Research On The Design Of Automatic Grabbing Device For Cocoons Without Ends In Supplier Of Correct End Cocoons

The automatic silk reeling machine uses the method of transporting cocoons by mobile mode and feeding end by fixed way to supply the correct end cocoons,that is,to meet the normal feeding of raw silk.The efficiency of the groping and picking ends machine can not reach 100%,so a certain number of cocoons without ends will be produced.The water flow identification device can not distinguish all cocoons without ends,and some cocoons without ends are mixed with correct end cocoons into the supplier of correct end cocoons.During the operation of the supplier of correct end cocoons,the internal vibration plate vibrates at a certain frequency,and the cocoons rub each other,resulting in a part of the correct end cocoons becoming cocoons without ends.Because the reeling workers manually grab the cocoons without ends in supplier of correct end cocoons,so that the removal work could not be completed in time,resulting in the cocoons without ends were added to the reeling tank,and the raw silk continued to drop fine.When the drop length exceeded the allowable length,the raw silk evenness score decreases.In order to solve the problem of manual grabbing of cocoons without ends in supplier of correct end cocoons,this paper developed a clamping type and a connecting rod type automatic grabbing devices for cocoons without ends in supplier of correct end cocoons,and carried out design analysis and experimental verification of the two devices.This paper mainly carries out the following work :(1)The production process of the automatic silk reeling machine is analyzed in detail.Through the analysis of the cocoon quantity used in the automatic silk reeling machine,the theoretical quantity expression of the supplier of correct end cocoons is derived,and the production line of the factory is counted,so as to obtain the actual quantity of the cocoons without ends.In this paper,the harm of cocoons without ends is analyzed.When the initial speed is 200 r/min,as long as there is one time to add the cocoons without ends into the reeling tank,it is possible to decrease the raw silk evenness.(2)Summarize the functional requirements of the automatic grabbing device,design a clamping automatic grabbing device,and select the electrical drive scheme after comparison.The motion characteristics of the slider-crank mechanism and the linear differential doubling mechanism of gear and rack contained in the transverse sliding rail mechanism are analyzed in detail.The optimal grabbing time node is calculated to be 1.4 s.Based on the calculation results,the grabbing action of the device is planned.After constructing the virtual prototype of the device,the motion simulation is carried out.The results show that the structure meets the design requirements.(3)Based on the clamping device,a connecting rod automatic grabbing device is proposed.The transmission scheme of the device is determined.The speed of the traverse stepping motor is 72.6 r/min,and the speed of the grabbing stepping motor is greater than or equal to 48 r/min.The expressions of displacement,velocity and acceleration of connecting rod are derived by complex vector method.According to the assembly geometric relationship,the theoretical maximum lifting height of the grabbing gripper is calculated to be 25.33 mm.The trajectory tracking of the marked points is carried out by simulation,and the maximum lifting height measured is consistent with the theoretical calculation.The results show that the structure meets the design requirements.(4)The prototype of the clamping device was built and the cocoons without ends grabbing experiment was carried out.The average number of grabbing was 1.55～3.55 after the closed claw was optimized into a sawtooth type.Each group of automatic silk reeling machine was equipped with four sets of devices to grab the total number of cocoons without ends greater than the original number of cocoons without ends;similarly,the prototype of the connecting rod device was built.When the speed of the stepping motor is 90 r/min,and the average number of grabbing is 2.45～5.37.Each group of automatic silk reeling machine installs two of the devices to grab the total number of cocoons without ends is greater than the original number of cocoons without ends.The results show that both devices meet the requirements of use.Through the design and analysis of the two schemes,the prototype was built for experimental measurement.The results show that the clamping scheme has more grabbing movements than the connecting rod scheme,but it can realize non-contact grabbing with the supplier of correct end cocoons,and the grabbing performance of connecting rod scheme is better.The research results provide new ideas for the treatment of cocoons without ends in supplier of correct end cocoons.