Pipe clamping prevention method for coil pipe unwinding

Abstract

The invention provides a method for preventing pipe clamping during coil pipe unwinding, which is used for preventing pipe clamping during unwinding of densely-arranged and wound copper coil pipes or aluminum coil pipes, and comprises the following steps: before unwinding, placing the copper coil pipes or the aluminum coil pipes on a soft fluid pad, and filling the soft fluid pad with gas or liquid wholly or locally, the lower end face of the copper coil pipe or the aluminum coil pipe makes contact with the soft fluid pad, the portion, making contact with a pipe under the action of internal drawing force, of the soft fluid pad deforms during internal drawing unwinding, the pipe is drawn out under the condition that the pipe is not damaged, and pipe-clamping-free unwinding is achieved. According to the coil pipe unwinding pipe clamping prevention method, the soft fluid pad is adopted to support the lower end face of the coil pipe, and the fluid on the soft fluid pad is easy to deform, so that the shape and the thickness of the fluid pad are changed when the coil pipe is drawn and unwound, the clamping force of the fluid pad on the pipe at the bottom layer of the coil pipe is reduced or eliminated, and the pipe can be easily pulled out; the problem of pipe clamping is avoided, and the purpose of the invention is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of copper tube and aluminum tube processing and application, and more specifically, to a coil unwinding and anti-stuck tube method. Background Art

[0002] The refrigeration and air conditioning industry generally uses copper or aluminum tubes as heat transfer tubes to manufacture heat exchangers. Professional copper or aluminum tube factories use casting, extrusion, rolling, drawing and heat treatment processes to manufacture copper or aluminum tubes, and finally make copper or aluminum tubes into copper coils or aluminum coils in a close-packed winding (called LWC in the industry) and provide them to users. The close-packed coils are neat and tight, and can ensure long-distance transportation even in poor road conditions, with very little transportation loss.

[0003] At the beginning of this century, an internal drawing unwinding method began to be popularized in air conditioner mainframe factories. This unwinding method omits a dedicated unwinding machine, and the unwinding process is convenient and simple, and occupies a small area. Taking copper tubes as an example, the air conditioner factory only needs to place the whole stack of tightly wound LWC coils horizontally at the unwinding position of the air conditioner bending machine, and continuously draw the copper tube upward from the middle of the inner hole of the LWC coil to complete the feeding of the copper tube, that is, the unwinding. Figure 1 It is a schematic diagram of the internal pull-out unwinding in the prior art. Figure 1 The two coils 101, 102 are packed together in one pile. The bottom of each coil is padded with a corrugated paper pad 6. The arrow in the figure is the direction in which the pipe 104 drawn out from the inside runs.

[0004] While enjoying the convenience of unwinding, air conditioner manufacturers have also discovered some problems, namely the so-called unwinding tube jam problem. Figure 2-1 and Figure 2-2 As shown, Figure 2-1 and Figure 2-2 This is a partial enlarged view of the draw-out coil in the horizontally placed LWC coil in the prior art. Figure 2-1 It can be seen that the pipe is circle ① to circle The order is drawn out continuously. Figure 2-1 The first row of tubes in the middle vertical row are unwound in order from coil ① to coil ④ in the direction of the arrow. After coil ① is unwound, coil ② is unwound, and so on. During the entire unwinding process of the first vertical row, coils and coils, and coils and packaging materials do not interfere with each other, and the tubes will not be stuck. Figure 2-2 This is the state of the bottom circle ⑤ of the second vertical row after the first row is finished. It is very likely that the tube will get stuck at this position. When unwinding, the gravity of circle ⑥ and the tubes above circle ⑥ press on circle ⑤ at point a. This pressure is rigid and cannot be overcome. Circle ⑤ can only be pressed Figure 2-2 The pipe will be ejected from the side first and then from the top in the direction of the arrow. Figure 2-2It can also be seen that the corrugated paper pad 6 as a cushion contacts the circle ⑤ at point b, and the circle ⑤ and the tube above it press and compact the corrugated paper pad 6 at point b, and at the same time, the corrugated paper pad 6 also applies an upward supporting force to the circle ⑤ at point b. The upper and lower points a and b of the circle ⑤ are simultaneously subjected to force to clamp and hold the circle ⑤ tightly. When unwinding, we can only hope that the cushion corrugated paper pad 6 below can deform and thin under the condition of small internal suction force and no damage to the tube, so that the distance X between points a and b becomes larger, so that the bottom tube can leave the LWC coil under the condition of small clamping force or no clamping force, so as to achieve unwinding without stuck tubes. However, so far, neither the corrugated paper pad nor other cushion materials and structures selected in the past have such performance. The corrugated paper pad compacted by the weight of the LWC coil does not have enough plasticity, and requires a large internal suction force to produce sufficient deformation to overcome the clamping resistance of ring ⑤. When unwinding, excessive clamping resistance will cause the tube to flatten, twist or bend, etc., that is, the above-mentioned tube jam phenomenon will occur, causing the entire unit to shut down. Figure 2-2 Circles in the same position lock up Pipe jams may also occur. Air conditioning plants are very efficient production operations, and such pipe jams are absolutely not allowed to occur.

[0005] In the first few years when this type of internal unwinding was popularized, the phenomenon of tube jamming was not serious because the tube diameter was large and the tube wall was thick. However, in recent years, with the rising prices of raw materials, especially the high copper prices, the cost pressure has made the wall thickness of copper tubes thinner and thinner. For thin-walled copper tubes, this phenomenon of tube jamming is more serious. The production of aluminum tubes also has a similar phenomenon. Compared with copper, aluminum is soft and sticky. More importantly, in order to improve the corrosion resistance of aluminum tubes, the aluminum surface must be sprayed with zinc. Compared with aluminum tubes without zinc spraying, the outer surface of aluminum tubes after zinc spraying is rougher, and the friction of the outer surface of aluminum tubes is greatly increased. When aluminum tubes are unwinding internally, the phenomenon of tube jamming will be more serious. In severe cases, the densely wound tubes cannot be stably unwound due to this reason, resulting in inability to produce.

[0006] In order to solve the problem of LWC coil unwinding and tube jamming, engineers and technicians in this field have designed a variety of technical methods and done a lot of work. A brief introduction is as follows:

[0007] One method attempts to predict the location of the stuck pipe, and predicts the position where the lower end face of the coil after winding will be pressed and contacted with the packaging liner through the principle of winding. It is envisaged that the liner will be thinned at this position so that the lower end face of the coil will not contact the liner at the stuck pipe position, thereby solving the stuck pipe problem. Japanese patents JP2006290619, JP2013237457, and Chinese patents CN102030224 and CN204713167 provide several specific technical solutions for this type of method, but none of these solutions have achieved satisfactory results. Because the diameter and ovality tolerances of the wound pipe will vary to a certain extent, the width of the winding reel of the winding machine will also vary to a certain extent, and the tightness between the pipes wound on the reel will also vary, these changes will cause a large deviation between the actual stuck pipe position and the theoretically predicted position, and this method has not achieved the desired effect.

[0008] Another method is to improve the winding method. The method of controlling the number of winding turns of odd-numbered layers to be one more than that of even-numbered layers during the LWC winding of the coil tubes attempts to solve the pipe jam problem. See Japanese patents JP2004292022 and JP2004142854. This method can only reduce the occurrence of pipe jams to a certain extent, but the user's requirement is to eliminate pipe jams. In addition, this winding method has high requirements on the accuracy of the winding machine and the technical level of the operating staff. For the difficult-to-wind soft zinc-sprayed aluminum tubes, the winding efficiency is very low and the scrap rate is very high.

[0009] In addition, Japanese patents JP2007145538 and JP2010222055 separate the bottom of the LWC coil from the gasket, and patent JP2010235234 applies silicone oil on the outer surface of the tube to reduce the friction on the tube surface. There are many similar patent solutions, the main purpose of which is to reduce or eliminate the clamping force between the lower end face of the coil and the gasket, so that the tube can be easily pulled out without deformation or less deformation. However, due to various reasons, the implementation effect of this type of patent is far from the inventor's idea, and the overall effect of this type of patent is a failure.

[0010] The cause of the tube sticking problem of close-packed wound LWC coils seems very simple but is extremely difficult to solve. Dozens of patents over the past 20 years have recorded the hard work of engineers and technicians in this field. Many of the world's top companies have worked on this, including Hitachi, Furukawa, Sumitomo, Kobe Steel, UACJ, etc. Although almost every patent claims to have solved this problem, the tube sticking problem still exists after a long period of verification. To this day, this problem still plagues the entire industry.

[0011] After the failure of the above technical solutions, in order to solve the problem of LWC unwinding and sticking, the engineers and technicians in this field have specially developed a new winding method, namely the so-called loose disc winding. Loose disc winding is like spreading a pancake, winding from the lower layer to the upper layer layer by layer, and unwinding from the top to the bottom layer by layer. Chinese patents CN107250014 and CN102470417 provide specific technical solutions for this method. This winding method completely solves the problem of sticking tubes in winding coils in principle, but on the one hand, it requires a large amount of expensive and complex special equipment, and needs to change the production process of copper and aluminum tubes. Another bigger problem is that loose disc winding is a loose winding. The layers and coils of the copper and aluminum coils after winding are not closely packed and in close contact. Long-distance transportation will cause friction and collision between the tubes, causing damage to the tubes. This phenomenon is more likely to occur in an environment with poor road conditions, and in severe cases, the entire pipe will be scrapped. The solution to one problem leads to the emergence of another more troublesome problem, which is the actual status of loose disc winding of copper and aluminum coils.

[0012] The present invention provides a method for preventing pipe jams during coil unwinding after carefully studying the above-mentioned specific problems and conducting a large number of experiments. The technical solution of the present invention can eliminate the pipe jam phenomenon during unwinding of closely packed coiled pipes under the premise of being very convenient and low-cost, thereby completely solving this long-standing technical problem. Summary of the invention

[0013] In order to solve the above technical problems, the present invention provides a method for preventing tube jamming during coil unwinding, which can solve the tube jamming problem during unwinding of densely wound copper coils or aluminum coils, and overcomes the defects of the prior art.

[0014] Specifically, the present invention provides a method for preventing tube jams during coil unwinding, which is used for preventing tube jams during unwinding of densely wound copper coils or aluminum coils. Before unwinding, the copper coil or aluminum coil is placed on a soft fluid cushion, which is filled with gas or liquid in whole or in part. The soft fluid cushion contacts the lower end surface of the copper coil or aluminum coil to bear the weight of the copper coil or aluminum coil. During internal drawing and unwinding, the soft fluid cushion is deformed at the contact point with the tube under the action of internal drawing force, so that the tube can be pulled out without being damaged, thereby realizing unwinding without tube jams.

[0015] By adopting the above-mentioned coil unwinding anti-stuck pipe method provided by the present invention, the soft fluid cushion as a cushion is pressed and compacted by the weight of the LWC coil. When the coil is unwinding, the bottom layer of the pipe is sandwiched between the upper layer of pipes and the soft fluid cushion as a cushion below, and the fluid cushion is filled with a fluid with good fluidity. Fluids do not have a fixed shape, and even in a compressed and compacted state, as long as a small force is applied, it can change in shape and size. The ability of the soft fluid cushion to be easily deformed under force enables the bottom layer of pipes to be easily pulled out without getting stuck. When the inner tube is unwound, the bottom tube is moved away from its original position by the extraction force. The squeezing force of the upper tube and the soft fluid cushion below on the bottom tube and the size between the upper tube and the soft fluid cushion form a clamping barrier to the pulling out of the tube. Since the soft fluid cushion can be easily deformed by only a small force, the thickness of the soft fluid cushion can be reduced with only a small extraction force, so that the size between the upper tube and the soft fluid cushion becomes larger. The increase in this size makes the clamping force acting on the bottom tube smaller or disappear, so that the bottom tube can be pulled out with little or no resistance, so that the tube will not be stuck when the coil is unwound. In addition, the pressure of the soft fluid cushion at the contact point with the bottom tube of the coil can be controlled, so that the bottom tube leaves the coil without support, so that the tube will not be stuck when the coil is unwound. While unwinding, the fluid filled in the soft fluid cushion also provides stable support for the copper coil or aluminum coil, bearing the weight of the copper coil or aluminum coil, and ensuring that the unwinding can be carried out stably.

[0016] Preferably, the soft fluid cushion is a bubble cushion.

[0017] Furthermore, the bubble cushion is a double-layer bubble cushion including a bubble layer and a flat film layer, the bubble layer is arranged on the flat film layer, and the bubble layer or the flat film layer is in contact with the lower end surface of the copper coil or the aluminum coil.

[0018] The original bubble cushion was invented in the 1960s. It is formed with cylindrical inflated bubbles arranged continuously on the plastic film. It has good shock absorption and impact resistance for the packaging of goods, and has good protection for the packaged goods. This type of bubble cushion is a product produced in large quantities industrially, with strict product specifications and standards. The simplest and most widely used bubble cushion is a double-layer bubble cushion, which consists of a layer of flat film and a layer of bubbles. There are also three-layer bubble cushions with a layer of bubbles sandwiched between two layers of flat film or five-layer bubble cushions with two layers of bubbles sandwiched between three layers of flat film. The diameter of the bubble is 6mm, 10mm and larger than 10mm. Among them, 6mm is called small bubble, 10mm is medium bubble, larger than 10mm is large bubble, and the standard large bubble is 25mm, 28mm, etc. The bubble cushion can also be compounded with pearl cotton, kraft paper, aluminum foil, chemical fiber and textile materials to make a composite bubble cushion. In order to enhance the carrying capacity of the bubble cushion, the thickness of the plastic film can be increased to make a reinforced bubble cushion. But this type of bubble cushion also has a problem. The gas is injected in advance when the bubble cushion is manufactured, and the transportation of the bubble cushion product will occupy a large volume. To solve this problem, new bubble cushions such as gourd-shaped bubbles and bubble columns have entered the market. This type of bubble cushion can be inflated before use by the user, solving the problem of transportation.

[0019] The core idea of ​​the present invention to solve the problem is to use a soft fluid cushion as the liner of the LWC coil. The soft fluid cushion has the performance of being able to withstand static pressure and being able to withstand dynamic force and being easily deformed. This type of cushion can easily produce sufficient deformation while bearing heavy loads, solving the problem of unwinding and jamming of densely packed LWC coils. If a bubble cushion is used as a soft fluid cushion, the weight of the coil is pressed on the bubble cushion during storage and transportation. Each bubble on the bubble cushion is like a tiny air bag that forms multi-point air pressure support for the coil, and all bubbles in contact with the lower end surface of the coil jointly bear the weight of the coil. Although the close contact with pressure between the bottom of the coil and the bubble cushion is intermittent and discontinuous, the bottom of the coil and the bubble cushion are only pressed and compacted at the position where there are bubbles, and there is no close contact between the two at the position where there are no bubbles. However, this support state will not affect the bearing effect at all. The applicant has conducted a long-distance transportation test, placing a 600kg coil on a single bubble cushion with a bubble diameter of Ф25mm and transporting it for 500km. The bubble cushion and LWC coil are intact after passing through different road conditions.

[0020] In addition to having good static pressure bearing capacity, the bubble cushion also has good dynamic force deformation performance. The bubbles are filled with gas, and heavy objects compress the bubbles when bearing. The gas pressure in the bubble increases and the volume decreases. However, even under high pressure, the gas in each bubble still maintains the basic properties of gas. It has no fixed volume and no fixed shape. Any force applied to the bubble by an object in contact with the bubble can easily change the shape and size of the bubble, including the thickness of the bubble. When the LWC coil is unwound to the bottom coil, the internal suction force causes the bottom pipe to move under force. The moving pipe only needs a small force to deform the stressed bubble, reduce the thickness of the bubble cushion, and make the bottom pipe break away from the upper pipe, so that the clamping force acting on this circle of pipes is reduced or eliminated, so that the pipe can be pulled out of the LWC coil without damage to achieve anti-stuck pipe unwinding.

[0021] The prior art generally uses corrugated paper pads or rubber plastics as pads under the LWC coils. These materials are also soft materials and have certain deformability. However, these materials are still solid materials. When loaded, the weight of the coils compresses and compacts them. These materials do not have the properties of the soft fluid pads selected by the present invention, which are easy to deform under pressure, and cannot prevent the tube from being stuck and unwinding.

[0022] Preferably, the bubble cushion is a single sheet or multiple sheets stacked together, and a single bubble cushion includes one bubble layer or multiple bubble layers. When the bubble cushion is a single sheet with one bubble layer, the diameter of the bubble is greater than 10 mm.

[0023] Furthermore, the bubbles of the bubble cushion are in the shape of a circle, an ellipse, a column, a gourd or a special shape.

[0024] In principle, all bubble cushion products have the same performance and can be used in the present invention. However, considering the specific operability, cost and other factors, it is necessary to use the preferred specifications. The test results show that a single Ф25mm large bubble cushion can be unwound without tube jamming. The anti-tube jamming effect of a single small bubble and medium bubble cushion is average. The bubble diameter of the small bubble and medium bubble cushion is too small, and the bubble thickness is also small. The thinning amount of the bubble in the thickness direction during internal extraction and unwinding is not enough, and the clamping resistance on the bottom tube cannot be reduced and eliminated. Two or more small and medium bubble cushions can increase the thinning amount of the bubble thickness exponentially, which can solve the tube jamming problem, but the cost is higher than that of a single large bubble cushion.

[0025] Both the bubble surface and the flat film surface of the bubble cushion can contact the lower end surface of the LWC coil to achieve unwinding without getting stuck. Special bubble cushions with suitable specifications, such as special-shaped bubbles, gourd bubbles, bubble columns, composite bubble cushions, etc., also belong to the bubble cushions described in the present invention, and can also achieve unwinding without getting stuck.

[0026] Preferably, the soft fluid cushion is an air-filled cushion or a water-filled cushion.

[0027] Furthermore, the inflatable air cushion or water-filled water cushion is provided with partitions, and the partitions corresponding to the bottom-layer pipe on the inflatable air cushion or water-filled water cushion are depressurized before the bottom-layer pipe is unwound, so that the bottom-layer pipe of the inner unwound roll can leave the copper coil or aluminum coil without lower support.

[0028] Preferably, the inflatable air cushion or the water-filled water cushion is provided with radial tension bars or circumferential vertical bars to divide the soft air cushion or the soft water cushion into radial partitions or circumferential partitions.

[0029] Inflatable air cushions and water-filled water cushions (for the convenience of description, we will collectively refer to them as inflatable (water) cushions) belong to the category of soft fluid cushions like bubble cushions. Their surface layer is made of soft rubber or plastic materials. Unlike bubble cushions, their inflatable (water) chambers are generally large or integral. But they can also have partitioned inflatable (water) chambers. Taking inflatable air cushions as an example, this type of air cushion is widely used in various industries such as tourism and outdoor, medical rehabilitation, sports and entertainment, such as air mattresses, hovercrafts, water-filled cushions, etc. There are many varieties of such products, which are closely related to people's daily lives.

[0030] Inflatable (water) cushions have all the properties and technical features of soft fluid cushions. A variety of liquids or gases can be filled into the fluid cushion. Considering the cost reasons, air is usually filled into the air cushion and water is usually filled into the liquid cushion. Both air and water are fluids. They can have a certain pressure and bear a certain load, but they do not have a fixed shape. Like bubble cushions, they have the characteristics of being able to bear static pressure and being easy to deform under dynamic force. They can easily produce sufficient deformation while bearing heavy loads. Once the inflatable (water) cushion is subjected to force at the force point, it will easily deform. In principle, using them as liners can completely prevent copper coils or aluminum coils from being stuck and unwinding, just like bubble cushions.

[0031] Compared with bubble cushions, the outer surface layer of air (water) cushions has better strength. Their air (water) filling amount and pressure are determined at the time of injection and can be adjusted and changed. Better quality surface materials can increase the service life of air (water) cushions. The increase in the overall thickness of the air (water) cushion can cause greater thickness thinning deformation during internal unwinding, making it easier to unwind without clamping tubes. The adjustable and changeable air (water) filling amount and pressure make the air (water) cushions have a more suitable bearing capacity and make unwinding more stable. However, the above advantages also increase their costs. The high cost makes them generally unsuitable for large-scale use as packaging materials, but this type of air (water) cushion can be used in the unwinding station of the air-conditioning main engine factory like bubble cushions. Lay them at the unwinding position of the factory and hang the LWC coil on them to complete the unwinding of the coil without clamping tubes.

[0032] Commercially available air (water) cushions can be used to unwind LWC coils to prevent them from getting stuck, but air (water) cushions specially designed to take into account the size and weight of LWC coils and the unwinding conditions when used by users will have better results. The outer diameter of a normal LWC coil is between Ф1000-1100mm, and the inner diameter is Ф600mm. It is more reasonable to design the air (water) cushion into concentric circular air (water) cushions of unequal heights. The outer diameter of the air (water) cushion should be larger than the outer diameter of the coil, so that the entire coil can be placed on the air (water) cushion in the outermost layer. The height of the part of the air (water) cushion that is smaller than the inner diameter of the LWC should be slightly lower than the height of the outer circular part, so that the middle part will not bulge out when filled with air (water) to affect the inner withdrawal and unwinding of the coil. The contact surface between the air (water) cushion and the lower end surface of the LWC coil can be flat, or it can be made into an uneven contact surface similar to bubbles like a bubble cushion. The uneven surface is filled with gas or water, which can achieve a good anti-stuck tube effect when unwinding.

[0033] A higher level of design is to design the inflatable (water) cushion into a partitioned soft fluid cushion, such as a partitioned soft air cushion or soft water cushion, and the pressure inside each partition can be adjusted. Before the inner draw and unwind to a certain circle of pipes at the bottom layer, the corresponding partition of the soft fluid cushion in contact with the circle of pipes will be depressurized, so that the circle of pipes at the bottom layer will be separated from the cushions below, so that the bottom layer of pipes can be drawn out of the LWC copper-aluminum coil without any clamping resistance.

[0034] Preferably, the soft fluid pad is a part of the copper coil or aluminum coil packaging, and the soft fluid pad is placed on the lower end surface of each copper coil or each aluminum coil during packaging.

[0035] Bubble pads are mass-produced products with excellent anti-stuck performance and are comparable in cost to corrugated paper pads. Such products are particularly suitable for use in large quantities as part of copper coil or aluminum coil packaging. When packaging, place suitable bubble pads as pads under each copper coil or aluminum coil. During storage and transportation, the bubble pads are always in contact with the lower end surface of the coil to bear its weight. The airbag performance of the bubbles can provide better shock absorption protection for the coil during transportation, and can also prevent the tube from being stuck when unwinding, achieving multiple goals at one stroke. Compared with bubble pads, inflatable (water) pads are slightly more expensive and are generally not used as part of the packaging, but can also be used as packaging pads when customers have special needs.

[0036] The bubble layer and flat film layer of the bubble pad are made of very thin plastic film, and its pressure resistance is limited after all. When the coil is hoisted onto the bubble pad, it should be placed slowly. A double-layer bubble pad with one bubble layer and one flat film layer cannot withstand the squeeze of objects protruding on both sides at the same time, and the bubbles are easily squeezed in this case. Therefore, when a single double-layer bubble pad is placed between the upper and lower coils, a layer of corrugated paper pad should be placed underneath. The corrugated paper pad can reduce the squeezing force of the lower coil on the bubble pad, so that the bubble pad can be used normally. The 3-layer bubble pad does not need the protection of corrugated paper, and the flat film layers on both sides of the bubble layer can provide good protection for the bubbles.

[0037] Furthermore, the packaging material includes a wooden pallet, a sandwich packaging tray, the soft fluid pad, a corrugated paper pad, an upper corrugated paper pad and a wrapping film, and the entire packaging from bottom to top is the wooden pallet, the sandwich packaging tray, the soft fluid pad, the first tray of the copper coil or aluminum coil, the corrugated paper pad, the soft fluid pad, the second tray of the copper coil or aluminum coil, the corrugated paper pad, the soft fluid pad, the third tray of the copper coil or aluminum coil, the upper corrugated paper pad and the sandwich packaging tray, and the wrapping film is wrapped around the outer surface.

[0038] The packaging of the copper coil or aluminum coil of the present invention includes a wooden pallet, a corrugated paper pad, a soft fluid pad, an upper corrugated paper pad, a sandwich packaging tray and a wrapping film. The packaged copper coil or aluminum coil is, from bottom to top, the wooden pallet, the sandwich packaging tray, the soft fluid pad, the first tray of the copper coil or aluminum coil; the corrugated paper pad, the soft fluid pad, the second tray of the copper coil or aluminum coil; the corrugated paper pad, the soft fluid pad, the third tray of the copper coil or aluminum coil, the upper corrugated paper pad and the sandwich packaging tray are arranged at the upper end of the copper coil or aluminum coil of the third tray, and the wrapping film is wrapped around the outer surface.

[0039] Theoretically, the number of coil packings can be determined as needed. The soft fluid pad and / or corrugated paper pad described in the present invention is placed between two adjacent coils for packaging. However, in actual production, due to weight and transportation requirements, more than two coils are usually packaged together. This embodiment provides a packaging structure of three coils in one stack. Such packaging is firm and convenient for safe transportation and shoveling. Users of air-conditioning factories also do not need to separately hoist the LWC coil onto the soft fluid pad when using it. Instead, they can directly perform the internal extraction and unwinding operations by removing the wrapping film, the upper corrugated paper pad and the sandwich panel packaging disc from the upper end.

[0040] In summary, the coil unwinding and anti-stuck pipe method provided by the present invention has at least the following advantages:

[0041] 1. Completely solve the problem of tube jamming when drawing and unwinding the coil

[0042] The problem of the copper or aluminum coil being stuck when unwinding has always been a headache for the industry and has not been solved for many years. A large amount of manpower and material resources have been spent but satisfactory results have not been achieved. The present invention introduces the material and structure of the soft fluid cushion for the liner of the LWC coil for the first time, and solves the problem that has not been solved in the art in principle by utilizing the characteristics of the fluid being able to bear dynamic force under static pressure and being easy to deform under dynamic force, and truly achieves the goal of not getting the pipe stuck when unwinding.

[0043] 2. No need to change the existing coil production process, technology and equipment

[0044] In order to solve the problem of pipe sticking, the existing technology changes from close-packed winding to loose coil winding. The change of winding process adds a lot of complex and expensive equipment and changes the process flow, but it brings a new problem that long-distance transportation will damage the coiled pipe. However, the present invention does not change the existing equipment and process of pipe production. It only needs to add a soft fluid cushion according to the present invention when unwinding or packaging to solve the problem. The technical solution is simple and fast.

[0045] 3. Low cost

[0046] The preferred bubble pad of the present invention is a standard mass-produced packaging product with stable product quality and low price. The packaging cost per ton of a single large bubble pad is similar to that of the existing corrugated paper pad, and the bubble pad can be reused, which can further reduce the cost.

[0047] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the internal pull-out unwinding of the LWC coil in the prior art.

[0049] Figure 2-1 It is a partially enlarged schematic diagram of the initial state of drawing and unwinding the coil in the horizontally placed LWC coil in the prior art.

[0050] Figure 2-2 It is a partially enlarged schematic diagram of the state in which the first vertical row of pipes in the horizontally placed LWC coil in the prior art is completely drawn out and unwound.

[0051] Figure 3-1 It is a schematic diagram of the partial structure of an embodiment of the bubble pad described in the present invention.

[0052] Figure 3-2 for Figure 3-1 Schematic top view of .

[0053] Figure 4-1 For LWC coils placed horizontally Figure 3-1 A partially enlarged schematic diagram of the bubble pad at the initial state of internal unwinding.

[0054] Figure 4-2 For LWC coils placed horizontally Figure 3-1 A partially enlarged schematic diagram of the state in which the first vertical row of tubes is drawn out and the bottom tube of the second vertical row is started to be placed on the bubble cushion.

[0055] Figure 5-1 to Figure 5-3 for Figure 4-2 The diagram shows the principle of not getting stuck when unwinding and drawing the tube and the process of bubble shape change of the bubble pad. Figure 5-1 This is a schematic diagram before the internal pumping begins. Figure 5-2 Schematic diagram of the bubble deforming downward under force. Figure 5-3 Schematic diagram of the tube easily leaving its original position.

[0056] Figure 6-1 , 6-2 Schematic diagram of the reasons why large bubble pads are better than small and medium bubble pads.

[0057] Figure 7-1 A schematic cross-sectional view of a circular inflatable (water) cushion according to an embodiment of the present invention, Figure 7-2 for Figure 7-1 Top view of the .

[0058] Figure 8 Schematic diagram of the LWC coil placed on an inflatable (water) cushion.

[0059] Figure 9-1 to Figure 9-3 It is a schematic diagram of the principle of not getting stuck when drawing and unrolling the air (water) cushion and the shape change process of the air (water) cushion. Figure 9-1 This is a schematic diagram before the internal pumping begins. Figure 9-2 This is a schematic diagram of the downward deformation of the inflatable (water) cushion surface under force. Figure 9-3 Schematic diagram of the tube easily leaving its original position.

[0060] Figure 10-1 Schematic diagram of the initial state of unwinding the LWC coil placed on an inflatable (water) cushion with radial partitions. Figure 10-2 Schematic diagram of a radially partitioned air (water) cushion being unrolled to the bottom tube of the 4th vertical row.

[0061] Fig.11 This is a schematic structural diagram of an embodiment of the bubble pad of the present invention as a part of the coil packaging.

[0062] in, Figures 1 to 11 The corresponding relationship between the reference numerals and the component names is as follows:

[0063] 2. Wooden pallet, 3. Upper corrugated paper pad, 4. Sandwich board packaging tray, 5. Stretch film, 6. Corrugated paper pad, 10. Copper coil or aluminum coil, 101. First coil of copper coil or aluminum coil, 102. Second coil of copper coil or aluminum coil, 103. Third coil of copper coil or aluminum coil, 104. Tubes drawn out from inside, 11. Bubble pad, 111. Bubble layer, 112. Flat film layer, 60. Inflatable (water) pad, 61. Surface of inflatable (water) pad, 62. Tension rod, 63. Vertical rod, 70. Unwinding station.

[0064] OO. Center line of coil, PP. Center line of air (water) cushion, BB. Center line where circles ⑤ and ⑥ coincide, FF. Center line of circle ⑤, EE. Center line of circle ⑥.

[0065] D. is the bubble diameter, H. is the bubble thickness, and d. is the diameter of the tube.

[0066] C. The depression in the middle of the air (water) cushion, H1. The thickness of the depression, H2. The thickness of the air (water) cushion, E. The radial partition pressure relief and the contact position where the bottom coil is disconnected.

[0067] U1-U8 are the area codes for the circumferential divisions of the inflatable (water) cushion.

[0068] W1-W7. Area codes for radial partition numbers of air (water) cushions.

[0069] a. The contact point where the upper tube presses down on the lower tube.

[0070] b. The upward support point of the gasket for the bottom pipe.

[0071] X. The height dimensions of points a and b before unwinding.

[0072] Y. The height dimensions of points a and b after the soft fluid cushion is deformed during internal reeling and unreeling.

[0073] T1. The gap between the bottom tube and the upper tube when the soft fluid cushion is deformed by internal suction.

[0074] T2. The length of the highest point of circle ⑤ is higher than the lowest point of circle ⑥.

[0075] The arrow in the figure indicates the direction of the internal suction force or the direction of movement of the tube.

[0076] ①, ②……, The number of turns of tube in a copper coil or aluminum coil.

[0077] L1, L2, ..., L11 are the numbers of the vertical rows of tubes in the copper coil or aluminum coil. DETAILED DESCRIPTION

[0078] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the specific implementation methods according to the present invention are described below in conjunction with the accompanying drawings. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0079] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0080] Some embodiments of the method for preventing tube jamming during coil unwinding of the present invention will be described below in conjunction with the accompanying drawings.

[0081] Figure 3-1 and Figure 3-2 The structural diagram of the double-layer bubble cushion is given, and the bubble cushion 11 is composed of a bubble layer 111 and a flat film layer 112, and the bubble layer 111 is arranged on the flat film layer 112. Among them, D is the diameter of the bubble, and H is the thickness of the bubble. The present invention provides a coil unwinding anti-stuck tube method, which is used for the anti-stuck tube when the closely packed copper coil or aluminum coil is unwound. Before unwinding, the bubble cushion 11 is placed on the copper coil or aluminum coil 10, and the bubble cushion 11 is provided with a large number of bubbles that are easily deformed by force, and the bubbles are filled with gas, such as Figure 4-1 , 4-2 As shown, the lower end surface of the copper coil or aluminum coil 10 is in contact with the bubble pad 11, and the bubble pad 11 serves as a cushion to support the weight of the coil. When unwinding, the bubble pad 11 and the tube under the action of the internal suction force produce sufficient deformation at the contact point, so that the tube can be pulled out without being damaged, thereby realizing unwinding without getting stuck.

[0082] The coil unwinding and anti-stuck pipe method provided by the present invention is adopted, as Figure 4-1 to Figure 5-3As shown, when the coil is unwound, the bottom tube is sandwiched between the upper tube and the bubble pad below. Because the bubbles can be easily deformed when subjected to force, and the thickness of the bubble pad can be easily changed, the bottom tube can be easily pulled out without deformation or jamming. When unwinding with internal extraction, the tube is pulled out of its original position by the extraction force. The upper tube and the bubble pad below squeeze and clamp the bottom tube, forming resistance to the extraction of the tube. Since the bubble can be easily deformed and easily changed in thickness with only a small force, that is, only a small extraction force can reduce the thickness H of the bubble, making the dimension Y larger. The increase in Y makes the clamping force acting on the bottom tube smaller or disappear, so that the bottom tube can be pulled out without damage under a small extraction force, so that the tube will not be jammed when the coil is unwound. At the same time, the bubbles can also bear the weight of the coil when stationary: one of the embodiments of the coil anti-stuck method of the present invention is to use the bubble pad as a cushion at the bottom of the coil, and each bubble on the bubble pad forms a multi-point air pressure support for the coil during storage and transportation of the coil. Each bubble on the bubble pad is like a small air bag that bears the weight of the coil together. The close contact with pressure between the bottom of the coil and the bubble pad is intermittent and discontinuous. The bottom of the coil and the bubble pad are only pressed and compacted at the position where there are bubbles, and there is no compression and compaction between the two at the position where there are no bubbles. Therefore, compared with the corrugated paper pads of the prior art, the bubble pad of the present invention has completely incomparable plastic variability in the thickness direction under pressure and load-bearing conditions. The material of the bubble pad is soft, and the gas in the bubble is a fluid with good fluidity. Such a bubble structure can change the shape and size of the bubble, especially the bubble thickness H, within a wide range as the weight of the object being carried changes. The thickness H of the bubble of a heavy object will become smaller, and the air pressure in the bubble will increase; the thickness H of the bubble of a light object will become larger, and the air pressure in the bubble will decrease. The combined action of many bubbles can carry a very heavy object, but each bubble can easily change its shape, size and thickness with only a small force. It is the ability of the bubbles on the bubble pad 11 to carry when statically compressed and to deform easily when dynamically stressed that enables them to easily produce sufficient deformation while bearing heavy loads, which in principle achieves the technical effect of the anti-stuck tube of the present invention, realizes the invention purpose of the present application, and overcomes the defects of the prior art.

[0083] Figure 4-1 and Figure 4-2 The figure shows the state where the bubbles of the bubble pad 11 are in contact with the lower end of the coil. Figure 4-1 This is a partial enlarged schematic diagram of the LWC coil placed horizontally on the bubble pad 11 at the initial state of internal unwinding and unwinding, which is the initial state of the coil in the internal unwinding and unwinding working position. The coil is placed on the bubble pad 11, and OO is the center line of the coil. When unwinding, the tube is discharged upward in the direction indicated by the arrow. Figure 4-2 For LWC coils placed horizontally Figure 3-1A partially enlarged schematic diagram of the state in which the first vertical row of tubes is drawn out and the bottom tube of the second vertical row is started to be placed on the bubble cushion. Figure 4-2 The middle circle ⑥ also presses down on circle ⑤ at point a. Circle ⑤ is under the pressure of the gravity of the pipe circles ⑥, ⑦, and ⑧ above. This force is rigid and cannot be crossed. It is impossible for circle ⑤ to exit the pipe upward. It can only exit the pipe sideways and then upwards in the direction of the arrow. Figure 2-2 Similarly, the bubble pad 11 also provides an upward support force to the circle ⑤ at point b, and the dimension between a and b is X when stationary. Since the bubbles are soft, the dimension X is generally smaller than the tube diameter d. However, since the upward support force on the bottom tube is generated by the bubble pad 11, which is very easy to deform under force, the force state and force magnitude change of the circle ⑤ are essentially different from those of the prior art. Figure 5-1 to Figure 5-3 It shows the process of the bubble shape changing when the bubble is affected by the internal suction force when loop ⑤ passes through a single bubble and exits the tube. Figure 5-1 The bubble in the middle supports circle ⑤ at point b, and circle ⑥ presses circle ⑤ down at point a. When stationary, points a and b clamp circle ⑤. When the internal suction force is applied to circle ⑤, the tube cannot move upward and can only move inward or downward in the direction of the arrow. Due to the characteristics of the bubble's fluid that is easily deformed by force, only a small force on the bubble is needed to deform the bubble, such as Figure 5-2 , 5-3 shown. Figure 5-2 The bubble in the middle is deformed downward by force, and the circle ⑤ is separated from the circle ⑥ downward by a distance of T1. When T1 is large enough, the dimension Y between points a and b is larger than the diameter d of the tube, which reduces or eliminates the clamping force on the original circle ⑤ tube. The circle ⑤ can easily leave the original position, such as Figure 5-3 shown.

[0084] The test shows that the flat film layer 112 can also be in contact with the lower end surface of the LWC coil. Figure 5-1 to Figure 5-3 The same effect as described above can also be achieved by unwinding without tube jamming. The test results also show that a single large bubble pad can achieve unwinding without tube jamming. The single small bubble and medium bubble pads are not effective in preventing tube jamming. The bubble diameter of the small bubble and medium bubble pad is too small, and the bubble thickness is only between 2-3mm, while the thickness of the Ф25mm and Ф28mm large bubbles is more than 5mm. The reduction in thickness of a single small bubble and medium bubble during internal unwinding cannot meet the need for preventing tube jamming, and cannot reduce and eliminate the clamping resistance on the bottom tube. The standard large bubble pad can meet the needs of the present invention. It can be seen that the specially designed single extra-large and extra-thick bubble pad with a diameter greater than Ф28mm has a better effect in preventing tube jamming.

[0085] Figure 6-1 , 6-2 A schematic diagram is given of the reasons why large bubble cushions are superior to small and medium bubble cushions. Figure 6-1The center lines of the middle circle ⑤ and circle ⑥ are the same center line BB. In this state, the tube can be unwound relatively easily in the direction of the arrow in the figure. Figure 6-2 The center lines FF and EE of the middle circle ⑤ and circle ⑥ are not on the same straight line. This situation often occurs in the actual winding process. Different tolerance ovality of the tube diameter, different tightness between the tubes wound on the reel, and different width of the winding machine reel will all cause such problems. Since FF and EE are not on the same center line, T2 will be generated. T2 is the length value of the highest point of circle ⑤ higher than the lowest point of circle ⑥. T2 will produce a great resistance to the tube discharge in the direction of the arrow of circle ⑤. The distance that circle ⑤ descends must exceed T2 to discharge the tube smoothly. A single small bubble and medium bubble pad does not have enough bubble thickness, and it cannot provide enough bubble thickness reduction. This is why a single small bubble and medium bubble film cannot stably prevent the tube from being stuck. Increasing the number of bubble pads, two or more small and medium bubble pads can double the amount of change in the thickness direction of the bubble pad, which can solve the problem of unwinding without stuck tubes. However, this will increase the cost and is not suitable for use as a packaging pad for LWC coils. The stacking of multiple large, medium and small bubble pads is more suitable for on-site unwinding in air-conditioning plants.

[0086] Figure 7-1 FIG. 1 is a schematic cross-sectional view of a circular inflatable (water) cushion according to another embodiment of the present invention. Figure 7-2 for Figure 7-1 Top view of the .

[0087] Figure 7-1 It is another embodiment of the soft fluid cushion described in the present invention. It is designed into a concentric circular structure of unequal heights, and the surface layer is filled with gas or water. The surface layer 61 is made of soft plastic rubber material, and the thickness of the surface layer is slightly thicker than the film thickness of the bubble cushion. It can withstand higher pressure and has better wear resistance and better service life. However, the surface layer cannot be too thick, otherwise it will affect the effect of preventing the pipe from being stuck. The outer diameter D1 of the inflatable (water) cushion should be larger than the outer diameter of the coil, so that the entire coil can be placed on the inflatable (water) cushion in the outermost layer. The center of the inflatable (water) cushion is PP, and the thickness of the part C that is smaller than the inner diameter of LWC, that is, smaller than D2, is slightly smaller than the thickness H2 of the outer circular part of the inflatable (water) cushion, and the height difference between the two is H1. When the inflatable (water) cushion is filled with air (water), the middle part will not bulge out to affect the internal extraction and unwinding of the coil. Figure 7-2U1-U8 shown are circumferential partitions divided by four radial soft lacing bars 62, which are filled with air (water). The upper surface of the soft fluid cushion filled with air (water) is kept horizontal, and the LWC coil can be placed horizontally and stably when placed on it. The contact surface between the surface layer 61 of the air (water) cushion and the lower end surface of the LWC coil can be a flat surface, or it can be made into an uneven contact surface similar to bubbles like a bubble cushion. The uneven surface is filled with gas or water, and a good anti-stuck effect can be obtained when unwinding.

[0088] Figure 8 The figure shows the unwinding of the LWC coil placed on the air (water) cushion, wherein the air (water) cushion is placed on the unwinding station 70 of the pipe bending machine in the air conditioner factory, and the LWC coil is placed on the air (water) cushion. The surface 61 of the air (water) cushion contacts the lower end surface of the coil, and the middle part C of the air (water) cushion is designed to be slightly lower than the thickness of the side thereof to form a depression. When unwinding to the bottom of the coil, the surface of the air (water) cushion at this position will not bulge to form an obstacle to the extracted pipe. In the production of the air conditioner factory, generally, one pipe bending machine needs 6-8 LWC coils to be fed at the same time. A workshop may have many pipe bending machines working at the same time. Dozens of coils are unwound at the same time, which will occupy a large factory area, but it is a very efficient production method.

[0089] The inflatable (water) cushion of this embodiment is the same as the bubble cushion, both of which are soft fluid cushions, and are made of a soft plastic or rubber surface layer filled with fluid. The only difference between them is that the bubble cushion only fills the bubbles with gas, which is a local filling. The inflatable (water) cushion is filled with gas or liquid in a relatively large area, which is an overall filling. Gas and liquid are both fluids, and they both do not have a fixed volume. They can bear heavy loads under static pressure conditions and are easily deformed under dynamic stress conditions. Therefore, when an inflatable (water) cushion is used as the LWC coil liner unwinding, it has the same anti-stuck pipe effect as the aforementioned bubble cushion of the present invention. Figure 9-1 , 9-2 9-3 gives the principle of not getting stuck when drawing and unrolling the air (water) cushion and the schematic diagram of the shape change process of the air (water) cushion. Figure 9-1 This is a schematic diagram before the internal pumping begins. Figure 9-2 This is a schematic diagram of the downward deformation of the inflatable (water) cushion surface under force. Figure 9-3 The figure shows how the pipe can easily leave its original position. Figure 9-2 The middle air (water) cushion 60 is deformed by the internal suction force. Since the air (water) cushion is filled with fluid, a very small internal suction force can produce this deformation, so that the rings ⑤ and ⑥ are separated at point a and Y increases. When this deformation is large enough, the clamping resistance acting on the ring ⑤ is reduced or disappears, and the ring ⑤ is pulled out of the LWC coil without damage in the direction of the arrow to complete the unwinding of the anti-stuck tube. Figure 9-3shown.

[0090] The embodiments of the present invention provide two types of soft fluid cushions used as liners for LWC coils to complete unwinding of tubes without getting stuck, including commercially available bubble cushion products and inflatable (water) cushions, both of which utilize the basic properties of fluids to complete unwinding of tubes without getting stuck. Due to cost and manufacturing difficulty, the applicable occasions of the two are different. Bubble cushions are low in cost and can be used in large quantities as packaging cushions for LWC coils. Of course, bubble cushions can also be laid at the unwinding station of the air conditioner factory to be used as support cushions for unwinding. Professionally designed inflatable (water) cushions are more suitable for unwinding in air conditioner factories. This type of inflatable (water) cushion can also have a higher level of design. The aforementioned bubble cushions and inflatable (water) cushions mentioned above will also contact the surface of the cushion when the bottom coil is unwound and leaves the LWC coil. See Figure 5-1 to Figure 5-3 , Figures 9-1 to 9-3 This contact will also produce a certain amount of friction resistance. Professionally designed air (water) cushions can completely eliminate this contact and resistance. Before pulling out the LWC coil in a circle of pipes in the bottom layer, the air (water) cushion is actively depressurized and disengaged from the contact point of a circle of pipes on the lower end of the coil. This circle of pipes leaves the coil without lower support, and the unwinding can be completely unstuck. The partitioned air (water) cushion can achieve this effect.

[0091] Figure 10-1 A schematic diagram of the initial state of the LWC coil with an air (water) cushion with radial partitions placed inside is given. Figure 10-2 This is a schematic diagram of the radially partitioned air (water) cushion unwinding to the bottom tube of the 4th vertical row. Figure 10-1 It can be seen that the air (water) cushion 60 has 7 360° annular radial partitions W1-W7, each partition being separated by a soft rubber and plastic material vertical rib 63. Each partition can be independently inflated and liquid-filled, and independently pressurized or depressurized. Figure 10-1 In the preparation stage before unwinding, the fluid is controlled to have enough pressure in each partition of the air (water) cushion W1-W7. The pressure of the fluid makes the surface layer of each partition of the air (water) cushion bulge and bear the load tightly against the lower end surface of the LWC coil. In the figure, L1-L11 represents the number of the pipes in the 1st to 11th vertical rows from the inside to the outside. When unwinding from the inside, the pipes are unwound from the 1st to the 11th vertical rows in sequence. The bottom layer of pipes in the even-numbered vertical rows painted black is the position where the pipes are easily stuck in the unwinding of the prior art. Figure 10-2The diagram is a schematic diagram of the tube 104 unwound to the bottom of the 4th vertical row leaving the LWC coil. Before the tube 104 is unwound from the bottom layer of the LWC coil, the partition W5 is actively depressurized. The depressurization causes the surface layer of W5 to deflate. At this time, the blackened tube that is unwound from the bottom layer of the LWC is completely separated from the pad below in the 360-degree direction of the circumference, as shown by the position indicated by point E in the figure. The LWC coil is unwound from the inside to the outside one by one. Before the bottom layer of the tube is placed, the corresponding partition of the inflatable (water) cushion is depressurized in advance, so that each circle of the bottom layer of the tube leaves the LWC coil without resistance from below. This method of controlling the partition pressure of the soft fluid cushion can make the tube unwound without clamping at all, and the effect of unwinding and preventing the tube from being stuck will be better.

[0092] According to another embodiment of the present invention, the soft fluid cushion is a part of the copper coil or aluminum coil packaging, and the soft fluid cushion is placed on the lower end surface of each copper coil or each aluminum coil during packaging. Fig.11 As shown, the bubble pad 11 is a part of the packaging of the copper coil or aluminum coil 10. When packaging, the bubble pad 11 is placed as a cushion on the lower end surface of each copper coil or each aluminum coil 10. The bubble pad 11 is used together with the wooden tray 2, the upper corrugated paper pad 3, the corrugated paper pad 6, the sandwich board packaging plate 4 and the wrapping film 5 to realize the packaging of the coil. The soft fluid pad described in the present invention is used as a part of the coil packaging. When the coil is packaged at the factory, it is placed at the bottom of each coil, and the coil is packaged together with other packaging materials, so that the packaging of the coil forms a new packaging structure, which is not only firm and convenient for safe transportation, but also does not need to be hung on the bubble pad when the user uses it. It only needs to open the wrapping film and send the pipe head into the pipe bending machine for internal extraction and unwinding. A large air conditioning heat exchange workshop uses dozens of tons of coils a day. If each coil needs to be hoisted, more than hundreds of coils will be hoisted a day. Saving this process also greatly improves efficiency.

[0093] Fig.11 A specific embodiment of the present invention in which the bubble pad is used as a part of the coil packaging is given. In this embodiment, the copper coil or aluminum coil 10 is packaged in three coils and one stack. The packaged copper coil or aluminum coil is, from bottom to top, the wooden pallet 2, the sandwich panel packaging tray 4, the bubble pad 11, the first tray of the copper coil or aluminum coil 101; the corrugated paper pad 6, the bubble pad 11, the second tray of the copper coil or aluminum coil 102; the corrugated paper pad 6, the bubble pad 11, the third tray of the copper coil or aluminum coil 103, the upper corrugated paper pad 3 and the sandwich panel packaging tray 4 are arranged on the upper end of the copper coil or aluminum coil 103 in the third tray, and the wrapping film 5 is wrapped around the outer surface.

[0094] Theoretically, the number of coils can be determined as needed, and the bubble pad and / or corrugated paper pad described in the embodiment of the present invention can be placed between two adjacent coils for packaging. However, in actual production, considering the weight, transportation and other requirements, three coils are usually packaged together to form one package. This embodiment provides a three-reel packaging structure, which is not only firm and convenient for safe transportation, but also does not require the user to place the above-mentioned bubble pad on the lower end surface of the coil when using it. The wrapping film, the upper corrugated paper pad and the sandwich panel packaging disc are removed from the upper end to directly perform the internal drawing and unwinding operation.

[0095] From the coil unwinding and anti-stuck pipe method described in the above embodiment provided by the present invention, it can be seen that the coil unwinding and anti-stuck pipe method provided by the present invention, because it contains a soft fluid cushion, and the fluid is easily deformed, the shape and thickness of the fluid change when the coil is unwound in the coil, so that the clamping force of the upper layer pipe and the fluid cushion on the bottom layer pipe of the coil is reduced or eliminated, and the pipe can be easily pulled out without the stuck pipe problem of the prior art. The technical problems that the prior art has always wanted to solve but failed to solve are solved, and the invention purpose of this application is achieved.

[0096] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Orientation terms such as "upper", "bottom", "upper" and "lower" should be understood and determined in conjunction with the accompanying drawings. Unless otherwise clearly specified and limited, the terms "disposed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0097] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preventing the coil from being stuck when unwinding a coil, which is used to prevent the copper coil or aluminum coil from being stuck when the coil is closely wound. It is characterized in that Before unwinding, the copper coil or aluminum coil is placed on a soft fluid cushion, which is filled with gas or liquid in whole or in part. The soft fluid cushion contacts the lower end surface of the copper coil or aluminum coil to bear the weight of the copper coil or aluminum coil. When unwinding, the soft fluid cushion is deformed at the contact point with the tube under the action of the internal suction force, so that the tube can be pulled out without being damaged, thereby realizing unwinding without getting stuck.

2. The method for preventing coiled pipe from being stuck during unwinding according to claim 1, It is characterized in that The soft fluid cushion is a bubble cushion.

3. The method for preventing coiled pipe from being stuck during unwinding according to claim 2, It is characterized in that The bubble cushion is a double-layer bubble cushion including a bubble layer and a flat film layer, wherein the bubble layer is arranged on the flat film layer, and the bubble layer or the flat film layer is in contact with the lower end surface of the copper coil or the aluminum coil.

4. The method for preventing coiled pipe from being stuck during unwinding according to claim 2, It is characterized in that The bubble cushion is a single sheet or multiple sheets are stacked, and a single bubble cushion includes a single bubble layer or multiple bubble layers. When the bubble cushion is a single sheet with a single bubble layer, the diameter of the bubble is greater than 10 mm.

5. The method for preventing coiled pipe from being stuck during unwinding according to claim 2, It is characterized in that The bubbles of the bubble cushion are in the shape of a circle, an ellipse, a column, a gourd or a special shape.

6. The method for preventing coiled pipe from being stuck during unwinding according to claim 1, It is characterized in that The soft fluid cushion is an air-filled air cushion or a water-filled water cushion.

7. The method for preventing coiled pipe from being stuck during unwinding according to claim 6, It is characterized in that The inflatable air cushion or water-filled water cushion is provided with partitions. Before the inner unwinding reaches the bottom-layer pipe, the partition on the inflatable air cushion or water-filled water cushion corresponding to the bottom-layer pipe is depressurized, so that the bottom-layer pipe of the inner unwinding can leave the copper coil or aluminum coil without lower support.

8. The method for preventing coiled pipe from being stuck during unwinding according to claim 7, It is characterized in that The inflatable air cushion or water-filled water cushion is provided with radial tension bars or circumferential vertical bars to divide the inflatable air cushion or water-filled water cushion into radial partitions or circumferential partitions.

9. The method for preventing coiled pipe from being stuck during unwinding according to any one of claims 1 to 8, It is characterized in that The soft fluid pad is a part of the copper coil or aluminum coil packaging. During packaging, the soft fluid pad is placed on the lower end surface of each copper coil or each aluminum coil.

10. The method for preventing coiled pipe from being stuck during unwinding according to claim 9, It is characterized in that The packaging material includes a wooden pallet, a sandwich packaging tray, the soft fluid pad, a corrugated paper pad, an upper corrugated paper pad and a wrapping film. The entire packaging from bottom to top includes the wooden pallet, the sandwich packaging tray, the soft fluid pad, the first tray of the copper coil or aluminum coil, the corrugated paper pad, the soft fluid pad, the second tray of the copper coil or aluminum coil, the corrugated paper pad, the soft fluid pad, the third tray of the copper coil or aluminum coil, the upper corrugated paper pad and the sandwich packaging tray, and the wrapping film is wrapped around the outer surface.

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