JPH10249726A - Automatic measurement method and device at grinding stone end - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and automatically measure the radius of the round shape of a grinding stone with the end in round shape and the position at the end thereof on a grinder. SOLUTION: A round shape of a grinding stone 19 with the end in round shape is put in contact with a sectionally circular reference piece 37 at three points, at least, to measure the longitudinal and vertical coordinates of the contact points between the grinding stone 19 and the reference piece 37 with a sensor 39. In accordance with the measured coordinates at three points, or more a radius of the round shape of the grinding stone 19 and the coordinates of the center position of the reference piece 37 are calculated by a processor 35. The grinding stone 19 is moved above the longitudinal center position of the reference piece 37 in accordance with the calculated value so that the center position of the radius at the end can conform thereto. Then, the grinding stone 19 is moved down to put the end of the grinding stone 19 in contact with the peak of the reference piece 37 for measuring the vertical coordinate at this time, so that the radius of the round shape of the grinding stone 19 and the position at the end thereof can be automatically measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for automatically measuring a radius and a tip position of a round portion of a grinding wheel having a round tip in a grinding machine.

[0002]

2. Description of the Related Art Conventionally, in a grinding machine, a grindstone having a round tip is used at the time of finishing. The shape of the tip of this kind of grindstone and the positional relationship between the work and the grindstone are usually tested by grinding materials such as carbon and dummy work, and the operator checks the ground shape of the ground material with a projection inspection machine. This has been done.

At present, there is a system which uses a reference piece on a table of a surface grinder to measure the position of the tip of a grindstone by a sensor provided on the reference piece. However, this system mainly has a flat tip. It measures the end face and side face of a whetstone having a shape, and does not correspond to a whetstone having a round tip.

[0004]

In the above-described conventional method and apparatus for automatically measuring the position of the tip of a grindstone, after processing a dummy work, the grinding shape of the work is checked with a projection inspection machine or the like. In addition, there is a problem in that a flat plate grinding machine requires a separate projection inspection machine.

Since the radius dimension of the grinding shape of the dummy work is checked according to the circle drawn on the chart, there is a problem that an error occurs due to a human.

[0006] A grindstone having a round tip is brought into contact with a reference piece,
In the method of measuring the position of the grindstone by detecting this contact with a sensor attached to the reference piece, it is necessary to align the center of the reference piece and the grindstone during the first alignment,
Since the tip of the whetstone is round and the reference piece is also round, there is a point contact between the whetstone and the reference piece.Therefore, if the tip of the whetstone deviates from the apex of the reference piece, the vertical position of the whetstone will also shift. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a grinder in which the radius and the tip position of a round portion of a grindstone having a round tip are easily measured in a grinding machine. To provide an automatic measurement method and apparatus therefor.

[0008]

In order to achieve the above object, a method of automatically measuring the tip of a grinding wheel according to the present invention according to claim 1 is to place a round portion of a grinding wheel having a round tip at a predetermined position on a grinding machine. Measure the coordinate values in the vertical and longitudinal directions at predetermined positions of the grindstone when the whetstone is brought into contact with at least three points of a reference piece having a circular cross section, and obtain a circular locus based on the measured coordinate values. Then, the radius of the circular locus is determined, the radius of the reference piece is subtracted from the radius of the circular locus to determine the radius of the round portion of the grinding wheel, and then the tip of the round portion of the grinding wheel is set to the reference piece. The vertical position of the contact point is measured while descending to make contact with the vertex position of the contact point. Measuring the coordinate value of the side More, it is characterized in that automatically measures the radius and the distal end position of the rounded portion of the wheel.

Therefore, even when the tip of the grinding stone has a round shape, when the round portion of the grinding stone is brought into contact with at least three places of the reference piece having a circular cross section, the vertical direction and the vertical direction at the predetermined position of the grinding stone are adjusted. When the coordinate values in the front-rear direction are measured, the measured coordinate values are input to, for example, an arithmetic processing device, and the radius of the round portion of the grinding stone is calculated based on a calculation formula previously input to the arithmetic processing device. Is calculated.

Then, the tip of the round portion of the grinding stone is brought into contact with the vertex position of the reference piece to measure the vertical coordinate value of the contact point, and one of the right and left of the circular cross section of the reference piece is measured. By contacting the round portion of the grindstone with the side position and also measuring the coordinate value of this contact point, the calculated value of the radius of the round portion of the grindstone is corrected and the tip position of the round portion of the grindstone is corrected. Measured automatically.

According to a second aspect of the present invention, there is provided an automatic measuring device for measuring the tip of a whetstone, wherein a table is provided so as to be movable in the left-right direction.
In a grinding machine in which a grindstone is movably provided in a vertical direction and a front-back direction, a vertical moving means for vertically moving a round-shaped grindstone and a vertical position of the grindstone moved by the vertical moving means are detected. Up and down position detecting means, front and rear moving means for moving the grinding wheel back and forth, front and rear position detecting means for detecting the position in the front and rear direction of the whetstone moved by the back and forth moving means, and a circular shape at a predetermined position of the grinding machine. A reference piece of a cross section, a sensor for detecting that the grindstone has contacted the reference piece, and coordinate values in the up-down direction and the front-back direction at predetermined positions when the grindstone is brought into contact with at least three points of the reference piece. Is detected and measured by the sensor, and after calculating a circular locus based on the measured coordinate values,
Find the radius of this circular locus, calculate the radius of the round part of the grinding wheel by subtracting the radius of the reference piece from the radius of this circular locus,
Next, the tip of the round portion of the whetstone is lowered to make contact with the vertex position of the reference piece, and the vertical coordinate value of the contact point is measured, and either one of the left and right sides of the circular cross section of the reference piece is measured. A control device that automatically measures the radius and tip position of the round part of the grinding stone by measuring the coordinate value of the side surface of the grinding stone by bringing the round part of the grinding stone into contact with the position. It is a feature.

Therefore, the operation is the same as that of the first aspect, and the sensor detects that the round portion of the grindstone has contacted the reference piece having the circular cross section. The coordinates of the direction are easily measured by the vertical position detecting means and the front and rear position detecting means.

When coordinate values in the up-down direction and the front-rear direction at predetermined positions of the grinding stone when the round portion of the grinding stone is brought into contact with at least three reference pieces having a circular cross section are measured. The radius of the round portion of the grinding wheel is calculated based on the calculation formula in which the measured coordinate values are input to the arithmetic processing device in advance.

Next, the tip of the round portion of the grinding wheel is brought into contact with the vertex position of the reference piece to measure the vertical coordinate value of the contact point, and one of the right and left of the circular cross section of the reference piece is measured. By contacting the round portion of the grindstone with the side position and also measuring the coordinate value of this contact point, the calculated value of the radius of the round portion of the grindstone is corrected and the tip position of the round portion of the grindstone is corrected. Measured automatically.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an automatic measuring method for a tip position of a grindstone and an apparatus therefor according to the present invention will be described with reference to the drawings.

Referring to FIG. 4, for example, a surface grinding machine 1 as a grinding machine according to the present embodiment is a guide rail extending on a box-shaped bed 3 in the Z-axis direction (left-right direction in FIG. 4). The guide rail 5 is provided.
The table 7 is provided on the guide rail 5 so as to be reciprocally movable in the Z-axis direction by a hydraulic cylinder (not shown) guided by the guide rail 5.

Behind the bed 3, as shown in FIG. 1, a column movable in the X-axis direction (front-back direction in FIG. 4) by an X-axis drive motor 9 (front-back drive means) such as a servomotor. 11 are provided.

A guide member 13 extending in the Y-axis direction (vertical direction in FIG. 4) is attached to the column 11, and is guided by the guide member 13 to serve as a servomotor or the like as shown in FIG. Wheel head 17 movable in the Y-axis direction by the Y-axis drive motor 15 (vertical drive means)
Are provided in the column 11.

The grindstone head 17 is provided with a grindstone 19 rotatable by a grindstone rotation drive motor (not shown).

The right side of the bed 3 has a surface grinder 1
An NC device 23 (control device) for automatically controlling the X-axis drive motor 9 and the Y-axis drive motor 15 is electrically connected to the NC device 23 as shown in FIG. A hydraulic cylinder (not shown) for reciprocating the table 7 in the Z-axis direction is also provided by the N
It is electrically connected to the C device 23.

As shown in FIG. 1, front and rear position detecting means 25 for detecting the position of the column 11 in the X-axis direction, and vertical position detecting means for detecting the position of the grinding head 17 in the Y-axis direction. 27 are provided, and the front / rear position detecting means 25 and the vertical position detecting means 27 are each provided with a CPU.
24 is electrically connected.

The CPU 24 has an input device 29 (input means) and a display device 31 (display means) for inputting and correcting data, the input device 29, the front / rear position detecting means 25, and the vertical position detecting means 27. And a processing unit 35 for performing a calculation based on the data input from the input device 29 and the data when the position of the grindstone 19 is detected in the memory 33 ( And an X-axis drive motor 9, a Y-axis drive motor 15, and a hydraulic cylinder (not shown) based on the numerical values calculated by the arithmetic processing unit 35.
Is configured to give a command to operate the.

Therefore, the data of the coordinate of the column 11 in the X-axis direction and the data of the coordinate of the grinding wheel head 17 in the Y-axis direction are respectively sent to the NC unit 23.

With the above configuration, the work W
Is placed, and the table 7 is automatically controlled by the NC device 23.
Is reciprocated in the Z-axis direction, the column 11 is moved in the X-axis direction, the grindstone head 17 is moved in the Y-axis direction, and the grindstone 19 is moved.
Is rotated to perform the grinding process on the work W.

Hereinafter, a method for measuring the tip of the main grinding wheel 19 according to the embodiment of the present invention will be described.

Referring to FIGS. 1 and 4, a circular bar-shaped reference piece 37 having a circular cross section is provided at a predetermined position on the table 7 of the surface grinding machine 1.
A contact sensor 39 (hereinafter simply referred to as a sensor) such as an AE sensor or a vibration sensor for detecting contact with the sensor 9 is provided. This sensor 39 is electrically connected to the NC device 23 via an amplifier.

As shown in FIGS. 2 and 3, the grindstone 19 is moved in the X-axis direction and the Y-axis direction, the table 7 is moved in the Z-axis direction, and The reference piece 3 is a curved portion having a cross section having a radius r.
7 is brought into contact with at least three different locations. The coordinate values in the X-axis direction and the Y-axis direction at the pre-designated position of the grinding wheel at the time of the contact are stored in the memory 33 of the NC device 23.

The pre-designated position of the grinding stone may be any point on the grinding stone, but in order to make the explanation easy to understand, in the example of the present embodiment, the center of the radius r of the round part of the grinding stone is used. Let point Ci be the pre-designated position of the whetstone.

First, as shown in FIG.
The X-axis coordinate of the grindstone 19 is set almost directly above the reference piece 37, and the Y-axis coordinate of the grindstone 19 is moved downward to contact the reference piece 37. At this time, the circle of the grindstone detected by the sensor 39 is used. Coordinate point A (x ₁ , y) of the center point Ci of the radius of the shape portion
₁ ) is measured, and the measured value is stored in the memory 3 of the NC device 23.
3 (step S1).

Next, as shown in FIG.
The round portion of the grindstone 19 is brought into contact with the reference piece 37 above the position of about 45 °, and the coordinate B point (x ₂ , y ₂ ) of the center point Ci detected by the sensor 39 at this time is measured. The measured value is stored in the memory 33 of the NC device 23 (Step S2).

Similarly, as shown in FIG. 2C, the grindstone 1 is moved upward at a position of about 45 ° opposite to the reference piece 37.
9 are brought into contact with each other, and at this time, the coordinates C of the center point Ci (x ₃ ,
y ₃ ) is measured, and the measured value is stored in the memory 33 of the NC device 23 (step S3).

The three points A, (x ₁ , y ₁ ), B (x ₂ , y ₂ ), and C (x ₃ , y ₃ ) of the three measured coordinates are calculated by the arithmetic processing unit 35 of the NC unit 23. , FIG. 2
As indicated by a two-dot chain line in (D), the coordinates (x ₀ of a circular cross section of the center C ₀ made by a radius R ₀ of the reference piece 37,
The distance from y ₀ ) to the center point Ci of the radius r of the round part of the grindstone, that is, the radius R of the circular locus is calculated.

As a calculation formula, for example, if the equation of the circular locus is set to x ² + y ² + ax + by + c = 0, the circular locus is calculated at the coordinate A points (x ₁ , y ₁ ) of the three measured points,
Point B (x _2, y _2), so passing through the point C _{(x 3, y 3),} x 1 2 + y 1 2 + ax 1 + by 1 + c = 0 x 2 2 + y 2 2 + ax 2 + by 2 + c = 0 definitive and _{^{x 3 2 + y 3 2 +}} ax 3 + by 3 + c = 0. A, b, and c are obtained by these three equations.

On the other hand, the above equation of the circular locus is

(X + a / 2) ² + (y + b / 2) ² = (a ²
+ B ² -4c) / 4

## EQU2 ## Coordinate (x ₀ , y ₀ ) of center C ₀ = (− a / 2,
−b / 2) Radius R = √ (a ² + b ² -4c) / 4, and radius R is calculated. However, when a ² + b ² -4c <0 is a Kyoen.

Therefore, the radius r of the round part of the grinding wheel is
It is obtained by subtracting the radius R ₀ of the reference piece 37 from the radius R of the circular locus (r = R−R ₀ ).

Next, as shown in FIG.
Since the coordinates (x ₀ , y ₀ ) of the center C ₀ are at predetermined positions, the coordinates Ci in the X-axis direction of the center Ci are calculated from the radius r of the round part of the grindstone calculated by the arithmetic processing unit 35 of the NC unit 23. coordinates, to move the grinding wheel 19 at the position of coordinates x ₀ in the X-axis direction, is again contacted with the grinding wheel 19 to the reference piece 37 a round shape of the grindstone 19 is lowered by the Y-axis direction, the sensor 3 at this time
9 coordinate point D at a radius of the center Ci of the rounded portion of the wheel when the detected (x _4, y ₄₎ is measured by, obtained by calculating from the radius r and the measured measurement coordinate values The coordinates are corrected by comparing with the coordinate values, and are stored in the memory 3 of the NC unit 23.
3 is stored.

Since the tip of the grindstone 19 is located immediately above the reference piece 37, the coordinate point D (x ₄ , y ₄ ) at this time is obtained.
Is formally registered in the memory 33 of the NC device 23 as the tip surface position of the grindstone 19 (step S5).

Regarding the position of the side surface of the grinding wheel 19, the grinding wheel 1
In the case of the left taper V shape due to the shape of the reference numeral 9, as shown in FIG. 2 (F), the right side of the grindstone 19 is moved so as to contact the left side of the reference piece 37.
The point E (x ₅ , y ₅ ) of the position detected by the position 9 is measured, the measured coordinate value is compared with the coordinate value calculated from the radius r, corrected, and formally set to NC. It is registered in the memory 33 of the device 23 (step S6).

Further, depending on the shape of the grindstone 19, the right side taper V
In the case of the shape, as shown in FIG.
Left side face 9 is moved to contact the right side of the reference piece 37, the coordinate point F of the position where the sensor 39 has detected this time (x _6, y ₆₎ is measured, and the measured measurement coordinate values The coordinates are corrected by comparing them with the coordinate values calculated from the radius r, and are formally registered in the memory 33 of the NC device 23 (step S6).

As described above, after measuring the three points A, B, and C, the end face position E of the tip of the grindstone 19 is measured.
Further, since the F point or the G point is measured according to the shape of the grindstone 19, even if the first three points are slightly misaligned, they are corrected.

In the above-described embodiment, the center point Ci of the radius r of the round portion of the grindstone is set to a predetermined position of the grindstone. However, if the predetermined position is another position of the grindstone, Although the center of the circular locus drawn by the measurement coordinates at the predetermined position does not coincide with the coordinates (x ₀ , y ₀ ) of the center C ₀ of the reference piece 37, the center position of the circular locus is determined by the reference piece 37. Is the same if it is slid to the center C ₀ of the circle locus, the radius R of the circular locus is simply
Is calculated, the radius r of the round portion of the grindstone can be calculated from the value of the radius R.

In the above-described embodiment, points A and B
Point and point C are measured, and the radius R is calculated based on this data.
And the radius r of the round part of the grindstone was calculated. However, the accuracy can be improved as the measurement data increases, so that four or more points are possible.

Further, as shown in FIG. 5, the calculation formula for calculating the radius R of the circular locus from the measurement data of three or more points is also obtained from the intersection of the perpendicular bisectors.

In FIG. 5, points P ₁ , P ₂ and P ₃ are measurement points at predetermined positions of the grinding wheel, and L ₁
Is a perpendicular bisector of a line connecting the points P ₁ and P ₂ , and L ₂
Is a perpendicular bisector of a line connecting _a point and P ₃ points P.

Therefore, the intersection of L ₁ and L ₂ is at the center C ₀
(X ₀ , y ₀ ). This center C ₀ (x ₀ , y
₀ ) and the distance from the point P ₁ (or the point P ₂ or P ₃ ) is the radius R value. Therefore, the radius r of the round portion of the grindstone is calculated from the radius R of the circular locus as in the above-described embodiment. It is obtained by subtracting the radius R ₀ of the reference piece 37.

The present invention is not limited to the above-described embodiment of the present invention, but can be embodied in other forms by making appropriate changes. In the present embodiment, a surface grinding machine has been described as an example of a grinding machine, but a copying grinding machine, a rotary surface grinding machine, and other grinding machines may be used.

[0047]

As can be understood from the above embodiments of the present invention, according to the first aspect of the present invention, even if the tip is a round stone, the round portion of the stone has a circular cross section. When the coordinate values in the up-down direction and the front-rear direction at the pre-designated position of the grinding stone when at least three positions are brought into contact with the reference piece are measured, the measured coordinate values are input to, for example, an arithmetic processing device. The radius of the round portion of the grinding wheel can be easily calculated based on a calculation formula previously input to the arithmetic processing unit.

Next, the tip of the round part of the grinding stone is brought into contact with the vertex position of the reference piece to measure the vertical coordinate value of the contact point, and one of the right and left of the circular cross section of the reference piece is measured. By contacting the round portion of the grindstone with the side surface position and also measuring the coordinate value of this contact point, the calculated value of the radius of the round portion of the grindstone is corrected and the tip position of the round portion of the grindstone is corrected. It can be measured automatically.

According to the second aspect of the present invention, it is the same as the effect of the first aspect, and it is detected by the sensor that the round portion of the grinding stone has come into contact with the reference piece having the circular cross section. The coordinates of the contact point in the front-back direction and the up-down direction can be easily measured by the up-down position detection unit and the front-back position detection unit.
When the coordinate values in the up-down direction and the front-rear direction at predetermined positions of the grindstone when the round portion of the grindstone is brought into contact with at least three points of the reference piece having the circular cross section are measured, the measured measurement is performed. The radius of the round portion of the grinding wheel can be calculated based on a calculation formula whose coordinate values are input in advance to the arithmetic processing unit.

Next, the tip of the round portion of the grinding wheel is brought into contact with the vertex position of the reference piece to measure the vertical coordinate value of the contact point, and one of the right and left of the circular cross section of the reference piece is measured. By contacting the round part of the grindstone with the side surface position and also measuring the coordinate value of this contact point, the calculated value of the radius dimension of the round part of the grindstone can be more accurately corrected and the round part of the grindstone can be corrected. The tip position can be measured automatically.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a schematic explanatory view of an automatic measuring device for a tip position of a grindstone.

FIGS. 2A and 2B show an embodiment of the present invention, and FIGS.
(G) is an explanatory view of an automatic measuring method of the tip position of the grindstone.

FIG. 3, showing an embodiment of the present invention, is a flowchart of a method for automatically measuring the tip position of a grindstone.

FIG. 4 is a perspective view of the surface grinder according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing another calculation method in the arithmetic processing device of the NC device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface grinder 7 Table 9 X-axis drive motor (front-back drive means) 11 Column 15 Y-axis drive motor (vertical drive means) 17 Grinding head 19 Grindstone 23 NC device (control device) 25 Front-back position detection means 27 Vertical position detection means Reference Signs List 29 input device (input means) 31 display device (display means) 33 memory 35 arithmetic processing unit (calculation unit) 37 reference piece 39 contact sensor (sensor)

Claims (2)

[Claims] 1. The method according to claim 1, wherein when a round portion of the grinding wheel having a round tip is brought into contact with at least three places of a reference piece having a circular cross section at a predetermined position of the grinding machine, each of the vertical direction at a predetermined position of the grinding wheel and The coordinate value in the front-rear direction is measured, a circular locus is obtained based on the measured coordinate values, the radius of the circular locus is obtained, and the radius of the reference piece is subtracted from the radius of the circular locus to obtain the whetstone. Then, the radius of the round portion of the grindstone is determined, and then the tip of the round portion of the grindstone is lowered to make contact with the vertex position of the reference piece, and the vertical coordinate value of the contact point is measured. By measuring the coordinate value of the side surface of the grindstone by contacting the round part of the grindstone with either the left or right side position of the circular cross section, the radius dimension and the tip position of the round part of the grindstone are automatically measured. The tip of a whetstone characterized by Automatic method of measuring. 2. A table is provided movably in the left-right direction,
In a grinding machine in which a grindstone is movably provided in a vertical direction and a front-back direction, a vertical moving means for vertically moving a round-shaped grindstone and a vertical position of the grindstone moved by the vertical moving means are detected. Up and down position detecting means, front and rear moving means for moving the grinding wheel back and forth, front and rear position detecting means for detecting the position in the front and rear direction of the whetstone moved by the back and forth moving means, and a circular shape at a predetermined position of the grinding machine. A reference piece of a cross section, a sensor for detecting that the grindstone has contacted the reference piece, and coordinate values in the up-down direction and the front-back direction at predetermined positions when the grindstone is brought into contact with at least three points of the reference piece. Is detected and measured by the sensor, and a circular locus is calculated based on the measured coordinate values.
Find the radius of this circular locus, calculate the radius of the round part of the grinding wheel by subtracting the radius of the reference piece from the radius of this circular locus,
Next, the tip of the round portion of the whetstone is lowered to make contact with the vertex position of the reference piece, and the coordinate value in the vertical direction of the contact point is measured, and either the left or right side of the circular cross section of the reference piece is measured. A control device that automatically measures the radius and tip position of the round part of the grinding stone by measuring the coordinate value of the side surface of the grinding stone by bringing the round part of the grinding stone into contact with the position. An automatic measuring device for the tip of a grinding wheel.