JP2016014352A - Cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head which inhibits accumulation of a coolant in an outlet cooling part of a water jacket.SOLUTION: A cylinder head 100 includes: an exhaust passage 110 including exhaust ports 111 respectively connected with cylinders 210, an assembly part 112 where the exhaust ports 111 are assembled, and an outlet part 113 which extends from the assembly part 112 in a curved manner. The cylinder head 100 includes an upper water jacket 120 which is provided along the exhaust ports 111 and the assembly part 112. The upper water jacket 120 has an outlet cooling part 122 extending along the outlet part 113. In the cylinder head 100, an introduction passage 125 connected with the outlet cooling part 122 is provided outside the upper water jacket 120.

Description

  The present invention relates to a cylinder head integrated with an exhaust manifold.

  Patent Document 1 discloses a cylinder head in which exhaust ports of respective cylinders are assembled in a cylinder head and an exhaust manifold is integrated. In this cylinder head, water jackets are provided above and below the exhaust passage so as to sandwich the exhaust passage. Patent Document 1 also discloses a configuration in which an outlet portion of an exhaust passage provided in the cylinder head is curved and directed downward. If such a configuration is adopted, the turbocharger can be disposed close to the cylinder block, and the internal combustion engine can be downsized.

Japanese Utility Model Publication No. 2-72347

  By the way, when adopting a configuration in which the outlet portion of the exhaust passage is curved downward as described above, the water jacket is directed downward along the outlet portion of the exhaust passage in order to cool the outlet portion. It is desirable to extend.

  However, when a part of the water jacket is extended along the outlet part and an outlet cooling part for cooling the outlet part is provided, the outlet cooling part becomes a bag path and the cooling water tends to stay. As a result, there is a possibility that the outlet portion, which is particularly likely to become hot, in the exhaust passage in the cylinder head cannot be sufficiently cooled.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cylinder head capable of suppressing the retention of cooling water in the outlet cooling portion of the water jacket.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A cylinder head for solving the above problems includes an exhaust passage having a plurality of exhaust ports connected to each cylinder, an aggregate portion in which the exhaust ports are aggregated, and an outlet portion that is curved and extends from the aggregate portion. I have. The cylinder head further includes a water jacket provided along the exhaust port and the collecting portion, and the water jacket includes an outlet cooling portion extending along the outlet portion. In this cylinder head, a cooling water passage connected to the outlet cooling section is provided outside the water jacket.

  According to the above configuration, the cooling water flows into the outlet cooling section through the cooling water passage connected to the outlet cooling section, and the cooling water outflow from the outlet cooling section through the cooling water passage connected to the outlet cooling section. As a result, a pressure difference is generated in the cooling water in the outlet cooling section, so that a flow easily occurs in the cooling water in the outlet cooling section. Therefore, the retention of the cooling water at the outlet cooling portion of the water jacket can be suppressed. As a result, cooling of an exit part can be accelerated | stimulated.

In one example of the cylinder head, the cooling water passage is an introduction passage for introducing cooling water into the outlet cooling section.
According to the above configuration, since the cooling water is introduced from the introduction passage to the outlet cooling portion, a pressure difference is generated in the cooling water in the outlet cooling portion, so that the cooling water in the outlet cooling portion is a collection of exhaust ports and exhaust passages. It flows into the part provided along the part and is discharged from the water jacket together with the cooling water flowing through the part.

Therefore, the circulation of the cooling water in the outlet cooling unit can be promoted and the retention of the cooling water can be suppressed.
In the cylinder head in which the introduction passage is connected to the outlet cooling section as described above, the introduction passage branches from a portion upstream of the water jacket in the cooling water circulation path, and the cooling water is supplied to the outlet cooling section. It is desirable to introduce.

  When cooling water introduced into the water jacket through a passage narrower than the water jacket flows into the water jacket wider than the passage, the pressure decreases. On the other hand, according to the above configuration, the cooling water before flowing into the water jacket and dropping in pressure can be introduced into the outlet cooling unit, so that the cooling water stays in the outlet cooling unit more effectively. Can be suppressed.

In one example of the cylinder head, the cooling water passage is a discharge passage for discharging cooling water from the outlet cooling section.
According to the said structure, a pressure difference arises in the cooling water in an exit cooling part because the cooling water in an exit cooling part is discharged | emitted through a discharge channel. Therefore, the cooling water flows into the outlet cooling section from the portion provided along the exhaust port and the collection section of the exhaust passage, so that the flowing cooling water is discharged from the outlet cooling section through the discharge passage. Become.

  Therefore, the circulation of the cooling water in the outlet cooling unit can be promoted and the retention of the cooling water can be suppressed.

The schematic diagram which shows the cooling water circulation path | route in an internal combustion engine provided with the cylinder head of 1st Embodiment. Sectional drawing which shows the cross-section of the exhaust side part in the cylinder head of 1st Embodiment. The schematic diagram which shows the positional relationship of the exhaust passage and water jacket in the cylinder head concerning 1st Embodiment. Sectional drawing which shows the cross-section of the exhaust side part in the cylinder head of 2nd Embodiment. The schematic diagram which shows the positional relationship of the exhaust passage and water jacket in the cylinder head concerning 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of a cylinder head will be described with reference to FIGS.
As shown in FIG. 1, the cylinder head 100 is assembled to a cylinder block 200 and constitutes a part of the internal combustion engine. The cooling water circulation path of the internal combustion engine including the cylinder head 100 includes a water pump 10, an in-block water jacket 11 provided in the cylinder block 200, an in-head water jacket 12 provided in the cylinder head 100, A radiator 13 is provided.

  As shown in FIG. 1, the discharge port of the water pump 10 is connected to the water jacket 11 in the block by a cooling water passage 14, and the cooling water discharged from the water pump 10 passes through the cooling water passage 14 in the block. Introduced into the water jacket 11.

  The water jacket 11 in the block and the water jacket 12 in the head are connected by a cooling water passage 15, and the cooling water that has passed through the water jacket 11 in the block is introduced into the water jacket 12 in the head through the cooling water passage 15. Is done.

  The in-head water jacket 12 is connected to the radiator 13 by the cooling water passage 16, and the cooling water that has passed through the in-head water jacket 12 is introduced into the radiator 13 through the cooling water passage 16.

  The radiator 13 is connected to the suction port of the water pump 10 by a cooling water passage 17, and the cooling water that has passed through the radiator 13 is sucked into the water pump 10 through the cooling water passage 17.

As shown in FIG. 2, the cylinder head 100 is provided with an exhaust passage 110 that is an exhaust passage exhausted from the cylinder 210 of the cylinder block 200.
The exhaust passage 110 has an exhaust port 111 connected to the cylinder 210 as shown in FIG. Although only one exhaust port 111 and one cylinder 210 are shown in FIG. 2, this internal combustion engine is an in-line four-cylinder internal combustion engine having four cylinders 210. Two are provided for each cylinder 210.

  The exhaust passage 110 is curved downward in FIG. 2 at the outlet portion 113, and the outlet portion 113 of the exhaust passage 110 is opened on the lower surface of the cylinder head 100. And the part which comprises an exhaust passage of the downstream side, such as a turbocharger, is connected to the part in which this exit part 113 in the cylinder head 100 is opening.

  Further, the cylinder head 100 is provided with an upper water jacket 120 and a lower water jacket 130 as the in-head water jacket 12 so as to sandwich the exhaust passage 110 from above and below.

  As shown in FIG. 2, the lower water jacket 130 is formed in the cylinder head 100 at a lower portion than the exhaust passage 110 so as to be along the exhaust passage 110, and below the exhaust passage 110 exposed to the exhaust. The side wall surface is cooled by heat exchange with the cooling water flowing inside.

  On the other hand, the upper water jacket 120 is formed on the upper side of the exhaust passage 110 in the cylinder head 100 as shown in FIG. 2 so as to extend along the exhaust passage 110, and the upper water jacket 120 is exposed to the exhaust. The upper wall surface is cooled by heat exchange with the cooling water flowing inside.

Next, the shapes of the exhaust passage 110 and the upper water jacket 120 will be described in detail with reference to FIG.
FIG. 3 shows the shapes of the exhaust passage 110 and the upper water jacket 120 when the cylinder head 100 is viewed from the direction indicated by the white arrow in FIG. 2, and the positional relationship between them. In FIG. 3, the upper water jacket 120 provided above the exhaust passage 110 so as to cover the exhaust passage 110 is indicated by a solid line, and the exhaust passage 110 is indicated by a broken line. Incidentally, the cross-sectional view of FIG. 2 shows a cross-sectional structure of the cylinder head 100 taken along line 2-2 in FIG.

  As shown by a broken line in FIG. 3, the exhaust passage 110 is provided with a plurality of exhaust ports 111 that are inlets, but only one outlet portion 113 that is an outlet. Therefore, in the exhaust passage 110, the exhaust ports 111 are gathered at the gathering portion 112, and the exit portion 113 is a single passage.

  The upper water jacket 120 for cooling the upper wall surface of the exhaust passage 110 having such a shape is a cylinder head so as to cover the portion where the exhaust ports 111 and the collecting portion 112 are formed from above as shown by the solid line in FIG. 100 has a shape extending long in the longitudinal direction.

  Thus, the upper water jacket 120 having a shape extending along the longitudinal direction of the cylinder head 100 is provided with an inflow port 123 at the right end in FIG. 3 and discharged at the left end in FIG. An outlet 124 is provided. The cooling water passage 15 is connected to the inflow port 123, and the cooling water passage 16 is connected to the discharge port 124. As a result, part of the cooling water flowing through the cooling water circulation path of the internal combustion engine is introduced into the upper water jacket 120 through the inlet 123, and the cooling water heated by cooling the wall surface of the exhaust passage 110 is discharged through the outlet 124. Is done.

  By the way, the outlet portion 113 is a portion in which exhaust gas collected through the collecting portion 112 flows in a concentrated manner, and thus is a portion that tends to be hot in the exhaust passage 110. In addition, as described above, in the cylinder head 100, the outlet portion 113 of the exhaust passage 110 extends in a curved manner toward the lower surface of the cylinder head 100. When the outlet 113 is curved in this way, the exhaust gas flowing from the upstream side collides with the wall surface of the portion surrounded by the alternate long and short dash line in FIG.

  On the other hand, in this cylinder head 100, as shown in FIGS. 2 and 3, a part of the upper water jacket 120 is disposed along the outlet portion 113 in order to cool the wall surface of the outlet portion 113 that is likely to become high temperature. The outlet cooling unit 122 is extended to the vicinity of the lower surface of the cylinder head 100.

  In other words, in this cylinder head 100, the upper water jacket 120 corresponds to “a water jacket having an outlet cooling portion extending along the outlet portion and provided along the exhaust port and the collecting portion”.

  By the way, simply providing the outlet cooling part 122 extending along the outlet part 113 may cause the cooling water to stay in the outlet cooling part 122 that is a bag path, and the wall surface of the outlet part 113 may not be sufficiently cooled. There is.

  Therefore, in this cylinder head 100, an introduction passage 125 for introducing cooling water is connected to the front end portion of the bag path of the outlet cooling portion 122 surrounded by a one-dot chain line in FIGS. 2 and 3, and the outlet cooling portion 122 is connected through this introduction passage 125. Cooling water is introduced into the.

  Specifically, as shown in FIG. 2, a connection portion 101 connected to the outlet cooling portion 122 of the upper water jacket 120 is provided outside the cylinder head 100, and an introduction passage 125 is formed by connecting a hose 140 to the connection portion 101. doing. The other end of the hose 140, that is, the other end of the introduction passage 125 is discharged from a portion upstream of the upper water jacket 120 in the cooling water circulation path of the internal combustion engine, for example, the water pump 10. The cooling water is connected to a cooling water passage 14 for introducing the cooling water into the water jacket 11 in the block.

  That is, as shown in FIG. 1, the introduction passage 125 branches off from the cooling water passage 14 that is a portion upstream of the upper water jacket 120 in the cooling water circulation passage of the internal combustion engine and has a lower pressure than the inside of the cooling water passage 14. This is a cooling water passage for introducing cooling water into the outlet cooling section 122.

In short, in the cylinder head 100, the introduction passage 125 is provided outside the upper water jacket 120 as a cooling water passage connected to the outlet cooling section 122.
Next, the operation of the cylinder head 100 according to the present embodiment will be described.

  Exhaust gas discharged from each cylinder 210 through each exhaust port 111 is collected through the collecting portion 112, passes through the outlet portion 113, and is discharged into a downstream exhaust passage such as a turbocharger.

At this time, the wall surface of the exhaust passage 110 is cooled by the cooling water flowing through the upper water jacket 120 and the lower water jacket 130.
As indicated by an arrow on the right side of FIG. 3, a part of the cooling water flowing through the cooling water circulation path of the internal combustion engine is introduced into the upper water jacket 120 through the inlet 123. Then, as indicated by an arrow on the left side of FIG. 3, the cooling water heated by cooling the wall surface of the exhaust passage 110 is discharged from the discharge port 124.

  Further, as indicated by an arrow at the bottom of FIG. 3, cooling water is introduced into the outlet cooling portion 122 of the upper water jacket 120 through the introduction passage 125 due to a pressure difference between the cooling water passage 15 and the outlet cooling portion 122. Is done. Then, due to the flow of the cooling water introduced from the introduction passage 125, the cooling water in the outlet cooling section 122 flows into the portions provided along the exhaust port 111 and the collecting section 112 as shown by arrows, The water is discharged from the upper water jacket 120 together with the flowing cooling water.

According to the first embodiment described above, the following effects can be obtained.
(1) Since the cooling water is introduced through the introduction passage 125, a pressure difference is generated in the cooling water in the outlet cooling unit 122, so that the cooling water in the outlet cooling unit 122 is likely to flow. Therefore, the retention of the cooling water in the outlet cooling part 122 of the upper water jacket 120 can be suppressed. As a result, cooling of the exit part 113 can be accelerated | stimulated.

  (2) Since the introduction passage 125 is connected to the front end portion of the bag path of the outlet cooling unit 122, the flow of cooling water is generated in the portion where it is most likely to stay, and the stay can be effectively suppressed.

  (3) When the cooling water introduced into the upper water jacket 120 through the cooling water passage 15 narrower than the upper water jacket 120 flows into the upper water jacket 120 wider than the cooling water passage 15, the pressure decreases. On the other hand, in the cylinder head 100 of the first embodiment, since the cooling water before flowing into the upper water jacket 120 and dropping in pressure can be introduced into the outlet cooling part 122, the outlet cooling part 122 The retention of the cooling water can be effectively suppressed.

  (4) Further, when the outlet cooling section 122 is a bag path, chips are collected in the outlet cooling section 122 when cleaning the chips generated by cutting or the like in the manufacturing process of the cylinder head 100. There is a possibility that the chips cannot be removed sufficiently. On the other hand, since the outlet cooling part 122 of the cylinder head 100 is provided with the connecting part 101 that constitutes the introduction passage 125, this connecting part is used when cleaning the chips generated by the cutting process during manufacturing. Chips are discharged through 101. Therefore, the chips can be easily cleaned in the manufacturing process.

In addition, the said 1st Embodiment can also be implemented with the following forms which changed this suitably.
-Although the example which connected the introduction passage 125 branched from the upper water jacket 120 to the exit cooling part 122 was shown, the cooling water is introduce | transduced into the exit cooling part 122, and the flow of the cooling water in the exit cooling part 122 Can be promoted, the branch position of the introduction passage 125 can be changed. For example, a configuration in which the introduction passage 125 is branched from the upper water jacket 120 as indicated by a broken line in FIG. That is, the introduction passage 125 is branched from a part where the pressure of the cooling water is higher than that in the outlet cooling part 122, such as a part closer to the inlet 123 than the outlet cooling part 122 in the upper water jacket 120, and is connected to the outlet cooling part 122. A configuration can also be adopted. Even when such a configuration is adopted, the flow of the cooling water in the outlet cooling unit 122 can be promoted by the cooling water introduced through the introduction passage 125, and the retention of the cooling water in the outlet cooling unit 122 can be suppressed. .

(Second Embodiment)
Hereinafter, a second embodiment of the cylinder head will be described with reference to FIGS. 4 and 5.

  In the cylinder head 100 of the first embodiment described above, the configuration in which the introduction passage 125 is connected to the outlet cooling unit 122 is illustrated, but in the cylinder head 100 according to the second embodiment, the introduction passage 125 is connected. Instead, a configuration in which the discharge passage 126 is connected to the outlet cooling unit 122 is adopted. Since the other configuration is the same as that of the cylinder head 100 in the first embodiment, the difference will be mainly described here, and the same components as those in the cylinder head 100 in the first embodiment are denoted by the same reference numerals. And omit redundant explanations.

  As shown in FIG. 4, also in the cylinder head 100 according to the second embodiment, a hose 140 is connected to the connecting portion 101. However, the other end of the hose 140 in the cylinder head 100 of the second embodiment is connected to a portion downstream of the upper water jacket 120 in the cooling water circulation path of the internal combustion engine, for example, the cooling water passage 16. (The chain line in FIG. 1). As a result, the cooling water in the outlet cooling section 122 is discharged to the downstream side of the upper water jacket 120 in the cooling water circulation path of the internal combustion engine through the connection section 101 and the hose 140. That is, unlike the first embodiment in which the introduction passage 125 is connected to the outlet cooling unit 122, in the cylinder head 100 of the second embodiment, the outlet cooling unit 122 is connected to the connection unit 101 and the hose 140. A configured discharge passage 126 is connected.

In short, in the cylinder head 100, the discharge passage 126 is provided outside the upper water jacket 120 as a cooling water passage connected to the outlet cooling section 122.
Next, the operation of the cylinder head 100 according to the second embodiment will be described with reference to FIG.

  FIG. 5 shows the shapes of the exhaust passage 110 and the upper water jacket 120 when the cylinder head 100 is viewed from the direction indicated by the white arrow in FIG. In FIG. 5, the upper water jacket 120 provided above the exhaust passage 110 so as to cover the exhaust passage 110 is indicated by a solid line, and the exhaust passage 110 is indicated by a broken line. Incidentally, the cross-sectional view of FIG. 4 shows a cross-sectional structure of the cylinder head 100 taken along line 4-4 in FIG.

  Exhaust gas discharged from each cylinder 210 through each exhaust port 111 is collected through the collecting portion 112, passes through the outlet portion 113, and is discharged into a downstream exhaust passage such as a turbocharger.

At this time, the wall surface of the exhaust passage 110 is cooled by the cooling water flowing through the upper water jacket 120 and the lower water jacket 130.
As indicated by arrows on the right side of FIG. 5, a part of the cooling water flowing through the cooling water circulation path of the internal combustion engine is introduced into the upper water jacket 120 through the inlet 123. Then, as indicated by an arrow on the left side of FIG. 5, the cooling water heated by cooling the wall surface of the exhaust passage 110 is discharged from the discharge port 124.

  Further, as indicated by an arrow in FIG. 5 and an arrow in FIG. 4, the cooling water is discharged from the outlet cooling portion 122 of the upper water jacket 120 to the cooling water passage 16 through the discharge passage 126. As the cooling water is discharged from the discharge passage 126 in this way, the pressure of the cooling water in the outlet cooling section 122 is lowered, and the portion provided along the exhaust port 111 and the collecting section 112 as indicated by arrows in FIG. A portion of the cooling water flowing through the outlet flows into the outlet cooling section 122 and is discharged through the discharge passage 126.

According to the second embodiment, the following effects can be obtained.
(1) Since the cooling water in the outlet cooling section 122 is discharged through the discharge passage 126, a pressure difference is generated in the cooling water in the outlet cooling section 122, so that the cooling water flows along the exhaust port 111 and the collecting section 112. A flow in which the cooling water that has flowed into the outlet cooling unit 122 from the provided portion is discharged from the outlet cooling unit 122 through the discharge passage 126 is generated. Thereby, circulation of the cooling water in the outlet cooling unit 122 can be promoted. Therefore, the retention of the cooling water in the outlet cooling part 122 of the upper water jacket 120 can be suppressed. As a result, cooling of the exit part 113 can be accelerated | stimulated.

  (2) Since the discharge passage 126 is connected to the front end portion of the bag path of the outlet cooling unit 122, the flow of cooling water is generated in the portion where it is most likely to stay, and the stay can be effectively suppressed.

  (3) Since the outlet cooling part 122 of the cylinder head 100 is provided with the connecting part 101 that constitutes the discharge passage 126, when the chips generated by the cutting process at the time of manufacturing are cleaned, the connecting part 101 is passed through the connecting part 101. Chips are discharged. Therefore, the chips can be easily cleaned in the manufacturing process.

In addition, the said 2nd Embodiment can also be implemented with the following forms which changed this suitably.
In the second embodiment, the downstream end portion is connected to the outlet cooling portion 122 at the upstream end portion of the discharge passage 126 connected to the downstream portion of the cooling water circulation path with respect to the upper water jacket 120. showed that. On the other hand, if the cooling water can be discharged from the outlet cooling unit 122 and the flow of the cooling water in the outlet cooling unit 122 can be promoted, the connection position of the downstream end of the discharge passage 126 is changed. Is possible. For example, a configuration in which the downstream end of the discharge passage 126 is connected to the upper water jacket 120 may be employed. That is, a configuration is adopted in which the downstream end of the discharge passage 126 is connected to a portion of the upper water jacket 120 where the pressure is lower than that in the outlet cooling portion 122, such as a portion closer to the discharge port 124 than the outlet cooling portion 122. You can also. Even when such a configuration is adopted, since the cooling water is discharged from the outlet cooling unit 122 through the discharge passage 126, the flow of the cooling water is promoted, so that the retention of the cooling water in the outlet cooling unit 122 is suppressed. Can do.

In addition, the following elements can be changed in common with each of the above embodiments.
Although the example in which the introduction passage 125 and the discharge passage 126 are connected to the front end of the bag path of the outlet cooling unit 122 has been shown, the introduction passage 125 can be used if the flow of the cooling water in the outlet cooling unit 122 can be promoted. In addition, the connection position of the discharge passage 126 may not be the tip of the bag path of the outlet cooling unit 122. For example, a configuration in which the introduction passage 125 and the discharge passage 126 are connected to a portion closer to the center of the outlet cooling unit 122 than the front end of the bag path may be employed.

  -Although the structure which connects the hose 140 and forms the introduction passage 125 and the discharge passage 126 was illustrated, the formation method of the introduction passage 125 and the discharge passage 126 can be changed suitably. For example, the introduction passage 125 and the discharge passage 126 can be cast into the cylinder head 100, or the introduction passage 125 and the discharge passage 126 can be formed by cutting with a drill or the like.

In addition, a pump may be provided in the introduction passage 125 and the discharge passage 126 to further promote the flow of the cooling water in the outlet cooling section 122.
-The introduction passage 125 and the discharge passage 126 are not limited to one, and a plurality of introduction passages 125 and discharge passages 126 may be provided.

A similar configuration can be applied to the lower water jacket 130.
The arrangement position of the water jacket 12 within the head in the cylinder head 100 is not limited to those exemplified in the above embodiments. For example, a cylinder head in which one of the upper water jacket 120 and the lower water jacket 130 is omitted and the water jacket is provided only on either the upper side or the lower side of the exhaust passage 110 has the same configuration. Can be applied.

  Further, the arrangement position of the water jacket 12 in the head is not limited to the upper side and the lower side of the exhaust passage 110. A similar problem can occur when the outlet cooling section is provided in the water jacket 12 in the head provided along the exhaust passage 110. As in each of the above embodiments, if a configuration in which a cooling water passage connected to the outlet cooling unit is provided outside the in-head water jacket 12, the problem can be solved as in the above embodiments. Become.

  Exemplified a configuration in which the outlet of the exhaust passage 110 is a single pipe and only one outlet portion 113 is provided. However, even if a plurality of outlet portions 113 are provided, the exhaust passage 110 gathers in the middle. The same problem can arise with an exhaust manifold integrated cylinder head. Also in the cylinder head provided with a plurality of outlet portions 113, the same configuration as in each of the above embodiments can be applied, and the retention of cooling water in the outlet cooling portion can be suppressed.

  In each of the above embodiments, a cylinder head in an in-line four-cylinder internal combustion engine has been exemplified. However, a similar problem may occur if the exhaust manifold 110 is a cylinder head integrated with the exhaust passage 110. The same configuration as in each of the above embodiments can be applied to cylinder heads having other cylinder arrangements such as in-line 6 cylinders, V-type 6 cylinders, V-type 8 cylinders, etc. The retention of the cooling water in the cooling unit can be suppressed.

  DESCRIPTION OF SYMBOLS 10 ... Water pump, 11 ... Water jacket in block, 12 ... Water jacket in head, 13 ... Radiator, 14, 15, 16, 17 ... Cooling water passage, 100 ... Cylinder head, 101 ... Connection part, 110 ... Exhaust passage, DESCRIPTION OF SYMBOLS 111 ... Exhaust port, 112 ... Collecting part, 113 ... Outlet part, 120 ... Upper water jacket, 122 ... Outlet cooling part, 123 ... Inlet, 124 ... Discharge port, 125 ... Introduction passage, 126 ... Discharge passage, 130 ... Bottom Water jacket, 140 ... hose, 200 ... cylinder block, 210 ... cylinder.

Claims (4)

An exhaust passage having a plurality of exhaust ports connected to each cylinder, a collective part in which the exhaust ports are gathered, and an outlet extending in a curved manner from the collective part;
A water jacket provided along the outlet part, having an outlet cooling part extending along the outlet part, and provided along the exhaust port and the collecting part;
A cylinder head comprising:
A cylinder head characterized in that a cooling water passage connected to the outlet cooling section is provided outside the water jacket. The cylinder head according to claim 1,
The cylinder head, wherein the cooling water passage is an introduction passage for introducing cooling water into the outlet cooling section. The cylinder head according to claim 2,
The cylinder head according to claim 1, wherein the introduction passage is branched from a portion upstream of the water jacket in the cooling water circulation path and introduces the cooling water to the outlet cooling section. The cylinder head according to claim 1,
The cylinder head according to claim 1, wherein the cooling water passage is a discharge passage for discharging cooling water from the outlet cooling section.