JPH06114732A - Grinding wheel side surface shaping method by on-machine discharge truing method - Google Patents

Abstract

PURPOSE:To form a reverse taper and stepping in a grinding wheel side surface by rotating a disk-shaped electrode, supplying grinding fluid between the electrode and a rotating conductive grinding wheel to generate a discharge therebetween to also place the grinding wheel to approach the electrode, and further parallelly moving the grinding wheel in the Z-axis and Y-axis directions, in grinding wheel side surface shaping of the conductive thin blade grinding wheel for a grinding machine. CONSTITUTION:A conductive thin blade grinding wheel 1 is mounted to a grinding machine rotary shaft 2, and a plus terminal 15 is connected to a power supply 4 of DC pulse current or the like, to form the grinding wheel 1 into a plus electrode. On the other hand, a disk-shaped electrode 3 is mounted to an electrode rotating device 8, set up on a table 7 of a grinding machine, to serve as a minus electrode by a minus terminal 14 connected to the power supply 4. The grinding wheel 1 and the electrode 3 are rotated, and machining fluid is supplied from a nozzle 5, so that the grinding wheel 1 approaches the electrode 3 to generate discharge therebetween. The grinding wheel 1 is parallelly moved in the Z-axis and Y-axis directions as shown by an arrow mark 9, to finish a grinding wheel side surface 11 into a specified shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-machine discharge truing / dressing method for a conductive thin-edged grindstone for a grinding machine.

[0002]

2. Description of the Related Art Conventionally, as an on-machine electric discharge truing method of a conductive thin blade grindstone, for example, an electric discharge machining electrode is mounted on a grinding machine (on machine) of Japanese Patent Laid-Open No. 4-201073, and then mounted on the grinding machine. Without removing the used conductive thin-edged grindstone from the machine, while rotating it on the machine to bring the outer peripheral part closer to it, and while moving parallel to the upper surface of the electrode, discharge between the electrode and the outer periphery of the conductive thin-edged grindstone There was an on-machine electric discharge truing / dressing method of a conductive thin-edged grindstone for shaping a part. Further, as a grinding wheel side surface forming method, there is a runout correction method of a metal bond diamond grinding wheel by an electric discharge machining method and a device therefor, which are disclosed in JP-A-58-66662.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The method of No. 073 describes the method of forming the outer peripheral portion of the thin blade grindstone. When the side surface truing of the grindstone is performed by this method, the side surface shape of the electrode is transferred to the side surface of the grindstone. It is difficult to shape the side surface with high precision, and in cutting and grooving with such a thin blade grindstone, the side deviation of the grindstone deteriorates the processing accuracy and increases chipping, and moreover the method of removing the side deviation of the grindstone on the grinder. Therefore, the side runout was determined when the whetstone was attached. Therefore, there is a problem that it is difficult to obtain stable processing accuracy because the processing accuracy and the chipping amount vary depending on the grindstone. In addition, shape shaping such as reverse taper or stepping was impossible.

Further, in the method of Japanese Patent Laid-Open No. 58-6662,
It was not possible to shape the reverse taper, stepped shape, etc. simply by correcting the run-out of the side surface of the grindstone, and if the electrodes were worn out, the shape of the grindstone could collapse, making it difficult to shape the side surface with high precision. there were. In any case, using the above methods to truing the side of the whetstone and removing the wobbling of the whetstone,
There was a problem that it was difficult to obtain a highly accurate grindstone shape. An object of the present invention is to enable high-precision side surface shaping of a conductive grindstone that is a full-form or thin blade grindstone including a superabrasive grindstone mixed with diamond and / or CBN abrasive grains, thereby cutting,
Deterioration of machining accuracy and increase of chipping due to wobbling of the whetstone side during grooving, stable machining accuracy can be obtained, and reverse taper and step can be made on the whetstone side on the grinder. It is to provide a grinding wheel side surface shaping method by an on-machine electric discharge truing method, which does not need to be prepared.

[0005]

Therefore, the present invention has solved the above-mentioned problems of the prior art by providing a grinding wheel side surface shaping method by an on-machine discharge truing method described in the claims.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the attached FIGS. FIG. 1 is a block diagram showing the configuration of a grindstone side surface shaping device by an on-machine discharge truing method used in an embodiment method of the present invention. Reference numeral 1 is a conductive grindstone which is a full-form or thin-edged grindstone containing a superabrasive grindstone mixed with diamond and / or CBN abrasive grains. It is a conductive thin blade grindstone. Reference numeral 2 is a spindle for rotating the electroconductive thin blade grindstone 1, 3 is a disk-shaped disc-shaped electrode for electric discharge machining for discharging between the outer peripheral surface of the electroconductive thin blade grindstone 1, 4
Is a DC pulse power supply for supplying a DC pulse current between the electrode 3 and the grindstone 1, 5 is a machining liquid nozzle for ejecting a grinding liquid or a machining liquid between the grindstone 1 and the electrode 3, and 6 is an electrode from the grinder body Insulating material that insulates 3, 7 is the table of the grinder, 8
Is an electrode rotating device for rotating the electrode 3, and 9 is a grindstone 1.
The moving locus, 10 is the inclination angle of the electrode rotating device, 14 is a negative terminal for supplying a negative DC pulse voltage to the electrode 3, and 15 is a positive terminal for connecting a positive voltage to the grindstone 1.

In operation, the electroconductive thin blade grindstone 1 mounted on the main shaft 2 which is the rotary shaft of the grinder is rotated while being mounted on the main shaft 2 of the grinder for the purpose of the grinding operation, and the DC pulse current or pulse shape is applied. The grindstone 1 receives a positive voltage from the positive terminal 15 connected to the DC power source 4 and operates as a positive electrode. On the other hand, the disk-shaped electrode 3 installed on the table 7 of the grinding machine and rotated by the electrode rotating device 8 receives a negative voltage from the negative terminal 14 connected to the power source 4 and acts as a negative electrode. The disk-shaped electrode 3 is rotated, a DC pulse voltage is applied between the conductive grindstone 1 and the disk-shaped electrode 3, and a discharge is made while applying a water-soluble grinding liquid from the machining liquid nozzle 5 between the both, and the conductive grindstone side surface 11 Is a disc-shaped electrode 3 which is rotated by being moved by an NC device (not shown).
The disk outer peripheral surface 31 is moved closer to the disk outer peripheral surface 31, and the conductive grindstone side surface 11 is moved toward the disk outer peripheral surface 31 by the Z direction as shown by an arrow 9.
The conductive grindstone 1 is shaped by causing electric discharge between the two while moving in parallel to the axial direction and / or the Y-axis direction. Thereby, in the present invention, (a) straight type (b) reverse taper type and (c) stepped type whetstone side surface shape shown in FIG. 2, which is a partial side view showing the relationship between the whetstone side surface shape and the whetstone moving method, respectively. Can be obtained.

FIG. 2 is a view similar to FIG. 1 showing a grinding wheel side surface shaping method by an on-machine electric discharge truing method according to a second embodiment of the present invention. In order to shape the side surfaces 11, 11 of a large number of grinding stones 1, 1, electrode rotation is performed. The shaft 34 is attached at an angle of about 10 degrees from a position substantially orthogonal to the conductive grindstone rotating shaft 21. In the apparatus, the same members as those in FIG. 1 are designated by the same reference numerals. In FIG. 2, the conductive grindstone side surface 11 is brought close to the disk outer peripheral edge 32 of the disk electrode 3, and the disk electrode 3 is rotated, as shown by an arrow 91, with respect to the disk outer peripheral edge 32 of the disk electrode 3. The conductive grindstone 1 is shaped by moving the conductive grindstone side surface 11 in parallel with the Z-axis direction and / or the Y-axis direction while causing electric discharge therebetween. As a result, on the side surfaces 11 and 11 of the large number of grindstones 1 and 1, (a) straight type (b) reverse taper type and
(c) It is possible to obtain a stepped grinding wheel side surface shape. By using this method, the side surface runout of the grindstone can be removed, and the shape of the side surface of the grindstone can be obtained with high accuracy because there is no deterioration of the shape due to electrode consumption. Further, the reverse taper or stepped shape can be shaped on a grinding machine.

(Experimental example) As an experimental example, a CNC precision surface grinder was equipped with a metal bond diamond grindstone having an outer diameter of 100 mm; t 0.6 and 5 mm, a discharge power source of 3 KVA, an outer diameter of 60 mm; t 0.3 m.
m copper disk-shaped rotating electrode, water-soluble grinding fluid as electrical discharge machining fluid, Alteik as workpiece (Al ₂ O ₃ -TiC; 50x50x4m
m) and, respectively, as the dressing conditions for GC, dresser GC grinding wheel # 600; grinding wheel rotation speed 9000 rpm; cutting depth a =
5 mm; feed rate f = 200 mm / min; dressing distance Ld = 100 mm were selected. Electric discharge truing conditions are grindstone / electrode rotation speed; S = 4500 / Sθ = 1000 rpm; feed speed = f = 5 ■ 50m
m / min; drive-in amount Z = 0.1 μm / pass; voltage / current Eo = 15
0V / Ip = 5 ■ 20A; pulse width τ _on / τ _off = 2/3 μs were selected.

(Experimental results) The side surface of a thin blade grindstone having a width of 0.6 mm was subjected to side surface shaping by the on-machine discharge truing method according to this method, and the truing ability and the side surface shaped grindstone shape were evaluated by transferring the shape to a ferrite. I went. The grinding performance was compared with the method using the GC wheel block. As a result, the side surface of the thin blade grindstone was subjected to on-machine electric discharge truing to shape the side surface of the grindstone. As a result, the method using the GC grindstone block gave 10 μm ^pp.
It has been reduced to m ^pp . Next, the grindstones with widths of 0.6 and 5 mm were subjected to reverse taper and step forming to obtain a desired shape. In this method, since the processing pressure is small, the deformation of the grindstone,
It was possible to mold with extremely high precision without causing damage. Width 0.6 mm
When the outer circumference of the grindstone of No. 2 was molded, the roundness was about 2.2 μm (average value) by the method using the GC grindstone block, but the straightness was reduced to 1.6 μm by this method. Further, in the method using the GC grindstone block, a large chipping was generated on one side of the cutting groove due to the side surface runout of the grindstone, but in the present method, the occurrence of the large chipping could be suppressed.

[0011]

As described above, by enabling highly accurate side surface shaping of the conductive thin blade grindstone, the deterioration of the working accuracy and the increase of chipping due to the wobble of the grindstone side surface at the time of cutting and grooving are eliminated, and the stability is stable. The processing precision that has been achieved has come to be obtained. Also, by tilting the electrode rotation axis from a position approximately orthogonal to the conductive grinding wheel rotation axis, it is possible to create a reverse taper or step on the grinding wheel side surface on the grinding machine, and prepare a new grinding wheel. I no longer need it.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a grindstone side surface shaping device by an on-machine discharge truing method used in an embodiment method of the present invention.

FIG. 2 is a view similar to FIG. 1, showing a grinding wheel side surface shaping method by an on-machine discharge truing method according to a second embodiment of the present invention.

FIG. 3 is a partial side view showing a relationship between a side surface shape of a grindstone and a method for moving the grindstone according to the present invention.

[Explanation of symbols]

 1. ． Conductive thin blade whetstone 2. ． Spindle 3. ． Disk-shaped electrode for electrical discharge machining 4. ． DC pulse power supply or pulsed DC power supply 7. ． Grinding machine table 8. ． Electrode rotating device 11, 12, 13. ． Conductive thin blade whetstone side surface 14. ． Negative terminal 15. ． Positive terminal 21. ． Conductive thin blade grindstone rotating shaft 31. ． Disk outer peripheral surface of disk electrode 32. ． 34. Disk outer peripheral edge of disk electrode 34. ． Disk electrode rotating shaft

Claims (2)

[Claims] 1. A conductive grindstone, which is a full-form or thin-edged grindstone including a superabrasive grindstone mixed with diamond and / or CBN abrasive grains mounted on a rotary shaft of a grinding machine, is not removed from the machine. The disc-shaped electrode for electric discharge machining is rotated by the electrode rotating device installed on the table of the grinding machine with respect to the conductive grindstone rotating shaft when the conductive grindstone rotating shaft is in the Y-axis direction. The axes are mounted so as to be orthogonal to each other such as the Z-axis direction, one voltage is supplied from the DC pulse power source or the pulse DC power source to the conductive grindstone, and the electric discharge machining is performed from the DC pulse power source or the pulse DC power source. The other voltage is supplied to the disk-shaped electrode for use, the side surface of the conductive grindstone is brought close to the disk outer peripheral surface of the disk-shaped electrode, and the disk-shaped electrode is rotated, and the conductive grindstone and the disk-shaped electrode are rotated. A direct current pulse voltage is applied between the electrodes to discharge while applying a water-soluble grinding liquid between the electrodes, and the side surface of the conductive grindstone is moved in parallel to the disk outer peripheral surface in the Z-axis direction and / or the Y-axis direction. A method for shaping a side surface of a grindstone by an on-machine discharge truing method, characterized in that the conductive grindstone is shaped by discharging while being discharged. 2. The electrode rotating shaft is attached so as to be inclined from a position substantially orthogonal to the conductive grindstone rotating shaft,
Discharge while moving the side surface of the conductive grindstone close to the outer peripheral edge of the disk of the disk-shaped electrode, rotating the disk-shaped electrode, and translating the side surface of the conductive grindstone in the Z-axis direction and / or the Y-axis direction. The method for shaping a side surface of a grindstone by the on-machine discharge truing method according to claim 1, wherein the conductive grindstone is shaped.