JP2003285227A - Wire electric discharge machine and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire electric discharge machine and a method for controlling the same, in which annealing means using annealing electrodes for correcting curling of the wire electrode of the wire electric discharge machine is able to keep the wire electrode within a predetermined temperature range. <P>SOLUTION: In a wire supply unit 21 of the wire electric discharge machine, when annealing for the wire electrode 33 is carried out between an upper annealing electrode 38 and a lower annealing electrode 42, which are brought into contact with the wire electrode 33, a current supply pattern for the upper annealing electrode 38 and the lower annealing electrode 42 is controlled by annealing electrode control means. By this method, the wire electrode 33 is kept within the predetermined temperature range, and curling of the wire electrode 33 is corrected. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wire electric discharge machine and a control method thereof.

[0002]

2. Description of the Related Art Generally, in a wire electric discharge machine,
The wire electrode for processing the workpiece is attached to the wire electric discharge machine by an automatic wire connecting device in order to enhance the efficiency of the wire connecting work.

The wire electrodes are connected, for example, by replacing the supply reel of the wire electrode with the change of the type of the wire electrode to be used, removing the wire electrode after finishing the work, and preparing the wire electrode for the next work preparation. It is performed during fusing work, replacement work with a new wire electrode due to disconnection during processing, and the like.

In the case of those operations, if the wire electrode has a bending tendency, the wire electrode may be caught in the middle of the path to close the path or deviate from the path, so that the automatic connection is smoothly performed. Sometimes it is not done. Therefore, normally, in a wire electric discharge machine, a pair of annealing electrodes that are in contact with the wire electrode in the middle of the wire electrode path at regular intervals are provided, and the bending tendency caused in the wire electrode by the annealing that energizes the annealing electrode is performed. Have been removed.

However, in the conventional annealing using the annealing electrode, the annealing electrode is normally energized continuously. The situation is shown in FIG. FIG. 7 shows a conventional energization pattern in which the horizontal axis represents time and the vertical axis represents current. That is, energization to the annealing electrode is continuously performed at a constant current ia from time T ₁ to time T ₂ .

[0006]

However, if the wire electrode is heated by the energization while the energization is continued, the temperature of the wire electrode continues to rise. When the inventor of the present application conducted various experiments using a wire electric discharge machine, when the temperature of the wire electrode continued to rise and exceeded a certain height during annealing by energizing the annealing electrode, FIG.
As shown in (a), it was found that the tensile strength and bending habit of the wire electrode sharply decreased. This is shown in FIG.
As shown in (b), it is considered that the elastic range in the stress-strain curve of the material metal of the wire electrode sharply narrows at a temperature higher than a certain height.

In FIG. 6A, the annealing temperature is t2.
The stress-strain curve is within the elastic range shown in FIG. 6 (b) and the tensile strength is kept at a constant value until the temperature reaches. If the wire electrode has a bending tendency,
As shown in (a), the bending habit is maintained at a certain size.

However, the annealing temperature becomes higher and t
When it exceeds 2, and reaches t3 or t4, for example, FIG.
As a result, the elastic range of the metal material of the wire electrode is sharply narrowed, and as a result, the material reaches its yield region and the bending tendency of the wire electrode is drastically reduced. In other words, the wire electrode that has reached the breakdown region is in a state where the bending habit that had occurred in the wire electrode before the annealing is removed and at the same time, the bending habit is likely to occur again.

The state will be described with reference to FIG. Figure 8
Shows a state in which the bending tendency of the wire electrode changes with a rise in temperature. The horizontal axis represents the temperature rise, which means that the temperature rise increases toward the right. The vertical axis represents the curl habit, and the higher the curve, the greater the curl habit. The wire electrode before annealing attached to the wire electric discharge machine has a certain bending tendency, for example, at the point A. This bending tendency is caused when it is wound on a supply reel, which will be described later. When this wire electrode is heated by annealing, the bending habit occurring in the wire electrode decreases along the curve AB as the temperature rises immediately after annealing. That is, the bending tendency that occurs in the wire electrode at room temperature before annealing generally decreases as the temperature rises. However, when the wire electrode continues to be heated and exceeds the yield point of the material metal, the wire electrode exceeds the elastic range and enters the plastic region, so that the wire electrode is likely to be bent again. Then, when the temperature rise exceeds a certain level, for example, the bending habit generated in the wire electrode increases again along the curve CD in FIG.

When the wire electrode is in a state of being easily bent, the wire electrode, which has passed through the annealing electrode, is bent again in the middle of the path, causing a catch in the path and closing the path. It is possible to deviate from the route. In particular, there is no member that guides the wire electrode in the area after the wire electrode that has passed through the upper wire guide portion described later and reaches the lower wire guide portion after passing through the annealing electrode. Therefore, if the wire electrode that has passed through the upper wire guide portion has a bending tendency, the wire electrode that has passed through the upper wire guide portion may deviate from the wire path in automatic connection, or the wire electrode may pass between the upper wire guide portion and the lower wire guide portion. There is a possibility that the lower wire guide portion cannot be reached by coming into contact with the work piece arranged at. or,
A deflecting roller or the like that changes the direction of the path of the wire electrode is provided on the path after passing through the lower wire guide portion, and if the path is curved, the wire electrode after passing through the deflecting roller is caused by the bending of the path. There is a possibility that a bending tendency is added and it is difficult to automatically connect the wire electrodes after passing through the turning roller.

Therefore, an object of the present invention is to provide a wire discharge for maintaining a wire electrode in a predetermined temperature range in an annealing means using an annealing electrode for removing a bending tendency generated in a wire electrode of a wire electric discharge machine. It is to provide a processing machine and its control method.

[0012]

In order to achieve the above-mentioned object, in the present invention, the bending tendency generated in the wire electrode for processing the workpiece is brought into contact with the wire electrode at regular intervals. In a wire electric discharge machine for removing by an annealing means using a pair of annealing electrodes, the annealing means is provided with an annealing electrode control means for keeping the wire electrode within a predetermined temperature range. Let's take a chance.

In the wire electric discharge machine according to the present invention, the annealing temperature of the wire electrode is kept within a predetermined temperature range by the annealing electrode control means, so that the bending tendency of the wire electrode is removed, and The automatic connection of the wire electrodes can be smoothly performed.

The anneal electrode control means may control an energization pattern for energizing the wire electrode. Then, it is possible to control the current value to be applied to the wire electrode, the energization time, the energization interval, and the number of times of energization, and it is possible to keep the wire electrode in a predetermined temperature range.

The anneal electrode control means is a storage means for storing in advance an energization pattern according to the type of wire electrode, a wire electrode setting means for setting the type of wire electrode, and a wire set by the wire electrode setting means. Extraction means for extracting the energization pattern of the electrode from the storage means may be provided, and the wire electrode may be kept in the temperature range based on the energization pattern extracted by the extraction means.

With this configuration, the energization pattern corresponding to the type of wire electrode can be stored in advance by the storage means, and when the type of wire electrode is set by the wire electrode setting means, the wire based on the setting is set. It is possible to extract the energization pattern of the electrode from the storage means by the extraction means, energize the wire electrode based on the extracted energization pattern, and maintain the wire electrode in a predetermined temperature range.

The annealing electrode control means may include a temperature setting means for setting the wire electrode in the temperature range. Thereby, the annealing temperature at which the wire electrode is annealed by the annealing electrode can be set.

The annealing electrode control means may further include wire electrode fusing means for fusing the wire electrode at a predetermined position. Thereby,
Wire electrode supply reel replacement work when the type of wire electrode used changes, removal at the end of processing of the work piece and fusing work of the wire electrode for the next processing preparation, new wire due to disconnection during processing The wire electrode can be melt-cut at a predetermined position during replacement work with the electrode.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a wire electric discharge machine. FIG. 2 is a diagram showing paths of wire electrodes of the wire electric discharge machine. FIG. 3 is a diagram showing a control device of the wire electric discharge machine.

In the wire electric discharge machine 20 of FIG.
Reference numeral 1 is a wire supply unit for supplying a wire electrode, 25 is a control device for the wire electric discharge machine 20, 33 is a wire electrode for processing a workpiece, 44 is an upper wire guide part, and 45 is a lower wire guide part. Wire electrode 3 of wire electric discharge machine 20
Route 3 will be described with reference to FIG.

In the wire supply unit 21 of FIG. 2, the wire electrode 33 is supplied from the supply reel 31 and sent out by the winding motor 32. The direction of the wire electrode 33 sent from the supply reel 31 is changed by the turning roller 34 and the turning roller 35, and reaches the tension generating mechanism 36. A required tension is applied to the wire electrode 33 in the tension generating mechanism 36.

Wire electrode 33 to which the required tension is applied
Are fed downward from the wire feed roller 37 and are a pair of annealing electrodes which are arranged at a constant interval in the middle thereof, that is, an upper annealing electrode 38 and a lower annealing electrode 4.
Touch 2. The wire electrode 33 is the upper annealing electrode 38.
After passing through the upper annealing electrode 38 and the lower annealing electrode 4
2 through a wire guide pipe 39 located between the two. At that time, annealing is performed by energizing the upper annealing electrode 38 and the lower annealing electrode 42.

An upper fusing electrode 41 is provided between the upper annealing electrode 38 and the lower annealing electrode 42. The upper fusing electrode 41 has a function of fusing the wire electrode 33 together with the lower fusing electrode 42 as needed.
The lower fusing electrode 42 is both a fusing electrode and a lower annealing electrode. Therefore, the lower fusing electrode 42, that is, the lower annealing electrode has both the annealing function and the fusing function of the wire electrode 33. By doing so, the number of parts of the wire electric discharge machine 20 can be reduced.

The wire electrode 33 that has passed through the lower annealing electrode 42 exits the wire supply unit 21, passes through the wire guide pipe 43, and is guided to the upper wire guide unit 44. The work piece is processed between the upper wire guide portion 44 and the lower wire guide portion 45.

The direction of the wire electrode 33 passing through the lower wire guide portion 45 is changed from the vertical direction to the horizontal direction by the turning roller 46, and reaches the wire winding roller 48 through the wire guide pipe 47. FIG. 3 shows an annealing electrode control means for annealing the wire electrode 33 between the upper annealing electrode 38 and the lower annealing electrode 42 in the path of the wire electrode 33 to keep the wire electrode 33 in a predetermined temperature range. .

In FIG. 3, annealing electrode control means 55
Is provided in the controller 25 of the wire electric discharge machine 20. A storage device 51, a display device 52, and an input panel 53 are attached to the control device 25. The annealing electrode control means 55 is an energization pattern control means 55.
a, storage means 55b, extraction means 55c, wire electrode setting means 55d, temperature setting means 55e, and wire electrode fusing means 55f.

The energization pattern control means 55a is used to anneal the wire electrode 33 passing between the upper annealing electrode 38 and the lower annealing electrode 42.
Is a means for controlling the current value, the energization time, the energization interval, and the number of times of energization for energizing the wire electrode 33 in order to maintain the temperature at a predetermined value. The parameter input section, the current calculation means, the current, the energization time extraction means, the calculation It is composed of a current judging means and an annealing execution part. These will be described later.

The storage means 55b is means for storing in advance an energization pattern corresponding to the type (diameter, material) of the wire electrode 33. That is, the current value and the energization time when the volume resistivity of the wire electrode 33 and the annealing temperature are used as parameters are calculated in advance and stored in the storage device 51.

The extracting means 55c is means for extracting from the storage device 51 the current value and the energization time stored in the storage device 51 by the storage means 55b. The wire electrode setting means 55d sets the type (diameter, material) of the wire electrode 33 and sets the diameter and material of the wire electrode 33 to the input panel 5.
3 is a means for inputting. In addition to the volume resistivity, specific heat and density are used to represent the material of the metal of the wire electrode 33.

The temperature setting means 55e is means for setting the annealing temperature through the input panel 53. The wire electrode fusing means 55f is a means for setting an energization pattern of the upper fusing electrode 41 and the lower fusing electrode 42 for fusing the wire electrode 33 between the upper fusing electrode 41 and the lower fusing electrode 42. .

Next, in the annealing of the wire electrode 33 passing between the upper annealing electrode 38 and the lower annealing electrode 42, the controlling method of the annealing electrode control means 55 for keeping the wire electrode 33 within a predetermined temperature range. Will be described with reference to the flowchart of FIG.

In FIG. 4, first, an operator inputs parameters into the input panel 53 attached to the controller 25 of the wire electric discharge machine 20 (S1).
0). Parameters input, the diameter of the wire electrode 33 (wire diameter) D, the volume resistivity [rho _Omega, an annealing temperature t _a and annealing times N.

Diameter D of wire electrode 33 and volume resistivity ρ
_Ω is set by the wire electrode setting means 55d and input to the input panel 53. The diameter D and the volume resistivity ρ _Ω of the wire electrode 33 are unique values determined by the type of the wire electrode 33. Annealing temperature t _a is the annealing temperature of the target, is set by the temperature setting means 55e, it is input to the input panel 53. The number of times N of annealing is preferably N ≧ 2. The reason is S15 described later.
Described in.

Next, the annealing electrode (the upper annealing electrode 3
8 and lower annealing electrode 42) is the time T
_ON (annealing ON time) and T _OFF (annealing OFF time), which is the time for stopping the energization of the annealing electrodes (the upper annealing electrode 38 and the lower annealing electrode 42) and cooling the wire electrode 33, are initialized (s11). . In this embodiment, for example, T _ON = 1 sec. Note that T _OFF may be a value unique to the wire electric discharge machine 20. In this embodiment, for example, T _OFF = 1 sec.

When the initial setting is completed, the anneal current i is calculated from the equation (1) by the current calculating means (S).
12).

[0036]

[Equation 1] Expression (1) is derived as follows. Upper annealing
Wire passing between pole 38 and lower anneal electrode 42
When annealing the electrode 33, the annealing current i
Time T to the electrode 33_ONWhen energized, upper annealing electrode
38 of the wire electrode between the lower annealing electrode 42 and the lower annealing electrode 42
Heat H added to 33₁Is according to Joule's law, H₁= R × i²× T_ON... (2) It is represented by. However, R is the upper annealing electrode 38 and the lower annealing electrode.
Resistance value of the wire electrode 33 in the portion between the Neil electrode 42
Is.

[0037] When the length of the upper annealing electrodes 38 and the portion between the lower annealing electrodes 42 wire electrodes 33 and l, which is _{R = ρ Ω × l / A} ··· (3). A is the cross-sectional area of the wire electrode 33, and the diameter is D
Since it is, when the [pi and pi, is ^{A = π × D 2/4} ··· (4).

On the other hand, the wire electrode 33 in the portion between the upper annealing electrode 38 and the lower annealing electrode 42, which was at room temperature t _o before energization, is heated by energization, and the annealing temperature t _a
Temperature reaches the temperature of the wire electrode 33 between the upper annealing electrode 38 and the lower annealing electrode 42 (t _a
Heat H ₂ generated by -t _o) is represented by _{H 2 = c × m × (} t a -t o) ··· (5). Here, c is the specific heat of the material metal of the wire electrode 33, and m is the mass of the wire electrode 33 between the upper annealing electrode 38 and the lower annealing electrode 42. When the density of the material metal of the wire electrode 33 and [rho, m is an m = ρ × l × π × D 2/4 ··· (6).

Here, the amount of heat H ₁ applied to the portion of the wire electrode 33 between the upper annealing electrode 38 and the lower annealing electrode 42 is equal to the amount of heat H ₁ applied to the wire electrode 33 between the upper annealing electrode 38 and the lower annealing electrode 42. Temperature rise (t _a −t _o )
Since it is equal to the amount H ₂ of heat generated by, H ₁ = H ₂ (7) That is, from the expressions (2) and (5), R × i ² × T _ON = c × m × (t _a −t _o ). From this, the annealing current i is derived as in equation (1).

Next, the calculated current judging means judges whether or not the calculated annealing current i exceeds the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20 (S13). The reason is that if the annealing current i is calculated, the exceeds the current maximum possible current i _MAX, in order to flow the annealing current i exceeding the current maximum possible current i _MAX to the wire electric discharge machine, therefore This is because it is necessary to specially provide the power source for the wire electric discharge machine, and the cost of the wire electric discharge machine 20 increases accordingly.

When the calculated annealing current i does not exceed the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20, the annealing is performed so that the current between the upper annealing electrode 38 and the lower annealing electrode 42 is increased. Wire electrode 3
Annealing current i is applied to 3 and annealing (annealing) is performed (S14).

When the calculated annealing current i exceeds the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20, the annealing time T _ON is changed to reduce the annealing current i. In this embodiment, for example, the annealing time T _ON is increased by 0.2 sec and T _ON = T
_{It is set to ON} +0.2 (S18). This is because it is necessary to increase the annealing time T _ON in order to decrease the annealing current i in the equation (1) representing the annealing current i.

In accordance with the changed annealing time T _ON , the annealing current i is calculated again by the current calculating means (S12), and the annealing current i is calculated by the calculated current judging means (S13) in the wire electric discharge machine 20. It is determined whether or not the maximum energizable current i _{MAX of} is exceeded.

When the calculated annealing current i does not exceed the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20, the annealing is performed so that the annealing between the upper annealing electrode 38 and the lower annealing electrode 42 is performed. Wire electrode 3
Annealing current i is applied to 3 and annealing (annealing) is performed (S14).

When the calculated annealing current i exceeds the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20, the annealing time T _ON is changed again to further reduce the annealing current i. It That is, in this embodiment, the annealing time T _ON is increased again by 0.2 sec. (S18).

Next, after annealing (annealing) is performed, the number of times N of annealing is checked (S15). The reason for setting the number of annealing times N to N ≧ 2 is as follows. Generally, if the annealing time T _ON is set too long in the annealing, the upper annealing electrode 38 and the lower annealing electrode 42 are formed.
The heat radiation of the wire electrode 33 and the heat conduction to the upper side annealing electrode 38 and the lower side annealing electrode 42, etc. occur between them. On the other hand, if the annealing time T _ON is too short, the central portion of the wire electrode 33 may not be sufficiently annealed. Therefore, by increasing the number of times N of annealing, a required temperature rise can be obtained, and further annealing can be performed up to the central portion of the wire electrode, and a more stable annealing effect can be obtained.

Then, it is judged whether the number of times N of annealing has reached the number of times set initially (S16). When the number of times N of annealing reaches the number of times set at the beginning, the completion of annealing is displayed on the display device 52 (S1).
7). When the number of times N of annealing does not reach the number of times set at the beginning, the execution of annealing is awaited for a time T _OFF during which the energization of the annealing electrode is stopped and the wire electrode is cooled, and after the time T _{OFF is} awaited, the annealing is performed again. (S19).

In this way, the annealing is performed by the annealing current i that does not exceed the maximum current i _MAX that can be passed by the annealing power source of the wire electric discharge machine 20, and the annealing between the upper annealing electrode 38 and the lower annealing electrode 42 is performed. Wire electrode 3
3 temperature is maintained at the annealing temperature t _a set first.

[0049] That is, the wire by the electrode setting unit 55d sets the diameter D and the volume resistivity [rho _Omega is the type of the wire electrode 33, setting the desired annealing temperature t _a by the temperature setting means 55e, energization pattern controller 55a the energization pattern is defined to keep the wire electrode 33 to the required annealing temperature t _a, annealing of the wire electrode 33 is executed on the basis of the energization pattern defined.

Next, another embodiment of the annealing electrode control means 55 is shown in FIG. FIG. 5 shows that the type (diameter, material) of the wire electrode and the annealing temperature can be selected as parameters, and the annealing current and the energization time corresponding to the selected parameters are stored in the storage device 51 in advance. The anneal electrode control means capable of performing anneal based on the anneal current and the energization time extracted from FIG.

[0051] The volume resistivity [rho _Omega and annealing temperature t _a of the wire electrode as a parameter to calculate the combination of the annealing current i and the annealing time T _ON which satisfies the equation (1) for each wire diameter D of the wire electrode 33, The calculation result is stored as a condition table in the storage device 51 in advance by the storage means 55b. Table 1 shows an example of the condition table.

[0052]

[Table 1] In Table 1, first, the wire electrodes are classified into ranges in which the volume resistivity of the wire is constant. For example, the wire volume resistivity parameter p11 is a wire electrode having a wire volume resistivity in the range of ρ _Ω1 to ρ _Ω2 . Next, a plurality of types (three types in this embodiment) of annealing temperatures are set as annealing temperature parameters for the volume resistivity parameter p11 of the wire. Then, for each annealing temperature, the annealing current i and the annealing time (energization time) T _ON that satisfy the formula (1) are extracted. The annealing current i and the annealing time (energization time) T _ON satisfying the equation (1) are calculated for each wire diameter D of the wire electrode 33, and are stored in the storage device 51.
Remembered in. For example, the annealing temperature parameter p
The annealing current i and the annealing time (energization time) T _ON when the wire electrode diameter is 0.2 mm with respect to No. 21 are extracted from Table 1 as I11 and T11, respectively. The annealing current i is preferably set to a value that does not exceed the maximum energizable current i _MAX of the annealing power source of the wire electric discharge machine 20.

Next, the combination of the required annealing current i and annealing time T _ON is extracted from the storage device 51 by the extraction means 55.
Then, the upper annealing electrode 38 and the lower annealing electrode 42 are energized to perform annealing based on the extraction result. Upper annealing electrode 38 and lower annealing electrode 42
A control method of another embodiment of the annealing electrode control means for maintaining the wire electrode 33 at a predetermined temperature during the annealing of the wire electrode 33 passing between and will be described with reference to the flowchart of FIG.

In FIG. 5, first, an operator inputs parameters into the input panel 53 attached to the control device 25 of the wire electric discharge machine 20 (S2).
0). The parameters are the diameter D of the wire electrode 33 and the volume resistivity parameter of the wire in the range of volume resistivity ρ _Ω ,
In the range of the annealing temperature t _a is the annealing temperature parameters and annealing times N. Note that N is preferably N ≧ 2. The reason is as described above.

Next, the energization of the annealing electrode is stopped and the
T, which is the time for cooling the electrode 33 _OFFIs initialized
It In addition, T_OFFIs a value specific to the wire electric discharge machine 20
Good as In this embodiment, for example, T_OFF= 1 sec
Yes (S21). When the above initial setting is completed, equation (1)
Annealing current i and energizing time T satisfying _ONIs the condition table
(S22).

Annealing is performed based on the annealing current i and the energization time T _ON extracted from the condition table (S23). Next, after annealing is performed, the number of times N of annealing is checked (S24).

That is, it is determined whether the number of times N of annealing has reached the number of times set initially (S25). When the number of times N of annealing reaches the number of times set initially, the annealing is completed and the fact is displayed on the display device 52 (S2).
6). When the number of times N of annealing does not reach the number of times set at the beginning, the execution of annealing is awaited for a time T _OFF during which the energization of the annealing electrode is stopped and the wire electrode is cooled, and after the time T _{OFF is} awaited, the annealing is performed again. (S27).

[0058] Thus, the annealing is executed by the annealing current i does not exceed the current maximum possible current i _{MA X} annealing power supply of a wire electric discharge machine 20, between the upper annealing electrodes 38 and the lower annealing electrodes 42 wire the temperature of the electrode 33 is kept at the annealing temperature t _a set first.

By doing so, the annealing current and the energization time corresponding to different wire electrode types (diameter, material) can be extracted from the condition table. In particular, in recent years, coated wire electrodes have been widely used, and the types of wire electrodes have increased. The coated wire electrode is obtained by coating a brass-based wire electrode with, for example, a zinc coating having a thickness of several μ to several tens μ. The electrical characteristics of the coated wire electrode differ depending on the material of the coating. Table 2 shows the electrical characteristics of several types of covered wire electrodes.

[0060]

[Table 2] In Table 2, the brass wire of the wire electrode type is a conventional wire electrode, and the wire electrode types A to E are coated wire electrodes in which brass-based wire electrodes are coated with coatings of different materials.

As shown in Table 2, the conventional brass wire electrode has a conductivity of approximately 22% (volume resistivity of 784).
Since it was 0 μΩcm), the annealing condition for removing the bending habit of the wire electrode only had to be set to the annealing condition that matched the electrical conductivity of the brass wire electrode of 22%. However, as the coated wire electrodes are used more frequently, and their electrical conductivity varies widely from 22% to 50% or more, one wire electric discharge machine can use different types of coated wire electrodes. In order to do so, a problem has arisen that a plurality of annealing conditions corresponding to different types of wire electrodes must be set in advance in the wire electric discharge machine.

According to this embodiment, even in such a case,
The electrical characteristics of different types of wire electrodes can be stored in the condition table in advance. Then, even if the type (diameter, material) of the wire electrode 33 changes, the required energization pattern corresponding to it can be extracted from the condition table, and one wire electric discharge machine can use different types of wire electrodes. You can

The annealing electrode control means 55 further includes wire electrode fusing means 55f for fusing the wire electrode 33 in FIG. 2 between the upper fusing electrode 41 and the lower fusing electrode 42 by energization. By the wire electrode fusing means 55f, a wire electrode supply reel replacement operation associated with a change in the type of wire electrode to be used, a removal operation associated with completion of processing of a workpiece and a wire electrode fusing operation for preparation for the next processing, processing It is possible to set an energization pattern having a sufficient current value and energization time for fusing the wire electrode 33 during replacement work with a new wire electrode due to disconnection inside.

As described above, in the wire electric discharge machine in which the bending tendency generated in the wire electrode for processing the workpiece is removed by the annealing means using a pair of annealing electrodes which are in contact with the wire electrode at regular intervals, the annealing is performed. The means has been described for the wire electric discharge machine and its control method, characterized in that it comprises an annealing electrode control means for maintaining the wire electrode in a predetermined temperature range,
The wire electrode according to claim 1 corresponds to the wire electrode 33, and the annealing electrode corresponds to the upper annealing electrode 38 and the lower annealing electrode 42. Further, the annealing electrode control means corresponds to the annealing electrode control means 55.

The energization pattern described in claim 2 corresponds to the energization pattern 55a. The storage means according to claim 3 corresponds to the storage means 55b, and the wire electrode setting means,
The wire electrode setting means 55d corresponds, and the extracting means corresponds to the extracting means 55c.

The temperature setting means according to the fourth aspect corresponds to the temperature setting means 55e. Also, the annealing electrode control means 5
5 is a wire electrode supply reel replacement operation accompanying a change in the type of wire electrode to be used, a wire electrode 33 is melted and cut off during removal of the work piece after completion of processing and preparation of the next work piece. Although it has been described that the wire electrode fusing means is further included, the wire electrode fusing means in claim 5 corresponds to the wire electrode fusing means 55f.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wire electric discharge machine.

FIG. 2 is a diagram showing a path of a wire electrode of a wire electric discharge machine.

FIG. 3 is a diagram showing a control device of the wire electric discharge machine.

FIG. 4 is a diagram showing a flow chart of an annealing electrode control means.

FIG. 5 is a view showing a flowchart of another embodiment of the annealing electrode control means.

FIG. 6 is a diagram showing changes in tensile strength and bending tendency of a wire electrode depending on an annealing temperature.

FIG. 7 is a diagram showing an energization pattern of an annealing electrode in conventional annealing.

FIG. 8 is a diagram showing a tendency of a bending tendency due to a temperature rise of a wire electrode.

[Explanation of symbols]

20: Wire electric discharge machine 21 ... Wire supply unit 25 ... Control device 31 ... Supply reel 32 ... Winding motor 33 ... Wire electrode 34, 35, 46 ... Turning roller 36 ... Tension generating mechanism 37 ... Wire feed roller 38 ... Upper annealing electrode 39, 43, 47 ... Wire guide pipe 41 ... Upper fusing electrode 42 ... Lower annealing electrode and lower fusing electrode 44 ... Upper wire guide part 45 ... Lower wire guide 48 ... Wire winding roller 51 ... Storage device 52 ... Display device 53 ... Input panel 55 ... Annealing electrode control means 55a ... energization pattern control means 55b ... Storage means 55c ... Extraction means 55d ... Wire electrode setting means 55e ... Temperature setting means 55f: Wire electrode fusing means

Claims (6)

[Claims] 1. A wire electric discharge machine in which a bending tendency generated in a wire electrode for processing a workpiece is removed by an annealing means using a pair of annealing electrodes in contact with the wire electrode at regular intervals. A wire electric discharge machine, characterized in that the means comprises an annealing electrode control means for maintaining the wire electrode in a predetermined temperature range. 2. The wire electric discharge machine according to claim 1, wherein the annealing electrode control means controls an energization pattern for energizing the wire electrode. 3. The annealing electrode control means is set by a storage means that stores in advance an energization pattern according to the type of wire electrode, a wire electrode setting means that sets the type of wire electrode, and the wire electrode setting means. Extraction means for extracting the energization pattern of the wire electrode from the storage means, and the wire electrode is maintained in the temperature range based on the energization pattern extracted by the extraction means. Wire electric discharge machine described. 4. The wire electric discharge machine according to claim 1, wherein the annealing electrode control means includes a temperature setting means for setting the wire electrode in the temperature range. 5. The wire electric discharge machine according to claim 1, wherein the annealing electrode control means further includes wire electrode fusing means for fusing the wire electrode at a predetermined position. 6. A method of controlling a wire electric discharge machine, wherein a bending tendency generated in a wire electrode for processing a workpiece is removed by an annealing means using a pair of annealing electrodes that are in contact with the wire electrode at regular intervals. By the annealing electrode control means for maintaining the wire electrode provided in the annealing means in a predetermined temperature range,
A method for controlling a wire electric discharge machine, comprising removing a bending tendency generated in the wire electrode.