JPH0372442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a high-precision grinding and cutting device for grinding and cutting hard materials such as ceramics with high precision.

[Prior art]

Many recent electronic component materials, including thin-film head substrates, use high-hardness ceramics. A diamond grindstone or the like is used for this cutting, but it has the drawback of rapid wear and high grinding resistance, which causes the grindstone to bend and prevent high-precision machining.

That is, as conventional hard material cutting means, a wire saw, a multi-blade saw, an inner circumferential slicer, an outer circumferential slicer, a dicer, etc. are employed. Wire saws and multi-blade saws do not directly use a grindstone as a cutting tool, but instead perform grinding while supplying free abrasive grains to the cutting tool, resulting in extremely poor cutting efficiency and the possibility of tapers, waviness, etc. on the cut surface. is likely to occur. Therefore, there was a drawback that high-precision cutting was not possible. In addition, the inner circumferential slicer grinds and cuts the inner circumference of a doughnut-shaped thin plate blade using a grindstone made of diamond or the like electrodeposited on the inner circumference, and has the disadvantage that the cutting resistance is extremely high when cutting ceramics or the like. Further, the outer circumferential slicer and dicer perform grinding and cutting on the outer circumferential side of a grindstone, and perform creep feed grinding in which a certain amount of cutting is determined in advance and the grindstone is fed as it is for cutting. Therefore, a large resistance is generated on the side surface of the grindstone, causing the grindstone to bend. For this reason, there was a drawback that high-precision cutting could not be performed.

[Purpose of the invention]

The present invention was devised to solve the above-mentioned drawbacks, and its purpose is to provide a high-precision grinding and cutting device that can perform grinding and cutting with high precision and reduce production costs.

[Summary of the invention]

In order to achieve the above object, the present invention comprises a micro-cutting device that makes a slight cut in the cutting direction of a grindstone, and a piezoelectric element, etc. that engages with the shaft of the grindstone and slightly displaces the grindstone in the axial direction. a first displacement means configured to slightly incline the grindstone in the cutting feed direction thereof, a second displacement means constituted of, for example, a piezoelectric element, and a detection detecting the grinding resistance of the grindstone and its grinding position. means for engaging the detection means and the first and second displacement means, operating the first and second displacement means in response to a signal from the detection means, and displacing the first and second displacement means; A control means for controlling the cutting amount is provided, and the grinding wheel is displaced in the axial direction and cuts while being inclined in the direction of the cutting depth, thereby reducing grinding resistance and waviness of the cut surface, thereby enabling high-precision cutting. It features a high-precision grinding and cutting device.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, an overview of the embodiment will be explained with reference to FIG.

The shaft portion 1 supporting the grinding wheel 7 has a first displacement means 2
and the grinding wheel shaft body 13 via the second displacement means 3
supported by. The grindstone shaft main body 13 engages with the minute cutting device 4 supported by the bed 18, and the grindstone 7 is slightly moved in the cutting direction. The first displacement means 2 includes four piezoelectric elements 2 that engage with the outer circumferential side of the shaft portion 1.
a, 2b, 2c, and 2d, and these piezoelectric elements 2a, etc. are provided so as to be displaced in the axial direction of the shaft portion 1 due to voltage changes, and are configured to move the shaft portion 1 and the grinding wheel 7 pivoted thereon. Make a slight displacement in the axial direction. The second displacement means 3 includes four piezoelectric elements 3a, 3b, 3c, and 3 that similarly engage with the outer peripheral side of the shaft portion 1.
These piezoelectric elements 3a and the like slightly displace the shaft portion 1 in a direction perpendicular to its axis due to voltage changes. Therefore, for example, the piezoelectric element 3a
By applying different voltages to the shaft portion 1 and the grindstone 7, the shaft portion 1 and the grindstone 7 can be tilted.

The detection means 12 includes a grinding resistance sensor 8 that detects grinding resistance and a table position sensor 9 that detects the grinding position.

The control means 11 is connected to the detection means 12 and the first and second displacement means, and adjusts the load voltage of the piezoelectric elements 2a, 3a, etc., based on the signal from the detection means 12, and displaces the grindstone 7. and inclination, the displacement of the piezoelectric elements 2a, 3a, etc. is controlled independently of the detection means 12, and the cutting conditions are adjusted and controlled so as to reduce the grinding resistance and the waviness of the cut surface.

As described above, it is possible to reduce waviness on the cut surface, reduce the cutting allowance, and reduce production costs.

Next, this example will be explained in more detail.

An extremely thin (for example, 0.2 m/m thick) grindstone 7 is attached to one end of the grindstone shaft 15 . The grindstone shaft 15 is pivotally mounted within the shaft portion 1, and a pulley 16 is attached to the other end. First and second displacement means 2 and 3, which will be described later, are engaged with the outer peripheral side of the shaft portion 1, and the shaft portion 1 is supported by the grindstone shaft body 13 via these displacement means 2 and 3. Ru. Grinding wheel shaft body 1
3 is provided with a grindstone shaft drive motor 14, and the rotation of the grindstone shaft drive motor 14 is transmitted to a pulley 16 via a belt 17, whereby the grindstone shaft 15 and the grindstone 7 are rotated.

The grindstone shaft main body 13 is supported by a micro-cutting device 4 provided on the lower side of the main body 13 so as to be freely movable in the cutting direction of the grindstone. Although the minute cutting device 4 is attached to the head 18 and is not clearly shown, for example,
The grindstone shaft main body 13 is supported via a ball screw, a pulse motor or the like is connected to the ball screw, the pulse motor is connected to a control means 11 to be described later, and the pulse motor is slightly rotated according to instructions from the control means 11. , is configured to slightly move the grindstone shaft body 13. The minute depth of cut varies depending on the material to be cut and the properties of the grindstone 7, but is between 2μm and 200μm.
A range of m is set.

The first displacement means 2 includes four piezoelectric elements 2a, 2
Consists of b, 2c, and 2d. The piezoelectric elements 2a and 2c are provided at the same position in the axial direction of the shaft portion 1 and facing each other on the outer peripheral side of the shaft portion 1. Furthermore, the piezoelectric elements 2b and 2d are the piezoelectric elements 2a and 2c of the shaft portion 1.
They are provided facing each other at the same position in the axial direction apart from. Moreover, piezoelectric elements 2a, 2b, 2c, 2
d are attached so as to be displaced in the axial direction of the shaft portion 1 in response to voltage changes. Therefore, due to the displacement of the piezoelectric element 2a, etc., the shaft portion 1 is displaced in the axial direction, and therefore the grindstone shaft 15 and the grindstone 7, which are pivotally connected thereto, are slightly displaced in the axial direction.

The second displacement means 3 includes four piezoelectric elements 3a, 3b,
Consists of 3c and 3d. These piezoelectric elements 3a
etc., the corresponding piezoelectric element 2a of the first displacement means 2
It is formed so as to engage with the outer side of the grindstone shaft body 13 and to be inserted into the inner peripheral side of the grindstone shaft body 13 and to support the shaft portion 1 with the piezoelectric element 2a of the first displacement means 2 interposed therebetween. There is. Therefore, piezoelectric elements 3a, 3b, 3c,
After applying a constant initial voltage to all 3d, the shaft 1 can be tilted by leaving the piezoelectric elements 3a and 3d as they are and increasing or decreasing the initial voltage of the piezoelectric elements 3b and 3c. When the shaft portion 1 is tilted, the grindstone 7 can be tilted with respect to the cutting direction. This slope can be adjusted as appropriate in the range of 0 to 0.005 rad.

A cut sample 6 made of a hard material such as ceramic is placed on a table 5, and the table 5 is placed on an indexing table 10, and the table 5 slides in the cutting direction along the indexing table 10, and also rotates along the axis of the grindstone. indexed and positioned in the direction.

The detection means 12 includes the grinding resistance sensor 8 as described above.
and a table position sensor 9. The grinding resistance sensor 8 is provided between the cut sample 6 and the table 5, and is formed of something that detects the grinding resistance using, for example, a strain gauge.
Further, the table position sensor 8 is provided between the table 5 and the indexing table 10, and detects the moving position of the table 5 using, for example, a Magnescale. This is to detect.

The control device 11 is connected to the grinding resistance sensor 8 and the table position sensor 9 of the detection means 12, and
It is connected to the piezoelectric element 2a etc. of the first displacement means 2 and the piezoelectric element 3a etc. of the second displacement means 3, respectively. Then, each piezoelectric element 2a etc. is
3a and is provided with calculation means (not shown) that can set optimal grinding and cutting conditions. Moreover, independent of the detection means 12, each piezoelectric element 2a, etc.
A microcomputer (not shown) is also provided that can control voltages such as, etc., and set optimal grinding and cutting conditions.

Next, the operation of this embodiment will be explained.

The cutting sample 6 is positioned by the indexing table 10 and the table 5, and the fine cutting device 4 gives a cutting depth of, for example, about 10 μm, and feeds the cutting sample. In the prior art, large grinding resistance is generated due to the creep feed cutting as described above, but the grinding resistance applied to the side surface of the grindstone 7 can be reduced by making a minute cut as described above.
Of course, in order to increase the same cutting efficiency as creep feed cutting, the feed speed of the table 5 is increased, but the grinding resistance is reduced as described above, and the waviness of the cut surface is reduced.

However, even when cutting with minute cuts, bending force acts on the grindstone 7 due to the asymmetry of the cutting edge distribution at the tip of the grindstone 7. In order to reduce this, as shown in FIG. 2, the voltage of the piezoelectric element 2a, etc. of the first displacement means 2 is adjusted, and the grindstone 7 is slightly moved while being displaced by a small amount in the axial direction. That is, grinding and cutting are performed while moving the grindstone 7 from one position to another. This makes it possible to reduce the above-mentioned waviness, but as the cutting depth becomes deeper, the resistance on one side of the grindstone 7 increases, causing the grindstone 7 to bend. In order to prevent this, as shown in FIG. 3, the grindstone 7 is tilted by the second displacement means 3, and the grinding and cutting feed is carried out while changing the direction of inclination to the positions shown in the figure. As a result of the above, waviness on the cut surface can be significantly reduced. The first of the above
The amount of displacement by the displacement means 2 and the second displacement means 3 depends on the grinding cutting conditions, the material of the cut sample 6, and the grindstone 7.
The optimum one can be set by the control means 11 depending on the shape of the material, the amount of cut into the material, the depth of cut, etc.

Furthermore, since the grinding resistance is reduced at the cutting entrance and exit of the grindstone 7, undulations will occur if grinding and cutting are performed under the same conditions as at other positions. To prevent this,
The grinding resistance sensor 8 or the table position sensor 9 detects the state, and this signal is sent to the control means 11.
, calculates the curvature of the grindstone 7, and adjusts the grindstone 7 to an optimal position. Of course, even at places other than the cutting entrance/exit, the grinding wheel 7
displacement can be adjusted to ensure optimal grinding and cutting.

Next, an experimental example will be explained.

Figure 4 shows the waviness of a cut sample made of ceramic with a thickness of about 4 m/m when it is cut with a grindstone of 0.2 m/m in thickness at a cutting efficiency of 150 mm ² /min. In the figure, the horizontal axis represents the cutting depth fμm, and the vertical axis represents the waviness δμm. Point B shows the case of cutting with a conventional creep feed, where waviness δ of approximately 40 μm or more is generated. On the other hand, the cutting depth f
In this example, where the waviness is 10 μm, as shown at point A, the waviness δ is significantly reduced to 10 μm. However, as described above, as the cutting depth f becomes deeper, the grindstone 7 bends as described above, and the waviness δ becomes larger. Even in this case, the waviness δ can be reduced by tilting the grindstone as shown in FIG. In other words, in the figure, if the horizontal axis is the slope θrad and the vertical axis is the waviness δμm, when the slope θrad is zero, the waviness δμm is 40μm or more, but when the slope θ is 0.005rad, it becomes 6μm as shown at point C. decreases to

Further, by controlling the bending of the grindstone 7 due to the change in the grinding resistance at the entrance and exit of the grindstone 7 by the control means 11, the waviness δ can be reduced to 3 μm or less, as shown at point D.

As described above, when the waviness δ is reduced, the cutting allowance required for cutting can be reduced. By reducing the cutting allowance, fewer cut samples are discarded due to cutting, and therefore production costs can be improved by about 10 to 20%.

In this embodiment, piezoelectric elements are used as the first and second displacement means 2 and 3, but the present invention is not limited to this. Moreover, although four piezoelectric elements 2a, 3a, etc. are used each, it is needless to say that the present invention is not limited to this. Furthermore, although the piezoelectric element 3a and the like are provided outside the piezoelectric element 2a and the like, the piezoelectric element 3a and the like may be provided in the opposite direction, or may be provided at different positions.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to perform grinding and cutting with high precision, and the production cost can be reduced.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram showing a state in which cutting is performed while displacing the grindstone in the axial direction, and Fig. 3 is an explanatory diagram showing a state in which cutting is performed while the grindstone is tilted in the cutting direction. Fig. 4 is a diagram showing the relationship between cutting depth and waviness;
The figure is a diagram showing the relationship between slope and waviness. DESCRIPTION OF SYMBOLS 1... Shaft part, 2... First displacement means, 3... Second displacement means, 2a, 2b, 2c, 2d, 3a,
3b, 3c, 3d...Piezoelectric element, 4...Minute incision device, 5...Table, 6...Cutting sample, 7...
... Grinding wheel, 8 ... Grinding resistance sensor, 9 ... Table position sensor, 10 ... Indexing table, 11 ...
... Control means, 12 ... Detection means, 13 ... Grindstone shaft body, 14 ... Grindstone shaft drive motor, 15 ... Grindstone shaft, 16 ... Pulley, 17 ... Belt, 18 ...
Betsudo.

Claims (1)

[Scope of Claims] 1. A micro-cutting device that makes a slight cut in the cutting direction of the grindstone; and a first displacement means that engages with the shaft portion of the grindstone and slightly displaces the shaft portion in the axial direction; , a second displacement means that engages with the shaft of the grindstone and slightly displaces the shaft in a direction orthogonal to the axis to tilt the grindstone in the cutting direction; a grinding resistance of the grindstone; a detection means for detecting the grinding position; the detection means engages with the first and second displacement means; the detection means operates the first and second displacement means in response to a signal from the detection means; A high-precision grinding and cutting device comprising: a control means for controlling the displacement amount of the first and second displacement means. 2. The high-precision grinding and cutting device according to claim 1, wherein the depth of cut of the minute cutting device is 2 μm to 200 μm, and the inclination by the second displacement means is 0 rad to 0.05 rad. . 3 The first displacement means is a piezoelectric element that is displaced in the axial direction of the shaft of the grindstone by a voltage change, and the second displacement means is a piezoelectric element that is displaced in a direction perpendicular to the axis of the shaft by a voltage change. The high-precision grinding and cutting device according to claim 1, characterized in that the device is a piezoelectric element that is displaced as follows.