JPH02198716A - Electrolytic finishing method - Google Patents

Abstract

PURPOSE:To improve a contact detection accuracy by a contact detector and to correctly measure a working amount by measuring an actual working amount after removing an oxide film, etc., formed on the work face of a work by the finishing work under first conditions. CONSTITUTION:When an oxide film or the like of the work face 4a of a work 4 is removed by finishing work, the working amt. of the work 4 is measured and accumulated working amount is calculated. Then, in the case that this accumulated working amount does not a specific valued against a designated work amount the next number of working times is calculated based on the working amount and the number of working times. This succeeding working times are set as the number of working times of the next finishing work and the next finishing work is performed by the specified peak current density and the working pulse for improving the surface roughness of the pulse width. Thus, an actual working amount is measured after removing the oxide film, etc., formed on the work face 4a of the work 4, so the contact detection accuracy is improved and the working amount can be correctly be measured.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electrolytic finishing method, and in particular improves contact detection accuracy and accurately measures the processing amount of a workpiece.
This invention relates to an electrolytic finishing method that provides high processing accuracy.

[Prior art] Conventionally, a workpiece that has been subjected to electric discharge machining and an electrode having an electrode surface that follows the machined surface of the workpiece are placed facing each other with a predetermined gap in a stationary electrolytic solution, and a single electrode is placed between the electrodes. In addition to supplying machining pulses, electrolyte is intermittently jetted into the gap.
An example of an electrolytic finishing method for finishing a workpiece while eliminating machining debris in the gap is disclosed in Japanese Patent Application Laid-Open No. 63-11.
The one disclosed in Japanese Patent No. 4815 is known.

[Problems to be Solved by the Invention] However, this electrolytic finishing method has the disadvantage that it is difficult to accurately control the amount of workpiece processed, and high processing accuracy cannot be obtained.

In other words, in this electrolytic finishing machining method, in order to confirm the roughness of the electrical discharge machined surface of the workpiece during finishing machining, and to obtain the required surface roughness, a monograph obtained through experiment (trial machining) is used. Enter the target machining amount from . In addition, a calculation formula is determined from the electrochemical equivalent of each material and experimental processing efficiency data, and using this calculation formula, the amount of coulombs per unit area corresponding to the amount of manual processing is calculated,
The number of processing times is set based on this coulomb amount.

Normally, if machining is performed under the same conditions as in the experiment, the machining accuracy (dimensional accuracy) will be within about ±5% for any amount of machining. However, it is difficult to perform actual processing under the same conditions as in the experiment due to changes in the electrolyte concentration, temperature, paper, etc. Furthermore, the surface shape of the workpiece is complex, and it is difficult to calculate its accurate surface area, and errors in the input surface area disturb the amount of coulombs per unit area, which adversely affects machining accuracy. Furthermore, it is difficult to perform flushing operations to remove the electrolyte in the gaps at the same level as in experiments, and for workpieces with complex shapes, it is difficult to reliably remove the electrolyte over the entire surface, resulting in poor machining efficiency. The current situation is that the actual machining amount is less than the amount of manual machining, and high machining accuracy cannot be achieved, such as the target dimensional accuracy not being achieved.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages, particularly to improve the accuracy of contact detection, to accurately measure the processing amount of a workpiece, and to realize an electrolytic finishing method that can obtain high processing accuracy.

[Means for Solving the Problem] In order to achieve this object, the first invention of this application includes a workpiece machined into a predetermined shape, and an electrode having an electrode surface patterned after the machined surface of the workpiece. The workpiece is placed facing each other at a predetermined gap in an electrolytic solution, and a machining pulse is supplied between the poles, and a jet of the electrolytic solution is supplied to the gap to remove machining debris while finish machining the workpiece. a step of setting a target machining amount of the workpiece, at least a first condition for obtaining a glossy surface on the machined surface of the workpiece, and a first condition for improving the surface roughness of the machined surface, which is different from the first condition. a step of setting conditions for the machining pulse, a step of measuring the amount of machining of the workpiece after finishing machining according to the first condition, and a step of determining the machining amount of the workpiece based on the measured amount of machining. The present invention is characterized by comprising a step of changing the number of times of machining under the second condition.

A second aspect of the present invention is the first aspect of the present invention, further comprising the step of centering the electrode and the workpiece after measuring the machining amount of the workpiece and before finishing machining under the second condition. A third aspect of the present invention is characterized in that, in the first or second aspect, the method further comprises a step of setting a maximum number of finishing operations according to the second condition.

[Operation] According to the configuration of the first invention of this application, the target processing amount is comprised of the first condition that a glossy surface is obtained on the machined surface of the workpiece, and the second condition that the surface roughness is improved. The machining pulse conditions were set, and the oxide film, machining debris, etc. generated and attached to the machined surface of the workpiece under the second condition were removed by finishing machining under the first condition, and the machined surface was left in a clean state. At the top, the electrode and the workpiece are brought into contact and the actual machining amount of the workpiece is measured. This improves contact detection accuracy and enables accurate measurement of processing amount. Then, from this measured amount of machining and the number of times of machining under the first condition to obtain this amount of machining, the number of times of machining under the next second condition is calculated, the setting is changed, and finishing machining is performed under the condition. This is repeated until the measured machining amount becomes a predetermined difference from the set machining amount, and finishing machining is completed.

Further, according to the configuration of the second invention, for example, the amount of machining is measured by moving the electrode, and after this measurement, the electrode and the workpiece are centered, and finishing machining is performed under the second condition. The electrode gap can be maintained constant over the entire machining surface, and the amount of machining can be made uniform. Furthermore, according to the configuration of the third invention, the maximum number of finishing operations based on the second condition for improving the surface roughness is set, and the finishing operation based on the first condition is performed every time the maximum number of operations is performed.
The formation of an oxide film and the processing debris in the electrode gap can be suppressed to a certain amount or less, and the processing efficiency of finishing processing can be improved.

[Example] Hereinafter, examples of the first to third inventions of this application will be described in detail and specifically with reference to the drawings.

In FIG. 1, an electrolytic finishing device 1 capable of implementing each invention of this application includes an electrode fixing device 3 for fixing an electrode 2;
A workpiece fixing device 5 that fixes the workpiece 4 and a servo motor 6
A drive conversion section 7 that converts rotational motion into reciprocating motion, a power supply device 8 that generates processing pulses, a control device 12 that includes a head drive control section 9, a processing condition control section 10, an electrolyte flow control section 11, etc., and various data. It consists of an input device 13 for inputting information, an electrolyte filtering device 14 for filtering the electrolyte, a processing tank 15, and the like.

The electrode fixing device 3 has an electrode 2 made of, for example, pure copper or graphite attached to the lower end of a rod 16 provided at the bottom thereof, and a gap 17 such that the electrode surface 2a and the processed surface 4a of the workpiece 4 are spaced in a three-dimensional direction. Fix it to keep it. This electrode fixing device 3 is moved up and down by the rotation of a servo motor 6 based on a control signal from the head drive control section 9, and the electrode surface 2a
and the processed surface 4a are set at a predetermined gap 17. Further, the workpiece fixing device 5 is a table made of highly insulating granite or ceramics, and a workpiece 4 subjected to die engraving electric discharge machining, for example, is fixed to the upper surface of the table using a setting jig or the like (not shown). Note that in FIG. 1, reference numeral 18 is a jet nozzle for jetting clean electrolyte into the gap 17.

The input device 13 improves the first condition for obtaining a glossy surface and the surface roughness of the material and machining area of the workpiece 4, the target machining amount D (hereinafter referred to as the designated machining amount), and machining pulses to be described later. The second conditions for this, the initial electrode gap δ, etc. are input, and these signals are output to the head drive control section 9 and processing condition control section 10 of the control device 12.

Further, the electrolyte filtration device 14 filters an electrolyte containing electrolytic products generated during machining, and based on a control signal from the electrolyte flow control section 11, the electrolyte filtration device 14 filters the electrolytic solution in the machining tank at the start of machining.
In order to supply the electrolytic solution to the electrode 5 and remove machining debris generated in the gap 17 between the electrode 2 and the workpiece 4 during machining, the gap 17 is A clean electrolyte is then jetted out through the jetting nozzle 18.

A power supply device 8 that supplies machining pulses under predetermined conditions between the electrode 2 and the workpiece 4, and the machining condition control unit 10 that controls the power supply device 8 are configured as shown in FIG. 2, for example. .

That is, the power supply device 8 includes a DC power supply section 19 and a charging/discharging section 20, and the DC power supply section 19 includes a transformer 21 and a rectifier 22.
A transformer 21 lowers the voltage to a predetermined value, a rectifier 22 rectifies the DC current, and supplies the direct current to capacitors 23-1 to 23-n, which will be described later.

The charging/discharging unit 20 also includes a plurality of capacitors 23-1 to 23-n that discharge charges between electrodes, and each of these capacitors 23-
Diodes 24-1 to 24-n connected to diodes 1 to 23-n to prevent backflow of charges to the DC power supply section 19 side, and a discharge switch 25-1 that is opened and closed to discharge charges to the discharge side.
25-n, a charging switch 26, etc., for supplying and disconnecting power from the DC power supply section 19 in order to charge each of the capacitors 23-1 to 23-n to a predetermined value.

The processing condition control unit 10 controls the capacitors 23-1 to 23-n.
a voltage detector 27 that detects the charging voltage value of the voltage detector 27; a voltage comparator 29 that compares the charging voltage value detected by the voltage detector 27 with the output value from the D/A converter 28; According to the output signal from the capacitors 23-1 to 23
A charge detector 30 detects the completion and start of charging of -n, a current detector 31 detects the current value of the charge discharged between the electrodes, and a peak value of the current value detected by this current detector 31. A peak hold circuit 32 that holds the peak value, a current comparator 34 that compares the peak value held by the peak hold circuit 32 with the output value of the D/A converter 33, and a pulse generator 37 that generates a pulse with a predetermined time width. Each of the discharge switches 25-1 to 25 is controlled by an input signal from a current waveform setting device 38 that sets the current waveform of the charge discharged between the electrodes.
-n, a gate circuit 35 that outputs an opening/closing drive signal, and a charging voltage setting device that sets a charging voltage value to be supplied to each of the capacitors 23-1 to 23-n and outputs the signal to the D/A converter 28. 36, a current setting device 39 that sets the current value flowing between the electrodes and outputs the signal to the D/A converter 33;
Processing conditions etc. are calculated based on the human power signals from each of the circuits mentioned above.
It consists of a CPU 40 for processing, a contact detector 41 for detecting contact between the electrode 2 and the workpiece 4, and the like. Note that the reference numeral 42 in the figure is a diode that prevents each of the discharge switches 25-1 to 25-n from being destroyed by back electromotive force.

As shown in FIG. 3, the contact detector 41 includes a reference power source 43 that supplies a reference voltage lower than the decomposition voltage between electrodes, a resistor 44 for current detection, and resistors 45 and 46 at both ends of this resistor 440. an amplifier 47 connecting its input side via
and a comparator 49 that compares the output signal of this amplifier 47 with a signal set by a variable resistor 48. Reference numeral 50 in FIG. 3 is a resistor for current detection of the current detector 31. Note that the decomposition voltage is the voltage at which the electrode reaction of the electric double layer consisting of the workpiece 4, electrolytic solution, and electrode 2 starts.

This contact detector 41 detects a current between the electrodes based on a reference voltage supplied from a reference power source 43, compares this current between the electrodes with a reference current set by the variable resistor 48, and determines that the current between the electrodes is the reference current. When the contact detection signal becomes larger than the current, a contact detection signal is output to the CPU 40.

Next, the first invention of this application will be explained based on the flowcharts of FIGS. 4 to 6.

During finishing, the electrode 2 used, for example, when performing die-sinking electric discharge machining on the workpiece 4 is fixed to the lower end of the rod 16 of the electrode fixing device 3, and the workpieces 4 are each fixed to the workpiece fixing device 5 (60) L. /, electrode 2 and work 4
After centering, the following data and the like are input using the input device 13 (61).

D: Specified machining amount δ: Initial electrode gap ipl: Peak current density tl of the first condition of the machining pulse:〃 Pulse width (pulse on time) n:〃 Number of machining i 92: Under the second condition of the machining pulse Peak current density t2: 〃 Pulse width N,:
〃 Initial processing number Then, when an electrolytic solution such as sodium nitrate is supplied to the processing tank 15 and automatic operation of finishing processing is started (62),
The CPU 40 supplies machining pulses according to the first condition from the power supply 8 and performs finishing machining 1 (63).

This finishing process 1 (63) is performed by setting the electrode 2 at a position that maintains the initial electrode gap δ (63-1), as shown in FIG.
) L/, a single machining pulse with a peak current density of ipl and a pulse width of t is supplied between the electrodes (63-2). When this machining pulse is turned off, the electrode 2 is raised (63-3), and the electrolytic solution is ejected from the jet nozzle 18 into the gap 17 (63-4), thereby producing an electrolytic product generated by supplying the machining pulse. The processing waste consisting of the like is removed from the gap 17, and the electrode 2 is lowered (63-5) and reset to the position set in the step (63-1). Then, the counter a (not shown) of the CPU 40 is cleared (63
-6) t, , the count number Ca of the counter a is +
1 (63-7), and also determines whether this count number Ca is a predetermined number, that is, the number of machining times n input and set in the step (61) (63-8) L/, and this determination (63-8). If NO in 8), step (63-2)
Steps (63-2) to (63-7) are repeated until the determination (63-8) becomes YES.

The machining pulses in this finishing machining 1 are used to remove the oxide film, etc. generated and attached to the machining surface 4a of the workpiece 4 by supplying machining pulses for improving surface roughness, which will be described later.The conditions are as follows: Current density jf)t is 30 to 5
The pulse width t1 is set to 0 A/cm2, the pulse width t1 is set to 20 m5ec or more, and the number of processing times n is set to 3 to 10.

By finishing machining 1 (63), the machined surface 4a of the workpiece 4
After removing the oxide film, etc., it is determined whether finishing processing 1 is the first processing (64) L/, and if it is the first processing, this judgment (64) becomes YES, and the process proceeds to step (70) described later. . Further, if finishing machining 1 is performed twice or more, the determination (64) becomes NO, and the machining amount Δdi of the workpiece 4 is measured (65). This step (65
) will be explained in detail based on FIG. First, in order to measure the machining amount Δd2 in the X-axis direction (65-1), CP
Clear counter b (not shown) of U40 (65-1a)
L/t, the count number cb of the counter b is +1 (6
5-1b) Lower the electrode 2 by a predetermined distance t, for example, 1 μm (65-1c). And the contact detector 41
Determine whether there is a contact detection signal from (65-1d) l,
,, If this judgment (65-1d) is No, return to step (65-1b), and repeat steps (65-1b) to (65-1c) until the judgment (65-1d) becomes YES.
repeat. If the judgment (65-1d) is YES, the movement amount Lz of the electrode 2 is calculated by the following formula (1) (65-1d).
1e) Written in CPU 40 Lz=CbXt
``Φ (1) However, cb is the count number of counter b.

In addition, this movement amount Lz is, for example, the step (63-
The lowest end of the electrode 2 on the Z axis set in 1) is memorized as the reference point A1, that is, the origin (0, 0, 0) of the X-Y-Z axis, and this reference point is used when the electrode 2 contacts the workpiece 4. It is calculated based on the Z-axis coordinates of point A.

Once the movement amount Lz is calculated, the machining amount Δdz in the X-axis direction is calculated based on this value using the following formula (2) (65-
If).

Δdz= (CbXt)−δ −−−(2) However, δ
is the initial electrode gap input and set using the input device 13.

When the processing amount Δdz is calculated, the electrode 2 is moved by the moving amount Lz (
Cb

Step (65-2) is the step (65-1a)
~ Step (65-2a) similar to (65-If) ~
(65-2f), first calculate the machining amount Δ dz (+) in the plus (+) direction of the X axis, then (+) and (-)
NO when determining whether measurements were taken in both directions (65-2g)
Then, step (65-2a) ~ (65-2f
), the machining amount Δdxc-) in the (-) direction of the X-axis is calculated. Then, the machining amount Δdx(+) and Δd in both directions
Once x(-) is calculated, the machining amount Δdx in the X-axis direction is calculated using the following equation (3) (65-2h).

Δdx=(Δdx(+)+Δdx())/2...(3
) After calculating the machining amount Δdx, move the electrode 2 by the moving amount Lx(-
) in the (+) direction and set it to the initial position (65-
2i) A series of steps (65-2) for measuring the machining amount Δdx in the L/X-axis directions is completed.

By this step (65-2'), the machining amount Δ in the X-axis direction is
After calculating dx, the machining amount Δacty in the Y-axis direction is measured (65-3) using the same method as this step (65-2) (the explanation thereof will be omitted). Then, based on the machining amount Δd Z %Δdx and Δdy of each axis, the machining amount Δdi is calculated using the following equation (4) (85-4).

Δdj=(Δd2+Δdx+Δdy)/3”・(
4) The above is the step (65) of calculating the processing amount Δdi.

When the machining amount Δdi is calculated in this step (65), the cumulative machining amount d is calculated based on this machining amount Δdi (66), and this cumulative machining amount d is input and set in the step (61). Determine whether or not the specified machining scale is within a predetermined value r (67) L/; if this determination (67) is No, that is, if the cumulative machining amount d has not reached Dtr, step (65) Based on the calculated processing amount Δdi and the number of processing times Ni, the number of processing times N1+1 is calculated using the following equation (5) (68).

N ill = αX (Ni/Δdi) ... (5
) This equation (5), for example, i=1, as shown in FIG.
In this case, a predetermined processing amount α (for example, α=
10 μm) is calculated, which is the second processing number N2 which is N ill.

Note that the dotted line A in FIG. 7 is a calculated machining straight line obtained in advance through experiments, etc., the dotted line A is a machining straight line based on the first N1 machining operations, and the solid line is an actual machining line.

Once the number of machining operations N i+1 is calculated, this N i+1 is set as the number of operations for the next step, finishing machining 2 (70) (69) L/, surface roughness improvement with a peak current density of ip2 and a pulse width of t2. Finishing machining 2 is performed N i +1 times using the machining pulses (70). This finishing process 2
Although the conditions of the machining pulse supplied between the poles are different,
Since the operation is exactly the same as the finishing process 1 (63), the explanation thereof will be omitted.

In addition, the machining pulse in this finishing machining 2 is, for example, jp2 is 30 to 50 A/cm2, t2 is 10 m5ec or less, and toff2 (pulse rest time) is 100 to 500 A/cm2.
A pulse train consisting of 5 consecutive m5ec single pulses is used, but of course the same single pulse as in finishing process 1 can also be used.

When finishing machining 2 has been performed a predetermined number of times Ni+1, the process returns to step (63) and finishing machining 1 is performed. Then, each step is repeated, and if the cumulative machining fld is within the predetermined value r for the specified machining scale in the judgment (67), the judgment (67) is made.
67) becomes YES, and the finishing process ends (71).

As described above, in this embodiment, after removing the oxide film etc. generated on the machined surface 4a of the workpiece 4 in the finishing process 1, the contact detector 41 measures the actual process amount Δdi. Improved contact detection accuracy and reduced machining amount Δd
i can be measured accurately. In addition, since the number of machining steps Ni for finishing machining 2 for improving surface roughness is calculated and changed based on the measured actual machining amount Δdi, finishing machining can be performed while controlling the machining amount. The amount can be brought close to the designated machining scale, and the dimensional accuracy of the workpiece 4 can be improved. Furthermore, the number of processing N for finishing processing 2
i is automatically calculated and set, and the finishing machining time can be shortened.

FIG. 8 is a flowchart showing an embodiment of the second invention of this application, and the feature of this embodiment is that the processing amount Δdi is measured (65) L/, and the cumulative processing amount d is calculated based on this (66 ) The point is that the electrode 2 and the workpiece 4 are aligned (72) after the electrode 2 and the workpiece 4 are removed.

Since the other steps are the same as those in FIG. 4, they are given the same reference numerals and detailed explanation thereof will be omitted.

In the centering step (72), the electrode 2 is moved in the Z, x, and Y axis directions when measuring the machining amount Δdi, so the electrode 2 is set at a predetermined position again before finishing machining 2. For example, it is performed as shown in FIG.

That is, first, the step (6) of measuring the processing amount Δdi is performed.
From the movement amounts Lx(+) and Lx(-) calculated in step 5) (65-2e...see Figure 6), the average movement amount Lx in the X-axis direction is calculated using the following formula (6). Calculation (72
-1) Do.

Lx=(Lx(÷)+Lx(-))/2...
・(6) Then, move the electrode 2 (72-2) so that the reference point A of the electrode 2 is located at the coordinate corresponding to this average movement amount LX, and also move the Y-axis direction as well as the X-axis direction. In exactly the same way, the average movement f! Calculate kLy (72-
3) L/, move the electrode 2 (72-4). Thereafter, the electrode 2 is lowered (72-5) and comes into contact with the workpiece 4 (72-5).
72-6), and from that position repeat step -(65-
1e...see FIG. 6) is increased (72-7) by the amount of movement Lz calculated.

Note that the method for centering the electrode 2 and the workpiece 4 may be such that steps (72-1) to (72-7') of the above embodiment are repeated a predetermined number of times, and after measuring the processing amount Δdi, The electrode 2 may be moved again in the (+) and (-) directions of the X and Y axes, respectively, to detect contact, and set at a position corresponding to the amount of movement 172. Furthermore, the direction of centering is also x, y, z.
The present invention is not limited to the three axes, and may be modified as appropriate, such as only in the X and Y axes, or adding the C-axis (rotation direction of the z-axis) to the three directions.

In this embodiment, after measuring the machining amount and before finishing machining 2, the moved electrode 2 and workpiece 4 are
For example, in order to perform centering with
Even if there is a difference in the machining amount in the ) and (-) directions, the electrode 2
Finishing machining 2 can be performed by correcting the position of the machining surface 4a, the electrode gap can be maintained constant over the entire machining surface 4a, and the amount of machining can be made uniform. It is effective when applied to three-dimensional shaped objects.

FIG. 10 is a flowchart showing an embodiment of the third invention of this application, and the feature of this embodiment is that in the finishing machining 2 of the first invention or the second invention, the number of times Ni
The point is that this is not done more than a predetermined number of times. This example will be explained below, but in this example, finishing machining 1 (83, 85) and finishing machining 2 (84, 93)
, Measurement of machining amount Δdi (88) and calculation of cumulative machining amount d (89), Comparison of cumulative machining amount d and specified machining amount (90)
), etc. are the same as in each of the above embodiments, so detailed explanation thereof will be omitted.

First, after the electrode 2 and the workpiece 40 are set (80), the data is manually input (81). input. This number of times Nr is the number of repetitions of finishing machining 1 (85) and finishing machining 2 (93), which will be described later. When the data is input and set in the CPU 40, automatic finishing operation is started (82), and finishing machining 1 (83) and finishing machining 2 (84) are performed as the first finishing machining. Then, finishing machining 1 is performed again (85), the number of times Nr is subtracted by 1 to obtain the number of times nr (86), and it is determined whether this number of times nr is smaller than O (87).

Since Nr is set to O at the start of machining, the judgment (87) is YES when nr=-1, and the machining amount Δdi is measured (87).
8) Calculation of L/, cumulative machining amount d (89), and determination of whether cumulative machining amount d is within a predetermined value r for the designated machining scale (
90). Then, the number of machining Ni+1 and the number of repetitions Nr of finishing machining 2 are calculated using the following equation (7), and the remainder number N i+1'' of the number of processing N i+1 is determined from this equation (7) (91).

Ni+1/β=N r (Ni+1')...
(7) However, N i+1 is the number of times of machining calculated by the above formula (5), β is the maximum number of times of finishing machining 2, and Nr is the number of repetitions.

When the number of times of each machining is calculated in step (91), this number of times is set (92) L/, and finishing machining 2 is performed based on this.
(93) and returns to step (85).

If the judgment (87) is No, that is, step (91)
), if the number of repetitions Nr calculated by
If No in 4), proceed to step (93), and if YES, set the number of machining β of finishing machining 2 to Ni+
Change the setting to 1' (95).

Here, the above steps will be explained based on a specific numerical example. For example, if β=50 is input and set in step (81) and the number of machining times N i+1 calculated in step (92) is 120, then Nr=2 and Ni+1=
20 is calculated. Then, after performing finishing machining 2 β (=50) times in step (93), step (85)
Returns to step (86) and enters the subsequent steps, but nr in step (86) is 1 as nr=2-1, and judgment (87) is No.
Then, the process moves to judgment (94).

Since nr is 1, this judgment (94) is NO,
The process moves to step (93) and finishing machining 2 is performed again β times.

Then, the process moves to step (86) again, but here nr
becomes 0, and the judgment (87) is NO1.The judgment (94) is YE.
S, and the process moves to step (95). This step (9
In 5), the number of machining β of finishing machining 2 in step (93) is changed to N i+1 ′, that is, the number of machining N i+1 ′ that is the remainder calculated in step (91),
Finishing process 2 is performed N i+1 ' times. As a result of the above, the number of processing times for finishing processing 2 in step (93) is β
+β+(N i+1'), and the machining is performed 120 times, which is the number of machining times N i+1 calculated in step (92). After this, the judgment (87) becomes YES, and the machining amount Δdi is measured by the number of machining operations (88).
)do.

Note that the maximum number of machining β for finishing machining 2 is the same as that of finishing machining 1.
25 to 6 from the effect of removing oxide film and processing waste
It has been confirmed through experiments that it is more preferable to set it to 0 times.

As described above, in this embodiment, if the calculated number of finishing operations 2 (Ni+1) is equal to or greater than the set maximum number of operations β, finishing operations 2 will not be performed consecutively more than β times, but will be repeated β times. Since finishing machining 1 is performed once after finishing machining, the formation of an oxide film on the machined surface 4a of the workpiece 4 due to finishing machining 2 and the machining debris in the machining gap can be suppressed to a certain amount or less, and the machining debris in the gap can be suppressed. Deterioration in machining accuracy and machining efficiency due to large amounts of interference can be prevented.

In addition, in each of the above examples, the timing of measuring the processing amount is
The measurement was performed based on the number of machining operations that resulted in a predetermined machining amount α, and the measurements were also performed in three directions: the Z-axis, the X-axis, and the Y-axis directions. However, the present invention is not limited to this in any way; From the amount and the number of machining operations, the number of machining steps N that will yield the target machining amount may be determined, and the amount of machining may be measured at every predetermined ratio of the number of machining steps N. Alternatively, the measurement direction may be set only in the Z-axis direction. Good too.

Furthermore, in each of the above embodiments, the electrode was moved when measuring the amount of processing, but the workpiece may also be moved.
Further, the flowcharts in each of the above embodiments are merely examples, and it goes without saying that the flowcharts can be combined or otherwise modified as appropriate without departing from the gist of each invention of this application.

[Effects of the Invention] Each of the inventions of this application is configured as described above, so that the following effects are achieved.

(First invention) ■ The actual amount of machining is measured after removing the oxide film etc. generated on the machined surface of the workpiece due to finishing machining under the first condition, so the accuracy of contact detection by the contact detector is improved. The amount of processing can be measured accurately.

■ Based on the measured actual amount of machining, the number of times of finishing machining under the second condition for improving surface roughness is changed, so finishing can be performed while controlling the amount of machining, and the target amount of machining can be achieved. High machining accuracy can be obtained, such as by making it possible to approach the amount of machining required, improving dimensional accuracy, etc.

- Since the number of finishing operations under the second condition is automatically calculated and set, the finishing processing time can be shortened.

(Second invention) In order to center the electrode and the workpiece after measuring the machining amount and before finish machining under the second condition, the electrode gap is maintained constant over the entire machining surface of the workpiece. This makes it possible to make the amount of processing uniform, and in particular, to obtain high processing accuracy even for three-dimensional shaped workpieces.

(Third invention) If the number of finishing operations under the second condition is equal to or greater than the set maximum number of operations, the finishing operation under the first condition is performed once after the maximum number of operations has elapsed. It is possible to suppress the formation of oxide film and the amount of machining debris in the machining gap below a certain amount, improving machining accuracy and machining efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an electrolytic finishing apparatus according to the present invention, FIG. 2 is a block diagram of the main parts, FIG. 3 is a circuit diagram of the contact detector, and FIG. Flowchart showing an embodiment, FIGS. 5 and 6 are flowcharts of the same essential parts, FIG. 7 is a diagram showing the relationship between the number of processing times and the amount of processing, and FIG. 8 is a flowchart showing an embodiment of the second invention. FIG. 9 is a flowchart of the main part, and FIG. 1O is a flowchart showing an embodiment of the third invention. 1... Electrolytic finishing processing device, 2... Electrode, 2a...
・Electrode surface, 4... Workpiece, 4 &... Machining surface, 8... Electric R device, 9... Head drive control section, 10... Machining condition control section 11... Electrolyte flow control Part, 12...control device, 18 fist...spray nozzle, 40◆◆◆CPU, 41...contact detector. Patent applicant Shizuoka Seiki Co., Ltd. Representative Shigeo Suzuki Figure 1 Figure 3 Figure 7 Figure 4 Figure 5 Ca: Count number of counter a Figure 8 Figure 9

Claims (3)

[Claims] (1) A. A workpiece machined into a predetermined shape and an electrode having an electrode surface that follows the machined surface of the workpiece are placed facing each other with a predetermined gap in an electrolytic solution, and a processing pulse is supplied between the electrodes. At the same time, the workpiece is finished machined while supplying a jet of electrolyte to the gap to remove machining debris, b) setting a target machining amount of the workpiece, and c) at least the steps of the above-mentioned. Setting conditions for the machining pulse, which are comprised of a first condition for obtaining a glossy surface on the machined surface of the workpiece, and a second condition for improving the surface roughness of the machined surface, which is different from the first condition. D. Measuring the amount of machining of the workpiece after the finishing machining under the first condition; E. Changing the number of times of machining under the second condition based on the measured amount of machining. An electrolytic finishing method comprising: (2) The electrolytic finishing method according to claim 1, further comprising the step of centering the electrode and the work after measuring the amount of work on the work and before finishing under the second condition. Electrolytic finishing method. (3) The electrolytic finishing method according to claim 1 or 2, further comprising the step of setting a maximum number of finishing operations under the second condition.