Draw Frame Roller
The roller drafting structure of the new high-speed comber has been changed from the traditional three-over-five-down to three-over-three-down curve drafting. The drafting roller is made of imported steel. After high-precision processing, the precision of the roller is greatly improved, thereby reducing the mechanical wave of the sliver in the drafting zone; the correct selection of a reasonable drafting ratio can improve the quality of the combed sliver.
Because the combing machine roller is a key part of cotton, its accuracy level has a great influence on the whole machine; therefore, the tooth profile processing of the whole roller of the combing machine is the key process. We use the cold extrusion method to design a new type of comber roller, which has more advantages than the original grinding tooth profile.
Tooth profile machining mainly consists of equipment and tools. The quality of processing equipment is related to the consistency and stability of the comber roller. Domestic equipment can meet the processing requirements, and the cutting tools are designed by each roller manufacturer. The design and processing level of the cutting tools directly affect the tooth profile state of the product. The tooth profile is first calculated theoretically by cold extrusion method, and the relevant design parameters are further derived to guide production.
The cutter tooth pitch is derived from the roller tooth pitch, see the following formula:
3.141 59XD(product diameter)=product teeth X pitch/cos helix angle
3.141 59X 35=70 X roller pitch/cos10°
Theoretically, roller pitch=1.545 5 mm
Theoretically, the roller pitch is the tool pitch, but there will be a slip coefficient between the actual tool pitch and the roller pitch, and the tool pitch is also
cannot achieve the accuracy of 0.0005 mm; set the tool pitch to 1.54mm or 1.55mm, based on the assumption that the model derives whether the above two pitches are appropriate.
Using the assumption that the tool pitch is 1. 54 mm, calculate the theoretical blank diameter before hobbing.
(1. 54/cos10)X70/3. 141 592 6=34. 834/slip coefficient=34.48 mm.
Here, the slip coefficient is 1.0105, and the theoretical billet diameter is 34.48 mm.
Then deduce whether the tooth profile extrusion area is reasonable:
The roller tooth depth is required to be 0.40mm, and the tooth depth is tentatively set to 0.60mm after the gear is rolled.