JPS5932247B2 - wire cutter - Google Patents

Description

[Detailed description of the invention] The present invention relates to a wire-cut electric discharge machining apparatus.

Wire-cut electric discharge machining usually requires a long time, but the machining time depends on the length of the contour line to be machined, the average current or peak current of the machining pulse, the length of on-time and off-time, and the length of the machining process. It can be predicted relatively easily from machining conditions such as the material of the workpiece, the plate thickness of the workpiece, the material and diameter of the wire used, and the properties of the machining fluid. However, the time required for this machining depends on the settings of the machining conditions.
Or even automatically calculate by giving a command,
No wire-cut electrical discharge machining apparatus has been proposed that is equipped with a display that displays and/or a display that constantly displays the remaining machining time or machining line length during machining.

Therefore, if such a wire-cut electric discharge machining apparatus is provided, it will be extremely convenient in terms of process control. The present invention has been made based on the above-mentioned viewpoint, and its purpose is to automatically display the total processing time as desired when processing conditions are set, and It is an object of the present invention to provide a wire-cut electrical discharge machining apparatus in which the machining time remaining during machining is displayed together with or independently of the total machining time required.

In addition, in an electrical discharge machine that performs wire-cut electrical discharge machining on a workpiece along a contour line, for example, 1 μm, 2 μm
, or the length of 10 μm is set as the length of the minimum setting unit, and the total processing time required to process the workpiece is set as the time required to process the length of this minimum setting unit in steps of 1 hour. Divide into the number of steps and automatically display the total machining time as desired, and display the remaining machining time during machining according to the total machining feed time step number and the machining feed time step number for the part that has already been machined. Provided is a wire-cut electrical discharge machining device that calculates and displays the results.

Additionally, as a modification of the present invention, the total machining line length of the contour to be machined of the workpiece is displayed based on the set machining conditions, and the remaining machining length during machining is displayed together with the total machining line length. , or configure it so that it is displayed alone,
Alternatively, the total machining line length required to process the workpiece is divided into the number of length steps by using the minimum set unit length or the set unit length as one length step, and automatically divides the length into the number of length steps as desired. A wire cutter that displays the total machining line length and also displays the remaining machining line length during machining by calculating it from the total machining feed length step number and the machining feed length step number of the part that has already been machined. It can also be configured as an electrical discharge machining device.

The details of the present invention will be explained below with reference to the drawings.

The drawing is a circuit diagram showing an embodiment of the wire cut electrical discharge machining apparatus according to the present invention, and in the drawing, 1 is a workpiece mounted on a cross table (not shown), 2 is a wire electrode,
3, 3 and 4, 4 are electrode feeding rollers, 5, 5 are current rollers, 6 is a DC power supply, 7 is a switching element, 8 is a processing pulse control circuit, 9 is an insertion resistor, 10, 10 is a diode, 11 is a capacitor , 12 is a discharge resistor, 13 is a Schmitt trigger circuit, 14 is a numerical control device, and 15 and 16 are connected to the cross table (not shown) in the X direction and Y direction, respectively.
A pulse motor that provides machining feed in the direction, 17 is a machining peak current value 1, and setting dials 18 and 19 are on-time τ of machining pulses. n and off-time τ. Ff setting dial, 20 is output selection circuit, 21 is decoder, 22,2
3 and 24 are the plate thickness t of the workpiece and the wire electrode d, respectively.
1 and a setter for the contour length L to be processed; 25, 26, and 27 are multiplication circuits; 28 is an encoder; 29 is a display;
30 is a timer that repeatedly transmits pulses at fixed time intervals;
1 is a subtraction counter, 32 is an adder, and 33 is a desired value such as 1 μm or 10 μm, which is set as the length of the minimum setting unit for machining feed. Either set the total machining line length as the number of steps, or set the total machining line length as the number of steps. Length of minimum setting unit of mechanical feed,
Alternatively, a setting device sets the time required to process a set unit length in one hour steps and sets the required total processing feed step number N, 34 is a ratio calculation circuit, 35 is a multiplication circuit, and 36 is a display. Then, setting dial 17
is linked with a changeover switch of the power supply circuit and/or a setter of the servo control circuit (not shown), and when the peak current value 1 of the machining pulse is selected or set during machining, the corresponding contact is selectively set. Connected.

Also, τ0n and τ. Ff setting dials 18 and 19
are τ0n and τ built into the processing pulse control circuit 8.
It is linked with the Ff setting or selection circuit, and τ
00 and τ. When Ff is set, the corresponding contacts are selectively connected. In such a case, the output selection circuit 20
produces an output at at least one specific output terminal, e.g. 20-1, determined according to the combination of contacts selectively connected by the setting dials 17, 18 and 19, respectively, and outputs to the corresponding input terminal of the output decoder 21. 21-1. In such a case, the decoder 21 outputs an analog quantity corresponding to the input terminal thereof, and the analog quantity is converted into a unit thickness by a wire electrode made of a commonly used material with a unit diameter under set conditions. It is configured to be proportional to the reciprocal of the machining speed (Mm/Min) obtained when machining a workpiece made of a predetermined material, that is, the time required to machine a unit machining length. The output of the decoder 21 is input to a multiplication circuit 25, where it is multiplied by a signal proportional to the thickness t of the workpiece inputted from the plate thickness t setter 22.

The output of the multiplier circuit 25 is further outputted by multiplier circuits 26 and 27 to its setter 23, which is proportional to the wire electrode diameter d.
is multiplied by the output of the setter 24 which is proportional to the contour length L to be machined, and therefore the multiplier circuit 27 outputs an analog quantity which is proportional to the time required for machining. The output of the multiplication circuit 27 is, on the one hand, converted by the encoder 28 into a coded signal indicating the required time for machining the workpiece 1, and the required machining time is loaded into the display 29 and the subtraction counter 31.

On the other hand, the workpiece 1 is processed and fed by the numerical control device 14 and other servo control devices (not shown) via a cross table (not shown) according to the rotation of the pulse motors 15 and 16, and wire cut by the wire electrode 2. When the trigger starts, an average current of a certain level or more flows through the insertion resistor 9, the voltage of the capacitor 11 rises, and the Schmitt trigger circuit 1
3 triggers.

Therefore, the timer 30 is activated, transmitting one pulse every unit time, and decreasing the displayed value of the subtraction counter 31. Since the timer 30 stops operating when electrical discharge machining is interrupted for some reason, the subtraction counter 31 always faithfully displays the remaining machining time.
Further, the output of the multiplication circuit 27 is inputted to the multiplication circuit 35 on the other side. The adder 32 is a counter that accumulates the number of times the pulse motors 15 and 16 are operated while the wire cutting process is progressing normally, that is, the number of steps in both positive and negative directions. Therefore, when a short circuit or other accident causes a backward movement or forward movement that was not initially programmed, the numerical control device 14 controls the adder 32.
stop the operation. Therefore, the adder 32 accumulates only the number of steps of the pulse motors 15 and 16 that operate to perform effective machining along the desired contour line, and the cumulative value is added to the machining contour line of the workpiece. Minimum setting unit of machining feed (
One output pulse is emitted for each increase in value corresponding to a desired integer multiple (eg, 10, 102, or 103) of (eg, 1 μm). On the other hand, the total number of steps N required to complete the desired machining is determined by the contour figure, dimensions, and interpolation method in numerical control, and is already known at the time of program creation.

The total number of steps N is set in the setter 33, and the setter 33 outputs an analog quantity proportional to the number of steps N. When the processing feed of n steps is repeated in rows N-n, the ratio calculation circuit 34 calculates ? This is a circuit that outputs an analog quantity proportional to .

This consists of, for example, a ladder circuit that first outputs a unit analog quantity, and then decreases the output by 1 or 1 x 103 each time one pulse from the adder 32 illustrated above is input. It is possible.

Further, in this embodiment, the step number N setting device 33 is coupled to the ratio calculation circuit 34, but this is coupled to the adder 32, and the adder 32 has one output for every N×10-3 pulses inputted. It is also possible to configure it to emit pulses, in which case the ratio calculation circuit 34 can be simplified. Thus, the multiplication circuit 35 outputs an analog quantity proportional to the product of the two human forces, and the output is displayed on the display 36.

Is this displayed value (between N-n for all required times) x? , that is, the remaining machining time.

M↓1 In the latter embodiment, the quantities set at the beginning, namely 1,
, τ0n, τ0ff, t, d, L, etc. Even if the error caused by other factors is large, the configuration is such that one pulse is emitted for every N×10-3 pulses input to the adder 32 as described above. For example, since the integer multiple thereof becomes the total addition step number N, the remaining processing, which is displayed by the difference between the total addition step number and the output of the adder 32, is performed when the value displayed on the display 36 becomes zero. It has the advantage of always finishing, and the advantage of being able to change the set values of these various quantities independently of other quantities at any time during machining, but high precision cannot be maintained at all points during machining, and machining Some errors may occur depending on the direction and interpolation method.

In order to strictly solve this problem, the adder 32 can be abolished, and instead, index points are provided on the contour line length L to be machined to divide the entire length into a large number of equal sections N', and the process progresses. Each time each index point is reached, a pulse is sent to the numerical control device 14, and the output pulse activates the ratio calculation circuit 34 to calculate the remaining total machining time or machining line length starting from each index point. Based on the ratio of the total number of sections and the number of remaining sections, calculate 1N-11 (L x ?) and display it on the display 36.
T′.

Further, in the above embodiment, the contour line length L to be processed is known, and this value is set in the setting device 24.

The value of L can be easily calculated from the drawing if the processed figure is relatively simple, but it may be difficult to calculate in some cases. In such a case, perform a test run using the given NC tape, calculate the total contour line length to be processed fully or semi-automatically, and input this into the L setting device 24. It is recommended to provide an auxiliary calculation mechanism that can be obtained. Then, instead of the machining time required, the length of the machining contour line is displayed, and the remaining amount of the line length is calculated as the remaining amount of machining, or continuously or as appropriate according to the output of the numerical control pulse. It may also be displayed in response to a command. Since the present invention is configured as described above, when according to the present invention, the time required to complete processing or the length of unprocessed wire is automatically displayed, and therefore,
It is possible to provide a wire cut electrical discharge machining device that is extremely convenient in terms of process control.

The configuration of the present invention is not limited to the embodiments described above, and the configuration of the entire arithmetic system may be a hybrid system as described above, a digital system, an analog system, or other methods. As for the constituent elements of each part, widely known ones can be used within the scope of the purpose of the present invention, and the present invention encompasses all of them.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of a wire cut electric discharge machining apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Workpiece, 2... Wire electrode, 13... Schmitt trigger circuit, 14... Numerical control device, 15,
16... Pulse motor, 17... Setting dial for peak current value p, 18... On time τ.

Claims (1)

[Claims] 1. A calculation device capable of calculating the total machining time required for a given contour machining based on set machining conditions, a measuring means capable of accumulating the actual machining time, and the above-mentioned calculation device A wire-cut electrical discharge machining apparatus, comprising: a display that displays the remaining machining time obtained by subtracting the accumulated value of the measuring means from the calculated value. 2 Based on the set machining conditions, a calculation device that can calculate the total machining time required for a given contour machining, and a calculation device that can calculate the total machining time required for a given contour machining based on the set machining conditions, and the total machining time calculated by this calculation device are Based on this, the time required for machining feed by the set unit length is divided into the number of steps of 1 hour step, and from the total machining feed time step number required for machining and the total machining feed time step number, calculate the amount of time already machined. A wire characterized by comprising: a display that displays the remaining machining time obtained by multiplying the calculated value of the calculation device by the ratio of the remaining machining feed time step number after subtracting the machining feed time step number. Cut electrical discharge machining equipment.