KR940006010Y1 - Grinding device - Google Patents

Abstract

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Description

Grinding device

1 is a conceptual diagram showing the basic configuration of the grinding device of the present invention.

Figure 2 is a side view showing a first embodiment of the grinding device of the present invention.

Figure 3 is a side view showing a second embodiment of the grinding device of the present invention.

Figure 4 is a side view showing a third embodiment of the grinding device of the present invention.

Figure 5 is a side view showing a fourth embodiment of the grinding device of the present invention.

6 is a characteristic diagram for explaining the operation of the grinding apparatus with respect to FIG.

7-9 (a), (b) are explanatory drawing which showed the structure about the conventional grinding apparatus.

* Explanation of symbols for main parts of the drawings

1: Workpiece 2: Collet Chuck

3: Workpiece Shaft Main Body 4: Whetstone

5: grinding wheel 10: electrode

11,13: feeding brush 15: weakly charged cooling medium

17: connecting member 18: moving member

19: drive unit

The present invention relates to an electrolytic inprocess dressing grinding apparatus for use in planar or spherical grinding.

In general, when grinding or polishing a workpiece, for example, an optical material by spherical phenomenon, it is common to use a tool such as a grindstone. Hereinafter, spherical processing will be described as an example of the conventional grinding processing technique.

Fig. 7 schematically shows the mechanism of the spherical grinding device by the forced processing method, and examples of the spherical grinding device already known as Japanese Patent Application Laid-Open No. 61-33665 and the technology of the lens prism (Central Science).

In FIG. 7, 1 is a workpiece | work created by the radius of curvature Ro, and is supported by the collet chuck 2 by the workpiece shaft.

3 is a workpiece shaft part main body, and the mechanism (not shown) is assembled so that the workpiece 1 may be ground in the a 'direction while rotating the workpiece 1. Moreover, in order to adjust the thickness of the workpiece | work 1, the workpiece | shaft shaft part main body 3 is made to move and adjust to a direction by the handle which is not shown in figure. 4 is a whetstone and 5 is a whetstone. In addition, a coolant (not shown) is supplied between the work 1 and the grindstone 4.

According to the spherical grinding device of the above-described configuration, as shown in FIGS. 7 and 8, when the machining diameter of the grindstone 4 for forming the workpiece 1 with the radius of curvature Ro is d, the grinding wheel shaft ( 5) by tilting the angle θo corresponding to sinθo = d / 2Ro, and using a handle not shown at the wheel side 5 with the handle (d) at the point P to match the center diameter of the workpiece axis. By moving and adjusting in the b direction, a spherical surface having a desired radius of curvature (OoP = Ro) can be created. Oo is the point where the center line of the workpiece axis intersects the center line of the grinding wheel axis and the center of curvature of the sphere. Moreover, the crossing angle is ((theta) o).

When several workpieces are processed by such grinding, a grindstone is clogged and grinding ability falls, and the grinding surface of a workpiece becomes rough and burns. In order to solve this problem, the dressing tool or the like has been conventionally used between grinding and grinding. On the other hand, in recent years, the electrolytic in-process dressing grinding method (Academic Lecture on Precision Engineering, 1988 (October 5, 1988)) has been proposed.

9 shows the principle diagram, (a) is a front view, and (b) is a left side view.

This method arranges the workpiece 1 between the rotating rotary table 3 and the grinding wheel 4 attached to the rotating grindstone shaft 5, and at the same time, the power supply device 12 via the power feeding brush 13. In this method, the weakly charged cooling medium 15 is ejected between the whetstone 4 serving as a (+) electrode and the opposite (-) electrode by being connected to the grindstone while grinding the whetstone 4 by electrolytic dressing.

In the above method, since the position of the negative electrode relative to the whetstone shaft 5 is fixed, the interval between the negative electrode and the grinding surface of the whetstone is always constant and adjusted so as not to interfere with the workpiece.

In general, grinding wheels vary in speed depending on the type, material of work, and processing conditions, but gradually wear out. When the grindstone is worn, there is a problem that the distance between the negative electrode and the electrode is widened, thereby reducing the electrolytic dressing effect.

The present invention has been made to solve the above problems, and an object thereof is to provide an electrolytic inpress dressing grinding device in which the electrolytic dressing effect is not deteriorated even if the length of the grindstone changes due to the wear of the whetstone.

The present invention provides a grinding device in which a workpiece holder for supporting a workpiece is installed so as to be freely rotated, and a grindstone having conductive conductivity that is rotated in contact with the surface of the workpiece supported by the workpiece holder is installed. At the time of out), an electrode is provided on the outer periphery of the workpiece holder so as to be a constant distance from the grinding surface of the grindstone, and a voltage is applied to these from the power supply so that the electrode becomes a cathode and the grindstone is an anode, and the Grinding device characterized in that to supply a weakly charged cooling medium between the grindstone and the electrode.

Prior to the implementation of the present invention, it is possible to further install a drive for moving the electrode back and forth with respect to the workpiece holder, and a control unit for controlling the drive.

1 shows a conceptual diagram of the present invention. In the figure, 1 is a workpiece | work and is supported by the workpiece holder 2 by the workpiece holder 2.

3 is a workpiece shaft main body, and a mechanism (not shown) is assembled so as to grind in the a 'direction while rotating the workpiece 1. Moreover, in order to adjust the thickness of the workpiece | work 1, the workpiece shaft part main body 3 can be moved and adjusted to a direction by the handle which is not shown in figure.

4 is a whetstone in which whetstone particles such as diamond powder are bonded with a conductive bond, and are attached to the whetstone shaft 5 and fixed so as to be freely detachable.

If the machining diameter of the grindstone 4 is d, the grindstone shaft 5 can be roughly d / 2 moved in the b direction perpendicular to the grindstone shaft with a handle (not shown) so that the workpiece 1 can be ground. do.

The grindstone 4 is supplied with a positive voltage from the power supply 12 via the power feeding brush 13.

On the other hand, the outer periphery of the workpiece holder 2 is provided so that the ring-shaped electrode 10 can be attached and detached by a fixing screw or the like so as to maintain a distance from the grindstone 4, and the power supply is supplied through the feed brush 11. A negative voltage is applied from (12).

In addition, the weak electrostatic cooling medium 15 is supplied between the processing surface of the work piece and the grindstone 4 and the electrode 10 by the water supply hose 14.

When grinding is performed in this state, even if the grindstone 4 is worn, the workpiece shaft portion main body 3 is moved in the a direction by a handle not showing the thickness adjustment of the workpiece 1 by that portion. Accordingly, the electrode 10 also moves in the a direction, whereby the positional relationship with the grindstone 4 can be maintained satisfactorily. Therefore, the effect of the electrolytic dressing of the grindstone 4 by the electrode 10 and the cooling medium 15 is not reduced.

(First embodiment)

2 is a view for explaining a first embodiment of the present invention. 1 is a workpiece | work created by the radius of curvature Ro, and is supported by the collet chuck 2 by the workpiece axis | shaft. 3 is a workpiece shaft part main body, and the mechanism (not shown) is assembled so that the workpiece 1 may be ground in the a 'direction while rotating the workpiece 1. Moreover, in order to adjust the thickness of the workpiece | work 1, the workpiece shaft part main body 3 can be moved and adjusted to a direction by the handle which is not shown in figure.

4 is a grindstone in which whetstone particles such as diamond powder are bonded with a conductive binder, and are attached to the whetstone shaft 5 and fixed so as to be freely detachable.

If the machining diameter of the grindstone 4 is d, the grindstone shaft 5 is inclined by θ = sin (d / 2Ro), and is about d / 2 in the b direction perpendicular to the grindstone shaft with a handle not shown. By movement adjustment, a spherical surface having a desired curvature radius Ro can be created.

The grindstone 4 is supplied with a positive voltage from the power supply 12 via the power feeding brush 13.

On the other hand, in the collet chuck 2 as the work holder, the electrode 10 having a tip shape having a radius of curvature R₁ at which the distance from the grindstone 4 becomes t at sparking out (the grinding amount is '0'). Is provided, and a negative voltage is applied from the power supply 12 via the power feeding brush 11.

In addition, the water supply hose 14 supplies the weakly conductive cooling medium 15 between the working surface of the work 1 and the grindstone 4 and the electrode 10.

If the grinding process is continued in this state, even if the grindstone is worn, the workpiece shaft part 3 is moved in the a direction with a knob not shown to adjust the thickness of the workpiece 1, so that between the grindstone 4 and the electrode 10 It is possible to maintain the interval t of. Therefore, the electrolytic dressing effect of the grindstone 4 by the electrode 10 and the cooling medium 15 does not decrease, and since the clogs of the grindstone 4 do not occur, the spherical surface can be efficiently formed.

Second Embodiment

3 shows a second embodiment of the deceased. In the figure, the same code | symbol is attached | subjected about the same member as FIG. 2, and the description is abbreviate | omitted. In addition, about the form change, it adds (').

In the present embodiment, the work 1 'is a concave spherical surface having a radius of curvature Ro, the grindstone 4' is a convex surface that forms the work 1 'as a concave surface, and the electrode 10' is sparked out. It has a U surface shape of a radius of curvature R2 which can secure the distance t with the grindstone 4 'at the time of the sieve.

When changing from the workpiece 1 to the workpiece 1 'in FIG. 2, the grindstone and the electrode may be changed at the same time, and the positioning of the collet chuck 2 and the electrode once precisely eliminates the necessity of fine adjustment of the interval t. The time required for change can be shortened.

(Third Embodiment)

4 shows a third embodiment of the present invention.

Also in this embodiment, the same code | symbol is attached | subjected about the same member as FIG. 2, and the description is abbreviate | omitted.

The characteristic of this embodiment is that the tip of the collet chuck 2 has a shape having a radius R of curvature so that a gap t is formed between the grindstone 4 when sparking out, and the collet chuck 2 This is to apply a negative voltage from the power supply 12 via the power feeding brush 11 to use the collet chuck itself as an electrode.

This embodiment is particularly effective when there is no space for installing electrodes on the outer circumference of the collet chuck when the diameter of the lens and the diameter of the grindstone are small.

(Example 4)

5 and 6 show a fourth embodiment of the present invention.

In the figure, the same code | symbol is attached | subjected about the member same as FIG. 2, FIG. 3, and the description is abbreviate | omitted.

In the present embodiment, the drive unit 19 for moving the electrode in the workpiece axis direction is provided in the workpiece shaft part main body 3.

The electrode 10 'is made to slide the outer periphery of the collet chuck 2 in the workpiece axis direction. The connection member 17 is fixed to the outer peripheral part of the electrode 10 '. The connecting member 17 is supported by the moving member 18 which is the moving part of the drive part 19. By the operation of the drive member 19, the electrode 10 ′ can move in the workpiece axis direction a ′ with respect to the workpiece shaft part body 3.

The movement in the a 'direction will be described with reference to FIG.

In the figure, the horizontal axis represents the time from the start of the processing to the end of the processing, and the vertical axis represents the movement amount of the collet chuck 2 and the electrode 10 'with respect to the work shaft main body 3.

The collet chuck 2 includes a fast feed process in which the collet chuck is conveyed a lot in a short time, a gentle feeding process in which the collet chuck is transported gradually so that the workpiece can be ground slowly, a spark out process in which the collet chuck is not conveyed at all, The collet chuck consists of a quick return process that returns quickly to the starting position.

On the other hand, the electrode 10 'starts to retreat when the collet chuck 2 starts a slow feeding process of slowly grinding the workpiece, and retreats at a speed proportional to the grinding speed. In the sparking out process of the collet chuck 2, the electrode 10 ′ does not move, and in the quick return process of the collet chuck 2, the electrode also returns to the original position.

The driving unit 19 is controlled to move to the opposite side to the collet chuck in synchronism with the movement of the collet chuck as described in FIG. Although the apparatus of control is not shown in detail and demonstrated, control apparatuses, such as a cam and NC, can be selected suitably.

According to the above apparatus, since the distance between the grindstone 4 'and the electrode 10' is always kept constant at the time of grinding, a dressing effect can be obtained uniformly from the beginning of a process to completion of a process.

In particular, the effect is great when processing with a large amount of grinding.

According to the present invention as described above, even if the length of the whetstone is changed due to the wear of the whetstone, the in-process dressing grinding can be performed without deterioration of the electrolytic dressing effect.

Claims (2)

In a grinding device, a workpiece holder for supporting a workpiece is installed so as to be free to rotate, and a grinding wheel having a conductive conductivity that is rotated in contact with the workpiece surface is provided in the workpiece holder. An electrode is provided at an outer circumference of the workpiece holder to be a constant distance, and a voltage is applied from the power source to the cathode so that the cathode becomes the anode, and a weakly charged cooling medium is supplied between the grindstone and the electrode. Grinding device characterized in that. The grinding apparatus according to claim 1, further comprising a driving device for moving the electrode back and forth with respect to the workpiece holder, and a control unit for controlling the driving device.