JPH0156364B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring the diameter of a workpiece machined with a large vertical lathe.

Conventionally, to measure the diameter of a workpiece machined on a large vertical lathe, a dedicated large micrometer was used, or blocks were placed at positions facing the outside diameter of the workpiece, and the distance between the blocks was measured inside. It was measured using a micrometer. In the former method, the large micrometer was heavy and difficult to operate, and there were problems with accuracy. In the latter method, it was difficult to place the block accurately in contact with the workpiece, and it was also difficult to connect the inside micrometer accurately. In addition to these methods, there is also a method in which the table on which the workpiece is placed is rotated, a roller with a known diameter is pressed against the measurement surface of the workpiece, and the diameter of the workpiece is calculated from the number of rotations of the roller. However, since there is a slip in the rotation speed of the roller in contact with the workpiece, accuracy decreases. Furthermore, when the roller is pressed, the part of the workpiece becomes glossy, which is objectionable.

The present invention has been made from this point of view, and its object is to provide an apparatus for accurately and efficiently measuring the diameter of a workpiece in a large vertical lathe.

The present invention will be explained below with reference to figures showing one embodiment. Figure 1 is a schematic side view of a large vertical lathe.
Above the bed 11 is a table 13 rotated by a drive mechanism 12, on which a workpiece 14 is placed. Columns 15 stand on both the left and right sides of the bed 11, and a horizontal digit 16 that moves up and down is attached to the column 15. A turret 17 that slides left and right is attached to the horizontal digit 16. A tool (not shown) is fixed to the tip of the ram 17A.

An inertial accelerometer 21 (hereinafter simply referred to as an accelerometer) for measuring the tangential acceleration of the workpiece 14 is attached to the measurement surface via a magnet or the like, in order to measure the diameter after cutting is completed. A protrusion 22, such as a dog or a magnet, for indexing one rotation is attached to the table 13, and an index detector such as a proximity switch or a magnetic sensor, which cooperates with the protrusion 22, is attached to the bed 11. 23 is fixed. The outputs of the accelerometer 21 and the index detector 23 are connected to an arithmetic display mechanism 24 attached to the horizontal digit 16 and the like.

Next, details of the above-mentioned arithmetic and display mechanism 24 will be explained with reference to FIG. 2, together with its operation. When the skating signal generator 31 is started with the table stopped, a reset signal from the generator 31 is sent to the velocity memory 33 of the integrator A 32 and the displacement memory 35 of the integrator B 34, resetting both memories 33 and 35. Next, the integration start signal from the start signal generator 31 activates the clock pulse generator 36, so that
Integrators A32 and B34 begin an integral operation.

Next, when the table 13 is started, the workpiece 14
The accelerometer 21 attached to the sensor sends out the tangential acceleration γθ at the center of sensitivity, and this signal is converted into a digital signal by the A/D converter 37 and input to the integrator A32. This digital signal is integrated moment by moment by an integrator A32, and the tangential velocity γθ is determined by the velocity memory 3.
3, and the output of the speed memory 33 is input to the integrator B.
34 receives and integrates the circumferential displacement γθ, and inputs the circumferential displacement γθ to the displacement memory 35. When the protrusion 22 attached to the table 13 faces the index detector 23 while the table 13 is rotating, the detection signal A of the index detector 23 resets the displacement memory 35 and the display section 40. As the rotation of the table 13 progresses and the protrusion 22 again faces the index detector 23, the detection signal B of the index detector 23 holds the displacement memory 35 and sends the held value to the 1/π unit 38.

The contents of the displacement memory 35 are the circumferential displacement during one rotation of the table, so the circumference length, that is, the diameter x π, is converted to a diameter by the 1/π unit 38, and then the accelerometer 21 with respect to the workpiece 14 The mounting surface of the accelerometer 21 and the sensitivity center position of the accelerometer 21 are corrected by the corrector 39 and then displayed on the table section 40. Display section 4
If the table 13 is stopped after confirming 0, the diameter measurement of the workpiece 14 is completed. Note that 1/π unit 38
is provided independently, but this is the A/D converter 3.
7 as a constant, or can be incorporated into the corrector 39.

As described above, the workpiece diameter measuring device for a large vertical lathe according to the present invention includes a table rotatably supported on the bed, and an acceleration sensor attached to the measurement surface of the workpiece placed on the table. an index detector that cooperates with a protrusion attached to the table and a protrusion fixed to the bed to index one rotation of the table; and an A/D that converts the analog signal of the accelerometer into a digital signal. A converter, two integrators connected in series to convert the accelerometer signal of the A/D converter into a circumferential displacement amount, and a circumferential length output from the rear integrator after one rotation. A 1/π device that makes the diameter after one rotation, a corrector that receives the output signal of the 1/π device to correct the sensitivity center position of the accelerometer with respect to the workpiece mounting surface of the inertial accelerometer, and It consists of a display section that displays the output.

Therefore, according to the measuring device of the present invention, there is no need to use a large and heavy micrometer or inside micrometer, and the workpiece can simply be rotated after attaching the accelerometer to the measurement surface of the workpiece. Therefore, the present invention has the effect of making it possible to perform highly accurate measurements because the operation is extremely easy and there is little room for error.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention, and FIG. 1 is a side view, and FIG. 2 is a mechanical diagram of the main part. 11... bed, 13... table, 14...
Workpiece, 21... Accelerometer, 22... Convexity, 2
3... Index detector, 31... A/D converter, 3
2, 35... Integrator, 37... 1/π unit, 38...
...corrector, 39...display section.

Claims (1)

[Claims] 1 a table rotatably supported on the bed;
An inertial accelerometer attached to the measurement surface of the workpiece placed on the table, a protrusion attached to the table for indexing one revolution of the table, and a protrusion fixed to the bed. a cooperating indexing detector; an A/D converter for converting the analog signal of the accelerometer into a digital signal;
Two integrators connected in series to convert the acceleration signal of the converter into circumferential displacement position, and a 1/π device that converts the circumference length output from the same integrator on the rear side after one rotation into the diameter. a corrector that receives the output signal of the 1/π converter for correcting the sensitivity center position of the inertial accelerometer with respect to the workpiece mounting surface; and a display unit that displays the output of the corrector. A workpiece diameter measuring device for large vertical lathes.