JPH0644574Y2 - Wire electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a wire electric discharge machine, and more particularly, to a device for vertically and accurately suspending a wire electrode.

“Prior Art” In wire electric discharge machining, the verticality of the wire electrode directly affects the machining accuracy and is important. A vertical gauge having a pair of upper and lower detection end faces is used to set the verticality of the wire electrode. For vertical work, use the above two vertical gauges and fix the detection surface composed of the detection end face on the XY table on which the workpiece is placed so that it is perpendicular to the X and Y axes, respectively. This is performed by finely adjusting the position of the wire guide so that the wire electrodes simultaneously contact the upper and lower detection end faces of the vertical gauge when the X axis or the Y axis is moved. The contact detection between the detection end face and the wire electrode is detected by the voltage change of the wire electrode.

As an apparatus for automating such vertical operation, Japanese Patent Laid-Open No.
In Japanese Laid-Open Patent Application No. -104099 and Japanese Patent Laid-Open No. 63-127830, a vertical gauge having a wire guide driving device and having a first detection surface perpendicular to the X axis and a second detection surface perpendicular to the Y axis is used. , A device for positioning the U axis of the wire guide so that the wire electrode is parallel to the first detection surface and then positioning the V axis of the wire guide so that it is also parallel to the second detection surface. .

[Problems to be solved by the device] However, the above-mentioned vertical alignment operation essentially adjusts the wire electrode parallel to the detection surface of the vertical alignment gauge, and in order to obtain sufficient vertical alignment accuracy, vertical alignment is required. It is necessary to arrange each detection surface of the gauge so as to be orthogonal to the X axis and the Y axis exactly. This point will be described with reference to FIG. FIG. 7 is a diagram in which a series of vertical movements of the wire electrode are orthographically projected on the XY plane (horizontal plane). The tilted wire electrode before being vertically extended is the center A ₀ , B of the upper and lower wire guides.
It is shown by a line segment connecting _0, and the line segment forms an angle β with the X axis. It is also assumed that the first detection surface P1 of the vertical gauge is not orthogonal to the X axis and is fixed at an angle θ.

Now, the position of the upper wire guide is moved in the U-axis direction using the first detection surface P1 so that the wire electrode is parallel to the detection surface P1 (A ₁ , B ₁ ). Then, the table is moved in the X-axis direction and the wire electrodes relatively move backward (A ₂ , B ₂ ). Then the upper wire guide position so as to be parallel to the second detection surface P2 is operated in the V-axis direction using the second detection surface _{P2 (A 3, B 3)} . Then, the table is moved in the Y-axis direction and the wire electrodes are retracted (A ₄ , B ₄ ), and the vertical alignment operation is completed. However, as is clear from the figure, points A ₄ and B ₄ do not match in the above operation. That is, the wire electrode is not perpendicular to the XY plane. This is the first detection surface P1 of the vertical gauge
This is because the vertical gauge was not attached so as to be orthogonal to the X axis, and this phenomenon tends to deteriorate the verticality of the wire electrode as the attachment angle error θ increases.

Further, even if the squareness accuracy of the two detection surfaces P1 and P2 of the vertical gauge is poor, it becomes impossible for any one of the detection surfaces to be perpendicular to the movement axis (X axis or Y axis) of the table exactly. In addition, the verticality of the wire electrode tends to deteriorate.

As described above, in the conventional device, it is necessary to accurately set the detection surface of the vertical gauge to be orthogonal to the X-axis and the Y-axis with high accuracy. There is a problem that fixing the gauge requires a troublesome paralleling work.

Further, there is a problem that high accuracy is required for the squareness of the two detection surfaces P1 and P2 of the vertical gauge.

The present invention has been made in view of the above problems, and an object of the present invention is not to require high accuracy in the perpendicularity of the detection surface of the vertical gauge, and also to install the vertical gauge in high accuracy. It is an object of the present invention to provide a wire electric discharge machine capable of automating a highly accurate vertical operation of a wire electrode without performing the above.

[Means for Solving the Problem] In order to achieve the above-mentioned object, in the present invention, as shown in FIG. 1, a table 10 on which a workpiece is placed is placed in an XY plane relative to a wire electrode 1. A workpiece feeding device 4 having orthogonal X and Y axes to be moved inside and at least one of a pair of upper and lower wire guides 2 and 3 on which wire electrodes are stretched are parallel to the X and Y axes for moving in the UV plane. A wire guide driving device 5 having orthogonal U and V axes, and a pair of upper and lower detection end faces 45, which are placed on the table 10 and are orthogonal to each other on the first and second detection faces P1 and P2. A vertical output gauge 40 having 46, 47, 48, and a contact detection means 6 for detecting contact of the wire electrode 1 with the pair of upper and lower detection end faces 45, 46, 47, 48 of the vertical output gauge 40 are provided. X in wire electric discharge machine
The contact between both of the pair of upper and lower detection end faces 45, 46 constituting the first detection surface P1 substantially orthogonal to the axis and the wire electrode 1 is detected by moving the detection surface P1 in the X-axis direction. ,
After moving the U-axis positions of the wire guides 2 and 3 so as to align the wire electrode 1 stretched between the upper and lower wire guides 2 and 3, both the detection end faces 45 and 46 and the wire electrode are moved. U-axis moving means 7 for moving the X-axis to a predetermined position where the contact with 1 is released, and the second axis substantially orthogonal to the Y-axis.
Of the upper and lower wire guides 2, 3 while detecting the contact between the wire electrode 1 and both of the pair of upper and lower detection end faces 47, 48 constituting the detection surface P2 of the above.
After moving the V-axis positions of the wire guides 2 and 3 so as to align the wire electrode 1 stretched between them, the contact between both of the detection end faces 47 and 48 and the wire electrode 1 is released. V-axis moving means 8 for moving the Y-axis to a predetermined position
And the vertical accuracy of the wire electrode 1 is determined on the basis of the movement operations of the U-axis moving means 7 and the V-axis moving means 8, and the U-axis until the determination value of the vertical accuracy converges within a predetermined allowable range. There is provided a wire electric discharge machine comprising: a moving unit 7 and a repeating unit 9 which repeats the moving operation by the V-axis moving unit 8 alternately a plurality of times.

"Operation" In the wire electric discharge machine configured as described above, the U-axis moving means 7 that makes the wire electrode 1 parallel to the first detection surface P1.
Then, the moving means by the V-axis moving means 8 which is parallel to the second detection surface P2 is repeatedly executed by the repeating means 9 a plurality of times until the vertical accuracy converges within a predetermined allowable range. Even if the detection surfaces P1 and P2 of the vertical gauge 40 are not exactly orthogonal to the X axis or the Y axis, the U axis moving means 7
The position of the wire guide 2 converges on the position where the wire electrode 1 is perpendicular to the XY plane every time the V-axis moving means 8 is combined with each other. Therefore, the verticality error of the wire electrode 1 is suppressed to a predetermined value or less regardless of the existence of the orthogonal error with respect to the X axis and the Y axis of each of the detection surfaces P1 and P2.

[Examples] Examples of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing a schematic configuration of a wire electric discharge machine equipped with a wire guide driving device. The table 10 forming the work mount is sent in the X-axis direction and the Y-axis direction by the X-axis motor 11 and the Y-axis motor 12 and is movable in the horizontal plane (the XY plane). The X axis and the Y axis are orthogonal to each other. X, Y axis motor 1
The feeding mechanism including 1, 12 constitutes the workpiece feeding device 4.

The wire electrode 1 is positioned by the upper and lower wire guides 2 and 3, and a predetermined tension is applied by a brake roller and a driving roller (not shown), and the wire electrode 1 is stretched substantially vertically. The lower wire guide 3 is fixed at a predetermined position. The upper wire guide 2 is sent in the U-axis direction and the V-axis direction by the U-axis motor 13 and the V-axis motor 14 and is movable in a horizontal plane (in a UV axis plane). The U axis is parallel to the X axis and the V axis is parallel to the Y axis. The U axis and the V axis are orthogonal to each other, and the feed mechanism including the U and V axis motors 13 and 14 constitutes the wire guide driving device 5. The inclination of the wire electrode 1 is controlled by the position of the upper wire guide 2 on the UV plane, and the verticality is adjusted.

The power supply terminal 15 is in sliding contact with the wire electrode 1, and a voltage is applied.

Each axis motor 11-14 is connected to the NC controller 20. NC
The control device is a CPU 21 (processor unit) and a memory 22.
With each axis controller 23-26 and driver 27-30
Each axis motor 11-14 is controlled via. The NC control device 20 is provided with a detection circuit 31 that detects contact between the wire electrode 2 and the vertical gauge 40.

At the time of vertical work, a vertical gauge 40 is placed and fixed on the table 10 of the wire electric discharge machine. Vertical gauge
40 is an upper and lower two detection pieces 4 made of an L-shaped metal plate
It has a structure in which 1,42 are connected by an insulating member 43.
2 has detection end faces 45 to 48 which are orthogonal to each other. The upper and lower detection end faces are combined with each other to form two sets of detection faces P1 and P2, that is, a first detection face P1 formed of the detection end faces (45,46) and a second detection face P2 formed of the detection end faces (47,48). To do. Each detection surface P
The detection end surfaces 45 to 48 of 1 and P2 are formed so as to be precisely perpendicular to the bottom surface of the vertical gauge 40. The vertical gauge 40 is fixed on the table 10 so that the first detection surface P1 is substantially orthogonal to the X axis.

The detection pieces 41, 42 and the power supply terminal 15 of the vertical gauge 40 are connected to the detection circuit 31. In the detection circuit 31, 5-10V to the power supply 15
Is supplied to electrically detect contact of the wire electrode 1 with the upper and lower detection end faces 45 to 48.

The CPU 21 executes a computer program stored in advance in the memory 22, and in accordance with a contact signal from the detection circuit 31, an X-axis motor 11, a Y-axis motor 12 and a U-axis motor 13, which drives the upper wire guide 2, The V-axis motor 14 is controlled, and the wire electrode 1 causes the vertical detection gauge 40 to have the first detection surface P1.
The U-axis position of the upper wire guide 2 is positioned at a position parallel to the above, and then the V-axis position of the upper wire guide 2 is positioned at a position at which the wire electrode 1 is parallel to the second detection surface P2.
Then, the above U-axis positioning and V-axis positioning are repeated one after another, and the upper wire guide 2 is positioned at a position where the verticality error of the wire electrode 1 becomes a predetermined value or less.

FIG. 3 is a flowchart showing the processing in the CPU that realizes such control, and FIG. 4 is an explanatory diagram showing the movement of the wire guide.

Processed when vertical control operation command is given to NC controller 20
100 is started. First, the item i is set to 0 as an internal preparation process (step 101), and the current positions of the U-axis and V-axis are i = 0 in the memory 22, so they are stored as U ₀ and U ₀ (step 102). .

Next, in steps 111 to 119, the U-axis position is the first detection plane P1.
And the U-axis position is stored. That is, in step 111, the U-axis motor 13 is driven to move the upper wire guide 2 by + ΔU, and the wire electrode 1 is forcibly tilted as shown in FIG. 4 (1). Next, the X-axis motor 11 is driven to move the table 10 in the X + direction (steps 112 and 113). Since the wire electrode 1 is tilted, as shown in FIG. 4 (2), the wire electrode 1 first comes into contact with the upper detection end surface 45 of the vertical gauge 40, but it does not matter if the X axis is fed. continue. As shown in FIG. 4C, the table 10 is stopped immediately when the wire electrode 1 contacts the lower detection end surface 46 (steps 113 and 114). At this time, the wire electrode 1 extending from the upper detection end surface 45 to the lower wire guide 3 has the first detection surface P1.
It is parallel to. Next, the U-axis motor 13 is driven to move the upper wire guide 2 in the U-direction to restore the inclination of the wire electrode 1 above the upper detection end face 45 (steps 115, 11).
6). Eventually, as shown in FIG. 4 (4), the wire electrode 1
The U-axis motor 13 is stopped and the upper wire guide 2 is positioned at the moment when is separated from the upper detection end face 45 (steps 116, 11).
7). At this time, the wire electrode 1 is parallel to the first detection surface P1 formed by the upper detection end surface 45 and the lower detection end surface 46. The U-axis position is stored in the memory 22 as Ui. Then, the table 10 is returned to the starting position and the wire electrode 1 is separated from the detection end faces 45 and 46 (step 119).

Next, in steps 121 to 129, the V-axis position is set to the second detection plane P2.
And the V-axis position is stored. The processing of steps 121 to 129 corresponds to each of the steps 111 to 119 except that the drive axis is the V axis and the Y axis, and therefore the description thereof is omitted.

At the step 129, the wire electrode 1 is parallel to the second detection surface P2 of the vertical gauge 40. It should be noted here that the two detection surfaces of the vertical gauge 40 are
If P1 and P2 are not exactly orthogonal to the X and Y axes,
By moving the V-axis (step 125), the wire electrode 1 and the first
That is, the parallelism with the detection surface P1 is broken.

Therefore, the processing of the U-axis moving means 7 composed of steps 111 to 119 and the processing of the V-axis moving means 8 composed of steps 121 to 129 are sequentially repeated while advancing the item i in step 131. And this U-axis position U ₁ and the previous U-axis position
U-axis movement amount indicated by the difference of U _1-1 | U ₁ -U _1-1 |, and V-axis movement amount indicated by the difference between the present V-axis position V ₁ and the previous V-axis position V _1-1 If both │V ₁ -V _1-1 │ are below the preset value α,
The process proceeds from step 130 to step 132, and the vertical processing of the wire electrode 1 is completed.

By repeating the U-axis moving means (steps 111 to 119) and the V-axis moving means (steps 121 to 129) described above, the position of the upper wire guide 2 converges to a position that makes the wire electrode 1 precisely vertical. This will be explained.

FIG. 5 is a diagram showing the center position of the upper wire guide 2 as a vector on the UV orthogonal coordinate plane with the center of the lower wire guide 3 as the origin. The X axis and Y axis along which the table 10 moves are parallel to the U axis and Y axis along which the wire guide 2 moves. Here, the detection surfaces P1 and P2 of the vertical gauge 40 are X-axis (U-axis) and Y-axis (V-axis)
It is assumed that they are not exactly orthogonal to each other and are fixed on the table 10 in a state of being inclined to a position forming an angle θ. Surfaces that are parallel to the first detection surface P1 and the second detection surface P2 of the vertical gauge 40 and pass through the origin are shown by dashed lines in the figure.

Now, the initial position of the center of the upper wire guide 2 is the distance from the origin
It is assumed that the position is indicated by the vector R ₀ of the angle β formed with the r and X axes.

R ₀ = [r cos β, r sin β] (1) First, the first U-axis moving means (steps 111 to 119, i =
According to 1), the upper wire guide 2 moves to the position indicated by the vector R _1X parallel to the first detection plane P1.

R _1X = [− r sin β tan θ, r sin β] (2) Next, the upper wire guide 2 is a vector parallel to the second detection plane P 2 by the V-axis moving means (steps 121 to 129, i = 1).
Move to the position indicated by R _1Y .

R _1Y = [− r sin β tan θ, −r sin θ tan ² θ] (3) Hereafter, the upper wire guide 2 is moved to the position indicated by the vector R _n after n vertical movements by the repeating means (steps 130, 131). Moving.

R _n = r sin β (-1) ⁿ [tan ^2n-1 θ, tan ²ⁿ θ] (4) Here, the angle θ is an angle caused by an attachment error of the vertical gauge 40 on the table 10, Its value is small, ta
The value of nθ is extremely small. Therefore, the above (4)
The vector R _n shown in the equation converges to the origin (0,0) extremely quickly. Since the origin is the center position of the lower wire guide 3, the position of the upper wire guide 2 converges on the position where the wire electrode 1 is stretched precisely perpendicular to the XY plane.

For example, if r = 20mm, β = 45 °, θ = 2 °, then | R
₁ ｜ ＝ 0.511mm, | R ₂ ｜ ＝ 6.23 × 10 ^-4 mm, | R ₃ ｜ ＝ 7.60 × 10 ^-7
mm, and the convergence speed is extremely fast.

Next, even if there is an error in the squareness between the first detection surface P1 and the second detection surface P2 of the vertical gauge 40, the position vector of the upper wire guide 2 should converge to the origin position. , With reference to FIG.

Now, it is assumed that there is an error in the squareness between the first detection surface P1 and the second detection surface P2 of the vertical gauge 40 by an angle Δ. The mounting angle error of the vertical gauge 40 is the same as the previous one, and if the angle formed by the initial vector R ₀ indicating the upper wire guide 2 position with the X axis is β, then R ₀ = [r cos β, r sin β] (5) In the first vertical alignment operation, R _1X = [− rsinβ · tan (θ + Δ), rsinβ] R ₁ ≡R _1Y = [− rsinβ · tan (θ + Δ), −rsinβ tan ² (θ +
Δ)] (6) In the second vertical movement, R _2X = r sin β [tan ³ (θ + Δ), −tan ² (θ + Δ)] R ₂ ≡R _2Y = r sin β [tan ³ (θ + Δ), tan ⁴ (θ + Δ)]…
(7) The general formula is given by the following formula.

R _n = r sin β (-1) ⁿ [tan ^2n-1 (θ + Δ), tan ²ⁿ (θ +
Δ)] (8) As is clear from the above equation (8), the convergence speed is tan ² (θ
+ Δ) / 1 time, which is slightly delayed, but the position of the upper wire guide 2 converges on the position (origin) where the wire electrode 1 is vertically stretched.

In the embodiment shown in FIG. 3, in order to confirm that the absolute value | R _n | of the vector R _n is sufficiently small and the verticality accuracy of the wire electrode 1 is within a predetermined allowable value, U-axis movement amount | U ₁ -U _1-1 | and V-axis movement amount | V ₁ -V _1-1 | are used as evaluation functions, and each value is determined to be less than or equal to the predetermined set value α. Yes (step 130). However, there are various possible functions for evaluating | R _n |
For example, the total amount of movement of the U and V axes | U ₁ -U _1-1 | + | V ₁ -V
_1-1 | may be used. Further, since the convergence speed is fast, evaluation is simply performed by the number of iterations i, and all three times (n
= 3) It is possible to use a means for repeating.

[Advantages of the Invention] Since the present invention is configured as described above, U-axis moving means for making the wire electrode parallel to the first detection surface,
Since the moving operation by the V-axis moving means that is parallel to the second detection surface is repeatedly executed by the repeating means alternately a plurality of times until the vertical accuracy converges within a predetermined allowable range, the vertical alignment gauge mounting accuracy Even if each detection surface is not exactly orthogonal to the X-axis or the Y-axis and the squareness accuracy of the detection surface is poor, the wire electrode can be vertically aligned with high accuracy by automatic operation. It is possible to achieve an excellent effect that the preparation work for the work of vertically extending the wire electrode does not take time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram clearly showing the configuration of the present invention, FIG. 2 is a block diagram showing the configuration of a wire electric discharge machine as an embodiment, and FIG. 3 shows actual processing in a CPU. FIG. 4 is a front view showing the operation of the upper wire guide, FIGS. 5 and 6 are vector diagrams showing the operation of the upper wire guide on the UV plane, and FIG. 7 is a wire on the XY plane. It is a top view which shows the movement of an electrode. 1 ... Wire electrode, 2, 3 ... Wire guide, 4 ... Work piece feeding device, 5 ... Wire guide driving device, 6 ... Contact detection means,
7 ... U-axis moving means, 8 ... V-axis moving means, 9 ... Repeating means, 10 ... Table, 21 ... CPU, 22 ... Memory, 31 ... Detection circuit (contact detection means), 40 ... Vertical gauge, 45, 46 ... Detection end faces that form the first detection face P1, 47, 48 ... Detection end faces that form the second detection face P2.

Claims (1)

[Scope of utility model registration request] 1. A workpiece feeding device having orthogonal X and Y axes for moving a table on which a workpiece is placed in an XY plane relative to a wire electrode, and a pair of upper and lower parts for stretching the wire electrode. Wire guide driving device having orthogonal U and V axes parallel to the X and Y axes for moving at least one of the wire guides in the UV plane, and first and second orthogonally mounted on the table. Wire discharge machining having vertical detection gauges each having a pair of upper and lower detection end faces on each of the two detection surfaces, and contact detection means for detecting contact of a wire electrode to the upper and lower detection end faces of the vertical alignment gauge. In the machine, the contact between the wire electrode and both of the pair of upper and lower detection end faces that constitute the first detection surface substantially orthogonal to the X-axis is detected by moving the detection surface in the X-axis direction, and Stretched between the wire guides After moving the U-axis position of the wire guide to align the wire electrode, the U-axis movement is performed to move the X-axis to a predetermined position where contact between both of the detection end faces and the wire electrode is released. The contact between the wire electrode and both the means and the pair of upper and lower detection end faces that constitute the second detection surface substantially orthogonal to the Y axis is detected by moving the detection surface in the Y axis direction. After moving the V-axis position of the wire guide so as to align the wire electrode stretched between the wire guides, the wire electrode reaches a predetermined position where the contact between both of the detection end faces and the wire electrode is released. The vertical accuracy of the wire electrode is determined based on the V-axis moving means for moving the Y-axis and the moving operation of the U-axis moving means and the V-axis moving means, and the vertical accuracy determination value is within a predetermined allowable range. Until the above Wire electric discharge machine characterized by comprising a repeating unit, a repeating movement operation by the axis movement means and the V-axis moving means in a plurality of times alternately.