JPH037795Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a detector for calibrating the acceleration of a vibration testing machine, which is used when calibrating or monitoring the acceleration of vibration during a vibration test.

Prior Art Generally, there are the following types of vibration testing machines.
For example, the output from a sinusoidal signal generator is amplified and input to an electro-hydraulic servo valve or drive coil to vibrate the actuator or vibration table.
This mechanical vibration is detected by an acceleration detector, such as a piezoelectric pickup, amplified by a charge amplifier, fed back to the output of the sine wave signal generator, and then a new output is amplified. Or input it to the drive coil. In this way, the vibration of the vibrating table is maintained, and the acceleration, velocity and amplitude of the vibration are varied by selecting the frequency and amplitude of the sinusoidal signal generated by the sinusoidal signal generator. Various test objects fixed on a vibrating table are vibrated together with the vibrating table, and their vibration resistance and impact resistance are tested in various ways.

When conducting such vibration tests, the reliability of acceleration detectors has traditionally been somewhat poor, so before starting the vibration test, it is necessary to use an acceleration detector consisting of a piezoelectric pickup, a charge amplifier, and a millivolt voltmeter. I am trying to calibrate the vibration level meter. In other words, a wedge-shaped calibration paper that allows easy visual observation of vibration amplitude is attached to the side of the vibration table, and calibration is performed using this as a reference.
For example, when the frequency display is 50 Hz and the wedge-shaped calibration paper is vibrating with a total amplitude of 2 mm, the amplification of the charge amplifier is adjusted so that the vibration level indicates the theoretical acceleration value of 10 G. This wedge-shaped calibration paper is also used for long-term monitoring of vibration conditions.

Problems that the invention aims to solve However, in a vibration test, when the test object is fixed to a vibration table under load, the vibration conditions must be maintained for a long period of time, or when strict vibration conditions are required, the vibration table must be Since the vibration conditions are different between the center and the periphery, it is necessary to place the wedge-shaped calibration paper near the center of the vibration table parallel to the vibration direction. This is quite difficult, and even if the gap between the test objects could be found and installed, it would still be difficult to visually observe them. In order to solve these drawbacks, this invention can be installed in a narrow space, is easy to fix to a vibration table, and does not take up much space.
It is an object of the present invention to provide an acceleration calibration detector that allows vibration amplitude to be easily determined visually.

Means for Solving the Problems In order to achieve the above object, this invention provides a member having a flat surface parallel to the vibration direction, a coupling means for fixing the member to a vibration table of a vibration tester, and the above-mentioned surface. The line segment is marked on the top, has a direction perpendicular to the vibration direction, has a predetermined equidistant interval, and is located in the shape of a staircase that vertically goes up and down at opposite positions. For example, the simplest detector for acceleration calibration of a vibration testing machine is a polygonal column, such as a hexagonal column, with a flat columnar surface parallel to the vibration direction, and a screw attached to the tip of the hexagonal column is attached to the screw hole of the vibration table. Since it is provided in a shape with During vibration, the marks appear as if adjacent line segments are connected in a straight line, so the vibration amplitude can be clearly determined visually.

Embodiment Next, an embodiment of this invention will be described with reference to the drawings. Fourth
The figure is an explanatory diagram of a conventional wedge-shaped proofreading paper.
In FIG. 4, the wedge-shaped calibration paper 11 has a wedge line segment 12 drawn on a graph paper as a solid line, and a vertical interval distance between the wedge line segment 12 below the wedge line segment 12 with an amplitude 13.
This is what is shown. This wedge-shaped proofreading paper 1
1 is pasted on a vibration table parallel to the vibration direction, and when it is vibrated, for example, when the total amplitude is 4 mm, wedge line segments 14 and 15 shown by broken lines will be visible, and their intersection will be directly above "4" of amplitude 13. . This is because during sine wave vibration, the wedge line segment 12 does not appear to have a high velocity near the center of the sine wave amplitude, but it remains stationary at both ends of the sine wave amplitude, so it seems that the wedge line segment 12 is divided into wedge lines 14 and 15. This is because it looks like amplitude 1
The amplitude display interval can be widened to read 3 more clearly, but the wedge line segments 14 and 15
The angle formed by the straight line that intersects with the . If you attach this paper to the side of the vibration table and visually observe the vibration state, it is convenient because you can read the vibration amplitude continuously, but there is a difference in the vibration state between the periphery and the center of the vibration table. When trying to detect the vibration state at the center, the paper requires a certain amount of area, and holding this paper parallel to the vibration direction occupies a considerable amount of space, so it is installed in the center of a limited vibration table. I had the inconvenience of not being able to do that.

FIG. 1 is an explanatory diagram showing one embodiment of the detector of this invention. Reference numeral 5 denotes a hexagonal column having a column surface 1 which is a flat surface parallel to the vibration direction, and 2 and 3 indicate screws which are coupling means for fixing the hexagonal column 5 to the vibration table of the vibration tester. 4-1, 4-2, and 4-3 are marked on the column surface 1, have a direction perpendicular to the above vibration direction, have a predetermined equal distance interval of 2 mm, and are vertically spaced apart from each other at opposite positions. These are three line segments located in the shape of stairs going up and down. The hexagonal column 5 is easily manufactured from a hexagonal bar, and when the column surface 1 is painted black and the line segment 4 is marked white, it is easy to visually observe the vibration state. Since the column surface 1 has six sides, six types of vibration amplitude can be set by marking six types of line segments 4 on each side, such as equidistant intervals of line segments 4 of 2.5 mm, 4.0 mm, etc. . Further, if an octagonal or decagonal polygonal prism is used, even more vibration amplitudes can be set. FIG. 2 is an explanatory diagram showing the vibration state of the line segment 4 marked on the columnar surface 1 shown in FIG. In Figure 2, line segments 4-1, 4-2, and 4-3 are line segments 7-1, which are 1 mm wide and are indicated by broken lines above and below during vibration.
and 8-1, 7-2 and 8-2, and 7-3 and 8-3. When the total amplitude of vibration reaches exactly 2 mm, lines 7-1 and 8-2 and lines 7-2 and 8
-3 and it appears to be in a straight line, so it can be clearly determined that the total amplitude of vibration has reached 2 mm. Also, Figure 3 shows line segment 4 in Figure 1.
Align the position of -3 to the level of line segment 4-1 and line segment 4
-4, line segments 7-1 and 8-2
and 7-4 appear to be connected in a straight line. At this time, as described above, the acceleration is calibrated by adjusting the amplification degree of the charge amplifier to the theoretical value of acceleration of 10 G when the vibration frequency is 50 Hz and the total amplitude is 2 mm.

Furthermore, if the screws 2 and 3 shown in Fig. 1 are used to connect the hexagonal column 5 to the vibration table, the right angle adapter can also be used as a connection means when the vibration table vibrates back and forth in the horizontal direction. It is possible, and in order to make it easier to see the vibration state from each direction, it is preferable to mark line segments 4 having the same shape on each side of the hexagonal column 5. Alternatively, the direction of the line segment 4 may be distinguished between horizontal and vertical directions and marked on every other side of the hexagonal prism. Furthermore, since there is a risk that the screws 2 and 3 may loosen due to vibration when connecting to the vibration table, it is best to use a locking nut to secure the screws firmly.

Effects of the invention In this way, when using the acceleration calibration detector of this invention, it can be used not only in the center of the vibration table but also in the place where the vibration state is to be detected, even if the place where the vibration state is to be detected is small, without taking up much space and by fixing the hexagonal bolt. It has the advantage of being easy to install and allowing the vibration amplitude to be clearly determined visually.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of one embodiment of the acceleration calibration detector of the vibration testing machine of this invention, and Figs. 2 and 3 show the vibration of the line segment 4 marked on the column surface 1 shown in Fig. 1. An explanatory diagram showing the state, FIG. 4 is an explanatory diagram of a conventional wedge-shaped proofreading paper. 1...Cylinder surface, 2 and 3...Screw, 4...Line segment, 5
...Hexagonal prism, 7 and 8...Line segment, 11...Wedge-shaped calibration paper, 12, 14, and 15...Wedge line segment,
13...Amplitude.

Claims (1)

[Claims for Utility Model Registration] (1) A member having a flat surface parallel to the vibration direction,
coupling means for fixing the member to a vibration table of a vibration testing machine; A detector for acceleration calibration of a vibration testing machine consisting of multiple line segments located in the shape of stairs going up and down. (2) A detector for acceleration calibration of a vibration testing machine according to claim 1, wherein the member is a polygonal prism having a flat columnar surface parallel to the vibration direction. (3) A detector for acceleration calibration of a vibration testing machine according to claim 1 of the utility model registration claim, wherein the coupling means is a screw.