JPH05104440A - Electrolytic dressing and grinding device - Google Patents

Abstract

PURPOSE:To prevent the variation of electrolytic strength caused by the variation of rotating speed in the radial direction of a rotating grinding tool. CONSTITUTION:Plural number of electrodes 7 functioning as a cathode with a minute clearance (h) maintained to the grinding face 2a of a conductive grinding tool 2 functioning as an anode are provided on a holder 4 for an insulating body. Electric current is applied to the electrode 7 through an inductive member 8 coming into contact with the upper end of the electrode 7. The conductive member 8 is formed so as to increase its area from the central part of the grinding tool 2 toward its outer periphery. Thus the rotating speed of the grinding tool 2 increases, and electrolytic action becomes weaker, and the electrolytic action of the grinding tool on its outer periphery becomes stronger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic dressing grinding apparatus capable of adjusting dressing in copy grinding of a workpiece such as a lens.

[0002]

2. Description of the Related Art Generally, grinding of a workpiece such as a lens is performed by rotating the grinding tool and swinging the workpiece on the grinding tool. However, there is a problem in that the grinding tool is clogged and the grinding ability is reduced, which requires a long time for grinding.

Therefore, in order to solve the above problems, a means for grinding while electrolytic dressing has been devised as disclosed in Japanese Patent Laid-Open No. 3-43144.

As shown in FIG. 23, the above-mentioned electrolytic dressing apparatus is provided with an anode 2 on a conductive grinding tool 1 and a ring-shaped cathode 5 on a holding plate 4 for holding a member 3 to be processed. Then, the processed surface of the grinding tool 1 and the cathode 5
A small gap d is provided between the machining surface and the cathode 5, and a coolant 6 is supplied between the machining surface and the cathode 5, and a voltage is applied to the grinding tool 1 and the cathode 5 from a DC power supply 7 that generates a pulse voltage for electric discharge machining. The machined surface is electrolytically dressed.

[0005]

However, in the above-mentioned prior art, the ring-shaped negative electrode 5 performs electrolytic dressing at each point of the grinding tool 1. Generally, in electrolytic dressing, the lower the peripheral speed of the grinding tool, the stronger the electrolysis, and the dressing progresses. Therefore, in the hemispherical grinding tool, the peripheral speed is different in the radial direction, and the peripheral speed is 0 (m / min) at the center. Therefore, in the ring-shaped negative electrode 5, the electrolysis becomes stronger as it gets closer to the center of the grinding tool 1 and the electrolysis becomes weaker as it goes to the outer periphery, so that the shape of the grinding tool 1 gradually collapses, and along with this, the work piece to be machined. The shape accuracy of the object is reduced. Furthermore, in the above-mentioned conventional technique, when the shape of the grinding tool 1 is broken, it is impossible to correct the shape by adjusting the electrolytic dressing.

The present invention has been made in view of the above-mentioned problems of the prior art, and can suppress the change in the electrolytic strength in the radial direction of the grinding tool to a minimum and maintain the shape of the grinding tool.
An object of the present invention is to provide an electrolytic dressing grinding device that can correct the shape of a grinding tool when the shape of the grinding tool is broken.

[0007]

In order to achieve the above object, the electrolytic dressing grinding apparatus of the present invention is configured so that a conductive grinding tool and a workpiece are relatively moved along a processing surface of a rotating conductive grinding tool. Oscillates to apply an anode to the conductive grinding tool and a cathode to the electrode that keeps a certain distance from the work surface of the conductive grinding tool. In an electrolytic dressing grinding apparatus via a coolant, a plurality of the electrodes are provided in an insulator, and one or more electrodes of the electrodes and the electrodes are applied to a cathode from the rotation center of the conductive grinding tool toward the outer peripheral direction. The conductive member having an increased number of portions to be applied is configured to be capable of being partially or continuously energized. In addition, along the machining surface of the rotating conductive grinding tool, the conductive grinding tool and the workpiece are relatively swung to apply an anode to the conductive grinding tool, and at the same time as the machining surface of the conductive grinding tool. In the electrolytic dressing grinding device, in which a cathode is applied to the electrode that maintains a constant distance between the electrodes, and a plurality of the electrodes are provided in an insulator in the electrolytic dressing grinding device in which a weakly electrically conductive coolant is interposed between the conductive grinding tool and the electrode, The one or more electrodes and the conductive member having a different contact portion may be configured to be partially or continuously energized.

[0008]

According to the electrolytic dressing device configured as described above, the contact between the electrode and the conductive member is partially or continuously increased from the center of rotation of the conductive grinding tool toward the outer peripheral direction to perform grinding. It is possible to prevent the strength of the electrolytic action caused by the different rotational speeds of the tool in the radial direction.

[0009]

[Embodiment 1] FIG. 1 is a sectional view showing an embodiment 1 of an electrolytic dressing apparatus of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. In the electrolytic dressing device 1 of the present invention,
The grinding tool 2 is integrally provided at the tip of a rotary shaft 3 connected to a drive source device (not shown). The grinding tool 2 has electroconductivity, and its tip portion (machined surface 2a) is formed in a hemispherical shape corresponding to the machined surface shape of the workpiece 5 held by the holder 4. The grinding tool 2 may be, for example, one in which abrasive grains such as diamond powder are bonded by a bond having conductivity.

The holder 4 is made of an insulating material and is arranged above the grinding tool 2. The holder 4 is formed in a dish shape and holds the workpiece 5 at a portion facing the processing surface 2 a of the grinding tool 2. Also, the holder 4
Is engaged with the spherical tip portion of the rod-shaped kanzashi 6 at the center of its upper surface and is swingably held. Although the swing 6 is swung by a swing device (not shown), it is provided so as not to rotate about its central axis. Then, by swinging the holder 4 and rotating the grinding tool 2, the workpiece 5 is ground into a grinding tool.

Inside the holder 4, a large number of rod-shaped negative electrodes 7 are provided so as not to contact each other. When the workpiece 5 is pressed against the machining surface 2a of the grinding tool 2 with the holder 4 holding the workpiece 5, the minus electrode 7 is provided between the machining surface 2a and the tip surface of the minus electrode. It is provided so that a slight gap h (preferably 0.1 mm to 0.2 mm) can be secured.

A conductive member 8 is provided on the upper end of the negative electrode 7.
Are slidably provided, and the non-conductive member 9 is fixed to the upper surface of the conductive member 8. The non-conductor member 9 is the nut 1
The spring 12 provided on the holder 11 fixed to the kanzashi 6 at 0
Is held by. The spring 12 urges the non-conductive member 9 and the conductive member 8 toward the grinding tool 2 in the direction of the central axis of the zigzag 6 to bring the negative electrode 7 and the conductive member 8 into contact with each other. Further, the spring 12 regulates the non-conductive member 9 and the conductive member 8 so as not to rotate around the central axis of the arrowhead 6.

The shape and mounting state of the conductive member 8 are as follows.
As shown in FIG. 2, a portion corresponding to the outer peripheral portion of the grinding tool 2 is configured to have a wider area in contact with the negative electrode 7. The conductive member 8 is a pulse power source 13
Is connected to the negative electrode of. The positive electrode of the pulse power supply 13 is connected to the grinding tool 2 through the rotating shaft 3 via the brush 14. On the other hand, since the holder 4 and the work piece 5 follow the rotation of the grinding tool 2, the nonconductive member 9 is rotatably attached to the holder 5 via the bearing 15. In the figure, 16 is a nozzle for supplying the coolant 16a between the grinding tool 2 and the negative electrode 7 from a coolant pump (not shown).

In this embodiment, when the grinding tool 2 is rotated and the workpiece 5 is ground while sliding on the machining surface 2a, the minus electrode 7 and the power source 1 are used.
By supplying the coolant 16a from the nozzle 6 between the grinding tool 2 and the grinding tool 2 applied to the anode via the brush 14, the workpiece 5 is ground while dressing the working surface 2a.

According to this embodiment, during the above-mentioned grinding process,
Since only the negative electrode 7 in contact with the conductive member 8 is energized, as shown in FIG. 2, the electrolytic area increases and the electrolytic strength increases from the center of the grinding tool 2 toward the outer periphery. Therefore, it is possible to cancel the change in the electrolytic speed due to the influence of the peripheral speed of the grinding tool 2 and maintain the shape of the grinding tool 2. Further, when more accuracy is required, or when the shape of the grinding tool 2 is modified, the nut 10 is loosened and a portion where the conductive area of the conductive member 8 is large so as to correspond to the portion where the electrolysis is to be partially strengthened. By moving and fixing with the nut 10, the shape of the grinding tool 2 can be finely adjusted.

[0016]

[Embodiment 2] FIG. 3 is a sectional view showing Embodiment 2 of the electrolytic dressing apparatus of the present invention, FIG. 4 is a plan view, and FIG. 5 is a sectional view taken along line BB in FIG. In the electrolytic dressing device 20 of the present invention, the grinding tool 2 is integrally provided at the tip of the rotary shaft 3 connected to a drive source device (not shown).
The grinding tool 2 has conductivity, and its processed surface 2a is formed in a hemispherical shape corresponding to the processed surface shape of the workpiece 5 held by the holder 4. The holder 4 is made of an insulator,
It is arranged above the grinding tool 2. The holder 4 is formed in a dish shape, holds the workpiece 5 at a portion facing the processing surface 2a of the grinding tool 2, and engages with the tip spherical portion of the rod-shaped kanzashi 6 at the center of the upper surface. , Swingably held. Then, by rotating the grinding tool 2, the workpiece 5 is ground into a spherical tool.

Inside the holder 4, a large number of bar-shaped negative electrodes 7 are provided so as not to contact each other. When the work piece 5 is pressed against the work surface 2a of the grinding tool 2 while the work piece 5 is held by the negative electrode 7 and the holder, a slight amount of space is left between the work surface 2a and the tip of the negative electrode 7. It is provided so that the gap h can be secured.

A conductive member 8 is provided on the upper end of the negative electrode 7.
Is slidably provided. As shown in FIGS. 4 and 5, the conductive member 8 is formed such that the area corresponding to the outer peripheral portion of the grinding tool 2 has a larger area in contact with the negative electrode 7. A non-conductive member 9 to which a magnet 21 is fixed is fixed to the upper surface of the conductive member 8, and the non-conductive member 9 is rotatably attached to the holder 4 via a bearing 15. The magnet 21 is provided on the upper surface of the non-conductive member 9 corresponding to the portion where the largest area of the conductive member 8 is formed.

An electromagnet 22 is provided outside the magnet 21. As shown in FIG. 4, the electromagnet 22 is divided into seven pieces, a to g, which are connected to the switch box 23, and are arranged so as to correspond to a half circumference on the circumference above the holder 5. The electromagnet 22 (electromagnet g in the figure) attracts the magnet 21 to prevent the non-conductive member 9 and the conductive member 8 from being driven by the rotation of the holder 4, and the widest portion of the conductive member 8 is ground. The conductive member 8 is fixed so as to correspond to the outermost peripheral portion of the tool 2.

In this embodiment, while the grinding tool 2 is rotated and the center of the ball is oscillated, the coolant 16a is supplied from the nozzle 16 between the negative electrode 7 and the grinding tool 2 to electrolyze the work surface 2a. The workpiece is ground while dressing.

According to this embodiment, as in the first embodiment, the electrolytic area increases and the electrolytic strength increases from the center to the outer periphery of the grinding tool 2. Therefore, it is possible to cancel the change in the electrolytic speed due to the influence of the peripheral speed of the grinding tool 2 and maintain the shape of the grinding tool 2. Also,
When more accuracy is required, or when the shape of the grinding tool 2 is to be corrected, the switch box 23 is operated to operate one of the electromagnets a to g, and the area of the conductive member 8 is reduced to the portion where electrolysis is to be strengthened. By moving a large portion, the shape of the grinding tool 2 can be finely adjusted.

In this embodiment, the case where the plate-shaped negative electrode 7 is used has been described, but as shown in FIG. 6, even if the bar-shaped negative electrode 6 is used, The same operation and effect as those of the embodiment can be obtained.

7 to 12 show a modification of the conductive member 8 used in the second embodiment. FIGS. 7 to 9 are plan views, FIG. 10 is a bottom view, FIG. 11 is a sectional view, and FIG. 12 is shown in FIG.
It is an expanded sectional view of the A section in. The conductive member 8a shown in FIG. 7 is formed in an elliptical shape, and is used when it is desired to enhance the electrolysis of the central portion and the outer peripheral portion of the grinding tool 2. The conductive member 8c shown in FIG. 8 is formed in a star shape and is used when it is desired to enhance the electrolysis of the central portion, the outer peripheral portion and the central portion of the grinding tool 2, and is rotated 45 degrees to weaken the electrolysis of the above portion. be able to. The conductive member 8c shown in FIG. 9 is formed by partially providing a protrusion, and is used when the electrolysis is performed by concentrating on the circumference of a part of the grinding tool 2. Conductive member 8d shown in FIG.
Is formed by providing an insulator 24 on a portion corresponding to a portion (fine portion) where the electrolysis action of the conductive member 8 is weakened, and by making the portion not electrically connected to the negative electrode 7, the strength of electrolysis can be increased. It is like this.

[0024]

[Third Embodiment] FIG. 13 is a cross-sectional view showing a third embodiment of the electrolytic dressing grinding apparatus of the present invention, FIG. 14 is an enlarged cross-sectional view of the tip of the kanzashi, and FIG.
14 is a sectional view taken along line DD in FIG. 14, FIG. 17 is a sectional view taken along line EE in FIG. 14, and FIG.
6 is a sectional view taken along line FF in FIG. In the electrolytic dressing device 30 of the present invention, the grinding tool 2 is integrally provided at the tip of a rotary shaft 3 connected to a drive source device (not shown). The grinding tool 2 has conductivity, and its processed surface 2a is formed in a hemispherical shape corresponding to the processed surface shape of the workpiece 5 held by the holder 4. The holder 4 is made of an insulating material and is arranged above the grinding tool 2. The holder 4 is
The workpiece 5 is held at a portion that is formed in a dish shape and faces the processing surface 2a of the grinding tool 2, and at the center of the upper surface, engages with the spherical tip portion of the rod-shaped kanzashi 6 to swing freely. Is held. Then, by rotating the grinding tool 2, the workpiece 5 is ground into a spherical tool.

Inside the holder 4, minus electrodes 7a, 7b and 7c arranged in three layers are provided so as not to contact each other. One end of each of the minus electrodes 7a, 7b, 7c has an engaging portion 4 that engages with the tip spherical portion 6a of the kanzashi 6.
It is exposed on the wall surface of a. On the other hand, the tips of the negative electrodes 7a, 7b, 7c are
b and 7c are provided in this order from the inside to the outside on the facing surface side of the grinding tool 2, and the workpiece 5 is pressed against the machining surface 2a of the grinding tool 2 while the holder 4 holds the workpiece 5. When processed, the processed surface 2a and the negative electrodes 7a, 7b, 7c
It is provided so that a slight gap h can be secured between it and the tip.

The minus electrode 7a is formed of a single member so that its tip is formed in a ring shape. The negative electrodes 7b and 7c are radially multi-divided, and the divided pieces are formed so as not to contact each other in the holder 4.

A conductive member 8 connected to the power source 13 is provided in the kanzashi 6, and the minus electrodes 7a, 7b, 7 are provided.
A contact portion 8e with c is provided on the surface of the tip spherical portion 6a. The contact portion 8e of the conductive member 8 is the negative electrode 7
It is connected to a part of the divided pieces of b and 7c, and the contact area with the negative electrode 7b is formed larger than the contact area with the negative electrode 7c (see FIGS. 17 and 18). Also,
The negative electrode 7a is formed so that it can be continuously connected (see FIGS. 14 and 16).

In this embodiment, while the grinding tool 2 is rotated and swayed in the spherical center, the coolant 16a is supplied from the nozzle 16 between the negative electrode 7 and the grinding tool 2 to electrolyze the work surface 2a. When grinding the workpiece while dressing, the kanzashi is fixed so that the center of the contact portion 8e of the conductive member 8 is connected to the negative electrodes 7b and 7c corresponding to the outer peripheral portion of the grinding tool 2.

According to the present embodiment, since only the negative electrode 7 in contact with the conductive member 8 is energized, the electrolytic area increases and the electrolytic strength increases from the center of the grinding tool 2 toward the outer periphery. Therefore, it is possible to cancel the change in the electrolytic speed due to the influence of the peripheral speed of the grinding tool 2 and maintain the shape of the grinding tool 2. Further, by rotating the hammer 6, the center of the contact portion 8e of the conductive member 8 can be moved to the portion where the electrolysis is strengthened, and the shape of the grinding tool 2 can be corrected.

[0030]

[Fourth Embodiment] FIG. 19 is a sectional view showing a second embodiment of the electrolytic dressing grinding apparatus of the present invention, and FIG.
It is a -G line sectional view. Electrolytic dressing device 4 of the present invention
No. 0, a grinding tool 2 is integrally provided at the tip of a rotary shaft 3 connected to a drive source device (not shown). The grinding tool 2 has conductivity, and its processed surface 2a is formed in a hemispherical shape corresponding to the processed surface shape of the workpiece 5 held by the holder 4. The holder 4 is made of an insulating material and is arranged above the grinding tool 2. The holder 4 is formed in a dish shape, holds the workpiece 5 at a portion facing the processing surface 2a of the grinding tool 2, and engages with the tip spherical portion of the rod-shaped kanzashi 6 at the center of the upper surface. , Swingably held. Then, by rotating the grinding tool 2, the workpiece 5 is ground into a spherical tool.

Inside the holder 4, a large number of plate-shaped negative electrodes 7 are provided so as not to contact each other. When the workpiece 5 is pressed against the machining surface 2a of the grinding tool 2 with the holder 4 holding the workpiece 5, the minus electrode 7 is slightly between the machining surface 2a and the tip of the minus electrode 7. It is provided so that a large gap h can be secured.

A conductive member 8 is provided on the upper end of the negative electrode 7.
Is slidably provided. The conductive member 8 is held by a nut 10 via a spring 12 provided on a non-conductive member 9 fixed to the knapsack 6. The spring 12 biases the conductive member 8 toward the grinding tool 2 in the direction of the central axis of the kanzashi 6 so as to contact the negative electrode 7, and prevents the conductive member 8 from rotating around the central axis of the kanzashi 6. Regulated to. The conductive member 8 is formed in a fan shape, and as shown in FIG. 20, the conductive member 8 is attached so that the contact area with the negative electrode 7 becomes wider toward the outer peripheral portion of the grinding tool 2.

In the present embodiment, while the grinding tool 2 is rotated and swayed in the spherical center, the coolant 16a is supplied from the nozzle 16 between the negative electrode 7 and the grinding tool 2 to electrolyze the work surface 2a. The workpiece is ground while dressing.

According to the present embodiment, since only the negative electrode 7 in contact with the conductive member 8 is energized, the electrolytic area increases and the electrolytic strength increases from the center of the grinding tool 2 toward the outer periphery. Therefore, it is possible to cancel the change in the electrolytic speed due to the influence of the peripheral speed of the grinding tool 2 and maintain the shape of the grinding tool 2. Further, by loosening the nut 10 and moving a portion of the conductive member 8 having a large energization area so as to correspond to a portion where the electrolysis is to be strengthened,
The shape of the grinding tool 2 can be modified. Further, the above-mentioned electrolytic adjustment can be performed more accurately by forming the line segments OA and OB from the apex of the fan shape with curved lines.
For example, the conductive member 8f shown in FIG. 21 is used to enhance electrolysis of the outer peripheral portion of the grinding tool 2, and the conductive member 8g shown in FIG. 22 is used to enhance electrolysis of the outer peripheral portion of the grinding tool 2. Be done.

In each of the above-mentioned embodiments, the pulse power supply is used as the electrolysis power supply 13. However, even if a pulse power supply or a DC power supply to which a DC component is added is used, the same operation and effect as those of the above embodiments can be obtained. It can be carried out while.

[0036]

According to the present embodiment, in the conventional grinding and polishing apparatus for lenses and the like, in order to suppress the change in the electrolytic speed in the radial direction of the rotating grinding tool, one or more negative electrodes and a conductive material are used. Since the member and the member are energized continuously at a certain portion and intermittently at a certain portion, the electrolytic strength at each point on the working surface of the grinding tool can be made uniform and the shape of the grinding tool can be maintained. Further, the shape of the grinding tool can be corrected by adjusting the energized portion of the negative electrode.

[Brief description of drawings]

FIG. 1 is a first embodiment of an electrolytic dressing grinding device of the present invention.
It is sectional drawing which shows.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a second embodiment of the electrolytic dressing grinding apparatus of the present invention.
It is sectional drawing which shows.

FIG. 4 is a plan view of an electrolytic dressing grinding device according to a second embodiment.

5 is a sectional view taken along line BB in FIG.

FIG. 6 is a plan view showing a modified example of the second embodiment.

FIG. 7 is a plan view showing a modified example of the second embodiment.

FIG. 8 is a plan view showing a modified example of the second embodiment.

FIG. 9 is a plan view showing a modified example of the second embodiment.

FIG. 10 is a plan view showing a modified example of the second embodiment.

11 is a cross-sectional view of the conductive member in FIG.

FIG. 12 is a cross-sectional view showing an enlarged part A in FIG.

FIG. 13 is a sectional view showing a third embodiment of the electrolytic dressing grinding apparatus of the present invention.

FIG. 14 is a partial cross-sectional view showing the main parts of the third embodiment.

15 is a cross-sectional view taken along the line CC in FIG.

16 is a sectional view taken along line DD in FIG.

17 is a cross-sectional view taken along the line EE in FIG.

18 is a sectional view taken along line FF in FIG.

FIG. 19 is a sectional view showing Example 4 of the electrolytic dressing of the present invention.

20 is a sectional view taken along line GG in FIG.

FIG. 21 is a plan view showing a modified example of the fourth embodiment.

FIG. 22 is a plan view showing a modified example of the fourth embodiment.

FIG. 23 is a sectional view showing a conventional electrolytic dressing grinding apparatus.

[Explanation of symbols]

 1, 20, 30, 40 Electrolytic dressing grinding device 2 Grinding tool 4 Holder 5 Workpiece 7 Negative electrode 8 Conductive member

Claims (2)

[Claims] 1. A conductive grinding tool and a workpiece are relatively swung along a processing surface of a rotating conductive grinding tool to apply an anode to the conductive grinding tool, A cathode is applied to an electrode that maintains a constant distance between the processed surface, and in an electrolytic dressing grinding device that uses a weakly electrically conductive coolant between the conductive grinding tool and the electrode, a plurality of the electrodes are provided in an insulator, One or more of the above electrodes,
An electrolytic dressing grinding device characterized in that a conductive member in which a portion for applying the electrode to the cathode increases from the rotation center of the conductive grinding tool toward the outer peripheral direction can be partially or continuously energized. .. 2. The conductive grinding tool and the work piece are relatively swung along the processing surface of the rotating conductive grinding tool to apply an anode to the conductive grinding tool and A cathode is applied to an electrode that maintains a constant distance between the processed surface, and in an electrolytic dressing grinding device that uses a weakly electrically conductive coolant between the conductive grinding tool and the electrode, a plurality of the electrodes are provided in an insulator, An electrolytic dressing grinding apparatus, characterized in that one or more of the electrodes and a conductive member having a different contact portion can be energized partially or continuously.