JP2016008328A - Method and apparatus for anodic oxidation treatment of cylinder member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for anodic oxidation treatment of a cylinder member which facilitates management of an anodic oxidation treatment solution.SOLUTION: An anodic oxidation treatment method of a cylinder member comprises the steps of: inserting a nozzle part 55 serving as a cathode into a cylinder member 11 from an opening 12 thereof; bringing a partition part 53 into contact with an edge surface 13a around the opening 12 of the cylinder member 11 to partition the inner surface 11b of the cylinder member 11 with respect to the outer surface 11a; and bringing a contact part 58 serving as an anode into contact with the outer surface 14a of the bottom part 14 of the cylinder member 11; pressing the cylinder member 11 with the contact part 58 and the partition part 53 to cause an anodic oxidation treatment solution L to be discharged from the nozzle part 55 and simultaneously electrifying a current between the contact part 58 and the nozzle part 55.

Description

  The present invention relates to a method for anodizing a cylinder member and an anodizing apparatus.

  Of the components constituting the master cylinder, anodizing (alumite treatment) is performed on a cylinder member that is an aluminum product (see, for example, Patent Document 1).

JP 2008-56953 A

  Normally, when anodizing a member made of an aluminum alloy, the entire member is immersed in an anodizing solution. However, if the anodizing treatment is performed in such a state that the entire member is immersed in the anodizing treatment solution, the management of the anodizing treatment solution becomes complicated.

  An object of the present invention is to provide an anodizing method and an anodizing apparatus for a cylinder member that makes it easy to manage an anodizing solution.

  In order to achieve the above object, an anodic oxidation method according to the present invention includes a step of inserting a nozzle portion serving as a cathode from an opening of the cylinder member into a cylinder member, and a partition portion on an edge surface around the opening of the cylinder member. Abutting the inner surface of the cylinder member with respect to the outer surface, contacting the outer surface of the bottom of the cylinder member with an abutting portion serving as an anode, and the abutting portion and the The method includes a step of pressing the cylinder member with the partition portion, and a step of discharging an anodizing solution from the nozzle portion and causing a current to flow between the contact portion and the nozzle portion.

  Further, the anodizing apparatus according to the present invention includes a nozzle portion inserted into the cylinder member from the opening of the cylinder member, and an inner surface of the cylinder member in contact with an edge surface around the opening of the cylinder member. A partition portion that is partitioned with respect to the partition portion, a contact portion that contacts the outer surface of the bottom portion of the cylinder member, and presses the contact portion and the partition portion against the cylinder member And a pump that discharges the anodizing solution from the nozzle part, and a current supply part that supplies current using the contact part as an anode and the nozzle part as a cathode.

  According to the anodizing method and the anodizing apparatus for a cylinder member according to the present invention, the management of the anodizing solution is facilitated.

It is sectional drawing which shows the cylinder member in which an anodizing process is performed with the anodizing method and the anodizing apparatus of one Embodiment concerning this invention. It is the front view which made a part the cross section which shows the anodizing apparatus of the same embodiment. It is the front view which made the cross section the part which shows the state which processes a cylinder member with the anodizing apparatus of the embodiment.

  An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 shows a cylinder member 11 that is subjected to high-speed anodizing treatment in the anodizing method and anodizing apparatus of this embodiment.

  The cylinder member 11 is a component that constitutes a master cylinder for a vehicle. In the master cylinder for a vehicle, although not shown, a force corresponding to the amount of operation of the brake pedal is introduced from the brake booster, and a piston disposed inside the cylinder member 11 is moved by the introduced force to operate the brake pedal. The brake fluid pressure corresponding to the amount is generated.

  The cylinder member 11 is an integrally molded product made of an aluminum alloy, and includes a cylindrical portion 13 having an opening 12 on one end side in the axial direction, and a bottom portion 14 that closes the opposite side of the cylindrical portion 13 with respect to the axial opening 12. And the bottomed cylindrical shape which has the mounting seat part 15 which protrudes toward the outward from the outer peripheral surface of the cylindrical part 13 is comprised. The outer surface 14a facing the opening 12 of the bottom portion 14 and the edge surface 13a around the opening 12 of the tubular portion 13 are both flat surfaces parallel to the plane orthogonal to the central axis of the tubular portion 13. It has become. The outer surface 14 a of the bottom portion 14 and the outer surface 13 b excluding the edge surface 13 a of the cylindrical portion 13 and the mounting seat portion 15 are the outer surface (surface) 11 a of the cylinder member 11. Further, the inner surface 14 b of the bottom portion 14 and the inner surface 13 c of the cylindrical portion 13 form an inner surface (surface) 11 b of the cylinder member 11.

  The mounting seat portion 15 is a portion to which a not-illustrated reservoir tank for storing brake fluid is mounted, and is disposed at the upper portion of the cylinder member 11 in the vertical direction when mounted on the vehicle. The mounting seat portion 15 has a mounting hole 21 on the bottom 14 side and a mounting hole 22 on the opening 12 side. The mounting holes 21 and 22 are formed at a predetermined depth from the opposite side to the cylindrical portion 13 in the mounting seat portion 15. The tubular portion 13 has a passage hole 23 for communicating the bottom of the attachment hole 21 on the bottom 14 side and the inside of the tubular portion 13, and the bottom of the attachment hole 22 on the opening 12 side and the inside of the tubular portion 13. And a passage hole 24 is formed. Two supply / discharge portions of the reservoir tank are fitted into the two mounting holes 21 and 22, whereby the inside of the reservoir tank and the inside of the cylinder member 11 are connected via the passage holes 23 and 24. Can communicate.

  Although not shown, the cylinder member 11 is slidably fitted with a secondary piston on the bottom 14 side and a primary piston on the opening 12 side. The secondary piston forms a secondary pressure chamber that discharges brake fluid to a predetermined wheel cylinder of the disc brake between the secondary piston and a portion on the bottom 14 side of the cylinder member 11. The primary piston forms a primary pressure chamber that discharges brake fluid to another wheel cylinder of the disc brake between the secondary piston and the cylinder member 11. Each of the primary pressure chamber and the secondary pressure chamber has a discharge port (not shown) for discharging brake fluid.

  The cylindrical portion 13 is formed with a bottom-side sliding inner diameter portion 28 in which the secondary piston is slidably fitted to the inner peripheral portion on the bottom portion 14 side. Is moved in the axial direction. The cylindrical portion 13 is formed with an opening-side sliding inner diameter portion 29 in which the primary piston is slidably fitted to the inner peripheral portion on the opening 12 side. Is moved in the axial direction.

  In the intermediate position in the axial direction in the formation range of the bottom sliding inner diameter portion 28, an annular shape that is recessed radially outward from the bottom sliding inner diameter portion 28 at the opening position into the tubular portion 13 of the passage hole 23. The passage groove 31 is formed. Further, in the formation range of the bottom sliding inner diameter portion 28, a circumferential groove 32 is formed on the bottom portion 14 side of the passage groove 31, and a circumferential groove 33 is formed on the opening 12 side of the passage groove 31. Each of the circumferential grooves 32 and 33 has an annular shape and is recessed outward in the radial direction from the bottom sliding inner diameter portion 28.

  At the intermediate position in the axial direction in the formation range of the opening-side sliding inner diameter portion 29, an annular shape that is recessed radially outward from the opening-side sliding inner diameter portion 29 at the opening position into the cylindrical portion 13 of the passage hole 24. A passage groove 36 is formed. Further, in the formation range of the opening-side sliding inner diameter portion 29, a circumferential groove 37 is formed on the bottom 14 side of the passage groove 36, and a circumferential groove 38 is formed on the opening 12 side of the passage groove 36. These circumferential grooves 37 and 38 are both in an annular shape and are recessed radially outward from the opening-side sliding inner diameter portion 29.

  An annular cup seal is disposed in the circumferential groove 32, and an annular partition seal is disposed in the circumferential groove 33. The cup seal disposed in the circumferential groove 32 has a gap between the secondary piston and the cylinder member 11 when the secondary piston advances toward the bottom 14 and the pressure in the secondary pressure chamber becomes higher than the pressure (atmospheric pressure) in the reservoir tank. On the other hand, if the secondary piston moves backward from the bottom 14 by the biasing force of the spring and the pressure in the secondary pressure chamber becomes lower than the pressure in the reservoir tank, the secondary pressure chamber is replenished with liquid from the reservoir tank. Make it possible. The partition seal disposed in the circumferential groove 33 always seals the gap between the secondary piston and the cylinder member 11.

  An annular cup seal is disposed in the circumferential groove 37, and an annular partition seal is disposed in the circumferential groove 38. The cup seal disposed in the circumferential groove 37 has a gap between the primary piston and the cylinder member 11 when the primary piston advances toward the bottom 14 and the pressure in the primary pressure chamber becomes higher than the pressure (atmospheric pressure) in the reservoir tank. While the primary piston is retracted to the opposite side of the bottom 14 by the biasing force of the spring, when the pressure in the primary pressure chamber becomes lower than the pressure in the reservoir tank, liquid is supplied to the primary pressure chamber from the reservoir tank. Is possible. The partition seal disposed in the circumferential groove 38 always seals the gap between the primary piston and the cylinder member 11.

  That is, the cylinder member 11 is a sliding member having a bottom side sliding inner diameter portion 28 and an opening side sliding inner diameter portion 29 that slide relative to the piston.

  FIG. 2 shows an anodizing apparatus 51 of the present embodiment that forms an oxide film on the surface of the cylinder member 11 shown in FIG. 1 by anodizing. The anodizing device 51 includes a pedestal 52, a partition 53, an anodizing solution tank 54, a nozzle 55, a pump 56, a pressing part 57, a contact part 58, and a current supply part 59. And a control unit 60.

  The pedestal 52 has an upper surface 52a that is horizontally disposed. The pedestal portion 52 has a plate shape and is arranged horizontally with the thickness direction along the vertical direction. A communication hole 61 is formed at a predetermined intermediate position of the pedestal 52 so as to penetrate the pedestal 52 in the vertical direction. The communication hole 61 has a circular horizontal cross section.

  The partition portion 53 is made of a plate-like material having a sealing property, and is attached to the upper surface 52 a of the pedestal portion 52 in an annular shape so as to surround the communication hole 61 on the horizontal outside. As shown in FIG. 3, the cylinder member 11 is mounted on the partition portion 53 at the edge surface 13 a on the opening 12 side. The partition 53 abuts the edge surface 13a on the opening 12 side of the cylinder member 11 mounted at a predetermined set position over the entire circumference to partition the inner surface 11b of the cylinder member 11 with respect to the outer surface 11a.

  The anodizing solution tank 54 is disposed vertically below the pedestal 52. The anodizing liquid tank 54 includes a tank main body 65 filled with the anodizing liquid L, and a cylindrical upper connecting pipe extending upward from the upper part of the tank main body 65 and connected to the communication hole 61 of the pedestal 52. 66 and a side connection pipe 67 that extends laterally from the side of the tank body 65 and is connected to the suction side of the pump 56.

  The tank body 65 communicates with the communication hole 61 through the upper connecting pipe 66 and communicates with the pump 56 through the side connecting pipe 67. The anodizing solution tank 54 is disposed in the tank body 65 and has a temperature adjusting unit 68 that adjusts the temperature of the anodizing solution L in the tank body 65 to be maintained at a predetermined maintenance temperature. Specifically, the temperature adjusting unit 68 is a heater that heats the anodizing solution L so as to reach a set maintenance temperature.

  The pump 56 discharges the anodizing solution L from the nozzle portion 55. The nozzle portion 55 is connected to the discharge side of the pump 56. The nozzle portion 55 extends upward from the pump 56, extends in the horizontal direction, is inserted into the upper connecting pipe 66, and extends vertically upward in the upper connecting pipe 66 and the communication hole 61. Of the nozzle portion 55, the nozzle body portion 75 along the vertical direction in the upper connecting pipe 66 and the communication hole 61 has a cylindrical shape, and is on the central axis of the upper connecting pipe 66, that is, on the central axis of the communication hole 61. And is extended upward by a predetermined length from the upper surface 52a of the pedestal portion 52.

  Only the upper end portion of the nozzle body portion 75 and the end portion on the pump 56 side of the nozzle portion 55 are opened, so that the anodizing liquid L discharged from the pump 56 to the nozzle portion 55 is pumped by the nozzle portion 55. It ejects upward at a predetermined flow rate from the upper end on the opposite side to 56. The nozzle body 55 of the nozzle portion 55 is covered with the cylinder member 11. At this time, the nozzle body 75 is inserted into the cylinder member 11 from the opening 12. Thereafter, the cylinder member 11 mounted at a predetermined set position of the partition part 53 has a clearance 76 between the inner surface 13c of the cylindrical part 13 and the nozzle body part 75 over the entire circumference, and the bottom part 14 also has an inner surface. 14b has a clearance 77 between the nozzle body 75 and the nozzle body 75.

  The pressing portion 57 has a support portion 85 erected in the vertical direction and an arm portion 86 that is supported by the upper portion of the support portion 85 so as to be vertically movable and extends horizontally from the support portion 85. A support member 87 that supports the portion 58, a support portion 85, that is, a rotation mechanism portion 88 that rotates the support member 87 about the vertical axis, and a lift drive portion 89 that moves the arm portion 86 up and down relative to the support portion 85. ing. The contact portion 58 is attached to the lower surface of the distal end portion of the arm portion 86 of the support member 87.

  The rotation mechanism unit 88 horizontally rotates the support column 85 as shown in FIGS. 2 and 3, so that the abutment portion 58 attached to the arm portion 86 becomes vertically aligned with the nozzle main body 75 as shown in FIG. 3. As shown in FIG. 2, the rotation is made between a rotation direction advance position located above and a rotation direction retreat position where the nozzle main body 75 is retreated from vertically above. When the abutting portion 58 is at the forward position in the rotational direction shown in FIG. 3, the abutting portion 58 is opposed to the partition portion 53 in the vertical direction, and is on the outer surface 14 a of the bottom portion 14 of the cylinder member 11 mounted on the partition portion 53. Opposite in the vertical direction.

  The raising / lowering drive part 89 raises / lowers the contact part 58 in a rotation direction advance position by raising / lowering the arm part 86 with respect to the support | pillar part 85. FIG. The raising / lowering drive unit 89 is separated from the outer surface 14a of the bottom part 14 of the cylinder member 11 mounted on the partition part 53 and the outer surface 14a of the bottom part 14 by separating the contact part 58 in the rotational direction advance position. The cylinder member 11 is moved up and down between the pressing position shown in FIG. When the elevating drive unit 89 positions the contact part 58 at the pressing position, the contact part 58 contacts the cylinder member 11, and the contact part 58 and the partition part 53 are pressed by the cylinder member 11. Therefore, the pressing part 57 presses the contact part 58 and the partition part 53 against the cylinder member 11. Here, instead of raising and lowering the arm portion 86 with respect to the support column 85, the entire support member 87 is raised or lowered, and the support member 87, that is, the contact portion 58, cannot be raised or lowered. Instead, the partition portion 53 or the pedestal portion 52 can be moved up and down. In short, it suffices if the abutting portion 58 and the partition portion 53 can be pressed against and released from the cylinder member 11.

  The nozzle portion 55 is made of a conductive metal material and is electrically connected to the cathode terminal 95 of the current supply portion 59 formed of a rectifier. The contact portion 58 is also made of a conductive metal material, and is electrically connected to the anode terminal 96 of the current supply portion 59. Therefore, the nozzle part 55 becomes a cathode of the current supply circuit in the anodizing apparatus 51, and the contact part 58 becomes an anode of the current supply circuit in the anodizing apparatus 51. That is, the current supply unit 59 supplies current using the contact portion 58 as an anode and the nozzle portion 55 as a cathode.

  Next, the anodizing method of this embodiment performed using the above-described anodizing apparatus 51 will be described. The anodizing method of this embodiment is a method of forming an oxide film on the inner surface 11b by anodizing the inner surface 11b of the cylinder member 11.

  The closing member 101 is fitted into the mounting hole 21 of the cylinder member 11 to close the mounting hole 21, and the closing member 102 is fitted to the mounting hole 22 to close the mounting hole 22. Further, the above-described discharge port (not shown) is also closed by the closing member. Thereby, the cylinder member 11 will be in the state which the inside and outside communicate only by the opening 12 of the one end of the cylindrical part 13. FIG.

  As shown in FIG. 2, the cylinder member 11 with the mounting holes 21 and 22 closed is attached to the anodizing apparatus 51 in a standby state in which the pressing portion 57 positions the contact portion 58 in the rotational direction retracted position. A process of covering the nozzle portion 55 is performed. This step is a nozzle insertion step of inserting the nozzle portion 55 serving as a cathode from the opening 12 inside the cylinder member 11.

  Subsequent to the nozzle insertion step, the cylinder member 11 is mounted at a predetermined set position of the partition portion 53 such that the edge surface 13a on the opening 12 side of the cylindrical portion 13 is brought into contact with the partition portion 53. I do. In this process, the partition 53 contacts the edge surface 13a on the opening 12 side of the cylinder member 11 installed at a predetermined set position over the entire circumference, thereby partitioning the inner surface 11b of the cylinder member 11 with respect to the outer surface 11a. It is a partitioning process.

  In this state, when a predetermined start operation is performed on the anodizing apparatus 51, the control unit 60 of the anodizing apparatus 51 places the contact portion 58 at the rotation direction advance position by the rotation mechanism unit 88 of the pressing unit 57. Then, the process of positioning the contact part 58 in the pressing position by the raising / lowering drive part 89 is performed. In this step, a contact step in which the contact portion 58 serving as an anode contacts the outer surface 14a of the bottom portion 14 of the cylinder member 11, and the cylinder member 11 is pressed from both sides in the axial direction by the contact portion 58 and the partition portion 53. It is the contact pressing process performed continuously with the pressing process.

  After the contact pressing step, the control unit 60 drives the pump 56 to discharge the anodizing treatment liquid L from the nozzle unit 55 at a predetermined flow rate, and the current supply unit 59 causes the contact unit 58 and the nozzle unit 55 to be discharged. During this period, an anodizing process is performed in which a current is supplied at a predetermined constant current density. Then, the anodizing treatment liquid L is ejected upward from the upper end portion of the nozzle body portion 75 of the nozzle portion 55. After a part of the anodizing treatment liquid L hits the inner surface 14b of the bottom part 14, it passes through the clearances 77 and 76 as it is, passes through the communication hole 61 and the upper connecting pipe 66, and falls into the tank main body 65. However, after hitting the inner surface 14b of the bottom portion 14, it reaches the inner surface 13c of the cylindrical portion 13 and travels along the inner surface 13c from the communication hole 61 and the upper connecting pipe 66 to the tank body 65, and a part thereof directly It hits the inner surface 13 c of the tubular portion 13 and falls through the inner surface 13 c of the tubular portion 13 from the communication hole 61 and the upper connecting pipe 66 to the tank body 65.

  As described above, the anodizing liquid L that contacts the inner surface 11b of the cylinder member 11 composed of the inner surface 13c of the cylindrical portion 13 and the inner surface 14b of the bottom portion 14 is removed from the outer surface of the bottom portion 14 of the cylinder member 11. An oxide film is formed on the inner surface 11b of the cylinder member 11 by the current supplied from the current supply part 59 with the contact part 58 in contact with 14a as the anode and the nozzle part 55 as the cathode. Here, the return flow rate returning from the communication hole 61 and the upper connection pipe 66 to the tank body 65 is sufficiently larger than the discharge flow rate of the anodizing liquid L from the nozzle portion 55. Therefore, the clearances 76 and 77 are not filled with the anodizing liquid L.

  An oxide film is formed on the inner surface 11b of the cylinder member 11 by the above anodic oxidation treatment. Thereafter, of the inner surface 11b of the cylinder member 11, the inner surface of the bottom-side sliding inner diameter portion 28 and the opening-side sliding inner diameter portion 29 on which the piston slides is subjected to a polishing process for smoothing. Become.

  In the above-described Patent Document 1, the outer surface is anodized in addition to the inner surface of the cylinder member. For this reason, the anodizing process is performed in a state where the entire cylinder member is immersed in the anodizing liquid. Thus, when the area for anodizing is large, the quality of the anodizing solution is likely to be deteriorated, and the management thereof becomes complicated.

  On the other hand, in the present embodiment, a nozzle portion 55 serving as a cathode is inserted into the cylinder member 11 from the opening 12, and the partition portion 53 is brought into contact with the edge surface 13 a around the opening 12 of the cylinder member 11. The inner surface 11b of the member 11 is partitioned from the outer surface 11a, and the anodizing solution L is discharged from the nozzle portion 55. Thereby, the anodizing treatment liquid L can be applied only to the inner surface 11b of the cylinder member 11 to perform the anodizing treatment. In other words, it has a bottom sliding inner diameter portion 28 and an opening side sliding inner diameter portion 29 with which the piston is slidably contacted, and requires wear resistance, and is essentially anodized which requires corrosion resistance because it is exposed to the brake fluid. The anodizing treatment liquid L can be applied to only the inner surface 11b that needs to be treated to perform the anodizing treatment. Therefore, the anodizing solution L can be used efficiently, its quality deterioration can be suppressed, and management thereof becomes easy.

  Further, in order to discharge the anodizing treatment liquid L from the nozzle portion 55 toward the inner surface 11 b of the cylinder member 11, the anodizing treatment liquid L is applied in an atmosphere of clearances 76 and 77 between the nozzle portion 55 and the cylinder member 11. Can be cooled. In addition, since the discharged anodizing liquid L passes through the communication hole 61 and the upper connecting pipe 66 and falls into the tank body 65, it is also cooled during that time. Therefore, the anodizing treatment liquid L can be efficiently cooled. In addition, the anodizing solution L returned to the tank body 65 is discharged again from the nozzle portion 55 toward the inner surface 11b of the cylinder member 11 while maintaining the temperature adjusting portion 68 at a constant temperature. The Joule heat of the inner surface 11b of the cylinder member 11 can be satisfactorily removed by the treatment liquid L. Therefore, it is possible to perform high-speed processing while suppressing burning generated in the cylinder member 11 during the anodizing process. Since high-speed processing is possible, batch processing is not required, and downsizing of equipment and in-line anodization processing are possible.

  Further, since the abutting portion 58 and the partition portion 53 press the cylinder member 11, the partition portion 53 comes into pressure contact with the cylinder member 11. Therefore, the partition part 53 can partition the inner surface 11b of the cylinder member 11 with respect to the outer surface 11a. In addition, since the abutting portion 58 and the partition portion 53 are disposed to face each other, the partition portion 53 is formed on the cylinder member 11 by the operation of bringing the abutting portion 58 as an anode into contact with the cylinder member 11 for electrical connection. It becomes possible to press-contact, and work efficiency can be improved.

  Further, in addition to the contact portion 58 as an anode being brought into contact with the cylinder member 11 for electrical connection, the partition portion 53 can be brought into pressure contact with the cylinder member 11, and the nozzle portion 55 with the contact portion 58 as an anode. Therefore, it is possible to suppress an increase in the size of the entire anodizing apparatus 51, a complicated structure of the anodizing apparatus 51, and a complicated control.

  In the present embodiment described above, the bottomed cylindrical cylinder member 11 is set in the anodizing apparatus 51 so that the opening 12 faces downward. However, the setting posture is not limited to this, and the opening is not limited to this. The posture 12 may be directed upward, laterally, or obliquely. For example, when the cylinder member 11 is set with the opening 12 facing upward, a pedestal portion, a partition portion, and a nozzle portion are arranged on the cylinder member 11, and the outer surface 14 a is arranged on the lower side of the cylinder member 11. Will abut.

  Further, in the present embodiment, the cylinder member 11 has the mounting holes 21 and 22 and the passage holes 23 and 24 that communicate the inside and the outside in the radial direction with the cylindrical portion 13. Anodization can also be performed on a bottomed cylindrical cylinder member that has no holes and opens only on the side opposite to the bottom of the cylindrical part.

  The cylinder member anodizing method of the present embodiment described above is an anodizing method in which the surface of a bottomed cylindrical cylinder member made of an aluminum alloy is anodized to form an oxide film on the surface. A step of inserting a nozzle portion serving as a cathode from the opening of the cylinder member into the cylinder member, and bringing a partition portion into contact with an edge surface around the opening of the cylinder member so that an inner surface of the cylinder member is an outer surface. A step of partitioning against the outer surface of the bottom of the cylinder member, a step of pressing the cylinder member between the contact portion and the partition portion, and the nozzle And a step of discharging an anodizing solution from the portion and causing a current to flow between the contact portion and the nozzle portion.

  The cylinder member anodizing apparatus of the present embodiment is an anodizing apparatus that forms an oxide film on the surface by anodizing the surface of a bottomed cylindrical cylinder member made of an aluminum alloy, A nozzle portion that is inserted into the cylinder member from an opening of the cylinder member, a partition portion that abuts an edge surface around the opening of the cylinder member and partitions an inner surface of the cylinder member with respect to an outer surface; An abutting portion provided to face the outer surface of the bottom of the cylinder member, a pressing portion for pressing the abutting portion and the partition portion against the cylinder member, and anodizing from the nozzle portion A pump that discharges the processing liquid; and a current supply unit that supplies current using the contact portion as an anode and the nozzle portion as a cathode.

  Therefore, according to the present embodiment, a nozzle part serving as a cathode is inserted into the cylinder member from its opening, and the partition part is brought into contact with an edge surface around the opening of the cylinder member so that the inner surface of the cylinder member is opposed to the outer surface. And anodizing solution is discharged from the nozzle portion. Therefore, since the anodizing treatment liquid can be applied only to the inner surface of the cylinder member, the deterioration of the quality of the anodizing treatment liquid can be suppressed, and its management becomes easy.

  Further, since the anodizing treatment liquid is discharged from the nozzle portion, the anodizing treatment liquid can be cooled. Therefore, it is possible to perform high-speed processing while suppressing burning generated in the cylinder member during the anodizing process. Since high-speed processing is possible, batch processing is not necessary, and downsizing of equipment and in-line processing are possible.

  Moreover, since the cylinder member is pressed by the contact part and the partition part, the partition part comes into pressure contact with the cylinder member. Therefore, the inner surface of the cylinder member can be well partitioned with respect to the outer surface at the partition portion. In addition, since the partition portion can be pressed against the cylinder member by the operation of bringing the contact portion as the anode into contact with each other for electrical connection, the working efficiency can be improved.

  Further, since the current is supplied with the contact portion as the anode and the nozzle portion as the cathode, the size and simplification can be achieved.

As shown in Table 1, a cylinder member made of AC4CH aluminum alloy was prepared as Example 1 of the present invention, and anodizing was performed by the anodizing apparatus 51 of the above embodiment under the following conditions.
A sulfuric acid aqueous solution having a concentration of 370 [g / L] is used as the anodizing treatment liquid L.
The temperature adjusting unit 68 is controlled so that the temperature of the anodizing solution L in the anodizing solution tank 54 is maintained at 36 [° C.].
A current is supplied at a constant current density of 30 [A / dm ² ] by the current supply unit 59.
The anodizing time (that is, the current supply time by the current supply unit 59) is set to 30 [sec].
The anodizing solution L is discharged from the nozzle portion 55 at a flow rate of 16 [m / s].

  In Example 1 in which anodization was performed under such conditions, the thickness of the oxide film was 4.5 [μm], the surface roughness (Ra) was 0.54 [μm], and the hardness (HV) was 435. It became. Moreover, there was no burning.

As Example 2 of the present invention, a cylinder member made of AC2A aluminum alloy was prepared, and anodizing was performed by the anodizing apparatus 51 of the above embodiment under the following conditions.
A sulfuric acid aqueous solution having a concentration of 370 [g / L] is used as the anodizing treatment liquid L.
The temperature adjusting unit 68 is controlled so that the temperature of the anodizing solution L in the anodizing solution tank 54 is maintained at 36 [° C.].
A current is supplied at a constant current density of 37 [A / dm ² ] by the current supply unit 59.
The anodizing time (that is, the current supply time by the current supply unit 59) is set to 30 [sec].
The anodizing solution L is discharged from the nozzle portion 55 at a flow rate of 16 [m / s].

  In Example 2 in which the anodizing treatment was performed under such conditions, the thickness of the oxide film was 4.4 [μm], the surface roughness (Ra) was 0.49 [μm], and the hardness (HV) was 358. It became. Moreover, there was no burning.

As a comparative example, a cylinder member made of an AC2A aluminum alloy was prepared, and anodizing was performed under the following conditions using an apparatus that was immersed in a bath of an anodizing solution as usual.
A sulfuric acid aqueous solution having a concentration of 300 to 330 [g / L] is used as the anodizing treatment liquid.
The temperature of the anodizing solution in the anodizing solution tank is set to −1 to 2 [° C.].
-The applied voltage is set to 20 to 27 [V].
The anodizing time is 2070 [sec].
The flow rate of the anodizing solution in the anodizing solution tank is 0.2 [m / s].

  In the comparative example in which the anodic oxidation treatment was performed under such conditions, the thickness of the oxide film was 4.2 [μm], the surface roughness (Ra) was 0.28 [μm], and the hardness (HV) was 352. became. Moreover, there was no burning.

  In other words, when anodizing is performed while suppressing the occurrence of burning, anodization is required to maintain the film thickness and hardness of the oxide film, which is an index for obtaining the same level of wear resistance and corrosion resistance. It can be seen that the processing time is 30 seconds in the first and second embodiments, and the speed can be increased to 1/60 or less (specifically, 1/69) compared to the comparative example that took 2070 seconds.

11 Cylinder member 11a Outer surface (surface)
11b Inner surface (surface)
DESCRIPTION OF SYMBOLS 12 Opening 13a Edge surface 14 Bottom part 14a Outer surface of the bottom part 51 Anodizing apparatus 53 Partition part 55 Nozzle part 56 Pump 57 Press part 58 Contact part 59 Current supply part L Anodizing liquid

Claims (2)

An anodizing method for forming an oxide film on the surface by anodizing the surface of a bottomed cylindrical cylinder member made of an aluminum alloy,
Inserting a nozzle portion serving as a cathode into the cylinder member from an opening of the cylinder member;
Partitioning the inner surface of the cylinder member with respect to the outer surface by bringing a partition portion into contact with an edge surface around the opening of the cylinder member;
Abutting a contact portion serving as an anode on the outer surface of the bottom of the cylinder member;
Pressing the cylinder member with the abutting portion and the partition portion;
A step of discharging an anodizing treatment liquid from the nozzle portion and flowing a current between the contact portion and the nozzle portion;
A method for anodizing a cylinder member including An anodizing apparatus that forms an oxide film on the surface by anodizing the surface of a bottomed cylindrical cylinder member made of an aluminum alloy,
A nozzle portion inserted into the cylinder member from an opening of the cylinder member;
A partition portion that abuts an edge surface around the opening of the cylinder member and partitions the inner surface of the cylinder member with respect to the outer surface;
An abutting portion provided facing the partitioning portion and abutting against an outer surface of a bottom portion of the cylinder member;
A pressing portion that presses the abutting portion and the partition portion against the cylinder member;
A pump for discharging the anodizing solution from the nozzle part;
A current supply unit configured to supply current using the contact portion as an anode and the nozzle portion as a cathode;
A cylinder member anodizing apparatus.

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