JP6787664B2 - Internal combustion engine cylinder head - Google Patents

Description

The present invention relates to a cylinder head of an internal combustion engine for a vehicle or the like, and is characterized by a cooling structure (a structure of a cooling water jacket).

As an exhaust structure of an internal combustion engine, there is a type in which an exhaust collecting space is formed inside a cylinder head and only one exhaust hole is formed on the exhaust side surface of the cylinder head. This type has the advantages of being compact as a whole and being able to effectively utilize heat, but has the problem that the cylinder head is exposed to a harsh thermal environment compared to the type in which the exhaust manifold is fixed.

Regarding this point, for example, as disclosed in Patent Document 1, the cooling water jacket is formed so as to project toward the exhaust collecting space in order to cool the portion of the exhaust collecting space. Since the exhaust collecting space extends long in the crank axis direction (cylinder row direction), the cooling water jacket is divided into upper and lower parts with the exhaust collecting space in between, and the upper and lower parts are the longitudinal end portion and the longitudinal portion. It communicates with the other end and also communicates with the middle part in the longitudinal direction.

Japanese Unexamined Patent Publication No. 2012-57468

When the cooling water jacket is projected to a portion of the exhaust collecting space as in Patent Document 1, if the cooling water flows evenly and evenly to the cooling water jacket, the portion of the exhaust collecting space can also be effectively cooled. However, as a result of analysis and research by the inventors of the present application, since the cooling water is pumped by a water pump, it tends to go straight from one end to the other end of the cooling water jacket, and the exhaust collecting space It turned out that the cooling of the part was incomplete. That is, the cooling of the most heated part was insufficient.

Further, in Patent Document 1, the cylinder head is basically cooled by the cooling water passing through the cooling water jacket of the cylinder block, and the amount of cooling water flowing to the exhaust collecting space is small and the cylinder block is used. Since the temperature has risen, it can be said that the cooling performance has become worse and worse.

The present invention has been made as a result of such findings and research, and an object of the present invention is to provide a more improved cooling structure in a cylinder head having an exhaust collecting space.

The present invention relates to a cylinder head, the cylinder head,
" A plurality of exhaust ports corresponding to a plurality of cylinders, an exhaust collecting space in which each of the exhaust ports communicates, and a cooling water jacket are formed therein, and the exhaust collecting space is the exhaust of the cylinder head. It opens as one exhaust hole from the side. "
It has a basic structure.

And in the above basic configuration
"The cooling water jacket has an exhaust side jacket that cools a portion closer to the exhaust side surface side than an area of an upper portion of each cylinder, and a combustion chamber side that cools mainly an area including an upper portion of each cylinder. It is divided into a jacket part
Both jackets have dedicated cooling water inlets located at one end of both front and rear ends facing the crank axis direction, and the cooling water allows the cooling water to move both jackets from one end to the other. It is designed to flow independently to the side of the wall and then gather.
Cooling water that does not pass through the cooling water jacket of the cylinder block flows into the cooling water inlet of the exhaust side jacket portion, and the cooling water jacket of the cylinder block enters the cooling water inlet of the combustion chamber side jacket portion. Cooling water flows in via
It is configured as.

Cooling the entrance of the jacket portion may be provided only in the longitudinal one end portion, it is possible to provide a supplementary cooling water inlet to the long hand the other end portion, and the like.

It is preferable that the cooling water flowing out of the two jackets is collected as one flow and then flowed to the control unit that controls the feeding to the radiator and the water pump, but the flow of the combustion chamber side jacket part and the exhaust side jacket part. It is also possible to collect and in the control unit . Further, the exhaust side jacket portion and the combustion chamber side jacket portion can be communicated with each other at one place or a plurality of places between one end portion and the other end portion as long as the cooling by the exhaust side jacket portion is not hindered. Is.

In the present invention, the cooling water jacket of the cylinder head is separated into an exhaust side jacket portion and a combustion chamber side jacket portion, and the cooling water flows into the respective cooling water inlets separately, so that the cooling water flows into the exhaust side jacket portion. also the cooling water have a straightness, a cooling water may be flowed evenly across the exhaust-side jacket portion. In other words, the exhaust side jacket part is in contact with the entire inner surface evenly while the cooling flows in a directional direction (straightness), which accurately cools the exhaust collecting space and the exhaust port. can do.

Then, although the portion is provided with the exhaust collecting space of the cylinder head becomes hottest is exposed to exhaust gas, in the present invention, the positions exhaust side jacket portions for cooling the exhaust gas collecting space, the cooling of the cylinder block Since the cooling water that has not been heated directly flows in without passing through the water jacket, the cooling performance of the exhaust collecting space can be significantly improved.

As described above, in the present invention, it is possible to accurately cool the part of the exhaust collecting space with the cooling water having a low temperature, thereby preventing the cylinder head from partially overheating at the part of the exhaust collecting space. Therefore, it is possible to prevent adverse effects such as distortion due to heat. Further, since the abnormal temperature rise of the exhaust gas can be suppressed, damage to the purification catalyst can be suppressed. Further, vehicle heating is generally performed by heating a heater with cooling water, but in the present invention, heat exchange from the cylinder head to cooling water is promoted, so that when applied to an internal combustion engine for vehicles, It is also possible to improve the effectiveness of the in-vehicle heating heater.

In addition, although the degree of temperature rise in the upper part of the cylinder head in the cylinder row is lower than that in the exhaust collecting space, the temperature is raised in the combustion chamber side jacket part via the cooling water jacket of the cylinder block. Since the water flows, it is possible to prevent the upper part of the cylinder row from being excessively cooled. Therefore, it is possible to equalize the thermal expansion of the cylinder head as much as possible.

Since the exhaust side jacket portion and the combustion chamber side jacket portion are separated in the width direction of the cylinder head, a partition wall long in the crank axis direction exists between the two jacket portions, and this partition wall is formed. Since it functions as a reinforcing portion that suppresses bending of the cylinder head, the strength of the cylinder head can be improved and thermal strain can also be suppressed.

It is a figure which shows the embodiment, the plan view of the cooling water jacket, (B) is a plan view of a cylinder head. (A) is a side view of the cooling water jacket as viewed from the exhaust side direction, and (B) is a side view of the cylinder head. (A) is a rear view of the cooling water jacket as viewed from the crank axis direction, and (B) is a rear view of the cylinder head. It is a perspective view of the cooling water jacket. It is a top view of the cooling water jacket. It is a partial plan view of a thin lid block. It is sectional drawing which cut the cylinder head by line VII-VII of FIG. It is sectional drawing which cut the cylinder head by line VIII-VIII of FIG.

Next, an embodiment of the present invention will be invented based on the drawings. In the present embodiment, the crank axis direction is defined as the front-rear direction, and the direction is clearly shown in FIG. Although not shown in the figure, the side where the timing chain is arranged is the front.

As can be understood from FIG. 1 (B) and FIG. 8, the upper surface in the cylinder head 1 is formed with upwardly open ended space, Therefore, the ambient is composed of an upward peripheral wall 2. Inside surrounded by the peripheral wall 2, three spark plug holding holes 3 are arranged in the longitudinal direction (direction of the crankshaft center 4).

Further, in the empty space of the cylinder head 1, a partition rib 5 constituting a bearing portion for holding the cam shaft extends in the width direction, and valve holding holes into which the valve shaft is fitted on both sides of the partition rib 5. 6 are formed two pairs.

The cylinder head 1 has an intake side surface 8 in which the intake port 7 is open. The intake side surface 8 is inclined so as to go outward as it goes down. Further, as shown in FIG. 7, the cylinder head 1 is formed with three combustion chambers 9 arranged in the direction of the crank axis. The combustion chamber 9 is formed in the shape of a pedestal that spreads downward, and naturally has the same diameter and concentricity as the cylinder 11 of the cylinder block 10.

Two exhaust ports (not shown) are formed in the cylinder head 1 corresponding to one combustion chamber, and the exhaust ports are gathered in one exhaust collecting space 12 shown in FIGS. 7 and 8. There is. As shown in FIGS. 2 and 7, the exhaust collecting space 12 has one exhaust hole 13, and the exhaust hole 13 is open to the exhaust side surface 14. The exhaust hole 13 is an oval-shaped elongated hole that is long in the longitudinal direction of the cylinder head 1.

As can be understood from the comparison of FIGS. 1 to 3, a cooling water jacket 15 through which the cooling water passes is formed inside the cylinder head 1. The parallel diagonal lines in FIGS. 1 to 3 are for clearly indicating the outer shape of the cooling water jacket 15, and are not a cross-sectional display. Further, in FIG. 5 , the cooling water jackets overlapping in the vertical direction (cylinder axis direction) are displayed as they are.

As can be easily understood from FIGS. 1 and 4, the cooling water jacket 15 includes an area including an exhaust side jacket portion 16 located on the side of the exhaust side surface 13 and an upper portion of each combustion chamber 9 (or cylinder 11). It is divided into a combustion chamber side jacket portion 17 for cooling in the center. The jacket portion 17 on the combustion chamber side extends on both sides of the crankshaft center 4 when viewed from the axial direction of the cylinder 11. Further, in FIG. 1A, the combustion chamber side jacket portion 17 has an outer portion 17a concentric with the combustion chamber, and the intake side meat portion 18 of the cylinder head 1 is surrounded by the outer portion 17a. However, the intake side meat portion 18 is a support portion of the intake valve.

Between the exhaust side jacket portion 16 and the combustion chamber side jacket portion 17, there is a partition wall portion 19 which is a meat portion of the cooling water jacket 15, and a support portion of the exhaust valve is formed in the partition wall portion 19. .. Since the partition wall portion 19 extends long in the front-rear direction, the strength of the cylinder head 1 is high. In addition, it is also suppressed that it warps in the left-right direction or in the up-down direction due to thermal expansion. Further, the intake side meat portion 18 also has a reinforcing function, but since the partition wall portion 19 and the intake side meat portion 18 are substantially symmetrical with respect to the crankshaft center 4, the partition wall portion 19 and the intake side meat portion 18 The reinforcing function is balanced, which further contributes to the suppression of strain due to heat.

As shown in FIG. 2, the exhaust side jacket portion 16 has an upper jacket portion 16a that covers the exhaust collecting space 12 from above and a lower jacket portion 16b that covers the exhaust collecting space 12 from below, and has upper and lower jackets. The portions 16a and 16b communicate with each other at both front and rear ends. Further, even in the inner part away from the exhaust side surface 14, communication is performed at a plurality of places. Therefore, the portion behind the exhaust collecting space 12 and the portion around the exhaust port are also accurately cooled.

In FIG. 1, there are three island-shaped exhaust-side meat portions 20 inside the exhaust-side jacket portion 16, which are meat portions for forming a head bolt insertion hole.

As shown in FIGS. 4 and 5, the front end portion (one end portion) of the exhaust side jacket portion 16 and the front end portion (one end portion) of the combustion chamber side jacket portion 17 are provided with cooling water inlets 21 facing the cylinder block 10. , 22 are connected. The exhaust side jacket portion 16 has one cooling water inlet 21, and the combustion chamber side jacket portion 17 has two cooling water inlets 22 on the left and right. In FIG. 1, the cooling water inlets 21 and 22 are indicated by black circles only at rough positions.

Since the jacket portion 17 on the combustion chamber side has a wide range on the left and right, two cooling water inlets 22 are provided so that the cooling water can flow evenly throughout. The flow of the cooling water ejected from the two cooling water inlets 22 generally flows toward the rear end portion (the other end portion) on both sides of the crankshaft center 4. Therefore, the cooling water flows through the combustion chamber side jacket portion 17 while maintaining the straightness as high as possible. Therefore, the flow resistance is small and the pressure loss can be suppressed. The same applies to the exhaust side jacket portion 16.

As shown in FIG. 6, the cylinder block 10 is formed with a block jacket 23 that surrounds a group of cylinders 11 , and has an exhaust side water supply port 24 that communicates with the cooling water inlet 21 of the exhaust side jacket portion 16 and a combustion chamber. The combustion chamber side water supply port 25 communicating with the cooling water inlet 22 of the side jacket portion 17 is provided at a portion near the front end of the cylinder block 10.

Cooling water is sent from the water pump to the block jacket 23 of the cylinder block 10 through a water supply hole 26 provided on the longitudinal side surface of the cylinder block 10, and the exhaust side water supply port 24 is water supply outside the block jacket 23. It communicates with the hole 26. Therefore, low-temperature cooling water that has not cooled the cylinder block 10 flows into the exhaust side jacket portion 16. Therefore, the location of the exhaust collecting space 12 and the location of the exhaust port are accurately cooled even with a relatively small amount of cooling water.

On the other hand, the exhaust side water supply port 24 communicates with the block jacket 23, and the cooling water that has been heated to some extent by cooling the cylinder block 10 flows in. Since the temperature of the combustion chamber side jacket portion 17 of the cylinder head 1 is not higher than that of the exhaust collecting space 12 and the exhaust port portion, even if the heated cooling water flows into the combustion chamber side jacket portion 17. , The temperature of the cooling water does not rise excessively.

The ratio of the amount of cooling water flowing into the jacket portion 16 on the exhaust side and the amount of cooling water flowing into the jacket portion 17 on the combustion chamber side may be the same, but the volume of both jacket portions 16 and 17 From the viewpoint of balance, it can be said that it is preferable that the inflow ratio to the jacket portion 17 on the combustion chamber side is large. Even if the flow rate to the combustion chamber side jacket portion 17 is large, the degree of temperature rise of the cooling water in the exhaust side jacket portion 16 is large, so that the end of the combustion chamber side jacket portion 17 and the exhaust side jacket portion 16 is cooled. The temperature of water can be raised to the same extent.

The exhaust collecting space 12 is curved in a laterally convex shape in a plan view, and in accordance with this, the outer portion of the exhaust side jacket portion 16 with the exhaust side meat portion 20 sandwiched is along an arch shape. Then, as is clearly shown in FIG. 5, since the cooling water inlet 21 of the exhaust side jacket portion 16 is located at the end of the bow-shaped passage, the cooling water has a direction (straight ahead) in the bow-shaped passage. Inflow (with sex). Therefore, the hottest portion of the cylinder head 1 can be accurately cooled. This point is one of the great advantages of this embodiment.

As shown in FIG. 7, the gasket 27 is interposed between the cylinder block 10 and the cylinder head 1, but the gasket 27 has holes at the water supply ports 24 and 25. Further, as shown in FIGS. 2 (A) and 3 (B), a large number of downward spaces 28 and 29 are connected to the exhaust side jacket portion 16 and the combustion chamber side jacket portion 17, but this is This is due to the provision of dummy legs for supporting the core mold in forming the exhaust side jacket portion 16 and the combustion chamber side jacket portion 17 by the core mold during casting . Since the downward spaces 28 and 29 are closed by the gasket 27, they are in the same state as they do not exist.

If the cooling water pumped into the water supply hole 26 of the cylinder block 12 leaks to the combustion chamber side water supply port 25 without going around the block jacket 23, the cooling of the cylinder block 10 becomes sparse and the combustion chamber side jacket portion 17 There is a risk of excessive cooling. Therefore, as shown by reference numeral 23a in FIG. 6, a stopper plate for preventing leakage of cooling water is provided at one end of the block jacket 23. The stopper plate 23a is formed of an annular spacer (not shown) that is fitted into the block jacket 23. Therefore, there is no increase in the number of members, and there is no concern about misalignment.

As can be easily understood from FIG. 1A, the rear end portion of the combustion chamber side jacket portion 17 and the rear end portion of the exhaust side jacket portion 16 communicate with each other via the joint portion 30. Therefore, the cooling water that has cooled the exhaust side jacket portion 16 flows into the terminal portion of the combustion chamber side jacket portion 17. A control unit 31 shown in shaded areas in FIGS. 1 and 2 is integrally connected to the end of the combustion chamber side jacket unit 17.

The control unit 31 has a first chamber 32, which is a relay chamber for returning from the radiator and the heater and sending to the water pump, and a second chamber 33, which is a relay chamber for sending to the radiator and the heater. In the cylinder head 1 as a finished product, the first chamber 32 and the second chamber are communicated with each other, but in the cast state, there is a slight dimensional gap 34 between the two (see also FIG. 5). .. Therefore, in the cast state, the cylinder head 1 has a wall separating the first chamber 32 and the second chamber 33.

Therefore, as shown in FIG. 1 (A) shaded and indicated by reference numeral 35, a communication hole 35 is formed in the wall formed at the gap 34 by drilling after manufacturing. The drill enters the wall from the direction indicated by arrow 36 through an outlet hole for feeding water to the water pump. Therefore, the drilling process cuts only the wall, and there is no need for post-processing such as plugging the holes made by the drilling process.

The cooling water that has passed through the exhaust side jacket portion 16 flows from the joint portion 30 to the rear end of the combustion chamber side jacket portion 17 , but flows into the joint portion 30 because the flow path is narrowed at the joint portion 30. Stagnation may occur around the flow, causing retention of cooling water. Then, when retention occurs, the cooling property of the cylinder head 1 deteriorates.

Therefore, in the present embodiment, as shown by reference numeral 37 in FIG. 5, an auxiliary water supply hole 37 communicating with the block jacket 23 of the cylinder block 10 is provided, and the temperature is lowered by mixing the cooling water having a low temperature, and the temperature is lowered from below. By disturbing the cooling of the exhaust side jacket portion 16 with the cooling water of the above, the stagnation of the cooling water is eliminated and the cooling water is guided toward the joint portion 30. In FIG. 5, the block jacket 12 displays the center line.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various ways. For example, both the exhaust side jacket portion and the combustion chamber side jacket portion can be embodied as needed. It is also possible to provide a plurality of cooling water inlets in the exhaust side jacket portion, or to have only one cooling water inlet in the combustion chamber side jacket portion. The exhaust side jacket portion is divided into an upper portion and a lower portion, and it is also possible to allow water to pass through the upper portion and the lower portion from separate cooling water inlets.

The present invention can be embodied in a cylinder head of an internal combustion engine. Therefore, it can be used industrially.

1 Cylinder head 4 Crankshaft center 7 Intake port 8 Intake side surface 10 Cylinder block 11 Cylinder 12 Exhaust assembly space 13 Exhaust hole 14 Exhaust side surface 15 Cooling water jacket 16 Exhaust side jacket part 17 Combustion chamber side jacket part 19 Both cooling water jacket parts Space partition between 21 Cooling water inlet of exhaust side jacket 22 Cooling water inlet of combustion chamber side jacket 23 Block jacket 24 Exhaust side water supply port 25 Combustion chamber side water supply port 30 Joint part 31 Control unit 32 1st room 33 2nd room 35 Communication hole 37 Auxiliary water supply hole

Claims (1)

Cylinder head
A plurality of exhaust ports corresponding to a plurality of cylinders, an exhaust collecting space in which each of the exhaust ports communicates, and a cooling water jacket are formed therein, and the exhaust collecting space is an exhaust side surface of the cylinder head. In a configuration that is open as one exhaust hole from
The cooling water jacket has an exhaust side jacket that cools a portion closer to the exhaust side surface side than an area of an upper portion of each cylinder, and a combustion chamber side jacket that cools mainly an area including an upper portion of each cylinder. It is divided into departments
Both jackets have dedicated cooling water inlets located at one end of both front and rear ends facing the crank axis direction, and the cooling water allows the cooling water to move both jackets from one end to the other. It is designed to flow independently to the side of the wall and then gather.
Cooling water that does not pass through the cooling water jacket of the cylinder block flows into the cooling water inlet of the exhaust side jacket portion, and the cooling water jacket of the cylinder block enters the cooling water inlet of the combustion chamber side jacket portion. Cooling water flows in via
Cylinder head of internal combustion engine.

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