JP3010809B2 - High silicon aluminum bore surface processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is used for finishing a bore surface of an aluminum alloy cylinder block having a high silicon content (high silicon aluminum cylinder block) prior to performing a surface treatment for projecting silicon. And a suitable processing method.

[0002]

2. Description of the Related Art In recent years, in order to further reduce the weight of an aluminum cylinder block and reduce the size of the cylinder cylinder by approaching the cylinder interval, a high-silicon silicon block has been used to secure the wear resistance and scuff resistance of the cylinder bore surface without providing a cast iron sleeve. Increasingly, after finishing the bore surface of an aluminum cylinder block, a surface treatment for protruding primary crystal silicon therefrom is performed.

By the way, when processing and surface treatment of the bore surface of such a cylinder block, conventionally, a cylinder bore portion of a high silicon aluminum cylinder block formed by casting or the like is roughened by a boring machine in a step not shown in advance. After performing a boring process to roughen the surface of the bore, a finishing process and a surface treatment are performed by a processing method as shown in FIG. 3, for example.

That is, in this case, fine boring is first performed on the cylinder bore portion 5a of the cylinder block 5 by the boring machine 6 using the cutting tool 7 in step 1 to obtain the center position accuracy of the bore surface 5b. Next, in step 2, rough honing is performed using a honing tool 9 with a honing machine 8 to remove a surface layer containing primary silicon crushed in the previous step 1 on the bore surface 5b.
As shown in FIG. 4 (a), only the machining of steps 1 and 2 still has unevenness on the bore surface 5b, so that in the next step 3, fine honing using the honing tool 9 with the honing machine 8 is performed. Then, as shown in FIG. 4 (b), a series of finishing processes are performed to finish the bore surface 5b smoothly and to a predetermined inner diameter while preventing the primary crystal silicon 10 from being crushed. The corrosion liquid 11 is injected into the cylinder bore portion 5a of the block 5, and the surface of the bore surface 5b is subjected to a surface corrosion treatment to remove the surface layer only of the aluminum alloy as shown in FIG. 10 had protruded.

[0005]

However, since the primary crystal silicon 10 is extremely easily crushed, when the fine boring of the bore surface 5b is performed, as shown in the enlarged view of FIG. Cracks 12 are formed not only in the crystalline silicon 10 but also in the inside of the bore portion 5a and crushed.

Therefore, in the above-mentioned conventional processing method, the primary crystal silicon crushed in the fine boring processing in the step 1 is used.
It is necessary to suppress the fine boring in step 1 so that the thickness of the surface layer including 10 (crushing depth) is equal to or less than the honing allowance in the rough honing in step 2 and realize such fine boring. For this purpose, it is necessary to perform machining using a boring machine 6 having high rigidity and using an expensive boring tool 7 using diamond or the like, and there has been a problem that the equipment cost is extremely increased.

In the rough honing step 2, the primary crystal silicon 10 is slightly crushed. Therefore, in the next fine honing step 3, it is necessary to remove the surface layer containing the crushed primary crystal silicon 10 as well. Therefore, there is a problem that the life of a special and expensive grindstone used for the honing tool 9 for fine honing that does not crush the primary crystal silicon 10 is short, and the facility cost also increases in this respect.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a processing method which advantageously solves the above-mentioned problems, and a method for processing the surface of a high-silicon aluminum bore according to the present invention is as follows. In performing a finishing process prior to performing a surface treatment for projecting silicon on the bore surface of the aluminum cylinder block, as the finishing process, fine boring, electrolytic or electric discharge machining, and fine honing are sequentially performed. It is characterized by performing.

[0009]

According to the working method, after the fine boring process is performed on the bore surface of the high silicon aluminum cylinder block, the surface layer of the bore surface including the primary crystal silicon crushed by the fine boring process is subjected to electrolytic machining or electric discharge machining. After that, fine honing of the bore surface is performed, and after that, surface treatment such as surface corrosion treatment (etching treatment) that makes silicon protrude is performed. It is not necessary to control the depth below the allowance for subsequent honing.

Therefore, according to this machining method, in the fine boring process, not a high-rigidity boring machine or an expensive boring tool using diamond or the like, but a normal boring machine or tool can be used. The high-rigidity boring machine and expensive tools can be eliminated to reduce the equipment cost, and since the equipment cost is lower than the honing machine, electrolytic machining equipment and electric discharge machining equipment can be used. Equipment costs can be reduced. In addition, instead of rough honing, the surface layer containing primary silicon crushed by fine boring in the previous process is removed by electrolytic machining or electric discharge machining, so that the margin for subsequent fine honing can be reduced. Therefore, the life of the special grinding wheel for fine honing can be extended, and the equipment cost can be further reduced.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a process chart showing an embodiment of a method for processing the surface of a high silicon aluminum bore according to the present invention. In this embodiment, when performing processing and surface treatment of the bore surface, a high silicon aluminum formed by casting or the like is used. Rough boring is performed on the cylinder bore portion of the cylinder block by a boring machine in a process not shown in advance in the same manner as in the conventional method, and the surface of the bore is roughened. Then, finishing is performed by the processing method shown in FIG. And surface treatment.

That is, in this case, first, in step 13, a normal boring machine
Perform fine boring using a normal cutting tool 18 with 17, and obtain the center position accuracy of the bore surface 5b,
As shown in FIG. 2 (a), only the fine boring process in this step 13 still has unevenness on the bore surface 5b, so in the next step 14, the electrode 20 is placed in the cylinder bore 5a by the electrolytic processing equipment 19. And electrolytic processing is performed by injecting the electrolytic solution 21 to perform the electrolytic processing, as shown in FIG.
The surface layer of the bore surface 5b containing the primary silicon 10 crushed by the above is removed, and in the next step 15, the honing machine 8
2B, a fine honing process is performed using a honing tool 9 to finish the bore surface 5b smoothly and to a predetermined inner diameter while preventing the primary crystal silicon 10 from being crushed as shown in FIG. 2C. After finishing,
Thereafter, in step 4, a corrosive liquid 11 is injected into the cylinder bore portion 5a of the cylinder block 5 and a surface corrosion treatment is performed on the bore surface 5b, so that only the surface of the aluminum alloy as shown in FIG. And the primary crystal silicon 10 is projected.

In the working method of this embodiment, the steps
Primary crystal silicon 10 crushed by fine boring
After removing the surface layer containing by the electrolytic processing in the step 14, the fine honing in the step 15 is performed. Therefore, in the fine boring, it is not necessary to suppress the crushing depth to less than the honing allowance.

Therefore, according to the working method of this embodiment,
In the fine boring process of the step 13, since a normal boring machine 17 or a normal cutting tool 18 can be used instead of a boring tool having a high rigidity or an expensive boring tool using diamond, etc. Since a boring machine and expensive tools can be eliminated, the equipment cost can be reduced, and since the electrolytic processing equipment 19, which is cheaper than the honing machine, can be used, the equipment cost can also be reduced in this regard. . In addition, the surface layer containing the primary silicon 10 crushed by the fine boring process in the previous step 13 is removed by electrolytic processing instead of the rough honing process in the step 14, so that the allowance for the fine honing processing in the step 13 is reduced. Since it is only necessary to use a small amount,
The life of a special and expensive grindstone that does not crush primary crystal silicon 10 can be extended, and the equipment cost can be further reduced.

Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above-described example. For example, in step 14 of the above-described example, electric discharge machining may be performed instead of electrolytic machining. The function and effect of can be brought about.

[0016]

As described above, according to the high silicon aluminum bore surface processing method of the present invention, in the fine boring process, not a high-rigidity boring machine or an expensive boring tool using diamond or the like but a normal boring tool is used. Since a boring machine or a tool can be used, the high-rigidity boring machine or an expensive tool can be unnecessary, and equipment costs can be reduced.
In addition, since the electrolytic machining equipment and the electric discharge machining equipment whose equipment cost is lower than that of the honing machine can be used, the equipment cost can be reduced also in this regard. In addition, since the surface layer containing primary crystal silicon crushed by the fine boring process in the previous process is removed by electrolytic machining or electric discharge machining instead of rough honing, the margin for fine honing in the subsequent process is small. Therefore, the life of the special grinding wheel for fine honing can be extended, and the equipment cost can be further reduced.

[Brief description of the drawings]

FIG. 1 is a process diagram showing one embodiment of a method for processing a high silicon aluminum bore surface of the present invention.

FIGS. 2A to 2D are cross-sectional views showing, in an enlarged manner, the state of a bore surface in each step of the processing method of the embodiment.

FIG. 3 is a process chart showing a conventional method for processing the surface of a high silicon aluminum bore.

FIGS. 4A to 4C are cross-sectional views showing the state of a bore surface in each step of the conventional processing method in an enlarged manner.

5 is a cross-sectional view showing the surface layer containing primary silicon crushed by the fine boring process and further showing the surface of the cylinder bore and the inside of the bore portion, further enlarged than FIG. 4;

[Explanation of symbols]

 5 Aluminum cylinder block 5a Bore 5b Bore surface 8 Honing machine 9 Honing tool 10 Primary crystal silicon 11 Corrosion liquid 13 Fine boring process 14 Electrochemical machining process 15 Fine honing process 16 Surface corrosion treatment process 17 Boring machine 18 Cutting tool 19 Electrolytic processing equipment 20 Electrodes 21 Electrolyte 21

Claims (1)

(57) [Claims] When performing a finishing process on a bore surface of a high silicon aluminum cylinder block prior to performing a surface treatment for projecting silicon, the finishing process includes fine boring, electrolytic machining or electric discharge machining, and fine boring. A method for processing the surface of a high-silicon aluminum bore, comprising sequentially performing honing.