JPH0714844Y2 - Dynamic balance tester - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a dynamic balance tester capable of easily switching between a soft type and a hard type.

B. Conventional Technology Conventionally, two types of dynamic balance testers, soft type and hard type, have been used for the dynamic balance test of the specimen.

The soft type dynamic balance testing machine is one in which the natural frequency of the measuring rack vibrating due to the imbalance of the test piece is sufficiently lower than the measurement rotational speed, and is configured as shown in FIG. 3, for example. This tester has a substantially U-shaped support plate 1, a leaf spring 3 suspended from a standing wall 1a, 1b of the support plate 1 by a fixture 2, and a lower end of the leaf spring 3 fixed by a retainer 4. A pair of supporting portions including the measurement base 5 are arranged at a predetermined interval, and both ends of a test rotary body such as a motor rotor are supported and rotated on the rollers 5a of the measurement base 5. If the test piece is unbalanced, the plate spring 3 is deformed and the measurement stand 5 vibrates. Therefore, the vibration is detected by the detector 6 such as a differential transformer to measure the unbalance.

On the other hand, the hard type dynamic balance tester is one in which the natural frequency of the pedestal vibrating due to the imbalance of the specimen is sufficiently higher than the measured rotation speed, and conventionally, for example, FIGS. 4 (a), (b),
It is configured as in (c). With these testing machines,
The base 110 and the independent pedestal 120 are integrally formed via a thick leaf spring 130, and support both ends of a rotor under test such as a motor rotor on the rollers 120a of the measurement pedestal 120 to rotate them. If the test piece is unbalanced, the leaf spring 130 is deformed and the measurement stand 120 vibrates. Therefore, if the vibration is detected by the detector 140, the imbalance can be measured. (A) uses a piezoelectric element as the detector 140, (b) uses a differential transformer, (c)
Uses a capacitance type sensor.

C. Problems to be solved by the invention In the former conventional testing machine, the mounting surface of the support plate 1
One side of the thin leaf spring 3 is brought into contact with 2a and sandwiched by the fixtures 2, and the other side of the lower end of the leaf spring 3 is attached to the mounting surface 3a of the measurement stand 5.
Since it is abutted against and clamped by the presser tool 4,
Since it was not possible to use leaf springs of different thickness, we had no choice but to use it as a dedicated soft type machine.

Also, in the latter test machine, all the supporting parts were integrated, and it was also a hard type special machine.

Therefore, it is necessary to prepare two types of testing machines, a hard type using a thick leaf spring and a soft type using a thin leaf spring.

The technical problem of the present invention is to enable measurement by a hard type and a soft type with one type of testing machine.

D. Means for Solving the Problem Referring to FIG. 1 showing an embodiment, a dynamic balance testing machine according to the present invention has a pair of standing walls 12a and 12b facing each other and fixed at a predetermined interval. A support plate 12, a measurement pedestal 40 that rotatably supports a rotating body, a leaf spring 14 that suspends the measurement pedestal 40 from each of the standing walls 12a and 12b, (24),
Regardless of the thickness of the leaf springs 14, (24), the leaf springs of the standing walls 12a, 12b, which are fixedly fixed in advance, and the leaf spring connection portion of the measuring stand 40 are maintained in the positional relationship. Springs 14, (24)
Fixing means 1 for connecting the support plate 12 and the measuring stand 40 to
3, 15 and a vibration detector 30 installed on the support plate 12 for detecting the vibration of the measurement pedestal 40 are provided, thereby solving the above technical problem.

E. Action The leaf spring 14 (24) used and the fixing means 13 according to its thickness
(23) is used to suspend the measurement stand 40 on the support plate 12. As a result, the positional relationship between the support plate 12 and the measurement pedestal 40 can be maintained even if the thickness of the leaf spring used varies depending on the soft type and the hard type, and the support plate 12 and the measurement pedestal 40 can be used in common.

In addition, the vibration detector 30 such as a differential transformer can be used to
To detect the vibration of. Based on the detection signal of the detector 30, the soft type calculates the eccentricity of the unbalanced composite amount, and the hard type calculates the unbalance amount. Thereby, the imbalance of the rotating body is measured.

It should be noted that, in the above D and E for explaining the configuration of the present invention, the drawings of the embodiments are used to make the present invention easy to understand, but the present invention is not limited to the embodiments.

F. Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 (a) is a plan view of the dynamic balance tester, and FIG. 1 (b) is a view taken along the line bb of FIG. There is.

A pair of support portions 10A and 10B are fixedly installed on the base 20 by a lock mechanism 21 at predetermined intervals. Each of the support portions 10A and 10B used for the soft type shown in the left half of FIG. 1 (b) includes a base plate 11, a substantially U-shaped support plate 12 erected on the base plate 11, and the support plate 12 respectively. Standing walls 12a, 12b
A thin leaf spring (14) suspended by a fixture (13), and a measuring stand (40) fixed to the lower end of the leaf spring (14) by a retainer (15).
That is, in the soft type, the measurement base 40 is attached to the thin leaf spring 14
Hang on.

On the other hand, in the case of the hard type shown in the right half of FIG. 1 (b), instead of the fixture 13 and the thin leaf spring 14 in the soft type, the fixture 23 and the thick leaf spring 24 are used to mount the measurement stand 40. Hang. The fixing means 13 and 15 constitute a fixing means.

As shown in FIG. 2, the soft type and hard type fasteners 13 and 23 are T-shaped hanging fittings 131 and 231 respectively.
And the pressing metal fittings 132, 232, and the leaf spring 14 (24) is provided with a bolt 13 between the hanging metal fittings 131, 231 and the pressing metal fittings 132, 232.
It is sandwiched by 3,233. Here, as shown in FIG. 2, depending on the thickness of the leaf spring used,
The A and A'dimensions are changed so that the leaf spring 14 (24)
So that both can be mounted parallel to the support plate 12,
The measurement stand 40 is also used.

As shown in FIG. 1, the measurement pedestal 40 includes a pedestal base 41 that is suspended from the standing walls 12a and 12b by leaf springs 14 (24) and a recessed portion on the upper side surface of the pedestal base 41. And a bearing portion 42 that rotatably supports a pair of rollers 42a and 42b.

Further, the coil portion 30b of the differential transformer 30 is attached to the side wall of each plate 12, and the movable core rod 30a thereof is connected to the gantry base 41 with the fixing screw 31.

In such a dynamic balance testing machine, a rotating body such as a motor rotor
When measuring the imbalance of RW, both ends of the rotary shaft of the rotor motor of the soft type and the hard type are held on the rollers 42a and 42b, respectively, and the rotor motor is rotated by a driving unit (not shown). If the rotor motor is unbalanced, the measurement stand 40 vibrates, and the differential transformer 30 outputs a detection signal corresponding to the vibration. The imbalance is measured by this detection signal.

Here, in the soft type, the detected output voltage E of the differential transformer 30 can be expressed by E = B · L · v (1) by using the magnetic velocity density B and the coil length L. Since B and L are known, the vibration velocity v can be obtained from the first equation. The vibration velocity v is expressed by v = e · ω (2) using the vibration amplitude e and the rotational angular velocity ω. Since v and ω are known, the eccentricity e ₀ due to the imbalance of the rotating body is calculated from the second equation. Therefore, the unbalance amount can be measured by the eccentricity e ₀ and the weight of the rotating body.

In the case of the hard type, the detected output voltage E of the differential transformer 30 is E = K · B · L · (mr) ω ³ (3) where K is a constant and K, B, L, Since ω is known, the unbalance amount mr can be obtained from the third equation.

In the embodiment configured as described above, when the thin leaf spring 14 is used as the spring fixture so that the positional relationship between the measurement base 40 and the support plate 12 does not change even if the thickness of the leaf spring is different, it is the second When the thick leaf spring is used, the A dimension shown in the figure is used alternatively. Therefore, the hard type and soft type dynamic balance testers can be configured by replacing only the integrated leaf spring and the fixture. Further, since the detected output voltage of the differential transformer 30 is substituted into the second equation or the third equation according to the software type and the hardware type to obtain the respective imbalances, the imbalances can be accurately measured in both types.

In the above embodiment, the upper fixing tool 13 is selectively used depending on whether it is a soft type or a hard type. However, in the soft type as well, the hard type fixing tool 23 is used and a spacer is provided between the lower end of the spring and the measurement base 40. You may make it pinch.

G. Effect of the device Since the device of the present invention is configured as described above, it is possible to easily switch between the soft type and the hard type, and it is possible to accurately measure the imbalance between both types with one testing machine, and it is highly cost effective. A dynamic balance tester can be provided.

[Brief description of drawings]

FIG. 1 and FIG. 2 are for explaining one embodiment.
FIG. 1 (a) is a plan view of a dynamic balance tester according to the present invention, and FIG. 1 (b) is a view taken along the line bb of FIG. 1, in which the left half is a soft type configuration and the right half is a hard type. The configuration is shown. Second
FIG. 2A is a sectional view showing a mounting state of a soft type leaf spring and a fixture, FIG. 2B is a sectional view showing a mounting state of a hard type leaf spring and a fixture, and FIG. Sectional view showing a conventional example of a soft type tester, FIG. 4 (a),
(B), (c) is sectional drawing which shows the conventional example of a hard type tester. 10A, 10B: Support 11: Base plate, 12: Support plate 14: Leaf spring for soft type 24: Leaf spring for hard type 15: Presser, 20: Base 30: Differential transformer, 30a: Movable core rod 30b: Coil, 40: Measuring stand 13: Fixture for soft type 23: Fixture for hard type 131,231: Hanging metal fittings, 132,232: Holding metal fittings 133,233: Bolts

Claims (1)

[Scope of utility model registration request] 1. A pair of support plates, which have standing walls facing each other and are fixedly installed at a predetermined interval, a measuring stand for rotatably supporting a rotating body, and a leaf spring for suspending the measuring stand from each of the standing walls. Irrespective of the thickness of the leaf spring, the leaf spring is measured with the support plate while maintaining the positional relationship between the leaf spring suspension portion of the standing wall and the leaf spring connection portion of the measurement stand which are fixedly fixed in advance. A dynamic balance tester comprising: a fixing unit connected to a gantry; and a vibration detector installed on the support plate for detecting vibration of the measuring gantry.