JPS6195829A - Method for protecting electrode in electrolytic deburring method - Google Patents

Abstract

PURPOSE:To prevent generation of failure of workpiece and electrode burning due to contact of the electrode and burr by applying initial voltage to be applied to the electrode at a low voltage and interrupting power source when overcurrent is detected by an overcurrent detector by the initial voltage. CONSTITUTION:An initial voltage is applied to an electrode 13 at a low voltage as shown in the line (b) to rise voltage gradually. This time, if a long burr 12' of a workpiece 11 is contacted to the electrode 13, the current value rises abnormally at a degree of 2-5V simultaneously with turning ON of power source. The overcurrent is detected by an overcurrent detector 16 to interrupt the power source 14. This current detecting time is short and the power source is interrupted before high voltage is not applied, then spark will not occur between the electrode 13 and the burr 12' and burning of the electrode will not occur. When the power source is interrupted, a pilot lamp lights and the burr 12' is not contacted to the electrode 13, and deburring work is re-started. Therefore, generation of defective workpiece and burning of electrode can be prevented.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an electrolytic deburring method for removing electrolytic burrs generated on cut or perforated metal products using an electrode and an electrolytic solution. It concerns protection methods.

[Prior art] This type of electrolytic deburring method is disclosed in Japanese Patent Publication No. 49-397.
The method disclosed in Japanese Patent Publication No. 44 and Japanese Patent Publication No. 50-31103 is known, in which an electrode is brought close to the burr of a metal product to be treated, that is, a workpiece, and a constant voltage is applied to the electrode while flowing an electrolyte. , which dissolves and removes burrs. In such an electrolytic deburring method, it is necessary to place an electrode close to the burr on the workpiece, and the installation position on the processing table is determined based on the size and shape of the workpiece. Also, the burr is mechanically arranged against the burr.

In this case, as shown in FIG. 3, the height of the burr 2 that is generated when the workpiece 1 is perforated, for example, is not necessarily constant, and the electrode 3 is mechanically positioned at a predetermined position. When disposed, the burr 2' having a high height often comes into contact with the electrode 3.

In this state, if a constant voltage necessary for electrolysis, such as the a-line shown in Figure 4, is applied to the M pole 3, a large current will temporarily flow, causing both the electrode 3 and the workpiece 1 to burn out. Not only will the treated workpiece be defective, but if this process is repeated, the electrode will become unusable. In particular, the electrodes used in this type of industry are relatively expensive, and the fact that they often need to be replaced due to burnout is a major economic disadvantage.

[Problems to be Solved by the Invention] The present invention attempts to solve the above-mentioned drawbacks of the prior art, namely, poor processing of workpieces due to contact between electrodes and burrs, and burnout of expensive electrodes.

[Means for Solving the Problems] The present invention provides specific means for solving the problems described above, in which an electrode is disposed close to the burr of the workpiece, and electrolysis is performed between the electrode and the workpiece. In an electrolytic deburring method in which a DC voltage is applied to an electrode while flowing a liquid, the initial voltage applied to the electrode is a low voltage, and when an overcurrent is detected by an overcurrent detector at the initial voltage, the power is turned off. The present invention provides an electrode protection method that is characterized by blocking, and even if there is contact between the electrode and the burr, which is unavoidable in the electrolytic deburring method, the electrode and workpiece will not burn out due to the low initial voltage. This eliminates electrode protection and workpiece failure.

[Example] Next, the method of the present invention will be specifically explained with reference to the illustrated circuit diagram. First, in Fig. 1, 11 is a workpiece,
The workpiece has a large number of burrs 12 due to the drilling process. Electrode 13 placed close to this burr 12
is connected to the power supply 14, and the workpiece 11 is also connected to the ammeter 15.
It is connected to the power supply 14 via. An overcurrent detector 16 is provided adjacent to the ammeter and shuts off the power supply 14 when an abnormal overcurrent is detected by the overcurrent detector. Note that reference numeral 17 is a voltmeter.

[Function] The present invention uses the circuit configuration as described above, and the electrode 1
The applied voltage for 3 is, as shown by line b in Figure 2,
It is important to apply a low initial voltage and gradually increase the voltage. In this way, if the initial voltage is applied at a low voltage, in other words, when deburring is performed with a soft start, if the long burr 12' of the workpiece 11 is in contact with the electrode 13, the deburring will occur as soon as the power is turned on. The current value increases abnormally after about 2 to 5 seconds. This abnormally increased current value, ie, overcurrent, is detected by overcurrent detector 16 and power supply 14 is shut off. In this case, the current detection time is about 1 second at most, and the power supply 14 is cut off before high voltage is applied, so there is no spark between the electrode 13 and the burr 12', and the electrode is not burnt out. is not connected. Further, when the power supply 14 is cut off, a pilot lamp or the like indicating that an abnormal situation has occurred is turned on to automatically notify the $ status. As the means for cutting off the power supply, commonly used means such as turning off a relay contact or turning off a switching circuit are used. If an abnormal situation occurs, the electrode 13 and workpiece 11 are inspected to prevent the long burr 12' from coming into contact with the electrode, and then the deburring operation is restarted. Of course, if there is no abnormality at all, the voltage is raised as is and the prescribed deburring is performed.

[Effects of the Invention] As explained above, the electrode protection method in the electrolytic deburring method according to the present invention applies a low initial voltage to the electrode, and detects an overcurrent at the initial voltage using an overcurrent detector. When the electrode is in contact with the burr, an overcurrent will naturally flow at a low voltage, and this will be detected before the high voltage required for electrolysis is applied. It has the excellent effect of completely protecting expensive electrodes from burning out by shutting off the power.

Furthermore, since an abnormal condition is detected before applying the high voltage necessary for electrolysis, there is also an excellent effect that no defective workpieces are generated and the yield is improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an example circuit diagram for actually carrying out the method of the present invention, Fig. 2 is a graph showing the initial applied voltage and time for carrying out the method, and Fig. 3 is a workpiece of a conventional example. FIG. 4 is a graph showing the relationship between voltage applied to the electrode and time. 1.11... Workpiece 2.12... Burrs 2', 12'... Long (high) burrs 3.13...
Electrode 14...Power supply 15...Ammeter 16
...Supercurrent detector 17...Voltmeter Patent applicant Best Engineering Co., Ltd. Figure 1b Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In an electrolytic deburring method in which an electrode is disposed close to a burr on a workpiece and a DC voltage is applied to the electrode while flowing an electrolyte between the electrode and the workpiece, the initial voltage applied to the electrode is An electrode protection method characterized by applying a low voltage and cutting off the power supply when an overcurrent is detected by an overcurrent detector at the initial voltage.