JPH0442756A - Device for supporting specimen - Google Patents

Abstract

PURPOSE:To make high accurate measurement possible of a test piece by vertically supporting its supporting shaft both ends by main and auxiliary shafts and pressing the auxiliary shaft, slidable in the axial direction, by a weight, in the case of a supporting device which supports a rotor of a brushless motor as the test piece. CONSTITUTION:A rotor 60 of a brushless motor, used as a test piece, is engage- supported to a pair of shafts 18, 30, opposedly arranged coaxially with a rotor shaft 62a, in both ends of the rotor shafts 62a vertically provided, and rotated with a main shaft 18 through a rotation transmitting means 33. Here, the auxiliary shaft 30 is supported rotatably and slidably in the axial direction by rotatably supporting the main shaft 18. In an upper end part of the auxiliary shaft 30, proper pressing force is given to both upper and lower ends of the rotor shaft 62a. A weight 42 is removably fitted to press the rotor 60, serving as the test piece, in the axial direction. In this way, the test piece can be high accurately measured by making its supporting shaft both ends supportable always by proper pressing force surely further in a stable condition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a support device for a test piece, and in particular to a support device for a test piece, and in particular a support device for supporting a test piece. This invention relates to a support device using a weight.

[Prior Art] In recent years, the development of audio equipment, video equipment, computers, etc. has been rapid, and as the performance has improved, sophistication of quality has been required6.In particular, AV equipment (audio-visual equipment) The motor installed in the machine is required to have small rotational irregularities, high efficiency, and stability.

However, as for the drive method, direct drive method has started to attract attention, and there is a need for a motor with low speed and extremely small rotational irregularities, and the axial flux brushless motor is the best motor to meet this requirement. This motor is commonly used in AVII devices.

That is, as shown in the cross-sectional views of brushless motors in FIGS. 4(a) and 4(b), the three-phase bipolar 8-pole brushless motor that is most commonly used has a flat outer shape with a smaller axial dimension than its diameter. The structure is as follows.

In this case, the rotor 60 serving as a test piece is formed of a disc-shaped magnet, and has an S configuration called axial flux, which is magnetized in the direction of the rotation axis perpendicular to the disc.

One of the rotating shafts 62a of the rotor magnet 62 is connected to a bearing 6 inserted into the boss 65a of the housing 65.
It is rotatably supported via 7a and 67b.

Further, an iron substrate (hereinafter referred to as a yoke 98) is fixed to the upper surface of a flange 65b formed on the housing 65, and six fan-shaped coils 96 are arranged in the shape of orange slices on the upper surface of the yoke 98, which becomes an insulating surface 98a. A stator 97 is configured.

The lower surface of the rotor magnet 62 is magnetized into an 8-pole fan shape, and this magnetized surface 62b and the coil 9 of the stator 97
The rotor magnet 62 is supported so as to form a slight cap δ between the rotor magnet 62 and the flat surface of the rotor magnet 62.

Further, the coil 96 has a positional relationship of ±7.5° based on the position where the magnetic pole and the center of the coil 96 overlap.
The torque-generating conductor (straight portion) of the coil overlaps a lot with the magnetic pole boundary, making the torque generated by the coil unstable, so it is disconnected from the motor circuit.

On the other hand, the coil 96 of 6@ has one phase in which two coils 96 facing each other around the rotor shaft 62a are connected in series, and the two phases that do not meet the above conditions are connected in series and the magnetic pole ( The direction of the current is controlled so that rotational torque is generated in one direction depending on the N pole (N pole, 5ffi).

In this type of motor, the coil of one of the three phases is always at rest, and this switching is performed by the driver IC every time the rotor 60 rotates 15 degrees.

That is, torque is generated by each coil simultaneously acting on all magnetic poles of the rotor magnet 62.
As the motor rotates, the armature current is sequentially switched from the coil forming one pole to the coil forming the next pole, and each coil takes charge of generating torque in turn.

The coil current of one pole is switched between positive and negative directions depending on the polarity of the approaching magnetic pole, and the switching of this current between positive and negative is performed at a synchronous frequency determined by the number of poles of the rotor magnet 62 and the rotational speed of the motor.

In addition, since the torque changes depending on the strength of the main magnetic flux and the relative positional relationship between the magnetic poles of the rotor magnet 62 and the coil 96 as well as the current of the coil, the relative positional relationship between the magnetic poles of the rotor magnet 62 and the coil 96 changes due to the rotation of the rotor magnet 62. The current in each coil must be controlled accordingly, so that the torque generated at any moment is always constant.

In this case, if the torque changes depending on the positional relationship of the rotor magnet 62, the rotational speed of the motor changes instantaneously, causing so-called wow and flutter. This wow and flutter is fatal to the AVII motor, so
It is necessary to suppress torque fluctuations as much as possible.

This control is performed by the Hall element 100 and the coil current control circuit, and the Hall element 100 is connected to the rotor magnet 62.
Based on the signal, electronic circuitry distributes the appropriate current to the coils of each phase.

Here, in order for the torque generation sequence to be performed accurately, the arrangement positions of the magnetic poles and Hall elements 100 must be accurate. This disturbs the periodicity of the sequence for controlling the coil current, and causes the torque to fluctuate over time within one rotation of the motor.

Further, as the rotor magnet 62 rotates, the magnetic poles that generate torque change sequentially, but if there is any unevenness in the magnetization of the magnet, this can immediately cause fluctuations in the rotational speed.

Therefore, it is necessary to measure the magnetization distribution state of the rotor magnets of various brushless motors in advance and collect data on magnetic flux density.

Therefore, when measuring the magnetization distribution of the rotor magnet 62, the detection head of the magnetic flux density measuring device is moved by the feeding mechanism while the rotor magnet 62 is rotating at a constant speed.
The magnetization distribution was determined by moving at a constant speed in the radial direction with respect to the rotor magnet 62 and using the output voltage of the detection head as a measurement value.

In order to obtain accurate measurement values for the test piece (such as a rotor) as a measurement object to be measured in this way, a support device is required to support the test piece reliably and in a stable state.

In this case, the conventional test piece support device engages and supports the upper and lower shaft ends of the support shaft provided on the test piece in a pressed state.
A pair of shafts are arranged oppositely on the same axis as this support shaft, and one or the other shaft facing the end of the support shaft is moved forward and backward in the axial direction by manual rotation of a long screw. It was configured to abut and engage with the end of the support shaft to support the test piece.

[Problems to be Solved by the Invention] However, such a conventional support device that manually operates one or the other shaft of a long screw to engage and support it in the axial direction does not support the rotation of this screw. When bringing the shaft end engaging part of the shaft moving by the shaft into contact with the engaging part (center) of the supporting shaft end of the test piece (rotor, etc.), an appropriate axial pressing force was applied to the supporting shaft engaging part. The shaft on the moving side must be positioned in the correct position.This pressing force will vary depending on the tightening force, so it is important to always set it to obtain the optimum pressing force.If this pressing force is insufficient, the test specimen However, if the pressing force is too strong, the rotational resistance becomes large and the power loss becomes excessive.

Therefore, an object of the present invention is to arrange a main shaft and an auxiliary shaft on the axis of the support shaft so as to vertically support both ends of the support shaft of the test specimen, and to provide a rotating and axial direction on the upper part of the support shaft. By configuring the slidably supported auxiliary shaft to be pressed by an appropriately weighed 1JL weight, both ends of the support shaft of the test piece can always be supported with an appropriate pressing force, and the pressing force due to individual differences can be avoided. An object of the present invention is to provide a test piece support device that can achieve highly accurate measurement without causing variations in the test piece.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a test piece in which the test piece is vertically supported at both ends of its support shaft, and a detection device is moved forward and backward on the test piece to perform a characteristic test on the test piece. A test piece support device includes a main shaft that is rotatably supported on a base and has an engaging portion at its tip that can be engaged with one end of the support shaft, and a main shaft that is rotatable and axially supported on the axis of the main shaft. an auxiliary shaft that is slidably supported and has an engaging part at its tip that faces the engaging part of the main shaft; a support provided on the base to support the auxiliary shaft; and an upper part of the auxiliary shaft. and a weight engaged with the test piece, and is configured such that both ends of the support shaft of the test specimen are engaged at the engagement portion between the main shaft and the auxiliary shaft, and at the same time, the weight is pressed and held by the weight. do.

In this case, it is preferable that the engaging portions formed at the tips of the main shaft and the auxiliary shaft have a convex or concave center.

Further, the main shaft may be rotatably driven and provided with a rotation transmitting means that engages only in the rotational direction to transmit the rotation of the main shaft to the test piece.

Further, the support may include an engaging portion that engages a portion extending from the test piece in a direction orthogonal to the support shaft so as to be movable only in the axial direction of the support shaft.

[Function] The test specimen support device according to the present invention has a main shaft and an auxiliary shaft arranged on the axis of the support shaft facing both ends of the test specimen in order to vertically support both ends of the support shaft, and an upper part of the support shaft. By configuring the auxiliary shaft, which is supported so as to be rotatable and slidable in the axial direction, to be pressed by an appropriately weighed weight, both ends of the support shaft of the test piece can always be supported with an appropriate pressing force. Highly accurate measurement of test pieces can be performed without causing variations in pressing force due to individual differences.

[Example] Next, an example of the test piece support device according to the present invention will be described in detail below with reference to the accompanying drawings.

For convenience of explanation, parts that are the same as those shown in FIGS. 4(a) and 4(b) are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 is a sectional view of a test piece support device showing an embodiment of the present invention.

In this figure, reference numeral 60 indicates a rotor of a brushless motor used as a test piece, and both shaft ends of a rotor shaft 62a provided above and below this rotor 60 are connected to a pair of rotor shafts 62a disposed oppositely on the same axis. is engaged and supported by the shaft of.

In this case, the lower end of the rotor shaft 62a is connected to a case 14, which will be described later.
The main shaft 18 is engaged and supported by an engagement portion 22 (concave center) at the tip of the main shaft 18 which is rotatably supported.

The case 14 is inserted into a through hole 15 formed in the base 10, and a housing 16 having a flange 16a formed on the upper edge is inserted into the opening of the case 14, and the flange 16a is fixed with bolts. This is fixed by tightening it.

A pair of bearings 20a are provided above and below the through hole formed in the center of the housing 16.

20b is inserted, and a main shaft 18 having a concave center 22 formed at its upper end is rotatably supported by the bearings 20a, 20b.

Furthermore, a pulley 19 that is rotatably driven by a drive source (not shown) is fixed to the lower part of the main shaft 18 via a right screw, and the lower bearing 20b is rotated in the axial direction by the boss portion of the pulley 19. A preload is applied to this.

Similarly, for the upper bearing 20a, a cap 36 is attached to the main shaft 18 that has passed through the upper bearing 20a.
By inserting a preload collar 37 and a wave washer 37a between the cap 36 and the upper bearing 20a and pressing them to fix the cap 36, the inner ring of the upper bearing 20a is elastically pressed and preloaded. is giving.

A pin 34 is provided on the side surface of this cap 36 to protrude in the radial direction, and a bracket 40 having a vertical pin 38 implanted therein to engage with this pin 34 is fixed to the lower end of the rotor shaft 62a, and the main shaft 18 is fixed to the lower end of the rotor shaft 62a. A rotation transmission means 33 is configured to transmit rotation to the rotor 60. As a result, the rotor 60 rotates together with the main shaft 18 by transmitting the rotation of the main shaft 18 which is decelerated and rotated by a drive source (not shown) via the pulley 19 via the rotation transmission means 33.

Furthermore, a rotary encoder 18R is connected to the lower end of the main shaft 18 via a coupling 17, and this encoder 18R generates pulses divided into a plurality of pulses for one rotation of the rotor 60, and measures this one rotation. When the process is completed, the probe 46 of the measuring device is moved one step in the radial direction of the rotor 60. By sequentially repeating this process, it is possible to accurately measure the magnetic distribution state on the coordinate-divided rotor 60.

On the other hand, the upper part of the main shaft 18 has a concave center 22 of the main shaft 18.
The auxiliary shaft 3 has a concave center 32 formed at its lower end to face the
0 are arranged on the same axis, and this auxiliary shaft 30 is connected to the support body 2.
4 is rotatably and axially slidably supported via a linear ball bearing 28 inserted in the shaft.

This linear ball bearing 28 is normally commercially available, and its outer ring is fixed in the insertion hole 26 of the support body 24, and a plurality of poles 28a are rotatably supported inside the bearing via a retainer. The structure is such that

In this way, both the upper and lower ends of the rotor shaft 62a are vertically engaged and supported by the main shaft 18 and the auxiliary shaft 30, and an appropriate pressing force is applied to the upper end of the auxiliary shaft 30 on both the upper and lower ends of the rotor shaft 62a. For this purpose, a weight 42 of an appropriate weight weighed in advance is removably inserted, thereby pressing the rotor 60 as a test piece in the axial direction and achieving stable support.

However, since the upper end of the rotor shaft 62a is engaged and supported by the concave center 30b of the auxiliary shaft 30 that is slidable in the axial direction, the rotor shaft 62a is supported at any time in accordance with the total shaft length Ll that changes depending on the type of test piece. can do.

Next, other embodiments will be described in detail with reference to the accompanying drawings.

That is, FIG. 2 is a cross-sectional view of a test piece support device showing another embodiment of the present invention, and is configured to support another test piece 48 using a support device having the same structure as the above-described embodiment. This is what I did.

In FIG. 2, the same reference numerals are given to the same components as in the above-described embodiment, and detailed explanation thereof will be omitted.

The test piece used in this example detects the position of the Hall element embedded in the probe 46 of the measuring instrument used to detect the magnetized state of the rotor 60, and determines the reference position that provides the highest sensitivity. This is a high magnetic flux density generator used for.

The test piece 48 as a high magnetic flux density generator has a parallel knife 5 at its tip facing vertically with a predetermined distance apart.
A pair of magnetic metal plates 52a, 52 forming a
The pair of metal plates 52a and 52b are designed to sandwich a magnet 53 of a predetermined thickness between the metal plates and support the magnet 53 with a predetermined distance between them.
A locking shaft 54 made of a non-magnetic material and a pair of support shafts 25a, 25b are arranged in front (knifetsu side) and behind between a and 52b, respectively.

Metal plates 52a, 5 are attached to stepped portions formed on 25b, 54.
2b and support them in parallel.

As a result, a predetermined minute interval is formed between the knives 50.

Locking portions 56 and 58 (convex centers) are respectively formed at the upper and lower ends of the support shaft 54 that has passed through the pair of metal plates 52a and 52b.
6.58 is suitably pressed by the main shaft 18 and the auxiliary shaft 30, which have the same structure as in the embodiment described above, and is engaged and supported in a stable state. Further, a protruding engagement portion 57 is provided at the rear end of one of the upper metal plates 52a, and this is engaged with an engagement hole 55 formed vertically on the inner surface of the support body 24 to secure the test piece 48. It is supported in a non-rotatable manner to prevent lateral vibration.

By configuring the test piece in this way, a focused magnetic flux is obtained from the opposing knife blades 50, and during this time, the probe 46 of the magnetic flux density measuring device 44 is moved in the direction orthogonal to the knife blade 50, for example, in the axial direction by a stepping motor (not shown). By moving in a straight line, it is possible to know the reference point where the Hall element that gives the highest sensitivity of this 10-b 46 is located.

However, when replacing the test piece 60 with another test piece 48 and performing measurement, the main shaft 1 of the support device that supports the test piece
8 and the auxiliary shaft 30 changes from Ll to L2,
The auxiliary shaft 30 that has been engaged with the rotor shaft end is moved in the axial direction to engage the concave center 32 of the auxiliary shaft 30 with the engaging portion (convex center) 58 of another test piece 48, Together with the main shaft 18 engaged with the other engaging portion (convex center) 56, both ends of the support shaft 54 can be supported with an appropriate pressing force.

By configuring the support device in this way, even if the type of test piece is different, the auxiliary shaft 30 can be disposed above the test piece.
The test piece can be exchanged and assembled extremely easily by simply moving the test piece up and down in the axial direction.Moreover, the locking shaft 54 can be moved with only the appropriate pressing force of the weight of the weight without adjusting the long screw. can be supported.

Therefore, even if the vertical dimension of the support shaft and the engagement position with the engagement hole differ depending on the type of test piece, this can be easily accommodated.

[Effects of the Invention] As is clear from the embodiments described above, the test specimen supporting device according to the present invention has a main shaft and an auxiliary shaft facing both ends of the support shaft of the test specimen in order to vertically support both ends of the support shaft. is placed on the axis of the support shaft, and an auxiliary shaft supported rotatably and slidably in the axial direction on the upper part of the support shaft is pressed by an appropriately weighed weight. The specimen can be supported with an appropriate pressing force at all times, and can be supported reliably and stably without variations in the pressing force due to individual differences. At the same time, the type of specimen can be supported at different positions. Even if the values are different, this can be easily accommodated. The support device is thus constructed simply and
It has the advantage of being able to measure various test pieces with high precision.

Although the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a test piece support device showing one embodiment of the present invention, FIG. 2 is a cross-sectional view of a test piece support device showing another embodiment of the present invention, and FIG. A-A sectional view of Figure 2,
FIG. 4 shows a brushless motor, FIG. 4(a) is a sectional view of the brushless motor, and FIG. 4(b) is a sectional view taken along line BB in FIG. 4(a). 10...Base 14...Case 18...
・Main shafts 20a, 20b...Bearings 22.32...Engaging portion (concave center) 24...Support body 25a, 25b...Support shaft 28...Linear ball bearing 30...Auxiliary shaft 33 ...Rotation transmission means 4
2... Weight 44... Magnetic flux density measuring device 4
6... Probe 50... Naifetsuji 52
a, 52b...Metal plate 53...Magnet 54...
・Latching shaft 55...Engagement holes 56, 58...
Convex center 57... Engaging portion 60.48... Test piece (rotor) 62... Rotor magnet 62a... Rotor shaft 62b... Magnetized surface 96.
...Coil 97...Stator 98...Yoke 100...Hall element FIG, 1 In the drawing? 8) Book FIG. Procedural amendment (method) 1. Display test piece support device in the case 3. Person making the amendment Relationship with the case Patent applicant address 167 Higashi-Ome-chome, Ome-shi, Tokyo Name 1: Representative of Nippon Chemi-Con Co., Ltd. @Toshi Fuji Akira 4, Daikanjin 6, Target of correction (1) Drawing FIG.

Claims (4)

[Claims] (1) A test piece support device that vertically supports both ends of the test piece support shaft and tests the properties of the test piece by moving a detection device relative to the test piece. a main shaft having an engaging portion at its tip that can be engaged with one end of the support shaft;
An auxiliary shaft is located on the axis of the main shaft, is supported rotatably and slidably in the axial direction, and has an engaging portion at its tip opposite to the engaging portion of the main shaft; It consists of a support provided, and a weight engaged with the upper part of the auxiliary shaft, which engages both ends of the support shaft of the test piece at the engaging portion between the main shaft and the auxiliary shaft, and at the same time, the weight engages both ends of the support shaft of the test piece. 1. A test piece support device configured to press and hold a test piece. (2) The test piece support device according to claim 1, wherein the engaging portions formed at the tips of the main shaft and the auxiliary shaft form a convex or concave center. (3) The test piece support device according to claim 1, wherein the main shaft is rotatably driven and is provided with a rotation transmitting means that engages only in the rotational direction to transmit the rotation of the main shaft to the test piece. (4) The support body is provided with an engaging portion that engages a portion of the support body extending from the test piece in a direction orthogonal to the support shaft so as to be movable only in the axial direction of the support shaft. 1. The test piece support device according to 1.