DE102013221231A1 - Water jacket structure for cylinder head for use in internal combustion engine of vehicle, has outlet water jacket provided with upper and lower outlet water jackets, which form independent flow channels within cylinder head - Google Patents

Abstract

The structure has a set of upper combustion chamber portions (21) formed in a lower surface of a cylinder head (2), and intake openings (22) and exhaust openings (23) communicated with the chamber portions. A collector (24) connects the exhaust openings with the head. An outlet water jacket (70) cools the collector, and comprises an upper outlet water jacket (80) and a lower outlet water jacket (90), where the upper- and lower jackets are respectively arranged at upper and lower sides of the collector in a cylinder axis direction and form independent flow channels within the head.

Description

Technical area

The present invention relates to a water jacket structure for a cylinder head or, more particularly, to a water jacket structure for a cylinder head integrally provided with an exhaust manifold adapted to merge a plurality of exhaust ports.

Technical background

Size reduction of an internal combustion engine has therefore been demanded against the background of the need to improve fuel efficiency and reduce carbon dioxide emissions. Such an internal combustion engine often includes a loader to compensate for a lack of torque attributable to the size reduction. Meanwhile, in order to make the internal combustion engine smaller in size and lighter in weight, there has been developed an internal combustion engine integrally formed in a cylinder head with an exhaust manifold adapted to bring together a plurality of exhaust ports extending from a plurality of combustion chambers. The exhaust collector easily reaches a high temperature. In particular, when a supercharger is located immediately downstream of the exhaust manifold, it is important to sufficiently cool the exhaust manifold to prevent heat damage to the supercharger. For this reason, in addition to the combustion chamber water jacket for cooling the combustion chambers, the cylinder head of this type is provided with an outlet water jacket to cool the exhaust ports and the exhaust manifold.

For example, Patent Document 1 discloses a water jacket structure for a cylinder head, wherein: exhaust water jackets are respectively provided on upper and lower sides of an exhaust manifold; and a connecting portion configured to communicate the exhaust water jackets on the upper and lower sides is formed between the exhaust collector and a side surface of the cylinder head where an exhaust port of the exhaust collector is provided.

Meanwhile, for a water jacket which improves the cooling effect of a cylinder head while avoiding an increase in the flow rate of coolant, a cylinder head integral with an exhaust manifold is known, wherein for cooling a side surface of an exhaust side exhaust manifold by the use of an improved method is achieved by arranging a water jacket core and an exhaust opening core during casting of the cylinder head (see, for example, Patent Document 2).

[Conventional documents]

[Patent Documents]

• [Patent Document 1] Japanese Patent Application Publication No. 2010-209749
• [Patent Document 2] German Patent Application Publication No. 10 2008 059 832

Summary of the invention

Problems to be solved by the invention

However, as described in Patent Document 1, the cooling passage structure for a cylinder head includes the connecting portion configured to communicate the exhaust water jackets on the upper and lower sides of the exhaust manifold with each other. This structure complicates the flow of coolant in the outlet water jackets. As a result, the flow rates of the coolant may be reduced, or the coolant may stop at a certain position (stagnant portion) within the outlet water jackets. Therefore, the cooling effect of the Auslasswassermäntel is likely to be worse. On the other hand, if the volumes of the water jackets are increased to increase the flow rate of the coolant to solve the above-mentioned problem, the size reduction of the cylinder head and a water pump is impaired.

Meanwhile, in the cylinder head integrated with the exhaust manifold, as described in Patent Document 2, the coolant circulates in the upper and lower outlet water jackets connected to each other through a communication passage to thereby improve and prevent the cooling effect for a portion between the exhaust ports and the like; that air remains in the water mantles. However, due to the provision of the communication passage therein, it is more likely that the refrigerant remains within the water jackets. Accordingly, it is necessary to take additional measures such as increasing the flow rate of the coolant to improve the cooling effect or to avoid insufficient cooling.

The present invention has been made in view of the above-mentioned problems. The object of the present invention is to provide a water jacket structure for a cylinder head which is capable of improving the cooling efficiency for an exhaust collector while avoiding an increase in the flow rate of coolant.

Another object of the present invention is to provide a water jacket structure for a To provide a cylinder head, which improves the cooling effect by improving a flow of coolant in a water jacket of a cylinder head.

A water jacket structure for a cylinder head of the present invention is characterized in that: the water jacket structure includes a plurality of upper combustion chamber portions formed in a lower surface of a cylinder head; a plurality of suction ports and a plurality of exhaust ports communicating with the plurality of upper combustion chamber portions; an exhaust manifold that merges the plurality of exhaust ports within the cylinder head; and an outlet water jacket configured to cool the exhaust manifold; wherein the outlet water jacket includes an upper outlet water jacket disposed in a cylinder axial direction on an upper side of the exhaust collector, and a lower outlet water jacket disposed in the cylinder axial direction on a lower side of the exhaust collector, and the upper outlet water jacket and the lower outlet water jacket within Cylinder head form independent flow channels.

In this configuration, the upper outlet water jacket and the lower outlet water jacket form the independent flow channels within the cylinder head. Therefore, the coolant does not necessarily need to be deflected and diverted within the cylinder head. Instead, it is possible to separate the refrigerant flows from each other and thereby to prevent a decrease in the flow velocity and the occurrence of a stagnant point (stagnant portion) of the refrigerant. Since the decrease in the flow velocity and the occurrence of the stagnant location (the stagnant water portion) of the coolant is avoided, it is possible to increase the flow velocity of the coolant flowing inside the outlet water jacket, and thereby effectively cool the exhaust collector with a small amount of refrigerant. Moreover, because the exhaust gas collector with the small amount of coolant can be effectively cooled, it is possible to reduce the volume of the Auslasswassermantels and possibly to achieve a size reduction of the cylinder head.

With respect to "the upper and lower sides in the cylinder axis direction", the upper side is defined as a side that is above an orthogonal cylinder plane, and the lower side is defined as a side that is below the orthogonal cylinder plane. Here, the orthogonal cylinder plane is a plane that is orthogonal to each cylinder axis.

Moreover, it is preferable that at least one of the upper outlet water jacket and the lower outlet water jacket should include a protrusion projecting toward the other outlet water jacket and disposed so as to face a downstream portion of the exhaust collector.

In this configuration, the entire exhaust manifold may be covered with the outlet water jacket, with the downstream portions of the exhaust manifold covered with the protrusions, while the upper outlet water jacket and the lower outlet water jacket form independent flow channels. This makes it possible to improve the cooling effect of the exhaust collector.

Further, it is preferable that the water jacket structure further comprises an inlet water jacket configured to cool the suction ports and a combustion chamber water jacket communicating with the inlet water jacket and configured to cool the upper combustion chamber sections; and the combustion chamber water jacket should be in communication with one of the upper outlet water jacket and the lower outlet water jacket.

In this configuration, one of the upper outlet water jacket and the lower outlet water jacket communicates with the combustor water jacket and the inlet water jacket. Accordingly, among plural cores used for casting the cylinder head, cores corresponding to the combustion chamber water jacket and the inlet water jacket, and a core corresponding to the upper outlet water jacket or the lower outlet water jacket may be formed into an integrated unit. Meanwhile, since the upper outlet water jacket and the lower outlet water jacket are separated from each other, it is not necessary to provide a separate core for forming a connection channel, unlike Patent Document 1. Thus, an increase in the number of cores is avoided and no alignment between the cores is required , Therefore, it is possible to avoid the complexity of a manufacturing process (installation of cores).

It is preferable that, from the upper outlet water jacket and the lower outlet water jacket, that communicating with the combustion chamber water jacket should be formed to flow coolant in a row direction of the upper combustion chamber portions.

In this configuration, from the upper outlet water jacket and the lower outlet water jacket, that to the combustion chamber water jacket is formed so as to generate a so-called longitudinal flow, wherein the coolant flows in a row direction of the upper combustion chamber portions (cylinder row direction). Therefore, the adjustment of the flow velocities is facilitated even if the flow channel areas are large. For this reason, it is easier to accelerate the flow rates and to improve the cooling effect with a small amount of refrigerant.

Another water jacket structure for a cylinder head of the present invention is characterized in that the water jacket includes: a plurality of upper combustion chamber portions formed in a lower surface of a cylinder head; a plurality of suction ports and a plurality of exhaust ports communicating with the plurality of upper combustion chamber portions; an exhaust manifold formed in the cylinder head and communicating with the plurality of exhaust ports; and an outlet water jacket configured to cool the exhaust manifold; wherein the outlet water jacket includes an upper outlet water jacket arranged in a cylinder axial direction on an upper side of the exhaust collector and configured to flow coolant in a row direction of the cylinders and a lower outlet water jacket disposed in the cylinder axial direction on a lower side of the exhaust collector and configured to flow the coolant in the row direction of the cylinders, each of the upper outlet water jacket and the lower outlet water jacket being provided with a coolant inlet configured to supply the coolant; a coolant outlet of the upper outlet water jacket and a coolant outlet of the lower outlet water jacket are provided on the cylinder head independently of each other; the upper outlet water jacket and the lower outlet water jacket are formed within the cylinder head from independent coolant channels; and the upper outlet water jacket and the lower outlet water jacket are formed such that a flow speed of the coolant flowing in the lower outlet water jacket becomes faster than a flow speed of the coolant flowing in the upper outlet water jacket.

In this configuration, in the water jacket structure for a cylinder head, the coolant outlet of the upper outlet water jacket and the coolant outlet of the lower outlet water jacket are provided independently of each other on the cylinder head, whereby the upper outlet water jacket and the lower outlet water jacket are formed of the coolant channels which are independent from each other. Thus, it is possible to easily adjust the flow rates of the coolant within the water jackets and to cause flow of the coolant without causing stagnation. As a result, the cooling effect can be improved by improving the flows of the coolant in the water jackets in the cylinder head. Moreover, compared to a structure of water jackets branching from a common coolant inlet, the water jacket structure for a cylinder head of the invention can easily be achieved adjusting optimum flow channels for the water jackets without providing branching measures such as ribs. Moreover, because the two water jackets form the independent coolant channels, it is possible to minimize the occurrence of stagnant water in the water jackets.

With respect to the "upper and lower sides in the cylinder axis direction", the upper side is defined as the side which is above the orthogonal cylinder plane, and the lower side is defined as the side which is below the orthogonal cylinder plane. Here, the orthogonal cylinder plane is the plane that is orthogonal to its cylinder axis.

Further, in this configuration, the upper outlet water jacket and the lower outlet water jacket form the independent flow channels within the cylinder head. Therefore, the coolant does not necessarily need to be deflected and diverted within the cylinder head. Instead, it is possible to separate flows of the refrigerant from each other and thereby to avoid a decrease in the flow velocity or the occurrence of a stagnant location (a stagnation water portion). Moreover, the outlet water jacket is formed such that the flow velocity of the coolant flowing in the lower outlet water jacket becomes faster than the flow velocity of the coolant flowing in the upper outlet water jacket. This increases the flow rate of the coolant flowing into the lower outlet water jacket located below the exhaust manifold, which is adjacent to the combustion chambers and reaches a higher temperature. As a result, it is possible to improve the cooling effect without increasing the total flow rate of the coolant. Meanwhile, because the cylinder head is cooled by the coolant having the faster flow rate, it is possible to cool the cylinder head to a lower temperature compared to another coolant channel having the same volume, which is attributable to the faster flow rate. Thus, it is possible to improve the cooling performance as well as the cooling effect, and possibly to achieve a size and weight reduction of the cylinder head.

Moreover, it is preferable that: one of the upper outlet water jacket and the lower outlet water jacket is connected to an inlet water jacket in which the coolant flows in the vicinity of the plurality of suction ports and connected to a combustion chamber water jacket configured to surround the upper combustion chamber sections to cool; and the water jacket structure should be configured such that a flow rate of the coolant in the combustion chamber water jacket takes the largest proportion of a flow rate of the coolant flowing inside the cylinder head, and a flow rate of the coolant in the lower outlet water jacket becomes the second largest proportion to the flow rate of the coolant in the combustion chamber water jacket ,

In this configuration, the coolant channels of the water jackets are formed such that the flow rate of the coolant in the combustion chamber water jacket occupies the largest proportion of the flow rate of the coolant flowing inside the cylinder head, and the flow rate of the coolant in the lower outlet water jacket becomes the second largest after that in the combustion chamber water jacket. Therefore, it becomes possible to effectively cool a mating surface portion of the cylinder head below the exhaust manifold, which is adjacent to the upper combustion chamber portions and reaches a high temperature.

Moreover, it is preferable that: the combustion chamber water jacket should be connected to one of the upper outlet water jacket and the lower outlet water jacket, and the combustion chamber water jacket should be configured to flow the coolant in a row direction of the cylinders.

In this configuration, the combustion chamber water jacket is formed such that the coolant flows in the row direction of the cylinders. Thus, the flow of the coolant above the combustion chambers, which have complicated shapes and reach high temperatures, is controlled in the row direction of the cylinders. Accordingly, it is possible to keep the flow rate and the cooling effect of the coolant low. Moreover, because the upper outlet water jacket or the lower outlet water jacket is provided as an independent coolant channel, it is possible to reduce the flow rate of the coolant flowing out to the exhaust collector side and thus effectively cool the neighborhood in the spark plug where the temperature is the highest Values reached.

It is preferable that: one of the upper outlet water jacket and the lower outlet water jacket should include a coolant inlet disposed on one side in the row direction of the cylinders; and one of the upper outlet water jacket and the lower outlet water jacket should include the plurality of coolant inlets disposed below the plurality of exhaust ports.

In this configuration, when the combustion chamber water jacket formed to cover the upper parts of the combustion chambers reaching high temperatures is provided, for example, with the coolant inlet at one end side in the row direction of the cylinders, the combustion chamber water jacket can cause the coolant As a longitudinal flow in the row direction of the cylinder flows without reducing the flow velocity, although it has a relatively complicated structure, and can thereby improve the cooling effect. The upper outlet water jacket or the lower outlet water jacket formed as the independent coolant channel includes the plurality of coolant inlets disposed below the plurality of outlet ports, and therefore, is capable of reliably cooling the combustion chamber side portions which are separation surfaces. Therefore, it is possible to improve the cooling effect of the exhaust manifold while reliably cooling the environments of the combustion chambers which reach high temperatures.

In the water jacket structure, the coolant is passed directly from the cylinder block to either the upper outlet water jacket or the lower outlet water jacket on the separated side. Therefore, it is possible to also let the coolant flow between the exhaust ports, thereby effectively cooling the cylinder head.

Moreover, it is preferable that: one of the upper outlet water jacket and the lower outlet water jacket should include a coolant inlet disposed on one side in the row direction of the cylinders; and one of the upper outlet water jacket and the lower outlet water jacket should include a plurality of the coolant inlets each disposed between a corresponding pair of the cylinders.

In this configuration, either the upper outlet water jacket or the lower outlet water jacket formed to the independent coolant passage is provided with the coolant inlets disposed between the cylinders and communicating with the coolant passage in the cylinder block, and therefore is capable of to reliably cool the combustion chamber side portions, which are the parting surfaces. Therefore, it is possible to improve the cooling effect of a collector in the exhaust manifold, while the environments of the Combustion chambers, which reach high temperatures, are reliably cooled.

Further, it is preferable that, from the upper outlet water jacket and the lower outlet water jacket, those not connected to the combustion chamber water jacket should have a plurality of the coolant inlets on sides of the upper combustion chamber portions and be formed such that the coolant flows and flows along the exhaust side surface of the cylinder head converges to a single flow, wherein the coolant flows sequentially in the row direction of the cylinder.

In this configuration, either the upper outlet water jacket or the lower outlet water jacket includes the plurality of coolant inlets formed near the upper combustion chamber portions instead of being formed at one end portion in the row direction of the cylinders. Therefore, the coolant received from the cylinder side coolant passage can enhance the cooling effect of the upper combustion chamber portions which reach high temperatures. Moreover, this coolant can perform uniform cooling while reducing uneven cooling with respect to the row direction of the cylinders. In addition, the water jackets are each provided with separate coolant inlets. Therefore, it is possible to easily and accurately adjust the flow rates of the coolant.

Moreover, it is preferable that the coolant inlet of the upper outlet water jacket, the coolant inlet of the lower outlet water jacket, and a coolant inlet of the combustion chamber water jacket communicate with seal coolant inflow holes, respectively, which are independently formed in a head gasket.

In this configuration, the setting of the flow channels for the coolant inlets of the respective water jackets can be easily achieved merely by adjusting the diameters of the inlets of the head gasket. Moreover, if either the upper outlet water jacket or the lower outlet water jacket is formed as the independent flow channel, it is not necessary to branch the flow channels at the coolant inlets. As a result, it is possible to avoid the stagnation of the coolant.

Moreover, it is preferable that, from the upper outlet water jacket and the lower outlet water jacket, that which is not connected to the combustion chamber water jacket should include an additional coolant inlet formed between the exhaust ports for the cylinder, which is furthest from the coolant outlet of the one Auslasswassermantels is arranged remotely.

In this configuration, from the upper outlet water jacket and the lower outlet water jacket, that not connected to the combustion chamber water jacket includes an additional coolant inlet formed between the cylinder outlet ports farthest from the coolant outlet of the relevant outlet water jacket. The additional coolant inlet may increase the flow rate and flow rate of the coolant. Thus, the occurrence of stagnant water of the coolant can be effectively prevented at a portion where the coolant merges with a refrigerant flow flowing through another cylinder.

[Effects of the Invention]

According to the present invention, it is possible to provide a water jacket structure for a cylinder head which is capable of improving the cooling effect of an exhaust collector while avoiding an increase in the flow rate of coolant.

Moreover, according to the present invention, it is possible to provide a water jacket structure for a cylinder head, which improves the cooling effect by improving the flow of a coolant in the water jacket of a cylinder head.

[Brief Description of the Drawings]

1 FIG. 10 is a cross-sectional view of an internal combustion engine incorporating a water jacket structure for a cylinder head according to an embodiment of the invention. FIG.

2 is a perspective view of the cylinder head.

3 FIG. 12 is a perspective view illustrating an exhaust manifold and a head-side water jacket within the cylinder head, as viewed through the cylinder head. FIG.

4 Fig. 12 is a perspective view showing the head-side water jacket and the exhaust manifold vertically separated.

5 is a bottom view of an inlet water jacket, a combustion chamber water jacket and an upper outlet water jacket.

6 is a bottom view of a lower outlet water jacket.

7 is a front view of the head-side water jacket and the exhaust collector, when viewed from the front.

8th FIG. 10 is an exploded perspective view for explaining refrigerant flows from the block-side water jacket to the inlet water jacket. FIG.

9 FIG. 10 is an exploded perspective view for explaining the flows of the coolant from the block-side water jacket to the lower outlet water jacket. FIG.

10 is a bottom view, which is shown by stacking the head-side water jacket and the block-side water jacket on a seal.

11 FIG. 12 is a bottom view for explaining the refrigerant flows in the inlet water jacket, the combustion chamber water jacket, and the upper outlet water jacket. FIG.

12 Fig. 10 is a bottom view for explaining the flows of the coolant in the lower outlet water jacket.

13A is an exploded perspective view, and 13B 1 is a perspective view showing a water jacket structure for a cylinder head of a first modified example of the embodiment.

14 FIG. 10 is a plan view showing an inlet water jacket, a combustion chamber water jacket and an upper outlet water jacket of the first modified example. FIG.

15 FIG. 10 is a bottom view showing a lower outlet water jacket, the inlet water jacket, and the combustor water jacket of the first modified example. FIG.

16 Fig. 10 is an exploded perspective view showing a water jacket structure for a cylinder head of a second modified example of the embodiment.

17 FIG. 10 is a bottom view showing a lower outlet water jacket, an inlet water jacket and a combustion chamber water jacket of the second modified example. FIG.

Modes for carrying out the invention

An embodiment of the present invention will be described with reference to FIG 1 to 12 described in detail. In the following descriptions, the same components are denoted by the same reference numerals, and an overlapping explanation is omitted. Meanwhile, descriptions are given in terms of directions based on the directions front, rear, left, right, up and down, as indicated in the drawings, each representing a state where an engine E is disposed in a vehicle.

1 FIG. 10 is a cross-sectional view of an internal combustion engine incorporating a water jacket structure for a cylinder head according to an embodiment of the invention. FIG.

As in 1 1, an engine E to which the present invention is applied includes an engine body provided with: a cylinder block 1 that is, for example, integral with four cylinders 1a (in 1 is just one of the cylinders 1a shown), which are arranged in series; a cylinder head 2 for connection to an upper end portion of the cylinder block 1 ; a seal 3 between the cylinder block 1 and the cylinder head 2 is arranged; and a head cover (not shown) connected to an upper end portion of the cylinder head 2 to connect.

The engine E is a multi-cylinder engine including: four cylinders 1a ; piston 4 , each in the corresponding cylinder 1a are used reciprocally; and a crankshaft 6 passing through connecting rods 5 with the pistons 4 connected is. The engine E is mounted transversely in a vehicle as a load object such that the rotational center line of the crankshaft 6 oriented in the left-right direction of the vehicle. Meanwhile, the engine E is arranged such that an intake side faces the rear of the vehicle and has its exhaust side toward the front of the vehicle.

For each of the cylinders 1a form the cylinder 1a , the corresponding piston 4 and the cylinder head 2 together a combustion chamber 7 in a space between the piston 4 and the cylinder head 2 in a cylinder axis direction, which is a direction parallel to a cylinder axis Lc of the cylinder 1a is.

In this embodiment, the engine E is arranged such that the cylinder axis Lc coincides with a vertical axis direction (i.e., up-down direction). However, the present invention is not limited to this configuration. For example, the engine E may also be arranged such that the cylinder axis Lc is inclined to the direction of the vertical axis.

In addition to the above-mentioned cylinders 1a and a crankcase (not shown) includes the cylinder block 1 a block side water jacket 10 , which is a flow channel for coolant for cooling the cylinder 1a represents. The block-sided water jacket 10 is a room in the form of a recessed groove, which is the totality of the four cylinders 1a surrounds and extends to a top of the cylinder block 1 opens (see 8th and 9 ). The coolant cooled with a cooler not shown becomes one end side of the block-side water jacket 10 fed. In addition, there is the block-side water jacket 10 with an inlet water jacket 50 and a lower outlet water jacket 90 of the cylinder head 2 , as will be described later, via through holes 32 . 35 and the like in the seal 3 connect and lead the water-coats 50 and 90 the coolant too. The block-sided water jacket 10 and the seal 3 will be described later in detail.

2 is a perspective view of the cylinder head. 3 FIG. 10 is a perspective view illustrating an exhaust manifold and a head-side water jacket within the cylinder head, as viewed through the cylinder head. FIG. In 3 are the contours of the cylinder head 2 drawn with dashed lines (double-dash chain lines).

The cylinder head 2 is a metal component produced by casting by means of cores. As in 1 to 3 (mainly in 1 ), contains the cylinder head 2 mainly: four upper combustion chamber sections 21 (In 1 only one of these is shown), which upper sections of the combustion chambers 7 group; suction 22 that are configured to move the air into the respective combustion chambers 7 allow; exhaust openings 23 that are configured to burn fuel gas from the combustion chambers 7 leave; an exhaust collector 24 inside the cylinder head 2 arranged and configured to the exhaust ports 23 merge; and a head-side water jacket 40 for cooling the aforementioned components. In addition, the cylinder head contains 2 a valve chamber 25 attached to an upper part of the cylinder head 2 is provided and adapted to receive a part of a valve drive (not shown).

The upper combustion chamber sections 21 are essentially conical recessed sections that are in a bottom 2a of the cylinder head 2 are formed. Each intake opening 22 causes the corresponding upper combustion chamber section 21 and a back 2 B of the cylinder head 2 communicate with each other. Every exhaust opening 23 causes the corresponding upper combustion chamber section 21 and the exhaust collector 24 communicate with each other. Two intake openings 22 and two exhaust ports 23 are for each upper combustion chamber section 21 provided, and each of the openings is with the inside of the upper combustion chamber portion 21 in connection. Here are not shown intake valves and exhaust valves in the intake ports 22 and the exhaust ports 23 arranged.

As in 2 shown, contains the exhaust collector 24 an opening 24a , which is an approximately central part of a front 2c of the cylinder head 2 opens in the left-right direction. The exhaust collector 24 is inside the cylinder head 2 formed, provided in such an area, in front of the cylinder head 1 is arched, and configured to with the exhaust ports 23 to be in communication (see 1 ).

The valve chamber 25 is a recessed space that is in a top 2d of the cylinder head 2 is trained. The valve chamber 25 receives a portion of the valve drive, not shown, including a camshaft, rocker arms, valves and the like. Meanwhile, there are outlet openings 63 . 83 and 93 (exhaust side outlets 2g ), which serve as outlets for the refrigerant from a head-side water jacket to be described later 40 serve, on a left side surface 2e (Exhaust side surface) of the cylinder head 2 educated. A water outlet (not shown) is on the left side surface 2e of the cylinder head 2 appropriate. The water outlet has the coolant coming from the outlet ports 63 . 83 and 93 delivered to a heater and the radiator.

The front 2c of the cylinder head 2 contains two support holes 2f , Every carrying hole 2f is formed during casting by a compound of a core disposed within a cavity and a core-print supported by a mold. The carrying holes 2f However, they are later closed with caps or the like.

As in 1 and 3 shown is the head-side water jacket 40 a space that serves as a flow channel for the coolant in the cylinder head 2 serves. The head-side water jacket 40 contains the inlet water jacket 50 for cooling the suction openings 22 , a combustion chamber water jacket 60 for cooling the upper combustion chamber sections 21 , and an outlet water jacket 70 for cooling the exhaust openings 23 and the exhaust collector 24 ,

As in 1 shown is the inlet water jacket 50 below the intake openings 22 intended. The combustion chamber water jacket 60 is just above the upper combustion chamber sections 21 and between the intake ports 22 and the exhaust ports 23 intended. The outlet water jacket 70 contains: an upper outlet water jacket 80 Located at an upper side of the exhaust vents 23 and the exhaust collector 24 is arranged in the cylinder axial direction Lc, and causes the coolant in a row direction Lb of the cylinder 1a flows; and a lower outlet water jacket 90 standing at a bottom of the exhaust vents 23 and the exhaust collector 24 is arranged in the cylinder axis direction Lc and causes the coolant in the row direction Lb of the cylinder 1a flows.

The inlet water jacket 50 stands with the water jacket on the block side 10 and with the combustion chamber water jacket 60 in connection (see dashed line in 1 ). The combustion chamber water jacket 60 stands with the water jacket on the block side 10 and the upper outlet water jacket 80 in connection. The lower outlet water jacket 90 stands with the water jacket on the block side 10 in connection. Incidentally, the lower outlet water jacket is 90 with the inlet water jacket 90 , the combustion chamber water jacket 60 or the upper outlet water jacket 80 not in contact. In other words, in the outlet water jacket 70 Form the upper outlet water jacket 80 and the lower outlet water jacket within the cylinder head 2 Flow channels that are independent of each other. The outlet water jacket 70 is formed such that a flow velocity of the lower Auslasswassermantel 90 flowing coolant is faster than a flow rate of the upper outlet water jacket 80 flowing coolant.

Next are detailed structures of the exhaust manifold 24 and the head-side water jacket 40 (namely the inlet water jacket 50 , the combustion chamber water jacket 60 , the upper outlet water jacket 80 and the lower outlet water jacket 90 ) in relation to 4 to 7 described.

4 Fig. 10 is a perspective view showing the head-side water jacket and the exhaust manifold, which are vertically separated. 5 is a bottom view of the inlet water jacket, the combustion chamber water jacket and the upper outlet water jacket. 6 is a bottom view of the lower outlet water jacket. 7 is a front view of the head-side water jacket and the exhaust collector, when viewed from the front.

It should be noted that in 4 to 7 for easier description of the exhaust manifold 4 and the head-side water jacket 40 which are in reality spaces, represented as if they were material objects (ie cores corresponding to the spaces).

As in 4 shown, contains the exhaust collector 24 : first collector 24b , which are each designed so that two exhaust ports 23 merge with the appropriate combustion chamber 7 keep in touch; and a second collector 24c which is designed to be the first four collectors 24b at a position immediately in front of the opening 24a merges. The second collector 24c and the opening 24a are at an approximately central part of the cylinder head in the left-right direction 2 intended. Among the four first collectors 24b are the first collectors 24b longer on the right and left sides than the other two first collectors 24b which are arranged between them. Side surfaces of the front side sections of the first collector 24b on the right and left sides represent downstream sections 24d of the exhaust collector 24 represented by protrusions 81 of the upper outlet water jacket 80 and the projections 91 the lower outlet water jacket 90 to be cooled, as described later (see 1 and 4 to 6 ). In plan view are the downstream sections 24d inclined so that the downstream sections 24d be placed further forward when the downstream sections 24d the opening 24a at the middle of the exhaust ports 23 get closer at the left and right ends.

As in 4 and 5 shown (mainly in 5 ), is the inlet water jacket 50 a flow channel region where the coolant flows, which the suction ports 22 cools (see 1 ). The inlet water jacket 50 extends under the intake ports 22 such that it crosses in the left-right direction meandering. The inlet water jacket 50 contains eight inlet-side inflow sections 51 , each of which is below the corresponding intake 22 is arranged and to the bottom 2a (please refer 2 ) of the cylinder head 2 opens. In addition, the inlet water jacket contains 50 connecting sections 52 that with the combustion chamber water jacket 60 keep in touch. The connecting sections 52 are either at positions between adjacent cylinders 1a are arranged (hereinafter referred to as "between the cylinder axes" if necessary) or at positions corresponding to the outsides of the rightmost and leftmost cylinders 1a , Zwischenachseinströmabschnitte 53 are each below the three connecting sections 52 provided between the cylinder axes. Each interaxle flow section 53 opens to the bottom 2a of the cylinder head 2 ,

The combustion chamber water jacket 60 is a flow channel region where the coolant flows, which are the upper combustion chamber sections 21 cools (see 1 ). The combustion chamber water jacket 60 extends above the upper combustion chamber sections 21 such that it traverses in the left-right direction. The combustion chamber water jacket 60 is wider in the front-rear direction than the inlet water jacket 50 , and surround spark plugs, which are not shown. The combustion chamber water jacket 60 contains two combustion chamber side inflow sections 61 (Coolant inlets), which are used as inlets for serve the coolant and the end portions on the right side of the combustion chamber water jacket 60 are arranged and move to the bottom 2a of the cylinder head 2 open (see 7 ). In addition, the combustion chamber water jacket contains 60 connecting sections 62 that with the upper outlet water jacket 80 keep in touch. Each connection section 62 is at a position corresponding to a space between two adjacent exhaust ports 23 arranged (see 1 ). In addition, the combustion chamber water jacket contains 60 an outlet opening 63 located in a left end portion of the combustion chamber water jacket 60 is arranged and facing the left side surface 2e of the cylinder head 2 opens to serve as an outlet for the coolant (see 2 ). The outlet opening 63 is wider in the front-rear direction than the combustion chamber water jacket 60 and extends forward.

As in 4 . 5 and 7 shown (mainly in 5 ), is the upper outlet water jacket 80 provided so that it covers the tops of the exhaust ports 23 and the exhaust collector 24 covered. The upper outlet water jacket 80 is formed to have a larger width dimension in the front-to-back direction, and has a smaller thickness dimension in the up-and-down direction (see 1 ) as the inlet water jacket 50 and the combustion chamber water jacket 60 , The upper outlet water jacket 80 contains the projections 81 coming from a front end portion of the upper outlet water jacket 80 protrude downwards (see 1 ). The protrusions are arranged to be toward the downstream portions 24d of the exhaust collector 24 point. Here are in one area 82 the front end portion of the upper outlet water jacket 80 no protrusions 81 provided, the area 82 the opening 24a of the exhaust collector 24 equivalent. The upper outlet water jacket 80 contains an outlet opening 83 (a coolant outlet) located at a left end portion of the upper outlet water jacket 80 is arranged and to the left side surface 2e of the cylinder head 2 opens to serve as an outlet for the coolant (see 2 ).

By the way, in terms of 5 , the intake openings 22 (not shown) in areas 55 between the inlet water jacket 50 and the combustion chamber water jacket 60 arranged. In addition, the spark plugs (not shown) are in areas 65 in the combustion chamber water jacket 60 arranged, with the areas 65 the middle sections of the cylinder 1a correspond. Further, the exhaust valves (not shown) are in areas 67 between the combustion chamber water jacket 60 and the upper outlet water jacket 80 arranged.

As in 4 . 6 and 7 shown (mainly in 6 ), is the lower outlet water jacket 90 designed so that it covers the undersides of the exhaust vents 23 and the exhaust collector 24 covered (see 1 ). The lower outlet water jacket 90 is formed in a flattened shape so as to have substantially the same thickness dimension as the upper outlet water jacket 80 has (see 1 ). The lower outlet water jacket 90 contains the projections 91 coming from a front end portion of the lower outlet water jacket 90 project upwards (see 1 ). The projections 91 are arranged so that they to the downstream sections 24d of the exhaust collector 24 point. Here are in one area 92 the front end portion of the lower outlet water jacket 90 no protrusions 91 provided, the area 92 the opening 24a of the exhaust collector 24 equivalent. The lower outlet water jacket 90 contains an outlet opening 93 (Coolant outlet) located at a left end portion of the lower outlet water jacket 90 is arranged and facing the left side surface 2e of the cylinder head 2 opens to serve as an outlet for the coolant (see 2 ). The lower outlet water jacket 90 contains eight outlet-side inflow sections 94 (Coolant inlets), which are to the bottom 2a of the cylinder head 2 to open. Each outlet-side inflow section 94 is at a rear end portion of the lower Auslasswassermantels 90 and at a position corresponding to a location below the corresponding exhaust port 23 arranged. Since the outlet-side inflow sections 94 immediately below the exhaust ports 23 are provided, as described above, the exhaust ports 23 be effectively cooled (see 4 ).

Meanwhile, there is an additional inflow section 95 (additional coolant inlet) between the two outlet-side inflow sections 94 at the from the outlet opening 93 farthest side (ie on the upstream side). In other words, from the upper outlet water jacket 80 and lower outlet water jacket 90 is the lower outlet water jacket 90 (Auslasswassermantel 70 ), with which the combustion chamber water jacket 60 is not connected, with the additional inflow section 95 provided (the additional coolant inlet) between the exhaust ports 23 the cylinder head is arranged from the outlet opening 93 (the coolant outlet) of the outlet water jacket 70 farthest away.

Meanwhile, the combustion chamber water jacket contains 60 the combustion chamber side inflow sections 61 (Coolant inlets) on the right side of the cylinders 1a in the row direction Lb. The combustion chamber water jacket 60 is formed such that the coolant flows in the row direction Lb. From the upper outlet water jacket 80 and lower Auslasswassermantel 90 , unlike the combustion chamber water jacket 60 , is the lower outlet water jacket 90 with the outlet-side inflow sections 94 (the coolant inlets) provided immediately below the exhaust ports 23 are arranged.

Here, as in 3 shown, the exhaust collector 24 and the head-side water jacket 40 Shaped by a second water jacket core 200 , an outlet core 300 and a first water jacket core 100 , the sand molds each with the in 4 illustrated embodiments, in a cavity of a mold (not shown) for the cylinder head 2 arranged in this order from below. In other words, the arrangement of the three cores is completed only by sequentially stacking these cores from the ground as described above. Therefore, the complexity of the core relation can be reduced.

8th FIG. 10 is an exploded perspective view for explaining the flows of coolant from the block-side water jacket to the inlet water jacket. FIG. 9 FIG. 10 is an exploded perspective view for explaining the flows of the coolant from the block-side water jacket to the lower outlet water jacket. FIG. 10 is a bottom view, which is shown by the head-side water jacket and the block-side water jacket, on a bottom view of the seal, are superimposed.

For easier description are in 8th and 9 other sections of the head-side water jacket 40 as the inflow sections are shown with dashed lines (double chain dashed lines). Meanwhile, in 10 the seal 3 hatched with dots, and the opening of the block-side water jacket 10 is shown with dashed lines (thick dashed lines).

As in 8th . 9 and 10 shown is the block-side water jacket 10 shaped so that he has the four cylinders 1a completely surrounds. The block-sided water jacket 10 includes an inlet section 11 for the coolant, in front of the extreme right cylinder 1a is arranged and has a greater width than the remaining areas of the block-side water jacket 10 , A separator 11a is in the inlet section 11 used to control the flow direction of the coolant. In this embodiment, a coolant pipe P is located at the left side of the inlet portion 11 relative to the separator 11a connected. In addition, the block-sided water jacket contains 10 narrowed sections 12 at areas corresponding to the positions between the cylinders 1a are arranged (between the cylinder axes). In addition, an interaxle slot 13 , which has a recessed groove shape and is configured, the narrowed sections 12 on the front and back sides to communicate with each other, formed between each pair of adjacent cylinder axes.

As in 8th . 9 and 10 (mainly in 10 ) is the seal 3 a sheet metal element made of metal and is configured to connect between the cylinder block 1 and a cylinder head 2 seal. The seal 3 contains four cylinder openings 31 that the four cylinders 1a of the cylinder block 1 correspond. The seal 3 Also includes: inlet-side through holes 32 and interaxis through holes 33 respectively at positions corresponding to the inlet side inflow sections 51 and the interaxle inflow sections 53 of the inlet water jacket 50 are trained; through-chamber through holes 34 at positions corresponding to the combustion chamber side inflow sections 61 of the combustion chamber water jacket 60 are trained; and outlet-side through holes 35 and an additional through hole 36 at positions respectively corresponding to the outlet side inflow sections 94 and the additional inflow section 95 the lower outlet water jacket 90 are formed. The inlet-side through holes 32 , the interaxle holes 33 , the combustion chamber side through holes 34 , the outlet-side through holes 35 and the additional through hole 36 are all at positions corresponding to the opening of the block-side water jacket 10 educated. From the inlet-side through holes 32 ( 32a to 32h ) and the exhaust side through holes 35 ( 35a to 35h ), have the holes that are arranged on the right side (that of the outlet openings 63 . 83 and 93 more distant holes) are generally larger in diameter, whereas the holes located on the left (which are the outlet ports 63 . 83 and 93 nearer holes) generally have smaller diameters, although there are a few exceptions. Thus, the through holes are formed such that the flow velocity of the coolant becomes faster as the coolant nears the exhaust ports 63 . 83 and 93 flows.

The outlet-side inflow sections 94 (the coolant inlets) of the lower outlet water jacket 90 stand with the combustion chamber side inflow sections 61 (the coolant inlets) of the combustion chamber water jacket 60 via seal coolant inflow holes ( 32 to 36 ) in the seal 3 (Head gasket) are formed, independently of each other and above the block-side water jacket 10 of the cylinder block 1 in connection. Meanwhile, the upper outlet water jacket is 80 formed such that the coolant through the connecting portions 62 (the coolant inlets) of the combustion chamber water jacket 60 passes through and into the upper outlet water jacket 80 flows.

From the inlet-side through holes 32 is, for example, the inlet-side through hole 32a at the end of the outlet 63 located furthest away (the exhaust side outlet 2g ), formed from a hole whose diameter is greater than 3 mm. The inlet side through hole 32b adjacent to the inlet-side through-hole 32a and closer to the outlet opening 63 is arranged, is formed with a slot whose major axis is greater than 3 mm. From the inlet-side through holes 32a are the inlet-side through-holes 32 ( 32c to 32h ), which at the outlet opening 63 even closer positions are arranged (the exhaust side outlet 2g ), formed by small holes, each with a diameter of 3 mm.

From the outlet side through holes 35 For example, each of the exhaust-side through holes 35a to 35d which are located at the farthest from the outlet opening positions (the exhaust side outlet 2g ), with a diameter of 6 mm. The exhaust-side through holes 35e to 35f next to the exhaust side through hole 35d and closer to the outlet opening 93 (the coolant outlet) are formed of holes each having a diameter of 5 mm. From the exhaust side through holes 35 are the exhaust side through holes 35g and 35h at the outlet opening 93 even closer positions are arranged (the exhaust side outlet 2g ), formed of small holes, each with a diameter of 4 mm.

As described above, the inlet-side through holes are 32 and the exhaust-side through holes 35 formed such that the seal coolant inflow holes, the outlet openings 63 and 93 are closer, which have smaller diameter, whereas the Dichtungskühlmitteleinströmlöcher that from the outlet openings 63 and 93 further away, which have larger diameters, as needed according to their positions.

In particular, the combustion chamber side through-holes are 34 designed so that they have the larger diameter than the through holes 32 . 33 . 35 and 36 , In this way, a longitudinal flow described later is easily formed.

As described above, the upper outlet water jacket stands 80 with the inlet water jacket 50 in conjunction, which is designed so that the coolant around the suction openings 22 flows around. In addition, the upper outlet water jacket 80 with the combustion chamber water jacket 60 connected, which is configured, the upper combustion chamber sections 21 to cool. Further, the combustion chamber water jacket 60 is formed to have a large flow channel cross-sectional area so that the flow rate of the coolant in the combustion chamber water jacket 60 the largest proportion of the flow rate of the cylinder head 2 flowing coolant. Meanwhile, the bottom outlet water jacket is 90 is formed so as to have such a flow channel sectional area that the flow rate of the coolant in the lower outlet water jacket 90 the second largest after that in the combustion chamber water jacket 60 becomes.

[Business]

Next, the coolant flows in the block-side water jacket 10 and the head-side water jacket 14 in relation to 8th to 12 described.

11 FIG. 12 is a bottom view for explaining the refrigerant flows in the inlet water jacket, the combustion chamber water jacket, and the upper outlet water jacket. FIG. 12 Fig. 10 is a bottom view for explaining the flows of the coolant in the lower outlet water jacket.

As in 8th and 9 2, the coolant (arrow Y1) flowing from the coolant pipe P flows into the inlet portion 11 flowed, in front of the cylinders 1a (Arrow Y2) to the left along the block-side water jacket 10 , After performing a turn (arrow Y3) on the left end section, the coolant flows to the back of the cylinder 1a (Arrow Y4) to the right along the block-side water jacket 10 , and then reaches the right end portion (arrow Y5). Meanwhile, the coolant flows from the narrowed sections 12 at the front to the narrowed sections 12 at the back over the interaxle slots 13 (Arrows Y6).

As in 9 shown, enters a portion of the coolant (arrow Y2), in front of the cylinders 1a to the left along the block-side water jacket 10 flows through the outlet-side through holes 35 and the additional through hole 36 that in the poetry 3 is formed, and flows into the lower outlet water jacket 90 from the outlet side inflow sections 94 and the additional inflow section 95 (Arrows Y7). In other words, the flows of the refrigerant in this embodiment constitute a so-called outlet-priority flow, in which the refrigerant enters the lower outlet water jacket 90 flows before it to the inlet water jacket 50 flows. Thus, the exhaust ports 23 and the exhaust collector 24 be cooled efficiently.

Meanwhile, as in 8th shown a part of the coolant (arrow Y4) coming from the back of the cylinder 1a to the right along the block-sided water jacket 10 flows through in the poetry 3 formed inlet-side through holes 32 ( 32a to 32h ) and flows from the inlet side inflow sections 51 in the inlet water jacket 50 into it (arrows Y8a). In this case, the inlet-side through-holes are 32c to 32h , the outlet opening 63 (the exhaust side outlet 2g ) are arranged so as to be smaller in diameter than the inlet-side through holes 32a and 32b have on from the outlet opening 63 (the exhaust side outlet 2g ) are arranged more distant positions. As a result, the flow rates of the coolant (the arrows Y8a) become faster, that in the inlet side inflow sections 51 flows, the outlet opening 63 (the exhaust side outlet 32g ) are arranged closer. As the flow rates of the coolant (arrows Y8a) become faster, the flow rates of the inlet side inflow portions become 51 flowing coolant per predetermined period of time in response to the flow rates greater. Thus, it is possible to reduce the cross-sectional areas of the respective coolant channels and to improve the cooling properties and cooling effect of the water jackets.

In addition, if the coolant flows (arrows Y6), which through the Zwischenachsschlitze 13 pass through, on the narrowed sections 12 meet at the rear, the coolant passes through the Zwischenachsdurchgangslöcher 33 through and flows from the Zwischenachseinströmabschnitten 53 in the inlet water jacket 60 (Arrows Y8b). The coolant (arrows Y6) coming out of the interaxle slots 13 out and into the Zwischenachseinströmabschnitte 53 flows in, flows out due to a reduction in the flow resistance, the formation of the Zwischenachsdurchgangslöcher 33 in the seal 3 at the positions corresponding to the respective narrowed sections 12 attributable to.

Meanwhile, the coolant (arrow Y5) that enters the right end portion of the block-side water jacket enters 10 has reached, through the combustion chamber side through holes 34 that in the seal 3 are formed to thereby from the combustion chamber side inflow sections 61 in the right end portion of the combustion chamber water jacket 60 to flow (arrows Y9). The combustion chamber side through holes 34 attached to the from the outlet opening 63 (the exhaust side outlet 2g ) are formed to be larger in diameter than the inlet-side through holes 32 and the interaxis through holes 33 have that at the outlet opening 63 (the exhaust side outlet 2g ) are arranged closer positions. As a result, the coolant (arrow Y9) flows in the combustion chamber side through holes 34 slowly.

As in 11 2, the coolant flowing from the combustion chamber side inflow portions flows 61 in the right end portion of the combustion chamber water jacket 60 flows, approximately straight ahead from right to left to the outlet opening 63 at the left end portion (arrow Y10). Accordingly, the flow of the coolant is smooth due to the low flow resistance. This flow (arrow Y10) forms a flow (a so-called longitudinal flow) in the row direction Lb (see 8th and 9 ) the cylinder 1a (ie the upper combustion chamber sections 21 ) in the combustion chamber water jacket 60 ,

Meanwhile, the coolant enters from the inlet side inflow sections 51 and the Zwischenachseinströmabschnitt 53 in the inlet water jacket 50 flows through the connecting sections 52 and flows into the combustion chamber water jacket 60 (Arrow Y11). Then, the coolant unites with the above-described longitudinal flow. The coolant (arrow Y10) from right to left inside the combustion chamber water jacket 60 has flowed, flows from the outlet opening 63 to the outside of the cylinder head 2 ,

Part of the coolant in the combustion chamber water jacket 60 flows, passes through the connecting sections 62 through and flows into the upper outlet water jacket 80 , Flows of coolant (arrows Y12) coming from the connecting sections 62 inflow converge on the front end side of the upper Auslasswassermantels 80 to thereby flow (so-called longitudinal flow) (arrow Y13) in the row direction Lb (see 8th and 9 ) the cylinder 1a to form (ie the upper combustion chamber sections 21 ).

Here is a right front section 80a of the upper outlet water jacket 80 so inclined that the right front section 80a is placed further forward when the right front end portion 80a the outlet opening 83 comes closer. Accordingly, the coolant coming from the connecting portions 62 flows in on the right side, through the right front section 80a of the upper outlet water jacket 80 guided, so that the coolant easily to the exhaust port 83 flows down. For this reason, the refrigerant flows smoothly without stopping, whereby a pressure loss is reduced. The coolant that flows from right to left inside the upper outlet water jacket 80 has flowed, flows from the outlet opening 83 to the outside of the cylinder head 2 ,

As in 12 2, the coolant flows (arrows Y14) flowing from the exhaust-side inflow portions flow 94 in the lower outlet water jacket 90 have flowed forward. The currents converge at the front End of the lower outlet water jacket 90 to thereby form a flow (so-called longitudinal flow) (arrow Y15) in the row direction Lb (see 8th and 9 ) the cylinder 1a to form (ie the upper combustion chamber sections 21 ). Here is a right front section 90a the lower outlet water jacket 90 so inclined that the right front section 90a is placed further forward when the right front end portion 80a the outlet opening 93 comes closer. Accordingly, the coolant flowing from the exhaust-side inflow portions becomes 94 and the additional inflow section 95 flows in on the right side and flows forward through the right front section 90a the lower outlet water jacket 90 guided, so that the coolant easily to the exhaust port 93 flowing at a faster flow rate than in the other positions in it. The coolant (arrow Y15) from right to left within the lower outlet water jacket 90 has flowed, flows from the outlet opening 93 to the outside of the cylinder head 2 ,

In this regard, compare the lower outlet water jacket 90 and the upper outlet water jacket 80 , In the only lower outlet water jacket 90 with the independent shape, the flow channels are formed in a manner that allows the coolant therein to be discharged from the plurality of outlet-side inflow sections 94 and the additional inflow section 95 flows in, flows smoothly without resistance to the outlet opening. Thus, the flow velocity of the lower Auslasswassermantel 90 flowing coolant made faster than the flow rate of the upper Auslasswassermantel 80 flowing coolant.

As described above, in the water jacket structure for a cylinder head of the embodiment, the upper outlet water jacket is formed 80 and the lower outlet water jacket 90 in the cylinder head 2 the flow channels, which are independent of each other. Thus, it is possible to separate the refrigerant flows from each other, and thereby to reduce a decrease in the flow velocity or the occurrence of a stagnant spot (stagnant section). Since the decrease in the flow velocity or the occurrence of the stagnant location (the stand-by water portion) can be minimized, it is possible to increase the flow velocity of the coolant inside the outlet water jacket 70 flows. Therefore, even if the coolant channels have small flow channel cross-sectional areas, the supply amount of the coolant per unit time can be increased, and therefore, the exhaust collector 24 and the like are cooled effectively. Thus it is possible to increase the volume of the outlet water jacket 70 to reduce, and possibly to achieve the size reduction of the cylinder head and the size reduction of a water pump.

Meanwhile, the upper outlet water jacket 80 and the lower outlet water jacket 90 each with projections 81 and 91 which project toward each other and are arranged to be to the downstream portions 24d of the exhaust collector 24 point. Thus, the downstream sections 24d of the exhaust collector 24 with the projections 81 and 91 are covered while the upper Auslasswassermantel 80 and the lower outlet water jacket 90 be provided as independent flow channels. By covering the entire exhaust manifold 24 with the outlet water jacket 70 Therefore, the cooling effect can be improved.

Here is the inlet water jacket 50 with the combustion chamber water jacket 60 in connection, while the combustion chamber water jacket 60 with the upper outlet water jacket 80 communicates. Accordingly, among the multiple cores used for casting the cylinder head 2 be used, the cores according to the inlet water jacket 50 , the combustion chamber water jacket 60 and the upper outlet water jacket 80 (ie the in 4 shown first water jacket core 100 ) are formed into an integrated unit.

Because meanwhile the upper outlet water jacket 80 and the lower outlet water jacket 90 Unlike in Patent Document 1, it is not necessary to provide an extra core for forming a connection channel. Therefore, an increase in the number of cores is avoided and no alignment of the cores is required. As a result, it is possible to avoid the complexity of the manufacturing process (installation of cores, positioning of cores, etc.).

The upper outlet water jacket 80 that with the combustion chamber water jacket 60 is formed to be the coolant in the row direction Lb of the upper combustion chamber sections 21 flow. Therefore, adjustment of the flow rates is facilitated even if the flow channel areas are large. For this reason, it is easy to accelerate the flow rates and to improve the cooling effect with a small amount of refrigerant. In addition, the lower Auslasswassermantel is also 90 in which the coolant is directly from the block-side water jacket 10 flows in, is formed so as to flow the coolant in the row direction Lb of the upper combustion chamber sections. Accordingly, the lower outlet water jacket generates 90 Effects similar to those described above.

In addition, the combustion chamber water jacket 60 , the upper outlet water jacket 80 and the lower outlet water jacket 90 each with the outlet openings 63 . 83 and 93 (the coolant outlets) provided that are independent of each other. Accordingly, in the case of designing the coolant channels having good cooling performance by accelerating the flow rates of the coolant therein, it is possible to control the flow rates by utilizing the relationships of the diameters of the exhaust ports 63 . 83 . 93 with the diameters of the combustor inflow sections 61 (the coolant inlets), the outlet-side inflow sections 94 (the coolant inlets) and the additional inflow section 95 (the additional coolant inlet). As a result, it is easy to adjust the flow rates of the coolant in the coolant channels as desired and also to control the flow rates of the coolant.

(First modified example)

Although the water jacket structure for a cylinder head according to the embodiment has been described above in detail with reference to the drawings, it goes without saying that: the present invention is not limited only to this embodiment; and, if necessary, various changes can be made within a range not deviating from the scope of the present invention.

Now, modified examples of the embodiment will be described below. Incidentally, the configurations already explained are denoted by the same reference numerals, and overlapping descriptions are omitted.

13A is an exploded perspective view, and 13B FIG. 10 is a perspective view showing a water jacket structure for a cylinder head of a first modified example of the embodiment. FIG. 14 FIG. 10 is a plan view showing an inlet water jacket, a combustion chamber water jacket and an upper outlet water jacket of the first modified example. FIG. 15 FIG. 10 is a bottom view showing a lower outlet water jacket, the inlet water jacket, and the combustor water jacket of the first modified example. FIG.

As for the above execution, as in 3 and 4 shown are the descriptions for the head-side water jacket 40 wherein the upper outlet water jacket 80 , the inlet water jacket 50 and the combustion chamber water jacket 60 are formed to the integrated unit and above the lower Auslasswassermantels 90 are provided. However, the present invention is not limited only to this configuration. As in 13A to 15 For example, the water jacket structure for a cylinder head according to the present invention may also include a head-side water jacket 40A wherein: an upper outlet water jacket 80A is provided on an upper side; and another water jacket by integrating a lower outlet water jacket 90A , an inlet water jacket 50A and a combustion chamber water jacket 60A is formed with each other, separately below the upper Auslasswassermantels 80A is provided.

In this case, as in 14 shown, the upper outlet water jacket 80A coolant inlets 84A which are arranged between the cylinders. Thus, the upper outlet water jacket 80A such that: the coolant flows (arrows Y20) from the coolant inlets 84A the cylinders pass and flow to front sections 80Ab of the upper outlet water jacket 80A ; then the coolant flows (arrow Y20) coming out of the coolant inlets converge 84A out, to a single flow of coolant (arrow Y21) within the front-side sections 80Ab ; and then the coolant (arrow Y21) flows straight on to an exhaust port 83A (Coolant outlet) as its flow rate increases.

In other words, from the upper outlet water jacket 80A and lower outlet water jacket 90A is a part (the upper outlet water jacket 80A ) of an outlet water jacket 70A that does not match the combustion chamber water jacket 60A connected to the coolant inlets 84A provided, which are respectively disposed near the upper combustion chamber sections. In addition, this part is designed such that the coolant flows coming from the coolant inlets 84A have flowed out, along the left side surface 2e (the exhaust side surface) of the cylinder head 2 flow and in the row direction Lb the cylinder 1a to the outlet opening 83A flow as they converge to the single flow.

Because the upper outlet water jacket 80A As described above, the areas in the vicinity of the cylinder and the front-side portions 80Ab (the exhaust side) of the upper outlet water jacket 80A be effectively cooled. Thus, this modified example enables the cooling of the front-side portions 80Ab which is impossible in the case of a conventional integrated type water jacket.

Here are the front sections 80Ab of the upper outlet water jacket 80 and the front sections 90ab of the lower one Auslasswassermantels 90 (see arrow Y22 in 15 ) on an inner side of a flat surface around the opening 24a of the exhaust collector 24 provided around. Accordingly, it is possible to lower the temperatures at female threaded portions N for connecting the mating surfaces as well as at regions where sealing beads (not shown) are to be arranged.

Here, it is preferable to have a sufficiently thick space between a cavity surface that surrounds the flat surface around the opening 24a around and where the first and second water jacket cores are defined 100A and 200A defined to prevent, during the casting process, the formation of a thin metal film of molten metal in the space due to the provision of an insufficient thickness.

In addition, the coolant inlets form 84A a longitudinal flow, wherein the coolant from portions between the cylinder axes to the outlet opening 83A (the coolant outlet) flows. Thus, it is possible to have a wide area above the exhaust ports 23 to cool. Each coolant inlet 84A is disposed between the respective pair of cylinders and thus is able to supply the coolant from the portion between the cylinder axes. Accordingly, it is not necessary to have a separate passage or bypass passage for supplying the coolant to the upper outlet water jacket 80A provided. In addition, the coolant inlets serve 84A as legs, for positioning in the course of adjusting the first water jacket core 100A to assist at the top. Thus, it is possible to assemble the core accurately in a predetermined position and to simplify the installation of the core.

The upper outlet water jacket 80A and the lower outlet water jacket 90 are formed from coolant channels that are independent of each other. In particular, the upper outlet water jacket 80A with the coolant inlets 84A provided to the coolant on the side of the cylinder block 1 supply. The lower outlet water jacket 90A is with combustion chamber side inflow sections 61A (Coolant inlets) provided to the coolant on one side of the cylinder block 1 supply. In addition, the outlet opening 83A (the coolant outlet) of the upper outlet water jacket 80A and an outlet opening 93A (Outlet opening) of the lower outlet water jacket 90A on the cylinder head 2 independently provided.

In addition, as in 15 shown, the lower outlet water jacket 90 with the inlet water jacket 50A connected, wherein the coolant in the vicinity of the suction openings 22 (please refer 1 ) flows, and is also with the combustion chamber water jacket 60A connected to the upper combustion chamber sections 21 covered (see 1 ). Accordingly, the upper and lower water jackets form parting surfaces in the vicinity of the upper combustion chamber portions 21 , Thus, the upper and lower water jackets can the upper combustion chamber sections 21 and the environment of a collector of an exhaust manifold, which reach high temperatures, cool effectively and reliably.

The lower outlet water jacket 90A and the combustion chamber water jacket 60A which is arranged so that it the upper combustion chamber sections 21 covered, and is configured to cool the environments of the combustion chambers are formed as a single unit, by means of the connecting portions 96A . 96A are interconnected, which are provided at two positions, namely the left and right end portions. In intermediate axle sections between the right and left connecting sections 96A . 96A is the lower outlet water jacket 90A of areas 67A of the combustion chamber water jacket 60 arranged away, with the areas 67A are arranged near the combustion chambers.

As in 15 shown are the combustion chamber water jacket 60 and the lower outlet water jacket 90A such that: the combustion chamber water jacket 60A the combustion chamber side inlet sections 61A (the coolant inlets) included on the right side in the row direction of the cylinders 1a are arranged; the combustion chamber side through holes 34A (Dichtungskühlmitteleinströmlöcher) are arranged at the same positions; the coolant flows (arrows Y22, Y23 and Y24) coming from the combustion chamber side inflow sections 61A there are flowed in the coolant channels in the row direction Lb of the cylinder 1a from the right ends of the inlet water jacket 50A , the combustion chamber water jacket 60A and the lower outlet water jacket 90A to the outlet opening 93A (the coolant outlet) at the left ends thereof.

As in 14 In order to achieve efficient cooling, each candle location environment section is shown 68A from the combustion chamber water jacket disposed on the lower side 60A formed, without any subdivisions on the entire circumference of the section 68A provided.

Meanwhile, every interaxle outlet section is 69A on the combustion chamber water jacket 60A formed on the lower side because of the Zwischenachsauslassabschnitt 69A at a position away from the flow lines (arrows Y20) of the upper outlet water jacket 80A flowing coolant is formed and efficient cooling by using the upper outlet water jacket 80A difficult.

As described above, when the present invention is carried out with the configuration of the first modified example, it is also possible to form the plurality of independent refrigerant passages by placing the water jackets in the upper outlet water jacket 80A located on the upper side, and the lower Auslasswassermantel 90A and the like arranged on the lower side. Thus, it is possible to easily adjust the flow rates of the coolant within each of the water jackets and to let the coolant flow without causing stagnation.

In particular, flows, as in 14 and 15 shown, each in the upper outlet water jacket 80A and lower outlet water jacket 90A the coolant (arrow Y21 or Y22) within the front-side sections 80Ab or the front sections 90ab from the right end portion to the outlet opening 83A or 93A (the coolant outlet) along the inner wall surfaces while increasing its flow velocity. Thus, the flow rate of the coolant is increased in proportion to the flow velocity. As a result, it is possible the exhaust vents 23 and the exhaust collector 24 of the cylinder head 2 to cool effectively (see 1 ).

Here, this modified example enables cooling of the front portions 80Ab which is impossible in the case of the conventional water jacket of the integrated type as described in Patent Document 1. In addition, the increase in the flow rate of the coolant improves the cooling performance and accordingly the cooling effect, so that the cross-sectional areas of the coolant channels can be reduced. Thus, it is possible to have a volume of the outlet water jacket 70A (the upper outlet water jacket 80A and the lower outlet water jacket 90A ) and reduce the size and weight of the cylinder head 2 to reach.

In addition, the upper outlet water jacket 80A cool the cylinder surroundings with the coolant (arrows Y20) and the combustion chamber water jacket 60A can the upper combustion chamber sections 21 effectively cool with the coolant (arrow Y23) from the right end portion to the outlet port 93A (the coolant outlet) flows at the left end portion. Further, the coolant (arrows Y24) flowing into the inlet water jacket flows 50A flows smoothly within the back sections along the inner surfaces to the outlet opening 93A (the coolant outlet), thereby achieving effective cooling).

As described above, the upper outlet water jacket forms 80A and the lower outlet water jacket 90A the independent flow channels of the separate outlet openings 83A and 93A (the coolant outlets). As a result, it is easy to make the flow rates of the coolant and the coolant channels for eliminating stagnant positions (stagnant portions) of the coolant.

(Second modified example)

16 Fig. 10 is an exploded perspective view showing a water jacket structure for a cylinder head of a second modified example of the embodiment. 17 FIG. 10 is a bottom view showing a lower outlet water jacket, an inlet water jacket and a combustion chamber water jacket of the second modified example. FIG.

In the version is the opening 24a of the exhaust collector 24 essentially in the central position of the cylinder head 2 formed in the left-right direction. Instead, as in 16 and 17 shown the opening 24a of the exhaust collector 24 also be formed at a position that is offset either to the right or left.

In addition, the upper outlet water jacket can 80B and the combustion chamber water jacket 60B in intermediate axle sections between right and left connecting sections 62B . 62B by providing connection sections 67B each of which is wider in the left-right direction than the connecting sections 62B . 62B , between the upper outlet water jacket 80B and sections of the combustion chamber water jacket 60B in the vicinity of the combustion chambers are firmly interconnected, as in 16 and 17 shown. By this measure, it is possible, the stiffness of cores for forming the upper Auslasswassermantels 80B and the combustion chamber water jacket 60B to improve and thereby break the connecting sections 67B to prevent during the pouring of the water coats.

The coolant flows into the in 16 and 17 shown water jackets are essentially the same as in the execution. Therefore, the currents are only briefly explained. In the water coats (the combustion chamber water jacket 60B , the upper outlet water jacket 80B and the lower outlet water jacket 90B ), the coolant flows (arrows Y30, Y31, Y32 and Y33) smoothly from the Dichtungsungskühlmitteleinströmlöchern 33B . 34B and 35B in the seal 3 , which serve as coolant inlets, to the outlet ports 63B . 83B and 93B which are arranged at the left end portions without meandering. The flow rate of the refrigerant increases gradually as the refrigerant flows out the discharge ports 63B . 83B and 93B comes closer. The positions where the seal coolant inflow holes 33B . 34B and 35B can be suitably changed, as long as the coolant channels of the water jackets are formed such that the coolant flows described above are achieved. For this reason, the additional through hole 36 and the additional inflow section 95 , in the 12 shown and described in the embodiment, be omitted as in 17 shown.

In addition, the lower outlet water jacket contains 90B Exhaust side through holes 35B formed in right and left portions at the peripheries of the respective cylinders. Thus, the lower Auslasswassermantel 90B Effectively cool the surroundings of the cylinders. The coolant flows (arrows Y30 and Y31) through the outlet-side through holes 35B have flowed in, flow to the front sections 90BB along interior surfaces. Thereafter, the coolant flows converge into a single flow, wherein the coolant to the outlet port 93B flows while its flow velocity is increased and the front-side portions 90BB as well as the exhaust collector 24 cools. Accordingly, the lower outlet water jacket 90B the front side surface and the vicinity of the exhaust manifold 24 effectively cool.

In addition, as in 16 shown, in addition to the outlet openings 63B . 83B and 93B , an extra outlet opening (not shown) can be arranged by a notch 93Ba in the lower outlet water jacket 90B at one of the outlet opening 93B is provided adjacent position.

(Other modified examples)

In the version is the combustion chamber water jacket 60 configured to work with the upper outlet water jacket 80 communicates. However, the present invention is not limited only to this configuration. For example, the combustion chamber water jacket 60 also be configured to work with the lower outlet water jacket 90 communicates, as long as the upper outlet water jacket 80 and the lower outlet water jacket 90 form independent flow channels. Nonetheless, the configuration that configures the combustion chamber water jacket 60 with the upper outlet water jacket 80 a larger width dimension of the connecting sections 62 in the vertical direction. As a result, this configuration can increase the rigidity of the first water jacket core 100 increase as in 4 shown.

Meanwhile, in the embodiment, the projections 81 and 91 both at the upper outlet water jacket 80 as well as the lower outlet water jacket 90 intended. However, the present invention is not limited only to this configuration. Such a projection can also only at one of the upper Auslasswassermantels 80 and the lower outlet water jacket 90 be provided. This configuration can be the downstream sections 24d of the exhaust collector 24 still cool while the upper outlet water jacket 80 and the lower outlet water jacket 90 are separated from each other.

Although the descriptions have been given for the present invention exemplifying the in-line four-cylinder internal combustion engine E, the present invention is not limited only to this configuration. The present invention is also applicable to other internal combustion engines E which include more or fewer cylinders, such as two-cylinder and three-cylinder configurations, and for example also V-type internal combustion engines. Moreover, it goes without saying that the present invention is not limited only to internal combustion engines for automobiles but is also applicable to other internal combustion engines E for ships, general engines, etc.

LIST OF REFERENCE NUMBERS

1

CYLINDER BLOCK

1a

CYLINDER

2

CYLINDER HEAD

2a

BOTTOM

2e

EXHAUST-WIDE SURFACE

2g

EXHAUST-WIDE OUTLET

3

SEAL (HEAD GASKET)

10

BLOCK-SIDE WATER COVER

21

TOP FIRE CHAMBER SECTION

22

suction

23

EXHAUST OPENING

24

COLLECTOR

32

INTRODUCTORY CONTINUITY LOCH (SEALANT COOLANT INSULATION OXYGEN)

33

ZWISCHENACHSDURCHGANGSLOCH (DICHTUNGSKÜHLMITTELEINSTRÖMLOCH)

34, 34A

COMBUSTION THROUGHPUT (GASKET INSULATION OXYGEN)

35, 35B

EXHAUST PIPE LOOP (SEALANT COOLANT MOUNTING OXYGEN)

36

ADDITIONAL CONTINUOUS LOCH (SEALANT COOLANT)

40, 40A, 40B

HEADLESS WATER COVER

50, 50A, 50B

INLET WATER COAT

60, 60A, 60B

COMBUSTION WATER COAT

61, 61A

COOLANT INLET

62

CONNECTION SECTION (COOLANT INLET)

63, 63B, 83, 83A, 83B, 93, 93A, 93B

EXHAUST OPENING (COOLANT EXHAUST)

70, 70A, 70B

AUSLASSWASSERMANTEL

80, 80A, 80B

BUNTER OUTDOOR WATER COVER

84A, 94

EXHAUST PIPE CIRCUIT (COOLANT INTAKE)

90, 90A, 90B

LOWER OUTDOOR WATER COVER

95

ADDITIONAL CIRCUIT SECTION (ADDITIONAL COOLANT INTAKE)

e

COMBUSTION ENGINE

lb

ORIENTATION OF CYLINDERS

Lc

CYLINDER AXLE

A water jacket structure for a cylinder head is provided, which comprises: a plurality of upper combustion chamber sections ( 21 ) located in a lower side of a cylinder head ( 2 ) are formed; a plurality of suction openings ( 22 ) and a plurality of exhaust ports ( 23 ) associated with the plurality of upper combustion chamber sections ( 21 ) keep in touch; an exhaust manifold ( 24 ), which has the majority of exhaust ports ( 23 ) within the cylinder head ( 2 ) merges; and an outlet water jacket ( 70 . 70A . 70B ), which is configured to the exhaust collector ( 24 ), wherein the outlet water jacket ( 70 . 70A . 70B ) an upper outlet water jacket ( 80 . 80A . 80B ) in a cylinder axis direction (Lc) on an upper side of the exhaust collector (FIG. 24 ) and a lower outlet water jacket ( 90 . 90A . 90B ) in the cylinder axis direction (Lc) at a lower side of the exhaust collector (FIG. 24 ), and the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) within the cylinder head ( 2 ) form independent flow channels.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2010-209749 [0005]
• DE 102008059832 [0005]

Claims (12)

A water jacket structure for a cylinder head, comprising: a plurality of upper combustion chamber portions ( 21 ) located in a lower side of a cylinder head ( 2 ) are formed; a plurality of suction openings ( 22 ) and a plurality of exhaust ports ( 23 ) associated with the plurality of upper combustion chamber sections ( 21 ) keep in touch; an exhaust manifold ( 24 ), which has the majority of exhaust ports ( 23 ) within the cylinder head ( 2 ) merges; and an outlet water jacket ( 70 . 70A . 70B ), which is configured to the exhaust collector ( 24 ), wherein the outlet water jacket ( 70 . 70A . 70B ) an upper outlet water jacket ( 80 . 80A . 80B ) in a cylinder axis direction (Lc) on an upper side of the exhaust collector (FIG. 24 ) and a lower outlet water jacket ( 90 . 90A . 90B ) in the cylinder axis direction (Lc) at a lower side of the exhaust collector (FIG. 24 ), and the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) within the cylinder head ( 2 ) form independent flow channels. The water jacket structure for a cylinder head of claim 1, wherein at least one of the upper outlet water jacket (FIG. 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) a lead ( 81 . 91 ) facing the other outlet water jacket ( 80 . 90 ) and is arranged so that it leads to a downstream section ( 24d ) of the exhaust collector ( 24 ). The water jacket structure for a cylinder head of claim 1 or 2, wherein the water jacket structure further comprises: an inlet water jacket (FIG. 50 . 50A . 50B ), which is configured to the suction openings ( 22 ) to cool; and a combustion chamber water jacket ( 60 . 60A . 60B ) connected to the inlet water jacket ( 50 . 50A . 50B ) and is configured to connect the upper combustion chamber sections ( 21 ) and the combustion chamber water jacket ( 60 . 60A . 60B ) with one of the upper Auslasswassermantels ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ). The water jacket structure for a cylinder head of claim 3, wherein, from the upper outlet water jacket (FIG. 80 . 80A . 80B ) and lower outlet water jacket ( 90 . 90A . 90B ), the one with the combustion chamber water jacket ( 60 . 60A . 60B ) is formed such that it has coolant in a row direction of the upper combustion chamber sections ( 21 ). A water jacket structure for a cylinder head, comprising: a plurality of upper combustion chamber portions ( 21 ) located in a lower side of a cylinder head ( 2 ) are formed; a plurality of suction openings ( 22 ) and a plurality of exhaust ports ( 23 ) associated with the plurality of upper combustion chamber sections ( 21 ) keep in touch; an exhaust manifold ( 24 ) inside the cylinder head ( 2 ) is formed and with the multiple exhaust ports ( 23 ); and an outlet water jacket ( 70 . 70A . 70B ), which is configured to the exhaust collector ( 24 ), wherein the outlet water jacket ( 70 . 70A . 70B ) an upper outlet water jacket ( 80 . 80A . 80B ) in a cylinder axis direction (Lc) on an upper side of the exhaust collector (FIG. 24 ) is arranged and configured, coolant in a row direction (Lb) of the cylinder ( 1a ) and a lower outlet water jacket ( 90 . 90A . 90B ) in the cylinder axis direction (Lc) at a lower side of the exhaust collector (FIG. 24 ) is arranged and configured, the coolant in the row direction (Lb) of the cylinder ( 1a ), each of the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) with a coolant inlet ( 84A . 94 ) configured to supply the coolant, a coolant outlet ( 83 . 83A . 83B ) of the upper outlet water jacket ( 80 . 80A . 80B ) and a coolant outlet ( 93 . 93A . 93B ) of the lower outlet water jacket ( 90 . 90A . 90B ) on the cylinder head ( 2 ) are provided independently of each other, the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) within the cylinder head ( 2 ) are formed from independent coolant channels, and the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) are formed such that a flow velocity of the in the lower Auslasswassermantel ( 90 . 90A . 90B ) flowing coolant is faster than a flow rate of the upper Auslasswassermantel ( 80 . 80A . 80B ) flowing coolant. A water jacket structure for a cylinder head of claim 5, wherein one of the upper outlet water jacket (FIG. 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) with the inlet water jacket ( 50 . 50A . 50B ), in which the coolant in the vicinity of the plurality of suction openings ( 22 ), and with a combustion chamber water jacket ( 60 . 60A . 60B ) configured to the upper combustion chamber sections ( 21 ) and the water jacket structure is configured such that a flow rate of the coolant in the combustion chamber water jacket ( 60 . 60A . 60B ) the largest proportion of a flow rate within the cylinder head ( 2 ), and a flow rate of the coolant in the lower outlet water jacket (FIG. 90 . 90A . 90B ) for the second largest fraction according to the flow rate of the coolant in the combustion chamber water jacket ( 60 . 60A . 60B ) becomes. The water jacket structure for a cylinder head of claim 6, wherein the combustion chamber water jacket ( 60 . 60A . 60B ) with one of the upper Auslasswassermantels ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ), and the combustion chamber water jacket ( 60 . 60A . 60B ) is formed such that it cools the coolant in a row direction (Lb) of the cylinders ( 1a ). The water jacket structure for a cylinder head of any one of claims 5 to 7, wherein one of the upper outlet water jacket (FIG. 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) a coolant inlet ( 84 . 94 ) having on one side in the row direction (Lb) of the cylinders ( 1a ) and one of the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) a plurality of the coolant inlets ( 84A . 94A ), which below the plurality of exhaust ports ( 23 ) are arranged. The water jacket structure for a cylinder head of any one of claims 5 to 7, wherein one of the upper outlet water jacket (FIG. 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) a coolant inlet ( 84A . 94 ) having on one side in the row direction (Lb) of the cylinders ( 1a ) and one of the upper outlet water jacket ( 80 . 80A . 80B ) and the lower outlet water jacket ( 90 . 90A . 90B ) a plurality of the coolant inlets ( 84A . 94 ), each between a corresponding pair of cylinders ( 1a ) are arranged. The water jacket structure for a cylinder head of any of claims 7 to 9, wherein, from the upper outlet water jacket ( 80 . 80A . 80B ) and lower outlet water jacket ( 90 . 90A . 90B ), the one that does not communicate with the combustion chamber water jacket ( 60 . 60A . 60B ), a plurality of the coolant inlets ( 84A . 94 ) on sides of the upper combustion chamber sections and is formed such that the coolant along the exhaust side surface ( 2e ) of the cylinder head ( 2 ) and converges into a single flow, wherein the coolant sequentially in the row direction (Lb) of the cylinder ( 1a ) flows. The water jacket structure for a cylinder head of any one of claims 7 to 10, wherein the coolant inlet ( 84A ) of the upper outlet water jacket ( 80 . 80A . 80B ), the coolant inlet ( 94 ) of the lower outlet water jacket ( 90 . 90A . 90B ) and a coolant inlet ( 61 . 61A ) of the combustion chamber water jacket ( 60 . 60A . 60B ) each with sealing coolant inlet holes ( 34 . 35 ; 34A . 35B ) in a head gasket ( 3 ) are formed independently of each other. The water jacket structure for a cylinder head of claim 11, wherein, from the upper outlet water jacket (FIG. 80 . 80A . 80B ) and lower outlet water jacket ( 90 . 90A . 90B ), the one that does not communicate with the combustion chamber water jacket ( 60 . 60A . 60B ), an additional coolant inlet ( 85 ) located between the exhaust ports ( 23 ) for the cylinder ( 1a ) disposed furthest away from the coolant outlet of the one outlet water jacket.

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