US2739583A

US2739583A - Acoustic detonation suppression and spark plug mounting device for internal combustion engines

Info

Publication number: US2739583A
Application number: US551261A
Authority: US
Inventors: Jr Albert G Bodine
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-12-06
Filing date: 1955-12-06
Publication date: 1956-03-27
Anticipated expiration: 1973-03-27

Description

March 27, 1956 o JR 2,739,583

ACOUSTIC DEITONATION SUPPRESSION AND SPARK PLUG MOUNTING DEVICE FOR INTERNAL. COMBUSTION ENGINES Original Filed July 2, 1951 2 Sheets-Sheet 1 FIG. I

FIG.2 28

INVENTOR. ALBERT G. BODINE JR.

A TORNE Y March 27, 1956 BODWE, ]R 2,739,583

ACOUSTIC DETONATION SUPPRESSION AND SPARK PLUG MOUNTING DEVICE FOR INTERNAL COMBUSTION ENGINES Original Filed July 2, 1951 2 Sheets-Sheet 2 FIGS 7 FIG.7

INVENTOR.

ALBERT G. BODINE JR.

A TTORNE Y United States Patcnt O A OUSTIC DETONATION SUPPRESSION AND SPARK PLUG MOUNTING DEVICE FOR IN TERNAL COMBUSTION ENGINES Albert G. Bodine, Jr., Van Nuys, Calif.

lication October 24, 1951, Serial No. 252,818, which a division of application Serial No. 234,688, July 2,

1951, now Patent No. 2,573,536, dated October 30,

1951. Divided and this application December 6, 1955, Serial No. 551,261

3 Claims. (Cl. 123-l91) This invention relates generally to internal combustion engines and to means for suppressing irregular burning and detonation of fuel-air mixture therein. The invent on is based on my discovery that detonation in COlTlbLlSilOl'l engines involves acoustic phenomena and can be alleviated by means of certain acoustic apparatus used in combination with t'ne combustion chamber.

The present application is a division of my copendlng application Serial No. 252,8l8, filed October 24, 1951, entitled Engine Detonation Control by Acoustic Methods and Apparatus, which was a division or my earlier appli cation Serial No. 234,688, filed July 2, 1951, entitled Engine Detonation Control by Acoustic Methods and Apparatus (now Patent No. 2,573,536), which last-mentioned case was in turn a continuation-in-part of my prior parent application Serial No. 24,744, filed May 3, l94 8, entitled Acoustic Means for Suppressing Detonation ll'l internal Combustion Engines. now abandoned.

The present invention is based on the fact that detonation in an engine combustion chamber produces sound waves, a large part of which are at high amplitude at resonant frequencies of the chamber, and On my discover that the sound waves produce the various well-known and harmful manifestations of detonation. According to my basic invention, 1 inhibit or attenuate these harmful eifects by interfering with or attenuating the high amplitude detonation-induced sound waves, and this is done by use in connection with the combustion chamber of acoustic attenuation means made responsive to the frequencies at which detonation induced sound waves appear at high amplitudes.

One type of acoustic attenuation means disclosed in my a'r'ore-mentioned earlier applications, with which the present application is connected by copendency, comprised a plug-in device adapted to be screwed into a part formed in a wall of the combustion chamber. The present invention is directed to a specific form of attenuator of this general character, including means for mounting a spark plug.

An object of the invention is the provision or an especially effective detonation controlling sound wave attenuator of a type capable of being screwed or plugged into a suitable port formed in a wall of the combustion chamber, such as the spark plug port with which the chamber is already equipped.

A further object is the provision of an acoustic sound wave attenuator capable of being plugged into the spark plug port of the combustion chamber wall and equipped with means for supporting the spark plug.

in my earlier aforementioned applications, detonation sound wave attenuators were described of a type involving porous absorbers as well as Helmholtz resonator forms embodying generally the concept of a Helmholtz resonator cavity with a porous plug or wall across the effective neck of the cavity. The basic theory and operation of said attenuators is fully set forth in said earlier applications, particularly in Patent No. 2,573,536.

2,739,583 Patented Mar. 27, 1956 ice An illustrative embodiment of the invention is shown in the drawing, which is a vertical medial section through an engine cylinder, cylinder head and piston.

The engine shown in the drawings is of the valve-inhead type, having a water-cooled block 10, water-cooled head 11, and piston 12 Working in a cylinder 13 within block 10. Head 11 comprises a generally domed or hemispherical chamber wall 14 defining a combustion chamber 15 over piston 12. In the center of head wall 14 is a threaded port 16 which may be of a size and type to receive the conventional spark plug, but into which the attenuator 17 of the present invention is installed, the spark plug 18 being carried by the attenuator.

Continuing with the description of the illustrative engine, intake and exhaust valves will be understood to open to combustion chamber 15 through wall 14, an exhaust valve 19 being shown, and it being understood that an intake valve (not shown) will be located symmetrically with respect to the exhaust valve, forwardly of the plane of the drawing.

Referring again to the attenuator 17, the same incorporates or has provision for mounting spark plug 18, as earlier mentioned, 30 that the device in this form may be used with conventional engines by simply screwing it into the spark plug port. Thus, into port 16 is screwed the externally threaded tubular stem 25 of a cylindrical porous body 26, the latter having cylindrical interior cavity 27, whose upper end is internally screw threaded to receive conventional spark plug 18. The body 26 is here shown to be enclosed within a metal closure shell 28, and is preferably formed, inside said shell, with an external circumferential channel 29 providing a Helmholtz resonator cavity space. It will be seen that l have thus interposed a porous body between the engine and the spark plug, the device serving as a spark plug adapter. The combustion chamber space immediately adjacent the spark plug is a common origin point for radial wave forms of detonation disturbance in engines like that shown in Fig. l, and by having this space immediateiy adjacent porous wall 26, the destructive detonation sound waves are materially absorbed in an area near their source. By employing the optional but preferred Helmholtz resonator cavity space 29, the device is made more frequency selective, and by choice of proper design constants for frequency response, depending upon the volume and shape of the combustion chamber in any given case, the particular detonation frequency desired to be combated is thereby selectively attenuated. An obvious optional arrangement is to form the stem 25 of solid material, for mechanical strength, and form the balance of the memher as of. porous material. Various materials are suitable for the porous body, for example, sintered powdered metal. Suitable porous materials and methods of fabrication, as well as the specific etfect of the porous materials on detonation, were disclosed fully in Patent No. 2,573,536, and need not be here repeated.

It will be understood that the drawings and description are merely illustrative of one specific embodiment of the invention, and that various changes in design, structure and arrangement may be made without departing from the spirit and scope of the appended claims.

I claim:

1. Detonation suppression means for an internal combustion engine having a combustion chamber, formed with a threaded port; a hollow porous body having a hollow, externally screw-threaded stem adapted to be screwed into said threaded port, said hollow body opening into said combustion chamber through said stern, said body having a multiplicity of fluid passageways of substantially capillary dimensions opening into its hollow interior.

2. Detonation suppression means for an internal combustion engine having a combustion chamber, formed with a threaded port; a hollow porous body having a hollow, externally screw-threaded stem adapted to be screwed into said threaded port, said hollow body opening into said combustion chamber through said stem, said body having a multiplicity of fiuid passageways of substantially capillary dimensions extending between an exterior surface of said body and the hollow interior thereof, and wall means enclosing a resonator cavity adjacent said exterior surface.

3. Detonation suppression means for an internal combustion engine having a combustion chamber, formed with a threaded port; a hollow porous body having a hollow, externally screw-threaded stem adapted to be screwed 4 into said threaded port, said hollow body opening into said combustion chamber through said stem, said body having a multiplicity of fluid passageways of substantially capillary dimensions opening into its hollow interior, and said body having also a threaded spark plug port opening into its said hollow interior.

References Cited in the file of this patent UNITED STATES PATENTS 1,116,364 Baker Nov. 10, 1914 1,466,432 Gerleman Aug. 28, 1923 1,490,849 Philip Apr. 15, 1924