in the cylinder. An exhaust valve that opens and closes the lower surface of the opening of the base end of the exhaust passage that is extended to and is open, a spark plug that is exposed and penetrated into the cylinder at the center of this exhaust valve, and the upper end surface has a bowl shape A cylinder mechanism for a gasoline engine, comprising a piston formed in a concave surface.