JPH06218560A - Manufacture of cylinder block - Google Patents

Abstract

PURPOSE:To manufacture a cylinder block with rigidity which is almost the same as that of a closed deck type by reducing a deformation and durability for a long time by a solid phase joining. CONSTITUTION:An open deck type cylinder block main body 1 is manufactured by casting, and a clogging member 5 which is another member, is joined to the main body 1 by a solid phase joining. In the solid phase joining, a new surface is made on a contact part by pushing. Simultaneously with that, the contact part is heated by a resistance heating by energizing to make the contact surface a metallic bond.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a cylinder block by joining a closing member to the upper end opening of a water jacket of an open deck type cylinder block body.

[0002]

2. Description of the Related Art Cylinder blocks include an open deck type cylinder block in which the upper end of a water jacket is open and a closed deck type cylinder block in which the upper end of the water jacket is closed except for water holes. The closed deck type cylinder block is superior to the open deck type cylinder block in that the deformation and vibration of the cylinder bore are small, but the sand mold must be used to form the water jacket, and die casting using a mold cannot be used. , Inferior to open deck type cylinder block.

As a method of manufacturing a cylinder block having the performance advantage of a closed deck type cylinder block and the casting advantage of an open deck type cylinder block, conventionally, an open deck type cylinder block body is produced by preliminarily die casting. The upper end opening of the water jacket is joined with a closing member that is separate from the cylinder block body to close the upper end of the water jacket, and the deformation and vibration of the cylinder bore are reduced to the same level as the closed deck cylinder block. Various block manufacturing methods have been proposed.

The conventional proposals are roughly classified into two groups. The first is
A method of joining by utilizing melting of metal, such as welding, brazing, and fusion, is disclosed in Japanese Utility Model Laid-Open No. 2-105557 and Japanese Utility Model Laid-Open No. 62-62.
The joining of Japanese Patent No. 165442 etc. belongs to this. Second,
This is a mechanical fixing method such as press fitting.

[0005]

However, in the joining method utilizing the melting of metal, since the heat input during the joining heating is large, the cylinder bore is apt to be distorted and the welding is performed by a large amount of gas generated from the aluminum casting. There was a problem that blow holes were generated in the nugget and it was difficult to obtain sufficient bonding strength. Further, the mechanical fixing method has a problem that the fixing is loosened due to deformation of the cylinder bore and the like and the long-term durability is deteriorated as the usage period becomes longer.

An object of the present invention is to provide a method for manufacturing a cylinder block, in which a cylinder block body and a closing member are joined using solid-state joining, which has different principles from conventional metal fusion joining and mechanical fixing such as press fitting. Therefore, it is to eliminate or reduce the deformation of the cylinder block due to the large heat input and the lack of long-term durability, which are problems of the conventional method.

[0007]

The above object can be achieved by the following method for manufacturing a cylinder block according to the present invention. That is, in the method of manufacturing a cylinder block, the closing member of the water jacket, which is a member different from the cylinder block main body, is pushed into the upper end opening of the water jacket of the open deck type cylinder block main body formed by casting to join the cylinder block. The surface of the contact portion between the upper end opening of the water jacket of the block main body and the closing member is scraped off by using the pushing force to generate a new surface and press the new surface against each other, and between the cylinder block body and the closing member. A method for manufacturing a cylinder block, comprising energizing and heating the contact portion by resistance heating to solid-phase join the contact portions of the new surfaces.

[0008]

Function: Solid phase welding is usually found in friction welding. For example, when the metal rods of the same type or different types are rotated relative to each other while being pressed against each other, the pressure contact surface is scraped off by frictional force and becomes the pressure contact between the new surfaces, and at the same time, the contact surface becomes high temperature due to friction heat generation, and both surfaces remain solid phase. To join. There is no nugget or bead at the joint as in welding. Utilizing the principle of this solid-phase joining, the cylinder block body of the present invention and the closing member are joined together. A new surface is formed at the contact portion by using the pushing force, and while the new surface is in contact with the air without being exposed to air, the contact surface is heated by resistance heating to heat the contact surface to join the contact portions. Since heating by frictional heat such as friction welding cannot be used, resistance heating is also used. Since heat input is not required until the metal is melted, the heat input is small, and it is possible to prevent thermal deformation of the bore and generation of blowholes due to gas generation from the molten aluminum.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the embodiment of the present invention comprises the steps of casting a cylinder block body 1 and a closing member 5, and a step of solid-phase joining the closing member 5 to the cylinder block body 1 to form a cylinder block 2. . 1 and 2 show the manufactured cylinder block. In the step of casting the cylinder block body 1, the cylinder block body 1 is formed of aluminum into an open deck type cylinder block in which the upper end of the water jacket 9 is opened by die casting using a die. The cylinder block body 1 has a cylinder outer peripheral wall 3 and a water jacket outer peripheral wall 4, and a water jacket 9 is formed between the outer peripheral walls 3 and 4.

The closing member 5 is also usually formed by die casting, and is made of, for example, aluminum. However, the solid-phase metal bond is established between different kinds of metals, so that it may be other than aluminum.
The closing member 5 is pushed into the upper opening of the water jacket 9 and joined to the cylinder block body 1. Although engine cooling water is exchanged between the cylinder block and the cylinder head, a water hole 8 through which the engine cooling water is passed is cast in the closing member 5. In addition, the closing member 5 includes
A connecting portion 6 for connecting the cylinder outer peripheral wall 3 and the water jacket outer peripheral wall 4 is appropriately formed. Connection part 6
At the four corners of the above, there are formed recesses 7 for concentrating electric current in the connecting portion 6 by leaving a gap between the cylinder outer peripheral wall 3 and the water jacket outer peripheral wall 4. FIG. 3 shows the closing member 5 in a perspective view.

Cylinder block body 1 and closing member 5
When the closing member 5 is pushed into the upper end opening of the water jacket in the step of forming, the surface of the contact portion between the closing member 5 and the upper end opening of the water jacket of the cylinder block body is scraped off to give a new surface. Means are formed. This chamfering means, in the embodiment of FIGS.
The cylinder block main body 1 includes a corner portion 11 of a step portion 10 formed at an upper end opening of the water jacket and tapered surfaces 12 formed on both side surfaces of the closing member 5.

In the state before the closing member 5 is pushed into the upper opening of the water jacket, the maximum width a of the closing member 5 is larger than the width e of the water jacket 9 at the connecting portion 6, as shown in FIG. The width of the water jacket 9 is smaller than the maximum width b of the step portion, and gaps c and d are formed between the water jacket 9 and the side surface of the step portion. Further, the minimum width f at the lower end of the tapered portion of the closing member 5 is smaller than the width e of the water jacket 9.

In the portion other than the connecting portion 6, as shown in FIG. 4, the width A of the closing member 5 is smaller than the width B of the water jacket 9 without steps, and the width A between the closing member 5 and the surface of the water jacket 9 is small. The gaps C and D are formed at. Due to the existence of the gaps C and D, no current flows between the closing member 5 and the cylinder block body 1 in the non-connecting portion, and the current concentrates in the connecting portion 6.

In joining and fixing the closing member 5 and the cylinder block body 1, the closing member 5 is pushed into the opening of the upper end of the water jacket, and electricity is applied between the closing member 5 and the cylinder block body 1. By pushing in the state of FIG. 6, the chamfering means is activated, that is, the corner 11 scrapes the surface of the tapered surface 12 and the corner 11 is also worn, so that the closing member 5 and the cylinder block main body water jacket upper end opening surface are removed. A new surface is generated at the contact portion of the new surface, and the new surface keeps the contact state between the new surfaces without being exposed to the outside air.

At the same time, the contact portion is heated by resistance heating by energization. By the contact between the new surfaces and the heating, the contact surfaces are metal-bonded and solid-phase bonded. Since it is solid-phase joining, unlike conventional welding joining, no knack is generated, and the amount of electric current does not require energy to melt the metal, so the heat input is reduced compared to conventional welding. Therefore, the thermal strain of the cylinder bore is also reduced. Further, since it is solid-phase joining, it is integral joining, and is superior in long-term durability to conventional press-fitting.

FIG. 7 shows another embodiment of the present invention.
In the embodiment of FIG. 7, the closing member 5A is not a continuous member as in FIG. 3, but is made of a member having an appropriate length, which is arranged at a position corresponding to the connecting portion 6 in FIG. This is a method of pressing into the upper opening of the water jacket of the block and performing solid phase bonding. Others are in accordance with the embodiment shown in FIGS.

FIG. 8 shows yet another embodiment of the present invention. In the embodiment of FIG. 8, the corner portion 11B of the chamfering means.
Is formed on the closing member 5B side, and the tapered surface 12B is formed on the upper end opening side of the water jacket of the cylinder block body. Others are in accordance with the embodiment shown in FIGS.

Next, the operation and effects of the embodiment of the present invention will be described. The cylinder block body 1 can be molded by a normal die-casting method. The closing member 5 is metal-bonded to this to form a cylinder block having the same rigidity as the closed deck type cylinder block. Therefore, the productivity is improved and the cost can be significantly reduced as compared with the conventional method for manufacturing a closed deck type cylinder block in which a sand core is used for casting. In the conventional method using the sand core, even when using a special core for die casting, it is necessary to inspect the water jacket for blockage due to cracking of the core, which increases the inspection man-hour, but in the present invention, it is It becomes unnecessary. Further, as compared with the conventional manufacturing method using a sand core, core molding, sand treatment, sand removal, and other various processes and treatments associated with the sand core are unnecessary.

Further, when the closing member is joined to the cylinder block body by brazing or conventional fusion welding, it is exposed to a high temperature for a long time as compared with resistance pressure welding.
Although the deformation is large and the machining allowance is large in the subsequent process, the method of the present invention can reduce this.

[0020]

According to the present invention, since the closing member is solid-phase joined to the cylinder block body, the heat input amount can be reduced as compared with the conventional welding, and the thermal distortion and thermal deformation of the cylinder block can be suppressed. In addition, the long-term durability can be improved as compared with the conventional press fitting. Also, since the closing member is made as a member separate from the cylinder block body and is joined to the cylinder block body to obtain the same rigidity as that of the closed deck cylinder block, it is not necessary to use a sand core. The cylinder block body can be produced by the die casting method using a die, and the productivity can be maintained well.

[Brief description of drawings]

FIG. 1 is a plan view of a cylinder block manufactured by a cylinder block manufacturing method according to an embodiment of the present invention.

2 is a cross-sectional view of the cylinder block of FIG. 1 taken along line 2-2.

FIG. 3 is a perspective view of a closing member in FIG.

FIG. 4 is a partial cross-sectional view taken along line 4-4 of FIG.

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

6 is a partial cross-sectional view of the state in which the closing member is pushed in from the state of FIG.

FIG. 7 is a partial perspective view of a cylinder block manufactured by a cylinder block manufacturing method according to another embodiment of the present invention.

FIG. 8 is a partial cross-sectional view of a cylinder block manufactured by a method of manufacturing a cylinder block according to yet another embodiment of the present invention.

[Explanation of symbols]

 1 Cylinder Block Main Body 2 Cylinder Block 3 Cylinder Outer Wall 4 Water Jacket Outer Wall 5 Closing Member 6 Connecting Part 7 Recess 8 Water Hole 9 Water Jacket 10 Step 11 Corner 12 Tapered Surface

Claims (1)

[Claims] 1. A method of manufacturing a cylinder block, wherein an open deck type cylinder block main body formed by casting is pushed into a top end opening of a water jacket, and a closing member of the water jacket, which is a member different from the cylinder block main body, is pressed and joined. The surface of the contact portion between the upper end opening of the water jacket of the cylinder block body and the closing member is scraped off by using a pushing force to generate a new surface and press the new surface against each other, and the cylinder block body and the closing A method for manufacturing a cylinder block, characterized in that a current is applied between members to heat the contact portion by resistance heating to solid-phase join the contact portions of the new surfaces.