A method for automatic correction of the oblique placement of a workpiece and perpendicularity error of coordinate axes

Abstract

The present application relates to wire cutting intelligent processing technical field, specifically to a kind of workpiece oblique placement and coordinate axis perpendicularity error automatic correction processing method, using workpiece oblique placement compensation algorithm and coordinate perpendicularity compensation algorithm, according to error value automatically calculates the accurate position after compensation, and download to controller, while reading the real-time position when processing, inverse calculation is matched with the position of processing figure as display.Meanwhile increase single-axis button movement, utilize manual pulse generator single-axis movement, can participate in compensation calculation, ensure the consistency of coordinate display and hand automatic function.The scheme reduces the difficulty of user operation by workpiece oblique placement compensation, improves the machining precision of machine tool by machine tool coordinate value perpendicularity compensation.

Description

Technical Field

[0001] This invention relates to the field of wire EDM intelligent machining technology, and in particular to an automatic correction method for workpiece tilting and coordinate axis perpendicularity errors. Background Technology

[0002] Wire EDM systems are proprietary control systems used in metal mold processing. They consist of host computer software and a slave controller (programmable logic controller, PLC, or control card, etc.). The system controls a molybdenum wire (guided through the workpiece by a guide nozzle or guide wheel) to move along the trajectory of the imported mold pattern, thus machining the molded workpiece. The workpiece placed on the actual machine tool must maintain the same orientation as the imported mold pattern to ensure the accuracy of the machined workpiece.

[0003] In existing wire EDM systems, during actual processing, manual placement of the workpiece on the machine tool cannot guarantee that the 0° reference line of the workpiece is parallel to the 0° reference line (X-axis) of the machine tool (i.e., the machining pattern is aligned with the workpiece direction). This necessitates multiple adjustments to the workpiece position using methods such as tapping and measuring sparks. This step is time-consuming and heavily relies on the operator's skill level, thus impacting processing efficiency and accuracy.

[0004] Furthermore, during the installation of existing wire EDM machines, due to objective factors such as manual calibration accuracy and installation tolerances, there are instances where the X and Y axes of the machine tool cannot be perfectly perpendicular. At the same time, the size of the molds that wire EDM machines need to process is increasing, and there are more and more machines with large strokes. The non-perpendicularity of the X and Y axes will affect the accuracy of the mold processing to some extent; and this error cannot be compensated for manually.

[0005] Therefore, a new technical solution is urgently needed to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of the prior art and provide an automatic correction method for workpiece tilting and coordinate axis perpendicularity errors. This method solves the technical problems that in the present technology, manual placement of workpieces on machine tools cannot guarantee that the processing pattern is consistent with the workpiece direction, and that existing wire cutting machine tools cannot guarantee that the X and Y axes of the machine tool coordinates are completely perpendicular due to the objective reason of manual installation, thus affecting the workpiece processing efficiency and accuracy.

[0007] The above objectives are achieved through the following technical solutions:

[0008] An automatic correction method for workpiece tilting and coordinate axis perpendicularity error includes workpiece tilting compensation and machine tool coordinate value perpendicularity compensation. The workpiece tilting compensation includes the following steps:

[0009] Step (1.1) Measure the calibration point according to the actual position of the workpiece on the machine tool, calculate the deflection angle of the workpiece based on the calibration point, and use it as the workpiece coordinate deflection angle; construct the workpiece tilt compensation algorithm based on the workpiece coordinate deflection angle.

[0010] Step (1.2) The wire EDM system analyzes the points of the two-dimensional graphic of the workpiece, calculates the compensated X-axis motion data and Y-axis motion data of the workpiece according to the workpiece tilting compensation algorithm described in the step, and sends the X-axis motion data and Y-axis motion data of the workpiece to the controller.

[0011] In step (1.3), the wire EDM system obtains the real-time position fed back by the controller when the control axis moves, and obtains the coordinate position of the workpiece when it is straightened by the inverse operation of the workpiece tilt compensation algorithm.

[0012] The perpendicularity compensation of the machine tool coordinate values ​​includes the following steps:

[0013] Step (2.1) Obtain the machine tool perpendicularity error angle by measurement, and construct a machine tool perpendicularity error compensation algorithm based on the machine tool perpendicularity error angle;

[0014] Step (2.2) Calculate the compensated actual X-axis position and actual Y-axis position data of the machine tool according to the machine tool perpendicularity error compensation algorithm, and send them to the controller;

[0015] In step (2.3), the wire cutting system obtains the real-time position of the machine tool fed back by the controller when the control axis moves, and obtains the coordinate position of the machine tool in the vertical state through the inverse operation of the machine tool perpendicularity error compensation algorithm.

[0016] Further, step (1.1) specifically includes:

[0017] Two calibration points, A and B, are set on one side of the workpiece. Then, a vector is given. According to the vector Find the deflection angle of the workpiece, denoted as θ, which is the workpiece coordinate deflection angle. Then we have:

[0018] Let the target position of the workpiece after rotation be denoted as (x', y'), then:

[0019] x' = x*cosθ + y*sinθ;

[0020] y' = y*cosθ + x*sinθ.

[0021] Further, step (1.1) specifically includes:

[0022] Let the coordinate system of the machine tool under normal conditions be (x, y), and the actual coordinate system of the machine tool be (x', y'). Let θ be the angle between y' and y, which is the machine tool perpendicularity error angle. Then we have:

[0023] x' = x;

[0024] y' = y*cosθ - x*sinθ.

[0025] Furthermore, the workpiece tilt compensation and the machine tool coordinate value perpendicularity compensation are performed simultaneously. The wire EDM system first performs machine tool coordinate value perpendicularity compensation based on the compensation value, and then performs workpiece tilt compensation.

[0026] The present invention provides an automatic correction machining method for workpiece tilting and coordinate axis perpendicularity error. It adopts the method of measuring two calibration points to calculate the deflection angle of the workpiece and directly compensates during machining without the need to forcibly straighten the workpiece, thus reducing the difficulty of operation for users. By measuring the perpendicularity error, the compensated position is automatically calculated during machining. The software can correct the error caused by mechanical installation, thereby improving the accuracy. Attached Figure Description

[0027] Figure 1 The flowchart is a process for automatically correcting workpiece tilting and coordinate axis perpendicularity error according to the present invention.

[0028] Figure 2 This is a schematic diagram of the workpiece tilting compensation algorithm in the automatic correction machining method for workpiece tilting and coordinate axis perpendicularity error described in this invention;

[0029] Figure 3 This is a schematic diagram of the machine tool coordinate axis perpendicularity error compensation algorithm in the automatic correction machining method for workpiece slant placement and coordinate axis perpendicularity error described in this invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This solution provides an automatic correction method for workpiece tilt and coordinate axis perpendicularity errors. To improve user convenience and machining accuracy, and to avoid errors caused by workpiece placement and machine tool misalignment during machining, workpiece tilt compensation algorithms and coordinate axis perpendicularity compensation algorithms are introduced. Based on the error value, the accurate position after compensation is automatically calculated and downloaded to the controller. Simultaneously, the real-time position during machining is read, and the position matching the machining graphic is calculated and displayed. Single-axis button movement and single-axis movement using a manual pulse generator are also added, both of which can participate in the compensation calculation, thus ensuring consistency between coordinate display and manual / automatic functions.

[0032] like Figure 1 As shown, this solution uses wire EDM software to perform compensation calculations on the machining data generated from the workpiece graphic before sending it to the controller. The real-time coordinate position fed back by the controller is displayed with inverse compensation, and the current machining graphic is displayed with compensation rotation to achieve the best effect of machining the tilted workpiece. It mainly includes workpiece tilt compensation and machine tool coordinate value perpendicularity compensation.

[0033] The workpiece tilt compensation includes the following steps:

[0034] Step (1.1) Measure the calibration point according to the actual position of the workpiece on the machine tool, calculate the deflection angle of the workpiece based on the calibration point, and use it as the workpiece coordinate deflection angle; construct the workpiece tilt compensation algorithm based on the workpiece coordinate deflection angle.

[0035] Step (1.2) The wire EDM system analyzes the points of the two-dimensional graphic of the workpiece, calculates the compensated X-axis motion data and Y-axis motion data of the workpiece according to the workpiece tilting compensation algorithm described in the step, and sends the X-axis motion data and Y-axis motion data of the workpiece to the controller.

[0036] In step (1.3), the wire EDM system obtains the real-time position feedback from the controller when the control axis moves, and obtains the coordinate position of the workpiece when it is aligned by the inverse operation of the workpiece tilt compensation algorithm. At the same time, other auxiliary axis shifting functions of the system participate in the calculation of the workpiece tilt compensation algorithm. When a manual pulse generator is used to specify a single axis movement, the single axis pulse generated is calculated by the workpiece tilt compensation algorithm and split into two-axis interpolation movements to ensure that the coordinate system is consistent.

[0037] The perpendicularity compensation of the machine tool coordinate values ​​includes the following steps:

[0038] Step (2.1) Obtain the machine tool perpendicularity error angle by measurement, and construct a machine tool perpendicularity error compensation algorithm based on the machine tool perpendicularity error angle;

[0039] Step (2.2) Calculate the compensated actual X-axis position and actual Y-axis position data of the machine tool according to the machine tool perpendicularity error compensation algorithm, and send them to the controller;

[0040] In step (2.3), the wire cutting system obtains the real-time position of the machine tool fed back by the controller when the axis moves, and obtains the coordinate position of the machine tool in the vertical state through the inverse operation of the machine tool perpendicularity error compensation algorithm, which is convenient for corresponding with the processing graphic.

[0041] The above solution uses workpiece tilt compensation and coordinate axis perpendicularity compensation algorithms to compensate for and correct errors in workpiece tilt and coordinate axis perpendicularity, ensuring accurate execution of the machining position. Simultaneously, it optimizes coordinate display and machining graphic display, allowing users to more intuitively understand the compensation method and improving the system's operational convenience.

[0042] In this embodiment, the workpiece tilt compensation algorithm in step (1.1) is a calculation that matches the actual workpiece position after the coordinate system is deflected. Specifically:

[0043] like Figure 2 As shown, two calibration points, calibration point A and calibration point B, are set on one side of the workpiece. Then, the vector is... According to the vector Find the deflection angle of the workpiece, denoted as θ, which is the workpiece coordinate deflection angle. Then we have:

[0044] Let the target position of the workpiece after rotation be denoted as (x', y'), then:

[0045] x' = x*cosθ + y*sinθ;

[0046] y' = y*cosθ + x*sinθ.

[0047] In this embodiment, the machine tool perpendicularity error compensation algorithm in step (1.1) is a calculation that transforms the position of the coordinate axis perpendicularly downwards into the position of the coordinate axis not perpendicularly downwards. Specifically:

[0048] like Figure 3 As shown, the coordinate system of the machine tool under normal conditions is set to (x, y), and the actual coordinate system of the machine tool is (x', y'). The angle between y' and y is θ, which is the machine tool perpendicularity error angle. The principle of machine tool perpendicularity compensation is to convert the original coordinate values ​​(x, y) to (x', y') according to the magnitude of the perpendicularity error. Therefore:

[0049] x' = x;

[0050] y' = y*cosθ - x*sinθ.

[0051] In this solution, the workpiece tilt compensation and the machine tool coordinate value perpendicularity compensation can be performed simultaneously. The wire EDM system first performs machine tool coordinate value perpendicularity compensation based on the compensation value, and then performs workpiece tilt compensation, thus achieving the effect of simultaneous compensation.

[0052] The above description is merely illustrative of the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for automatically correcting errors in workpiece tilting and coordinate axis perpendicularity, characterized in that, This includes workpiece tilt compensation and machine tool coordinate value perpendicularity compensation. The workpiece tilt compensation includes the following steps: Step (1.1) Measure the calibration point according to the actual position of the workpiece on the machine tool, calculate the deflection angle of the workpiece based on the calibration point, and use it as the workpiece coordinate deflection angle; construct the workpiece tilt compensation algorithm based on the workpiece coordinate deflection angle. Step (1.2) The wire EDM system analyzes the points of the two-dimensional graphic of the workpiece, calculates the compensated X-axis motion data and Y-axis motion data of the workpiece according to the workpiece tilt compensation algorithm described in step (1.1), and sends the X-axis motion data and Y-axis motion data of the workpiece to the controller. Step (1.3) The wire EDM system obtains the real-time position fed back by the controller when the control axis moves, and obtains the coordinate position of the workpiece when it is straightened by the inverse operation of the workpiece tilt compensation algorithm; The perpendicularity compensation of the machine tool coordinate values ​​includes the following steps: Step (2.1) Obtain the machine tool perpendicularity error angle by measurement, and construct a machine tool perpendicularity error compensation algorithm based on the machine tool perpendicularity error angle; Step (2.2) Calculate the compensated actual X-axis position and actual Y-axis position data of the machine tool according to the machine tool perpendicularity error compensation algorithm, and send them to the controller; Step (2.3) The wire cutting system obtains the real-time position of the machine tool fed back by the controller when the control axis moves, and obtains the coordinate position of the machine tool in the vertical state through the inverse operation of the machine tool perpendicularity error compensation algorithm.

2. The automatic correction machining method for workpiece skew and coordinate axis perpendicularity error according to claim 1, characterized in that, The specific steps (1.1) are as follows: Two calibration points, A and B, are set on one side of the workpiece. Then, a vector is given. According to vector Calculate the deflection angle of the workpiece, denoted as . That is, the workpiece coordinate deflection angle, then we have ; The target position after the workpiece deflection is denoted as... ,but: ； 。 3. The automatic correction machining method for workpiece skew and coordinate axis perpendicularity error according to claim 1, characterized in that, The specific steps (2.1) are as follows: The coordinate system of the machine tool under normal conditions is set as follows: The actual coordinate system of the machine tool is , and The included angle between them is That is, the perpendicularity error angle of the machine tool; then we have: ； 。 4. The automatic correction machining method for workpiece skew and coordinate axis perpendicularity error according to claim 1, characterized in that, The workpiece tilt compensation and the machine tool coordinate value perpendicularity compensation are performed simultaneously. The wire EDM system first performs machine tool coordinate value perpendicularity compensation and then performs workpiece tilt compensation based on the compensation value.

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