家蚕种茧切削智能夹具设计与试验

为了提高家蚕种茧切削机械的自动化和智能化水平,适应不同品种的家蚕种茧制种切削需要,该文设计研究了一种家蚕种茧切削智能夹具。该夹具具有自动调整种茧位置状态并固定种茧的功能,能够迅速、准确地将以任意方式进入夹具内的不同形状和大小的种茧,自动调整为理想切削状态并固定,使高速转动的切削刀具沿夹具顶面水平切割种茧时不会伤到蚕蛹,且削口平整、便于实现蚕蛹与茧壳的自动分离。通过对10个不同种茧品种的切削试验表明:该智能夹具自动定位与固定功能的成功率达到98%以上,刀盘切削成功率大于97%,切削伤蛹率小于2%;不同形状和大小的单粒种茧以任意方式进入夹具内,到该智能夹具将其调整固定到位并切削完成所需时间为6~8 s,对各品种的家蚕种茧具有普遍适用性。

Design and experiment of intelligent fixture for cutting breeding cocoons of bombyx mori

Abstract: In China, silkworm raisers have to hire workers to cut breeding cocoons of bombyx mori manually, as domestic cocoon-cutting machines have been technically immature until now. The reported cutting machines and devices for breeding cocoons of bombyx mori cannot be used practically because the cutting mechanism is unable to locate the cocoons accurately for the clamping mechanism and is incapable of adjusting the posture of the cocoons and the clamping force of the fixture. As traditional fixtures are not applicable to clamp cocoons with different sizes and shapes in cutting, we designed an intelligent fixture. It works as follows: when a cocoon is dropped into the intelligent fixture in any posture, it will be immediately accurately detected by the detecting mechanism. Then, the actuator is dictated to adjust the posture of the cocoon, and to regulate the clamping force of the fixture by the control system. As a result, the cocoon is adjusted to be upright and firmly fixed. When the fixed cocoon is cut along the top surface of the fixture by the cutting device, the cut is flat and moderate, so the silkworm chrysalis can easily be separated from the cocoons without being hurt. Ten kinds of hybrid cocoons were randomly selected to be experimental samples, each five kilograms, such as Furong×Xianghui, Chunlei×Zhenzhu, 871×872 etc. 400 cocoons of each variety were randomly sampled to be tested by the intelligent fixture one by one. In addition, the fixing results, the cutting results, and the whole time were recorded when each cocoon was tested. Experimental results showed that the intelligent fixture can be used for clamping different kinds of cocoons with different sizes and shapes. About 98% of the selected cocoons can be adjusted to an appropriate location and fixed firmly by the intelligent fixture. When the intelligent fixture worked with the cutting device, the success rate of cutting was greater than 97%, and the injury rate of pupa was lower than 2%. Besides, it took 6-8 seconds from the time a cocoon fell into the jig to be cut successfully. In conclusion, the intelligent fixture can be used for clamping different kinds of breeding cocoons of bombyx mori in a cutting machine.