喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== 喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請放心下載，，有疑問咨詢QQ:414951605或者1304139763 ======================== 安裝有許多對角裂縫零件的一維縱扭振動轉(zhuǎn)換器 Jiromaru Tsujino*, Tetsugi Ueoka, Kenichi Otoda, Atsushi Fujimi Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan 摘要：為了提高一維縱扭振動轉(zhuǎn)換器可得到的振動速度，對旨在減少振動節(jié)點(diǎn)部分的最大振動應(yīng)力水平并且要避免安裝在轉(zhuǎn)換器的縱向節(jié)點(diǎn)位置的帶有許多裂縫的零件的新型的復(fù)雜振動轉(zhuǎn)換器進(jìn)行了研究。轉(zhuǎn)換器的自由端以橢圓或圓形軌跡振動。帶有從橢圓形到圓形或者從長方形到正方形軌跡的復(fù)雜振動系統(tǒng)可有效應(yīng)用于需要大功率的場合，包括金屬或者塑料的超聲波焊接，超聲波焊線的集成電路，大規(guī)模集成電路和裝置和超聲波馬達(dá)。安裝有許多帶裂縫部件的轉(zhuǎn)換器比只安裝一個帶有裂縫零件的轉(zhuǎn)換器在振動應(yīng)力水平和品質(zhì)因數(shù)方面會得到提高。 關(guān)鍵詞：圓形振動軌跡 復(fù)雜的振動 復(fù)雜振動超聲波焊接 縱扭振動轉(zhuǎn)換器 超聲波馬達(dá) 超聲波塑料焊接 帶有對角裂縫的振動轉(zhuǎn)換器 1.簡介 帶有從橢圓形到圓形或者從長方形到正放形位點(diǎn)的復(fù)雜振動系統(tǒng)適用于大功率場合的使用。在縱向振動節(jié)點(diǎn)區(qū)域安裝有一個裂縫零件且由縱向振動系統(tǒng)驅(qū)動的一維縱扭振動轉(zhuǎn)換器適用于大規(guī)模場合的應(yīng)用，這些場合包括：各種材料的超聲波焊接，超聲波焊線的集成電路，大規(guī)模集成電路和裝置和超聲波馬達(dá)。為了提高振動的優(yōu)點(diǎn)和增加轉(zhuǎn)換器的可獲得振動速度，對帶有許多裂縫零件的新型轉(zhuǎn)換器做了研究。裂縫零件可以安裝在許多位置，但是要避免安裝在縱向節(jié)點(diǎn)位置處以便減少振動節(jié)點(diǎn)部分的最大應(yīng)力振動數(shù)值。使用很多裂縫零件可以使最大振動應(yīng)力和質(zhì)量因數(shù)增加，同時在相同的驅(qū)動電壓下最大振動振幅會明顯增大。這種轉(zhuǎn)換器由很突出的優(yōu)點(diǎn)，因?yàn)楹椭挥幸粋€裂縫零件的轉(zhuǎn)換器相比，其最大振動應(yīng)力較小，而且這種振動器的最大振動振幅會明顯增加。沿著轉(zhuǎn)換器分布的振動軌跡，振動速度和相分布可以通過激光多普勒測振儀進(jìn)行測量。這種新型的轉(zhuǎn)換器用于超聲波塑料焊接和超聲波馬達(dá)中。 這種新型轉(zhuǎn)換器可獲得的最大振動速度會顯著增加。使用復(fù)雜的振動轉(zhuǎn)換器可以使塑的焊接優(yōu)點(diǎn)得以提高。 超聲波馬達(dá)聲使用的15mm直徑的新型振動器的縱扭振動幅和以前的轉(zhuǎn)換器相比，在相同的驅(qū)動電壓60v,55kHz條件下，會從6um增加到將近12um. 安裝有多縫隙零件的轉(zhuǎn)換器在提高振動的優(yōu)點(diǎn)和增加可得到的復(fù)雜振動速度方面是很有效的。 2振動轉(zhuǎn)換器的構(gòu)造 兩個直徑為20mm，長度為79mm的振動轉(zhuǎn)換器的構(gòu)造如圖1所示，而且這兩種轉(zhuǎn)換器在除了縱向節(jié)點(diǎn)部分外安裝有裂縫零件。用鋁合金（JISA7075B）制造的圓柱形縱扭轉(zhuǎn)換器在圓周的縱向振動節(jié)點(diǎn)部分的兩端安裝有兩個裂縫零件。轉(zhuǎn)換器由縱向振動源驅(qū)動。在實(shí)驗(yàn)中使用了具有相同角度和不同角度對角裂縫零件的各種轉(zhuǎn)換器。振動轉(zhuǎn)換器有18個呈45°或135°的對角裂縫，這些10mm寬，0.5mm寬的裂縫是用電火花機(jī)床加工出來的。裂縫深度從1.0mm到30.mm之間變化。轉(zhuǎn)換器的自由端部分以縱扭的方式振動并且軌跡呈橢圓形。 圖1，安裝有一對裂縫零件的不同的一維縱扭振動轉(zhuǎn)換器 3帶有兩個裂縫零件的轉(zhuǎn)換器的振動特點(diǎn) 對轉(zhuǎn)換器的整個振動系統(tǒng)的自由進(jìn)入循環(huán)進(jìn)行了測量。具有不同角度裂縫零件（a）和具有相同角度裂縫零件（b）的質(zhì)量因數(shù)︱Ymo︳，在890Kpa的穩(wěn)定壓力條件下焊接，其數(shù)值大致是600和30ms。由于縱向振動和扭轉(zhuǎn)振動的共振頻率很接近，所以轉(zhuǎn)換器振動系統(tǒng)的進(jìn)入循環(huán)顯示出單一的圓形。兩個系統(tǒng)的質(zhì)量因數(shù)是很大的。在轉(zhuǎn)換器的自由邊沿可以得到橢圓位點(diǎn)。 4復(fù)雜振動超聲波塑料焊接 4.1復(fù)雜振動轉(zhuǎn)換器的振動特點(diǎn) 圖2顯示了驅(qū)動頻率和帶有復(fù)雜振動系統(tǒng)的振動轉(zhuǎn)換器的扭轉(zhuǎn)振動速度之間的關(guān)系。驅(qū)動電壓穩(wěn)定在20V。扭轉(zhuǎn)振動速度在26.3kHz和26.4kHz附近的不同頻率處有最大的數(shù)值。在轉(zhuǎn)換器的自由邊沿會出現(xiàn)橢圓的軌跡。 帶有一對裂縫零件的復(fù)雜振動轉(zhuǎn)換器，在頻率為26.8kHz時，其扭轉(zhuǎn)徑向的振動速度分布如圖3所示。扭轉(zhuǎn)振動速度的節(jié)點(diǎn)部分通常位于左側(cè)的裂縫區(qū)域，并且振動速度在自由邊沿達(dá)到最大數(shù)值。 圖2，沿著（a)和（b)復(fù)雜振動轉(zhuǎn)換器扭轉(zhuǎn)徑向振動速度的分布。驅(qū)動電壓為20V。 圖3，帶有復(fù)雜振動系統(tǒng)的振動轉(zhuǎn)換器（A)驅(qū)動頻率和縱扭振動速度之間的關(guān)系。驅(qū)動電壓為20V。 帶有一對裂縫零件的復(fù)雜振動轉(zhuǎn)換器的徑向振動速度分布也可以用圖3所示。徑向振動速度最大位置處也即縱向振動節(jié)點(diǎn)位置，并且縱向節(jié)點(diǎn)位置位于兩裂縫零件之間。在徑向節(jié)點(diǎn)位置處轉(zhuǎn)換器的應(yīng)力分布有一個最大數(shù)值，然而兩個裂縫區(qū)域并不存在于這個位置。 4.2復(fù)雜振動超聲波塑料焊接的焊接特點(diǎn) 焊接時間，焊接部分試件的變形厚度和用頻率為27kHz帶有復(fù)雜振動系統(tǒng)的轉(zhuǎn)換器（a）和（b）搭接的聚丙烯板的強(qiáng)度之間的關(guān)系如圖4所示。通過轉(zhuǎn)換器（a）所得到的焊接強(qiáng)度要大于通過轉(zhuǎn)換器（b）所得到的強(qiáng)度。由于（a）中振動系統(tǒng)有一個更大的扭轉(zhuǎn)振動元件，相比之下，其所需的焊接時間要短。在焊接部分試件變形厚度的減少通常和所得的強(qiáng)度是一致的。和帶有縱向振動系統(tǒng)的轉(zhuǎn)換器相比，帶有復(fù)雜振動系統(tǒng)的轉(zhuǎn)換器焊接工件的時間要短。復(fù)雜振動既對金屬材料的焊接有效，又適用于塑料的超聲波焊接。 5帶有扭轉(zhuǎn)轉(zhuǎn)換器的超聲波馬達(dá) 5.1超聲波馬達(dá)的構(gòu)造 圖4，焊接時間，變形焊接高度和搭接起來的聚丙烯板的焊接強(qiáng)度之間的關(guān)系（厚度為1.0mm)，使用一個頻率為27kHz復(fù)雜振動系統(tǒng)的轉(zhuǎn)換器（a)和（b)進(jìn)行焊接。 超聲波馬達(dá)和直徑為15mm的振動轉(zhuǎn)換器的構(gòu)造如圖5所示。圖5（a）和（b）分別顯示了安裝有一個裂縫零件的直徑為15mm的馬達(dá)和安裝有一對裂縫零件的直徑為15mm的馬達(dá)。拿安裝有一個裂縫零件的轉(zhuǎn)換器為例，裂縫零件是沿著圓柱形扭轉(zhuǎn)振動轉(zhuǎn)換器安裝在縱向振動的節(jié)點(diǎn)位置。相反，安裝有一對裂縫零件的轉(zhuǎn)換器，其裂縫零件不安裝在縱向振動節(jié)點(diǎn)位置。帶有對角裂縫的轉(zhuǎn)換器是由兩個直徑為15mm,厚度為5.0mm的壓電陶瓷片的縱向振動源驅(qū)動的。振動轉(zhuǎn)換器裂縫零件有12個呈45°或者135°，0.5mm寬，10mm或者5mm長的對角裂紋。這些裂紋是沿著鋁合金制的轉(zhuǎn)換器的圓周用點(diǎn)火花機(jī)床加工而成的。直徑為15mm轉(zhuǎn)換器裂紋的深度從1.5mm到3.5mm之間變化。轉(zhuǎn)換器的自由邊沿以縱扭的方式振動，且振動軌跡呈橢圓形。 PZT縱向振動傳感器，它是安裝有一個用于支撐馬達(dá)的凸緣的縱向振動棒和裂縫圓柱通過螺栓連接而成的。轉(zhuǎn)換器的驅(qū)動部分和轉(zhuǎn)子部分通過使用彈簧來壓緊。使用1500-2000的網(wǎng)拋光粉可以把轉(zhuǎn)換器的驅(qū)動表面和轉(zhuǎn)子研磨得光滑平整。 5.2直徑為15mm的超聲波馬達(dá)的振動特點(diǎn) 當(dāng)驅(qū)動頻率變化的時候，轉(zhuǎn)換器自由邊沿的縱扭振動振幅可以由兩臺激光多普勒測振儀進(jìn)行測量。這些轉(zhuǎn)換器有和圖2相近的縱扭共振頻率。在頻率為50-55kHz之間不帶有轉(zhuǎn)子的單一和一對裂縫零件的轉(zhuǎn)換器的最大縱向振動振幅大約為6um和12um。在頻率接近55kHz時，帶有轉(zhuǎn)子轉(zhuǎn)換器的最大縱向振動振幅大致為3um和9um。和只帶有一個裂縫零件轉(zhuǎn)換器的振幅相比，帶有一對裂縫零件的轉(zhuǎn)換器的最大振幅是其2-3倍。 5.3轉(zhuǎn)換器驅(qū)動表面的振動位點(diǎn) 圖5，使用安裝有單一裂縫零件（a)和一對裂縫零件（b)的縱扭振動轉(zhuǎn)換器的直徑為15mm的超聲波馬達(dá)的構(gòu)造 在這些例子中，縱向振動部分轉(zhuǎn)化為裂縫零件的扭轉(zhuǎn)振動，且轉(zhuǎn)換器的圓柱部分縱扭地振動。自由邊沿的振動軌跡是由不同的振動階段決定的。縱扭轉(zhuǎn)換器驅(qū)動表面的振動位點(diǎn)是由兩臺獨(dú)立工作的激光多普勒測振儀測得的。振動軌跡會在數(shù)字記憶示波器屏幕上顯示李薩如圖形。圖六顯示了帶有一對深為3.3mm，長為5mm的裂縫零件的超聲波馬達(dá)轉(zhuǎn)換器在驅(qū)動頻率為55.1kHz和54.26kHz情況下其驅(qū)動表面的振動位點(diǎn)。當(dāng)超聲波馬達(dá)旋轉(zhuǎn)時，轉(zhuǎn)換器振動表面的振動軌跡振幅會稍微減小。 圖6，帶有轉(zhuǎn)子零件和不帶轉(zhuǎn)子零件在直徑為15mm轉(zhuǎn)換器的驅(qū)動部分的振動位點(diǎn) 6結(jié)論 為了增加復(fù)雜振動轉(zhuǎn)換器的可獲得振動速度，對安裝有許多裂縫零件的新型轉(zhuǎn)換器進(jìn)行了研究。 這種轉(zhuǎn)換器在許多位置上安裝有很多裂縫零件，為了減小震動節(jié)點(diǎn)部分最大振動應(yīng)力數(shù)值，裂縫零件要避免安裝在節(jié)點(diǎn)位置。帶有復(fù)雜振動的超聲波塑料的焊接特點(diǎn)得到了研究，并且安裝有一對裂縫零件的轉(zhuǎn)換器的直徑為15mm的超聲波馬達(dá)得到了檢驗(yàn)。 縱向振動節(jié)點(diǎn)部分位于轉(zhuǎn)換器兩裂縫零件之間。和只安裝有單一裂縫零件的轉(zhuǎn)換器相比，在相同驅(qū)動電壓下，轉(zhuǎn)換器的驅(qū)動表面和帶有一對裂縫零件的超聲波馬達(dá)的振動速度。 安裝有一對裂縫零件的轉(zhuǎn)換器明顯的提高了塑料的超聲波焊接優(yōu)點(diǎn)。直徑為15mm的超聲波馬達(dá)和安裝有一對裂縫零件的轉(zhuǎn)換器的轉(zhuǎn)速達(dá)到300rpm。 安裝有許多裂縫零件的轉(zhuǎn)換器在提高振動的優(yōu)點(diǎn)和增加可獲得復(fù)雜振動速度方面是很有效的。 參考文獻(xiàn) [1] J. Tsujino, T. Ueoka, T. Shiraki, K. Hasegawa, R. Suzuki, M. parts were tested. Takeuchi, Proc. Int. Congress on Acoustics (1995) 447–450.. [2] J. Tsujino, Proc. IEEE 1995 Ultrasonics Symp., IEEE, New York, The longitudinal vibration nodal part was located 1996, pp. 1051–1060. [3] J. Tsujino, T. Uchida, K. Yamano, T. Iwamoto, T. Ueoka, Proc. [4] J. Tsujino, T. Uchida, K. Yamano, T. Iwamoto, T. Ueoka, Proc. [5] J. Tsujino, T. Ueoka, Proc. IEEE 1999 Ultrasonics Symp., IEEE, New York, 1999, pp. 723–728 Ultrasonics 38 (2000) 7276www.elsevier.nl/locate/ultrasOne-dimensional longitudinaltorsional vibration converterwith multiple diagonally slitted partsJiromaru Tsujino*, Tetsugi Ueoka, Kenichi Otoda, Atsushi FujimiFaculty of Engineering, Kanagawa University, Yokohama 221-8686, JapanAbstractFor increasing the available vibration velocity of the one-dimensional longitudinaltorsional vibration converter, a new typeof complex vibration converter with multiple slitted parts installed in the positions avoiding longitudinal nodal positions alongthe converter for decreasing the maximum vibration stress level at the vibration nodal part was studied. The free end of theconverter vibrates in an elliptical or circular locus. Complex vibration systems with elliptical to circular or rectangular to squareloci can be applied effectively for various high-power applications, including ultrasonic welding of metal or plastics, ultrasonicwire bonding of IC, LSI and electronic devices, and also ultrasonic motors. The converter with multiple slitted parts was improvedin the vibration stress level and the quality factor compared with the converter with single slitted part. 2000 Elsevier ScienceB.V. All rights reserved.Keywords: Circular vibration locus; Complex vibration; Complex vibration ultrasonic welding; Longitudinaltorsional vibration converter;Ultrasonic motor; Ultrasonic plastic welding; Vibration converter with diagonal slits1. Introductionvibration characteristics because the maximum vibrationstress along the converter is decreased in comparison tothe converter with a slitted part, and the maximumComplex vibration systems with elliptical to circularvibration amplitude of the converter increases signifi-or rectangular to square loci are effective for variouscantly. Vibration locus, and vibration velocity and phasehigh-power applications. A one-dimensional longitudi-distributions along the converter were measured by twonaltorsional vibration converter with a slitted part atlaser Doppler vibrometers. The new-type converterslongitudinal vibration nodal area driven by a longitudi-were used for ultrasonic plastic welding and ultrasonicnal vibration system is useful for high-power applica-motors.tions including ultrasonic welding of various materials,The maximum available vibration velocity increasedultrasonic wire bonding of bonding of IC, LSI andsignificantly with the new converter. Welding character-electronic devices, and also ultrasonic motors 14. Aistics of plastic materials were improved by the complexnew type of converter with multiple slitted parts, forvibration converter.improving the vibration characteristics and increasingThe longitudinal and torsional vibration amplitudesthe available vibration velocity of the converter, isof a 15 mm diameter of a new converter for an ultrasonicstudied. The slitted parts are installed in multiple posi-motor increased to about 12 mm (peak-to-zero value)tions avoiding longitudinal nodal positions along thefrom 6 mm with a former converter under the sameconverter for decreasing the maximum vibration stressdriving voltage 60 Vrms at 55 kHz.level at the vibration nodal part. Using multiple slittedThe converter with multiple slitted parts was foundparts, the maximum vibration stress along a converterto be effective for improving the vibration characteristicsdecreases and the quality factor increases, and theand increasing the available complex vibration velocity.maximum vibration amplitude increases significantly atthe same driving voltage 5. The converter has superior2. Configurations of vibration converters* Corresponding author. Tel.: +81-45-481-5661;Configurations of two examples of the vibrationfax: +81-45-491-7915.E-mail address: tsujinocc.kanagawa-u.ac.jp (J. Tsujino)converters 20 mm in diameter and 79 mm in length, with0041-624X/00/$ - see front matter 2000 Elsevier Science B.V. All rights reserved.PII: S0041-624X(99)00175-473J. Tsujino et al. / Ultrasonics 38 (2000) 72764. Complex vibration ultrasonic plastic welding4.1. Vibration characteristics of a complex vibrationconvertersFig. 2 shows the relationship between driving fre-quency and longitudinal and torsional vibration velocityof a complex vibration system with the vibration con-verter (a). The driving voltage is kept constant at20 Vrms. Longitudinal and torsional vibration velocitieshave maximum values at different frequencies at around26.3 and 26.4 kHz. The elliptical locus is obtained atthe free edge of the converter.Torsional and radial vibration velocity distributionsat 26.8 kHz along a complex vibration converter withFig. 1. Various one-dimensional longitudinal to torsional vibrationdouble slitted parts (a) and (b) are shown in Fig. 3. Oneconverters with double slitted parts.torsional vibration velocity nodal part is within a leftslitted area, and the vibration velocities have maximumvalues at the free edge.The radial vibration velocity distribution along aslitted parts that were installed avoiding a longitudinalcomplex vibration converter with double slitted partsnodal part, are shown in Fig. 1. The cylindrical longitu-dinaltorsional vibration converters, made of aluminumalloy (JISA7075B), had two slitted parts on both sidesof a longitudinal vibration nodal part at its circumfer-ence. The converters were driven by a longitudinalvibration source. Various converters with (a) differentand (b) the same angle diagonally slitted parts weremade in the trials. The vibration converter part had 18diagonal slits of 45 or 135, 10 mm width and 0.5 mmwidthwerecut alongitscircumferenceusinganelectrosparking machine. The slit depth was altered from1.0 to 3.0 mm. The free edge part of the convertervibrated longitudinally and torsionally and vibrated inan elliptical locus.Fig. 2. Torsional and radial vibration velocity distributions along com-plex vibration converters (a) and (b). Driving voltage: 20 Vrms.3. Vibration characteristics of the converters with twoslitted partsThe free admittance loops of the total vibrationsystems with the converters Fig. 1(a) and (b) weremeasured. The quality factor and motional admittance,|Ymo|, of the vibration system with a converter withdifferent angle slitted parts (a) and the same angle slittedparts (b) were about 600 and 30 mS under weldingconditions of two 1.0 mm thick polypropyrene sheetswith a static pressure of 890 kPa. The admittance loopsof the vibration system with the converters show singlecircular shapes because the resonance frequencies of thelongitudinal and torsional vibrations are close. Thequality factors and motional admittances of the bothFig. 3. Relationship between driving frequency, and longitudinal andsystems are large. Elliptical loci were obtained at thetorsional vibration velocity of a complex vibration system with a vibra-tion converter (A). Driving voltage: 20 Vrms.free edges of the converters.74J. Tsujino et al. / Ultrasonics 38 (2000) 7276(a) is also shown in Fig. 3 (dotted line). A radialand double slitted parts. In the case of the converterwith single slitted part, the slitted part is positioned atvibration velocity maximum position means a longitudi-a nodal position of the longitudinal vibration along thenal vibration nodal position, and the longitudinal nodalcylindrical longitudinaltorsional vibration converters.position is positioned between two slitted parts. TheOn the contrary, in the case of the converter with twotwo slitted areas exist out of the longitudinal nodalslitted parts, the slitted parts are positioned avoidingposition where the vibration stress has a maximum valuethe longitudinal vibration nodal position. The converteralong the converter.with diagonal slits is driven by a longitudinal vibrationsource of two piezoelectric ceramic (leadzircontita-4.2. Welding characteristics of complex vibrationnate; PZT) disks, 15 mm in diameter and 5.0 mm inultrasonic plastic weldingthickness. The vibration converter slitted part has 12diagonal slits of 45 or 135 and 0.5 mm in width and 10The relationship between welding time, specimenor 5 mm in length, cut by an electrosparking machinedeformed thickness at the welded parts and the weldalong the circumference of these converters fabricatedstrength of the lapped polypropyrene sheets (1.0 mm infrom aluminum alloy (JISA7075B). The slit depths ofthickness), welded using a 27 kHz complex vibrationthe 15 mm diameter converter are altered from 1.5 tosystem with a converter (a) and (b), is shown in Fig. 4.3.5 mm. The free edge of the converter vibrates longitu-The weld strengths obtained by the system with con-dinally and torsionally and vibrates in an elliptical locus.verter (a) are larger than those with a converter (b).The PZT longitudinal vibration transducers, a longi-The welding time required becomes shorter using thetudinal vibration rod with a flange for supporting thevibration system (a) with a larger torsional vibrationmotor and a slitted cylinder are clamped by a connectingcomponent. The decrease in specimen deformed thick-bolt. The driving part of the converter and the rotorness at the welded parts roughly corresponds to thepart are statically pressed using corned disk springs byobtained weld strength. Specimens were welded in aa center bolt and nuts. The driving surfaces of theshorter welding time using a complex vibration systemconverter (JISA7075B) and the rotor (steel: SKD-61 orcompared with a longitudinal vibration system. ComplexSK-4: tempered) are ground to be flat and smooth usingvibration is effective for ultrasonic welding of plastic15002000 mesh polishing powder.materials as for metal materials.5.2. Vibration characteristics of 15 mm diameterultrasonic motors5. Ultrasonic motors with a longitudinaltorsionalconverterThe longitudinal and torsional vibration amplitudesat the free edge of these converters were measured by5.1. Configuration of ultrasonic motorstwo laser Doppler vibrometers when the driving fre-quency was altered. These converters have near-reso-The configurations of the ultrasonic motors andnance frequencies of the longitudinal and torsionalvibration converters, 15 mm in diameter, are shown invibrations similar to Fig. 2. The largest longitudinalFig. 5. Fig. 5(a) and (b) show the configurations ofvibration amplitudes of the converter of single and two15 mm diameter motors using a converter with singleslitted parts without a rotor part were about 6 and12 mm (peak-to-zero value) at frequencies of 5055 kHz.The largest longitudinal vibration amplitudes of theseconverters with a rotor part are about 3 and 9 mm atfrequencies near to 55 kHz. The largest vibration ampli-tudes of a converter with double slitted parts are abouttwo to three times compared with the amplitudes of aconverter with single slitted part.5.3. Vibration loci at the driving surface of the converterIn these cases, the longitudinal vibration is partiallyconverted to torsional vibration at the slitted parts, andthe cylinder part of the converter vibrates longitudinallyand torsionally. The vibration locus at the free edge isdetermined by the vibration phase difference betweenFig. 4. Relationship between welding time, deformed weldment heightthese vibrations. Vibration loci at the driving surfacesand weld strength of the lapped polypropyrene sheets (1.0 mm in thick-of longitudinaltorsional converters were measuredness), weldedusing a 27 kHz complexvibration systemwith a converter(a) and (b).using two laser Doppler vibrometers (20 MHz) that75J. Tsujino et al. / Ultrasonics 38 (2000) 7276Fig. 5. Configurations of 15 mm diameter ultrasonic motors using a longitudinaltorsional vibration converter with single slitted part (a) anddouble slitted parts (b).detect longitudinal and torsional vibrations indepen-length of the ultrasonic motor of 15 mm diameter in thedriving frequency 55.1 kHz (without a rotor) anddently. The vibration locus is shown on a digital memoryoscilloscope screen as a Lissajous figure. Fig. 6 shows54.26 kHz (with a rotor). The vibration locus amplitudeat the driving surfaces of converter decreases slightlythe vibration loci at the driving surfaces of converterswith double slitted parts of 3.3 mm depth and 5 mmwhen the ultrasonic motor rotates.Fig. 6. Vibration loci at a driving part of a 15 mm diameter converter with and without a rotor part.76J. Tsujino et al. / Ultrasonics 38 (2000) 72766. Conclusionmaterials.The15 mmdiameterultrasonicmotor,together with a converter with double slitted parts,rotated at over 300 rpm.For increasing the available vibration velocity of thecomplex vibration converter, a new type of converterThe converters with multiple slitted parts were foundto be effective for improving the vibration characteristicswith multiple slitted parts was studied.This converter has multiple slitted parts that areand increasing the available complex vibration velocity.installed in multiple positions, avoiding nodal positionsalong the converter for decreasing the maximum vibra-tion stress level at the vibration node part. The weldingReferencescharacteristics of ultrasonic plastic welding using com-plex vibrations were studied. Also, 15 mm diameter1 J. Tsujino, T. Ueoka, T. Shiraki, K. Hasegawa, R. Suzuki, M.ultrasonic motors using converters with double slittedTakeuchi, Proc. Int. Congress on Acoustics (1995) 447450.parts were tested.2 J. Tsujino, Proc. IEEE 1995 Ultrasonics Symp., IEEE, New York,The longitudinal vibration nodal part was located1996, pp. 10511060.between two slitted parts of the converters. The driving3 J. Tsujino, T. Uchida, K. Yamano, T. Iwamoto, T. Ueoka, Proc.2nd World Congress on Ultrasonics, Yokohama, Japan (1997)surface of the converter and the ultrasonic motor with152153.double slitted parts vibrated at higher vibration velocities4 J. Tsujino, T. Uchida, K. Yamano, T. Iwamoto, T. Ueoka, Proc.than those with a single slitted part at the same driv-IEEE1997UltrasonicsSymp.,IEEE,NewYork,1998,ing voltage.pp. 855860.The converter with double slitted parts significantly5 J. Tsujino, T. Ueoka, Proc. IEEE 1999 Ultrasonics Symp., IEEE,New York, 1999, pp. 723728.improved the ultrasonic welding characteristics of plastic