ISO 8626:1989 振動を発生させるためのサーボ油圧試験装置—特性を記述する方法 | ページ 6

5.5.1

供給圧力

_p

流量q _{v n} で水力発電システムによって生成される圧力。供給圧力は、圧力調整器の出口でバールまたはパスカルで測定されます。

5.5.2

油圧システムの流量

q _{V n}

供給圧力_s で電力システムが供給できる最大流量。圧力調整器の出力で測定され、リットル/分または立方センチメートル/秒で測定されます。

5.5.3.1

定格トラベル

振動発生器の可動要素が通常動作し、それを超えると製造業者によって性能が保証されなくなる、ミリメートル単位の限界。

5.5.3.2

停留所間の移動

定格移動量に、制動に使用される各限界における安全マージンを加えたもの。

5.5.7.2.1.1

定格試験力

_フロムト

特定のテストマス用

_t

最大加速度a _{max は}試験荷重に関連して定義されます (5.4 を参照) a _値が得られる周波数範囲は、試験荷重m _t の定格周波数範囲です。

5.5.7.2.1.2

定格荷重

F _o

注記 1:定格動的力F _o は、静的負荷力F _st とは異なる場合がありますが、アクチュエータに疲労損傷を引き起こしてはなりません。

5.5.7.2.2

定格ランダム力、広帯域

F _​

5.1

hydraulic vibration generator

A test device in which the vibratory linear movement of the test table or power take-off ¹⁾ is produced by the action of a fluid on a piston.

A schematic diagram of the test table power take-off vibration generator is shown in figure 7.

The hydraulic vibration comprises the constituent parts defined in 5.1.1 to 5.1.3.

5.1.1

moving element

5.1.2

pedestal

Constituent part that connects the body of the actuator to the foundation, the reaction mass or baseplate, if fitted.

5.1.3

gravity compensation device

Constituent part fitted, in certain cases, to the hydraulic vibration generators in order to resist the static forces caused by the material under test.

5.2

servovalve control device

Note 1 to entry: In certain cases or for certain servovalves, the valve may not include the hydromechanical position transducer; this should then be a function of the control system.

Note 2 to entry: In order to minimize the harmonic distortion factors, this device may be fed with acceleration, velocity or pressure data In addition to the vibration signal and Its slide valve position data.

5.3

hydraulic power supply

The complete hydraulic installation necessary for feeding the hydraulic vibration generators.

A schematic diagram is given in figure 8.

The hydraulic power supply designed for feeding the hydraulic vibration generator is generally made up of the elements defined in 5.3.1 to 5.3.8

5.3.1

hydraulic fluid

The power transfer agent between the hydraulic power supply and the vibration generator.

5.3.2

reservoir

Container for storing the hydraulic fluid and the capacity of which generally depends on the maximum flow rate of the hydraulic pump.

5.3.3

hydraulic pump

Equipment which produces the flow rate and pressure necessary for feeding the hydraulic vibration generator; it can have a constant or variable flow rate.

5.3.4

pressure regulator

Equipment which keeps the pressure between certain limits fixed by the vibration generator manufacturer; it may have a proportional or on-off action.

5.3.5

filtration system

Series of filters in the reservoir discharge and return circuits which keep the hydraulic circuits clean, as required for servovalve applications.

5.3.6

heat exchangers

Devices which maintain the temperature of the hydraulic fluid in the reservoir within the temperature range set by the manufacturer.

5.3.7

accumulator

Pressurized fluid reservoir which compensates for pressure surges in the hydraulic (discharge and return) circuits and attenuates hammering in the installation.

5.3.8

auxiliary equipment

Equipment comprising the accessories used, the device providing information, and the alarm and safety systems (see 10.3.2).

5.4

test masses

m_t

Mechanical masses selected by the manufacturer and used for the testing of hydraulic vibration generators.

Note 1 to entry: For requirements on shape, dimensions, flatness, surface roughness and fixing of the test mass, see annex C.

5.4.1

test mass

m₀

The special case where the test mass is zero and only the moving table is driven.

5.4.2

test mass

m₁

A load permitting a peak acceleration of approximately 1 g under sinusoidal conditions.

5.4.3

test mass

m₂

A load permitting a peak acceleration of approximately 4g under sinusoidal conditions.

5.4.4

test mass

m₃

A load permitting a peak acceleration of approximately 10g under sinusoidal conditions.

5.4.5

test mass

m₄

A load permitting a peak acceleration of approximately 20g under sinusoidal conditions.

5.4.6

test mass

m₅

A load permitting a peak acceleration of approximately 40g under sinusoidal conditions.

5.5.4

rated velocity

X_n

Maximum velocity amplitude of the moving element which can be obtained under sinusoidal conditions with test mass m₀ without the use of any resonance effect. The rated velocity is given in millimetres per second or metres per second.

5.5.5

mass of the moving element

m_e

The mass, in kilograms, of the moving element, as described in 5.1.1.

Note 1 to entry: This mass does not include the mass of the moving hydraulic fluid.

5.5.6

frequency of the normal hydraulic model

f_oh

Note 1 to entry: The viscous damping b may be disregarded.

5.5.7

force

For the purposes of this International Standard, the force in newtons or kilonewtons, developed by a hydraulic vibration generator which can be delivered to a load mounted on the test table or connected to the power take-off, i.e. output force.

5.5.7.1

static force

F_st(at zero velocity)

The force of the moving element at zero velocity and supply pressure p_s; this is the product of the supply pressure p_s and the useful cross-section A: F_st = P_sA

Note 1 to entry: If fitted, the gravity compensation device does not affect this definition (see 5.1.3 and 7.2.7).

5.5.7.2

dynamic forces

Practical loads may include spring forces and/or damper forces which will influence the performance of the generator. Characteristics of vibration generators are normally specified for mass loading which is the basis of this International Standard. A manufacturer should, however, be expected to give actuator performance with pure spring loading or pure damper loading, if required.

5.5.8.1

acceleration power spectral density

Φ(f)

The limiting value of when Δf tends towards zero ここで, a_b is the r.m.s. value of an acceleration waveform with Gaussian amplitude distribution and Δf is a frequency band centred about frequency f.

5.5.8.2

displacement power spectral density

θ(f)

The limiting value of when Δf tends towards zero ここで, xb is the r.m.s. value of a displacement waveform with Gaussian amplitude distribution and Δf is a frequency band centred about frequency f.

The graph of the acceleration and displacement power spectral density functions may be specified in terms of the lowest operating frequency f_l a displacement-velocity transition frequency f₂, a velocity-acceleration transition frequency f₃, a cut-off frequency f₄, a second cut-off frequency f₅, if required, and the highest operating frequency, f₆. Between f₁ and f₂ the displacement power spectral density is constant, between f₃ and f₄ the acceleration power spectral density is constant.

5.5.9.1

r.m.s. value of displacement

x_b

5.5.9.2

r.m.s. value of acceleration

α_b

5.5.10.1.1

acceleration distortion

5.5.10.1.2

velocity distortion

When the acceleration signal is integrated to obtain a velocity signal, each component is divided by its own frequency and the ratio between the harmonic components and the fundamental is deduced. If the harmonic components are much larger than the noise, as is usually the case, the velocity distortion will be much lower than the acceleration distortion. If velocity rather than acceleration distortion is intended, the words"velocity distortion" shall be clearly stated.

5.5.10.1.3

displacement distortion

When the velocity signal is integrated again to obtain a displacement signal, if the harmonic components of displacement are larger than the displacement noise, which may be the case, the displacement distortion will be less than the velocity distortion. If displacement distortion rather than acceleration distortion d is intended, the words"displacement distortion" shall be clearly stated.