JPH08190999A - Multipole field measuring device - Google Patents

Abstract

PURPOSE: To manufacture at a high measuring accuracy and at a low cost, by measuring the relation between the magnetic field center of an electromagnet, and the geometric center of the gap between the magnetic poles easily. CONSTITUTION: While an electromagnet to be measured (not shown) is rotated in the directions X, Y, and Z, it is installed on a driving board 18 movable horizontally and vertically, a rotary coil 1 is inserted in the electromagnet, the rotary coil 1 is rotated by a coil driver 20, and the magnetic field generated from the electromagnet is measured. Before the electromagnet is installed on the driving board 18 prior to the measuring, the geometric slippage of the center axis of the rotary coil 1 is found beforehand by the displacement sensor of a rotary shaft measuring device (not shown) set to the driving board 18, and from this slippage and the magnetic field center found at the installing time of the electromagnet, the slippage between the magnetic field center of the elentromagnet, and the geometric center of the gap between the magnetic poles, is found.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field measuring device for an electromagnet used in a charged particle accelerator or the like.

[0002]

2. Description of the Related Art In an accelerator such as a synchrotron radiation experimental facility, how much the geometric center of the magnetic pole gap of a multipole electromagnet deviates from the magnetic field center in order to achieve low emittance and high brightness. It is necessary to estimate by magnetic field measurement, and a magnetic field measuring device that can measure not only the magnetic field strength but also the magnetic field center has come to be used.

FIG. 13 is a side view of a conventional multipole magnetic field measuring apparatus described in, for example, the catalog MULTIPOLE MAGNET MEASUERMENTSYSTEM MODEL 692 of DANFYSIK, Netherlands. In FIG. 13, 1 is a rotary coil, 2a and 2b are bearings, and 3
Is a DC motor, 4 is a rotary encoder, 5a,
5b is a flexible coupling, 6 is an electromagnet mount, 7
a and 7b are driving devices, 8 is a laser, 9a and 9b are photodetectors, and 10a and 10b are photodetector support bases. 11 is a laser support base, 12 is a base mount, 1
Reference numeral 3 is an electromagnet to be measured.

FIG. 14 shows the structure of the electromagnet 13 for measurement, and in this figure, the case of a 4-pole electromagnet is shown.
FIG. 15 is a perspective view showing the structure of a rotating coil of a conventional multipole magnetic field measuring apparatus. In FIG. 15, 14a and 14b are winding frames, which hold the pickup coil 15 by sandwiching it from both sides and fixing it with fixing bands (not shown) using four grooves in the circumferential direction. 16 is a signal extraction lead, 17a,
17b is a chucking collar made of non-magnetic metal such as brass,
Both ends of the reels 14a and 14b are held. 16 is a perspective view showing the winding state of the pickup coil 15, and FIG. 17 is a flow chart of the measuring operation.

Next, the operation will be described with reference to the flowchart of FIG. As shown in FIG. 13, in the multipole magnetic field measuring device, the measured electromagnet 13 fixed to the electromagnet mount 6 can be rotated about three axes orthogonal to the horizontal and vertical translation by the driving devices 7a and 7b. It has become.

The electromagnet 13 to be measured is mounted on the drive base 18 so that the geometric center of the gap between the magnetic poles of the electromagnet 13 to be measured is substantially aligned with the rotation axis A formed by the bearings 2a and 2b (step S1).

The DC motor 3 is removed, the rotary coil 1 is inserted from the bearing into the gap between the magnetic poles of the electromagnet 13 to be measured, and the rotary coil 1 is fixed to the rotary encoder 4 by the flexible coupling 5b.
And similarly fixed to the rotary coil with the flexible coupling 5a. (Step S2)

In this state, the measured electromagnet 13 is excited,
When the rotating coil is rotated by the DC motor 3, FIG.
A pickup coil 15 shown in FIG. 5 crosses the magnetic field and a voltage is induced in the signal extraction lead 16. By measuring this induced voltage, integrating this induced voltage at the angle detected by the rotary encoder 4, and performing frequency analysis etc.,
The strength of the multipole component of the magnetic field and the center position of the magnetic field are obtained (step S3).

Further, the beam axis of the laser 8 installed on the support 11 is adjusted by using the photodetectors 9a and 9b installed on the supports 10a and 10b on the axis B parallel to the rotation axis of the rotary coil shown in FIG. Is placed on the B-axis and, while watching the result of frequency analysis of the signal output of the rotating coil, it is moved by using the driving devices 7a and 7b until the rotating axis of the rotating coil 1 coincides with the central axis of the magnetic field (step S4). .

Finally, the relative positional relationship between the photodetector installed on the electromagnet 13 to be measured and the rotary axis of the rotary coil 1 is measured by using the laser beam aligned on the B axis, and the gap between the magnetic poles is measured. A deviation between the geometric center and the magnetic field center is obtained (step S5).

In this example, the above equipment is installed on the common base mount 12, but the mount of the electromagnet and the driving device may be separately installed.

Further, as shown in FIG. 15, the rotating coil 1 is formed by dividing a solid rod of an insulating material into a rod and grooving it.
4a and 14b, the pickup coil is wound along the groove and attached, then assembled into a cylinder, and chucking collars 17a and 17b mainly made of metal are attached. When incorporating the rotating coil into the multipole magnetic field measurement device,
The chucking collar is attached to the bearing to support rotation.

[0013]

Since the conventional multipole magnetic field measuring apparatus is configured as described above, the reference of a photodetector or the like indicating an axis parallel to the rotation axis of the rotating coil is
It is necessary to place it on the measuring device with high accuracy in advance, and it is necessary to process and install the support, etc. on which the photodetector is installed with high accuracy. Further, a jig for measurement attached to the bearing portion is required to determine the rotation axis of the rotating coil. Further, there is a problem that the rotation axis obtained by this is the rotation center of the bearing portion or the jig for measurement and does not exactly coincide with the actual rotation center including the deflection of the rotation coil.

Further, since the rotary coil of the conventional multi-pole magnetic field measuring apparatus is a winding frame which is obtained by dividing a solid bar of an insulating material and processing the rod into bars, the positional accuracy of the pickup coil is the winding frame. It was determined by the machining accuracy of the round bar and the groove, and a great deal of labor was required for this machining. Further, there is a problem in strength such as a large deflection due to its own weight.

The present invention has been made to solve the above problems, and the relationship between the rotational axis of the rotating coil or the magnetic field center coincident therewith and the geometric center of the gap between the magnetic poles of the electromagnet can be easily measured. An object of the present invention is to obtain a multi-pole magnetic field measuring device which has high measurement accuracy and can be manufactured at low cost.

[0016]

[Means for Solving the Problems]

(1) A multipole magnetic field measuring device according to the present invention includes a cylindrical rotating coil that has a built-in winding that rotates in a magnetic field of an electromagnet for measurement that generates a multipolar magnetic field and outputs the generated voltage. A rotating device for removably gripping both ends of the rotating coil by bearings and rotating the rotating coil, an angular position detecting means for outputting a rotational angular position signal according to the rotation of the rotating coil, and an output signal from the rotating coil. Magnetic field center predicting means for predicting the magnetic field center of the electromagnet from the rotation angle position signal, and the magnetic field center of the electromagnet and the center of the rotating coil based on this prediction result of the electromagnet and the rotating coil A drive device for changing the relative positional relationship and a position displacement deriving means for deriving the position displacement between the center axis of the rotating coil and a preset alignment reference are provided, and the drive device drives the electric current. The displacement between the geometric center of the electromagnet and the magnetic field center is obtained from the position information obtained by matching the magnetic field center of the stone and the center of the rotating coil, and the position displacement obtained by the position displacement deriving means. It was done.

(2) Further, the position displacement deriving means obtains the displacement amount with respect to the rotational position by rotating the rotary coil, and based on the displacement amount at this position and the preset alignment reference, the central axis of the rotary coil is preset. This is a means for deriving the displacement of the position with respect to the alignment reference.

(3) Further, the rotary coil is an outer cylinder, and is a cylinder concentric with the outer cylinder, which holds both ends of the outer cylinder, and a chucking collar held by the rotating device, and the inside of the outer cylinder. The winding frame disposed on the winding frame, the windings held by the winding frame and wound in symmetry and parallel to the central axis of the outer cylinder, and the winding and the winding frame provided on the outer cylinder. Position adjusting means for movably supporting the outer cylinder in the radial direction to adjust the position,
It is composed of a measuring hole provided on the outer cylinder and capable of measuring the reel position from the outside.

(4) Further, another winding for detecting a magnetic field near the surface of the outer cylinder is added.

(5) In the rotating device, the drive source for driving the rotary coil is a drive motor, and the drive motor is arranged at a position deviated from the rotation axis of the rotary coil.
The rotary coil is driven from the drive motor via a power transmission means, and the rotary coil is insertable and removable in the rotation axis direction. (6) Further, the gripping mechanism of the rotating device that holds the rotating coil is rotatably held from the bearing side of the rotating device, and
In addition to providing a taper in the direction of the rotation axis on the inside, a rotation shaft into which the rotation coil is inserted, a taper spring collet for gripping the rotation coil with a taper facing the taper of the rotation shaft, and a rotation of this taper spring collet. It is composed of pressing means for pressing in the axial direction and tightening to grip the rotating coil.

(7) Further, the gripping mechanism of the rotary device for gripping the rotary coil is rotatably held from the bearing side of the rotary device, and the rotary shaft into which the rotary coil is inserted, and A thrust sleeve that rotates with the rotating shaft and slides in the axial direction and has a taper in the rotating shaft direction inside thereof, and a taper that faces the taper of the thrust sleeve, and moves in the rotating shaft direction A reverse taper spring collet for holding the rotary coil, and a pressing means for holding the rotary coil by tightening the reverse taper spring collet by pressing the thrust sleeve in the rotation axis direction. is there.

[0022]

[Action]

(1) The multipole magnetic field measuring apparatus of the present invention rotates the rotating coil in the magnetic field of the electromagnet, predicts the magnetic field center of the electromagnet from the generated voltage and the position signal of the rotation angle, and based on this prediction result, the electromagnet. The relative position relationship between the electromagnet and the rotating coil is changed by the drive device so that the center of the magnetic field of the rotating coil coincides with the center of the rotating coil, while the displacement of the position between the central axis of the rotating coil and the preset alignment reference. From the position information obtained as a result of matching the magnetic field center of the electromagnet with the center of the rotating coil by the driving device, and the position displacement obtained by the position displacement deriving means. Find the deviation between the center and the center of the magnetic field.

(2) Further, the positional displacement deriving means obtains the displacement amount with respect to the rotational position by rotating the rotary coil, and based on the displacement amount at this position and the preset alignment reference, the central axis of the rotary coil is preset. The displacement of the position with respect to the performed alignment reference is derived.

(3) Further, the rotary coil holds both ends of the outer cylinder with chucking collars, and holds the winding wound symmetrically and parallel to the central axis of the outer cylinder, and this winding. The reel and the reel are movably supported in the radial direction of the outer cylinder for positional adjustment, and the reel position is measured using the measurement hole.

(4) Further, for the winding, another winding for detecting a magnetic field near the surface of the outer cylinder is added, and an induced voltage corresponding to the magnetic field is also generated from this winding.

(5) Further, in the rotating device, the drive motor for driving the rotating coil is arranged at a position deviated from the rotating shaft of the rotating coil so that the rotating coil can be inserted and removed in the rotating shaft direction. . (6) Further, the gripping mechanism of the rotating device that grips the rotating coil presses the taper spring collet in the rotation axis direction to grip the rotating coil.

(7) Further, the gripping mechanism of the rotating device for gripping the rotary coil presses the thrust sleeve in the direction of the rotary shaft and grips the rotary coil by the inverse taper spring collet.

[0028]

【Example】

Example 1. A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the main body of the multipole magnetic field measuring apparatus, and FIG.
Is a side view showing the rotary shaft measuring device attached to the left main body, FIG. 3 is a perspective view showing a displacement sensor driving portion of the rotary shaft measuring device, and FIGS. 4 and 5 are flowcharts of the measuring operation.

In the figure, reference numerals 1, 4, and 12 are the same as in the conventional example, and the description thereof is omitted. Reference numeral 18 is a drive stand including an electromagnet stand and its drive device, 19 is a lever for fixing the electromagnet, and 2
0 is a coil rotation drive unit including a bearing and a drive device, 2
Reference numeral 1 is a coil signal extracting portion including a bearing and a rotary encoder, 22a and 22b are alignment position reference bases, 23 is a displacement sensor driving portion, and 24a and 24b are displacement sensors. For example, a commercially available eddy current displacement sensor has a size of 1 μm. Can be detected with an output voltage of 1 mV. Reference numeral 25 is a measurement stand, 26 is a rotating cylinder, 27 is a linear guide rail, 28 is a measurement position reference stand, and 29 is a measurement ring.

Next, the operation will be described with reference to the flow charts of FIGS. A measurement frame 25 having a linear guide rail 27 is installed on the drive table 18, and a displacement sensor drive unit 23 is installed on the measurement table 25. The measurement position reference table 28 is attached, and the displacement sensors 24a and 24b are attached to the rotary cylinder 26. The displacement sensor drive unit 23 is, as shown in FIG.
It can be moved in the horizontal and vertical directions by the drive table 18, and can be rotated in the X, Y, and Z directions. Further, it can be moved on the linear guide rail 27.

The displacement sensor driving unit 23 includes a displacement sensor 2
There is a rotating cylinder 26 to which 4a and 24b are attached, and displacement sensors 24a and 24b rotate around the rotating coil 1 to measure the displacement. The displacement sensor drive unit 23 of FIG.
The scale on the right side of is a scale for reading the rotation angles of the displacement sensors 24a and 24b.

The measurement position reference table 28 is the displacement sensor driving unit 2
3, the positional relationship with the rotation axis C (shown in FIG. 3) of the rotation cylinder 26 is accurately measured by a three-dimensional measuring device or the like. Then, the measurement pedestal 25 and each device on the measurement pedestal 25 constitute a rotary shaft driving device and are fixed by the electromagnet fixing lever 19 (step T1).

Next, the rotary coil 1 is connected to the coil rotary drive unit 20.
Is inserted from the side of, and is inserted through the rotating cylinder 26 to the coil signal extracting portion 21 and fixed (step T).
2).

The rotating coil 1 is rotated and displacement sensors 24a and 24b arranged on both sides of the rotating cylinder 26 measure the displacement of the rotating coil 1. This is the displacement sensor 24
When the measurement positions of a and 24b are changed, for example, by changing the vertical and horizontal directions, the positional relationship of the actual rotation axis of the rotation coil with respect to the rotation axis of the rotation cylinder 26 can be measured. Further, the displacement sensor driving unit 23 slides on the linear guide rail 27 to perform the above measurement at an arbitrary position on the axis of the rotating coil (step T3).

Finally, the positional relationship between the measurement position reference base 28 and the alignment position reference bases 22a and 22b attached to the main body of the multi-pole magnetic field measurement device is measured by an optical system measurement device such as a laser to obtain a rotating coil. The positional relationship between the actual rotation axis and the alignment reference is determined at any position (step T4).

After the above measurement is completed, the rotary coil 1 is removed, the rotary shaft drive is removed, the electromagnet 13 to be measured is mounted on the drive base 18, and the rotary coil 1 is inserted (steps T5 and T6).

A magnetic field that changes periodically is generated by exciting the electromagnet 13 to be measured, and the rotating coil 1 is rotated in this magnetic field to output an induced voltage, and an angular position signal is output from the rotary encoder 4. Is output and frequency analysis is performed using both outputs to obtain the strength of the multipole component of the magnetic field and the center position of the magnetic field. When the above rotary shaft driving device is installed and the displacement sensors 24a and 24b use the same rotary coil, the measurement may be performed once and does not need to be performed again even if the electromagnet 13 to be measured changes. .

Next, while looking at the result of predicting the magnetic field center of the electromagnet by frequency analysis, the drive table 18 is used to move the coil until the rotation axis of the rotating coil 1 and the center axis of the magnetic field coincide (step T7).

The amount of displacement of the position of the rotary coil 1 relative to the alignment reference obtained in step T4, and the above step T
The deviation between the geometric center of the electromagnet and the magnetic field center is obtained from the magnetic field center position obtained in step 7 (step T8).

Therefore, the magnetic center can be easily and accurately obtained, and if the center position is marked, the magnetic center can be easily confirmed even if the electromagnet is moved to another place. Since the magnetic center is usually located in the space and cannot be marked at that position, the magnetic center in the space is replaced with, for example, the mechanically measurable position shown in the upper part of FIG. deep.

When an eddy current type sensor is used as the displacement sensor, a metal ring for generating an eddy current is required, and as shown in FIG. 1, a metal measuring ring accurately processed into a circle. 29 is attached to the rotating coil 1. By doing so, further improvement in accuracy can be expected.

As described above, it is not necessary to perform accurate adjustment or measurement so that the conventional rotary shaft of the bearing and the position reference base have a predetermined positional relationship. The actual center of rotation of the coil can be measured at any position, and the accuracy of processing and assembling the alignment position reference stand attached to the main body of the multipole magnetic field measurement device is reduced. It has the effects of improving the manufacturability and improving the measurement accuracy.

Further, conventionally, it was assumed that the axis formed by the rotation center of the bearing coincides with the rotation axis of the rotary coil.
In the present invention, the actual rotation axis of the rotary coil, that is, the magnetic center axis, including deformation due to bending of the rotary coil, is obtained.

Example 2. A second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a perspective view showing a rotating coil of the multipole magnetic field measuring apparatus.

In the figure, the pickup coil 15, the signal extraction lead 16 and the chucking collar 17 are the same as those in the conventional example, and their explanations are omitted. An outer cylinder 30 is made of glass epoxy, alumina epoxy, or the like. Reference numeral 31 is a measuring hole, 32 is a coil winding frame, a groove (not shown) around which the pickup coil 15 is wound is provided in parallel with the rotation center axis, and the material thereof is glass epoxy or the like. Reference numeral 33 is an adjusting bolt.

The position adjusting mechanism using the adjusting bolt 33 is shown in FIG.
Shown in The adjusting bolts 33 are screwed into the screw holes provided in each of the three positions (six positions in the illustrated example) of the outer cylinder 30, and the coil winding frame 32 is moved.

Next, the manufacturing procedure will be described. Outer cylinder 30
The chucking collar 17 attached to the coil coil 3 is processed with good coaxiality on both sides so that there is no eccentricity during rotation, and the pickup coil 15 is processed with high precision.
Wrap it around 2 and install it in the outer cylinder.

In order to accurately position the pickup coil 15, the coil bobbin 32 is measured with the adjusting bolts 33 attached to the outer cylinder with reference to the chucking collars at both ends which are processed with good coaxiality. Use 31 to adjust and fix while measuring. In addition, the measurement of the coil winding frame position is performed by, for example, checking the chucking collar 17 on a horizontal surface plate.
Hole 31 provided on the outer cylinder 30 by supporting the
It may be measured using a height gauge or a dial gauge (not shown).

In this way, the chucking collar 17 and the coil winding frame 32 attached to the outer cylinder 30 can be machined individually, and can be machined easily and highly accurately. Further, since the rotary coil is composed of a cylinder (outer cylinder) and a thin plate (reel), it is characterized by less deflection due to its own weight than a solid round bar having the same outer shape as the outer cylinder in terms of material mechanics. For example, the conventional one has about 75 kg × 2 m and about 18 kg, but the embodiment of the present invention can reduce the amount to about 1/3.

Further, since the outer shape of the coil and the position of the pickup coil can be arbitrarily adjusted, the groove processing of the winding frame and the outer peripheral processing of the cylinder can be performed separately, which has the effect of improving the manufacturability and the assembling accuracy.

Example 3. A third embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a perspective view showing a rotating coil of the multipole magnetic field measuring apparatus.

In the figure, 15, 16, and 17 are the same as the conventional example, and 30, 31, 32, and 33 are the same as those in the second embodiment, and the description thereof is omitted. 34 is a groove for coils. FIG. 9 shows a diagram of a main part in which the pickup coil 15 is wound around the coil groove 34. The pickup coil 15 is provided separately from the pickup coil 15 shown in FIG. 6 of the second embodiment, and the two pickup coils are usually connected in series. Therefore, the pickup coil 15 can measure the magnetic field near the magnetic pole of the electromagnet 13 to be measured with higher sensitivity and accuracy.

Next, the manufacturing procedure will be described. Outer cylinder 30
The chucking collar 17 attached to the coil coil 3 is processed with good coaxiality on both sides so that there is no eccentricity during rotation, and the pickup coil 15 is processed with high precision.
A coil groove 34 is formed by winding a portion to be a winding on the inner diameter side around 2 and incorporating it in an outer cylinder, and further, with the chucking collar processed with good coaxiality as a reference, processed with good parallelism to the outer cylinder.
And the winding on the outer side of the pickup coil.

Next, in order to align the winding on the center side of the pickup coil 15 with or parallel to the rotation axis, the adjustment bolt 33 attached to the outer cylinder 30 with reference to the chucking collar 17 is used for measurement. The hole 31 is used for measurement while adjusting and fixing. The measurement of the coil winding frame position is performed by, for example, a chucking collar supported by a V block or the like on a horizontal surface plate, and a measurement hole 31 provided in the outer cylinder 30.
It may be measured using a height gauge or a dial gate (not shown).

In this way, a pickup coil having substantially the same radius as the outer cylinder can be manufactured, and the measurement area can be set as close to the bore diameter of the electromagnet as possible, which has the effect of improving the measurement accuracy. Further, the chucking collar and the coil bobbin attached to the outer cylinder can be machined individually, so that the machining can be performed easily and with high accuracy. In addition, since the rotating coil is composed of a cylinder (outer cylinder) and a thin plate (reel), it is characterized by less deflection due to its own weight compared to a solid round bar with the same outer diameter as the outer cylinder in terms of material mechanics. .

Example 4. A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a perspective view showing a method of installing a drive motor of the multipolar magnetic field measurement apparatus. In the figure, 1,
4, 15 are the conventional example, 18, 19, 20, 22a, 22
Since b and b are the same as those in the first embodiment, description thereof will be omitted.

21-1 is a bearing portion, 35 is a drive motor,
36 is a power transmission belt, 37 is a rotary connector, 3
Reference numeral 7-1 is a connector, which is detachably connected to the signal line of the rotary coil 1 and transmits a signal to the rotary connector 37.
Reference numeral 37-2 is a fitting, which is rotatably attached to the rotary connector 37, and can be rotated about 90 degrees toward the coil rotation drive unit 20 side by a hinge (not shown) beyond the drawing.

Next, the operation will be described. First, the case where the rotary coil 1 is removed from the state of FIG. 10 will be described. The connector 37-1 is removed from the rotary coil 1 side, and the mounting bracket 37-2 with the connector 37-1 and the rotary connector 37 still attached is rotated by about 90 degrees, and the rotary coil 37 side of the rotary coil 1 is attached. Get rid of obstacles.

The portion where the rotary coil 1 is fastened to the bearing portion 21-1 is loosened, and the portion where the rotary coil 1 is fastened on the opposite side of the belt pulley of the coil rotation drive portion 20 is loosened. The rotary coil 1 is pulled out from the coil rotation drive unit 20 side and removed.

When the rotary coil 1 is attached, it is attached in the reverse order of the above removal. That is, the rotation coil 1 is attached by inserting it from the coil rotation drive unit 20 (on the left side in the drawing), inserting and attaching it to the bearing unit 21-1, and connecting the connector 37-1. In this way, the rotary coil 1 can be easily attached and detached.

The rotation of the rotary coil 1 is driven by the drive motor 35 via the power transmission belt 36. The output signal from the rotary coil passes through the connector 37-1 and is taken out from the rotary connector 37. By thus extracting the signal through the rotary connector 37, the rotary coil 1 can be continuously rotated, and by employing indirect drive using a belt or the like, the rotary coil can be removed without removing the drive motor. Can be attached and detached. Further, since the equipment can be attached to both ends of the rotary coil, the rotary encoder can continuously rotate the rotary coil to extract the signal repeatedly, which has the effect of improving the measurement accuracy.

Although the indirect drive power transmission system has been described as a belt, it may be a chain or a gear. Since other operations are the same as those in the first embodiment, the description thereof will be omitted.

Example 5. A fifth embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a side view showing the rotating coil gripping mechanism of the multipole magnetic field measuring apparatus. (It is a cross-sectional view of the signal extraction unit 21 of the first embodiment.) In the figure, the rotary coil 1 and the rotary encoder 4 are the same as those in the conventional example, and the description thereof is omitted. 38 is a tightening ring, 39 is a spring collet, 40 is a rotating shaft, 41
Is a disc spring, 42a and 42b are ball bearings, and 43a and 4
3b is a collar, 44 is a bearing nut, 45 is a bearing stand, and 46 is a taper ring.

Next, the operation will be described. Rotating coil 1
After inserting into the rotating coil 1, the clamping ring 3
By turning 8, the following operation is performed. The tightening ring 38 is screwed to the rotating shaft 40, and when the tightening ring 38 is rotated, it moves to the right in FIG. 11. At this time, the tightening ring 38 and the taper ring 46 similarly move to the right and hold the spring collet 39 with the taper portion of the rotary shaft 40, so that the springlet 39
It becomes smaller in the inner diameter direction, and the rotary coil 1 can be clamped and gripped.

When a rotational force is applied to the rotary coil 1, the rotary shaft 40 causes the bearing nut 44 and the disc spring 4 to move.
1. Ball bearing 42 fixed by collars 43a and 43b
Since it is supported by a and 42b, the rotating coil 1 rotates smoothly. If the gripping mechanism is configured in this way, the rotating coil 1 can be fixed in the rotation direction and the axial direction by the width of the spring collet 39, and can be rotated via the ball bearings 42a and 42b.

Therefore, since the end of the rotary coil is gripped over a certain length, the moment acting on the end of the rotary coil can be fixedly supported, the deflection due to its own weight is reduced, and the measurement accuracy is improved.

While this embodiment has been shown as an example applied to the coil signal extracting portion 21 of FIG. 1 of the first embodiment, it can also be applied to the coil rotation driving portion 20 of FIG. Example 4
10 can be similarly applied to the bearing portion 21-1 of FIG. 10 and the gripping mechanism of the coil rotation driving portion 20.

When applied to the coil rotation drive unit 20 of FIG. 10, although not shown, the portion of the rotary shaft 40 on the bearing nut 44 side of FIG. 11 is extended in the axial direction (to the right), and the extended portion is shown. The pulley on which the power transmission belt 36 shown in FIG. Further, since the rotary encoder 4 is not provided, the rotary coil 1 can be extracted rightward. With such a structure, it is possible to easily insert and remove the rotary coil 1 in the axial direction without being disturbed by the drive mechanism.

Example 6. A sixth embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a side view showing the rotating coil gripping mechanism of the multipole magnetic field measuring apparatus. (It is a cross-sectional view of the signal extraction unit 21 of the first embodiment.)

In the figure, 1 and 4 are the conventional example and 38 and 4 respectively.
1, 42a, 42b, 43a, 43b, 44, 45 are
Since it is similar to the fifth embodiment, its description is omitted. 47 is a thrust sleeve, 48 is a reverse taper spring collet, 4
Reference numeral 9 denotes a collet fixed type rotary shaft, into which an inverse taper spring collet 48 is fitted, which is fixed in axial movement and is rotatably supported in the circumferential direction. Reference numeral 50 is a rotation stop pin of the thrust sleeve 47.

Next, the operation will be described. Rotating coil 1
For gripping, the tightening ring 3 is inserted after inserting the rotary coil 1 inside.
By turning 8, the following operation is performed. The tightening ring 38 is screwed to the fixed collet type rotary shaft 49, and when the tightening ring 38 is rotated, the tightening ring 38 moves to the right in the drawing. At this time, the tightening ring 38 and the thrust sleeve 47 similarly move to the right and hold the reverse taper spring collet 48 by the taper portion, so that the reverse taper spring collet 48 becomes smaller in the inner diameter direction and the rotating coil 1
Tighten.

At this time, the reverse taper spring collet 48
Is fitted to the collet fixed rotary shaft 49 and does not move in the axial direction, so that the rotary coil 1 can be tightened without applying an axial force to the rotary coil 1. Further, since the rotation stop pin 50 stops the rotation of the thrust sleeve 47, the reverse taper spring collet 48 also does not rotate and does not give a twisting force to the rotating coil 1.

When a rotating force is applied to the rotating coil 1,
A rotary shaft 49 has ball bearings 42a, 42 fixed by bearing nuts 44, disc springs 41, collars 43a, 43b.
Since it is supported by b, the rotating coil 1 rotates smoothly. If the gripping mechanism is configured in this manner, the rotary coil 1 can be fixed by the width of the inverse taper spring collet in the rotational direction and the axial direction without applying the axial force and the twisting force, and the ball bearings 42a and 42b can be fixed. Can be rotated through.

Therefore, in addition to the effect of the fifth embodiment, when the rotary coil is gripped by the reverse taper spring collet, the rotary coil is not pulled in the axial direction, and the rotary coil can be gripped without giving unnecessary force in the axial direction. This has the effect of improving the measurement accuracy without deforming the rotating coil.

Although this embodiment has been shown as an example applied to the coil signal extracting portion 21 of FIG. 1 of the first embodiment, it can also be applied to the coil rotation driving portion 20 of FIG. Example 4
10 can be similarly applied to the bearing portion 21-1 of FIG. 10 and the gripping mechanism of the coil rotation driving portion 20.

When applied to the coil rotation drive section 20 of FIG. 10, although not shown, the portion of the rotary shaft 40 on the bearing nut 44 side of FIG. 12 is extended in the axial direction (to the right), and the extended portion is illustrated. The pulley on which the power transmission belt 36 shown in FIG. Further, since the rotary encoder 4 is not provided, the rotary coil 1 can be extracted rightward. With such a structure, it is possible to easily insert and remove the rotary coil 1 in the axial direction without being disturbed by the drive mechanism.

Example 7. The above embodiments can be used in combination. That is, other embodiments may be applied based on the first embodiment. Either one of the gripping mechanisms of the fifth embodiment and the sixth embodiment is applied. However, even if the fifth embodiment is applied to one of the right end side and the left end side of the rotary coil 1 and the sixth embodiment is applied to the other. Good.

[0078]

【The invention's effect】

(1) As described above, according to the present invention, the rotary coil, the rotary device, the angular position detecting means, the magnetic field center predicting means, the driving device, and the positional displacement deriving means are included. And the measurement accuracy is improved, and the actual rotation axis of the rotary coil, that is, the magnetic center axis is required, including deformation due to deflection of the rotary coil.

(2) Further, since the position displacement deriving means is provided, the relationship between the alignment reference and the displacement amount of the rotary coil can be obtained in advance, the manufacturability of the multipole magnetic field measuring device main body is improved, and the measurement is performed. It also has the effect of improving accuracy.

(3) Further, since the rotary coil is composed of the outer cylinder, the chucking collar, the winding, the winding frame, the adjusting bolt and the measuring hole, the rotary coil can be made lighter and is manufactured by a solid round bar. This has the effect of reducing the deflection due to its own weight. Further, since the outer shape of the coil and the position of the pickup coil can be arbitrarily adjusted, the bobbin and the outer cylinder can be processed separately, which improves the manufacturability and the assembling accuracy.

(4) Further, since another winding for detecting the magnetic field near the surface of the outer cylinder is added, a pickup coil having substantially the same radius as the outer cylinder can be manufactured, and the measurement area can be the bore diameter of the electromagnet. It is possible to bring them as close as possible, and there is an effect that the magnetic field can be measured with higher sensitivity and accuracy.

(5) Further, a drive motor for driving the rotary coil is arranged at a position off the rotary shaft of the rotary coil,
Since the rotating coil is configured to be insertable / removable in the rotating shaft direction, the rotating coil can be attached / detached without removing the drive motor, and the rotating coil or the electromagnet can be easily replaced.
This has the effect of increasing the efficiency of measurement work.

(6) Further, since the gripping mechanism of the rotary coil of the rotary device is constituted by the rotary shaft, the taper spring collet and the pressing means, the rotary coil end is gripped by gripping the end of the rotary coil over a certain length. The moment acting on can be fixedly supported, the deflection due to its own weight can be reduced, and the measurement accuracy can be improved.

(7) Further, since the gripping mechanism of the rotary coil of the rotating device is constituted by the rotary shaft, the thrust sleeve, the reverse taper spring collet and the pressing means, when the rotary coil is gripped by the reverse taper spring collet, the axial direction Is prevented from being pulled in, the rotary coil can be gripped without applying unnecessary force in the axial direction, and the measurement accuracy is improved without the rotary coil being deformed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main body of a multipole magnetic field measuring apparatus according to a first embodiment of the present invention.

FIG. 2 is a side view showing the rotating shaft measuring device attached to the main body of the multipole magnetic field measuring device according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a displacement sensor driving unit of the rotation axis measuring apparatus of the multipole magnetic field measuring apparatus according to the first embodiment of the present invention.

FIG. 4 is a flowchart of a measuring operation according to the first embodiment of the present invention.

FIG. 5 is a flowchart of a measurement operation according to the first embodiment of the present invention.

FIG. 6 is a perspective view showing a rotating coil of a multipole magnetic field measuring apparatus according to a second embodiment of the present invention.

7 is a sectional view showing a position adjusting mechanism of the pickup coil of FIG.

FIG. 8 is a perspective view showing a rotating coil of a multipole magnetic field measuring apparatus according to a third embodiment of the present invention.

9 is a cross-sectional view of a wound portion of the pickup coil of FIG.

FIG. 10 is a perspective view showing an installed state of a drive motor of a multipole magnetic field measurement apparatus according to Example 4 of the present invention.

FIG. 11 is a side view showing a rotating coil gripping mechanism of a multipole magnetic field measuring apparatus according to a fifth embodiment of the present invention.

FIG. 12 is a side view showing a rotating coil gripping mechanism of a multipole magnetic field measuring apparatus according to Embodiment 6 of the present invention.

FIG. 13 is a side view showing a conventional multipole magnetic field measurement apparatus.

FIG. 14 is a sectional view of a multipolar electromagnet.

FIG. 15 is a perspective view showing a structure of a rotating coil of a conventional multipole magnetic field measuring apparatus.

16 is a perspective view showing the structure of the pickup coil of FIG.

FIG. 17 is a flowchart showing a conventional measurement operation.

[Explanation of symbols]

1 rotary coil, 4 rotary encoder, 12
Base stand, 13 electromagnet for measurement, 15 pickup coil, 18 drive stand, 19 electromagnet fixing lever,
20 coil rotation drive part, 21 coil signal extraction part, 21-1 bearing part 22, 22a, 22b alignment position reference stand, 23
Displacement sensor drive, 24 Displacement sensor, 25 Measuring stand, 26 Rotating cylinder, 27 Linear guide rail, 28
Measuring position reference stand, 29 measuring ring, 30 outer cylinder, 3
1 measuring hole, 32 coil reel, 33 adjusting bolt,
34 coil groove, 35 drive motor, 36 power transmission belt, 37 rotary connector, 37-1 connector, 37-2 mounting bracket, 38 tightening ring, 39
Spring collet, 40 rotating shaft, 41 disc spring, 4
2a, 42b ball bearings, 43a, 43b collar, 4
4 bearing nut, 45 bearing stand, 46 taper ring, 47 thrust sleeve, 48 reverse taper spring collet, 49 collet fixed rotary shaft, 50
Thrust sleeve rotation stop pin.

Claims (7)

[Claims] 1. A cylindrical rotating coil having a built-in winding for outputting a voltage generated by rotating in a magnetic field of an electromagnet for measurement that generates a multipolar magnetic field, and both ends of the rotating coil are detachable. A rotating device that is gripped and rotated by a bearing portion, an angular position detecting unit that outputs a rotational angular position signal in response to the rotation of the rotary coil, an output signal from the rotary coil, and the rotary angular position signal from the electromagnet. A magnetic field center predicting means for predicting the magnetic field center, and a drive device for changing the relative positional relationship between the electromagnet and the rotating coil so as to match the magnetic field center of the electromagnet with the center of the rotating coil based on the prediction result. A position displacement deriving means for deriving a position displacement between the central axis of the rotating coil and a preset alignment reference, and the magnetic field center of the electromagnet and the rotating coil by the driving device. It is characterized in that the deviation between the geometric center of the electromagnet and the magnetic field center is obtained from the position information obtained as a result of matching the center of the magnet and the position displacement obtained by the position displacement deriving means. Polar magnetic field measuring device. 2. The position displacement derivation means according to claim 1, wherein the rotation coil is rotated to obtain a displacement amount with respect to a rotational position, and the center axis of the rotation coil is determined from the displacement amount at this position and a preset alignment reference. A multipole magnetic field measuring apparatus, characterized in that it is a means for deriving a displacement of a position with respect to the preset alignment reference. 3. The chucking collar according to claim 1 or 2, wherein the rotary coil is an outer cylinder and a cylinder concentric with the outer cylinder, which holds both ends of the outer cylinder and is gripped by the rotating device. A winding frame disposed in the outer cylinder, windings held by the winding frame and wound in symmetry and parallel to the central axis of the outer cylinder, and windings provided on the outer cylinder. And a bobbin movably supported in the radial direction of the outer cylinder to adjust the position, and a measuring hole provided in the outer cylinder so that the reel position can be measured from the outside. A multi-pole magnetic field measuring device characterized in that 4. The multipole magnetic field measuring apparatus according to claim 3, wherein the winding is provided with another winding for detecting a magnetic field near the surface of the outer cylinder. 5. The method according to any one of claims 1 to 4,
The rotating device uses a drive motor as a drive source for driving the rotating coil, disposes the drive motor at a position deviated from the rotation axis of the rotating coil, and drives the rotating coil from the driving motor via a power transmission means. A multipole magnetic field measuring device characterized in that it is driven and configured such that the rotating coil can be inserted and removed in the direction of the rotation axis. 6. The method according to any one of claims 1 to 5,
The gripping mechanism of the rotating device that holds the rotating coil is rotatably held from the bearing side of the rotating device, and is provided with a taper in the rotating shaft direction inside thereof, and a rotating shaft into which the rotating coil is inserted, A taper spring collet for gripping the rotary coil, which has a taper facing the taper of the rotary shaft, and a pressing means for clamping the rotary coil by pressing the taper spring collet in the direction of the rotary shaft. Multi-pole magnetic field measuring device. 7. The method according to any one of claims 1 to 5,
The gripping mechanism of the rotating device that grips the rotating coil is rotatably held from the bearing side of the rotating device, and the rotating shaft into which the rotating coil is inserted and the rotating shaft that rotates together with the rotating shaft. A thrust sleeve that slides in the direction of the arrow and has a taper in the direction of the rotation axis provided inside thereof, and a taper that faces the taper of the thrust sleeve, and
A reverse taper spring collet for gripping the rotary coil, the movement of which in the direction of the rotary axis is restricted; and a pressing means for tightening the reverse taper spring collet by pressing the thrust sleeve in the rotary axis direction to grip the rotary coil. A multi-pole magnetic field measuring device characterized in that