JPH0475873A - Grinding device - Google Patents

Abstract

PURPOSE:To enable an electrolytic in-process dressing in which a DC power source is used, by rotating a rectifying member on which a conductive part and insulation part are arranged alternately together with a conductive grinding tool. CONSTITUTION:When a grinding tool 11 is rotated for grinding a work 21, a rectifying member 13 is also rotated integrally, its conductive part 13a and insulation part 13b are brought into contact with a brush 14 alternately and a DC voltage is impressed so that the grinding tool 11 becomes an anode intermittently. Electrolysis is caused on the work face of the grinding tool 11 with this intermittent impression and also a weak electrolytic coolant 17 fed from a coolant feeding means performs dressing of the work face of the grinding tool 11 evenly. Therefore, an electrolytic in-process dressing grinding can be performed with the simple structure for which a pulse generation power source becomes unnecessary, because of an intermittent voltage impression onto the grinding tool 11 becoming possible by utilizing the rotation of the grinding tool 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grinding device for grinding using electrolytic imbrication.

[Conventional technology]

Grinding objects such as metals, ceramics, or glass (
Hereinafter referred to as work. ) into desired shapes and dimensions, a grinding device using a rotating grindstone or the like as a grinding tool is used. Figures 9 and 10 show a conventional grinding device disclosed in Japanese Patent Publication No. 61-33665 and 1/Lens Prism Machining Techniques (Chuo Kagakusha (ed.)) for grinding the spherical surface of I/Lens etc. It shows. A work l created with a radius of curvature R is held by a collet chuck 2 of a work shaft main body 3. The workpiece shaft main body 3 has a built-in mechanism for cutting the workpiece 1 in the direction of arrow a' while rotating it.

Further, the work shaft main body 3 is adjusted to move in the direction of arrow a by operating a handle (not shown) to adjust the wall thickness of the work l. The grindstone 4 that grinds the workpiece 1 is held by a grindstone shaft 5 and rotates, and this rotation processes the workpiece 1. During processing, a coolant 1 (not shown) is placed between the workpiece 1 and the grindstone 4. ) is now supplied.

According to the spherical grinding device having the above configuration, the processing diameter of the grinding wheel 4 that creates the workpiece 1 with the radius of curvature R0 is d as shown in FIG.
Then, the grinding wheel shaft 5 is sin θ. −d/ 2 Angle θ corresponding to the R number. Adjust the grinding wheel shaft 5 by moving it in a direction perpendicular to the grinding wheel shaft (Fig. 9) using a handle (not shown) so that the machining diameter d coincides with the workpiece shaft center line at point P. The desired radius of curvature is 0゜P.
= A spherical surface with Ro can be created. 0° is the point where the workpiece axis center line and the grindstone axis center line intersect, and is also the center of curvature of the spherical surface. Also, the angle at which they intersect is θ. It is.

When a large number of workpieces are processed by such grinding, the grinding wheel becomes clogged, resulting in a decrease in grinding ability, deterioration of the surface roughness of the workpiece's ground surface, and the occurrence of burnout.

To solve this problem, conventionally the grindstone was dressed with a dressing tool or the like between grinding operations.

For such grinding, an electrolytic in-process dressing grinding method has been proposed in recent years, in which the grinding process is continued while electrolytic dressing is carried out by spraying a weakly electrical coolant while the grindstone is being ground. (For example, the 1986 Society for Precision Engineering Academic Lecture Proceedings (10/5, 1986)).

Fig. 11 shows a grinding device that performs grinding using this electrolytic in-process dressing. A contact terminal 7 such as a brush is in contact with a grindstone holder 6 holding the grindstone 4 , and an anode of a power source 8 is applied to the grindstone 4 via the contact terminal 7 . The cathode of the power source 8 is
The coolant 10 is disposed at a constant distance from the grinding surface of the grinding wheel 4, and a weakly electric coolant 10 is ejected between the cathode 9 and the grinding wheel 4 serving as an anode. As the power source 8, a power source is used that can generate a discharge between the grinding wheel 4 and the cathode 9 by generating a constant pulse, and electrolytic in-process dressing is performed by this discharge and supply of a weakly conductive coolant. Is going.

[Problem to be solved by the invention]

However, the above-mentioned conventional grinding apparatus that performs electrolytic in-process dressing needs to be able to apply a dischargeable voltage as a power source, and is itself expensive and impractical. Further, when this grinding device is incorporated into a device for creating a spherical surface as shown in FIG. 9, there is a problem that the structure becomes complicated.

The present invention has been made in view of these conventional problems, and is a grinding device that can perform electrolytic in-process dressing using an inexpensive DC power source without a discharge function, and has a simple structure. The purpose is to serve as a gift.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a rotating conductive grinding tool, a conductive part and an insulating part arranged alternately on a circumferential surface, and integrated with the grinding tool in a state of conduction with the grinding tool. a rectifying member that rotates, an electrode body disposed with a gap between the processing surface of the grinding tool, and applying a direct current so that the rectifying member serves as an anode and the electrode body serves as a cathode. It is characterized by comprising a direct current and a coolant supply means for supplying a weakly electrical coolant between the machining surface of the grinding tool and the electrode body.

FIG. 1 shows the basic structure of this grinding device.

An electrically conductive grinding tool 11 is integrally formed with a rotating shaft 12 connected to a rotational drive source (not shown), rotates in the direction of the arrow, and conducts with the grinding tool 11 to the zero rotating shaft 12 that grinds the workpiece. The rectifying member 13 is attached to rotate together. A brush 14 is in contact with the rectifying member 13.

FIG. 2 shows a cross-sectional view of the rectifying member 13, and the conductive part 1
The rectifying member 13 is configured by the insulating portions 3a and the insulating portions 13b being alternately located on the circumferential surface.

An electrode II5 is provided at a position corresponding to the machining surface of the grinding tool 11 with a slight distance therebetween, and this electrode plate 15 and the brush 14 are connected to a direct current 16. DC power supply 16
is the brush 14, that is, the rectifying member 13 and the rectifying member 1
A voltage is applied to these so that the grinding tool electrically connected to 3 becomes an anode and the electrode plate 15 becomes a cathode. Furthermore, a configuration is such that a weakly electrical coolant is supplied between the machining surface of the grinding tool 11 and the electrode body 15 from a nozzle 18 connected to a coolant supply means (not shown).

[For production]

According to the grinding apparatus t of the present invention having the configuration as described above, for grinding the grinding tool 11, the 2-1 rectifying section rotates integrally with the conductive section 13a. Insulating section 13
b): is in alternating contact with the brush] 4, and the grinding tool 1
A DC voltage is applied so that 1 becomes an anode intermittently. This intermittent application generates electrolysis on the machined surface of the grinding tool 11, and the weakly electrically conductive coolant 17 supplied from the coolant 1 supply stage 1' evenly dresses the machined surface of the grinding tool 11. . Therefore, use the rotation of the grinding tool! Intermittent voltage application to the grinding tool is possible from J2! Bina 1. Because it is. Electrolytic in-processed 1/sodging grinding can be performed with a simple structure that eliminates the need for a pulse generator @ source.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, a specific description will be given based on an embodiment ε illustrating a grinding apparatus of the present invention. It should be noted that in each embodiment C, the same elements are designated by the same reference numerals, so that the redundant explanation will be omitted.

(First Embodiment) FIG. 3 is a side view showing the configuration of the first embodiment of the present invention. Radius of curvature R. = The created work 2I is one Luso (・
By being chucked by Chiya Tsuku 22 Muni,
It is held by the work shaft main body 23.

A machine IJI (not shown) that cuts in the direction of arrow a while rotating the workpiece 21 is incorporated in the work shaft main body 23, and is adjusted to move in the direction of arrow a by a handle (not shown). The thickness W of the workpiece 21 is adjusted by moving the . Work 21
A grinding tool 11 such as a whetstone for grinding is removably attached to a rotating shaft 254, and its rotation causes the processing surface to process the workpiece 21 into a spherical surface. In such a configuration, as shown in FIGS. 9 and 10, the machining diameter d of the grinding tool 24 is
, the rotating shaft 25 is set at θ-5in-' (d/2
Ro) In the tilted state, use the handle (not shown) to
By moving and adjusting the rotating shaft 25 by /2 in the direction of arrow 1, it is possible to create a spherical workpiece 21 with a desired radius of curvature R6.

The above configurations = KA, Hino r, the base of Grinding King XL (S 4
A rectifying part (A13) in which conductive parts 13a and 13' and absolute length parts 13b are alternately arranged is attached to the outer surface of the grinding tool 11 so as to rotate integrally with the grinding tool 11.

Moreover, if this rectifying member 13iff is used, the DC power supply 16 is
A brush 14 connected to the pole is in contact. In this case, the grinding tool 11 is formed by bonding abrasive grains such as diamondor 1' powder with a conductive bond, so that the grinding tool lI is conductive and the brush I4 is connected to the rectifying part $413. When it comes into contact with the conductive part 13a of the grinding tool 11
A DC voltage is applied so that it intermittently becomes an anode.

On the other hand, the collet chuck 22 as a work holder is made of a conductive material.
The electrode body 1 has a tip shape with a radius of curvature R that forms a gap between it and the grinder R11 at spark out 14' (when O grinding is performed with a cut a' and no cut).
5 is installed on the outside.

Further, a power supply brush 19 connected to the (-) pole of the DC power source 1G is in contact with the outer surface of the collet chunk 22, and a DC voltage is applied so that the electrode body 15 becomes a cathode.

Further, in the gap between the grinding tool 11 and the electrode body 15, a nozzle 1 connected to a coolant supply means (not shown) is provided.
A weakly electric coolant 17 is supplied from 8.

In the above ten configurations, the grinding shaft 1 is rotated by the rotation of the rotating shaft 25.
1 and the rectifying member 13 rotate integrally, and the conductive portion 13a and the insulating portion 13b of the rectifying member 13 alternately contact the brush 14. FIG. 4 is a timing chart of the current and voltage applied to the grinding tool 11 through the rectifying member 13, and shows that during T seconds when the conductive part 13a is in contact with the brush 14, →-E(V) is applied, while the voltage becomes 0 (V) for 111 seconds while the insulating portion 13b is in contact with the brush 14, and this cycle is repeated every T seconds. As a result, the pressure (g) is intermittently applied to the grinding tool 11, so that the grinding tool 11 can be electrolytically dressed, and a spherical surface can be created efficiently without clogging the grinding tool 11. be able to.

(Second example) FIG. 5 is a sectional view showing a second embodiment of the present invention.

Although not shown, a conductive grinding tool 11 is integrally formed at the tip of a rotating shaft 31 connected to a drive device. The distal end surface of this grinding tool 11 is formed in a hemispherical shape, and the hemispherical surface of a workpiece 21 having a workpiece surface having the same shape as the grinding surface is in contact with the grinding surface on the upper surface.

The grinding tool 11 has electrical conductivity by bonding abrasive grains such as diamond powder with a conductive bond, and has a rectifying section in which conductive parts 13a and insulating parts 13b are alternately arranged on the outer peripheral surface of the base side. A member 13 is attached, and the (+) pole of a DC power supply 16 is connected to this rectifying member 13.

The upper end surface of the workpiece 21 is held by a holding plate 31 formed to have the same diameter as the workpiece 21. This holding plate 31
A concave portion is formed in the center of the upper surface, and a rod-shaped needle 32 having a spherical portion at its tip engages with this concave portion. Although not shown, the knife 32 is configured to be connected to a drive source and driven to swing, and is also configured to press the workpiece 21 through the holding plate 31 using a pressurizing means. There is.

Further, this cap 32 is connected to the (-) pole of the DC power supply 16, and an annular electrode body 15 is attached to the outer circumferential surface of the holding plate 31 connected to the cap 32. A DC voltage is applied so that the body 15 serves as a cathode.

The electrode body 15 is attached to the grinding tool 1 while holding the workpiece 21.
It is fixed to the holding plate 31 so as to provide a slight gap 1 between it and the processing surface of the holding plate 31. A weakly electric coolant 17 is ejected from a nozzle 18 into this gap l, and the machined surface of the grinding tool is electrolytically dressed by the voltage applied to each of them.

Next, a grinding method using the above configuration will be described.

In the above configuration, when the workpiece 21 is ground, along with the swinging drive of the holding plate 31 and the rotational drive of the grinding tool 11,
The coolant supply means is also driven to supply the grinding tool 11 and the electrode body 1.
A coolant 17 is ejected and intervenes in the gap l between the main body 5 and the main body 5. Further, the voltage applied to the grinding tool 11 and the electrode body 15 by the DC power supply 16 causes electrolysis to occur on the processed surface (abrasive grain surface) of the grinding tool 11, thereby uniformly dressing the surface.

That is, dressing can be performed efficiently and evenly during the grinding process.

When grinding is performed in the above state, the position of the electrode body 15 is moved while maintaining the gap l with respect to the grinding tool 11 due to the oscillating movement, so that the processed surface of the grinding tool 11 can be dressed evenly.

On the other hand, when the predetermined machining of the work 21 is completed, the next work is replaced and the machining is performed again.As this machining continues, the grinding tool gradually wears out, but the work 21 is supplied with a predetermined size. Therefore, the gap l can be secured regardless of the wear of the grinding tool 11. Further, in the case of a workpiece that does not have a predetermined size, the gap l can be easily secured by adjusting the position of the electrode body 15 with respect to the holding plate 31.

Note that if the workpiece 21 is made of metal or other conductive material, an insulator may be interposed between the workpiece 21 and the holding plate 31.

(Third example) FIG. 6 shows a side view of a third embodiment of the invention.

In this third embodiment, the grinding tool 11 is integrally fixed to the tip of a holder 41, and by detachably attaching the holder 41 to the output part 42 of the rotating shaft 25,
The grinding tool 11 is mounted. 43 is a bolt for performing this attachment and detachment.

On the other hand, the rectifying member 13 is integrally fixed to the outer peripheral surface of the tip of the output portion 42 of the rotating shaft 25, and the brush 14 is in contact with the rectifying member 13. In such a configuration, when the rotating shaft 25 is driven, the rectifying member 13 rotates together with the grinding tool 11 to apply intermittent power to the grinding tool 11. However, since the rectifying member 13 is fixed to the rotating shaft 25, , there is no need to adjust the position of the brush 14 when replacing the grinding tool 11.

Therefore, electrolytic in-process dressing can be performed on grinding tools of different types, shapes, and sizes as they are.

(Fourth Embodiment) FIG. 7 shows a design example of the rectifying member 13, in which the conductive parts 13a and the insulating parts 13b are alternately formed by fitting insulators at predetermined intervals on the circumferential surface of a row of conductive rings. It is located.

The length of the circumferential surface of this conductive part 13a is β, and the length of the insulating part 13 is
If the length b is d, the circumferential surface of the rectifying member 13 has a dimension γ
It is divided into n (n - integer) by (7=d+β).

Here, the number of rotations of the rectifying member 13 is N (r.p, m,
); The period of intermittent voltage application is 0 seconds, the division number n is determined by N, and therefore γ is determined by.

For example, N= 1000 (r, p, m,), C=
When grinding at 0.001 (s e c), n
';60. By setting r=6 (deB), the desired electrolytic deionization can be performed.

Therefore, by preparing in advance various rectifying members 13 that are suitable for machining conditions such as the number of revolutions and the voltage application cycle, this can be done quickly. Alternatively, a plurality of rectifying members 13 having different division numbers n may be arranged in parallel, and the brush may be switched to contact the rectifying member having the desired conditions to perform electrolytic dosing that matches the processing conditions. .

FIG. 8 shows a modified example of the rectifying member 13, in which convex portions and four portions are alternately formed on the outer circumferential surface, so that the convex portions are formed on the brush 1.
The conductive part 13a is in contact with the brush 14, and the concave part is an insulating part 13b that does not come into contact with the brush 14.
It has the advantage of being easy to manufacture because there is no need to separate it.

(Effects of the Invention) As explained above, according to the present invention, by rotating the rectifying member in which the conductive parts and the edges are arranged alternately together with the R-conducting grinding tool, the grinding tool can be Since the anode is made to act as an anode, it is possible to perform electrolytic in-process cleansing grinding using a DC power source, making it possible to eliminate the need for an expensive pulse generation power source, and to have a simple structure.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the basic configuration of the grinding device of the present invention, Fig. 2 is a plan view of its rectifying member, Fig. 3 is a partially cutaway side view not showing the first embodiment of the invention, and Fig. 4 The figure is a timing chart showing the application of the grinding member, FIG. 5 is a sectional view showing the second embodiment, and FIG. 6 is a partially cutaway side view showing the third embodiment.
Fig. 7 is a plan view for explaining a design example of the rectifying member, Fig. 8 is a plan view showing a modified example of the rectifying member, Fig. 9 is a partial side view showing a conventional grinding device, and Fig. 10 is a plan view for explaining a design example of the rectifying member. A side view illustrating the grinding process, FIG. 11 shows a conventional grinding device that performs electrolytic in-process dressing grinding, (a) is a front view thereof, and (b) is a left side view thereof. 13... Rectifier member 13a... Conductive part 13b... wA recording part 15... Electrode body 16... DC power supply 17... Weakly conductive coolant

Claims (1)

[Claims] (1) A rotating conductive grinding tool, a rectifying member having conductive parts and insulating parts arranged alternately on a circumferential surface and rotating integrally with the grinding tool in a state of conduction with the grinding tool; an electrode body disposed with a distance from the machining surface of the grinding tool; a direct current to which a direct current is applied such that the rectifying member serves as an anode and the electrode body serves as a cathode; A grinding device comprising: a coolant supply means for supplying a weakly electrical coolant between a processing surface and an electrode body.