Techniques of automatic division of labor and data

2022-08-03
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EDM is an important process of mold manufacturing, especially in injection mold manufacturing. At the same time, the CNC machine tools used in modern mold manufacturing enterprises are becoming more and more advanced. Most of the CNC EDM machine tools have multi axis CNC systems, which can process and shape more complex workpieces. In practice, NC EDM is generally to set up one axis or three axis linkage to realize the axial servo machining of formed electrode according to the actual situation, so as to stabilize the electrode in the machining process, reduce the loss and improve the machining accuracy of mold parts. The difference between NC EDM machine tools and ordinary EDM machine tools is that NC EDM machine tools mostly control the whole machining process through program G code, which realizes the advantages of automation and intelligent control of mold machining. At present, there are still many mold enterprises that use CNC EDM machine tools, but the relevant operation and process level are not perfect, making their production efficiency, machining accuracy, smoothness and so on imperfect. Many advantages of machine tools can not be allowed to play. The common operating skills of EDM in mold enterprises are introduced below

in many enterprises, if the parts need to be machined with multiple electrodes, in order to make the operation of numerical control EDM simple and accurate, the method of machining electrodes touching the reference ball is adopted. The advantage of centering the electrode to the reference ball is that it avoids the need to move a large stroke of the electrode, saves the operation time, improves the accuracy of electrode contact number and the simplicity of operation. In the process of contact counting, the parts to be processed are placed on the machine tool, and then a reference ball is placed on it after being calibrated by the dial gauge. The position of the reference ball shall not hinder the electrode processing position, so as to avoid unnecessary interference. Place another reference ball on the z-axis of the NC EDM machine (the reference ball can be divided into two types. One is that a strong magnet is set under the base of the reference ball, which can be directly adsorbed on the steel material. The other is that the reference ball is installed on the fixture, which can be directly installed on the machine tool). The data retrieval process can be divided into the following steps

1. Select the coordinate 1 of the machine tool, and use the reference ball installed on the Z axis of the machine tool to separate the center of the machined parts

2. Select the coordinate 2 of the machine tool, use the reference ball installed on the Z axis of the machine tool to separate the center of the reference ball installed on the part, and move it to the center position. Check the value of machine coordinate 1 and write it down

3. Select the coordinate 2 of the machine tool, touch the marked electrode on the drawing with the reference ball installed on the Z axis of the machine tool, take the Z axis data reference plane and set it to zero. Z-axis rises to a certain height, x-axis and y-axis move to the zero position, touch the z-height value, and record the value

these values are measured to provide corresponding values for subsequent electrode processing. As shown in the figure

figure

during the operation, it should be noted that the benchmark ball placed on the machined parts must be stable, with a share price of 1.45 euros per share, and cannot be loosened, shaken or set at a more inclined position. In the process of counting the number of touches, it is necessary to touch several times for accurate data. In particular, the z-axis data stored in the single chip microcomputer must be the number of hits between the reference ball and the highest point of the reference ball center, so as to ensure the accuracy of the number of hits

in terms of operation, many enterprise operators take notes of these data manually. After the NC EDM is replaced with the electrode to be machined, touch the center of the reference ball on the part, and manually input the relevant data to the machine coordinate. Such operation is easy to input wrong data due to the error of operators in actual work. At the same time, such an operation process is cumbersome and takes a certain amount of time to operate the machine. Because many CNC EDM machine tools are controlled by G code, and manual programming mode is provided, the machine tool can be controlled flexibly. In order to solve the above error prone operation steps, at the same time, the EDM drawings of most mold manufacturing enterprises now indicate the size of electrode reference position and other data, which provides a more convenient space for automatic data retrieval. Taking Beijing Sadik machine tool as an example, a simple centring and data input program is written with G code to realize the automatic centring and relevant data input of electrodes, so as to make the operation of NC EDM more intelligent and improve the production speed of molds. The following describes the operation process of the program through the drawing case shown in the figure below. In the figure, the measured position dimensions of the reference ball are x=+84.55, y=+68.84, z=+30.07. The electrode reference size is 24x45

mold and reference ball position diagram

electrode diagram

diagram

hooo=+ (x-axis moving distance)

h001=+ (Y-axis moving distance)

h002=+ (Z-axis moving distance)

h003=+ (fallback distance)

h004=+ (x-axis reference ball to mold center)

h005=+ (Y-axis reference ball to mold center)

h006= + (number from the highest point of z-axis reference ball to the die reference plane)

h007=+ (Z-axis reference ball contact number position dimension)

g90 g54

g80x- due to the impact of the oil crisis in the 1970s and in order to improve the operational power of military aircraft and the reliability of civil aircraft

g55 G92 x0 Y0 z0

g54

g91 M05 G00 x h003

z h002

g92 x0

g00 x – hooo

z -h002

g80 x+

g80 91 M05 G00 x -h003

z h002

g82 x

g92 x h004

g91 G00 y +h001

z -h002

g80 y-

m05 G00 y +h003

z h002

G92 y 0

g91 G00 y -h001

y -h001

z -h002

g80 y+

g91 M05 G00 y -h003

z h002

g82 y

g92 y h005

g55 G90 G00 x-h007

z10.0

g80 z-

g54

g92 zh006

m05 G91 G00 Z h003

m02

during the design process, the electrode Z touch number position shall have a void avoidance position of more than 4mm, which shall be determined according to the actual application. As shown in the above figure. It should be noted during operation that the diameter of the reference ball in this example is 6mm. As the electrode needs to move to the approximate position of the reference ball on the X axis, the approximate position of the electrode center on the Y axis and the approximate position of the electrode reference center on the Z axis during the touch count. Therefore, a certain safety value, usually (5 ~ 6) mm, should be added when setting the actual relevant value. As shown in the above figure

figure

(e Chinese patent: 201510659107.1) nd)

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