JP2002254250A - Control unit for wire electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire electric discharge machine that can improve a machining speed and machining accuracy and prevent a wire-like electrode from breaking. SOLUTION: A counter 7 counts the number of electric discharge pulses generated between a wire-like electrode 4 and a workpiece 5 every specified time. A comparison determination unit 9 computes the ratio Px/Ps (where Px is enumerated data and Ps is the number of pulses stored in a reference electric discharge pulse number memory 8). According to the ratio, a feed amount obtained by a feed pulse arithmetic unit 13 in a specified time is controlled. In addition, according to the ratio Px/Ps or the like, an electric discharge downtime control unit 16 controls a downtime controlled by a detection voltage generator 2. Furthermore, according to the ratio Px/Ps, a liquid amount control unit 17 controls a coolant amount. This stops surplus energy supply, improves the machining speed and machining accuracy, and prevents the wire-like electrode from breaking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a wire electric discharge machine, and more particularly to a control method capable of improving machining speed and machining accuracy.

[0002]

2. Description of the Related Art FIG. 18 is a diagram showing an outline of a control device of a conventional wire electric discharge machine. The discharge pulse generator 1 applies a voltage to a gap between the wire electrode 4 and the workpiece 5 in order to perform electric discharge machining, and includes a DC power supply, a circuit including switching elements such as transistors, a charge / discharge circuit for a capacitor, and the like. It consists of. The detection voltage generator 2 applies a pulse voltage between the wire electrode 4 and the workpiece 5 to detect whether or not the gap between the wire electrode 4 and the workpiece 5 can be discharged. , A circuit comprising active elements, resistors, capacitors, etc., a DC power supply, and the like.

[0003] An energizing brush 3 is for energizing the wire electrode 4 and is connected to one terminal of a discharge pulse generator 1 and one terminal of a detection voltage generator 2, respectively. The workpiece 5 includes a discharge pulse generator 1 and a detection voltage generator 2
Are connected to the other terminals of the A discharge pulse generator 1 is provided between the traveling wire electrode 4 and the workpiece 5.
And a pulse voltage generated from the detection voltage generator 2 is applied.

A discharge gap detecting device 6 is connected to the workpiece 5 and the wire-shaped electrode 4, and determines whether the discharge gap is in a dischargeable state based on a transition of a detection pulse voltage from the detection voltage generating device 2, and outputs a discharge pulse input signal. Generate Further, a reference voltage setting device is passed through an averaging processing circuit 22 for comparing a pulse-shaped gap voltage of several microseconds to several tens of microseconds or more with the reference voltage for the feed control and matching the processing speed of the feed pulse calculation device. 23 to obtain a voltage deviation. Then, based on the voltage deviation, the feed pulse calculating device 24 generates a pulse train in which the feed pulse interval is controlled, and outputs it to the feed pulse distribution device 12. The feed pulse distributing device 12 distributes the X-axis and Y-axis driving pulses from the pulse train according to the machining program and drives the X-axis motor control device 10 and the Y-axis motor control device 11 for driving the table on which the workpiece 5 is mounted. It is configured to output.

First, as described above, in order to detect whether or not discharge is possible between the workpiece 5 and the wire-shaped electrode 4, a detection pulse voltage is generated by the detection voltage generator 2 and the workpiece 5 is detected. And the wire-shaped electrode 4. Workpiece 5
When a current is generated between the wire electrode 4 and the workpiece 5, and a voltage drop occurs between the workpiece 5 and the wire electrode 4, the discharge gap detecting device 6 detects the voltage drop and determines that discharge is possible. ,
A discharge pulse input signal is sent to the discharge pulse generator 1 to generate a discharge pulse, and a discharge pulse current flows through the gap between the workpiece 5 and the wire electrode 4. Then, after an appropriate pause time for cooling the gap, the detection pulse is applied to the gap again. This operation cycle is repeatedly executed to perform electric discharge machining.

[0006] In this manner, a process of removing a part of the workpiece 5 from the workpiece 5 every time a discharge pulse is generated. That is, a minute conductive path of several tens μm or less formed in the gap between the opposing wire-shaped electrode 4 and the workpiece 5 is searched by the detection pulse voltage, and a discharge pulse current is immediately supplied to heat, evaporate or melt. Discharge is started by scattering. The removal amount of one discharge pulse and the machining performance are determined by the characteristics of the magnitude of the discharge pulse current, the heat of fusion and thermal conductivity of the material of the wire electrode 4 and the workpiece 5, the viscosity at the time of melting, and the coolant (working fluid). It depends on the characteristics related to cooling and sludge discharge. Further, the next discharge following the above-mentioned discharge generation tends to occur mainly in the vicinity where there are many fine conductive paths via generated sludge immediately after the end of the discharge.
Therefore, accurate servo feed control and pause time control are required so that discharges that occur one after another do not concentrate at one place.

FIG. 19 is a view showing monitor waveforms of a machining voltage, a machining current and a machining speed when the prism of the die steel shown in FIG. 13 is cut out by a conventional method. Corners where the processing direction changes to a right angle will be momentarily fed by the gap. Therefore, the machining current decreases and the machining voltage increases. Therefore, the feed speed command increases. After the change of direction, the gap between the wire-like electrode and the workpiece is reduced more than necessary, and the sludge is not smoothly discharged. As a result, the sludge density increases, causing discharge concentration and short-circuiting, or the wire-shaped electrode is disconnected. Therefore, in the conventional control, servo feed (relative feed between the wire electrode and the workpiece), discharge pause time, and the fluid pressure of the machining fluid are evaluated in advance by machining for a fixed period or distance immediately after the corner. Processing had to be added. Moreover, accuracy correction corresponding to a change in the thickness of a workpiece and a corner shape has been a very complicated and difficult process.

[0008]

As described above, the conventional feed control lacks the accuracy of the feed because the detection is performed by using the gap voltage, and it is easy to break the wire particularly when the wire-like electrode is strongly stretched, and there is a demand for an improvement in the processing speed. Could not respond to. In addition, the wire is easily broken particularly at the corners of the processed shape, and in order to prevent this, it has been necessary to add a corner control process such as reducing the feed rate and the processing current in advance. An object of the present invention is to solve such a problem.

[0009]

A wire electric discharge machine for performing electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. In the control device, the invention according to claim 1 is characterized in that a discharge pulse number counting means for counting the number of input discharge pulses at predetermined time intervals, and that the wire-shaped electrode and the workpiece are moved along a processing path based on a movement command. Moving means for relatively moving the reference pulse number, a reference discharge pulse number storing means for storing a reference discharge pulse number, and a ratio of a numerical value obtained by the discharge pulse number counting means to a numerical value stored in the reference discharge pulse number storing means. Means, and a distance obtained by multiplying the relative movement distance between the wire-shaped electrode and the workpiece determined by the set feed speed and the predetermined time by the ratio is a movement command, and the movement is performed at the predetermined time intervals. And to and means for outputting the stage.

[0010] The invention according to claim 2 is based on claim 1.
In the invention according to the present invention, the time integral value of the discharge pulse current is used in place of the discharge pulse number, and the discharge pulse current integration for integrating the input discharge pulse current at predetermined time intervals instead of the discharge pulse number counting means. Arithmetic means is provided,
Instead of the reference discharge pulse number storage means, a reference discharge pulse current integrated value storage means for storing a time integration value of a reference discharge pulse current is provided.
Means is provided for calculating the ratio between the numerical value obtained by the discharge pulse current integrated value calculating means and the numerical value stored in the reference discharge pulse current integrated value storage means.

According to a third aspect of the present invention, there is provided an electric discharge machining method in which a discharge pulse current is applied between the wire electrode and the workpiece while the wire electrode and the workpiece are relatively moved. In the control device of the wire electric discharge machine that performs
Discharge pulse number counting means for counting the number of input discharge pulses every predetermined time; moving means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; and a discharge pulse serving as a reference. Reference discharge pulse number storage means for storing the number, a means for comparing the numerical value obtained at every predetermined time by the discharge pulse number counting means with the numerical value stored in the reference discharge pulse number storage means, hand,
Means for controlling the discharge pause time so that the numerical value obtained at every predetermined time by the discharge pulse number counting means matches the numerical value stored in the reference discharge pulse number storage means, or to suppress the excessive input of energy. It is characterized by having.

According to a fifth aspect of the present invention, as in the second aspect of the present invention, the discharge pause time is controlled based on a reference discharge pulse current integrated value instead of the number of discharge pulses in the third and fourth aspects of the present invention. It is intended to be used.

According to a sixth aspect of the present invention, there is provided a liquid amount control device for increasing or decreasing the amount of the coolant instead of the means for controlling the discharge pause time according to the third aspect of the present invention. Further, the invention according to claim 7 is provided with a liquid amount control device for controlling the increase / decrease of the cooling liquid amount instead of the means for controlling the discharge pause time according to the invention according to claim 5.

The invention according to claims 8 and 9 is based on claims 3 and 4.
In the invention according to the fourth aspect, the amount of movement of a movement command output to the moving means at predetermined time intervals is controlled. In the invention according to claim 10, the amount of the coolant is further controlled.

In the invention according to claims 11 to 15, a discharge pulse current is applied between the wire-shaped electrode and the workpiece while the wire-shaped electrode and the workpiece are relatively moved. In a control device for a wire electric discharge machine which performs machining, the invention according to claim 11 has means for controlling a relative moving distance between the wire-shaped electrode and the workpiece based on a machining amount of the workpiece by an electric discharge pulse. According to a twelfth aspect of the present invention, there is provided a discharge pause time control device for controlling a discharge pause time based on a machining amount of a workpiece by a discharge pulse.
The invention according to 3 is characterized in that it has a liquid amount control device for controlling the amount of cooling liquid based on the amount of processing of the workpiece by the discharge pulse. The invention according to claim 14 is
The control based on the amount of processing of the workpiece by the discharge pulse, based on a count value of the number of input discharge pulses every predetermined time, and a predetermined value obtained in advance, further, claim, The invention according to the fifteenth aspect is performed based on a value obtained by integrating an applied discharge pulse current at predetermined time intervals and a predetermined value obtained in advance.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the operation principle of the present invention will be described. FIG. 3 is an explanatory diagram of a relationship between input machining energy and machining amount in wire electric discharge machining. The workpiece 5, if the processing of delta _S portion and the delta _X portion is performed, holds the following relationship. _{P S * w = Δ S *} t * g P X * w = Δ X * t * g ... ·· (1) In other words, Ps / Δs = Px / Δx = t * g / w ... and ... (2) Become.

Here, t is the plate thickness of the workpiece 5, P _S and P _X are the number of discharge pulses generated per unit time T in each part, w is the machining amount per discharge pulse, Δ _S
The distance can move discharge pulse number P _S, the distance delta _X is able to move in the discharge pulse number P _X, g is the kerf width. If the machining amount w per discharge pulse is constant,
Discharge pulse number P _S and P _X indicates a value proportional to the machining amount generated per unit time T.

If the processing groove width g is constant under the condition that the thickness t does not change, the following equation is obtained. P _S / P _X = Δ _S / Δ _X (3) That is, if the change in the number of discharge pulses per unit time T and the change in the amount of feed movement can be made equal to each other, the machining groove width g means constant.

[0019] The reference movement amount delta _S per unit time T obtained from the set feed speed SPD as a reference for setting input by the following equation. _{Δ S = SPD * T ...... ·} (4) (3) amount of movement delta _X from equation (4) is obtained from the following equation. _{Δ X = SPD * T * (} P X / P S) ...... · (5) The above equation (5) is changed set feed speed SPD, to the feed speed of the SPD * (Px / Ps) Means FIG. 4 shows the movement amount Δ on the horizontal axis and the number of discharge pulses P on the vertical axis.
Represents the relationship of equations (3) and (5). Setting the feed speed SP serving as the reference become discharge pulse number P _S and the reference
D can generate a movement amount delta _X by pre counts discharge pulse number P _X per every moment change units time T during machining is set as the dotted line. This movement amount Δx can also be expressed as follows from Expression (1): Δx = (Px * w) / (t * g) Px * w in this equation is the machining amount when only the discharge pulse Px is generated. Since the moving amount Δx is obtained by dividing the amount of processing by the product of the thickness of the workpiece and the width of the processing groove, moving the wire electrode by the amount of moving Δx means that the wire electrode was processed by the discharge pulse of Px. The wire electrode is moved by an amount. That is,
Equation (5) is based on the reference discharge pulse number Ps and unit time T
The moving amount Δx of the wire electrode corresponding to the machining amount by the discharge pulse is generated from the count value Px of the number of discharge pulses per hit.

In general, the relationship between the movement amount Δ and the number of discharge pulses P changes depending on the material of the workpiece, the thickness t of the workpiece, the width g of the machining groove, and the like. For example, when the thickness t of the workpiece and the width g of the processing groove are constant, the relationship between the movement amount Δ and the number of discharge pulses P is as shown in FIG. The slope α of the straight line in FIG. 5A corresponds to (t * g / w) in equation (2), but since t and g are constant, the slope α is (1 / w) in equation (2). Is represented. In FIG. 5A, the carbide W
The fact that the inclination α of C is larger than that of die steel means that
This means that the carbide WC has a smaller machining amount w per discharge pulse than the die steel. This is a carbide W
This is consistent with the fact that electrical discharge machining is more difficult for C than for die steel.

When the machining groove width g is constant and the plate thickness t is changed with a workpiece of the same material, the relationship between the moving amount Δ and the number P of electric discharge machining pulses is as shown in FIG. become. In this case, since g and w in equation (2) are constant, FIG.
The slope β of the straight line in (b) represents the thickness t of the workpiece.

FIG. 5 (c) shows the ratio (P / Δ) of the number of discharge pulses P to the amount of movement Δ, with the processing groove width g constant.
From the equation (2) showing the relationship with the plate thickness t of the workpiece, t = (w / g) * (P / Δ). Therefore, the slope γ of the straight line in FIG. 5C is (w / g) Becomes Here, since the processing groove width g is fixed, the inclination γ of the straight line represents the processing amount w per discharge pulse. In FIG. 5C, the fact that the inclination γ of aluminum is large and the inclination γ of carbide WC is small means that the machining amount w per discharge pulse is large for aluminum and small for carbide WC. ing. This is consistent with the fact that aluminum is generally easy to perform electrical discharge machining, and carbide WC is difficult to perform electrical discharge machining.

As described above, the relationship between the amount of movement Δ and the number of discharge pulses P varies depending on the material of the workpiece, the thickness t of the workpiece, the width g of the machining groove, and the like. In controlling the moving amount Δx for the wire-shaped electrode based on
The relationship between the reference discharge pulse number Ps and the reference set feed speed SPD (= Δs / T) is determined in advance. That is, for workpieces of various materials, the plate thickness of the workpiece and the diameter of the wire electrode (machining groove width) are variously changed, and the number of discharge pulses per unit time T (P / T (= Ps)) The relationship with the moving speed Δ / T (= Δs) per time T is obtained,
The ratio of the number of discharge pulses P to the moving amount Δ, κ = P / Δ (6) is determined as shown in Tables 1 to 3. By multiplying the determined κ by the set feed speed SPD, the reference discharge pulse number Ps (= κ * SPD) can be determined.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

Before starting the electric discharge machining, κ is read from the above table based on the material of the workpiece, the thickness of the workpiece, and the diameter of the wire electrode set as the machining conditions, and is set to the read κ. The reference discharge pulse number Ps (= κ * SPD) is obtained by multiplying the feed rate SPD. When the electric discharge machining is performed, the moving amount (relative moving amount) of the wire electrode with respect to the workpiece is controlled based on the equation (5) while detecting the number of discharge pulses P per unit time.

Although the plate thickness set as the processing condition does not always exist in the above table, in such a case,
The κ corresponding to the set plate thickness may be obtained from the known κ existing in the table. For example, when the set plate thickness is between the plate thickness 1 and the plate thickness 2, the set plate thickness is corresponded by a method such as proportional distribution from κ1 corresponding to the plate thickness 1 and κ2 corresponding to the plate thickness 2. Can be obtained. Further, an approximate curve of κ with respect to the plate thickness can be obtained from the value of κ corresponding to the plate thickness 1 to the plate thickness N, and κ corresponding to the set plate thickness can be obtained. Alternatively, it is possible to manually set κ while referring to the table.

Further, even when the material of the workpiece to be actually subjected to the electric discharge machining does not exist in the above table, κ can be set based on the following concept. As shown in equation (6), a large κ means that the number of discharge pulses required for machining the same distance is large, that is, the machining amount w per discharge pulse is small. vice versa,
The fact that κ is small means that the number of discharge pulses required for machining the same distance is small, that is, the discharge pulse 1
This means that the processing amount w per shot is large. For this reason, κ is small in a material for which electrical discharge machining is easy, and κ is large for a material in which electrical discharge machining is difficult. Therefore, even if the material of the workpiece to be actually subjected to the electric discharge machining does not exist in the above table, if the machining difficulty of the material is known from the past experience and the like, the machining difficulty of the material is the same. What is necessary is just to look up the material of the processing difficulty of the above from the above table and set it as the material of the workpiece. Alternatively, if it is found that the machining difficulty of the workpiece to be actually subjected to the electric discharge machining is intermediate between the machining difficulty of the material A and the machining difficulty of the material B, the κ of the material A and the material An intermediate value between B and κ may be manually set.

Next, control of the pause time will be described.
FIG. 8 is a view showing the processing state of the workpiece 5 and the processing voltage between the workpiece 5 and the wire-shaped electrode 4 for explaining the downtime,
It is a figure showing the state of current. In FIG. 8, _{P X} and P
_{X + 1} is delta _X and delta _{X + 1} number of discharge pulses per unit time T at _position, V _{X, V X + 1} Each average machining voltage, _{V P} is the no-load _{voltage, T ON} is a current pulse width, T
_OFF is a pause time, and _{TW (X)} and _{TW (X + 1 )} are each an average no-load time per unit time T. or,
P _S , V _S , and T _{W (S)} are the reference number of discharge pulses per unit time T, the average machining voltage, and the average no-load time. _{P X = T / (T W} (X) + T ON + T OFF) P X + 1 = T / (T W (X + 1) + T ON + T OFF) P S = T / (T W (S) + T ON + T OFF) V X = _VP * _{TW (X)} / ( _{TW (X)} + _TON + T
_OFF ) VX _{+ 1} = _VP * _{TW (X + 1)} / ( _{TW (X + 1)} +
_{T ON + T OFF) V S} = V P * T W (S) / (T W (S) + T ON + T
_OFF ) Further, assuming that T _ON << T _W + T _OFF , each T _W + T _ON + T _{OF F} is replaced with a substantial pause time τ, and the above equation is arranged. _{T W (X) + T OFF} = τ X ...... · (7) T W (X + 1) + T OFF = τ X + 1 ...... · (8) T W (S) + T OFF = τ S ...... · (9) P X = T / τ _X (10) P _{X + 1} = T / τ _{X + 1} (11) P _S = T / τ _S (12) V _X = V _P * (τ _X -T _OFF ) _{/ τ X = V P * (} 1-T OFF / τ X) ... (13) V X + 1 = V P * (τ X + 1 -T OFF) / τ X + 1 = V P * (1-T OFF / τ X + 1) ... ... (14) V _S = V _P * (τ _S −T _OFF ) / τ _S = V _P * (1−T _OFF / τ _S )... (15) Also, the average per each unit time T Processing current I
_{m (S)} , _{Im (X)} , _{Im (X + 1)} , and average machining current densities _{Id (S)} , _{Id (X)} , _{Id (X + 1 )} are obtained by the following equations. Note that t is the plate thickness, and g is the width of the processing groove. _{I m (S) = I p} * T ON * P S ...... · (16) I d (S) = I m (S) / (t * g) ...... · (17) I m (X) = I _p * T _ON * P _X (18) _{Id (X)} = I _{m (X)} / (t * g) (19) _{Im (X + 1)} = I _p * T _ON * P _{X + 1} (20) _{Id (X + 1)} = _{Im (X + 1)} / (t * g) (21) The following equation is obtained from the above equation (5) and the above equation. _{Δ S / Δ X = P S} / P X = I d (S) / I d (X) ...... · (22) Δ S / Δ X + 1 = P S / P X + 1 = I d (S) / I d ( _{X + 1)} (23) That is, the expressions (22) and (23) mean that
When processing is performed based on the above equation (5), it means that the average processing current density per unit time T also increases or decreases.

FIG. 6 will be described in this regard. FIG.
In (a), the horizontal axis is the sludge concentration S _C in the discharge gap, and the vertical axis is the average machining voltage Vm. The graph represents the trend of the average machining voltage Vm sludge concentration S _C during discharge machining.
Average machining voltage Vm fine conductive path through the sludge when the sludge concentration S _C begins to fill up is detected number as a trigger discharge is believed to follow a curve such as the graph. FIG. 6B will be described. The horizontal axis is the sludge concentration S _C in the discharge gap, and the vertical axis is the number of discharge pulses P generated per unit time and the actual pause time τ. The graph represents the trend of the discharge pulse number P and substantial downtime per sludge concentration S _C and the unit time changes every moment during discharge machining tau. Sludge concentration S _C is started when the fine conductive path through the sludge increased introduction of many detected and discharge pulse as a trigger of the discharge increases, follows a curve as shown in graph substantially quiescent time τ is minimized. Unloading time T _W becomes shorter, the process proceeds to concentrated discharge from peculiarities of the foregoing discharge products, causing nonuniform deterioration and the groove width of the wire breakage or MenAra of. Conventionally, the worst case has been avoided by setting the pause time T _OFF to a large value in advance. In addition, when the machining area is small at the time of cutting the end face of the workpiece, discharge concentrates, or when the amount of machining fluid to the discharge portion escapes and cooling is insufficient, a large pause time T _OFF is set in advance.

The present invention automatically solves the above problem by automatically setting the pause time (T) so that the number of discharge pulses does not increase beyond the limit.
_OFF ) was solved. FIG. 7A will be described. The horizontal axis is the actual pause time τ, and the vertical axis is the unit time T
The number of discharge pulses P per unit is taken, and equations (11) and (12) are illustrated. Wherein (5) the processing amount for the discharge pulse number P and substantially quiescent time τ per unit time T when processing based on the type and the sludge concentration S _C according FIGS. 7 (a)
It changes so as to follow the solid line shown in FIG. When the reference discharge pulse number P _{S at} which the optimum discharge pulse density is obtained and the actual pause time τ _S at that time are set at point B on the line, and the discharge pulse number P _{X + 1} exceeding the reference discharge pulse number P _S occurs. Will be described.

P in FIG. 7A_{X + 1}> P_SRelease of point A
Number of electric pulses P_{X + 1}Is the reference discharge pulse number P_SApproach
In order to achieve this, the effective pause time τ_{X + 1}And τ_SThe difference between
In other words, the no-load pause time T_WIs set as much as
Semi-pause time T_{OFF (S)}Can be extended as shown in Fig. 9.
No. FIG. 9 shows a voltage waveform between the wire electrode and the workpiece.
FIG. 9C is a diagram showing the electric current at point B in FIG.
It is a voltage waveform and a reference voltage waveform. Also, FIG.
In the voltage waveform at point A in FIG.
It is a waveform of. FIG. 9A is the same as FIG.
Shows the voltage waveform at point A when the present invention is applied.
is there. As is apparent from FIG. 9, the discharge in FIG.
Although the number of times is large, the number is small in FIG.
I understand. The pause time to be controlled is T_{OFF (X + 1)}Tomorrow
Then, the following equation is obtained. τ_S−τ_{X + 1}= T_{OFF (X + 1)}-T_{OFF (S)} …… ・ (24) Ｔ T_{OFF (X + 1)}= Τ_S−τ_{X + 1}+ T_{OFF (S)}(25) The following equation is obtained from the equations (11) and (12). T_{OFF (X + 1)}= (1 / P_S−1 / P_{X + 1}) * T + T_{OFF (S)} (26) That is to say, the point B is matched to obtain the optimum discharge pulse density.
In order to control the pause time, the discharge pulse
Number P_SAnd the number of discharge pulses P at point A _{X + 1}of
The difference from the reciprocal is calculated for each unit time T, and the difference is used as the basis.
Semi-pause time T_{O FF (S)}Achieved by extending from
Is done.

[0034] Next point C falls below the reference discharge pulse number P _S in FIG. 7 (b), the words for pause time control when the discharge pulse number P _X occurs will be described. As in FIG. 7A, the horizontal axis represents the actual pause time τ, and the vertical axis represents the number of discharge pulses P and the average machining voltage Vm (10), (12), and (1).
3) and (15) are changed so as to follow each graph. Since the machining amount is usually small at the point C, a discharge pulse having a long no-load time _{TW (X)} and a long effective pause time is generated as shown in FIG. However, the no-load time T through the sludge due to the above-described specificity of discharge generation.
_The possibility of a continuous short discharge pulse of _{W (x)} is also included, causing wire breakage. That is, the phenomenon that the voltage instantaneously drops from the point C 'to the point B' of the average machining voltage and a short discharge pulse with no load time _{TW (X)} is applied to the gap is often observed. Accordingly to this short discharge pulse does not become less over substantially quiescent time tau _X is tau _S be the average machining voltage do not want to be charged into the gap is reduced beyond the point B 'in the processing 10 This object is achieved by extending the pause time in advance as shown in FIG.

That is, the average machining voltages at the points B 'and C' are made equal.
The pause time controlled from _{OFF (X)}Tomorrow
In this case, the following equation is obtained from equations (13) and (15). V_P* (Τ_X-T_{OFF (X)}) / Τ_X= V_P* (Τ_S-T_{OFF (S)}) / Τ_S …… ・ (27) Ｔ T_{OFF (X)}= T_{OFF (S)}* Τ_X/ Τ_S (28) The following equation is obtained by rearranging the equations (10) and (12). T_{OFF (X)}= T_{OFF (S)}* (P_S/ P_X) (29) That is, the reference pause time T_{OFF (S)}Discharge discharge
Loose number P_SAnd the number of discharge pulses P_XMultiplied by the reciprocal of the ratio of
Pause time T_{OFF (X)}By changing this purpose
Is achieved. Thus, based on the equations (26) and (29),
Based on the evaluation function
The discharge pause time is controlled so as to suppress it.

In controlling the discharge pause time on the basis of the equations (26) and (29), various materials, plate thicknesses, and diameters of the wire-like electrodes are determined in advance in the same manner as described above. Can be used. In this case, the obtained κ is multiplied by the set feed speed SPD to obtain a reference discharge pulse number Ps (= κ * SPD).
Using s, the calculations of the equations (26) and (29) are performed.

FIG. 10 is a diagram showing a voltage waveform between the wire electrode and the workpiece, and FIG. 10 (c) is a voltage waveform at point B in FIG. 7 (b), which is a reference voltage waveform. Also, FIG.
0 (b) is the voltage waveform at point C in FIG. 7 (b), which is the waveform before applying the present invention. FIG. 10A shows a voltage waveform at point C when the present invention in FIG. 7B is applied.

At the start of machining or machining of a portion where idle feeding occurs at a corner, even when a voltage is applied between the wire-like electrode and the workpiece, discharge is unlikely to occur (no-load pause time _TW is large). , The discharge pulse number Px is smaller than the reference pulse number Ps. Therefore, the pause time T obtained by the equation (29)
_{OFF (X)} becomes larger than the reference resting time _{T OFF (S).} However, during this time, the wire-shaped electrode relatively moves with respect to the workpiece, and the gap becomes smaller. Therefore, the no-load pause time T _W becomes smaller and discharge occurs earlier, and the number of discharge pulses Ps per unit time T becomes Ps. Will increase. As the number of discharge pulses Ps increases, the pause time T _{OFF (X)} obtained by the equation (29) becomes shorter, and approaches the reference pause time T _{OFF (S)} .

When the number of discharge pulses Px exceeds the number of reference pulses Ps, the pause time T is calculated by the equation (26).
_{OFF (X + 1)} is obtained, and this pause time T
_{OFF (X + 1)} is longer than the reference pause time T _{OFF (S)} . Rest time _{T OFF (X + 1)} if longer the more discharge pulse number _{P X + 1} acts towards the smaller (when no load quiescent time _{T W} is constant, quiescent time _{T OFF (X + 1)} is discharged The longer Number of pulses P
_{X + 1} becomes smaller). In this manner, the pause time T is set such that the discharge pulse number Px matches the reference pulse number Ps.
_{OFF (X)} is controlled.

On the other hand, if the number of discharge pulses fluctuates, the amount processed by the discharge and the temperature rise will fluctuate. Therefore, the present invention controls the temperature rise of the gap as the number of discharge pulses per unit time T increases / decreases, and controls the amount (flow rate) of the coolant (machining fluid) for discharging sludge generated by machining. . That is, the unit time T
When the number of discharge pulses per unit is increased and the machining amount is large, the amount of coolant is increased to suppress the rise in temperature of the gap, and sludge is removed smoothly. The processing amount is small and the unit time T
When the number of discharge pulses per unit is small, the amount of cooling liquid is reduced to prevent overcooling and suppress the vibration of the wire to stabilize the discharge.

FIG. 11 and FIG. 12 show the relationship between the machining state and the coolant amount.
FIG. 4 is an explanatory diagram for explaining a relationship. From this FIG.
Get the relationship. P_S∝Q_S/ W …… ・ (30) P_X∝Q_X/ W …… ・ (31) Q_X/ FR_X∝Q_S/ FR_S (32) where w is the amount of sludge per discharge pulse, Q_S,
Q_XIs the number of discharge pulses P _S, P_XSludge removed by
Quantity, FR_S, FR_XIs the amount of each liquid. The above equation (3
0), (31) and (32), the following equation is obtained. FR_X∝FR_S* (P_X/ P_S(33) That is, it is a standard to control the amount of liquid according to the amount of sludge.
Setting FR_SThe number of discharge pulses P_SAnd at the time of change
Discharge pulse number P_XOf the evaluation function
Achieved by creating a number and changing the fluid volume FR
You.

In changing the liquid amount FR based on the equation (33), it is necessary to use κ obtained in advance for various materials, plate thicknesses, and diameters of the wire-shaped electrodes in the same manner as described above. Can be. That is, by multiplying the obtained κ by the set feed speed SPD, the reference discharge pulse number Ps (=
κ * SPD) is calculated, and the equation (33) is calculated using the discharge pulse number Ps.

An embodiment of the present invention will be described below based on the principle of the present invention described above. FIG. 1 is a block diagram showing a main part of a control device of a wire electric discharge machine according to an embodiment of the present invention. The same elements as those in the conventional example shown in FIG. 18 are denoted by the same reference numerals. In FIG. 1, reference numeral 1 denotes a discharge pulse generator including a circuit including an active element such as a transistor for generating a discharge pulse current, a capacitor charge / discharge circuit, a DC power supply, and the like. The other is connected to the workpiece 5 and supplies a discharge pulse current between the traveling wire-shaped electrode 4 and the workpiece 5. Reference numeral 2 denotes a detection voltage generating device including an active element such as a transistor for generating a detection voltage for detecting a gap state, a circuit including a resistor and a capacitor, and a DC power supply. The other end is connected to the upper and lower conducting brushes 3. A table (not shown) on which the workpiece 5 is mounted is driven and controlled by an X-axis drive motor control device 10, a Y-axis drive motor control device 11, and a feed pulse distribution device 12, which constitute moving means.

Reference numeral 6 denotes a discharge gap detecting device for judging whether or not the gap can be discharged based on the detected voltage. One of the inputs is connected to the workpiece 5, and the other is connected to the upper and lower energizing brushes 3. . When it is determined that discharge is possible, a discharge pulse input signal is output to the discharge pulse generator 1. At the same time, it also outputs to the discharge pulse number counting device 7.

The discharge pulse number counting device 7 counts a discharge pulse input signal during the unit time (predetermined period) T output from the operation clock 14 based on the signal every unit time (predetermined period). It counts discharge pulses generated between the wire electrode 4 and the workpiece 5.

Reference numeral 8 denotes a reference discharge pulse number storage device that stores a reference discharge pulse number Ps to be input in advance.
The discharge pulse number comparing and judging device 9 counts and stores the discharge pulse number Px for each unit time (predetermined cycle) T by the discharge pulse number counting device 7 and the reference stored in advance from the reference discharge pulse number storage device 8. The number of discharge pulses Ps is compared for each unit time (predetermined cycle) T, and the ratio of the number of discharge pulses Px to the reference number of discharge pulses Ps (Px / Ps) is sent to the pulse calculator 13, the discharge pause time controller 16, and the liquid volume. Control device 1
7 is output.

The feed pulse calculating device 13 calculates the distance (SPD * T) obtained from the feed speed SPD sent from the feed speed setting means 15 and the predetermined period T for each signal from the operation clock 14 at every predetermined period T. Is multiplied by the ratio (Px / Ps) of the number of discharge pulses Px sent from the number-of-discharge-pulses comparing and judging device 9 to the number of reference discharge pulses Ps to obtain a movement amount (distance) Δx. That is, the movement amount Δx is obtained by performing the calculation of the expression (5), and a pulse train corresponding to the movement amount Δx is output to the feed pulse distribution device 12. The feed pulse distribution device 12 distributes the X-axis and Y-axis drive pulses from the pulse train to the X-axis drive motor control device 10 and the Y-axis drive motor control device 11 according to the processing program, and drives the table on which the workpiece is mounted. The X-axis motor and the Y-axis motor are driven.

When Px ≦ Ps, the discharge pause time control unit 16 calculates the equation (29) according to the ratio (Px / Ps) output from the discharge pulse number comparison / judgment unit 9, and calculates Px> In the case of Ps, the operation of Expression (26) is performed, and
The pause time T _OFF is obtained and output to the detection voltage generator 2. Detection voltage generator 2, after only pause the quiescent time T _OFF, so that a voltage is applied between the workpiece 5 and the wire electrode 4. In this way, the discharge pause time is controlled based on the evaluation function set in advance to suppress the excessive input of energy. In addition, the liquid amount control device 17 outputs the discharge pulse number Px output from the discharge pulse number comparison / determination device 9.
And the reference discharge pulse number Ps ratio (Px / Ps), the liquid amount is controlled based on an evaluation function as shown in Expression (33).

As described above, the ratio (Px / P) of the number of discharge pulses Px to the number of reference discharge pulses Ps is determined at predetermined time intervals.
Based on s) and the like, the moving distance, the pause time, and the coolant amount were controlled to suppress excessive input of energy, thereby improving the processing speed and the processing accuracy.

FIG. 2 is a block diagram of a main part of a control device of a wire electric discharge machine according to a second embodiment of the present invention. Only parts different from the first embodiment shown in FIG. 1 will be described.
In the second embodiment, instead of counting and storing the number of discharge pulses, the integrated value of the discharge pulse current is obtained from the current detection circuit 18 and the integrated discharge pulse current value operation storage device 19, and the reference value is used instead of the reference discharge pulse number. A reference discharge pulse current integrated value storage device 20 is provided in the control unit, and a discharge pulse current integrated value comparison / judgment circuit 21 for comparison calculates and outputs a feed pulse, a discharge pause time, and a ratio for controlling a liquid amount.

That is, instead of setting the reference discharge pulse current integral value instead of the reference discharge pulse number Ps and counting the discharge pulse number Px per unit time T that changes every moment during machining, What is necessary is just to calculate the discharge pulse current integral value during machining. Also, similarly to the determination of κ, it is also possible to determine a reference value for various materials, plate thicknesses, and diameters of the wire-like electrodes, and use the values.

The second embodiment is different from the first embodiment in that an integrated value of a discharge pulse current is used instead of the number of discharge pulses. Other components are the same as those of the first embodiment, and have the same operation and effect. It is. FIG. 14 shows a monitor waveform when a workpiece (material SKD11) having a thickness of 60 mm is cut from the end face using a wire-like electrode of φ0.2 mm (material brass). The horizontal axis is the processing elapsed time (10 seconds / scale),
On the left vertical axis, the machining voltage (V), the rest time (μsec), the number of discharge pulses per unit time are taken, and on the right vertical axis, the machining speed (mm / min) and the machining current (A) are taken. Hereinafter, description will be given according to the processing elapsed time.

From the start of monitoring, a machining voltage of 70 V, a pause time of 12 μs, and a discharge pulse number of 0 up to about 18 seconds have elapsed.
The level and the processing current change at 0 A, the processing speed changes at 3.5 mm / min, and the processing feed by the conventional method is executed. From 18 seconds to 20 seconds, the machining voltage drops to 60 V or less, and the machining current starts to flow. Detecting this point, the feeding of the present invention starts. As the machining amount increases, the number of discharge pulses gradually increases correspondingly, and at the same time, the pause time gradually approaches the set pause time. The processing speed is gradually increased from about 1 mm / min, and has reached almost the target processing performance level after about 60 seconds. From this result, it was confirmed that the problem of concentrated discharge, which is a problem at the time of cutting the end face, and disconnection due to insufficient amount of liquid to the discharge part due to escape of the machining liquid could be avoided.

FIG. 15 shows a monitor waveform when the punch shape shown in FIG. 13 is cut out and passes through a corner portion.
The wire electrode has a diameter of 0.2 mm (brass material), and the workpiece has a plate thickness of 60 mm (material SKD11). The horizontal axis represents machining elapsed time (10 seconds / scale), the left vertical axis represents machining voltage (V), pause time (μsec), the number of discharge pulses per unit time, and the right vertical axis represents machining speed (mm / mm). Minute), and read the machining current (A). Description will be given as the processing time elapses.

Until 26 seconds have elapsed since the start of monitoring, the state immediately before the corner is shown. The machining voltage is about 42 V, the rest time is about 12 μs, the number of discharge pulses is about 30 levels, the machining current is about 3.6 A, and the machining speed is about 1.5 mm / min. The machining voltage is about 50 V, the pause time is about 20 μs, the number of discharge pulses is about 20 levels, the machining current is about 2 A, the machining current is about 2 A, and the machining speed is about 26 seconds after entering the right-angled corner and about 32 seconds after the gap is driven. Changes to about 1 mm / min, reducing the input energy. Thereafter, the speed is gradually increased, and after about 60 seconds, the workpiece has returned to the machining state almost immediately before the corner. It can be confirmed that the problem at the corner by the conventional control, that is, the concentrated discharge due to the excessive feeding and the excessive input energy is avoided.

FIG. 16 shows a workpiece (material: die steel) having a plate thickness of 60 mm using a wire-like electrode of φ0.2 mm (material: brass) shown in FIG.
A 5 mm zigzag shape is continuously machined for about 1 hour, and a machining voltage, a machining current, a pause time, and a machining speed are monitored. The horizontal axis is the processing elapsed time (2 minutes / scale),
The processing voltage (V) and the rest time (μsec) are read on the left vertical axis, and the processing speed (mm / min) and the processing current (A) are read on the right vertical axis. Description will be given as the processing time elapses. Since the machining starts at the cut from the end face, the pause time is extended to about 20 μsec by the control of the present invention, and the machining current and the machining speed are also controlled correspondingly. The maximum processing speed is reached at about 5 mm from the corner. The machining voltage at that time is about 35 V, the rest time is about 10 μs, the machining current is about 6.7 A, and the machining speed is about 2.6 mm / min.
Immediately after passing through the corner, the machining voltage is about 47 by the control of the present invention.
The machining speed is reduced to about 1.5 mm / min, and the machining current is reduced to about 3.6 A. As described above, the problem in the conventional control, that is, the avoidance of the disconnection immediately after the cut processing of the end face of the workpiece and immediately after passing through the corner has been confirmed by the long-time processing according to the present invention.

[0057]

According to the present invention, since the machining feed corresponding to the number of discharge pulses can be realized, the following effects are obtained. . It is possible to maintain the optimal machining current. Wire breakage at the beginning of cutting when the machining amount changes or immediately after passing a corner could be avoided. . The processing speed at high wire tension has been greatly improved. . The processing accuracy of the corner has been improved. . The variation of the processing enlargement was reduced.

[Brief description of the drawings]

FIG. 1 is a main block diagram of a control device of a wire electric discharge machine showing an embodiment of the present invention.

FIG. 2 is a main block diagram of a control device of a wire electric discharge machine showing another embodiment of the present invention.

FIG. 3 is a diagram for explaining generation of a movement amount due to a change in a processing amount.

FIG. 4 is an explanatory diagram of a movement amount with respect to a change in a processing amount.

FIG. 5 is an explanatory diagram illustrating characteristics of electric discharge machining depending on a material of a workpiece.

FIG. 6: Sludge concentration and average machining voltage, number of discharge pulses,
It is a figure explaining the relation of a substantial pause time.

FIG. 7 is a diagram for explaining the relationship between the substantial pause time, the number of discharge pulses, and the average machining voltage.

FIG. 8 is a diagram for explaining a relationship between a pause time, a processing amount, and the like.

FIG. 9 is a diagram for explaining pause time control at point A in FIG. 7 (a).

FIG. 10 is a diagram for explaining pause time control at point C in FIG. 7 (b).

FIG. 11 is a diagram for explaining control of a liquid amount based on a change in a processing amount.

FIG. 12 is a diagram for explaining control of a liquid amount based on the change in the processing amount.

FIG. 13 shows the shape of the workpiece when the monitor waveforms of FIGS. 14, 15, and 19 are obtained.

14 shows a machining voltage, a machining current, the number of discharge pulses, a machining speed, and a machining immediately after machining when machining the shape shown in FIG.
It is a monitor waveform of a pause time.

15 is a monitor waveform of a machining voltage, a machining current, the number of discharge pulses, a machining speed, and a pause time immediately after passing a corner when the shape shown in FIG. 13 is machined.

16 is a monitor waveform of a machining voltage, a machining current, the number of discharge pulses, a machining speed, and a pause time when the shape of FIG. 17 is machined.

FIG. 17 is a diagram illustrating an example of a processing shape.

FIG. 18 is a block diagram of a main part of a control device of a conventional electric discharge machine.

FIG. 19 shows monitor waveforms of machining voltage, machining current, number of discharge pulses, machining speed, and pause time when machining FIG. 13 by a conventional electric discharge machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 discharge pulse generator 2 detection voltage generator 3 energizing brush 4 wire electrode 5 workpiece 6 discharge gap detector 7 discharge pulse counter 8 reference discharge pulse counter 9 discharge pulse comparison and judgment device 10 X-axis motor Drive device 11 Y-axis motor drive device 12 Feed pulse distribution device 13 Feed pulse calculation device 14 Calculation clock 15 Feed speed setting means 16 Discharge pause time control device 17 Liquid volume control device 18 Current detection circuit 19 Discharge pulse current integration value calculation storage device 20 Reference discharge pulse current integrated value storage device 21 Discharge pulse current integrated value comparison / judgment device

Claims (15)

[Claims] 1. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse counting means for counting the number of discharged discharge pulses every predetermined time; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; Reference discharge pulse number storage means for storing the number of pulses; means for calculating a ratio of a numerical value obtained by the discharge pulse number counting means to a numerical value stored in the reference discharge pulse number storage means; a set feed speed and the predetermined time And a means for outputting the distance obtained by multiplying the relative movement distance of the wire-shaped electrode and the workpiece to be obtained by the ratio as a movement command to the moving means every predetermined time. Control device for wire electric discharge machine. 2. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse current integration calculating means for performing an integration calculation of the supplied discharge pulse current at predetermined time intervals; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; and a reference. Reference discharge pulse current integration value storage means for storing a time integration value of the discharge pulse current, and a ratio between a value obtained by the discharge pulse current integration value calculation means and a value stored in the reference discharge pulse current integration value storage means. Means, and a distance determined by multiplying the relative movement distance between the wire-shaped electrode and the workpiece determined by the set feed speed and the predetermined time by the ratio is a movement command and the predetermined time is used as the movement command. Means for outputting to the moving means each time. 3. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse counting means for counting the number of discharged discharge pulses every predetermined time; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; Reference discharge pulse number storage means for storing the number of pulses, means for comparing the numerical value obtained by the discharge pulse number counting means for each predetermined time with the numerical value stored in the reference discharge pulse number storage means, and Accordingly, means for controlling the discharge pause time such that the numerical value obtained by the discharge pulse number counting means at every predetermined time matches the numerical value stored in the reference discharge pulse number storage means. A control device for a wire electric discharge machine. 4. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse counting means for counting the number of discharged discharge pulses every predetermined time; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; Reference discharge pulse number storage means for storing the number of pulses, means for comparing a numerical value obtained by the discharge pulse number counting means for each predetermined time with a numerical value stored in the reference discharge pulse number storage means, A control device for a wire electric discharge machine, comprising: a pause time control device that controls a discharge pause time so as to suppress excessive input of energy in response thereto. 5. A control device for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse current integration calculating means for performing an integration calculation of the supplied discharge pulse current at predetermined time intervals; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; and a reference. A reference discharge pulse current integration value storage means for storing a time integration value of the discharge pulse current, and a numerical value obtained for each predetermined time by the discharge pulse current integration value calculation means and the reference discharge pulse current integration value storage means. A control device for a wire electric discharge machine, comprising: means for comparing a numerical value; and a pause time control device for controlling a discharge pause time so as to suppress the input of surplus energy according to the comparison result. Place. 6. A control device for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse counting means for counting the number of discharged discharge pulses every predetermined time; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; Reference discharge pulse number storage means for storing the pulse number, and means for calculating the ratio of the numerical value obtained every predetermined time by the discharge pulse number counting means and the numerical value stored in the reference discharge pulse number storage means,
A control device for a wire electric discharge machine, comprising: a liquid amount control device configured to increase and decrease a cooling liquid amount according to the ratio. 7. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse current integration calculating means for performing an integration calculation of the supplied discharge pulse current at predetermined time intervals; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; and a reference. A reference discharge pulse current integration value storage means for storing a time integration value of the discharge pulse current, and a numerical value obtained for each predetermined time by the discharge pulse current integration value calculation means and the reference discharge pulse current integration value storage means. Means for determining a ratio with a numerical value;
A control device for a wire electric discharge machine, comprising: a liquid amount control device configured to increase and decrease a cooling liquid amount according to the ratio. 8. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse counting means for counting the number of discharged discharge pulses every predetermined time; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; Reference discharge pulse number storage means for storing the pulse number, and comparison means for comparing the numerical value obtained by the discharge pulse number counting means with the numerical value stored in the reference discharge pulse number storage means, based on the comparison result And controlling a discharge pause time and controlling a feed amount of a movement command output to said moving means at every predetermined time. 9. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A discharge pulse current integration calculating means for performing an integration calculation of the supplied discharge pulse current at predetermined time intervals; a movement means for relatively moving the wire-shaped electrode and the workpiece along a machining path based on a movement command; and a reference. A reference discharge pulse current integrated value storing means for storing a time integrated value of the discharge pulse current, and comparing a numerical value obtained by the discharge pulse current integrated value calculating means with a numerical value stored in the reference discharge pulse current integrated value storing means. Comparing means for controlling the discharge pause time and controlling the feed amount of the movement command output to the moving means at every predetermined time based on the comparison result. A control device for a wire electric discharge machine. 10. The control device for a wire electric discharge machine according to claim 8, wherein a cooling liquid amount is controlled based on a comparison result by the comparing means. 11. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A controller for controlling a relative moving distance between the wire-shaped electrode and the workpiece based on a machining amount of the workpiece by the discharge pulse. 12. A control device for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A control apparatus for a wire electric discharge machine, comprising: a discharge pause time control device that controls a discharge pause time based on a machining amount of a workpiece by a discharge pulse. 13. A control apparatus for a wire electric discharge machine which performs electric discharge machining by applying a discharge pulse current between the wire electrode and the workpiece while relatively moving the wire electrode and the workpiece. A control device for a wire electric discharge machine, comprising a liquid amount control device for controlling a cooling liquid amount based on a processing amount of a workpiece by an electric discharge pulse. 14. The control based on the machining amount of the workpiece by the discharge pulse is performed based on a count value obtained by counting the number of discharged discharge pulses every predetermined time and a predetermined value obtained in advance. 14. The control device for a wire electric discharge machine according to claim 11, wherein: 15. The control based on a machining amount of a workpiece by the discharge pulse is performed based on a value obtained by integrating an applied discharge pulse current at predetermined time intervals and a predetermined value obtained in advance. 14. The method according to claim 11, wherein:
The control device of the wire electric discharge machine described in the above.