JP3077263B2 - Cutting tool edge position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the position of a cutting edge of a processing tool used for grinding.

[0002]

2. Description of the Related Art In grinding, it is necessary to know a contact position between a work to be processed and the tip of a grinding wheel in order to determine a processing start position. Conventionally, as a method of obtaining the contact position of the tip of the grinding wheel, as shown in FIG. 7, the grinding wheel head 1 is fed in the Z-axis direction, and the tip of the grinding wheel 2 supported by the grinding wheel head is brought close to the work 3 to some extent. When it is visually confirmed that the grinding wheel 2 has been manually moved, the grinding wheel head 1 is moved by a minute amount (about 1 μm) in the Z-axis direction while rotating the grinding wheel 2 manually. The coordinate position in the Z-axis direction of the grindstone head when it stops rotating is regarded as the contact position, that is, the processing start position.

[0003]

However, in such a conventional positioning method, the grinding wheel is almost stationary. On the other hand, at the time of machining, the grinding wheel is rotated at a high speed by the high-frequency motor built in the grinding wheel head. Therefore, when the high-frequency motor is heated, the grinding wheel shaft elongates. For this reason, the grinding wheel 2 positioned at the position shown by the solid line in FIG. 8 changes to the position shown by the broken line, and the Z-axis coordinate position P ₀ positioned with great effort is displaced to the position P ₁ , and the Z The axis coordinate position becomes unreliable.

Further, in the method of determining the processing start position by bringing the tip of the grinding wheel 2 into contact with the workpiece 3, the grinding wheel cuts the workpiece at the time of positioning, so that there is a problem that it is difficult to accurately grasp the tip of the grinding wheel. there were. There is also a method of using a contact detection pin, but since this is a vibration type touch sensor type, it has a problem that it is liable to malfunction and lacks accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a blade edge position detecting device capable of detecting a blade edge position of a processing tool such as a grinding wheel in a non-contact manner.

[0006]

The present invention will be described with reference to FIG. 1 in the claim correspondence diagram.
A processing tool 1 that moves relative to the upper workpiece W in the cutting direction.
10 and a scanning beam intersecting point 12 in two directions by irradiating the processing tool 110 with two intersecting scanning beams 120a and 120b installed on a table 11 and intersecting.
Non-contact type position detecting means 120 for detecting a relative position between the tool tip 0c and the cutting tool edge, and scan beams 120a, 120 based on an output signal from the non-contact type position detecting means 120.
The control means 130 controls the relative movement of the table 11 and the processing tool 110 to a position where b and the cutting tool edge are in contact with each other.

[0007]

With the above arrangement, the non-contact type position detecting means 1 is provided.
Scan beams 120a, 120b in two directions from 20
Is irradiated toward the processing tool 110, the position signal output from the non-contact type position detecting means 120 differs depending on the position of the processing tool 110 with respect to the scan beam. If the table 11 and the processing tool 110 are controlled so that the cutting tool edges 120a and 120b are in contact with the processing tool blade edge, the processing tool 11
The zero cutting edge can be positioned at a predetermined position in contact with the scan beam. Accordingly, the position of the cutting edge of the processing tool 110 can be detected under the same conditions at the time of processing and without contact.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a schematic configuration diagram of a grinding machine provided with a device for detecting a cutting edge of a grindstone. In FIG. 2, the grinding machine 10
Is a slide table 11 that moves in the X-axis direction and a servomotor 1 that moves the slide table in the X-axis direction.
2 and a grinding wheel head 1 that supports and rotates a grinding wheel 13
4 and a servomotor 15 for moving the wheel head 14 in the Z-axis direction. A work W is placed on the slide table 11 via a work mounting jig 16 made of a low thermal displacement member, and a non-contact type position detector for detecting the cutting edge position of the grinding wheel 13 in a non-contact manner, for example, A laser scan micrometer 18 is provided.

The laser scan micrometer 18 is provided with a laser generator 19 and a light receiver 20 which are opposed to each other at a predetermined interval on the slide table 11 in a direction orthogonal to the direction of movement thereof. Two laser beams 1 scanned in two perpendicular directions as shown in FIG.
9 a and 19 b are emitted toward the light receiving unit 20. The light receiving unit 20 includes a light detecting element (not shown) such as a silicon photodiode for separately detecting the light spot positions of the laser beams 19a and 19b in two perpendicular directions. Then, output terminals 21a, 21b and 22a, 22b for taking out a photocurrent generated at each laser beam incident position are connected to the light receiving section 20.
It is provided in.

FIG. 3 is a block diagram showing the overall configuration of a feeder for a grinding machine provided with a mechanism for detecting the cutting edge of a grindstone.
3, a numerical controller 23 includes a central processing unit (hereinafter referred to as a CPU) 24 for managing and controlling the whole, a storage device 25, an X-axis pulse generation circuit 26, and a Z-axis pulse generation circuit 2.
7 and an interface 28, and command pulses transmitted from the pulse generation circuits 26 and 27 are supplied to the corresponding X-axis drive circuit 29 and Z-axis drive circuit 30, respectively. An X-axis servomotor 12 and a Z-axis servomotor 15 are connected to the drive circuits 29 and 30, respectively.

The storage device 25 stores a program for detecting the position of the grindstone, a work processing program, and a grinding point (beam) from the origin corresponding to the intersection of the laser beams 19a and 19b detected by the laser scan micrometer 18. Distance a to contact point A, see FIG.
X from the machining start point C (see FIG. 6) to the grinding wheel grinding point A
Position data in the axial direction (X = w + H ₃ + a), position data in the Z-axis direction from the processing start point C of the workpiece W to the grinding point A (Z = H ₁ −H ₂ −h), and the like are stored. . The interface 28 is connected to the laser scan micrometer 18.

In the above embodiment, the grinding wheel 13 controls the processing tool 110, the laser scan micrometer 18 controls the position detecting means 120, the laser beams 19a and 19b control the scan beams 12a and 12b, and the numerical controller 23 controls the control means. 130 are respectively constituted.

Next, the operation of this embodiment will be described with reference to FIGS. When the grinding machine 10 starts operating, first,
A whetstone tip detection program is executed. When the program starts to detect the tip of the grindstone, first, C
The X-axis pulse generation circuit 26 is operated according to the command value from the PU 24, and the pulse signal sent from the pulse generation circuit 26 is transmitted to the servo motor 12 via the drive circuit 29.
Then, the servo motor 12 is driven to move the slide table 11 rightward in the X-axis direction by the number of command pulses. As a result, the grindstone table 14 located at the position where the detection of the tip of the grindstone is started as shown in FIG. 4 is relatively moved to a position opposed to the laser beam 19a of the laser scan micrometer 18 as shown by the arrow.

Thereafter, the Z-axis pulse generation circuit 27 is operated in accordance with the command value sent from the CPU 24 in accordance with the analysis of the grinding wheel position detection program by the CPU 24, and the pulse signal sent from the pulse generation circuit 27 is supplied to the drive circuit. By applying the servo motor 15 to the servo motor 15 through the wheel 30, the grinding wheel head 14 is lowered by the number of command pulses in the Z-axis direction as shown by the arrow in FIG. It descends until it crosses the laser beam 19a scanned in the direction. At this time, the grinding wheel 13 is rotating at the same high speed as during processing.

Next, the grinding wheel head 14 is raised and slightly moved in the processing direction to move the tip of the grinding wheel up and down around the laser beam 19a, thereby searching for a point immediately before the point A for detecting the grinding point A of the grinding wheel. Here, "immediately before" means that when the diameter d of the laser beam 19a is substantially 1/2 d blocked by the tip 13a of the grinding wheel 13 as shown in FIG. 5, it is recognized as the tip of the grinding wheel. The position immediately before whether or not the boundary is exceeded is immediately before.

When detecting immediately before the grinding point A of the grinding wheel, FIG.
As shown by the arrow, the grindstone table 14 is raised from a position where the tip of the grinding wheel 13 is once lowered to a state where the tip crosses the laser beam 19a. The detection signal is detected by a semiconductor photodetector in the device 20, and the detection signals are output to output terminals 21a and 21a.
By taking in the CPU 24 through b, it is determined whether or not the grinding wheel grinding point A is detected immediately. If it is determined that it is immediately before, the processing shifts to detection immediately before the next grinding wheel grinding point B.

In detecting immediately before the grinding point B, first, the X-axis pulse generation circuit 26 is operated in accordance with the command value sent from the CPU 24.
6 is applied to the servo motor 12 via the drive circuit 29, whereby the servo motor 12
To move the slide table 11 rightward in the X-axis direction as shown by the arrow in FIG. 4, and rightward until the grinding point B side of the grinding wheel 13 crosses the laser beam 19 b scanned in the vertical direction. I do.

Thereafter, the slide table 11 is moved leftward from the position where the tip of the grinding wheel 13 on the point B side is once moved rightward until it intersects the laser beam 19b greatly.
The position of the laser beam 19b interrupted on the side of the point B of 3 is detected by the semiconductor light detecting element in the light receiving section 20, and this detection signal is taken into the CPU 24 through the output terminals 22a and 22b, thereby detecting the grinding wheel grinding point B. It is determined whether it is immediately before. If it is determined that it is immediately before, the immediately preceding detection of the grinding wheel grinding point ends.

When the detection immediately before the grinding points A and B is completed, the distances a and b from the origin (0, 0), which is the intersection of the laser beams 19a and 19b, to the grinding points A and B (see FIG. 6). Is calculated by the CPU 24, and this is stored in the storage device 25. Therefore, as shown in FIG. 6, the distance H1 from the slide table 11 to the origin (0,0), the height H of the work mounting jig 16, the distance H3 from the work mounting jig 16 to the origin (0,0), And the height h of the workpiece W,
Distance w from the side end surface of work mounting jig 16 to work W
When the upper surface of the workpiece W is ground at the grinding point A, X = (w + H ₃ + a) and Z = (H ₁ −
The processing start position C at the right end of the upper surface of the work W can be determined based on the position of the grinding wheel grinding point A obtained from H ₂ -h), and the automatic cutting edge correction can be performed based on the detected position data. Similarly, when the right side of the workpiece W is ground at the grinding point B, the grinding point B obtained from X = (w + H ₃ ) and Z = (b + H ₁ −H ₂ −h) is obtained.
, The processing start position C at the upper end of the side surface of the work W can be determined.

In this embodiment, the tip of the grinding wheel is formed by using a laser scan micrometer 18 for scanning a laser beam in two directions at right angles, and a table 11 and a grinding wheel base 14 controlled by output signals from the laser scanning micrometer 18. The tip of the grindstone is moved with respect to the laser beam to a position where the grinding wheel and the laser beam block about 1/2 of the beam diameter, so that the grinding wheels A and B can be detected.
In a state where the grinding wheel 13 is rotated under the same conditions as in the machining, the position of the tip of the grinding wheel can be detected accurately and automatically without contact, and can be positioned. Can also be determined accurately.

In addition, when detecting the position of the tip of the grinding wheel, it can be detected simply by inserting the tip of the grinding wheel into the range scanned by the laser beam, so that the position can be detected easily in a short time. be able to. Furthermore, there is an advantage that the risk of breaking the grinding wheel is reduced as compared with the conventional method of positioning the grinding wheel in contact with a workpiece or the like.

As another embodiment, instead of moving the slide table 11 in the X-axis, the wheel head 14 may be moved in the X-axis direction. The embodiments of the present invention can be variously modified without departing from the scope described in the claims.

[0023]

As described above, according to the present invention,
Using a measuring means consisting of a beam scan micrometer, the processing tool is controlled to move to the position where the scan beam and the processing tool tip are in contact with each other, so that the processing tool tip can be detected. Under the conditions, the position of the cutting edge of the processing tool can be automatically detected in a non-contact manner, and the position of the processing tool can be precisely positioned.

[Brief description of the drawings]

FIG. 1 is a view corresponding to a claim of a device for detecting the position of a blade edge of a working tool according to the present invention.

FIG. 2 is a schematic configuration diagram of a grinding machine showing an embodiment to which the blade edge detecting device of the present invention is applied.

FIG. 3 is a block diagram of a feed control device in the present embodiment.

FIG. 4 is an explanatory diagram showing an operation state of position detection of the tip of the grinding wheel in the embodiment.

FIG. 5 is an explanatory diagram showing a relationship between a laser beam and a grindstone at the time of detection of a grindstone tip in the present embodiment.

FIG. 6 is an explanatory diagram showing a relationship in detecting the position of the tip of the grindstone between the grindstone, the laser beam, the table, and the work in the embodiment.

FIG. 7 is an explanatory view showing a conventional method of positioning the tip of a grinding wheel.

FIG. 8 is an explanatory view of a conventional grindstone positioning.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Grinding machine 11 X-axis table 12 Servo motor 13 Grinding wheel 14 Grinding wheel stand 15 Servo motor 18 Laser scan micrometer 19 Laser generating unit 20 Light receiving unit (light detecting element) 23 Numerical control device 24 CPU 25 Storage device 120 Position detecting means 130 Control means

Continuation of the front page (56) References JP-A-62-88555 (JP, A) JP-A-59-31402 (JP, A) JP-A-4-315556 (JP, A) JP-A-4-190103 (JP) , A) Jpn. 47-34494 (JP, U) J. Jpn. 48-3196 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23Q 17/24 B24B 49/12

Claims (1)

(57) [Claims] 1. A processing tool which moves relative to a workpiece on a table in a cutting direction, and a scanning beam in two directions which is set on the table and which irradiates the processing tool with two intersecting scan beams. Non-contact type position detecting means for detecting the relative position between the intersection and the cutting tool edge,
Control means for controlling relative movement of the table and the processing tool to a position where a scan beam and a processing tool blade edge are in contact with each other based on an output signal from the non-contact position detecting means. Blade position detection device.