Design of FA415 Roving Frame

Design of FA415 Roving Frame

Yuan Jingshan
(Wuxi Textile Machinery Factory) The article originates from a two-day blog- https://2days.org/3312.html

[Abstract] This paper gives a comprehensive description of the selection and design of AF415 roving frame and the improvement of the prototype, and introduces the production situation and product quality.
The main technical features of the development of modern cotton roving frames are:
Improve the working quality and reliability of the drafting system to improve the quality of roving. This system mostly adopts four roller or three roller double apron drafting, and is pressurized with high-quality spring cradle or pneumatic cradle. It has a reliable upper and lower roller cleaning system. The second is to increase the package capacity, high speed and high efficiency in order to increase the output of roving machine and reduce the number of workers in roughing and spinning processes. New types of roving frames all use suspended flyers. The upper rib carrying the flyer is fixed to separate the roving output from the front roller from the flyer and bobbin. Once the roving ends are broken, the fiber will not flow and cause yarn defects. The suspended flyer meets the requirements of high speed and large package of the roving machine, and creates conditions for automatic doffing and roving connection of the roving machine. The maximum mechanical speed of the Qingze 660 roving machine can reach 1800r/min. The textile mill introduced this machine in China has reached 1200r/min, and its package capacity points are 2 times and 1.85 times of the A464 roving machine. Thirdly, the degree of electromechanical integration is high: the new roving frames generally adopt slow start, infrared photoelectric auto stop, three fixed doffing, and three automatic cone wheel doffing, and realize simple semi-automatic doffing. Most new roving frames have the function of automatic display or monitoring of spinning process parameters. For the more advanced roving machine, the cone wheel, forming reversing mechanism, gearbox, etc. are eliminated, and the whole machine operation, drafting, winding and lifting movements are realized by microcomputer program control. The whole machine speed change and full automatic doffing are adopted. Compared with foreign new roving frames, the cotton spinning roving frames manufactured and widely used in China have a large gap in spinning quality, output, package and automation, which has become one of the weakest links in China's cotton ring spinning project. In order to make cotton spinning roving frames step into the international advanced ranks as soon as possible and achieve the goal of improving yarn quality and labor productivity, the Ministry of Textile Industry listed the development of new roving frames as one of the national key scientific and technological research projects during the "Seventh Five Year Plan" period, and carried out pre selection for bidding. Wuxi Textile Machinery Factory was one of the pre selected bid winners, undertaking the task of designing and manufacturing new suspension roving frames. After more than three years of efforts, FA415 roving frame has been born, and after nearly one and a half years of production test run, it has passed the ministerial production appraisal and bidding acceptance and achieved the expected results. The article originates from a two-day blog- https://2days.org/3312.html

1、 Analysis on Selection of FA4 Skillful Roving Frame

The development of new roving frame is based on the digestion, absorption and transplantation of foreign advanced technology. We believe that the digestion and transplantation of foreign advanced technology should take into account the technological advancement, but more importantly, it should be suitable for the national conditions. The following three points should be taken into consideration: first, the manufacturing technology and equipment should adapt to the advanced nature of the new machine, The second is that the manufacturing cost should be compatible with the economic affordability of users, and the third is that the operation, maintenance and accessories should be consistent with the specific domestic conditions. Since the 1980s, China's textile mills have introduced many new types of roving machines, among which Germany's Qingze 660 roving machine has advanced technology and exquisite manufacturing, and Japan's Toyota FL16 and Fenghe RMK-I II roving machines are of medium technical level, but the import price of the former is about twice that of the latter,
The manufacturing precision of its parts, oil pollution prevention technology, electrical accessories, etc., are difficult for most of China's machinery plants to reach economically. Forcibly tackling key problems is bound to take a long time, and the manufacturing cost is expensive and difficult to be accepted by users. Although Toyota F1L6 and Fenghe RMK I II belong to the middle level of technology, their manufacturing degree and difficulty in localization of accessories are more consistent with the national conditions, and the resulting manufacturing costs are more acceptable to domestic textile users, and they can have strong price competitiveness in the international market. Therefore, it is suggested in the bidding pre selection contract of the Ministry of Textile that F1L6 and RMK - Ⅱ should be the main reference prototypes for the design and development of new roving frames, which is a correct decision to combine advanced technology with national conditions. According to this suggestion, we have formulated the design specification of FA415 roving frame. The main technical characteristics and process parameters are listed in Table 1 compared with A454 roving frame. The article originates from a two-day blog- https://2days.org/3312.html

The article originates from a two-day blog- https://2days.org/3312.html

2、 Design of FA415 Roving Frame

We determine that the guiding ideology of the new roving frame design is digestion, transplantation and improvement.
（1） Key points of digestive transplantation
Digestion and transplantation is to digest the reasonable and advanced parts of the introduced technology and transplant them to the new roving frame. The main reference prototype is Japan Fenghe RMK-II roving frame:
1. Four roller double short apron traction device
This drafting device has three drafting areas, namely, back draft, main draft and finishing draft. The back draft provides the whisker structure and reasonable fiber amount of the best drafting conditions for the main draft, while the setting of the finishing draft area mainly has the following functions. First, the fiber is subject to a large tractive force in the main drafting area, and the fiber straightens well. However, when the fiber leaves the front jaw of the main drafting area, it will rebound sharply, disturbing the structure of the parallel arrangement of fibers in the whiskers. After 1.05 times of finishing and drafting, the fiber can still remain in the state when it leaves the front jaw, which is conducive to even twisting and improved evenness. For spinning chemical fibers, This function is more necessary. Secondly, four roller double short apron drafting places the cotton collector in the finishing and drafting area, and implements the principle of drawing without bunching and bunching without drafting. With less fiber diffusion, the cotton collector with smaller opening can be used, so that the cotton gathering function can be fully exerted without damaging the fiber movement, thus improving the evenness of roving sliver. In addition, due to the use of cotton collectors with small openings, the untwisted area of roving whiskers can be reduced when the front roller is output, which is conducive to preventing accidental elongation. In the four roller double short apron drafting device, the two rollers are driven by the front roller, and the second roller is removed to form a three roller double short apron drafting device. The spacing can be enlarged, and with appropriate upper and lower pins, medium and long fibers can be spun.
2. Fine adjustment device for roving tension
Because high-speed large package will increase the difference of roving tension and elongation, modern roving frames generally use efficient false twister and tension fine adjustment compensation device to reduce the change of roving tension as much as possible to reduce the difference of elongation in addition to increasing roving twist coefficient in process. The reference prototype adopts a differential template type tension fine adjustment compensation device. The "additional displacement method" is used to make the cone pulley belt outside the normal displacement, and then a positive or negative additional displacement is added by the template through the differential mechanism, so as to change the winding speed to minimize the change of roving tension. The structure of the device is shown in Figure 1. The belt fork that controls the position of the tapered pulley belt is fixed on the cross tooth bar. When the bobbin is wound with a layer of roving, the forming ratchet rotates through half a tooth to drive the cross tooth bar to make the tapered pulley belt have a normal displacement of a certain value x. At this time, the template fixed on the cross tooth bar makes the vertical tooth bar have a vertical displacement of △ h. The vertical tooth bar drives the 23 tooth gear through the horizontal axis to make the differential mechanism obtain variable speed input, Finally, an additional displacement △ x is generated for the cross tooth bar. The relationship between the two is as follows:
△x=51X2.5πXnc。= 0.598△h The article originates from a two-day blog- https://2days.org/3312.html

1 A cross tooth bar; 2 - against formwork; 3 - Vertical gear rod; 4 - Change gear; 5 - forming ratchet; 6 - vertical shaft; 7 - upper cone wheel; 8 - Lower cone wheel.
The template is connected by five steel plates with scales. When adjusting, the upward inclination △ x of the template is negative, the roving tension increases, and the downward inclination △ x of the template is positive, the roving tension decreases. Practice has proved that the differential template type tension fine adjustment compensation device is highly intuitive, easy to master, and effective.
3. The transmission route is designed reasonably
When the roving machine is stopped, if the output speed of the front roller is zero and the winding speed of the bobbin is still not zero, the roving will produce the closing details of the weak twist area. Generally, the anti detail device is set in the transmission line of the winding speed, and the front roller speed and the winding speed are adjusted to be zero synchronously when the car is closed, so as to achieve the purpose of anti detail. However, the anti detail device increases the complexity of the transmission mechanism, and the effect is poor when the adjustment is not correct. RMK-II roving frame does not use anti detail device. From the perspective of reasonable design of transmission route, the front roller and winding speed are synchronized to zero when the car is shut down. This not only simplifies the transmission mechanism, but also avoids the disadvantages caused by improper adjustment of anti detail device. In practice, the transmission route of the reference prototype is retained in the design of the new machine after multiple tests of irrelevant car details.
4. The automatic mechanism has complete and reliable functions
The reference prototype has the functions of reactance slow start, three fixed doffing (fixed length, orientation and positioning), three automatic cone wheel, roving shoulder fall prevention, roving sliver breakage infrared photoelectric automatic stop, etc. These functions have proved essential in practice, and created favorable conditions for simple semi-automatic doffing, improving labor productivity and reducing labor intensity, Therefore, all these functions are retained and further improved in the new machine design.
5. Active rotary belt cleaning device
The roving yarn defects directly affect the spinning quality and the end breakage rate. The reference prototype adopts double short apron drafting, the upper and lower rollers can adopt active rotary velvet belt, and the lower cleaning velvet belt is sucked into the cotton collecting box from the air port. This cleaning device can effectively prevent the occurrence of yarn defects at the drafting part, In the design of FA415 roving frame, the active rotary belt cleaning device is still used, but its shortcomings are improved.
（2） Improve focus
The reference prototype is the equipment introduced in the early 1980s, which only has the international technical level at the end of the 1970s, and has exposed some shortcomings in the long-term production practice. Therefore, it must be improved.
1. Standardization
In addition to the implementation of relevant national standards and professional standards for raw materials, standard parts and accessories, FA415 roving frame has implemented six national basic standards and professional standards of the Ministry of Textile in terms of technical software, and resolutely implemented the professional standards of the Equipment Department of the Ministry of Textile in terms of special parts of textile machinery, which can facilitate the supply of accessories for users. Such as roller, roller bearing, upper roller bearing, etc.
In order to maintain the normal winding of the roving machine, the speed of the front roller output sliver must always be slightly lower than the winding speed of the bobbin, and the difference between the two must be approximately constant. The diameter of the front roller of the reference prototype is φ 28.5mm, while the national standard FJ/JQ47-84 Drafting Roller of Cotton Roving Frame is printed 28mm. The adoption of this standard will inevitably affect the cone wheel curve. Figure 2 is the schematic diagram of the winding drive of the new roving machine. Through calculation and analysis, the cone wheel curve equation of the machine is obtained: The article originates from a two-day blog- https://2days.org/3312.html

The article originates from a two-day blog- https://2days.org/3312.html

  The article originates from a two-day blog- https://2days.org/3312.html

The article originates from a two-day blog- https://2days.org/3312.html

Figure 2
DF - front roller diameter;
Ne - output gear speed of differential device;
Dx - diameter of roving bobbin;
Y - working radius of upper cone wheel at x;
No - spindle speed;
C - sum of working radius of upper and lower cone wheels;
Nl - spindle speed of differential device;
IB - transmission ratio of differential device;
Nc - constant speed gear speed of differential device;
I1~i6 - transmission ratio.
Obviously, the above formula shows that the cone roller curve is related to the diameter of the front roller dF, but because the thickness of each layer of yarn during roving winding is related to many factors, the cone roller curve must be repeatedly and carefully corrected according to the measurement results of the actual elongation of roving. After the roller diameter is standardized, if we modify the cone wheel curve, it will inevitably increase the difficulty and time of tackling key problems. Therefore, we do not change the cone wheel curve in the design, but adopt the method of changing the transmission ratio after the standardization of the front roller diameter to make the right half of the curve equation the same as the calculation result of the original roller diameter. After a long period of production practice, it has been proved that the elongation of roving in the first doffing process is within the specified range, and the above design has achieved good results.
2. Localization
Digest and transplant the imported advanced technology. Under the condition of meeting the product performance, the manufacturing of parts and components and the supply of supporting parts should be based on domestic to reduce the equipment manufacturing cost and use cost. At present, the spinning quality of the textile machinery and equipment introduced in the early 1980s is declining to varying degrees, and the passive situation that the supply of accessories depends on imports often occurs. Therefore, localization must be a major goal in the design of new machines. At present, the main special parts and general parts of FA415 roving frame, such as flyer, cradle, motor, bearing, etc., are all matched domestically. For the key parts that are difficult to solve at the moment, imported parts are used to ensure the reliability of normal operation of the textile mill. For example, the cone pulley belt has been produced in China, but first, the rigidity of the base is poor, and the heating becomes soft after operation, affecting the three automatic functions of the cone pulley; Second, the service life is short, so on the one hand, the belt manufacturer is organized to continue to tackle key problems, on the other hand, some cone pulley belts are imported to increase the reliability of equipment operation. At present, the localization rate of FA415 roving machine parts has exceeded 99.9% in terms of parts types and 99.5% in terms of value ratio, which has achieved good results in reducing manufacturing costs and use costs.
3. Serialization and generalization
FA415 roving frames are designed in series to meet the needs of different users. Spindle spacing and number of roving frames involve floor area, matching of front and rear processes, and it is a key point to consider for the transformation of old factories: the number of spindles of old roving frames around the 1950s is generally 132-144 spindles, the package is small, but the spindle speed can also reach about 800 r/min. When the old factories transform and update the roving frames, it is necessary to consider that the output of the whole machine should be improved compared with the old ones, The number of spindles of the roving frame with φ 52x400mm package will be reduced by 10~15% compared with the old one, so the spindle speed must be increased by 30-40% compared with the old one. In this way, if the process level is the same, the output of the new machine is still higher than that of the old machine. In addition to the whole process transformation, the spring cradle is used to strengthen the fiber control ability and improve the roving quality, so the spinning drafting capacity can be improved and the number of roving units can be properly reduced. Therefore, FA415 roving frame has good adaptability to the construction of new factories and the transformation of old factories.
4. Mechatronics
Mechatronics is an important feature of modern textile machinery. The mechatronics degree of the reference prototype is relatively low. The FA415 roving frame adopts YH701 microcomputer process parameter monitoring and fixed length control device, which can complete signal collection, data processing, keyboard input, panel display and other operations. In addition to setting and controlling fixed length, the instrument can also display data such as spindle speed, front roller speed, draft multiple, twist, roving ration, output per spindle hour, cumulative length of spinning in one doffing, and cumulative production of methyl ethyl propyl butyl per shift. The degree of electromechanical integration has basically reached the level of the mid-1980s. The microcomputer display and control buttons are concentrated on the front panel of the car, with neat appearance and convenient operation and management.
5. Ingot wing
Flyer is the key part of roving frame. The reference prototype uses open upper spindle rod suspension type flyer, with the maximum mechanical speed of 1200r/min, which is the same as the bidding requirements of the new roving machine.
At present, most of the suspension roving frames provided by major textile machine manufacturers in the world use closed flyers, with stainless steel tubes embedded in the flyer arms as the roving channels. Compared with open flyers, closed flyers have the advantages of high speed adaptability, strong yarn defect resistance, good aerodynamic characteristics, convenient manufacturing, and low cost. Their maximum mechanical speed is more than 1400r/min, The closed type flyer has the disadvantage of more troublesome snagging, but generally, the broken end rate of suspension roving frame is significantly lower than that of the old machine, and the wiping cycle is also longer. Therefore, due to the little increase in the dwell time affected by the snagging operation, this disadvantage is not prominent after the operation habit is adapted. Therefore, we focus on the closed flyer, hoping to take a lead in developing a new type of roving frame with the world level in the 1990s. There is a section of roving exposed between the flyer spindle and the hollow arm used on the FA415 roving frame appraisal prototype, which increases the possibility of hanging flowers and fiber loss. The fully enclosed flyer hanging on the flyer spindle without flyer exposed has been developed, and its high-speed running performance has reached the level of the same type of flyer abroad. When the flyer spindles are 1400r/min, the single arm expansion is less than 8mm.
The flyer of FA415 roving frame uses steel pressing palm with yarn guide hook. Under the condition that the roving ration is the same as the package size and the roving elongation meets the requirements, the net weight of single spindle roving increases by 17% compared with the reference prototype. We believe that the large package includes two factors: increasing package size and winding density. The ultimate meaning of large package is to increase the yarn capacity. The closed upper spindle suspension type flyer used in FA415 roving frame has the advantages of good high-speed performance, less yarn defects, low power consumption and low price. In addition, it also has the characteristics of increasing yarn capacity when combined with the use of efficient false twister. It is an inevitable type of upper spindle rod suspended wing with spindle speed above 1400r/min.
6. Cleaning device
The production of high-quality roving must be guaranteed by a reliable cleaning system. The reference prototype cleaning system consists of the upper roller active rotary velvet belt, the lower roller active rotary velvet belt, the lower cleaning suction duct, the cotton collecting box, and the surface line blowing cleaning device. During the design of FA415 roving frame, the composition of the cleaning system of the reference prototype has been selected and improved. First, the line blowing cleaning device has been eliminated. This is a set of air flow cleaning device on the vehicle surface, which is driven by the spindle drive shaft and located in the front of the upper rib housing to form air blowing to the rear air intake. The wind force seen on the site is very small and has no cleaning effect, Therefore, if the new design is cancelled, the cost can be reduced by about 1000 yuan. The second is to enlarge the eccentricity of the cleaning transmission gear by 2mm, which increases the motion range of each motion of the rotary velvet belt and the cleaning reciprocating motion range, and improves the cleaning effect. The third is to increase the upper cleaning operation rod (patent number: 90212009 · 3), As the package height of FA415 roving machine increases and the upper spindle rod suspension type flyer is used, the height of the car surface is 315 mm higher than that of A454 roving machine. After the upper cleaning cover plate is opened, the operating female workers of general stature can not reach the cleaning cover plate when standing on the pedal, and often the brushed belt resets the cover plate. As time goes by, the length of the four velvet belts cleaned varies, resulting in the rotation failure of the velvet belt, which seriously affects the cleaning effect, There are a lot of yarn defects. In addition, the upper cleaning cover plate collides violently with the roller seat when it falls. Most of the cleaning cover plate supports of the reference prototype have been deformed and damaged, and there have been several industrial accidents of smashing the operator's fingers. In order to improve the operating performance of the upper cleaner, avoid the failure of the rotary velvet belt and safe operation, we have designed a set of simple operating links, which have achieved the expected effect in practice, It is welcomed by operators.
7. Appearance design
Although the shape of textile machinery is limited by the internal structure, it must be carefully designed in combination with the characteristics of the times. With reference to the disordered appearance of the prototype and the overlapping burden of the cover, the contour and rounded corners of the model FA415 roving machine are disordered. On the condition that the cover is safe and sealed, the model FA415 roving machine adopts a shape design with strong integrity and simple lines, which has a distinctive flavor of the times, giving people a sense of manufacturing accuracy and equipment reliability. Since the contour adopts right angle small arc design, the cover can be processed by using the ready-made standard die on the three-point bending machine, which saves the process preparation time and tooling costs.
The microcomputer process parameter display and control buttons are all concentrated on the control panel in front of the locomotive, which brings convenience to operation and management, and also appears harmonious and unified in appearance. The article originates from a two-day blog- https://2days.org/3312.html

3、 Production and Operation of FA415 Roving Frame

The FA415 roving frame has been included in the normal operation test in Wuxi No. 1 Cotton Spinning Workshop No. 3 since November 1988, with the spindle speed of 940r/min, and increased to 1000r/min since December. The test data has been accumulated. After nearly a year of trial production and operation, it was put into production after being assessed by experts in May 1990. In September, the Ministry of Textiles organized experts to conduct tender acceptance and won the final bid. Wuxi Yimian stated in the Trial Production and Operation Report that "all indicators of this machine are similar to those of imported equipment. After spindle by spindle test, it is included in normal production under normal conditions of broken ends. There are no sudden yarn defects in the yarn, and the maintenance workers and the on duty workers reflect well". Assessment Report of the Expert Group of the Ministry of Textiles Mentioned in "The process spindle speed of FA415 roving machine reaches 1000 r/min, and the roll diameter is 152 x 406 mm. It has been in production for 5 months. The production is normal, the machine appearance is beautiful, and the operation is convenient. Since it was put into production, there has been no electrical equipment failure or abnormal mechanical failure. It adopts the active rotary up and down cleaning device with fixed length, speed, and output of yarn breaking, broken bar infrared light automatic stop, tension fine adjustment, dropping three automatic, and downward suction And other data displays, reflecting mechatronics ". The existing problem is that the machine vibration is large. Although the roving forming has reached the level of the reference prototype, it still needs to be improved.
The spinning quality of FA415 roving frame is listed in Table 2-4 according to the on-site retest data of the assessment group of the Ministry of Textiles.
Variety: 13tex polyester/cotton raw cotton, average grade 1.66, average length 30.48mm, polyester 1.65dtex (1.5D), length 38mm.
Draft ratio: 8.38
Roving weight: 4.98g/10m
Ingot speed: 1001r/min
Table 2

Note: 30 samples for each of the two models

epilogue

A new type of cotton spinning equipment needs close cooperation and joint efforts in product design, manufacturing, installation, maintenance, operation and other aspects from its birth to its mature application in textile mills. It is wrong to think that product development will be completed once the prototype has been identified. Although the development level of modern science and technology is high and the supporting ability of industrial infrastructure is strong, the time for product development will be shortened, However, the improvement of textile quality requirements and the ever-changing variety development, as well as the improvement of the comprehensive technical and economic performance of the equipment, require the manufacturer to continuously improve and improve the textile machinery. We know that the FA415 roving machine still needs to be further improved, improved and enhanced in production practice, and will earnestly summarize and modestly study, Work hard to provide newer and better equipment for the textile industry.

Link: https://pan.baidu.com/s/1JmVd0Lw26UasBWKZU841Ww?pwd=qd7i Extract code: qd7i copies this content and opens Baidu online disk mobile app, which is more convenient to operate