US2886945A

US2886945A - Exhaust pipe

Info

Publication number: US2886945A
Application number: US486939A
Authority: US
Inventors: Hofer Max
Original assignee: MAN Maschinenfabrik Augsburg Nuernberg AG
Current assignee: MAN AG
Priority date: 1954-02-13
Filing date: 1955-02-08
Publication date: 1959-05-19
Anticipated expiration: 1976-05-19

Description

M. HOFER EXHAUST PIPE May 19, 1959 2 Sheets-Sheet 1 Filed Feb. 8, 1955 V mvENToR MAX Hon-:R

BY Mugj ATTORNEYS May 19, 1959 M. Hol-ER 2,886,945

EXHAUST PIPE Filed Feb. 8. 1955 2 Sheets-ShamI 2 INVENTOR MAX HOFER ATTORNEYS United States Patent O i EXHAUST PIPE Max Hofer, Augsburg, Germany, assiguor to Maschinenfabrik Augsburg-Numberg A.G., Augsburg, Germany, a corporation of Germany This invention relates to exhaust pipe constructions and, more particularly, to such constructions for multicylinder internal combustion engines in which the exhaust gases are utilized for driving an exhaust gas turbine.

Since the individual cylinders of multicylinder internal combustion engines lire and exhaust at different times and are located dilerent distances from the end of the exhaust pipe which is connected to an exhaust gas turbine, it is desired to collect and conduct separately to the turbine the exhausted gases from different cylinders or different groups of cylinders so that the exhaust pressure impulses lfrom the various cylinders do not interfere with each other. Particularly with large multicylinder Diesel engines, the exhaust pipe may be quite long so that provision must be made to compensate for the longitudinal heat expansion thereof. lf separate exhaust pipes are provided for each individual cylinder or group of cylinders, either led separately or within a common casing to the exhaust turbine, the expense and complexity or" the construction problem is multiplied, and, especially with regard to engines having a V-shaped arrangement of cylinders, the question of adequate space becomes important.

According to the invention, however, an exhaust pipe construction is provided to be assembled from a plurality of substantially identical or similar individual units mounted in end-toend relation, with the length of each unit corresponding approximately to the distance between the axes of adjacent cylinders, and with each unit comprising a plurality of separate spirally congured gas conducting channels. Furthermore, each unit is a substantially complete entity, including an individual water jacket, so that interchange or replacement of the single unit is quite readily accomplished, and the cost and complexity of construction reduced.

lt is accordingly one object of this invention to provide an exhaust pipe construction of the character described having a plurality of separate units including integral internal gas channels for mounting in end-to-end relation to form the exhaust pipe.

A further object of this invention is to provide at `the adjacent ends of such units and their channels means for compensating for longitudinal thermal expansion movement thereof with respect to each other .and for maintaining a gas-tight joint at the junctures' of the separate channels in each unit during longitudinal heat expansion movement thereof.

Another object of this invention is to provide,in an exhaust pipe of the character described, a plurality of readily interchangeable units each of which has individual cooling means and a number of separate exhaust gas channels.

Other objects and advantages of the present invention will be apparent from the following description, the accompanying drawing and the appended claims.

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In the drawing,

Fig. 1 shows a longitudinal section pipe embodying the invention;

Fig. 2 is a transverse section on the line II-II of Fig. l on an enlarged scale;

Fig. 3 is a section on the line III-III of Fig. 2 on an enlarged scale; j

Fig. 4 is a detail of the juncture of two individual units, in longitudinal section and on an enlarged scale; and Fig. 5 is a transverse section along the line of Fig. 1. i

Referring to the drawing, a preferred embodiment of this invention is illustrated as an exhaust pipe construction particularly adapted to an eight cylinder Vftype internal combustion engine. The exhaust pipe (Fig. 1) comprises a plurality of individual units 1 and 2 which are substantially similar to each other. Each of the units 1 and 2 has an outer casing or jacket S within which are a plurality of integral longitudinal partitions 6, and each unit has a socket or connection 7 through each of which exhaust gases of two of the eight cylinders are introduced. It will be noted that the length of the individual units 1 and 2 corresponds approximately to the distance between the axes of adjacent cylinders.

In the illustrated embodiment, the cross section of the outer casing 5 is divided into four separate channels by the partition 6-i.e., one channel for each pair of cylinders. Thus, considering the cylinders tiring or exhausting in pairs, the exhaust impulses are led from each cylinder or group of cylinders to the exhaust gas turbine (not shown) through a separate channel within the casing 5 without admixture or interference with the exhaust gas impulses of other cylinders tiring and exhausting at a dilerent moment. It will be understood, of course, that the number of separate channels formed by partitions 6 may be varied and depends upon the number of different cylinders and/or groups of cylinders which tire and exhaust at different moments.

The internal partition 6 of each unit 1 and 2 is preferably congured as indicated in Fig. 1 to form the separate channels having a substantially spiral configuration for a portion of the length of 4the unit and a substantially ilat conliguration for the remainder of the length. As indicated in Fig. l, the units l and l2 are assembled in end to end relation to form" the exhaust pipe construction with the spiral channel ends of each unit pointing in opposite directions. The extent of the spiraling is preferably determined by the number of in dividual channels within each unit. In the illustrated embodiment, there being four channels, the extent of the annular displacement of a given channel at one end `of a unit with respect to the position of that same chan nel at the opposite end of the unit amounts to approximately but with a three-channel unit, such displacement preferably would amount to etc. VFor sim plicity of` construction, as noted in Figs. 3 and 4, the outer casing 5 and its integral internal partitions 6 are preferably cast from a single piece of heat resistant steel.

As 'shown more particularly in Fig. 4, adjacent ends ofthe outer casing 5 of each unit 1 or 2 are provided with an interlitting sliding or telescoping` joint including an outer portion 21*dimensioned for sliding interitting engagement around the opposite end 22 of the outer casing S. This arrangement provides a substantially gas-tight seal or joint between adjacent units while permitting for longitudinal thermal expansion movement of the individual units with respect to each other. Internal sealing members 8 are provided for separately sealing the individual gas channels at the junctures thereof between adjacent units, This member 8 is rotatably xed to a central through an exhaust assauts boss 9 at one end ofthe internal partition 6 as Vby means of a bolt 23, while the opposite face of sealing member 8 interftts slidably with a groove l@ in the opposite end of the internal partitions 6 to provide a gasltight joint ldes'pite longitudinal thermal expansion movement ot the individual units relative to each other. Also the rotatability of the member 8 about the bolt 23 aids in elim inating and equalizing any production inaccuracies of the intertttingunits or the partitions 6 therein.

The outer casing of each unit is 'surrounded with a layer 11 of heat insulating material and, outside layer '11, a Water jacket l2 for coolant circulation. Jacket i2 is formed as a double tube on each unit l and 2 sealed at each end with a Welded flange i3. Flange 13 also serves to connect the individual units l. and 2 as by means Vof bolts 14. The vwater jacket on eachlunit l or 2 is preferablyindependent of water jackets on 'other units, and `isprovided with two inlets 15, a` gutter 16and a discharge opening 17 for 'coolant circulation. The exhaust connecting sockets 7 to the individual cylinders through which exhaust gases are introduced from the.. individual cylinders are likewise-surrounded 4by the water jacket which is sealed around'socket 7 by asealing iiange 18 which also servesk as a means for connecting the socket 7 to the individual cylinder connections 19 as-by means of -bolts or screws (not shown) in known manner.

As will be apparent from the foregoing description, developing an exhaust `pipe construction in this manner and fastening it to the internal combustion engine primarily at water jacketed portions thereof permits the outer jacket S and its internal partitions 6 to shift axially in each unit as necessitated by thermal expansion, while the water jacket 12 and the connections 1S to the cylinder outlets are not subject to substantial heat expansion movement because of the insulation and cooling. For easier production of the water jacket l2, it preferably consists of four semicylindrical parts which are Welded together around the sealing flanges 1S and 13, as well as along longitudinal seams 20, to form a water-tight double pipe. Because of the individuality of the water jackets l2 in each unit It and 2 and the interconnection thereof by the bolts 14 through flanges 13, the exhaust pipe is formed from a plurality of complete individual units each substantially free of joints or areas for gas or coolant leakage into or out of the pipe. At one end of the illustrated embodiment, a water cooled connection ring 24 is shown for connection to an exhaust gas turbine, while the oppo- 'site end of the pipe is sealed 0E by a suitably insulated cover 25.

It will accordingly be seen that, by the foregoing, an exhaust pipe construction is provided for multi-cylinder internal combustion engines in which the exhaust impulses from individual cylinders or groups of cylinders are separately led to an exhaust gas turbine, and yet provision is made for longitudinal heat expansion of the yheated portions of the exhaust pipe, as well as for the ready repair and/or replacement of the individual seltcontained units thereof.

While the forms of apparatus herein describedconstitute preferred embodiments of the invention, it is to be understood that the invention is not limited to Vthese precise forms of apparatus, and that changes Ymay be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. An exhaust pipe construction for multicylinder internal combustion engines comprising in combination a plurality of similar individual units for mounting in endto-end relation to form said pipe, an outer casing in each said unit, a plurality of internal longitudinal partitions defining Within said casing a plurality of separate longitudinal passages, said partitions being substantially planar throughout approximately one-half the length of each said unit and helically configured throughout the remaining portions of the length of each said unit, and means for mounting said units in end-to-end relation with vsaid helically configured channel portions of adjacent units tacin in opposite directions, said mounting means-including means on adjacent ends of said casing and said partitions for compensating for longitudinal thermal expansionmovement of said units with respect to each other.

2. An exhaust pipe construction for multicylinder internal combustion engines comprising in combination a plurality of identical individual units for mounting in end-to-end relation to form said pipe, an outer casing on each said unit, a plurality of internal longitudinal parti tions defining within said casing'a plurality of separate longitudinal pa-ssages,said partitions being substantially straight throughout a substantial portion of the length of each said unit and helically congured throughout the remaining portion of the length of eachsaid unit, means for mounting saidunits in end-to-end relation in pairs with said helicalty configured portions faced together in each said pair of units, and means for mounting a plurality of said pairs of units in end-toend relation with said straight portionsV of said partitions therein faced together, said mounting means including means on adjacent ends of each said casing and said partitions for compensating for longitudinal thermal expansion movement of said units with respect to each other.

3. An exhaust pipe construction as recited in claim 2 in `which the length of each said individual unit corrcspouds approximately to the distance between the exhaust outietsof adjacent cylinders of said engine and said individual units including means for introducing the exhaust gas of dierent cylinders into different ones of said separate longitudinal passages.

4. An exhaust pipe construction as recited in claim 2 including inteltting sealing members on adjacent ends of said individual units for maintaining a substantially gas-tight seal between adjacent units during longitudinal thermal expansion movement thereof with respect to each other.

5. An exhaust pipe construction as recited in claim 2 including individual and separate water jacket means for each said individual unit.

6. An exhaust pipe construction as recited in claim 2 including individual water jacket means around each unit substantiallyindependent of the water jackets on other said units, said water jacket means including means for coupling said units in end-to-end relation and means for mounting said units on said engine.

References Cited in the le of this patent UNITED STATES PATENTS