JP4868969B2 - Method for forming resin coating on metal strip and metal strip holding and reversing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for forming a resin coating on a metal strip for producing a metal strip with a resin coating, which is a material constituting pipes and structures to which an outer surface anticorrosion coating has been applied. The present invention relates to a method of forming a thick film coating of 3 mm or more on the outer surface of a material with a small thickness deviation.
The present invention also relates to a “metal strip holding and reversing device” suitable for carrying out the “method for forming a resin coating on a metal strip”.
The deformed metal strip means a metal strip having a curved portion or a branch, and the metal strip means a metal tube such as a steel pipe or a metal strip such as a shaped steel.

A typical example of a resin coating formation method on a metal strip is a polyethylene coating on the outer surface of a steel pipe or the like. For the method, there are an extrusion coating method, a uniaxial rotating powder lining method, a fluidized dipping method, etc. It is known (see, for example, Patent Documents 1 to 4).
Specifically, for example (see, for example, Patent Document 1), a straight steel pipe is heated, and then a polyethylene powder is sprinkled on the outer surface of the steel pipe while holding the steel pipe horizontally and rotating its axis to form a coating. And the coating thickness obtained by this uniaxial rotating powder lining method was 1.7 mm to 3.0 mm.

Moreover, after heating a steel pipe (for example, refer patent document 2), the steel pipe of a heating state is immersed in the fluidized tank (fluid immersion tank) with which polyethylene powder was loaded, a coating is formed, and in the course of the coating formation, There is a known outer surface lining method for metal pipes that stops the flow of the powder and sucks the air in the flow tank to increase the bulk density of the resin powder to obtain a good quality coating. In this case, the steel pipe was a straight pipe and was held horizontally in the fluidized tank.
Furthermore (for example, refer to Patent Document 3), there is a lining technique for maintaining the metal strip at a preferable temperature for obtaining a good quality coating by applying electric heating to the metal strip in the middle of fluid immersion. Are known. In this case, the metal strip was still a straight pipe, but was carried into and out of the fluidized tank while being suspended vertically. The coating thickness thus obtained was 1.4 mm to 1.6 mm.

  Others (for example, see Patent Document 4), a smooth continuous layer formed by heating a steel pipe in the longitudinal direction or axial direction, heating with an induction coil, a burner or the like, and fusing powder by a vibration method or a fluid immersion method Technology to increase impact strength by continuously forming the primary film and the secondary film of the discontinuous uneven layer by fusing pellet particles by vibration method or rocking method It has been known. Also in this case, the metal strip was a straight pipe and was installed horizontally. The coating thickness obtained when polyethylene powder and polyethylene pellets having a diameter of about 3 mm were used was 1 mm for the primary film and 1.5 mm for the secondary film, and the total thickness was about 2.5 mm.

  Of these resin coating forming technologies, the extrusion coating method and the uniaxial rotating powder lining method are both widely used for straight pipes or straight metal strips, and metal strips having deformed portions such as curved portions and branches ( It is difficult to apply this to resin coating formation on a deformed metal strip in this specification. For this reason, fluid dipping is often used for forming a resin coating on a deformed metal strip. In addition, when the deformed metal strip is a large material, for example, in the case of a bent pipe having a diameter of several hundred mm or more and a length of several thousand mm or more, the equipment that can be used for holding and transferring is limited. It is frequently used and suspended with the pipe end as a cue, so that both ends are almost the same height and the center or middle center of gravity or the vicinity of the center of gravity is lowered to a stable posture. A transfer process, a fluid immersion process, a transfer process, and a melt solidification process are performed in that order.

  In the heating process, the whole of the deformed metal strip is heated to the melting point of the coating resin or higher by induction heating or gas heating, and in the next transfer process, the deformed metal is held in the above-described suspended state, that is, suspended by two-end pulling. In the fluid immersion process, the deformed metal strip is placed in the fluid immersion tank and attached to the outer surface in the fluid immersion process, and the powder powder is attached to the outer surface. The deformed metal strip is taken out of the fluidized immersion tank in the suspended state and transferred to the stationary place, and in the last melting and solidifying process, the low center of gravity posture by the two-end bearing etc. that has taken over the suspended state in the stationary place. Then, wait until the deformed metal strip is placed quietly, and the powder resin is completely melted by the heat of the base metal, and then the deformed metal strip is cooled by air blow or the like to the hollow of the tube body. The resin coating solidifies.

In the case of such a polyethylene coating, the anticorrosion performance can be long-term anticorrosion of 20 to 30 years or more with a thickness of 0.5 mm or more for most environments. Therefore, the film thickness is often about 1 to 2 mm for further safety. Each of the above examples is also such, and there is no positive disclosure of forming a thick film coating of 3 mm or more, and any mention of a technique for forming a thick film coating of 3 mm or more with little thickness deviation. Absent.
However, an extra large film thickness of 5 mm may be required in cases where a large mechanical damage action such as drilling in the ground reaches. In such a case, a costly response such as laminating a tape winding coating on a normal powder lining layer has been unavoidable.

JP 56-095359 A JP-A-52-141349 Japanese Patent Laid-Open No. 52-112645 Japanese Patent Publication No. 51-036904

In addition, the method of resin coating formation by such a combination of tape lamination is difficult to automate, especially when the object to be coated is a deformed metal strip, and it is performed exclusively by hand, so the work efficiency is not good. Also, the burden of inspection such as coating thickness is heavy. Therefore, it is desired to form a thick film coating only by the powder lining method.
However, when a coating made of a thermoplastic resin such as polyethylene is formed by a powder lining method, a molten coating is first formed by bringing the resin powder into contact with a heated tube and the like and melting it with the heat of the base material. In this case, the coating is obtained by cooling and solidifying, but in this case, the film thickness deviation which is not a problem with the conventional coating thickness of about 1 to 2 mm becomes a problem.

That is, as described above, in the resin coating formation on a large deformed metal strip, the resin powder adheres by fluid immersion, is transferred from the fluid tank to the stationary place, the resin is melted, and the resin coating is cooled. Solidification is performed in a state where the center of gravity is lower than the two ends for stability, but as the resin coating thickness increases, the resin waiting time increases and the flow of the molten resin under its own weight is accelerated. For this reason, it has been found that the film thickness deviation increases drastically in combination, and the film thickness deviation occurs at a level that cannot be ignored in practice (for example, ± 30% with respect to the central film thickness of 5 mm).
Accordingly, it is a problem to provide a coating forming technique capable of suppressing a thickness deviation in a thick film coating of 3 mm or more within an allowable level (for example, ± 10%).

  The method for forming a resin coating on a metal strip according to the present invention (Claim 1) was devised in order to solve such a problem, and is a target for coating a metal strip having a deformed portion such as a curved portion. A method for forming a resin coating on a metal strip by forming a coating having a thickness of 3 mm or more with a thermoplastic resin on a surface while suppressing thickness deviation, wherein the melting point of the thermoplastic resin by heating the metal strip The powder was applied to a powder coating facility in a state where the temperature was exceeded, and the thermoplastic resin powder was brought into contact with the entire surface to be coated and adhered by the heat of the base material, thereby proceeding to the melting process. After forming the in-process coating, the metal strip with the in-process coating is taken out of the powder coating equipment and allowed to age in a stationary state, so that the in-process coating is completely melted by the heat of the base material. The in-process coating that reaches and progresses over time In order to correct the thickness deviation due to the flow of the dead weight, the posture of the stationary form is reversed upside down to switch the flow direction of the dead weight to the reverse flow direction with respect to the in-plane orientation once or plural times during the time period. It is characterized in that it is applied and then transferred to a cooling process to obtain a solidified coating.

  Moreover, the resin coating formation method (Claim 2) to the metal strip of the present invention is the resin coating formation method to the metal strip according to Claim 1, and further flows as the powder coating equipment. Using an immersion tank, an operation for maintaining the powder of the thermoplastic resin loaded in the fluidized immersion tank in a fluidized state by an upward air flow, an operation for immersing the metal strip in the fluidized powder, The operation of increasing the bulk density of the powder in the tank by stopping the upward air flow while immersing and releasing the flow state and sucking the gas in the tank and adjusting the immersion time in the state where the bulk density is increased Then, the amount of the adhesion of the powder is set to an amount suitable for the coating thickness.

  Furthermore, the method for forming a resin coating on a metal strip according to the present invention (Claim 3) includes a heating step of heating a metal strip having a deformed portion such as a curved portion with a heating facility, and the metal strip at two ends thereof. A first transfer step of moving from the heating equipment to the fluidized immersion tank in a suspended state with a low center of gravity posture with the suspension fulcrum positioned at the bottom, and in the fluidized immersion tank while maintaining the suspended state In the flow dipping process in which the thermoplastic resin powder is adhered to the entire area of the metal strip covering target, the metal strip is transferred from the fluid dipping tank to the next process location in the suspended state. In the method of forming a resin coating on a metal strip through a second transfer step and a melt-solidification step in which the molten resin powder is cooled after waiting for complete melting, in the fluid dipping step, the resin powder faces upward Immerse the heated metal strip in a state where it is made to flow in an air current. After that, the amount of adhesion of the resin powder is reduced by stopping the upward air flow while being immersed and sucking the gas in the tank and increasing the bulk density of the powder in the tank over time. In the melting and solidifying step, a metal strip holding and reversing device installed at the construction site is used, and the metal strip is placed in the low center of gravity posture with this device. While waiting for the resin powder to completely melt and become a molten resin, the metal strip holding and inverting device is used to turn the metal strip upside down one or more times. Thus, the thickness of the molten resin is corrected by alternately taking the low center-of-gravity posture and the high-center-of-gravity posture in which the top and bottom are replaced on the metal strip.

  Further, the metal strip holding and reversing device of the present invention (Claim 4) is held with a function of holding a metal strip having a deformed portion such as a curved portion and holding the two ends in a stationary manner. A metal strip holding and reversing device having a metal strip top-and-bottom reversal function by a large-scale reversal operation in which a metal strip is lifted at one of its two ends and then passed over the other and lowered. A pair of end grippers that can support either one of the two ends in the lower half in the open state and grip the end in support in the closed state; A first mounting pedestal with a fixed position where one of the end gripping tools is supported via a coupling member and the coupling member support is pivotable in the horizontal axis, and the other of the end gripping tools is A non-fixed second mounting pedestal supported via a coupling member, and holding in the stationary mode and the And characterized in that enabling and turned upside down by rotation reversing operation.

  Further, the metal strip holding and reversing device according to the present invention (Claim 5) has a function of holding a metal strip having a deformed portion such as a curved portion and holding the two ends in a stationary manner. A metal strip holding and reversing device having a metal strip top-and-bottom reversal function by a small turn reversal operation in which the standing posture is switched to the top and bottom in a state where the heights of the two end portions are balanced. It is a gripping tool that has a split structure that can open and close half, and has an arcuate outer contour, and in the open state it can support either one of the two ends in the lower half, and in the closed state the end being supported A pair of end gripping tools to be gripped and a pair of mounting bases that support each of the end gripping tools in an axial center direction switching permissible mode are arranged, and holding in the stationary mode and reversing the small turn It is characterized in that it can be turned upside down by movement.

  Further, the metal strip holding and reversing device according to the present invention (Claim 6) has a function of holding a metal strip having a deformed portion such as a curved portion and holding the two ends in a stationary manner. A metal strip holding and reversing device having a metal strip top-and-bottom reversal function by a small turn reversal operation in which the standing posture is switched to the top and bottom in a state where the heights of the two end portions are balanced. A pair of end grips that can open and close half, and in the open state, the lower half can support either one of the two ends, and in the closed state grips the end being supported; The pair of end gripping tools that support one of the ends, and at least part of the outer contour is arcuate, and the paired bodies are used in a positional relationship in which they face each other in a core shape. A pair of mounting bases that support each of the ring bodies in an axial center direction switching permissible mode; Placed in, and characterized in that enabling and turned upside down by the holding and the maneuverability reversing operation in the static 置態 like.

  Moreover, the resin coating formation method (Claim 7) to the metal strip of this invention is the resin coating formation method to the metal strip of Claim 3 above, Furthermore, as said metal strip holding | maintenance inversion apparatus The metal strip holding and reversing device according to any one of claims 4 to 6 is used.

  Moreover, the resin coating formation method (Claim 8) to the metal strip of this invention is the resin coating formation method to the metal strip of Claim 1, Claim 2, Claim 3, or Claim 7. In addition, the metal strip having the deformed portion is a metal bent pipe.

In such a resin coating forming method on the metal strip of the present invention (Claims 1 and 3), the resin coating is formed on the metal strip by the flow dipping method suitable for the deformed metal strip. This is the same as before, but since the coating has become thick, the operation from after the resin powder has been adhered in the fluidized immersion tank to the cooling is different from the conventional one. The metal strip is not left standing in a fixed posture from beginning to end, but the top and bottom are intermittently reversed on the basis of standing. And if the molten resin flows under its own weight and the film thickness deviation increases, before it exceeds the permissible level, or before it reaches a level that can not be corrected at the latest, the metal strip is turned upside down, The direction under the gravity flow is reversed, and the film thickness deviation is corrected. In addition, if the metal strip is moved without interruption, for example, in a continuous rotation, in the deformed metal strip with the deformed portion, an undesired strong force such as centrifugal force is continuously applied to the deformed portion, which is due to gravity. The film thickness deviation in different directions may occur, or the molten resin may scatter, but this can be avoided by intermittent top-and-bottom inversion.
Therefore, according to this invention, the thickness deviation in the thick film covering over 3 mm can be suppressed within an allowable level.

Moreover, in the resin coating formation method (Claim 2, Claim 3, Claim 7) to the metal strip of the present invention, when the resin powder is adhered to the metal strip in the fluidized immersion bath, By temporarily stopping the upward air flow and sucking the gas in the tank to increase the bulk density of the powder in the tank, the amount of resin powder required for forming a thick film of 3 mm or more is reliably obtained. In addition to being able to adhere, since the adhesion is completed in a short time, the retained heat of the base material still remains, and the fluidity necessary to correct the film thickness deviation by reversing the top and bottom in the melt solidification process The time zone that the molten resin has is secured without shortage. Thereby, the metal strip can be reversed upside down to correct the film thickness deviation with certainty.
Therefore, according to the present invention, it is possible to reliably suppress the thickness deviation in the thick film covering of 3 mm or more within an allowable level.

Furthermore, in the method for forming a resin coating on the metal strip according to the present invention (claims 3 and 7), in addition to the two functions and effects described above, the following functions and effects are also exhibited. That is, as a simple and safe handling method for deformed metal strips, it is often performed to suspend or support the metal strip with a low center of gravity posture with the fulcrum at the two ends and the center of gravity positioned downward, In the present invention, since the crane equipment and the pedestal are frequently used, the transfer after heating, the next transfer during the fluid immersion, the receipt by the metal strip holding and reversing apparatus are all performed with a low center of gravity posture. Therefore, the work efficiency is good and the cost of adding equipment is also small. However, as described above, when the series of operations is performed in a low center of gravity posture, the increase in the thickness deviation is accelerated. However, since the metal strip is transferred and received quickly under the low center of gravity posture, the metal There is no concern that the time from when the strip is set in the metal strip holding and reversing device to when the top and bottom is reversed is undesirably shortened, and an increase in the grace time can be expected.
Therefore, according to the present invention, it is possible to reliably and efficiently suppress the thickness deviation in the thick film covering of 3 mm or more within an allowable level.

  Further, in the metal strip holding and reversing device of the present invention (claims 4, 5 and 6), the metal strip can be held at two ends, so that the metal strip is a deformed metal strip. Even if it is, it is suitable for holding and allowing it to stand without touching the center part having the molten resin layer, and since it has a reversal function, the metal strip during standing is intermittent It can also be turned upside down. In addition, since the end gripping tool has a split structure, the gripping tool can be attached to the metal strip even when the metal strip is suspended or supported with the end as a clue, so the metal strip is deformed. Even if it is a deformed metal strip having a portion, the work of setting the metal strip on the metal strip holding and reversing device becomes easy. In addition, since the upper half of the end gripping tool with a split structure opens and closes, when receiving the metal strip that has been suspended and transported in a stable posture with the end as a clue, it matches the lowering timing of the metal strip. Thus, the metal strip can be received easily and quickly by opening and closing the end gripping tool.

  With respect to one embodiment (first embodiment) of the method for forming a resin coating on the metal strip of the present invention, the procedure and the like will be described with reference to the drawings. 1A to 1F are side views of the main part.

  A typical example of the metal strip material to be constructed is a curved tube 10 having a curved central portion (see FIG. 1A). Hereinafter, resin coating formation on the curved tube 10 will be described. The material may be other deformed metal strip material as long as it has two or more ends and can hold the two ends as a clue. For example, there may be a branch, there may be both a curved portion and a branch, and the directions of the two end portions may or may not be on a straight line.

The bent tube 10 has many large-diameter tubes having a length of 1000 mm to 6000 mm, a diameter of 200 mm to 800 mm, and a wall thickness of 5 mm to 30 mm, but may be other sizes. When the bent pipe 10 (unshaped metal strip) is lifted by a crane or the like through a lifting tool 11 such as a wire or a chain, for example, a stable posture with a low center of gravity (low center of gravity) lower than both ends (two ends) (low Suspended in the center of gravity posture).
In this case, the surface to be coated is substantially the entire outer peripheral surface of the curved pipe 10, but both end portions and the inner peripheral surface of the outer peripheral surface are not targets.
A typical example of the thermoplastic resin for coating (resin powder 14 and resin coating 16 described later) is polyethylene that is most frequently used, and its melting point is about 110 ° C to 140 ° C. Other thermoplastic resins such as various fluororesins may also be used.

  Here, the following series of steps is performed on the curved pipe 10. That is, a heating process for heating the curved pipe 10 with a heating facility, a first transfer process for suspending the curved pipe 10 in a stable posture and transferring it from the heating facility to the fluidized immersion bath 13, and a fluidized immersion bath 13 while maintaining the stable posture. Next, a flow dipping step in which the thermoplastic resin powder 14 is adhered to the curved pipe 10 and a coated metal strip 17 with a resin coating 16 attached to the bent pipe 10 in a stable posture and then suspended from the fluid dipping tank 13. Resin coating while changing the posture between the second transfer step to be moved to the metal strip holding base 18 installed at the construction site of the process, the low center of gravity posture taking over the stable posture and the high center of gravity posture where the posture is replaced A solidification process in which the metal strip 17 is cooled after waiting for complete melting; a third transfer process in which the coated metal strip 17 is suspended in a stable posture and transferred from the metal strip holding base 18 to the stand 19 of the stationary place; Completely quiet with a low center of gravity posture A standing step of returning to a normal temperature by is performed in that order. Hereinafter, each process is explained in full detail.

In the heating step (not shown), the bent tube 10 is heated with heating equipment after being cleaned with grit blast, sand blast or the like. As a heating facility, various facilities such as a gas furnace, an electric furnace, and an induction heating device may be used as long as the entire bent tube 10 or a portion including the surface to be coated can be heated. The heating temperature is about 100 ° C. to 250 ° C. higher than the melting point of the thermoplastic resin (resin powder 14 and resin coating 16 described later) as a guide, taking into account the temperature drop during coating formation.
In the first transfer step (see FIG. 1A), the bent pipe 10 is lifted and hung by the lifting tool 11 to be in a stable posture (low center of gravity posture), and is taken out of the heating equipment in that state. Then, with the stable posture, as a preparation for fluid immersion, a cap 12 for blocking the inner surface of the tube from the powder is attached to the end of the tube, and if there is a gap or other portion that you do not want to cover, there is also masking there. And the temperature of the outer peripheral surface of the bent tube 10 is measured. When it is confirmed that the temperature is appropriate, the bent tube 10 is moved into the fluid immersion bath 13 by the lifting tool 11 while maintaining a stable posture.

  In the fluid immersion process (see FIG. 1B), the curved pipe 10 is maintained in a stable posture while being suspended by the lifting tool 11 even in the fluid immersion tank 13. In the fluid immersion tank 13, the thermoplastic resin powder 14 is adhered to the curved pipe 10 with high quality. Therefore, the resin powder 14 is moved upward in the fluid immersion tank 13 by switching the operation of the blower 15. The operation of flowing and the operation of stopping the upward air flow and sucking the gas in the fluidized immersion tank 13 to increase the bulk density of the resin powder 14 in the fluidized immersion tank 13 are sequentially performed. Here, in order to make the amount of adhesion of the resin powder 14 suitable for coating with a thickness of 3 mm or more, the coating is performed while the air flow is stopped and the gas in the fluidized immersion tank 13 is sucked. For example, an in-process coating having a thickness of 5 mm can be obtained under the condition that the curved pipe 10 is pulled up from the fluid immersion tank 13 after being maintained for a predetermined time in which adhesion of 3 mm or more is suitable.

  In the second transfer step (see FIG. 1 (c)), the bent tube 10 is suspended from the fluid immersion tank 13 while being suspended by the suspension tool 11 and maintaining a stable posture. At this time, the bent tube 10 has the in-process resin coating 16 that has been transferred to the melting process adhered to the outer peripheral surface thereof to form a metal strip 17 with in-process coating. The metal strip 17 with the in-process coating is also suspended by the lifting tool 11 to maintain a stable posture, and excess resin powder is removed from the in-process resin coating 16 by air blow or the like, and the cap 12 and masking are also bent tube 10. Then, a cutback for removing the excess in-process resin coating 16 from the pipe end of the bent pipe 10 is applied to the in-process coating-coated metal strip 17. The tube end exposed by this cutback has a width of, for example, about 50 mm to 200 mm, and is used for gripping and supporting in each subsequent process, and also used for connection with another tube. Then, the metal strip 17 with the in-process coating is moved down above the metal strip holding base 18 by the lifting tool 11 in a stable posture and then lowered.

  In the melting and solidifying process (see FIGS. 1D to 1F), waiting for complete melting of the in-process resin coating 16 and cooling the in-process resin coating 16 after the complete melting are set in advance at the construction site. This is performed using the metal strip holding base 18 that has been prepared. The metal strip holding pedestal 18 basically holds the curved pipe 10 by holding the curved pipe 10, which is a deformed metal strip, at its two ends in a shape in which the rotation around a straight line connecting the two ends is restricted. Specifically, it is left stationary, and the holding position is turned upside down intermittently by a manual operation using a crane or a lever handle. In the melting and solidifying process using the metal strip holding pedestal 18, first (see FIG. 1D), the metal strip 17 with the in-process coating is lowered onto the metal strip holding pedestal 18 while maintaining a stable posture. Both ends of the strip-coated metal strip 17 are held by the metal strip holding base 18 in a low center of gravity posture that has taken over the suspended state.

  Thereafter, for example, the in-process-covered metal strip 17 is temporarily left in a low center of gravity posture for about 5 to 10 minutes. That time, when the metal strip 17 with in-process coating continues to have a low center of gravity, the metal strip 17 with in-process coating having the greatest thickness deviation among the in-process resin coating 16 that progresses melting. The time during which the thickness deviation at the center and both ends is within an allowable level is determined in advance through experiments and calculations. And (refer FIG.1 (e)), when the predetermined time passes, the metal strip 17 with an in-process covering will be reversed by the operation using a crane etc., and the attitude | position of the metal strip 17 with an in-process coating will be in the attitude | position. It becomes a high center of gravity posture with a higher center of gravity than the two ends, and is restrained and held so as to maintain this posture. Even in this high center-of-gravity posture, the in-process covering metal strip 17 is left still for a while, and after a predetermined time determined in the same manner as described above, it is inverted again.

  In this way, by making the metal strip 17 with the in-process coating alternately take the low center of gravity posture and the high center-of-gravity posture, the thickness deviation of the molten resin in the in-process resin coating 16 is corrected and suppressed to within an allowable level. It is done. In the meantime (see FIG. 1 (f)), since the in-process resin coating 16 is completely melted, cooling is performed until the temperature of the in-process resin coating 16 falls below the melting point of the thermoplastic resin for coating. The resin coating 16 is solidified. For cooling, for example, air is blown into the hollow from one end of the bent pipe 10 (see the arrow in FIG. 1 (f)), the temperature of the bent pipe 10 is lowered, and thereby the in-process resin coating 16 is indirectly cooled. Is good. Thereafter, if the metal strip holding base 18 is empty, the metal strip 17 with in-process coating may be left as it is to return to room temperature, but here, as in most cases, the metal with in-process coating is used. The strip 17 is returned to the low center of gravity posture, which is a stable posture, and is transferred to the resting place by the lifting tool 11.

In the third transfer step (see FIG. 1 (g)), as in the second transfer step described above, the metal strip 17 with in-process coating is suspended by the lifting tool 11 while maintaining a stable posture. Transferred from the material holding pedestal 18 to the stand 19 of the resting place.
In the stationary process (see FIG. 1 (h)), the low-center-of-gravity posture in which both ends of the metal strip 17 with in-process coating are supported by the gantry 19 and the metal strip 17 in-process coating takes over the stable posture. And let it stand still in its posture and return to room temperature.
In this way, even if the thickness of the resin coating is about 5 mm, for example, the in-process coated metal strip 17 having a small thickness deviation is efficiently manufactured.

  About another embodiment (2nd form) of this invention, the structure of a metal strip holding | maintenance inversion apparatus is demonstrated referring drawings. 2A and 2B are perspective views of the end gripping tool 21, FIG. 2C is a perspective view of the coupling member 22, FIG. 2D is a side view of the mounting base 24, and FIG. FIG. 4 is a side view of the metal strip holding and reversing device 20, (f) is a device side view immediately after the in-process coating metal strip 17 is set, and (g) is a device side view after the top and bottom is reversed.

  In this metal strip holding and reversing device 20 (see FIG. 2 (e)), a pair of end grippers 21, a pair of coupling members 22, a pair of mounting bases 24, and a connecting member 25 are appropriately used. The number and the rotation support shaft 26 and the fixed base 27 which form a reversing mechanism are provided. And (refer FIG.2 (f)), the metal strip 17 with an in-process covering is hold | maintained at the both ends, and the metal strip 17 with an in-process coating is left still for a while. Further, (see FIG. 2 (g)), one side (left side in the figure) of both ends of the metal strip 17 with in-process coating during standing is lifted and then passed over the other (center in the figure) ( The metal strip 17 with the in-process coating can be inverted upside down by a large turning reversal operation in the manner of lowering (to the right in the figure).

  The end gripping tool 21 (see FIGS. 2A and 2B) is a surrounding tightening gripping tool, and has a round hole that can be fitted to the end of the bent tube 10. This hole is appropriately deformed so as to adapt to the end profile of the metal strip. Further, the end gripping tool 21 has a split structure that is divided into upper and lower parts, and the upper half can be opened and closed. It is convenient to connect the upper and lower sides with a hinge or the like as shown in the figure, but they may be completely separated. If the lower half is fixed, in the open state, the end portion of the bent pipe 10 that has descended can be received and supported by the lower half, and then the upper half is closed and closed, The end portion is gripped to prevent the bent tube 10 from slipping and falling off.

The coupling member 22 (see FIG. 2C) is, for example, a bracket with an angle processed, and a pair of mounting holes 23 for fixing the lower half of the end gripping tool 21 by, for example, bolt fastening, or more. Is formed. One attachment hole 23 is a long hole so that the inclination of the end gripper 21 can be adjusted. In order to easily adjust the holding height of the metal strip 17 with the in-process coating, the pairs or sets of mounting holes 23 may be formed in multiple stages.
The mounting base 24 (see FIG. 2D) is basically a plate-like body that is used upright, and an end gripping tool 21 is mounted on one side via a coupling member 22.

In such a mounting base 24 (see FIG. 2E), the pair 24, 24 is connected by connecting members 25, 25 with the attachment member 22 mounting side facing each other. Although only one set of the connecting members 25, 25 that does not hide the other members is shown in the figure, it may be attached to other parts, may be many, and in short, the relative position of the pair of end gripping tools 21 can be adjusted. And it is enough if it can be fixed.
In this metal strip holding and reversing device 20, the pair of mounting bases 24, 24 are composed of a fixed first mounting base 24a and an unfixed second mounting base 24b, which are not equal. The first mounting base 24a is equipped with a rotation support shaft 26 and a fixed base 27, and a coupling member support portion is rotatable about a horizontal axis. That is, the end gripping tool 21 and the coupling member 22 are rotated about the rotation support shaft 26, but the position of the fixed base 27 is not moved. On the other hand, the 2nd mounting base 24b can be lifted and floated (refer FIG.2 (g) two-dot chain line), and a position can also be changed (FIG.2 (f), (g) solid line). reference).

The fixed base 27 has a lower end fixed to the floor or the like, holds the rotation support shaft 26 horizontally, and supports smooth shaft rotation of the rotation support shaft 26 with a bearing or the like.
The rotation support shaft 26 extends horizontally substantially through the center of the first mounting base 24a (in the drawing, extends vertically through the paper surface), and the first mounting base 24a and thus the end gripping tool 21 there. Is supported so as to be pivotable about the horizontal axis.
When the first mounting pedestal 24a and its end gripper 21 rotate about the rotation support shaft 26, the second mounting pedestal 24b connected by the connecting members 25 and 25 and the end gripping tool therefor are connected. 21 also turns around the sky, but still rotates around the horizontal rotation support shaft 26 as a central axis. Therefore, if the in-process covering metal strip 17 is set between the end grippers 21, 21 It can be turned upside down.

  About the metal strip holding | maintenance inversion apparatus 20 of this embodiment (2nd form), the use aspect and operation | movement are demonstrated referring drawings. 2E is a side view of the apparatus 20 alone, FIG. 2F is a side view of the apparatus immediately after setting the in-process-covered metal strip 17, and FIG. 2G is a side view of the apparatus after turning upside down.

  The metal strip holding and reversing device 20 is used in the melting and solidifying process. Specifically, the metal strip 17 with in-process coating is used to hold the metal strip 17 with in-process coating at both ends, and is allowed to stand still for a while. It is also used for reversing the metal strip 17 with the in-process coating upside down by lifting one end side of the metal strip 17 and passing it over the other end and lowering it.

  More specifically, when moving from the second transfer step to the melt solidification step, the metal strip 17 with in-process coating is lowered onto the metal strip holding and reversing device 20 by the lifting tool 11 in a stable posture. At this time, in the metal strip holding and reversing device 20, if the upper half of the end gripping tool 21 is opened in advance, the end of the metal strip 17 with the in-process coating is supported by the lower half of the end gripping tool 21. Therefore, before removing the lifting tool 11, the upper half is closed and the metal strip 17 with in-process coating is firmly grasped, and the metal strip with in-process coating 17 is left still for a while in a low center of gravity posture taking over the suspended state. (Refer to FIG. 2 (f)). And (refer FIG.2 (g)), if predetermined time passes, the 2nd mounting base 24b will be lifted with the crane which suspended the lifting tool 11, or other appropriate equipment, and the 1st mounting base 24a will be empty. Gently go down to the other side.

In this way, the metal strip 17 with the in-process coating is turned upside down and has a high center-of-gravity posture, and the metal strip 17 with the in-process coating is temporarily left still for a while. Thereafter, when the top and bottom positions are reversed again from the high center of gravity posture to return to the low center of gravity posture, the second mounting base 24b is lifted and gently lowered to the opposite side after passing over the first mounting base 24a.
Thus, the thickness deviation of the molten resin in the resin coating of the in-process coating metal strip 17 is corrected by causing the in-cover coating metal strip 17 to alternately take the low center of gravity posture and the high center of gravity posture. To within an acceptable level. When the resin coating is completely melted, it is solidified by the subsequent cooling operation, and the metal strip 17 with in-process coating is suspended from the metal strip holding and reversing device 20 in a stable posture.

  About another embodiment (3rd form) of this invention, the structure of a metal strip holding | maintenance inversion apparatus is demonstrated referring drawings. 3A and 3B are perspective views of the end gripper 31, FIG. 3C is a perspective view of the mounting base 33, and FIG. 3D is a perspective view of the end gripping tool 31 placed on the mounting base 33. However, end view (e) is a side view of the device 30 alone.

  The metal strip holding and reversing device 30 (see FIG. 3 (e)) includes a pair of end grippers 31, a pair of mounting bases 33, an appropriate number of connecting members 36, and a mounting base 33 as a reversing mechanism. And a number of rollers 34 incorporated therein. As described above, the metal strip 17 with in-process coating is held at its two ends, and the metal strip 17 with in-process coating is allowed to stand for a while and the metal strip 17 with in-process coating is intermittently inverted. Although it is the same as the metal strip holding and reversing device 20, the specific aspect of the top and bottom reversal is different from the metal strip holding and reversing device 20, and the two ends of the metal strip 17 with the in-process coating are balanced in height. In this state, the metal strip 17 is turned upside down by a small turn reversal operation in a manner of turning around a horizontal axis extending along the direction connecting the two ends of the in-process covering metal strip 17. .

The end gripping tool 31 (see FIGS. 3 (a) and 3 (b)) is obtained by rounding the outer periphery of the end gripping tool 21 described above so that it can roll on a roller. Although not essential, the end gripping tool 31 has an appropriate number of temporary fixing holes 32 perforated.
The mounting pedestal 33 (see FIGS. 3C to 3E) is specifically bent so that the end gripping tool 31 is supported in the axial center direction switching mode. A roller 34 longer than the width of the end gripper 31 is provided so that the end gripper 31 can be placed on the top and supported from below even if the end gripper 31 is inclined. A pair of rollers 34 is incorporated in each mounting base 33 and provided horizontally and in parallel. Therefore, when the end gripping tool 31 is placed on the mounting base 33, the end gripping tool 31 can be rotated on the spot. The pair of mounting bases 33 are also connected by connecting members 36 and 36 and fixed so that their relative positions can be adjusted. The mounting base 33 is not necessarily essential, but an appropriate number of temporary fixing holes 35 are perforated.

  About the metal strip holding | maintenance inversion apparatus 30 of this embodiment (3rd form), the use aspect and operation | movement are demonstrated referring drawings. 3 (e) is a side view of the apparatus 30 alone, (f) is a side view of the apparatus when the in-process-covered metal strip 17 is set, (g) is an end view of the apparatus during the upside down operation, and (h). FIG. 3 is a side view of the apparatus after the top and bottom are reversed.

  The metal strip holding and reversing device 30 is also used in the melting and solidifying process. More specifically, when the transition from the second transfer step to the melt solidification step, the in-cover-covered metal strip 17 is transferred to the metal strip holding and reversing device 30 with the lifting tool 11 in a stable posture. Before completely lowering, the end gripping tool 31 is attached to both ends of the work cover-covered metal strip 17 by opening and closing or the like, and then the end gripping tool 31 is quietly placed on the roller 34 of the mounting base 33. The in-process coated metal strip 17 is lowered. At that time, in the metal strip holding and reversing device 30, the metal strip 17 with the in-process coating maintains the low center of gravity posture that has inherited the suspended manner in the stable posture. Leave still for a while (see FIG. 3F). And (refer FIG.3 (g)), when predetermined time passes, the edge part etc. of the edge part holding tool 31 will be pulled or pushed with the crane which suspended the lifting tool 11, or other appropriate equipment, and end holding The tool 31 can be half-rotated on the spot, and in this example, the half-rotation state is fixed by inserting locking bars into the temporary fixing holes 32 and 35.

In this way, the metal strip 17 with in-process coating is turned upside down and has a high center of gravity posture (see FIG. 3 (h)), and the metal strip 17 with in-process coating is left still for a while. Thereafter, the end gripper 31 is also rotated halfway on the spot when the top and bottom positions are reversed again to return to the low center of gravity posture.
And also in this case, the thickness deviation of the molten resin in the resin coating of the metal strip 17 with in-process coating is caused by causing the metal strip 17 with in-process coating to alternately take the low center of gravity posture and the high center of gravity posture. Corrected and kept within acceptable levels. When the resin coating is completely melted, it is solidified by the subsequent cooling operation, and the metal strip 17 with the in-process coating is suspended from the metal strip holding and reversing device 30 in a stable posture (low center of gravity posture).

  In the metal strip holding and reversing device 30, if the bending of the metal strip 17 with in-process coating is steep, the deviation between the straight line connecting both ends of the metal strip 17 with in-process coating and the position of the center of gravity. Therefore, if the end gripper 31 is kept in a simple ring shape, the rotational load is large and the stability is also impaired. Therefore, the inner periphery and the outer periphery of the end gripper 31 are decentered so that the rotation center axis passes through the center of gravity. Anyway. Even in such a situation where the stabilization treatment is performed, in order to prevent unexpected rotation, it is preferable to insert a temporary fixing pin into the temporary fixing holes 32 and 35, or an end gripping tool such as a brake (not shown). 31 may be stopped. When the inclination of the end gripper 31 is tight, the outer periphery of the end gripper 31 may be elliptical so that the projection onto the vertical plane becomes a perfect circle.

  About another embodiment (4th form) of this invention, the structure of a metal strip holding | maintenance inversion apparatus is demonstrated referring drawings. 4A is a side view of an example of a ring body 41, FIG. 4B is an end view thereof, FIG. 4C is a side view of another example of a ring body 41, and FIG. An end view, (e) is a side view where the ring body 41 and the like are placed on the mounting base 44, and (f) is an end view thereof. FIG. 5A is a side view of the metal strip holding and reversing device 40.

  This metal strip holding and reversing device 40 (see FIG. 5A) includes a pair of end gripping tools 21, a pair of coupling members 22, a pair of rings 41, and a pair of mounting bases 44. And an appropriate number of connecting members 46. Each mounting base 44 is provided with a pair of rollers 45 as a reversing mechanism. And, in the same manner as the metal strip holding and reversing device 30, the two ends of the metal strip 17 with in-process coating are connected in a direction connecting the two ends of the metal strip 17 with in-cover coating in a balanced state. The metal strip 17 is turned upside down by a small turn reversal operation in a manner of turning around a horizontal axis extending along the horizontal axis.

  The ring body 41 (see FIGS. 4A and 4B) is a disk-like body (all-round ring body) that is used standing on the mounting base 44, and is connected to the one surface via the coupling member 22. An end gripping tool 21 is attached. As a gripper-wheel body joint position setting mechanism for setting the joint position of the end gripper 21 on the ring body 41 so as to be adjustable, a plurality of sets of mounting holes 23, 23 are formed in the joint member 22 in this apparatus. Is formed. Shown is an example of a multistage switching type, in which each set of mounting holes 23 is composed of one round hole and two long holes, and three sets are provided. In each set, the position away from the axis of the ring body 41 and the tilt adjustment range of the end gripping tool 21 are different, and various kinds of in-process covering metal strips 17 can be held.

For example, when the bending of the in-process covering metal strip 17 is not tight, the end gripping tool 21 is attached to the coupling member 22 using the middle mounting hole 23a (see FIGS. 4A and 4B). When the in-process covering metal strip 17 is tightly bent, it is preferable to attach the end gripping tool 21 to the coupling member 22 using the end mounting hole 23b (see FIGS. 4C and 4D).
In addition, the adjustment setting of the gripper-wheel body coupling position is not limited to such a multistage switching type, and may be another multistage switching type using a notch or the like, for example, a desired distance slide It may be a continuously variable switching type that is fixed after being allowed to move, or may be an electric drive type.
Furthermore, a form based on a dedicated connection specification prepared for each dimension and shape of the in-process coating-coated metal strip 17 is also useful in situations such as low-volume, large-scale construction.

  The mounting base 44 (see FIGS. 4 (e) and 4 (f)) is a roller 45 slightly longer than the width of the ring body 41 so that the ring body 41 can be placed upright and supported from below. Is equipped. A pair of rollers 45 is incorporated in each mounting base 44 and provided horizontally and in parallel. Therefore, when the ring body 41 is placed on the mounting base 44, the ring body 41 can rotate on the spot. Although illustration is omitted, one or both of the rollers 45 are driven to rotate by an electric motor. The pair of mounting bases 44 (see FIG. 5A) are also connected by connecting members 46 and 46 and are fixed after the relative position is adjusted. A ring body 41 is placed on each mounting base 44 so that the mounting side of the end gripping tool 21 and the coupling member 22 is opposed to each other, so that the pair of ring bodies 41 are parallel to each other in a core shape. It is used in a positional relationship.

  About the metal strip holding | maintenance reversing apparatus 40 of this embodiment (4th form), the use aspect and operation | movement are demonstrated referring drawings. 5A to 5C are side views.

  This metal strip holding and reversing device 40 is also used in the melting and solidifying process, and while waiting for the resin powder to completely melt and become a molten resin, as in the case of using the metal strip holding and reversing device 30. In addition, the in-process coated metal strip 17 is turned upside down by a small turn reversing operation, but there are also the following unique operations. That is, the end gripping tool 21 does not roll in direct contact with the roller 45, but the end gripping tool 21 rolls indirectly on the roller 45 via the ring body 41. If the bending of the metal strip 17 is loose, the in-process coated metal strip 17 rotates smoothly even if it is sudden.

  More specifically, if the bending of the metal strip 17 with the in-process coating is loosened, the end gripping tool 21 is attached to the ring body 41 using the mounting hole 23a formed in the middle of the coupling member 22. The And when it transfers to a melt-solidification process from a 2nd transfer process, the metal strip 17 with an in-process coating | cover is lowered | hung on the metal strip holding | maintenance inversion apparatus 40 with the suspension tool 11 with a stable posture. At that time, in the metal strip holding and reversing device 40, if the upper half of the end gripping tool 21 is opened in advance, the end of the metal strip 17 with the in-process covering is below the end gripping tool 21 that has been subjected to the tilt alignment adjustment. Since it is supported in half, before removing the lifting tool 11, the upper half is closed to firmly grip the metal strip 17 with the in-process coating, and the metal strip 17 with the in-process coating in a low center of gravity posture that takes over its stable posture. Is allowed to stand for a while (see FIG. 5A).

Then, when the predetermined time has elapsed, the roller 45 is driven by a motor, whereby the ring body 41 is rotated halfway on the spot, and the metal strip 17 with covering is turned upside down by its small turn reversal operation, and the high speed is reversed. The posture becomes the center of gravity (see FIG. 5B). Even in this posture, the in-process covering metal strip 17 is temporarily left standing for a while, and then, after a predetermined time has passed again, the roller 45 is driven by a motor, whereby the ring body 41 is rotated halfway on the spot, and its small turn As a result of the reversal operation, the in-process coated metal strip 17 is turned upside down and returns to the low center of gravity posture (see FIG. 5A).
And also in this case, the thickness deviation of the molten resin in the resin coating of the metal strip 17 with in-process coating is caused by causing the metal strip 17 with in-process coating to alternately take the low center of gravity posture and the high center of gravity posture. Corrected and kept within acceptable levels.

  Further, (see FIG. 5C), if the bending of the metal strip 17 with the work cover is abrupt, the end gripping tool 21 can be mounted using the mounting hole 23b formed near the end of the coupling member 22. Mounted on the ring body 41. At that time, the inclination of the end gripping tool 21 is adapted to the bending condition of the metal strip 17 with in-process coating, and whether the center of gravity of the metal strip 17 with in-process coating is on the extension of the axis of the ring body 41. Try to get closer. When the center of gravity of the in-process covering metal strip 17 moves away from the extension line of the axis of the ring body 41, the end gripping tool 21 is reattached to another mounting hole. Moreover, the overlapping degree of the connection members 46 and 46 is increased / decreased, and the confrontation distance of the ring bodies 41 and 41 is adapted to the length of the metal strip 17 with a covering. After that, the metal strip is left for a while and turned upside down in the same manner as described above. In this way, the metal strip reversing device 40 is used for the various strip-coated metal strips 17.

  Regarding another embodiment (fifth embodiment) of the present invention, the configuration of a metal strip holding and reversing device will be described with reference to the drawings. 6A to 6C are end views. In the illustration, each member is hatched to clarify the punched portion.

  The metal strip holding and reversing device 50 is different from the metal strip holding and reversing device 40 described above in that the mounting base 44 is a mounting base 51 without the roller 45 and the all-round ring body 41 is different. This is a point where a partly arc-shaped ring body 52 is formed. Although illustration is omitted, in order to set the end gripping tool 21 that supports the metal strip 17 with the in-process coating at its two ends and the engagement position of the end gripping tool 21 on the ring body 52 to be adjustable. The coupling member 22 formed with a plurality of sets of mounting holes 23, 23 is taken over as it is. The balance of the center of gravity is important when processing deeply bent metal strips such as 90 ° bent pipes (this is also the case with the fourth embodiment using the metal strip holding and reversing device 40). In such cases, the balance of the center of gravity can be adjusted by adjusting the position of the end gripper to eliminate the instability of holding when the metal strip is in a high center of gravity posture, and to stand in a low center of gravity posture. And standing in a high center of gravity posture can be performed with the same stability.

The mounting pedestal 51 is composed of H-shaped steel and groove-shaped steel rails installed horizontally, and has a length close to the total length of the circumference of the ring body 52 in order to enable the loaded ring body 52 to roll. Cost.
The ring body 52 is cut into a straight line in which both sides of the circular edge are substantially parallel (upper and lower parts in FIG. 6A). Further, in order to reduce the weight of the self and offset the deviation of the center of gravity of the metal strip 17 with the in-process coating, a large punch 53 is formed on one linear cut side, and the other linear cut side is formed. A small punch 53 is formed.

The metal strip holding and reversing device 50 is also used in the melting and solidifying process, and the paired ring bodies 52 and 52 are used in a positional relationship in which the bodies pass through each other in parallel to face each other for smooth rolling. .
When the posture is changed from the stationary state in the low center of gravity posture (see FIG. 6A) to the stationary state in the high center of gravity posture (see FIG. 6C), or vice versa, the punch 53 is removed. The ring body 52 is rolled on the mounting base 51 by, for example, hooking a hook of a crane on the side, and this involves a lateral movement. Other than that is the same as the usage mode and operation of the metal strip holding and reversing device 40.

[Others]
In the above embodiment, the deformed metal strip is a simple curved pipe. However, the deformed metal strip may be a three-end or multi-end branch pipe, and is not limited to a round pipe, and may be a square pipe or a solid pipe. It may be. When the outer shape of the end of the deformed metal strip is not round, the shape of the hole of the end gripping tool 21 is deformed so as to match it.

A resin coating was formed on the metal strip by the method described above. The metal strip is a curved pipe with a sleeve of 600 mm at both ends of a 90 ° bend, and is made of a steel pipe having a diameter of 600 mm. Polyethylene was adopted as the thermoplastic resin for coating.
In the heating process, the curved pipe is heated to a temperature of 230 ° C. to 330 ° C., in the fluid immersion process, it is immersed for 7 minutes to form an in-process resin coating having a thickness of 6.0 to 6.5 mm, and in the second transfer process, 2 minutes. It was transported after spending some time. In the melt-solidifying step, the in-process coated metal strip was inverted every 5 minutes. One minute was spent on each inversion.
Then, a metal strip with a coating was completed through a third transfer step and a stationary step, and when the thickness of the resin coating was measured, the minimum value was 5.6 mm and the maximum value was 6.5 mm.

  A method for forming a resin coating on a metal strip and a metal strip holding and reversing device according to the present invention coat a resin coating having a thickness of 3 mm or more on the outer surface of a curved pipe with a small thickness deviation, and lay it with a thick film. Prevent breakdown caused by lightning strikes in pipelines and improve withstand voltage characteristics. In addition, by improving the impact resistance at the time of laying and after laying, it becomes easier to lay and becomes hard to be damaged. As a result, the service life is extended, so that it can be applied to oil and gas transportation pipelines.

About one Embodiment (1st form) of this invention, the procedure of the resin coating formation method to a metal strip, etc. are shown, (a)-(f) is a side view of the principal part. About other embodiment (2nd form) of this invention, the structure, operation | movement, etc. of a metal strip holding | maintenance inversion apparatus are shown, (a), (b) is a perspective view of an edge part holding tool, (c) is a joint. (D) is a side view of the mounting base and the like, (e) is a side view of the device alone, and (f) and (g) are side views of the device when the metal strip is set. About other embodiment (3rd form) of this invention, the structure, operation | movement, etc. of a metal strip holding | maintenance reversing apparatus are shown, (a), (b) is a perspective view of an edge part holding tool, (c) is mounted. (D) is an end view of the end gripper placed on the mounting pedestal, (e) is a side view of the apparatus alone, (f) is a side view of the apparatus when the metal strip is set, g) is an end view of the apparatus during the upside down operation, and (h) is a side view of the apparatus after the upside down. About other embodiment (4th form) of this invention, the structure of a metal strip holding | maintenance inversion apparatus is shown, (a) is a side view, such as a ring body, (b) is the end view, (c) is a ring body. (D) is an end view thereof, (e) is a side view of a ring body or the like placed on a mounting base, and (f) is an end view thereof. The procedure etc. of the resin coating formation method to the metal strip of this invention using the metal strip holding | maintenance inversion apparatus are shown, (a)-(c) are all side views. About other embodiment (5th form) of this invention, the structure of a metal strip holding | maintenance inversion apparatus is shown, (a)-(c) are all end views.

Explanation of symbols

10 ... Curved pipe (deformed metal strip), 11 ... Suspension tool (suspension equipment),
12 ... Tube end cap, 13 ... Fluid immersion tank (powder coating equipment),
14 ... resin powder (thermoplastic resin), 15 ... blower,
16 ... In-process resin coating, 17 ... Metal strip with in-process coating,
18 ... metal strip holding base, 19 ... frame,
20 ... Metal strip holding and reversing device,
21 ... End gripping tool, 22 ... Connecting member, 23 ... Mounting hole,
24: mounting base, 24a: first mounting base, 24b: second mounting base,
25 ... Connecting member, 26 ... Rotating support shaft, 27 ... Fixed base,
30 ... Metal strip holding and reversing device,
31 ... End gripping tool, 32 ... Temporary fixing hole, 33 ... Mounting base,
34 ... Roller, 35 ... Temporary retaining hole, 36 ... Connecting member,
40. Metal strip holding and reversing device,
41 ... Ring body, 44 ... Mounting base, 45 ... Roller, 46 ... Connecting member

Claims (5)

  A function for holding a metal strip having a deformed portion such as a curved portion in a stationary state by gripping the two ends, and lifting the held metal strip from one of the two ends and then on the other A metal strip holding and reversing device having a metal strip top-and-bottom reversing function by a reversing action of a large turn in a mode of passing through and lowering, and a gripping tool having a split structure capable of opening and closing the upper half and in the open state One of the two end portions can be supported in half, and in the closed state, a pair of end gripping tools for gripping the end portion being supported, and one of the end gripping tools are supported and joined via a coupling member. A position-fixed first mounting pedestal in which a member support part is rotatable in a horizontal axis; a position-non-fixed second mounting pedestal that supports the other of the end gripping members via a coupling member; , To enable the holding in the stationary mode and the top-to-bottom reversal by the large-turn reversing operation. Metal strip material holding reversing device to.   In a state in which the metal strip having a deformed portion such as a curved portion is held in a stationary state by gripping the two ends, and the height of the two ends is balanced with the held metal strip It is a metal strip holding and reversing device having a metal strip top and bottom reversing function by a small turn reversing operation in which the standing posture is switched to the top and bottom, and has a split structure that can open and close the upper half and has an arcuate outer peripheral contour A pair of end grippers that can support either one of the two ends in the lower half in the open state and grip the end in support in the closed state, and each of the end grippers. A pair of mounting pedestals that are supported in an axial direction switching permissible mode, and capable of holding in the stationary mode and reversing the top and bottom by the small turn reversing operation. Inversion device.   In a state in which the metal strip having a deformed portion such as a curved portion is held in a stationary state by gripping the two ends, and the height of the two ends is balanced with the held metal strip It is a metal strip holding and reversing device having a metal strip top and bottom reversing function by a small turn reversing operation of a mode in which the standing posture is switched to the top and bottom, and is a gripping tool having a split structure that can open and close the upper half, and in an open state One of the two ends can be supported by the lower half, and in the closed state, a pair of end grips for gripping the supported end, and one of the end grips are supported, and the outer contour At least a part is arcuate, and a pair of rings used in a positional relationship in which each pair of bodies passes parallel to each other in a core shape, and each of the rings is supported in an axial center direction switching allowable mode. A pair of mounting pedestals, and holding in the stationary mode and the small turn reversal operation Metal strip material holding reversing device being characterized in that to allow the vertical reversal caused. A heating process in which a metal strip having a deformed portion such as a curved portion is heated by a heating facility, and a suspended state in a low center of gravity posture in which the metal strip is suspended at two ends and a center of gravity is positioned downward. In the first transfer step of transferring from the heating equipment to the fluidized immersion bath, the thermoplastic resin powder is agglomerated over the entire surface to be coated with the metal strip in the fluidized immersion bath while maintaining the suspended state. Fluid dipping process to be applied, a second transfer process in which the metal strip is moved from the fluid dipping tank to the construction site of the next process in the suspended state, and melting to cool after waiting for complete melting of the adhered resin powder In the resin coating forming method on the metal strip through the solidification step,
In the fluidized immersion step, after the heated metal strip is immersed in the state in which the resin powder is flowed by the upward airflow, the upward airflow is stopped while being immersed and the gas in the tank is sucked into the tank. By performing a series of operations over time in a state where the bulk density of the powder is increased, the amount of adhesion of the resin powder is set to an amount suitable for coating with a thickness of 3 mm or more,
In the melting and solidifying step, the metal strip holding and reversing device according to any one of claims 1 to 3 already installed at a construction site of the step is used, and the metal strip is Receive the low center of gravity posture, and once wait for the resin powder to completely melt and become a molten resin, the metal strip holding and reversing device once turns the metal strip upside down. Or by correcting the thickness deviation of the molten resin by alternately taking the low center of gravity posture and the high center of gravity posture in which the top and bottom are replaced, by applying the metal strip multiple times.
A method for forming a resin coating on a metal strip characterized by the above. The method for forming a resin coating on a metal strip according to claim 4 , wherein the metal strip having the deformed portion is a bent metal pipe.

Images