JPH02172627A - Electrolytic working method - Google Patents

Abstract

PURPOSE:To flow the current in the regulated current density between a work and an electrode irrespective of the working face shape of the work, to omit the area calculation of the work working face and to reduce the man/hour, by impressing a voltage so that the potential difference between the work and electrode becomes at a reference voltage value. CONSTITUTION:The resistance rate P of a work liquid 7, an interpolarity distance land the current density (d) necessary for working of a work 3 are input to a calculation part 20 from a keyboard 10. A reference voltage value V0 is set by calculating based on these input values. A movable terminal position designating signal (a) is output from a generator 21 according to the calculation of this reference voltage value V0. This signal (a) is input to a motor 13, the axial part 12 thereof is rotated, a movable piece 14 is displaced and a movable terminal 15 is set at the position corresponding to the content of the signal (a). A switch 8 is turned ON in this state, the voltage V1 of a DC power source 9 is divided by a partial pressure resistance 17 and the electrolytic voltage V2 equivalent to the reference voltage value V0 is impressed between the work 3 and electrode 6. Thus the current of a constant current density (d) can be flowed between the both 3, 6, irrespective of the working face shape of the work 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrolytic processing method performed using an electrolytic processing apparatus.

(Prior Art) Generally, in electrolytic machining, the current density of the current supplied between the workpiece and the electrode has a large effect on machining accuracy. Conventionally, the current density necessary for machining the workpiece is set, the surface area (machining area) of the machining shape surface of the workpiece is calculated, and the current value to be supplied is calculated by multiplying the current density and the machining area. For example, as disclosed in Japanese Patent Application No. 62-181405 by the inventors of the present invention, electrolytic machining has been carried out by applying the current calculated in this manner to the workpiece/electrode for the workpiece machining time.

By the way, the shape of the machined surface of a workpiece is generally complex, and it is not easy to accurately calculate its area.

In this case, an approximate value was usually used as the processing area.

(Problem to be Solved by the Invention) However, in the conventional electrolytic processing method as described above, rough processing area data is used to determine the current to be supplied. Even if a certain current is supplied, the current density will not reach the desired value, and as a result, there is a risk that the workpiece processing accuracy will be reduced.

In addition, the area of the machined surface of such a complex shape can be expressed as three-dimensional C.
It is conceivable to calculate using an AD method to obtain an accurate value, but this would require large-scale equipment and increase the number of man-hours required for this calculation, so it could not be an appropriate solution.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an electrolytic machining method that can process a workpiece with high precision without substantially increasing the number of man-hours.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a distance between a workpiece and an electrode that is immersed in a machining fluid filled in a machining fluid tank of an electrolytic machining device, and a distance between the machining fluid and the machining fluid. and the resistivity of the workpiece.
A reference voltage value is set in advance based on the current density applied to the electrode, and the electrode and a workpiece with an arbitrary machined surface shape are immersed in the machining liquid filled in the machining liquid tank with the distance between the electrodes. The method is characterized in that a voltage is applied so that the potential difference between the workpiece and the electrode becomes the reference voltage value.

(Function) According to the present invention, during electrolytic machining, the resistivity and the distance between the electrodes are kept constant, and a voltage equivalent to the reference voltage value is applied between the workpiece and the electrode. Regardless of the shape of the machined surface of the workpiece, current density = applied voltage / (
As is clear from the resistivity (x distance between electrodes), a current with a specified current density flows. As a result, a product with high processing accuracy can be obtained without calculating the area of the processing surface.

(Example) An electrolytic processing method according to a first example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows an electrolytic processing apparatus to which the same electrolytic processing method is applied. In the figure, a conductive work table 2 is provided at the bottom of a machining liquid tank 1, and a work 3 is placed on the work table 2. In this placed state, the workpiece 3 and the worktable 2 are electrically connected.

A holder 4 is provided above the work table 2 so as to be three-dimensionally displaceable, and an electrode head 5 is attached to the holder 4.
is installed. A substantially hemispherical electrode 6 is provided on the lower surface of the electrode head 5 . The electrode 6 and the workpiece 5 are arranged with a distance of rat heat between the electrodes. A machining liquid tank 1 contains a machining liquid, and a workpiece 3 and an electrode 6 are immersed in the machining liquid Z.

A DC power supply 9 having a voltage vo is connected to the electrode head 5 and the work table 2 via a switch 8 so that the work table 2 side is positive. A resistor 11 of a variable resistor 1o is provided in parallel with the DC power supply 9.

The variable resistor 10 has a shaft portion 12 arranged in parallel with the resistor 11.
a motor 13 that rotationally drives the shaft 12; a movable piece 14 that is fitted into the shaft 12 and moves up and down as the shaft 12 rotates; and a movable piece 14 that is supported by the movable piece 14 and comes into sliding contact with the resistor 11. A terminal 15 is provided. The movable terminal 15 is connected to the electrode head 5.

Connection end 16 of resistor 11 on the anode side of DC power supply 9
The voltage V1 of the DC power supply 9 is divided by the resistor 11 (hereinafter referred to as voltage dividing resistor B, 17) from to the contact part of the movable terminal 15, and the voltage obtained by this division (hereinafter referred to as electrolytic voltage)
V2 is applied to the workpiece 6 and electricity 81!6.

The motor 13 has a control device 1 connected to a keyboard 18.
9 is connected. The control device 19 is composed of a 74-color processor, and executes a preset program to perform data processing, which will be described later. To explain using a virtual circuit block that has all the processing functions, this control device 1
The reference numeral 9 generally includes a reference voltage value calculation section 2o and a movable terminal position selection signal generation section 21.

The reference voltage value calculation unit 2o inputs data indicating the resistivity ρ between the electrodes, the distance t between the electrodes, and the current density d from the keyboard 18, and performs all calculations of the following formula (1) (% formula %) to calculate the reference voltage. Calculate and set the value Vo. Note that the resistivity ρ between the electrodes is the resistivity ρ of the machining fluid.

In contrast, we used experimentally obtained data.

The movable terminal position designation signal generation section 21 generates a movable terminal position designation signal a indicating the content according to the reference voltage value V0 calculated by the reference voltage value calculation section 20, and outputs this to the motor 13. The motor 13 receives the movable terminal position designation signal a, rotates according to the content thereof, and stops the movable terminal 15 at a position corresponding to the content of the signal a.

In the electrolytic machining apparatus configured as described above, the switch 8 is turned off, and in this state, a workpiece 3 of an arbitrary machining shape is placed on the workpiece cheaple 2, and a distance t is maintained between the machining parts and the workpiece 3. The electrode 6 is placed above the workpiece 5, and the machining liquid tank 1 is filled with a machining liquid 7 having a resistivity ρ.

The resistivity ρ of the machining liquid 7, the distance t between machining electrodes, and the current density d necessary for machining the workpiece 3 are input from the keyboard 18 (step (hereinafter referred to as ST) 31). Then,
The reference voltage value calculation unit 20 calculates the reference voltage value v based on equation (11).

is calculated (ST32). In response to the calculation of this reference voltage value V0, the movable terminal position designation signal generation section 21 generates the movable terminal position designation signal a (ST35).

The motor 13 receives the signal a and rotates the shaft 12.
T34), the movable piece 14 is displaced and the movable terminal 15 is set to a position corresponding to the content of the signal a (ST35).

When the switch 8 is turned on at the stage where the movable terminal 15 is set in this way, the voltage l of the DC power supply 9 is divided by the voltage dividing resistor 17, and an electrolytic voltage V corresponding to the reference voltage value vo is generated.
2 is obtained, and this electrolytic voltage V2 is applied to the workpiece 3 and the electrode 6. By determining the applied voltage, resistivity ρ, and interpolar distance d, as is clear from equation (1), the current density d is constant regardless of the shape of the machined surface of the workpiece 6.
A current flows from the workpiece 3 to the electrode 6 via the machining fluid 7.

As a result, the workpiece 3 is electrolytically processed with high precision.

In addition, when electrolytically machining a workpiece 3a with a different machined surface shape, turn off the switch 8, take out the workpiece 5 from the machining liquid tank 1 in this state, and replace the workpiece 3a with the workpiece 3a.
All the workpieces are placed on the work table 2 and the switch 8 is turned on.

Then, in the same way as described above, an electrolytic voltage 2 corresponding to the reference voltage value 2o is applied to the workpiece 3a and the electrode 6. In this case as well, a current with a constant current density d is applied, so that the workpiece 3a can be electrolytically processed with high accuracy.

In this way, without calculating the area of the machined surface,
Since it is possible to flow current at the current density necessary for machining workpieces of various shapes, workpieces can be electrolytically machined with high accuracy without increasing the number of man-hours.

FIG. 3 shows an electrolytic processing apparatus to which a second embodiment of the present invention is applied.

In FIG. 3, a power supply circuit 42 is connected to the electrode head 5 and work table 2 via a capacitor 40 and a thyristor 41. The power supply circuit 42 receives supply voltage information S, which will be described later, and applies a supply voltage 3 corresponding to the supply voltage information S to the capacitor 40.
to charge. The thyristor 41 becomes conductive when the gate signal t is turned on, and supplies current to the electrode head 5 and the work table 2.

A voltmeter 43 is connected to the electrode head 5 and the work table 2 to measure the voltage (hereinafter referred to as the inter-electrode voltage) V4 at the relevant part, and the data corresponding to the inter-electrode voltage V4 (hereinafter referred to as the inter-electrode voltage) is measured. (referred to as v4) is designed to output full output.

A control device 44 is provided connected to the voltmeter 45, thyristor 41, and power supply circuit 42. Control device 44
The microprocessor executes a preset program to perform the data processing described below. To explain using a virtual circuit block having this processing function, this control section ff1i44 generally includes a memory 451 for voltage between electrodes, a memory 46 for calculation formula, a calculation section 47, a control section 48
and the above-mentioned reference voltage value calculation section 2°.

The interelectrode voltage memory 45 is connected to the voltmeter 43 via the control unit 49.
Stores the voltage between poles V4 sent from the terminal.

The calculation formula memory 46 stores the following calculation formula (2).

V3=VO+(VOV4) --f2) Here, (VO-V4) corresponds to the voltage drop caused by changes in processing conditions, internal resistance, etc., and equation (2) calculates this voltage drop by It is added to the reference voltage Vo.

The calculation unit 47 applies the reference voltage value ■o and the voltage between electrodes v4 transferred via the control unit 48 to equation (2) to obtain data corresponding to the supply voltage V3 (hereinafter referred to as supply voltage ■3).
Calculate.

The control unit 48 causes the reference voltage value calculation unit 20 to calculate the reference voltage value V0 by calculating the formula (1) as described above, and also calculates the reference voltage value V0 from each of the memos 1J45 and 46 in response to the instruction signal U from the keyboard 18. The stored data is read out and transferred to the arithmetic unit 48, where it is computed and the supply voltage v
3 is calculated, and supply voltage information S is sent to the power supply circuit 42 based on this supply voltage v3. Well, the control unit 48 is
The gate signal t is turned on or off depending on the processing content to control the conduction of the thyristor 41 and adjust the current application time to the workpiece 3 and the electrode 6.

In the electrolytic machining apparatus having such a configuration, first, the voltage V4 between the electrodes is measured by the voltmeter 45 prior to machining, and this measurement data is stored in the memory 45 for voltage between the electrodes. When the keyboard 18 is operated to process the workpiece 3 and the inter-electrode resistivity ρ, the inter-electrode distance t, the electric current variation, and the instruction signal U are sent to the control section 49, the control section 49 controls the reference voltage value Vo. At the same time, the stored data is read from each memory 45 and 46, and the arithmetic unit 48 is made to calculate the equation (2) to obtain the supply voltage (3).

Then, supply voltage information S is sent to the power supply circuit 42 based on this supply voltage v3. And power supply circuit 4
2 outputs the supply voltage V3. In this case, the voltage drop that occurs between the workpiece 3 and the electrode 6 is already the supply voltage V3.
Therefore, the reference voltage value V is applied to the workpiece 5 and electrode 6. A considerable voltage will be applied. As a result,
Work 3 is processed with high precision.

Also, when machining workpiece 3ai instead of workpiece 3, the reference voltage value ■ is used as described above. A considerable voltage can be applied. Further, a current having a current density necessary for machining can be applied to workpieces having various machining shapes without calculating the area of the machining surface. As a result, the workpiece can be electrolytically processed with high precision without increasing the number of man-hours.

In the second embodiment, the voltage drop is calculated in advance by measuring the inter-electrode voltage before machining, and the supply voltage is determined by adding this voltage drop to the reference voltage value. The output is output during machining, but the voltage between the machining electrodes is measured during machining, the voltage drop is calculated, and the supply voltage is corrected in real time based on this voltage drop.
This supply voltage may also be applied.

(Effects of the Invention) As explained above, the present invention can apply a voltage equivalent to the reference voltage value to the workpiece and electrode during electrolytic machining, and by applying this voltage, a specified distance between the workpiece and the electrode can be established regardless of the shape of the machined surface of the workpiece. Since it is possible to flow a current with a current density of have

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an electrolytic processing apparatus to which a first embodiment of the present invention is applied, FIG. 2 is a flowchart showing the same embodiment, and FIG. 6 is a diagram showing a second embodiment of the present invention. 1 is a diagram schematically showing an electrolytic processing apparatus to which an example is applied. DESCRIPTION OF SYMBOLS 1... Processing liquid tank, 5, 3a... Workpiece, 6... Electrode, 7... Processing liquid, 9... DC power supply, 20... Reference voltage value calculation part. Patent Applicant: Toyota Motor Corporation Agent, Patent Attorney: Yumi Hagi (2 people) Figure 1: Prisoner

Claims (1)

[Claims] (1) Based on the distance between the workpiece and electrode that are immersed in the machining liquid filled in the machining liquid tank of the electrolytic machining device, the resistivity of the machining liquid, and the current density applied to the workpiece and electrode. A reference voltage value is set in advance, and the electrode and a workpiece with an arbitrary machined surface shape are immersed in the machining liquid filled in the machining liquid tank with the distance between the electrodes, and the potential difference between the workpiece and the electrode is set to the reference voltage value. An electrolytic processing method characterized by applying a voltage so that