Title of Invention

"A CYLINDER HEAD WITH TWO-PLANE WATER JACKET"

Abstract

This invention relates to a cylinder head (10) for a combustion engine comprising at least two cylinders having a lower wall defining a firing deck (18) for each cylinder, and a hollow interior space forming a water jacket, the water Jacket having a lower cooling section adjacent the fring decks (18) comprising inlets (24) for receiving coolant and an upper transport section having at least one coolant outlet (72), the tower cooing section is connected to the upper transport section by channels (40) associated to the cylinders. An Injector nozzle sleeve (32) is provided in the channel (40) and in that an injector nozzle sleeve (32) is provided in the channel (40) and in that the channel (40) is formed between an inner surface (42) of a bore (16) provided for receiving the injactor nozzle sleeve (32).

Full Text

FIELD OF INVENTION The present invention relates to a cylinder head for an engine and in particular to a cylinder head having a two-plane water jacket in which a tower chamber at one plane through the head coole the fre deck of each cylider and a cross-flow passage spaced above the tower chambers in a second plane through the head directs coolant to an outfet Less variability in fre deck temperature results from separating the lower chambers of each cylinder from one another. Description of the Related Art Typical heavy-duty diesel engine design relies on water Jacket cooling that produces inconsistent cooling with higher temperature at one end of the cylinder head fire deck than at the other. This results from a water jacket in which coolant from the cylinder head fre deck furthest from the coolant outlet flows through the cylinder head past the fre decks of the remaining cylinders as the coolant travels toward the coolant outlet. The fire deck of the cylinder nearest the coolant outlet is hotter than the fre deck of the cylinder furthest from the coolant outlet. Summary of the Invention The present invention overcomes the inconsistent cooling of prior designs by providing a water jacket with two 'planes', or levels, of cooling in the cylinder head coolrtg circuit. The lower, drected cooing plane allows the coolant flowing into the cylider head from the cylinder block to cool the fre deck of only one cylinder. The coolant flows upward from the drected cooling plane to an upper transport plane contorting a cross-flow passage that drects the coolant outlet without the coolant interacting with the direct cooling of the fire deck area of any other cylinders. An upward flow channel is provided between the drected cooling plane and the upper transport plane. Preferably, this is an annular channel surrounding the injector noazle sleeve where access to the bore surface from outside the head is provided so that the surface of the bore can be machined. Since the bore surface ri ......„.„.„...„.„........„„..„....„.„...... the head and the injector nozzle sleeve surface are machined, the size of the channel is controlled by machine tolerances rather than by casting tolerances. This results in very little flow variation from one cylinder to the other, producing even cooling among the cylinders. Brief Description of the Drawings Fig. 1 is a vertical sectional view of the cylinder head showing the water jacket according to the present invention. Fig. 2 is a horizontal sectional view as seen substantial along the 2-2 of Fig. 1. Fig. 3 is a horizontal sectional view of the cylinder head of the present invention as seen from substantial line 3-3 of Fig. 1. Fig. 4 is a horizontal sectional view as seen substantial along the 2-2 of Fig. 1 of an alternative embodiment of the present invention. Fig. 5 is a perspective view of one end of the cylinder head. Description of the Preferred Embodiment With reference to Fig. 1, the cylinder head of the present invention is shown and labeled generally as 10. The cylinder head includes a cast iron body 12 that is cast with various passages therein in a known manner. The passages include the bores 14 for mounting bolts, bores 16 for a fuel injector, various passages for intake and exhaust valves (shown in Figs. 2 and 3) as well as passages forming a water jacket as described in greater detail below. A lower wall 20 forms the lower surface of the cylinder head that is the fire deck 18 for each cylinder. The fire deck forms the upper surface of the combustion chamber of each cylinder and is the portion of the cylinder head that requires the greatest cooling. The water jacket of the cylinder head provides directed cooling of the fire deck. The cylinder head of the present invention is provided with a water jacket arranged on two separate planes of the cylinder head. A lower directed cooling plane includes a lower chamber 22 shown in Figs. 1 and 2. The lower chamber 22 is immediately above a lower wall 20 of the cylinder head, the lower surface of which forms the fire deck 18. The lower chamber 22, as best seen in Fig. 2, is generally 2 rectangular in shape with inlets 24 in the four corners that receive coolant from the water jacket of the engine block. The lower chamber 22 surrounds the passage 26 for intake air and passages 28 for exhaust gas. While the invention is shown in an engine having two intake and two exhaust valves, it will be readily appreciated that the cylinder head of the present invention can be used with an engine having more or fewer valves. Several branches 34 extend from the lower chamber 22 that are formed by portions of the casting core that support the core in the casting mold. Branches 34 are closed by freeze plugs 48. The lower chamber 22 includes branches 30 for coolant flow between the passages 26 and 28 to the center of the lower chamber 22 surrounding the fuel injector nozzle sleeve 32. The nozzle sleeve 32 is fitted within the bore-16 and extends through to the fire deck 18. A seal 35 is formed at between the sleeve 32 and the lower wall 20 to prevent coolant from leaking from the water jacket lower chamber 22 into the combustion chamber therebelow. An O-ring seal 47 seals the upper end of the injector sleeve 32 to the cylinder head body 12. The water jacket further features an upper transport plane containing a cross-flow channel 36 and a connecting portion 38. The transport plane is connected to the lower cooling plane by an annular channel 40 formed between the injector sleeve 32 and the inner surface 42 of the injector bore 16. The cross-flow channel 36 is shown in Fig, 3 and directs coolant to a reservoir 52 at one end of the head. The cross-flow channel 36 is also formed with branches 54. The branches 54 are formed by portions of the casting core that support the core in the casting mold. These branches are closed by additional freeze plugs 58. Fig. 3 further shows the intake air and exhaust gas passages 26,28 through the head as well as the valve guides 64, 66 for the intake and exhaust valves. The coolant reservoir 52 includes a bypass outlet 68 for coolant flow when the engine is cold that is controlled by a thermostat, not shown, mounted in an upper opening 70 in the reservoir, shown in Fig. 5. The other opening 72 in the reservoir is the coolant outlet for heated coolant exiting the cylinder head 10 and is also thermostatically controlled. The reservoir 52 also has a freeze plug 74. Coolant flows into the cylinder head through the inlets 24 at the four comers of the lower chamber 22. The coolant flows radially inward, around the intake and exhaust passages 26, 28 to the center of the lower chamber 22 and to the flow channel 40. There, the coolant rises to the transport plane where the coolant passes through the connecting portion 38 to the cross-flow passage 36. Once in the cross-flow passage 36, the coolant is directed to the coolant outlet 72 at the end of the head. The lower, directed cooling plane of the water jacket includes a lower chamber 22 for each cylinder for a multi cylinder engine with the lower chambers 22 being separated from one another. A portion of a lower chamber 22 of an adjacent cylinder is shown in Fig. 2. The adjacent lower chambers 22 are separated by a wall 44 in the cast body 12. Coolant must flow from the lower chamber 22 through the flow channel 40 to the upper transport plane where the coolant is directed by the cross-flow channel 36 to the coolant outlet 72 (Fig. 5) at one end of the head. Coolant that is heated from the fire deck in one lower chamber 22 does not flow into another lower chamber 22. The fire deck for each cylinder receives the same degree of cooling, producing better control of the mean temperature in the lower chamber 22 and the fire deck 18. There is less variation in temperature among the fire decks of the multiple cylinders. One feature of the cylinder head that enhances control of the coolant flow through the head is that the surface 42 of the bore 16 is a machined surface as is the outer surface of the injector sleeve 32. The size of the flow channels 40 is controlled within machining tolerances instead of casting tolerances, whereby variation in the size of the flow channels 40 among the cylinders is more precisely controlled. The precise control of the size of the flow channel 40 is made possible by locating the channels in the injector bores where access from the outside is possible for machining the bore surface. An alternative embodiment of the invention is shown in Fig. 4. There, a small interconnecting passage 50 through the wall 44 is provided between adjacent lower chambers 22 on one or both sides. The interconnecting passages 50 are the result of connecting portions of the sand core that form the lower chambers 22 in the cast body 12. Greater stability of the core may be provided by connecting the lower chambers 22 with a small connector that forms the passage 50. With the coolant flow 4 as described above, little interchange of coolant from one lower chamber 22 to another is likely to occur. As a result, the benefits described above can be substantially achieved even with an interconnection between adjacent lower chambers 22. The invention should not be limited to the above-described embodiment, but should be limited solely by the claims that follow, 5 WE CLAIM 1. Cylinder head (10) for a combustion engine comprising at least two cylinders having a lower wall definig a firing deck (18) for each cylinder, and a hollow interlor space forming a water jacket, the water jacket having a lower cooIing section adjacent the firing decks (18) comprising inlets (24) for receiving coolant and an upper transport section having at least one coolant outlet (72), the lower cooling section is connected to the upper transport section by channels (40) associated to the cylinders, characterized in that an injector nozzle sleeve (32) is provided in the channel (40) and in that the channel (40) is formed between an inner surface (42) of a bore (16) provided for receiving the injector nozzle sleeve (32). 2. Cylinder head as clamed in claim 1, wherein the inner surface (42) of the bore (16) is machined. 3. Cylinder head as claimed in claim 1 or 2, wherein the cooling section comprises cooling chambers (22) adjacent the firing decks (18). 4. Cylinder head as claimed in claim 3, wherein the cooling chambers (22) are at least substantially separated from each other. 5. Cylinder head as claimed in claim any of the preceding claims wherein at least one of the channels (40) is formed by a bore having a preferably machined surface. 6 7 6. Cylinder head as claimed in any of the preceding claims wherein at feast one of the channels (40) is at least substantially ring shaped. This invention relates to a cylinder head (10) for a combustion engine comprising at least two cylinders having a lower wall defining a firing deck (18) for each cylinder, and a hollow interior space forming a water jacket, the water Jacket having a lower cooling section adjacent the fring decks (18) comprising inlets (24) for receiving coolant and an upper transport section having at least one coolant outlet (72), the tower cooing section is connected to the upper transport section by channels (40) associated to the cylinders. An Injector nozzle sleeve (32) is provided in the channel (40) and in that an injector nozzle sleeve (32) is provided in the channel (40) and in that the channel (40) is formed between an inner surface (42) of a bore (16) provided for receiving the injactor nozzle sleeve (32).

Documents:

00076-cal-2001-abstract.pdf

00076-cal-2001-claims.pdf

00076-cal-2001-correspondence.pdf

00076-cal-2001-description(complete).pdf

00076-cal-2001-drawings.pdf

00076-cal-2001-form-1.pdf

00076-cal-2001-form-18.pdf

00076-cal-2001-form-2.pdf

00076-cal-2001-form-26.pdf

00076-cal-2001-form-3.pdf

00076-cal-2001-form-5.pdf

00076-cal-2001-letters patent.pdf

00076-cal-2001-priority document.pdf