Externally ignited four cycle gas engine

Abstract

An external auto-ignited four stroke cycle gas engine with a combustion chamber which is arranged in the piston rotation symmetrically with regard to the cylinder axis and which in the upper dead center point of the piston absorbs nearly the total gas-air mixture. The engine, furthermore, includes means for imparting turbulence upon the gas-air mixture about the longitudinal cylinder axis, and also has a trough which is arranged in the cylinder head, and into which a spark plug extends. The combustion chamber in the form of a truncated cone open and widening toward the cylinder head has a substantially plane bottom while the greatest diameter of this truncated cone-shaped combustion chamber equals from 55 to 70% of the piston diameter and the depth of this combustion chamber is in a range from 15 to 20% of the piston diameter. The mantle surface of the combustion chamber is at an angle of from 10.degree. to 30.degree. inclined relative to the longitudinal axis of the cylinder. The trough into which the spark plug extends is truncated cone shaped and located entirely above the opening of the combustion chamber. The greatest diameter of the trough amounts to about twice the diameter of the thread of the spark plug while the depth of the trough amounts to from 20 to 25% of the trough diameter. Adjacent to and communicating with the trough is an ignition passage which ends in a tip at the longitudinal cylinder axis.The present invention relates to an external auto-ignited four-stroke cycle gas engine with a combustion chamber which is arranged in the piston rotation-symmetrically with regard to the cylinder axis and which in the upper piston dead center point absorbs approximately the entire gas-air mixture, the gas engine being provided with means for generating turbulence of the gas-air mixture about the cylinder axis and furthermore being provided with a depression provided in the cylinder head while an ignition plug extends into this depression.It is an object of the present invention to provide an engine of this type which in spite of the fact that its exhaust gases are substantially free from harmful components has a low fuel consumption and a high output.

Description

Claims

1. An external auto-ignited four stroke cycle gas engine which includes: a cylinder, a piston reciprocable in said cylinder, a piston head mounted on and connected to said cylinder, said piston having that end thereof which faces said cylinder head provided with a truncated cone-shaped combustion chamber having a substantially flat bottom and widening and opening toward said cylinder head and being adapted in the upper dead center position of said piston to take in nearly the total gas-air mixture supplied per cycle to said cylinder, said cylinder head being provided with inlet valve means for admission of a gas-air mixture, means provided in said cylinder for imparting turbulence upon the gas-air mixture being admitted through said inlet valve means, said cylinder head also being provided with a truncated cone-shaped trough arranged completely in said cylinder head and communicating with said combustion chamber, a spark plug provided with a connecting thread and extending into said trough, the greatest diameter of said combustion chamber amounting to from about 55 to 70% of the diameter of said piston, and the depth of said combustion chamber equalling from about 15 to 20% of the diameter of said piston while the mantle surface of said combustion chamber is inclined at an angle of from 10.degree. to 30.degree. relative to the longitudinal axis of said cylinder, the greatest diameter of said trough equalling about twice the diameter of said connecting thread of said spark plug, and the depth of said trough amounting to from about 20 to 25% of the diameter of said trough, and wedge-shaped ignition passage means extending from said trough toward the longitudinal axis of said cylinder while tapering toward said last mentioned axis so that the tip of said taper ends flat at said cylinder axis.

2. An engine according to claim 1, in which said cylinder head is also provided with an exhaust outlet valve, and in which the central axes of said inlet and outlet valves are offset in the same direction relative to the vertical longitudinal axis of said cylinder, said trough being offset to said last mentioned cylinder axis in a direction opposite to said first mentioned direction.

3. An engine according to claim 2, in which the center of said trough is located in a plane extending through the center of the shortest distance between said inlet and outlet valves and forming the longitudinal plane of symmetry of said trough.

4. An engine according to claim 2, in which each of said inlet and outlet valves respectively has associated therewith a valve seat, and in which the shortest distance between the rim of said trough and each of said two valve seats approximately equals the shortest distance between said two valve seats.

5. An engine according to claim 1, in which said spark plug has two electrodes of different length, and in which the shorter electrode ends in a plane passing about through the bottom of said trough.

6. An engine according to claim 1, which when employing liquid gas has a compression ratio of 10-12.

7. An engine according to claim 1, which when employing earth gas has a compression ratio of about 13-15.