US3709320A - Exhaust means for multiple cylinder internal combustion engine - Google Patents

Abstract

The exhaust device for multiple cylinder internal combustion engines of the type where the waste gas pipes lead separately from cylinder to the exhaust sound muffler, the lengths of which is of different magnitude between motor and sound muffler, while individual waste gas pipes inside the sound muffler are prolonged by a certain amount, is characterized in that the waste gas pipes which are prolonged inside the sound muffler have at least one enlargement in their cross-section.

Description

United States Patent 1191' Hiillerl et a1.

1 1 Jan. 9, 1973 [54] EXHAUST MEANS FOR MULTIPLE CYLINDER INTERNAL COMBUSTION ENGINE [75] Inventors: Alois Hiillerl; Karl Landgraf, both of Schoensee, Germany [73] Assignee: Firma Otto Meinel-Ceorgadel M'etallwarenfahrik, Schoensee/Oberpfalz, Germany [22] Filed: Oct. 12, 1971 21 Appl. No.: 188,413

[30] Foreign Application Priority Data Oct. 15, 1970 Germany ..G 70 38 137.2

[52] US. Cl ..l8l/40, 181/56, 181/35 C, 181/57 [51]" Int.Cl ..F01n7/06,F0ln 7/10, FOln7/l8 [58] Field of Search ...-.....181/36 D, 40, 46, 56, 35 C,

[56] References Cited UNlTED STATES PATENTS 2,255,579 9/1941 Blanchard 2,660,257 11/1953 Bourne et a1. ...18 1/36 D 2,940,249 6/1960 Gospodar ..18l/35 C FOREIGN PATENTS OR APPLICATIONS 313,807 6/1929 Great Britain ..181/40 Primary Examiner-Robert S. Ward, Jr. Attorney-Robert H Jacob [57] ABSTRACT The exhaust device for multiple cylinder internal combustion engines of the type where the waste gas pipes lead separately from cylinder to the exhaust sound muffler, the lengths of which is of different magnitude between motor and sound muffler, while individual waste gas pipes inside the sound muffler are prolonged by a certain amount, is characterized inthat the waste gas pipes which are prolonged inside the sound muffler have at least one enlargement in their cross-section.

8 Claims, 4 Drawing Figures PATENTED JAN 9 I975 SHEET 1 BF 3 PATENTEDJAR 9 ma 3. 709 .320

SHEET 2 [IF EXHAUST MEANS FOR MULTIPLE CYLINDER INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION exhaust sound muffler, the lengths between motor and sound muffler are different, while individual waste gas pipes within the muffler are prolonged by a certain amount.

In a known exhaust device of this type, the individual waste gas pipes are prolonged inside the sound muffler by such an amount that together they have the same total length. By these means it is intended to accomplish that the waste gases enter from the cylinders in the sound mufiler at equal time periods so that no increase occurs in the amplitude of the pressure, by means of which the noises would be amplified and the sound muffler would be mechanically subjected to increased loads. r

In this known exhaust device, there exists the shortcoming that due to construction of the internal combustion engine shorter waste gas pipes within the second muffler must be prolonged by a considerable amount in order to be just as long as the waste gas pipes that are longer due to the'construction of the internal combustion engine. As a result, the total length of the waste gas muffler of the exhaust device becomes excessively large, which requires a high expenditure of material. To this is added a considerable concentration of heat in the prolonged parts of the waste gas pipes which noticeably decrease the life of known sound mufflers.

SUMMARY OF THE INVENTION- It is an object of the invention to provide an exhaust device of the type mentioned above which does not have the shortcomings mentioned and which excels particularly by small requirement of material, a favorable gas discharge and increased durability.

Accordingly, the invention provides for the waste gas pipes that are prolonged within the sound muffler that they have at least one expansion or enlargement in their cross-section. As a result of the expansion of the cross-section which results in a reduction of the speed of the waste gases, a very advantageous exhaust discharge is obtained and, furthermore, shortening of the waste gas pipes which is likewise advantageous for the reasons mentioned. In particular, it is no longer necessary that the waste gas pipes prolonged within the second muffler extendparallel and at a small distance from one another over the larger part of their extent and thus heat themselves due to the radiation of heat, as well as one another, as a result of which the thermal stress which is already high is further increased, and thereby the durability of the exhaust muffler parts is considerably decreased.

Advantageously the widening of the cross-section may be in the form of a bulge. It is particularly advisable in the exhaust device for four cylinder combustion engines having waste gas pipes that extend in opposite directions inside the sound muffler and are staggered so that the bulges extend in opposite directions as related to the longitudinal axis of the sound muffler. In this manner the space of the sound muffler that is available is optimally utilized, so that minimum space dimensions result. In addition to this, favorable thermal stress is obtained while the bulges of both prolonged waste gas pipes essentially increase the surface as compared to the known form of construction, and thus the heat conduction and radiation are considerably improved.

In regard to conducting the heat away, it is also advantageous that the bulges are of the same shape and volume. It is essential and particularly advantageous that the bulges be provided with bores for the exit of the waste gases at the gas discharge pipes or at the parts that are remote from their prolonged parts. In this manner a particularly satisfactory, even and favorable discharge of the waste gases is obtained. Besides, the waste gases do not flow entirely to the end of the prolongations of the waste gas pipes, but they expand and press already against the walls ahead of the bulges so that they are radiated from a comparatively large surface. Thus, the thermal stress of these parts remains within moderate limits whereby the durability is prolonged.

The advantages that may be obtained in accordance with the invention can be realized at relatively small cost, for example the parts provided with the bulges of the water gas tubes that are prolonged in the sound muffler can be formed in that two metal sheets that extend longitudinally of the sound muffler are maintained as to form or material which rest with their flat sides that define the recesses forming the bulges in the muffler upon one another are, made the same as to form or material.

BRIEF DESCRIPTION OF THE DRAWINGS Further details, features and advantages of the invention will become apparent from the embodiment of the invention illustrated in the drawings in which:

FIG. 1 is a view of one-half of the sound muffler of an exhaust device with the waste gas pipes,

FIG. 2 is a section taken along line Il-Il in FIG. 1,

FIG. 3 is a section taken along line IIIIII in FIG. 1, and

FIG. 4 is a schematic plan view of the motor and muffler with the waste gas pipes which connect them.

DESCRIPTION OF THE INVENTION FIG. 1 shows themuffler housing 1 of an exhaust device for multiple cylinder combustion engines. The exhaust pipes 2-5 lead into themuffler housing 1 of a combustion engine which in this example has four cylinders. Due to the construction or design of such motors, the distances between the connecting locations of the waste gas pipes on the motor to the corresponding connecting locations of the waste gas pipes on the muffler are of different lengths. The waste gas pipe 2,3 which for these reasons are longer lead by way of conically shaped stubs 8, 9 that are provided with gas discharge apertures 6, 7 into the sound muffler housing The discharge pipes, 4, 5 which for the aforementioned reasons are shorter, are prolonged by a certain amount inside thesound muffler 1 by means of the pipe members 10, 11. However, the total length of the waste gas pipes 4, 5 that are lengthened by means of the pipe members l0, 11 is less than the total length of the waste gas pipes 2, 3 which are not prolonged. This is schematically illustrated in FIG. 4. Each of the pipes 10, 11 comprises an expansion of the cross-section defined by a bulge l2, 13. Thebulges 12, 13 are each of the same shape and volume and extend in opposite directions as related to the longitudinal axis of thesound muffler 1 at their ends that are remote from the waste gas pipes 4, or the prolongations 10, 11. They are provided with a multitude ofbores 14,15 which affect to a considerable extent the even conveyance of gas and heat because the discharge cross-section for the waste gases is correspondingly large.

The bulges may be defined in a separate insert member which suitably is made of two pressed or formedsheet metal halves 16, 17 that are welded together. This is shown particularly in the sections of FIGS. 2 and 3. In FIG. 2 a'section is illustrated at the location of the sound muffler l where the pipe section 11 of the waste gas pipe 5 enters the insert member.

It is understood that a corresponding second shell 1' of the muffler is associated symmetrically with theshell 1 that is drawn in solid lines. For reasons of greater clearness, the shell 1' is only shown in dash and dot lines in FIGS. 2 and 3. While waste gas pipes 2,5 lead to one shell half 1 (see also FIG. 1), theother shell half 1 is provided with theexhaust pipes 29 which also are illustrated only in dash and dot lines through which the waste gases pass to the exterior.

As reflected by FIG. 3, thesheet metal members 16, 17 that constitute the insert are placed upon one another with 'their flat sides in such a manner that recesses in them on both sides definebulges 12, 13. Thesheet metal members 16, 17 may be unitarily and materially connected with muffler l, for example by welding.Flanges 18, 19 or 20, 21 serve for connecting the waste gas pipes 4 or 5 to two of the four cylinders of the combustion engine. The waste gas pipes 2, 3 are provided withsuitable flanges 22, 23 (FIG. 4).

The size of thebulges 12, 13 is such that the available cross-section of thesound muffler 1 is extensively utilized. As a result such an increase of the cross-section of the waste gas pipes is already sufficient for solving the problem on which the invention is based. In special cases, however, more than one increase of the crosssection may be provided for each prolonged waste gas pipe. In view of the volume increase caused by thebulges 12, 13, the prolongations 10, 11 of the exhaust pipes 4, 5 may be made so small that they do not overlap, or only so little that in practice mutual heating by heat radiation does not result.

- Thesheet metalmembers 16, 17 separate the space ,27 fromspace 28 which leads to the exhaust pipes partly. Thereforebores 25 may be provided inthembers 16, 17, as well asperforations 26, as a result of which the waste gases in space27 can reach thespace 28 and therefore theexhaust pipes 29 more easily or quickly.

As shown particularly in FIG. 3, the bulges may have a flattened shape so that the thickness of the sound muffler need not be enlarged in that area.

The sheet metal members l6, 17 as viewed in the longitudinal direction fill the entire cross section of the sound muffler and are welded on to the sound muffler at their upper and lower longitudinal edges (see particularly FIGS. 2 and 3).

avmg now described our invention with reference to the embodiments illustrated in the drawings, what we desired to protect by letters patent is set forth in the appended claims.

We claim:

1. Exhaust device for multiple cylinder internal combustion engines comprising a housing defining an exhaust sound muffler and waste gas pipes, of the type having a waste gas pipe for each cylinder of the associated engine, said pipes leading separately to the exhaust sound muffler, the lengths of said pipes between the motor and said muffler being different, while individual waste gas pipes are prolonged by a certain amount inside said muffler, and said waste gas pipes inside said muffler having expanded cross-sections.

'2. Exhaust device in accordance withclaim 1, where said expanded cross-sections are in the form of bulges.

3. Exhaust device in accordance withclaim 1, comprising two prolonged waste gas pipes extending within said muffler in opposite directions relative to the longitudinal axis of said muffler, and where said bulges extend longitudinally relative to the longitudinal axis of said muffler and in opposite directions relative to each other.

4. Exhaust device in accordance with claim 3, where said bulges have equal shapes and are of the same volume.

5. Exhaust device in accordance with claim 4 where apertures are defined in said bulges at the ends remote from said waste gas pipes.

6. Exhaust device in accordance with claim 5, where said parts of said pipes having said expanded sections are definedby sheet metal having flat sides disposed upon and connected with one another and having recesses defining said bulges.

7. Exhaust device in accordance withclaim 6, where portions of said parts of sheet metal away from said bulges are provided with apertures for the passage of waste gases.

8. Exhaust device in accordance with claim 7 where said bulges present flat sides.

Patent N5. 5,709,520

Dated January 9, 1975 Inventor(s L I 0 af It is eertified that error appears in the above-identified patent and that said Letters Patent are hereby con eated as shown below:

Claim 5,line 1 Ghange numeral "1" to 2 Signed and's'ealed this 22nd of May 1973,

SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GO TTSCHALK Attesting Officer h I Commissioner of Patents FORM (m'59) uscoMM-Dc scan-ps9 A 1.5. GOVERNMENT PRINTING QFFICE 21969 ()"365'334 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION- Patent Ne. 520 r I Dated J y Inventor(s) A I Qj S Igr I Kg II La, ndgraf It is eertified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 5,line 1 change numeral "1" to --2-'.

Signed andsealed this 22nd of May 1973,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I v ROBERT GOTTSICHALK Attesting Officer Commissioner of Patents F ORM PO-105O (10-69) USCOMM-DC 60376-P69 U.S. GOVERNMENT PRINTING QFFICE: I959 0-355-334

Claims (8)

1. Exhaust device for multiple cylinder internal combustion engines comprising a housing defining an exhaust sound muffler and waste gas pipes, of the type having a waste gas pipe for each cylinder of the associated engine, said pipes leading separately to the exhaust sound muffler, the lengths of said pipes between the motor and said muffler being different, while individual waste gas pipes are prolonged by a certain amount inside said muffler, and said waste gas pipes inside said muffler having expanded cross-sections.

2. Exhaust device in accordance with claim 1, where said expanded cross-sections are in the form of bulges.

3. Exhaust device in accordance with claim 1, comprising two prolonged waste gas pipes extending within said muffler in opposite directions relative to the longitudinal axis of said muffler, and where saId bulges extend longitudinally relative to the longitudinal axis of said muffler and in opposite directions relative to each other.

4. Exhaust device in accordance with claim 3, where said bulges have equal shapes and are of the same volume.

5. Exhaust device in accordance with claim 4 where apertures are defined in said bulges at the ends remote from said waste gas pipes.

6. Exhaust device in accordance with claim 5, where said parts of said pipes having said expanded sections are defined by sheet metal having flat sides disposed upon and connected with one another and having recesses defining said bulges.

7. Exhaust device in accordance with claim 6, where portions of said parts of sheet metal away from said bulges are provided with apertures for the passage of waste gases.

8. Exhaust device in accordance with claim 7 where said bulges present flat sides.

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