JP4452828B2 - Acceleration tube disk outer diameter measuring method and acceleration tube disk outer diameter measuring device - Google Patents

Description

  The present invention relates to a disk outer diameter measuring method and a disk outer diameter measuring apparatus.

  Currently, an electron / positron linear collider (LC) is being developed for high-energy electron-positron collision experiments. For the electron / positron linear collider, an so-called X-band accelerator tube is used. For this acceleration tube, an acceleration tube disk called HDDS (High Phase Advance Damped Detuned Structure) disk is used, and this acceleration tube disk is required to have a processing accuracy on the order of submicrometers. Therefore, for the inspection, it is necessary to measure the outer diameter of a disc of about 60 mm processed with a precision lathe on the order of submicrometers.

  However, at present, a method and apparatus for measuring the outer diameter of the disk with high accuracy on the order of submicrons have not yet been established.

  An object of the present invention is to provide a novel method and apparatus capable of measuring the outer diameter of a disk with high accuracy and at low cost.

In order to achieve the above object, the present invention arranges a reference disk with a known outer diameter and a measuring disk with an unknown outer diameter along a predetermined direction with their axes parallel to each other, and these disks are fixed to the stage. And a positional relationship that linearly divides the reference disk and the measuring disk in a plane between a pair of non-contact distance measuring sensors that are fixed to each other and arranged to face each other with the disks interposed therebetween. While maintaining , both the outer peripheral surfaces of the both disks are relatively displaced in the predetermined direction with respect to the stage so as to continuously and integrally scan , and each of the virtual lines on the virtual lines that divide the surface linearly . A step of continuously measuring the distance from the distance measuring sensor to the outer peripheral surfaces of both disks, and the reference disk from each pair of distance measuring sensors; Based on the sum of the measurement distances to the outer peripheral surface, the sum of the measurement distances from each pair of distance measurement sensors to the outer peripheral surface of the measurement disk, and the known outer diameter of the reference disk, the outer diameter of the measurement disk A method for measuring the outer diameter of the accelerating tube disk.

The present invention also provides a stage for fixing a reference disk having a known outer diameter and a measuring disk having an unknown outer diameter, arranged in a predetermined direction so that their axes are parallel to each other, and both of the fixed disks. It is arranged so as to be opposed to each other with a gap therebetween, and continuously scans the outer peripheral surfaces of both disks continuously and integrally while maintaining the positional relationship of linearly dividing the surfaces of both disks. the are relatively displaced in the predetermined direction with respect to the stage, a pair of distance measuring sensors of the non-contact type for measuring the distance to the outer peripheral surface of said both disks respectively on a virtual line that divides the inside of the plane in a straight line, an outer diameter measuring apparatus of the accelerating tube disc, characterized in that it comprises a driving means for displacing along the distance measuring sensor in the predetermined direction.

  The inventors of the present invention have intensively studied to achieve the above object. As a result, particularly when a capacitance sensor is arranged on the outer periphery of the disk, the capacitance of the space formed by the outer periphery of the disk and the capacitance sensor is different from that of the outer periphery and the static in the space. We found that it depends on the distance to the capacitance sensor.

For example, the capacitance of the reference space formed by the outer periphery of the reference disk and the capacitance sensor is Cr, the distance between the disk outer periphery and the capacitance sensor in the reference space is dr, and the measurement disk The capacitance of the measurement space formed by the outer periphery of the disk and the capacitance sensor is Cm, and the distance between the disk outer periphery and the capacitance sensor in the measurement space is dm.
dr = P / Cr (1)
dm = P / Cm (2)
The following relational expression holds.

Here, the P, the area of the electrostatic capacitance sensor S, the dielectric constant εr of the insulator (air in this apparatus), the dielectric constant epsilon ₀ of a vacuum,
P = εrε ₀ S (3)
It can be regarded as a constant value regardless of the material to be measured. The P can be known from actual measurement. Thus, the capacitance can be uniquely converted into the distance from the above-described relational expression. Hereinafter, the “sensor output value” indicates dm and dr obtained by converting the capacitance into a distance.

Now, for example, when the distance L between the center of each disk and the capacitance sensor is constant, the outer diameter of the reference disk is Dr, and the outer diameter of the measurement disk is Dm.
L = Dr / 2 + dr (4)
L = Dm / 2 + dm (5)
Therefore, the outer diameter Dm of the target measurement disk is
Dm = Dr + 2 (dr−dm) = Dr + 2P (1 / Cr− / Cm) (6)
Can be obtained as

  In the equation (6), Cr and Cm are known through the above-described measurement, and further, P and Dr are also known. Therefore, the outer diameter Dm of the target measurement disk can be derived by using these values. . In the expressions (4) and (5), L is canceled and may be unknown.

  In the measurement described above, it is necessary to keep the distance between the reference disk center and the capacitance sensor and the distance between the measurement disk center and the capacitance sensor the same. Further, the reference disk and the measurement disk are arranged in the measurement direction of the capacitance sensor.

  In the above apparatus, it is sufficient to prepare at least a reference disk for the measurement disk and a capacitance sensor for measuring the capacitance of these disks, so that the apparatus configuration can be simplified, Cost can be reduced.

  The capacitance of the reference disk with respect to the reference space and the capacitance of the measurement disk with respect to the measurement space are determined by driving means such that a capacitance sensor is placed on the side surface of the reference disk and the measurement disk. Can be obtained by relatively scanning along. In this case, the capacitance can be measured over the entire reference space and the measurement space without depending on the size of the reference disk and the measurement disk, the measurement range of the capacitance sensor, and the like. These capacitances can be measured accurately.

  Further, it is preferable to prepare at least two capacitance sensors, dispose these capacitance sensors on both sides of the reference disk and the measurement disk, and scan relative to the reference disk and the measurement disk. . In this case, the capacitance of the reference space and the measurement space can be measured using a plurality of sensors, so that the measurement accuracy of the capacitance, that is, the outer diameter of the measurement disk can be improved.

  When using at least two capacitance sensors, the at least two capacitance sensors have a central axis of the at least two capacitance sensors of 0.05 rad or less on both sides of the reference disk and the measurement disk. It is preferable to arrange them at an angle.

  Accordingly, the reference disk and the measurement disk can be scanned by the at least two capacitance sensors so as to divide the reference disk and the measurement disk substantially linearly. Can be scanned almost uniformly, and the capacitance over the entire reference space and measurement space can be measured more accurately. As a result, the capacitances of the reference space and the measurement space can be measured more accurately, and the outer diameter measurement accuracy of the measurement disk can be further improved.

Further, it is preferable to use the peak value of the sum of each of the at least two capacitance sensors as the capacitance in the reference space of the reference disk and the capacitance in the measurement space of the measurement disk.

When the peak value of each capacitance sensor is used, this peak value may mean that the scan meanders or fluctuates up and down during the relative scan of the disk and the capacitance sensor as described above. It will fluctuate by being done. As a result, the capacitance of the reference space or the like cannot be accurately measured, and the outer diameter of the measurement disk cannot be accurately measured. On the other hand, the peak value of the sum of the capacitance sensors does not change even when meandering or up and down in the scan. Therefore, the outer diameter of the measurement disk can be accurately measured.

  Further, it is preferable that the temperature of the reference disk and the temperature of the measurement disk are set within a predetermined temperature range, specifically within ± 0.2 ° C. The outer diameters of the reference disk and the measurement disk may have a relatively large temperature dependency depending on the material components. Therefore, when the capacitances of the reference space and the measurement space for both disks are measured at different temperatures, the value of the capacitance includes an error caused by a temperature difference, and as a result, the measurement disk The outer diameter also includes an error due to the temperature difference. As a result, it may be impossible to accurately measure the outer diameter of the measurement disk based on the method and apparatus of the present invention.

  In such a case, by setting the temperature of the reference disk and the temperature of the measurement disk within a predetermined temperature range, specifically, within ± 0.2 ° C., the temperature dependency of both the disks described above. Etc. can be almost ignored, and the above-mentioned problems do not occur.

  As described above, according to the present invention, it is possible to provide a novel method and apparatus capable of measuring the outer diameter of a disk with high accuracy and low cost.

  Details of the present invention and other features and advantages will be described below based on the best mode.

  FIG. 1 is a schematic configuration diagram showing an example of a disk outer diameter measuring apparatus according to the present invention. The outer diameter measuring apparatus 10 shown in FIG. 1 has a reference disk 11 and a measurement disk 12 arranged at a predetermined distance on a predetermined stage 21, a fixing jig 15 and 16, a temperature sensor 17 and 18 is fixed on the stage 21. The stage 21 is fixed to the upper side 22 of a pair of fixing plates 22 and 23 that are opposed to each other and spaced apart from each other.

  Capacitance sensors 13 and 14 are fixed to the lower fixing plate 23 while maintaining a distance L, and the sensor portions 13A and 14A of these sensors are located above the opening 22A provided on the upper fixing plate 22. Are opposed to each other via the reference disk 11 and the measurement disk 12, and are positioned so that the measurement axes coincide with each other. An actuator 24 is provided between the fixed plates 22 and 23 and is configured to drive the upper fixed plate 22 relative to the lower fixed plate 23.

  In this case, the capacitance sensors 13 and 14 are fixed to the lower fixed plate 23, and the reference disk 11 and the measurement disk 12 are fixed to the upper fixed plate 22 via the stage 21, so that the actuator 24 By the above driving, the capacitance sensors 13 and 14 scan along the side surfaces of the reference disk 11 and the measurement disk 12.

  Note that the outer diameter of the reference disk 11 is known, and the outer diameter of the measurement disk 12 is measured based on this apparatus and the method described below.

  Next, a preferred outer diameter measuring method using the apparatus shown in FIG. 1 will be described. FIG. 2 is a diagram for explaining an outer diameter measuring method using the apparatus shown in FIG. 1, and FIGS. 3 and 4 are diagrams conceptually showing output values of the capacitance sensor obtained by the measurement. It is.

  First, as shown in FIG. 1, after the reference disk 11 and the measurement disk 12 are arranged on the stage 21, the temperatures of the reference disk 11 and the measurement disk 12 are monitored by the temperature sensors 17 and 18, and preferably the reference disk. 11 and the measurement disk 12 wait until the temperature difference is within a predetermined range, preferably within ± 0.2 ° C. In this case, the outer diameter measurement error of the measurement disk 12 due to the temperature dependence of both disks can be almost ignored.

  In order to achieve such a temperature difference at an early stage, it is preferable to place the apparatus shown in FIG. 1 in a temperature-controlled room, for example, and perform measurement in such a room. Further, it is preferable that the reference disk 11 and the measurement disk 12 are also stored in a predetermined temperature-controlled room before being mounted on the apparatus shown in FIG.

Next, the actuator 24 is driven to move the upper fixing plate 22 relative to the lower fixing plate 23. At this time, as described above, the capacitance sensors 13 and 14 scan along the side surfaces of the reference disk 11 and the measurement disk 12 (see FIG. 2). At this time, the capacitance Cr in the reference space S1 formed by the outer periphery of the reference disk 11 and the capacitance sensors 13 and 14 and the outer periphery of the measurement disk 12 and the capacitance sensors 13 and 14 are formed. The capacitance Cm of the measurement space S2 is obtained as a peak value of the sum of the outputs of the capacitance sensors 13 and 14 by a measuring means (not shown) or the like.

  Therefore, if the distance between the outer periphery of the disk 11 and the capacitance sensors 13 and 14 in the reference space S1 is dr, and the distance between the outer periphery of the disk 12 and the capacitance sensors 13 and 14 in the measurement space S2 is dm. The relationship between the above-described equations (1) and (2) can be obtained.

On the other hand, in this example, since the distance between the capacitance sensors 13 and 14 is L, in this case, instead of the above-described equations (4) and (5),
L = Dr + 2dr (7)
L = Dm + 2dm (8)
This relationship is established. Therefore, the outer diameter Dm of the target measurement disk is the same as the above equation (6).
Dm = Dr + 2 (dr−dm) = Dr + 2P (1 / Cr− / Cm) (9)
Can be obtained as

  In the equation (9), Cr and Cm are known through the above-described measurement, and P and Dr are also known. Therefore, the outer diameter Dm of the target measurement disk can be derived by using these values. . In the expressions (7) and (8), L is canceled and may be unknown.

  In the above-described measurement, since the distance between the opposing capacitance sensors 13 and 14 is L, the distance between the reference disk center and the capacitance sensor and the measurement disk center as described above are used. -It is not necessary to keep the distance between the capacitive sensors the same. Therefore, the measurement operation can be simplified.

In this example, as described above, the capacitances Cr and Cm of the reference space S1 and the measurement space S2 are set to the peak value of the sum of the outputs from the capacitance sensors 13 and 14. Therefore, for example, as shown in FIG. 3, even when the stage 21 rolls and the scanning of the capacitance sensors 13 and 14 meanders, the outputs of the capacitance sensors 13 and 14 respectively. Although the values are different, their sum is the same as when the scan was performed linearly.

Further, as shown in FIG. 4, even when scanning is performed with the stage 21 tilted, the output values of the capacitance sensors 13 and 14 are different, but the sum of them is the state where the stage 21 is parallel. This is the same as when a scan is performed at. Therefore, the measurement accuracy of the capacitance of the reference disk 11 and the measurement disk 12 is improved, and the measurement accuracy of the outer diameter of the measurement disk 12 based on the above-described derivation method is improved.

  However, as shown in the upper side of FIGS. 3 and 4, when the stage 21 is parallel and the scan is performed linearly, the peak output values of the capacitance sensors 13 and 14 are equal to each other. By averaging these values and using them, the capacitances of the reference space S1 and the measurement space S2 can be measured with high accuracy, and the outer diameter of the measurement disk 12 can be measured with high accuracy.

  FIG. 5 is a diagram showing a preferable arrangement state of the capacitance sensors 13 and 14 in the apparatus shown in FIG. In FIG. 1, the capacitance sensors 13 and 14 are arranged so as to face each other with the disks 11 and 12 interposed therebetween. At this time, as shown in FIG. And the central axis 14C of the capacitance sensor 14 is preferably set to 0.05 rad or less.

  In this case, the capacitive sensors 13 and 14 can scan the reference disk 11 and the measurement disk 12 so as to divide the surface of the reference disk 11 and the measurement disk 12 almost linearly. The entire surface can be scanned almost uniformly, and the capacitance over the entire reference space S1 and measurement space S2 can be measured more accurately. As a result, the capacitances of the reference space S1 and the measurement space S2 can be measured more accurately, and the outer diameter measurement accuracy of the measurement disk 12 can be further improved.

  As described above, according to the apparatus shown in FIG. 1 and the above-described method using the apparatus, the outer diameter measurement error of the measurement disk 12 can be improved to within ± 2 μm, for example. As a result, the apparatus and the method can be suitably used for measuring the outer diameter of an HDDS (High Phase Advance Damped Detuned Structure) disk used as an acceleration tube disk.

In addition to the measurement disk 12, the apparatus 10 shown in FIG. 1 includes only the reference disk 11 and the capacitance sensors 12, 13, and only inexpensive components such as the temperature sensors 17, 18 and the stage 21. Yes. Therefore, the apparatus 10 can be configured at low cost, and the above-described measurement can be performed at low cost.

  As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and all modifications and changes are made without departing from the scope of the present invention. It can be changed.

Further, the outer diameter of the measurement disk 12 can be measured in a non-contact manner by using a laser length measuring device or the like instead of using the capacitance sensor.

It is a schematic block diagram which shows an example of the outer diameter measuring apparatus of the disk in this invention. It is a figure for demonstrating the outer diameter measuring method using the apparatus shown in FIG. It is a figure which shows notionally the output value of the electrostatic capacitance sensor obtained by the method of this invention. Similarly, it is a figure which shows notionally the output value of the capacitance sensor obtained by the method of the present invention. In the apparatus shown in FIG. 1, it is a figure which shows the preferable arrangement | positioning state of a capacitance sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 External diameter measuring apparatus of disk 11 Reference disk 12 Measuring disk 13, 14 Capacitance sensor 15, 16 Fixing jig 17, 18 Temperature sensor 21 Stage 22 Upper fixing plate 23 Lower fixing plate 24 Actuator

Claims (6)

Arranging a reference disk of known outer diameter and a measuring disk of unknown outer diameter along a predetermined direction in a posture in which their axes are parallel to each other, and fixing these disks to the stage;
A pair of non-contact type distance measuring sensors, which are fixed to each other and arranged so as to face each other with the disc interposed therebetween, are maintained while maintaining the positional relationship of linearly dividing the plane of the reference disc and the measuring disc. From each distance measurement sensor on a virtual line that linearly divides the surface in a straight line by relative displacement in the predetermined direction with respect to the stage so that both outer peripheral surfaces of both disks are continuously and integrally scanned. Continuously measuring the distance to the outer peripheral surface of both discs;
The sum of the measurement distances from each pair of distance measurement sensors to the outer peripheral surface of the reference disk, the sum of the measurement distances from each pair of distance measurement sensors to the outer peripheral surface of the measurement disk, and the reference disk based on the known outer diameter, the outer diameter measuring method of the accelerating tube disc, characterized in that it comprises a step of calculating the outer diameter of the measuring disc. And the temperature of the reference disc, said measuring disc and temperature, the outer diameter measuring method of the accelerating tube disk according to claim 1 comprising a step of setting to a predetermined temperature range. And the temperature of the reference disc, said measuring a temperature of the measurement disc, the difference between these temperatures, the outside of the accelerating tube disk according from getting within a predetermined temperature range to claim 1 or 2 starts the measurement Diameter measurement method. As the non-contact type distance measuring sensor, a capacitance sensor is used, and the distance from the outer peripheral surface of each of the reference disk and the measuring disk to the corresponding non-contact type distance measuring sensor is set to each of the reference disk and the measuring disk. The outer diameter measuring method of the acceleration tube disk in any one of Claims 1-3 calculated | required from the electrostatic capacitance of the space formed with the electrostatic capacitance sensor corresponding to an outer peripheral surface of this. A stage for fixing a reference disk having a known outer diameter and a measuring disk having an unknown outer diameter, arranged in a predetermined direction in a posture in which their axes are parallel to each other;
It is fixed to each other and arranged so as to face each other with both the discs in between, and the outer peripheral surfaces of both the discs are continuously maintained while maintaining the positional relationship of linearly dividing the surfaces of the both discs. and integrally to relative displacement in the predetermined direction with respect to said stage to scan, a pair of non-measuring respective distances to the outer peripheral surface of said both disks on the virtual line that divides the inside of the plane in a straight line A contact-type distance measuring sensor;
Outer diameter measuring apparatus of the accelerating tube disc, characterized in that it comprises a driving means for displacing along the distance measuring sensor in the predetermined direction. 6. The non-contact type distance measuring sensor is a capacitance sensor that measures a capacitance of a space formed between each of the reference disk and the outer peripheral surface of the measurement disk. The outer diameter measuring device of the acceleration tube disk described in 1.

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