JPH075978Y2 - Electric discharge dressing device for rotary whetstone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a discharge dressing device for a rotary grindstone, and more particularly, to a contact dressing device using a pair of electrodes.
The present invention relates to a contact dressing device capable of performing reliable dressing and simultaneously performing truing.

[Prior Art] Although a metal bond diamond grindstone or the like is used for grinding ceramics, mechanical dressing is difficult, and discharge dressing for melting and removing the metal bond by discharge is performed. Recently, in this discharge dressing, contact dressing using a pair of electrodes was proposed (Proceedings of Hitachi Regional Conference P139.
No. 141 (1988)), the slip ring-brush mechanism is not required, and the device cost can be significantly reduced because the voltage can be lowered.

The outline of the device for performing this contact dressing will be described with reference to FIG. 7. The outer peripheral grinding surface 1a of the circular grindstone 1 rotating in the direction of the arrow.
Includes a pair of electrode plates 2A and 2B provided at intervals in the circumferential direction.
The end surfaces of the electrodes are in contact with each other, and a voltage is applied from the voltage source 4 between the electrode plates 2A and 2B.

As shown in FIG. 8, the grinding surface 1a is formed by embedding and holding a large number of superabrasive grains 92 in a conductive bonding material 91 such as a metal bond. When the electrode end face 21 is cut by the superabrasive grains 92, as shown in FIG. A flow-shaped tip 22 is generated along the grinding surface 1a, an intermittent discharge is generated between the tip 22 and the grinding surface 1a, the conductive bonding material 91 is melted and removed, and new superabrasive grains 92 are projected to perform dressing. Be seen.

[Problems to be Solved by the Invention] Although the contact dressing device can perform efficient dressing as described above, efficient truing is also demanded for diamond grinding stones and the like.

The present invention has been made in view of the above background, and an object of the present invention is to provide an electric discharge dressing device for a rotary grindstone capable of performing effective truing as well as dressing.

[Means for Solving the Problem] The electric discharge dressing device for a rotary grindstone according to the present invention is provided with a grinding surface 1a (first of which a large number of superabrasive grains are embedded and held by a conductive bonding material).
A pair of electrodes for arranging the end faces of the rotary grindstone 1 having the figure) at intervals along the grinding surface 1a and forming flow-shaped chips along the grinding surface 1a from the end faces ground by the superabrasive grains. A voltage source 4 (FIG. 7) for applying a voltage between the plates 2A and 2B and the electrode plates 2A and 2B to generate an intermittent discharge between the chip and the grinding surface 1a to melt and remove the conductive binder. And, the pair of electrode plates 2A, 2B are integrally provided with whetstone plates 3A, 3B, 3C made of a normal whetstone whose end faces are ground together with the electrode plates 2A, 2B by the superabrasive grains. It is a thing.

Further, a truer 7 is integrally provided on a holding table 6 (FIG. 3) which holds the electrode plate.

[Operation] In the discharge dressing device having the above structure, the conductive bonding material is melted and removed by the discharge between the chip and the grinding surface of the electrode plate, and new superabrasive grains are projected to perform dressing.
At this time, the sizes of the respective superabrasive grains are not exactly the same, and the embedding position and posture in the bonding material are different, so that the protrusion amount of the superabrasive grains as a whole is not uniform.

Here, in the apparatus of the present invention, the grinding surface grinds the grindstone plate together with the electrode plate, and during the grinding of the grindstone plate, the abrasive grains that largely protrude are dropped off. And
This detachment is performed extremely efficiently because the binder is softened by the heat of discharge, and as a result, the amount of protrusion of the abrasive grains is promptly made uniform and truing is performed.

Here, in the initial stage of dressing, as described above, the discharge may not be performed favorably, but this may be due to the insulating superabrasive grains on the ground surface of the grindstone that requires dressing, depending on the type of metal bond. This is because the metal bond may spread on the surface of and cover it, which causes a short circuit. By the grinding of the grindstone plate, which is performed together with the grinding of the electrode plate, the spread layer is quickly removed, and good discharge is started from the initial dressing without causing a short circuit.

Further, in the structure in which the truer is integrally provided on the electrode holding base, it is possible to immediately shift to the trueing after the electric discharge dressing, and in this case also, the true true is made to the binder softened by the electric discharge. .

[First Embodiment] FIGS. 1 and 2 show an embodiment of the dressing device of the present invention, and particularly show the structure of the electrode installation part thereof. First
In the figure, immediately below the diamond grindstone 1 rotating in the direction of the arrow, a holding table 6 is provided on a circular metal substrate 5 fixed on a magnet table.

The holding table 6 is composed of a circular base 61 and a rectangular open container 62 formed on the base 61. The base 61 has arcuate slots 611 formed at left and right positions to rotate within a certain angle range. The position can be adjusted. Then, in the container portion 62, those in which the electrode plates 2A, 2B and the grindstone plates 3A, 3B, 3C are closely contacted,
These base ends are integrally fixed and held, and the tip end surface is in contact with the outer peripheral grinding surface 1a of the rotary grindstone 1.

The pair of electrode plates 2A and 2B are made of a metal material such as aluminum that generates a flow-type chip, and are positioned along the grinding surface 1a so as to be separated from each other by a predetermined distance. The grindstone plates 3A to 3C are located outside the electrode plates 2A and 2B and between them,
Normal whetstones such as green carborundum (GC) grindstone or white alundum (WA) grindstone can be used.

Electrode bolts 63, 64 are respectively provided penetrating the left and right side walls of the container portion 62 and the grindstone plates 3A, 3C, and the electrode bolts 63,
The respective tips of 64 abut on the electrode plates 2A and 2B, respectively, and are electrically connected thereto. DC voltage source 4 for each electrode bolt 63, 64
The current-carrying wires 41 and 42, which have reached from FIG. 7, are connected.

In the dressing device having such a structure, the rotary grindstone 1 requiring dressing is lowered by a predetermined amount, and the electrode plates 2A and 2B and simultaneously the grindstone plates 3A to 3C are cut and ground. At the initial stage of this grinding, even if the diamond abrasive grains on the grindstone grinding surface 1a are covered with the spread layer of the metal bond, this is promptly removed by the grindstone plates 3A to 3C. As a result, the surface of the insulating abrasive grains appears, and the subsequent discharge dressing is started well. Incidentally, it is desirable to stop the energization to the electrode plates 2A and 2B at the initial stage of this grinding.

When grinding is performed with a voltage applied between the electrode plates 2A and 2B, as described above, flow-type chips are generated from the end faces of the electrode plates 2A and 2B, and intermittent discharge occurs between this chip and the metal bond of the grinding surface 1a. Occurs, the metal bond is melted and removed, and dressing proceeds.

At this time, the grinding surface 1a together with the electrode plates 2A and 2B is a grindstone plate 3A.
Grinding up to 3C is also performed, and during the grinding of the grindstone plate, the abrasive grains that have largely protruded compared to other general abrasive grains are dropped off, the amount of protrusion of the abrasive grains becomes uniform, and truing is performed.
The dropout of the protruding abrasive grains is performed in a state where the metal bond is softened by the electric discharge, and therefore can be efficiently performed by the above-mentioned grindstone plates 3A to 3C made of a WA grindstone or the like.

[Second Embodiment] FIG. 3 shows another embodiment of the present invention. In the figure, a pair of electrode plates 2A, 2B are held inside the container portion 62 of the holding table 6 by arranging insulators 10A, 10B, 10C outside and in the middle of the base. A part of the container portion 62 is projected laterally to form a truer holding portion 63, and a groove-shaped notch 631 is formed in the holding portion 63 to form a diamond compax (registered trademark of General Electric Company). 7 is fixed by screws.

As shown in FIG. 4, the diamond compax 7 is formed by sintering a diamond layer 72 to a thickness of about 0.3 mm on a rectangular cemented carbide plate 71 having a thickness of about 1.5 mm. It is located on the center line between the electrode plates 2A and 2B.

Then, the electrode plates 2A and 2B are fed laterally between A and B in FIG.
After the dressing of the rotary grindstone 1 is carried out by the method described above, it is sent to the side as it is and sent back and forth between C and D, so that it is possible to shift to the truing by the diamond compax 7 without wasting time.

In addition to the diamond compaxes described above, a single stone diamond dresser, an impure dresser, or the like may be used.

Further, in the case where truing is continuously performed with respect to the general-purpose rotary grindstone, as shown in FIG. 6, a diamond block dresser 8 is provided in front of the holding table 6 on the substrate 5, and dressing is performed between E and F in the figure. After performing the
Like H, it is vertically fed onto the block dresser 8 for truing.

In the first embodiment, three grindstone plates are provided so as to sandwich the electrode plate, but the number of grindstone plates may be two or less, and the plate thickness is appropriately selected according to the application. Further, the electrode plate and the grindstone plate do not necessarily have to be provided in close contact with each other.

Further, by using the configuration of the first embodiment in which the grindstone plate is provided and the configuration of the second embodiment in which the truer is provided in combination, it is possible to perform truing with higher efficiency and accuracy.

[Advantages of the Invention] As described above, in the discharge dressing device of the present invention, the grindstone plate is provided integrally with the electrode plate, and the grindstone plate is ground at the same time when the electrode plate is ground by the rotary grindstone. As a result, the structure can be extremely simple and inexpensive, and truing can be efficiently performed in parallel with the dressing of the rotary grindstone.

Further, since the truer is integrally provided on the holder for the electrode plate, it is possible to immediately shift to the effective truing immediately after the dressing of the rotary grindstone.

[Brief description of drawings]

1 and 2 show a first embodiment of the present invention.
FIG. 1 is a sectional view of an electrode mounting portion of a discharge dressing device, which is a sectional view taken along the line I-I of FIG. 2, FIG. 2 is a partial sectional plan view of the electrode mounting portion, and FIGS. FIG. 3 is a partial cross-sectional plan view of the electrode installation portion of the discharge dressing device, FIG. 4 is a perspective view of Diamond Compax, and FIG. 5 is a schematic side view of the electrode installation portion for explaining the process. FIG. 6 is a side view showing another example of the electrode installation portion, FIG.
FIG. 8 is a diagram showing the overall configuration of the discharge dressing device, and FIG. 8 is a diagram conceptually showing the dressing process. 1 …… Rotating wheel 1a …… Grinding surface 2A, 2B …… Electrode plate 3A, 3B, 3C …… Grinding plate 4 …… Voltage source 7 …… Diamond Compax (truer) 10A, 10B, 10C …… Insulating material

Claims (2)

[Scope of utility model registration request] 1. A rotary grindstone having a grinding surface in which a large number of superabrasive grains are embedded and held by a conductive bonding material, and end faces thereof are positioned at intervals along the grinding surface and ground by the superabrasive grains. A voltage is applied between the pair of electrode plates that generate flow-shaped chips along the grinding surface from the end surface and the electrode plates to generate intermittent discharge between the chips and the grinding surface to melt and remove the conductive binder. In the electric discharge dressing device for a rotary grindstone including a voltage source, the pair of electrode plates is integrally provided with a grindstone plate made of a normal grindstone whose end face is ground together with the electrode plates by the superabrasive grains. Discharge dressing device for rotating grindstone. 2. A rotary grindstone having a grinding surface in which a large number of superabrasive particles are embedded and held by a conductive bonding material, with its end faces positioned at intervals along the grinding surface and ground by the superabrasive particles. A voltage is applied between the pair of electrode plates that generate flow-shaped chips along the grinding surface from the end surface and the electrode plates to generate intermittent discharge between the chips and the grinding surface to melt and remove the conductive binder. A rotary grinding wheel electric discharge dressing apparatus comprising a voltage source, wherein a truer is integrally provided on a holding table for holding the pair of electrode plates.