JP4215049B2 - Rotational vibration testing machine - Google Patents

Description

  The present invention relates to a rotational vibration testing machine applied to, for example, evaluation of rotational vibration of a magnetic disk device.

  In recent years, in magnetic disk devices, track density (TPI: Tracks per inch) has increased and seek speed has increased, and accordingly, it has become important to improve the positioning accuracy of the magnetic head. On the other hand, a rotary actuator is used as a rotational drive source of the magnetic disk device, and has a structure that is weak against rotational disturbance, that is, vibration in the rotational direction. This rotational disturbance is adversely affecting the positioning accuracy.

  Under such circumstances, in the development of magnetic disk devices, it is essential to evaluate rotational vibration and take sufficient measures, and a small rotational vibration testing machine with a wide measurement frequency band is required. It is desired.

  Conventionally, as described in, for example, US Pat. No. 5,644,087, unidirectional vibration generated by a linear vibration generator is converted into rotational vibration using a link mechanism and transmitted to a rotary table. A rotational vibration testing machine that vibrates (oscillates) a rotary table around a rotation axis has been proposed.

  As described above, the conventional rotational vibration tester uses the link mechanism to convert the linear reciprocating vibration generated by the linear vibration generator into the rotational reciprocating vibration, so the measurement frequency band is limited by the resonance of the link mechanism. There was a problem of being done.

  In addition, since the linear vibration generator and the link mechanism are combined, there is a problem that the apparatus becomes large and the transportability is lowered.

  The present invention has been made in order to solve the above-described problems, and transmits a torque generated by a vibration source directly to a rotary table, and a small rotational vibration tester having a wide measurement frequency band. The goal is to achieve this and make it applicable to tests with higher accuracy.

    The rotational vibration testing machine according to the present invention is a rotational vibration testing machine comprising a base, a rotary table rotatably supported by the base, and a vibration means for vibrating the rotary table in the rotation direction. The oscillating means is disposed so as to cross the magnetic field generated by the magnetic field generating unit that generates a magnetic field, and generates a force in the rotation direction of the rotary table when energized. The rotating table is provided with a mounting board and a shaft centered at the center of the mounting board and rotatably supported by the base. And a flange provided on the lower surface of the mounting board, wherein the magnetic field generator is attached to the base, and the coil is attached to the flange. It is.

  According to such a configuration, the conventional link mechanism becomes unnecessary, and it is possible to avoid the restriction of the frequency band due to the characteristics of the link mechanism, and thus, a small rotational vibration tester with a wide measurement frequency band can be obtained. be able to.

  Further, in the rotational vibration testing machine according to the present invention, the rotary table is erected on a lower surface of the mounting board with a disk-shaped mounting board and an axial center aligned with the center of the mounting board, The shaft is rotatably supported by the base, and the coil is attached to the table.

  According to such a configuration, since the coil is attached to the turntable side, the weight of the turntable can be reduced compared to the case where the magnetic field generator is attached, and the force generated in the coil can be efficiently applied to the turntable. It can be transmitted as rotational force.

  In the rotational vibration testing machine according to the present invention, the coil is attached to a coil frame, and the coil frame is attached to the table.

  According to such a configuration, the assembling property of the coil can be improved.

  In the rotational vibration testing machine according to the present invention, the coil frame can be configured so that a plurality of the coils can be mounted, and according to such a configuration, by mounting the coil on the coil frame, The positional relationship between the coils is ensured, and assemblability can be improved.

  In the rotational vibration testing machine according to the present invention, an engaging portion for positioning the coil frame is provided on the mounting board.

  According to such a configuration, the mutual positional relationship between the coil and the rotary table is ensured, and the assemblability can be improved.

  Further, in the rotational vibration testing machine according to the present invention, a plurality of the magnetic field generation units and the coils are arranged at an equiangular pitch with the rotation center as a center.

  According to such a configuration, the force generated by energizing the coil is transmitted to the rotary table in a well-balanced manner, and stable vibration in the rotational direction is obtained.

  In the above configuration, when the coil is de-energized, it is provided with position return means for returning the positional relationship between the coil and the magnetic field generator to a predetermined positional relationship. It is possible to prevent the occurrence of damage to the coil and the magnetism generation unit due to the displacement.

  Further, by feeding back the current flowing through the coil, it is possible to control the current flowing through the coil to be constant, and by generating a constant current through the coil, a constant force can be generated. Therefore, it can generate a constant acceleration vibration and can be applied to a highly accurate test.

  Furthermore, if an acceleration sensor for detecting the acceleration of the rotary table is attached and the detection signal of the acceleration sensor is fed back, the current flowing in the coil can be controlled so that the acceleration of the rotary table is constant. For example, even if resonance occurs in the tester, vibration with a constant acceleration can be generated, so that it can be applied to a test with higher accuracy.

  The rotary vibration testing machine according to the present invention described above includes an arm projecting from the rotary table and a stopper, and the arm is used as the stopper by excessively rotating the rotary table by the vibration means. If it is made to collide, the rotational vibration testing machine which added the impact test function is obtained.

  According to the present invention, the limitation of the frequency band due to the characteristics of the link mechanism is avoided, the measurement frequency band is wide and a small rotational vibration tester can be obtained, and the vibration of constant acceleration can be generated by feedback control, There is an effect that it can be applied to a highly accurate test. In addition, the position return means has an effect of preventing the occurrence of a damage accident of the coil and the magnetism generation unit due to the displacement of the coil. Furthermore, the structure which makes an arm collide with a stopper has an effect of obtaining a rotational vibration testing machine to which an impact test function is added.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a partially broken top view showing a rotational vibration testing machine according to Embodiment 1 of the present invention, and FIG. 2 is a partially broken side view showing the rotational vibration testing machine according to Embodiment 1 of the present invention.

  1 and 2, in the rotary vibration testing machine, a rotary table 1 on which a test object is placed is rotatably mounted on a base 2, and four voice coil motors (VCM) 10 as vibration means are rotated. The table 1 is arranged on the same circumference around the rotation center X of the table 1 at an equiangular pitch. Further, the rotational vibration tester includes a power supply device 11 for driving the VCM 10.

  The rotary table 1 includes a mounting plate 1a formed in a disk shape, a shaft 1b whose axis is aligned with the center of the mounting plate 1a and fastened to the lower surface of the mounting plate 1a, and a mounting plate 1a. And a cylindrical flange 1c provided coaxially with the shaft 1b. The axis of the shaft 1b is the rotation center X of the turntable 1.

  The base 2 is fastened and fixed on the gantry 3, and the bearing housing 4 is fastened and fixed to the base 2. The two bearings 5 are appropriately preloaded by the coil springs 6 and accommodated in the bearing housing 4, and the rotary table 1 is rotatably mounted on the base 2 with the shaft 1 b supported by the two bearings 5. ing.

  The VCM 10 includes a magnetic circuit 12 and a coil 13 bonded and fixed to an aluminum coil frame 14. The four coil frames 14 each having the coil 13 mounted thereon are fastened and fixed to the flange 1c at an equiangular pitch with the rotation center X as the center.

  On the other hand, the magnetic circuit 12 includes an upper yoke 15 and a lower yoke 16 formed in a substantially trapezoidal shape, two side yokes 17 that connect these two yokes 15 and 16 at both ends, and a stud 18; It is composed of two permanent magnets 20A and 20B as magnetic field generating portions that are bonded and fixed to the lower surface of the upper yoke 15 and the upper surface of the lower yoke 16, respectively. The lower yoke 16 is disposed on the base 2, the upper yoke 15 is disposed so as to face the lower yoke 16 with the side yoke 17 interposed therebetween, and the upper yoke 15 and the lower yoke 16 are integrally fastened to the base 2. It is fixed.

  Thereby, the upper yoke 15 and the lower yoke 16 are magnetically coupled by the side yoke 17. A predetermined gap (magnetic gap) is secured between the permanent magnet 20A fixed to the lower surface of the upper yoke 15 and the permanent magnet 20B fixed to the upper surface of the lower yoke 16, and the coil 13 has two. Two permanent magnets 20A and 20B are inserted in the gap. The stud 18 is provided with a rubber ring 19 for buffering the contact with the coil frame 14.

  As shown in FIG. 3, the permanent magnet 20 </ b> B fixed to the lower yoke 16 is surrounded by a concentric inner peripheral surface 21 and an outer peripheral surface 22 centering on the rotation center X, and two radial surfaces 23. It is a curved flat plate, and is divided into an S pole and an N pole with a line L that bisects the permanent magnet 20B in the circumferential direction passing through the rotation center X as a boundary.

  On the other hand, the permanent magnet 20A fixed to the upper yoke 15 is formed in the same shape as the permanent magnet 20B. The permanent magnet 20A is separated so that the area facing the south pole of the permanent magnet 20B is the north pole and the area facing the north pole of the permanent magnet 20B is the south pole.

  Here, the operation of the VCM 10 will be described with reference to FIG. FIG. 4 is a diagram for explaining the operation of the VCM, and shows a state in which the upper yoke 15 is removed from the magnetic circuit 12.

  The coil 13 is attached to the turntable 1 in such a positional relationship that its center coincides with a line L passing through the rotation center X. Effective portions 13a and 13b of the coil 13 are located in the N-pole region and the S-pole region of the permanent magnet 20B, respectively. In the N pole region of the permanent magnet 20B, a magnetic field is generated perpendicular to the paper surface in FIG. 4 and from the back surface to the front surface. In the S pole region, the magnetic field is perpendicular to the paper surface in FIG. Has occurred. Therefore, when a current is passed through the coil 13, reverse current flows in the effective portions 13a and 13b, and thrust in the same direction is generated in the effective portions 13a and 13b.

  In FIG. 4A, a current is passed counterclockwise through the coil 13, a thrust fa is generated in the coil 13, and the coil 13, that is, the rotary table 1 rotates clockwise about the rotation center X. Is done.

  In FIG. 4B, a current is passed clockwise through the coil 13, a thrust fb in the direction opposite to fa is generated in the coil 13, and the turntable 1 counterclockwise around the rotation center X. Rotated around.

  In this way, by alternately changing the direction of the current supplied to the coil 13 by the power supply device 11, the rotary table 1 swings around the rotation center X in a predetermined angle range, that is, vibrates in the rotational direction (hereinafter referred to as rotational vibration). Will be done).

  In the first embodiment, the rotary table 1 is configured to swing within a range of ± 2 °. The four coils 13 are connected so as to be connected in series so that a force acts in the same direction when a current is passed.

  Next, the operation of the rotational vibration testing machine configured as described above will be described.

  First, a magnetic disk device, which is a device under test, is fixed on the mounting board 1 a of the rotary table 1. Next, the alternating current of a predetermined frequency is supplied to the coil 13 by the power supply device 11 so that the rotary table 1 rotates and vibrates around the rotation center X in a range of ± 2 °. As a result, rotational vibration is applied to the magnetic disk device, and a test evaluation for rotational disturbance of the magnetic disk device is performed.

  Here, the performance of the rotational vibration testing machine configured as described above will be described.

When the magnetic flux density of the magnetic circuit 12 is Bg (T) and the effective length of the coil 13 is L (m), the force F generated in the VCM 10 when a current of 1 (A) is passed through the coil 13 is
F = BL (N / A)
It becomes.

When the distance from the rotation center X to the coil 13 is r (m), the number of VCMs 10 is n, and n VCMs are connected in series, the torque generated by the VCM is
T = nFr = nBLr (Nm / A)
It becomes.

On the other hand, when the moment of inertia of the rotary table 1 is J (kgm ² ), the performance of the rotary vibration tester at no load is
d ² θ / dt ² = T / J = nBLr / J (rad / s ² / A)
It becomes.

In the present embodiment, as shown in FIG. 5, d ² θ / dt ² = 670 (rad / s ² / A), that is, about 57 dB in dB display is achieved in a frequency band of 1 KHz or less at no load. is doing.

FIG. 5 shows the frequency characteristics of the rotational vibration testing machine according to the embodiment. The acceleration is approximately constant 57 dB (rad / s ² ) for a current of 1 A up to about 1 KHz, and As in the case of acceleration, the phase is recognized to be almost 0 (deg) up to about 1 KHz, indicating a broadband characteristic.

  As described above, according to the first embodiment, the VCM 10 is used as the vibration means, and the rotary table 1 is directly rotated and oscillated by the thrust generated by the VCM 10. Therefore, the linear reciprocating force is applied to the rotational force via the link mechanism. The rotary table 1 can be efficiently rotated and oscillated as compared with the conventional apparatus in which the rotary table is oscillated and rotated. In addition, a link mechanism is not required, and downsizing can be achieved, and a wider measurement frequency can be realized. Furthermore, since the VCM 10 itself is small, the number of VCMs 10 can be increased or decreased as necessary, and the excitation force can be easily adjusted.

  In addition, since the coil 13 that is lighter than the magnetic circuit 12 is attached to the mounting board 1a, the rotary table 1 can be efficiently rotated by the thrust generated by passing an electric current through the coil 13.

  Moreover, since the coil frame 14 to which the coil 13 is mounted is attached to the flange 1c of the mounting board 1a, the coil 13 can be easily attached to the turntable 1.

  Further, since the VCM 10 is arranged at an equiangular pitch around the rotation center X, the thrust generated by flowing current through the coil 13 acts on the rotary table 1 in a balanced manner, and the rotary table 1 is stably rotated. Can be made.

  In the first embodiment, four VCMs 10 are used. However, the number of VCMs 10 is not particularly limited as long as it can generate the required excitation force.

  Further, the VCM 10 is not necessarily arranged at an equiangular pitch, but it is desirable to arrange the VCM 10 at an equiangular pitch in order to apply thrust to the rotary table 1 in a balanced manner.

  In the first embodiment, the magnetic circuit 12 is attached to the base 2 and the coil 13 is attached to the turntable 1. However, the magnetic circuit 12 is attached to the turntable 1 and the coil 13 is attached to the base 2. However, the same effect can be obtained.

  In the first embodiment, the four coils 13 are connected in series. However, in consideration of the resistance and inductance of the coil 13, the four coils 13 may be connected in parallel, or in series and in parallel. May be connected in combination, whereby a circuit according to the specifications of the power supply device 11 can be realized.

Embodiment 2. FIG.
In the first embodiment, a VCM is used in which the coil 13 is in a horizontal posture (the arrangement of the effective portions 13a and 13b is horizontal). However, in the second embodiment, the coil 13 is in a vertical posture (the effective portions 13a and 13b). It is assumed that a VCM in which the arrangement of 13b is vertical) is used.

  FIG. 6 is a sectional view showing a rotational vibration testing machine according to Embodiment 2 of the present invention.

  In FIG. 6, the VCM 10 </ b> A as the vibration means is composed of a magnetic circuit 12 </ b> A and a coil 13 that is bonded and fixed to the coil frame 14. The four coil frames 14 each having the coil 13 mounted thereon are fastened and fixed to the flange 1c at an equiangular pitch with the rotation center X as the center.

  The magnetic circuit 12A includes an upper yoke 15, a lower yoke 16, and an intermediate yoke 22 formed in a substantially trapezoidal shape, and a side yoke (not shown) that connects these three yokes 15, 16, and 22 at their ends. And two permanent magnets 21A and 21B that are bonded and fixed to the lower surface of the upper yoke 15 and the upper surface of the lower yoke 16, respectively. The permanent magnet 21A is formed into the same curved flat plate as the permanent magnet 20A in the first embodiment, and the lower surface is magnetized to the N pole. Similarly, the permanent magnet 21B is formed in the same shape as the permanent magnet 21A, and its upper surface is magnetized to the N pole. A predetermined gap (magnetic gap) is secured between the permanent magnets 21A and 21B and the intermediate yoke 22, and the coil 13 is disposed with the effective portions 13a and 13b inserted into the gaps. Yes.

  Here, the operation of the VCM 10A will be described.

  A magnetic field from the permanent magnet 21A to the intermediate yoke 22 is generated between the permanent magnet 21A and the intermediate yoke 22, and a magnetic field from the permanent magnet 21B to the intermediate yoke 22 is generated between the permanent magnet 21B and the intermediate yoke 22. Has occurred.

  When a current is passed through the coil 13, reverse current flows in the effective portions 13a and 13b, and thrust in the same direction is generated in the effective portions 13a and 13b. Therefore, by alternately changing the direction of the current supplied to the coil 13 by the power supply device 11, the rotary table 1 is swung around the rotation center X within a predetermined angle range, that is, is rotated and vibrated.

Thus, since this VCM 10A also operates in the same manner as the VCM 10, this second embodiment also has the same effect as the first embodiment.
Embodiment 3 FIG.
In the first embodiment, the coil 13 is attached to the flange 1c provided on the mounting board 1a. In the third embodiment, the coil 13 is attached to the shaft 1b.

  FIG. 7 is a cross-sectional view schematically showing a rotational vibration testing machine according to Embodiment 3 of the present invention.

  In FIG. 7, the rotary table 1 has a shaft 1b supported by two bearings 5 and is rotatably attached to a base 2A. The magnetic circuit 12 is fixed in the base 2A at an equiangular pitch around the axis of the shaft 1b. Further, a coil frame 14 fitted with the coil 13 is fastened and fixed to the shaft 1b at an equiangular pitch. Thereby, the coil 13 is inserted between the permanent magnets 20 </ b> A and 20 </ b> B of the magnetic circuit 12.

  In this Embodiment 3, the thrust which generate | occur | produces in the coil 13 by sending an electric current through the coil 13 is transmitted to the shaft 1b via the coil frame 14, and the turntable 1 is rotated. Therefore, by alternately changing the direction of the current supplied to the coil 13 by the power supply device 11, the rotary table 1 is swung around the rotation center X within a predetermined angle range, that is, is rotated and vibrated.

Therefore, the third embodiment also has the same effect as the first embodiment.
Embodiment 4 FIG.
In the fourth embodiment, as shown in FIG. 8, a groove 24 as an engaging portion for positioning is provided at the lower end of the outer periphery of the flange 1c, and the coil frame 14 is fitted into the groove 24 so as to be attached to the flange 1c. Fastened and fixed.

  Other configurations are the same as those in the first embodiment.

In Embodiment 4, since the groove 24 is provided in the flange 1c, the coil frame 14 is positioned by fitting the coil frame 14 into the groove 24. Therefore, the positional relationship between the magnetic circuit 12 and the coil 13 can be easily secured with high accuracy, and the assemblability can be improved.
Embodiment 5 FIG.
In the fourth embodiment, the groove 24 as the engaging portion for positioning is provided at the lower end of the outer periphery of the flange 1c. In the fifth embodiment, as shown in FIG. 9, the outer periphery of the flange 1c is provided. A step 25 as an engaging portion for positioning is provided at the lower end portion, and the same effect is obtained.
Embodiment 6 FIG.
In the sixth embodiment, as shown in FIG. 10, an annular fitting portion 26a fitted to the outer peripheral end portion of the flange 1c, and extending radially outward from the fitting portion 26a at an equiangular pitch. The coil frame 26 composed of the four coil mounting portions 26b is used.

  Other configurations are the same as those in the first embodiment.

  In the sixth embodiment, after the coil 13 is bonded and fixed to each coil mounting portion 26b, the fitting portion 26a is fitted into the flange 1c, the coil frame 26 is fastened and fixed to the flange 1c, and the coil 13 is fixed to the turntable 1. It is attached to.

  Therefore, the four coils 13 can be attached to the turntable 1 at a time, and the assemblability can be improved.

  Further, since the four coil attachment portions 26b are integrally formed with the fitting portion 26a, the rigidity is increased and excellent durability is obtained. Furthermore, since the positional relationship between the coil attachment portions 26b (coils 13) can be ensured with high accuracy, the positional relationship between the magnetic circuit 12 and the coil 13 can be easily adjusted, and assemblability can be improved accordingly.

In the sixth embodiment, the four coil attachment portions 26b are integrally formed. However, the integrally formed coil attachment portions are not limited to four. For example, two coil attachment portions are provided. You may make it integrally mold.
Embodiment 7 FIG.
In the sixth embodiment, the four coil mounting portions 26b are formed integrally with the fitting portion 26a. However, in the seventh embodiment, as shown in FIG. 11, the flange 1c of the turntable 1 is formed. Four coil attachment portions 27 are extended radially outward at an outer peripheral end portion at an equiangular pitch.

  In the seventh embodiment, the coil 13 is attached to the turntable 1 by bonding and fixing the coil 13 to each coil attachment portion 27.

  Therefore, since the step of attaching the coil frame is omitted, the assemblability can be improved.

Further, since the coil mounting portion 27 is integrally formed with the flange 1c, the rigidity is enhanced and excellent durability is obtained. Furthermore, since the positional relationship between the coil attachment portions 27 (coils 13) can be ensured with high accuracy, the positional relationship between the magnetic circuit 12 and the coil 13 can be easily adjusted, and assemblability can be improved accordingly.
Embodiment 8 FIG.
In the eighth embodiment, as shown in FIG. 12, the cooling fan 28 is arranged on the outer peripheral side of each VCM 10.

  Other configurations are the same as those in the first embodiment.

  When the VCM 10 is activated, a large amount of current is passed through the coil 13 and the coil 13 generates heat. And the malfunction that the performance of a rotational vibration testing machine will be restrict | limited to the heat_generation | fever in the coil 13 has arisen.

According to the eighth embodiment, by operating the cooling fan 28 when the VCM 10 is operated, the cooling air is blown to the coil 13 and the temperature rise of the coil 13 is suppressed, and the performance limit can be further increased. It becomes like this.
Embodiment 9 FIG.
FIG. 13 is a top view schematically showing a rotational vibration testing machine according to Embodiment 9 of the present invention.

  In FIG. 13, an arm 29 is extended radially outward from the flange 1 c of the turntable 1, a pair of support columns 30 are erected on the base 2 so as to face each other with the arm 29 interposed therebetween, and coil springs 31 and 32 are provided. Arranged between the arm 29 and the pair of support columns 30. The arm 29, the pair of support columns 30, and the coil springs 31 and 32 constitute position return means. The balance positions of the coil springs 31 and 32 are set so that the center of the coil 13 matches the line L (the center of the magnetic circuit 12) that bisects the permanent magnets 20A and 20B in the circumferential direction through the rotation center X. ing.

  Other configurations are the same as those in the first embodiment.

  In the first embodiment, the VCM 10 is stopped by an external force caused by the tension applied to the cord of the device under test placed on the placement board 1a or an input offset caused by a direct current component of the current flowing through the coil 13. In this case, the center of the coil 13 may be shifted from the center of the magnetic circuit 12. When the VCM 10 is operated with the center of the coil 13 shifted from the center of the magnetic circuit 12 to rotate the rotary table 1, the coil frame 14 collides with the rubber ring 19 and damages the coil 13 and the magnetic circuit 12. There was a risk of letting it go.

  According to the ninth embodiment, when energization to the coil 13 is released, the arm 29 is returned to the balance position of the coil springs 31 and 32, and the center of the coil 13 is always returned to the center of the magnetic circuit 12. Therefore, it is possible to prevent damage to the coil 13 and the magnetic circuit 12 caused by operating the VCM 10 in a state where the center of the coil 13 is shifted from the center of the magnetic circuit 12.

Here, if the arm 29 resonates due to rotational vibration of the turntable 1, it may affect the performance of the testing machine. Therefore, it is desirable to increase the rigidity of the arm 29. For example, a stainless steel arm is used. Can do.
Embodiment 10 FIG.
FIG. 14 is a top view schematically showing a rotational vibration testing machine according to Embodiment 10 of the present invention.

  In FIG. 14, the arm 29 is extended radially outward from the flange 1 c of the turntable 1, the magnet 33 is fixed to the tip of the arm 29, and the pair of magnets 34 generates a repulsive force against the magnet 33. Are fixed to the base 2 opposite to each other with the magnet 33 interposed therebetween. The arm 29, the magnet 33, and the pair of magnets 34 constitute a position return means, and when the center of the coil 13 coincides with the center of the magnetic circuit 12, the balance of repulsive force acting on the magnet 33 from the pair of magnets 34 is balanced. The positional relationship of the magnets 33 and 34 is set so that it can be taken.

  Other configurations are the same as those in the first embodiment.

According to the tenth embodiment, when energization of the coil 13 is released, the arm 29 is returned to the balance position of the magnets 33 and 34, and the center of the coil 13 is always returned to the center of the magnetic circuit 12. Therefore, it is possible to prevent the coil 13 and the magnetic circuit 12 from being damaged due to operating the VCM 10 with the center of the coil 13 being shifted from the center of the magnetic circuit 12.
Embodiment 11 FIG.
FIG. 15 is a top view schematically showing a rotational vibration testing machine according to Embodiment 11 of the present invention.

  In FIG. 15, the magnet 33 is fixed to the tip of the arm 29 extending radially outward from the flange 1 c of the turntable 1, and the block composed of the magnets 35 and 36 is attached to the base 2 so as to surround the magnet 33. It is fixed. A position return means is constituted by a block constituted by the arm 29, the magnet 33 and the magnets 35 and 36.

  Other configurations are the same as those in the first embodiment.

  In the eleventh embodiment, the center of the block constituted by the magnets 35 and 36 becomes a stable point, and the magnet 33 balances at this position. Therefore, the block is installed so that the center of the coil 13 coincides with the center of the magnetic circuit 12 when the magnet 33 is in the center of the block.

According to the eleventh embodiment, when the power supply to the coil 13 is released, the magnet 33 is returned to the center position of the block constituted by the magnets 35 and 36, and the center of the coil 13 is set to the center of the magnetic circuit 12. Always regressed. Therefore, it is possible to prevent the coil 13 and the magnetic circuit 12 from being damaged due to operating the VCM 10 with the center of the coil 13 being shifted from the center of the magnetic circuit 12.
Embodiment 12 FIG.
FIG. 16 is a top view schematically showing a rotational vibration testing machine according to Embodiment 12 of the present invention.

  In FIG. 16, an arm 36 is extended radially outward from the flange 1 c of the turntable 1, and a stopper 37 is erected on the base 2.

  Other configurations are the same as those in the first embodiment.

  In the twelfth embodiment, a direct current is supplied to the coil 13 by the power supply device 11 and the rotary table 1 is excessively rotated in one direction, whereby the arm 36 collides with the stopper 37 and is placed on the placement board 1a. A predetermined impact force can be applied to the test object.

  Therefore, according to the twelfth embodiment, a rotational vibration testing machine to which an impact test function is added can be obtained.

In the twelfth embodiment, the arm 36 and the stopper 37 are provided. However, the same applies when the rubber ring 19 of the magnetic circuit 12 is used to cause the coil frame 14 to collide with the rubber ring 19. The effect is obtained.
Embodiment 13 FIG.
FIG. 17 is a block diagram for explaining current control in the rotational vibration testing machine according to Embodiment 13 of the present invention.

  In the thirteenth embodiment, the magnitude of the current flowing through the coil 13 of the rotational vibration testing machine is detected as the voltage across the sense resistor 40 connected in series with the coil 13, and the voltage across the sense resistor 40 is detected. I have feedback. As a result, the power amplifier 41 operates so that the difference between the command value and the fed back voltage value becomes zero, and the current supplied to the coil 13 is controlled to be constant.

Accordingly, since the VCM generates a thrust proportional to the current flowing through the coil 13, the current supplied to the coil 13 is controlled to be constant so that vibration with a constant acceleration can be generated. . Therefore, since a constant acceleration is obtained over a wide measurement frequency band, it can be applied to a highly accurate rotational vibration test.
Embodiment 14 FIG.
FIG. 18 is a block diagram for explaining current control in the rotational vibration testing machine according to Embodiment 14 of the present invention.

  In the fourteenth embodiment, an acceleration sensor 42 such as a piezoelectric accelerometer is attached to the turntable 1, the acceleration of the turntable 1 is detected as a voltage value by the acceleration sensor 42, and the voltage value detected by the acceleration sensor 42 is fed back. is doing. As a result, the power amplifier 41 operates so that the difference between the command value and the fed back voltage value becomes zero, and the current supplied to the coil 13 is controlled.

In general, when there is resonance in the test machine, the acceleration is not constant near the resonance frequency, but according to the fourteenth embodiment, the coil is controlled so that the acceleration of the rotary table 1 is constant, that is, the command value. Since the current supplied to 13 is controlled, even if there is resonance in the testing machine, vibration with a constant acceleration can be generated, which can be applied to a more accurate rotational vibration test.
Embodiment 15 FIG.
FIG. 19 is a block diagram illustrating current control in the rotational vibration testing machine according to Embodiment 15 of the present invention.

  In this fifteenth embodiment, the amplitude is made constant with respect to the fourteenth embodiment. The command value and the output of the acceleration sensor 42 are Fourier-transformed by fast Fourier transformers 43 and 45, respectively, and an adder 46 is added. In addition, an inverse fast Fourier transformer 44 is provided on the input side of the power amplifier 41, and its output is used as an input to the power amplifier. According to this embodiment, it is possible to perform control to make the acceleration amplitude of rotational vibration constant, and it can be applied to a highly accurate rotational vibration test.

  In each of the above embodiments, a permanent magnet is used as the magnetism generating means. However, the magnetism generating means is not limited to a permanent magnet, and any magnetism generating means may be used, for example, an electromagnet may be used. .

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the small rotational vibration testing machine which can be applied to a test with a wide measurement frequency band and higher accuracy.

It is a partially broken top view which shows the rotational vibration testing machine which concerns on Embodiment 1 of this invention. It is a partially broken side view which shows the rotational vibration testing machine which concerns on Embodiment 1 of this invention. It is a top view which shows the positional relationship of the lower yoke of a magnetic circuit and a permanent magnet in the rotational vibration testing machine which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the voice coil motor in the rotational vibration testing machine which concerns on Embodiment 1 of this invention. It is a graph showing the frequency characteristic in the rotational vibration testing machine which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the rotational vibration testing machine which concerns on Embodiment 2 of this invention. It is sectional drawing which shows typically the rotational vibration testing machine which concerns on Embodiment 3 of this invention. It is a perspective view which shows the principal part of the rotational vibration testing machine which concerns on Embodiment 4 of this invention. It is a perspective view which shows the principal part of the rotational vibration testing machine which concerns on Embodiment 5 of this invention. It is a perspective view which shows the structure of the coil frame in the rotational vibration testing machine which concerns on Embodiment 6 of this invention. It is a perspective view which shows the structure of the coil frame in the rotational vibration testing machine which concerns on Embodiment 7 of this invention. It is a perspective view which shows the rotational vibration testing machine which concerns on Embodiment 8 of this invention. It is a top view which shows typically the rotational vibration testing machine which concerns on Embodiment 9 of this invention. It is a top view which shows typically the rotational vibration testing machine which concerns on Embodiment 10 of this invention. HYPERLINK “http://webpat.lip.fujitsu.com/patimage/f8/dl/f8dl3a3o.tif” FIG. 20 is a top view schematically showing a rotational vibration testing machine according to an eleventh embodiment of the present invention. It is a top view which shows typically the rotational vibration testing machine which concerns on Embodiment 12 of this invention. It is a block diagram explaining the current control in the rotational vibration testing machine which concerns on Embodiment 13 of this invention. It is a block diagram explaining the current control in the rotational vibration testing machine which concerns on Embodiment 14 of this invention. It is a block diagram explaining the current control in the rotational vibration testing machine which concerns on Embodiment 15 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary table 1a Mounting board 1b Shaft 2 Base 11 Power supply device (vibration means)
13 Coil (Excitation means)
14, 26 Coil frame 20A, 20B, 21A, 21B Permanent magnet (vibration means, magnetic field generator)
24 groove (engagement part)
25 Step (engagement part)
27 Coil mounting part 36 Arm 37 Stopper

Claims (6)

In a rotary vibration testing machine comprising a base, a rotary table rotatably supported by the base, and a vibration means for vibrating the rotary table in the rotation direction,
The vibration means is configured to generate a magnetic field, a coil that is arranged so as to cross the magnetic field generated by the magnetic field generation unit, and generates a force in the rotation direction of the rotary table when energized. It consists of a power supply unit that energizes with alternating current direction,
The rotary table is provided with a mounting board, a shaft that is provided with its center aligned with the center of the mounting board, and is rotatably supported by the base, and a flange provided on the lower surface of the mounting board And consists of
The magnetic field generator is attached to the base;
The coil is attached to the flange;
A rotary vibration testing machine comprising a feedback control unit for performing feedback control of a current flowing through the coil. The rotational vibration testing machine according to claim 1, wherein the feedback control unit detects the magnitude of a current flowing through the coil as a voltage across a sense resistor connected in series with the coil, A rotary vibration tester characterized by feeding back the voltage at both ends. 2. The rotational vibration testing machine according to claim 1, further comprising an acceleration sensor for measuring the acceleration of the rotary table, wherein the feedback control unit feeds back the output of the acceleration sensor, and the acceleration of the rotary table becomes constant. In this way, the rotational vibration testing machine is characterized in that the current flowing through the coil is controlled. The rotational vibration testing machine according to claim 1, further comprising an acceleration sensor that measures acceleration of the rotary table, wherein the feedback control unit performs Fourier transform on each of the command value and the output of the acceleration sensor by a fast Fourier transformer. In addition to the adder, a rotational vibration tester characterized in that an inverse fast Fourier transformer is provided on the input side of the power amplifier and its output is used as an input to the power amplifier. 5. The rotational vibration testing machine according to claim 1, wherein when the energization of the coil is released, the position returning means returns the positional relationship between the coil and the magnetic field generation unit to a predetermined positional relationship. A rotational vibration testing machine characterized by comprising: In the rotational vibration testing machine according to any one of claims 1 to 5,
The magnetic field generator is attached to the base;
The coil is attached to the flange;
A rotary vibration testing machine comprising: an arm protruding from the rotary table; and a stopper, wherein the rotary table is excessively rotated by the vibration means to cause the arm to collide with the stopper.

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