JPH02198768A - Noncontact detection method for grinding face of grindstone - Google Patents

Abstract

PURPOSE:To detect the position of the grinding face for a reference point with high accuracy by the change in the feeding air pressure of an air micrometer by discharging the air of the air micrometer toward the grinding face from the reference point provided at the work fixing part. CONSTITUTION:A reference point 5 is provided at the work fixing side, the air of an air micrometer is discharged thereby, the grinding face 1a of a grindstone 1 is approached to this discharging air and the position of the grinding face 1a of the grindstone 1 for the reference point is detected by the variation of the feeding air pressure of the air micrometer. By this method, the distance from the reference point 5 of the grindstone grinding face 1a reduced by grinding or dressing can be measured with high accuracy with non-contact. The approaching speed of the grindstone and grinding start point can thus be determined according the distance thereof, and the measuring time is shortened and without damaging the grindstone grinding face 1a a high accurate grinding can be automatized further as well.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to a method for detecting the position of a grinding surface of a grindstone in a non-contact manner.

<Conventional technology> Grinding machines use fine cutting blades, or abrasive grains, to perform processing, so they can produce surfaces with higher finishing accuracy than milling machines, lathes, etc. However, on the other hand, the approach distance of the grinding wheel is Since it is unknown, it has the disadvantage that the grinding start point and approach speed, which serve as the reference for the depth of cut, are not constant. This is because the abrasive grains fall off from the grinding wheel during grinding, and the grinding surface is also worn due to shape correction work using a dresser or the like. Therefore, even when processing workpieces of the same size, it is necessary to gradually increase the feed of the grinding wheel in the direction of the workpiece as the grinding start point moves.

Therefore, in order to detect the grinding start point, there is a manual feeding method in which the grinding wheel is manually fed 9 in the direction of the workpiece or the fixed workpiece, and judgment is made based on the sound emitted when the grinding wheel and the workpiece come into contact. Generally used.

Furthermore, a method using high-frequency sound is known as a non-contact method for detecting the grinding start point. This utilizes the fact that high-frequency sound emitted from a grinding wheel that rotates at high speed is transmitted to the workpiece or the side where the workpiece is fixed as it approaches, and is considered as a means of automating grinding.

<Problems to be Solved by the Invention> However, the methods for detecting the grinding start point and approach speed described above each have their own drawbacks.

For example, with a manual feed method, it is obvious that grinding cannot be automated, and it is necessary to make the feed very small so that the depth of cut into the workpiece or the side where the workpiece is fixed does not become excessive. In particular, when performing high-precision mirror finishing, excessive feed will damage the grinding surface of the grinding wheel that has been dressed for a long time. (ii) A minute feed was required, which required time to detect the grinding start point and caused high tension and fatigue to the operator.

In addition, in the method using high-frequency sound, the high-frequency sound, amplitude, and wavelength emitted from the grinding surface are affected by the grain size and dressing condition of the grinding wheel.
It may change depending on the outer diameter, the adhesion status of rif abrasive, etc. Therefore, this method can only be used under certain conditions, and it has been difficult to apply it to general-purpose machines that grind various types of workpieces.

Furthermore, as the grinding wheel is used for mirror surface grinding, the grinding surface of the grinding wheel has almost no irregularities, and the ultrasonic energy becomes weak, making it difficult to detect the position of the grinding wheel without contact.

However, if the grinding wheel has a fine finish that has been dressed for a long time, a cut of 1 μm will ruin the dressed grinding surface, so after contact, the position of the grinding wheel is detected with a submicron table. That is important.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a reference point on the fixed side of the workpiece, discharges air from the air micrometer from the reference point, and uses the discharged air to grind the grinding wheel. The grinding surface of the grindstone is moved close to each other, and the grinding surface of the grindstone is moved closer to the grinding surface of the grindstone, and the grinding surface of the grindstone is detected by changing the air pressure supplied to the air micrometer.

As the grindstone approaches the reference point on the fixed workpiece side, the compressed air jetting out from the air discharge part of the air micrometer is blocked by the grinding surface of the grindstone, so the air pressure supplied to the air micrometer increases. By detecting this with an air micrometer, the distance between the grindstone and the reference point on the fixed workpiece side can be determined. This automatically determines the distance between the workpiece fixed side surface and the grinding surface of the grindstone.

Embodiment> A non-contact detection method for a grinding surface of a grindstone according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a front view of an embodiment of the non-contact detection method for a grinding surface of a grinding wheel according to the present invention, and FIG. 2 shows an A-A in FIG.
A cross-sectional view is shown.

1 is a grinding wheel of a grinding machine, which has a grinding surface 1a on the outer periphery;
The center is fixed by a rotating shaft (not shown), and horizontal axis plane grinding is performed, as well as vertical movement (Y direction in the figure) and n1
Jt& (two directions in the figure).

2 is a table of the grinding machine, which moves left and right (in the X direction in the figure). Further, the X, Y, and Z axes are each driven by NC and operate on the numerical side.

3 is a magnet table for a workpiece chuck fixed on the table 2.

Reference numeral 4 denotes an air discharge line body of the air micrometer, which is also fixed on the table 2, and a compressed air discharge hole 5 is provided with openings on the top and side surfaces of the air discharge line body 4.

The opening of the discharge hole 5 on the upper surface of the air discharge line main body 4 is the reference point. At the side opening of the discharge hole 5 in the air discharge main body 4, a nipple 6 connects the tip end to the air discharge line main body 4.
The internal hole 7 and the discharge hole 5 are electrically connected to each other.

8 is a flexible pipe, the tip of which is attached to the nipple 6.

The flexible pipe 8 communicates with an air micrometer body (not shown).

By the way, the upper surfaces of the magnet table 3 and the air discharge section main body 4 are self-blinded by the grinding wheel 1 so that they are uniform.

The operation of this embodiment will be described below.

The center of the grinding wheel 1 is moved over the center of the discharge hole 5 of the air discharge section main body 4, and the direction of the compressed air from the discharge hole 5 and the normal line of the grinding wheel 1 are made to coincide.

Subsequently, the grinding wheel 1 is moved downward while maintaining the above relationship.

As a result, the distance between the discharge hole 5 that blows out air and the grinding surface 1a of the grinding wheel 1 is shortened, and the pressure in the air discharge path changes.

The grinding wheel 1 is fed quickly while the pressure detected by an air micrometer (not shown) is small, and is slowed down as the pressure increases. Then, when a predetermined pressure value is reached, feeding is stopped, but the distance between the grinding surface 1a and the reference point at this point is determined in advance through experiments or the like.

This relatively serves as the lower reference surface of the workpiece.

The top surface of the magnet table 3 and the grinding surface 1a of the grinding wheel 1
This means that the distance between the two can be measured accurately.

Although this embodiment mainly focuses on finding the distance between the grinding surface of the grinding wheel and the reference point, it can also be applied to finding the distance between the side surface of the grinding wheel and the reference point.

<Effects of the Invention> According to the non-contact detection method of the grinding surface of the grinding wheel according to the present invention, compressed air discharged from the reference point on the workpiece fixed side is applied to the grinding surface of the grinding wheel, and the reference point on the workpiece fixed side, that is, the Since the distance between the side surface and the grinding surface of the whetstone is detected without contact, the distance from the reference point of the grinding surface of the whetstone, which has been reduced due to grinding or dressing, can be measured with high precision without contact. The grinding start point and approach speed of the grinding wheel can be determined accordingly, reducing measurement time, and since it is a non-contact detection, there is no damage to the grinding surface of the grinding wheel, making it possible to automate high-precision grinding.

[Brief explanation of the drawing]

1 is a front view of an embodiment of the non-contact detection method for a grinding surface of a grindstone according to the present invention, and FIG. 2 is a cross-sectional view taken along line A-A in FIG. In the figure, 1. Grinding wheel, 1a. Grinding wheel, 3. Magnet table, 4. Air discharge unit body, 5. Discharge hole. Patent applicant Mitsubishi Heavy Industries, Ltd. Agent

Claims (1)

[Claims] A reference point is provided on the fixed side of the workpiece, air from the air micrometer is discharged from the reference point, the grinding surface of the grinding wheel is brought close to this discharged air, and the grinding surface of the grinding wheel relative to the reference point is adjusted by changing the air pressure supplied to the air micrometer. A non-contact detection method for a grinding surface of a whetstone, characterized in that the position of the grinding surface of a whetstone is detected.