A control method for improving the yield rate of automobile sheet produced by a rewinding unit

Abstract

The present invention belongs to the technical field of rewinding unit production, and specifically relates to a control method for improving the yield rate of automobile plates produced by rewinding units, which avoids saddle marks by lowering the unwinding coil and laying a PE plate on the unwinding saddle, widens the middle distance of the saddle of the upper coil trolley to eliminate strapping marks, uses adhesive tape instead of the inner ring iron clip to fix the inner core of the steel coil to eliminate the inner ring clip mark, and makes an oil collection box on the on-site steering roller to eliminate oil stains that repeatedly drip onto the steel coil. In summary, the above four measures realize the control of improving the yield rate of automobile plates produced by rewinding units, control unnecessary process cutting losses of automobile plates, and improve the comprehensive yield rate of automobile plates. The control logic of this method is clear and easy to implement, and it has strong applicability. It can be promoted and applied to rewinding units of other enterprises, etc. At present, this control method has been implemented in the rewinding unit of the cold rolling mill of Shandong Steel Rizhao Co., Ltd., and the yield rate has dropped from 6.28% to 1.15%. After the implementation of the method, the yield rate has been significantly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of re-coiling unit production, and in particular relates to a control method for improving the yield rate of automobile plates produced by a re-coiling unit. Background Art

[0002] The surface quality requirements for automotive steel sheets are higher than those for ordinary strip steel, and they require offline grinding and inspection for soft embossing. However, due to internal and external factors such as lifting, transportation, and on-line production, the sheets entering the rewinding production line for inspection can easily suffer scratches and soft embossing, resulting in cut damage, which greatly reduces the yield rate of automotive steel sheets. Currently, the following four major influencing factors have been found in the rewinding process control, equipment precision control, production process stability control, and internal and external factor control:

[0003] 1. Because the unloaded coils from the previous process are handled by the intelligent logistics system, the saddles on the trolleys of the intelligent logistics system are made of relatively hard nylon. When receiving automotive steel coils, the trolleys lift the coils and easily produce soft impressions on the bottom. Conventional unwinding saddles are made of polyurethane and are less prone to soft impressions. Furthermore, sometimes the coils are misaligned during delivery, triggering the intelligent logistics saddle's centering device. This causes multiple unwinds, rubbing the outer ring of the coil, further damaging the bottom of the coil and creating soft impressions on the outer ring, resulting in approximately 25-30 meters of reeling.

[0004] 2. The space between the steel coil buffer saddle and the upper coil trolley of the rewinding unit is too small. When the car plate needs to be tied with two straps or the bundle is tilted and rolled onto the steel coil buffer saddle, or when the upper coil trolley is rolling up, the steel coil is pressed against the strap and causes strap marks, resulting in the cutting of about 15-27 meters.

[0005] 3. The inner ring of the incoming material is relatively loose, which affects the automatic winding. Thin materials are prone to core pulling after winding. The rewinding personnel need to fix the inner ring with a steel clip for automatic winding operation to prevent core pulling. The clip mark at the tail of the tape needs to be cut off about 14 meters.

[0006] 4. During the initial production process of automobile sheets, the roller surface was stained with oil and scraped off by the scraper. The oil accumulated too much and dripped back onto the strip surface, affecting the surface quality and causing a cutting loss of about 8 meters.

[0007] In summary, the four types of defects in on-site production, namely strap marks, saddle marks, oil spots, and inner ring clip marks, are the main reasons for increasing the cutting loss of automotive plates and reducing the yield rate. The defect cutting loss caused by these four types of problems affects the overall yield rate of automotive plates by 6.28%. Summary of the Invention

[0008] The purpose of the present invention is to provide a control method for reducing coil process loss, forming an optimal control production process for automobile plates, and forming a standardized production re-coiling unit to produce automobile plates and improve the yield rate.

[0009] The technical solution adopted by the present invention to solve the technical problem is: a control method for improving the yield rate of automobile plates produced by a rewinding unit, comprising the following steps:

[0010] 1) Directly unload the coils from the production line without going through the logistics channel. Set up a special storage area for automotive plates in the buffer area and clean it regularly. Lay black rubber pads or soft PE sheets on the buffer saddles in the buffer area. Arrange the storage location of the steel coils in advance before the previous process is offline to reduce the number of lifting times.

[0011] 2) Measure the offset distance of the widest strap. The width between the coil loading trolley and the coil loading buffer saddle was widened from 10cm to 40cm.

[0012] 3) To prevent the steel coil core from being pushed up by the coiling and uncoiling machine, fix the inner ring with 3M tape;

[0013] 4) All scrapers on the entire line are manufactured with oil collection boxes. The shift handover regulations require checking the use of scrapers and requiring regular inspection and replacement of scrapers.

[0014] The present invention has the following beneficial effects: according to the characteristics of the production conditions of automobile plates entering the re-coiling unit, the present invention adjusts the transportation of steel coils in the previous process and the process control of the re-coiling unit itself to achieve the purpose of improving the yield rate of automobile plates and re-optimizing the production process of automobile plates. It fully consults and coordinates with the previous process, standardizes the operation process specifications for automobile plate production, and cuts out the four types of defects in the on-site process production that have the greatest impact on the yield rate, namely, strapping marks, saddle marks, oil spots, and inner circle clip marks, and improves them one by one. It relies on lowering the coil and laying PE boards on the coil-dropping saddle to avoid saddle marks, widening the middle distance of the saddle of the coil-up trolley to eliminate strapping marks, using tape instead of the inner circle iron clip to fix the inner core of the steel coil to eliminate the inner circle clip mark, and making an oil receiving box with the on-site steering roller to eliminate oil stains that repeatedly drip onto the steel coil. In summary, the above four measures have achieved the control of improving the yield rate of automobile plates produced by the recoiling unit, controlled the unnecessary process cutting loss of automobile plates, and improved the comprehensive yield rate of automobile plates. The control logic of this method is clear and easy to implement, with strong applicability. It can be promoted and applied to the recoiling units of other enterprises. At present, this control method has been implemented in the recoiling unit of the cold rolling mill of Shandong Steel Rizhao Co., Ltd., and the yield rate has been reduced from 6.28% to 1.15%. After the implementation of the method, the yield rate has been significantly improved. DETAILED DESCRIPTION

[0015] The following are specific embodiments of the present invention to further describe the technical solution of the present invention, but the scope of protection of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the scope of protection of the present invention.

[0016] A control method for improving the yield rate of automobile sheet produced by a rewinding unit, comprising the following steps:

[0017] 1) The coils are dropped directly off the line without going through the logistics channel. A special storage area for automotive plates is set up in the buffer area and cleaned regularly. Black rubber pads or soft PE boards are laid on the buffer saddles in the buffer area. The storage location of the steel coils is arranged in advance before the previous process is offline to reduce the number of lifting times. The yield rate is reduced to 3.58%.

[0018] 2) By measuring the offset distance of the widest strap, the width between the coil loading trolley and the coil loading buffer saddle was widened from 10 cm to 40 cm. After the above measures were implemented, the yield rate was reduced to 1.78%.

[0019] 3) To prevent the steel coil core from being pushed up by the unwinder, the use of clips for fixation was abandoned and the inner ring was fixed with 3M tape. This avoided the formation of clip marks and did not affect normal coiling. After the above measures were implemented, the yield rate was reduced to 1.32%.

[0020] 4) All scrapers on the production line are equipped with oil collecting boxes, and the use of scrapers is checked during the shift handover. Regular inspection and replacement of scrapers are required during the shift handover. After the above measures are implemented, the yield rate is reduced to 1.15%.

[0021] During the production of automotive steel sheets, process optimization was initiated, resulting in standardized operating procedures. Before starting production, the roller system was cleaned, the shear blades of the circular shears were inspected, and the scrapers throughout the line were checked. Any scrapers with curled blades were promptly replaced to prevent rubbing marks. The oil collection box was also checked for damage and the oil drums on one side were checked for fullness and cleaned promptly. The inlet and outlet saddles were inspected and wiped to prevent foreign matter from damaging the strip.

[0022] When the previous process is notified that the automotive sheet will be unloaded, PE sheets or black rubber pads are laid in advance in the special buffer area for automotive sheet steel coils. The unloading coils are directly unloaded from the previous process to the ordinary unloading saddles with PE sheets or black rubber pads laid. During production, inner corner guards are added for lifting and production on the line. The steel coil straps are placed in the widened saddle seam of the saddle to prevent saddle marks. The inner ring is fixed with 3M tape to prevent the steel coil core from collapsing and loosening. The pre-welding guide plate is replaced with a pulley block smooth strip to prevent the strip from being scratched on the lower surface when the strip head runs to the welding machine. It is uniformly stipulated that grinding begins 10 meters away from the weld and is performed for one to two cycles (each cycle is about 4.2 meters). When producing automotive sheets, the speed is set to within 120mpm, and a detailed inspection is carried out. The steel coil is unloaded after it is coiled.

[0023] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the guidance of the present invention, and any technical solutions that are the same or similar to those of the present invention, fall within the scope of protection of the present invention.

[0024] The technology, shape, and structure not described in detail in the present invention are all well-known technologies.

Claims

1. A control method for improving the yield rate of automobile steel sheets produced by a rewinding unit, characterized in that: The following steps are involved: 1) Directly unload the coils from the production line without going through the logistics channel. Set up a special storage area for automotive plates in the buffer area and clean it regularly. Lay black rubber pads or soft PE sheets on the buffer saddles in the buffer area. Arrange the storage location of the steel coils in advance before the previous process is offline to reduce the number of lifting times. 2) Measure the offset distance of the widest strap. The width between the coil loading trolley and the coil loading buffer saddle was widened from 10cm to 40cm. 3) To prevent the steel coil core from being pushed up by the coiling and uncoiling machine, fix the inner ring with 3M tape; 4) All scrapers on the entire line are manufactured with oil collection boxes. The shift handover regulations require checking the use of scrapers and requiring regular inspection and replacement of scrapers.