JP3282922B2 - Structure and manufacturing method of cylinder block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder block for an internal combustion engine, and more particularly to a structure and a method of manufacturing a cylinder block capable of improving the cooling performance of a wall between cylinder bores.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for reducing the weight and shortening the overall length of a multi-cylinder engine, and in order to meet the demand, it is necessary to develop a cylinder block having a reduced dimension between cylinder bores. Conventionally, a cooling water passage between the cylinder bores is also formed by a sand mold core that forms a water-cooling jacket when the cylinder block is cast, so that the dimension L between the cylinder bores B, B is reduced as shown in FIG. However,
The liner cut c is performed so that the liner thickness between the cylinder bores is reduced to the minimum necessary, and the width d of the cooling water passage D between the cylinder bores is made as small as possible.

As shown in FIG. 5, a cooling water passage is not formed between the cylinder bores, but a plate creel P is cast into a wall W between the cylinder bores. The one protruding into the cooling water passage C is proposed.

[0004] As a similar technical means, Japanese Utility Model Laid-Open No. 61457/1985 discloses a cooling fin protruding into a cooling water passage cast between cylinder bores.

Further, Japanese Utility Model Laid-Open No. 59-7242 discloses that
The portion corresponding to between the cylinder bores in the core forming the water-cooling jacket is formed not by a sand mold but by a water passage component member having a space serving as a cooling water passage between a pair of plate members, and both ends thereof are embedded in the sand mold. Thus, a configuration in which both side portions of the water channel constituent member protrude into the cooling water passage of the water cooling jacket is disclosed.

[0006]

However, in the structure shown in FIG. 4, the cooling water passage D between the core cylinder bores is provided.
Is required to have strength to withstand the pressure of the casting liquid, so that the width d of the cooling water passage D between the cylinder bores
The limit is about 3 mm, which cannot be made smaller, and there is a problem that the dimension L between cylinder bores cannot be further reduced.

[0007] In the structure shown in FIG.
Is cooled by water on both sides thereof to cool the wall W between the cylinder bores only by the heat transfer by the plate Keren P, and is not directly cooled by the cooling water. Therefore, the cooling capacity is small, and the temperature of the wall W between the cylinder bores is low. As a result, problems arise in terms of durability and defects due to thermal deformation.

In the structure disclosed in Japanese Utility Model Laid-Open Publication No. Sho 59-7242, the cooling water passage is formed between a pair of plate members, so that the strength and the cooling capacity are ensured. Therefore, there is a problem that the dimension L between the cylinder bores cannot be reduced too much because the thickness of the plate and the appropriate width of the cooling water passage are required.

The present invention has been made in view of the above problems, and provides a structure and a manufacturing method of a cylinder block capable of effectively cooling a wall between cylinder bores while reducing the size between cylinder bores. With the goal.

[0010]

The structure of the cylinder block according to the first invention of the present application is to provide a cooling water passage between bores communicating with main cooling water passages on both sides of a water cooling jacket on a wall between cylinder bores. A window having both sides projecting into the main cooling water passages on both sides is disposed in the cooling water passage, and a window which opens over the main cooling water passages on both sides and forms a part of the inter-bore cooling water passage in the plate cooling water. Through in the thickness direction
It is characterized by being formed in.

The method of manufacturing a cylinder block according to the second invention of the present application is directed to a core for forming a water-cooling jacket in which a sheet keren is embedded in a portion corresponding to a cooling water passage between bores to be formed in a wall between cylinder bores. the cast cylinder block installed in the mold, by performing shot blasting from the formed main cooling water passage toward the inside window of the plate Keren a method of manufacturing the cylinder block that form a cooling water passage between the bore
In addition, the sheet keren has opposite ends on both sides of the water cooling jacket.
To the main cooling water channel formation part of
The outlet is directed upstream or downstream of the water flow in the main cooling channel.
And is opened over both of the extensions.
A) A window that forms part of the cooling water channel between
Characterized in that that.

[0012]

According to the present invention, since the cooling water passage between the bores is provided in the wall between the cylinder bores, the wall between the cylinder bores can be effectively cooled, and there is no problem in terms of durability and thermal deformation.
In addition, since the sheet metal is disposed in the cooling water passage between the bores, even if the width of the cooling water passage between the bores is small, sufficient strength can be secured against the pressure of the casting liquid during casting. Because the window that forms a part of the cooling water passage between the bores, the dimension between the cylinder bores does not increase by the thickness of the sheet keren, and it is necessary to reduce the dimension between the cylinder bores while having sufficient cooling capacity And the overall length of the engine can be shortened.

Further, according to the manufacturing method of the present invention, after casting using a core for forming a water-cooling jacket in which the sheet metal having the window formed therein is embedded, a shot is formed from the inside of the main cooling water passage toward the window. By blasting, it is possible to easily and surely remove sand from both sides of the plate inside the window of the plate and between the windows, and it is possible to easily form the small-width cooling water passage between the bores.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a cylinder block of a multi-cylinder engine, in which a plurality of cylinder bores 2 are arranged in a line. Reference numeral 3 denotes a wall between the cylinder bores 2 and 2, and reference numeral 4 denotes a main cooling water passage of a water cooling jacket formed on both sides of the two rows of cylinder bores. Reference numeral 5 denotes an inter-bore cooling water passage formed in the wall 3 between the cylinder bores 2 and 2 so as to communicate with the main cooling water passages 4 on both sides. A portion between the cylinder bores 2 and 2 in the liner 6 on the outer periphery of the cylinder bore 2 is A liner cut 6a is formed in the cooling water passage 5 between the bores so as to have a necessary minimum thickness. Inside the cooling water passage 5 between the bores, a plate creel 7 is disposed, and upper and lower end portions thereof and an appropriate portion in a vertical direction as necessary are cast into the wall 3. Further, both sides of the sheet keren 7 protrude into the main cooling water passage 4, and the water flow guides bent toward the upstream or downstream side of the cooling water flow in the main cooling water passage 4 at the protruding portions. An inclined portion 8 is formed. Further, a plurality of windows 9 having an appropriate width in the vertical direction extending in the vicinity of both side ends thereof are formed in the vertical direction. Both sides of this window 9 are water flow guide slopes 8
Is formed over.

When the cylinder block 1 is manufactured, the cooling water passage 5 between the bores as described above is formed in the wall 3 between the cylinder bores 2 and 2.
As shown in FIG. 3, as shown in FIG. 3, a sheet metal member 7 having the window 9 is embedded in a portion 11 corresponding to the inter-bore cooling water passage 5 in the core 10 for forming a water cooling jacket. Then, the core 10 for forming a water-cooled jacket is placed in a mold to cast a cylinder block. After casting, the mold sand in the main cooling water passage 4 is removed by vibration or the like as in the prior art, and then, as shown by a virtual line in FIG. The projection nozzle 13 of the polisher is inserted into a portion facing one side of the cooling water passage 5 between the bores, and the blast material is projected toward the window 9 of the plate creel 7. As described above, the cooling water passage 5 between the bores having a small width is formed by removing the mold sand on the both sides of the plate kerren 7 in the window 9 and between the windows 9, 9. At this time, since both sides of the window 9 are formed over the water flow guide inclined portion 8, the shot blasting into the window 9 is performed without the projection nozzle 13 interfering with the side end portion of the sheet keren 7 during the cleaning. It can be carried out. The mold sand used for the portion 11 corresponding to the inter-bore cooling water passage 5 is designed so that casting defects hardly occur even when the width of the portion 11 is small, and is relatively easily decomposed and removed after casting. Is used.

According to the structure of the cylinder block 1 thus formed, since the cooling water passage 5 between the bores is provided in the wall 3 between the cylinder bores, the wall 3 between the cylinder bores can be effectively cooled, and the durability and thermal deformation can be improved. There is no problem with respect to the above. In addition, with the sheet metal helmet 7 disposed in the inter-bore cooling water passage 5, even if the width of the inter-bore cooling water passage 5 is small, it is possible to secure sufficient strength against casting pressure during casting. Moreover,
Since the window 9 formed in the sheet metal member 7 forms a part of the cooling water passage 5 between the bores, the dimension between the cylinder bores is not increased by the thickness of the sheet metal member 7 and sufficient cooling capacity is provided. While holding, the dimension between the cylinder bores 2 and 2 can be reduced, and the overall length of the engine can be reduced. In addition, since the water flow guide inclined portions 8 are provided on both sides of the sheet keren 7 protruding into the main cooling water passage 4, the cooling water flowing in the main cooling water passage 4 is directed to the inter-bore cooling water passage 5. Therefore, even if the width of the inter-bore cooling water passage 5 is narrow, the wall 3 between the cylinder bores can be efficiently cooled.

As a specific example of numerical values, the thickness of the flat plate 7 can be set to 0.7 to 1.0 mm, and the width of the cooling water passage 5 between the bores can be set to approximately 1.5 to 2.0 mm. The size between the bores 2 and 2 can be reduced by about 1.0 to 1.5 mm as compared with the conventional limit of about 3 mm, and the overall length of the engine can be shortened.

[0019]

According to the structure of the cylinder block of the first invention of the present application, since the cooling water passage between the bores is provided in the wall between the cylinder bores as described above, the wall between the cylinder bores can be effectively cooled. No problem in terms of durability and thermal deformation,
In addition, since the sheet metal is disposed in the cooling water passage between the bores, even if the width of the cooling water passage between the bores is small, sufficient strength can be secured against the pressure of the casting liquid during casting. Because the window that forms a part of the cooling water passage between the bores, the dimension between the cylinder bores does not increase by the thickness of the sheet keren, and it is necessary to reduce the dimension between the cylinder bores while having sufficient cooling capacity And the overall length of the engine can be shortened.

Further, according to the manufacturing method of the second aspect of the present invention, after casting using a water-cooling jacket forming core in which the sheet metal having the window formed therein is embedded, the water-cooling jacket is directed toward the window. By performing the shot blasting, it is possible to easily and surely remove the sand on both sides of the Keren inside the window of the plate Keren and between the windows, and it is possible to easily form the small-width cooling water passage between the bores.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view of a main part of a cylinder block according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a cooling water passage portion between the bores of the embodiment.

FIG. 3 is a cross-sectional plan view of a main part of the core for forming a water-cooled jacket of the embodiment.

FIG. 4 is a cross-sectional plan view of a main part of a conventional cylinder block.

FIG. 5 is a cross-sectional plan view of a main part of another conventional cylinder block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder bore 3 Wall between cylinder bores 4 Main cooling water passage 5 Cooling water passage between bores 7 Sheet metal 9 Window 10 Core for forming water cooling jacket

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02F 1/14 F02F 1/00 F01P 3/02

Claims (2)

(57) [Claims] An inter-bore cooling water passage communicating with main cooling water passages on both sides of a water cooling jacket is provided in a wall between cylinder bores. The cooling plate is formed so as to extend through the main cooling water passages on both sides thereof and form a part of the inter-bore cooling water passage in the plate thickness direction. Structure of cylinder block. 2. A water-cooling jacket forming core in which a sheet keren is embedded is placed in a mold at a portion corresponding to a cooling water passage between bores to be formed in a wall between cylinder bores, and a cylinder block is cast and formed. A method of manufacturing a cylinder block in which a cooling water passage between bores is formed by performing shot blasting from inside the main cooling water passage into the window of the plate cooling water, wherein both ends of the plate cooling water are provided on both sides of the water cooling jacket. Of the cooling water passage between the bores, and both of the extending portions are bent toward the upstream or downstream side of the water flow in the main cooling water passage, and open over the both extending portions. A method for manufacturing a cylinder block, wherein a window forming a part thereof is formed.