JP2004053485A - Transfer characteristic measuring procedure and its device of power train - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire a highly-accurate transfer characteristic similar to the actual operation state of a power train, and to reconcile weight reduction of the power train with radiation sound reduction in a high dimension. <P>SOLUTION: The power train 1 is constituted of at least a cylinder block 4 and a cylinder head 5. The cylinder block 4 is equipped with a piston 9, a connecting rod 10, a crankshaft 11 and a lower block 12. The cylinder head 5 has an injector insertion hole 5a penetrating from the upper part to the bottom part of the cylinder head 5. The piston 9 is set on a position approximately near the top dead center in the state where the cylinder head 5 is installed over the cylinder block 4, and an exciting device 19 is fitted in the injector insertion hole 5a to excite a piston 9 head, and the transfer characteristic on an optional portion of the power train 1 is acquired based on a vibration acceleration measured by an acceleration sensor 12 at the piston 9 head excitation time. <P>COPYRIGHT: (C)2004,JPO

Description

【００４０】
図５は、放射音響パワーレベルＬｗの周波数特性を示すグラフ図、図６は、実測した音圧レベルの周波数特性を示すグラフ図である。
図５、６に示すように算出した放射音響パワーレベルＬｗと実測した音圧レベルは、傾向はほぼ一致している。
従って、本伝達特性計測手法を用いれば、実稼動状態に近いシリンダブロック壁面から放射される放射音の定性的予測が可能となる。
【００４１】
本伝達特性計測手法によって得られた伝達特性の一例を図７、８に示す。
図７は、周波数帯域別に評価したシリンダブロック全体の伝達特性のグラフ図である。
太字の実線は、本実施形態のシリンダブロック全体の周波数別に評価した伝達特性を示している。尚、太字点線は、理想的な騒音特性の優れたシリンダブロックの周波数帯域別のあるべき伝達特性の周波数特性を示している。
図８は、シリンブロックの部位別に評価した伝達特性のグラフ図である。
トップデッキ部位は、太字の点線で、シリンダ部位は、細字の点線で、スカート部位は、細字の実線で、オイルパンレール部位は、太字の実線で、伝達特性を示している。
この結果によれば、２ｋＨｚ〜３ｋＨｚの周波数帯域で、シリンダ部位とオイルパンレール部位の伝達特性が大きく、改善する必要があるということがわかる。
【００４２】
次に、本発明の実施形態の作用を説明する。
図１、図２に示すように、シリンダヘッド５とシリンダブロック４とを連結した状態で加振し、伝達特性を求めるよう構成されるため、実稼動状態での伝達特性に近い、高い精度のシリンダブロック５の伝達特性を求めることができる。また、インジェクタ挿入孔５ａを利用して略上死点近傍の位置にセットされたピストン９の頭部を加振することができるため、実稼動状態と同様コネクティングロッド１０及びクランクシャフト１１を介してシリンダブロック４に伝達される振動成分に基いて伝達特性を求めることができ、実稼動状態での伝達特性に近い、高い精度の伝達特性を求めることができる。
【００４３】
荷重調整用ナット２２ａにより荷重を作用させた状態でピストン９頭部が加振されるため、ピストン９からシリンダブロック４まで振動が伝わる間のクリアランスを少なくすることができ、シリンダブロック４に伝わる振動にノイズを発生することなく加振することができる。
【００４４】
一般的に広く使用されている加速度センサ−１２を用いることで、簡易に振動加速度を求めることができる。
【００４５】
シリンダブロック４の部位別の伝達特性を計測することができるため、シリンダブロック４の部位別の評価を行うことができる。
【００４６】
加振装置１９は、正弦波によるスイープ加振とランダム加振を選択することができるため、正弦波によるスイープ加振を行う場合には、シリンダブロック４の放射音低減には、周波数別の伝達特性を計測する必要があり、周波数が徐々に変化していくため、一度の設定作業で周波数別の伝達特性を見ることができ、作業性を向上することができる。また、大きな加振力をあたえる場合や被試験物が非線形性の場合に適している。
一方、ランダム加振を行う場合には、短時間で異なる複数の周波数の振動を入力することができるため、周波数別の伝達特性を計算（周波数分析）を行うことによって短時間で求めることができる。
また、１ＫＨｚ以下の周波数は、実稼動状態では、放射音の影響が少ない周波数帯域のため、その領域の伝達特性の計測を省略することができ、作業を簡略化することができる。
【００４７】
図３に示すように、加振棒２２が分割され、Ｗナット２２を調整することで加振棒２１の全長を調節することができるため、各パワートレインの違いによって加振装置とピストン間の距離が相違する場合であっても上記加振装置とピストン頭部との間における加振棒の長さの調整が行え、ピストン９に与える荷重の量を容易に調整することができる。
【図面の簡単な説明】
【図１】本発明の実施形態を示すパワートレイン概略図。
【図２】シリンダヘッドを底辺側からみたシリンダヘッド平面図。
【図３】本発明の実施形態を示す加振装置拡大図。
【図４】本発明の実施形態の伝達特性計測手法を示すブロック図。
【図５】放射音響パワーレベルＬｗの周波数特性を示すグラフ図。
【図６】実測した音圧レベルの周波数特性を示すグラフ図。
【図７】周波数帯域別に評価したシリンダブロック全体の伝達特性のグラフ図。
【図８】シリンダブロックの部位別に評価した伝達特性のグラフ図。
【符号の説明】
１．パワートレイン
２．エンジン
３．トランスミッション
４．シリンダブロック
４ａ．シリンダ
５．シリンダヘッド
５ａ．インジェクタ挿入孔（燃焼関連部品装着孔）
５ｂ．燃焼室
６．ロアブロック（支持部）
７．オイルパン
８．タイミングベルトカバー
９．ピストン
１０．コネクティングロッド
１１．クランクシャフト
１２．加速度センサー（測定手段）
１３．トップデッキ部位
１４．シリンダ部位
１５．スカート部位
１６．オイルパンレール部位
１７．吸気ポート
１８．排気ポート
１９．加振装置
２０．加振器
２１．加振棒
２１ａ．第１加振棒
２１ｂ．第２加振棒
２２．Ｗナット（荷重付加機構）
２２ａ．荷重調整用ナット（第１ナット）
２２ｂ．ロック用ナット（第２ナット）
３０．演算装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for measuring transfer characteristics of a power train.
[0002]
[Prior art]
Conventionally, it has been desired to reduce noise from a power train.
As a cause of the noise from the power train, it is known that the sound radiated from the cylinder block occupies a large weight.
In order to reduce the radiated sound of the cylinder block, it is necessary to grasp the part where the radiated sound is generated and the frequency band in which it is generated, and change the structure of the cylinder block based on the result.
Therefore, it is known to use an evaluation process in which an experimental analysis method and a calculation analysis method (CAE) are combined in order to grasp the state of generation of radiation noise from a cylinder block.
In this evaluation process, the transfer characteristics of the cylinder block are measured by an actual machine using an experimental analysis method, and then, based on the measured transfer characteristics (in general, the transfer characteristics are subjected to FFT processing) by a calculation analysis method (CAE). Thus, the mode characteristic is identified). This is an evaluation process in which a high-precision analysis is performed in a shorter time than an evaluation process in which only a calculation analysis method is performed.
By examining the transfer characteristics and the mode characteristics, it is possible to clarify a frequency band and a part to be improved. Further, since it is possible to predict how the structural change will change the radiation sound, it is possible to satisfy both conflicting demands for reducing the radiation sound and reducing the weight of the cylinder block.
[0003]
By the way, in the past, the cylinder block, in which radiation noise is the most problematic, was used as the test object, and the transfer characteristics of only the cylinder block were measured (see, for example, JP-A-10-38748).
[0004]
However, the actual radiated sound is not the radiated sound of the cylinder block alone, but the radiated sound of the cylinder head, oil pan, transmission, etc. attached to the cylinder block. In the evaluated radiated sound, the generated portion and the frequency band may be shifted from the actual radiated sound.
The sound radiated from the cylinder block is generated as a result of the explosive power in the combustion chamber being transmitted to the cylinder block via a piston, a connecting rod, and a crankshaft. Since the transfer characteristic at that time was measured by shaking, unlike the actual radiation sound generation mechanism, the generation place and the frequency band may be shifted.
Conventionally, the structural change of the cylinder block has been made with a margin such as widening the reinforcement range in consideration of these deviations, but in recent years further weight reduction of the power train has been demanded, and higher precision has been required. It is required to grasp the radiation sound situation.
[0005]
Therefore, the cylinder head is attached to the cylinder block, and the piston is adjusted to approximately the top dead center position with the piston, connecting rod and crankshaft integrated, and the piston head is vibrated to achieve an accuracy close to the actual operating state. It is conceivable to configure so as to obtain a transfer characteristic measurement with a high level.
[0006]
However, such a configuration has a problem that the piston head cannot be vibrated because the cylinder head is attached to the cylinder block.
[0007]
[Problems to be solved by the invention]
Therefore, the present invention is intended to solve the above problem, and the problem is to seek a highly accurate transmission characteristic close to the actual operation state of the power train, and to reduce the weight of the power train and reduce the radiated sound. It is to be compatible with.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
[0009]
The invention according to claim 1 of the present application is provided with a vibration device that vibrates a power train, and a measuring unit that measures a vibration component at an arbitrary position of the power train when the vibration is excited by the vibration device. In the transfer characteristic measurement method of obtaining the transfer characteristic of the power train based on the measured vibration component,
The power train includes at least a cylinder block, and a cylinder head mounted above the cylinder block,
The cylinder block includes a piston slidably fitted to the cylinder, a connecting rod connected to the piston, a crankshaft connected to the connecting rod, and a support portion for supporting the crankshaft.
The cylinder head has a combustion-related component mounting hole that penetrates from the top to the bottom of the cylinder head at a position facing the piston head, and in which a component related to combustion is mounted.
In a state where the cylinder head is mounted above the cylinder block, the piston is set at a position substantially near the top dead center,
Vibrating the piston head by passing the vibration device through the combustion component mounting hole,
The transmission characteristic of an arbitrary part of the power train is obtained based on a vibration component measured by the measuring means at the time of the piston head vibration.
[0010]
According to the above configuration, since the vibration is applied in a state where the cylinder head and the cylinder block are connected to each other and the transmission characteristics are obtained, the transmission characteristics of the cylinder block with high accuracy close to the transmission characteristics in the actual operation state are obtained. You can ask.
In addition, since the upper surface of the piston set near the top dead center can be vibrated using the combustion component mounting hole, the piston is transmitted to the cylinder block via the connecting rod and the crankshaft as in the actual operation state. The transfer characteristic can be obtained based on the vibration component to be obtained, and the transfer characteristic with high accuracy close to the transfer characteristic in the actual operation state can be obtained.
[0011]
The invention according to claim 2 of the present application is such that the vibration device is configured to vibrate while applying a load to the piston head.
[0012]
According to the above configuration, the piston is vibrated while applying a load, so that the clearance between the transmission of vibration from the piston to the cylinder block can be reduced, and the vibration transmitted to the cylinder block can be reduced without generating noise. Can be shaken.
[0013]
The invention according to claim 3 of the present application is configured such that the measuring means is an acceleration sensor.
[0014]
According to the above configuration, the vibration acceleration can be easily obtained by using an acceleration sensor that is generally widely used.
[0015]
The invention according to claim 4 of the present application is configured such that the vibration method of the vibration device is a sweep vibration in which vibration is performed while increasing or decreasing the frequency gradually with a sine wave.
[0016]
According to the above configuration, in order to reduce the radiation noise of the cylinder block, it is necessary to measure the transfer characteristics for each frequency. Another transfer characteristic can be measured, and workability can be improved. It is also suitable for applying a large excitation force or for a non-linear test object.
[0017]
The invention according to claim 5 of the present application is configured such that the vibration method of the vibration device is a random vibration for simultaneously generating a plurality of different frequencies.
[0018]
According to the above configuration, since vibrations of a plurality of different frequencies can be input in a short time, transfer characteristics for each frequency can be obtained in a short time by calculation (frequency analysis).
[0019]
The invention according to claim 6 of the present application is such that the vibration method of the vibration device is configured to vibrate while changing the frequency at 1 kHz or more.
[0020]
According to the above configuration, in a frequency band of less than 1 KHz in the actual operation state, the influence of the radiated sound is small, so that the measurement of the transfer characteristic in that region can be omitted, and the operation can be simplified.
[0021]
According to a seventh aspect of the present invention, the measuring means includes a top deck portion at a substantially upper end, a cylinder portion corresponding to a cylinder, a skirt portion corresponding to a crankshaft, and a lower portion at a substantially lower end portion on a wall surface of the cylinder block. For each oil pan rail portion fastened to the block or the oil pan, a plurality of portions are provided in the cylinder row direction of each portion,
Find the scalar sum of the transfer characteristics for each of the above parts,
The configuration is such that the transmission characteristics for each part are compared for each frequency.
[0022]
According to the above configuration, it is possible to measure the transfer characteristics of each part of the cylinder block, and thus it is possible to evaluate each part of the cylinder block.
[0023]
The invention according to claim 8 of the present application provides a vibration device that vibrates a power train,
Measuring means attached to an arbitrary place of the power train to measure a vibration component at the time of vibration of the vibration device,
A transfer characteristic measuring device comprising a calculating device for calculating a transfer characteristic of the power train based on the vibration component measured by the measuring means,
The power train includes at least a cylinder block, and a cylinder head mounted above the cylinder block,
The cylinder block includes a piston slidably fitted to the cylinder, a connecting rod connected to the piston, a crankshaft connected to the connecting rod, and a support portion for supporting the crankshaft.
The cylinder head has a combustion-related component mounting hole that penetrates from the top to the bottom of the cylinder head at a position facing the piston head, and in which a component related to combustion is mounted.
The vibrating device includes a vibrating rod that penetrates through the combustion-related component mounting hole and whose tip end abuts on the piston head at a position near the top dead center, and a vibrator that vibrates the vibrating rod And a configuration composed of
[0024]
According to the above configuration, since the vibration is applied in a state where the cylinder head and the cylinder block are connected to each other and the transmission characteristics are obtained, the transmission characteristics of the cylinder block with high accuracy close to the actual operation state can be obtained. .
In addition, since the head of the piston set near the top dead center can be vibrated by using the combustion-related component mounting hole, the cylinder block is connected via the connecting rod and the crankshaft as in the actual operation state. The transmission characteristics can be obtained based on the vibration component transmitted to the motor, and the transmission characteristics with high accuracy close to the transmission characteristics in the actual operation state can be obtained.
[0025]
The invention according to claim 9 of the present application is configured such that the vibration device includes a load applying mechanism that applies a load to the piston head.
[0026]
According to the above configuration, the piston is vibrated while applying a load, so that the vibration is transmitted from the piston to the cylinder block, that is, the clearance at each of the contact portions of the piston, the connecting rod, the crankshaft, and the cylinder block is reduced. The vibration transmitted to the cylinder block can be excited without generating noise.
[0027]
The invention according to claim 10 of the present application is characterized in that the load applying mechanism is configured by the vibrating rod, and the load acting on the piston head is adjusted by adjusting the length of the vibrating rod. It was done.
[0028]
According to the above configuration, the length of the vibrating rod can be adjusted, and the load acting on the piston head can be adjusted.
[0029]
In the invention according to claim 11 of the present application, the load applying mechanism includes a first nut arranged to connect one end of each of the divided two vibrating rods, and a first nut adjacent to the first nut. A second nut for locking provided, wherein the total length of the vibrating rod is adjusted by adjusting the first and second nuts, and the load acting on the piston head is adjusted. This is the configuration that has been performed.
[0030]
According to the above configuration, since the vibrating rod is divided, the overall length of the vibrating rod can be adjusted by adjusting the nut, and the amount of load can be easily adjusted. Therefore, even when the clearance between the components is different due to the difference between the power trains, the excitation can be performed under an appropriate load.
[0031]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the transmission characteristic of a cylinder head with high precision close to the transmission characteristic of an actual operation state can be calculated | required, and the weight reduction of a power train and the reduction of radiation noise can be made compatible with a high dimension.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a power train showing an embodiment of the present invention, FIG. 2 is a plan view of a cylinder head as viewed from the bottom side of the cylinder head, and FIG. 3 is an enlarged view of a vibrating device showing an embodiment of the present invention.
[0033]
As shown in FIG. 1, a power train 1 according to the present embodiment includes an engine 2 having four cylinders and a transmission 3. The engine 2 is mainly composed of a cylinder block 4, a cylinder head 5, a lower block 6, an oil pan 7, and a timing belt cover 8. In the cylinder block 4, a piston 9 and a piston 9 are connected. A connecting rod 10 and a crankshaft 11 connected to the connecting rod 10 are provided. The engine 2 is provided with auxiliary equipment such as an alternator and an air compressor (not shown).
[0034]
A number of acceleration sensors 12 are attached to the cylinder block 4. On the wall surface of the cylinder block 4, a top deck portion 13 at a substantially upper end portion, a cylinder portion 14 corresponding to the cylinder 4 a, and a skirt portion 15 corresponding to the crankshaft 11. In addition, a plurality of oil pan rail portions 16 at substantially lower ends are provided in the cylinder row direction. The acceleration sensor 12 measures a vibration component of the attached portion, that is, a vibration acceleration, and outputs the vibration component to the arithmetic device 30. Incidentally, a laser vibrometer can be used instead.
[0035]
The cylinder head 5 has an injector insertion hole 5a that penetrates in the up-down direction (cylinder axis direction) and into which an injector (not shown) as a combustion-related component is mounted. The injector insertion hole 5a is shown in FIG. Thus, it is formed at a position surrounded by the two intake ports 17 and the two exhaust ports 18, that is, substantially at the center of the combustion chamber 5b.
Note that, instead of the injector insertion hole 5a, an ignition plug insertion hole penetrating in the up-down direction can be used instead.
[0036]
In the present embodiment, a vibration device 19 for vibrating the head of the piston 9 is mounted in the injector insertion hole 5a. Hereinafter, the vibration device 19 will be described in detail.
As shown in FIG. 3, the vibration device 19 includes a vibration device 20, a vibration rod 21, and a W nut 22 as a load applying mechanism.
The vibrating rod 21 is divided into two parts, a first vibrating rod 21a and a second vibrating rod 21b. The first vibrating rod 21a has its upper end connected to the vibrator 20 while its lower end has W. The nut 22 is fitted into a load adjusting nut 22a.
The upper end of the second vibrating rod 21b is fitted into the locking nut 22b for fixing the load adjusting nut 22a and the load adjusting nut 22a of the W nut 22, while the lower end is in contact with the cavity 9a of the piston 9. The piston 9 has a shape corresponding to the cavity 9 a of the piston 9.
In the vibration device as described above, by adjusting the load adjusting nut 22a, the total length of the two vibration bars 21a and 21b can be adjusted, and the cavity 9a of the piston 9 of the second vibration bar 21b can be adjusted. The load corresponding to can be adjusted.
The vibrator 20 vibrates the vibrating rod 21 and arbitrarily selects one of a sweep wave and a random wave to perform vibration, as is well known in the related art.
[0037]
Here, the frequency characteristics of the transfer characteristics will be described in detail.
The plurality of acceleration sensors 12 measure the vibration acceleration of each part and output it to the arithmetic unit 30. On the other hand, the vibration device 19 outputs the vibration force at the time of the measurement to the calculation device 30. Then, in the arithmetic unit 30, the vibration acceleration per unit input is obtained based on the vibration acceleration and the exciting force, and the scalar sum of the vibration acceleration per unit input is divided by the angular frequency (ω = 2πf). , The transfer characteristic H is required. The transfer characteristic H is obtained for each part, and an overall value obtained by summing the transfer characteristics H obtained for each part is also obtained.
[0038]
FIG. 4 is a block diagram illustrating a transfer characteristic measuring method according to the embodiment of the present invention.
In step S1, the acceleration sensor 12 is mounted on each part of the wall surface of the cylinder block 4 of the power train 1 where the transmission 3 and the engine 2 are connected. Note that a laser vibrometer can be used instead of the acceleration sensor 12. In step S2, the piston 9 is adjusted to a substantially top dead center position. Specifically, by moving and fixing a flywheel (not shown), the piston 9 is adjusted and fixed at a position substantially at the top dead center.
In step S3, the cylinder head 5 is detached from the cylinder block 4 and set so that the tip of the second vibrating rod 21b fits into the cavity of the piston 9.
In step S4, the cylinder head 5 is mounted on the cylinder block 4 such that the second vibrating rod 21b is inserted into the injector insertion hole 5a of the cylinder head 5.
In step 5, the W nut 22 is adjusted so that the second vibrating rod 21b and the first vibrating rod 21a are connected, and the vibrator 20 is mounted on the cylinder head 5.
In step S6, the load is adjusted by adjusting the load adjusting nut 22a, and the nut 22a is locked by the locking nut 22b.
In step S7, sweep excitation or random excitation by a sine wave is performed by the vibration exciter 20.
In step S <b> 8, the transfer characteristic for each frequency band is measured based on the vibration acceleration measured by the acceleration sensor 12 and the excitation force by the exciter 20.
In step S9, a radiated sound power level is calculated from the transfer characteristics.
[0039]
Here, the radiated sound power level will be described in detail.
Using the above-described transfer characteristic H, the radiated sound power level Lw is obtained from the following equation.
(Equation 1)

[0040]
FIG. 5 is a graph showing the frequency characteristics of the radiated sound power level Lw, and FIG. 6 is a graph showing the frequency characteristics of the actually measured sound pressure level.
As shown in FIGS. 5 and 6, the radiated sound power level Lw calculated and the actually measured sound pressure level have almost the same tendency.
Therefore, by using the present transfer characteristic measuring method, it is possible to qualitatively predict the radiation sound radiated from the cylinder block wall which is close to the actual operation state.
[0041]
FIGS. 7 and 8 show examples of transfer characteristics obtained by the present transfer characteristic measuring method.
FIG. 7 is a graph showing the transfer characteristics of the entire cylinder block evaluated for each frequency band.
A bold solid line indicates a transfer characteristic evaluated for each frequency of the entire cylinder block of the present embodiment. The bold dotted line indicates the frequency characteristics of the desired transfer characteristics for each frequency band of the cylinder block having the ideal noise characteristics.
FIG. 8 is a graph of transfer characteristics evaluated for each site of the sylin block.
The transmission characteristics are indicated by a bold dotted line for the top deck portion, a thin dotted line for the cylinder portion, a thin solid line for the skirt portion, and a bold solid line for the oil pan rail portion.
According to this result, it is understood that the transmission characteristics between the cylinder part and the oil pan rail part are large in the frequency band of 2 kHz to 3 kHz and need to be improved.
[0042]
Next, the operation of the embodiment of the present invention will be described.
As shown in FIGS. 1 and 2, vibration is applied in a state where the cylinder head 5 and the cylinder block 4 are connected to determine the transmission characteristics. The transmission characteristics of the cylinder block 5 can be determined. In addition, since the head of the piston 9 set at a position near the top dead center can be excited by using the injector insertion hole 5a, the connecting rod 10 and the crankshaft 11 can be used similarly to the actual operation state. The transfer characteristic can be obtained based on the vibration component transmitted to the cylinder block 4, and a highly accurate transfer characteristic close to the transfer characteristic in the actual operation state can be obtained.
[0043]
Since the head of the piston 9 is vibrated while the load is being applied by the load adjusting nut 22a, the clearance between the transmission of the vibration from the piston 9 and the cylinder block 4 can be reduced, and the vibration transmitted to the cylinder block 4 can be reduced. Can be excited without generating noise.
[0044]
By using the acceleration sensor 12 that is generally widely used, the vibration acceleration can be easily obtained.
[0045]
Since the transmission characteristics of each part of the cylinder block 4 can be measured, the evaluation of each part of the cylinder block 4 can be performed.
[0046]
Since the excitation device 19 can select the sweep excitation by the sine wave or the random excitation, when the sweep excitation by the sine wave is performed, the transmission by frequency is required to reduce the radiation sound of the cylinder block 4. Since it is necessary to measure the characteristics and the frequency gradually changes, the transfer characteristics for each frequency can be seen with a single setting operation, and the workability can be improved. It is also suitable for applying a large excitation force or for a non-linear test object.
On the other hand, when random excitation is performed, vibrations of a plurality of different frequencies can be input in a short time, so that the transfer characteristics for each frequency can be calculated (frequency analysis) in a short time. .
In addition, since the frequency of 1 KHz or less is a frequency band in which the influence of the radiated sound is small in the actual operation state, the measurement of the transfer characteristic in the region can be omitted, and the operation can be simplified.
[0047]
As shown in FIG. 3, the exciting rod 22 is divided, and the overall length of the exciting rod 21 can be adjusted by adjusting the W nut 22. Even when the distance is different, the length of the vibrating rod between the vibrating device and the piston head can be adjusted, and the amount of load applied to the piston 9 can be easily adjusted.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a power train showing an embodiment of the present invention.
FIG. 2 is a plan view of the cylinder head as seen from the bottom side.
FIG. 3 is an enlarged view of a vibration device according to the embodiment of the present invention.
FIG. 4 is a block diagram showing a transfer characteristic measuring method according to the embodiment of the present invention.
FIG. 5 is a graph showing a frequency characteristic of a radiated acoustic power level Lw.
FIG. 6 is a graph showing frequency characteristics of actually measured sound pressure levels.
FIG. 7 is a graph showing transfer characteristics of the entire cylinder block evaluated for each frequency band.
FIG. 8 is a graph of a transfer characteristic evaluated for each part of the cylinder block.
[Explanation of symbols]
1. Powertrain2. Engine 3. Transmission 4. Cylinder block 4a. Cylinder 5. Cylinder head 5a. Injector insertion hole (combustion-related parts mounting hole)
5b. Combustion chamber 6. Lower block (support)
7. Oil pan8. Timing belt cover 9. Piston 10. Connecting rod 11. Crankshaft 12. Acceleration sensor (measuring means)
13. Top deck part 14. Cylinder part 15. Skirt part 16. Oil pan rail part 17. Intake port 18. Exhaust port 19. Vibration device 20. Shaker 21. Exciting rod 21a. First vibration rod 21b. Second vibration rod 22. W nut (load adding mechanism)
22a. Nut for load adjustment (1st nut)
22b. Locking nut (second nut)
30. Arithmetic unit

Claims (11)

A vibration device that vibrates the power train; and a measuring unit that measures a vibration component at an arbitrary position of the power train when the vibration device is vibrated by the vibration device. The power is measured based on the vibration component measured by the measurement unit. In the transfer characteristic measurement method to find the transfer characteristics of the train,
The power train includes at least a cylinder block, and a cylinder head mounted above the cylinder block,
The cylinder block includes a piston slidably fitted to the cylinder, a connecting rod connected to the piston, a crankshaft connected to the connecting rod, and a support portion for supporting the crankshaft.
The cylinder head has a combustion-related component mounting hole that penetrates from the top to the bottom of the cylinder head at a position facing the piston head, and in which a component related to combustion is mounted.
In a state where the cylinder head is mounted above the cylinder block, the piston is set at a position substantially near the top dead center,
Vibrating the piston head by passing the vibration device through the combustion component mounting hole,
A transmission characteristic measurement method for a power train, wherein a transmission characteristic of an arbitrary portion of the power train is obtained based on a vibration component measured by the measurement unit when the piston head is vibrated. The method of measuring transmission characteristics of a power train according to claim 1, wherein in the vibration method of the vibration device, a vibration is applied by applying a load to the piston head. 3. The method according to claim 1, wherein the measuring unit is an acceleration sensor. 4. The vibration method according to claim 1, wherein the vibration method of the vibration device is a sweep vibration in which the vibration is performed while increasing or decreasing the frequency gradually with a sine wave. Powertrain transfer characteristic measurement method. The method according to any one of claims 1 to 3, wherein a vibration method of the vibration device is a random vibration for simultaneously generating a plurality of different frequencies. 6. The power train transfer characteristic measuring method according to claim 1, wherein in the vibration method of the vibration device, the vibration is performed while changing the frequency at 1 kHz or more. The measuring means is fastened to a top deck portion at a substantially upper end portion, a cylinder portion corresponding to a cylinder, a skirt portion corresponding to a crankshaft, and a lower block or oil pan at a substantially lower end portion on a wall surface of the cylinder block. For each oil pan rail part, a plurality of parts are provided in the cylinder row direction of each part,
Find the scalar sum of the transfer characteristics for each of the above parts,
The transmission characteristic measurement method for a power train according to any one of claims 1 to 6, wherein the transmission characteristic for each part is compared for each frequency. A vibration device for vibrating the power train,
Measuring means attached to an arbitrary place of the power train to measure a vibration component at the time of vibration of the vibration device,
In a power train transfer characteristic measuring device comprising a computing device for calculating a power train transfer characteristic based on a vibration component measured by the measuring means,
The power train includes at least a cylinder block, and a cylinder head mounted above the cylinder block,
The cylinder block includes a piston slidably fitted to the cylinder, a connecting rod connected to the piston, a crankshaft connected to the connecting rod, and a support portion for supporting the crankshaft.
The cylinder head has a combustion-related component mounting hole that penetrates from the top to the bottom of the cylinder head at a position facing the piston head, and in which a component related to combustion is mounted.
The vibrating device includes a vibrating rod that penetrates through the combustion-related component mounting hole and whose tip end abuts on the piston head at a position near the top dead center, and a vibrator that vibrates the vibrating rod And a transmission characteristic measuring device for a power train. 9. The power train transmission characteristic measuring device according to claim 8, wherein the vibration device includes a load applying mechanism for applying a load to the piston head. 10. The load applying mechanism according to claim 9, wherein the load applying mechanism is constituted by the exciting rod, and a load acting on the piston head is adjusted by adjusting a length of the exciting rod. Powertrain transfer characteristics measurement device. The load applying mechanism includes a first nut disposed to connect one end of each of the divided two vibrating rods, and a second locking nut disposed adjacent to the first nut. Wherein the total length of the vibrating rod is adjusted by adjusting the first and second nuts, and the load acting on the piston head is adjusted. Item 11. A power train transfer characteristic measuring device according to item 10.

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