JP3344024B2 - High-speed alumite processing method and processing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed alumite processing method and apparatus for forming an oxide film on the surface of a member to be processed by subjecting the surface of the member to be processed made of an aluminum alloy to high-speed alumite processing.

[0002]

2. Description of the Related Art Heretofore, as this kind of prior art, those shown on pages 1090 to 1094 of Surface Anodizing Edition (published by Koshinsha on June 15, 1983), which is a surface technology overview, are known. . This is a high-speed alumite treatment method in which the surface of a work made of an aluminum alloy is subjected to high-speed alumite treatment to form an oxide film on the surface of the work.Specifically, a work as an anode is placed in an alumite treatment tank and anodized. A cathode is disposed in the treatment tank so as to face the workpiece, and the alumite solution is circulated at high speed using a pump in the alumite treatment tank to make the concentration and temperature of the alumite solution in the alumite treatment tank uniform, and then the anode is formed. -An oxide film is formed on the surface of the work by increasing the amount of electricity applied between the cathodes. Here, by incorporating silicon into the aluminum alloy, the strength of the work is improved, and the fluidity of the molten aluminum during casting of the work is improved.

[0003]

When an electric current is passed between the anode and the cathode, silicon contained in the aluminum alloy becomes an electric resistance. However, when the work is subjected to alumite treatment at a low speed, the electric resistance becomes low. small. However, when the workpiece is anodized at a high speed, the electrical resistance of silicon increases. As a result, an oxide film is less likely to be formed in a portion of the aluminum alloy where silicon is dispersed in a large amount, and the film thickness is eventually reduced. A film is easily formed, and the film thickness eventually increases. Therefore, the thickness of the oxide film formed on the surface of the work becomes uneven, and the surface of the oxide film becomes rough. On the other hand, since the surface of the work before forming the oxide film is also rough, the surface of the oxide film formed on the surface of the work is naturally rough.

[0004] In order to improve the surface roughness of the oxide film surface, it is conceivable to process (polish) the oxide film surface after forming the oxide film on the work surface by high-speed alumite treatment. It is disadvantageous in terms of man-hours.

If the alumite treatment is performed at a low speed, the thickness of the oxide film becomes substantially uniform and the surface roughness is improved.
Excessive alumite processing time is required, which is disadvantageous in terms of man-hours.

Therefore, an object of the present invention is to improve the surface roughness of an oxide film surface without increasing the number of working steps.

[0007]

The technical means (hereinafter referred to as first technical means) taken in the invention of claim 1 for solving the above technical problem is a member to be processed made of an aluminum alloy. in high speed alumite treatment method of the surface of high speed alumite treated with alumite solution to form an oxide film on the surface of the member to be processed, the Alma
As the site liquid, one that does not contain abrasive grains is used, and an oxide film is formed on the surface of the member to be processed, and the surface of the oxide film is processed to be flat.

[0008] To solve the above technical problem, claim 2
The technical means (hereinafter referred to as the second technical means) taken in the invention of the present invention is an alumite liquid tank filled with an alumite liquid, connected to the alumite liquid tank via a pump and a supply pipe, and connected to the alumite liquid tank. An alumite treatment tank connected to the tank via a discharge pipe, a member to be treated which is disposed in the alumite treatment tank and is an anode made of an aluminum alloy, and disposed opposite to the member to be treated, and is disposed on the surface of the member to be treated. A cathode on which an oxide film is formed, and a processed portion for flattening the surface of the oxide film formed on the member to be processed is provided on the cathode.

[0009] To solve the above technical problem, a third aspect of the present invention is provided.
The technical means (hereinafter referred to as the third technical means) taken in the invention of the invention is that the member to be processed is a hollow cylindrical body, the cathode is formed in a cylindrical shape, and the inside of the cylindrical body is formed in the axial direction. The processing portion is formed on the outer peripheral surface of the cathode so as to be movable and rotatable in the circumferential direction.

[0010]

According to the first technical means, aluminum is used.
Using alumite liquid for the surface of the member to be treated made of alloy
High-speed alumite treatment to oxidize the surface of the workpiece
In the high-speed alumite treatment method for forming a film,
As the lumite liquid does not contain abrasive grains, it is processed so that the surface of the oxide film is flat while forming the oxide film on the surface of the workpiece, so that the surface roughness of the oxide film surface is improved. This eliminates the need for processing (polishing) the oxide film surface after forming the oxide film on the work surface by high-speed alumite treatment. That is,
The surface roughness of the oxide film surface can be improved without increasing the number of operation steps. Furthermore, the alumite liquid is
Since an alumite solution containing abrasive grains was used,
Eliminates the complexity of controlling the concentration of abrasive grains compared to when it is employed
Pump that sucks and discharges alumite liquid by abrasive grains
May cause damage or shortened service life
There is no.

According to the second technical means, since the cathode disposed opposite to the member to be treated with the anode is provided with a processing portion for flattening the surface of the oxide film formed on the member to be treated, While forming an oxide film on the surface of the member to be processed (high-speed alumite treatment), the surface of the oxide film can be processed to be flat. As a result, the same operation as the first technical means can be obtained.

According to the third technical means, the cylindrical cathode is provided inside the hollow cylindrical member to be processed so as to be movable in the axial direction of the member to be processed. By moving, not only can the entire inner peripheral surface of the member to be processed be processed uniformly, but also the temperature of the alumite liquid in the alumite processing tank can be made uniform. That is, the heat generated on the oxide film surface by the amount of electricity applied between the two electrodes is dispersed in the alumite treatment tank, and there is no problem even if the amount of electricity is increased. Therefore, there is no need to increase the flow rate of the alumite liquid by increasing the discharge pressure of the pump in order to equalize the temperature of the alumite liquid in the alumite treatment tank,
The pump can be downsized accordingly.

[0013]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a high-speed alumite processing apparatus according to this embodiment.

In the high-speed alumite processing apparatus 10 shown in FIG. 1, an alumite liquid tank 11 is filled with an alumite liquid 12, and a cooler 12a is disposed in the alumite liquid tank 11 so that the alumite liquid 12 is always kept at a predetermined temperature (approximately). 5 ° C). The alumite liquid 12 is supplied to the alumite processing tank 15 via the supply pipe 13, and the alumite liquid in the alumite processing tank 15 is returned to the alumite liquid tank 11 via the discharge pipe 19. A pump 14 for pumping the alumite liquid 12 is disposed in the middle of the supply pipe 13, and an end of the supply pipe 13 on the side of the alumite treatment tank 15 is an injection nozzle 13 a.

A work (object to be processed) 16 having a hollow cylindrical shape is arranged in the alumite processing tank 15, and the work 16 is formed of an aluminum alloy and contains silicon for improving strength. The upper end of the work 16 is exposed outside the alumite treatment tank 15, and the work 1
The upper end of 6 is electrically connected to the anode terminal 17a of the rectifier 17, so that the work 16 is an anode. still,
In FIG. 1, the work 16 is a brake master cylinder, and has a plurality of through holes 18 formed therein.

A cylindrical cathode 21 is disposed inside the work 16 with a predetermined clearance 20 therebetween, and is movable vertically and rotatable in the circumferential direction. The cathode 21 is connected to the drive mechanism 22 and is also electrically connected to the cathode terminal 17b of the rectifier 17. The alumite liquid 12 in the alumite liquid tank 11 is supplied through an injection nozzle 13 a into a clearance 20 formed between the inner peripheral surface of the work 16 serving as an anode and the cathode 21. Therefore, while supplying the alumite liquid to the clearance 20, the work 1
An oxide film is formed on the inner peripheral surface of the work 16 by applying a current to the cathode 6 and the cathode 21. Cathode 2
A plurality of grindstones (working portions) 23 are provided on a lower outer peripheral surface of the workpiece 1, and a honing process (polishing) is performed on an oxide film formed on the inner peripheral surface of the work 16 by the plurality of grindstones 23. .

FIG. 2 is a schematic diagram of a cooling mechanism for cooling the cathode. In the cooling mechanism 30 shown in the figure, a cooling space 24 is formed inside the cathode 21, and the cooling space 24 is filled with a coolant such as cooling water. The coolant space 24 is connected to a coolant tank 26 via a supply passage 25, and a pump 27 for pumping the coolant in the coolant tank 26 to the cooling space 24 is provided in the middle of the supply passage 25. The cooling space 24 is connected to a refrigerant tank 26 through a discharge passage 28, and a cooler 29 for cooling the refrigerant is provided in the refrigerant tank 26.

In FIG. 2, a cooling space 24 for filling the inside of the cathode 21 with a refrigerant is provided. However, the present invention is not limited to this. For example, a cooler is provided in the alumite treatment tank 15. May be provided.

A processing method using the high-speed alumite processing apparatus 10 configured as described above will be described.

After placing the work 16 in the alumite treatment tank 15 as shown in FIG.
The cathode 21 is formed on the outer peripheral surface of the cathode 21 in a contracted state, and the cathode 21 is inserted into the work 16. Here, the grindstone 23 expands in the radial direction, but a minute clearance is formed between the grindstone 23 and the inner peripheral surface of the work 16. Next, the alumite solution 12 in the alumite solution tank 11 is
At the same time, a large amount of current is supplied to the work 16 and the cathode 16 to perform a high-speed alumite treatment. As a result, work 1
An oxide film is formed on the inner peripheral surface of No. 6. The alumite liquid in the clearance 20 enters the alumite treatment tank 15 through the through-hole 18 and returns to the alumite liquid tank 11 through the discharge pipe 19. That is, the alumite liquid tank 11
The alumite liquid 12 in the supply pipe 13 and the injection nozzle 13
a, the liquid is circulated to the alumite liquid tank 11 via the clearance 20, the through hole 18, the alumite treatment tank 15, and the discharge pipe 19.

On the other hand, simultaneously with performing the above-described high-speed alumite treatment, the driving means 22 rotates the cathode 21 in the vertical direction while moving it in the vertical direction, thereby forming the cathode 21 on the inner peripheral surface of the work 16 by the grindstone 23. Honing the oxide film. As a result, the surface of the oxide film becomes flat.
That is, at the time of high-speed alumite treatment, the electrical resistance of silicon contained in the work 16 increases, so that the roughness of the oxide film surface formed on the inner peripheral surface of the work 16 deteriorates. By performing honing processing on the oxide film while performing the alumite treatment, the roughness of the oxide film surface is improved, and the oxide film surface can be planarized. When the honing is performed, the cathode 21 is constantly cooled by the refrigerant in the cooling space 24.

As described above, according to the high-speed alumite treatment method according to the present embodiment, since the oxide film is formed on the inner peripheral surface of the work 16 so as to make the surface of the oxide film flat, The surface roughness of the film surface can be improved, and it is not necessary to process (polish) the oxide film surface after forming the oxide film on the inner peripheral surface of the work 16 by high-speed alumite treatment. That is, the surface roughness of the oxide film surface can be improved without increasing the number of operation steps.

Further, according to this embodiment, since the cathode 21 is movably disposed inside the work 16, the temperature of the alumite solution in the alumite treatment tank 15 can be made uniform by sliding the cathode 21. . In other words, even if excessive heat is generated on the surface of the oxide film by the current flowing between the electrodes 16 and 21, the heat is dispersed in the alumite treatment tank 15 by sliding the cathode 21, and There is no problem even if is increased. Therefore, the alumite treatment tank 15
There is no need to increase the discharge pressure of the pump 14 to increase the flow rate of the alumite liquid in order to equalize the temperature of the alumite liquid therein, and the pump 14 can be downsized accordingly.

Since the cooling space 24 is provided inside the cathode 21 and the cooling space 24 is filled with the refrigerant, it is possible to prevent the temperature in the alumite treatment tank 15 from rising.
That is, even if excessive heat is generated between the two electrodes 16 and 21 when forming an oxide film on the inner peripheral surface of the work 16 as described above, the heat is absorbed by the above-described refrigerant and the temperature of the clearance 20 increases. Can be prevented. Therefore, pump 1
4 can be further miniaturized. Further, since the plurality of grindstones 23 are provided on the outer peripheral surface of the cathode 21 and the cathode 21 is rotatably disposed, the oxide film formed on the entire inner peripheral surface of the work 16 can be uniformly processed.

In this embodiment, the case where the work 16 is a hollow body having a cylindrical shape has been described. However, in the method and apparatus of the present invention, the shape of the work need not be limited to this. It can also be applied to workpiece shapes. For example, when performing high-speed alumite processing on a plate-shaped work, the plate-shaped work is placed in the alumite processing tank 15 and a cathode is placed opposite to the plate-shaped work. Should be provided.

[0027]

The invention of claim 1 has the following effects.

Since the oxide film is formed on the surface of the member to be processed while the oxide film is flattened, the surface roughness of the oxide film surface can be improved without increasing the number of working steps. . In addition, the alumite liquid is
Alumite containing abrasive grains is used because it does not contain grains
Compared to the case where liquid is used, the concentration control of abrasive grains is more complicated
It is released, and the polish that absorbs and discharges alumite liquid by abrasive grains
May cause pump damage or shortened service life.
Never.

The invention of claim 2 has the following effects.

Since a processing portion for flattening the surface of the oxide film formed on the member to be processed is provided on the cathode disposed opposite to the member to be processed as the anode, the surface of the oxide film can be formed without increasing the number of working steps. The surface roughness can be improved.

The invention of claim 3 has the following effects.

Since the cylindrical cathode is movably disposed inside the hollow cylindrical member to be treated, the temperature of the alumite liquid in the alumite treatment tank can be made uniform, and the pump can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a high-speed alumite processing apparatus according to the present embodiment.

FIG. 2 is a schematic diagram of a cooling mechanism according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Alumite liquid tank 12 Alumite liquid 13 Supply piping 14 Pump 15 Alumite processing tank 16 Workpiece (member to be processed) 19 Discharge passage 21 Cathode 23 Grindstone (working part)

Claims (3)

(57) [Claims] 1. A high speed alumite treatment method of the surface of the member to be processed made of an aluminum alloy at high anodized using the alumite solution to form an oxide film on the surface of the member to be processed, the abrasive grains as the alumite solution Including
A high-speed alumite treatment method characterized in that an oxide film is formed on the surface of the member to be treated and the surface of the oxide film is processed so as to be flat, using an unprocessed material. 2. An alumite liquid tank filled with an alumite liquid; an alumite treatment tank connected to the alumite liquid tank via a pump and a supply pipe, and connected to the alumite liquid tank via a discharge pipe; A member to be processed which is disposed in the alumite processing tank and is an anode made of an aluminum alloy; anda cathode which is disposed to face the member to be processed and forms an oxide film on a surface of the member to be processed, A high-speed alumite processing apparatus, wherein the cathode has a processed portion for flattening the surface of the oxide film formed on the member to be processed. 3. The member to be processed is a hollow cylindrical body,
The cathode has a cylindrical shape and is disposed inside the cylinder so as to be movable in the axial direction and rotatable in the circumferential direction, and the processed portion is formed on an outer peripheral surface of the cathode. The high-speed alumite processing device according to claim 2.