JP3130985B2 - Vibration measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration measuring device.

[0002]

2. Description of the Related Art In general, when a motor is manufactured, it is necessary to inspect noise accompanying mechanical damage of a bearing, vibration generated based on electromagnetic noise, and the like.

[0003] However, the conventional inspection method is based on hearing.

[0004]

However, in recent years, the noise characteristics of the motor have been improved, and the size of the motor has been reduced. For this reason, accurate manufacturing quality could not be secured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration measuring apparatus which can ensure high reliability and can accurately inspect a motor having a high natural frequency due to miniaturization. .

[0006]

To SUMMARY OF THE INVENTION To achieve the above object, the vibration measurement device according to the present invention is a measuring object model
A motor holding base for holding one end of a non-rotating part of the motor, a pressing element for pressing the other end of the non-rotating part of the motor on the motor holding base, and a direction in which the pressing element is aligned with the rotation axis of the motor. whether a pressurizing means for pressing <br/> pressure by adding a predetermined pressure to the non-rotating portion, a detector for detecting the motor vibration acceleration is continuously provided on the pushing element, the detected acceleration is below a predetermined level And a determination means for determining whether

[0007]

A motor is held by a motor holding base, and a non-rotating portion of the motor (for example, a shaft in the case of a fixed shaft type motor) is pressed by a pressing element via a pressurizing means to thereby rotate the non-rotating portion. If a predetermined pressure is applied to the section and the motor is driven to rotate in this state, the motor vibration acceleration can be detected by the detector.

Then, it is judged by the judging means whether or not the acceleration level is equal to or lower than a predetermined level.

By the way, generally, the vibration velocity is a displacement amount per unit time, and V (t) = A · 2πfcos2π
ft, where the vibration acceleration is a variable in velocity per unit time, and a (t) = − A · (2πf) ² si
It is represented by n2πft. f is the frequency, A is a constant, and t is time.

Therefore, the amplitude of the velocity is 2πfA, the amplitude of the acceleration is (2πf) ² A, and the amplitude of the acceleration is
Since it becomes large with the increase in frequency, as in the present invention,
If the inspection is performed with acceleration, the sensitivity is increased, and the quality can be reliably determined.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

[0012] Figure 1 shows the overall simplified view of a vibration measuring device according to the present invention, the apparatus, the motor 2 to be measured non
The motor holder 1 that holds one end of the rotating part and the other end of the non-rotating part of the motor 2 on the motor holder 1 (in this case, the shaft 3 because it is a fixed shaft type) are pressed against each other. Presser 4 and presser 4 coincide with the rotation axis of motor 2
Pressing means 5 for pressing in the direction of movement, a detector 6 connected to the pressing element 4 for detecting motor vibration acceleration, and determining means 7 for determining whether the detected acceleration is below a predetermined level.
If the detected acceleration is equal to or higher than a predetermined level, it is determined to be defective.

The motor holder 1 is held on a base 8 as shown in FIG.

The base 8 comprises an upper member 9 and a lower member 10 and is integrally connected by bolts S. Lower member 10
On the upper surface 11, a disk-shaped protruding portion 12 is provided, a pressure detector 13 is attached to the protruding portion 12, and a concave groove 15 reaching one end surface 14 from the protruding portion 12 is provided. The lead 16 of the detector 13 is drawn out through the concave groove 15.

The upper member 9 has a large diameter portion 17a and a small diameter portion 17a.
17b is provided, and the small diameter portion 17b is a protruding portion.
The diameter is larger than 12.

Therefore, as shown in FIG.
When 10 is fixed integrally, the axial center of the through hole 17 and the protrusion
The twelve axes are arranged on the same axis, and a fitting recess 18 into which the holding table 1 is fitted is formed. Note that a cushioning material 19 is provided on the back side of the base 8.

Thus, the motor holding base 1 includes a main body 20 formed of a cylindrical body, and legs 21 connected to the lower surface of the main body 20,
And are integrated by bolts S.

As shown in FIG. 3, an inner flange 22 is provided at the upper end of the inner peripheral surface of the main body 20, and a notch 23 in the circumferential direction is provided at the upper end of the inner peripheral surface of the inner flange 22. I have. That is, the bracket 24 of the motor 2 is locked in the notch 23.

Further, a notch 26 is provided in a part of the peripheral wall 25 of the main body 20, and a small disk 27 is fixed to a bottom surface 26a of the notch 26. The outer peripheral surface of the small disk 27
An uneven portion for preventing slippage is formed on 27a.

On the upper surface 8a of the base 8 (see FIG. 2), a disk 28 having a diameter larger than that of the small disk 27 is erected. In addition, the outer peripheral surface 28a of the disk body 28 is also provided with an uneven portion for preventing slip.

A locking member 29 such as an O-ring is wound around the disk 28 and the small disk 27. That is, the locking member 29
Accordingly, the motor holding base 1 is pulled in the direction of arrow A, and the motor holding base 1 is prevented from rotating in the directions of arrows B and C. That is, when the motor 2 is mounted and started, the holding table 1 is moved by the reaction of the generated torque, thereby preventing erroneous measurement from occurring.

As shown in FIG. 2, the leg portion 21 is formed of a disk having a large diameter portion 21a and a small diameter portion 21b, and a recess 30 is provided on the lower surface. Recess for mating 18
When the large diameter portion 21a is fitted to the large diameter portion 17a of the base 8,
And the raised portion 12 is fitted into the recess 30.

In this case, the lower member 10 includes the detector 13
A presser 31 is provided for contacting or pressing against the lower surface of the leg 21.
32 does not come into contact with the upper surface 11 of the lower member 10, the upper surface 34 of the recess 30 of the leg 21 does not come into contact with the upper surface 35 of the ridge 12, and the motor holder 1 is in a so-called floating state. I have.

Next, the pressing element 4 is formed of a spherical body,
36 are fitted in fitting recesses 37. Further, the above-mentioned detector 6 is connected to the holder 36.

The detector 6 uses a piezoelectric transducer and detects the acceleration of the vibration of the motor 2 received through the presser 4.

The pressing means 5 comprises a shaft 38 erected on the base 8 and a cylinder 39 attached to the shaft 38.
And a mounting arm 40 protruding from the cylinder 39. The vertical movement of the cylinder 39 causes the arm 40 to move up and down, and the detector 6 attached to the tip of the arm 40 moves up and down. Between the mounting arm 40 and the detector 6, a cushioning material K such as a vibration-proof rubber is interposed. With this cushioning material K,
The detector 6 and the mounting arm 40 are substantially separated from each other to prevent the natural frequency of the detector 6 from lowering and to block unnecessary external noise and vibration components.

That is, the upper and lower substrates 41 and 42 are attached to the shaft 38.
A cylinder holding frame portion 44 having a guide rod 43 disposed between the substrates 41, 41 is provided. The cylinder 39 is guided by air supply / discharge from an air supply device 45 (see FIG. 1). Rod
Move up and down along 43 ...

As shown in FIG. 1, the air supply device 45 has an air regulator 46, and when the switch 47 is turned on (when the operation projection 47a is tilted to the ON side),
The cylinder 39 descends.

Further, as shown in FIG.
A frequency analyzer 48 is connected. That is, the frequency analyzer 48 has a high-pass filter 49 and a low-pass filter 50, and allows the high-pass filter 49 to pass signals of 1 KHz or more and the low-pass filter 50 to pass signals of 15 KHz or less.

Therefore, the frequency analyzer 48 determines that the frequency is 1K.
Hz to 15 KHz.

Then, 1KH that has passed through the frequency analyzer 48
Within the range of z to 15 KHz, the determination means 7 determines whether or not the acceleration level at a certain frequency is smaller than a reference (predetermined) level. Specifically, 3KHz and 7KHz
Is determined. That is, the reference setter
The frequency level to be determined is set at 51, a reference value is input from the reference setting device 51 to the determination means 7, and the reference value is compared with the detected acceleration level.

The display means 52 displays the result of the comparison (determination). That is, if the level of the vibration acceleration is higher than a predetermined (reference) level, it is a defective product, and a defective display is performed. If the vibration acceleration level is lower than the predetermined level, the product is a good product and a good display is performed. It is also preferable to display only when there is a defect.

Therefore, as the display means 52, a display light which is different in color between good and bad lights, a display light which lights only in the case of bad light, and characters "good" and "bad" are displayed. There are various things such as those performed. Further, in the case of a failure, it is also preferable to generate a sound indicating that the failure has occurred.

Next, a method of inspecting the motor 2 using the vibration device having the above-described configuration will be described.

First, one end of the non-rotating portion of the motor 2 is
As shown in FIG. In this case, the bracket 24 of the motor 2 is locked in the notch 23 in the circumferential direction of the holding table 1.

Then, the power cord 53 of the motor 2 is pulled out through the notch 26 of the motor holding base 1 and, as shown in FIG.
The connector 57 of the cord 56 from the circuit switch 55 is connected.

Therefore, if the switch 55 is turned on (the operation projection 55a is tilted to the ON side), the motor 2
(Specifically, the hub 58) is driven to rotate. Of course, when the switch 55 is in the OFF state (the operation projection 55a is tilted to the OFF side), the rotation is stopped.

When the switch 47 is turned on,
The presser 4 is lowered, and the presser 4 is pressed against the shaft end face 3a ( the other end of the non-rotating portion) exposed from the hub 58,
A predetermined pressure is applied to the shaft end face 3a. That is, the pressing element 4
In the direction coinciding with the rotation axis of the motor 2
A predetermined pressure is applied to the end face 3a. Thereby, the motor 2
Is securely held by the motor holding base 1. Here, the predetermined pressure is about 1 to 3 kgf.

Then, in this state, the motor 2 is driven to rotate, and the detection by the detector 6 is started.

That is, as shown in the flowchart of FIG. 4, a predetermined frequency (1 to 15 KHz) is
Only, the acceleration levels at certain frequencies (3 KHz and 7 KHz) within this range are picked up, and it is determined whether or not these levels are below a predetermined level. If the level is equal to or higher than a predetermined level, a defective display is performed.

As shown in FIG. 5, when the horizontal axis represents the frequency (frequency) and the vertical axis represents the sensitivity, the displacement of the motor vibration increases as the frequency increases, as indicated by the two-dot chain line. The sensitivity is reduced, and the speed of the motor vibration is constant as shown by the dashed line, and the acceleration of the motor vibration is
The sensitivity increases as the frequency increases.

Accordingly, if this device is used, the determination is made based on the motor vibration acceleration, so that the small motor 2 (having a high natural frequency) can be inspected with high accuracy.

Further, according to this embodiment, the pressing element 31 attached to the motor holder 1 is attached to the detector provided on the base 8.
13, the pressure on the non-rotating part of the motor 2 by the pressing element 4 can be detected, and it can be confirmed whether this pressure is constant, and a more accurate inspection can be performed. Further, the base material 8 and the detector 6 have a cushioning material 19, K, respectively.
Since this is attached, this inspection is stable.

FIG. 6 is a simplified view of a main part of another embodiment. In this case, the motor 2 is of a rotary shaft type.

That is, the bracket 24 is
(The non-rotating portion) is mounted and fixed, and the pressing element 4 is rotated by the motor 2
By pressing in a direction coinciding with the axis, the presser 4 is pressed against the bracket 24.

However, in this case, the pressing element 4 is
A lower end surface 61 of which is a bracket 24.
Is pressed against the upper surface 62 of

[0047] Also in the embodiment shown in FIG. 7, a motor 2 shaft rotary, so that the hub 58 facing downward, to hold the bracket 24 to the motor holding base 1, a pressing
Presses the armature 4 in the direction coincident with the rotation axis of the motor 2.
And by, and it is pressed against the presser 4 into the bracket 24.

The pressing element 4 in this case is also shown in FIG.
As in the embodiment shown, it consists of a cylinder having an upper wall 63,
The lower end surface 64 is pressed against the upper surface of the bracket 24.

Therefore, even if the motor 2 is of the rotary shaft type, the motor vibration acceleration can be detected by using the apparatus shown in FIGS . 6 and 7 , similarly to the embodiment shown in FIGS.
Pass / fail judgment can be made reliably.

It should be noted that the present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the gist of the present invention. For example, the range of frequencies to be passed by the frequency analyzer 48 may be changed. The frequency to be discriminated can be freely changed within the passed frequency range.

Further, the pressing means 5 is not limited to the one in the embodiment, and a predetermined pressure can be applied to the non-rotating portion of the motor 2 by pressing the pressing element 4 connected to the detector 6. As long as the screw rod is used, a screw rod and a nut member screwed to the screw rod may be provided. That is, the nut member is connected to the detector 6, the screw rod is rotated around its axis, the nut member is moved up and down, and the presser 4 connected to the detector 6 is moved up and down. There may be.

[0052]

Since the present invention is configured as described above, the following effects can be obtained.

With respect to the small motor 2 having a high natural frequency, the noise caused by the mechanical damage of the bearing incorporated in the motor 2 and the vibration generated based on the electromagnetic noise and the NRRO are further reduced. Inspection can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is an enlarged perspective view of a motor holding base.

FIG. 4 is a flowchart.

FIG. 5 is a graph showing the relationship between the frequency of acceleration / velocity / displacement and the sensitivity.

FIG. 6 is a simplified diagram of a main part of another embodiment.

FIG. 7 is a simplified view of a main part of another embodiment .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor holding stand 2 Motor 4 Presser 5 Pressurizing means 6 Detector 7 Discriminating means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01H 17/00 G01H 11/08 G01R 31/34

Claims (1)

(57) [Claims] 1. A non-rotating part of a motor 2 which is an object to be measured.
A motor holder 1 for holding the end , a pressing member 4 for pressing against the other end of the non-rotating portion of the motor 2 on the motor holding member 1, and the pressing member 4 in a direction coinciding with the rotation axis of the motor 2. A pressurizing means 5 for pressing to apply a predetermined pressure to the non-rotating portion; and a detector 6 connected to the presser 4 for detecting motor vibration acceleration
And a determining means 7 for determining whether the detected acceleration is equal to or lower than a predetermined level.