JP2599924B2 - Measurement method of electrode guide position in wire electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] In a method for measuring a position of an electrode guide in a wire electric discharge machine configured to perform electric discharge machining by generating electric discharge between a workpiece and a wire electrode. Moving the upper electrode guide in the U-axis direction or the V-axis direction parallel to the plane of movement of the processing table, and further moving the upper electrode guide in the Z-axis direction perpendicular to the plane of movement. The jig plate placed on the table senses contact with the wire electrode, and moves the working table in the X and Y directions when the contact sensing is performed, and the U, V and Z directions of the upper electrode guide. The equivalent vertical distance between the lower electrode guide and the upper surface of the mounting table on the actual machining apparatus, and the reference on the Z-axis scale prepared in advance with the lower electrode guide. Measurement method of the position of the electrode guide in a wire electric discharge machine that calculates the equivalent vertical distance on the actual machining device with the upper electrode guide when the origin of the axis holding the upper electrode guide is aligned with the origin It is about.

[Conventional technology]

A schematic configuration diagram of a general wire electric discharge machine is shown in FIG. In FIG. 4, reference numeral 1 denotes a workpiece, 2
Is a processing start hole, 3 is a processing locus, 4 is a wire electrode, 5 is a mounting table, which is fixed on a table (not shown) movably provided in orthogonal X and Y directions, 6 is Table driving device, 7 is a wire supply roll, 8 is an upper electrode guide, 9 is a lower electrode guide, 10 is a wire winding roll, 11
Is a guide driving device, and the upper electrode guide 8 is orthogonal to the U and V directions (the U and V directions are parallel to the X and Y directions) and the Z direction (the Z direction is relative to the U and V directions). (Vertical), 12 is a machining power supply, 13 and 14 are electronic devices, and 15 is an NC device.

In the wire electric discharge machine shown in FIG. 4, a machining power source is provided between the wire electrode 4 traveling via the upper electrode guide 8 and the lower electrode guide 9 and the workpiece 1, as is generally well known. By supplying a pulsed current from the device 12, a discharge is generated via the machining fluid, and the positions of the workpiece 1 and the upper electrode guide 8 are controlled based on conditions predetermined by the NC device 15. Thereby, processing having a desired inclination angle and shape is performed. The processing start hole 2 is a processing start position, and the position control by the NC device 15 is performed with reference to the processing start hole 2. Hereinafter, the workpiece 1 by the NC device 15 will be described.
The control mode of the upper electrode guide 8 will be described with reference to FIG. FIG. 5 shows a control mode diagram in the case of taper processing in which the control of the processing position is performed using the lower surface of the workpiece 1 as a reference plane, and the arrow H indicates the lower electrode guide 9 and the workpiece 1. actual machining apparatus the equivalent vertical distance between the lower surface (upper surface of the mount base 5), shown by the arrow G ₀ is (discussed below in connection with FIG. 7) Z-axis scale is prepared in advance a reference position on the (not When the origin of the axis holding the upper electrode guide 8 is aligned with the arrow Z ₀ ), the equivalent vertical distance between the upper electrode guide 8 and the lower electrode guide 9 on the actual processing apparatus, and Z is the upper electrode guide 8 and the vertical distance between the Z-axis reference position Z ₀ (hereinafter, referred to as upper guide vertical distance) representing the. As will be described later with reference to FIG. 7, the Z-axis scale indicates the position of the upper electrode guide 8 in the Z-axis direction.

In the case of straight machining, graphic information corresponding to the shape to be machined is provided to the NC device 15, while in the case of taper machining, the graphic information (for example, graphic information on the lower surface of the workpiece 1) is provided. The tilt angle information (tilt angle θ or tan θ) and the position in the Z-axis direction of the upper electrode guide 8 read on the Z-axis scale according to the thickness of the workpiece 1, that is, the upper guide vertical distance Z are given. .
Then, the inclination of the wire electrode 4 is adjusted by moving the upper electrode guide 8 to U,
This is done by moving in the V direction. That is, as shown in FIG. 5, the wire electrode is calculated by the above-described tilt angle information and the arithmetic processing based on the upper / lower guide distance (G ₀ + Z) obtained from the equivalent vertical distance G ₀ and the upper guide vertical distance Z. The moving distance a from the position of the upper electrode guide 8 in the vertical state 4 is obtained. In addition, the wire electrode 4
Causes a displacement b with respect to the shape and dimensions to be processed. The value of the displacement b is obtained by a calculation based on the inclination angle information of the wire electrode 4 and the equivalent vertical distance H. The position of the workpiece 1 is controlled based on the graphic information, the tilt angle information, and the equivalent vertical distance H. That is, by performing the electric discharge machining while controlling the movement of the upper electrode guide 8 and the position of the workpiece 1, machining of a desired shape is performed. Conventionally, the equivalent vertical distances H and G ₀ are measured in advance and stored in the NC device 15 as device-specific constants.

On of improving the machining accuracy of the electric discharge machining according to [invention will to problems Solved] wire electric discharge machine, it is necessary to accurately grasp the value of the equivalent vertical distance H and G _0. However, when the upper electrode guide 8 or the lower electrode guide 9 is worn out or when the wire electrode 4 is replaced with one having a different wire diameter, the above-mentioned upper electrode guide 8 or the lower electrode guide 9 is replaced. In such a case, the equivalent vertical distance H after the replacement of the guide and
The value of G _0, there may be discrepancies between the between the value stored in advance in the NC device 15 as a device-specific value. That is, as shown in FIG. 7, the equivalent vertical distance G ₀ is the distance of the Z axis 19 holding the upper electrode guide 8 with respect to the reference position Z ₀ on the Z axis scale 17 prepared in advance. This is the vertical distance between the upper electrode guide 8 and the lower electrode guide 9 when the origin (the illustrated pointer 20) is aligned. In the conventional case, when the origin is aligned with respect to the reference position Z ₀ on the Z-axis scale 17 as described above, the wire electrode holding position of the upper electrode guide 8 is correctly positioned with respect to the reference position Z ₀ . It was deemed to be located at a predetermined distance L _0. However, the wire electrode holding position of the upper electrode guide 8, without becoming as located at a distance L ₀ correctly given from the reference position Z ₀ on the Z-axis scale 17, displacement of the arrow dimension e occurs. That is, the deviation dimension e changes depending on the mounting state of the upper electrode guide 8 and the like. Therefore, in order to perform high-precision machining, it is necessary to consider the existence of the deviation dimension e, but it is practically impossible to eliminate the deviation dimension e. The same can be said for the equivalent vertical distance H because the lower electrode guide 9 exists.

In addition, as shown by the solid line in FIG. 6, the wire electrode 4 has an inclination angle of the wire electrode 4 on the assumption that the wire electrode 4 is in a vertical state between the upper electrode guide 8 and the lower electrode guide 9. Control and relative position control between the workpiece 1 and the wire electrode 4 are performed. However, the rigidity of the wire electrode 4
Due to the elasticity and the like, the refraction point of the wire electrode 4 shifts as shown by the dotted line in FIG. 6 to cause an inclination angle error and a processing position error. In order to solve this problem, means for correcting the inclination angle error and the processing position error based on the pulling force, Young's modulus and the like of the wire electrode 4 have already been proposed. Due to the change in the surface state of the upper electrode guide 8 and the lower electrode guide 9, the distortion of the strain generated in the wire electrode 4 due to the friction between the wire electrode 4 and the upper electrode guide 8 and the lower electrode guide 9 occurs. Therefore, the accuracy of the correction has been a problem.

Therefore, conventionally, in electric discharge machining requiring high machining accuracy, test machining is performed before main machining, and the inclination angle and machining shape before machining performed by the test machining are actually measured, and the NC device 15 is used in advance. It corrects the equivalent vertical distance H and G ₀ is input, complicated processing steps, such as carrying out the present process after accordingly have been taken. Note that, in the present invention, the distances H and Go obtained by the above measurements are respectively equivalent to the equivalent vertical distances H ′ and
G ₀ '.

[Means for solving the problem]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. Therefore, a method for measuring the position of an electrode guide in a wire electric discharge machine according to the present invention comprises: a machining table moving in the X and Y axis directions; A work table on which the workpiece is fixed and a wire electrode running between the upper electrode guide and the lower electrode guide moving in the U, V, and Z axis directions. In a wire electric discharge machine configured to generate electric discharge between a workpiece placed on a table and the wire electrode to perform electric discharge machining, the upper electrode guide is moved in the U and / or V direction and the Z direction. In the X and Y directions of the working table at the time of the execution of the contact detection. Transfer Distance and, the electrode upper guide of U, based on the moving distance of the V and Z directions, the equivalent vertical distance G ₀ on the actual machining device between the lower electrode guide and Nobutsu stand top 'and lower When the origin of the axis that holds the upper electrode guide is aligned with the origin of the electrode guide and the reference position on the previously prepared Z-axis scale, the equivalent vertical distance H ′ between the upper electrode guide and the actual machining apparatus on the actual processing apparatus is calculated. It is characterized in that it is calculated. Hereinafter, description will be made with reference to the drawings.

〔Example〕

FIG. 1 is a schematic configuration diagram of an embodiment of a wire electric discharge machine to which the present invention is applied, FIG. 2 is an explanatory diagram of an embodiment of a method for measuring the position of an electrode guide in the wire electric discharge machine of the present invention, and FIG. The figure shows a flowchart for explaining the measuring process of the present invention. Reference numerals 4, 5, 6, 8, 9, 11 and 15 in the figure correspond to those in FIG. 4, and reference numeral 16 denotes a jig plate which has an edge-like shape at the tip of the lower surface mounted on the stage 5. 17 is a Z-axis scale, 17-0 is a vertical reference position, the base point of the Z-axis scale 17, and 18 is an arithmetic unit, which is an equivalent vertical distance H by a measuring method described later. 'and
G ₀ ′ is calculated.

The embodiment shown in FIG. 1 is a wire electric discharge machine basically having a configuration similar to that of FIG. 4 described at the beginning of the specification of the present application. And when implementing the measuring method of the present invention,
As shown in FIG. 1, a jig plate is mounted on the stage 5.
The upper electrode guide 8 is moved in the U or V direction, and further moved in the Z direction. Under the respective stopped states, the wire electrode 4 is moved by the jig plate 16.
Of the touch. The method of performing the contact sensing is as follows.
Although it is already well known, the description is omitted, but the jig plate 16 at the time of performing the contact sensing is described.
, Ie, X and Y of the machining table not shown
The arithmetic unit 18 performs an arithmetic process based on the moving distance in the direction of the upper electrode guide 8 and the moving distance of the upper electrode guide 8 in the U and V directions or the moving distance of the upper electrode guide 8 in the Z direction. G ₀ ′ is calculated. The second
The measuring method of the present invention will be sequentially described with reference to the drawings and the flowchart shown in FIG.

“Start” After setting the upper electrode guide 8 to an arbitrary height Z ₁ (reading of the Z-axis scale 17), the upper electrode guide 8 is moved to make the wire electrode 4 vertical (the wire electrode 4 is vertical). The method of making the state known is known). In FIG. 2, the position of the upper electrode guide 8 when the wire electrode 4 is in the vertical state, that is, the start position is indicated by an arrow in the drawing. During this time, the jig plate 16 is retracted to a position where it does not contact the wire electrode 4. Then, in a state where the wire electrodes 4 are vertically set, the jig plate 16 performs contact sensing. That is, the processing table (not shown) is stopped at the position where the jig plate 16 contacts the wire electrode 4. In the present invention,
This is performed while the wire electrode 4 is running.

Reading Z ₁ of the Z-axis scale 17 of the start position of the "Z ₁ value reading" upper electrode guide 8 (arrow) is, the computation unit via the NC device 15
Loaded at 18.

"U (V) axis fixed amount a movement" The upper electrode guide 8 is moved by a predetermined distance a in the U or V axis direction (U axis direction in the embodiment shown in FIG. 2). The position of the upper electrode guide 8 after the movement is indicated by the arrow shown in FIG. 2, and the inclination angle of the wire electrode 4 is the arrow angle α shown in the figure. And the moving distance a is the NC device.
The data is read by the arithmetic unit 18 via the reference numeral 15.

“X (Y) axis feed” Due to the “U (V) axis fixed amount a movement”, the jig plate 16 and the wire electrode 4 are in a non-contact state. Therefore, in order to detect contact with the jig plate 16, a processing table (not shown) is moved in the X or Y axis direction (the X axis direction in the embodiment shown in FIG. 2).

"Contact detection" The movement of the processing table is continued until the contact between the jig plate 16 and the wire electrode 4 is detected. When the contact is detected, the movement of the processing table is stopped.

“Reading of X (Y) axis movement distance b” The movement distance b of the processing table is read by the calculation unit 18 via the NC device 15.

"Z axis fixed amount c lowering" The upper electrode guide 8 is lowered by a predetermined distance c in the Z axis direction. The position of the upper electrode guide 8 after the movement is the second position.
The inclination angle of the wire electrode 4 is the indicated arrow angle β. And the moving distance c is NC
The data is read by the arithmetic unit 18 via the device 15.

“X (Y) axis feed” The jig plate 16 and the wire electrode 4 are in a non-contact state due to the “Z axis fixed amount c descent” described above. Therefore, in order to perform contact detection by the jig plate 16, a processing table (not shown) is moved in the X or Y axis direction (the X axis direction in the embodiment shown in FIG. 2).

"Contact detection" The movement of the processing table is continued until the contact between the jig plate 16 and the wire electrode 4 is detected. When the contact is detected, the movement of the processing table is stopped.

“Reading of X (Y) axis moving distance d” The moving distance d of the above-mentioned processing table is read into the calculation unit 18 via the NC device 15.

Calculating section 18 "calculation of the equivalent vertical distance H 'and G _0' 'reads Z ₁ of the Z-axis scale 17 in the starting position of the upper electrode guide 8, a moving distance a, b, c and d
Based on the above, the equivalent vertical distances H ′ and G ₀ ′ are calculated. That is, in FIG. 2, the following equations (1) and (2) hold.

From the above equations (1) and (2), the equivalent vertical distances H ′ and G ₀ ′ can be calculated as in the following equations (3) and (4).

That is, the arithmetic unit 18, the a read in the measurement process of the Do aforementioned stone, b, c, by performing arithmetic processing based on numerical values of d and Z ₁ (described above (3) and (4)) , The equivalent vertical distances H ′ and G ₀ ′.

The purpose of the above is to provide the electrode guide 8
Displacement of Z ₁ read on the Z-axis scale 17 in the initial setting position movement amount from the vertical position a, and gives a moving amount c in the Z-axis direction, at the upper surface position of the workpiece stage 5 the wire electrode 4 By obtaining b and d, the equivalent vertical distances H ′ and G ₀ ′ are calculated, and the procedure from the above is not limited. Note that the above-described procedures are exemplified as those in which the number of operation steps of the processing is the smallest.

〔The invention's effect〕

As described above, according to the present invention, the upper electrode guide is moved in the U or V direction and the Z direction, and the wire electrode is formed by the jig plate placed on the above-mentioned stage under the respective stopped states. And the lower electrode guide is determined based on the moving distance of the working table in the X and Y directions and the moving distance of the upper electrode guide in the U, V and Z directions when the contact sensing is performed. Vertical distance H ′ on the actual processing device between the object and the upper surface of the stage,
Equivalent vertical distance G ₀ on the actual machining device between the upper electrode guide in upon combined origin the origin of the axis to hold the upper electrode guide with respect to a reference position on the Z-axis scale is prepared in advance as the lower electrode guide ′ Can be easily and accurately determined.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a wire electric discharge machine to which the present invention is applied, FIG. 2 is an explanatory diagram of an embodiment of a position measuring direction of an electrode guide in the wire electric discharge machine of the present invention, and FIG. FIG. 4 is a flowchart for explaining a measurement process of the present invention. FIG. 4 is a schematic configuration diagram of a general wire electric discharge machine, and FIG. 5 is a control mode explanatory diagram of electric discharge machining in the wire electric discharge machine shown in FIG. FIG. 6 is an explanatory diagram relating to the running state of the wire electrode, and FIG. 7 is an explanatory diagram relating to the equivalent vertical distance. In the drawing, 1 is a workpiece, 2 is a processing start hole, 3 is a processing locus,
4 is a wire electrode, 5 is a stage, 6 is a table driving device,
7 is a wire supply roll, 8 is an upper electrode guide, 9 is a lower electrode guide, 10 is a wire take-up roll, 11 is a guide drive device, 12 is a processing power supply device, 13 and 14 are electronic devices, 15 is an NC device, 17 Denotes a Z-axis scale, 17-0 denotes a vertical reference position, and 18 denotes a calculation unit.

Claims (1)

(57) [Claims] 1. A processing table that moves in the X-axis direction and the Y-axis direction, a work table fixed to the processing table and on which a workpiece is mounted, and a work table parallel to the X-axis direction and the Y-axis direction. At least a wire electrode that moves between the upper electrode guide and the lower electrode guide that moves in the U-axis direction, the V-axis direction, and moves in the Z-axis direction perpendicular to the X-axis direction and the Y-axis direction, An electric discharge machining is performed by generating an electric discharge between a workpiece placed on a worktable and the wire electrode, and a treatment that is mounted on the worktable and has a contact portion formed at a tip thereof. and tool plate, in the position measuring method of an electrode guide in the wire electric discharge machine equipped with a calculation section that performs calculation relating to the position of the upper electrode guide and a lower electrode guide, sets the upper electrode guide arbitrary height Z ₁ Vertical running wire electrode Performing the contact sensing by the jig plate in the above state, and moving the upper electrode guide by a predetermined distance a in the U-axis direction and / or the V-axis direction, and sending the distance a to the calculation unit. Moving the working table in the X-axis direction and / or the Y-axis direction to sense contact with the jig plate, and sending the moving distance b of the working table to the calculation unit; and moving the upper electrode guide in the Z-axis direction. Moving the working table in the X-axis direction and / or the Y-axis direction to sense contact with the jig plate, and moving the working table in the X-axis direction and / or the Y-axis direction. A step of sending an addition value d of the moving distance and the distance b to a calculation unit, wherein the calculation unit calculates the numerical values a, b, c, d obtained in the respective steps.
And Z ₁ (However, H ′ is an equivalent vertical distance on the actual processing apparatus between the lower electrode guide and the upper surface of the stage, and G ₀ ′ is relative to the lower electrode guide and a reference position on a previously prepared Z-axis scale. When the origin of the axis holding the upper electrode guide is aligned with the origin, the equivalent vertical distance on the actual processing device with respect to the upper electrode guide is calculated.) The calculation result is used in actual processing. A method for measuring the position of an electrode guide in a wire electric discharge machine.