JP3535324B2 - Cylinder head structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a cylinder head having a recess forming a combustion chamber, an intake port and an exhaust port, and more particularly to a cooling structure using a cooling medium such as cooling water.

[0002]

2. Description of the Related Art As a cooling structure for a cylinder head, for example, there is one disclosed in Japanese Utility Model Publication No. 1-18814. In this structure, a cooling structure above a lower surface of the cylinder head to form a combustion chamber is provided. a first cooling passage, and a second cooling passage surrounding the recess is provided in the cylinder head.

[0003]

By the way, during engine operation
Cooling passages allowed to flow a cooling medium coming circulated from shea cylinder block side is, when provided in the cylinder head is formed by metal mold casting, reduces the number of machining steps for machining after die casting minimized to Is desired.

Therefore, the present invention is to provide a cylinder head structure in which a cooling passage can be easily formed in a cylinder head formed by die casting by minimizing machining after die casting. and purpose.

[0005]

In order to achieve the above-mentioned first object, according to the invention as defined in claim 1, with the top of a piston slidably fitted in a cylinder provided in a cylinder block. A recess that forms a combustion chamber therebetween is provided in the lower surface of the cylinder head, and an intake port that allows the inner end to pass through the recess and has an outer end opened to the first side surface on one side in the width direction of the cylinder head; In a cylinder head structure in which a cylinder head formed by die casting is provided with an exhaust port through which an end is opened and an outer end is opened to a second side surface on the other side in the width direction of the cylinder head, the width direction of the cylinder head is substantially the same. A first cooling passage formed at the time of die casting by a first core extending linearly in a direction orthogonal to each other is provided above the recess at the center portion in the width direction of the cylinder head. A second cooling passage formed during die casting by a second core linearly extending from the second side surface of the cylinder head substantially along the width direction passes through from the second side surface to the first cooling passage. provided, the outer end portion of the first core is formed as a large portion overhanging on both sides in the width direction of the cylinder head, the exhaust port that <br/> are arranged second cooling passage only on one side On the other side, there is an enlarged portion of the first cooling passage formed during die casting by the enlarged portion of the first core.

According to the invention of claim 2, cillin
Freely slidable on the 1st to 4th cylinders provided on the double block
That forms a combustion chamber between the top of the piston and
Part is provided on the lower surface of the cylinder head, and the inner end is
The cylinder head on one side in the width direction of the cylinder head.
1 Intake port that opens the outer end on one side and the recess
While passing through the inner end, the other side in the width direction of the cylinder head
The second and the exhaust port allowed to the outer end apertures on the sides, mold
Directly installed on the cylinder head formed by casting
In a cylinder head structure for a row 4 cylinder internal combustion engine,
Extends linearly in a direction substantially orthogonal to the width direction of the Linda head.
First cooling formed by die-casting first core during mold casting
The passage is located above the recess at the widthwise center of the cylinder head.
Is provided in the width direction from the second side surface of the cylinder head.
During die casting by the second core that extends in a straight line almost along
A second cooling passage formed in the first cooling passage from the second side surface.
The outer end of the first core is provided so as to penetrate up to the reject passage.
Formed as a bulge on both sides of the Linda head in the width direction
The exhaust ports corresponding to the first to third cylinders respectively.
Between the second cooling passages on both sides of each exhaust port.
Exhaust corresponding to the 4th cylinder, while being arranged
The port has a second cooling passage arranged only on one side thereof.
On the other side, when the die is cast by the enlarged part of the first core
There is an enormous portion of the first cooling passage formed in.

According to the invention of claim 3, syrin
Slidingly fits to the cylinder provided in the double lock
The recess that forms the combustion chamber between the top of the piston and the cylinder
It is provided on the lower surface of the da head, and the inner end is passed through the recess.
On the first side surface on one side in the width direction of the cylinder head.
The intake port that opens the end and the inner end through the recess
And the second side surface on the other side in the width direction of the cylinder head
The exhaust port that opens the outer end to the
Cylinder head provided in the formed cylinder head
In the structure, it is almost orthogonal to the width direction of the cylinder head
Die casting with a pair of first cores extending linearly in the direction
The first cooling passage that is sometimes formed is the width of the cylinder head.
It is provided above the recess at the center of the cylinder, and
A second linearly extending from the two side surfaces substantially along the width direction
The second cooling passage formed by the core during die casting,
Is provided so as to penetrate from the second side surface to the first cooling passage,
The pair of first cores have their inner ends in contact with each other.
It is arranged so that the first core of one of them is
The inner end has a concave portion and a convex portion, and the inner core of the other first core
The end has a convex portion and a concave portion, respectively, at the inner end of the first core.
A concave portion and a convex portion that are fitted together are provided.

According to the above-mentioned constitution of each invention of claims 1 to 3,
In this case, the first and second cooling passages connected to each other can be simultaneously formed by the first and second cores respectively corresponding to the cooling passages during die casting of the cylinder head, thus forming the cooling passages. It is not necessary to perform machining for this purpose on the cylinder head after die casting.

Further, according to the structure of the invention of claim 1, in particular, since the outer end portion of the first core is formed as an enlarged portion that extends to both sides in the width direction of the cylinder head, these enlarged portions It is possible to increase the circulation area of the cooling medium in the cylinder head as much as possible, and to further accelerate the cooling of the cylinder head. Also there is a possibility that cooling of the exhaust port only that is disposed second cooling passage on one side is insufficient, the other side ampulla of the first core (hence whereby gold of the exhaust port Due to the presence of the enlarged portion of the first cooling passage formed during die casting, the cooling of the exhaust port by the cooling medium can be compensated.

Further, in particular, according to the above configuration of the invention of claim 2,
For example, the outer ends of the first core are on both sides in the width direction of the cylinder head.
It is formed as an overhanging part of the
Circulation surface of the cooling medium in the cylinder head due to the enormous part
Increase the product as much as possible to further accelerate the cooling of the cylinder head
be able to. Also compatible with 1st to 3rd cylinders respectively
The exhaust ports are the second ones on either side of each exhaust port.
While it is located between the cooling passages, the fourth cylinder
The corresponding exhaust port has a second cooling passage on one side.
Exhaust corresponding to the 4th cylinder
Possibly insufficient cooling of the port, but the first core
Bulge (thus formed by die casting)
Exhaust corresponding to the fourth cylinder in the enormous part of the first cooling passage)
Corresponds to the 4th cylinder by being on the other side of the port
It is possible to compensate the cooling by the cooling medium of the exhaust port.
Wear.

According to the above construction of the invention of claim 3,
For example, by fitting the inner ends of the pair of first cores in a concave and convex shape.
To produce a labyrinth effect during die casting of the cylinder head.
At the inner end contact parts of both first cores
The burrs and insertion of the occurrence can it to prevent.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on an embodiment of the present invention shown in the accompanying drawings.

1 to 6 show an embodiment of the present invention. FIG. 1 is a side view of a cylinder head as seen from the direction of arrow 1 in FIG. 2, and FIG. 2 is a bottom view, FIG. 3 is a vertical cross-sectional view of the cylinder head taken along line 3-3 of FIG. 2, FIG. 4 is a vertical cross-sectional view of the cylinder head taken along line 4-4 of FIG. 2, and FIG. Fig. 5 is a sectional view taken along line 5-5, and Fig. 6 is a plan view showing the arrangement of the cores during die casting.

1 to 4, the cylinder head 10 is formed for a four-cylinder internal combustion engine, for example, by die casting of an aluminum alloy.
The first to fourth four cylinders 12 _{1 to} 12 ₄ are fastened to the upper surface of a cylinder block 11 provided in parallel.

The lower surface of the cylinder head 10 is provided with recesses 15 ... Forming combustion chambers 14 with the tops of pistons 13 ... Slidably fitted in the cylinders 12 _{1 to} 12 ₄ , respectively. . Also in the cylinder head 10, an intake port 16 ..., each of which corresponds one example in each of the cylinders 12 ₁ to 12 _4, each of the cylinders 12 ₁ to 12 ₄
For example, one exhaust port 17 for each ...
And are provided. Thus, the intake ports 16 ... Are made to pass through the inner ends of the recesses 15 ... and the width of the cylinder head 10 in a plane along the width direction of the cylinder head 10 orthogonal to the arrangement direction of the cylinders 12 _{1 to} 12 _4. The exhaust port 17 is formed so as to open the outer end on the first side face 10a on one side in the direction, and the exhaust ports 17 ... Extend the inner end into the recesses 15 ... In a plane along the width direction and the width of the cylinder head 10. is intended to be formed so as to allowed to open the outer end to the second side surface 10b of the direction the other side, the intake port 16 and exhaust port 17 ... in each of the cylinders 12 ₁ to 12 _4, each of the cylinders 12 ₁ to 12 ₄ Are arranged so that their inner ends communicate with the recesses 15 at positions displaced from each other along the arrangement direction of.

Further, the cylinder head 10 has a plurality of plug mounting holes 18 for mounting the spark plug so that the tip of the spark plug (not shown) can be inserted into the recess 15 from the first side surface 10a of the cylinder head 10. , A plurality of press-fitting holes 1 for press-fitting guide cylinders for intake valves, which can be seated on valve seat members 36 provided at the inner ends of the intake ports 16 ...
9 and a plurality of press-fitting holes 20 into which guide cylinders for exhaust valves that can be seated on valve seat members 37 provided at the inner ends of the exhaust ports 17 are press-fitted.
, 19 ..., 20 ... are punched by machining the cylinder head 10 after die casting.

Referring also to FIG. 5, the cylinder head 1
In order to allow a cooling medium such as cooling water to circulate, a _first linear extension 0 extends in a direction substantially orthogonal to the width direction of the cylinder head 10, that is, a direction substantially along the arrangement direction of the cylinders 12 _{1 to} 12 ₄ . 22 ₂ and a plurality of second cooling passages 22 ₁ ... 22 ₂ that linearly extend in a direction substantially along the width direction of the cylinder head 10, and the first cooling passage 21 and the second cooling passages 22 ₁ ... 22 ₂ There plurality of third cooling passage 23 ₁ ... extending substantially perpendicular to the direction i.e. the vertical direction to the extending direction, respectively, 23 ₂ ..., 23 ₃ ..., 23 ₄ ... and are provided.

The first cooling passage 21 is provided in the cylinder head 10.
Is formed so as to extend along the arrangement direction of the cylinders 12 _{1 to} 12 ₄ above the concave portions 15 at the center portion in the width direction of the cylinder head, which extends along the arrangement direction of the cylinders 12 _{1 to} 12 _4. At both ends of the first cooling passage 21
Both ends of are open. Thus, in the cylinder head 10,
A lid member (not shown) that closes one end of the first cooling passage 21.
And a lead-out pipe (not shown) communicating with the other end of the second cooling passage 21 is connected.

The second cooling passage 22 ₁ ..., 22 _2, which is provided so as to penetrate from the second side surface 10b of the cylinder head 10 to the first cooling passage 21, ₁ ... and the second cooling passage 22, First and second cylinders 12 ₁ and 12
Between each _two corresponding exhaust ports 17 and 17, respectively corresponding between the second and third cylinder 12 _2, respectively 12 ₃ corresponding exhaust ports 17 and 17, and the third and fourth cylinder 12 _3, 12 ₄ Exhaust port 17,
The second cooling passages 22 ₂ are arranged at three places between the first cooling cylinders 17 and the second cooling passages 22 ₁ in the first cylinder 12 ₁ . Moreover, the second cooling passages 22 _1, ..., 22 ₂ have their outer ends opened to the second side face 10b of the cylinder head 10, but at least in the portion near the second side face 10b, below the exhaust ports 17. It is formed in a shape close to each exhaust port 17 ... As a result, the contact area between the cylinder head 10 around the exhaust ports 17 ... And the cooling medium flowing through the second cooling passages 22 ₁ ..., 22 ₂ is increased, and the cylinder head 10 around the exhaust ports 17 ... It becomes possible to cool more effectively.

By the way, an exhaust manifold 25 communicating with each exhaust port 17 is fastened to the second side face 10b of the cylinder head 10 so as to close the outer end openings of the second cooling passages 22 ₁ ..., 22 _2. The exhaust manifold 25 is provided on the second side surface 10b of the cylinder head 10.
Are provided with a plurality of bottomed screw holes 26, and the second cooling passages 22 _1, ..., 22 ₂ are formed so as to be close to the screw holes 26.

Third cooling passages 23 ₁ ..., 23 ₂ ..., 23 ₃
,, 23 ₄ are provided so as to penetrate from the mating surface 24 of the cylinder head 10 to the cylinder block 11 to the first cooling passage 21 or the second cooling passages 22 ₁ ..., 22 ₂ . Third cooling passage 23 _1, ..., 2
Lower end of 3 ₂ ..., 23 ₃ ..., 23 ₄ ..., that is, mating surface 2
The opening end to ₄ is arranged so as to surround the cylinders 12 _{1 to} 12 ₄ and communicate with the upper end of the cooling passage 27 provided in the cylinder block 11.

[0022] In Thus, the third cooling passage 23 ₁ ... are their upper end the second cooling passage 22 ₁ ..., as providing communication respectively 22 _2, the second side surface of the cylinder head 10 10b and the recesses 15 It is arranged between the cylinders 12 _{1 to} 12 ₄ and is formed in an arc shape having the same center. The third cooling passages 23 ₂ are provided in pairs at both ends of the cylinder head 10 along the arrangement direction of the cylinders 12 _{1 to} 12 ₄ so that their upper ends communicate with both ends of the first cooling passage 21, respectively. To be Third cooling passage 23
₃ ... is as establishing communication respectively their upper to the first cooling passage 21, is disposed in three places of the portion of the first side surface 10a side of the cylinder head 10 between the recesses 15 ... mutually. Further, the third cooling passages 23 ₄ have their upper ends communicated with the first cooling passages 21 and their side portions communicated with the second cooling passages 22 ₁ , respectively, so that the cylinders are provided between the recesses 15 ... Head 1
It is arranged at three places near the second side surface 10b of 0.

In FIG. 6, during the die casting of the cylinder head 10, the first cooling passage 21 has a pair of first cores 31 ₁ , 31 extending linearly in a direction substantially orthogonal to the width direction of the cylinder head 10. and those formed by _2, both the first core 31 _1, 31 _2, they 31 _1, 31
The inner ends of the _two are placed in contact with each other. Moreover, the concave portion 38 ₁ and the convex portion 3 are provided at the inner end of the first core 31 _1.
9 ₁ is provided in the first inner end of the core 31 ₂ recesses 38 ₂
And the projecting portion 39 ₂ is provided, the convex portion 39 ₂ of the first core 31 ₂ is fitted into the recess 38 of the _first core 31 _1,
The first core 31 _{and second} recesses 38 ₂ to the first core 31 _{of the} projecting portion 3
9 ₁ is fitted. In this way, both first cores 31 ₁ , 3
The labyrinth effect can be exerted at the time of die casting of the cylinder head 10 by fitting the inner end portions of 1 ₂ into concave and convex portions, and burrs at inner end contact portions of both the first cores 31 ₁ and 31 ₂ It is possible to prevent the insertion.

Both first cores 31₁, 31₂Outer edge of
Is an enlarged portion that extends to both sides in the width direction of the cylinder head 10.
40₁, 40₂Are formed as
40₁, 40₂Cooling in the cylinder head 10
Cool the cylinder head 10 by increasing the distribution area of the medium as much as possible.
Rejection can be promoted more. In particular, the first cylinder 1
Two₁The exhaust port 17 corresponding to the
Road 22₂, 22₁Located between and second and third syrin
Da 12₂, 12₃Exhaust port 17 corresponding to ...
Are the second cooling passages 22 on both sides thereof.₁, 22₁In between
The four cylinders 12 are arranged respectively._FourTo
The corresponding exhaust port 17 has a second cooling passage 2 on one side thereof.
Two₁Is only arranged in the fourth cylinder 12_Four
The exhaust port 17 may not be adequately cooled
There is the first core31 ₂ Huge part 40₂Is the 4th Sirin
Da 12_FourOn the other side of the exhaust port 17 corresponding to
From the fourth cylinder 12_FourCorresponding to the exhaust port 17
The cooling by the cooling medium can be compensated.The aboveEnormous
Part 40₁, 40₂At the end of the die casting, both first cores 31
₁, 31₂To remove from the mold in the direction to separate from each other.
Formed into a shape that allowsIt Thus, in this embodiment
The first core 31 ₂ And its enormous part 40 ₂ Is the claim
The "first core" and the "major part" in the first and second inventions are included.
Each of them is composed, and both first cores 31 ₁ , 31
₂ Is a "pair of first cores" in the invention of claim 3.
Is made.

The second cooling passages 22 ₁ ..., 22 ₂ have second cores 32 extending along the width direction of the cylinder head 10.
₁ ..., 32 ₂ respectively,
The second core 32 ₁ ... inner ends of are arranged so as to be fitted respectively in the recess 41 ₁ ... provided in the first core 31 _1, 31 _2, a second inner end of the core 32 ₂ Is arranged so as to be fitted into the recess 41 ₂ provided in the first core 31 ₁ , and can be removed from the mold toward the other side along the width direction of the cylinder head 10 at the end of mold casting. It is formed in the shape. Thus, by fitting the inner ends of the second cores 32 ₁ ..., 32 ₂ and the side parts of both the first cores 31 ₁ , 31 _{2 in} a concavo-convex manner, a labyrinth effect is obtained during die casting of the cylinder head 10. The second core 32 ₁ ...,
It is possible to prevent burrs and insertions from occurring at the contact portions of 32 ₂ and the first cores 31 ₁ and 31 ₂ .

Third cooling passages 23 ₁ ..., 23 ₂ ..., 23 ₃
..., 23 ₄ ... are the third cores 33 ₁ ... 33 extending in the vertical direction.
33 ₂ ..., 33 ₃ ..., 33 ₄ ... are formed respectively by a third core 33 ₁ ... the upper second core 32 ₁ ..., 32
The third core 33 is arranged so as to be in contact with the _second core 33.
₂ ..., 33 ₃ ... are arranged so that the upper ends thereof come into contact with the first cores 31 ₁ and 31 ₂ , and the third cores 33 ₄ ... Have their upper ends come into contact with the first cores 31 ₁ and 31 _2. The side surface is arranged so as to contact the second core 32 ₁ . Moreover, all the third cores 33 ₁ ..., 33 ₂ ..., 33 ₃ ..., 3
3 ₄ ... are formed in a shape that allows the metal mold to be pulled downward from the cylinder head 10 at the end of mold casting.

With particular attention to FIG. 4, each exhaust port 17 ...
In the cylinder head 10, a portion of the cylinder head 10 close to the second side face 10b is provided with the second core 32 during the die casting of the cylinder head 10.
4th which enables to pull out in the direction parallel to ₁ ..., 32 ₂
It is formed by the core 34 and is not limited to a linear shape as long as the fourth core 34 can be pulled out from the mold.

Next, the operation of this embodiment will be described. Each recess 15 is formed in the central portion of the cylinder head 10 in the width direction.
A first cooling passage 21 located in the upper, second cooling passages 22 passing through from the second side surface 10b of the cylinder head 10 to the first cooling passage 21 ₁ ..., 22 ₂ are cylinder head 1
, 0, and the second cooling passages 22 ₁ ..., 22 ₂ are provided at least in the portion near the second side face 10b, and the exhaust port 17
It is formed in a shape close to. Therefore, heat transfer between the cooling medium flowing through the second cooling passages 22 ₁ ..., 22 ₂ and the cylinder head 10 around the exhaust port 17 is promoted, and the cooling medium is rapidly raised when the engine is started. Not only can the engine be warmed up to warm up the engine in a relatively short time, but also the exhaust side valve seat member 37 can be efficiently cooled, and the vicinity of the exhaust manifold 25, which has a high temperature, can be provided. With the cooling, it is possible to mitigate the heat influence on the head cover made of synthetic resin and the gasket interposed between the head cover and the cylinder head 10.

Further, bottomed screw holes 26 for fastening the exhaust manifold 25 are provided in the second side face 10b of the cylinder head 10, and the second cooling passages 22 _1, ..., 22 are provided.
₂ is formed in a shape close to the screw holes 26, so that the cylinder head 10 is prevented from becoming excessively high in temperature in the vicinity of the screw holes 26 ... It is possible to alleviate the fatigue and to prevent the reduction of the fastening strength in the screw holes 26.

Further, in the cylinder head 10, from the mating surface 24 of the cylinder head 10 with the cylinder block 11, the first cooling passage 21 or the second cooling passage 22 is provided.
A plurality of third cooling passages 23 penetrating to ₁ ..., 22 _2.
1 ..., 23 ₂ ..., 23 ₃ ..., 23 ₄ ... Are provided, and the cooling medium flowing from the cooling passage 27 of the cylinder block 11 is transferred from the third cooling passage 23 ₁ to the second cooling passage 22 ₁ ... It is circulated to the first cooling passage 21 via 22 ₂ , or the third cooling passage 23 ₁ ..., 23 ₂ ..., 23 ₃ ...,
It is possible to cool the cylinder head 10 by allowing the fluid to flow from 23 ₄ to the first cooling passage 21. Moreover, such cooling passages 21, 22 _1, ..., 22 ₂ , 23 ₁ ,.
23 ₂ ..., 23 ₃ ..., 23 ₄ ... are the cylinder heads 10.
Cores 31 ₁ , 31 ₂ , 32 _1, ..., 3 during die casting of
2 ₂ , 33 ₁ ..., 33 ₂ ..., 33 ₃ ..., 33 ₄ ... and each cooling passage 21, 22 ₁ ..., 2
The communicating parts of 2 ₂ , 23 _1, ..., 23 ₂ ..., 23 ₃ ..., 23 ₄ ... are cores 31 ₁ , 31 ₂ , 32 ₁ ..., 32 ₂ , 33 _1.
, 33 ₂ ..., 33 ₃ ..., 33 ₄ ... are formed by mutual contact, so that the cooling passages 21, 22 ₁ ..., 2
2 _2, 23 ₁ ..., 23 ₂ ..., 23 ₃ ..., the cylinder head 10 machined to form a 23 ₄ ... after die casting
It is not necessary to apply it to the above, and the number of processing steps can be reduced.

Further, in the exhaust port 17, the portion of the cylinder head 10 near the second side face 10b is formed so that it can be formed by the fourth core 34 parallel to the second cores 32 _1, ..., 32 _2. As a result, a part of the exhaust port 17 ... Is formed during die casting, and the number of processing steps can be further reduced.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible to do.

For example, the present invention is not limited to the cylinder head for a multi-cylinder internal combustion engine, but is applicable to a cylinder head for a single-cylinder internal combustion engine, and the first cooling passage 21 has a single first cooling passage 21. The intake port 16 and the exhaust port 17 may be formed by a core.
Can also be applied to a cylinder head in which a plurality of cylinders are provided.

[0034]

As described above, according to each of the first to third aspects of the invention, the first and second cooling passages connected to each other are respectively connected to the cooling passages at the time of die casting of the cylinder head. in the so that can be formed simultaneously by the first and second core, machining for forming the cooling passages is unnecessary to be applied to the cylinder head after the die casting, it is possible to reduce the number of processing steps.

Further, according to the above configuration of the invention of claim 1, the outer end portion of the first core is formed as an enlarged portion which is extended to both sides in the width direction of the cylinder head. It is possible to increase the circulation area of the cooling medium in the cylinder head as much as possible, and to further accelerate the cooling of the cylinder head. Also there is a possibility that cooling of the exhaust port only that is disposed second cooling passage on one side is insufficient, the other side ampulla of the first core (hence whereby gold of the exhaust port Due to the presence of the enlarged portion of the first cooling passage formed during die casting, the cooling of the exhaust port by the cooling medium can be compensated.

According to the invention of claim 2, in particular,
The outer edge of the child overhangs both sides of the cylinder head in the width direction.
Since these are formed as enormous parts,
The cooling medium distribution area in the cylinder head is increased as much as possible.
It can greatly accelerate the cooling of the cylinder head.
It In addition, the exhaust ports corresponding to the 1st to 3rd cylinders respectively.
Between the second cooling passages on both sides of each exhaust port.
While it is located in the
The air port has a second cooling passage arranged on one side thereof.
Only the cooling of the exhaust port corresponding to the 4th cylinder
There is a possibility that it will be insufficient, but the enormous part of the first core
(Thus, by this, the first cooling formed during die casting
The enormous part of the passage) is the exhaust port corresponding to the 4th cylinder.
Exhaust port corresponding to the 4th cylinder by being on the other side
The by the coolant cooling can and compensation child.

According to the invention of claim 3, in particular, a pair of
By fitting the inner end of the first core in a concavo-convex shape, the cylinder
To exert a labyrinth effect during head die casting
Burr and insertion at the inner end contact parts of both first cores
It is possible to prevent the occurrence of only the defects.

[Brief description of drawings]

FIG. 1 is a side view of a cylinder head as viewed from the direction of arrow 1 in FIG.

FIG. 2 is a bottom view taken along the arrow 2 in FIG.

3 is a vertical cross-sectional view of the cylinder head taken along line 3-3 of FIG.

4 is a vertical cross-sectional view of the cylinder head taken along line 4-4 of FIG.

5 is a sectional view taken along line 5-5 of FIG.

FIG. 6 is a plan view showing an arrangement of cores during die casting.

[Explanation of symbols]

10 ... Cylinder head 10a ... Cylinder head first side surface 10b ... Cylinder head second side surface 11 ... Cylinder block 12 ₁ , 12 ₂ , 12 ₃ , 12 ₄ ... Cylinder 13 ... piston 14 ... combustion chamber 15 ... recess 16 ... intake port 17 ... exhaust port 21 ... first cooling passage 22 _1, 22 ₂ ... second cooling passage path 24 ... mating surface 25 ... exhaust manifold 26 ... screw hole 31 _1, 31 ₂ ... first core 32 _1, 32 ₂ ... second in children

Front page continuation (72) Inventor, Yasushi Ito, 1-4-1, Chuo, Wako, Saitama Prefecture, Research Institute of Honda, Ltd. (56) References: JP-A-59-20548 (JP, A), Shoukai 60-195946 (JP, U) Actual Kaihei 3-32155 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02F 1/00-11/00 F01P 3/14

Claims (3)

(57) [Claims] 1. A recessed portion forming a combustion chamber (14) between the cylinder (12 _{1 to} 12 ₄ ) provided in a cylinder block (11) and the top of a piston (13) slidably fitted therein. 15) is provided on the lower surface of the cylinder head (10) to allow the inner end to pass through the recess (15) and the first side surface (10a) on one side in the width direction of the cylinder head (10).
An intake port (16) having an outer end opened to the inner end, and an exhaust port (16) having an inner end passed through the recess (15) and an outer end opened to the second side face (10b) on the other side in the width direction of the cylinder head (10). 17) is a cylinder head structure provided in a cylinder head (10) formed by die casting, wherein a first core ( 31) extending linearly in a direction substantially orthogonal to the width direction of the cylinder head (10) _{The second} cooling passage (21) formed during die casting by means of ₂ ) is provided above the recessed portion (15) at the center of the cylinder head (10) in the width direction, and the second side surface of the cylinder head (10) ( 10b) linearly extending substantially in the width direction from the second core (32 ₁ ,
The second cooling passages (22 ₁ , 22 ₂ ) formed by the casting die 32 ₂ ) at the time of casting are provided so as to penetrate from the second side surface (10b) to the first cooling passage (21). The outer end of ( 3 1 ₂ ) is the cylinder head (1
Ampulla with overhanging on both sides in the width direction of 0) is formed as a (4 0 _2), the other side of the second cooling passage (22 ₁₎ is discharged <br/> air ports that are disposed only on one side (17) The cylinder head structure is characterized in that there is an enlarged portion of the first cooling passage (21) formed during die casting by the enlarged portion (40 ₂ ) of the first core ( 31 ₂ ). 2. A combustion chamber (14) between the top of a piston (13) slidably fitted in _first to _fourth cylinders (121 to 124) provided in a cylinder block (11).
Is formed in the lower surface of the cylinder head (10) to allow the inner end to pass through the recess (15) and the outer end on the first side surface (10a) on one side in the width direction of the cylinder head (10). Intake port (16)
And a second side surface (10b) on the other side in the width direction of the cylinder head (10) while allowing the inner end to pass through the recess (15)
In a cylinder head structure for an in-line four-cylinder internal combustion engine, an exhaust port (17) for opening an outer end of the cylinder head is provided in a cylinder head (10) formed by die casting, in a width direction of the cylinder head (10). substantially orthogonal first core extending linearly in a direction (3 1 ₂₎ by a first cooling passage that is formed during the die casting (21), the recess (15 in the width direction central portion of the cylinder head (10) to provided above the) second side (second core (32 linearly extending substantially along the 10b) in the width direction ₁ of the cylinder head (10),
The second cooling passages (22 ₁ , 22 ₂ ) formed by the casting die 32 ₂ ) at the time of casting are provided so as to penetrate from the second side surface (10b) to the first cooling passage (21). The outer end of ( 3 1 ₂ ) is the cylinder head (1
0) it is of a width-directional side as ampulla with overhanging (4 0 _2), first to third cylinder (12 _1, 12 _2, 12 ₃₎ to an exhaust port corresponding respectively (17,17,17) is the second cooling passage on both sides of the exhaust port of each (22 _2, 22
₁ ; 22 ₁ , 22 ₁ ; 22 ₁ , 22 ₁ ), the exhaust port (17) corresponding to the fourth cylinder (12 ₄ ) has a second cooling passage only on one side thereof. (22
₁ ) is arranged, and on the other side, the first core ( 31
Wherein the enlarged portion of the first cooling passage that is formed during the die casting (21) by the enlarged portion of ₂₎ (40 ₂₎ is located, a cylinder head structure for a four-cylinder internal combustion engine. 3. A recess (which forms a combustion chamber (14) between the cylinder (12 _{1 to} 12 ₄ ) provided in the cylinder block (11) and the top of a piston (13) slidably fitted therein. 15) is provided on the lower surface of the cylinder head (10) to allow the inner end to pass through the recess (15) and the first side surface (10a) on one side in the width direction of the cylinder head (10).
An intake port (16) having an outer end opened to the inner end, and an exhaust port (16) having an inner end passed through the recess (15) and an outer end opened to the second side face (10b) on the other side in the width direction of the cylinder head (10). 17) is a cylinder head structure provided in a cylinder head (10) formed by die casting, wherein a pair of first cores (which linearly extend in a direction substantially orthogonal to the width direction of the cylinder head (10) ( The first cooling passages (21) formed at the time of mold casting by 31 ₁ and 31 ₂ ) are
The recessed part (15) is formed in the widthwise central part of the cylinder head (10).
A second core (32 ₁ , which extends linearly from the second side surface (10 b) of the cylinder head (10) substantially along the width direction.
32 ₂₎ second cooling passage that is formed during the die casting (22 _1, 22 ₂₎ is by provided through from the second side surface (10b) to the first cooling passage (21), the pair first The first cores (31 ₁ , 31 ₂ ) are arranged such that the inner ends of the first cores (31 ₁ , 31 ₂ ) are in contact with each other, and a recess (38 ₁ ) is formed at the inner end of one of the first cores (31 ₁ ). )
And the convex portion (39 ₁ ) and the other first core (31
_At the inner end of ₂ ), a concave portion (38 ₂ ) and a convex portion (39 ₂ ) are fitted to the convex portion (39 ₁ ) and concave portion (38 ₁ ) of the inner end of the _one first core (31 ₁ ), respectively. ) Are respectively provided in the cylinder head structure.