Development ofbandsaw to control washboard during sawing

当齿的通过频率略高于带锯的固有频率时，出现了搓板状的粗糙锯面。这是因为当齿通过频率略高于带锯固有频率时，锯切时锯切阻力横向分量的方向与带锯瞬时打算振动的方向一致。在最后的研究中，为了干扰锯切阻力横向分量的方向或大小，对市售带锯进行了改造。一个市场上销售的具有均匀螺距齿的带锯的齿被随机磨掉。然后，一个间距被打乱，一个市场上销售的具有均匀间距的带锯的一侧被定期或随机地磨掉。与市场上销售的具有均匀螺距的带锯相比，改造后的带锯显著地控制了粗糙的锯面，如搓板。然而，所有改变的节距都是整的，比均匀节距的19mm节距多10倍。因此，它似乎不能完美地控制粗糙的锯表面，如搓板。然后，在这项研究中，我们制作了两个带有随机节距的锯齿牙的打字手锯，其中一个节距不是很长。这些类型-1的间距被确定为从15mm到24mm的10个级别，以1mm为步长，这些间距使用随机数表进行分配。2型间距以1mm为步长确定为17mm - 21mm的5个11级，并采用随机数表进行分配。1型带锯的结果如下。在扭转振动模态2或扭转振动模态3下，出现了搓板等凹凸不平的锯面。带锯轮的转速从150rpm到350rpm，带锯轮的转速范围从约lOrpm以下到约30rpm以上的速度，在此速度下，表观齿通过频率与带锯机的固有频率相等。在上述范围内，带锯轮的转速以2rpm为步长变化。2型带锯的实验结果如下：在所有的横向振动模式和所有的扭转振动模式下，都不会出现像搓板一样粗糙的锯面。最后，采用随机节距锯齿齿的2型带锯，完美地控制了搓板般凹凸不平的锯面。对振动控制的有效性进行了数值评价。当锯切过程中锯切阻力横向分量的方向与带锯在该时刻瞬时打算振动的方向一致时，将侧面的锯切深度记为加号。当锯切时锯切阻力横向分量的方向与带锯在瞬间打算振动的方向相反时，侧面的锯切深度记为负值。在锯齿振动的一个周期内，对切削深度进行积分。类型2的积分值为负值。少

The rugged sawn surface like washboard occurred, when the tooth passing frequencies were slightly higher than the natural frequencies of bandsaw. It was because when the tooth passing frequencies were slightly higher than natural frequencies of bandsaw, the direction of lateral component of the cutting resistance during sawing agreed with the direction which bandsaw instantaneously intended to vibrate in the moment. In the last study, the marketed bandsaw were remodeled in order to disturb the direction or the size of lateral component of cutting resistance during sawing. The tooth of one marketed bandsaw with uniform pitch teeth was randomly ground off. Then, a pitch was disarranged One side of set of one marketed bandsaw with uniform pitch swage set teeth was regularly or randomly ground off. The remodeled bandsaw remarkably controlled the rugged sawn surface like the washboard in comparison with marketed bandsaw with uniform pitch swage set teeth. However, all changed pitch is integ … More er multiples of the 19mm pitch of the uniform pitch swage set teeth. Therefore, it seemed to be able to not perfectly control the rugged sawn surface like washboard.Then, in this study, we made two typed handsaws with swage set teeth of random pitch in which a pitch was not very long. These pitches of type-1 were decided to be the 10 levels from 15mm to 24mm in step of 1mm, and these pitches were assigned using table of random numbers. These pitches of type-2 were decided to be the 5 1evels from 17mm to 21mm in step of 1mm, and these pitches were assigned using table of random numbers.The results of type- 1 bandsaw are follows. The rugged sawn surface like washboard occurred under the torsional vibration mode 2 or the torsional vibration mode 3.The revolution speed of the bandsaw wheel is from 150rpm to 350rpm and the revolution speed range of the bandsaw wheel is from about lOrpm below to about 30 rpm above the speed at which the apparent tooth passing frequency becomes equal to the natural frequency of the bandsaw. In the above-mentioned range, the revolution speeds of the bandsaw wheel were varied in steps of 2rpm.The results of type-2 bandsaw are follows. The rugged sawn surface like washboard did not occur under all transverse vibration modes and all torsional vibration modes.At last, type-2 bandsaw with swage set teeth of random pitch perfectly controlled the rugged sawn surface like washboard.We tried the numerical evaluation about the effective of vibration control.When the direction of lateral component of the cutting resistance during sawing agrees with the direction which bandsaw instantaneously intended to vibrate in the moment, the depth of cut on the side is denned as plus value. And when the direction of lateral component of the cutting resistance during sawing inverses to the direction which bandsaw instantaneously intended to vibrate in the moment, the depth of cut on the side is denned as minus value. The depth of cut was integrated during one period of sawteeth vibration. The integration value of type-2 was minus value. Less