JPH0453669B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a polishing head suitable for polishing workpieces such as diamond, which have different degrees of polishing difficulty depending on their crystal orientation.

[Background of the invention]

Conventionally, when polishing workpieces such as diamonds, which have different levels of polishing difficulty depending on their crystal orientation, it is necessary to align the easy polishing direction with the polishing direction in order to increase polishing efficiency. This was done by relying on the skill of the operator and by visual inspection.

Generally, to polish a workpiece such as a diamond, the workpiece is held in a holder, brought into contact with the grinding surface of a grindstone, and the holder is rotated around an axis perpendicular to the grinding surface. The polishing was performed while adjusting the polishing direction to match the polishing direction of the workpiece as much as possible with the direction of easy polishing of the workpiece.
As mentioned above, this adjustment work depended on the operator's visual skill, so the crystal orientation was approximately ±
In addition to an error of 10°, it was common for the deviation between the easy polishing direction and the actual polishing direction to differ by about ±30°. Therefore, there was a drawback that the polishing time was increased and the polishing efficiency was lowered.

Of course, it is possible to accurately measure crystal orientation using X-rays, but it takes time to measure, requires expensive equipment, and requires an expensive indexing device for accurate positioning. There was a drawback.

[Purpose of the invention]

The present invention was devised to solve the above-mentioned drawbacks, and its purpose is to improve polishing efficiency by accurately finding the easy polishing direction by a simple means, and making the polishing direction coincide with the easy polishing direction. The aim is to provide a head.

[Summary of the invention]

In order to achieve the above object, the present invention holds a workpiece in a holder, rotates the holder to change the polishing direction of the workpiece, and adjusts the grinding temperature of the workpiece. The detection signal is detected by the detection means, this detection signal is input to the adjustment means, a signal for adjusting the polishing direction is input to the control means, and the holder is rotated according to instructions from the control means to adjust the polishing direction and the polishing direction of the workpiece. The polishing head is characterized by a polishing head formed so that the polishing direction coincides with the easy direction.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

First, the outline of this embodiment will be explained with reference to FIG.

The holder 2 holding the workpiece 1 is supported by the main body 3 of the polishing head 20 so as to be rotatable as shown by the arrow B around a vertical axis perpendicular to the grinding surface of the grindstone 5 rotating in the direction of the arrow A. A thermocouple 8, which is temperature detection means for measuring the grinding temperature of the workpiece 1, is attached to the holder 2. This detection signal is inputted to the adjustment means 10 via the amplifier 9, and a signal for adjusting the polishing direction is inputted to the control means 11, which rotates the holder 2 to make the polishing direction coincide with the polishing easy direction. . Thereafter, this process is repeated to achieve efficient polishing.

Next, this embodiment will be explained in detail.

A workpiece such as a diamond is easiest to polish when it is polished in a direction parallel to its crystal axis, and the polishing temperature is the lowest. Therefore,
By measuring the temperature of the workpiece 1 during polishing, it can be determined whether the polishing direction and the easy polishing direction match. The above is the theoretical basis of this embodiment.

FIG. 2 shows the results of measuring the grinding temperature of the workpiece by rotating the workpiece and alternately achieving easy and difficult polishing. In the figure, point (a) indicates the difficult case, and point (b) indicates the easy case.
It can be seen that the temperature at point (a) is the highest and the temperature at point (b) is the lowest. Point (b) corresponds to the case where the polishing direction and the easy polishing direction match. Therefore, by changing the polishing direction to point (b) based on temperature measurement, the easy polishing direction and the polishing direction can be matched.

As shown in FIG. 1, the polishing head 20 includes a holder 2 that holds the workpiece 1 vertically, and a main body 3 that forms a mechanism for rotating the holder 2 around the vertical axis.
, a driving means 4 which is a source of rotational power for the main body 3, and a polishing plate 5 that supports the main body 3 and is placed on a pedestal 6. This polishing head 20 is engaged with temperature detection means, adjustment means 10 and control means 11, which will be described later.

The grindstone 5 is supported by a spindle 7 on a pedestal 6, and its grinding surface coincides with a horizontal plane perpendicular to the vertical axis. Also, the whetstone 5 rotates as shown by arrow A.
The holder 2 rotates as indicated by arrow B. Therefore, by rotating the holder 2, the direction in which it is easy to polish the workpiece 1 can be made to coincide with the rotation direction of the grindstone 5.

A thermocouple 8 serving as temperature detection means is attached to the holder 2 to detect the grinding temperature of the workpiece 1. This detection signal is input to the adjustment means 10 via the amplifier 9. The adjustment means 10 sends the required signal to the control means 11 until the grinding temperature reaches the minimum temperature.

The control means 11 controls the driving means 4 of the polishing head 20.
The driving means 4 is operated in response to the above signal to rotate the holder 2 by the necessary amount in a desired direction. Since the above-mentioned loop forms a closed loop, the control operation is performed until the grinding temperature reaches the minimum temperature.

As described above, by measuring the grinding temperature and rotating the holder 2 so that the grinding temperature becomes the lowest temperature, it is possible to align the easy grinding direction with the polishing direction. First, the crystal orientation can be found accurately using a simple means, and polishing can be performed efficiently.

In this embodiment, the workpiece 1 is held by the holder 2 and is formed to rotate around the vertical axis, but the polishing direction of the workpiece 1 can be changed with respect to the rotational direction of the grindstone 5. Control means 11 for controlling other means
The same applies even if the device is engaged with the device.

FIG. 3 shows an embodiment in which the thermocouple 8 is not embedded in the holder 2 but is brought into direct contact with the workpiece 1 using a clip 12. Thereby, the sensitivity of temperature detection can be increased.

Further, the temperature detecting means is not limited to a thermocouple, and a thermistor, a resistance temperature detector, or the like may be used.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the effect of improving polishing efficiency can be achieved by using simple means.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a graph showing temperature measurement results when polishing is easy and difficult, and FIG. 3 is a partial perspective view showing details of the temperature detection means. 1...Workpiece, 2...Holder, 3...Main body,
4... Drive means, 5... Grindstone, 6... Frame, 7...
...Spindle, 8...Thermocouple, 9...Amplifier, 1
0... Adjustment means, 11... Control means, 12... Clip.

Claims (1)

[Claims] 1. In a polishing head having a mechanism for holding workpieces having different degrees of polishing difficulty depending on crystal orientation and changing the polishing direction of the workpiece, a temperature detection means for detecting the grinding temperature of the workpiece; an adjusting means for generating a required signal until the grinding temperature reaches the lowest temperature in accordance with a detection signal from the detecting means; and an adjusting means for operating the mechanism in response to the required signal from the adjusting means so that the grinding temperature reaches the lowest temperature. A polishing head comprising: a control means for changing the polishing direction of a workpiece so that the polishing direction of the workpiece coincides with an easy polishing direction.