共查询到19条相似文献，搜索用时 593 毫秒
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圆锯片适张应力分布状况及锯片平整性量化分析方法的研究 总被引：2，自引：0，他引：2
本文重点论述了用锯片端面圆跳动和其在特定加载条件下的刚度作为评价锯片平整性和适张应力分布状况量化指的理论依据及为此研制开发的以８０３１单片机为核心的检测系统。应用该方法及检测系统对多种木工圆锯和大型金刚石锯片所做的实测结果表明，该方法及检测系统应用于工业现场是切实可行的。 相似文献
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圆锯片适张度量化分析方法的研究 总被引：1，自引：0，他引：1
从研究、选取表征锯片适张状态主要指标——适张度的特征参量入手，研究开发了一种以８０３１单片机为主体，以基２复序列ＦＦＴ算法为核心的锯片适张度检测系统。运用该系统对国内外几十种不同规格锯片的实测结果表明，该方法及研制开发的检测系统运用于工业现场是切实可行的。 相似文献
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张占宽 《林业机械与木工设备》2005,33(6):13-15
将未适张、辊压适张、锤击适张圆锯片装在不同直径的夹盘上，施以相同的夹紧力后进行振动模态分析。实验证明，不论是未适张圆锯片，还是辊压和锤击适张圆锯片，随着夹盘增大，锯片各阶固有频率都有不同程度的提高，其中辊压适张圆锯片二阶振动模态的固有频率没有增加或只有少量增加，锤击适张圆锯片四阶以上振动模态的固有频率有显著增加。 相似文献
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本文提出了一种分析圆锯振动及弹性稳定性的一般方法,即采用有限元法来计算特征值,这种方法考虑到了锯片几何形状,自然振动,变形以及临界转速等因素对内应力的影响。该方法分析了由于滚压和热扭曲张紧引起的形变,并计算了受临界滚压力作用时沿锯片半径方向温度差的极限值。该方法还可以应用振动频率－转速表来计算临界转速,同时考虑到锯片形状,张紧系数,热梯度等因素的作用。该方法是用于求张紧系数（转动力、转动半径）和工 相似文献
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文章在分析讨论了影响圆锯片极限转速的一些重要因素后认为 ,包括锯片材料、结构、尺寸、内应力影响的最低共振临界转速是制约锯片极限转速的重要因素 .考虑到诸多影响因素后 ,文章建议圆锯片的最高极限转速以不超过该锯片未适张时的最低临界转速的 50 %～ 6 0 %较为适宜 相似文献
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利用非线性理论和矩阵摄动理论，研究了离心力场，切削温度场及辊压适张度位置对圆锯片动态特性和临界转速的影响，对离心力场，切削温度场共同作用下锯片最佳辊压适张处理位置进行了计算分析，还分析了锯夹半径对最佳辊压位置的影响。 相似文献
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李军伟 《林业机械与木工设备》1999,(11)
1圆锯片适张度检查和修正的必要性锯片锯割时，圆锯做回转运动，圆锯片除了受木材摩擦力外，还受到离心力的作用。锯齿与木材摩擦产生的切削热量，在边缘处比中间部分大得多，所以外口膨胀伸长，边缘部分松驰。因离心力与回转速度（切线速度）的平方成正比，因此，转速大的锯片边缘部分较中央部分伸张的多，这也造成了边缘的松驰。由于锯片边缘部分和中央部分的张紧程度不同，因此在切割木材时，锯片不稳定，其圆周不能保持在一条直线上，而变成“波浪形”，导致锯割困难，锯出的材面不平，甚至无法进行锯割。为了克服这种现象，首先要对适… 相似文献
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花军 《林业机械与木工设备》1993,(4):69-72
引言用于制材厂和木制品厂的大多数圆锯片都是通过张紧和整平来改善其切削性能的.张紧能给予锯片有利的平面应力,以改善锯片平面的几何偏差,且可减少其跑偏现象.不合适的张紧或整平会使锯片在工作过程中产生震动,增加锯路宽度,降低木材的尺寸精度,且能导致加工表面质量的恶化. 相似文献
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《Wood material science & engineering》2013,8(2):99-106
ABSTRACTLack of a monitoring system for guided circular saws marks one of the most critical machines in sawmills as a production bottleneck. Monitoring systems are being researched and developed for machine tools, especially for the metal cutting industry; but there are limited studies on the development of monitoring systems for circular saws in wood manufacturing process. In this study, sensors with the possibility to indicate sawing deviation were chosen that could be mounted in or on the saw guides. The sensors were: a microphone, an accelerometer, temperature sensor, an acoustic emission (AE) sensor, and a newly developed displacement sensor. A load cell was used to measure the lateral force on the guides. The outputs from these sensors were compared to the standard deviation of the board surface measured at the top of the cut. The signals from the displacement sensor, microphone, accelerometer, guide force sensor, and AE senor had no correlation to changes in the sawing deviation as measured by the standard deviation at the top of the board. Under laboratory conditions, the sound level and the AE signal did indicate the beginning and end of the cut. It was found that blade temperature is a good indicator of saw cutting performance. A newly developed temperature sensor can provide accurate temperature of the saw during cutting. The sensor can be used for measuring the rate of heating to cooling over time which can be used as a monitoring system to detect if there is any issue in the system. 相似文献
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"啸声"是木工硬质合金圆锯片空转的主要噪声源,是一种自激振动噪声.本文主要研究径向槽对硬质合金圆锯片噪声的影响.研究结果表明,采用金属铜填塞径向槽底部圆孔技术,可以消除硬质合金圆锯片在整个测试转速范围的"啸声".而其他两种普通径向槽的圆锯片只能在较高转速下消除"啸声".此外,径向槽底部塞有金属铜圆锯片的空气动力性噪声比未塞有金属铜的圆锯片略低2～3 dB(A). 相似文献
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加热适张度是利用氧一乙炔焰,将锯身的一定部位加热,使该部在冷却收缩中产生同辊压张力一样的变形,从而获得适张度。圆锯片气焊加热适张度机配有带锯夹锯装置,可用于圆、带锯的加热适张度及辊压处理,实现了一机多用。经该机修整的锯片,具有作业时间短、适张度均匀且不易消失,锯末端加热部分不易变形,厚度均匀,锯切质量高等优点。 相似文献
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ABSTRACTThis paper investigates the effect of rotation speed and vibration response of a circular saw on the sawing process of Douglas-fir wood. An idling test was conducted on a guided circular saw to determine its stable operation speeds and vibration behavior. Short-time Fourier transform analysis was performed on saw idling test data, and variation of excited frequencies of the blade as a function of rotation speed was obtained. The saw blade critical speeds and the rotation speeds that correspond to saw flutter instability were identified. Then experimental cutting tests were conducted at different cutting conditions and the effect of rotation speed and saw vibration response on cutting power consumption and sawing accuracy was investigated. The results showed that conducting a saw idling test and vibration response analysis can identify the saw critical and flutter speeds, which is essential for identifying the optimum rotation speed of circular saw. There was a significant increase in power consumption when cutting at super-critical and super-flutter speed. The effect of rotation speed on sawing accuracy is complex and nonlinear. This effect interacts with feed speed, which makes it difficult to generalize sawing accuracy versus rotation speed in the circular sawing process. 相似文献
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The sound pressure level of differently designed circular saw blades were investigated during idling. Nine blade samples were used: three differently designed blade bodies (without slots, with four radial slots, and with four slots with copper cork), each with three diameters (260,280, and 300 mm). The sound pressure level was measured at different rotational frequencies ranging from 25 to 65 rps in increments of 1 rps. Rubber damping rings 80mm in diameter and 0.3 mm thick were placed between the saw blade and the collars, and the emitted noise was measured. Because of the whistling sound the blades without slots emitted high sound pressure levels. There were no significant changes when rubber damping rings were used. The use of rubber damping rings on the samples with radial slots eliminates the whistling noise. The saws with copper corks did not emit a whistling noise at all, and their aerodynamic noise was 2–3 dB (A) lower than the aerodynamic noise of the saws with radial slots. The relation between sound pressure emitted by the damped idling saw and peripheral velocity can be described by the power function with the exponent value between 4.8 and 5.2.Part of this report was presented at the 14th International Wood Machining Seminar, Epinal, France, September 1999 相似文献
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The natural frequencies, aerodynamic noise, whistling noise, and self-excited vibration between the common circular saw with uniform thickness and the circular saw with step thickness (thin on its outer part and thick on its inner part) were researched during idling. The natural frequencies of the circular saw with step thickness increased with an increase in the thickness and in the radius of the thick part. The frequencies of the circular saws with step thickness (thick at the inner part) were higher than that of the thin circular saw with a uniform thickness of 0.5mm. The aerodynamic sound pressure level induced from circular saw teeth increased with an increase in the tooth thickness. The whistling noise and self-excited vibration easily occurred in the thick circular saws (1.5, 2.0, and 2.5mm). The whistling sound pressure level and the vibration amplitude increased with an increase in the thickness of the saw. None of the designed circular saws with step thickness generated whistling noises or self-excited vibration during idling.Part of this report was presented at the 45th annual meeting of the Japan Wood Research Society at Tokyo, April 1995 and the 12th International Wood Machining Seminar at Kyoto, October 1995 相似文献
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In this paper, a 2-D and 3-D finite element model of roll tensioning process of circular saw blade were established by Static/General module of ABAQUS software based on finite element method. The rolling force and tensioning stress distribution of circular saw blade were calculated by these two models which were proved to be true and reliable. The effects of yield strength of circular saw blade on tensioning stress distribution and rolling force were studied. The research achievements showed that a circular saw blade made with high yield strength obtained a higher tangential compressive stress and radial compressive stress in the rolled region during roll tensioning process, which has both advantages and disadvantages for the stability of the saw blade. Besides, a circular saw blade made with high yield strength also put forward higher requirements for roll tensioning equipment because of the large rolling force during roll tensioning process. 相似文献