JPH079338A - Dressing device - Google Patents

Abstract

PURPOSE:To prevent generation of a scratch on the surface of a work owing to the removal of abrasive grains. CONSTITUTION:In this dressing device, a voltage is applied between electrodes 25 and 26 by a power source device 27 in a grinding process, a weak current is fed to a grinding wheel 21, and a dressing is carried out in an electrytic in-process dressing method. A pushing member 30 squeezed to the working surface of the grinding wheel 21 at a specific pressure is provided between the electrode 26 and a work 22, and the surface of the grinding wheel 21 is rubbed by the pushing member 30 so as to remove the abrasive grains removable with a weak force, from the surface of the grinding wheel 21, before the dressed surface reaches to the work 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dressing apparatus for dressing a grindstone using an electrolytic in-process dressing method.

[0002]

2. Description of the Related Art Recently, in an apparatus for grinding a surface of a workpiece with a metal bond grindstone, the metal bond grindstone is used as an anode (+ pole), and a cathode (-pole) electrode is installed facing the work surface. An electrolytic in-process dressing method has been developed in which a weakly conductive grinding fluid is caused to flow between both electrodes to cause a weak current to flow through a metal bond grindstone during processing, thereby performing dressing by electrolytic action.

This electrolytic in-process dressing method will be described with reference to FIG. As shown in FIG. 5A, the metal bond grindstone 11 is an abrasive grain 1 such as diamond.
2 is held by a metal bond 13 such as cast iron.
When a weak current is applied as described above during the grinding process using the metal bond grindstone 11, the surface of the metal bond 13 is oxidized and eluted as shown in FIG. A certain passivation film 14 is formed, current stops flowing, and oxidation does not proceed any further. Further, when the surface of the grindstone 11 comes into contact with the workpiece during processing, as shown in FIG. 5C, the passivation film 14 is peeled off as the abrasive grains are worn, and a current flows again at that part. . Then, as shown in FIG. 5D, the surface of the metal bond 13 is again oxidized and eluted to start dressing.
Then, as shown in FIG. 5B, the passive film 14 is again formed.
Is formed and the dressing is completed. Further, as the grinding process progresses, the cycles (b) to (d) are repeated to keep the abrasive grains from sticking out.

[0004]

However, in this electrolytic in-process dressing method, the metal bond 13 is scraped more uniformly than the surface layer with respect to the abrasive grains 12 which are irregularly distributed inside the grindstone 11. Since the dressing method is an electrochemical action and the dresser and the grindstone are not in contact with each other, as shown in FIG. 6, after the dressing, many abrasive grains 12a that easily fall off with a weak force are present on the grindstone surface. There is. When a workpiece is machined with the grindstone in such a state, the abrasive grains 12a fall off at the initial stage of contact between the workpiece and the grindstone, and the abrasive grains 12a are sandwiched between the grindstone and the workpiece, and are useless on the surface of the workpiece. However, there is a problem that it may cause scratches.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dressing device capable of preventing the generation of scratches on the surface of a workpiece due to the removal of abrasive grains.

[0006]

SUMMARY OF THE INVENTION A dressing apparatus of the present invention comprises a cathode electrode provided facing a work surface of a metal bond grindstone and a metal bond grindstone used as an anode, and between the metal bond grindstone and the electrode. In addition, for example, a current supply means for flowing a weak current by flowing a weakly conductive grinding fluid, and an electrode arranged in the rotating direction of the metal bond grindstone and the workpiece, and a predetermined surface on the work surface of the metal bond grindstone. And a pressing member that is pressed by pressure.

[0007]

In this dressing apparatus, the abrasive grains which are easily removed from the surface of the metal bond grindstone after being dressed by the electrolytic action are positively removed by the pressing member before reaching the workpiece.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the dressing device of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view showing a main part of a grinding machine including a dressing machine according to a first embodiment of the present invention.

This embodiment is an example in which the dressing device of the present invention is applied to a grinding device using a cylindrical grindstone. The grinding device supports a cylindrical metal bond grindstone 21 rotated by a motor (not shown), a workpiece 22 facing the grindstone 21, and can move back and forth in a direction orthogonal to the axial direction of the grindstone 21. And a table 23. The grindstone 21 is configured to hold the abrasive grains 12 with a metal bond 13 as in the case shown in FIG.

The dressing device of this embodiment is provided with a grindstone 21.
A brush-shaped anode electrode 25 that comes into contact with the workpiece, a cathode electrode 26 that is provided facing the working surface of the grindstone 21, and an electrode 25.
A power supply device 27 for applying a voltage between the electrode 26 and the electrode 26 to flow a weak current to the grindstone 21, and a work surface of the grindstone 21 arranged between the electrode 26 and the workpiece 22 in the rotating direction of the grindstone 21. A pressing member 30 that is pressed against the surface with a predetermined pressure
It has and. Further, a weakly conductive grinding fluid supplied by a grinding fluid supply device (not shown) is flown between the grindstone 21 and the electrode 26.

The pressing member 30 is slidably housed in a housing 31 fixed to the grinding machine side in a direction orthogonal to the work surface of the grindstone 21, and a spring 32 housed in the housing 31 houses the grindstone 21. It is urged to press against the work surface. As a material of the pressing member 30, for example, a material of ceramics or a general grindstone such as WA or GC is preferable. Further, the pressing force of the pressing member 30 is preferably set to be approximately the same as the processing load. In addition to the spring 32, a cylinder, a piezoelectric element, a solenoid, or the like can be used as the means for generating the pressing force.

Further, as shown in FIG. 2, the pressing member 30 is slightly inclined with respect to the axial direction of the grindstone 21 so that the abrasive grains removed by the pressing member 30 do not accumulate on the pressing member 30. It is desirable to arrange them along the direction.
Next, the operation of this embodiment will be described with reference to FIG.

In the grinding apparatus shown in FIG. 1, during the grinding process,
A voltage is applied between the electrodes 25 and 26 by the power supply device 27, a weak current is passed through the grindstone 21, and the grindstone 21 is dressed by the electrolytic in-process dressing method. That is, as shown in FIG. 3 (a), the surface of the metal bond 13 of the grindstone 21 is oxidized and eluted by the current flowing through the grindstone 21, and the passivation film 14 that is an oxide film is formed. The passivation film 14 gradually advances and dressing is performed at any time.

By the way, as shown in FIG. 3A, immediately after the dressing is performed by the electrolytic in-process dressing method, the abrasive grains 12a which easily fall off with a weak force are present on the surface of the grindstone 12. . Such abrasive grains 12a
Not only has no processing capability, but also causes unnecessary scratches on the surface of the work piece 22.

In this embodiment, since the pressing member 30 is provided between the electrode 26 and the workpiece 22 in the rotating direction of the grindstone 21, as shown in FIG. Before the dressed surface reaches the workpiece 22 after the surface of the grindstone 21 is rubbed, the abrasive grains 12a that easily fall off with a weak force are dropped from the grindstone surface. In FIG. 3B, reference numeral 12b indicates the dropped abrasive grains. Therefore, when the grindstone 21 actually acts on the workpiece 22, only the abrasive grains having a sufficient machining ability act, and a good machined surface free from scratches due to the removal of the abrasive grains can be obtained.

FIG. 4 is an explanatory view showing a main part of a grinding machine including a dressing machine according to a second embodiment of the present invention. The present embodiment is an example in which the dressing device of the present invention is applied to a grinding device using a cup grindstone. This grinding apparatus includes a cup grindstone 32 connected to a grindstone shaft 31. The cup grindstone 32 is a metal bond grindstone constituted by holding the abrasive grains 12 with a metal bond 13 as in the first embodiment. The grindstone shaft 31 is connected to a drive motor 36 via a pulley 33, a belt 34, and a pulley 35, and is rotated by the drive motor 36. Also,
The grinding device includes a table 38 that supports a workpiece 37 and that is rotated by a motor (not shown) below the grindstone 32.

The dressing device of this embodiment is provided with a grindstone 32.
An unillustrated anode electrode, a cathode electrode 39 provided facing the working surface of the grindstone 32, and a voltage between the two electrodes for applying a weak current to the grindstone 32. A power supply device (not shown) and a pressing member 40, which is arranged between the electrode 39 and the workpiece 37 in the rotating direction of the grindstone 32 and is pressed against the work surface of the grindstone 32 with a predetermined pressure, are provided.

A shaft 41 is connected to the pressing member 40,
The shaft 41 is slidably housed in a housing 42 laterally fixed to the grindstone 32 on the side of the grinder, and slidably in a direction orthogonal to the work surface of the grindstone 32, and is moved upward by a spring 43 housed in the housing 42. Is urged by. As a result, the pressing member 40 is pulled upward, and the grindstone 3
The work surface of No. 2 is pressed with a predetermined pressure.

The material and the pressing force of the pressing member 40 are the same as those in the first embodiment. In addition to the spring 43, a cylinder, a piezoelectric element, a solenoid, or the like can be used as the means for generating the pressing force. Other actions and effects are similar to those of the first embodiment.

[0020]

As described above, according to the present invention, the abrasive grains that are likely to come off on the surface of the metal bond grindstone after being dressed by the electrolytic action are positively pressed by the pressing member before reaching the workpiece. I decided to exclude it,
There is an effect that it is possible to prevent the generation of scratches on the surface of the workpiece due to the removal of the abrasive grains.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a main part of a grinding device including a dressing device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement of pressing members in the dressing device according to the first embodiment of the present invention.

FIG. 3 is an explanatory view showing the operation of the dressing device according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a main part of a grinding device including a dressing device according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining a conventional electrolytic in-process dressing method.

FIG. 6 is an explanatory diagram showing abrasive grains that are easily removed by a conventional electrolytic in-process dressing method.

[Explanation of symbols]

 21 grindstone 22 workpiece 23 table 25, 26 electrode 27 power supply device 30 pressing member 31 housing 32 spring

Claims (1)

[Claims] 1. A cathode electrode provided to face a work surface of a metal bond grindstone, and a current supply means for flowing a weak current between the metal bond grindstone and the electrode, using the metal bond grindstone as an anode. A dressing device, comprising: a pressing member that is disposed between the electrode and the workpiece in the rotation direction of the metal bond grindstone and that is pressed against the work surface of the metal bond grindstone with a predetermined pressure.