CA1062568A - Internal combustion engines - Google Patents
Internal combustion enginesInfo
- Publication number
- CA1062568A CA1062568A CA281,044A CA281044A CA1062568A CA 1062568 A CA1062568 A CA 1062568A CA 281044 A CA281044 A CA 281044A CA 1062568 A CA1062568 A CA 1062568A
- Authority
- CA
- Canada
- Prior art keywords
- region
- heat
- cooling
- internal combustion
- conducting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/26—Cylinder heads having cooling means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P3/00—Liquid cooling
- F01P3/12—Arrangements for cooling other engine or machine parts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/26—Cylinder heads having cooling means
- F02F1/36—Cylinder heads having cooling means for liquid cooling
- F02F1/38—Cylinder heads having cooling means for liquid cooling the cylinder heads being of overhead valve type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/14—Direct injection into combustion chamber
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F2001/244—Arrangement of valve stems in cylinder heads
- F02F2001/247—Arrangement of valve stems in cylinder heads the valve stems being orientated in parallel with the cylinder axis
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
Abstract
ABSTRACT
A structural unit for an internal combustion engine, including an engine region (for instance, a part of a cylinder head directly exposed to the cylinder firing zone) that requires direct cooling in use. Instead of applying the cooling to the region itself, it is applied to a separate structure with a connexion to the region, the section of the connexion corresponding in shape with that of the region itself. Both gaseous and liquid cooling of the structure are described.
A structural unit for an internal combustion engine, including an engine region (for instance, a part of a cylinder head directly exposed to the cylinder firing zone) that requires direct cooling in use. Instead of applying the cooling to the region itself, it is applied to a separate structure with a connexion to the region, the section of the connexion corresponding in shape with that of the region itself. Both gaseous and liquid cooling of the structure are described.
Description
This invention relates to units of structure for internal combustion engines, and in particular to regions of the engine structure that will be heated in use to such high temperatures that they require direct cooling. One typical application of the invention is thus to certain regions of the cylinder head above the surface directly exposed to the cylinder firing zonesO
It is customary to cool the cylinder blocks and heads of the internal combustion engines, especially diesel engines, by means of massive cooling water jackets surrounding the block and extensive water cooling passages formed within both the head and the block.
Proposals have recently been made to do away entirely with the customary jackets and to confine the passages to those regions of the structure surrounding the cylinder that are most in danger of overheating when in use. It has been found that other parts which normally run at unnecessarily low temperatures - due to the massive cooling provided by the normal jackets - are then adequately cooled by lateral flow of heat through the walls surrounding the cylinder.
In many diesel engines, only those regions of the cylinder head close to the injection nozzles, the valve guides and exhaust valve seats, and the valve bridge require direct cooling; those regions of the cylinder bore walls which lie closer to the cylinder head also need direct cooling.
Although cylinder blocks and heads can be mass-produced with restricted water passages around the danger zones to provide the ~k 106Z5~8 localised cooling just described, the machining of the passageways naturally adds to the cost of the units. Another consideration is that although the arrangements described have proved effective in controlling temperatures satis-factorily while removing less heat than normal, the control they provide over the heat removal process is far from complete. ~ne aspect of this is that the supply and return passages, as distinct from the local cooling passages proper, extract heat from regions which it is not desired to cool directly. Yet another consideration is that it is sometimes difficult to match the shape of the cool-ing passages proper with the parts they are to cool directly; for instance it is often easiest to machine an annular passage but if this is applied to the structure around a fuel injection nozzle or an exhaust valve seat, where the hot zone usually lies mostly to one side of the nozzle or seat rather than the other, the annulus will extend to the other, cooler side also and will remove heat unnecessarily from that side also.
The present invention provides scope for achieving a more accurate register between a positive cooling system and the regions requiring direct cooling.
According to the present invention there is provided a structural unit for an internal combustion engine comprising:- a deck defining a cylinder cover having an extending surface and a region within said surface less in area than said extending surface, said region having a sub-surface that is heated in use so as to require direct cooling, to prevent over-heating of said region; a heat-conducting structure; heat-conducting connection means between said deck region and said heat-conducting structure; and fluid-flow cooling means associated with said heat-conducting structure, whereby to remove heat conducted to it through said heat-conducting connection means from said region of said unit, and in which the section through said connection means at the location between said connection means and said deck matches in shape and -~ ~ -2-registers with said region Tequiring direct cooling to conduct heat from said region to said heat conducting structure, said region being under substantial influence from no other fluid flow cooling meansJ and said fluid flow cooling means providing only minimum cooling of said heat-conducting structure so as to prevent over-heating of said region.
The invention will now be described, by way of example, with refer-ence to the accompanying drawings in which:--2a-:.,,: , 106Z56#
Figure 1 is a transverse cross-section of a cylinder head of a multi-cylinder four-stroke diesel engine, on the line F-F in Figure 2;
Figure 2 is a section of the line B-B in Figure 1;
Figure 3 is a section on the line C-C in Figure 1;
Figure 4 is a section on the line A-A in Figure 5;
Figure 5 is a section on the line D-D in Figure 4, and Figure 6 is a section on the line E-E in Figure 4.
Figures 1 to 3 show an example of the engine using a liquid, namely water~ as coolant. A part of the lower surface 8' of the lower deck 8 of the cylinder head appertaining to each cylinder is exposed in use to the combustion zone of that cylinderO According to the invention heat is conducted away from certain regions of the upper surface 8" by a cooled heat-conducting structure3 ~hrough the connection region 3' in the plane BBo The plane of the section of Figure 1 includes the axis of the fuel injector housing 1 and is very close to the axis of a cylinder and of one of the columns 2 surrounding the several studs by which the cylinder head is attached to the cylinder blockO The heat-conducting structure is maintained at relatively low temperature bya flow of water which reaches it from a pump at one end of the engine via a supply manifold 4, passes through two drilled passages 5 and 6 and returns via the return manifold 7 to the end of the engine, where it is cooled by a radiator. The water extracts heat from structure 3 via the surfaces of the two manifolds as wéll as via the surfaces of the passages 5 and 6 though it will be appreciated that the temperature of the lower deck 8 is much higher than that of the upper deck 9 of the head9 so that the local heat transfer rates will be highest at the lower ends of the passages 5 and 60 In Figure 2 the air inlet port in deck 8 is seen at 10 and the air ex~aust port at 11. The position of the cylinder bore in relation to the cylinder head is indicated by 129 and the position of an offset combustion chamber bowl in the piston crown is indicated by 130 It is the cylinder head surface opposite this bowl that is most int~nsely heatedO All the stud columns 2 surrounding this cylinder are seen in sectionO The section ~-~ is taken just above deck 8 and shows the cross-section 14 of the connection region 39 between the cooled heat-conducting structure 3 and the deckO This section registers with the area of the deck : 15 that requires direct cooling to maintain satisfactory temperatures throughout the componentO This area includes the bridge between the air port 10 and the exhaust port llo It extends round most of that part of the air port 10 which lies above the combustion chamber bowl 13 and it extends somewhat further round the exhaust port because the exhaust valve seat receives more heatO The area also includes the whole of the area below the nozzle cap sealing washer 15 but it will be appreciated that the heat extracted from deck 8 on that side of the nozzle remote from the cylinder axis will be considerably less than by an annular water-cooling passage, while on the hotter side9 where more effeGtive cooling is necessary9 this is provided by the flow of water in passage 6~ It will be noted that the manifolds 4 and 7 fulfil an extra task of cooling the inlet and outlet valve guide housings that are situated between them.
As an example of the control of lateral heat flow to the directly-cooled region by choice of local thickness of the component, Figures 1 and 2 show in broken lines an optional depression 16 in the upper surface 8" of deck 8 which limits lateral flow of heat to the cooled structure 3 from that part of the deck below the air inlet passage, this being a region of the deck where in some cases the metal temperatures would otherwise be unnecessarily low.
Figure 3 shows the part of the cylinder head covering one cylinder, in the longitudinal plane of the valve axes~
~ igures 4 to 6 show another example of the invention1 using air 15 as the coolant fluid. Here what requires cooling is a region of the lower deck 30 of a cylinder head consisting of an upper part 21 and a lower part 22. The heat-conducting structure includes cooling fins 32 connected to the top surface 30l of deck 30~ parts of the lower surface 30ll of which are exposed in use to the combustion zones of the cylindersO Part 21 comprises upper decks 23 and 241 bridged by a number of cylinder head stud columns 25 and valve guides 26, and joined by sides 27 and 28 forming a box structure with projecting walls 29 which form the lower part of an enclosure for the valve levers and associated partsO Part 22 comprises the lower deck 30 25 and various projectionsO The two parts are located in relationship to one another by dowels and are clamped together and to the cylinder clock (not shown) by the cylinder head studs and nuts.
The two parts form a passage for the flow of cooling airO The passage comprises an inlet portion 31, a central portion in which 5 are mounted the cooling fins 32, one of which is seen9 and an outlet portion 33. Holes through the three decks and a seating at 34 are provided to accommodate a fuel injectorO The cooling fins 32 make contact with lower deck 30 over a limited area through a connection region including the raised portion 35 of the deck, and beyond this area the fins are separated from the deck by the air gaps 36 and 370 The area of raised portion 35 upon surface 30 l of lower deck 30 registers as nearly as possible with the area of the surfaoe region that needs direct cooling in order to maintain satisfactory temperatures throughout the componentO Were it preferred to mount fins 32 directly upon surface 30~ 9 instead of directly upon the raised portion 359 the envelope of the areas of contact between all the individual fins and the surface should substantially correspond to the cross-section of portion 350 Figure 5 shows the configuration of the air passage walls9 38 20 and 39, which act also as cooling fins swept by air on one side, and of two cooling fins 32 and 40 arranged above the cylinder bore (which is indicated by the broken line 41) one on either side of the injector seating 34, and dividing the space between the walls 38 and 39 into three passages, presenting six heat exchange surfacesO Inlet cooling 25 air approaching the fuel injector is channelled into the central passage and the remaining air passes through the outer passagesO
The minimum combined width of the flow passages9 passage walls and fins is equal to the minimum distance between the air inlet passage 42 and the exhaust passage 43 which is "siamesed" with the similar 5 passage 44 of the adjacent cylinder, these three passages being seen here in plan view. After passing the fins, the cooling air flows with little resistance to the outlet at the side of the cylinder head, since the outlet portion of the passage extends under the exhaust passage 430 The inlet and exhaust passages are made of heat-resistant steelO Figure 5 shows the outline 359 and thus the extentof the area of the raised portion 35 (Figure 4) of deck 30 constituting the link region through which direct cooling is appliedO
This area is similar in shape to the corresponding area requiring cooling in Figures 1 to 30 Cooling of the parts, such as 469 of the 5 raised portion 35 which would otherwise project beyond the cooled passage walls is improved by locally increasing the width of the passage walls near the deck 309 as indicated for example at 470 An air duct conveying air from a fan or other source (not shown) in known manner, and which may serve also to supply air for cooling the cylinder, is connected to the inlet portion 31 of the cylinder head air passage by means of studs mounted in tapped hol~s. 48 (Figure 4) . After passing through the outlet portion 33 of the passage, the cooling air escapes in the normal way directly to the atmosphere~
The section of Figure 6, which shows the part of the cylinder head covering one cylinder, is taken in the longitudinal plane of the valve axes.
It will be noted that when air is used as the coolant, the cool body (i.e. heat-conducting structure) applied to the selected areas of the deck from which heat is to be extracted comprises essentially a block of metal in which are formed air flow pas~ages instead of the water flow passages of the water-cooling version. The cool body thus becomes a number of fins, the outer fins conveniently forming the walls of the air flow passage through the cylinder head.
The main featùres distinguishing such an arrangement from the normal use of cooling fins in air-cooled engines are that the fins are attached to the limited selected areas corresponding withthe regions to be cooled, and that their projections beyond these areas are separated from the cylinder head deck by air gaps. Another difference is that in known designs, cooling fins are placed all over the cylinder head and only a fraction of the air passes over the critical central regions, so that these critical regions are cooled largely by lateral heat flow through the deck. To maintain the critical regions at acceptable temperatures by this means, it is necessary to cool the surrounding regions to well below acceptable temperatures, thus removing heat unnecessarily.
In another alternative to the use of the r-aised portion 35 in Figures 3-6 the three air passages between the fins, best seen in Figure 6, may be carried much lower so that in the connection region between fins and deck the thickness of the deck 30 is reduced to one half or less of that existing elsewhere, the fins and the structure of upper decks 23~ 24 providing adequate support of the deck against cylinder gas pressure; The choice will depend on the extent to which the cooling effect needs to be localised in a particular application.
As an alternative to the fin design shown in Figure 6, the fins may slope outwards to make more use of the space between the two gas passages and the two valve guides, thus providing more area for air flow. Fins may also be attached directly to the valve guides to cool them. The two-part construction facilitates casting of the fins, which would be further assisted by tapering the fins in accordance with common practiceO
It is customary to cool the cylinder blocks and heads of the internal combustion engines, especially diesel engines, by means of massive cooling water jackets surrounding the block and extensive water cooling passages formed within both the head and the block.
Proposals have recently been made to do away entirely with the customary jackets and to confine the passages to those regions of the structure surrounding the cylinder that are most in danger of overheating when in use. It has been found that other parts which normally run at unnecessarily low temperatures - due to the massive cooling provided by the normal jackets - are then adequately cooled by lateral flow of heat through the walls surrounding the cylinder.
In many diesel engines, only those regions of the cylinder head close to the injection nozzles, the valve guides and exhaust valve seats, and the valve bridge require direct cooling; those regions of the cylinder bore walls which lie closer to the cylinder head also need direct cooling.
Although cylinder blocks and heads can be mass-produced with restricted water passages around the danger zones to provide the ~k 106Z5~8 localised cooling just described, the machining of the passageways naturally adds to the cost of the units. Another consideration is that although the arrangements described have proved effective in controlling temperatures satis-factorily while removing less heat than normal, the control they provide over the heat removal process is far from complete. ~ne aspect of this is that the supply and return passages, as distinct from the local cooling passages proper, extract heat from regions which it is not desired to cool directly. Yet another consideration is that it is sometimes difficult to match the shape of the cool-ing passages proper with the parts they are to cool directly; for instance it is often easiest to machine an annular passage but if this is applied to the structure around a fuel injection nozzle or an exhaust valve seat, where the hot zone usually lies mostly to one side of the nozzle or seat rather than the other, the annulus will extend to the other, cooler side also and will remove heat unnecessarily from that side also.
The present invention provides scope for achieving a more accurate register between a positive cooling system and the regions requiring direct cooling.
According to the present invention there is provided a structural unit for an internal combustion engine comprising:- a deck defining a cylinder cover having an extending surface and a region within said surface less in area than said extending surface, said region having a sub-surface that is heated in use so as to require direct cooling, to prevent over-heating of said region; a heat-conducting structure; heat-conducting connection means between said deck region and said heat-conducting structure; and fluid-flow cooling means associated with said heat-conducting structure, whereby to remove heat conducted to it through said heat-conducting connection means from said region of said unit, and in which the section through said connection means at the location between said connection means and said deck matches in shape and -~ ~ -2-registers with said region Tequiring direct cooling to conduct heat from said region to said heat conducting structure, said region being under substantial influence from no other fluid flow cooling meansJ and said fluid flow cooling means providing only minimum cooling of said heat-conducting structure so as to prevent over-heating of said region.
The invention will now be described, by way of example, with refer-ence to the accompanying drawings in which:--2a-:.,,: , 106Z56#
Figure 1 is a transverse cross-section of a cylinder head of a multi-cylinder four-stroke diesel engine, on the line F-F in Figure 2;
Figure 2 is a section of the line B-B in Figure 1;
Figure 3 is a section on the line C-C in Figure 1;
Figure 4 is a section on the line A-A in Figure 5;
Figure 5 is a section on the line D-D in Figure 4, and Figure 6 is a section on the line E-E in Figure 4.
Figures 1 to 3 show an example of the engine using a liquid, namely water~ as coolant. A part of the lower surface 8' of the lower deck 8 of the cylinder head appertaining to each cylinder is exposed in use to the combustion zone of that cylinderO According to the invention heat is conducted away from certain regions of the upper surface 8" by a cooled heat-conducting structure3 ~hrough the connection region 3' in the plane BBo The plane of the section of Figure 1 includes the axis of the fuel injector housing 1 and is very close to the axis of a cylinder and of one of the columns 2 surrounding the several studs by which the cylinder head is attached to the cylinder blockO The heat-conducting structure is maintained at relatively low temperature bya flow of water which reaches it from a pump at one end of the engine via a supply manifold 4, passes through two drilled passages 5 and 6 and returns via the return manifold 7 to the end of the engine, where it is cooled by a radiator. The water extracts heat from structure 3 via the surfaces of the two manifolds as wéll as via the surfaces of the passages 5 and 6 though it will be appreciated that the temperature of the lower deck 8 is much higher than that of the upper deck 9 of the head9 so that the local heat transfer rates will be highest at the lower ends of the passages 5 and 60 In Figure 2 the air inlet port in deck 8 is seen at 10 and the air ex~aust port at 11. The position of the cylinder bore in relation to the cylinder head is indicated by 129 and the position of an offset combustion chamber bowl in the piston crown is indicated by 130 It is the cylinder head surface opposite this bowl that is most int~nsely heatedO All the stud columns 2 surrounding this cylinder are seen in sectionO The section ~-~ is taken just above deck 8 and shows the cross-section 14 of the connection region 39 between the cooled heat-conducting structure 3 and the deckO This section registers with the area of the deck : 15 that requires direct cooling to maintain satisfactory temperatures throughout the componentO This area includes the bridge between the air port 10 and the exhaust port llo It extends round most of that part of the air port 10 which lies above the combustion chamber bowl 13 and it extends somewhat further round the exhaust port because the exhaust valve seat receives more heatO The area also includes the whole of the area below the nozzle cap sealing washer 15 but it will be appreciated that the heat extracted from deck 8 on that side of the nozzle remote from the cylinder axis will be considerably less than by an annular water-cooling passage, while on the hotter side9 where more effeGtive cooling is necessary9 this is provided by the flow of water in passage 6~ It will be noted that the manifolds 4 and 7 fulfil an extra task of cooling the inlet and outlet valve guide housings that are situated between them.
As an example of the control of lateral heat flow to the directly-cooled region by choice of local thickness of the component, Figures 1 and 2 show in broken lines an optional depression 16 in the upper surface 8" of deck 8 which limits lateral flow of heat to the cooled structure 3 from that part of the deck below the air inlet passage, this being a region of the deck where in some cases the metal temperatures would otherwise be unnecessarily low.
Figure 3 shows the part of the cylinder head covering one cylinder, in the longitudinal plane of the valve axes~
~ igures 4 to 6 show another example of the invention1 using air 15 as the coolant fluid. Here what requires cooling is a region of the lower deck 30 of a cylinder head consisting of an upper part 21 and a lower part 22. The heat-conducting structure includes cooling fins 32 connected to the top surface 30l of deck 30~ parts of the lower surface 30ll of which are exposed in use to the combustion zones of the cylindersO Part 21 comprises upper decks 23 and 241 bridged by a number of cylinder head stud columns 25 and valve guides 26, and joined by sides 27 and 28 forming a box structure with projecting walls 29 which form the lower part of an enclosure for the valve levers and associated partsO Part 22 comprises the lower deck 30 25 and various projectionsO The two parts are located in relationship to one another by dowels and are clamped together and to the cylinder clock (not shown) by the cylinder head studs and nuts.
The two parts form a passage for the flow of cooling airO The passage comprises an inlet portion 31, a central portion in which 5 are mounted the cooling fins 32, one of which is seen9 and an outlet portion 33. Holes through the three decks and a seating at 34 are provided to accommodate a fuel injectorO The cooling fins 32 make contact with lower deck 30 over a limited area through a connection region including the raised portion 35 of the deck, and beyond this area the fins are separated from the deck by the air gaps 36 and 370 The area of raised portion 35 upon surface 30 l of lower deck 30 registers as nearly as possible with the area of the surfaoe region that needs direct cooling in order to maintain satisfactory temperatures throughout the componentO Were it preferred to mount fins 32 directly upon surface 30~ 9 instead of directly upon the raised portion 359 the envelope of the areas of contact between all the individual fins and the surface should substantially correspond to the cross-section of portion 350 Figure 5 shows the configuration of the air passage walls9 38 20 and 39, which act also as cooling fins swept by air on one side, and of two cooling fins 32 and 40 arranged above the cylinder bore (which is indicated by the broken line 41) one on either side of the injector seating 34, and dividing the space between the walls 38 and 39 into three passages, presenting six heat exchange surfacesO Inlet cooling 25 air approaching the fuel injector is channelled into the central passage and the remaining air passes through the outer passagesO
The minimum combined width of the flow passages9 passage walls and fins is equal to the minimum distance between the air inlet passage 42 and the exhaust passage 43 which is "siamesed" with the similar 5 passage 44 of the adjacent cylinder, these three passages being seen here in plan view. After passing the fins, the cooling air flows with little resistance to the outlet at the side of the cylinder head, since the outlet portion of the passage extends under the exhaust passage 430 The inlet and exhaust passages are made of heat-resistant steelO Figure 5 shows the outline 359 and thus the extentof the area of the raised portion 35 (Figure 4) of deck 30 constituting the link region through which direct cooling is appliedO
This area is similar in shape to the corresponding area requiring cooling in Figures 1 to 30 Cooling of the parts, such as 469 of the 5 raised portion 35 which would otherwise project beyond the cooled passage walls is improved by locally increasing the width of the passage walls near the deck 309 as indicated for example at 470 An air duct conveying air from a fan or other source (not shown) in known manner, and which may serve also to supply air for cooling the cylinder, is connected to the inlet portion 31 of the cylinder head air passage by means of studs mounted in tapped hol~s. 48 (Figure 4) . After passing through the outlet portion 33 of the passage, the cooling air escapes in the normal way directly to the atmosphere~
The section of Figure 6, which shows the part of the cylinder head covering one cylinder, is taken in the longitudinal plane of the valve axes.
It will be noted that when air is used as the coolant, the cool body (i.e. heat-conducting structure) applied to the selected areas of the deck from which heat is to be extracted comprises essentially a block of metal in which are formed air flow pas~ages instead of the water flow passages of the water-cooling version. The cool body thus becomes a number of fins, the outer fins conveniently forming the walls of the air flow passage through the cylinder head.
The main featùres distinguishing such an arrangement from the normal use of cooling fins in air-cooled engines are that the fins are attached to the limited selected areas corresponding withthe regions to be cooled, and that their projections beyond these areas are separated from the cylinder head deck by air gaps. Another difference is that in known designs, cooling fins are placed all over the cylinder head and only a fraction of the air passes over the critical central regions, so that these critical regions are cooled largely by lateral heat flow through the deck. To maintain the critical regions at acceptable temperatures by this means, it is necessary to cool the surrounding regions to well below acceptable temperatures, thus removing heat unnecessarily.
In another alternative to the use of the r-aised portion 35 in Figures 3-6 the three air passages between the fins, best seen in Figure 6, may be carried much lower so that in the connection region between fins and deck the thickness of the deck 30 is reduced to one half or less of that existing elsewhere, the fins and the structure of upper decks 23~ 24 providing adequate support of the deck against cylinder gas pressure; The choice will depend on the extent to which the cooling effect needs to be localised in a particular application.
As an alternative to the fin design shown in Figure 6, the fins may slope outwards to make more use of the space between the two gas passages and the two valve guides, thus providing more area for air flow. Fins may also be attached directly to the valve guides to cool them. The two-part construction facilitates casting of the fins, which would be further assisted by tapering the fins in accordance with common practiceO
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A structural unit for an internal combustion engine comprising:- a deck defining a cylinder cover having an extending surface and a region within said surface less in area than said extending surface, said region having a sub-surface that is heated in use so as to require direct cooling, to prevent over-heating of said region; a heat-conducting structure; heat-conducting con-nection means between said deck region and said heat-conducting structure; and fluid-flow cooling means associated with said heat-conducting structure, where-by to remove heat conducted to it through said heat-conducting connection means from said region of said unit, and in which the section through said connection means at the location between said connection means and said deck matches in shape and registers with said region requiring direct cooling to conduct heat from said region to said heat conducting structure, said region being under substantial influence from no other fluid flow cooling means, and said fluid flow cooling means providing only minimum cooling of said heat-conducting struc-ture so as to prevent over-heating of said region.
2. A structural unit for an internal combustion engine, according to claim 1, in which said fluid-flow cooling means to cool said heat-conducting structure comprise passages for cooling fluid formed integrally within said heat-conducting structure.
3. A structural unit for an internal combustion engine, according to claim 2, in which said heat-conducting structure, said heat-conducting con-nection means and said region to be cooled are all formed integrally with each other.
4. A structural unit for an internal combustion engine, according to claim 1, in which:- said internal combustion engine comprises at least one cylinder and cylinder head, and said region comprises a part of said head con-fronting the hottest area of the firing zone of said cylinder.
5. A structural unit for an internal combustion engine, according to claim 4, in which:- said engine is a diesel engine, and said region comprises part of said cylinder head closely surrounding at least one of the following features:- a fuel injection nozzle; inlet valve seats; exhaust valve seats, and a 'bridge' region between said inlet and exhaust valve seats.
6. A unit as in claim 1, wherein said engine has valve seats and means for injecting fuel and wherein said region at least partially encompasses said injecting means and valve seats for cooling the same.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB25901/76A GB1588231A (en) | 1976-06-22 | 1976-06-22 | Cooling internal combustion engines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1062568A true CA1062568A (en) | 1979-09-18 |
Family
ID=10235188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA281,044A Expired CA1062568A (en) | 1976-06-22 | 1977-06-21 | Internal combustion engines |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS531735A (en) |
| CA (1) | CA1062568A (en) |
| DE (1) | DE2726095A1 (en) |
| FR (1) | FR2356008A1 (en) |
| GB (1) | GB1588231A (en) |
| IT (1) | IT1083540B (en) |
| SE (1) | SE7707193L (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54111510U (en) * | 1978-01-26 | 1979-08-06 | ||
| JPS5949354A (en) * | 1982-09-14 | 1984-03-21 | Sanshin Ind Co Ltd | Cylinder head for water-cooled internal-combustion engine |
| JP6759160B2 (en) * | 2017-06-30 | 2020-09-23 | 株式会社クボタ | Water-cooled engine |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2191485A (en) * | 1938-01-10 | 1940-02-27 | Grace E Jensen | Exhaust valve seat insert retaining and cooling means |
| US2456272A (en) * | 1946-08-02 | 1948-12-14 | Fairchild Engine & Airplane | Engine cylinder construction |
| US2450998A (en) * | 1947-05-05 | 1948-10-12 | Richard H Sheppard | Cylinder head construction, bridge cooling |
| DE1426101A1 (en) * | 1960-12-20 | 1968-12-12 | Daimler Benz Ag | Cylinder head for an air-cooled internal combustion engine |
| FR1321963A (en) * | 1962-05-14 | 1963-03-22 | Ricardo & Co Engineers | Liquid-cooled cylinder heads for internal combustion engines |
| FR1420329A (en) * | 1964-01-29 | 1965-12-03 | Hatz Motoren | Internal combustion engine with injection |
| FR1540095A (en) * | 1967-10-04 | 1968-09-20 | Davey | Removable protective plate insertable between the cylinder head and the combustion chamber of an engine |
-
1976
- 1976-06-22 GB GB25901/76A patent/GB1588231A/en not_active Expired
-
1977
- 1977-06-10 DE DE19772726095 patent/DE2726095A1/en not_active Withdrawn
- 1977-06-21 SE SE7707193A patent/SE7707193L/en not_active Application Discontinuation
- 1977-06-21 IT IT68443/77A patent/IT1083540B/en active
- 1977-06-21 JP JP7432077A patent/JPS531735A/en active Pending
- 1977-06-21 CA CA281,044A patent/CA1062568A/en not_active Expired
- 1977-06-21 FR FR7718978A patent/FR2356008A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS531735A (en) | 1978-01-10 |
| GB1588231A (en) | 1981-04-15 |
| SE7707193L (en) | 1977-12-23 |
| FR2356008A1 (en) | 1978-01-20 |
| DE2726095A1 (en) | 1978-01-12 |
| IT1083540B (en) | 1985-05-21 |
| FR2356008B1 (en) | 1983-12-16 |
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