TWI401127B - Devices of measurement and compensation for a linear tool's processing position deflection - Google Patents

Description

Flexural measurement and compensation device for processing position of linear cutter

The invention relates to a processing position deflection measuring and compensating device for a line tool processing device; in particular, a processing position deflection measuring and compensating device suitable for a wire cutting tool in a wire cutting electric discharge machine.

In the field of wire-cut electric discharge machine, the metal wire type electrode is used as a machining tool, and the high-hardness metal is cut by electric discharge machining. Since the metal wire type tool is elastic, obvious deflection deformation occurs when the metal is cut by discharge. . In the functions of the device disclosed in the "Automatic Adjustment Method and Device for Machining Parameters of Wire EDM Machines" of the Republic of China Invention Patent No. 330872, only the automatic adjustment function of the machining parameters of the wire-cut EDM is not included. Type tool line deflection measurement function. In the technical content disclosed in the "Wire Cutting Machine Wire Deflection Measurement Method" of the Republic of China Invention Patent Bulletin No. 379152, the method first finds the gap value of the discharge in the edge finding path, and then processes the processed path. The original program track is deducted from the discharge gap value, and is used as a new path for the empty running motion. It is recorded in the position where each corner and the short-circuit curve path are short-circuited or changed, and then the different compensation values are changed, and the different corners and short-circuit curve paths are emptied and recorded in each. Whether there is a short circuit at the corner; after the compensation value is modified several times for the air run measurement, the compensation value of each group of corner angles is found by the position where the short circuit is just released or the short circuit condition happens, and the compensation value is calculated again. The amount of deflection of the line at the corner position.

In the above-mentioned prior art measurement method, there is no means for directly measuring and obtaining the amount of deflection of the wire, and it takes a lot of time to perform a pre-processing path and a plurality of empty running experiments, and waste a lot of workpiece material to be processed, In particular, the angles and arc paths for different angles must be repeated for multiple experimental measurements.

SUMMARY OF THE INVENTION The object of the present invention is to provide a device for visually measuring the amount of flexural deformation of a linear machining tool and thereby adjusting the function of compensating the machining parameters to achieve the purpose of improving the accuracy of the machining accuracy.

The invention relates to a processing position deflection measuring and compensating device for a linear tool. The main device comprises a visual sensing unit, and the image generated by the visual sensing unit records different predetermined height positions of the workpiece to be processed, different times. The generated discharge spark phenomenon; a digital processing unit can generate lines of different height positions by processing the operation time of the difference between the time difference of the discharge spark occurring in the first appearance of the workpiece at different predetermined height positions and the moving speed of the linear tool The amount of deflection; a compensation adjustment unit further selects different compensation adjustment processes according to different processing path modes to generate corrected machining parameters according to the data of the deflection amount of the line; a machining control unit, with the corrected machining parameters, It is sent to the machining control unit to control the actual machining movement of the machine tool processed by the discharge type, so as to improve the accuracy of the machining accuracy.

As shown in FIG. 1, a digital video recording device 1 is disposed at a fixed position to record a phenomenon of spark discharge when the wire electrode 3 approaches the workpiece to be processed, and generates digital data; the two sets of wire guides include the upper wire guide 21, and The lower wire guide 22; and a continuously running thin wire type wire electrode 3 run in the clamping of the upper wire guide 21 and the lower wire guide 22, and are cut perpendicularly to the horizontal plane of the workpiece 4 to be processed. The direction 5 is horizontally moved, and when the wire electrode 3 travels to a region close to the workpiece 4 entering the gap discharge, a phenomenon of spark discharge is started, and a line deflection phenomenon is also accompanied.

As shown in FIG. 2, when the line electrode 3 travels to the position a, the digital video device 1 has not captured any digital image of the discharge spark; when the line electrode 3 travels to the position b, the bottom of the workpiece is relatively high and the top is opposite. The lower end positions are captured by the digital video recording device 1 to the digital image of the beginning of the discharge spark; when the wire electrode 3 travels to the position c, respectively, the relatively higher end of the bottom of the workpiece is opposite to the top of the top, A discharge spark image with a length of several mm was captured by a digital video device. Since the discharge phenomenon will occur at the front and side of the line electrode, the discharge time will be counted when the first discharge spark occurs. When reaching a state of stable cutting discharge, measuring the end point of the side of the workpiece to the intermediate point of the side of the workpiece to be processed, the discharge spark position is gradually moved from the two ends of the side of the workpiece to the middle. point.

Figure 3 is an example of an image of a discharge spark recorded by the digital video recording device 1. The I picture shows the image of the first spark discharge at the bottom and the top of the workpiece. The II picture shows the bottom side of the workpiece being processed. The higher end is opposite to the top, and there are discharge spark images of several mm length respectively. The III map shows the phenomenon that the spark discharge phenomenon gradually extends from the bottom and top ends of the side of the workpiece to the intermediate point. .

As shown in the program flow of the digital processing unit of FIG. 4, the program 41 can process a plurality of image digital data generated by the digital video device 1 in a unit time, and the program 42 detects the first predetermined spark position of the workpiece to be processed. The time difference, in relation to the program 43 linear tool moving speed, can be calculated by the program 44 to generate line deflections corresponding to different predetermined height positions, and the program 45 stores line deflections at different predetermined height positions to provide an adjustment compensation unit. .

By calculating the time difference between the different predetermined height positions at the first spark, this line deflection can be defined as:

ΔS=Δt×f

ΔS represents the amount of line deflection; f represents the cutting speed mm/min; Δt represents the time difference; therefore, when the video apparatus of the embodiment generates 30 digital images in one second, the cutting speed of the wire electrode is fixed at 2.4 mm/min, So the amount of line electrode displacement represented by each image is equal to

(2.4mm/min) × (min / 60sec) × (1sec / 30F) = 1.333um / F

In this way, it is determined that the different predetermined height positions of the workpiece to be processed need to pass through several images before the first spark discharge occurs, and the amount of line deflection of the workpiece at different height positions can be obtained.

For example, the wire cutting electrical discharge machine has the following processing conditions: machining workpiece material SKD11, ∮0.25mm copper wire electrode wire cutting electrical discharge machine processing parameters

Starting voltage = 90V

Discharge = 14 (0.7us)

Power failure = 9 (9us)

Arc start = 9 (0.45us)

Arc end = 8 (8us)

Wire tension = 1200g

Line speed = 10m/min

Gap voltage = 44V

Feed rate = 2.4mm/min

The thickness of the processed workpiece is 50mm, and the video device produces 30 digital images in one second. The cutting speed of the wire electrode is fixed at 2.4mm/min, which can generate the data as shown in Table 1.

A line deflection amount map can also be generated for the multi-dot line deflection amount data at different predetermined height positions as shown in the above table.

As shown in Figure 5, the program flow of the adjustment compensation unit is programmed in the program 51 such as the starting voltage, the discharge time, the power-off time, the arc start time, the arc end time, the line tension, the line speed, and the gap voltage. , feed rate, etc., plus the amount of line deflection obtained by the above-mentioned digital processing unit, enter the program 52 processing path mode selection, according to different processing trajectory paths, select different linear mode or arc mode or corner mode, Enter the compensation adjustment of the linear mode of the program 53 respectively. 1. The compensation adjustment of the program 54 arc mode 2. The compensation adjustment of the program 55 corner mode 3. After the compensation adjustment of different means, enter the program 56 to generate the corrected machining parameters, and then enter Program 57 provides a control unit to control the actual machining of the wire-cut EDM. The above control unit is a controller for a wire-cut EDM machine.

In summary, the main apparatus of the present invention as shown in FIG. 6 includes a visual sensing unit 61 that generates an image of a discharge spark phenomenon generated at different predetermined height positions of the workpiece to be processed at different times; a digital processing unit 62 The time difference between the occurrence of the discharge spark in the first appearance of the workpiece being processed at different predetermined height positions by the processing operation, and the relationship between the movement speed of the line electrode and the line deflection speed can generate the amount of line deflection at different height positions; a compensation adjustment unit 63, further According to the data of the deflection amount of the line, different compensation adjustment processes are selected according to different processing path modes, and different linear mode or arc mode or corner mode is selected, and the compensation adjustment of the linear mode or the compensation adjustment of the arc mode or the corner is respectively entered. The compensation adjustment of the mode is performed after the compensation adjustment by different means, and the correction processing parameter is generated; a machining control unit 64 can control the actual machining movement of the wire-cut electrical discharge machine with the corrected machining parameter. In this way, the correction of the machining path error caused by the deflection of the wire electrode can be adjusted, thereby improving the accuracy of the machining accuracy of the wire-cut EDM machine.

The present invention has been described by way of example, and the invention is not limited by the scope of the embodiments, and various modifications and changes are intended to be included in the scope of the invention.

(1). . . Digital video device

(twenty one). . . Upper threader

(twenty two). . . Lower wire guide

(3). . . Wire electrode

(4). . . Machined workpiece

(5). . . Cutting direction

(6). . . Vertical position

(41). . . Image digital data

(42). . . The time difference between the first occurrence of discharge sparks at different predetermined height positions

(43). . . Set the linear tool movement speed

(44). . . Operation processing produces line deflection

(45). . . Storage line deflection data

(51). . . Set processing parameters, line deflection

(52). . . Processing path mode selection

(53). . . Compensation adjustment

(54). . . Compensation adjustment II

(55). . . Compensation adjustment three

(56). . . Correct processing parameters

(57). . . Processing control

(61). . . Visual sensing unit

(62). . . Digital processing unit

(63). . . Compensation adjustment unit

(64). . . Machining control unit

Figure 1: Schematic diagram of the positional relationship between a digital video device and a processing tool and a workpiece being machined.

Figure 2: Schematic diagram of the movement deflection of the linear machining tool.

Figure 3: Digital image recorded by a digital video device.

Figure 4: Flow chart of the operation of the digital processing unit.

Figure 5: Flow chart of the action of the compensation adjustment unit.

Figure 6 is a schematic view of the apparatus of the present invention.

(61). . . Visual sensing unit

(62). . . Digital processing unit

(63). . . Compensation adjustment unit

(64). . . Machining control unit

Claims (7)

A bending position measuring and compensating device for processing position of a linear cutter mainly comprises: a visual sensing unit for generating a discharge spark image generated at different predetermined height positions and different times of the workpiece to be processed; a digital processing unit, processing operation The time difference of the first occurrence of the discharge spark at the different predetermined height positions, and the relationship between the fixed moving speed of the linear cutter and the fixed moving speed of the linear cutter, respectively, the amount of deflection of the line at the different predetermined height positions, which is caused by the amount of deflection of the line The time difference of the first occurrence of the discharge spark at the different predetermined height position is multiplied by the moving speed of the linear tool; a compensation adjustment unit uses the deflection amount of the line as a basis for adjusting the processing parameters, and selects different compensation according to different processing paths. The adjustment generates a correction processing parameter; a machining control unit controls the actual machining motion of the machine tool processed by the discharge type with the modified machining parameter. The processing position deflection measuring and compensating device for a linear cutter according to claim 1, wherein the visual sensing unit generates a recording discharge spark image by using a digital video recorder. The processing position deflection measuring and compensating device for the linear cutter according to claim 2, wherein the time difference of the first occurrence of the discharge spark in the digital processing unit is recorded by the visual sensing unit. And detecting the number of images that have passed when the first spark discharge occurs at different predetermined height positions of the workpiece to be processed. The processing position deflection measuring and compensating device for the linear tool according to claim 1, wherein the compensation adjusting unit selects different compensation adjustments according to a straight line or an arc or a corner machining path. The processing position deflection measuring and compensating device for the linear cutter according to claim 1, wherein the linear cutter is a wire electrode. The processing position deflection measuring and compensating device for the linear tool according to the fifth aspect of the invention is the wire cutting electric discharge machine. The processing position deflection measuring and compensating device for a linear tool according to claim 6 is the wire cutting electric discharge machine controller.