CN109500460B - Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft - Google Patents
Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft Download PDFInfo
- Publication number
- CN109500460B CN109500460B CN201811493206.7A CN201811493206A CN109500460B CN 109500460 B CN109500460 B CN 109500460B CN 201811493206 A CN201811493206 A CN 201811493206A CN 109500460 B CN109500460 B CN 109500460B
- Authority
- CN
- China
- Prior art keywords
- electrode
- workpiece
- servo
- shaft
- short
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H1/00—Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H11/00—Auxiliary apparatus or details, not otherwise provided for
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Abstract
A method for measuring the commutation period and overshoot amplitude of an electric spark servo machining shaft; firstly, driving the electrode to move to make the electrode contact with the workpiece, sending a short-circuit signal to a system, and stopping the movement of the servo processing shaft by the system; secondly, moving the electrode to contact with the workpiece, receiving a short-circuit signal by the system, executing a backspacing command, and sending a non-short-circuit signal to the system when the electrode is reversely disconnected; the system records the position coordinate data of the servo processing shaft at the moment; repeating the above actions and averaging to obtain an actual contact position; moving the electrode until the display coordinate value =0, stopping, enabling the electrode to contact the workpiece, and recording a coordinate difference value L1 and a time difference value T1 when the power supply short-circuit signal is detected; the time difference is recorded as T2 when the electrode is reversely moved and the power supply non-short circuit signal is received; repeating the above steps and averaging to obtain L1 ', T1 ' and T2 '; the commutation period of the servo machining shaft is T = T2 ' -T1 ', and the overshoot amplitude L = L1 '. During machining, the T and the L are inserted into a servo machining algorithm for real-time compensation, and the purpose of stable machining is achieved.
Description
Technical Field
The invention relates to the field of electric machining, in particular to a method for measuring a reversing period and an overshoot amplitude of an electric spark servo machining shaft.
Background
The working principle of the electric spark forming machining is as follows: the method is characterized in that periodic voltage pulses are applied between a forming electrode and a machined workpiece, the distance between the electrode and the workpiece is adjusted through servo feeding of a machining shaft, pulse discharge is generated when the electrode approaches the workpiece, and then workpiece materials are eroded, so that the purpose of cavity machining is achieved.
In the process of pulse discharge machining, the average voltage of actual operation is unstable due to the influence of different machining materials, different discharge periods and the like. In order to control the stability of the average voltage, a voltage servo control system is arranged to maintain the average value of the actual working voltage within a target range, the specific method is that when the average value of the working voltage is lower than the target range, the voltage servo control system controls the machining shaft to move to enable the electrode to be separated from the workpiece and stop pulse discharge, when the average value of the working voltage is higher than the target range, the voltage servo control system controls the machining shaft to move to enable the electrode to approach the workpiece and regenerate the pulse discharge, the separation and approach process is called as the servo micro-jitter of the machining shaft, and during machining, the servo shaft continuously and randomly jitters, which is a remarkable characteristic of electric spark machining.
As known to those skilled in the art, in order to achieve stable machining, the amplitude of the servo jitter of the machining axis is small, but the frequency is high, and the occurrence of large amplitude jitter with low frequency represents unstable machining, which not only has adverse effect on the machining quality, but also affects the machining efficiency, and even causes frequent open circuit and short circuit.
Therefore, how to solve the above-mentioned deficiencies of the prior art is a problem to be solved by the present invention.
Disclosure of Invention
The invention aims to provide a method for measuring a commutation period and an overshoot amplitude of an electric spark servo machining shaft.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for measuring the commutation period and overshoot amplitude of an electric spark servo machining shaft; the method comprises the following steps:
first, the electrode is driven to move to make it contact with the workpiece
The method comprises the following steps:
firstly, a voltage servo control system controls a servo processing shaft to enable an electrode at the end part of the servo processing shaft to move to have a gap with a workpiece, and a voltage is applied between the electrode and the workpiece, wherein the voltage is a direct current voltage or a direct current pulse voltage;
then, driving the servo machining shaft to enable the electrode to continuously move towards the workpiece; when the electrode is contacted with the workpiece, a short-circuit signal is sent to the system, and the system stops the movement of the servo processing shaft;
second, determining the actual contact position of the electrode and the workpiece
The method comprises the following steps:
firstly, manually operating a servo machining shaft to stop when an electrode moves to be close to a workpiece;
then, the system drives the servo processing shaft to move the electrode slowly at a first speed to make the electrode contact with the workpiece; at this time, the power applied between the electrode and the workpiece is short-circuited, and a short-circuit signal is sent to the system; the system executes a backspacing command, the electrode moves reversely at a first speed, and a non-short circuit signal is sent to the system at the moment when the electrode is separated from the workpiece; when the system receives the non-short circuit signal, the position coordinate data of the servo processing shaft at the moment is recorded, and meanwhile, the servo processing shaft continuously backs for a certain distance, so that a gap is kept between the electrode and the workpiece;
then, automatically repeating the action for N times, wherein N is a positive integer greater than 1, and confirming a coordinate value obtained by averaging the obtained N data as an actual contact position of the electrode and the workpiece;
third, start measurement
Repeating the second step at a second speed faster than the first speed by:
firstly, the system drives the servo processing shaft to move towards the workpiece at the second speed, and when the electrode moves to a coordinate value =0 on a display device of the system, the operation is stopped, and the actual position of the electrode does not reach the position of the coordinate value;
then, continuing to move the electrode in the positive direction to make the electrode contact the workpiece, and recording a coordinate difference L1 and a time difference T1 when a power supply short-circuit signal between the electrode and the workpiece is received;
subsequently, the electrode is moved in reverse until the system receives a signal that the power supply between the electrode and the workpiece is not shorted, and the time difference is recorded as T2;
repeating the above actions M times, wherein M is a positive integer greater than 1, and recording numerical values and averaging to obtain L1 ', T1' and T2 ', wherein L1' is an average value of a plurality of coordinate difference values L1, T1 'is an average value of a plurality of time difference values T1, and T2' is an average value of a plurality of time difference values T2;
the commutation period T = T2 ' -T1 ' of the servo machining shaft, and the overshoot amplitude L = L1 '.
The relevant content in the above technical solution is explained as follows:
1. in the above solution, the contact sensing function is a standard configuration for an electrical machine tool.
2. In the above scheme, in the second step, the actual contact position of the electrode and the workpiece is determined, and the coordinate value is set to 0; the coordinate value is set to 0 so as to directly obtain the coordinate difference value, the coordinate value is not required to be cleared, the coordinate value can be recorded, and finally the coordinate difference value is obtained through calculation.
3. In the above scheme, in the third step, the system drives the servo processing shaft to move the electrode toward the workpiece, and when the electrode is moved to a coordinate value =0 on a display device of the system at the second speed, the time is cleared; the time value is cleared to facilitate directly obtaining the time difference value, the time value is not necessarily cleared, the moving time value can also be recorded, and finally the time difference value is obtained through calculation.
4. In the scheme, before the first step, an 'actual contact position program of an electrode and a workpiece' and a 'systematic measuring program of an online reversing period and an overshoot amplitude' are compiled in advance according to the measuring principle of the online reversing period and the overshoot amplitude of the servo machining shaft;
when the actual contact position of the electrode and the workpiece is determined in the second step, executing an actual contact position program of the electrode and the workpiece; at the beginning of the measurement in the third step, a "systematic determination procedure of the on-line commutation period and the overshoot amplitude" is carried out.
5. In the scheme, the first speed is 1mm/min, and the second speed is 2-200 mm/min.
The working principle and the advantages of the invention are as follows:
the invention relates to a method for measuring the reversing period and the overshoot amplitude of an electric spark servo machining shaft; the method comprises the following steps: firstly, driving the electrode to move to make it contact with the workpiece; firstly, moving an electrode to a position with a gap from a workpiece, and applying a voltage between the electrode and the workpiece; then the electrode is continuously moved towards the workpiece, when the electrode and the workpiece are contacted, a short circuit signal is sent to the system, and the system stops moving the servo machining shaft; secondly, determining the actual contact position of the electrode and the workpiece; firstly, manually operating to make the electrode move to be close to the workpiece and stop; then, the electrode is slowly moved at a first speed to be contacted with the workpiece, the power supply between the electrode and the workpiece is short-circuited, the system receives a short-circuit signal and executes a backspacing command, the electrode moves reversely at the first speed, and a non-short-circuit signal is sent to the system when the workpiece is separated; when the system receives the non-short circuit signal, the position coordinate data of the servo processing shaft at the moment is recorded, and meanwhile, the electrode is continuously retracted to keep a gap between the electrode and the workpiece; repeating the above actions for N times, and determining the coordinate value obtained after averaging as the actual contact position; thirdly, starting measurement; repeating the second step at a second speed: stopping when the electrode moves to the coordinate value =0 on the display device, then continuing to move the electrode in the forward direction to contact the workpiece, and recording the coordinate difference L1 and the time difference T1 when the power supply short-circuit signal between the electrode and the workpiece is received; then moving the electrodes in reverse until the system receives a power supply no-short circuit signal and recording the time difference as T2; repeating the above operations M times, and averaging to obtain L1 ', T1 ' and T2 ' respectively; the commutation period of the servo machining shaft is T = T2 ' -T1 ', and the overshoot amplitude L = L1 '.
The invention utilizes the contact sensing function of the electric spark equipment and the shaft programming, counting and timing functions controlled by the system to measure the reversing period and the overshoot amplitude of the electric spark servo machining shaft at different moving speeds on line.
The data can be used for inserting corresponding commutation period and overshoot amplitude data into a servo processing algorithm by table lookup according to the current actual servo speed of a servo processing shaft during actual processing, real-time compensation is carried out, the real-time performance of a servo tracking strategy is improved, and the purpose of stable servo processing is achieved.
Detailed Description
The invention is further described below with reference to the following examples:
example (b): a method for measuring the commutation period and overshoot amplitude of an electric spark servo machining shaft;
in advance, based on the principle of measuring the on-line commutation period and the overshoot amplitude of the servo machining shaft, a 'program of the actual contact position of an electrode and a workpiece' and a 'system measuring program of the on-line commutation period and the overshoot amplitude' are programmed.
The determination method comprises the following steps:
first, the electrode is driven to move to make it contact with the workpiece
The method comprises the following steps:
firstly, a voltage servo control system controls a servo processing shaft to enable an electrode at the end part of the servo processing shaft to move to have a gap with a workpiece, and a voltage is applied between the electrode and the workpiece, wherein the voltage is a direct current voltage or a direct current pulse voltage of 12-24 v;
then, driving the servo machining shaft to enable the electrode to continuously move towards the workpiece; when the electrode is contacted with the workpiece, a short-circuit signal is sent to the system (for an electric machining machine tool, the contact sensing function is in a standard configuration), the system stops the equidirectional movement of the servo machining shaft, and the moving stroke of the servo machining shaft generates overshoot; the action is used for anti-collision protection, and meanwhile, the action can also be used for realizing the alignment of the positions of the workpiece, such as corner alignment, center alignment and the like.
Second, determining the actual contact position of the electrode and the workpiece
The method comprises the following steps:
firstly, manually operating a servo machining shaft to stop when an electrode moves to be close to a workpiece;
then, executing a 'program of actual contact position of the electrode and the workpiece', wherein the system drives the servo processing shaft to slowly move the electrode at a first speed of 1mm/min so as to make the electrode contact with the workpiece; at this time, the power applied between the electrode and the workpiece is short-circuited, and a short-circuit signal is sent to the system; the system executes a backspacing command, the electrode moves reversely at a first speed, and a non-short circuit signal is sent to the system at the moment when the electrode is separated from the workpiece; when the system receives the non-short circuit signal, the position coordinate data (namely the position data of the electrode) of the servo processing shaft at the moment is recorded, and meanwhile, the servo processing shaft continuously backs for a certain distance to ensure that a gap is kept between the electrode and the workpiece;
then, automatically repeating the action for N times, wherein N is a positive integer larger than 1, and determining coordinate values obtained by averaging the acquired data of the N disengaging positions as actual contact positions of the electrode and the workpiece;
third, start measurement
And executing a system measuring program of the on-line commutation period and the overshoot amplitude, and repeating the second step at a second speed of 2-200 mm/min, wherein the specific process is as follows:
firstly, the system drives the servo processing shaft to move towards the workpiece at the second speed, and when the electrode moves to a coordinate value =0 on a display device (such as a CRT) of the system, the operation is stopped, and the actual position of the electrode does not reach the position of the coordinate value;
then, continuing to move the electrode in the positive direction to make the electrode contact the workpiece, and recording a coordinate difference L1 and a time difference T1 when a power supply short-circuit signal between the electrode and the workpiece is received;
subsequently, the electrode is moved in reverse until the system receives a signal that the power supply between the electrode and the workpiece is not shorted (i.e., the instant the electrode is disconnected from the workpiece), and this time difference is recorded as T2;
repeating the above actions M times, wherein M is a positive integer greater than 1, and recording numerical values and averaging to obtain L1 ', T1' and T2 ', wherein L1' is an average value of a plurality of coordinate difference values L1, T1 'is an average value of a plurality of time difference values T1, and T2' is an average value of a plurality of time difference values T2;
the commutation period T = T2 ' -T1 ' of the servo machining shaft, and the overshoot amplitude L = L1 '.
In the second step, the actual contact position of the electrode and the workpiece is determined, and the coordinate value is set to be 0; the coordinate value is set to 0 so as to directly obtain the coordinate difference value, the coordinate value is not required to be cleared, the coordinate value can be recorded, and finally the coordinate difference value is obtained through calculation.
In the third step, the system drives the servo processing shaft to face the workpiece moving electrode, and when the servo processing shaft moves to the coordinate value =0 on the display device of the system at the second speed, the time is cleared; the time value is cleared to facilitate directly obtaining the time difference value, the time value is not necessarily cleared, the moving time value can also be recorded, and finally the time difference value is obtained through calculation.
The invention utilizes the contact sensing function of the electric spark equipment and the shaft programming, counting and timing functions controlled by the system to measure the reversing period and the overshoot amplitude of the electric spark servo machining shaft at different moving speeds on line.
The data can be used for inserting corresponding commutation period and overshoot amplitude data into a servo processing algorithm by table lookup according to the current actual servo speed of a servo processing shaft during actual processing, real-time compensation is carried out, the real-time performance of a servo tracking strategy is improved, and the purpose of stable servo processing is achieved.
The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (5)
1. A method for measuring the commutation period and overshoot amplitude of an electric spark servo machining shaft; the method is characterized in that: the method comprises the following steps:
first, the electrode is driven to move to make it contact with the workpiece
The method comprises the following steps:
firstly, a voltage servo control system controls a servo processing shaft to enable an electrode at the end part of the servo processing shaft to move to have a gap with a workpiece, and a voltage is applied between the electrode and the workpiece, wherein the voltage is a direct current voltage;
then, driving the servo machining shaft to enable the electrode to continuously move towards the workpiece; when the electrode is contacted with the workpiece, a short-circuit signal is sent to the system, and the system stops the movement of the servo processing shaft;
second, determining the actual contact position of the electrode and the workpiece
The method comprises the following steps:
firstly, manually operating a servo machining shaft to stop when an electrode moves to be close to a workpiece;
then, the system drives the servo processing shaft to move the electrode slowly at a first speed to make the electrode contact with the workpiece; at this time, the power applied between the electrode and the workpiece is short-circuited, and a short-circuit signal is sent to the system; the system executes a backspacing command, the electrode moves reversely at a first speed, and a non-short circuit signal is sent to the system at the moment when the electrode is separated from the workpiece; when the system receives the non-short circuit signal, the position coordinate data of the servo processing shaft at the moment is recorded, and meanwhile, the servo processing shaft continuously backs for a certain distance, so that a gap is kept between the electrode and the workpiece;
then, automatically repeating the action for N times, wherein N is a positive integer greater than 1, and confirming a coordinate value obtained by averaging the obtained N data as an actual contact position of the electrode and the workpiece;
third, start measurement
Repeating the second step at a second speed faster than the first speed by:
firstly, the system drives the servo processing shaft to move towards the workpiece at the second speed, and when the electrode moves to a coordinate value =0 on a display device of the system, the operation is stopped, and the actual position of the electrode does not reach the position of the coordinate value;
then, continuing to move the electrode in the positive direction to make the electrode contact the workpiece, and recording a coordinate difference L1 and a time difference T1 when a power supply short-circuit signal between the electrode and the workpiece is received;
subsequently, the electrode is moved in reverse until the system receives a signal that the power supply between the electrode and the workpiece is not shorted, and the time difference is recorded as T2;
repeating the above actions M times, wherein M is a positive integer greater than 1, and recording numerical values and averaging to obtain L1 ', T1' and T2 ', wherein L1' is an average value of a plurality of coordinate difference values L1, T1 'is an average value of a plurality of time difference values T1, and T2' is an average value of a plurality of time difference values T2;
the commutation period T = T2 ' -T1 ' of the servo machining shaft, and the overshoot amplitude L = L1 '.
2. The method for measuring according to claim 1, wherein: in the second step, the actual contact position of the electrode with the workpiece is determined, and the coordinate value is set to 0.
3. The method for measuring according to claim 1, wherein: in the third step, the system drives the servo processing shaft to move the electrode towards the workpiece, and when the electrode is moved to the coordinate value =0 on the display device of the system at the second speed, the time is cleared.
4. The method for measuring according to claim 1, wherein: the first speed is 1 mm/min.
5. The method for measuring according to claim 1, wherein: the second speed is 2-200 mm/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811493206.7A CN109500460B (en) | 2018-12-07 | 2018-12-07 | Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811493206.7A CN109500460B (en) | 2018-12-07 | 2018-12-07 | Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109500460A CN109500460A (en) | 2019-03-22 |
| CN109500460B true CN109500460B (en) | 2020-09-11 |
Family
ID=65751946
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811493206.7A Active CN109500460B (en) | 2018-12-07 | 2018-12-07 | Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109500460B (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4700039A (en) * | 1984-08-08 | 1987-10-13 | Amada Company, Limited | Method and device for controlling the tool electrode in an electrical discharge machine tool |
| JPS6156829A (en) * | 1984-08-27 | 1986-03-22 | Amada Co Ltd | Setting of machining conditions of electric discharge machine |
| CN100413645C (en) * | 2004-10-29 | 2008-08-27 | 大连理工大学 | Method for detecting discharge condition in tenuous electric spark process interval |
| CN101249617A (en) * | 2008-03-20 | 2008-08-27 | 上海交通大学 | Measurement method of electro discharge machining gapping place |
| CN103752962B (en) * | 2013-12-13 | 2016-04-06 | 南京航空航天大学 | For the reciprocal gradual self adaptation feed control method of electric spark machine tool |
| CN109570657B (en) * | 2018-11-22 | 2019-10-29 | 清华大学 | Electrical discharge machining axis system servo response delay measurement system and method |
-
2018
- 2018-12-07 CN CN201811493206.7A patent/CN109500460B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109500460A (en) | 2019-03-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5204321B1 (en) | Wire electrical discharge machine that detects the machining state and calculates the average voltage between the electrodes | |
| US4321451A (en) | Servo system and method for controlling the gap spacing between a tool and workpiece electrodes in an EDM machine | |
| CN103447644B (en) | Penetration detection method of spark erosion drilling machine | |
| US10315263B2 (en) | Wire electric discharge machine operating with constant inter-pole distance | |
| US3531615A (en) | Electrical discharge machining with step driven electrode | |
| KR100479153B1 (en) | Method of and apparatus for wire electric-discharge machining | |
| CN109500460B (en) | Method for measuring commutation period and overshoot amplitude of electric spark servo machining shaft | |
| CN103962659A (en) | Method and system for electric spark machining control | |
| US3825714A (en) | Method and apparatus for controlling the feed of an electrode-tool relative to a workpiece in electrical discharge machining | |
| US4527034A (en) | Electrode positioning method and apparatus for NC-EDM | |
| JP3733538B2 (en) | Positioning device and method for electric discharge machine | |
| CN104107967A (en) | Intelligent-control high frequency pulse power supply | |
| JPH0911043A (en) | Electric discharge machining method and electric discharge machining device | |
| JPS6325889B2 (en) | ||
| JP5361783B2 (en) | Die-sinker electrical discharge machine and jump control method | |
| JP4348506B2 (en) | Electric discharge machining method and apparatus | |
| JPS61111813A (en) | Spark erosion apparatus | |
| JPH03166021A (en) | Method of electric discharge machining | |
| CN112388079B (en) | Composite pulse working method of wire cut electrical discharge machining pulse power supply | |
| JPS6119370B2 (en) | ||
| SU1301594A1 (en) | Method of extremum control of electro-erosion process | |
| JPH01115515A (en) | Controller for electric discharge machine | |
| JPH05329713A (en) | Wire electric discharge machine having core cutting off detecting device | |
| JP2762198B2 (en) | Electric discharge machining method and apparatus | |
| JPH0138614B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |