JP2006175528A - Micro tool grinding apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro tool grinding apparatus and method capable of processing a micro tool having a smooth surface roughness and high dimensional accuracy, and having a large aspect ratio and a very fine aspect with high processing efficiency and in a short time.
SOLUTION: A workpiece holding device 20 that holds an elongated rod-like workpiece 1 in a predetermined position, and a grindstone 31 of the same shape that is arranged axially symmetrically or equidistantly about a workpiece axis Z and that processes an outer peripheral surface of the workpiece. And a grindstone moving device 40 that moves the plural grindstones toward the workpiece. The grindstone moving device 40 moves each grindstone 31 toward the workpiece 1 in axial symmetry or synchronously with equal intervals, and the deformation of the workpiece 1 during grinding is suppressed by the grindstone itself.
[Selection] Figure 1

Description

  The present invention relates to a microtool grinding apparatus and method for grinding an ultrafine micro tool having a large aspect ratio.

  In recent years, in the field of manufacturing ultra-compact parts with fine shapes, research on high-speed rotation and high-speed feed cutting using ultra-fine tools with a large aspect ratio and high precision, and research on high-precision and high-quality machining have made remarkable progress. ing. In addition, development of machine tools corresponding to these processing techniques has been rapidly carried out. Hereinafter, in the present invention, a very fine tool having a large aspect ratio is referred to as a “micro tool”.

However, micro tools that are indispensable in micromachining such as precision cutting and precision grinding require a lot of time and cost to manufacture, which hinders improvement in work efficiency. In addition, the micro tools that can be manufactured relatively easily at present are limited to those having a representative diameter of about sub-millimeters.
That is, when processing an ultrafine micro tool having a large aspect ratio, there is a problem in that breakage or bending (distortion) is likely to occur due to processing resistance.
Even if finer processing is possible, if the processing surface is rough, the processing is extremely difficult for various reasons, such as cracks are likely to start from unevenness (scratch marks) due to processing. .
Therefore, for example, manufacturing a microtool having a diameter of 100 μm or less and a large aspect ratio (a ratio of length to diameter) (for example, 10 or more) with a smooth surface roughness and high dimensional accuracy is Conventionally, it has been very difficult.

  Therefore, the inventors of the present invention first created and applied for Patent Document 1. As shown in FIG. 19, “ELID grinding apparatus for fine shape processing” of Patent Document 1 is provided close to the outer peripheral surface of the conductive grindstone 72, the XY table, and the grindstone, and is centered on the Z axis. An electrolysis electrode 76 that can freely rotate and an electrode guide device 78 are provided. The electrode guide device 78 includes two contacts whose one end is fixed to the electrode 76 for electrolysis. Each contact extends in a diametrical direction centering on the Z axis at a distance from the grindstone and the workpiece. Is partly held at intervals.

  This apparatus can grind the outer surface of the work 71 with a grindstone by rotating the conductive grindstone 72 and moving the work in a horizontal XY plane so as to contact the grindstone. Further, since the electrode 76 for electrolysis freely rotates around the Z-axis, and this electrode is always guided to a position away from the work 71 by the electrode guide device 78, the electrode is mounted on the grindstone while avoiding contact between the electrode and the work. Can always be positioned in close proximity to the outer peripheral surface. Therefore, in this state, a conductive grinding fluid is passed between the electrode and the grindstone, and the grindstone is conspicuous by electrolytic dressing, so that the conductive grindstone containing fine abrasive grains is obtained by ELID grinding (electrolytic in-process dressing grinding). Clogging can be prevented, and the machining resistance can be greatly reduced.

  In addition, this ELID grinding can achieve high-efficiency machining with high efficiency and excellent surface roughness. Therefore, coupled with a small machining resistance, ultra-fine parts with a diameter of 100 μm or less, elongated parts with a large aspect ratio, irregular shapes Ultra fine pins such as odd-shaped parts having a cross section can be processed.

Japanese Patent Application Laid-Open No. 2002-1657, “ELID grinding apparatus for fine shape processing”

  The inventors of the present invention have succeeded in grinding a pyramid type microtool having a tip of 2 μm square using the apparatus of Patent Document 1 described above. Furthermore, the micro-press test was performed on the thin metal sheet using the manufactured micro tool, and a very high quality fine hole was obtained.

  However, the processing time required for cylindrical grinding of this microtool is as long as 180 minutes, and there is a problem that processing efficiency is low.

  The present invention has been made to solve such problems. That is, an object of the present invention is to provide a micro tool grinding apparatus and method capable of processing a micro tool having a smooth surface roughness, a high dimensional accuracy, a large aspect ratio, and a very fine micro tool with high processing efficiency in a short time. Is to provide.

According to the present invention, there are provided a plurality of workpiece holding devices that hold an elongated rod-shaped workpiece in a predetermined position, and a grindstone that is arranged axially symmetrically or equidistantly about the axis of the workpiece and that processes the outer peripheral surface of the workpiece. A grindstone device, and a grindstone moving device that moves the plurality of grindstones toward a workpiece,
A microtool grinding apparatus, wherein the grindstone moving device moves the grindstones toward the workpiece in an axially symmetrical manner or synchronously with equal intervals, and suppresses deformation of the workpiece during grinding by the grindstone itself. Provided.

Further, according to the present invention, the elongated rod-shaped workpiece is held at a predetermined position,
A plurality of grindstone devices having a grindstone shaped to machine the outer peripheral surface of the work are arranged symmetrically or equidistantly about the axis of the work,
There is provided a microtool grinding method characterized in that each grindstone is moved toward the workpiece in an axial symmetry or synchronously at equal intervals and deformation of the workpiece during grinding is suppressed by the grindstone itself.

  According to a preferred embodiment of the present invention, the workpiece holding device is a workpiece rotating device that rotationally drives the workpiece around an axis.

  According to another preferred embodiment of the present invention, the work holding device is a work index device that rotates the work by a predetermined angle about an axis.

The grindstone is a conductive grindstone that is driven to rotate about its axis,
Furthermore, provided with a plurality of electrodes for electrolysis provided close to the outer peripheral surface of each grindstone,
A conductive grinding fluid is allowed to flow between the plurality of pairs of electrodes and the grindstone, and the workpiece is ground with the plural grindstones while each grindstone is conspicuous by electrolytic dressing.

It is preferable that the grindstone is a cylindrical grindstone having a constant radius around the axis.
Moreover, it is preferable that the said grindstone is a cone-shaped grindstone which has a taper part where the radius from an axial center increases gradually.

According to the present invention, it is provided with a plurality of grindstone devices having a grindstone having a shape (preferably the same shape) arranged symmetrically or equidistantly about the workpiece axis, and each grindstone is axially symmetric toward the workpiece. Alternatively, since the outer peripheral surface of the workpiece is ground in an axially symmetric or equidistant position by moving in synchronization with the equal interval, the machining force acting on the workpiece becomes axially symmetric or equidistant, and the deformation of the workpiece during grinding is caused by the grindstone itself. Can be suppressed. Therefore, it is possible to make incisions from a plurality of directions that are axially symmetric or equally spaced, so that deformation (deflection) of the workpiece during the incision can be suppressed, and even a micro tool with a large aspect ratio and a very fine size has high machining efficiency. It can be processed in a short time.
Further, the grindstone is a conductive grindstone, and by providing a plurality of electrodes for electrolysis provided close to the outer peripheral surface of each grindstone, the workpiece is ground with the plural grindstones while conspicuous each grindstone with electrolytic dressing. In addition, a microtool having a smooth surface roughness and high dimensional accuracy can be manufactured.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  1 is a plan view showing a first embodiment of a microtool grinding apparatus according to the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. It is.

  As shown in FIG. 1, the microtool grinding apparatus 10 of the present invention includes a workpiece holding device 20, a grindstone device 30, and a grindstone moving device 40.

  The work holding device 20 has a function of holding the work 1 in a predetermined position. The workpiece 1 is a material for manufacturing a microtool, and is, for example, an elongated rod-shaped super hard metal or ceramic member having a diameter of about 0.5 to 5 mm and a length of about 10 to 120 mm.

As shown in FIG. 2, in this example, the work holding device 20 includes a pair of chucks 22 for gripping both ends of the work 1, power transmission means 24 for rotating the chucks at both ends in synchronization, and the work 1 on its axis. The rotary drive device 26 rotates around the center (Z axis).
In this example, the power transmission means 24 includes two sets of pulleys 24a, a pair of timing belts 24b, and a power transmission shaft 24c. In place of the pulley and the timing belt, a gear or other power transmission mechanism may be used.
The rotation driving device 26 may be a workpiece rotating device that rotates the workpiece 1 around the axis, or may be an index device that rotates the workpiece 1 by a predetermined angle around the axis.
In this example, the axis (Z-axis) of the workpiece 1 is supported horizontally, but the present invention is not limited to this, and the Z-axis can be vertical or any other direction.

  The grindstone device 30 includes a grindstone 31 having the same shape, and has a function of machining the outer peripheral surface of the workpiece 1 that is arranged axially symmetrically or equidistantly about the axis (Z axis) of the workpiece 1. The grindstone 31 may be a conductive grindstone. Further, in this example, the grindstone 31 is a disk-shaped conductive grindstone (straight grindstone) having a constant radius, and is driven to rotate around its axis by an electric motor 32. In this example, the axis of the grindstone 31 is parallel to the axis of the workpiece 1 (Z axis), but the present invention is not limited to this, and may be inclined.

  Further, as shown by a two-dot chain line in FIG. 3, the microtool grinding apparatus 10 of the present invention further includes a plurality of electrolysis electrodes 12 provided in the vicinity of the outer peripheral surface of the conductive grindstone 31, and the electrolysis electrodes 12. The ELID power source 14 for applying an electrolysis voltage between the electrode 12 and the conductive grindstone 31, and a grinding fluid supply device (not shown) for flowing a conductive grinding fluid between the electrode and the grindstone, and the electrode 12 and the grindstone A conductive grinding fluid is passed between the workpiece 31 and the grinding stone 31 is moved by the electrolytic dressing, and the grinding stone 31 is moved and brought into contact with the outer peripheral surface of the workpiece 1 for processing.

The grindstone moving device 40 has a function of moving the plurality of grindstones 31 toward the workpiece 1.
As shown in FIG. 3, in this example, the grindstone moving device 40 includes a pair of left and right tables 42 to which an electric motor 32 that drives the grindstone 31 is fixed, a ball screw nut 43 attached to the lower portion of each table, and each nut. A pair of ball screws 44 that are screwed together, a manual handle 45 that rotationally drives each ball screw about its axis (X axis), a stepping motor 46, and an electromagnetic clutch that detachably connects the ends of the pair of ball screws 47.
A pair of ball screws 44, one of which is a right-hand screw and the other of which is a left-hand screw, are rotationally driven in a state where they are connected by an electromagnetic clutch 47, thereby moving each grindstone 31 toward the workpiece 1 in an axially symmetric manner. The deformation of the workpiece during grinding is suppressed by a grindstone at an axially symmetric position.
Note that the electromagnetic clutch 47 can be disconnected to separate the pair of ball screws 44 so that the manual handle 45 and the stepping motor 46 can be moved separately. Further, the manual handle 45 may be used only for the left and right position adjustment.

  Furthermore, the microtool grinding apparatus 10 of the present invention includes an axial feed device (not shown) that moves the workpiece 1 in the axial direction (Z-axis direction) with respect to the grindstone 31. The axial direction feeding device may move the workpiece holding device 20 or the grindstone device 30.

FIG. 4 is a perspective view of the workpiece 1 and the grindstone 31 in the apparatus of FIG. 1 and shows the shaft configuration during cylindrical machining.
Using the apparatus described above, according to the method of the present invention, as shown in this figure, an elongated rod-shaped workpiece 1 is held at a predetermined position by a workpiece holding device 20, and a plurality of grindstones 31 having the same shape are held on the workpiece 1. Axisymmetrically or equidistantly arranged around the axis (Z axis), the grindstone moving device 40 moves each grindstone 31 toward the workpiece 1 in the X axis direction in synchronism with the axisymmetric or equidistant interval. By grinding the outer peripheral surface of the workpiece or at equally spaced positions, the working force acting on the workpiece becomes axisymmetric or equally spaced, and the deformation of the workpiece during grinding is suppressed by the grindstone itself.

FIG. 5 is an arrangement example in the case of processing using a plurality of straight grindstones having the same shape. In this figure, (A) shows the case where there are two whetstones, (B) shows three, and (C) shows four.
When the grindstone 31 is an even number, the grindstone is arranged symmetrically about the axis of the workpiece 1. When the grindstone 31 is an odd number, the grindstones are arranged at equal intervals in the circumferential direction around the axis of the work 1.

In FIG. 5, when two or more ordinary straight grindstones are used for processing, the minimum microtool diameter that can be processed increases as the number increases. For example, in the case of three sheets (B), the workable work diameter is about 0.155R with respect to the grindstone radius R, and when R = 37.5 mm, it is about 194 μm. When there are four sheets (C), it is about 0.414R.
Therefore, in order to process an extremely fine microtool, it is most preferable to use two straight grindstones as shown in (A).

FIG. 6 is an arrangement example in the case of machining using a plurality of the same conical grindstones. In this example, the conical grindstone has a taper portion in which the radius from the axis gradually increases, and (A) shows two conical grindstones and (B) three cases.
If a grindstone with a conical tip is used as shown in this figure, even if the number of grindstones is increased by 3, 4 or less, the restriction on the minimum diameter of the micro tool that can be processed can be reduced.

FIG. 7A is a diagram showing the relationship between the grindstone and the workpiece in the cross section A of FIG. 6B. As shown in this figure, the cross section of the grindstone is not a perfect circle but an ellipse, so it can be seen that a sufficiently small microtool can be machined without any interference between the grindstones (the correlation figure with the cone is ellipse).
FIG. 7B is a similar cross-sectional view when there are four grindstones. As illustrated in this figure, ELID grinding (electrolytic in-process dressing grinding) can be easily performed by attaching a rod-like (−) electrode 12 between the grindstones.
FIG. 20 is a second arrangement example in the case of processing using two straight whetstones and two conical whetstones having the same shape, (A) is a plan view, and (B) is a cross-sectional view at a cut surface. is there. As shown in this figure, even in a composite system in which two straight whetstones and two conical whetstones are configured in pairs, the effect of efficiency, miniaturization, and deflection suppression is high.

FIG. 8 is a third arrangement example in the case of processing using three straight grindstones having the same shape, (A) is a front view, and (B) is a plan view.
As a means for processing a micro tool having a diameter as small as possible by using a plurality of ordinary straight whetstones, the grindstone 31 is made as thin as possible as shown in this figure, and the positions are shifted and simultaneously processed. Strictly speaking, it is not a cut from the same position on the axis Z of the microtool, but since it is a deviation of the grinding wheel thickness, the deformation is small and practical.

FIG. 9 is a diagram showing a positional relationship between the workpiece holding device and the grindstone device. FIG. 9A shows a case where the axis of the grindstone 31 is parallel to the axis of the workpiece 1 (Z axis), and FIG. This is a case where the axis of the grindstone 31 is inclined with respect to the axis (Z axis) of the workpiece 1.
In FIG. 9A, the two grindstone axes can be controlled independently, and can be cut into the workpiece 1 simultaneously or separately. Further, the right and left Z-axis movement may be performed by moving the grindstone axis or moving the work axis instead of the grindstone axis. Furthermore, the Z-axis movement of the two grindstone axes can be performed separately. For example, in the case of machining with a particularly long workpiece 1 by chucking both sides, the tool can be machined with only one grindstone, and the tip can be cut with the other grindstone.
As shown in FIG. 9B, by rotating / tilting the grindstone shaft itself, it is possible to taper other than the straight microtool.

FIG. 10 shows a case where a workpiece is machined into a polygon using two straight grindstones having the same shape, and FIG. 10A shows a case where the polygon is an even angle (for example, a square or a hexagon). ) Is a case where the polygon is an odd-numbered angle (for example, a pentagon).
As shown in FIG. 10A, when processing into an even number of angles, opposing surfaces can be processed simultaneously.
In addition, when processing to an odd number of corners, if it is attempted to process with three or more grindstones, it is necessary to make the grindstone diameter quite small. Therefore, as shown in FIG. The workpiece can be machined by tilting θ and preventing the workpiece 1 from being bent by the backup member 2.
(Reference Example 1)

(Micro tool machining by vertical cylindrical grinding machine)
Micro tool processing was performed by a small vertical cylindrical grinding machine equipped with the swing electrode type ELID grinding system of Patent Document 1. FIG. 11 shows a structural diagram of the processing machine, and FIG. 12 shows a schematic diagram of the processing method. 11 and 12, 51 is a workpiece, 52 is a conductive grindstone, 56 is an electrode for electrolysis, 60 is a Z-axis feed stage, 61 is an ELID power source, and 62 is a grinding fluid supply device.
Using this processing machine, under the processing conditions shown in Table 1, a pyramidal microtool was processed by controlling the XY stage without giving a rotational motion to the cemented carbide workpiece. In particular, by using an ELID grinding system using a cast iron bonded diamond grindstone # 4000 and a high precision truing method, a pyramidal microtool with a 2 μm tip was successfully manufactured.

図１３は、従来装置で製作したマイクロツールの走査型電子顕微鏡（ＳＥＭ）像であり、（Ａ）はワーク５１の加工部全体、（Ｂ）はそのＡ部拡大図である。この図からもわかるように、優れた加工表面性状とシャープなエッジ部が得られ、そのマイクロツールの機械的強度の上昇が確認できている。この結果から、特許文献１の装置により加工されたマイクロツールは、ミーリングやマイクロプレスのようなツールとしての機能を十分に果たすことが期待できる。
しかしながら、この円筒研削に要した加工時間は１８０分と長いことから、実用化のためにはより加工効率を向上させることが必要である。

FIG. 13 is a scanning electron microscope (SEM) image of a microtool manufactured by a conventional apparatus. FIG. 13A is an entire processed part of the workpiece 51, and FIG. 13B is an enlarged view of the A part. As can be seen from this figure, excellent surface properties and sharp edges were obtained, and an increase in the mechanical strength of the microtool was confirmed. From this result, it can be expected that the micro tool processed by the apparatus of Patent Document 1 sufficiently fulfills the function as a tool such as milling or micro press.
However, since the processing time required for this cylindrical grinding is as long as 180 minutes, it is necessary to improve the processing efficiency for practical use.

(Development of a new desktop type cylindrical grinding machine)
In the micro tool processing, a desktop type cylindrical grinding machine (micro tool grinding device shown in FIG. 1) using two grinding wheels was developed for the purpose of further improving processing efficiency. Table 2 shows the main specifications of the developed processing machine.

This processing machine (microtool grinding apparatus) is very compact, like the small vertical cylindrical grinding machine of FIG. 11, and has outer dimensions of width 580 mm × depth 580 mm × height 610 mm. In addition to the compactness of the main body, this processing machine is characterized in that two grinding wheel heads (grinding wheel device 30) are mounted as shown in FIGS.
That is, the two grindstones 31 arranged so as to face each other on the X axis can be stepped from both directions by the electromagnetic clutch 47 shown in FIG. Since it becomes symmetrical, deformation (deflection) of the workpiece at the time of cutting can be suppressed, and a highly accurate micro tool can be manufactured.

  Each component axis employs precision grade slide guides and achieves a parallelism of 5 μm for a slide length of 510 mm. During Z-axis machining, Z-axis feed is manually performed by an axial feed device (not shown). Of course, a motor is attached and automation is easy.

As shown in FIG. 3, the X-axis on which the two grinding wheel heads (grinding wheel device 30) are mounted is controlled by 1) a method of manually cutting with a manual handle 45 and 2) a stepping motor 46. One of the automatic cutting methods can be selected.
The workpiece dimensions are φ0.5 mm to 5.0 mm and the maximum length is 120 mm.
2 may be an index unit that rotates the workpiece 1 by a predetermined angle around the axis, thereby processing the cross-sectional shape of the microtool into an arbitrary polygonal shape. . This index unit can be divided into 100 equal parts with respect to the circumference of the workpiece.
Furthermore, this processing machine can be equipped with an ELID grinding system as shown in FIG. 3, and in addition to polygonal (cross-sectional shape) processing, long cylindrical processing, end surface processing, cutting processing, taper processing, etc. Many processing methods can be selected.
With these developed processing machines, cylindrical and polygonal micro tools were processed by ELID grinding, and the processing characteristics are described below.

(Micro cylindrical tool processing)
The micro cylindrical tool was processed by ELID grinding using a cast iron bonded diamond wheel # 1200 as the grindstone 31. In addition, before processing, after correcting the shape of the grindstone processing surface by truing of the grindstone on the processing machine, ELID initial dressing was performed and processing was started. The main machining conditions are shown in Table 3. These machining conditions are based on the conditions proved by the small vertical cylindrical grinder.

The workpiece 1 was machined with a 0.5 mm diameter carbide pin with a step cut of 1.0 μm and a total cut of 100 μm. Here, in the micro cylindrical tool processing, the surface roughness and shape accuracy due to the difference in the grinding wheel rotation direction were examined. As shown in Table 4, there are three types of combinations of the grindstone rotation directions: Type--A; downward machining / downward machining, Type-B; downward machining / upward machining, Type-C: upward machining / upward machining.
Note that upward machining means machining in which the rotation direction is opposite at the contact point between the workpiece and the grindstone (so-called upcut), and downward machining means machining in which the rotation direction is the same at the contact point between the workpiece and the grindstone (so-called downcut). FIG. 14 shows Type-A downward machining / downward machining.

With respect to the workpiece machined under these conditions, the machined surface properties were first observed with a scanning electron microscope (SEM).
Further, the roughness of the processed surface according to the present invention was measured with a three-dimensional surface structure analysis microscope (manufactured by Zygo: NewView 5032). The measurement results are shown in FIG. As a result of comparing the differences in the grinding wheel rotation direction, it can be seen that Type-C; the results of downward machining / downward machining are PV: 1.265 μm, Ra: 0.089 μm, and the most machined surface roughness is the best. Next, the results of Type-A were PV: 1.427 μm and Ra: 0.113 μm.
Further, as evaluation of the shape accuracy, the roundness of the micro cylindrical tool according to the present invention was measured by a roundness measuring device (manufactured by Mitutoyo Corporation: roundness measuring device). An example of the measurement results is shown in FIG. 16, but the roundness of each was 0.3 μm or less, and no great difference was recognized. These facts suggested that the machined surface roughness was affected by the grinding wheel rotation direction.

  If the processing efficiency, which is the reason for the development of a new tabletop cylindrical grinding machine, is organized, as shown in Table 5, the required processing time is shortened to 1/30 compared to the conventional small vertical cylindrical grinding machine. It was. This processing time is a comparison result when micro tool processing is performed with the same material and the same finished workpiece size.

(Micro polygon tool processing)
An index unit was mounted on the spindle head, and a micro polygon (cross-sectional shape) tool using cemented carbide was processed. In particular, in consideration of actual cutting using a micro tool, we focused on polygonal shape processing that can become a cutting edge. Table 6 shows the main processing conditions for micro polygon tool processing. In this example, as shown in FIG. 9A, the workpiece 1 was processed with one end supported.

In addition, before processing, after correcting the shape of the grindstone processing surface by truing of the grindstone on the processing machine, ELID initial dressing was performed and processing was started. As an example of the micro hexagonal tool processing result, an observation result by a scanning electron microscope (SEM) is shown in FIG. (A) is the whole process part of the workpiece | work 1, (B) is the A section enlarged view.
From this observation result, it can be seen that by using an index for the spindle head portion, polygonal microtool processing having a large aspect ratio and good processing surface roughness and shape accuracy is performed.

Note that this processing machine has a two-axis configuration of an X-axis and a Z-axis, and when processing a polygonal microtool, the R shape of the grindstone is transferred to the processing surface on one side of the polyhedron. That is, since the grindstone diameter used in this example is 75 mm, the grindstone R37.5 mm is transferred as shown in FIG. However, when the length of one side is 40 μm, the amount corresponding to the depth of the concave shape due to R is 5 nm in theory. Therefore, it is in a plane state close to the R dimension ∞, and it is considered that there is no significant influence on the polygonal microtool manufactured this time.

As described above, according to the present invention, a plurality of grindstone devices 30 having grindstones 31 having the same shape and arranged symmetrically or equidistantly about the axis Z of the workpiece 1 are provided. Since the outer peripheral surface of the workpiece is ground at an axially symmetric or equidistant position by moving axially symmetrically or at equal intervals toward the workpiece, the machining force acting on the workpiece 1 becomes axially symmetric or equally spaced, and the workpiece during grinding Can be suppressed by the grindstone itself. Therefore, it is possible to make incisions from a plurality of directions that are axially symmetric or equally spaced, so that deformation (deflection) of the workpiece during the incision can be suppressed, and even a micro tool with a large aspect ratio and a very fine size has high machining efficiency. It can be processed in a short time.
Further, the grindstone 31 is a conductive grindstone, and includes a plurality of electrodes 12 for electrolysis provided close to the outer peripheral surface of each grindstone. The microtool having a smooth surface roughness and high dimensional accuracy can be manufactured.

  In addition, this invention is not limited to the Example and embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

It is a top view which shows 1st Embodiment figure of the micro tool grinding apparatus of this invention. It is sectional drawing in the AA of FIG. It is sectional drawing in the BB line of FIG. It is a perspective view of the workpiece | work and grindstone in the apparatus of FIG. It is an arrangement example in the case of processing using a plurality of straight grindstones having the same shape. It is an arrangement example in the case of processing using a plurality of the same conical grindstones. It is a figure which shows the relationship between the grindstone in the cross section A, and a workpiece | work. It is the 3rd example of arrangement at the time of processing using three straight grindstones of the same shape. It is a figure which shows the positional relationship of a workpiece | work holding | maintenance apparatus and a grindstone apparatus. It is a figure which shows the case where a workpiece | work is processed into a polygon using two straight grindstones of the same shape. It is a structure figure of the processing machine of patent documents 1. It is a schematic diagram of the processing system of patent document 1. FIG. It is a scanning electron microscope (SEM) image of the micro tool manufactured with the conventional apparatus. It is a figure which shows an upward process / upward process. It is a measurement result of the processing surface roughness by this invention. It is a roundness measurement result of the micro cylindrical tool by this invention. 1 is a scanning electron microscope (SEM) image of a microtool according to the present invention. It is a figure which shows the transfer of the grindstone shape of the microtool by this invention. 1 is a schematic diagram of an “ELID grinding apparatus for fine shape processing” in Patent Document 1. FIG. It is the 2nd example of arrangement at the time of processing using two straight whetstones and two conical whetstones of the same shape.

Explanation of symbols

1 Workpiece, 2 Backup material,
10 Microtool grinding machine, 12 Electrolysis electrode, 14 ELID power supply,
20 Work holding device, 22 Chuck, 24 Power transmission means,
24a pulley, 24b timing belt,
24c power transmission shaft, 26 rotation drive device,
30 grinding wheel device, 31 grinding wheel (conductive grinding wheel), 32 electric motor,
40 grinding wheel moving device, 42 table,
43 Ball screw nut, 44 Ball screw,
45 Manual handle, 46 Stepping motor,
47 Electromagnetic clutch

Claims (7)

A workpiece holding device for holding an elongated rod-shaped workpiece in a predetermined position, a plurality of grinding wheel devices having a grinding wheel having a shape that is arranged axially symmetrically or equidistantly around the axis of the workpiece and processes the outer peripheral surface of the workpiece; A grindstone moving device that moves a plurality of grindstones toward the workpiece,
A microtool grinding apparatus, wherein the grindstone moving device moves the grindstones toward the workpiece in an axially symmetric or equidistant manner and suppresses deformation of the workpiece during grinding by the grindstone itself.   2. The microtool grinding apparatus according to claim 1, wherein the workpiece holding device is a workpiece rotating device that rotationally drives the workpiece around an axis.   2. The micro tool grinding apparatus according to claim 1, wherein the work holding device is a work index device that rotates the work by a predetermined angle about an axis. The grindstone is a conductive grindstone that is driven to rotate about its axis,
Furthermore, provided with a plurality of electrodes for electrolysis provided close to the outer peripheral surface of each grindstone,
2. The microtool grinding according to claim 1, wherein a conductive grinding fluid is allowed to flow between the plurality of pairs of electrodes and the grindstone, and the workpiece is ground with the plurality of grindstones while each grindstone is conspicuous with electrolytic dressing. apparatus.   The microtool grinding apparatus according to claim 4, wherein the grindstone is a cylindrical grindstone having a constant radius around an axis.   The microtool grinding apparatus according to claim 4, wherein the grindstone is a conical grindstone having a tapered portion whose radius from an axis gradually increases. Hold the elongated rod-shaped workpiece in place,
A plurality of grindstone devices having a grindstone shaped to machine the outer peripheral surface of the work are arranged symmetrically or equidistantly about the axis of the work,
A microtool grinding method, wherein each grindstone is moved toward the workpiece in axial symmetry or synchronously at equal intervals, and deformation of the workpiece during grinding is suppressed by the grindstone itself.

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