JP3618062B2 - Pantograph contact force measuring method and contact force measuring device - Google Patents

Description

【００２８】
したがって、接触力Ｆｃは、
【数２】

で表される。つまり、接触力Ｆｃを測定するためには、剪断力τＡ、τＢと区間ＡＢにおける慣性力Ｆ_ｉｎａがわかればよい。剪断力τＡ、τＢは、２軸用歪みゲージ３１により歪みを計測することにより得られる。慣性力Ｆ_ｉｎａは、加速度計による計測結果から求めることができる。
【００２９】
次に、図８を参照し舟体の慣性力の測定方法に関して説明する。
最初に、慣性力Ｆ_ｉｎａは分布力であることに注意しておく。いま、図８に示すように座標Ｘ、Ｙ（すなわち図８の横方向がＸ、縦方向がＹ）を定め、この座標のＸ軸上において舟体１２の位置ｌＡ、ｌＢをとる。このとき、区間ＡＢの慣性力は、ｎ次の振動モードまでを考慮すると、各モードの慣性力の和、すなわち、
【数３】

で表される。
【００３０】
この線密度分布ρを一定と見なし、慣性力Ｆ_ｉｎａが舟体１２のｎ箇所の位置ｘｊ（ｊ＝１〜ｎ）における加速度の重み付き加算（加速度と重み係数の線形和）と等しいとする。
【数４】

【００３１】
そして、「数３」と「数４」を等しいとおくと、以下が成り立つ。
【数５】

【００３２】
したがって、この方程式系を満足するようなｗｊ（ｊ＝１〜ｎ）を求めればよい。以上により、慣性力Ｆ_ｉｎａを求めることができる。
【００３３】
これにより、ｎ個のモードが支配的である場合、ある区間ＡＢの慣性力Ｆｉｎａは、舟体１２のｎ箇所の加速度に、重み係数ｗｊと区間ＡＢの質量を掛けて加算することにより推定可能である。なお、区間ＡＢの質量ρ（ｌＡ−ｌＢ）を舟体の等価質量と呼ぶ。
【００３４】
ところで、実際の測定に際しては、加速度重み係数と等価質量は加振試験により求めるのがよい。すなわち、既知の加振力により加振を行い、上述した「数２」式により推定した加振力と実際の加振力とが等しくなるような加速度重み係数と等価質量を求める。例えば、図３において、各加速度計３５ａ〜３５ｆの計測値をそれぞれ順にａ５〜ａ１０とし、舟体１２Ａ、１２Ｂの等価質量をそれぞれ順にＭ１、Ｍ２としたとき、各舟体１２Ａ、１２Ｂに対する慣性力Ｆ_{ｉｎａ，１}、Ｆ_{ｉｎａ，２}の補正は次式により行う；
【数６】

【００３５】
また、簡便な方法として、各舟体１２Ａ、１２Ｂに対して２個の加速度計により舟体曲げ１次モードの慣性力を補正してもよい。すなわち、舟体１２Ａにおいては加速度計３５ａ、３５ｄの検出値を用い、舟体１２Ｂにおいては加速度計３５ｂ、３５ｅの検出値を用いる。このとき、各舟体１２Ａ、１２Ｂに対する慣性力Ｆ_{ｉｎａ，１}、Ｆ_{ｉｎａ，２}の補正は次式により行う；
【数７】

この場合は、舟体の端部の加速度計（舟体１２Ａでは加速度計３５ｃ、３５ｄ；舟体１２Ｂでは加速度計３５ｅ、３５ｆ）が左右同じ検出値になると見做していることに相当する。
【００３６】
次に、図９を参照しトロリ線の偏位の推定に関して説明する。
図９に示すように、接触力Ｆｃと剪断力τＡ、τＢとの間には、慣性力を無視すると次式が成り立つ；
【数８】

したがって、
【数９】

が成り立つ。これにより、接触位置の推定が可能である。このような推定は、慣性力の無視できるような低い周波数に限定されるが、車上から見た架線の折れ曲がり等は、例えば車両速度が２７０ｋｍ／ｈのときに０．７５Ｈｚ（５０ｍ径間、２径間１サイクルの場合）であるため、この方法でも十分推定可能である。
【００３７】
次に、上記の方法により接触力測定を行った結果の具体的な事例について述べる。なお、従来の接触力測定方法では、慣性力を舟体中央に取り付けた１個の加速度計のみで推定している。
（１）舟体の等価質量の実測値（図３参照）
舟体１２Ａの等価質量Ｍ１＝約２．４ｋｇ、舟体１２Ｂの等価質量Ｍ２＝約２．１ｋｇである。
【００３８】
（２）重み係数（図３参照）
この重み係数に関しては、次の２つの仮定をおく；
（ａ）舟体の端部の加速度計（舟体１２Ａでは加速度計３５ｃ、３５ｄ；舟体１２Ｂでは加速度計３５ｅ、３５ｆ）については同じ値である。これは、舟体の振動モードが左右対称あるいは点対称になっていると仮定することに相当する。
（ｂ）各重み係数の合計は１である。これは、並進モード（図１０（Ａ）参照）が完全な剛体振動であると仮定することに相当する。
この仮定を考慮して求めた重み係数は、
舟体１２Ａについて：ｗ１＝０．７５、ｗ２＝ｗ３＝０．１２５
舟体１２Ｂについて：ｗ４＝０．８３、ｗ５＝ｗ６＝０．０８３
である。
【００３９】
図１１は従来の接触力の測定結果（加速度計を図１０（Ａ）のように舟体の中央部の１ヶ所に取り付けた場合）を示すグラフである。図１２は上記の値を用いた場合の本発明の接触力の測定結果（加速度計を図１０（Ｃ）のように舟体に３個取り付けた場合）を示すグラフである。これらのグラフは、横軸が舟体振動の周波数（単位Ｈｚ）を示し、縦軸が接触推定力を加振力で割った値を示す。なお、この試験では、加振力を測定可能な加振器でパンタグラフを振動させた。
【００４０】
図１１に示すように、従来の方法では、特に振動周波数４０Ｈｚ以上において、接触推定力の誤差が著しくなっている。しかし、図１２に示す本発明の方法では、振動周波数１００Ｈｚであっても、接触推定力の誤差がほとんど生じていないことがわかる。なお、所見によれば、加速度計が２個の場合であっても、加速度計が３個の場合より若干精度が低下するが、振動周波数８０Ｈｚ程度までは十分に実用的な精度を得ることができる。
【００４１】
このように、従来の方法では、振動モード２に相当する約４０Ｈｚ以上の振動周波数においては、舟体の接触力の推定誤差が大きかった。本発明においては、加速度計の計測値に基づいた舟体の弾性振動を考慮することにより、慣性力Ｆ_ｉｎａを精度良く推定することができる。
【００４２】
以下、本発明の他の実施例について説明する。以下の実施例では、第１実施例と同一構成部分については説明を省略する。
｛第２実施例｝
以下、本発明の第２実施例について説明する。
図１３は、本発明の第２実施例を説明する図である。
図１３（Ａ）に示すパンタグラフは、舟体４２を支持する枠組が、図１３（Ｂ）に示すようなシングルアーム２７となっている。復元ばね１５は、舟体４２の中央部底面とシングルアーム２７上端間に１個だけ介在している。
【００４３】
図１３（Ａ）に示すパンタグラフにおいては、第１実施例における歪みゲージに代えて、舟体４２の支持ばね１５の変形を測定するレーザ変位計３２が設けられている。同レーザ変位計３２は、シングルアーム２７の上端に取り付けられている。レーザ変位計３２は、舟体４２の底面に向けてレーザ光線を照射して、舟体４２の変位を計測する。そして、この変位に支持ばね１５のばね定数を掛けて舟体４２を支持する力を算出する。さらに、舟体支持力から慣性力を差し引いてトロリ線接触力を算出する。
【００４４】
｛第３実施例｝
以下、図１４を参照して本発明の第３実施例について説明する。
図１４に示すパンタグラフは、第１実施例における歪みゲージに代えて、ロードセル３４が設けられているものである。ロードセル３４は、舟体４２底面と復元ばね１５間に配置されている。このロードセル３４により、舟体４２にかかっている力を計測する。このロードセル３４による力の計測値が、第１実施例における左右の剪断力の差に相当する。したがって、この計測値から舟体の慣性力を差し引きして、トロリ線接触力を算出する。
【００４５】
｛第４実施例｝
以下、図１５を参照して本発明の第４実施例について説明する。
図１５に示すパンタグラフは、２軸用歪みゲージ３１が舟体４２中央部（すなわち復元ばね１５の取付部）にのみ貼られている。シングルアーム２７に対しては、２個の２軸用歪みゲージ３１で十分な接触力推定を行うことができる。
【００４６】
｛第５実施例｝
以下、本発明の第５実施例について説明する。
図１６及び図１７は、本発明の第３実施例を説明する図である。
これらの各図に示す各パンタグラフは、枠組が図１３（Ｂ）に示すようなシングルアーム２７となっている。このシングルアーム２７の上端には、天井管１９が取り付けられている。復元ばね１５は、舟体４３の上端部と天井管１９間に２個介在されている。
【００４７】
図１６に示すパンタグラフは、２軸用歪みゲージ３１が舟体４３底面に貼られている。この場合は、舟体４３の曲げ歪みを適切に測定できる。一方、図１７に示すパンタグラフは、２軸用歪みゲージ３１は舟体４３側面に貼られている。この場合は、舟体４３の剪断歪みを適切に測定できる。
【００４８】
【発明の効果】
以上の説明から明らかなように、本発明によれば、測定可能な周波数範囲を増やすことにより、高い周波数成分を含む接触力変動現象（例えば離線現象）に対応することができる効果がある。さらに、誤差の少ない正確な接触力を求めることができる効果がある。
【図面の簡単な説明】
【図１】本発明の第１実施例に係る電気鉄道のパンタグラフを示す模式的正面図である。
【図２】図２（Ａ）は図１のパンタグラフの歪みゲージ部分を示す裏面側拡大図であり、図２（Ｂ）は同表面側拡大図であり、図２（Ｃ）は同側面断面図であり、図２（Ｄ）は歪みゲージの構成図である。
【図３】図１のパンタグラフの舟体の詳細を示す斜視図である。
【図４】図１のパンタグラフの舟体の具体的な寸法を説明する図である。
【図５】図１のパンタグラフの支持構造の詳細を示す模式的側面断面図である。
【図６】図１のパンタグラフの変形例を示す模式的正面図である。
【図７】本発明に係る接触力測定方法を説明するための図である。
【図８】舟体の慣性力の推定方法を説明するための図である。
【図９】トロリ線の変位の推定方法を説明するための図である。
【図１０】舟体の振動モードについて説明するための図である。
【図１１】従来の接触力の測定結果を示すグラフである。
【図１２】本発明の接触力の測定結果を示すグラフである。
【図１３】図１３（Ａ）は本発明の第２実施例に係る電気鉄道のパンタグラフを示す模式的正面図であり、図１３（Ｂ）は同側面図である。
【図１４】本発明の第３実施例に係る電気鉄道のパンタグラフを示す模式的正面図である。
【図１５】本発明の第４実施例に係る電気鉄道のパンタグラフを示す模式的正面図である。
【図１６】本発明の第５実施例に係る電気鉄道のパンタグラフを示す模式的正面図である。
【図１７】本発明の第５実施例に係る電気鉄道のパンタグラフを示す模式的正面図である。
【符号の説明】
９ トロリ線 １０ パンタグラフ
１２、４２、４３ 舟体 １４ 摺り板
１５ 復元ばね １８ 舟支え
１９ 天井管 ２２ ロッド
２６ 枠組 ２７ シングルアーム
３１ ２軸用歪みゲージ ３２ レーザ変位計
３４ ロードセル ３５ 加速度計[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for measuring a contact force acting between a trolley wire and a pantograph in an electric railway. In particular, the present invention relates to a pantograph contact force measuring method and a contact force measuring device capable of measuring a contact force with a small error corresponding to a contact force fluctuation phenomenon including a high frequency component.
[0002]
[Prior art and problems to be solved by the invention]
In current electric railways for business use, a method of sending electric power from a trolley line to a vehicle body via a pantograph is common. The contact force between the trolley line and the boat body of the pantograph varies depending on the height variation and vibration of the trolley line, the vibration of the vehicle and the pantograph, and the like. If this variation in contact force is too great, the pantograph hull may move away from the trolley line (this is called separation). If this separation occurs frequently, a spark is generated between the two and damage to the sliding plate is promoted, resulting in a problem. Even when the line does not reach the line, the contact force of the pantograph should be as small as possible.
[0003]
Therefore, there is a demand to measure the contact force between the trolley wire and the pantograph while the train is running, and to use the obtained measurement result as a reference for measures for suppressing separation. Alternatively, in the future, it is considered to actively control the contact force in real time.
[0004]
As such a pantograph contact force measurement technique, the following is known.
(1) Japanese Patent Laid-Open No. 7-291001 discloses a method of measuring the amount of expansion and contraction of a boat body support spring and calculating the contact force by calculating the pressing force of the spring from this amount. The amount of expansion and contraction of the hull support spring is measured by measuring the dimension between the hull and the hull support pipe using an eddy current type or optical distance sensor.
However, in this method, the inertial force of the boat body (including the sliding plate) is ignored, and a measurement error of the contact force occurs.
[0005]
(2) Proceedings of the 74th General Meeting of the Japan Opportunity Society No. 97-1, (I), 2149, p. 699-700 discloses a pantograph contact force measuring device in which a load cell is provided between a hull and a sliding plate, and an accelerometer is attached to the sliding plate. In this apparatus, the force measured by the load cell is corrected by an inertial force obtained by multiplying the equivalent mass of the sliding plate by acceleration. Accordingly, a relatively accurate contact force is required.
However, in this apparatus, the pantograph is not energized and has been subjected to a special process of loading a load cell, so that it cannot be applied to ordinary business trains.
[0006]
(3) Proceedings of the 5th Annual Meeting of the Japan Opportunity Society 96-51, 1115, p. 127 to 130 disclose a method for measuring the distortion and acceleration of a boat body. In this method, the force applied to the hull (static force excluding inertial force) is calculated from the distortion of the hull. Then, this force is corrected by an inertial force obtained by multiplying the equivalent mass of the boat by acceleration. Also in this case, a relatively accurate contact force is required.
However, in this method, the boat body does not vibrate as a mere mass point, but vibrates as a beam, so it is difficult to identify the equivalent mass. Further, in the vicinity of the natural frequency (for example, near 100 Hz and 200 Hz) of the boat body, the contact force measurement error is significant.
[0007]
As described above, each of the conventional contact force measurement techniques has drawbacks. Furthermore, in the above (1) to (3), since the elastic deformation and rolling of the hull are not taken into account when obtaining the inertial force, the measurable frequency range is limited to about 40 Hz.
The present invention has been made to solve the above-described problem, and a contact force measurement method and a contact force measurement of a pantograph capable of measuring a contact force with a small error corresponding to a contact force fluctuation phenomenon including a high frequency component. An object is to provide an apparatus.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the pantograph contact force measuring method according to the first aspect of the present invention is a method for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector). Obtaining the contact force by obtaining the inertial force of the pantograph hull considering the elastic deformation of the hull, and subtracting the inertial force from the force applied to the hull obtained separately. It is characterized by.
The contact force measurement range can be increased by obtaining the inertial force in consideration of the elastic deformation of the hull. Furthermore, it is possible to measure contact force with little error even at high vibration frequencies.
[0009]
The pantograph contact force measuring method according to the second aspect of the present invention is a method for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector);
Obtain the inertial force of the pantograph hull after considering the elastic deformation between the two longitudinal sections including the sliding plate of the hull, and subtract the inertial force from the separately obtained shear forces of the two longitudinal sections. Thus, the contact force is obtained.
The sliding board of the boat contacts the trolley line. In order to measure the contact force of the pantograph, it is only necessary to know the shear force of two longitudinal sections including the sliding plate and the inertial force of the boat body between these sections. That is, the contact force can be obtained by subtracting the inertial force from the sum of the shearing forces of the two longitudinal sections (however, since the signs of both shearing forces are opposite to each other, they are actually different). it can.
[0010]
The pantograph contact force measuring method according to the third aspect of the present invention is a method for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector);
Attach n (n ≧ 2) accelerometers to the hull of the pantograph, determine the n-th vibration mode of the hull with the accelerometer, determine the inertial force of the hull, The contact force is obtained by subtracting the inertial force from the force applied to the body.
[0011]
The inertial force is a distributed force that changes in size along the longitudinal direction of the hull. In the past, inertial force was obtained by a single accelerometer attached to the center of the hull. For this reason, when the vibration frequency is about 60 Hz or more, the measurement error of the contact force is large. In this aspect, n (n ≧ 2) accelerometers are used to determine the inertial force after grasping the nth-order vibration mode of the hull, thereby realizing contact force measurement with little error even at high frequencies. can do.
For example, in order to grasp the rolling mode (vibration frequency of about 12 Hz) of the boat body, at least two accelerometers are used. On the other hand, in order to grasp the bending primary mode (vibration frequency of about 80 Hz), at least three accelerometers are required.
[0012]
The contact force measuring device for a pantograph according to the first aspect of the present invention is a device for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector);
N (n ≧ 2) accelerometers provided on the hull of the pantograph and the n-th vibration mode of the hull from the detected value of the accelerometer, and then the inertial force applied to the hull An inertial force estimating means for estimating the strain, a strain detecting means for detecting the distortion of the longitudinal section at two locations including the sliding plate of the boat body, and a shear for calculating the shearing force of the longitudinal section from the detection value of the strain detecting means A force calculating means; and a contact force calculating means for calculating the contact force by subtracting the estimated value of the inertial force estimating means from the calculated value of the shear force calculating means.
By providing n (n ≧ 2) accelerometers, the inertial force corresponding to the n-th vibration mode of the hull can be accurately obtained. As a result, contact force measurement with less error can be performed even at high frequencies.
[0013]
In the pantograph contact force measuring device of the present invention, a rod hanging from the bottom of the hull, a boat support disposed on the outer periphery of the rod, a frame for supporting the boat support, and the boat bottom above It is preferable that a restoring spring for urging is provided, and a linear bearing is interposed between the rod and the boat support.
In a conventional general pantograph, the restoring spring may be stiff due to air resistance. If the restoring spring is stiff, the dynamic characteristics change between stationary and running, and many errors are included when obtaining the inertial force. In the present invention, the rigidity of the restoring spring is eliminated by the linear bearing interposed between the rod and the boat support.
[0014]
The pantograph contact force measuring device according to the second aspect of the present invention is a device for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector);
N (n ≧ 2) accelerometers provided on the hull of the pantograph and the n-th vibration mode of the hull from the detected value of the accelerometer, and then the inertial force applied to the hull Inertia force estimation means for estimating the above, a restoring spring that urges the bottom of the hull upward, a laser displacement meter that measures the displacement of the hull accompanying vibration of the restoring spring, and a measured value of the laser displacement meter And the spring constant of the restoring spring to calculate the restoring spring load, and the contact force is calculated by subtracting the estimated value of the inertial force estimating means from the calculated value of the load calculating means. And a contact force calculating means.
[0015]
Further, the pantograph contact force measuring device according to the third aspect of the present invention is a device for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector); N (n ≧ 2) accelerometers provided on the body, and an inertial force for estimating the inertial force applied to the hull after grasping the n-th vibration mode of the hull from the detected value of the accelerometer A force estimating means, a restoring spring for urging the bottom of the hull upward, a load cell provided between the restoring spring and the bottom of the hull for detecting the force applied to the hull, and the load cell Contact force calculating means for calculating the contact force by subtracting the estimated value of the inertial force estimating means from the detected value.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, it demonstrates, referring drawings.
In the following description, the longitudinal direction of the rail (the traveling direction of the vehicle) is the front-rear direction, the direction perpendicular to the rail longitudinal direction on the track surface is the left-right direction, and the track surface, as in the ordinary railcar technology. The vertical direction is called the vertical direction.
Further, in the following description, it is assumed that a general JR Shinkansen is used. In this normal example, the trolley wire is a copper wire having a diameter of about 15 mm. An AC voltage of about 25 kV is applied to the trolley wire. The trolley line is suspended by a suspension line every about 5 m. This suspension line is supported by columns about every 50 m.
[0017]
{First Example}
FIG. 1 is a schematic front view showing a pantograph of an electric railway according to a first embodiment of the present invention.
2 (A) is a rear side enlarged view showing a strain gauge portion of the pantograph of FIG. 1, FIG. 2 (B) is a front side enlarged view, and FIG. 2 (C) is a side sectional view. FIG. 2D is a configuration diagram of the strain gauge.
FIG. 3 is a perspective view showing details of the hull.
FIG. 4 is an explanatory diagram for explaining specific dimensions of the hull.
FIG. 5 is a schematic side sectional view showing details of the support structure of the pantograph of FIG.
[0018]
As shown in FIGS. 1 to 5, the pantograph 10 includes a boat body 12. The hull 12 extends along the left-right direction. In many cases, a total of two hulls 12 are provided apart from each other in the front-rear direction. However, there are also some that are constituted by only one hull. The boat body 12 in this example is a hollow box-shaped member having a width of 40 mm, a length of 1.2 m, and a weight of 3.5 kg (see FIG. 4). The hull 12 is made of an aluminum alloy. The force (static contact force) by which the hull 12 is pressed against the trolley wire 9 when the vehicle is stopped is 50 to 70N. A sliding plate 14 is affixed to the upper surface of the boat body 12. The sliding plate 14 is made of an iron-based or copper-based sintered alloy, or made of a carbon-based material. This sliding plate 14 is in direct contact with the trolley wire. Since the sliding plate 14 wears with time due to contact with the trolley wire 9, it is periodically replaced.
[0019]
As shown in FIG. 5, rods 22 are fixed to the bottom surface of the boat body 4 near the left and right ends. The rod 22 hangs downward from the bottom surface of the boat body 12. A stopper 22 a is formed at the lower end of the rod 22. The boat support 18 is integrally formed with two front and rear sleeves 18a and 18b. These sleeves 18a and 18b are open in the vertical direction. A rod 22 of the front hull is fitted to the front sleeve 18a, and a rod 22 of the rear hull is fitted to the rear sleeve 18b. A linear bearing 24 is interposed in the gap between the rod 22 and the sleeves 18a and 18b. By this linear bearing 24, the boat support 18 slides up and down along the rod 22. The boat support 18 is retained by a stopper 22 a of the rod 22.
[0020]
A restoring spring 15 is disposed on the outer periphery of the rod 22 between the bottom surface of the boat body 12 and the boat support 18. The restoring spring 15 is a rubber spring or a coil spring. The boat support 18 supports the boat body 12 through the restoring spring 15. Under the boat support 18, a link-shaped frame 26 that moves up and down the entire pantograph 10 is provided. The frame 26 has a link shape and is moved up and down by a coil spring or an air cylinder (not shown). For example, when the pantograph 10 is not used, the frame 26 is folded and lowered, and the hull 12 is separated from the trolley line 9.
[0021]
A biaxial strain gauge 31 is affixed to the hull 12. The biaxial strain gauge 31 uses a non-inductive gauge in order to prevent induction of noise due to the collected current. With this biaxial strain gauge 31, the shear strain of the cross section of the boat body 12 is measured. In this example, two biaxial strain gauges 31 are attached to each side surface of the boat body 12. Therefore, a total of four biaxial strain gauges 31 a to 31 d are provided for one boat body 12. These four biaxial strain gauges 31a to 31d are bridge-connected as shown in FIG. By bridging the biaxial strain gauges 31a to 31d, the sensitivity of the boat body 12 to bending and twisting in the front-rear direction is lowered, and only shear strain with respect to the vertical load is easily measured.
The strain gauge may be attached to the bottom of the hull 12 as shown in FIG. In this case, it is convenient to measure the bending distortion of the hull 12.
[0022]
Further, an accelerometer 35 is attached to the hull 12. In this example, three accelerometers 35 are attached to the left and right and the center of one hull 12. By attaching three accelerometers 35, it is possible to cope with a tertiary vibration mode (bending primary mode) of the hull 12 described later. A bake plate (not shown) is interposed between the housing of the accelerometer 35 and the boat body 12. The bake plate insulates the housing of the accelerometer 35 from the boat body 12. As a result, no current flows through the shield wire of the signal cable, and the noise of the output signal is reduced.
[0023]
Each of the biaxial strain gauges 31a to 31d and the accelerometer 35 is connected to a control device (not shown). This control device calculates the contact force between the hull 12 and the trolley wire according to the following principle based on the measurement values of the biaxial strain gauge 31 and the accelerometer 35.
Hereinafter, the contact force measurement principle will be described with reference to FIGS.
FIG. 7 is a view for explaining a contact force measuring method according to the present invention.
FIG. 8 is a diagram for explaining a method for estimating the inertial force of the boat.
FIG. 9 is a diagram for explaining a method of estimating the deviation of the trolley line.
FIG. 10 is a diagram for explaining the vibration mode of the boat.
[0024]
First, the vibration mode of the boat body 12 will be described with reference to FIG.
FIG. 10A shows a primary vibration mode (translation mode). In this mode, the left and right of the hull 12 move up and down almost simultaneously. This mode occurs when the vibration frequency of the boat body 12 is about 7 Hz. In this mode, in order to measure the acceleration of the hull 12, at least one accelerometer 35 attached to the hull 12 may be used.
FIG. 10B shows vibration mode 2 (rolling mode). In this mode, the left and right ends of the hull 12 move up and down in opposite directions and swing around the longitudinal axis. This mode occurs when the vibration frequency of the hull 12 is about 12 Hz. In this mode, in order to measure the acceleration of the hull 12, at least two accelerometers 35 attached to the hull 12 are required.
[0025]
FIG. 10C shows the vibration mode 3 (first bending mode). In this mode, the left and right ends and the center of the hull 12 move up and down in opposite directions. This mode occurs when the vibration frequency of the hull 12 is about 80 Hz. In this mode, in order to measure the acceleration of the hull 12, at least three accelerometers 35 attached to the hull 12 are required.
FIG. 10D shows the vibration mode 4 (secondary bending mode). In this mode, the hull 12 is deformed into a wave shape. This mode occurs when the vibration frequency of the hull 12 is about 200 Hz. In this mode, in order to measure the acceleration of the hull 12, four or more accelerometers 35 attached to the hull 12 are necessary.
[0026]
Therefore, when the three accelerometers 35 are attached to the boat body 12 as in this embodiment, the contact force for the vibration modes 1 to 3 (that is, up to about a vibration frequency of about 100 Hz) can be measured. However, the present invention can be applied even in the vibration mode 4 or higher by increasing the number of accelerometers.
[0027]
Next, the contact force of the hull will be described with reference to FIG.
As shown in FIG. 7, it is assumed that a contact force Fc with the trolley wire 9 acts on the boat body 12. On the other hand, when the section AB including the sliding plate 14 of the boat body 12 is considered, it is assumed that shear forces τA and τB are generated in the cross sections A and B (both ends of the section AB). Further, the total inertial force of the hull 12 acting on the section AB is F _ina And At this time, contact force Fc, shearing force τA and inertial force F _ina If the sign (force direction) of is considered as + and the sign (force direction) of the shear force τB is considered as-, the following equation holds:
[Expression 1]

[0028]
Therefore, the contact force Fc is
[Expression 2]

It is represented by That is, in order to measure the contact force Fc, the shearing forces τA and τB and the inertial force F in the section AB. _ina I just need to know. The shear forces τA and τB are obtained by measuring the strain with the biaxial strain gauge 31. Inertia force F _ina Can be obtained from the measurement result by the accelerometer.
[0029]
Next, a method for measuring the inertial force of the hull will be described with reference to FIG.
First, inertia force F _ina Note that is a distributed force. Now, as shown in FIG. 8, coordinates X and Y (that is, the horizontal direction in FIG. 8 is X and the vertical direction is Y) are determined, and the positions 1A and 1B of the hull 12 are taken on the X-axis of these coordinates. At this time, the inertial force in the section AB is the sum of the inertial forces in each mode, taking into consideration up to the n-th vibration mode, that is,
[Equation 3]

It is represented by
[0030]
Considering this linear density distribution ρ as constant, inertia force F _ina Is equal to the weighted addition of acceleration (linear sum of acceleration and weighting coefficient) at n positions xj (j = 1 to n) of the hull 12.
[Expression 4]

[0031]
If “Equation 3” is equal to “Equation 4”, the following holds.
[Equation 5]

[0032]
Therefore, wj (j = 1 to n) that satisfies this equation system may be obtained. In this way, inertia force F _ina Can be requested.
[0033]
As a result, when n modes are dominant, the inertia force Fina in a certain section AB can be estimated by multiplying the acceleration in n positions of the hull 12 by the weight coefficient wj and the mass of the section AB and adding them. It is. Note that the mass ρ (lA-lB) of the section AB is referred to as an equivalent mass of the hull.
[0034]
By the way, in actual measurement, the acceleration weighting coefficient and the equivalent mass are preferably obtained by a vibration test. That is, excitation is performed with a known excitation force, and an acceleration weight coefficient and an equivalent mass are obtained so that the excitation force estimated by the above-described “Equation 2” is equal to the actual excitation force. For example, in FIG. 3, when the measured values of the accelerometers 35a to 35f are respectively a5 to a10 and the equivalent masses of the hulls 12A and 12B are M1 and M2, respectively, the inertial force with respect to the hulls 12A and 12B. F _{ina, 1} , F _{ina, 2} Is corrected by the following formula:
[Formula 6]

[0035]
Further, as a simple method, the inertia force of the boat body bending primary mode may be corrected by two accelerometers for each boat body 12A, 12B. That is, the detected values of the accelerometers 35a and 35d are used in the boat body 12A, and the detected values of the accelerometers 35b and 35e are used in the boat body 12B. At this time, the inertia force F with respect to each hull 12A, 12B _{ina, 1} , F _{ina, 2} Is corrected by the following formula:
[Expression 7]

In this case, this corresponds to assuming that the accelerometers at the end of the hull (accelerometers 35c and 35d in the hull 12A; accelerometers 35e and 35f in the hull 12B) have the same detection value on the left and right.
[0036]
Next, estimation of trolley line deviation will be described with reference to FIG.
As shown in FIG. 9, the following formula is established between the contact force Fc and the shearing forces τA and τB when the inertial force is ignored:
[Equation 8]

Therefore,
[Equation 9]

Holds. Thereby, estimation of a contact position is possible. Such estimation is limited to a low frequency at which the inertial force can be ignored. For example, the bending of the overhead line as viewed from above the vehicle is, for example, 0.75 Hz when the vehicle speed is 270 km / h. Since this is a case of one cycle between two diameters), this method can be sufficiently estimated.
[0037]
Next, specific examples of results of contact force measurement by the above method will be described. In the conventional contact force measurement method, the inertial force is estimated by only one accelerometer attached to the center of the hull.
(1) Measured value of the equivalent mass of the hull (see Fig. 3)
The equivalent mass M1 of the boat body 12A is about 2.4 kg, and the equivalent mass M2 of the boat body 12B is about 2.1 kg.
[0038]
(2) Weight coefficient (see Fig. 3)
For this weighting factor, we make the following two assumptions:
(A) Accelerometers at the ends of the hull (accelerometers 35c and 35d for the hull 12A; accelerometers 35e and 35f for the hull 12B) have the same value. This is equivalent to assuming that the vibration mode of the boat body is left-right symmetric or point symmetric.
(B) The sum of each weighting factor is 1. This is equivalent to assuming that the translation mode (see FIG. 10A) is complete rigid body vibration.
The weighting factor obtained by considering this assumption is
Regarding the hull 12A: w1 = 0.75, w2 = w3 = 0.125
Regarding the hull 12B: w4 = 0.83, w5 = w6 = 0.083
It is.
[0039]
FIG. 11 is a graph showing a conventional measurement result of the contact force (when an accelerometer is attached to one central portion of the hull as shown in FIG. 10A). FIG. 12 is a graph showing the measurement result of the contact force according to the present invention when the above values are used (when three accelerometers are attached to the hull as shown in FIG. 10C). In these graphs, the horizontal axis represents the frequency (unit: Hz) of boat vibration, and the vertical axis represents the value obtained by dividing the contact estimated force by the excitation force. In this test, the pantograph was vibrated with a vibrator capable of measuring the vibration force.
[0040]
As shown in FIG. 11, in the conventional method, the error of the contact estimation force is remarkable especially at the vibration frequency of 40 Hz or more. However, in the method of the present invention shown in FIG. 12, it can be seen that there is almost no error in the contact estimation force even at a vibration frequency of 100 Hz. According to the findings, even when there are two accelerometers, the accuracy is slightly lower than when there are three accelerometers, but sufficiently practical accuracy can be obtained up to a vibration frequency of about 80 Hz. it can.
[0041]
Thus, in the conventional method, the estimation error of the contact force of the hull was large at the vibration frequency of about 40 Hz or more corresponding to the vibration mode 2. In the present invention, the inertial force F is obtained by taking into account the elastic vibration of the hull based on the measurement value of the accelerometer. _ina Can be estimated with high accuracy.
[0042]
Hereinafter, other embodiments of the present invention will be described. In the following embodiments, the description of the same components as those in the first embodiment is omitted.
{Second Example}
The second embodiment of the present invention will be described below.
FIG. 13 is a diagram for explaining a second embodiment of the present invention.
In the pantograph shown in FIG. 13A, the frame supporting the boat body 42 is a single arm 27 as shown in FIG. Only one restoring spring 15 is interposed between the bottom of the center of the boat body 42 and the upper end of the single arm 27.
[0043]
In the pantograph shown in FIG. 13A, a laser displacement meter 32 for measuring the deformation of the support spring 15 of the boat body 42 is provided in place of the strain gauge in the first embodiment. The laser displacement meter 32 is attached to the upper end of the single arm 27. The laser displacement meter 32 irradiates a laser beam toward the bottom surface of the boat body 42 and measures the displacement of the boat body 42. Then, the force for supporting the boat body 42 is calculated by multiplying this displacement by the spring constant of the support spring 15. Further, the trolley wire contact force is calculated by subtracting the inertia force from the hull support force.
[0044]
{Third embodiment}
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.
The pantograph shown in FIG. 14 is provided with a load cell 34 instead of the strain gauge in the first embodiment. The load cell 34 is disposed between the bottom surface of the boat body 42 and the restoring spring 15. With this load cell 34, the force applied to the hull 42 is measured. The measurement value of the force by the load cell 34 corresponds to the difference between the left and right shearing forces in the first embodiment. Therefore, the trolley wire contact force is calculated by subtracting the inertial force of the hull from this measured value.
[0045]
{Fourth embodiment}
A fourth embodiment of the present invention will be described below with reference to FIG.
In the pantograph shown in FIG. 15, the biaxial strain gauge 31 is attached only to the center portion of the boat body 42 (that is, the attachment portion of the restoring spring 15). With respect to the single arm 27, sufficient contact force estimation can be performed with the two biaxial strain gauges 31.
[0046]
{Fifth embodiment}
The fifth embodiment of the present invention will be described below.
16 and 17 are diagrams for explaining a third embodiment of the present invention.
Each pantograph shown in each of these figures has a single arm 27 as shown in FIG. 13B. A ceiling tube 19 is attached to the upper end of the single arm 27. Two restoring springs 15 are interposed between the upper end of the boat body 43 and the ceiling pipe 19.
[0047]
In the pantograph shown in FIG. 16, a biaxial strain gauge 31 is attached to the bottom surface of the boat body 43. In this case, the bending distortion of the boat body 43 can be measured appropriately. On the other hand, in the pantograph shown in FIG. 17, the biaxial strain gauge 31 is attached to the side surface of the boat body 43. In this case, the shear strain of the hull 43 can be measured appropriately.
[0048]
【The invention's effect】
As is clear from the above description, according to the present invention, there is an effect that it is possible to cope with a contact force fluctuation phenomenon (for example, a separation phenomenon) including a high frequency component by increasing the measurable frequency range. Furthermore, there is an effect that an accurate contact force with less error can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing a pantograph of an electric railway according to a first embodiment of the present invention.
2A is an enlarged view of the back surface side showing the strain gauge portion of the pantograph of FIG. 1, FIG. 2B is an enlarged view of the same surface side, and FIG. FIG. 2D is a configuration diagram of a strain gauge.
FIG. 3 is a perspective view showing details of the boat body of the pantograph of FIG. 1;
FIG. 4 is a diagram illustrating specific dimensions of the boat body of the pantograph of FIG.
5 is a schematic side cross-sectional view showing details of the support structure of the pantograph of FIG. 1. FIG.
6 is a schematic front view showing a modified example of the pantograph of FIG. 1. FIG.
FIG. 7 is a diagram for explaining a contact force measuring method according to the present invention.
FIG. 8 is a diagram for explaining a method for estimating the inertial force of a hull.
FIG. 9 is a diagram for explaining a method for estimating a displacement of a trolley wire.
FIG. 10 is a diagram for explaining a vibration mode of a boat body.
FIG. 11 is a graph showing measurement results of conventional contact force.
FIG. 12 is a graph showing measurement results of contact force according to the present invention.
FIG. 13 (A) is a schematic front view showing a pantograph of an electric railway according to a second embodiment of the present invention, and FIG. 13 (B) is a side view thereof.
FIG. 14 is a schematic front view showing a pantograph of an electric railway according to a third embodiment of the present invention.
FIG. 15 is a schematic front view showing a pantograph of an electric railway according to a fourth embodiment of the present invention.
FIG. 16 is a schematic front view showing a pantograph of an electric railway according to a fifth embodiment of the present invention.
FIG. 17 is a schematic front view showing a pantograph of an electric railway according to a fifth embodiment of the present invention.
[Explanation of symbols]
9 Trolley line 10 Pantograph
12, 42, 43 hull 14 sliding board
15 Restoration spring 18 Boat support
19 Ceiling tube 22 Rod
26 Frame 27 Single arm
31 Two-axis strain gauge 32 Laser displacement meter
34 Load cell 35 Accelerometer

Claims (6)

A method for measuring a contact force acting between a trolley wire (feed line) and a pantograph (current collector);
The inertial force of the pantograph hull is determined in consideration of the elastic deformation of the hull,
A method for measuring a contact force of a pantograph, wherein the contact force is obtained by subtracting the inertial force from a force applied to the hull obtained separately. A method for measuring the contact force acting between a trolley wire (feed line) and a pantograph (current collector);
The inertial force of the pantograph hull is determined in consideration of the elastic deformation between the two longitudinal sections including the sliding plate of the hull,
A method for measuring a contact force of a pantograph, wherein the contact force is determined by subtracting the inertial force from the shear forces of the longitudinal sections obtained separately. A method for measuring the contact force acting between a trolley wire (feed line) and a pantograph (current collector);
Attach n (n ≧ 2) accelerometers to the hull of the pantograph, find the n-th vibration mode of the hull with the accelerometer, and determine the inertial force of the hull,
A method for measuring a contact force of a pantograph, wherein the contact force is obtained by subtracting the inertial force from a force applied to the hull obtained separately. A device for measuring a contact force acting between a trolley wire (feed wire) and a pantograph (current collector);
N (n ≧ 2) accelerometers provided on the hull of the pantograph,
An inertial force estimating means for estimating an inertial force applied to the hull after grasping the n-th vibration mode of the hull from the detected value of the accelerometer;
Strain detecting means for detecting strains in two longitudinal sections including the sliding plate of the hull;
A shear force calculating means for calculating a shear force of the longitudinal section from a detection value of the strain detecting means;
Contact force calculating means for calculating the contact force by subtracting the estimated value of the inertial force estimating means from the calculated value of the shear force calculating means;
A pantograph contact force measuring device comprising: A device for measuring a contact force acting between a trolley wire (feed wire) and a pantograph (current collector);
N (n ≧ 2) accelerometers provided on the hull of the pantograph,
An inertial force estimating means for estimating an inertial force applied to the hull after grasping the n-th vibration mode of the hull from the detected value of the accelerometer;
A restoring spring for biasing the bottom of the hull upward,
A laser displacement meter for measuring the displacement of the boat body accompanying the vibration of the restoring spring;
Load calculating means for calculating a restoring spring load by multiplying the measured value of the laser displacement meter and the spring constant of the restoring spring;
Contact force calculating means for calculating the contact force by subtracting the estimated value of the inertial force estimating means from the calculated value of the load calculating means;
A pantograph contact force measuring device comprising: A device for measuring a contact force acting between a trolley wire (feed wire) and a pantograph (current collector);
N (n ≧ 2) accelerometers provided on the hull of the pantograph,
An inertial force estimating means for estimating an inertial force applied to the hull after grasping the n-th vibration mode of the hull from the detected value of the accelerometer;
A restoring spring for biasing the bottom of the hull upward,
A load cell for detecting a force applied to the hull, provided between the restoring spring and the bottom of the hull;
Contact force calculation means for calculating the contact force by subtracting the estimated value of the inertial force estimation means from the detection value detected by the load cell;
A pantograph contact force measuring device comprising:

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