JP2009052110A - Electrolytic grinding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic grinding apparatus for continuously treating a plurality of individual piece-like workpieces in which high grade treatment is carried out by controlling current so as to obtain a desired current density to the workpieces to cope with the change of the number of the workpieces, the omission of the workpieces or the change of the current density due to deficiency. <P>SOLUTION: The electrolytic grinding apparatus 1 is for electrolytically grinding the workpieces W by continuously passing the individual piece-like workpieces W through an electrolyte 2a filled in an electrolytic cell 2 and is provided with a sensor 3 for detecting the workpieces charged in the electrolytic cell 2 and a control part 4 for controlling the current for electrolytic grinding corresponding to the number of the workpieces based on the detected result of the sensor 3. The control part 4 controls the whole current for the electrolytic grinding so as to get the value of current obtained by multiplying the optimum current value per one workpiece by the number of the workpieces to attain high grade treatment. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electropolishing apparatus for electrolytically polishing a workpiece by continuously passing a plurality of individual workpieces.

  2. Description of the Related Art Conventionally, a so-called electropolishing apparatus that electrochemically polishes the surface of a workpiece by passing a direct current in the electrolyte using a conductive workpiece (workpiece) immersed in the electrolyte as a positive electrode has been used as a metal. Widely used for surface finishing. Electropolishing is understood as the reverse reaction of electroplating.

  In such electropolishing, in order to keep the processing quality by electropolishing stable, it is important to keep the current density in the workpiece constant as in the case of ensuring the plating quality. When the current density fluctuates, the polishing removal amount on the workpiece surface fluctuates in proportion to the current density, or the surface condition such as surface roughness changes, and these fluctuations cause quality defects. However, when processing a plurality of individual workpieces continuously, as a simple method, the constant current source is used to control the total current supplied to all the workpieces present in the electrolytic solution to maintain the current. The density is kept constant.

  As an example of controlling the above-described current density in more detail, a multilayer wiring board plating apparatus is known (see, for example, Patent Document 1). In this example, the current supplied to the exposed surface exposed in the plating solution is increased in accordance with a predetermined condition corresponding to the expansion of the exposed surface area, and the current density of the current supplied to the exposed surface is kept constant. Yes.

In addition, as an example of an electrolytic polishing apparatus that electrolytically polishes a workpiece by continuously passing a plurality of individual workpieces, a transport mechanism is formed by arranging a number of rollers in the electrolytic solution. There is known an apparatus for applying a voltage between a counter electrode inside and performing an electrolytic polishing process on a workpiece (for example, see Patent Document 2).
JP 2007-23368 A JP 2001-207300 A

  However, in the apparatus as shown in Patent Document 1 described above, the change in the exposed area is obtained mathematically in advance by calculating the area change rate that is expected depending on the shape of the workpiece and the way the current flows. It cannot cope with unexpected changes. Further, Patent Document 2 described above does not describe any control of current density.

  Here, the control of the current density will be further described. In an electrolytic polishing apparatus for electrolytically polishing a workpiece by continuously passing a plurality of the same type of individual workpieces through an electrolytic cell (in an electrolytic solution), when the device is operating normally, Since the number of workpieces contained is constant, the current density can be made constant by keeping the entire current constant. However, the number of workpieces charged into the electrolytic cell increases from zero to a fixed number at the start of operation of the equipment, and decreases from a fixed number to zero at the end of the operation. It cannot be kept constant.

  The above-described problem of current fluctuation at the start and end of processing can be solved by inserting a dummy workpiece, but it is necessary to prepare a dummy for each type of workpiece. However, when trouble occurs that fails to throw in the workpiece during steady operation, the actual number of workpieces in the electrolytic cell will fluctuate, so the overall current is still constant. The current density cannot be kept constant by itself.

  Furthermore, even when the number of workpieces in the electrolytic cell is maintained at a constant number, if the contact resistance becomes extremely large due to poor electrical contact between the power supply unit and the workpiece, the total current It is not possible to keep the current density constant only by keeping the constant. Thus, there are various factors that cause the current density to fluctuate. And even though the constant current source is carrying a constant current, the missing part of the workpiece, poor contact, etc. occurs and the effective electrode area varies, so a defect in just one workpiece causes a variation in current density, As a result, the machining quality of all the workpieces contained in the electrolytic cell is adversely affected.

  The present invention solves the above-mentioned problems, and with a simple configuration, a desired current density for a workpiece can be obtained in response to a change in the number of workpieces in the electrolytic cell, a dropout of workpieces, or a change in current density due to defects. An object of the present invention is to provide an electropolishing apparatus capable of controlling current and realizing high-quality processing.

  In order to achieve the above object, the invention of claim 1 is an electropolishing apparatus for electrolytically polishing a work by passing a plurality of pieces of work continuously through an electrolytic solution filled in an electrolytic cell. A sensor for detecting a workpiece put in the electrolytic cell; and a control unit for controlling a current for electropolishing according to the number of workpieces based on a detection result by the sensor. The overall current for electropolishing is controlled so as to be a current value obtained by multiplying the optimum current value by the number of workpieces.

  According to a second aspect of the present invention, in the electropolishing apparatus according to the first aspect, the sensor detects a work by measuring a current for electropolishing flowing through one work.

  According to a third aspect of the present invention, in the electropolishing apparatus according to the second aspect, the sensor is disposed at an inlet portion of the electrolytic cell, and measures an electric current for electrolytic polishing flowing through a workpiece newly introduced into the electrolytic cell. Is.

  According to a fourth aspect of the present invention, there is provided the electropolishing apparatus according to the second aspect, wherein the sensors are arranged at two locations, an inlet portion and an outlet portion of the electrolytic cell, and currents flowing through the workpiece to be charged and discharged, respectively. The control unit detects whether or not a workpiece is input based on the current measurement result of the sensor at the inlet portion, and sets the current value measured by the sensor at the outlet portion as a desired current value. It controls the overall current for electropolishing.

  According to a fifth aspect of the present invention, in the electrolytic polishing apparatus according to the fourth aspect, when the control unit reaches the outlet portion of the electrolytic cell, the work that has been poorly inserted based on the current measurement result of the sensor at the inlet portion. In addition, the overall current for electrolytic polishing is controlled based on the number of workpieces in the electrolytic cell without performing current control based on the current value measured by the sensor at the outlet portion.

  According to a sixth aspect of the present invention, in the electropolishing apparatus according to the first aspect, the control unit monitors a voltage of a current source for supplying a current for electropolishing, and a new work is put into the electrolytic cell. At this time, when the rate of change of the voltage exceeds a predetermined voltage range, it is considered that a loading failure has occurred in the workpiece.

  According to the first aspect of the present invention, the number of workpieces charged is counted by the sensor, and the current for electropolishing is controlled based on the number of workpieces in the electrolytic cell. The current can be controlled so as to obtain a desired current density for the workpiece in response to a change in current density due to dropout or chipping, and high quality processing can be realized. That is, by providing a sensor for detecting a workpiece, the current density can be kept constant by controlling the number of workpieces in the electrolytic cell accurately, and defects can be prevented. Further, according to the present invention, the problem of current fluctuation at the start and end of processing can be solved without introducing a dummy workpiece.

  According to the invention of claim 2, compared with a method of detecting the presence or absence of a workpiece using an infrared sensor or a proximity sensor, a method of detecting a workpiece by measuring a current value flowing through one workpiece is Abnormalities relating to electrical connections that cannot be determined (such as poor contact between the power feeding unit and the workpiece) can be detected, and the current density for workpieces other than the abnormal location can be controlled to a desired value based on the current measurement result.

  According to the invention of claim 3, by arranging the ammeter at the entrance portion, the work detection function can be achieved with the minimum number of sensors. Normally, it is considered that the number of workpieces does not fluctuate in the electrolytic cell. Therefore, it is possible to detect the missing workpiece due to a failure of loading at the entrance part at an early stage to minimize the influence on other workpieces already processed in the electrolytic cell. Can be limited.

  According to the invention of claim 4, since current can be measured by at least two sensors spaced apart from each other, even if the workpiece is missing at one of the two sensors, The current flowing through the workpiece at the other sensor position can be measured. Moreover, since the current value measured by the sensor at the exit portion is used for control, the entire current can be controlled based on the current per work, that is, the current density, and high quality processing can be realized. In other words, by using an ammeter provided at the exit part, the entire current is controlled so that the current value for a normal workpiece at the exit part is optimized, so that accurate current density control with feedback of the state is performed. can do.

  In this case, the control is more suited to the situation during processing than the control method of controlling the overall current for electrolytic polishing so that the current value obtained by multiplying the optimum current value per work by the number of works is obtained. Can do. In addition, since the same amount of current flows through the work in the electrolytic cell that is at least in the same shape and in the same electrical state as the work of the outlet portion that is the standard for current control, It is possible to solve the conventional problem that a defect in the workpiece causes a fluctuation in current density and adversely affects the machining quality of all the workpieces contained in the electrolytic cell.

  According to the invention of claim 5, since the current value in the work at the exit portion can be referred to and when it cannot be referred to, current control can be performed by an optimum method in that scene, and high quality processing can be realized.

  According to the sixth aspect of the present invention, when the constant current control is performed, the voltage value increases and the current density also increases when the number of workpieces in the electrolytic cell is reduced or there is a defect that current does not flow. Since the rise in the voltage value is monitored based on this, it is possible to effectively detect an abnormality in the current supply to the workpiece, and to implement high quality processing reflecting the current density control. In this case, since the resistivity of the electrolyte varies depending on the temperature of the solution and the concentration of metal ions in the solution, current supply abnormality is not determined by determining whether the voltage value exceeds the threshold, but by looking at the rate of change of the voltage value. It can serve the function of detection. According to this method, it is possible to determine a defect with a simple configuration.

  Hereinafter, an electropolishing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1A shows the overall configuration of the electropolishing apparatus according to the first embodiment of the present invention, and FIG. 1B shows the flow of the electropolishing process. The electropolishing apparatus 1 is an electropolishing apparatus for electropolishing the workpiece W by continuously passing a plurality of individual workpieces W through an electrolytic solution 2 a filled in an electrolytic bath 2. The electropolishing apparatus 1 includes a sensor 3 that detects a workpiece W put into the electrolytic cell 2, and a control unit 4 that controls a current for electropolishing according to the number of workpieces based on the detection result of the sensor 3. ing. The control unit 4 controls the overall current for electrolytic polishing so as to obtain a current value obtained by multiplying the optimum current value per workpiece by the number of workpieces, thereby realizing high quality processing. Details will be described below.

  The electropolishing apparatus 1 includes equipment for performing pretreatment and posttreatment before and after electropolishing in order to electropolish each workpiece W made of a metal piece. The entire process includes, for example, seven steps of workpiece attachment a, electrolytic polishing b, liquid drain c, cleaning d, liquid drain e, drying f, and workpiece removal g. The workpiece W is electrolytically polished through these steps in order.

  Corresponding to each of the above-described steps, a workpiece automatic mounting device (not shown), an electrolytic bath 2, a liquid discharge nozzle 12 for jetting air 12a, a cleaning bath 13, a liquid discharge nozzle 15 for jetting air 15a, and hot air 16a are jetted. The drying nozzle 16 and the automatic workpiece removal device (not shown) are arranged in this order, and the ring-shaped metal belt 10 that circulates at a constant speed in one direction is arranged above the space where these are arranged. Yes.

  The metal belt 10 plays a role of conveyance of the workpiece W and a power feeding path to the workpiece W, and the machining time of the workpiece W is kept constant as the metal belt 10 conveys the workpiece W at a constant speed. The metal belt 10 includes metal square bars for suspending and transporting the workpiece W at regular intervals. Each metal square bar is provided with a clip for fixing the workpiece W (these structures are shown as metal square bar 10a and clip 10b in FIG. 4 described later).

  The metal belt 10 is connected to the positive electrode of the current source 5 through the power supply roller 51, and the workpiece W being conveyed is supplied with power through the metal belt 10, the metal square bar 10a, and the clip 10b. The negative electrode side of the current source 5 is connected to an electrode plate (not shown, shown as an electrode plate 52 in FIG. 2 described later) provided in the electrolytic solution 2a of the electrolytic cell 2.

  The sensor 3 may be any sensor that detects the workpiece W put into the electrolytic cell 2 and transmits the detection result to the control unit 4. The sensor 3 is, for example, an infrared sensor, a proximity sensor, or a switch that mechanically contacts and turns on and off the workpiece W (for example, a minute contact interval and a snap action mechanism that are operated by a lever disposed at the inlet portion of the electrolytic cell 2) A so-called micro switch having

  Here, the operation of the electropolishing apparatus 1, that is, the processing for the workpiece W will be described in order. The workpiece W before processing is stored in the magazine 11. The automatic workpiece attachment device (not shown) takes out the workpiece W from the magazine 11 and attaches it to the metal square bar 10a of the metal belt 10 moving at a constant speed using the clip 10b before the entrance of the electrolytic cell 2.

  The workpieces W are successively attached to the metal belt 10, transported, and put into the electrolytic cell 2. At the entrance portion of the electrolytic cell 2, the workpiece W into which the sensor 3 is inserted is detected, and the detection result is transmitted to the control unit 4. The controller 4 grasps the number of workpieces W present in the electrolytic cell 2 from the number of workpieces W discharged from the electrolytic cell 2 over time and the number of loaded workpieces W transmitted from the sensor 3. Can do. The control unit 4 controls the current source 5 so as to output a current having a current value obtained by multiplying the optimum current value per work by the number of works, thereby controlling the overall current for electropolishing.

  The workpiece W that has passed through the electrolytic bath 2 is blown away (that is, drained) by the air 12a ejected from the liquid discharge nozzle 12, and is introduced into the cleaning bath 13 and cleaned by the cleaning liquid 13a. The cleaning liquid 13 a is circulated by a pump (not shown), is regenerated by the ion exchange resin 14 outside the cleaning tank 13, and flows while overflowing from the downstream side to the upstream side of the cleaning tank 13. .

  The work W that has passed through the cleaning tank 13 is blown away by the air 15a ejected from the liquid discharge nozzle 15 and dried by hot air 16a ejected from the drying nozzle 16, and is removed from the metal belt 10 by an automatic workpiece removal device (not shown). It is removed and stored in the magazine 17, and the processing by the electropolishing apparatus 1 is completed.

  The above-described electrolytic cell 2 will be further described. The inlet side and the outlet side of the electrolytic cell 2 have a double box structure, and are provided with slits through which the workpiece W can pass (not shown). Further, the inner electrolyte 2a overflows from the slit of the inner box and overflows to the outer box, and the overflowed electrolyte 2a is collected by the outer box. The workpiece W enters the electrolytic solution 2a through the slit in which the electrolytic solution 2a overflows, and similarly exits from the electrolytic solution 2a through the slit in which the electrolytic solution 2a overflows. When the workpiece W enters the electrolytic solution 2a, a current flows through the workpiece W, and the workpiece W is electrolytically polished.

  Here, the length of the electrolytic cell 2 where the workpiece W is effectively electropolished is defined as an effective electrolysis length L. Further, the pitch at which the workpiece W is thrown, that is, the pitch of the metal square bars 10 a attached to the metal belt 10 is defined as a pitch D. At this time, if the effective electrolysis length L is an integral multiple of the pitch D, that is, L = n × D, where n is an integer, the number of workpieces W existing inside the effective electrolysis length L is always n. (However, there is no mounting defect of the workpiece W). That is, for example, when the workpiece W enters the effective electrolytic length L by one third on the inlet side, similarly, the workpiece W comes out of the effective electrolytic length L by one third on the outlet side, When only half of the effective electrolytic length L has entered the inlet side, only half of it has come out on the outlet side.

  In addition, when there is an attachment defect of the work W, it is possible to determine where the position of the defect part is in the effective electrolysis length L based on the conveyance speed of the metal belt 10 and to determine the work W in the effective electrolysis length L. Can be calculated.

  In the present invention, the plurality of workpieces W to be processed are all assumed to have the same shape. The workpiece W has a large number of processed holes in a thin metal piece such as an outer blade of an electric razor, for example, and a processed portion of the workpiece W that has been machined or etched is electropolished. Moreover, in this invention, if the workpiece | work W is a piece-like thing, it is applicable and it is not limited to the magnitude | size and shape.

  According to the electrolytic polishing apparatus 1 of the present embodiment, the number of workpieces W that have been input is counted based on the detection result of the sensor 3, and the current for electrolytic polishing is based on the number of workpieces W that are in the electrolytic cell 2. Therefore, it is possible to control the current so as to obtain a desired current density for the workpiece W in response to a change in the number of workpieces, a drop in the workpiece W, and a change in the current density due to the chipping, thereby realizing high quality processing. That is, by providing the sensor 3 for detecting the workpiece W, the number of the workpieces W contained in the electrolytic cell 2 can be accurately managed. Therefore, the current density can be kept constant, and defects can be prevented. be able to. Further, since the current can be controlled in accordance with the number of workpieces W in the electrolytic cell 2 that changes sequentially, the problem of current fluctuation at the start and end of processing can be solved without introducing a dummy workpiece.

(Second Embodiment)
2 shows a plan view of an electrolytic cell of an electropolishing apparatus according to the second embodiment and a block configuration of current control, FIGS. 3A to 3D show a state of current measurement of a workpiece, and FIG. The appearance and operation of the clamp part for current measurement are shown. The electropolishing apparatus 1 according to the present embodiment includes a sensor 3 that detects the work W by measuring the current for electropolishing flowing through one work W in the first embodiment described above. 3 is arranged at the entrance of the electrolytic cell 2 and measures the current for electropolishing flowing through the workpiece W newly introduced into the electrolytic cell 2.

  Based on FIG. 2, the structure of the detailed part of the electrolytic cell 2 is demonstrated. The metal belt 10 is connected to the positive electrode of the current source 5 via the power supply roller 51. In the electrolytic cell 2, electrode plates 52 are provided on both sides of the workpiece W, and are connected to the negative electrode of the current source 5.

  The sensor 3 is a clamp-type ammeter, and the clamp portion 31 is disposed at the entrance of the electrolytic cell 2. The clamp unit 31 can move in synchronization with the movement of the metal belt 10 and measures the current flowing through the new workpiece W every time a new workpiece W enters the electrolytic cell 2.

  The movement of the clamp part 31 will be further described. In FIG. 3A, the clamp unit 31 is a position that approaches the workpiece W from the retracted position for current measurement with respect to the newly loaded workpiece W. After approaching the workpiece W, the clamp portion 31 is disposed so as to surround the metal square bar 10a as shown in FIGS. The metal square bar 10a is a conductor that electrically and mechanically connects the metal belt 10 and the workpiece W, and the clamp unit 31 measures the current flowing through the metal square bar 10a, and hence the current flowing through the workpiece W.

  As shown in FIG. 3C, the clamp unit 31 moves in synchronization with the movement of the metal belt 10, and measures the current flowing through the metal square bar 10 a during that time. Before moving the mounting pitch (the above-mentioned pitch D) of the workpiece W, the clamp part 31 moves backward from the metal square bar 10a as shown in FIG. Returning to the state shown, current measurement is started for the next newly loaded workpiece W. Therefore, as shown by the arrow p in FIG. 3, the clamp unit 31 repeats the approach, movement, retreat, and return operations, and measures the current flowing through the newly loaded workpiece W.

  Based on the current measurement result sent from the sensor 3 described above, the control unit 4 determines the presence / absence of the workpiece, the contact failure determination, the count of the number of workpieces in the electrolytic cell, Current control is performed by controlling the current source 5.

  The above-described workpiece presence / absence determination and defect determination are performed by determining that the current value for the workpiece W newly entering the electrolytic cell 2 is out of the preset range. The state where there is no workpiece W is also included in the defect. In a state where there is no workpiece W, current flows only from a small area where the metal square bar 10a is immersed in the electrolyte 2a, so that the measured value is very low compared to other normal workpieces W. It is necessary to determine the range of the current value serving as the discrimination criterion based on the range of current variation allowed from the quality requirement.

  Further, the count of the number of workpieces W in the electrolytic cell 2 can be obtained based on the determination result, the effective length of the electrolytic cell 2, and the conveyance speed of the metal belt 10. The control unit 4 constantly calculates position information indicating in which location in the electrolytic cell 2 the defective workpiece W is moving. The control unit 4 refers to the position information of the defective workpiece W and obtains and stores the number of workpieces W in the electrolytic cell 2. The control unit 4 calculates an overall current I for electrolytic polishing in accordance with the number of workpieces W present in the electrolytic cell 2 and controls the current source 5 so that the overall current I flows.

  According to the electropolishing apparatus 1 of the present embodiment, the work W is detected by measuring the value of the current flowing through one work W as compared to the method of detecting the presence or absence of the work W using an infrared sensor or a proximity sensor. This method can also detect abnormalities related to electrical connection that cannot be determined by appearance, for example, poor electrical contact of the workpiece W in the clip 10b serving as a power feeding unit. Further, it is possible to control the current density with respect to the workpiece W other than the abnormal part to be a desired value based on the current measurement result.

  In addition, by arranging the sensor 3 made of an ammeter at the entrance portion, the work W detection function can be achieved with the minimum number of sensors. Normally, it is considered that the number of workpieces W does not fluctuate in the electrolytic cell 2, so that the detection of a missing workpiece W due to a failure of loading or the like at the entrance portion is performed early and another workpiece W already being processed in the electrolytic cell 2 Can be minimized.

(Third embodiment)
FIG. 5 shows a plan view of an electrolytic cell of an electropolishing apparatus according to a third embodiment and a block configuration of current control. The electropolishing apparatus 1 of the present embodiment is obtained by adding a sensor 3 to the outlet portion of the electrolytic cell 2 in the electropolishing apparatus 1 of the second embodiment. That is, in the electropolishing apparatus 1, the sensor 3 is arranged at two locations of the inlet portion and the outlet portion of the electrolytic cell 2 and measures the current flowing through the workpiece W that is input and discharged. The clamp part 31 at the outlet part performs the same operation as the clamp part 31 at the inlet part, measures the current flowing through the workpiece W being discharged, and the measurement result is transmitted to the control part 4.

  The control unit 4 detects whether the workpiece W is inserted or not based on the current measurement result of the sensor 3 at the entrance portion, and performs electropolishing so that the current value measured by the sensor 3 at the exit portion is a desired current value. Control the total current I.

  Each measured current value is input to the control unit 4. Based on the input information, the control unit 4 performs workpiece presence / absence discrimination, contact failure discrimination, electrolytic cell workpiece count, and current value calculation, and outputs a current command signal to the current source 5. The current source 5 performs constant current control so as to output the current value instructed by the control unit 4.

  According to the electropolishing apparatus 1 of the present embodiment, since the current can be measured by at least two sensors 3 that are separated from each other, the workpiece W is missing at one of the two sensors 3. However, the current flowing through the workpiece W at the other sensor position can usually be measured. Further, since the current value measured by the sensor 3 at the exit portion is used for control, the entire current can be controlled based on the current per work W, that is, the current density, and high quality processing can be realized.

  Ideally, it is desirable to feed back the current values for all the workpieces W. However, monitoring all is not practical, and it is the minimum necessary by monitoring the current value at one location of the exit portion. Effective control can be realized with a limited number of sensors. In other words, by using an ammeter provided at the exit portion to control the current value for the normal workpiece W at the exit portion to be optimal, accurate current density control with feedback of the state can be performed. it can. In this case, the control is more suited to the situation during processing than the control method of controlling the overall current for electrolytic polishing so that the current value obtained by multiplying the optimum current value per work by the number of works is obtained. Can do.

(Fourth embodiment)
6 and 7 show flowcharts of the electrolytic current control of the electropolishing apparatus according to the fourth embodiment. The electropolishing apparatus 1 of the present embodiment is a more detailed control of the current for electropolishing in the electropolishing apparatus 1 of the above-described third embodiment. That is, in the electrolytic polishing apparatus 1, the control unit 4 uses the sensor 3 at the outlet portion to measure when the work W that has been made defective based on the current measurement result of the sensor 3 at the inlet portion reaches the outlet portion of the electrolytic cell. The overall current for electrolytic polishing is controlled based on the number of workpieces in the electrolytic cell 2 without performing current control based on the current value.

  The above-described current control process will be described separately for the process at the inlet part of the electrolytic cell 2 and the process at the outlet part of the electrolytic cell 2. The control unit 4 controls each sensor 3, that is, an ammeter provided with the clamp unit 31, and at the entrance of the electrolytic cell 2, as shown in FIG. Current measurement is performed (# 1). Based on the current measurement result, the control unit 4 determines the quality of the newly inserted workpiece W (# 2), and calculates the number of non-defective workpieces in the electrolytic cell 2 based on the result (# 3). ).

  Thereafter, the control unit 4 determines whether or not the process is finished. If the process is not finished (No in # 4), the process is performed in step # 1 in order to perform the above process on the next newly introduced workpiece W. Return, and so on. When the process is finished (Yes in # 4), the process is finished.

  The processes in steps # 1 to # 4 described above are performed at a time interval based on the timing at which a new workpiece W is thrown into the electrolytic cell 2, that is, the moving speed of the metal belt 10 and the mounting pitch D of the workpiece W. Repeated at time ΔT).

  The control unit 4 stores the above-described determination result of the quality of the workpiece W, and grasps the number of the non-defective workpiece W and the position of the defective workpiece W in the electrolytic cell 2 at each time point during the electrolytic treatment. is doing. These pieces of information are referred to in the processing at the outlet portion of the electrolytic cell 2 described below.

  As shown in FIG. 7, in the process at the outlet portion of the electrolytic cell 2, a timer is set by the control unit 4 in the first step of the repeated process (S1). This timer is set to a time obtained by subtracting a predetermined time from the above-described time ΔT. The predetermined time includes a time required for the above-described clamp unit 31 to return.

  In the next step, the control unit 4 determines the quality of the workpiece W that is the object of current measurement at the outlet portion of the electrolytic cell 2 based on the information obtained in the processing of FIG. 6 described above (S2). ). In addition, the defective work is expressed including a case where the work is missing.

  When the target workpiece W is a non-defective workpiece W (Yes in S2), the control unit 4 measures the current flowing through the target workpiece W (S3) and outputs a new current command value for commanding the output to the current source 5. In is determined (S4).

  The current command value In is determined by In = Ic + k (id−ie). Here, Ic is the current current command value for the current source 5, k is a constant, id is the optimum current value for each work W, and ie is a measured value of the current flowing through the target work W by the ammeter at the exit portion. It is.

  As described above, the new current command value In is determined based on the current value ie (measured value) flowing through the non-defective workpiece W at the exit portion so as to feedback control the current flowing through the other workpiece W. Therefore, the constant k is a constant that determines the effectiveness of feedback, and is determined based on a general feedback method.

  Further, in the above-described step S2, when the target workpiece W is a defective product (No in S2), a new current command value In is determined based on the number n of non-defective workpieces W in the electrolytic cell 2. (S5). That is, it is determined by In = n × id using the above id.

  As described above, the new current command value In determined according to the quality of the workpiece W is given to the current source 5 by the control unit 4, and the current source 5 outputs the current In (overall current I) ( S6).

  Thereafter, when the timer has not expired (No in S7), the control unit 4 repeats the process from step S2 described above. When the workpiece W at the exit portion is a non-defective product, the measured value ie by the ammeter at the exit portion is the optimum current value id per workpiece by repeating the feedback control by the current command value In according to the mathematical expression in step S4 within a certain time. Converge to Further, when the current value cannot be referred to because the work W at the exit portion is defective, the current command value In in step S5 is used, so that the control unit 4 can perform current control by an optimum method in that scene.

  The time-out of the above-mentioned timer is interpreted as an instruction that the workpiece W that is currently subject to current measurement is discharged, and that the workpiece W to be discharged next should be the target of current measurement. The clamp unit 31 switches (changes) the measurement target to the next workpiece W.

  When the timer expires (Yes in S7), the control unit 4 determines whether or not the entire process is completed (S8). If it is determined in step S8 that the process is not terminated (No in S8), the control is repeated from step S1, and if the process is terminated in step S8 (Yes in S8), the process is terminated.

  According to the electropolishing apparatus 1 of the present embodiment, since the current value flowing through the workpiece W at the exit portion can be referred to and when it cannot be referred to, current control can be performed by an optimum method in that scene, and high quality can be achieved. Processing can be realized. The determination of good or bad at the entrance portion described with reference to FIG. 6 (# 2) is preferably performed as soon as possible after the workpiece W is input. However, according to the current control of this embodiment, the electrolytic cell As long as there is no defective workpiece W at the same time at the two inlet portions and the outlet portion, it may be performed during the time ΔT.

(Fifth embodiment)
In the electropolishing apparatus 1 according to the fifth embodiment, in the electropolishing apparatus according to the first to fourth embodiments described above, the control unit 4 monitors the voltage of the current source 5 through which the current for electropolishing flows. In addition, when a work W is newly put into the electrolytic cell 2 and the rate of change of the voltage exceeds a predetermined voltage range, it is considered that a throwing failure has occurred in the work W.

  According to the electropolishing apparatus 1 of the present embodiment, when constant current control is performed, the voltage value increases when the number of workpieces W in the electrolytic cell 2 is reduced or there is a defect in which no current flows. Since the increase in the voltage value is monitored based on the increase in the current density, an abnormal current supply to the workpiece W can be detected effectively, and high quality processing can be realized by reflecting the current density control.

  In this case, since the resistivity of the electrolytic solution 2a usually changes depending on the temperature of the solution and the concentration of metal ions in the solution, attention should be paid to the rate of change of the voltage value, not to determine whether the voltage value exceeds the threshold value. Thus, the function of detecting an abnormality in current supply can be performed reliably and effectively. According to this method, it is possible to determine a defect with a simple configuration.

  The present invention is not limited to the above-described configuration, and various modifications can be made. For example, the configurations of the above-described embodiments can be combined with each other within a consistent range, and such embodiments that can be combined are naturally included in the present invention even if they are not specified. Since electropolishing and electroplating are in a reverse process relationship, the present invention can be applied to an electroplating apparatus as well as an electropolishing apparatus.

  Moreover, in 3rd, 4th embodiment, although measuring the electric current which flows into the workpiece | work W in the exit part of the electrolytic cell 2 and making it the object of electric current control (making it the reference | standard of electric current control), this was described. In this case, the current measurement position at the outlet portion (more specifically, the range of movement) is at least inside the effective electrolysis length L of the electrolytic cell 2, downstream of the workpiece W at the inlet portion, and mounted on the workpiece. A position where a current can be effectively measured in the pitch D range is preferable.

  Further, in the fourth embodiment, as needed, for one work W to be noticed at the exit portion, the noticed work W is used as a reference for current control for a distance of approximately twice the pitch D. May be. This can be dealt with by increasing the moving distance of the clamp part 31. By adopting such a configuration, when the workpiece W at the outlet portion is defective, instead of current control based on the number of workpieces W in the electrolytic cell 2, the overall current is based on the current value flowing through the normal workpiece W. Can be controlled more appropriately.

(A) is a whole block diagram of the electropolishing apparatus which concerns on the 1st Embodiment of this invention, (b) is a series of process drawing of electropolishing. FIG. 5 is a plan view of a current control block configuration and an electrolytic cell of an electropolishing apparatus according to a second embodiment. (A)-(d) is a top view of the entrance part of the electrolytic cell explaining the electric current measurement of the workpiece | work in an electropolishing apparatus same as the above. The perspective view explaining operation | movement of the sensor for current measurement same as the above. FIG. 9 is a plan view of a current control block configuration and an electrolytic cell of an electropolishing apparatus according to a third embodiment. The flowchart of the process in the electrolytic vessel inlet part of the electropolishing apparatus which concerns on 4th Embodiment. The flowchart of the process and electric current control in the electrolytic vessel exit part of an electropolishing apparatus same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electropolishing apparatus 2 Electrolytic tank 2a Electrolytic solution 3 Sensor 4 Control part 5 Current source I Overall current W Workpiece

Claims (6)

In an electropolishing apparatus for electropolishing the workpiece by continuously passing a plurality of individual workpieces through an electrolytic solution filled in an electrolytic cell,
A sensor for detecting a workpiece placed in the electrolytic cell;
A controller that controls the current for electropolishing according to the number of workpieces based on the detection result by the sensor,
The said control part controls the whole electric current for electropolishing so that it may become the electric current value obtained by multiplying the optimal electric current value per work | work, and the number of workpieces.   The electropolishing apparatus according to claim 1, wherein the sensor detects a work by measuring a current for electropolishing flowing through one work.   The electropolishing apparatus according to claim 2, wherein the sensor is disposed at an inlet portion of the electrolytic cell and measures an electric current for electropolishing flowing through a workpiece newly input into the electrolytic cell. The sensor is arranged at two locations of the inlet portion and the outlet portion of the electrolytic cell, and measures the current flowing through the workpiece to be charged and discharged,
The control unit detects the quality of the workpiece input based on the current measurement result of the sensor at the inlet portion, and is used for electrolytic polishing so that the current value measured by the sensor at the outlet portion is a desired current value. The electropolishing apparatus according to claim 2, wherein the entire current is controlled.   The control unit performs current control based on a current value measured by the sensor of the outlet portion when a work that has been poorly charged based on the current measurement result of the sensor of the inlet portion reaches the outlet portion of the electrolytic cell. 5. The electropolishing apparatus according to claim 4, wherein the entire current for electropolishing is controlled based on the number of workpieces in the electrolyzer without performing.   The control unit monitors the voltage of a current source that supplies a current for electropolishing, and when the rate of change of the voltage exceeds a predetermined voltage range when a new work is put into the electrolytic cell, The electropolishing apparatus according to claim 1, wherein the work is considered to have failed to be charged.

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