JP3738593B2 - Method for measuring excitation force of vibration generator - Google Patents

Description

で示され、最小二乗法によりω0 、ζ、ＦＫ4j(0)の３つの未知数を決定する。なお、ω0 は加振器アーマチャ共振周波数、ζは加振器アーマチャ減衰係数、ＦＫ4j(0)は加振力（強制力）の０切片であり、式１ではこれらを未知数として取り扱う。
【００２１】
実質的に無限大の質量を加振した場合の励振力は、ある周波数までは周波数が高いほど増大し、したがって上記のようにして加速度ゼロ近傍の点での加振力をつないだ線が、実質的に無限大の質量体を加振した場合の各周波数での加振力を表す。なお、このような無限大の質量体を加振した場合の加振力は、複数の加振入力レベルごとに求める。このようにして求めた周波数ωごとの励振力Ｆの例を図５に示してある。
【００２２】
この発明の方法では、このようにして励振力の知られた加振器１によって振動発生体である供試体６を加振し、その際の各周波数ごとの加振力や加速度などの振動に伴う物理量を測定する。その供試体６の加振状態を図１に示してある。すなわち基台７，７の上に、弾性支持部材であるエアーバネ８，８が固定されており、そのエアーバネ８，８の上に供試体６が載せられている。これらのエアーバネ８，８は、供試体６を下から支持する部材であって、供試体６の３次元方向への移動を自由に生じさせるように構成されており、特にその共振点は、測定するべき振動周波数の範囲の最低値の約１／４よりも低周波数側になるように設定されている。なお、共振点がこの程度に低い構造のものであれば、エアーバネ８，８以外の支持部材であってもよい。
【００２３】
一方、加振器１は、所定の基台９上に載せて固定し、そのアーマチャを供試体６の予め決めた加振箇所に接続ブロック１１を介して連結する。そしてその加振点にインピーダンスヘッド（３軸加速度センサー）などのセンサー１０を取り付ける。この状態で加振器１に適宜の周波数の交流電流を印加して供試体６を加振し、その際に検出された加速度と加振器１の励振力とに基づいて伝達関数を求める。なお、加速度や加振力の測定は、互いに直交するＸ，Ｙ，Ｚの３つの方向のいずれかの方向に加振している場合に３方向のすべてについて加速度や加振力を測定し、これをＸ，Ｙ，Ｚの３方向の加振の際にそれぞれおこなう。結局、１つの測定部位について９つの測定をおこなう。なお、接続ブロック１１は、系の振動特性に影響を与えない小型のものである。
【００２４】
その場合、供試体６を含む系全体の振動特性を変化させないために、Ｘ，Ｙ，Ｚの３方向の加振をおこなうための加振器１をそれぞれ取り付けたままとすることが必要となる。しかしながら、加振器１のアーマチャは一方向にのみ往復運動するように構成されているので、互いに直交する３方向に加振器１を連結した状態では、各アーマチャに対する直交方向の振動が規制されるために、結局、いずれの方向にも自由な振動ができなくなってしまう。そこで、このような不都合を解消するために、供試体６を運転する場合には図６に示すように、加振器１に替えて、加振器１の可動部の質量分だけ重くした接続ブロック１１を、供試体６に取り付ける。このようにすれば、供試体１の自由な振動が規制されないので、正確な振動の測定をおこなうことができる。
【００２５】
加振器１によって供試体６を加振し、所定のデータを取った後、供試体６を動作させ、その際の振動について、各周波数ごとに、かつＸ，Ｙ，Ｚの３方向の加速度を測定する。得られた加速度をＡ、前記伝達関数をＨとすると、供試体６が動作することにより振動で発生する励振力Ｆは、
【式２】

の行列式の演算で求められる。
【００２６】
上記のようにして測定をおこなうこの発明に係る上記の方法では、加振器１が供試体６に小型の接続ブロック１１のみが連結されているので、外乱要因が少なくなる。また、供試体６を支持しているエアーバネ８により系の共振点が低くなるので、測定データに基台７からの外乱が入らず、もしくは無視できる程度に抑制される。その結果、上記の方法では、高精度な測定をおこなうことができる。
【００２７】
ところで供試体を加振する場合や供試体を動作させて振動を生じさせる場合、その供試体を何らかの手段で支持する必要があり、上述した例では、エアーバネによって下側から支える構造とした。この発明では、これに替えて、以下に述べる構造の支持部材を使用して供試体６を支持して測定をおこなってもよい。
【００２８】
すなわちセンサーが所定の測定方向に往復移動することにより加速度を測定することができるのであるから、測定方向とは異なる方向にセンサーが移動すれば、これが外乱となって測定精度が低下することになる。したがって供試体を支持する支持部材の剛性を、測定方向に対して低く、これとは異なる方向では高くすれば、センサーが測定方向以外には移動しにくくなって、検出される信号に含まれるノイズ成分が小さくなる。
【００２９】
図７に示す構成の支持部材１２は、リング状の基体部１３における中心軸線に沿う方向の支持剛性を低くし、これとは異なる方向での支持剛性を高くした構造のものである。すなわち基体部１３の円周上の４箇所で鉛直線に対して４５度傾斜した位置に、基体部１３の半径方向で互いに対向する薄板状のそれぞれ１対のアーム１４が、軸線方向に延びて取り付けられ、各アーム１４の先端部にブロック１５が取り付けられている。また、各ブロック１５には、基体部１３の軸線方向に直角で互いに対向する薄板状のそれぞれ１対のサブアーム１６が、基体部１３の中心軸線に向けて延びて取り付けられている。これらのサブアーム１６の先端部に、基体部１３の中心軸線に中心部を一致させた可動ブロック１７が取り付けられている。
【００３０】
したがって、前記ブロック１５を基体部１３に対して取り付けている各アーム１４は、その板厚方向に対して容易に変形するがその幅方向（面方向）には殆ど変形しないうえに、これらのアーム１４が互いに円周方向に９０度の間隔で設けられているので、全体として上下方向および左右方向に対しての剛性が高く、これらの方向への移動が規制される。また、前記ブロック１５から中心軸線方向に延びたサブアーム１６は、その板厚方向にのみ変形しやすい構造であるから、結局、その先端部に取り付けられた可動ブック１７は、基体部１３の軸線方向に対して低剛性で支持され、これとは直交する方向に対して高剛性で支持されている。
【００３１】
この支持部材１２を使用した供試体６についての振動の測定状態を図８に示してある。供試体６は、前記可動ブロック１７から突出された連結桿１８の先端部に固定され、懸吊状態で保持されている。これに対して加振器１は、その可動ブック１７に前記基体部１３の中心軸線に沿って連結され、さらに可動ブロック１７に加速度センサーなどのセンサー１０が取り付けられている。したがって測定方向は図８の左右方向すなわち基体部１３の中心軸線に沿う方向である。
【００３２】
図８に示す状態で加振器１を駆動して供試体６を加振し、あるいは供試体６を動作させて振動させた場合、加振器１および供試体６を連結してある可動ブロック１７が、前記基体部１３の軸線方向に容易に変位し、これとは異なる方向に対して高い剛性で支持されていて変位しにくくなっているので、可動ブロック１７に取り付けられているセンサー１０によって得られる信号中のノイズ成分が少なくなる。例えば、加振器１で加振した場合の加速度は、図９に示すように、測定方向では比較的低い周波数域で高い値を示し、これとは異なる方向では高い周波数域で大きくなる。したがって図９に示す低周波数域ｆでは、Ｓ／Ｎ比が大きくなるので、この範囲のデータを使用することにより、高精度の測定をおこなうことができる。
【００３３】
なお、ノイズあるいはクロストークは、センサーが測定方向とは異なる方向に振動することによって生じるから、支持部材はこのようなセンサーの挙動を防止するために、剛性の異方性を備えていれば良く、したがって図１０に示す構成であっても良い。この図１０に示す構成を具体的に説明すると、基盤１９の上にベアリング式のリニアスライダー２０が取り付けられており、可動部２１がそのリニアスライダー２０の可動部分に取り付けられている。
【００３４】
振動の測定をおこなう場合、その可動部２１に加振器および供試体が連結され、供試体はこの可動部２１を介して支持される。また、センサーはこの可動部２１に取り付けられる。したがってセンサーは、可動部２１と共に一方向にのみ容易に変位し、これとは異なる方向に対して移動が規制されるので、ノイズに対してシグナルが充分高くなり、その結果、図７に示す支持部材１２を用いる場合と同様に、高精度の測定をおこなうことができる。
【００３５】
【発明の効果】
以上説明したように請求項１の発明によれば、供試体である振動発生体と加振器とが所定の接続ブロックを介して連結されるので、加振器で振動発生体を加振した場合および振動発生体を動作させた場合のそれぞれで得られるデータに含まれる外乱が少なくなり、高精度の測定が可能になる。
【００３６】
また、請求項２の発明によれば、振動発生体を動作させて振動を生じさせる場合、加振器が不要であるが、これに替わる質量体が付加されているので、加振器で振動発生体を加振する場合と同様もしくは実質的に同様な振動系となり、そのため、測定誤差を生じさせることなく加振器を取り外すことができ、加振器の必要数を少なくして測定装置のコストの低廉化を図ることができ、また同時に高精度の測定をおこなうことができる。
【００３７】
さらに、請求項３の発明によれば、振動発生体を支持部材によって保持し、その状態で加振器によって加振し、もしくは振動発生体を動作させて振動を生じさせ、かつ必要な物理量を測定するが、その支持部材の剛性が、測定するべき振動の方向に対して低く、これに交差する方向で高いので、得られるデータに含まれるノイズ成分もしくはクロストーク成分が少なくなり、その結果、精度の高い測定をおこなうことができる。
【図面の簡単な説明】
【図１】 この発明の方法を実施している状況の一例を示す図である。
【図２】 加振器による励振力を測定するために加振器で治具を加振する状態を示す側面図である。
【図３】 その治具の斜視図である。
【図４】 その治具を加振した場合の加速度の測定結果の一例を示す線図である。
【図５】 加振器の入力レベルごとの励振力の測定結果であるマップの例を示す図である。
【図６】 この発明の方法において加振器の可動部の質量分重くした接続ブロックを取り付けた状態を示す図である。
【図７】 この発明の方法を実施するために使用する支持部材の一例を示す斜視図である。
【図８】 その支持部材を使用したこの発明の方法の一例を示す側面図である。
【図９】 その加速度の測定結果を示す図である。
【図１０】 この発明の方法で使用することのできる支持部材の他の例を示す斜視図である。
【符号の説明】
１…加振器、 ２…治具、 ６…供試体（振動発生体）、 ８…エアーバネ、 １０…センサー、 １１…接続ブロック、 １２…支持部材、 １９…基盤、 ２０…リニアスライダー、 ２１…可動部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for measuring an excitation force by a vibration generator that generates vibrations by operating an engine, a transmission, a propeller shaft, or the like.
[0002]
[Prior art]
In a device that performs rotational motion or linear reciprocating motion, such as an engine or a transmission, vibration occurs due to mass point deviation, elasticity of components, or play. Knowing the force that generates the vibration, that is, the vibration force and the frequency characteristics of the vibration is indispensable for the design and manufacture of devices and mounts for mounting these devices.
[0003]
Measurement of vibration characteristics for this purpose is conventionally performed by attaching a target device, that is, a specimen, to a predetermined jig, operating the specimen in that state, and measuring vibration acceleration and frequency at that time. In addition, the operating state of the specimen is simulated by vibrating the specimen attached to the jig with a vibrator, and the force acting between the specimen and the jig at that time, that is, the excitation force by the specimen is measured. It is also measured.
[0004]
When the specimen is attached to the jig in this way, the entire structure including the jig constitutes the vibration system. Therefore, in order to know the vibration characteristics unique to the specimen, some process to remove the influence of the jig is required. Further, the influence of the jig cannot be completely removed, so that it is necessary to carry out difficult operations and processing for obtaining the vibration characteristics of the specimen, and it is difficult to obtain accurate vibration characteristics.
[0005]
The same applies to the case where the force exerted by the vibrating specimen on the support structure such as a jig is measured, and the jig affects the vibration characteristics of the entire system including the specimen. If the structure is different, the force (transmission force) acting on the support structure from the specimen differs, and eventually only a relative value specifying the jig can be obtained.
[0006]
Furthermore, when obtaining the excitation force by the vibrator, the predetermined object such as the jig described above is vibrated, the force generated between the two is measured, and this is generated by the vibrator. It is power. However, the force includes the characteristics of the jig due to the vibration of the jig. Eventually, only a relative value specifying the jig can be obtained.
[0007]
In order to eliminate such inconvenience, the absolute value of the excitation force by the vibrator or specimen, that is, the excitation force (excitation) acting on the counterpart material when the counterpart material with infinite mass is vibrated The applicant has already proposed a method and apparatus for measuring force). The method according to the proposal is a method of measuring the excitation force at a point where the acceleration is zero when the vibration is applied by the vibrator, and using this as the excitation force of the vibrator. In this way, a test piece attached to a predetermined jig is vibrated together with the jig by a vibrator having a known excitation force, and the acceleration and force at that time are measured, and the transfer function of the vibration system is determined. Ask. Next, the specimen is moved and the acceleration and force of vibration associated therewith are measured. Since the relationship between the known excitation force and the force and acceleration when excited by that excitation force, that is, the transfer function is known, the acceleration and force obtained by operating the specimen are divided by the transfer function. By doing so, the absolute value of the excitation force by the specimen, that is, the excitation force can be obtained.
[0008]
[Problems to be solved by the invention]
In the above-mentioned method and apparatus proposed by the present applicant, the specimen is supported by a jig, vibrated by a vibrator in that state, and the specimen is operated, and acceleration and force are measured in that state. . In that case, the jig vibrates in a three-dimensional direction, and acceleration accompanying vibration in a direction different from the measurement direction may act as a disturbance. As a result, measurement errors may occur due to such behavior of the jig.
[0009]
In addition, in the method proposed by the applicant described above, the specimen is operated after being vibrated with a vibrator and obtaining predetermined data. This is because the vibration is generated by exciting with a known excitation force. This is because the transfer function of the system is obtained, and the excitation force of the specimen is obtained using the inverse of the transfer function. Therefore, it is necessary that the vibration characteristics when vibrating with the vibrator and the vibration characteristics when operating the specimen are the same, and even when the specimen is operated, the vibrator is controlled. It is necessary to connect to the tool. Therefore, for example, when measuring in each of the X, Y, and Z axes, three vibrators are required, which increases the equipment and cost required for the measurement, and further excites the vibrator. Generally, a vibrator has a high rigidity structure in a direction perpendicular to the excitation direction. Therefore, if the vibrators are connected in three directions perpendicular to each other, the vibrators interfere with each other. There is a disadvantage that it is impossible to vibrate in either direction.
[0010]
The present invention has been made against the background described above, and an object of the present invention is to provide a method capable of measuring the excitation force generated by the vibration generator with high accuracy.
[0011]
[Means for Solving the Problem and Action]
In order to achieve the above object, the invention according to claim 1 is that a vibration generator that generates vibrations when operated is vibrated by a vibrator in a non-operating state, and a physical quantity associated with the vibration of the vibration generators. In the method for measuring the excitation force of the vibration generator, the resonance point being lower than about ¼ of the lowest value of the frequency range of the vibration to be measured, The vibration generating body is supported from below by an elastic support body, and the vibration generating body is excited by connecting the vibration generator to the vibration generating body through a predetermined connection block. It is a method characterized by measuring a physical quantity accompanying vibration.
[0012]
Therefore, in the first aspect of the present invention, the vibration generator and the vibration exciter, which are specimens, are connected via a predetermined connection block, and no member constituting the vibration system is interposed between them. Here, the connection block is a small one that does not greatly affect the vibration characteristics of the system. As a result, the connection block can be obtained when the vibration generator is vibrated with the vibrator and when the vibration generator is operated. Disturbances included in the data are reduced, and highly accurate measurement is possible.
[0013]
The invention of claim 2 is to vibrated by the vibrator in its non-activated state vibration generator which generates by Ri vibrations to operate, also to operate the vibration generator member, by these vibrator In the method for measuring an excitation force of a vibration generator, the physical quantity associated with the vibration during the vibration and the operation of the vibration generator is measured, and the excitation force of the vibration generator is obtained based on the obtained data. when operating the is a method characterized by adding a quality-mer having the same mass and the movable portion of the vibrator before Symbol vibration generator in place of the vibrator.
[0014]
Therefore, in the second aspect of the present invention, when the vibration generator is operated to generate vibration, a vibration exciter is unnecessary, but a mass body that replaces this is connected. The vibration system is the same as or substantially the same as that in the case of vibrating. The mass body is, for example, a connection block that has the same mass as the movable part of the vibrator, so that the vibrator can be removed without causing measurement errors, and the need for a vibrator By reducing the number, the cost of the measuring device can be reduced.
[0015]
Further, the invention according to claim 3 is obtained by vibrating a vibration generator that generates vibration by operating with a vibrator in a non-operating state, and measuring a physical quantity associated with the vibration of the vibration generator. In the vibration generator excitation force measurement method for obtaining the excitation force of the vibration generator based on the data, the rigidity is low in the direction of the vibration to be measured and the rigidity in the direction intersecting the direction is high. In the state in which the vibration generating body is held by a supporting member, the vibration generating body is vibrated or the vibration generating body is operated to measure a physical quantity associated with vibration.
[0016]
Therefore, in the invention of claim 3, the vibration generator is held by the support member, and in that state, the vibration generator is vibrated by the vibrator, or the vibration generator is operated to generate vibration, and the necessary physical quantity is measured. However, since the rigidity of the support member is low with respect to the direction of vibration to be measured and high in the direction crossing this, the noise component contained in the obtained data is reduced, and as a result, the measurement accuracy is increased.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described more specifically with reference to the drawings. As described above, the method of the present invention can be carried out on the premise of the method already proposed by the present applicant. Therefore, first, the presumed method will be briefly described.
[0018]
The method already proposed by the present applicant is to measure the excitation force of an exciter, that is, the excitation force when an infinite mass is vibrated, and to vibrate the vibration generator as a specimen with the known excitation force. The transfer function is obtained. Next, the specimen is operated to generate vibration, and the obtained data is divided by the transfer function to obtain the excitation force of the specimen.
[0019]
The excitation force of the vibration exciter is the excitation force at a point where the vibration acceleration existing between resonance points when a suitable vibrating body is vibrated with the vibration exciter is zero. FIG. 2 schematically shows a state in which the jig 2 is vibrated by the vibrator 1, and the vibrator 1 has an electromagnetic coil disposed on the outer peripheral side of an armature provided with a permanent magnet, for example. By applying an alternating current of an appropriate frequency to the electromagnetic coil, a thrust force that moves back and forth in the axial direction is generated in the armature. The jig 2 is a flat plate having a relatively large area in the illustrated example, and a large number of measurement points 3 are provided in a matrix as shown in FIG. As shown in FIG. 2, the jig 2 is vertically held on a surface plate 4 and held by a predetermined block 5, and the vibrator 1 is connected and vibrated. Here, the reason for oscillating the jig 2 that is a flat plate having a relatively large area is that the flat plate vibrates in a complicated manner and has a large number of resonance points. This is because there are a large number of points in the vicinity, and as a result, a large number of data representing the excitation force at that point are obtained.
[0020]
The jig 2 is vibrated with the vibrator 1 and the acceleration at the vibration point is measured. The relationship between the obtained acceleration and frequency is as shown in FIG. 4, for example. In other words, there is a point where the acceleration becomes near zero between the resonance points where the acceleration becomes a maximum value. The excitation force at a frequency at which the acceleration becomes near zero is plotted on a predetermined graph. Then, an intermediate value of the excitation force thus obtained is interpolated with an approximate curve. An example of the approximate expression is
[Formula 1]

The three unknowns ω0, ζ, and FK4j (0) are determined by the least square method. Ω0 is the vibrator armature resonance frequency, ζ is the vibrator armature damping coefficient, and FK4j (0) is the 0 intercept of the vibration force (forced force).
[0021]
When a substantially infinite mass is vibrated, the excitation force increases up to a certain frequency as the frequency increases. Therefore, the line connecting the excitation forces at points near zero acceleration as described above, It represents the exciting force at each frequency when a substantially infinite mass body is vibrated. The excitation force when such an infinite mass is vibrated is obtained for each of the plurality of excitation input levels. An example of the excitation force F for each frequency ω obtained in this way is shown in FIG.
[0022]
In the method of the present invention, the specimen 6 which is a vibration generating body is vibrated by the vibrator 1 having a known excitation force in this way, and the vibration such as the exciting force and acceleration at each frequency at that time is vibrated. Measure the physical quantity involved. The vibration state of the specimen 6 is shown in FIG. That is, air springs 8, 8 that are elastic support members are fixed on the bases 7, 7, and the specimen 6 is placed on the air springs 8, 8. These air springs 8 and 8 are members that support the specimen 6 from below, and are configured to freely cause the specimen 6 to move in the three-dimensional direction. In particular, its resonance point is measured. The frequency is set to be lower than about ¼ of the lowest value of the range of vibration frequencies to be performed. It should be noted that a support member other than the air springs 8 and 8 may be used as long as the resonance point has such a low structure.
[0023]
Meanwhile, vibrator 1, and fixed mounted on a predetermined base 9 is connected via a connecting block 11 that armature to predetermined vibration portion of the specimen 6. A sensor 10 such as an impedance head (3-axis acceleration sensor) is attached to the excitation point. In this state, an alternating current having an appropriate frequency is applied to the vibrator 1 to vibrate the specimen 6, and a transfer function is obtained based on the acceleration detected at that time and the excitation force of the vibrator 1. Note that the acceleration and excitation force are measured by measuring the acceleration and excitation force in all three directions when the excitation is in one of the three directions X, Y, and Z orthogonal to each other. This is performed in each of the three directions of X, Y, and Z. Eventually, nine measurements are performed for one measurement site. The connection block 11 is a small one that does not affect the vibration characteristics of the system.
[0024]
In that case, in order not to change the vibration characteristics of the entire system including the specimen 6, it is necessary to leave the vibrator 1 for vibrating in the three directions of X, Y, and Z attached. . However, since the armature of the vibrator 1 is configured to reciprocate only in one direction, in the state where the vibrator 1 is connected in three directions orthogonal to each other, vibration in the orthogonal direction with respect to each armature is restricted. As a result, free vibration is not possible in any direction. Therefore, in order to eliminate such inconvenience, when the specimen 6 is operated, as shown in FIG. 6, instead of the vibrator 1, the connection is made heavy by the mass of the movable part of the vibrator 1. The block 11 is attached to the specimen 6. In this way, since free vibration of the specimen 1 is not regulated, accurate vibration measurement can be performed.
[0025]
After the specimen 6 is vibrated by the vibrator 1 and predetermined data is taken, the specimen 6 is operated, and the vibration at that time is accelerated at each frequency and in three directions of X, Y, and Z. Measure. Assuming that the obtained acceleration is A and the transfer function is H, the excitation force F generated by the vibration due to the operation of the specimen 6 is
[Formula 2]

It is calculated by the determinant of
[0026]
In the above-described method according to the present invention, in which the measurement is performed as described above, since only the small connection block 11 is connected to the specimen 6 in the vibrator 1, the disturbance factor is reduced. Further, since the resonance point of the system is lowered by the air spring 8 supporting the specimen 6, the disturbance from the base 7 does not enter the measurement data or is suppressed to a negligible level. As a result, the above method can perform highly accurate measurement.
[0027]
By the way, when the specimen is vibrated or when the specimen is operated to generate vibration, the specimen needs to be supported by some means. In the above-described example, the structure is supported from below by an air spring. In this invention, it may replace with this and may support and measure the specimen 6 using the supporting member of the structure described below.
[0028]
In other words, since the acceleration can be measured by reciprocating the sensor in a predetermined measurement direction, if the sensor moves in a direction different from the measurement direction, this becomes a disturbance and the measurement accuracy decreases. . Therefore, if the rigidity of the support member that supports the specimen is low in the measurement direction and high in a different direction, the sensor will not move easily in the direction other than the measurement direction, and noise included in the detected signal Ingredients become smaller.
[0029]
The support member 12 having the configuration shown in FIG. 7 has a structure in which the support rigidity in the direction along the central axis of the ring-shaped base portion 13 is lowered and the support rigidity in a direction different from this is increased. That is, a pair of thin plate-like arms 14 facing each other in the radial direction of the base portion 13 extend in the axial direction at positions inclined at 45 degrees with respect to the vertical line at four locations on the circumference of the base portion 13. A block 15 is attached to the tip of each arm 14. Each block 15 is attached with a pair of thin plate-like sub-arms 16 facing each other at right angles to the axial direction of the base portion 13 so as to extend toward the central axis of the base portion 13. A movable block 17 whose center is aligned with the center axis of the base body 13 is attached to the tip of these sub arms 16.
[0030]
Therefore, each arm 14 that attaches the block 15 to the base portion 13 is easily deformed in the thickness direction, but hardly deforms in the width direction (plane direction). Since 14 are provided at intervals of 90 degrees in the circumferential direction, the rigidity in the vertical direction and the horizontal direction is high as a whole, and movement in these directions is restricted. Further, since the sub arm 16 extending from the block 15 in the central axis direction is easily deformed only in the plate thickness direction, the movable book 17 attached to the front end portion of the sub arm 16 is eventually in the axial direction of the base body portion 13. Is supported with low rigidity, and is supported with high rigidity in a direction orthogonal thereto.
[0031]
FIG. 8 shows the vibration measurement state of the specimen 6 using the support member 12. The specimen 6 is fixed to the distal end portion of the connecting rod 18 protruding from the movable block 17, and is held in a suspended state. On the other hand, the vibrator 1 is connected to the movable book 17 along the central axis of the base portion 13, and a sensor 10 such as an acceleration sensor is attached to the movable block 17. Therefore, the measurement direction is the left-right direction in FIG. 8, that is, the direction along the central axis of the base portion 13.
[0032]
In the state shown in FIG. 8, when the vibrator 1 is driven to vibrate the specimen 6, or when the specimen 6 is operated and vibrated, the movable block in which the vibrator 1 and the specimen 6 are connected. 17 is easily displaced in the axial direction of the base portion 13 and is supported with high rigidity in a direction different from this, and is difficult to displace. Therefore, the sensor 10 attached to the movable block 17 The noise component in the obtained signal is reduced. For example, as shown in FIG. 9, the acceleration when the vibrator 1 vibrates shows a high value in a relatively low frequency region in the measurement direction, and increases in a high frequency region in a different direction. Therefore, since the S / N ratio becomes large in the low frequency region f shown in FIG. 9, it is possible to perform highly accurate measurement by using data in this range.
[0033]
Since noise or crosstalk is generated when the sensor vibrates in a direction different from the measurement direction, the support member only needs to have rigidity anisotropy in order to prevent such sensor behavior. Therefore, the configuration shown in FIG. The configuration shown in FIG. 10 will be specifically described. A bearing type linear slider 20 is attached on a base 19, and a movable portion 21 is attached to a movable portion of the linear slider 20.
[0034]
When vibration is measured, a vibrator and a specimen are connected to the movable part 21, and the specimen is supported via the movable part 21. The sensor is attached to the movable part 21. Therefore, the sensor is easily displaced only in one direction together with the movable portion 21, and the movement is restricted in a direction different from this, so that the signal with respect to noise becomes sufficiently high, and as a result, the support shown in FIG. As in the case of using the member 12, highly accurate measurement can be performed.
[0035]
【The invention's effect】
As described above, according to the first aspect of the present invention, the vibration generator and the vibration exciter, which are the specimens, are coupled via the predetermined connection block, so the vibration generator is vibrated with the vibration exciter. The disturbance included in the data obtained in each of the case and the case of operating the vibration generator is reduced, and high-precision measurement is possible.
[0036]
According to the second aspect of the present invention, when the vibration generator is operated to generate vibration, a vibration exciter is unnecessary. However, since a mass body is added instead, vibration is generated by the vibration exciter. The vibration system is the same as or substantially the same as when the generator is vibrated, so that the vibrator can be removed without causing a measurement error, and the number of vibrators required is reduced. The cost can be reduced, and at the same time, highly accurate measurement can be performed.
[0037]
Further, according to the invention of claim 3, the vibration generator is held by the support member, and in that state, the vibration generator is vibrated by the vibrator, or the vibration generator is operated to generate vibration, and the necessary physical quantity is obtained. Although the rigidity of the supporting member is low with respect to the direction of vibration to be measured and high in the direction crossing this, the noise component or the crosstalk component included in the obtained data is reduced, and as a result, Highly accurate measurement can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a situation in which a method of the present invention is implemented.
FIG. 2 is a side view showing a state in which a jig is vibrated by a vibration exciter in order to measure an excitation force by the vibration exciter.
FIG. 3 is a perspective view of the jig.
FIG. 4 is a diagram showing an example of an acceleration measurement result when the jig is vibrated.
FIG. 5 is a diagram showing an example of a map that is a measurement result of excitation force for each input level of a vibrator.
FIG. 6 is a view showing a state in which a connection block having a mass of a movable part of a vibrator is attached in the method of the present invention.
FIG. 7 is a perspective view showing an example of a support member used for carrying out the method of the present invention.
FIG. 8 is a side view showing an example of the method of the present invention using the supporting member.
FIG. 9 is a diagram showing a measurement result of the acceleration.
FIG. 10 is a perspective view showing another example of a support member that can be used in the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Exciter, 2 ... Jig, 6 ... Specimen (vibration generating body), 8 ... Air spring, 10 ... Sensor, 11 ... Connection block, 12 ... Supporting member, 19 ... Base, 20 ... Linear slider, 21 ... movable part.

Claims (3)

A vibration generator that generates vibration by operating is vibrated by a vibration exciter in its non-operating state, and a physical quantity associated with the vibration of the vibration generator is measured, and based on the obtained data, the vibration generator In the method for measuring the excitation force of a vibration generator for obtaining the excitation force,
The vibration generator is supported from below by an elastic support having a resonance point lower than about 1/4 of the minimum value of the frequency range of vibration to be measured, and the vibration generator is connected to the vibration generator by a predetermined connection block. A method for measuring an excitation force of a vibration generator, characterized in that the vibration generator is vibrated by being connected to each other and a physical quantity associated with the vibration of the vibration generator is measured. It vibrated by a vibrator in its non-activated state vibration generator which generates by Ri vibrations to operate, also to operate the vibration generator member, the operation of these shaker by pressing Futoki the vibration generator In the method for measuring the excitation force of the vibration generator, the physical quantity associated with vibration with time is measured, and the excitation force of the vibration generator is determined based on the obtained data.
Wherein when operating the vibration generator is a vibration generating body characterized by adding a quality-mer having the same mass and the movable portion of the vibrator before Symbol vibration generator in place of the vibrator Excitation force measurement method. A vibration generator that generates vibration by operating is vibrated by a vibration exciter in its non-operating state, and a physical quantity associated with the vibration of the vibration generator is measured, and based on the obtained data, the vibration generator In the method for measuring the excitation force of a vibration generator for obtaining the excitation force,
Exciting the vibration generator in a state where the vibration generator is held by a support member having low rigidity with respect to the direction of vibration to be measured and high rigidity in a direction intersecting the direction, or A method for measuring an excitation force of a vibration generator, wherein the physical quantity associated with the vibration is measured by operating the vibration generator.

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