JPH0814100A - cylinder head - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the passage volume from increasing when the wall thickness is reduced,
A cylinder head that is easy to manufacture is also provided. [Composition] A passage 10 for circulating cooling water L inside
In the cylinder head in which the passage 1 is formed.
A filler layer 12 is formed by partially filling a filler 11 made of a resin or a rubber material in a position other than the exhaust port 4 and the periphery of the combustion chamber in 0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water cooled engine cylinder head.

[0002]

2. Description of the Related Art Passages for circulating cooling water are defined in a cylinder head of a water-cooled engine.
Cooling water such as LLC is normally circulated in this passage for cooling. The cylinder head is connected to the cylinder block to define the top of the combustion chamber, and also has intake and exhaust ports inside. In particular, since hot exhaust gas exists in the combustion chamber and the exhaust port, the cylinder head is exposed to high temperature mainly due to heat received from them. Therefore, the passages are sufficiently considered in arrangement, shape, volume, etc. so that the cooling water can absorb the heat from them in the most efficient manner and that the temperature difference of the entire cylinder head is eliminated and cracks are not generated. .

[0003]

By the way, recent engines have tended to have high output and large displacement, and accordingly, the cylinder head has been made larger, and the intake and exhaust ports have similarly expanded cross-sectional areas. It's starting. There is a problem that the size of the cylinder head is increased and the weight thereof is increased. On the other hand, it is conceivable to reduce the weight by making the cylinder head thin.

However, if this is done, the volume of the cooling water passage, which is the internal space, will inevitably increase, and if this happens, the amount of cooling water injected will also increase, and it will take time for the water temperature to rise at the cold start and the warm-up time will increase. There is a drawback that invites.

As a solution to this problem, for example, Japanese Utility Model Laid-Open No. 57-58747
As reported in Japanese Patent Publication, it is considered that the inside of the passage is appropriately partitioned to form a cavity in which cooling water does not flow, and the passage volume is substantially reduced to reduce the amount of cooling water. However, according to this, since the partition wall is formed at the same time when the cylinder head is cast, the weight is increased due to the fact that it is a metal, and the core at the time of casting has two layers for the passage and the cavity. Therefore, there are problems such as difficulty in casting and difficulty in removing sand after casting.

Therefore, the present invention has been devised in view of the above circumstances, and an object thereof is to provide a cylinder head which prevents an increase in passage volume when the wall thickness is reduced and is easy to manufacture. It is in.

[0007]

In order to achieve the above object, the present invention is directed to a cylinder head in which a passage for circulating cooling water is defined and formed in the exhaust port and the periphery of the combustion chamber in the passage. A filling material layer is formed by partially filling a filling material made of a resin or a rubber material in a position to be removed.

[0008]

According to the above construction, even if the passage volume is increased by thinning the passage, the passage volume can be substantially reduced by forming the filler layer in the passage. Therefore, it is possible to prevent an increase in the amount of cooling water and an increase in warm-up time. Further, the cooling water is circulated around the relatively high temperature exhaust port in the passage and the combustion chamber, so that the cooling can be efficiently performed. This filler layer is formed only by filling the filler after the cylinder head is cast, and is therefore very easy to manufacture.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a cylinder head according to the present invention, particularly showing a state cut at the position of an exhaust port.

As shown in the figure, the cylinder head 1 is an integrally cast product made of aluminum light alloy, cast iron or the like, which is elongated in the longitudinal direction according to the number of cylinders of the engine.
The cylinder head 1 is a cylinder block (not shown).
Is connected to the top of the combustion chamber, and the bottom surface of the peripheral edge serves as a connection surface 2 with the cylinder block, and the central bottom defines a combustion chamber top 3. The inlet ends of the exhaust ports 4 and 4 are opened at the top 3 of the combustion chamber, that is, two exhaust ports 4 are provided in this example, and these exhaust ports 4 are gathered while bending sideways to exhaust the exhaust gas on the side wall of the cylinder head 1. It communicates with the mouth 5. A valve seat 6 for an exhaust valve (not shown) is formed at the top 3 of the combustion chamber, and a shaft chamber 7 of the exhaust valve is formed above the valve seat 6 in the cylinder axial direction. Further, 8 is a bridge guide insertion hole, and 9 is a bolt hole for attaching the exhaust manifold. Although not shown in the figure, an intake port is also provided adjacent to the exhaust port 4.

A passage 10 is formed in the cylinder head 1 for passing cooling water L such as LLC. The passage 10 includes a relatively large volume opposed passage 10a formed on the opposite side of the exhaust port 5, a small passage 10b formed between the inlets of the exhaust ports 4 and 4, and above and below the exhaust port collecting portion 4a. It is mainly composed of an upper passage 10c and a lower passage 10d formed in the. Obviously, however, the passage 10 extends over the entire cylinder head 1 in a complicated shape, and the figure shows only one section thereof. These passages 10a to 10d are all communicated with each other at an appropriate place inside the cylinder head 1, so that the cooling water L
Will also be circulated in the passages 10a to 10d.

In particular, the opposing side passage 10a and the upper passage 10c are partially filled with a filler 11 made of a synthetic resin or a rubber material, whereby a filler layer 12 is formed. Specifically, as shown in FIG. 2, the filler layer 12 is formed by turning the cylinder head 1 after casting upside down and tilting the connecting surface 2 with respect to the horizontal plane H by an angle θ, and in that state, it is in a liquid or gel state. By pouring and fixing the filling material 11 in the above, the upper portion in the opposite-side passage 10a and the upper portion in the upper passage 10c and the passage 10a side are formed obliquely inclined. The filler layer 12 is not formed on the bottom wall of the upper passage 10c. When the filler layer 12 adheres in this way, its specific gravity becomes smaller than the specific gravity of the cooling water L, and conversely speaking, such a filler 11 is selected here. As a matter of course, the cylinder head 1 and the cooling water L can withstand high temperatures sufficiently.

The pouring or pouring of the filling material 11 is carried out by casting sand dropping holes 13 and 14 (14 are blinded by a sealing cup 15) formed in the cylinder head 1 and cooling, as shown in FIG. It is performed using a large number of holes such as the outlet hole 16 for the water L. The hole 13 is also used as the outlet of the cooling water L, and the injection is performed from one hole to the passage 10
It may be distributed through the communication part between a and 10c, or may be carried out little by little from several holes.

Thus, the filler layer 11 results in the passage 1
Therefore, the cooling water L is circulated or circulated around the exhaust port 4 and the combustion chamber.

Next, the operation of the above embodiment will be described.

When the cylinder head 1 becomes large in size as it becomes thin, the volume of the passage 10 which is an internal space inevitably increases, but the filler layer 12 is provided in the passage 10 as in the above embodiment. If formed, the passage volume can be substantially reduced, which can prevent an increase in the amount of cooling water and thus an increase in warm-up time. In particular, when the cylinder head 1 is made large, the width and length are determined by the bore pitch and the like, so that the extension in the height direction is remarkable, but along with this, the passage 10 is enlarged at the upper part of the cylinder head 1. However, by forming the filler layer 12 in this enlarged portion, it is possible to prevent the passage volume from increasing.

Further, since the filler layer 11 is formed at a position excluding the exhaust port 4 and the periphery of the combustion chamber, and the cooling water L is circulated or circulated around the relatively high temperature, the heat from them is surely secured. It is possible to absorb and cool efficiently, and at the same time, it is possible to eliminate the temperature difference in the entire cylinder head 1 and prevent the occurrence of cracks and the like.

Further, the filler layer 12 has a specific gravity of the cooling water L.
Since the specific gravity is smaller than that of the aluminum light alloy or cast iron forming the cylinder head 1, the weight increase due to the filler layer 12 is negligible and the weight reduction can be achieved. Further, even if the filler layer 12 is not adhered, it does not sink into the cooling water L and floats up, so that heat transfer from the lower combustion chamber or the exhaust port 4 to the cooling water L is not hindered.

In addition, the filler layer 12 is the cylinder head 1
It is formed only by injecting or filling the filling material 11 by the above-mentioned method after casting, so that the manufacturing is very easy. It is also possible to inject the filling material 11 by inclining the cylinder head 1 in the longitudinal direction.

Further, it is possible to expect a damping effect on the filler layer 12, which may reduce the sound emitted from the cylinder head 1.

As a further modification, as shown in FIG. 1, a plurality of protrusions 17 may be formed on the inner walls of the passages 10a and 10c where the filler layer 12 is formed. In this way, when the filler 11 is fixed and becomes the filler layer 12, it can be firmly fixed and durability and reliability are improved. Further, the shape of the protruding portion 17 may be various shapes such as a square shape and an I shape in addition to the mountain shape as shown in the figure, or the surface of the core may be intentionally roughened to provide irregularities.

As described above, the cooling water is circulated in the places where cooling is required, and the filler layer is formed in the places where the cooling is not required. Therefore, it is possible to achieve the weight reduction without impairing the cooling performance, and at the same time. It is possible to prevent an increase in warm-up time. In the above description, only the peripheral portion of the exhaust port has been described, but the cooling water passage in the peripheral portion of the intake port may have the same configuration.

[0024]

The present invention exhibits the following excellent effects.

(1) The passage volume can be substantially reduced, which can prevent the amount of cooling water and the warm-up time from increasing.

(2) The weight can be reduced without impairing the cooling performance.

(3) Manufacture is easy.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a cylinder head according to the present invention.

FIG. 2 is a side sectional view showing a method of filling a filling material.

FIG. 3 is a perspective view showing a cylinder head.

[Explanation of symbols]

 4 Exhaust Port 10 Passage 11 Filler 12 Filler Layer 17 Projection L Cooling Water

Claims (3)

[Claims] 1. A cylinder head in which a passage for circulating cooling water is defined, wherein a filler made of a resin or a rubber material is partially provided at a position in the passage except the exhaust port and the periphery of the combustion chamber. A cylinder head, characterized in that a cylinder is filled to form a filler layer. 2. The cylinder head according to claim 1, wherein the filler layer has a specific gravity smaller than that of the cooling water flowing in the passage. 3. The cylinder head according to claim 1, wherein a protrusion for fixing the filler layer is formed on an inner wall of the passage.