Title of Invention

COOLING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE

Abstract

This invention relates to novel cooling system for an internal combustion engine comprising of radiator, coolant pump, coolant distribution rail, a cylinder head with two or more layered coolant jackets, a cylinder block, coolant collector rail and a thermostat, wherein said coolant distribution rail is connected to said cylinder head, and said coolant distribution rail is provided with single inlet and plurality of outlets, said outlets are connected to individual cylinders of the cylinder head, said cylinder head is provided with two layers of coolant jackets one at top and another at bottom, said top layer coolant jacket is in interface with all cylinders, said bottom layer is provided with plurality of coolant jackets, one for each cylinder, without any interface in-between them, said top layer coolant jacket is connected to the individual jackets of the bottom layer through a central coolant passage provided around each injector, said all bottom layer coolant jackets are connected to the said cylinder block through respective individual passages, said cylinder block is provided with circumferential cooling jackets around cylinders, said circumferential jackets are further connected to the collector rail provided on opposite side of the said cylinder block, said collector rail is connected to the said radiator through thermostat and a method of cooling internal combustion diesel engine wherein the cooled coolant from the radiator is circulated to the cylinder head first and then circulated to the cylinder block. In the conventional system, cooled coolant is circulated to the cylinder block first and then to the cylinder head.

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION Novel cooling system for an internal combustion engine and method of cooling thereof APPLICANTS TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India INVENTORS Mr.Suryakant R.Gore and Mr.Saravanaraja T. both Indian Nationals of TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention relates to internal combustion engine and more particularly to the cooling system and method for cooling cylinder head and cylinder block of internal combustion engine. BACKGROUND OF INVENTION In internal combustion engines, during the combustion lot of heat energy is generated. Due to this, temperature of the components which come in the vicinity of combustion increases significantly. Materials used for these components can withstand only up to certain temperatures without loosing its mechanical strength below acceptable limits. Hence, these parts need to be cooled continuously to keep the temperatures within the limit. Main components which need to be cooled are the cylinder head and cylinder block. Basically cooling is done by the circulation of cooling fluid in passages or cooling jackets formed in the cylinder head and in the cylinder block. Fig 1, schematic layout, explains about the conventional cooling system. The major components related to the cooling system are coolant pump, cylinder block, cylinder head and Radiator. Coolant pump is used to pump the coolant from the radiator outlet to the cylinder block to cool the cylinders and then to the cylinder head through various coolant passage connections between cylinder block and cylinder head. Basically coolant flows in the upwards direction i.e., from cylinder block to cylinder head. Hot coolant from the cylinder head is collected in a passage and then sent to radiator via thermostat. This arrangement is in general, used for all liquid cooled internal combustion engines. Basic drawback of the above system is, since the coolant moves in the upward direction from cylinder block to cylinder head, the bottom deck comprising of the flame deck and valve bridges of the cylinder head are not cooled effectively, i.e., coolant does not flow uniformly and effectively over these thermally critical areas. As the coolant flows from the crankcase to the cylinder head through multiple openings from the cylinder block and hot coolant tends to rise up, thus preventing effective cooling of the bottom deck and valve bridges in the cylinder head which are very critical. Hence the conventional cooling system can be used only for engines where the thermal load is moderate / low and durability requirement is also low. In order to overcome the above drawbacks the said invention is devised. OBJECTS OF INVENTION The main object of this invention is to provide a novel cooling system for higher powered internal combustion engines, which can be easily accommodated within the minimum space. Yet another object of this invention is to provide a novel cooling system for internal combustion engines which will be able to give uniform cooling for all the individual cylinders. Yet another object of this invention is to provide a novel cooling system for internal combustion engines which will be simple in construction and cost effective. BRIEF DESCRIPTION OF INVENTION Novel cooling system for an internal combustion engine in accordance with this invention basically comprises of a radiator, coolant pump, oil cooler, coolant distribution rail, a cylinder head with two or more layered coolant jackets, a cylinder block, a coolant collector rail and a thermostat. Said Coolant pump inlet is connected to the radiator outlet. Outlet of said coolant pump is connected to the coolant passage provided in the said cylinder block through oil cooler. Said cylinder head is provided with coolant passage and is mounted on said cylinder block; during normal operation said passage of cylinder head comes in contact with passage of said cylinder block. Said coolant distribution rail is connected with said passage of cylinder head, and is also provided with plurality of outlets and are connected to individual cylinders on the cylinder head. A gasket is provided in between coolant distribution rail outlets and the said cylinder head. Said cylinder head is provided with two layers of coolant jackets one at top and another at bottom. Said top layer coolant jacket is in interface with all cylinders. Said bottom layer is provided with plurality of coolant jackets for each cylinder, without any interface in-between them. Said coolant jacket from top layer is connected to the individual jackets of the bottom layer through a central coolant passage provided around each injector. Said all bottom layer coolant jackets are connected to the said cylinder block through respective individual passages. Said cylinder block is provided with circumferential cooling jackets around cylinders, said circumferential jackets are further connected to the collector rail provided on opposite side of the said cylinder block. Said collector rail is connected to the said radiator through thermostat. In operation coolant pump, pumps the coolant from radiator to the cylinder block passage through oil cooler. Said oil cooler is used to reduce the temperature of engine lubricating oil. Coolant from said passage flows to corresponding passage provided in the cylinder head, from where the coolant flows to the coolant distribution rail. From coolant distribution rail, coolant flows into the top coolant layer provided in the cylinder head. This flow is regulated by the variation in the gasket flow areas provided at outlets of coolant distribution rail. Coolant flow is regulated to achieve uniform distribution of coolant to the top layer of the coolant jacket. From top layer coolant jacket coolant flows to the individual bottom layer coolant jacket through individual passages provided at the centre of each cylinder. Since coolant flows from top jacket to the bottom jacket through a single opening, coolant is forced on the flame deck and valve bridges so that they are cooled effectively. Coolant then flows from cylinder head to the cylinder block through the respective passages. Coolant in the cylinder block is made to pass around the cylinders through circumferential coolant passages provided around cylinders to achieve uniform cooling of cylinders before it is collected in the collector rail. From collector rail coolant flows to the radiator through the thermostat. BRIEF DESCRIPTION OF DRAWINGS Fig 1 shows schematic layout of the conventional cooling system. Fig 2 shows schematic layout of the cooling system in accordance with this invention. Fig 3 shows sectional view of cylinder head with top and bottom layer cooling jackets Fig 4 shows sectional view of cylinder head with bottom layer cooling jacket, coolant passage in flame deck /valve bridges of the cylinder head Fig 5 shows the sectional view of the cylinder block with circumferential coolant passage. DESCRIPTION OF PREFERRED EMBODIMENTS: Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same. Referring to figures 2 to 5: The Schematic layout of the cooling system is shown in Figure-2. This cooling system consists of coolant pump (1), cylinder block (2), oil cooler (3), coolant passage in the cylinder block (4), cylinder head (5), coolant distribution rail (6), coolant collection rail (7), thermostat (8) and radiator (9). Figure -3 shows the vertical sectional view of the cylinder head (5) with top layer of the coolant jacket (10), the bottom layer coolant jacket (11), central coolant passage (13) around injector and the flame deck (12). Figure -4 shows the horizontal sectional view of the cylinder head (5) above the flame deck (12) with valve bridges (14) and the flow direction of coolant. Figure -5 shows the sectional view of the cylinder block (2) with coolant passage (15) which receives coolant from the cylinder head (5), cylinder wall (17), coolant passage (16) which connects the coolant jacket around each cylinder to the coolant collector rail (7). Novel cooling system for an internal combustion engine in accordance with this invention basically comprises of a radiator (9), coolant pump (1), oil cooler (3), coolant distribution rail (6), a cylinder head (5) with two or more layered coolant jackets (10,11), a cylinder block (2), coolant collector rail (7) and a thermostat (8). Said radiator (9) outlet is connected to the Coolant pump (1) inlet. Coolant pump assembly is mounted on the Cylinder block (2). Coolant pump (1) out let is connected to the coolant passage (4) provided in the said cylinder block (2). Said Oil cooler (3) is placed in the said cylinder block coolant passage (4). Coolant passage (4) is connected to the corresponding passage in the cylinder head (5). During normal assembly of the cylinder head (5) and cylinder block (2), the coolant passage (4) from the cylinder block (2) is connected to corresponding coolant passage in the cylinder head (5). Said coolant distribution rail (6) is mounted on the cylinder head (5). Coolant distribution rail (6) has one inlet and plurality of outlets equal to the number of cylinders. Outlets of the coolant distribution rail (6) are connected to the corresponding coolant passages provided on the cylinder head (5). A gasket is provided in-between coolant distribution rail outlets and the said cylinder head (5). Said cylinder head (5) is provided with two layers of coolant jackets one at top and another at bottom. Said top layer coolant jacket (10) is in interface with all cylinders. Said bottom layer (11) is provided with plurality of coolant jackets (not shown), one for each cylinder, without any interface in-between them. Said coolant jacket from top layer coolant jacket (10) is connected to the individual jackets of the bottom layer (11) through the central coolant passage (13) provided around each injector. Said central coolant passage (13) is connected to the coolant flow passages over the valve bridges (14) on the flame deck (12) of the cylinder head (5). Said coolant flow passages over the valve bridges (14) are part of bottom layer coolant jacket (11). Said all bottom layer coolant jackets (11) are connected to the corresponding coolant passages (15) provided in the said cylinder block (2). Said cylinder block (2) is provided with circumferential cooling jackets around cylinder walls (17) and are further connected to the collector rail ( 7) provided on opposite side of the said cylinder block (2) through the coolant passage (16) . Said collector rail is connected to the said radiator (9) through thermostat (8). In operation coolant pump (1), pumps the coolant from radiator (9) to the cylinder block passage (4) through oil cooler (3). Said oil cooler (3) is used to reduce the temperature of engine lubricating oil. Coolant from said passage (4) flows to corresponding passage provided in the cylinder head (5), from where the coolant flows to the coolant distribution rail (6). From coolant distribution rail (6), coolant flows into the top coolant layer (10) provided in the cylinder head (5). This flow is regulated by the variation in the gasket flow areas provided at outlets of coolant distribution rail. Coolant flow is regulated to achieve uniform distribution of coolant to the top layer (10) of the coolant jacket. From top layer coolant jacket (10), coolant flows to the individual bottom layer coolant jacket (11) through the central coolant passages (13) provided at the centre of each cylinder. Since all the coolant flows from top coolant jacket to the bottom coolant jacket through a single central coolant passage (13), coolant is designed to uniformly flow over all the valve bridges (14) on the flame deck (12). Valve bridges (14) on the flame deck (12) of the cylinder head (5) are the most thermally critical parts on the cylinder head (5). Hence by this cooling method, uniform, sufficient and effective cooling is achieved for the thermally critical parts on the cylinder head (5) and thus enhancing its durability. Coolant then flows from cylinder head (5) to the coolant passage (15) provided on the cylinder block (2). Thus received coolant in the cylinder block (2) is then made to pass around the cylinders through circumferential coolant passages provided around cylinders (17). Since the inlet (15) and outlet (16) coolant passages are located on the opposite sides of the cylinders (17), coolant uniformly flows around each cylinder (17). This is done to achieve uniform cooling of all cylinders (17) and in turn to reduce cylinder bore distortion due to thermal imbalance. Coolant from each cylinder is then connected to coolant collector rail (7) via coolant passages (16). All the coolant thus collected in the collector rail (7) flows to the thermostat (8) and then to the Radiator (9). The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof. WE CLAIM 1. A cooling system for an internal combustion engine comprising of radiator (9), coolant pump (1), coolant distribution rail (6), a cylinder head (5) with two or more layered coolant jackets (10, 11), a cylinder block (2), coolant collector rail (7) and a thermostat (8), wherein said coolant pump (1) drives coolant from the radiator (9) to the cylinder head, from where the coolant flows to the coolant distribution rail (6), said coolant distribution rail (6) is connected to said cylinder head (5), and said coolant distribution rail (6) is provided with single inlet and plurality of outlets, said outlets are connected to individual cylinders of the cylinder head (5), said cylinder head (5) is provided with two layers of coolant jackets one at top and another at bottom (10, 11), said top layer coolant jacket (10) is in interface with all cylinders, said bottom layer (11) is provided with plurality of the coolant jackets, one for each cylinder, without any interface in-between them, said top layer coolant jacket (10) is connected to the individual jackets of the bottom layer (11) through a central coolant passage (13) provided around each injector, said all the bottom layer (11) coolant jackets are connected to the cylinder block (2) through respective individual passages (15) for flow of the coolant from said cylinder head (5) to the cylinder block (2), said cylinder block (2) is provided with circumferential cooling jackets around the cylinders, said circumferential jackets are further connected to the collector rail (7) provided on opposite side of the cylinder block (2), said collector rail (7) is connected to the radiator (9) through the thermostat (8). 2. A cooling system for an internal combustion engine as claimed in claim 1, wherein coolant passage (4) from the coolant pump (1) to the coolant distribution rail (6) is integrally provided with the cylinder block (2) and the cylinder head (5). 3. A cooling system for an internal combustion engine as claimed in any of claims 1 and 2, wherein an oil cooler (3) provided in the coolant passage (4) of the cylinder block (2) to cool the engine lubricating oil. 4. A cooling system for an internal combustion engine as claimed in any of claims 1 to 3, wherein said coolant distribution rail (6) is provided with axial inlet and plurality of radial outlets. 5. A cooling system for an internal combustion engine as claimed in any of claims 1 to 4, wherein said coolant collector rail (7) is integrally provided with said cylinder block (2). 6. A cooling system for an internal combustion engine as claimed in any of claims 1 to 5, wherein said coolant pump inlet is connected to the radiator outlet, outlet of said coolant pump (1) is connected to the coolant passage (4) provided in the cylinder block (2). 7. A method of cooling internal combustion engine comprises the steps of: a. providing a circulating flow of coolant through a passage (4) in a cylinder block (2) and a coolant pump (1), b. pumping the coolant from a radiator (9) to the cylinder block passage (4) through an oil cooler (3) by said coolant pump, c. directing the coolant flow from said passage (4) to corresponding passage provided in a cylinder head (5), from where the coolant flows to a coolant distribution rail (6), d. directing the coolant flow from said coolant distribution rail (6) into top layer (10) of coolant jacket for achieving the uniform distribution of the coolant in the top layer, e. directing the coolant flow from the top layer coolant jacket (10) into individual bottom layer coolant jacket (11) through central coolant passage (13) provided at center of each cylinder, said coolant of the bottom layer coolant jacket (11) flows uniformly over all valve bridge (14) on flame deck (12) of said cylinder head (5), f. directing the coolant flow from the bottom layer coolant jacket (11) to coolant passage (15) provided on the cylinder block (2), said coolant in the cylinder block (2) is then made to pass around the cylinders (17) for achieving uniform cooling of all the cylinders (17), g. directing the coolant flow from each cylinder to a coolant collector rail (7) through a coolant passage (16), and h. directing the coolant flow from the collector rail (7) to a thermostat (8) and then again to the radiator (9). 8. The method of cooling internal combustion engine as claimed in claim 7, wherein the coolant from the cylinder head (5) flows to the cylinder block (2) through plurality of passages, one per cylinder, and the coolant is made to circulate around each cylinder and collected in the opposite side of the coolant entry. 9. The method of cooling internal combustion engine as claimed in any of claims 7 and 8 wherein, uniform coolant distribution to the coolant top layer in the cylinder head (5) is achieved by varying the gasket flow areas at the each outlets the of coolant distribution rail (6). ABSTRACT Novel cooling system for an internal combustion engine and method of cooling thereof This invention relates to novel cooling system for an internal combustion engine comprising of radiator, coolant pump, coolant distribution rail, a cylinder head with two or more layered coolant jackets, a cylinder block, coolant collector rail and a thermostat, wherein said coolant distribution rail is connected to said cylinder head, and said coolant distribution rail is provided with single inlet and plurality of outlets, said outlets are connected to individual cylinders of the cylinder head, said cylinder head is provided with two layers of coolant jackets one at top and another at bottom, said top layer coolant jacket is in interface with all cylinders, said bottom layer is provided with plurality of coolant jackets, one for each cylinder, without any interface in-between them, said top layer coolant jacket is connected to the individual jackets of the bottom layer through a central coolant passage provided around each injector, said all bottom layer coolant jackets are connected to the said cylinder block through respective individual passages, said cylinder block is provided with circumferential cooling jackets around cylinders, said circumferential jackets are further connected to the collector rail provided on opposite side of the said cylinder block, said collector rail is connected to the said radiator through thermostat and a method of cooling internal combustion diesel engine wherein the cooled coolant from the radiator is circulated to the cylinder head first and then circulated to the cylinder block. In the conventional system, cooled coolant is circulated to the cylinder block first and then to the cylinder head.

Documents:

385-MUM-2008-ABSTRACT(3-9-2014).pdf

385-mum-2008-abstract.doc

385-mum-2008-abstract.pdf

385-MUM-2008-ANNEXURE 1(3-9-2014).pdf

385-MUM-2008-CLAIMS(AMENDED)-(7-6-2012).pdf

385-mum-2008-claims.doc

385-mum-2008-claims.pdf

385-mum-2008-correspondence(14-3-2008).pdf

385-mum-2008-correspondence-received.pdf

385-mum-2008-description (complete).pdf

385-MUM-2008-DRAWING(3-9-2014).pdf

385-MUM-2008-DRAWING(7-6-2012).pdf

385-mum-2008-drawings.pdf

385-MUM-2008-FORM 1(3-9-2014).pdf

385-MUM-2008-FORM 13(3-9-2014).pdf

385-MUM-2008-FORM 13(7-6-2012).pdf

385-mum-2008-form 18(14-3-2008).pdf

385-mum-2008-form 2(title page)-(25-2-2008).pdf

385-MUM-2008-FORM 2(TITLE PAGE)-(3-9-2014).pdf

385-MUM-2008-FORM 3(3-9-2014).pdf

385-mum-2008-form 8(14-3-2008).pdf

385-mum-2008-form 9(14-3-2008).pdf

385-mum-2008-form-1.pdf

385-mum-2008-form-2.doc

385-mum-2008-form-2.pdf

385-mum-2008-form-26.pdf

385-mum-2008-form-3.pdf

385-MUM-2008-GENERAL POWER OF ATTORNEY(7-6-2012).pdf

385-MUM-2008-MARKED COPY(3-9-2014).pdf

385-MUM-2008-MARKED COPY(7-6-2012).pdf

385-MUM-2008-REPLY TO EXAMINATION REPORT(7-6-2012).pdf

385-MUM-2008-REPLY TO HEARING(3-9-2014).pdf

385-MUM-2008-SPECIFICATION(AMENDED)-(3-9-2014).pdf

385-MUM-2008-SPECIFICATION(AMENDED)-(7-6-2012).pdf