JP5130825B2 - Cylinder head of internal combustion engine - Google Patents

Description

  The present invention relates to a cylinder head of an internal combustion engine in which a combustion chamber is configured by being fastened to an upper portion of a cylinder block, and an intake port and an exhaust port are provided for the combustion chamber. The present invention relates to a cooling structure that cools by flowing a cooling medium around.

  In general, in an internal combustion engine, a cylinder head is assembled to an upper portion of a cylinder block and fastened by a plurality of fastening bolts, and a plurality of combustion chambers are arranged in a straight line. An intake port and an exhaust port are formed opposite to each combustion chamber, and an intake passage is communicated with each intake port, while an exhaust passage is communicated with each exhaust port. It can be opened and closed by an exhaust valve. In addition, an injector that injects fuel into each intake port or each combustion chamber is mounted, and an ignition plug that ignites the air-fuel mixture in the combustion chamber is mounted. An intake pipe is connected to each intake port via an intake manifold, while an exhaust pipe is connected to each exhaust port via an exhaust manifold.

  Therefore, when the intake valve is opened, air is sucked into the combustion chamber through the intake port, and fuel is injected from the injector into the intake port or the combustion chamber, and in this combustion chamber, the air-fuel mixture is mixed. Compressed as the piston rises, this high-pressure air-fuel mixture is led to a spark plug, ignites and explodes, and driving force can be obtained. When the exhaust valve is opened, exhaust gas after combustion is discharged through the exhaust port. Is done.

  By the way, in such an internal combustion engine, there is one in which an exhaust collecting portion for collecting a plurality of exhaust ports is provided in the cylinder head without fixing a separate exhaust manifold to the cylinder head. In the internal combustion engine having this exhaust collecting portion, it is possible to reduce the size by eliminating the need for a separate exhaust manifold, and at the time of warm-up, it is possible to activate the catalyst early by suppressing the heat release amount of the exhaust gas. On the other hand, after the engine is warmed up, the exhaust gas can be efficiently cooled to prevent thermal deterioration due to a rise in the temperature of the catalyst, and the fuel consumption can be improved without the need for cooling the catalyst.

  In addition, as a cylinder head of such a conventional internal combustion engine, for example, there is one described in Patent Document 1 below. The cylinder head described in Patent Document 1 integrally forms an exhaust collection portion in which exhaust ports extending from a plurality of combustion chambers arranged on a cylinder row are gathered, and the exhaust ports extend. By providing water jackets at the top and bottom of the part and making the volume of the lower water jacket larger than that of the upper water jacket, the cooling water capacity of the water jacket on the side of the exhaust collecting part with high heat load is expanded, and the exhaust collecting part This increases the cooling efficiency.

Japanese Patent Laid-Open No. 2002-070551

  By the way, in the internal combustion engine, when the combustion gas combusted in the combustion chamber, that is, the exhaust gas is discharged from the combustion chamber through the exhaust port, the exhaust gas flows relatively along the upper wall surface of the exhaust port. In the conventional cylinder head described above, the volume of the upper water jacket is reduced, and the exhaust gas discharged from the combustion chamber through the exhaust port cannot be sufficiently cooled. There is a possibility that the temperature rises due to the gas and the heat deteriorates. Further, when the volume of the lower water jacket is increased, the combustion gas in the combustion chamber is cooled, and at the time of warm-up, it becomes difficult to cool the exhaust gas excessively and activate the catalyst at an early stage.

  An object of the present invention is to provide a cylinder head for an internal combustion engine that improves the cooling efficiency of the internal combustion engine and improves the exhaust gas purification efficiency by the catalyst. .

In order to solve the above-described problems and achieve the object, a cylinder head of an internal combustion engine of the present invention includes a plurality of combustion chambers, a plurality of intake ports communicating with the plurality of combustion chambers, and one end portion of the plurality of intake ports. An exhaust port that communicates with each of the combustion chambers and gathers at the other end, an upper exhaust water jacket provided above the exhaust port, and a lower exhaust water jacket provided below the exhaust port. In the cylinder head of the internal combustion engine, the upper exhaust side water jacket and the lower exhaust side water jacket extend from the center side of the combustion chamber to the exhaust port side, and the upper exhaust side water jacket is connected to the lower exhaust side water jacket. It is longer extended from the jacket, the upper exhaust side water jacket, in each of the plurality of combustion chambers by a partition wall The defined space portion communicates with the end portion on the side away from the combustion chamber, and the lower exhaust-side water jacket has a space portion partitioned by the plurality of combustion chambers by a partition wall of the upper exhaust-side water jacket. It communicates with each space part .

  In the cylinder head of the internal combustion engine of the present invention, an intake side water jacket is provided around the intake port, and the lower exhaust side water jacket communicates with the upper exhaust side water jacket on the combustion chamber side, and It is characterized in that it is communicated with the water jacket on the intake side.

  In the cylinder head of the internal combustion engine of the present invention, the lower exhaust-side water jacket has a partition that is partitioned for each of the plurality of combustion chambers, and the upper exhaust-side water jacket is arranged in the direction in which the plurality of combustion chambers are arranged. And the cooling medium supplied to the lower exhaust water jacket flows along the plurality of combustion chambers while being guided by the partition walls and flows to the upper exhaust water jacket, and the intake water It is characterized by flowing into the jacket.

In an internal combustion engine cylinder head of the present invention, while the supply of the cooling medium at the bottom of the lower exhaust-side water jacket is provided, it is characterized in that the discharge portion of the cooling medium to the intake side water jacket is provided.

According to the cylinder head of the internal combustion engine of the present invention, an exhaust port having one end communicating with a plurality of combustion chambers and the other end gathering is provided, and an upper exhaust water jacket is provided above the exhaust port, A lower exhaust side water jacket is provided below the port, and the upper exhaust side water jacket and the lower exhaust side water jacket are extended from the center of the combustion chamber to the exhaust port side, and the upper exhaust side water jacket is extended from the lower exhaust side water jacket. It extends long and communicates with the upper exhaust-side water jacket at the end portion on the side separated from the combustion chamber by the partition walls separated by a plurality of combustion chambers, and at the lower exhaust-side water jacket by the partition walls. A space section divided for each of the plurality of combustion chambers communicates with each space section of the upper exhaust-side water jacket. Therefore, when the internal combustion engine is at a high load, the high-temperature exhaust gas flowing along the upper wall surface of the exhaust port is cooled by the large upper exhaust water jacket, and the cooling efficiency of the internal combustion engine can be improved. When the engine is warmed up, cooling by the lower exhaust water jacket with a small volume is suppressed, and the catalyst can be activated early to improve the exhaust purification efficiency.

  Hereinafter, an embodiment of a cylinder head of an internal combustion engine according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a schematic configuration diagram of an engine to which a cylinder head of an internal combustion engine according to an embodiment of the present invention is applied. FIG. 2 is an exhaust port of the engine to which the cylinder head of the internal combustion engine of this embodiment is applied. FIG. 3 is a longitudinal sectional view of an ignition plug of an engine to which the cylinder head of the internal combustion engine of this embodiment is applied, and FIG. 4 is an illustration of the engine to which the cylinder head of the internal combustion engine of this embodiment is applied. FIG. 5 is a horizontal cross section (IV-IV cross section in FIG. 2) showing the exhaust side water jacket, and FIG. 5 is a vertical cross section (V in FIG. FIG. 6 is a schematic view showing a mold for manufacturing the cylinder head of the internal combustion engine of this embodiment, and FIG. 7 is a schematic view showing the flow of engine cooling water in the internal combustion engine of this embodiment.

  In the engine as the internal combustion engine of the present embodiment, as shown in FIG. 7, an engine main body 101 is configured by fastening a cylinder head 12 to an upper portion of a cylinder block 11, and a water jacket described later is formed therein. Yes. A cooling water supply passage 105 and a cooling water discharge passage 106 are provided between the water inlet 102 and the water outlet 103 of the cylinder block 11 and the radiator 104, and the water inlet 102 has a thermostat valve 107 and an electric water heater. A pump 108 is attached. In addition, a throttle body 110, a heater core 111, an ATF warmer 112, a turbocharger 113, and the like are connected to the cylinder block 11 through a cooling water passage 109, and these are connected to a water outlet 103 through a cooling water passage 114. Has been.

  Accordingly, when the electric water pump 108 is driven, cooling water (cooling medium) flows from the cylinder block 11 of the engine body 101 to the cylinder head 12 to cool them, and then flows to the throttle body 110 and the turbocharger 113. While these are cooled, it flows to the ATF warmer 112 to warm up the ATF, and flows to the heater core 111 to be used for heating and returned to the water outlet 103.

  The above-described engine main body 101 is an in-line four-cylinder engine, and as shown in FIGS. 1 to 5, a cylinder head 12 is assembled to the upper part of a cylinder block 11 and fastened by a plurality of fastening bolts (not shown). A plurality (four in the present embodiment) of cylinder bores 13 are formed in a straight line on the cylinder block 11, and a piston 14 is fitted to each cylinder bore 13 so as to be movable along the axial direction thereof. A crankshaft (not shown) is rotatably supported at the lower portion of the cylinder block 11, and each piston 14 is connected to the crankshaft via a connecting rod 15.

  The cylinder head 12 is formed with combustion chambers 16 corresponding to the cylinder bores 13 and positioned above the cylinder bores 13. The combustion chamber 16 is surrounded by the inner wall surface of the cylinder bore 13, the lower surface of the cylinder head 12, and the top surface of the piston 14, and is inclined so that the center portion of the ceiling portion (lower surface of the cylinder head 12) is higher. It has a pent roof shape. An intake port 17 and an exhaust port 18 are opened above each combustion chamber 16, that is, on the lower surface of the cylinder head 12 so as to face each other.

  The four intake ports 17 have one end branched into two and communicated with each combustion chamber 16, and the other end opened to the outside. On the other hand, the exhaust port 18 has four exhaust port portions 18 a corresponding to the four combustion chambers 16, and one end portion of each exhaust port portion 18 a branches into two and communicates with each combustion chamber 16. The other end portion of the port portion 18a opens to the outside through an exhaust collecting port portion 18b that gathers together.

  An intake valve 19 and an exhaust valve 20 are located with respect to the intake port 17 and the exhaust port 18, respectively. The intake valve 19 and the exhaust valve 20 are supported by the stem guides 21 and 22 fixed to the cylinder head 12 so as to be movable along the axial direction, and the intake ports 17 and the exhaust ports are supported by the valve springs 23 and 24. It is urged and supported in a direction to close 18. Further, an intake camshaft 25 and an exhaust camshaft 26 are rotatably supported on the cylinder head 12, and an intake cam 27 and an exhaust cam 28 fixed to the intake camshaft 25 and the exhaust camshaft 26. Is in contact with the upper end portions of the intake valve 19 and the exhaust valve 20 via the lifters 29 and 30. A cylinder head cover 31 is fixed to the upper portion of the cylinder head 12 so as to cover the intake camshaft 25 and the exhaust camshaft 26.

  Therefore, when the intake camshaft 25 and the exhaust camshaft 26 rotate in synchronization with the internal combustion engine, the intake cam 27 and the exhaust cam 28 move up and down the intake valve 19 and the exhaust valve 20 via the lifters 29 and 30 at a predetermined timing. As a result, the intake port 17 and the exhaust port 18 can be opened and closed, and the intake port 17 and the combustion chamber 16 can be communicated with each other.

  Further, injectors 32 for injecting fuel into the intake ports 17 are mounted on the side portions of the cylinder head 12 so as to correspond to the intake ports 17. A spark plug 33 is mounted at the center of the cylinder head 12 so as to be positioned at the center of the ceiling of each combustion chamber 16. The vehicle is equipped with an electronic control unit (ECU) (not shown), which can control the fuel injection timing of the injector 32, the ignition timing by the spark plug 33, and the like. The fuel injection amount, injection timing, ignition timing, and the like are determined based on the engine operating state such as the amount, throttle opening (accelerator opening), and engine speed.

  An intake manifold 34 communicating with each intake port 17 is fixed to one side surface of the cylinder head 12, and a surge tank 35 is connected to the intake manifold 34. The intake pipe 36 has an air cleaner 37 attached to the upstream air intake port, and a downstream end connected to the surge tank 35. The intake pipe 36 is positioned between the air cleaner 37 and the surge tank 35 and has a throttle valve. An electronic throttle device 38 is provided.

  On the other hand, an exhaust pipe 39 communicating with the exhaust collecting port portion 18b of the exhaust port 18 is connected to the other side of the cylinder head 12, and an exhaust purification catalyst (three-way catalyst) 40 is attached to the exhaust pipe 39. Yes.

  Here, the cooling system in the engine of the present embodiment will be described in detail. In the engine of the present embodiment, as described above, the cylinder head 12 has the four exhaust port portions 18a communicating with the four combustion chambers 16, and the exhaust collecting port portion 18b that collects the exhaust port portions 18a into one. The exhaust port 18 is integrally formed, and a separate exhaust manifold is unnecessary.

  The cylinder block 11 is formed with an exhaust water jacket 41 and an intake water jacket 42. The exhaust water jacket 41 is formed on the exhaust port 18 side of each cylinder bore 13 arranged in a straight line, and a cooling water supply unit 43 is provided at one lower portion in the arrangement direction of each cylinder bore 13. On the other hand, the intake-side water jacket 42 is formed on the intake port 17 side of each cylinder bore 13 arranged in a straight line, and a cooling water discharge portion 44 is provided at the other lower portion in the arrangement direction of each cylinder bore 13.

  The cylinder head 12 is provided with an upper exhaust water jacket 45 located above the exhaust port 18 and a lower exhaust water jacket 46 located below the exhaust port 18. On the other hand, the cylinder head 12 is provided with an intake water jacket 47 located around the intake port 17.

  The upper exhaust-side water jacket 45 and the lower exhaust-side water jacket 46 are arranged on the exhaust port 18 side of each combustion chamber 16 arranged in a straight line, and are provided as space portions located above and below each exhaust port 18. ing. The space portions of the upper exhaust-side water jacket 45 and the lower exhaust-side water jacket 46 are divided into four space portions by support columns 48 and partition walls 49 provided between the combustion chambers 16. The upper exhaust-side water jacket 45 is divided into four spaces by the support pillars 48 and the partition walls 49, and each combustion chamber 16 is inserted into the combustion chamber 16 by an insertion passage 50 provided at an end portion on the side away from the combustion chamber 16. It communicates along the arrangement direction. On the other hand, the lower exhaust-side water jacket 46 communicates with the upper portion of the exhaust-side water jacket 41 for each space portion where the lower portion is defined by the support column 48 and the partition wall 49, and is connected to the cylinder from the exhaust-side water jacket 41 of the cylinder block 11. This is a supply unit for supplying cooling water to the lower exhaust-side water jacket 46 of the head 12.

  In this case, the volume of the upper exhaust side water jacket 45 is set larger than the volume of the lower exhaust side water jacket 46. Specifically, the upper exhaust side water jacket 45 and the lower exhaust side water jacket 46 are extended from the center side of the combustion chamber 16 to the exhaust port 18 side, and the upper exhaust side water jacket 45 is more than the lower exhaust side water jacket 46. It is extended for a long time.

  On the other hand, the intake side water jacket 47 is provided as a space around each intake port 17 on the intake port 17 side of each combustion chamber 16 arranged in a straight line, and a partition wall 51 corresponding to the partition wall 49. And is communicated along the arrangement direction of each combustion chamber 16 by the air vent passage 52. The intake-side water jacket 47 communicates with the upper portion of the intake-side water jacket 42 for each space portion where the lower portion is partitioned by the partition wall 51. It is a discharge part for discharging cooling water to the jacket 42.

  The lower exhaust-side water jacket 46 communicates with the upper exhaust-side water jacket 45 through four upper and lower communication passages 53 provided corresponding to the combustion chambers 16, and is provided corresponding to the combustion chambers 16. The intake water jacket 47 communicates with the four horizontal communication passages 54. In this case, the upper and lower communication passages 53 are passages in which cooling water flows from the lower exhaust-side water jacket 46 to the upper exhaust-side water jacket 45 through the periphery of the two exhaust ports 18 and the spark plug 33, and the horizontal communication passage 54. The cooling water flows from the lower exhaust side water jacket 46 to the intake side water jacket 47 through the periphery of the two exhaust ports 18, the spark plug 33, and the two intake ports 17.

  In the engine body 101 of the present embodiment configured as described above, when the cooling water is supplied from the cooling water supply unit 43 of the cylinder block 11 to the exhaust-side water jacket 41, the cooling water in the exhaust-side water jacket 41 is Each cylinder flows into the lower exhaust-side water jacket 46 of the cylinder head 12. Then, the cooling water that has flowed into the lower exhaust-side water jacket 46 flows to the upper exhaust-side water jacket 45 so as to be reversed through each of the upper and lower communication passages 53, merges through the insertion passage 50, and the cylinder block 11. To the intake-side water jacket 42.

  The cooling water that has flowed into the lower exhaust-side water jacket 46 flows to the intake-side water jacket 47 through the exhaust ports 18, the spark plugs 33, and the surroundings of the intake ports 17 while being guided by the plurality of partition walls 49. Then, the air flows from the intake water jacket 47 to the intake water jacket 42 of the cylinder block 11. Then, the cooling water that has flowed from the intake-side water jacket 47 to the intake-side water jacket 42 of the cylinder block 11 is discharged from the cooling water discharge portion 44 to the outside.

  That is, in each of the water jackets 45, 46, 47 of the cylinder head 12, the cooling water supplied from below the exhaust side flows above the exhaust port 18 and also flows to the intake port 17 side. The engine cooling structure has a so-called cooling water lateral flow structure in which cooling water flows in the lateral direction (exhaust side-intake side) of the engine body 101.

  Accordingly, the combustion gas combusted in each combustion chamber 16 is discharged as exhaust gas to the exhaust port 18. When the amount of exhaust gas is large, such as when the engine is at a high load, this exhaust gas is relatively higher than the exhaust port 18. It flows along the wall. However, in this embodiment, the volume of the upper exhaust-side water jacket 45 is set larger than the volume of the lower exhaust-side water jacket 46, and the tip of the upper exhaust-side water jacket 45 is longer than the tip of the lower exhaust-side water jacket 46. It is extended. Therefore, the exhaust gas discharged from each combustion chamber 16 through the exhaust port 18 is appropriately cooled by the cooling water of the upper exhaust water jacket 45 having a large volume. That is, even when the exhaust gas temperature is high, such as when the engine is under high load, the exhaust gas is sufficiently cooled, and the exhaust purification catalyst 40 is prevented from thermal degradation due to the high-temperature exhaust gas.

  Further, when the amount of exhaust gas is small, such as when the internal combustion engine is cold started, the exhaust gas flows along the center of the exhaust port 18. Therefore, the combustion gas in each combustion chamber 16 and the exhaust gas discharged to the exhaust port 18 are not so much cooled by the cooling water of the lower exhaust side water jacket 46 having a small volume. That is, in an operating state where the exhaust gas temperature is low, such as when the engine is cold started, the exhaust gas purification catalyst 40 is activated early by flowing the exhaust gas to the exhaust gas purification catalyst 40 without being cooled much.

  The cylinder head 12 described above is manufactured by casting, and a casting mold for manufacturing the cylinder head 12 includes a lower mold, a middle mold, a pair of horizontal molds, and an upper mold. Among these, as shown in FIG. 6, the middle mold 71 includes a water jacket core 72 corresponding to the three water jackets 45, 46, 47 described above and an exhaust port core 73 corresponding to the exhaust port 18. The water jacket core 72 corresponds to the upper exhaust side core 74 corresponding to the upper exhaust side water jacket 45, the lower exhaust side core 75 corresponding to the lower exhaust side water jacket 46, and the intake side water jacket 47. The exhaust port core 73 is assembled to the intake side core (not shown).

  In this embodiment, in the cylinder head 12, the volume of the upper exhaust side water jacket 45 is set larger than the volume of the lower exhaust side water jacket 46, and the protrusion extends from the center side of the combustion chamber 16 to the exhaust port 18 side. The amount of the upper exhaust water jacket 45 is set longer than that of the lower exhaust water jacket 46. Therefore, in the water jacket core 72, the protrusion amount of the lower exhaust side core 75 is shorter than the protrusion amount of the upper exhaust side core 74. In addition, 76 is a communication part with the exhaust side water jacket 41 of the cylinder block 11, 77 is a mounting hole of the spark plug 33, and 78 and 79 are connection parts with an upper mold | type.

  Accordingly, since the exhaust port core 73 has a shape corresponding to the exhaust port 18, the tip end portion is curved downward, and the exhaust port core 73 is connected to the water jacket core 72. When assembling, as shown by a two-dot chain line in FIG. 6, the distal end portion is inserted into the through hole of the water jacket core 72 and assembled with the base end portion positioned downward. In this case, since the protruding amount of the lower exhaust side core 75 is shorter than the protruding amount of the upper exhaust side core 74, the exhaust port core 73 is assembled properly without contacting the lower exhaust side core 75. be able to.

  As described above, in the cylinder head of the internal combustion engine of the present embodiment, the plurality of intake ports 17 that communicate with the plurality of combustion chambers 16 are provided, respectively, while one end portion communicates with the plurality of combustion chambers 16 and the other end. The exhaust port 18 in which the parts gather is provided, the upper exhaust side water jacket 45 is provided above the exhaust port 18, and the lower exhaust side water jacket 46 is provided below the exhaust port 18, and the volume of the upper exhaust side water jacket 45 is provided. Is set larger than the volume of the lower exhaust-side water jacket 46.

  Therefore, when the engine is heavily loaded, the high-temperature exhaust gas flowing along the upper wall surface of the exhaust port 18 is efficiently cooled by the upper exhaust water jacket 45 having a large volume, and the engine cooling efficiency can be improved. When the engine is warmed up, the cooling by the lower exhaust side water jacket 46 having a small volume is suppressed, and the exhaust purification catalyst 40 can be activated early to improve the exhaust purification efficiency.

  Further, the upper exhaust side water jacket 45 and the lower exhaust side water jacket 46 are extended from the center side of the combustion chamber 16 to the exhaust port 18 side, and the upper exhaust side water jacket 45 is extended longer than the lower exhaust side water jacket 46. ing. Therefore, when the engine is heavily loaded, the high-temperature exhaust gas flowing along the upper wall surface of the exhaust port 18 is efficiently cooled by the long upper exhaust-side water jacket 45, and the engine cooling efficiency can be improved.

  In this case, a middle mold for casting the cylinder head 12 is constituted by a water jacket core 72 corresponding to each water jacket 45, 46, 47 and an exhaust port core 73 corresponding to the exhaust port 18, and the upper exhaust side. The protrusion amount of the lower exhaust side core 75 corresponding to the lower exhaust side water jacket 46 is shorter than the protrusion amount of the upper exhaust side core 74 corresponding to the water jacket 45. Therefore, when the exhaust port core 73 is assembled to the water jacket core 72, the exhaust port core 73 can be properly assembled without contacting the lower exhaust side core 75.

  Further, in the cylinder head of the internal combustion engine of the present embodiment, the intake side water jacket 47 is provided around the intake port 17, and the lower exhaust side water jacket 46 is connected to the combustion chamber 16 side by the upper and lower communication passages 53 and the upper exhaust side water jacket 45. To the intake side water jacket 47 through the horizontal communication passage 54. Therefore, in the cylinder head 12, the cooling water flows from the exhaust side to the intake side, and it becomes possible to circulate a large amount of cooling water by reducing the flow rate of the cooling water, thereby improving the cooling efficiency of the engine. it can.

  Further, in the cylinder head of the internal combustion engine of the present embodiment, the lower exhaust side water jacket 46 is partitioned by the partition wall 49 for each combustion chamber 16, and the upper exhaust side water jacket 45 is arranged in the direction in which each combustion chamber 16 is disposed by the insertion passage 50. The cooling water supplied to the lower exhaust-side water jacket 46 is guided to the partition wall 49 and flows above the combustion chambers 16 to flow to the upper exhaust-side water jacket 45 and to the intake-side water jacket. 47 to flow. Accordingly, it is possible to read the cooling water from the exhaust side to the intake side in the cylinder head 12, and to reduce the flow rate of the cooling water and to circulate a large amount of cooling water, thereby improving the cooling efficiency of the engine. can do.

  Further, in the cylinder head of the internal combustion engine of the present embodiment, the cooling water can be supplied from the exhaust side water jacket 41 of the cylinder block 11 to the lower exhaust side water jacket 46, and the upper exhaust side water jacket 45 and the intake side water jacket. The cooling water 47 can be discharged to the intake water jacket 42 of the cylinder block 11. Therefore, the cooling water can be circulated efficiently between the cylinder block 11 and the cylinder head 12.

  In the above-described embodiment, the internal combustion engine is described as an in-line four-cylinder engine. However, the present invention is not limited to this type. In the above-described embodiments, the description has been made of the port injection type internal combustion engine that injects the fuel into the intake port. However, the same effect as described above can be applied to a cylinder injection type internal combustion engine that injects the fuel directly into the combustion chamber. There is an effect.

  As described above, the cylinder head of the internal combustion engine according to the present invention improves the cooling efficiency of the internal combustion engine by making the volume of the upper exhaust side water jacket larger than the volume of the lower exhaust side water jacket. This type of internal combustion engine is also suitable.

1 is a schematic configuration diagram of an engine to which a cylinder head of an internal combustion engine according to an embodiment of the present invention is applied. It is a longitudinal cross-sectional view in the exhaust port of the engine to which the cylinder head of the internal combustion engine of a present Example was applied. It is a longitudinal cross-sectional view in the ignition plug of the engine to which the cylinder head of the internal combustion engine of a present Example was applied. It is a horizontal section (IV-IV section of Drawing 2) figure showing the exhaust side water jacket of the engine to which the cylinder head of the internal-combustion engine of this example was applied. It is a longitudinal section (VV section of Drawing 2) figure showing an exhaust side water jacket of an engine to which a cylinder head of an internal-combustion engine of this example is applied. It is the schematic showing the casting_mold | template which manufactures the cylinder head of the internal combustion engine of a present Example. It is the schematic showing the flow of the engine cooling water in the internal combustion engine of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Cylinder block 12 Cylinder head 14 Piston 16 Combustion chamber 17 Intake port 18 Exhaust port 32 Injector 33 Spark plug 41 Exhaust side water jacket 42 Intake side water jacket 43 Cooling water supply part 44 Cooling water discharge part 45 Upper exhaust side water jacket 46 Lower part Exhaust side water jacket 47 Intake side water jacket 49,51 Bulkhead 53 Vertical communication path 54 Horizontal communication path

Claims (4)

A plurality of combustion chambers, a plurality of intake ports communicating with the plurality of combustion chambers, an exhaust port having one end communicating with each of the plurality of combustion chambers and the other end collecting, and above the exhaust port In a cylinder head of an internal combustion engine including an upper exhaust water jacket provided and a lower exhaust water jacket provided below the exhaust port, the upper exhaust water jacket and the lower exhaust water jacket are the combustion extending from the center side of the chamber to the exhaust port side, said upper exhaust side water jacket is longer extended from the lower exhaust side water jacket, said upper exhaust side water jacket, in each of the plurality of combustion chambers by a partition wall The partitioned space portion communicates with the end portion on the side away from the combustion chamber, and the lower exhaust side water Jacket is a cylinder head of an internal combustion engine, wherein the plurality of space portions partitioned for each combustion chamber communicating with the respective space portions of the upper exhaust side water jacket by a partition wall. An intake side water jacket is provided around the intake port, and the lower exhaust side water jacket communicates with the upper exhaust side water jacket on the combustion chamber side and communicates with the intake side water jacket. 2. A cylinder head for an internal combustion engine according to claim 1 , wherein The lower exhaust-side water jacket has a partition wall that is partitioned for each of the plurality of combustion chambers, and the upper exhaust-side water jacket is continuous along a direction in which the plurality of combustion chambers are disposed, claims coolant supplied to the jacket while flowing into the upper exhaust side water jacket to flow upward of the plurality of combustion chambers while being induced in the partition wall, characterized in that the flow into the intake side water jacket Item 3. The cylinder head of the internal combustion engine according to Item 2 . The cylinder head of the internal combustion engine according to claim 3 , wherein a cooling medium supply part is provided at a lower part of the lower exhaust side water jacket, and a cooling medium discharge part is provided at the intake side water jacket.

Images