JP5522482B2 - Surface treatment equipment - Google Patents

Description

  The present invention relates to a surface treatment apparatus.

The conventional surface treatment apparatus is, for example, a positive electrode member that is electrically connected to a metal workpiece having a circumferential groove as an annular treatment region on the outer circumferential surface, and the outer circumferential surface and the circumferential groove. Electrolysis along the circumferential groove is performed by sealing a gap between the inner circumferential surface and a frame member having inner circumferential surfaces facing each other with a gap therebetween, and both sides of the outer circumferential surface sandwiching the circumferential groove. A non-conductive elastic sealing material capable of forming a liquid passage, a negative electrode member provided in the electrolyte passage, and an electrolyte flow means for flowing the electrolyte along the electrolyte passage. Yes.
The surface treatment apparatus forms an electrolyte passage along the annular treatment area on the outer peripheral surface of the object to be treated, and allows the electrolyte solution to flow along the electrolyte passage while, for example, anodizing. The surface treatment can be efficiently performed on the annular processing region.
In the conventional surface treatment apparatus, the frame member is formed of a conductive material, and the frame member is annularly opposed to the outer peripheral surface of the object to be processed and the annular treatment region (circumferential groove) with a space therebetween. The negative electrode member which has the inner peripheral surface of is comprised (for example, refer patent document 1).

JP 2003-119593 A (paragraph number [0024])

In the above surface treatment apparatus, due to energization between the positive electrode member and the negative electrode member at the time of the surface treatment, metal components such as copper which is easily cationized dissolved in the electrolytic solution are deposited on the surface of the negative electrode member. Easy to deposit.
Since the conventional surface treatment apparatus is provided with a negative electrode member having an annular inner peripheral surface, the deposited metal tends to adhere and deposit uniformly on the inner peripheral surface of the negative electrode member over the entire circumference, and the deposited precipitation When the passage cross-sectional area of the electrolyte passage is narrowed by the metal, the smooth flow of the electrolyte is hindered.
In addition, when the frame member constitutes a positive electrode member having an annular inner peripheral surface that is opposed to the outer peripheral surface of the object to be processed and the annular processing region with a gap, the frame member is dissolved in the electrolytic solution. The same phenomenon occurs when non-metallic components such as chlorides and sulfides that are easily anionized are deposited on the surface of the positive electrode member.
The temperature of the electrolytic solution is increased in the vicinity of the surface of the annular treatment region due to heat generated by the electrode reaction, and when the smooth flow of the electrolytic solution is hindered, the temperature of the electrolytic solution is likely to increase.
When the temperature of the electrolytic solution rises, for example, so-called burns tend to occur in the surface treatment in which a film such as an alumite film is formed in the annular treatment region, and there is a possibility that the surface treatment cannot be efficiently and repeatedly performed at a high voltage.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a surface treatment apparatus capable of efficiently and repeatedly performing surface treatment at a high voltage.

A first characteristic configuration of a surface treatment apparatus according to the present invention is a positive electrode member or a negative electrode that is electrically connected to a cylindrical metal workpiece having an annular treatment region along the circumferential direction of the outer peripheral surface. One of the members, a frame member having a non-conductive inner peripheral surface facing the outer peripheral surface and the annular processing region with a space therebetween, and sandwiching the annular processing region among the outer peripheral surfaces By sealing a gap between each of the both sides and the inner peripheral surface, a non-conductive elastic sealing material capable of forming an electrolyte passage along the annular processing region, and a tip portion in the electrolyte passage The other of the rod-shaped positive electrode member or negative electrode member protruding toward the object to be processed so as to enter, and the electrolyte solution flow means for flowing the electrolyte solution along the electrolyte passage It is in the point to have.

In this configuration, the frame member has a non-conductive inner peripheral surface that is opposed to the outer peripheral surface of the object to be processed and the annular processing region with a space therebetween. Nonmetallic components do not precipitate on the inner peripheral surface of the frame member.
In addition, since the other of the rod-shaped positive electrode member or negative electrode member is projected, the surface area of the other of the positive electrode member or negative electrode member is made smaller than before, so that metal components and non-metal components are deposited. The adhesion area of the component to the other of the positive electrode member or the negative electrode member can be reduced, and the adhesion strength of the deposited component to the other of the positive electrode member or the negative electrode member can be weakened.
And since the other end of the rod-shaped positive electrode member or the negative electrode member is projected toward the object to be processed so that the tip portion enters the electrolyte passage, the rod-shaped positive electrode member or the negative electrode member The deposited component having a weak adhesion strength deposited on the other side of the electrode is easily removed from the other of the rod-shaped positive electrode member or the negative electrode member by the force of the electrolyte flowing along the electrolyte passage, and the rod-shaped positive electrode member Or the deposited component deposited on the other of the negative electrode members is difficult to grow greatly.
Therefore, a smooth flow of the electrolytic solution in the electrolytic solution passage can be ensured over a long period of time, and a temperature increase in the vicinity of the surface of the annular processing region can be suppressed over a long period of time.
Therefore, with the surface treatment apparatus of this configuration, the surface treatment can be efficiently and repeatedly performed at a high voltage.

  The second characteristic configuration of the present invention comprises a plurality of electrolyte supply nozzles that open toward the annular region to be processed, and a peripheral groove formed with a constant groove width on the inner peripheral surface of the frame member, Each of the electrolyte solution supply nozzles is disposed in the groove of the circumferential groove so as to be spaced apart from each other in the circumferential direction of the groove, and a circumferential groove portion between adjacent electrolyte solution supply nozzles of the circumferential grooves is provided. , Which is formed as an electrolyte solution discharge channel, and the distance between the adjacent electrolyte solution supply nozzles is set to be the narrowest at the nozzle tip portion.

For example, in the surface treatment in which a film such as an alumite film is formed in the annular processing region, when the temperature of the electrolytic solution in the vicinity of the reaction surface rises, a film having a low hardness may be formed and a film having a target hardness may not be formed.
With the surface treatment apparatus of this configuration, it is easy to form a film having a target hardness uniformly in the surface treatment for forming the film in the annular processing region.

That is, in the surface treatment apparatus of this configuration, the circumferential groove is formed with a constant groove width on the inner circumferential surface of the frame member, and each of the electrolyte supply nozzles is spaced from each other in the circumferential direction of the groove in the circumferential groove. They are spaced apart.
For this reason, it is easy to make uniform the temperature distribution of the electrolyte flowing through the electrolyte passage and to make the hardness of the coating formed in the annular processing region uniform.

Moreover, the circumferential groove part between adjacent electrolyte solution supply nozzles of the circumferential groove is formed as an electrolyte solution discharge flow path.
For this reason, the electrolytic solution flowing so as to swirl along the electrolytic solution passage can be vigorously flowed into the peripheral groove portion (electrolytic solution discharge flow channel) between the electrolytic solution supply nozzles by centrifugal force. .

Furthermore, the interval between adjacent electrolyte supply nozzles is set to be the narrowest at the nozzle tip.
For this reason, the flow area of the electrolyte solution can be increased by narrowing the channel cross-sectional area of the electrolyte solution discharge channel at the tip of the nozzle.
When the flow rate of the electrolyte near the nozzle tip is increased, the flow accompanying the flow of the electrolyte having a high flow rate (the accompanying flow) can prevent the high temperature electrolyte from staying near the nozzle tip. In addition, it is easy to quickly replace an electrolytic solution having a high temperature in the electrolytic solution passage with an electrolytic solution having a low temperature supplied from the electrolytic solution supply nozzle.

Therefore, the temperature rise of the electrolyte solution in the electrolyte passage can be suppressed while the hardness of the coating film is made uniform, and the coating film having the target hardness can be formed uniformly.
Moreover, the temperature rise of the electrolyte solution flowing through the electrolyte passage can be suppressed, and the melting of the coating film due to heat can be prevented.

  The second characteristic configuration of the present invention is that a plurality of the other of the rod-shaped positive electrode member or the negative electrode member is distributed along the circumferential direction of the electrolyte passage.

  With this configuration, the electric field generated between the other of the rod-shaped positive electrode member or negative electrode member and the annular treatment area is dispersed along the annular treatment area to form a uniform film. easy.

  The third characteristic configuration of the present invention is that the other of the rod-shaped positive electrode member or the negative electrode member is projected so that its longitudinal direction is perpendicular to the outer peripheral surface.

  In this configuration, an electric field is generated between the other of the rod-shaped positive electrode member or the negative electrode member and the annular processed region portions located on the left and right sides with respect to the other of the rod-shaped positive electrode member or the negative electrode member. It is generated symmetrically and it is easy to form a uniform film.

  The 4th characteristic structure of this invention exists in the point which has formed the other outer peripheral surface of the said rod-shaped positive electrode member or negative electrode member in the uneven surface.

  With this configuration, the other surface area of the rod-shaped positive electrode member or negative electrode member can be increased, so that a large current can flow, and a film having a desired thickness can be efficiently formed in a short time. easy.

  The fifth characteristic configuration of the present invention is that the shape of the tip of the other of the rod-shaped positive electrode member or the negative electrode member is formed in a convex curve shape.

  With this configuration, it is difficult for current to concentrate on the tip portion close to the object to be processed, and it is difficult for sparks to be generated, so that it is easy to form a uniform film.

It is the schematic of a surface treatment apparatus (anodization processing apparatus). (A) is a top view of the 2nd electrode part in the II-II line arrow of FIG. 1, (b) is an enlarged plan view of a 2nd electrode part. (A) is sectional drawing which shows the fixed structure of a negative electrode member, (b) is the IIIb-IIIb arrow directional side view in (a). It is sectional drawing which shows the electrolyte solution supply nozzle part of a 2nd electrode part. It is a side view which shows the inner peripheral side of a 2nd electrode part. It is sectional drawing which shows the state from which the elastic sealing material of the 2nd electrode part is spaced apart from the outer peripheral surface of a piston. It is sectional drawing which shows the state by which the elastic sealing material of a 2nd electrode part is press-contacted to the outer peripheral surface of a piston. It is a graph which shows correlation with discharge area ratio (S1 / S2) and the hardness (Hk) of the alumite film formed in the cyclic | annular to-be-processed area | region. It is a graph which shows correlation with discharge | emission area ratio (S1 / S2) and rising temperature (DELTA) T of the electrolyte solution discharged | emitted through an electrolyte solution discharge flow path. It is a side view which shows the negative electrode member in the surface treatment apparatus (anodization apparatus) of 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
1 to 7 show an anodizing apparatus as an example of a surface treating apparatus according to the present invention. This anodizing apparatus performs anodizing treatment for forming an alumite film on the surface of a piston ring groove A1 of an aluminum alloy piston A as an example of a metal workpiece.

Specifically, the outer periphery including the surface of the piston ring (compression ring) groove A1 on the top side of the three piston ring grooves A1, A2 and A3 formed from the top to the skirt of the cylindrical piston A Anodizing is performed on the surface (hereinafter referred to as piston outer peripheral surface) B.
The piston ring groove A1 corresponds to a circumferential groove as an annular process area on the piston outer peripheral surface B.

As shown in FIG. 1, the anodizing apparatus includes an electrolytic solution tank 1, an electrolytic solution supply unit 2, an oxidation processing unit 3, and an energization unit 4.
The electrolytic solution tank 1 is made of vinyl chloride or stainless steel, and has a container shape with an open top. The electrolytic solution tank 1 receives and collects the electrolytic solution that naturally flows after passing through the oxidation treatment unit 3 and supplies the electrolytic solution. A reflux path 5 for refluxing the part 2 is provided.

  The electrolytic solution supply unit 2 includes a cooling tank 6 for cooling the electrolytic solution refluxed from the electrolytic solution tank 1, a supply path 7 for supplying the electrolytic solution in the cooling tank 6 to the oxidation treatment unit 3, and a supply path 7 and a supply control unit 9 for controlling the operation of the supply pump 8 so that the electrolytic solution is supplied to the oxidation treatment unit 3 at a predetermined timing.

  The cooling tank 6 includes a cooler 10 for cooling the recovered electrolyte solution, and a cooler 10 based on detection information of the electrolyte temperature by the temperature sensor 11 so that the electrolyte solution is cooled to a predetermined temperature. And a cooling control unit 12 for controlling the operation of the above.

  The energization unit 4 energizes the oxidation treatment unit 3. The energization section 4 preferably has current control means so that the current density can be adjusted. As the current control means, a conventionally known one composed of an ammeter, a voltmeter, a rectifier or the like can be used.

The oxidation processing unit 3 includes a first electrode (anode) unit 13 and a second electrode (cathode) unit 14.
The first electrode portion 13 includes a positive electrode member 15 made of metal such as copper or stainless steel having conductivity, and an elevating device 16 that moves the positive electrode member 15 up and down with respect to the second electrode portion 14. .
The positive electrode member 15 is also used as a holder for holding the piston A, and is electrically connected to the anode terminal 4a of the energizing portion 4, and is electrically connected to the piston A by holding the piston A. Connected.

  The holder (positive electrode member) 15 includes a locking claw (not shown) that can be freely engaged with and disengaged from the inner peripheral surface of the piston A at its lower end. By locking the locking claw to the inner peripheral surface of the piston A, the piston A is held in a posture in which the axial center is along the vertical direction and is electrically connected.

  As shown in FIG. 2 (a), the second electrode portion 14 is formed in a circular shape when viewed from above, and has a circular shape when viewed in a plan view in which the piston A is inserted in a posture in which its axial center is along the vertical direction. The insertion hole 25 is formed concentrically.

As shown in FIGS. 1 to 3, the second electrode portion 14 includes a frame member 17 to which a plurality of round electrode members 41 are fixed, and fixing plates 18 and 19 disposed above and below the frame member 17. The support base 20 is connected to each other by bolts. Each negative electrode member 41 is formed of platinum (Pt) or conductive stainless steel (SUS).
The number of negative electrode members 41 is desirably 4 to 20, and in the present embodiment, 14 negative electrode members 41 are dispersedly arranged along the circumferential direction of the frame member 17.
The frame member 17, the fixing plates 18, 19 and the support base 20 are all formed of a nonconductive material (insulator) such as vinyl chloride resin.

  As shown in FIGS. 1, 3, and 4, the frame member 17 includes an annular upward concave surface portion 21 in which the lower surface outer peripheral side of the upper fixing plate 18 is recessed upward, and an upper surface outer periphery of the lower fixing plate 19. It is fitted between an annular downward concave surface portion 22 having a side recessed downward and is bolted to each other.

  As shown in FIG. 1, the frame member 17 is configured by connecting two frame plates, that is, an upper first frame plate 23 and a lower second frame plate 24, as shown in FIGS. As shown in FIG. 5, the negative electrode member 41 is sandwiched and fixed between the first frame plate 23 and the second frame plate 24.

As shown in FIGS. 4 to 6, the frame member 17 includes a circumferential groove 26 formed with a constant groove width on an inner circumferential surface (hereinafter referred to as a frame plate inner circumferential surface) 31.
The circumferential grooves 26 are opposed plate portions 27, 28 that make the first frame plate 23 and the second frame plate 24 face each other with a space therebetween, and the piston insertion holes 25 along the inner peripheral side of the opposed plate portions 27, 28. Side plate portions 29 and 30 projecting to the side are formed in an annular shape and provided on the piston insertion hole 25 side of the first frame plate 23 and the second frame plate 24.

The inner side of the inner peripheral surface 31 of the frame plate formed by the inner peripheral surfaces of the flange plates 29 and 30 is formed as a piston insertion hole 25.
Therefore, the frame member 17 is a frame plate inner peripheral surface 31 formed as a non-conductive annular inner peripheral surface that is opposed to the piston outer peripheral surface B and the piston ring groove A1 at a predetermined interval over the entire periphery. It has.

As shown in FIG. 1, the lower fixing plate 19 has the same diameter as the piston insertion hole 25, the concentric circular concave surface portion 32, and the top of the piston A in a posture in which the shaft core is vertically aligned. A piston mounting portion 35 for mounting and supporting the surface is provided.
Over the lower fixing plate 19 and the support base 20, the connection flow path 33 connected to the electrolytic solution supply path 7 and the electrolytic solution accumulated in the circular concave surface portion 32 are discharged into the electrolytic solution tank 1 by natural flow. A discharge hole 34 is provided.

  Therefore, as shown in FIG. 1, the piston A held by the holder (positive electrode member) 15 with the shaft core electrically connected in a posture along the vertical direction is inserted through the piston insertion hole 25, By placing the top surface on the piston mounting portion 35, as shown in FIGS. 3 and 4, a constant interval is provided between the piston outer peripheral surface B and the frame plate inner peripheral surface 31 over the entire circumference. It is positioned concentrically with a gap C.

  As shown in FIGS. 1 and 3 to 7, on the frame member inner peripheral surface 31 side of the frame member 17, two upper and lower non-conductive annular elastic sealing materials 40 are vertically moved over the entire circumference. The front end portion 44 is mounted so as not to come off at an interval and so as not to protrude from the inner peripheral surface 31 of the frame plate to the piston outer peripheral surface B side.

  Each elastic sealing member 40 is formed in an annular shape with a non-conductive material (insulator) such as rubber, and as shown in FIG. 7, it extends so that its tip 44 is pressed against the piston outer peripheral surface B. The annular electrolyte passage 45 along the circumferential groove A1 can be formed by sealing the gap C between the both sides of the piston outer circumferential surface B across the circumferential groove A1 and the inner peripheral surface 31 of the frame plate. is there.

  Each elastic sealing material 40 is formed with a series of recessed portions 42 that open toward the outer peripheral side thereof over the entire circumference, and upper and lower side wall portions 43 and a tip end portion 44 that is brought into contact with the piston outer peripheral surface B. Are formed in a transverse U-shaped transverse cross-sectional shape.

  As shown in FIGS. 1, 6, and 7, by simultaneously supplying pressurized air as a pressurized fluid to the outer peripheral side of each elastic sealing material 40, the inner peripheral side (tip portion 44) of these elastic sealing materials 40. ) Is press-contacted to the piston outer peripheral surface B over the entire circumference, and a pressurizing mechanism 51 capable of releasing the press-contact is provided.

  The pressurizing mechanism 51 includes an air supply / discharge device 52 that can freely supply and discharge pressurized air, a supply / discharge control unit 53 that controls the air supply / discharge operation of the air supply / discharge device 52, and a recessed portion of the elastic seal material 40. 42, an air supply / discharge passage 54 communicating with each of the air supply / discharge passages 42, and a pipe joint 56 connecting the air supply / discharge passage 55 of the air supply / discharge device 52 and the air supply / discharge passage 54.

  The air supply / discharge paths 54 are provided at three locations in the circumferential direction of the second electrode portion 14, and are connected to the air supply / discharge pipes 55 for each of the air supply / discharge paths 54, with respect to the recessed portions 42 of the elastic sealing materials 40. Thus, pressurized air can be freely supplied and discharged from three locations in the circumferential direction.

The operation of the pressurizing mechanism 51 will be described.
As shown in FIG. 6, when the piston A is inserted into the piston insertion hole 25 and placed on the piston placement portion 35, the supply / exhaust control portion 53 passes through the air supply / exhaust passage 54 to insert the recessed portion of each elastic seal material 40. The air supply / exhaust device 52 is operated so that pressurized air is supplied to each of 42.

  When pressurized air is supplied to the recessed portion 42 of the elastic seal material 40, the elastic seal material 40 elastically extends toward the piston outer peripheral surface B, and the tip end portion 44 faces the piston outer peripheral surface B. As shown in FIG. 7, the tip 44 is pressed against the piston outer peripheral surface B.

  As shown in FIG. 7, the tip 44 of the elastic seal material 40 is brought into pressure contact with the piston outer peripheral surface B, so that a gap C between the piston outer peripheral surface B and the frame plate inner peripheral surface 31 is formed on both sides of the peripheral groove A1. Sealed to form an annular electrolyte passage 45 along the circumferential groove A1.

As shown in FIGS. 2A, 3, and 5, each of the negative electrode members 41 is an electrode that protrudes toward the piston A so that the tip 46 a enters the electrolyte passage 45. It is formed in a straight round bar shape including a shaft portion 46, a fixing shaft portion 47 that is fixed to the frame member 17, and a connection shaft portion 48 that is electrically connected to the cathode terminal 4 b of the energization portion 4. .
The shape of the tip end portion 46a of the electrode shaft portion 46 is formed in a convex curved surface shape having no corners.

The negative electrode members 41 have an angle range of 75 degrees or less so that the longitudinal direction (axial center direction) is the same direction as the direction orthogonal to the piston outer peripheral surface B. It is desirable to arrange so as to be inclined at
In the present embodiment, the plurality of negative electrode members 41 are connected to the piston insertion holes 25 so that the longitudinal direction of the electrode shaft portion 46 is orthogonal to the piston outer peripheral surface B as shown in FIG. Are arranged radially at equal intervals along the circumferential direction of the electrolyte passage 45.

  As shown in FIGS. 3 and 5, each negative electrode member 41 has an electrode shaft portion 46 projecting toward the piston A side through an electrolyte discharge flow path 38, which will be described later, and a connecting shaft portion as shown in FIG. The fixing shaft portion 47 is sandwiched and fixed between the first frame plate 23 and the second frame plate 24 so that 48 protrudes to the outer peripheral side of the frame member 17.

As shown in FIG. 2A, the connection shaft portion 48 of each negative electrode member 41 is electrically connected to a common connection terminal plate 49 that is electrically connected to the cathode terminal 4 b of the energization portion 4. .
The connection terminal plate 49 is formed in an annular shape surrounding the frame member 17, and each of the connection shaft portions 48 is shown in FIG. 3.
As shown in (b), the connection terminal plate 49 and the receiving plate 50 bolted to the connection terminal plate 49 are sandwiched and electrically connected.

  Therefore, when replacing the negative electrode member 41, the connection between the connection shaft portion 48 and the connection terminal plate 49 is released, and the negative electrode member 41 to be replaced is placed between the first frame plate 23 and the second frame plate 24. It is possible to easily replace the negative electrode member 41 by inserting it between the first frame plate 23 and the second frame plate 24 and connecting it to the connection terminal plate 49.

As shown in FIG. 2A, FIG. 4, and FIG. 5, the opposing plate portion 27 and the saddle plate portion 29 in the first frame plate 23, and the opposing plate portion 28 and the saddle plate portion 30 in the second frame plate 24. A plurality of electrolyte supply nozzles 36 that open toward the piston ring groove A <b> 1 are arranged at regular intervals in the groove circumferential direction.
It is desirable to dispose the same number of electrolyte supply nozzles 36 as the negative electrode members 41. In the present embodiment, 14 electrolytic electrode supply nozzles 36 having the same number as the negative electrode members 41 are disposed.

As shown in FIGS. 4 and 5, each electrolyte supply nozzle 36 is connected to the connection flow path 33 and includes a supply flow path 37 for supplying the electrolyte solution to the electrolyte passage 45. 37 opens on the inner peripheral surface 31 of the frame plate toward the piston ring groove A1.
As shown in FIG. 2A, the electrolyte supply nozzle 36 is inclined at an angle range of 5 to 75 degrees with respect to the tangent line of the inner peripheral surface 31 of the flow path axis X of the supply flow path 37. It is desirable to be provided as follows.

  As shown in FIGS. 1 and 5, the circumferential groove portion between adjacent electrolyte solution supply nozzles 36 in the circumferential groove 26, that is, the upper and lower facings between the electrolyte solution supply nozzles 36 adjacent in the circumferential direction. A space between the plate portions 27 and 28 and a space between the upper and lower plate portions 29 and 30 are provided as the electrolyte discharge flow path 38.

  Each electrolytic solution supply nozzle 36 can supply the electrolytic solution to the electrolytic solution passage 45 from a direction inclined with respect to the tangent to the inner peripheral surface 31 of the frame plate so that the electrolytic solution flows along the electrolytic solution passage 45. It is arranged.

  Therefore, the electrolytic solution supply unit 2 including these electrolytic solution supply nozzles 36 is provided as an electrolytic solution flow means for flowing the electrolytic solution along the electrolytic solution passage 45, as shown by an arrow a in FIG. Since the electrolytic solution flows so as to surround the surface of the electrode shaft portion 46, it is easy to remove the deposited metal deposited on the electrode shaft portion 46 with low adhesion strength by the force of the electrolytic solution.

  Since it is easy to remove the deposited metal deposited on the electrode shaft portion 46, it is difficult for sparks to be generated due to the deposited deposited metal coming into contact with the piston outer peripheral surface B or the circumferential groove A1, and the formed alumite film is dissolved by the spark and processed quality. Is less likely to decrease.

  As shown in FIG. 2A, a through-hole penetrating the lower opposing plate portion 28, the lower fixing plate 19 and the support base 20 at a position between the electrolyte supply nozzles 36 adjacent in the circumferential direction. 39 is formed, and the electrolytic solution in the electrolytic solution discharge flow path 38 naturally flows down from these through holes 39 and is discharged to the electrolytic solution tank 1.

  The electrolyte supply nozzle 36 is formed in a rectangular shape in plan view, and the interval between the adjacent electrolyte supply nozzles 36 is set to be the narrowest at the tip of the nozzle, so that the flow of the electrolyte discharge channel 38 can be reduced. The road cross-sectional area is narrowed at the tip of the nozzle.

  That is, as shown in FIG. 2B, the nozzle tip surface 36a and the nozzle side surface 36b of the nozzle tip portion of one of the two electrolyte solution supply nozzles 36 adjacent to each other intersect each other. The shortest distance L from the corner 58 to the other electrolyte supply nozzle 36 is the distance from the other part (the nozzle side surface 36b and the nozzle rear end surface 36c) of the one electrolyte supply nozzle 36 to the other electrolyte supply nozzle 36. It is set to be shorter.

  In the anodizing apparatus of this embodiment, the deposited metal deposited on the negative electrode member 41 is large and difficult to grow. Therefore, the electrode is used until the deposited thickness of the deposited metal reaches a thickness that requires replacement of the negative electrode member 41. The time is approximately twice as long as that of a conventional anodizing apparatus having a negative electrode member having an annular inner peripheral surface facing the outer peripheral surface B and the peripheral groove A1 of the piston A with a space therebetween. It was.

  As shown in Table 1, when an alumite film having a film thickness of 15 μm is formed, the burn voltage is 50 V or more higher than the conventional anodizing apparatus disclosed in Patent Document 1, and the set voltage is 30 V. By increasing the above, the processing time could be shortened by 30% or more.

FIG. 8 shows the correlation between the discharge area ratio (S1 / S2), which is the ratio of the discharge channel cross-sectional area S1 and the supply channel cross-sectional area S2, and the hardness (Hk) of the alumite coating formed in the circumferential groove A1. It is a chart which shows.
The discharge channel cross-sectional area S1 is the sum of the minimum channel cross-sectional areas at the nozzle tip positions between the adjacent electrolyte solution supply nozzles 36 in the electrolyte solution discharge channel 38.
The supply channel cross-sectional area S2 is the sum of the channel cross-sectional areas of the supply channels 37 in the electrolyte solution supply nozzles 36.

FIG. 9 is a chart showing a correlation between the discharge area ratio (S1 / S2) and the rising temperature ΔT of the electrolyte flowing down the through hole 39.
The rising temperature ΔT is a temperature that has risen from the supply temperature of the electrolyte to the supply flow path 37.

FIG. 9 indicates that the heat recovery rate increases as the discharge area ratio (S1 / S2) increases, that is, as the discharge flow path cross-sectional area S1 becomes larger than the supply flow path cross-sectional area S2. As a result, the temperature rise of the electrolytic solution in the electrolytic solution passage 45 is suppressed.
Therefore, as shown in FIG. 8, it can be seen that as the discharge area ratio (S1 / S2) increases, an alumite film having higher hardness is formed.

[Second Embodiment]
FIG. 10 shows a negative electrode member 41 in another embodiment of the surface treatment apparatus (anodizing apparatus) according to the present invention.
In the present embodiment, an uneven surface 57 having convex and concave curved surfaces alternately in the axial direction is formed on the outer peripheral surface thereof so that the surface area of the electrode shaft portion 46 is increased. The convex curved surface and the concave curved surface are formed in a spiral shape around the axis of the electrode shaft portion 46.
Other configurations are the same as those of the first embodiment.

[Other Embodiments]
1. The surface treatment apparatus according to the present invention may perform a surface treatment on a convex surface (mountain shape) or a planar annular region to be processed which is provided on the outer peripheral surface of an object to be processed.
2. The surface treatment apparatus according to the present invention includes a negative electrode member that is electrically connected to a metal object to be processed, and a protrusion that projects toward the object to be processed so that the tip portion enters the electrolyte passage. A certain rod-shaped positive electrode member may be provided.
3. The surface treatment apparatus according to the present invention may include the other of a positive electrode member or a negative electrode member in the shape of an ellipse or polygonal bar.
4). The surface treatment apparatus according to the present invention may include the other of a single rod-like positive electrode member or negative electrode member.
5. In the surface treatment apparatus according to the present invention, the other of the rod-shaped positive electrode member or the negative electrode member may be provided so that the longitudinal direction thereof is an oblique direction with respect to the outer peripheral surface of the workpiece.
6). In the surface treatment apparatus according to the present invention, the other of the rod-like positive electrode member or the negative electrode member is projected so that the longitudinal direction thereof is an oblique direction toward the upper side of the electrolyte flow direction in the electrolyte passage. Alternatively, it may be provided so as to project in an oblique direction toward the lower side in the flow direction.
7). The surface treatment apparatus according to the present invention may be an electroplating apparatus for performing an electroplating process as a surface treatment.

2 Electrolyte flow means 15 One of positive electrode member or negative electrode member (positive electrode member)
17 Frame member 26 Circumferential groove 31 Non-conductive inner peripheral surface 36 Electrolyte supply nozzle 38 Electrolyte discharge channel 40 Elastic seal material 41 The other of the rod-shaped positive electrode member or negative electrode member (negative electrode member)
45 Electrolyte passage 46a Tip portion 57 Uneven surface A Object A1 Annular region (circumferential groove)
B Outer peripheral surface C Clearance

Claims (6)

One of a positive electrode member or a negative electrode member electrically connected to a cylindrical metal object to be processed having an annular treatment area along the circumferential direction of the outer peripheral surface;
A frame member having a non-conductive inner peripheral surface facing the outer peripheral surface and the annular processing region with a gap therebetween;
A non-conductive elastic seal capable of forming an electrolyte passage along the annular processing region by sealing a gap between each of the outer peripheral surfaces sandwiching the annular processing region and the inner peripheral surface. Material,
The other of the rod-shaped positive electrode member or negative electrode member protruding toward the object to be processed so that the tip portion enters the electrolyte passage,
A surface treatment apparatus comprising: an electrolyte solution flow means for causing the electrolyte solution to flow along the electrolyte solution passage. A plurality of electrolyte supply nozzles opening toward the annular processing region;
A circumferential groove formed with a constant groove width on the inner circumferential surface of the frame member,
Each of the electrolyte solution supply nozzles is disposed in the circumferential groove at a distance from each other in the circumferential direction of the groove,
Of the circumferential groove, a circumferential groove portion between adjacent electrolyte supply nozzles is formed as an electrolyte discharge flow path,
The surface treatment apparatus according to claim 1, wherein an interval between the adjacent electrolyte supply nozzles is set to be narrowest at a nozzle tip portion.   The surface treatment apparatus according to claim 1 or 2, wherein a plurality of the other of the rod-shaped positive electrode members or negative electrode members are dispersedly arranged along the circumferential direction of the electrolyte passage.   The surface treatment according to any one of claims 1 to 3, wherein the other of the rod-shaped positive electrode member or the negative electrode member is projected so that the longitudinal direction thereof is perpendicular to the outer peripheral surface. apparatus.   The surface treatment apparatus of any one of Claims 1-4 which has formed the other outer peripheral surface of the said rod-shaped positive electrode member or negative electrode member in an uneven surface.   The surface treatment apparatus according to any one of claims 1 to 5, wherein a shape of a tip portion of the other of the rod-shaped positive electrode member and the negative electrode member is formed in a convex curved surface shape.

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