JP2008284613A - Method for correcting inclination angle in wire-cut electric discharge machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve machining accuracy by correcting the error caused in an inclination angle. <P>SOLUTION: When the error of the inclination angle of a wire electrode is caused by the horizontal displacement of the supporting point for supporting a wire electrode, the correcting amount for correcting the error of the inclination angle is specified as the actual horizontal displacements εU, εV of the supporting point RU' of the wire electrode E with respect to a reference position RU. Then, a control target position RUset in the positional control for a wire guide 9 tensionally supporting the wire electrode E is set based on the correcting displacements εU, εV. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for correcting a taper direction angle in a wire cut electric discharge machining apparatus that corrects an error in a taper direction angle of a wire electrode caused by a displacement of a fulcrum position supporting a wire electrode.

  Wire cut electric discharge machining, in which electric discharge machining by intermittent electric discharge between a machining electrode and a workpiece is applied to a saw blade-like cutting process using a wire electrode for a plate-like workpiece, has been widely known and widely used. In the cutting process, so-called taper machining is already widely performed in a state where the wire electrode is tilted with a desired tilt angle (hereinafter referred to as taper angle) in a desired angular direction (hereinafter referred to as taper direction angle). Are known.

The taper machining in the wire cut electric discharge machining is, for example, in a wire guide having a ring-shaped main guide portion and a sub guide portion in which an inner peripheral surface for guiding the wire electrode has an arc surface having a large radius of curvature. This is performed as shown in FIGS. In the following, the movement axis in the left-right direction of the lower wire guide 10 as viewed from the front side of the electric discharge machining apparatus is the X axis, the movement axis in the direction perpendicular to the X axis in the horizontal direction is the Y axis, and the upper wire guide 9 The vertical movement axis is the Z axis, the horizontal movement axis is the U axis, the horizontal movement axis is perpendicular to the U axis (see FIGS. 1 to 3), and the taper direction angle is: The angle formed by the combined movement direction of the wire electrode on the U axis and the V axis and the U axis and the taper angle are described as an angle formed by the wire electrode and the vertical direction.

As shown in FIG. 15, in this taper processing, first, the positional relationship in the horizontal direction of the wire guides 9 and 10 over which the wire electrode E is stretched is finely adjusted to accurately set the taper angle θ = 0 °. Perform positioning.

And as shown in FIG. 16, while setting the ring hole center position of the main guide parts 9a and 10a to the fulcrum positions RU and RL (hereinafter, referred to as reference positions RU and RL) that support the wire electrode E, , A line segment passing through the movement position O of the wire electrode E set on the upper surface of the work table 6 (a position offset by a predetermined amount with respect to the processing shape of the work W), and a desired taper angle with respect to the vertical direction A line segment that forms an angle equal to θset and that forms an angle equal to the desired taper direction angle φset with respect to the U-axis is defined as a reference guide locus EB of the wire electrode E, and the reference position RU corresponds to the reference guide locus EB. , RL are included so that the positions of the wire guides 9 and 10 are controlled.

The position control of the wire guides 9 and 10 is performed by moving the wire guides 9 and 10 in the horizontal direction while keeping the vertical positions constant with the reference positions RU and RL as control positions. The coordinates in the horizontal direction (coordinates of the control target position) when included in the reference guide locus EB are the origin position at the movement position O of the wire electrode E, and the vertical coordinates of the reference positions RU and RL are ZU0, When ZL0 (the distance in the vertical direction from the upper surface of the work table 6 of RU and RL) is used, the calculation is performed as shown in Equation 1.

(Equation 1)
Control target position UU of RU in the U-axis direction = UU = ZU0 × tan θset × cosφset
Control target position VU of RU in the V-axis direction VU = ZU0 × tan θset × sinφset
Control target position XL of RL in the X-axis direction XL = ZL0 × tan θset × cosφset
RL Y-axis control target position YL = ZL0 × tan θset × sinφset

However, as is clear from the figure, the reference guide trajectory EB and the inner peripheral surfaces of the sub guide portions 9a and 10a cross each other, so that the wire electrode E can be guided along the reference guide trajectory EB. Actually, the actual fulcrum positions RU ′ and RL ′ supporting the wire electrode E are displaced in the vertical direction along the central axes SU and SL of the wire guides 9 and 10 with respect to the reference positions RU and RL. Due to this displacement, the desired taper angle θset differs from the actual taper angle θ, which contributes to a significant decrease in machining accuracy.

Therefore, as shown in FIG. 17 and Formula 2, conventionally, the control target position is set with the vertical displacements ΔZU and ΔZL as correction amounts so that the actual fulcrum positions RU ′ and RL ′ are included in the reference guide locus EB. The taper angle correction method is employed in which the position of the wire guides 9 and 10 is controlled by correcting the error and the error occurring in the taper angle is corrected. For a specific correction method in such a case, for example, the technique disclosed in Patent Document 1 is referred to.

(Equation 2)
UU correction position UU0 = (ZU0−ΔZU) × tan θset × cosφset
VU correction position VU0 = (ZU0−ΔZU) × tan θset × sinφset
XL correction position XL0 = (ZL0−ΔZL) × tan θset × cosφset
YL correction position YL0 = (ZL0−ΔZL) × tan θset × sinφset

JP 2006-239807 A

However, as shown in FIG. 18 (for the sake of convenience, only the upper wire guide 9 side is shown), for example, the wire guide 9 may be slightly tilted due to a manufacturing error, an installation error, or the like. The center axis SU is inclined, and the actual fulcrum position RU ′ may be displaced in the horizontal direction with respect to the reference position RU. Due to such displacement of the fulcrum position, the desired taper direction angle φset and the actual taper direction angle φ are different, and an error is caused in the taper direction angle, and the machining accuracy may be reduced by several tens of μm.

The horizontal displacement of the fulcrum position varies according to the taper direction angle according to the study by the present inventors, and it is natural that only the position control of the wire guide is performed using the vertical displacement of the fulcrum position as a correction amount as described above. Even if the vertical position is determined and the positional relationship of the wire guide in the horizontal direction at the taper angle θ = 0 ° is finely adjusted, it cannot be eliminated.

The present invention has been made in view of such circumstances, and provides a correction method of a taper direction angle in a wire-cut electric discharge machining apparatus capable of improving machining accuracy by correcting an error occurring in the taper direction angle. With the goal.

In order to achieve the above object, the invention of claim 1 corrects an error occurring in the taper direction angle when an error occurs in the taper direction angle of the wire electrode due to the horizontal displacement of the fulcrum position supporting the wire electrode. A correction amount for the wire guide is specified as a displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to a predetermined reference position, and a control target position in the position control of the wire guide is set based on the specified correction amount. To do.

According to the present invention, the correction amount for correcting the error occurring in the taper direction angle is specified as the displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to the predetermined reference position, and the wire is determined based on the specified correction amount. Since the control target position in the guide position control is set, this error is accurately corrected even if an error occurs in the taper direction angle of the wire electrode due to the horizontal displacement of the fulcrum position supporting the wire electrode. can do.

According to the second aspect of the invention, when the actual fulcrum position supporting the wire electrode is displaced in the horizontal direction, the actual taper direction angle of the wire electrode causes an error with respect to the desired taper direction angle. The correction amount for correcting the generated error is specified as the displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to the predetermined reference position, and the control target position in the position control of the wire guide is set based on the specified correction amount It is characterized by doing.

According to the present invention, the correction amount for correcting the error occurring in the taper direction angle is specified as the displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to the predetermined reference position, and the wire is determined based on the specified correction amount. Since the control target position in the guide position control is set, the actual taper direction angle of the wire electrode causes an error from the desired taper direction angle due to the horizontal displacement of the actual fulcrum position supporting the wire electrode. Even in some cases, this error can be corrected accurately.

According to the third aspect of the present invention, when the actual fulcrum position supporting the wire electrode is displaced in the horizontal direction, the actual taper direction angle of the wire electrode causes an error with respect to the desired taper direction angle. A step of setting a reference position, a step of specifying a correction amount for correcting an error occurring in the taper direction angle as a displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to the set reference position, and the specified correction amount And setting a control target position in the position control of the wire guide based on the above.

According to the present invention, the correction amount for correcting the error occurring in the taper direction angle is specified as the displacement of the actual fulcrum position of the wire electrode in the horizontal direction with respect to the reference position set in the wire guide in a predetermined step. Since the control target position in the position control of the wire guide is set based on the specified correction amount, the actual taper direction angle of the wire electrode is desired by the horizontal displacement of the actual fulcrum position supporting the wire electrode. Even when an error occurs with respect to the taper direction angle, this error can be accurately corrected.

Here, a plurality of actual fulcrum position displacements in the horizontal direction with respect to the reference position are specified, and an arithmetic expression related to the actual fulcrum position in the horizontal direction is based on the reference position and the specified plurality of horizontal displacements. In addition, the trajectory drawn on the horizontal plane at the actual fulcrum position when the taper angle is changed under the condition where the taper angle is constant is assumed to be an elliptical shape, and is generated in the horizontal direction by the generated arithmetic expression. The correction amount for specifying the actual fulcrum position and correcting the error occurring in the taper direction angle can be the displacement in the horizontal direction specified by the arithmetic expression with respect to the reference position.

According to the present invention, it is possible to improve machining accuracy by correcting an error occurring in the taper direction angle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Overall configuration of wire-cut electrical discharge machine]
FIG. 1 is a perspective view showing an outline of a wire cut electric discharge machining apparatus showing an embodiment of the present invention. The outline of the wire cut electric discharge machining apparatus 1 will be described with reference to FIG. 1. The wire cut electric discharge machining apparatus 1 includes a base 2 serving as a base of the apparatus 1, a column 3 erected from the rear part of the base 2, and a column 3, a processing head 4 mounted on the upper front of the base plate 3, a processing tank 5 placed on the front part of the base 2, and a work table 6 accommodated in the processing tank 5 on which the work W is placed. An upper guide assembly 7 is provided on the machining head 4, and a lower guide assembly 8 is provided at the lower front portion of the column 3 so as to sandwich the workpiece W. That is, as shown in FIGS. 2 and 3, the upper and lower guide assemblies 7 and 8 have ring-shaped main guide portions 9a and 10a and circular arc surfaces having a large curvature radius on the inner peripheral surface for guiding the wire electrode. The wire guides 9 and 10 having the sub-guide portions 9b and 10b are accommodated, respectively, and the wire electrode E is stretched between the wire guides 9 and 10.

The wire-cut electric discharge machining apparatus 1 is provided with an NC control device 20, and the NC control device 20 controls the amount of movement of a predetermined moving means so that the positions of the wire guides 9 and 10 are appropriately controlled to obtain a desired value. Taper processing can be performed under the taper angle and the taper direction angle. The position control of the wire guides 9 and 10 is performed by moving the wire guides 9 and 10 in the horizontal direction with the vertical positions of the wire guides 9 and 10 being fixed.

[Correction principle of taper angle and taper direction angle]
Hereinafter, the correction principle of the taper angle and the taper direction angle when the wire guides 9 and 10 are tilted and the fulcrum position is displaced in the horizontal direction in addition to the vertical direction will be described. In the following description, the horizontal displacement generation direction of the actual fulcrum position RU ′ with respect to the reference position RU will be described as a direction orthogonal to the desired taper direction. The following correction principle and the like are the same on the upper wire guide 9 side and the lower wire guide 10 side, and the illustration and description may be omitted on the lower wire guide 10 side.

As shown in FIG. 4, first, the moving position O of the wire electrode E on the upper surface of the work table 6 that is the origin position is set, and the reference position RU is set in the wire guide 9. The reference position RU is a position for specifying the displacement of the fulcrum position of the wire electrode E, and is a position that also functions as a control position when controlling the position of the wire guide 9. In the present embodiment, the reference position RU is set to the ring hole center position of the wire guide 9 when it is assumed that the wire guide 9 is not tilted and the center axis SU is held vertically.

As in the prior art, the line segment passes through the moving position O of the wire electrode E, forms an angle equal to the desired taper angle θset with the vertical direction, and forms a desired taper with the U axis. A line segment having an angle equal to the direction angle φset is defined as a reference guide locus EB of the wire electrode E.

At this time, assuming that the actual fulcrum position RU ′ is displaced ΔZU in the vertical direction with respect to the reference position RU and further displaced in the horizontal direction by ε in the direction orthogonal to the desired taper direction, By simply controlling the position of the wire guide 9 using the correction amount as a correction amount, the error in the taper direction angle based on the displacement ε remains even though the error based on the taper angle ΔZU is corrected.

Therefore, as shown in FIG. 5, the position control of the wire guide 9 is performed so that the error of the taper direction angle is also corrected. That is, the control target position RUset (UUset, VUset, ZUset) of the reference position RU that can also correct the error in the taper direction angle is the coordinate of the reference position RU when only the taper angle is corrected based on ΔZU. RU0 (UU0, VU0, ZU0), and further, a correction amount for correcting an error caused by the displacement ε in the taper direction angle, more specifically, a U-axis component εU and a V-axis component εV of the displacement ε are produced in the taper direction angle. When the correction amount is used to correct the error, the calculation is performed as shown in Equation 3. And the error which arises in a taper direction angle can be correctly correct | amended by performing control which aligns the reference position RU to this control target position RUset.

(Equation 3)
UUset = UU0 + εU
VUset = VU0 + εV
ZUset = ZU0

Here, UU0 and VU0 are calculated as follows based on ZU0, ΔZU, desired taper angle θset, and desired taper direction angle φset.
(Equation 4)
UU0 = (ZU0−ΔZU) × tan θset × cosφset
VU0 = (ZU0−ΔZU) × tan θset × sinφset

Further, each correction amount ΔZU, εU, εV is calculated as a difference between coordinate values of RU0 and the actual fulcrum position RU ′ as follows.
(Equation 5)
ΔZU = ZU0-ZU '
εU = UU0−UU ′
εV = VU0−VU ′

  Here, in the present embodiment, since the position of the wire guide 9 in the vertical direction remains fixed, ZU0 is set to be constant regardless of the taper angle and the taper direction angle, and θset and φset. Is a desired value, so if the coordinates (UU ', VU', ZU ') of the actual fulcrum position RU' can be specified, a reference position that does not cause an error in the taper angle and the taper direction angle from Equation 3 to Equation 5 The control target position RUset of RU can be set.

[Outline of correction method of taper angle and taper direction angle]
Next, an outline of the taper angle and the taper direction correction method when the wire guide 9 is tilted and the fulcrum position is displaced in the horizontal direction will be described with reference to the flowchart of FIG.

That is, first, in step S10, in order to be able to specify the vertical coordinate ZU ′ of the actual fulcrum position RU ′ at an arbitrary taper angle and taper direction angle, various data related to the ZU ′ are detected, etc. In addition to generating the database, in step S20, in order to be able to specify the horizontal coordinates UU 'and VU' of the actual fulcrum position RU 'at an arbitrary taper angle and taper direction angle, various types of UU' and VU 'are specified. A predetermined arithmetic expression is generated by detecting data or the like.

Subsequently, in step S30, the correction amounts ΔZU, εU, εV at the desired taper angle θset and the desired taper direction angle φset are specified, and the taper angle and the taper direction are determined based on the correction amounts ΔZU, εU, εV, etc. The control target position RUset of the reference position RU that does not cause an error in the angle is calculated, and the control for aligning the reference position RU with the control target position RUset is performed to correct the error occurring in the taper angle and the taper direction angle.

[Details of data detection and database generation methods regarding ZU ']
Next, details of various data detection and database generation methods relating to ZU ′ in step S10 will be described with reference to FIGS.
That is, first in step S100, the vertical position of the wire electrode E is determined and the vertical axis O 'is set.

Next, in step S101, the upper wire guide 9 is moved in the horizontal direction while fixing the position in the vertical direction while the lower wire guide 10 is fixed, and the wire electrode E is appropriately moved under a predetermined taper direction angle φ11. The state is inclined.
Subsequently, in step S <b> 102, predetermined data is obtained using the contact detector 30. In other words, the contact detector 30 has upper and lower detection edges 30a and 30b provided by shifting the distance H in the vertical direction, and the lower detection edge 30b is arranged at a position B in the vertical direction from the upper surface of the work table 6. While moving in the taper direction, the upper and lower detection edges 30a, 30b are brought into contact with the wire electrode E, and deviations α11, β11 in the taper direction with respect to the vertical axis O ′ of the contact portions are detected.
Next, in step S103, the actual taper angle θ11 of the wire electrode E is calculated by the following equation 6 based on the deviation amounts α11, β11 detected in step S102.

(Equation 6)
θ11 = tan−1 {(α11−β11) / H}
In step S104, the wire electrode diameter d (diameter) and the amount of movement U of the upper wire guide 9 from the vertical axis O ′ are obtained in advance, and the wire electrode diameter d and the amount of movement U are further calculated in step S103. Based on the actual taper angle θ11 and the like, ZU′θ11 is calculated by the following equation (7).

(Equation 7)
ZU'θ11
= {U−β11 + (d / 2) × (−1 + 1 / cos θ11)} / tan θ11 + B
Thereafter, the amount of inclination of the wire electrode E is changed, and the taper direction angle is also changed to a predetermined value such as φ12,..., Φ1n, and steps S101 to S104 are repeated, and the taper angles θ12,. ,..., ZU′θ1n is obtained.

In step S105, ZU′θ11,..., ZU′θ1n obtained in step S104 is databased in association with taper angles θ11,..., Θ1n and taper direction angles φ11,. The ZU ′ in the angle is set in a state that can be specified.

[Details of detection method of various data relating to UU 'and VU' and generation of arithmetic expressions]
Next, details of the detection of various data relating to UU ′ and VU ′ in step S20 and the generation method of the arithmetic expression will be described with reference to FIGS.

That is, first, in step S200, the actual taper angle is set to θ21 and the taper direction angle is set to a predetermined angle φ21. More specifically, a data detection control target position RUdet (UUdet, VUdet, ZUDet) of the reference position RU is calculated by Equation 8, and the actual taper angle is obtained by aligning the reference position RU with the calculated position. A state in which the taper direction angle is appropriately set to φ21 is set to θ21. In addition, since the vertical position ZU′θ21 of the actual fulcrum position RU ′ corresponding to the taper angle θ21 and the taper direction angle φ21 is specified by the database obtained in step S105 described above, ΔZU is calculated based on Equation 5. RUdet can be calculated.

(Equation 8)
UUdet = (ZU0−ΔZU) × tan θ21 × cosφ21
VUdet = (ZU0−ΔZU) × tan θ21 × sin φ21
ZUDet = ZU0

In step S201, predetermined data is obtained using the contact detector 30. That is, while the lower detection edge 30b of the contact detector 30 is arranged at a position B in the vertical direction from the upper surface of the work table 6, the detection edge 30a is moved up and down in the direction perpendicular to the desired taper direction in the horizontal direction. 30b is brought into contact with the wire electrode E, and shift amounts α21 and β21 in the direction orthogonal to the desired taper direction at the contact portion of the wire electrode E in the horizontal direction are detected.

Subsequently, in step S202, ZU ′ corresponding to the taper angle θ21 and the taper direction angle φ21 is specified by the database obtained in step S105, and the specified ZU ′ and the shift amounts α21, β21 detected in step S201, etc. Based on the above, the displacement εφ21 in the direction perpendicular to the desired taper direction in the horizontal direction of the actual fulcrum position RU ′ with respect to the reference position RU is calculated by the following equation (9).

(Equation 9)
εφ21 = β21 + (α21−β21) × (ZU′−B) / H
Hereinafter, the taper direction angle is changed to φ22,..., Φ2n to a predetermined value, and the actual taper angle is also changed to θ22,..., Θ2n to obtain εφ22,.

In step S203, the locus drawn by the actual fulcrum position RU ′ when the taper direction angle is changed under a condition where the taper angle is constant is regarded as an elliptical shape on the UV plane, and is obtained in step S202. Based on the displacements .epsilon.21,..., .Epsilon..phi.2n, etc., arithmetic expressions for UU 'and VU' using the taper direction angle .phi. As shown in FIG. 11, the calculation formula is generated as UU′21,..., UU′2n, VU′21,..., VU′2n for each actual taper angle θ21,. The taper angle θ and the taper direction angle are interpolated based on the obtained arithmetic expression. Thus, UU ′ and VU ′ at an arbitrary taper angle θ and taper direction angle φ are set in a state that can be specified.

Details of the method for generating the UU′2n and VU′2n formulas will be described below by taking as an example the case where the taper direction angle φ changes from 0 ° to 45 ° under the actual taper angle θ2n to supplement step S203. Will be explained.

First, as shown in FIG. 12, when the reference position RU is aligned with a predetermined data detection control target position, the positions are RU0 °, RU45 °, and the actual fulcrum positions are RU′0 °, RU′45 °. The displacements in the direction perpendicular to the desired taper direction in the horizontal direction with respect to the reference positions RU0 ° and RU45 ° of the actual fulcrum positions RU′0 ° and RU′45 ° are ε0 ° and ε45 °, and the displacement in the vertical direction is ΔZU0 °. , ΔZU45 °, and the vertical position of the reference position RU is ZU0.

Further, the intersection of the line segment passing through RU′0 ° and parallel to the U axis and the line segment passing through RU′45 ° and having an angle of 45 ° is the center point A and center point A of the elliptical locus. And RU′0 ° and RU′45 °, that is, when the radius of the elliptical locus is r1 and r2, respectively, these r1 and r2 are based on the geometric relationship shown in an enlarged manner in FIG. It can be calculated by Equation 10.

(Equation 10)
r1 = (ZU0−ΔZU0 °) × tan θ2n + 2 ^0.5 × ε45 ° −ε0 °
r2 = (ZU0−ΔZU45 °) × tan θ2n + ε45 ° −2 ^0.5 × ε0 °
Returning to FIG. 12, when the radius parallel to the V axis in the extrapolated elliptical trajectory is r3 and the parameter is φ ′ for convenience, the elliptical trajectory equations UU′2n (A) and VU′2n ( A) can be determined as shown in Equation 11 with the center point A as the origin.

(Equation 11)
UU′2n (A) = r1 × cos φ ′
VU′2n (A) = r3 × sinφ ′
Further, since this elliptical locus includes the fulcrum position RU′45 °, the relationship between r1 and r2 can be expressed as shown in Expression 12 when the parameter φ ′ at the time of inclusion is φ0 ′.

(Equation 12)
r1 × cosφ0 ′ = r2 × cos45 °
Therefore, φ0 ′ can be calculated as in Expression 13.
(Equation 13)
φ0 ′ = cos ⁻¹ {(r2 / r1) × cos45 °}
= Cos ⁻¹ {(r2 / r1) × 1/2 ^0.5 }

Similarly, the relationship between r2 and r3 can be expressed as in Expression 14 using the parameter .phi.0 '.
(Equation 14)
r3 × sin φ0 ′ = r2 × sin45 °
Here, ΔZU0 ° and ΔZU45 ° are specified by the database relating to ZU ′ generated in step S10 described above and Equation 5 and the like, and ε0 ° and ε45 ° are specified in step S202. Based on these, r1 and r2 are calculated in Equation 10, and φ0 ′ is calculated in Equation 13 using these r1 and r2, and therefore r3 is calculated by Equation 14.

Further, when the taper direction angle φ changes from 0 ° to 45 °, the parameter φ ′ changes from 0 ° to φ0 ′. Therefore, φ ′ can be calculated as shown in Equation 15 using linear interpolation.
(Equation 15)
φ '= φ0' × φ / 45 °

Using the r3, φ ′, etc. obtained in this way and further considering the positional difference between the center point A of the elliptical locus and the movement position O of the wire electrode E, the taper direction angle changes from 0 ° to 45 °. UU′2n and VU′2n at the time can be calculated as in Expression 16.
(Equation 16)
UU′2n = r1 × cos φ′−2 ^0.5 × ε45 ° + ε0 °
VU′2n = r3 × sin φ ′ + ε0 °

[Details of taper angle and taper direction angle correction method]
Next, details of the correction method of the taper angle and the taper direction angle in step S30 will be described with reference to FIG.
That is, first, in step S300, the movement position O of the wire electrode E on the upper surface of the work table 6 is set. This movement position O is a position offset by a predetermined amount with respect to the machining shape of the workpiece W, and is the origin position.

Next, a reference position RU is set in the wire guide 9 in step S301. The reference position RU is a ring hole center position of the wire guide 9 when it is assumed that the wire guide 9 is not tilted and the center axis SU is held vertically.
Subsequently, in step S302, the position of the wire guide 9 in the vertical direction is set. In this embodiment, the position control of the wire guide 9 is performed by moving the wire guide 9 in the horizontal direction with the vertical position of the wire guide 9 being fixed. The vertical coordinate ZU0 of the nine reference positions RU is set.

In step S303, a desired taper angle θset and a desired taper direction angle φset are determined.
Next, in step S304, ZU ′ corresponding to the desired taper angle θset and the desired taper direction angle φset is specified from the database obtained in step S105.
Subsequently, in step S305, the correction amount ΔZU is specified by Equation 5 based on ZU0 set in Step S302 and ZU ′ specified in Step S304, and UU0 and VU0 are calculated by Equation 4.
Next, in step S306, the UU ′ and VU ′ corresponding to the desired taper angle θset and the desired taper direction angle φset are specified based on the arithmetic expressions of UU ′ and VU ′ obtained in step 203.

In step S307, correction amounts εU and εV are specified by Equation 5 based on UU0 and VU0 calculated in step S305 and UU ′ and VU ′ specified in step S306.
Subsequently, in Step S308, the control target position RUset of the reference position RU that does not cause an error in the taper angle and the taper direction angle according to Equation 3 based on the correction amounts ΔZU, εU, εV, etc. specified in Step S305 and Step S307. Set.

In step S309, control for aligning the reference position RU with the control target position RUset set in step S308 is performed. As a result, even when an error occurs in the taper angle and the taper direction angle due to the vertical and horizontal displacements of the actual fulcrum position RU ′ with respect to the reference position RU, this error can be corrected accurately.

In addition, this invention is not limited to embodiment mentioned above, A various application implementation or deformation | transformation implementation is possible as needed.
For example, the correction amount of the taper angle is set as the vertical displacement of the actual fulcrum position with respect to the reference position, but the vertical position of the actual fulcrum position is set as the correction amount, and (Equation 4) is expressed as (Equation 17) below. It is good also as changing the position control of a wire guide.

(Equation 17)
UU0 = ZU ′ × tan θset × cosφset
VU0 = ZU ′ × tan θset × sinφset
The horizontal displacement generation direction of the actual fulcrum position with respect to the reference position is set to a direction orthogonal to the desired taper direction. However, when a displacement occurs in a direction other than the orthogonal direction, an appropriate correction amount should be specified. Thus, the control target position of the reference position that does not cause an error in the taper angle and the taper direction angle can be set as a matter of course.

Furthermore, although the reference position is the center position of the ring hole of the main guide portion, the position difference from the actual fulcrum position is properly grasped, and errors occurring in the taper angle and the taper direction angle based on this position difference are appropriately determined. Other positions may be used as long as they can be corrected.

The present invention can be used for an electric discharge machining apparatus. Specifically, it is useful for correcting an error in the taper angle and taper direction angle of the wire electrode due to the displacement of the fulcrum supporting the wire electrode.

It is a perspective view which shows the whole structure of the electric discharge machining apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the upper wire guide with which the same electric discharge machine is equipped. It is sectional drawing which shows the structure of the lower wire guide with which the same electric discharge machining apparatus is equipped. It is a figure for demonstrating the correction method of a taper angle and a taper direction angle. It is a figure for demonstrating the correction method of a taper angle and a taper direction angle similarly. It is a flowchart for demonstrating the outline | summary of the correction method of a taper angle and a taper direction angle. It is a flowchart for demonstrating the detail of the detection method of various data regarding ZU ', and the production | generation method of a database. It is a figure for demonstrating the detection method of the various data regarding ZU '. It is a flowchart for demonstrating the detection method of various data regarding UU ', VU', and the production | generation method of an arithmetic expression. It is a figure for demonstrating the detection method of the various data regarding UU 'and VU'. It is a figure for demonstrating the interpolation method of UU 'and VU'. It is a figure for demonstrating the production | generation method of the arithmetic expression of UU 'and VU'. It is a figure for demonstrating the production | generation method of the arithmetic expression of UU 'and VU' similarly. It is a flowchart for demonstrating the detail of the correction method of a taper angle and a taper direction angle. It is a figure for demonstrating the correction method of the conventional taper angle and taper direction angle. It is a figure for demonstrating the correction method of the conventional taper angle and taper direction angle similarly. It is a figure for demonstrating the correction method of the taper angle which correct | amends the error which arises in the conventional taper angle. It is a figure for demonstrating the error of the taper direction angle produced by the fall of a wire guide.

Explanation of symbols

E: Wire electrode EB: Reference guide locus O: Wire electrode movement position (origin position)
RU: Reference position RU ′: Actual fulcrum position of wire electrode SU: Center axis of wire guide W: Workpiece ΔZU: Vertical displacement (correction amount) of fulcrum of wire electrode
θ: taper angle φ: taper direction angle ε: horizontal displacement of wire electrode fulcrum (correction amount)
εU: U-axis component of ε (correction amount)
εV: V-axis component of ε (correction amount)
1: Electrical discharge machining device 2: Base 3: Column 4: Processing head 5: Processing tank 6: Work table 7: Upper guide assembly 8: Lower guide assembly 9: Upper wire guide 9a: Main guide portion 9b: Sub guide portion 10: Lower wire guide 10a: Main guide portion 10b: Sub guide portion 20: NC control device 30: Contact type detector 30a: Upper detection edge 30b: Lower detection edge

Claims (4)

When an error occurs in the taper direction angle of the wire electrode due to the horizontal displacement of the fulcrum position supporting the wire electrode, a correction amount for correcting the error generated in the taper direction angle is set in the horizontal direction with respect to a predetermined reference position. In the wire cut electrical discharge machining apparatus, characterized in that the control target position in the position control of the wire guide is set based on the specified correction amount. Correction method. When the actual taper direction angle of the wire electrode causes an error with respect to the desired taper direction angle due to the horizontal displacement of the actual fulcrum position supporting the wire electrode, the error generated in the taper direction angle is corrected. A correction amount for the wire guide is determined as a displacement of the actual fulcrum position of the wire electrode in a horizontal direction with respect to a predetermined reference position, and a control target position in the position control of the wire guide is set based on the specified correction amount. A taper direction angle correction method in a wire-cut electric discharge machining apparatus. In the case where the actual taper direction angle of the wire electrode causes an error with respect to the desired taper direction angle because the actual fulcrum position supporting the wire electrode is displaced in the horizontal direction,
Setting a reference position in the wire guide;
Specifying a correction amount for correcting an error occurring in the taper direction angle as a displacement of an actual fulcrum position of the wire electrode in a horizontal direction with respect to the set reference position;
Setting a control target position in position control of the wire guide based on the specified correction amount;
A method of correcting a taper direction angle in a wire cut electric discharge machining apparatus, comprising: A plurality of displacements of the actual fulcrum position in the horizontal direction relative to the reference position are specified, and an arithmetic expression related to the actual fulcrum position in the horizontal direction is based on the reference position and the specified plurality of displacements in the horizontal direction. And the trajectory drawn on the horizontal plane of the actual fulcrum position when the taper direction angle is changed under a condition where the taper angle is constant is generated as if it is an elliptical shape, and the generated calculation formula The actual fulcrum position in the horizontal direction is specified by the above, and the correction amount for correcting the error occurring in the taper direction angle is the displacement in the horizontal direction specified by the arithmetic expression with respect to the reference position. The correction method of the taper direction angle in the wire cut electric discharge machining apparatus of Claim 1 thru | or 3.

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