JP3876159B2 - Auto tuning probe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an auto tuning probe used in an NMR apparatus.
[0002]
[Prior art]
The NMR apparatus irradiates a sample to be measured placed in a static magnetic field with high frequency, and then detects a minute high frequency signal (NMR signal) emitted from the sample to be measured, and information on the molecular structure contained therein. Is a device for analyzing the molecular structure of a sample to be measured.
[0003]
In the NMR method, since various nuclides having nuclear spins are to be measured, the frequency of the high frequency applied to the sample to be measured varies greatly. Therefore, in order to save the trouble of setting measurement conditions, an auto-tuning probe that can automatically set the high-frequency frequency according to the nuclide to be measured and can automatically adjust the tuning frequency of the probe has been put into practical use ( Patent No. 3034299).
[0004]
FIG. 1 is a configuration diagram of a conventional example of an NMR apparatus provided with an auto tuning probe. The drive unit 1 of the auto tuning probe includes a drive circuit 2 that drives the tuning dial 6 of the auto tuning probe 5. The drive circuit 2 and the tuning dial 6 are connected by a flexible shaft 4. The drive circuit 2 is controlled by the computer 3. The drive circuit 2 drives the tuning dial 6 in response to an instruction from the computer 3 to change the capacitance of the variable capacitor 7 so that tuning can be achieved.
[0005]
[Problems to be solved by the invention]
By the way, the auto tuning probe 5 of the NMR apparatus has a tuning dial 6 and a drive circuit 2 connected by a flexible shaft 4 and the dial value is managed by the computer 3 on the drive unit 1 side. Since the connection of the shaft 4 is structured to be detachable, once the flexible shaft 4 is removed and the tuning dial 6 of the auto tuning probe 5 is manually turned, the dial value managed on the drive side The actual dial value of the probe may not match.
[0006]
In addition, when a plurality of auto tuning probes are exchanged, when the probes are exchanged, the dial value of the probe before the exchange remains in the computer 3 on the drive unit side, so that it does not match the dial value of the probe after the exchange. There was a case.
[0007]
Further, when the power source of the driving unit 1 is turned off during the measurement, the managed dial value may be lost.
[0008]
Therefore, when the auto tuning probe 5 and the flexible shaft 4 are connected or when the power source of the drive unit 1 is turned on, first, the operator reads the actual dial value of the auto tuning probe 5 and It is to be input to the computer 3.
[0009]
However, if the operator forgets to input the actual dial value of the auto-tuning probe 5 to the computer 3 of the drive unit 1 or enters it incorrectly, the dial value possessed by the computer 3 of the drive unit 1 Because the dial value of the actual auto-tuning probe 5 does not match, auto-tuning is not normally performed, and in some cases, the dial is driven beyond the variable range of the dial, and the variable capacitor for tuning is damaged. There was a problem that caused an accident.
[0010]
In such a case, if the probe is equipped with a mechanism that automatically detects the dial value, it is possible to prevent a situation where the tuning variable capacitor is damaged due to overdrive when the dial is driven. It may become. However, current NMR instrument probes are:
(1) Since it is installed inside the SCM, it cannot incorporate components that are affected by strong magnetic fields.
[0011]
(2) The space inside the SCM is narrow, so bulky parts cannot be installed.
For this reason, it is actually difficult to provide a dial value detection mechanism in the probe.
[0012]
In view of the above-described points, the object of the present invention is to provide a tuning variable even when an erroneous tuning dial value is input due to an erroneous operation by an operator and the dial may be driven beyond the variable range of the dial. An object of the present invention is to provide an auto-tuning probe that does not damage a capacitor.
[0013]
[Means for Solving the Problems]
In order to achieve this object, the auto-tuning probe of the present invention is
A probe for irradiating a sample with a high frequency and detecting an NMR signal emitted from the sample immediately after irradiation. The probe has a mechanism for varying tuning on the probe side, and a transmission unit from a separately provided drive unit. In an auto-tuning probe that drives the tuning variable mechanism to achieve synchronization,
The transmission means is a shaft for transmitting rotation; a screw portion screwed on the shaft; and a rotation-stopped moving member screwed with the screw portion and moving in the axial direction of the shaft according to the rotation of the shaft; A stopper having a protrusion that is fixed to the shaft and protrudes in a direction perpendicular to the axial direction of the shaft that rotates together with the shaft;
Stopping the rotation of the shaft the stopper to rotate together with the shaft comes into contact with the moving element has moved with the rotation of the shaft, is characterized in that so as to regulate the drive range of the tuning variable mechanism.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an embodiment of an auto-tuning probe according to the present invention. In this embodiment, a mechanical stopper 9 is provided between the auto tuning unit 1 and the auto tuning probe 5 via two joints 8.
[0017]
FIG. 3 is an enlarged view of the mechanical stopper 9 portion. The shaft 10 in the mechanical stopper 9 is threaded. A nut slider 11 is attached to the threaded portion of the shaft 10. Since the rotation of the nut slider 11 is restricted by a guide 13 made of a rectangular cylinder attached to the support 12, when the screw shaft 10 rotates, the nut slider 11 slides up and down in the guide 13. .
[0018]
Protrusions 14 are provided at positions on the upper and lower surfaces of the nut slider 11 away from the screw shaft 10. Further, near the upper end and near the lower end of the guide 13, a protruding stopper 15 is provided in a direction orthogonal to the axial direction of the screw shaft 10 and is fixed to the screw shaft 10. When the screw shaft 10 rotates in the clockwise direction, the nut slider 11 slides upward in the guide 13 (FIG. 4). When the nut slider 11 moves to the vicinity of the upper end of the guide 13, the stopper 15 fixed to the screw shaft 10 collides with the protrusion 14 of the nut slider 11 and the rotation of the screw shaft 10 is forcibly stopped (FIG. 5). Similarly, when the screw shaft 10 rotates counterclockwise, the nut slider 11 slides downward in the guide 13 (not shown). When the nut slider 11 moves to the vicinity of the lower end of the guide 13, the stopper 15 fixed to the screw shaft 10 hits the protrusion 14 of the nut slider 11, and the rotation of the screw shaft 10 is forcibly stopped (not shown).
[0019]
If the rotatable range of the screw shaft 10 at this time is set in advance according to the allowable rotation range of the tuning variable capacitor 7 in the probe, the drive range of the tuning variable mechanism is naturally restricted, and the tuning variable capacitance The overdrive of the capacitor 7 can be prevented beforehand.
[0020]
As described above, since it is possible to regulate the drive range of the tuning variable capacitor by using a mechanical stopper with a simple structure, the tuning variable capacitor is damaged by the overdrive of the tuning variable mechanism. It ’s gone.
[0021]
In the above-described embodiment, the mechanical stopper is used to prevent the tuning variable mechanism from being overdriven. Instead of the mechanical stopper, an electrical switch is provided on the upper and lower ends of the guide 13 and provided on the nut slider 11. By pressing the switch with the protrusion 14, overdrive of the tuning variable mechanism may be prevented.
[0022]
【The invention's effect】
As described above, according to the auto-tuning probe of the present invention, a probe for irradiating a sample with a high frequency and detecting an NMR signal emitted from the sample immediately after irradiation, and having a mechanism for varying tuning on the probe side. And an automatic tuning probe configured to drive and tune the tuning variable mechanism from a separately provided drive unit via a transmission means , wherein the transmission means is a shaft for transmitting rotation, and the shaft A screw portion screwed to the shaft, a mover that is screwed with the screw portion and moves in the axial direction of the shaft according to the rotation of the shaft, and an axial direction of the shaft that is fixed to the shaft and rotates together with the shaft A stopper having a protrusion protruding in a direction perpendicular to the shaft, and the stopper that rotates together with the shaft is a shaft. Stopping the rotation of the shaft by abutting the moving element has moved with the rotation of the bets, since so as to regulate the drive range of the tuning variable mechanism, the tuning dial value Erroneous erroneous operator It is possible to provide an auto-tuning probe that does not damage the variable capacitor for tuning even when there is a possibility that the dial is driven beyond the variable range of the dial.
[Brief description of the drawings]
FIG. 1 is a diagram showing a conventional example.
FIG. 2 is a diagram showing an embodiment of the present invention.
FIG. 3 is a diagram showing an embodiment of the present invention.
FIG. 4 is a diagram showing an embodiment of the present invention.
FIG. 5 is a diagram showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Drive part (auto tuning unit) of auto tuning probe, 2 ... Drive circuit, 3 ... Computer, 4 ... Flexible shaft, 5 ... Auto tuning probe, 6 ... Tuning dial 7 ... Variable capacitors, 8 ... Joint, 9 ... Mechanical stopper, 10 ... Screw shaft, 11 ... Nut slider, 12 ... Support, 13 ... Guide, 14 ..Protrusions, 15 ... stoppers.

Claims (1)

A probe for irradiating a sample with a high frequency and detecting an NMR signal emitted from the sample immediately after irradiation. The probe has a mechanism for varying tuning on the probe side, and a transmission unit from a separately provided drive unit. In an auto-tuning probe that drives the tuning variable mechanism to achieve synchronization,
The transmission means is a shaft for transmitting rotation; a screw portion screwed on the shaft; and a rotation-stopped moving member screwed with the screw portion and moving in the axial direction of the shaft according to the rotation of the shaft; A stopper having a protrusion that is fixed to the shaft and protrudes in a direction perpendicular to the axial direction of the shaft that rotates together with the shaft;
Auto, characterized in that the stopper that rotates with the shaft to stop the rotation of the shaft by abutting the moving element has moved with the rotation of the shaft, and adapted to regulate the drive range of the tuning variable mechanism Tuning probe.

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