叉車主體結構模態(tài)分析與減振設計
發(fā)布時間：2019-04-16 20:23
【摘要】：結構動力學性能是叉車整體性能中十分重要的因素。振動帶來的危害長期影響著叉車的壽命和舒適度，此外，劇烈的振動還會導致零件產生裂紋、齒輪傳動失效、緊固零件松脫。隨著市場競爭的加劇以及振動噪聲控制技術的不斷發(fā)展，對叉車舒適性的要求也越來越嚴格。在國內，叉車結構動力學性能的研究一直未得到重視，使得自主品牌的叉車與國外同類產品在振動表現上差距較大。為了避免叉車在正常運行中的共振現象、確保其安全可靠，并提升舒適度，，本文深入研究了其結構的動態(tài)特性，并利用結構動力學修改對叉車車架結構進行了優(yōu)化。 車架和護頂架是叉車主體結構，其中車架是主要承載基體，護頂架是與駕駛室結合最緊密的大型結構，兩者的模態(tài)不僅反映了叉車的整體動態(tài)性能，而且是控制整車振動特性的關鍵。叉車振動系統(tǒng)的振源主要是發(fā)動機和坑洼路面，本文主要研究發(fā)動機激勵下叉車的動態(tài)特性，降低振動水平的方法是避免發(fā)動機常用激勵頻率跟車架或護頂架固有頻率接近所引起的共振。利用解析法和試驗法獲得叉車車架和護頂架的模態(tài)參數，深入研究車架和護頂架的動態(tài)特性后，將車架結構合理的改進，改善了車架的動態(tài)特性，降低了振動水平，增加了整車的舒適性。 對該型號叉車運行時的振動信號進行了采集，找出振動能量最大時刻的信號并側重其進行分析。然后對護頂架和車架分別做了模態(tài)分析，將解析和測試得到模態(tài)參數與現場振動檢測結果相比較。在此基礎上，確定該型號叉車振動主要原因是護頂架和車架在發(fā)動機怠速附近激勵下產生同時共振，且由于共振頻率在發(fā)動機常用轉速激勵范圍內，導致叉車長時間共振。最后，對車架做了結構動力學修改，并通過實車驗證了方案可以有效降低叉車振動水平。本文所述的減振設計方法全面考慮了振動信號特點和模態(tài)參數，對叉車護頂架與車架兩個主要結構同時進行了分析，為叉車振動控制的研究提供了經驗和參考。
[Abstract]:Structural dynamic performance is a very important factor in the overall performance of forklift truck. The damage caused by vibration affects the life and comfort of forklift truck for a long time. In addition, severe vibration will lead to cracks in parts, failure of gear transmission and loosening of fastening parts. With the intensification of market competition and the continuous development of vibration and noise control technology, the comfort requirements of forklift trucks are becoming more and more strict. In China, the research on the dynamic performance of forklift structure has not been paid attention to, which makes the vibration performance of forklift truck with its own brand is far from that of other similar products in foreign countries. In order to avoid resonance phenomenon of forklift truck in normal operation, ensure its safety and reliability, and improve comfort, the dynamic characteristics of its structure are deeply studied in this paper, and the structure of forklift truck frame is optimized by structural dynamic modification. The frame and roof protection frame are the main structure of forklift truck, in which the frame is the main bearing matrix, and the roof frame is the large structure which is most closely combined with the cab. The modes of the two modes not only reflect the overall dynamic performance of the forklift truck, but also reflect the dynamic performance of the forklift truck. And it is the key to control the vibration characteristics of the whole vehicle. The vibration source of forklift vibration system is mainly engine and pothole pavement. This paper mainly studies the dynamic characteristics of forklift under engine excitation. The way to reduce the vibration level is to avoid the resonance caused by the common excitation frequency of the engine close to the natural frequency of the frame or roof frame. The modal parameters of forklift truck frame and roof guard frame are obtained by analytical method and test method. After deeply studying the dynamic characteristics of forklift frame and roof guard frame, the frame structure is improved reasonably, the dynamic characteristics of the frame are improved, and the vibration level is reduced. Increased the comfort of the whole car. The vibration signal of the forklift truck is collected, and the signal of the maximum vibration energy is found and analyzed. Then the modal analysis of the roof-protecting frame and the frame is carried out, and the modal parameters obtained from the analysis and test are compared with the results of vibration detection in the field. On this basis, the main reason for the vibration of the forklift is the simultaneous resonance caused by the excitation of the hood and the frame near the idle speed of the engine, and the long-term resonance of the forklift is caused by the resonance frequency within the excitation range of the common speed of the engine. Finally, the structural dynamics of the frame is modified, and it is verified that the scheme can effectively reduce the vibration level of forklift truck. The vibration reduction design method described in this paper takes the vibration signal characteristics and modal parameters into account, and analyzes the two main structures of forklift roof support frame and truck frame simultaneously, which provides experience and reference for the study of forklift vibration control.
【學位授予單位】：中國計量學院
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH242
[Abstract]:Structural dynamic performance is a very important factor in the overall performance of forklift truck. The damage caused by vibration affects the life and comfort of forklift truck for a long time. In addition, severe vibration will lead to cracks in parts, failure of gear transmission and loosening of fastening parts. With the intensification of market competition and the continuous development of vibration and noise control technology, the comfort requirements of forklift trucks are becoming more and more strict. In China, the research on the dynamic performance of forklift structure has not been paid attention to, which makes the vibration performance of forklift truck with its own brand is far from that of other similar products in foreign countries. In order to avoid resonance phenomenon of forklift truck in normal operation, ensure its safety and reliability, and improve comfort, the dynamic characteristics of its structure are deeply studied in this paper, and the structure of forklift truck frame is optimized by structural dynamic modification. The frame and roof protection frame are the main structure of forklift truck, in which the frame is the main bearing matrix, and the roof frame is the large structure which is most closely combined with the cab. The modes of the two modes not only reflect the overall dynamic performance of the forklift truck, but also reflect the dynamic performance of the forklift truck. And it is the key to control the vibration characteristics of the whole vehicle. The vibration source of forklift vibration system is mainly engine and pothole pavement. This paper mainly studies the dynamic characteristics of forklift under engine excitation. The way to reduce the vibration level is to avoid the resonance caused by the common excitation frequency of the engine close to the natural frequency of the frame or roof frame. The modal parameters of forklift truck frame and roof guard frame are obtained by analytical method and test method. After deeply studying the dynamic characteristics of forklift frame and roof guard frame, the frame structure is improved reasonably, the dynamic characteristics of the frame are improved, and the vibration level is reduced. Increased the comfort of the whole car. The vibration signal of the forklift truck is collected, and the signal of the maximum vibration energy is found and analyzed. Then the modal analysis of the roof-protecting frame and the frame is carried out, and the modal parameters obtained from the analysis and test are compared with the results of vibration detection in the field. On this basis, the main reason for the vibration of the forklift is the simultaneous resonance caused by the excitation of the hood and the frame near the idle speed of the engine, and the long-term resonance of the forklift is caused by the resonance frequency within the excitation range of the common speed of the engine. Finally, the structural dynamics of the frame is modified, and it is verified that the scheme can effectively reduce the vibration level of forklift truck. The vibration reduction design method described in this paper takes the vibration signal characteristics and modal parameters into account, and analyzes the two main structures of forklift roof support frame and truck frame simultaneously, which provides experience and reference for the study of forklift vibration control.
【學位授予單位】：中國計量學院
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH242
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相關期刊論文 前10條
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