US3897851A

US3897851A - Muffler for two cycle diesel pile hammer

Info

Publication number: US3897851A
Application number: US483205A
Authority: US
Inventors: Russel L Heacox
Original assignee: P AND Z CO Inc
Current assignee: P AND Z CO Inc
Priority date: 1974-06-26
Filing date: 1974-06-26
Publication date: 1975-08-05
Anticipated expiration: 1992-08-05
Also published as: JPS512850A

Abstract

A muffler for a two cycle internal combustion cylinder having a common intake and exhaust port is disclosed. The muffler finds preferred use on a two cycle diesel pile hammer having a common intake and exhaust port. The muffler includes a short pipe communicating to and from the port. The short pipe is communicated concentrically to a larger perforated cylindrical sleeve open at the top and at the bottom. This larger perforated cylindrical sleeve has a lower heavily perforated portion, an upper less perforated portion, and a pipe extending substantially transverse of the sleeve between the upper and lower portions. During intake of the air to be combusted interior of the pile hammer diesel cylinder, air is drawn mainly through the lower heavily perforated portion of the sleeve to provide an air intake to the hammer substantially uncontaminated by exhaust. During discharge of the combusted air from the interior of the pile hammer, the blast of discharged air -typically at speeds approaching sonic velocity- bypasses the lower sleeve portion. This air impacts the pipe extending transverse of the perforated sleeve and thereafter is muffled in sound as it passes through the remainder of the sleeve and the sleeve''s perforation. Reduction in sound by as much as 10 decibels can occur without appreciable loss in pile hammer impact efficiency.

Description

United States Patent 1 1 Heacox 1 1 MUFFLER FOR TWO CYCLE DIESEL PlLE HAMMER [75] Inventor: Russel L. Heacox, Tiburon Calif.

[73] Assignee: P & Z Company. Inc., South San Francisco. Calif.

22 Filed; June 26, 1974 121 App]. No.: 483,205

[52] US. Cl 181/36 R; 181/36 D; 181/49. 123/65 SP; 173/46; 173/D1G. 2 [51] Int. Cl. FOlN 3/06 [58] Field of Search... 181/35 A, 36 11,36 A. 36 D 181/40, 41. 49, 55. 56, 61], 72; 611/314;

123/65 R. 65 SP. 46 H 139 H. 79 R; 173/46 134, )(1. DIG. 2

Primary E.i'amiIzerStephen J. Tomsky Assistant Examiner-lohn F. Gonzales Attorney, Agent or Firm-Townsend and Townsend Lil [ 71 ABSTRACT A muffler for a two cycle internal combustion cylinder having a common intake and exhaust port is disclosed. The muffler finds preferred use on a two cycle diesel pile hammer having a common intake and exhaust port. The muffler includes a short pipe communicating to and from the port. The short pipe is communicated concentrically to a larger perforated cylindrical sleeve open at the top and at the bottom. This larger perforated cylindrical sleeve has a lower heavily perforated portion, an upper less perforated portion, and a pipe extending substantially transverse of the sleeve between the upper and lower portions During intake of the air to he combusted interior of the pile hammer diesel cylinder, air is drawn mainly through the lower heavily perforated portion of the sleeve to provide an air intake to the hammer substantially uncontaminated by exhaust. During discharge of the combusted air from the interior of the pile hammer. the blast of discharged air typically at speeds approaching sonic velocity bypasses the lower sleeve portion. This air impacts the pipe extending transverse of the perfo rated sleeve and thereafter is muffled in sound as it passes through the remainder of the sleeve and the sleeves perforation. Reduction in sound by as much as 11) decibels can occur without appreciable loss in pile hammer impact efficiency.

9 Claims 5 Drawing Figures MUFFLER FOR TWO CYCLE DIESEI, PILE HAMMER This invention relates to mufflers and. more particu larly. to a tnufller for a two cycle cylinder having a common intake and exhaust port. Specifically. the mul ller is adapted to the intake exhaust port of a diesel pile hammer.

SUMMARY OF 'l'Hl'f PRIOR ART To the extent that noise produced by the exhaust from internal combustion cylinders is understood. the sound apparently emanates from the exhaust port when it opens. Specifically, the instant the exhaust port opens. gases interior of the cylinder are exhausted with great energy and force. 'l'hese gases are pushed past the port at velocities approaching sonic velocities. Moreover. the energy with which the exhaust gases are pushed by the opening port exceeds that energy re quired to drive the gases at the speed of sound. Loud noise apparently results.

Diesel pile hammers and their internal combustion cylinder exhausts are particularly obnoxious. The sound and vibration of the hammer impact combines with the sound and vibration of the noise generated by the diesel exhaust. llie two sounds combined in sulv stantially the same instant of time result in an intolerable loud. obnoxious noise. More recently. this type of noise has been referred to as acoustical pollution."

Mufflers heretofore known have been used on either air intakes or air exhausts. but not both. Where niachincry utilizes the same port for both intake and ex haust. a peculiar problem arises. Providing a muffler with an elongate. circuitous muflling path not only generates undesirable back pressure resulting in ma chine inefficiencybut additionally results in exhaust air being rechanneled into the machinery upon cylinder stroke intake. Pile hammer efficiency drops and even damage to the hammer can result. Conventional oneway mufflers. either of the exhaust or intake variety. are of little use in muffling two cycle internal combustion equipment having a common intake and exhaust port.

SUMMARY OF THE INVENTION A muffler for a two cycle internal combustion cylin der having a common intake and exhaust port is dis closed. The muffler finds preferred use on a two cycle diesel pile hammer having a common intake and exhaust port. The muffler includes a short pipe communicating to and from the port. The short pipe is communicated concentrically to a larger perforated cylindrical sleeve open at the top and at the bottom. This larger perforated cylindrical sleeve has a lower heavily perforated portion. an upper less perforated portion. and a pipe extending substantially transverse of the sleeve be tween the upper and the lower portions. During intake of the air to be combusted interior of the pile hammer diesel cylinder. air is drawn mainly through the lower heavily perforated portion of the sleeve to provide an air intake to the hammer substantially Ul'ttD ntaminated by exhaust. During discharge ofthc combusted air from the interior of the pile hammer. the blast of discharged air -typically of speeds approaching sonic velocitybypasses the lower sleeve portion. This air impacts the pipe extending transverse of the perforated sleeve and thereafter is muffled in sound as it passes through the remainder of the sleeve and the sleeves perforation. Reduction in sound by as much as l() decibels can occur without appreciable loss in pile hammer impact efficiency.

OBJECTS. FliA'lURES AND ADVAN'IAGIIS OF THE lNVliN'llON An object of this invention is to disclose a muffler for the common intake-exhaust port on a two cycle internal combustion cylinder. According to this aspect of the invention. the port is discharged concentrically into a cylinder having lower and upper perforated sleeves. 'fhese sleeves are divided by a transverse pipe. Preferably. the lower perforations are more numerous than the upper perforations.

An advantage of the muffler is that intake occurs largely through the lower. more perforated sleeve portion. Small amounts of exhaust gas are therefore cn trained during the intake stroke. The result is that no appreciable loss occurs in cylinder efficiency.

Another advantage of this invention is that the exhaust largely bypasses the lower. grossly perforated portion of the sleeve. Specifically. it passes upwardly and is deflected at a transverse pipe extending over the exhaust port. 'l'hereafter. the deflected gas impinges on the sleeve sides. typically at the upper. less perforated portion of the sleeve. Muffling of approximately ll) percent of the acoustical vibration occurs. Reductions from 99 dba have been made to 88 dba using such apparatus on a diesel pile hammer internal combustion cylinder.

An object of this invention is to disclose a muffler which can be used on a two cycle pile hammer. preferably a diesel pile hammer.

A further advantage of this invention is to decouple the sound ofthe exhaust port opening from the physical impact of a pile hammer with a pile. This decoupling results in an acoustically much more tolerable sound which is appreciably less disruptive ofthc environment. Both operating crews and persons inevitably present in the operating environment are much less offended by pile hammer noise pollution.

A further object of this invention is to disclose a mufller that can hold together in the vibrating ambient of a pile hammer. According to this aspect of the invention. the perforated sleeve is constructed of a heavy steel. This steel sleeve is bolted directly to the pile hammer and moves in vibration with the pile hammer.

An advantage of the disclosed muffler is that the muffler can hold together for virtually the same period of time as the pile hammer itself.

A further advantage of the muffler is that the use of flexible connections between a muffler and the vibrat ing hammer is not required. Instead. the muffler assembly is capable of integral attachment to the pile hammer itself.

Other objects. features and advantages of this invention will become more apparent after referring to the following specification and attached drawing in which:

FIG. 1 is a front elevation in perspective illustrating a diesel pile hammer mounted to conventional pile leads, with the exhaust muffler of this invention attached thereto;

FIG. 2 is a view of a portion of the pile hammer illustrating a conduit attached leading to the muffler;

FIG. 3 is a side elevation of the completed muffler attached to the exhaust conduit;

FIG. 4 is a side elevation of the large perforated sleeve of the invention; and,

FIG. 5 is a section of the pile hammer taken along lines S5 of FIG. 4.

Referring to FIG. 1, a pile hammer A is illustrated mounted to conventional pile leads 8 driving at a hammer C a pile D. Intake-exhaust ports 14 are illustrated having a pipe segment 16 with the muffler E of this invention attached thereto.

The pile hammer here illustrated is a Kobe Model KB-42 diesel pile hammer, a product of Kobe Steel Limited of Kobe, Japan. In the FIG. I here shown, two mufflers are illustrated. In the actual pile hammer, two mufflers appear on the front or illustrated side of the hammer. Similarly, and in complementary positions in the rear, two mufflers are installed to similar exhaust ports 14 at the rear of the pile hammer. These rear pile exhaust ports 14 are not shown.

Referring to FIG. 2, a four-inch tube 16 is welded to the exhaust port of the pile hammer. Preferably, the tube has a minimum length so as to communicate the intake and exhaust to the concentrically mounted, larger, outer perforated sleeve 40. On a pile hammer of the Kobe manufacture, the four-inch pipe 16 of 12 inches in length has been found satisfactory.

It is typically preferable to angle the discharge port away from the pile hammer. To this end, an angle of approximately 8 is placed in the four-inch pipe leading away from the exhaustintake port 14 of the pile hammer.

Referring to FIG. 2, paired bolts 28, are welded to diametrically opposite portions of pipe segment 16. These bolts are approximately 6 inches in length and have threaded thereto at their

upper portion nuts

31, 32. As will hereinafter more fully appear, the sleeve constituting the muffler of this invention is mounted on top of nuts 3], 32. Thereafter, nuts 61, 62 complementary to

nuts

31, 32 are threaded over the ends of the

bolts

28, 30 to securely capture the muffler there between.

The simplified construction of the muffler of this invention can readily be understood with reference to FIGS. 3, 4 and 5. Referring to FIG. 4, it will be seen that a cylinder 40 is provided. As specifically applied to the Kobe hammer, cylinder 40 is approximately 14 inches in length, 6 inches in diameter, and constructed of 3/16 inch wall tubing. The area of the outside sleeve 40 exceeds the area of the concentrically communicating pipe by a ratio of approximately 50 percent. I

A pipe 42 extends transverse of the sleeve sidewalls. As here shown, it extends between the sidewalls of the cylindrical sleeve and provides a cylindrical surface over which the exhaust gases pass. Pipe 42 here shown is a one-inch diameter pipe.

The perforated portions of the sidewalls 40 of the cylinder above and below the pipe can be very briefly discussed. Above the pipe, the perforated portions 44 of the cylinders constitute an interruption of approximately 20 to 40 percent of the sleeve 40 sidewalls. Below the pipe 42, the perforations 46 in the sides of the pipe interrupt between 40 and 60 percent of the sidewall area. The perforations below are evenly disbursed and many are elongate in nature axially of the cylindrical length of the cylinder. As will hereinafter be explained, the apertures 46 are those apertures through which the greater portions of the intake occurs.

Mounting of the sleeve can easily be understood. Specifically, and medially of the perforated sleeve, two

ears

50, 52 are cut and thereafter bent horizontally from the sleeve 40 sidewalls (see FIGS. 4 and 5). These ears are bent horizontally and transpierced by apertures 54.

In installation of the sleeve, the apertures are passed over the upper portions of

bolts

28, 30. Thereafter,

bolts

61, 62 rigidly secure the perforated sleeve to the exhaust pipe 16. It should be noted that both ends of sleeve 40 are open. Moreover, sleeve 40 overlaps pipe 16 by 4 inches of the embodiment here shown or more than one half a diameter of the sleeve.

Operation can readily be understood. During intake, the bulk of the intake gases pass inwardly through the conduit 16 to the pile hammer port 14 through apertures 46. Upon exhaust discharge from the hammer, gases at high velocity impinge upon pipe 42 mounted transversely of the perforated cylinder 40. Muffling of the sound by passage around the pipe and impingement on the upper perforation of the sleeve occurs. Sound is correspondingly reduced.

It should be apparent that the embodiment here shown will admit of modifications. For instance, the in vention can be utilized with virtually any type of two cycle engine device having a common intake and exhaust port. Moreover, its use to a particular type of pile hammer is not required. It can be used with virtually any type of diesel pile hammer. Further, it will be realized by those skilled in the engine art that two cycle gas as well as two cycle diesel internal combustion devices having common intake and exhaust ports can utilize the invention herein disclosed. Likewise, other modifications can be made to this invention.

I claim:

1. A muffler for a two cycle internal combustion engine having a common intake and exhaust port comprising: a perforated cylindrical sleeve; a conduit communicating from said common intake and exhaust port to one of the open ends of said sleeve; means for mounting said sleeve and conduit to said common port; and, an obstructing member mounted transverse of said perforated sleeve over the outlet of said conduit.

2. The invention of claim 1 and wherein said conduit extends interiorly of said sleeve by a distance equal to one half the diameter of said sleeve.

3. The invention of claim 1 and wherein said obstructing member comprises a cylindrical surface mounted transverse of said sleeve.

4. The invention of claim I and wherein the cross sectional area of said sleeve exceeds the cross sectional area of said conduit by 50 percent.

5. In combination, a pile hammer having at least one two cycle internal combustion cylinder with a common intake and exhaust port; a perforated cylindrical sleeve; a conduit communicating from said common intake and exhaust port to one of the open ends of said perforated sleeve; means for mounting said sleeve and conduit to said pile hammer; and, an obstructing member mounted transverse of said perforated sleeve over the outlet of said conduit.

6. The combination of claim 5 and wherein said mounting means includes said conduit rigidly welded to said pile hammer, and said sleeve rigidly attached to said conduit only.

sleeve and the perforations below said obstructing transverse member, and towards said conduit interrupt 20 to 40 percent of the area of said sleeve sidewalls.

9. The invention of claim 5 and wherein said pile hammer is a diesel pile hammer.

Claims

4. The invention of claim 1 and wherein the cross sectional area of said sleeve exceeds the cross sectional area of said conduit by 50 percent.

7. The invention of claim 5 and wherein the perforations of said sleeve interrupt at least 20 percent of the sidewall area of said cylindrical sleeve.

8. The invention of claim 5 and wherein the interruption of said sleeve above said obstructing member interrupts 40 to 60 percent of the sidewall area of said sleeve and the perforations below said obstructing transverse member, and towards said conduit interrupt 20 to 40 percent of the area of said sleeve sidewalls.