KR20160109688A

KR20160109688A - Electro-discharge Truing System of Metal-bonded Grinding Wheel

Info

Publication number: KR20160109688A
Application number: KR1020150034558A
Authority: KR
Inventors: 곽태수
Original assignee: 경남과학기술대학교 산학협력단
Priority date: 2015-03-12
Filing date: 2015-03-12
Publication date: 2016-09-21

Abstract

The present invention relates to an electro-discharge truing system of a metal-bonded grinding wheel. The electro-discharge truing system of a metal-bonded grinding wheel comprises: an ELID power supply device (100); a metal-bonded diamond grinding wheel (200); an electrolytic dressing electrode (300); an electro-discharge truer (400); an electro-discharge spindle motor controller (500); an injection type grinding liquid supply device (600); a PC monitor (700); and a user control unit (800). Therefore, a worker monitors an electro-discharge current in accordance with an intensity of an application voltage to correct the electro-discharge current.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a metal-bonded grinding wheel,

[0001] The present invention relates to a discharge truing system for grinding a metal-bonded grinding wheel, and more particularly, to a discharge truing system for a metal-bonded grinding wheel in which an ELID grinding apparatus and a discharge truing electrode are formed to provide a smooth discharge truing and electrolytic dressing process. To a discharge truing system of a binder grinding wheel.

Recently, high efficiency, high quality and high precision of hard materials such as ceramics, composites, super hard alloys and reinforced plastics have been demanded along with the development of high-tech industries.

The grinding process is a maternal machining method in which the shape is reproduced on the surface of the workpiece according to the action surface of the grinding wheel. The machined surface is influenced by the protruding state of the abrasive grains distributed on the grinding wheel surface. Particularly, in the case of a metal-bonded diamond grinding stone, when the truing is performed by a general discharge truing method, the metal binder covering the truing grains is difficult to fall off due to the rigidity of the cast iron, so that the grain tends not to protrude remarkably .

To overcome the disadvantages of such a general discharge truing method, a discharge truing pattern diagram using an electric discharge machining principle is introduced. The principle of the discharge truing is a method in which the metal binder surrounding the abrasive particles is dropped off by a discharge phenomenon generated by the ionizing action in the grinding wheel and the gap formed on the electrode surface by the applied voltage. That is, the diamond abrasive grains partially protruding from the surface of the abrasive grindstone come into contact with the surface of the abrasive grindstone during truing, and the metal binder that fixes the abrasive grains contacts with the electrode in the magnetic state by the voltage, and sparks are generated. At this time, a portion of the metal binder is released by the spark to protrude the diamond abrasive grains and at the same time, the surface of the grinding abrasive is trued (refer to FIG. 1).

Such a discharge truing method can be applied to a machine tool to precisely and precisely truing it when touched with a metal binder grinding wheel, regardless of the width of the grinding wheel and the size of the grinding wheel. It also has the advantage that it can save time than existing truing.

However, this technology still has the problem that discharging truing which can dislodge abrasive grains is possible, but the electro-discharge truing and dressing combined with the ELID grinding machine are not possible at the same time.

Accordingly, the present invention proposes a discharge truing system of a new metal binder grinding wheel capable of simultaneously performing a discharge truing and a dressing process combined with an ELID grinding apparatus.

DISCLOSURE Technical Problem Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide an ELID grinding apparatus and a PC monitor, which have a copper electrode and a discharge truer, The present invention aims to provide a discharge truing system of a metal-bonded grinding wheel in which a smooth discharge truing and dressing process are possible at the same time as well as a discharge current according to an applied voltage intensity can be monitored and corrected by an operator.

According to an aspect of the present invention, there is provided an ELID power supply apparatus for supplying a stable high frequency DC pulse power to a metal-bonding diamond grindstone and an electrolytic dressing electrode during ELID grinding; The copper electrode of the discharge truer receiving the positive (+) power from the ELID power supply device and receiving the negative (+) power and the metallic binder covering the abrasive due to the spark caused by the glow discharge are subjected to ultra- A diamond-like diamond wheel 200; An electrolytic dressing electrode 300 facing the metal-polishing diamond grindstone and receiving a negative power from the ELID power supply device to cause a reduction reaction in the electrolysis process to form an oxide film on the surface of the metal-bonded diamond grindstone; (-) power source of the ELID power supply unit, and generates a spark due to the metal-bonded diamond grindstone receiving the (+) power and the glow discharge to thereby tilt the metal binder of the metal- )Wow; A discharge spindle motor controller 500 for controlling the rotation speed of the discharge spindle motor 410 to have a rotation speed relative to the rotation speed of the metal-binding diamond grindstone; A spray type grinding fluid supply device 600 for flowing a conductive liquid between the metal-bonded diamond grindstone and the copper trough of the discharge truer to increase discharge truing and electrolytic dressing; A PC monitor 700 having a monitoring program for collecting and confirming every second the voltage, the number of revolutions, and the output voltage and current generated during the discharge truing, which is applied from the ELID power supply device to the copper electrodes of the metal-bonded diamond grindstone and the discharge truer, )Wow; And a user manipulation unit 800 for correcting and inputting a reference current value to be selected by the user through the PC monitor information. The present invention also provides a discharge truing system for a metal-bonded grinding wheel.

According to another embodiment of the present invention, in the metal-bonded diamond grindstone, the oxide film formed on the surface of the grindstone by the electrolytic dressing electrode is absorbed by abrasive protruded when the workpiece is worked, thereby improving the surface roughness during grinding.

According to another embodiment of the present invention, the electrolytic dressing electrode may be switched to supply (-) power from the ELID power supply device so as to form an oxide film on the surface of the metal- And is turned on.

According to another embodiment of the present invention, the discharge truer includes a discharge spindle motor 410 for rotating the truer spindle, a truer spindle 420 connected to the discharge spindle motor for rotating at high speed, And a copper electrode 430 connected to generate a glow discharge.

According to another embodiment of the present invention, the discharge truer is designed such that the total size of the discharge truer is 270x160x100 mm, the diameter of the copper electrode is 80 mm, the thickness is 8 mm, the number of revolutions is 8200 rpm, And a brush 440 is mounted on the rear portion of the truer spindle so that a current flows inside the spindle.

According to another embodiment of the present invention, the user manipulation unit may set an applied voltage to 85 [V] through the PC monitor, and based on the time when the copper electrode and the surface of the metal- The discharge current is selected to be 0.2 [A] at the gap distance of 2 [탆] when the Z-axis of the Z-axis is inserted and brought into contact with the gap distance of 2 [m] to 2 [m] at a time.

According to the discharge truing system of the metal-bonded grinding wheel of the present invention, the following effects can be obtained.

By constructing an electro-discharge truer with a copper electrode combined with an ELID grinding machine,

(1) Metal binder When toughening the diamond grindstone, it is possible to perform more accurate and sharp truing in order to easily protrude the abrasive covering the metal binder, regardless of the width of the grindstone and the size of the grindstone.

(2) Smooth Discharge Truing and dressing processes are possible at the same time, enabling high-efficiency, high-quality and high-precision grinding of difficult materials such as ceramics, composites, super hard alloys and reinforced plastics.

(3) The discharge current according to the intensity of the voltage applied to the metal-coupled diamond grindstone and the electro-discharge truer supplied with the negative (-) power is supplied to the user There is a unique effect that can be monitored and corrected by the operator (or operator).

1 shows a discharge truing mode diagram by a conventional discharge phenomenon
2 is a schematic view of a discharge truing system of a metal binder grinding wheel according to a preferred embodiment of the present invention;
3 is a block diagram showing the overall configuration of a discharge truing system of a metal binder grindstone according to a preferred embodiment of the present invention
FIG. 4 is a view showing a discharge truer for a discharge truing system of a metal-bonded grinding wheel according to a preferred embodiment of the present invention,
5 is a block diagram illustrating monitoring of a discharge truing system of a metal-bonded grinding wheel according to a preferred embodiment of the present invention
FIG. 6 is a photomicrograph and a partial enlarged view of a discharge truing system of a metal binder grinding wheel according to a preferred embodiment of the present invention

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. Although the same reference numerals are used in the different drawings, the same reference numerals are used throughout the drawings. The prior art should be interpreted by itself. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 to 6, the structure of a discharge truing system of a metal-bonded grinding wheel according to an embodiment of the present invention is roughly divided into an ELID power supply 100, a metal-bonded diamond grindstone 200, A plasma display apparatus includes an electrode 300, a discharge truer 400, a discharge spindle motor controller 500, a spray type grinding liquid supply apparatus 600, a PC monitor 700 and a user operation unit 800, The positive (+) power of the ELID power supply is connected to a metal-bonded diamond grindstone, and the negative (-) power supply of the ELID power supply is connected to an electro-discharge truer 400, There is a unique feature that the user (or operator) can confirm and correct the discharge current.

Referring to FIGS. 1 and 2, the ELID power supply 100 supplies a power source for generating a stable DC pulse (DC pulse) to the grindstone and electrodes for electrolytic dressing grinding Electrolysis and chemical reaction.

Here, the ELID (Electrolytic In-process Dressing) grinding technique is attracting attention as a high-efficiency grinding technique along with various kinds of materials such as semiconductor, glass, ceramics and cemented carbide. It is a technique to improve the machining characteristics between the abrasive grain and the workpiece by using the power source that generates the grindstone and pulse waveform, and the continuous dressing by forming an oxide film on the grindstone surface using the water-soluble grinding fluid accompanied by the nonlinear electrolytic phenomenon. In addition, continuous dressing reduces the phenomenon of snowing during machining. Therefore, it is possible to use a grinding wheel with high grain size. Therefore, it is possible to realize the nano grade surface smoothness by using the grinding wheel of # 8000 or more. have. Initial truing and dressing are essential for ELID grinding.

1 to 3, the metal-bonded diamond grindstone 200 is a grinding wheel for ultra-precision grinding, which receives positive (+) power from the ELID power supply 100, and the ELID power supply 100 The metallic binder covering the abrasive grains with a spark generated by the glow discharge in proximity to the discharge trough 400 which is supplied with the negative (- And it is a grinding wheel that enables ultra-precision grinding through sharply trued abrasive with clearly protruding abrasive.

In addition, in the ELID grinding process, the metal-binding diamond grinding wheel 200 may be provided with an electrolytic dressing electrode 300 supplied with a negative (-) power source, and an anode (+) Power source, and is an abrasive grindstone that contacts the workpiece (or workpiece) to perform ELID grinding. A metal binder is bonded to the grindstone and electrolytic and chemical reactions are caused by a DC pulse of high frequency supplied in connection with a positive (+) power source of the ELID power supply device 100, A nonconductor is formed on the surface of the diamond grindstone 200. That is, an insulator, such as an anodized oxide such as Alumite, which is a thin film of oxide that covers the surface of the metal binder bonded to the metal-bonded diamond grindstone, is continuously formed, so that ultra-precision grinding can be performed. When the oxide film is formed on the surface of the grindstone, further electric conduction becomes difficult to complete the electrolytic dressing, and the oxide film is easily peeled off during the work and is absorbed into the protruded abrasive grains (cushioning effect). In addition, since the naturally occurring action is activated, the abrasive grains can be maintained well.

1 and 2, the electrolytic dressing electrode 300 is connected to a negative (-) power source of the ELID power supply device 100 and is used as an electrode for performing a reduction reaction in the electrolysis process. Cathode), and is installed so as to be opposed to the metal-binding diamond grinding wheel 200 with a predetermined gap therebetween.

Here, the electrolytic dressing electrode 300 may stop due to the end of current flow if an oxide film is formed on the surface of the diamond grindstone 200, but when the discharge truing is performed, the negative electrode (-) of the ELID power supply device 100, (-) power supply of the ELID power supply device 100 only from the beginning with the copper electrode 430 of the discharge truer 400, It can be switched on. However, it is a feature of the present invention that the discharge truer and the electrolytic dressing process are simultaneously performed when the discharge truer is coupled with the ELID grinding apparatus.

3 to 4, the discharge truer 400 is connected to a negative (-) power supply of the ELID power supply 100, and the ELID power supply 100 The metallic binder 200 is brought close to the metallic diamond diamond grindstone 200 at a predetermined interval to generate sparks due to glow discharge to thereby tune the metal binder of the metallic diamond diamond grindstone 200 more precisely and sharply. To enable ultra-precision grinding through the abrasive grain of the metal-bonded diamond grinding wheel.

Here, the discharge truer 400 according to the embodiment of the present invention includes an electric discharge spindle motor 410 for rotating a truer spindle, and a discharge spindle motor 410 connected to the discharge spindle motor, A rotating truer spindle 420 and a copper electrode 430 connected to the truer spindle to cause a glow discharge.

The discharge truer 400 according to the preferred embodiment of the present invention has a copper electrode 430 having a diameter of 80 mm and a thickness of 8 mm and the truer spindle 420 A brush 440 is attached to the rear portion of the truer spindle.

Also, the distance between the copper electrode 430 and the discharge truer 400 is designed to be 80 to 100 mm so that the metal-bonded diamond grindstone 200 is sufficient to transfer back and forth during discharge truing. The overall size of the discharge truer 400 is designed to be 270.times.160.times.100 mm and the number of revolutions of the electrode is designed to be up to 8200 rpm.

2 and 4, the discharge spindle motor controller 500 is a means for controlling the rotational speed of the discharge spindle motor 410, and rotates relative to the rotational speed of the metal-binding diamond grinding wheel 200 A glow discharge is caused to occur between the metal-polishing diamond grindstone 200 supplied with a positive (+) power and the copper electrode 430 of the discharge truer 400 supplied with a negative (-) power source, So that the discharge truing of the diamond grindstone 200 is effectively generated.

In other words, by the ionizing action in which the positive ions and the negative ions are brought into contact with each other in the gap between the metal-polishing diamond grindstone 200 magnetized by the applied voltage and the surface of the copper electrode 430 of the discharge truer 400, There is a need to control the rotation speed so that the surrounding metal binder can easily be burned (or eliminated). Generally, since the grinding wheel has a rotation speed of up to 2000 rpm, the discharge truer speed of the copper electrode having a maximum of 8200 rpm is adjusted to the relative speed of the polishing grindstone so that the metal binder is more precisely and sharply trued, It is possible to make ultra-precision grinding through the abrasion of the metal-bonded diamond wheel. At this time, in order to confirm the gap distance between the metal-polishing diamond grindstone 200 and the surface of the copper electrode 430 of the discharge truer 400, it is necessary to confirm the discharge current at the time when the surface of the grindstone contacts with the electrode.

Therefore, in the embodiment of the present invention, the applied voltage is set to 85 [V] according to the principle of discharge, and the Z axis of the ELID grinding machine is raised based on the time when the copper electrode and the surface of the metal- ] 2 by 6 [㎛], the discharge current was found to be 0.2 [A] at the gap distance of 2 [㎛] when it was inserted into the gap distance.

Referring to FIGS. 2 and 3 again, the sprayable grinding fluid supply device 600 allows a conductive liquid to flow between the metal-bonded diamond grindstone 200 and the copper electrode 430, thereby improving discharge truing and electrolytic dressing effects It is a means of doubling.

3 and 5, the PC monitor 700 has a PC function and can be sensed with the ELID power supply device 100 and the discharge truer 400, and a user (or a worker) And is a kind of monitoring means for controlling the discharge spindle motor controller 500 as well as a voltage applied to the copper electrode 430 of the discharge truer 400 in the ELID power supply 100 through the PC monitor.

5, a monitoring program 710 according to an embodiment of the present invention includes a monitoring program 710 for monitoring discharge truing due to a discharge phenomenon, a discharge generated on the surface of the metal-bonded diamond grindstone 200 and the electrode 430, The current was collected through a preset monitoring program. That is, the voltage applied to the metal-bonded diamond grindstone 200 and the copper electrode 430 of the discharge truer 400 in the ELID power supply apparatus 100 and the output voltage and current generated during the rotation number, It is programmed to collect at the same time every second (sec).

Referring again to FIG. 3, the user operation unit 800 controls the voltage applied to the copper electrode 430 of the metal-bonded diamond grindstone 200 and the discharge truer 400, which are displayed on the PC monitor 700, , The number of revolutions, the output voltage generated during discharge truing, and the display information on the current.

FIG. 6 is a photographic view and a partial enlarged view of a discharge truing system of a metal-bonded grinding wheel according to a preferred embodiment of the present invention in which the above-described technical structures are combined.

As described above, the discharge truing system of the metal-bonded grinding wheel according to the preferred embodiment of the present invention includes a copper electrode and a copper electrode of an electro-discharge truer combined with an ELID grinding machine having a metal- By configuring the PC monitor, the discharge truing process and the electrolytic dressing process can be performed at the same time, and the discharge current according to the intensity of the applied voltage can be monitored and corrected by the operator.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: ELID power supply
200: Metal binder diamond wheel
300: electrolytic dressing electrode
400: discharge truer
410: Discharge spindle motor 420: Truer spindle
430: copper electrode 440: brush
500: Discharge spindle motor controller
600: Injection grinding fluid feeder
700: PC monitor
800:

Claims

An ELID power supply 100 for supplying a stable high-frequency DC pulse power to the metal-bonded diamond grindstone and the electrolytic dressing electrode during ELID grinding;
The copper electrode of the discharge truer receiving the positive (+) power from the ELID power supply device and receiving the negative (+) power and the metallic binder covering the abrasive due to the spark caused by the glow discharge are subjected to ultra- A diamond-like diamond wheel 200;
An electrolytic dressing electrode 300 facing the metal-polishing diamond grindstone and receiving a negative power from the ELID power supply device to cause a reduction reaction in the electrolysis process to form an oxide film on the surface of the metal-bonded diamond grindstone;
(-) power source of the ELID power supply unit, and generates a spark due to the metal-bonded diamond grindstone receiving the (+) power and the glow discharge to thereby tilt the metal binder of the metal- )Wow;
A discharge spindle motor controller 500 for controlling the rotation speed of the discharge spindle motor 410 to have a rotation speed relative to the rotation speed of the metal-binding diamond grindstone;
A spray type grinding fluid supply device 600 for flowing a conductive liquid between the metal-bonded diamond grindstone and the copper trough of the discharge truer to increase discharge truing and electrolytic dressing;
A PC monitor 700 having a monitoring program for collecting and confirming every second the voltage, the number of revolutions, and the output voltage and current generated during the discharge truing, which is applied from the ELID power supply device to the copper electrodes of the metal-bonded diamond grindstone and the discharge truer, )Wow;
And a user operation unit (800) for correcting and inputting a reference current value to be selected by the user through the PC monitor information.

The method according to claim 1,
Wherein the metal-coated diamond grindstone absorbs the oxide film formed on the surface of the grindstone by the electrolytic dressing electrode into the abrasive grains protruded when the workpiece is machined, thereby improving the surface roughness during grinding.

The method according to claim 1,
Wherein the electrolytic dressing electrode is switched on so that a negative power is supplied from the ELID power supply device so as to form an oxide film on the surface of the metal-bonded diamond grindstone at the same time of discharge truing. Discharge Truing System of Binder Grinding Wheel.

The method according to claim 1,
The discharge truer includes a discharge spindle motor 410 for rotating the truer spindle, a truer spindle 420 connected to the discharge spindle motor to rotate at high speed, and a copper electrode 420 connected to the truer spindle for causing a glow discharge 430). &Lt; RTI ID = 0.0 > 5. &Lt; / RTI >

5. The method of claim 4,
The discharge truer is designed such that the total size of the discharge truer is 270x160x100 mm, the diameter of the copper electrode is 80 mm, the thickness is 8 mm, the number of revolutions is 8200 rpm, and the current is supplied from the ELID power supply to the inside of the truer spindle And a brush (440) is mounted on the rear portion of the truer spindle.

The method according to claim 1,
The user operation unit sets an applied voltage to 85 [V] through the PC monitor and increases the Z axis of the ELID grinding machine to 2 [탆] at a time based on the time when the copper electrode and the surface of the metal- Wherein a discharge current is set to a reference current of 0.2 [A] at a gap distance of 2 [mu m] when the gap is inserted and contacted by a gap distance of 2 to 6 [mu m].