JPH0314582B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and device for measuring the feed accuracy of a machine tool, and more specifically to a gauge bar fixed at predetermined angles on the table of a machine tool. By relatively moving the detector of an electric micrometer or air micrometer attached to the main shaft of the machine tool in sliding contact along the reference plane of It is proposed to measure the feed accuracy of the machine.

[Conventional technology]

Until now, when measuring the linear feed accuracy of machine tools, especially numerically controlled machine tools such as machining centers, the workpiece fixed on the table was actually cut using linear motion, and the cut surface of the machine tool was measured. This was done using a secondary method of visually observing and measuring with a surface roughness measuring device or shape accuracy measuring device.

[Problem to be solved by the invention]

In the conventional method for measuring linear feed accuracy described above, the measurement data is only qualitatively analyzed after the workpiece has been processed, and it is not easy to obtain measurement accuracy that is practically satisfactory. Furthermore, since there is no means for recording measurement data, it has been completely impossible to quantitatively and systematically analyze the linear feed accuracy prior to machining the workpiece. For this reason, when attempting to completely understand the operating characteristics of a feed system, it takes a long time to analyze the data, leading to problems such as having to stop the numerically controlled machine tool that is the subject of analysis for a long time. Ta.

The main object of the present invention is to provide a linear feed system for numerically controlled machine tools that improves the recording performance and quantitative analysis function of measurement data, which can solve the above-mentioned problems found in conventional linear feed accuracy measuring means. An object of the present invention is to provide a method and device for measuring accuracy.

[Means to solve the problem]

In view of these objectives, the present invention (1) moves the feed axis of a machine tool linearly at predetermined angle intervals, and uses an electric micrometer or an electric micrometer whose main axis is pressed against the reference surface of a gauge bar attached so as to be parallel to the feed axis of the machine tool. A method for measuring the linear feed accuracy of a machine tool, which is characterized by reading the geometric error of behavior appearing in a direction perpendicular to the direction of linear movement while the detector of an air micrometer is in contact with the sensor; A gauge bar that is given an index position on a table at each predetermined rotation angle, an electric micrometer or an air micrometer that is fixed to the main shaft of a machine tool and whose detector measures the reference surface of the gauge bar while making contact with the reference surface of the gauge bar. A machine tool consisting of an analog/digital converter for electrical signals sent from the detector of an electric micrometer or air micrometer, a microcomputer connected to the analog/digital converter, and a recorder for measured values. The gist of this paper is a measuring device for linear feed accuracy.

〔Example〕

FIG. 1 is a perspective view of the device of the present invention used for measuring feed accuracy during linear feed. Also, Figure 2A
to F are graphs recording measured values during linear feeding.

As shown in FIG. 1, the device _M1 for measuring the feed accuracy when a table moves linearly by simultaneous control of two axes, the X-axis direction feed axis and the Y-axis direction feed axis, according to the present invention, For example, a pedestal 2 fixed on a table 1 of a machining center, a pivot 3 fixed to the top surface of the pedestal, a gauge bar 4 fitted and supported so as to be horizontally rotatable with respect to the pivot, and a gauge bar 4 fixed at a fixed position. The reference surface 4a of the gauge bar 4 is fixed to the main shaft 5 of a stationary machine tool.
It is composed of an electric micrometer 6 or an air micrometer equipped with a detector 6a that measures the temperature while making contact with it. The gauge bar 4 is attached and detached through the gauge bar 4 and the pedestal 2 so that the gauge bar 4 is locked at an indexed position at a predetermined rotation angle through engagement with a pivot 3 fixed to the center of the upper surface of the pedestal 2. It is equipped with a flexible pin (not shown). The measuring device _M1 includes an amplifier 7 for the electrical signal sent from the electric micrometer 6, an analog signal to digital signal converter 8 sequentially connected to the amplifier, and a RAM as a means for recording measured values. Or a microcomputer 9 connected to ROM and CPU and a measured value recorder 10
are installed in succession.

When measuring the feed accuracy, the table 1 is moved linearly along the reference surface with the detector 6a of the electric micrometer 6 in contact with the reference surface 4a of the gauge bar 4 fixed at a plurality of index positions. The measured values are continuously read when the detector 6a moves forward and backward. As a result, Figure 2A
As illustrated in F to F, the error in the movement amount of the feed system along the direction orthogonal to the linear movement direction of the table 1 is recorded as a series of curved waveforms on the recording paper for each indexing angle θ of the gauge bar 4.

The linear feed error at each indexing position can be read from the height of this waveform, and the height of the waveform measured at each predetermined angle, as well as its period and directionality, as well as the behavior when the direction is reversed, can be used to determine the feed axis. Movements caused by each element that makes up the movement, such as uneven feed (drunk walking movement), rattling (backlash), and static motion, can also be detected from a series of curved minute waveforms. Microscopic movements that cannot be read from measured data can be quantitatively analyzed.

〔Effect of the invention〕

As can be understood from the above explanation, by employing the method of the present invention, it is possible to quantitatively measure, record, and analyze the feed accuracy of the feed system of a numerically controlled machine tool. In addition, because the measurement is performed directly on the machine, there is no need to actually process and measure the workpiece as in the past. Since there are no measurement error factors, only the error factors in the feeding system can be accurately determined, improving the reliability of measurement data.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the device of the present invention used for measuring feed accuracy during linear feed, and Figures 2A to F
is a graph recording measured values during linear feed. 1...Table, 2...Pedestal, 3...Pivot, 4...Gauge bar, 5...Spindle, 6...Micrometer, 7...Amplifier, 8...Analog/digital converter, 9...Microcomputer ,
10...Recorder.

Claims (1)

[Claims] 1. The feed axis of a machine tool is linearly moved at predetermined angles, and the reference plane of a gauge bar attached to the machine tool is moved parallel to the feed axis of an electric micrometer or an air micrometer attached to the main axis. A method for measuring the linear feed accuracy of a machine tool, which is characterized by reading a geometric error in behavior that appears in a direction perpendicular to the direction of linear movement while a detector is in contact with it. 2. A gauge bar that is given an index position at every predetermined rotation angle on the table of the machine tool, and an electric micrometer or air micrometer that is fixed to the main shaft of the machine tool and that measures while the detector touches the reference surface of the gauge bar. A meter, an analog/digital converter for the electrical signal sent from the detector of the electric micrometer or air micrometer, a microcomputer connected to the analog/digital converter, and a recorder for the measured values. A device for measuring linear feed accuracy of machine tools.