JPH04274708A - Automatic measuring apparatus - Google Patents

Abstract

PURPOSE:To measure by a touch measuring element by automatically evading a point which becomes an obstacle to the measurement, for example, a tap hole or the like of an object to be measured. CONSTITUTION:The presence or absence of a tap hole at the upper face of a motor 10 is detected by a tap hole detecting photosensor 62. if a tap hole is present, a motor 10 is rotated by a predetermined rotating angle corresponding to a driving current of one pulse generated from a driving circuit 30 in response to a driving start signal from a sequencer 76. If no tap hole comes to be detected because of the rotation, an electromagnetic valve 42 is activated on the basis of a signal from the sequencer 76, thus lowering a slider 40. As end parts of a first measuring probe 58 and a second measuring probe 60 are brought in touch with a predetermined position of the motor 10, the height between the end parts is measured.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention uses a contact probe to measure a portion where tap holes, etc., which are an obstacle to making measurements by contacting the contact probe, are present at a constant central angle. This invention relates to an automatic measuring device for

0002

[Prior Art and Problems to be Solved] For example, when a rotor hub in a spindle motor has an annular end face with a narrow radial width, and tap holes are provided at a certain central angle on the annular end face, contact measurement is required. If you try to measure the height etc. of the annular end surface by bringing the contact probe into contact with the annular end surface, you must avoid the tap hole and bring the contact probe into contact with the annular end surface, which is a problem in automating measurement. It became.

The present invention has been made in view of the above-mentioned problems existing in the prior art, and its purpose is to eliminate obstacles to measurement using a contact probe such as a tapped hole in an object to be measured. It is an object of the present invention to provide an automatic measuring device for automatically removing such troubled parts and measuring them with a contact measuring element.

0004

[Means for Solving the Problems] In order to achieve the above object, the automatic measuring device of the present invention is arranged so that the trouble points that become obstacles to contact measurement are fixed at regular angles around the rotational axis of the rotating part of the object to be measured. A measuring device that performs measurement by bringing a contact probe into contact with a part existing on the object, a detection means for detecting the presence or absence of a faulty part, a moving means for moving the contact probe to contact a predetermined position of an object to be measured, and a rotation means for rotating the object to be measured by approximately a predetermined rotation angle, and the angle between the position to be detected by the detection means and the contact probe centered around the rotational axis position of the object to be measured is The rotation means rotates the object to be measured when the detection means detects an obstacle, and when the detection means does not detect an obstacle, the moving means moves the contact probe. The measurement is performed by touching the object to be measured.

[0005]

[Operation] Since the angle between the position to be detected by the detection means and the contact probe when centered around the rotational axis position of the object to be measured is an integral multiple of the central angle between adjacent fault points,
When the detection means detects a faulty part, the position of the contact probe at that time corresponds to the faulty part, and if the detection means does not detect a faulty part, the position of the contact probe at that time does not correspond to the faulty part.

[0006] When the detecting means detects a faulty part, the rotating means rotates the object to be measured by approximately a predetermined rotation angle, and this rotation allows the contact probe to escape from the faulty part. If the detection means does not detect any faulty part, the moving means moves the contact probe to contact a predetermined position of the object to be measured, and performs measurement.

[0007]

[Embodiment] An embodiment of the present invention will be explained based on the drawings. The drawings are all about embodiments of the present invention, and FIG. 1 is a block diagram, FIGS. 2 and 3 are sectional views of main parts, and FIG.
5 is a bottom view of the cup member, FIGS. 5 and 6 are plan views of the motor, and FIG. 7 is a flowchart explaining the software.

10 is a brushless spindle motor for a hard disk drive (object to be measured); 12 is a motor 1;
0 is a fixed part, and 14 is a rotor hub. When the motor 10 is activated, the rotor hub 14 rotates relative to the fixed part 12. Reference numeral 16 indicates a collar-like portion of the fixing portion 12, and reference numeral 18 indicates a circular downward protrusion. At the bottom of the rotor hub 14 is an overhang 20.
As shown in FIGS. 5 and 6, six tapped holes 24 (failure points) are provided at every 60 degrees central angle on the upper surface of the rotor hub 14, that is, on the same circumference of the annular tapped surface 22. is provided. This tapped hole 24 is for attaching a clamp member for fixing the hard disk.

Reference numeral 26 denotes a workpiece support member having a circular recess 28 on its upper surface. In the motor 10, the lower protrusion 18 of the fixed part 12 is housed in the circular recess 28, and the lower surface of the peripheral edge of the brim part 16 is supported by the peripheral edge of the circular recess 28 on the upper surface of the workpiece support member 26. , a drive circuit 30 (rotating means) is connected to the motor 10. By inputting a drive start signal, this drive circuit 30
A drive current of one pulse with a pulse width that causes the motor 10 to rotate by approximately a predetermined rotation angle is generated.

Reference numeral 32 designates a support base, 34 a guide provided on the support base 32, and 36 a pneumatic cylinder (moving means) fixed to the support base 32. A slider 40 is fixed to the rod 38 of the pneumatic cylinder 36.
0 moves up and down along the guide 34 as the rod 38 expands and contracts. Further, the pneumatic cylinder 36 is controlled by a solenoid valve 42.

A horizontal support plate 44 is fixed to the guide 34, and a cup member 50 for fine angle adjustment is supported on the support plate 44 via a support bolt 46 and a compression spring 48. The center axis of the cup member 50 is the center axis of the workpiece support member 26, that is, the motor 10 supported thereon.
almost coincides with the axis of rotation. The lower end portions of the support bolts 46 provided at every central angle of 120 degrees are fixed to the cup member 50, and the upper shaft portions of the support bolts 46 are loosely fitted into through holes 52 provided in the support plate 44. Further, the compression spring 48 is fitted onto each support bolt 46 .

The cup member 50 has a total of three support legs 54 at each central angle of 120 degrees, and the lower end of each support leg 54 is formed into an abutment portion 56 with a cutout on the inner circumferential side. ing. When the support plate 44 is lowered by the pneumatic cylinder 36 and the lower surface of the contact portion of each support leg 54 is pressed against the upper surface of the workpiece support member 26, the cup is pressed against the support plate 44 while maintaining the pressure contact force by the compression spring 48. The member 50 is freely tilted, and the rotational axis of the motor 10 to be measured and the central axis of the cup member 50 are almost completely parallel.

58 is a first measurement probe, 60 is a second measurement probe, and 62 is a photosensor (detection means) for detecting tapped holes, all of which are fixed so that their axes are parallel to the central axis of the cup member 50. . Therefore, if the central axis of the cup member 50 is parallel to the rotational axis of the motor 10, these axes will also be parallel to the rotational axis of the motor 10. The first measuring probe 58 and the second measuring probe 60 are located on the same radial line, and their eccentric distance is
This corresponds to the eccentric distance between the tap surface 22 and the upper surface of the overhang portion 20 at 0. The central angle between the position of the first measurement probe 58 and the position of the tapped hole detection photosensor 62 is 1
It is 20 degrees. The detection target position of the tapped hole detection photosensor 62 is below in the axial direction in FIGS. 1 to 3. At the tips of the first measurement probe 58 and the second measurement probe 60, a first measurement probe 64 and a second measurement probe 66 are provided, respectively.
is provided. Also, the first measurement probe 58 and the second measurement probe 58
The measurement probe 60 is connected to a measuring device 68. Then, by bringing the first measuring element 64 and the second measuring element 66 into contact with the tap surface 22 of the motor 10 and the upper surface of the overhang section 20, respectively, the height of the tap surface 22 from the upper surface of the overhang section 20 is measured by the measuring device 68. Measure.

Reference numeral 70 denotes a photosensor for detecting the presence or absence of a motor for detecting whether or not the motor 10 is supported at a predetermined position on the workpiece support member 26. 72 is an AD converter. The measured value by the measuring device 68 is measured by this AD converter 72.
After being converted into a digital signal, it is input to the data processing device 74. Further, after the measurement is finished, a measurement completion signal is input from the AD converter 72 to the sequencer 76 (PC controller). The sequencer 76 also receives detection outputs from the tap hole detection photosensor 62 and the motor presence/absence detection photosensor 70, and outputs a drive start signal to the drive circuit 30 based on these input information.
It also outputs a control signal to the solenoid valve 42.

Next, the operation will be explained with reference to the flowchart shown in FIG. P1 to P12 in FIG. 7 indicate each step of the flowchart. Before starting, the slider 40 is in the upper position, and the support plate 44 and cup member 50 are spaced apart above the workpiece support member 26, as shown in FIG. In this state, the motor 10 is placed at a predetermined position so that its rotational axis coincides with the central axis of the workpiece support member 26, and the drive circuit 30 and the motor 10 are connected.

After the start, at P2, the photo sensor 70 for detecting the presence or absence of a motor detects whether or not the motor 10 is placed at a predetermined position on the workpiece support member 26. If the motor 10 is not detected, step P2 is repeated at a certain timing.

When the motor 10 is detected, the sequencer 76 instructs the solenoid valve 42 to lower the slider 40 and position the abutment portion 56 of the cup member 50 slightly above the workpiece support member 26 at P3. A signal for controlling the pressure cylinder 36 is output. This results in a state as shown in FIG. 1, and the tapped hole 24 can be detected by the tapped hole detection photosensor 62.

In this state, at P4, the presence or absence of the tapped hole 24 is detected by the tapped hole detection photosensor 62. As shown in FIG. 5, if there is a tapped hole 24 at the detection target position of the tapped hole detection photosensor 62, there is also a tapped hole 24 below the first measurement probe 58 in the axial direction, and in that state, the first measurement It is unsuitable for contact measurement using the child 64. In that case, a drive start signal is output from the sequencer 76 to the drive circuit 30 at P5, and the motor 10 rotates by approximately a predetermined rotation angle corresponding to one pulse of drive current generated by the drive circuit 30. This rotation angle is set so that the detection target position of the tapped hole detection photosensor 62 and the contact measurement target position by the first probe 64 can avoid the tapped hole 24 .

If the tap hole 24 is detected again by the tapped hole detection photosensor 62 at P6, a drive start signal is further outputted from the sequencer 76 to the drive circuit 30 at P7, and the motor 10 is rotated by approximately a predetermined rotation angle. P
If the tapped hole 24 is further detected at step 8, it is determined that the motor is malrotating, and the motor 10 is replaced.

If the tap hole 24 is not detected at P4, P6 or P8, for example as shown in FIG. A signal is output to control the pneumatic cylinder 36 so that the lower surface of the contact portion 56 of the support leg 54 is brought into pressure contact with the upper surface of the workpiece support member 26 . As a result, as shown in FIG. 3, the rotational axis of the motor 10 to be measured becomes almost completely parallel to the central axis of the cup member 50, and the first probe 64 and the second probe 66 are connected to the taps of the motor 10, respectively. It comes into contact with the surface 22 and the upper surface of the overhang 20, and becomes in a state where the height of the tap surface 22 from the upper surface of the overhang 20 can be accurately measured.

In this state, in P11, the height is measured by the measuring device 68, and after the measurement is completed, in P12, the slider 40 is raised from the sequencer 76 relative to the solenoid valve 42, and the cup member 50 is moved as shown in FIG. A signal is outputted to control the pneumatic cylinder 36 so as to separate it above the workpiece support member 26. This allows another motor 10
It is possible to exchange. The motor 10 can be replaced, for example, by replacing it with another workpiece support member 26 that supports another motor 10, or by replacing only the motor 10 using the same workpiece support member 26.

[0022] In the above embodiment, a completed motor is the object of measurement, but if, for example, only the rotor hub 14 as a component is to be measured, the rotor hub 14 is coaxially supported by a rotary support means such as a rotary table. The present invention can be carried out by rotating this rotation support means by a predetermined rotation angle using a stepping motor or the like to rotate the rotor hub 14 by the predetermined angle.

[0023]

Effects of the Invention In the automatic measuring device of the present invention, when the contact probe is located at a position corresponding to an obstacle, the detection means detects the obstacle, and the rotating means thereby drives the object to be measured to bring it into contact. Remove the probe from the faulty area. If the contact probe is not located at a position corresponding to the faulty location, the detection means does not detect the faulty location, and the moving device continues to bring the contact probe into contact with the object to perform measurement. Therefore, it is possible to automatically remove the contact probe from the troubled area and perform measurements appropriately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram.

FIG. 2 is a sectional view of main parts.

FIG. 3 is a sectional view of main parts.

FIG. 4 is a bottom view of the cup member.

FIG. 5 is a plan view of the motor.

FIG. 6 is a plan view of the motor.

FIG. 7 is a flowchart.

[Explanation of sign]

10 Motor 14 Rotor hub 24 Tapped hole 30 Drive circuit 36 Pneumatic cylinder 40 Slider 44 Support plate 50 Cup member 62 Photo sensor for tap hole detection 64 1st probe 66 Second probe

Claims (1)

[Claims] [Claim 1] A measuring device that performs measurement by bringing a contact probe into contact with a part of the object to be measured in which there are faulty points that impede contact measurement at certain angles around the rotational axis of the object, the presence or absence of a faulty point. , a moving means for moving a contact probe to contact a predetermined position of an object to be measured, and a rotating means for rotating the object to be measured by approximately a predetermined rotation angle, The angle between the position to be detected by the detection means and the contact measuring element centered around the rotational axis position is an integral multiple of the fixed angle, and when the detection means detects a faulty part, the rotation means An automatic measuring device characterized in that when an object to be measured is rotated and the detection means does not detect an obstacle, the moving means moves a contact probe to contact the object to be measured and performs measurement.