JP2003293851A - Cylinder head and its casting mold for direct injection type diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate forming of a cooling water passage in a cylinder head for a direct injection type diesel engine. <P>SOLUTION: An external wall of an exhaust port 14A and an external wall of an intake port 12 of an adjacent cylinder are partially shared (a shared external wall 17). In the exhaust port 14A in a terminal part of the cylinder head 11, an inserting space for an exhaust port forming core is secured by thickly forming a part of the external wall since there are no adjacent intake ports 12 or 13. The cooling water passage 16 is easily secured around a nozzle hole 15A when the exhaust port forming core is used as a boss 15 for attaching a cylinder head integrated type fuel injection nozzle by allowing insertion of a cooling water jacket forming core so that an insertion locus is bent while by-passing a fuel injection nozzle attaching position by using a part of an existing space of an intake port forming core or a thick part of the external wall. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-valve direct injection diesel engine cylinder head and its casting structure, and more particularly to a water passage forming technique for the cylinder head.

[0002]

2. Description of the Related Art Conventionally, an intake air and an exhaust air which are provided in a cylinder head with two intake valves and two exhaust valves, respectively, and which are opened and closed by the four valves (two intake valves and two exhaust valves) in the cylinder head. A four-valve direct-injection diesel engine is known in which each of the four ports is provided with a fuel injection nozzle at a portion corresponding to substantially the center of the four ports of the cylinder head.

In such a four-valve direct injection diesel engine, as shown in FIG. 8 and FIG. 9, as a structure advantageous for forming a cooling water passage around a nozzle hole of a fuel injection nozzle of a cylinder head, etc. The structure is adopted. That is, the cylinder head 1 is made of cast iron, and the mounting boss 6 of the fuel injection nozzle provided at the portions corresponding to the substantially central portions of the intake ports 2 and 3 and the exhaust ports 4 and 5 of the cylinder head 1 is the same as the cylinder head 1. Is formed by press-fitting a separate pipe into the cylinder head 1.

Further, the arrangement of the four valves is so-called diamond type, and the four valves are arranged at a position where the valve center is twisted with respect to the central axis of the cylinder bore. That is, the intake valve and the exhaust valve are arranged side by side in a direction inclined at a predetermined angle with respect to the direction orthogonal to the axial direction of the crankshaft. In such a 4-valve direct injection diesel engine, the mounting boss 6 of the fuel injection nozzle is formed by press-fitting a pipe into the cylinder head 1. Therefore, the cooling water passage around the nozzle hole of the fuel injection nozzle is formed. Cylinder head 1 made of cast iron with the advantage of easy formation
Therefore, since the material strength is high and the press-fitting margin of the pipe can be made large, the surface pressure of the press-fitting portion can be made large and the sealing property of cooling water and gas is excellent, and the arrangement of the four valves 2 to 5 is a diamond type. Therefore, it is easy to form a cooling water passage between the mounting boss 6 of the fuel injection nozzle and the exhaust ports 4 and 5, and since the cylinder head 1 is made of cast iron, the wall thickness can be reduced. It has an advantage that the cooling water passage can be sufficiently secured.

[0005]

When a direct injection diesel engine having a DOHC type aluminum cast cylinder head is manufactured, the conventional four-valve direct injection diesel engine configuration described above is adopted. , There are the following problems. That is, when the mounting boss of the fuel injection nozzle is formed by press-fitting the pipe into the cylinder head, the press-fitting margin of the pipe cannot be large because of the material strength of aluminum, so It is difficult to secure high pressure and it is difficult to secure the sealing property of cooling water and gas.

In addition, the separate pipe press-fitting system is disadvantageous in terms of material and processing cost. Further, when the arrangement of the four valves is a diamond type, it is difficult to adopt the DOHC type valve operating system arrangement, and the rocker arm type SOHC is used.
Although the format or the OHV format is adopted, it is difficult to secure the output in the high speed range of the engine with such a format.

[0007] Considering the above circumstances, DOHC
In a direct-injection diesel engine having a cast aluminum cylinder head, two intake valves and two exhaust valves for each cylinder are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft. Therefore, it is necessary to form the mounting boss for the fuel injection nozzle integrally with the cylinder head.

However, with such a structure, it is difficult to form a cooling water passage around the nozzle hole of the fuel injection nozzle, and a cooling water passage is formed between the mounting boss of the fuel injection nozzle 3 and the exhaust port. There is a problem that it is difficult to do. Therefore, the present invention has been made in order to solve the above conventional problems, and two intake valves and two exhaust valves for each cylinder are substantially orthogonal to the central axis direction of the crankshaft. It is an object of the present invention to facilitate formation of a cooling water passage in a cylinder head of a direct injection type diesel engine which is arranged in parallel with each other in a direction and in which a mounting boss for a fuel injection nozzle is integrally formed with a cylinder head.

[0009]

For this reason, the invention according to claim 1 provides a cast cylinder head with two cylinders each.
Two intake valves and two exhaust valves are provided in the cylinder head, and four intake and exhaust ports are opened and closed by the four valves for each cylinder in the cylinder head. In a direct-injection diesel engine in which two exhaust valves are arranged side by side in a direction substantially orthogonal to the central axis direction of the crankshaft, the rear side with respect to the intake port opening position on the cylinder head side wall of the adjacent cylinder as a reference The outer wall of each intake port and the outer wall of each exhaust port adjacent to the intake port are connected at their closest points to share the port outer wall, and one end wall of the cylinder head in the cylinder column direction is formed. The outer wall of the exhaust port located on the side is formed to be thicker than the outer walls of the other portions, and is formed on the substantially central axis of the cylinder bore of each cylinder of the cylinder head. A fuel injection nozzle is provided upright, a mounting boss for the fuel injection nozzle is integrally formed with a cylinder head, and a cooling water passage is provided between each throat portion of the two exhaust ports and the mounting boss for the fuel injection nozzle. Was formed.

In the invention according to claim 1, in the method of inserting the port forming core at the time of casting of the cylinder head into the cooling water jacket forming core at a right angle to the cylinder longitudinal direction, the exhaust gas is used. It is difficult to form a cooling water passage between the throat portion of the port and the mounting boss of the fuel injection nozzle. Therefore, the outer wall of the exhaust port and the outer wall of the intake port of the adjacent cylinder are partially shared, and the exhaust port at the end of the cylinder head has no adjacent intake port, and therefore a part of the outer wall is thick-walled. By forming the exhaust port forming core, it is possible to secure an insertion space for the exhaust port forming core, and use the exhaust port forming core by utilizing a part of the existence space of the intake port forming core or by a thick portion of the outer wall. It can be inserted into the cooling water jacket forming core so as to have a curved insertion locus while bypassing the fuel injection nozzle mounting position.

According to a second aspect of the present invention, the two intake ports are opened as a helical port and a tangential port, respectively, on one side wall surface of the cylinder head to communicate with the intake manifold, and the two exhaust ports are connected to each other. As a single exhaust port where the flow from the throat portion of each port merges in the middle, it was opened to the other side wall surface of the cylinder head and communicated with the exhaust manifold.

In the invention according to claim 3, the cylinder head is made of aluminum casting. In the invention according to claim 4, the diesel engine is a DOHC type engine. According to a fifth aspect of the present invention, cooling water jackets are provided at the upper and lower portions of the exhaust port and the lower portion of the intake port, respectively, and the cooling water passage around the mounting boss of the fuel injection nozzle cools the upper portion and the lower portion. Communicated with the water jacket.

According to a sixth aspect of the present invention, there is provided a casting die for casting the cylinder head of the direct injection type diesel engine according to the fifth aspect, wherein an exhaust port forming core and a cylinder head lower die at a throat portion of the exhaust port. The split surface T3 between the upper surface height of the cooling water passage between the throat portions of the exhaust port or the upper height of the cooling water jacket at the lower portion of the exhaust port, T1, the upper wall thickness T2 of the exhaust port, the cylinder The height T4 of the lower head type port positioning tenon and the margin Δ were set so as to satisfy the following equation.

T3> T1 + T4-T2-Δ In the invention according to claim 5, it is possible to set the intake port forming core from above the cooling water jacket forming core. In this case, if cooling water passages are to be provided above and below the exhaust port, it is necessary to insert the exhaust port forming core horizontally into the exhaust port forming core arrangement space of the water jacket forming core.

In the invention according to claim 6, the total height of the exhaust port is lowered, the settability of the core for forming the exhaust port is improved, and the upper and lower cooling water passage widths are maximized. There is. As a result, the exhaust port forming core is used as a space for the cooling water jacket forming core, which serves as a wall on the upper side of the exhaust port, and is lifted using the space for the exhaust port forming core of the water jacket forming core. Will be inserted in the insertion part.

According to a seventh aspect of the present invention, a cast cylinder head is provided with two intake valves and two exhaust valves for each cylinder, and the cylinder head is opened and closed by the four valves for each cylinder. Each cylinder has four ports for intake and exhaust, and two intake valves for each cylinder and two exhaust valves are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft. In a direct-injection diesel engine, cooling is performed around the nozzle hole by curving the insertion trajectory of the core for forming the exhaust port used for casting with respect to the core for forming the cooling water jacket while bypassing the nozzle hole of the fuel injection nozzle. A water passage was formed.

[0017]

According to the inventions of claims 1 and 7, for example, as in the inventions of claims 3 and 4, in a DOHC four-valve direct injection diesel engine having excellent output performance, a lightweight aluminum cast cylinder is used. Cooling passage around the fuel injection nozzle mounting part when using the head as a boss for mounting the fuel injection nozzle of the cylinder head integrated molding type, which is advantageous in production cost and less likely to cause problems such as gas and water leakage. Can be easily secured, and cooling performance and durability can be improved.

According to the second aspect of the invention, a strong swirl flow (swirl flow) in the lateral direction of the cylinder is formed by the intake air, so that the intake port shape and the exhaust port shape can be improved to improve the combustion performance. According to the invention of claim 5, the settability of the intake port forming core can be improved,
You will be able to increase productivity.

According to the invention of claim 6, the settability of the exhaust port forming core can be improved, and the upper and lower cooling water passage widths can be secured to the maximum.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In FIGS. 1 and 2, a cylinder head 11 made of cast aluminum of a direct injection diesel engine is provided with two direct acting intake valves and two exhaust valves (not shown), respectively, and the cylinder head 11
4 ports (intake ports 12, 13 and exhaust ports 14A, 14B) that are opened and closed by the four valves are formed in the.

The two intake valves and the two exhaust valves for each cylinder are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft. Further, the two intake ports 12 and 13 serve as a helical port and a tangential port, respectively, and are opened on one side surface of the cylinder head 11 to communicate with an intake manifold (not shown).

Furthermore, two exhaust ports 14A and 14B
Is a single exhaust port 14 in which the flows from the throat portions of the ports 14A and 14B join together, and is opened to the other side surface of the cylinder head 11 to communicate with an exhaust manifold (not shown). On the other hand, a fuel injection nozzle (not shown) is provided upright on the substantially central axis of the cylinder bore of each cylinder of the cylinder head 11, and the mounting boss 15 for the fuel injection nozzle is integrally formed when the cylinder head 11 is cast.

A cooling water passage 16 is formed between each throat portion of the exhaust ports 14A and 14B and the mounting boss 15 of the fuel injection nozzle. Here, in a direct injection diesel engine equipped with two intake valves, in order to improve combustion performance,
In order to form a strong swirl flow (swirl flow) in the lateral direction of the cylinder by intake air, it is necessary to have an intake port shape (helical or tangential) that is asymmetrically arranged with respect to the cylinder.

Along with this, the exhaust ports are also asymmetrically arranged. In such a configuration, the cylinder head 11 of the port
The port toward the throat portion, which is recessed with respect to the end face of the side wall, has the length from the center of the cylinder to the position advanced from the center. Therefore, in the method of inserting the port forming core during casting of the cylinder head 11 into the cooling water jacket forming core 20 (see FIG. 2) at right angles to the cylinder longitudinal direction, the exhaust port It is difficult to form a cooling water passage between the throat portion and the boss for mounting the fuel injection nozzle (every portion where you want to form a cooling water passage due to the insertion locus of the port forming core in the deep port throat portion) It will be crap.)

Therefore, in the present construction, the insertion path of the exhaust port forming core 26 (see FIG. 2) is curved while bypassing the nozzle hole 15A of the fuel injection nozzle as shown in FIG. The cooling water passage 16 is formed around the nozzle hole 15A. In this case, in order to secure the insertion space for the exhaust port forming core 26, the outer wall of the exhaust port 14A and the outer wall of the intake port 12 of the adjacent cylinder are partially shared (see FIGS. 1, 3 and 4). Common outer wall 17).

As a result, the core 26 for forming the exhaust port is formed.
Can be inserted using a part of the existing space of the intake port forming core 27 (see FIG. 2) while detouring the nozzle hole 15A so as to form a curved insertion locus.
Further, as shown in FIG. 5, in the exhaust port 14A at the end portion of the cylinder head 11, there are no adjacent intake ports 12 and 13, so the exhaust port forming core 2
In order to secure the insertion space for 6, a part of the outer wall is formed thick (thick portion 11A).

Therefore, the order of inserting the port forming cores is
Exhaust port forming core 26, intake port forming core 2
The order is 7,28. Further, since the intake ports 12 and 13 have a smaller heat load than the exhaust ports 14A and 14B,
No cooling water jacket is needed on top of it. Therefore,
Cooling water jackets are provided above and below the exhaust ports 14A and 14B and below the intake ports 12 and 13, respectively.
The cooling water passage around the mounting boss 15 of the fuel injection nozzle connects the upper and lower cooling water jackets.

As a result, the intake port forming core 27,
As shown in FIG. 2, 28 can be set from the upper portion of the core 20 for forming the cooling water jacket, so that the settability can be improved and the productivity can be increased. On the other hand, since the exhaust ports 14A and 14B are shaped so as to traverse the cylinder head 11, their overall length is long.

Therefore, when it is attempted to provide cooling water passages above and below the exhaust ports 14A and 14B, the exhaust port forming core 26 is arranged horizontally with respect to the exhaust port forming core arrangement space of the water jacket forming core 20. Need to be inserted.
Therefore, in the present configuration, the exhaust port forming core 26
Is a parting line 3 between the core 26 and the cylinder head lower die 29.
The height of the exhaust port 1 is set to a height T3 of 0 (the split surface between the exhaust port forming core 26 and the cylinder head lower die 29 in the throat portion of the exhaust ports 14A and 14B).
The total height of 4A and 14B is reduced, the settability of the exhaust port forming core 26 is improved, and the upper and lower cooling water passage widths are secured to the maximum.

In this case, as shown in FIG.
And the height of the upper surface of the cooling water passage 10B between the throat portions of the exhaust ports 14A and 14B or the exhaust ports 14A and 14B.
The higher dimension T1 of the cooling water jacket 10A upper part of the lower part of B, the upper wall thickness T2 of the exhaust ports 14A and 14B, the height T4 of the port positioning tenon 29A of the cylinder head lower mold 29, and a margin. Various dimensions are set so that the relationship with the margin Δ is the following expression.

T3> T1 + T4-T2-Δ In such a construction, the exhaust port forming core 26 uses the space of the cooling water jacket forming core 20 which is the upper wall of the exhaust ports 14A, 14B to lift water. The jacket forming core 20 is inserted into an insertion portion 19 (see FIG. 4) which is a space for disposing the exhaust port forming core.

As a result, the core 26 for forming the exhaust port is formed.
Is set to a predetermined position by clearing the portion 22 (see FIG. 7) corresponding to the lower water jacket portion of the cooling water jacket forming core 20 and the positioning tenon 29A provided on the upper surface of the throat portion of the cylinder head lower mold 29. To be done. still,
The margin allowance Δ takes into consideration the dimensional variation of the core and the position balance at the time of setting.

The throat portions of the exhaust ports 14A, 14B are formed in a substantially cylindrical shape, and are formed by a core portion 29B formed by extending from the lower cylinder head mold 29 in a substantially cylindrical shape, and machined by a throat cutter or the like. The shape is finished with. Incidentally, in FIG. 4 and FIG.
A and 18B are the insertion portions of the intake port forming cores 27 and 28 in the cooling water jacket forming core 20, and 23 is
An intake port lower cooling water jacket forming portion, 25 is an exhaust port lower cooling water jacket forming portion, and 24 is an upper and lower cooling jacket communication passage forming portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a cylinder head of a direct injection diesel engine according to the present invention.

FIG. 2 is a perspective view showing a method of setting the port forming core to the cooling jacket forming core of the cylinder head of the same.

FIG. 3 is a vertical sectional view of an exhaust port forming portion of the same jacket.

FIG. 4 is a perspective view of a core for forming a cooling jacket of the above cylinder head.

FIG. 5 is a cross-sectional view of the cylinder head of the above.

FIG. 6 is a longitudinal sectional view of the cylinder head of the above.

FIG. 7 is a perspective view from below of a core for forming a cooling jacket of the cylinder head of the same.

FIG. 8 is a cross-sectional view of a conventional cylinder head.

FIG. 9 is a cross-sectional view of a conventional cylinder head.

[Explanation of symbols]

11 cylinder head 11A thick part 12,13 Intake port 14,14A, 14B Exhaust port 15 Fuel injection nozzle mounting boss 16 Cooling water passage 17 common outer wall 20 Core for forming cooling water jacket 26 Core for forming exhaust port 27,28 Intake port forming core 30 parting line

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[Procedure amendment]

[Submission date] May 12, 2003 (2003.5.1)
2)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Cylinder head of direct injection diesel engine and its casting mold

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head of a four-valve direct injection diesel engine and its casting mold , and more particularly to a technique for forming a cooling water passage in the cylinder head.

[0002]

Conventionally, to open and close the cylinder head, with each cylinder every respective two intake valves and two exhaust valves, and by the cylinder head 4 valves (two intake valves and two exhaust valves) A four-valve direct injection diesel engine is known in which each has four ports for intake or exhaust, and a fuel injection nozzle is provided at a portion corresponding to a substantially central portion of these four ports.

In such a four-valve direct injection diesel engine, as shown in FIG. 8 and FIG. 9, as a structure advantageous for forming a cooling water passage around a nozzle hole of a fuel injection nozzle of a cylinder head, etc. It adopts the one . That is, the cylinder head 1 is made of cast iron, the intake ports 2 and 3 of the cylinder head 1, the fuel injection mounting boss 6 of the nozzle provided in the portion corresponding to the substantially central portion of the exhaust port 4 and 5, the cylinder head 1 It is formed by press-fitting a pipe separate from the above into the cylinder head 1.

Further, the arrangement of the four valves is so-called diamond type, and the four valves are arranged at a position where the valve center is twisted with respect to the central axis of the cylinder bore. That is, the direction perpendicular to the central axis direction of the crankshaft has become disposed in a row and the intake and exhaust valves in a direction inclined at a predetermined angle. Such 4-valve direct injection diesel engine, a mounting boss 6 of the fuel injection nozzle, since a structure formed by press-fitting the pipe in the cylinder head 1, the cooling water passage around the nozzle hole of the fuel injection nozzle Cylinder head 1 made of cast iron with the advantage of easy formation
Therefore, since the material strength is high and the press-fitting margin of the pipe can be made large, the surface pressure of the press-fitting portion can be made large and the sealing property of cooling water and gas is excellent, and the arrangement of the four valves 2 to 5 is a diamond type. Therefore , the boss 6 for mounting the fuel injection nozzle
It is easy to form a cooling water passage between the exhaust port 4 and the exhaust port 4, and since the cylinder head 1 is made of cast iron, the wall thickness can be made thin, so that the cooling water passage can be sufficiently secured. Has advantages.

[0005]

THE INVENTION Problems to be Solved] However, DOH
A case of manufacturing a direct injection diesel engine having a C format aluminum cast cylinder head, in the case where the configuration of the 4-valve direct injection diesel engine as described above, the following problems is there. Rukoto That is, the mounting boss of a fuel injection nozzle, in the case where the configuration formed by press-fitting the pipe in the cylinder head, and increases the press-fitting allowance of the surface or Lapa type of material strength aluminum
I can't. Rukoto Therefore, a large surface pressure of the press section
Can not be achieved, and it is difficult to secure the sealing property of cooling water and gas.

In addition, the separate pipe press-fitting system is disadvantageous in terms of material and processing cost. Further, if the placement of the four valves are diamond-shaped, it is difficult to employ a valve system disposed in the DOHC type, using the rocker arm
The adoption of the SOHC type or OHV format was, but these forms, ensuring output of a high-speed region of the engine becomes difficult.

[0007] Considering the above circumstances, DOHC
In the direct-injection diesel engine having the form of aluminum cast cylinder head is parallel to the direction substantially perpendicular to the central axis direction of the two intake valves and between the two exhaust valves between a respective crankshaft of the air cylinder place manner, certain mounting boss of the fuel injection nozzle needs to be <br/> structure molded integrally with the cylinder head.

[0008] However, in such a configuration, die
Unlike Ya type, with the formation of the cooling water passages around the nozzle hole of the fuel injection nozzle it is difficult, the fuel injection Nozzle
Problem shape formed is difficult <br/> cooling water passage between the mounting boss and the exhaust port resulting in occurrence of. The present invention, two intake valves and between the two exhaust valves of the respective air cylinders are arranged such that parallel in a direction substantially perpendicular to the central axis of the respective crankshaft, the mounting boss of a fuel injection nozzle in <br/> cylinder head and a cylinder head integrally molded direct injection diesel engine, for the purpose that you formation <br/> cooling water passage such as around the nozzle hole easily.

[0009]

Means for Solving the Problems] Therefore, in the invention according to claim 1, comprising a respective cylinder every respective two intake valves and two exhaust valves are opened and closed by one One each cylinder each of the four valves Each has 4 ports for intake or exhaust, 2 for each cylinder
In a cylinder head of a direct injection diesel engine , in which one intake valve and two exhaust valves are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft, during casting, Cooling of the exhaust port core used
Check the insertion path of the water jacket core for the exhaust port.
Forming core bypasses the nozzle hole of the fuel injection nozzle
The cooling water passage was formed around the nozzle hole .

The intake valve and the exhaust valve are respectively located at the center of the crankshaft.
Directly arranged in parallel to each other in a direction substantially orthogonal to the axial direction.
In the injection diesel engine, at the time of casting of the cylinder head
Arrange the exhaust port forming core to be used with the cooling water jacket forming core from the side of the cylinder head to arrange the valves.
If parallel to the insertion and direction is the fuel injection nozzle Nozuruho
It is difficult to form a cooling water passage around the base. There
The exhaust port forming core against the cooling water passage forming core.
The exhaust path forming core is
Be curved so as to bypass the nozzle hole
In this case, it becomes easy to form this cooling water passage.

[0011] In the invention according to claim 2, each cylinder odor
Te, the two intake ports, respectively as a helical port and a tangential port, open to one side <br/> of the cylinder head through the intake manifold and the communication, the two exhaust ports, the flow from the throat portion As a single exhaust port that merges on the way, it was opened on the other side surface of the cylinder head and communicated with the exhaust manifold.

[0012] In the invention according to claim 3, and cylinder head made of cast aluminum. Invention according to claim 4
In the, and the diesel engine as the engine of DOHC format. In the invention described in claim 5, the upper and lower exhaust ports, and the respective cooling water jackets formed in the lower portion of the intake port, by cold <br/>却水passage around the nozzle hole of the fuel injection nozzle These upper and lower cooling water jackets were connected.

[0013] In the invention according to claim 6, manufacturing a cylinder head of a direct injection diesel engine of the invention according to 請 Motomeko 5
In casting mold for forming the height T3 of the cut surface of the exhaust port-forming core and the cylinder head lower die in the throat portion of the exhaust port, put between the throat portion of the exhaust port
That coolant dimensions higher of the upper surface height and top height of the cooling water jacket exhaust ports lower passages T1, the exhaust port
Thickness in developing wall T2, was set to be the following relationship with respect to the height T4 and margin Δ port positioning tenon type lower cylinder head. T3> T1 + T4-T2-Δ

[0014] The direct-injection diesel d of the invention according to 請 Motomeko 5
In a cylinder head of the engine, it is possible to install from above intake port forming core relative <br/> cooling water jacket-forming core. This ensures that the intake port forming core
Is easier to set, but cooling water jets are placed above and below the exhaust port.
Attempting to form a jacket, exhaust port-forming core
Needs to be inserted in a horizontal direction with respect to the configuration space of the exhaust port-forming core coolant jacket forming the core.

Therefore, the relationship defined in claim 6 is established.
In that case, the core for forming the exhaust port should be located above the exhaust port.
Through the space inside the core for forming the cooling water jacket
And then insert it while lifting it up and put it in the space
As a result, the setability of the core for forming the exhaust port is improved.
To do. Also , the overall height of the exhaust port can be lowered.
Since, Ru can be secured the width of the exhaust port and below the coolant jacket to the maximum.

[0016] In the invention according to claim 7, direct injection di
A cylinder head of a diesel engine , each cylinder having two intake valves and two exhaust valves, and each cylinder having four intake or exhaust ports opened and closed by the four valves, two intake valves and between the two exhaust valves each other, each crankshaft axial direction to the casting mold in <br/> Oite those formed by arranging such that parallel in a direction substantially perpendicular of each, adjacent cylinder On the side wall of the cylinder head
The intake port that extends inward with respect to the opening position of the air port.
Outside of the exhaust port adjacent to this intake port and this intake port
Form a common outer wall that is connected to the wall at its most recent contact point
The first part and one end of the cylinder head in the cylinder row direction.
The exhaust port provided on the end wall side and formed at that position
The second outer wall is formed thicker than the outer walls of other parts.
Upright on the central axis of the cylinder bore of each cylinder
The fuel injection nozzle mounting boss
A third part that is integrally molded with the engine and two exhausts for each cylinder
Each throat of the port and the boss for mounting the fuel injection nozzle
And a fourth portion that forms a cooling water passage between the exhaust port and
Cooling at the top and bottom of the inlet and the bottom of the intake port
A fifth part forming a water jacket is provided and the exhaust port
The cooling water passages above and below the
Connected by the cooling water passage around the mounting boss of the injection nozzle
Connect the fourth and fifth parts as shown in
Exhaust port forming core and seal at port throat
The height T3 of the split surface with the lower Linda head die
The height of the top surface of the cooling water passage between the throat parts and the exhaust port
The higher dimension T of the upper heights of the cooling water passage at the bottom of the port
1, exhaust wall upper wall thickness T2, cylinder head lower mold
For the height T4 of the port positioning tenon and the margin allowance Δ
Were set so as to satisfy the following equation . T3> T1 + T4
-T2-Δ According to the casting die having such a configuration, the exhaust port
Part of the outer wall of the cylinder and the outer wall of the intake port of the adjacent cylinder.
Since it is decided to share it, the core for forming the intake port is
Use the storage space to secure the insertion space for the exhaust port forming core.
Can be kept around the fuel injection nozzle mounting position
Can be inserted like. Because of this, the exhaust port
Between the throat of the vehicle and the boss for mounting the fuel injection nozzle
The formation of the drainage passage becomes easy. On the other hand, the cylinder head
The exhaust port on the end wall side has an adjacent intake port.
It does not exist, but by forming a part of its outer wall to be thick
This secures an insertion space for the core for forming the exhaust port.
In the same way as other exhaust port forming cores, the fuel injection nozzle
Can be inserted so as to bypass the mounting position of.

[0017]

Effects of the Invention According to the invention of claim 1 or 7, intake
The air valve and exhaust valve are approximately perpendicular to the central axis of the crankshaft.
Fuel injection in a cylinder head of a four-valve direct injection diesel engine arranged in parallel
Around the nozzle hole of the nozzle or the throat of the exhaust port
A cooling water passage between the fuel injection nozzle and the mounting boss for the fuel injection nozzle can be easily formed .

The lever by the invention according to claim 2, to form a strong swirling flow in the lateral direction of the cylinder (the swirl flow) by the intake air, it is possible to make improved combustion performance. In claim 3
According to this invention, the cylinder head is cast from aluminum.
By making it, you can configure a lightweight engine.
It According to the invention of claim 4, a DOHC format disc
By using a diesel engine, the output performance of the engine
Can be improved. According to the invention of claim 5, to improve the set of the intake port forming core, Siri
Ru can increase the productivity of the cylinder head.

[0019] by the invention according to claim 6 lever, to improve the set of exhaust ports forming core, the raw cylinder head
It is possible to increase the production of, Ki <br/> Ru emanating to ensure the width of the exhaust port and below the coolant jacket to the maximum.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 illustrates an embodiment of the present invention .
Cylinder of cylinder head of direct injection diesel engine
It shows a cross section taken along a plane perpendicular to the central axis of the dowel.
The cylinder head 11 made of cast aluminum of a direct injection diesel engine has two direct-acting intake valves and two direct-acting intake valves, respectively.
One of the exhaust valve (not shown) are provided, and sheet cylinder head 11, four ports (intake ports 12, 13 and the exhaust port 14A which is opened and closed by the four valves, 1
4B) has been formed.

The two intake valves and between the two exhaust valves of the respective air cylinders are arranged to parallel in a direction substantially perpendicular to the central axis of the respective crankshaft. Further, the two intake ports 12 and 13 serve as a helical port and a tangential port, respectively, and are opened on one side surface of the cylinder head 11 to communicate with an intake manifold (not shown).

Furthermore, two exhaust ports 14A and 14B
Is a single exhaust port 14 where the flows from the throat portions of the ports 14A and 14B join together on the way , and is opened to the other side surface of the cylinder head 11 to communicate with an exhaust manifold (not shown). On the other hand, the fuel injection nozzle is provided which is not shown it is vertically on the substantially central axis of the cylinder bore of each cylinder of the cylinder head 11, the mounting boss 15 of the fuel injection nozzle, the casting of the cylinder head 11
It is integrally molded with the cylinder head 11 (casting die “3rd
Part of ) .

[0023] Also, an exhaust port 14A, between each throat portion and a fuel injection nozzle mounting boss 15 of the 14B, Ru Tei is cooling water passage 16 is formed (casting mold of the "fourth parts
Minute. ) . Here, in a direct-injection diesel engine equipped with two intake valves, in order to improve combustion performance, a strong swirl flow (swirl flow) in the lateral direction of the cylinder is formed by intake air, so that it is asymmetrically arranged with respect to the cylinder. Intake port shape (helical, tangential) is required.

Along with this, the exhaust ports are also asymmetrically arranged. In such a configuration, an exhaust port 14A toward the throat portion recessed with respect to the side wall end face of the cylinder head 11 of the exhaust port, the length to the position advanced before the cylinder center. Therefore, the cylinder head 11
An exhaust port-forming core for use in casting, array side of the hand valve to the cooling water jacket-forming core 20 (see FIG. 2)
It is difficult to form a cooling water passage between the throat part of the exhaust port and the mounting boss of the fuel injection nozzle by the method of inserting the pipe parallel to the direction (the inner part of the core for forming the exhaust port <br / > Due to the insertion path of the core part that forms the closed throat part , all the parts where you want to form the cooling water passage become useless).

Therefore, in this structure , as shown in A of FIG. 1 , the insertion locus of the exhaust port forming core 26 (see FIG. 2) is such that the core portion forming the deep throat portion is the fuel injection nozzle. It is curved so as to bypass the nozzle hole 15A
By doing so, the cooling water passage 16 can be formed around the nozzle hole 15A. In this case , in order to secure the insertion space for the exhaust port forming core 26, the outer wall of the intake port 12 of the cylinder adjacent to the outer wall of the exhaust port 14A.
DOO Ru is shared part (FIG. 1, a common outer wall 17 of FIG. 3 and FIG. 4: According to the "first portion" of the casting mold.).

[0026] This ensures that the exhaust port-forming core 26
Through the arrangement space of the intake port forming core 27 (see FIG. 2) with respect to the cooling water jacket forming core 20 .
Then, it can be inserted to bypass the Roh Zuruhoru 15A. Further, as shown in FIG. 5, at the end wall side of the cylinder head 11 is in contact next to the exhaust port 14A intake port 1
Since there is no 2 or 13, the exhaust port forming core 26
In order to secure the insertion space of the outer wall, a part of the outer wall is formed thick (thick part 11A : by the "second part" of the casting die).
It ).

Therefore, the order of inserting the port forming cores is
Exhaust port forming core 26, intake port forming core 2
The order is 7,28. Further, since the intake ports 12 and 13 have a smaller heat load than the exhaust ports 14A and 14B, a cooling water jacket is not required above them. Therefore, cooling water jackets are provided above and below the exhaust ports 14A and 14B, and below the intake ports 12 and 13, respectively.
Formed (according to the "fifth" part of the casting mold.), This by the cooling water passage 16 around the mounting boss 15 of the fuel injection nozzle
A structure for communicating the cooling water jacket of these upper and lower.

As a result, the intake port forming core 27,
28, as shown in FIG. 2, it is possible to install from above side of the cooling water jacket-forming core 20, to improve the setting property, Ru can increase productivity. On the other hand, an exhaust port 14A, 14B are the shape transverse to the cylinder head 11, a long its entire length.

Therefore, when it is attempted to provide cooling water passages above and below the exhaust ports 14A and 14B , the exhaust ports are horizontally oriented toward the space for disposing the exhaust port forming core 26 in the cooling water jacket forming core 20 . It is necessary to insert the forming core 26. Therefore, in the present configuration , the exhaust port forming core 26 has the height T3 of the parting line 30 between the core 26 and the cylinder head lower die 29 (the exhaust port forming core in the throat portion of the exhaust ports 14A and 14B). 26 and the cylinder head lower mold 29, the height of the split surface) is increased to lower the total height of the exhaust ports 14A and 14B to improve the settability of the exhaust port forming core 26.
And so that to ensure maximum width of the upper and lower cooling water passages.

In this case , as shown in FIG.
3, put in between the throat portion of the exhaust port 14A, 14B
That the height of the upper surface of the cooling water passage 10B and the exhaust port 14A,
The dimensions T1 higher of the 14B lower portion of the upper height of the cooling water jacket 10A, exhaust ports 14A, 14 B upper wall
The various dimensions are set so that the relationship between the wall thickness T2 of the cylinder head, the height T4 of the port positioning tenon 29A of the cylinder head lower mold 29, and the allowance Δ is as follows .

[0031] T3> T1 + T4-T2- Δ In such a configuration, the exhaust port-forming core 26, the exhaust port 14A, while lifting by way of the space of the cooling water jacket-forming core 20 to be 14B upper wall cooling <br/> Exhaust port forming core in the water jacket forming core 20
It is inserted into the insertion portion 19 (see FIG. 4) which serves as the arrangement space for the 26 .

[0032] This ensures that the exhaust port-forming core 26
Is beyond the bottom of the cooling water jacket formed part 2 2 of the cooling water jacket-forming core 20 (see FIG. 7), and a positioning tenon 29A provided on the upper surface of the throat forming portion of the cylinder head lower die 29 , Installed in place. The allowance Δ takes into consideration the dimensional variation of the core and the position balance at the time of setting.

The throat portion of the exhaust port 14A, 14B is orienter higher in a substantially cylindrical shape from sheet cylinder head lower die 29
Was formed by the Riryaku cylindrically core portion 29B which is formed, its shape is finished by machining by the throat cutter and the like. Incidentally, in FIGS. 4 and 7, 18A, 18B
The insertion portion of the intake port forming core 27, 28 in the cooling water jacket-forming core 20, 23, forming part of the cooling water jacket of the intake port bottom 25, an exhaust port
Is the formation portion of the coolant jacket of the upper portion. Also , 24
Is a formation part of the cooling water passage 16 around the nozzle hole.
Ri, it is connected to the forming unit 23 and 25.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a cylinder head of a direct injection diesel engine according to the present invention.

FIG. 2 is a perspective view showing a method of installing the port forming core to the cooling water jacket forming core of the cylinder head.

FIG. 3 is a vertical sectional view of an exhaust port forming portion of the same jacket.

FIG. 4 is a perspective view from above of a core for forming a cooling water jacket of the above cylinder head.

FIG. 5 is a cross-sectional view of the cylinder head of the above.

FIG. 6 is a longitudinal sectional view of the cylinder head of the above.

FIG. 7 is a perspective view from below of a core for forming a cooling water jacket of the cylinder head of the above.

FIG. 8 is a cross-sectional view of a conventional cylinder head.

FIG. 9 is a cross-sectional view of a conventional cylinder head.

[Explanation of symbols] 11 cylinder head 11A thick part 12,13 Intake port 14,14A, 14B Exhaust port 15 Fuel injection nozzle mounting boss 16 Cooling water passage 17 common outer wall 20 Core for forming cooling water jacket 26 Core for forming exhaust port 27,28 Intake port forming core 30 parting line

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (7)

[Claims] 1. A cast cylinder head is provided with two intake valves and two exhaust valves for each cylinder, and the cylinder head has four intake and exhaust valves opened and closed by the four valves for each cylinder. In a direct-injection diesel engine having ports, two intake valves for each cylinder, and two exhaust valves for each cylinder are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft, The outer wall of each intake port extending inward with respect to the intake port opening position on the cylinder head side wall of the adjacent cylinder and the outer wall of each exhaust port adjacent to the intake port are connected at their closest points to share the port outer wall. In addition to the above structure, the outer wall of the exhaust port located on the one end wall side in the cylinder row direction of the cylinder head is formed thicker than the outer walls of the other portions. A fuel injection nozzle is provided upright on a substantially central axis of a cylinder bore of each cylinder of the cylinder head, and a mounting boss of the fuel injection nozzle is integrally formed with the cylinder head, and each throat portion of the two exhaust ports and the fuel are provided. A cylinder head for a direct injection diesel engine, characterized in that a cooling water passage is formed between the injection nozzle and a mounting boss. 2. The two intake ports serving as a helical port and a tangential port, respectively, are opened in one side wall surface of a cylinder head and communicate with an intake manifold,
The two exhaust ports are opened to the other side wall surface of the cylinder head and communicate with the exhaust manifold as a single exhaust port where the flow from the throat portion of each port joins in the middle. 1. A cylinder head for a direct injection diesel engine according to 1. 3. The cylinder head for a direct injection diesel engine according to claim 1, wherein the cylinder head is made of aluminum casting. 4. The cylinder head for a direct injection diesel engine according to claim 1, wherein the diesel engine is a DOHC type engine. 5. A cooling water jacket is provided on each of the upper and lower portions of the exhaust port and the lower portion of the intake port, and the upper and lower cooling water jackets are provided by the cooling water passage around the mounting boss of the fuel injection nozzle. The cylinder head of the direct injection diesel engine according to any one of claims 1 to 4, wherein 6. A casting die for casting a cylinder head of a direct injection diesel engine according to claim 5, wherein a split surface T3 between the exhaust port forming core and the cylinder head lower die in the throat portion of the exhaust port is an exhaust port. Of the height of the upper surface of the cooling water passage between the throat portions or the height of the upper portion of the cooling water jacket at the lower portion of the exhaust port, the upper wall thickness T2 of the exhaust port, the cylinder head lower die port positioning tenon. A cylinder head casting mold for a direct injection diesel engine, characterized in that the height T4 and the margin allowance Δ are set to satisfy the following equation. T3> T1 + T4-T2-Δ 7. A cast cylinder head is provided with two intake valves and two exhaust valves for each cylinder, and the cylinder head has four intake and exhaust valves opened and closed by the four valves for each cylinder. In a direct-injection diesel engine having ports, two intake valves for each cylinder, and two exhaust valves for each cylinder are arranged in parallel in a direction substantially orthogonal to the central axis direction of the crankshaft, A cooling water passage is formed around the nozzle hole by bending the insertion path of the exhaust port forming core used for casting with respect to the cooling water jacket forming core while bypassing the nozzle hole of the fuel injection nozzle. A cylinder head for a direct injection diesel engine, which is characterized by