JPH0219770A - Method and device for measuring exciting force - Google Patents

Abstract

PURPOSE:To reduce an undesirable influence of acceleration onto an experiment under a space environment, and also, to execute the experiment by a simple device by confirming on the ground whether vibrationproofing force of a space experimental apparatus has been suppressed below a design value or not. CONSTITUTION:At the time of measuring vibrationproofing force of an experimental apparatus 8, first of all, the apparatus 8 to be measured is fixed to the upper face of a sheet 6, and also, an accelerometer 9 is attached in the vicinity of the apparatus 8, and by operating the apparatus 8 in this state, acceleration a1 generated at that time is measured by the accelerometer 9. Subsequently, the apparatus 8 is stopped, and an exciting machine 10 whose vibrationproofing force F2 is known is allowed to abut on the lower face of the sheet 6 on which the apparatus 8 is positioned and the apparatus 8 is excited together with the sheet 6, and acceleration a2 generated at that time is measured by the accelerometer 9. In such a way, exciting force F1 generated from the apparatus 8 can be calculated from an expression of F1=F2Xa1/a2, and accordingly, in the case of executing an experiment in a space, whether the exciting force F1 of the experimental apparatus has been suppressed below a prescribed design value or not can be confirmed on the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for measuring excitation force of equipment such as space experiment equipment.

[Conventional technology] Space experimental equipment used for experiments in zero gravity environments such as outer space is usually manufactured on the ground, or, since each of these equipment has an excitation force, is transported directly to space. When conducting an experiment, the excitation force of the experimental equipment may generate acceleration, which may have an adverse effect on the experiment. Therefore,
In order to minimize this negative effect, it is necessary to suppress the excitation force of these experimental devices to a certain design value or less when manufacturing the ground-L.

[Problems to be Solved by the Invention] However, conventionally, it has been difficult to measure minute excitation forces on the ground, such as those required for equipment used in experiments in zero gravity.

Therefore, since it is not always possible to suppress the excitation force of the experimental equipment being manufactured below a certain design value, the problem remains unresolved that the negative impact of acceleration on experiments may become significant. is the reality.

In view of the above-mentioned circumstances, the present invention has been made with the object of making it possible to measure minute excitation forces of experimental equipment such as those used in zero gravity on the ground.

[Means for Solving the Problems] The first invention is to fix experimental equipment to the upper surface of a thin plate supported from the ground via an elastic body with a small repulsion constant and resting on the surrounding area, and to perform the experiment. An accelerometer is attached near the equipment, and in this state, the experimental equipment is operated and the acceleration is measured by the accelerometer. The method is characterized in that the thin plate and the experimental equipment whose operation has been stopped are vibrated by a machine, and the acceleration is measured by the accelerometer.

Further, the second invention is a device for carrying out the method of the first invention, which includes a resilient body having a small spring constant, a resilient body supported from the ground via the resilient body, a weight placed around the periphery, and a top surface. A thin plate capable of fixing experimental equipment, an accelerometer attached near the experimental equipment, and a vibrator installed on the ground to vibrate the thin plate and the experimental equipment. It is something to do.

[Operation] Operate the experimental equipment on the thin plate and measure its acceleration α1,
Next, by exciting the thin plate and the stopped experimental equipment together using a vibrator whose excitation force F2 is known in advance, and determining the acceleration α2 at that time by 71111, the excitation force F1 of the experimental equipment can be changed to F1. , -p+x-.

α2 Prevent ground vibrations from being added to the minute acceleration α1 when the experimental equipment is operated by having an elastic body or thin plate with a small repulsion constant between the ground and the experimental equipment. I can do it.

[Example] Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which an upper member 2 is connected approximately horizontally to each of the upper parts of four upright members l fixed upright on the ground at intervals, and the upper member 2 An intermediate member 3 is connected in between, and a support frame 4 is formed by said members 1.2.3. A plurality of pieces (
A thin plate 6 is suspended and supported via springs 5 with a small spring constant (12 pieces in the figure), and a weight 7 such as a sand bag is placed on the upper surface of the periphery of the thin plate 6 to absorb vibrations of the thin plate 6. .

In addition, 8 in the figure is the experimental equipment for which the excitation force should be determined by 71?1, and 9
is an accelerometer installed near the experimental equipment 8 to measure the acceleration of the experimental equipment 8, and lO is an exciter installed on the ground to give vibration to the experimental equipment 8.

The reason why the spring constant of the spring 5 is made small in the double device is as follows. That is, since the operating frequency of the experimental equipment 8 is usually relatively high, if a spring 5 with a large spring constant is used to support the thin plate 6, the natural frequencies of the experimental equipment 8 and the spring 5 will be approximately the same. This is because resonance occurs and it becomes difficult to determine the total acceleration.

To measure the excitation force of the experimental equipment 8, first, the experimental equipment 8 to be measured is fixed to the upper surface of the thin plate 6, and an accelerometer 9 is attached near the experimental equipment 8. 8, and the acceleration αl generated at that time is measured by the accelerometer 9. Next, the experimental equipment 8 is stopped, and the vibration exciter 1O having a known excitation force F2 is brought into contact with the lower surface of the thin plate 6 on which the experimental equipment 8 is located to vibrate the experimental equipment 8 together with the thin plate B. and the acceleration α2 that occurs at that time
is measured by the accelerometer 9.

As a result, the excitation force F1 generated from the experimental equipment 8 is F, -F'2x! It is possible to calculate α2 from the following formula, and therefore, when conducting experiments in space, it is possible to check on the ground whether the excitation force F1 of the experimental equipment is kept below a certain design value. Become.

In addition, in the above-mentioned embodiment, the thin plate 6 is suspended and supported from above by the support frame 4 via the springs 5, or
The thin plate 6 may be supported from below by an air spring or magnetic spring having a small spring constant, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] According to the present invention, it is possible to check on the ground whether or not the excitation force of the space experiment equipment is kept below the design value. There is no fear that experimental equipment will be thrown into space, and therefore the adverse effects of acceleration on experiments in the space environment can be reduced, and the equipment can be simple and can produce excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an explanatory perspective view of one embodiment of the present invention. In the figure, 4 is a support frame, 5 is a spring, 6 is a thin plate, 7 is a wall, and 8
9 indicates the experimental equipment, 9 indicates the accelerometer, and 10 indicates the exciter.

Claims (1)

[Scope of Claims] 1) Experimental equipment is fixed to the upper surface of a thin plate supported from the ground via an elastic body with a small spring constant and a weight is placed around the periphery, and an accelerometer is attached near the experimental equipment, In this state, the experimental equipment is operated and the acceleration is measured by the accelerometer, and then, in the above state, the thin plate and the experimental equipment whose operation has been stopped are measured using a vibrator installed on the ground whose excitation force is known. A method for measuring an excitation force, comprising: excitation and measuring acceleration using the accelerometer. 2) An elastic body with a small spring constant, a thin plate that is supported from the ground via the elastic body and has a weight placed around it so that experimental equipment can be fixed on the top surface, and an acceleration plate that is attached near the experimental equipment. 1. An excitation force measuring device comprising: a vibrating force meter; and a vibrating machine installed on the ground for vibrating the thin plate and the experimental equipment.