JP2004108787A - Roundness measurement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roundness measurement device, which can carry out the measurement, even when the angle of a contact probe when a measurement program is prepared is different from that when the automatic measurement is carried out, by properly instructing the correction of the angle of the contact probe, and which does not damage a detector due to contact of the contact probe with the object to be measured, when the detector is moved. <P>SOLUTION: The detector 50 is moved to the position adjacent to the object W to be measured in front of the measurement position, where it is confirmed that the contact probe 51 is not brought into contact with the object W. A control part 60 for confirming the contact state of the contact probe 51 at the measurement position is provided. A display means 70 for instructing the correction of the angle of the contact probe at each position, if necessary, is provided so that the angle of the contact probe can be easily corrected according to the instruction. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a roundness measuring machine, and more particularly to a roundness measuring machine capable of performing automatic measurement according to a predetermined measurement program.
[0002]
[Prior art]
2. Description of the Related Art As a device for measuring the roundness or cylindricity of an object to be measured having a cylindrical shape, a roundness measuring device is conventionally known (for example, see Patent Document 1).
[0003]
When the roundness of a device under test is automatically measured by the roundness measuring machine, a measurement program for automatic measurement is created in advance by a manual operation of an operator. For example, when measuring the roundness of an object to be measured, a measurement position in the Z direction, which is the center line direction of the object to be measured, is set, the detector is moved in the Z direction, and the position coordinates in the Z direction at that time are used as data. In. Next, the detector is moved in the X direction which is the radial direction of the object to be measured, and the stylus of the detector is brought into contact with the side surface of the object to be measured, and the position coordinates in the X direction at this time are data-in.
[0004]
Here, the object to be measured or the detector is rotated once, and a detection signal from the detector is collected. When data for one rotation is collected, the detector is retracted in the X direction, and the coordinates of the retracted position are entered.
[0005]
In this manner, the data of the moving direction and the moving point of the stylus of the detector, the moving speed, and the like are sequentially input along the measurement path, and a series of automatic measurement programs are created. As a roundness measuring device that performs automatic measurement along this pre-programmed path, a roundness that continuously and automatically measures the outside and inside of a cylindrical object to be measured without switching the detection direction of a detector. A degree measuring device has been proposed (for example, see Patent Document 2).
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 62-276405
[Patent Document 2]
JP-A-8-313247
[Problems to be solved by the invention]
As a detector used in such a roundness measuring machine, a detector of an electric micrometer using a differential transformer is generally used. In order to increase the versatility of measurement, the electric micrometer detector can freely change the mounting angle of the stylus with respect to the detector body so that measurement can be performed even in various postures of the detector. I have.
[0009]
Therefore, in most cases, the stylus angle with respect to the detector body when the measurement program for automatic measurement is created is different from the stylus angle when the automatic measurement is actually executed. Also, with such a detector in which the stylus angle can be freely changed, it is difficult to reproduce the stylus angle at the time of creating the measurement program at the time of automatic measurement.
[0010]
For this reason, when trying to perform automatic measurement based on this measurement program for automatic measurement, the stylus may interfere with the object to be measured, or the stylus may not contact the object at the measurement point. However, there is a problem that the measurement cannot be performed.
[0011]
In other words, it is not possible to perform measurement because the stylus contacts the object before the detector reaches the measurement position, or the stylus does not contact the object after reaching the measurement position. It is a problem.
[0012]
In addition, when the stylus comes into contact with the object to be measured while the detector is moving, if the moving speed is high, the detector cannot be stopped suddenly, so that the detector may be damaged.
[0013]
The present invention has been made in view of such circumstances, and even if the stylus angle with respect to the detector body is different between when a measurement program for automatic measurement is created and when automatic measurement is performed, automatic Before the measurement or during the automatic measurement, the measurement can be performed by appropriately instructing the correction of the stylus angle, and when the stylus comes into contact with the workpiece while the detector is moving. An object of the present invention is to provide a roundness measuring device that does not damage a detector.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a roundness measuring machine that rotates an object to be measured relative to a detector and measures the roundness of the object to be measured. An X-direction driving means for moving the detector in the radial direction of the object to be measured, and moving the detector in the direction of the center line of the object to be measured. A true circle having Z-direction driving means and a table for mounting the object to be measured and rotating the object to be measured relative to the detector, and capable of automatic measurement according to a predetermined measurement program The degree measuring machine has a control unit that determines whether the angle of the stylus needs to be corrected before or during automatic measurement, and display means for instructing the angle correction. It is characterized by.
[0015]
According to the first aspect of the present invention, it is determined whether or not the stylus angle needs to be corrected before or during the automatic measurement, and if necessary, the angle correction is instructed. Even if the stylus angle with respect to is different between when a measurement program for automatic measurement is created and when automatic measurement is executed, automatic measurement can be executed by correcting according to the instruction.
[0016]
Further, in the roundness measuring device according to claim 2, the control unit moves the detector to a close position toward the measured object, and determines whether the stylus is in contact with the measured object. It is determined whether or not the angle of the stylus needs to be corrected, and the detector is further moved to a measurement position toward the object to be measured, and whether or not the stylus has contacted the object to be measured before reaching the measurement position. Alternatively, it is determined whether or not the angle of the stylus needs to be corrected based on whether or not the stylus is in contact with the object to be measured even when the stylus reaches the measurement position.
[0017]
According to the invention of claim 2, the detector is moved to a position close to the measured object before the measuring position, and it is checked whether the stylus is in contact with the measured object. The contact state of the stylus is checked at the position, and the correction of the stylus angle is instructed at each position as necessary. The angle of the stylus can be corrected appropriately without damaging the detector, even if it differs from the time of execution.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a roundness measuring machine according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same members are given the same numbers or reference numerals.
[0019]
FIG. 1 is a perspective view showing the appearance of a roundness measuring instrument according to the present invention. FIG. 2 is a block diagram showing the configuration. As shown in FIGS. 1 and 2, the roundness measuring device 10 has a table 40 and a column 12 on which a workpiece W is placed and rotated, and is provided on a main body base 11.
[0020]
The column 12 incorporates a Z-direction driving unit 30 for moving the Z-table 31 in the Z-direction shown in FIG. The Z table 31 incorporates X direction driving means 20 for driving the X table 21 in the X direction of FIG.
[0021]
An arm 25 is attached to the X table 21, and a detector 50 having a stylus 51 is attached to a tip of the arm 25. The mounting angle of the stylus 51 can be freely changed by applying an external force to the main body of the detector 50. (Hereafter, the mounting angle of the stylus 51 with respect to the main body of the detector 50 is referred to as a stylus angle.)
A differential transformer is incorporated in the detector 50, and converts the movement of the ball at the tip of the stylus 51 into an electric signal.
[0022]
The detector 50 is automatically moved by the X-direction driving means 20 and the Z-direction driving means 30 to arbitrary positions in the X direction, which is the radial direction of the object W, and the Z direction, which is the center line direction of the object W. Is sent and positioned.
[0023]
The roundness measuring device 10 further includes a control unit 60 stored inside the main body, a display means 70 for displaying various programs such as a measurement program and a measurement result, a keyboard 66 for inputting various data, and a printer 75 for printing the measurement results and the like. Etc.
[0024]
As shown in FIG. 2, a table 40 on which the object W is mounted and which rotates the object W is a rotary table 41 supported by bearings 42 and rotated by a motor 43, and an encoder for accurately detecting a rotation angle. It consists of 44 mag. A static pressure air bearing is used for the bearing 42, which supports the rotary table 41 with a high rotational accuracy of 0.05 μm.
[0025]
The X-direction driving means 20 includes an R-axis direction feeding device 22, a motor 23, an encoder 24, and the like, and sends the X table 21 in the radial direction of the workpiece W. The R-axis direction feeding device 22 includes a linear air guide and a ball screw, and the motor 23 rotates the ball screw. The number of rotations of the motor 23 is counted by the encoder 24 attached to the motor 23, and the movement of the X table 21 is controlled.
[0026]
The Z-direction driving means 30 includes a Z-axis direction feeding device 32, a motor 33, an encoder 34, and the like, and feeds the Z table 31 in the axial direction of the workpiece W. Similarly to the R-axis direction feeder 22, the Z-axis direction feeder 32 includes a linear air guide and a ball screw, and the motor 33 rotates the ball screw. The number of rotations of the motor 33 is counted by the encoder 34 attached to the motor 33, and the movement of the Z table 31 is controlled.
[0027]
The control unit 60 includes an arithmetic unit 64 composed of a computer, a servo control board 61, a program storage unit 65, an amplifier 62, and an A / D converter 63. The measurement program stored in the program storage unit 65 is used by the arithmetic unit. Called at 64.
[0028]
The servo control board 61 receives the rotation table signal from the encoder 44 of the table 40, the R-axis signal from the encoder 24 of the X-direction drive unit 20, and the Z-axis signal from the encoder 34 of the Z-direction drive unit 30, and calculates Then, the motor 43 of the table 40, the motor 23 of the X-direction drive unit 20, and the motor 33 of the Z-direction drive unit 30 are drive-controlled based on a command from the calculation unit 64.
[0029]
The detector signal from the detector 50 is amplified by the amplifier 62, converted from an analog signal to a digital signal by the A / D converter 63, and the measurement result is calculated by the calculation unit 64. The calculation result is displayed on the display means 70 and printed by the printer 75.
[0030]
FIG. 3 shows the positional relationship of the detector 50 with respect to the measured object W and various stylus angles of the stylus 51. FIG. 3A shows a state in which the detector 50 is positioned at the measurement position and the stylus 51 is in contact with the side surface of the workpiece W when the operator creates a measurement program for automatic measurement. . Therefore, the measurement program created at this time is created based on the stylus angle shown in FIG.
[0031]
However, since the stylus angle can be freely changed so as to be compatible with various measurements, the stylus angle shown in FIG. 3A is not always maintained. For this reason, the stylus angle must be appropriately corrected before or during the automatic measurement.
[0032]
Next, a procedure for correcting the stylus angle in the roundness measuring device 10 of the present invention will be described. FIG. 4 is a flowchart showing a procedure for correcting the stylus angle. In this correction procedure, first, the detector 50 is moved by the X-direction driving means 20 to a position close to the measurement position (step S1).
[0033]
If the detector angle is the same angle as when the measurement program was created, the stylus 51 will not come into contact with the object W at this close position, but the detector angle may have been changed. The control unit 60 checks whether or not the stylus 51 is in contact with the workpiece W at the close position (step S2).
[0034]
When the stylus 51 is in contact with the object to be measured W (the state shown in FIG. 3B), the display means 70 shows a diagram indicating this state and an instruction of "Please roughly adjust the stylus angle." The displayed stylus angle is roughly adjusted by the operator to the state shown by the dotted line in FIG. 3B (step S3). When step S3 is performed, the process returns to step S1.
[0035]
On the other hand, when the stylus 51 is not in contact with the workpiece W in step S2, the detector 50 is moved from this close position to the measurement position at a sufficiently low speed (step S4). During this movement, it is monitored whether or not the stylus 51 contacts the object W (step S5). If the stylus 51 contacts the object W before the detector 50 reaches the measurement position (FIG. 3). (State (c)), the movement of the detector 50 is immediately stopped to prevent damage to the detector 50 (step S6).
[0036]
Here, a diagram showing this state and an instruction of "Please roughly adjust the stylus angle" are displayed on the display means 70, and the stylus angle is roughly adjusted by the operator to the state shown by the dotted line in FIG. Is performed (step S7). When step S7 is executed, the process returns to step S4.
[0037]
If the stylus 51 does not contact the object W before the detector 50 reaches the measurement position, it is checked whether the stylus 51 does not contact the object W at the measurement position. (Step S8).
[0038]
When the stylus 51 is not in contact with the workpiece W when the detector 50 is positioned at the measurement position (the state shown in FIG. 3D), the display means 70 shows this state, "Adjust the angle." Is displayed, and the stylus angle is adjusted by the operator to the state shown by the dotted line in FIG. 3D (step S9). When step S9 is executed, the process returns to step S4.
[0039]
When it is confirmed in step 8 that the stylus 51 is in contact with the workpiece W, it is determined that the stylus angle is close to the angle when the measurement program was created, and the automatic measurement program is executed. (Step S10).
[0040]
In step S3, the procedure of steps 5, 6, and 7 can be omitted by coarsely adjusting the stylus angle so as to obtain the state shown in FIG. Can be shortened.
[0041]
The above-described stylus angle correction procedure is appropriately executed before the automatic measurement or during the automatic measurement, so that the stylus 51 comes into contact with the object W to be measured and Damage is prevented, and the problem that the stylus 51 does not come into contact with the object W at the measurement point and the measurement cannot be executed is also solved.
[0042]
【The invention's effect】
As described above, according to the roundness measuring apparatus of the present invention, it is determined whether or not the stylus angle correction is necessary before or during the automatic measurement, and if necessary, the angle correction is performed. Therefore, even if the stylus angle with respect to the detector body differs between when the automatic measurement measurement program is created and when the automatic measurement is executed, the automatic measurement is executed by correcting according to the instruction. be able to.
[0043]
In addition, move the detector to a position close to the DUT before the measurement position, check whether the stylus is in contact with the DUT, and then contact the stylus at the measurement position. Is checked, and correction of the stylus angle is instructed at each position as necessary, so that the stylus angle can be easily and appropriately corrected without damaging the detector. Automatic measurements can be performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an appearance of a roundness measuring machine according to an embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a roundness measuring machine according to an embodiment of the present invention. FIG. 4 is a front view showing a contact state between a stylus and a device under test caused by a stylus angle. FIG. 4 is a flowchart showing a procedure for correcting a stylus angle.
DESCRIPTION OF SYMBOLS 10 ... Roundness measuring device, 20 ... X direction drive means, 25 ... Arm, 30 ... Z direction drive means, 40 ... Table, 50 ... Detector, 51 ... Stylus, 60 ... Control part, 70 ... Display means, W: DUT

Claims (2)

A circularity measuring machine that rotates the device under test relative to the detector and measures the roundness of the device under test,
The angle of the stylus of the detector can be freely changed,
X-direction driving means for moving the detector in the radial direction of the object to be measured, Z-direction driving means for moving the detector in the direction of the center line of the object to be measured, and And a table for rotating the detector relative to the detector,
In a roundness measuring machine capable of automatic measurement according to a predetermined measurement program,
Before the automatic measurement, or in the middle of the automatic measurement, a controller to determine whether the stylus angle correction is necessary,
Display means for instructing the angle correction. The control unit,
Move the detector to the proximity position toward the object to be measured, determine whether the angle correction of the stylus is necessary by whether the stylus is in contact with the object to be measured,
Further, the detector is moved to the measurement position toward the object to be measured, and whether or not the stylus has contacted the object to be measured before the measurement position is reached, or the stylus is measured even if the measurement position is reached. The roundness measuring device according to claim 1, wherein it is determined whether or not the angle of the stylus needs to be corrected depending on whether or not the object is in contact with an object.

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