JP3030307B1 - Mass measuring device that operates under zero gravity environment - Google Patents

Abstract

An object of the present invention is to provide a mass measuring device capable of performing simple and accurate mass measurement in a zero gravity environment. SOLUTION: An internal force is applied between a container 2 holding an object to be measured 1 and a reference weight 3 by a spring 5, air pressure or the like.
The linear velocity of the container 2 and the reference weight 3 before and after that is measured. The container 2 and the reference weight 3 are connected by a linear guide 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a mass measuring instrument that operates in a weightless environment.

[0002]

2. Description of the Related Art In a zero-gravity environment, only mass in an international unit system represented by four basic units, m, kg, s, and A, cannot be measured by a measuring instrument normally used on the ground. This is because balances, load cells, and the like, which are measuring devices used for measuring mass, perform measurements that depend on a uniform and constant gravitational acceleration field.

Mass can be compared and measured in the form of force, momentum, energy, and the like by the action of acceleration. In order to measure mass in a zero-gravity environment, it is necessary to artificially create an acceleration field in some form.At this time, pay attention to the temporal and spatial uniformity of the acceleration field There is a need.

If they are not uniform, it is necessary to consider the density distribution and velocity distribution of the object to be measured. 2. Description of the Related Art Conventionally, a method using a natural frequency and a method using a centrifugal force have been studied as a method for measuring mass under a zero gravity environment.

[0005]

However, in the method using the natural frequency, since the acceleration field is not uniform in time and space, the density distribution and the velocity distribution of the object to be measured must be considered. Therefore, it is difficult to measure something other than a rigid body.

The method using centrifugal force has the advantage that a uniform acceleration field can be realized in time. However, since the acceleration changes in the radial direction, it is necessary to know the position of the center of gravity of the object to be measured. In addition, there is a disadvantage that the device size and the measurement period are increased.

In the future, the laboratory at the space station,
With the progress and diversification of human activities in space such as factories,
It is desired to develop various measuring means from various viewpoints such as a measuring range, accuracy, a measuring object, a rigid body, an elastic body, a liquid, a powder, a mixture, an apparatus size, and a measuring time.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned demands, and a proper timing is set so that a container for storing an object to be measured and a reference weight are linearly separated and approached from each other. It is an object of the present invention to provide a measuring device which operates in a zero gravity environment by measuring the moving speed of each of a container and a reference weight with a speed measuring device by driving with a force of an appropriate magnitude.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a mass measuring device which operates in a zero-gravity environment, comprising: a container for holding an object to be measured; a reference weight; A linear guide that couples the reference weight so as to be separated and approached to each other in a linear direction; and a driving unit that applies a force in a direction to separate or approach the container and the reference weight to each other in the linear direction. And a speed measuring device for measuring a moving speed of each of the container and the reference weight in the linear direction.

[0010] The container may hold an object to be measured via a damper for attenuation.

[0011] The driving means may be a coil spring or a rubber spring whose compression state or tension state is released by a self-timer.

The drive means for separating the container and the reference weight from each other in the linear direction or for applying a force in the direction includes:
An air spring whose compression state is released by a self-timer may be used. The activation of the driving means is not limited to the self-timer, but may be a wireless or wired electromagnetic switch.
However, in the case of a wired type, it is necessary to consider the force transmitted through the lead wire. Further, when using the electromagnetic force as the driving force of the mechanical switch, it is necessary to consider the magnetism of the surrounding material.

[0013] The linear guide may be composed of two members that are slidably combined with each other in the linear direction and that are fixed to the container and the reference weight, respectively.

The container, the reference weight, the linear guide, the driving means, and the speed measuring device are disposed in a housing, and the container and the reference weight connected by the linear guide are connected to a clamp mechanism attached to the housing. It is good also as composition which is grasped and released. A guide made of a shock-absorbing material such as a sponge may be provided around the container, the reference weight, and the linear guide so as not to move more than necessary even when the clamp mechanism is released.

An optical interferometer may be used as the speed measuring device.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mass measuring device according to the present invention which operates in a zero gravity environment will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing the configuration of the present invention. According to the present invention, a driving force for separating or approaching the container 2 holding the DUT 1 and the reference weight 3 in a linear direction by a spring, an air spring, or the like is applied, thereby moving the container 2 and the reference weight 3. Is a mass measuring device that operates in a zero-gravity environment and operates in a zero-gravity environment.

More specifically, referring to FIG. 1, the mass measuring device of the present invention has a housing 11. Inside the housing 11, a container 2 having a mass m _C for holding the DUT 1 having a mass m _O is provided. DUT 1
Is held in the container 2 via the damper 10 for attenuation. For the damper 10 for damping, a buffer material such as rubber or sponge is used.

The container 2 is connected to a mass via a linear guide 8.
It is combined with the reference weight 3 of m _R. The linear guide 8 is
It comprises a cylinder 8a attached to one side surface of the reference weight 3 and a piston 8b attached to the side surface of the container 2 which slides in the cylinder 8a. With this linear guide 8, the container 2 and the reference weight 3 are moved in a linear direction A indicated by an arrow.
At a distance from each other.

Driving means is provided for applying a force in a direction to separate or approach the container 2 and the reference weight 3 in the linear direction A. This drive means
The compression or tension coil spring or the rubber spring is constrained in a compression state or a tension state to release the restriction, and the container 2 and the reference weight 8 are moved in a direction of separating or approaching. This movement may be only one-way movement, or may vibrate continuously after one-way movement.

As another mode of the driving means, although not shown, the above-described container 2 is formed by using a compressed air spring (compressed air pressure) having a structure in which air is sealed in a cylinder provided with a tank and released from a compressed state. And the reference weight 8 may be moved in the direction of separation.

This driving means will be specifically described in the embodiment shown in FIG. In FIG. 1, a compression coil spring 5 is attached to one side surface of the reference weight 3 as a driving means. The compression coil spring 5 is normally compressed and mechanically restrained by mechanical restraining means controlled by a self-timer (not shown), and is configured to be released during mass measurement. ing. When the restraint of the compression coil spring 5 is released, the container 2 and the reference weight 8 move so as to be separated by the elastic force of the compression coil spring 5.

The joined body in which the container 2 and the reference weight 3 are joined via the linear guide 8 is usually clamped and restrained in the housing 11 by a manual or magnetic clamping mechanism 9 fixed in the housing 11. It is held, and this clamp is released when measuring the mass.

The respective speeds of the container 2 and the reference weight 3 are measured with high accuracy by a speed sensor, for example, a light wave interferometer 6. The light wave interferometer 6 is a Michelson type interferometer that emits a stabilized helium neon laser. The laser beam 7 of the light wave interferometer is applied to the container 2 and the reference weight 3 via the corner cube prism 4 and the moving speed of each is measured by measuring the beat frequency.

The operation of the mass measuring instrument having the above configuration will be described in accordance with the measurement procedure. First, the clamp mechanism 9 is released to release the restraint of the combined body of the container 2 and the reference weight 3 to a free state. At that time, the total momentum and the total angular momentum of the combined body of the container 2 and the reference weight 3 are almost zero, and thereafter maintain the values unless a non-negligible external force acts.

Next, the compression state of the compression coil spring 5 is released and released by a self-timer or the like, and the container 2 and the reference weight 3 respectively start accelerating movements by the resilience. After the acceleration by the driving means is completed, if the frictional force of the piston 8b against the cylinder 8a of the linear guide is constant or sufficiently small, the relative movement between the DUT 1 and the container 2 is quickly attenuated by the action of the damper 10. Is done.

At this time, the following equation is established. ( _{M C} + m _O ) α _C = -m _R α _R = F _F (1) (m _C + m _O ) δv _C = -m _R δv _R (2) where α _C , Α _R , δv _C , δv _R are the acceleration of the container, the acceleration of the reference weight, the speed change from the initial value of the container,
This is the speed change from the initial value of the reference weight.

The mass m _O of the DUT 1 is obtained from the above equations 1 and 2 as follows. _{m O = - (α R /} α C) m R - m C ··· (3) m O = - (δv R / δv C) m R - m C ··· (4) The reference weight 3 And the masses m _R and m _C of the container 2 are measured in advance. That is, under conditions where m _R and m _C are known in advance, m _O can be obtained by measuring α _R / α _C or Δv _R / δv _C.

If the container 2 and the reference weight 3 are moved relative to each other without the linear guide 8, it is sufficient to consider the change in posture and their relative positions of the center of gravity and the measurement points by the speed sensor. . When the DUT 1 is not a rigid body but an elastic body, a liquid, a powder, a particle, a mixture thereof, or the like, the speed and the acceleration may be measured with respect to the center of the vibration.

The embodiments of the mass measuring apparatus according to the present invention have been described based on the embodiments. However, the present invention is not limited to the embodiments, and various embodiments of the present invention are possible within the scope of the claims. Needless to say, there is.

[0030]

According to the present invention, the object to be measured is not limited to a rigid body, but can be a variety of objects such as an elastic body, a liquid, a powder, a mixture, and the like. Therefore, it is possible to realize a measuring instrument that operates in a zero-gravity environment and that is extremely excellent in applicability and that performs mass measurement.

[Brief description of the drawings]

FIG. 1 is a drawing for explaining an embodiment of a mass measuring device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measurement object 2 Container for holding a measurement object 3 Reference weight 4 Corner cube prism 5 Compression coil spring 6 Light wave interferometer 7 Laser beam of light wave interferometer 8 Linear guide, linear bearing, 9 Clamp mechanism 10 Damper 11 Mass measuring instrument housing

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyuki Fujimoto 1-1-4 Umezono, Tsukuba, Ibaraki Pref. Inspector in the National Institute of Advanced Industrial Science and Technology Masao Einaga (56) References JP-A-62-39725 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01G 9/00

Claims (7)

(57) [Claims] 1. A mass measuring device that operates in a zero-gravity environment, comprising: a container for holding an object to be measured; a reference weight; and the container and the reference weight being linearly separated from and approached to each other. Linear guide, and the container and the reference weight, the drive means for applying a force in the direction of separating or approaching each other in the linear direction, the respective moving speed, acceleration of the container and the reference weight in the linear direction, A speed measuring device for measuring a ratio of a moving speed or a ratio of an acceleration, wherein the mass measuring device operates in a zero gravity environment. 2. The mass measuring device according to claim 1, wherein the container holds an object to be measured via a damping damper. 3. The device according to claim 1, wherein the driving means is a coil spring or a rubber spring whose compression state or tension state is released by a self-timer or a wireless or wired electromagnetic switch. A mass measuring device that operates in a zero gravity environment. 4. An air spring in which a driving means for applying a force in a direction for separating the container and the reference weight from each other in the linear direction is released by a self-timer or a wireless or wired electromagnetic switch. The mass measuring device operating under a zero gravity environment according to claim 1 or 2, wherein: 5. The linear guide according to claim 1, wherein the linear guide is composed of two members slidably coupled to each other in the linear direction, each of which is fixed to the container and a reference weight. 5. A mass measuring device which operates in a zero gravity environment according to 2, 3, or 4. 6. The container, a reference weight, a linear guide,
The driving means and the speed measuring device are arranged in a housing, and the container and the reference weight connected by the linear guide are gripped and released by a clamp mechanism attached to the housing. Terms 1, 2, 3,
6. A mass measuring device that operates in a zero gravity environment according to 4 or 5. 7. The mass measuring instrument operating in a zero gravity environment according to claim 1, wherein the velocity measuring device is a light wave interferometer.