JPS62282745A - Consumable pattern for casting cylinder head for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the cooling performance and rigidity of a cylinder head by providing directional control parts for cooling water flow in a water jacket to a consumable pattern divided by the respective parting lines running near the base and top surface of the jacket. CONSTITUTION:The parting line D, E, F, G, H for dividing the corresponding consumable pattern to six parts and forming said patterns are set to the cylinder head 11 approximately horizontally from a suction side lateral face 22 toward an exhaust side lateral face 23. The parting lines D, F are set in this stage so as to runn respectively near the base and top surface of the water jacket 19 positioned right above the bottom surface 17 of the cylinder head to divide the consumable pattern. Flow regulating plates 31, 37, 38 and ribs 32-35 as the directional control parts for controlling the flow direction of the cooling water flowing in the jacket 9 are respectively provided to the respective divided consumable patterns. The construction of the cylinder head provided with both the cooling performance and rigidity is thereby obtd.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fugitive model for casting that becomes a gaseous state and disappears due to the action of the molten metal that has been cast, and particularly relates to The present invention relates to a divided structure of a fugitive casting model used for casting engine cylinder heads.

[Conventional technology]

Traditionally, coreless (coreless) castings are produced by making an actual model using a material that becomes gaseous and disappearing due to the action of molten metal, and then pouring molten metal into this model while it is buried in sand.
Core Less) casting method is known (Special Publication Act 5
2-14206).

Furthermore, the structure of a seven-ring head for a diesel engine manufactured by this casting method is also known.

[Problem that the invention seeks to solve]

In conventional water-cooled engines, the cooling water that flows within the water jacket of the cylinder head usually flows in the longitudinal direction of the engine. That is, the cooling water flows through each cylinder of the engine in sequence. Therefore, the passage resistance of the water jacket in the cylinder head increases as the number of cylinders increases.If the zero passage resistance increases, the flow rate of the cooling water decreases, the cooling water stagnates, and the cooling effect deteriorates. Therefore, with such a cylinder head structure, it is very difficult to sufficiently cool the cylinder head of today's gasoline engines, which further require high output (high compression).

FIG. 7 shows a partial cross-section of the cylinder head of the diesel engine described above. In FIG. ), but if you try to make a cylinder head using a polygon model, it is very difficult to make the polyester model in one piece due to the complicated shape of the cylinder head due to the casting process of the polyester model. , it is necessary to create a poly model by dividing it. Therefore, parting lines (dividing lines) A, B, and C are set on this cylinder head 1, and the poly model for casting Rad 1 into this cylinder is horizontally divided into four parts by the parting lines. There is.

However, in the cylinder head of this diesel engine, only the strength and productivity of the cylinder head are emphasized, and although the degree of freedom in design is increased by dividing the poly model into multiple parts, the cooling capacity of the cylinder head is improved. There is little consideration given to how the cooling water flows.

The present invention focuses on the great degree of freedom in design, which is an advantage of coreless casting, and provides a cylinder head for a gasoline engine that combines excellent cooling performance and high rigidity using a separable fugitive model. The purpose is to increase the output of the engine.

Means for Solving Problem c] A fugitive model for casting a cylinder head for an internal combustion engine according to the present invention in accordance with this object is used for casting a cylinder head for an internal combustion engine, and is used for casting a cast molten metal. In a fugitive model for casting a cylinder head for an internal combustion engine that becomes a gas state and disappears due to the action, the fugitive model is formed with a first parting line extending along the bottom surface of a water jacket located directly above the lower surface of the cylinder head. , the water jacket is divided by a second parting line passing near the upper surface of the water jacket, and each of the divided fugitive models is provided with a direction control unit that controls the flow direction of the cooling water passing through the water jacket. Consists of what has been set up.

Further, it is preferable that the direction control section is formed to extend in a direction perpendicular to the longitudinal direction of the engine.

[Effect]

In the fugitive model for casting a cylinder head for an internal combustion engine configured in this way, the fugitive model is divided by the first parting line and the second parting line, so the degree of freedom in the design of the cylinder head is increased. Even if the size of the cylinder head is increased and the shape of the cylinder head becomes complicated, the model can be cast easily. That is, the cylinder head can be made into a complex structure that has both excellent cooling performance and high rigidity.

Since the direction control section of the cylinder head controls the flow direction of the cooling water flowing in the water jacket in one direction, a decrease in the flow speed of the cooling water or stagnation due to merging is prevented. Therefore, the cooling capacity of the cylinder head is significantly increased,
High output of the engine is achieved.

Furthermore, since the direction control section also acts as a reinforcing member, the rigidity of the cylinder head is increased, resulting in a structure that can sufficiently withstand high compression ratios.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a fugitive model for casting a cylinder head for an internal combustion engine according to the present invention will be described below with reference to the drawings.

In this embodiment, the shape and division structure of the fugitive model will be explained using a completed cylinder head, and the actual fugitive model used to cast the cylinder head is not shown. Furthermore, expanded polystyrene is used as the fugitive model material.

1 to 6 show a cylinder head cast using a fugitive model (hereinafter referred to as a poly model) of a cylinder head for an internal combustion engine according to an embodiment of the present invention,
In particular, it shows the cylinder head of a six-cylinder DOHC gasoline engine that has been machined after being cast.

FIG. 6 shows the entire cylinder head.

In the figure, 11 indicates a cylinder head, and 12 indicates a plug tube of each cylinder. Plug tube 12
A valve lifter guide 13 on the intake side is provided on the upper side of the figure, and a pulp lifter guide 14 on the exhaust side is provided on the lower side.

Furthermore, cam journal portions 15a and 15b are provided on the left and right sides of each plug tube 12, respectively.

FIG. 1 shows a cross section along line 1-1 in FIG.
Figure 2 shows a cross section along the line ■-■ in Figure 1.
In the figure, 16 indicates a sand removal hole, and sand removal hole 1
A tight plug boss 36 is formed below 6. Cylinder head attachment holes 81 + 82 are provided on the left and right sides of the tight plug boss 36 for attaching the cylinder head 11 to the cylinder block (as shown). 17 indicates the lower surface of the cylinder head, and the lower surface 1 of the cylinder head
A water jacket 19 is formed above 7.

Inside the water jacket 19, there is a water jacket 1.
A rectifier plate 31 is disposed as a direction control unit that controls the flow direction of cooling water passing through the cooling water.

The current plate 31 is disposed between the boats 83 and 84 located between the cylinders, and extends upward from the lower surface 17 of the cylinder head, with the tip of the current plate 31 extending upward from the lower surface 17 of the cylinder head. It is located midway in the vertical direction.

The rectifier plate 31 has a diamond-shaped cross-section in the horizontal direction.
It extends perpendicular to the engine longitudinal direction. As a result, the cooling water power ζ flowing through the water jacket 19,
It is formed to flow in a direction perpendicular to the longitudinal direction of the engine. The water jacket 19 is attached to the current plate 31.
A recess 31a opening on the side is provided, thereby reducing the weight and increasing the contact area with the cooling water, thereby improving the cooling capacity.

On the upstream side of the current plate 31, ribs 32 and 33 are arranged as direction control sections that control the flow direction of the cooling water passing through the water jacket 19. Rib 32°33 is
The cylinder head mounting hole 81 is provided in a head bolt hole boss 87, and the rib 33 is located above the rib 32 with a slight spacing therebetween.

These extend obliquely downward from the cylinder head mounting hole 81 side toward the rectifier plate 31 side.

On the downstream side of the current plate 31, ribs 34 and 35 are arranged as direction control sections that control the flow direction of the cooling water passing through the water jacket 19 in the same manner as described above. rib 3
4.35 is provided at a head bolt hole boss 89 in which the cylinder head mounting hole 82 is formed, and the rib 35 is located above the rib 34 with a slight interval. The ribs 34 and 35 are connected to the cylinder head mounting hole 8 on the exhaust side.
It extends diagonally downward from the second side toward the rectifier plate 31 side.

The tight plug boss 36 is located directly above the current plate 31, and the tight plug boss 36 has current plates 37 and 38 as a direction control unit that controls the flow direction of the cooling water passing through the water jacket 19. It is formed. The current plate 37 is adjacent to the above-mentioned rib 33, and is formed into a triangular shape whose sides become longer as they go upward. The current plate 38 is adjacent to the rib 35, and is formed into a triangular shape whose sides become longer as they go upward, as described above. A tight plug boss 85 is provided on the exhaust side side surface 23 of the cylinder head 11 to remove sand after casting, and a rib 86 is formed at the upper end of the tight plug boss 85. The rib 86 is for filling the space formed to secure machining space on the back side of the tight plug boss 85 during machining of the tight plug boss 85, and thereby prevents cooling water from stagnation. There is.

FIG. 3 shows a cross section taken along the line ■-■ in FIG. 2.

In the figure, '83.84 indicates a boat. boat 83
is connected to the head bolt hole boss 87 via a rib 88. The boat 84 is connected to a head bolt hole boss 89 via a rib 90. By connecting these parts, the rigidity of the cylinder rod 11 is increased.

The cylinder head 11 thus integrally constructed is cast using a poly mold made with the same dimensions as the cylinder head 11. The poly model has a split structure due to the casting process, and the split positions of the poly model are set by parting lines, which will be described later. In this embodiment, the poly model is divided into six parts by a first parting line, a second parting line mF, and other parting lines E, C, and H.

In FIG. 1, the first parting line vItD is the parting line located at the lowest position, and the first parting line is on the intake side side surface of the cylinder head 11 and below the intake manifold mounting hole 39. It extends horizontally from the cylinder head through the cylinder head mounting hole 81 to the water jacket 19 side. The first parting line extends along the bottom surface of the water jacket 19, passes through the cylinder head attachment hole 82, and extends horizontally in the direction of the exhaust side side surface 23.

The parting line E extends diagonally downward from above the intake manifold mounting screw hole 39 on the intake side side surface 22 of the cylinder head 11 and reaches between the ribs 32 and 33.

The parting VAE further extends from this position, passes between the ribs 34 and 35, and extends substantially horizontally in the direction of the exhaust-side side surface 23 of the cylinder head 11.

The second parting line F extends horizontally from directly above the above-mentioned parting line E toward the tight plug post 36 on the intake side side surface 22 of the cylinder head 11, and extends horizontally from the cylinder head mounting hole 8
1.82 and the upper base of the rib 33.35, and extends directly to the cylinder in the direction of the exhaust-side side surface 23 of the Rad 11.

The parting gland G extends horizontally from a portion located on the intake side side surface 22 of the cylinder head 11 and between the valve stem hole 24 and the valve lifter guide 13 to the valve stem hole 2.
4.25 and extends toward the exhaust side surface 23 of the rad 11 toward the cylinder.

The parting line H is the intake side side surface 22 of the cylinder head 11, and the valve lifter guide 13 and the cam journal 15a.
It extends horizontally from a portion located between the valve lifter guides 13 and 14 toward the exhaust-side side surface 23 of the cylinder head 11, passing over the tops of the valve lifter guides 13 and 14.

In this way, for example, if the cylinder head 11 is divided along the parting line in FIG. 1, the cylinder block 11 will be divided into blocks 101, 102, 103,
, 104.105.106. Each of the blocks is provided with a direction control section that controls the flow direction of the cooling water described above. That is, the block 101 is provided with the current plate 31, and the block 102 is provided with the current plate 31.
are provided with ribs 32,34. And block 1
03 is provided with ribs 33.35, and the block 104
are provided with rectifying plates 37 and 38.

FIG. 5 shows a cross section of the cylinder head taken along line V-V in FIG. 6. In the figure, 18 indicates a combustion chamber, and a plug tube 12 into which a spark plug (path shown) is inserted is formed directly above the combustion chamber 18. The plug tube 12 penetrates from the upper surface 41 of the cylinder head 11 to the combustion chamber 1, and the lower part of the plug tube 12 is a plug threaded portion 12a. The cylinder head member 42 forming the plug tube 12 becomes thinner toward the combustion chamber 18, and its tip is formed integrally with the upper wall 43 of the combustion chamber 18.

Cylinder head member 42 forming plug tube 12
A water jacket 19e is formed on the outer periphery of the water jacket. The water jacket 19e is connected to the plug tube 12
It is surrounded by a cylinder head member 42 forming an intake port 21 and an exhaust boat 22, cylinder head members 44a and 44b forming an intake port 21 and an exhaust boat 22, and an upper wall 43 forming a part of a combustion chamber. As a result, especially the combustion chamber 18
The upper wall 43 is capable of contacting the water jacket 19e over a wide area.

At positions in the vertical direction of the plug tube 12 and on the outer periphery of the plug tube 12, water jackets 19f and 19g each having a parallelogram cross-sectional shape are provided. Cam journal parts 15a and 15b are provided above the water jackets 19f and 19g.

In addition, in the figure, 26 indicates a blow-by gas passage,
45 is an insertion hole into which a fuel injection valve (path shown) is inserted.

In the cross section of the cylinder head in FIG. 5, the first parting line extends horizontally from the intake side 122 of the cylinder Rad 11 to the bottom of the water jacket 19e through the vicinity of the bottom of the blow-by gas passage 26. . Then, the parting line is the mountain-shaped combustion chamber 1, which is the earthen wall of the combustion chamber 18 and the bottom of the water jacket 19e.
The rod 1 extends along the upper wall 43 of the cylinder 8, crosses the plug threaded portion 12a, and extends from the point where it finishes descending the upper wall 43 to the cylinder.
It extends horizontally toward the exhaust side side surface 23 of 1.

The parting NIAE is the intake side side surface 2 of the cylinder Rad 11.
2 along the center line of the intake boat 20, and extends so as to reach the bottom surface of the water jacket t9a. Further, the parting IE on the exhaust boat 21 side also extends from the bottom surface of the water jacket 198 along the center line of the exhaust boat 21 toward the exhaust side side surface 23 of the cylinder head 11.

The second parting point vAF extends horizontally above the intake boat 20 and from the intake side side surface 22 of the cylinder Rad 11 toward the plug tube 12. Further, the parting line F is located above the exhaust bow 1-21, and this portion is horizontal.

The parting line G is located above the above-mentioned parting line F, extends horizontally from the intake side side surface 22 of the rad 11 to the cylinder, crosses the water jacket 19f, the plug tube 12, and the water jacket 19g, and connects the rad 11 to the cylinder for exhaust gas. It extends toward the side surface 23. Note that a part of the parting line G on the outer periphery of the plug tube 12 extends downward and also stands up. That is, the joint portion of the polygon model in this part has a fitting structure, so that the polymorphism model can be easily aligned and the positioning accuracy is improved.

The parting line H extends horizontally from the intake side side surface 22 of the cylinder Rad 11, and the parting line H at this position
The height is equal to the height of the parting line H shown in FIG. When the parting line H comes directly under the cam journal portion 15a, it rises once, extends slightly in the horizontal direction, and then descends again, and continues horizontally at the same level as the starting point. and,
When the parting line H comes directly under the cam journal part 15b, it partially rises and extends horizontally in the same way as described above, and then goes down again and returns to the original level to meet the exhaust side surface 23 of the cylinder Radar 11.
extending towards. That is, the parting line H rises in a convex shape only directly below the cam journal parts 15a and 15b, and in the poly model, this part has a fitting structure. This facilitates positioning of the polygon model and ensures a predetermined positioning accuracy.

In this embodiment, five parting lines are set on the cylinder head 11, and the corresponding poly model is divided into six parts. However, the poly model is not limited to six parts, and the poly model can be further divided into many parts. This increases the degree of freedom in design and makes it possible to obtain a cylinder head structure with excellent functionality. Further, the present invention is applicable not only to gasoline engines but also to diesel engines.

Next, the operation of the above-mentioned fugitive model for casting a cylinder head for an internal combustion engine will be explained.

As mentioned above, the cylinder head 11 has first and second parting lines F extending from the intake side side surface 22 of the cylinder head 1.1 toward the exhaust side side surface 23 of the cylinder head 11, and other parting lines. Parting lines E and G.

H is set, and the poly model used to cast the cylinder head 11 using these parting lines is
It is divided into 6 parts. The poly model divided into 6 parts is accurately aligned, and the joining surface (partition'!a) of the poly model is
are adhered and adhered with adhesive.

In FIG. 1, water jacket 19, cylinder head 11 blocks 101, 102, . 103.10
4, and the joint surface (first parting line D) between the block 101 and the block 102 is connected to the water jacket 1 located directly above the lower surface 17 of the cylinder head.
9 extends substantially horizontally along the bottom surface.

Therefore, the bonding surface of the polygon model becomes a horizontal plane, preventing the adhesive from dripping from the bonding surface, and eliminating the occurrence of stiffness due to adhesive dripping. Further, the second parting line F also extends horizontally from the intake side side surface 22 of the Rad 11 toward the tight plug boss 36, and passes through the upper base of the rib 33.35 disposed in the water jacket 19 to the cylinder. Since it extends in the direction of the exhaust-side side surface 23 of the helad 11, the joint surface between the block 103 and the block 104 becomes a horizontal surface. Therefore, in the same way as described above, the occurrence of cracks and the like due to dripping of the adhesive from the joint surfaces is prevented, and the flow resistance of the cooling water is reduced.

The cooling water flowing inside the water jacket 19 flows from the intake side side surface 22 of the cylinder head 11 toward the exhaust side side surface 23, as shown in FIG.

In this case, the flow of the cooling water is divided into cylinders by a streamline plate 31 located between the cylinders, so that the flow velocity of the cooling water does not decrease due to merging or the like. Further, the current plate 31 not only increases the strength of the cylinder head lower surface 17, but also fills unnecessary water jacket space and prevents cooling water from stagnation.

Additionally, the tight plug post 36 provided below the sand removal hole 16 also fills in unnecessary space and prevents cooling water from stagnation. And this tight plug boss 3
6 are provided with rectifier plates 37 and 38, so that the cooling water above the water jacket flows toward the lower surface 17 of the cylinder head, where the temperature is high, and the cooling effect of the Rad 11 to the cylinder is enhanced.

The ribs 32 and 33 provided on the head bolt hole boss 87 control the flow direction of the cooling water in the same manner as the above-mentioned current plate, so that stagnation of the cooling water due to merging is prevented. moreover,
The ribs 32,33 act as reinforcing members and increase the rigidity of the head bolt hole boss 87. The action of the ribs 34, 35 is also similar to that of the ribs 32,38.

In this way, since the flow of cooling water is independent for each cylinder, each cylinder is cooled uniformly and the flow rate of the cooling water is increased, so that the cooling ability of the cylinder head is significantly improved.

〔Effect of the invention〕

As explained above, when using the fugitive model of the cylinder head for an internal combustion engine of the present invention, the fugitive model is defined as the first parting line extending along the bottom surface of the water jacket located directly above the lower surface of the cylinder head; Since the water jacket is divided by the second parting line passing near the upper surface of the water jacket, it becomes possible to form a large number of direction control parts for controlling the flow direction of the cooling water inside the water jacket.

As a result, the flow direction of the cooling water can be made independent for each cylinder, and the flow rate of the cooling water can be increased, resulting in the effect that the cooling performance of the cylinder head can be significantly improved. Therefore, the high compression ratio of the engine can be further increased, and a high output engine can be obtained.

Further, since the direction control portion acts as a reinforcing member, the rigidity of the cylinder head is increased, and a cylinder head that can sufficiently withstand high compression can be obtained.

Furthermore, by forming the bonding surface of the fugitive model to be a horizontal surface, it is possible to prevent the adhesive from dripping or protruding, thereby achieving the effect of preventing the occurrence of flakes.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a cylinder head manufactured by a fugitive model for casting a cylinder head for an internal combustion engine according to an embodiment of the present invention, and is a sectional view taken along line I-I''&il in FIG. 6. is a sectional view taken along line ll-Tl in Fig. 1, Fig. 3 is a sectional view taken along line m-m in Fig. 2, and Fig. 4 is an exploded view of the cylinder head section shown in Fig. 1 divided by parting lines. Figure 5 is a cross-sectional view along V-V cotton in Figure 6;
FIG. 7 is a plan view of the entire cylinder head, and FIG. 7 is a sectional view of a conventional diesel engine cylinder head manufactured using a fugitive model. 11・・・・・・・・・・・・・・・Cylinder head 17・・・・・・・・・・・・・・・Cylinder head bottom surface 19・・・・・・・・・・・・・・・・・・
・Water jacket 31, 37.38... Current plate 32, 33, 34, 35... as a direction control section
...Rib D as a direction control part...
・・・・・・・・・First parting line F・・・・・・・・・
......Second parting line 101, 102.1
03.104.105.106...Cylinder head block in DOHC engine divided by parting line Patent Applicant Toyota Motor Corporation Figure 2

Claims (2)

[Claims] (1) In a fugitive model for casting a cylinder head for an internal combustion engine, which is used to cast a cylinder head for an internal combustion engine and disappears by turning into a gaseous state due to the action of the molten metal that has been cast, the fugitive model is , a first section extending along the bottom surface of the water jacket located directly above the bottom surface of the cylinder head.
and a second parting line passing near the top surface of the water jacket, and each divided evanescent model is provided with a direction control unit that controls the flow direction of the cooling water passing through the water jacket. What is claimed is: 1. A fugitive model for casting a cylinder head for an internal combustion engine, characterized in that each of the following is provided. (2) A fugitive model for casting a cylinder head for an internal combustion engine according to claim 1, wherein the direction control member is formed so as to extend in a direction perpendicular to the longitudinal direction of the engine.