GB2033962A

GB2033962A - Inlet and Exhaust Passage Arrangements for a Turbocharged I.C. Engine

Info

Publication number: GB2033962A
Application number: GB7937451A
Authority: GB
Original assignee: Cummins Engine Co Inc
Current assignee: Cummins Inc
Priority date: 1978-11-07
Filing date: 1979-10-29
Publication date: 1980-05-29
Also published as: FR2441064A1; DE2943560A1; MX149248A; JPS5569723A; BR7906979A; IT1119431B; IN152511B; GB2033962B; SE7909144L; DE2943560C2; JPS5853173B2; ES485717A1; IT7969167A0

Abstract

The engine includes a block 20, Fig. 1, a head 22 fastened to the upper side of the block, a rocker housing 60 fastened to the upper side of the head 27, and a turbo-charger 61 mounted on on e side of the engine block. Air intake openings 86, Fig. 13, are formed in the upper surface of the head and air intake passages 122 are formed in the rocker housing. An air intake duct 63 and manifold 64 and exhaust manifold 62 connect to the turbocharger. The intake air passages of the head are formed and located to provide an advantageous heat transfer relation between the intake air and the engine ports, of which as described there are two intake and two exhaust to each cylinder, with a centrally situated fuel injector. <IMAGE>

Description

SPECIFICATION Internal Combustion Engine In a conventional diesel engine, the intake and exhaust passages formed in the head of the engine extend to manifolds fastened to opposite sides of the head. When such an engine is turbo-charged, the turbocharger is fastened to one side of the engine and an air duct extends from the compressor and over the top of the head to the intake manifold.

Such an arrangement has the disadvantages that the intake air duct across the top of the engine increases the overall engine height, and the length of the duct produces pressure losses.

It is a general object of the present invention to provide an improved internal combustion engine which avoids the foregoing disadvantages, and which also provides improved heat transfer characteristics in the head.

An engine in accordance with the present invention includes a head, a plurality of exhaust passages formed in said head, exhaust openings formed in one side of said head and communicating with said exhaust passages, a plurality of intake air passages formed in said head, intake openings formed in the upper surface of said head and communicating with said air passages, a rocker housing fastened to the upper surface of said head, a plurality of intake air passages formed in said housing, an intake air manifold fastened to said housing on the side of the engine which is adjacent the exhaust openings, said air passages of said housing communicating with said air manifold and with said intake openings of said head.

The following listed patents disclose internal combustion engines but none is considered to disclose the features described and claimed herein: Patent No. Patentee Date United States 1,132,255 E. G. Gunn 3/16/15 United States 3,094,976 C. H. May 6/25/63 United States 3,500,805 J. Reisacher 3/17/70 United States 3,973,548 A.Celli 8/10/76 Great Britain 839,955 British Patent 6/29/60 The foregoing and other advantages and features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying figures of the drawings, wherein: Fig. 1 is a view partially in section of an engine embodying the present invention; Fig. 2 is an exploded view of the engine shown in Fig. 1; Fig. 3 is a plan view of the head, taken on the line 3-3 of Fig. 2; Fig. 4 is a side view of the head, taken on the line 4-4 of Fig. 3; Fig. 5 is a fragmentary enlarged sectional view taken on the line 5-5 of Fig. 4; Fig. 6 is a view of the rocker housing, taken on the line 6-6 of Fig. 2;; Fig. 7 is a view taken on the line 7-7 of Fig. 6; Fig. 8 is a view taken on the line 8-8 of Fig. 6; Fig. 9 is a sectional view taken on the line 9-9 of Fig. 6; Fig. 10 is a view of a cover of the rocker housing; Fig. 11 is a view taken on the line 11-11 of Fig. 10; Fig. 12 is a sectional view taken on the line 12-12 of Fig. 10; Fig. 13 is an enlarged sectional view taken on the line 13-13 of Fig. 3, showing the head and the rocker housing; and Fig. 14 is an enlarged sectional view taken on the line 14-14 of Fig. 3.

The drawings illustrate the invention as applied to an in-line six cylinder diesel engine, but it should be understood that the principles of the invention may also be applied to other engine types, such as in-line four or eight cylinder engines, or V-type engines.

With reference to Figs. 1 and 2, the engine includes a block 20, a crankcase and pan 21, a head 22, and other parts to be described hereinafter. Formed in the block 20 are six in-line cylinders 23 through 28, the No. 1 cylinder 23 being shown in section in Fig. 1. While the cylinders 23 through 28 are shown as being without liners, it should be understood that such liners may be provided in accordance with conventional practice. Reciprocating within each of the six cylinders 23 through 28 is a piston 31 fastened to the upper end of a connecting rod 32. The six connecting rods 32 are rotatably fastened to a crankshaft 33 which in turn is rotatably supported on the block of the engine 20 by main bearings (not shown).The crankcase and pan 21 are secured to the underside of the block 20 and enclose various operating parts of the engine and form a sump or reservoir for the lubricant of the engine.

The head 22 of the engine is secured to the upper side of the block 20 by a plurality of bolts or studs 34 (Fig. 1) and the head supports, for each of the cylinders, a fuel injector 37, a pair of intake valves and a pair of exhaust valves. One intake valve 35 and one exhaust valve 36 are shown in Fig. 1, and the valve arrangement will be described in greater detail hereinafter. The injector 37 and the four valves of each cylinder are operated in synchronism with the other operating parts of the engine by a camshaft 38 that has a series of cams 39 mounted on it. For each cylinder, one cam operates the injector 37, another cam or cams operates the two intake valves and another cam or cams operates the two exhaust valves. For the injector 37, for example, a cam follower'mechanism 41 follows the outer surface of the associated cam 39.A push tube 43 connects the follower mechanism 41 with one end of a rocker arm 43 that is pivotally supported on a rocker shaft 44. The other end of the rocker arm 43 engages a link 46 that extends between the rocker arm 43 and a plunger of the injector 37. During operation of the engine, toward the end of each compression stroke of the piston 31 , the injector cam drives the push tube 43 upwardly, thereby forcing the link 46 and the injector plunger downwardly in order to inject fuel into the upper end of the cylinder 23 chamber.

Similar cam drives are provided for the intake and exhaust valves as previously mentioned, the intake valves being opened during the intake stroke of the piston 31 and the exhaust valves being opened during the exhaust stroke of the piston 31.

As shown in Fig. 1, the camshaft 38 is rotatably mounted near the upper end of the biock 20 and the cam follower mechanisms are located in an opening 47 formed in the block 20 adjacent the associated cylinder, one opening 47 being provided for each of the cylinders as shown in Fig. 2. A plurality of openings 48 are also formed in the head 22 above the openings 47, the cam follower mechanisms and the push tubes extending through the head openings 48. Fig. 3 is a top plan view of the head 22 and shows the openings 48.

With reference to Fig. 1, each of the valves 35 and 36 is mounted in an intake or exhaust port formed in the lower surface of the head 22, and each valve includes a valve part 51 secured to the lower end of a valve stem 52. A valve return spring 53 encircles the stem 52 and is mounted between the upper end of the valve stem 52 and the upper surface of the head 22, the springs 53 normally urging the valves upwardly to their closed positions. However, at the appropriate times in the cycle of the engine, the cam driven mechanisms force the valve stems 52 and the valve heads 51 downwardly to open the ports, as is well known to those skilled in the art.

Intake air and exhaust passages are formed in the head 22 and in a rocker housing 60 as will be described in more detail hereinafter, and a turbocharger unit 61 is provided to supply the intake air, the turbocharger 61 being driven by the exhaust gases of the engine. The turbocharger may be generally conventional in design and includes a turbine part that receives exhaust gases through an exhaust manifold formed by a plurality of ducts 62 connected between the head 22 and the turbine 61. The turbocharger 61 further includes a compressor part that supplies intake air under pressure to the engine cylinders, the compressor output being connected by a duct 63 to the adjacent side of the rocker housing 60. An aftercooler having a conventional design may be provided in a part 64 fastened to the side of the housing 60 or in a separate housing (not shown) between the duct 63 and the part 64.

It will be noted from Fig. 1 that the turbocharger unit 61 is mounted on one side of the engine and that the exhaust and intake ducts 62 and 63 connect with the head 22 and with the rocker housing 60 on the same side of the engine, and this is an important feature of the present invention as will be discussed in more detail hereinafter.

Figs. 3 to 5, 1 3 and 14 illustrate the construction of the head 22 in greater detail. The head 22 normally is a cast member and includes two end walls 71 and 72 (Figs. 3 and 4), and two outer side walls 73 and 74, the four walls 71 through 74 forming a generally rectangular configuration as shown in Fig. 3. The head further includes upper and lower walls 91 and 92 and, as shown in Fig. 5, an inner wall 76 that extends between the two end walls 71 and 72. The spaces between the outer wall 73 and the inner wall 76 form the openings 47 for the cam followers 41 and for the push tubes 43.

The arrangement of the intake and the exhaust ports and the injectors for the cylinders is best illustrated in Figs. 3 and 5. For each cylinder, indicated in dashed lines, the associated injector 37 is secured in the head 22 on the axial centerline of the cylinder. The lower end of the injector extends into the cylinder or combustion chamber as shown in Fig. 1 and as is well known to those skilled in the art.

For each cylinder there is also provided in the head 22 two exhaust ports 81 and two intake ports 82, the four ports 81 and 82 being spaced at 900 intervals around the injector and the axis or centerline of the cylinder. The valves 35 and 36 are, of course, mounted in the ports. For each of the cylinders, the centers of one of the ports 81 and one of the ports 82 are located in a vertical plane extending parallel to the side wall 73 and 74 and passing through the cylinder axis. The other two of the ports of each cylinder are in a vertical plane extending perpendicular to the first mentioned plane and passing through the cylinder axis. The port 82 of each cylinder which is closest to the side wall 73 is an intake port whereas the port 81 which is most closely adjacent the other side wall 74 is an exhaust port. The two cylinders 23 and 24 form a pair, the cylinders 25 and 26 form another pair, and the two cylinders 27 and 28 form still another pair, and the intake ports of each of the pairs of cylinders receive intake air through a common intake opening. The most closely adjacent ports of the pair of cylinders 23 and 24 are intake ports 82 and are on opposite sides of an intake opening 86 formed in the upper wall 91 of the head 22. Similarly, the most closely adjacent intake ports 82 of the pair of cylinders 25 and 26 are on opposite sides of an intake opening 87, and the most closely adjacent intake ports 82 of the pair of cylinders 27 and 28 are on opposite sides of an intake opening 88.Connecting the openings 86, 87 and 88 with the intake ports 82 are three separate intake air passages or chambers 93 formed within the head 22 between the upper and lower walls 91 and 92 (Figs. 5 and 13). The chamber or intake passages 93 for the pair of cylinders 23 and 24, for example, extends from closely adjacent the outer side wall 74 to the inner wall 76. As best shown in Fig. 5, the chamber 93 opens up in a fan-shape from the associated opening 86 and extends over or includes the areas adjacent the four intake ports 82 of the pair of cylinders 23 and 24 and around the adjacent sides of the injectors 37 of the two cylinders 23 and 24. The chamber 93 thus overlies approximately one-half the area of each of the cylinders 23 and 24 and is separated from the injectors by a thin wall.

While pairs of cylinders receive intake air from common passages, the two exhaust ports 81 of the cylinders are connected by separate passages 96 (Figs. 5 and 14) to exhaust openings 97 formed in the side wall 74 of the block 22. Each of the passages 96 extends around the associated ports 81, and it curves upwardly and toward the side wall 74. As previously mentioned and as shown in Fig. 1, the exhaust manifold is formed by a plurality of ducts which separate the exhaust cases in accordance with well known pulse turbine techniques. With specific reference to Fig. 14, a vertical hole 101 is formed through the head 22 above each exhaust port 81 and the stem of the associated valve 36 extends through the hole 101.Threaded holes 102 are formed in the side 74 of the head 22 for use in bolting the exhaust manifold ducts 62 to the side 74 of the head.

With reference to Fig.13, the air intake passage or chamber 93 for the pair of cylinders 23 and 24 communicates with the opening 86 and curves downwardly and away from the side wall 74. The head 22 includes internal walls having holes 103 formed in them for securing the head 22, using bolts, to the upper surface of the block 20, and internal cavities 104, and the intake air chamber 93 extends around these internal walls.

The engine further includes the previously mentioned rocker housing 60 which encloses the rocker arms and has intake air passages formed in it for conducting the intake air from the intake manifold 64 to the openings 86, 87 and 88 in the head. With specific reference to Figs.1,2 and 13, the rocker housing 60 includes a housing part 125 and a cover part 126. The part 125 is secured to the head 22 and is formed by a generally rectangular outer wall having substantially the same outer dimensions as the outer walls of the head. The side 110 of the housing wall is adjacent t6 the intake manifold 64 has a greater vertical height than the opposite side wall 111, and the upper surface of the housing part 125 slants downwardly from the wall 110 to the wall 111, the upper surface being indicated by the numeral 112.The lower surface 113 of the housing part 125 is generally horizontal and open as shown in Fig. 13.

With reference to Figs. 7 and 13, three intake air openings 11 6, 11 7 and 118 are formed in the side wall 110, these three openings 11 6 through 11 8 being adjacent the openings 86, 87 and 88, respectively. Internal walls 119, 120 and 121 (Figs. 6 and 13) are formed as part of the housing part 125 and from passages 1 22 which lead from the openings 11 6 to 11 8 to the openings 86 to 88. As best shown in Fig. 13, each passage 122 curves from the associated opening in the wall 110 inwardly and downwardly to the associated opening 86, 87 or 88.The intake air manifold 64 extends across and is secured to the side 110 of the rocker housing part 125 and encloses the three openings 11 6, 11 7 and 118, and consequently intake air flows from the ducts 63, through the three passages 122, into the three chambers 93, and to the air intake ports 82 of the six cylinders.

As is best shown in Fig. 13, the space between the outer wall 111 and the internal walls 119 is open and forms an enclosure for the rocker arms and for the upper ends of the valves and the injectors.

The cover part 126 is normally bolted to the upper side of the housing part 125. As shown in Figs. 1, 11 and 12, the rocker cover 126 is right angular in cross-section and when attached to the upper side of the housing part, completely encloses and covers the rocker arms. The rocker cover 1 26 includes end walls 127 in addition to the upper and side walls 128 and 129, and a number of internal reinforcing ribs 1 31. The construction of the rocker housing 60 in two parts is advantageous because it enables access to the rocker arm mechanisms and to the valves and the injectors without necessitating the complete removal of the rocker housing and disconnection of the housing from the intake manifold.

It will be apparent from the foregoing that an improved and novel engine construction has been provided. The turbocharger unit 61 is located on one side of the engine and the intake and exhaust manifolds are also located entirely on the same side of the engine. Such an arrangement makes it unnecessary to provide a long duct leading from the compressor of the turbocharger to the intake manifold which, in conventional engines, are located on opposite sides of the engine.

Claims

1. An internal combustion engine comprising a block having a plurality of engine cylinders formed therein, a head fastened to said block, and having a plurality of air intake and exhaust ports formed therein, said ports communicating with said cylinders, a turbocharger mounted on one side of said block and said head, a plurality of exhaust openings formed in said one side of said head, a plurality of exhaust passages formed in said head and communicating with said exhaust openings, a plurality of intake openings formed in the upper surface of said head, a plurality of first intake air passages formed in said head and communicating with said intake openings, a rocker housing fastened to the upper surface of said head, a plurality of second intake air passages formed in said rocker housing, intake air ducts connected to said turbocharger and to said housing on said one side of the engine which is adjacent the exhaust openings, said second air passages of said rocker housing communicating with said air ducts and with said intake openings of said head, and exhaust ducts on said one side and connecting said turbocharger with said exhaust openings.

2. An engine as in Claim 1, wherein each of said first intake air passages in said head communicates with the air intake ports of a pair of adjacent cylinders, each of said intake openings being formed between the associated pair of cylinders.

3. An engine as in Claim 2, wherein each of said first intake air passages of said head forms an enlarged chamber extending across approximately one-half of the upper surfaces of the pair of cylinders.

4. An engine as in Claim 2, wherein said exhaust passage of each cylinder is separate from the other exhaust passages.

5. An engine as in Claim 1, wherein said rocker housing includes a housing part and a cover part, said housing part being attached to said head and to said intake air ducts and having said second intake air passages formed therein, said housing part having an open upper side, and said cover part being secured to said housing part and extending across said open upper side of said housing part.

6. An engine as in Claim 1, wherein said plurality of intake openings are formed in the upper surface of said head.

7. An engine as in Claim 1, wherein each of said cylinders includes a pair of said air intake ports and a pair of said exhaust ports, each of said intake air passages communicating with two pairs of said air intake ports of adjacent cylinders.

8. An engine as in Claim 7, wherein each of said exhaust passages communicates with a pair of said exhaust ports of one of said cylinders, and each of said intake air passages extends between a pair of said exhaust passages.

9. An engine as in Claim 7, wherein said ports of said pairs of ports of each cylinder are arranged at generally 900 angular intervals, one of said exhaust ports being relatively close to said one side of said engine and one of said intake ports being relatively close to the other side of said engine, and the others of said intake and exhaust ports being intermediate said sides.

10. A head for an internal combustion engine, the engine including a plurality of cylinders formed in a block, said head being secured to the block and forming the upper side of said cylinders, an opening formed in said head substantially on the axis of each of said cylinders for receiving a fuel injector, four intake air and exhaust ports formed in said head for each of said cylinders, said four ports being arranged at substantially 900 angular intervals around said injector opening, said two intake air ports of each cylinder being adjacent each other and being adjacent the two intake air ports of the next adjacent cylinder, a chamber formed in head between a pair of said cylinders and in air flow communication with said intake air ports of said pair of said cylinders, and an air intake opening formed in the upper surface of said head above each of said chambers for receiving intake air.

11. A head as in Claim 10, and further including an exhaust passage formed in said head for each of said cylinders and connected to said pair of exhaust ports, said exhaust passages extending between said chambers and said air intake openings.

12. An internal combustion engine substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

13. Any novel feature or combination of features disclosed herein.