JP4548819B2 - Stripping method of resin layer of resin-coated metal pipe - Google Patents

Description

  The present invention relates to a chipping during traveling in a metal pipe having a relatively small diameter of 20 mm or less, which is disposed in a lower part of a vehicle body as a hydraulic pipe, a fuel pipe, an air pipe or other pipe used in an automobile or the like. In order to have corrosion resistance against (stepping stones) and splash (muddy water), it has a film-like resin layer on its outer peripheral surface, and in order to perform end processing such as grooves, spools, bulges, flares, etc. And / or a method for removing the film-like resin layer of the resin-coated metal tube in order to form a grip portion for a clamp member in the intermediate portion.

In recent years, hydraulic pipes such as power steering, fuel main pipes, return pipes, evaporation pipes, and other pipes and other pipes installed in the lower part of automobiles have been coated with resin to provide chipping resistance and splash resistance. A number of resin-coated metal tubes are used that are formed at least in the form of a thin film and, if necessary, in the form of a thick film.
As a specific example of such a coated metal tube, a chromate is formed on the outer peripheral surface of the metal tube on a plated layer of zinc or zinc / nickel or the like by a plating method such as electricity, chemistry, or melting, if necessary. A film is formed, and further, an epoxy primer having a thickness of about 20 μm and polyvinyl fluoride (PVF) are coated, and a heat-shrinkable tube is further applied over the entire length to form a polymer coating layer. Polyamide resin (PA) or polypropylene (such as PA11 or PA12 having a thickness of about 200 to 300 μm on the formed or zinc or zinc / aluminum plating layer provided on the outer peripheral surface of the metal tube. A product obtained by extruding a resin such as PP) is known.

  When carrying out terminal processing such as grooves, spools, bulges, flares, etc. on such coated metal tubes or polymerized coated metal tubes, or when forming a gripping portion by a clamp member, the outer resin layer is peeled off in advance. There is a need. As a method for removing such a resin layer, there is a method by cutting. However, in the method using cutting, the resin layer cannot be removed uniformly due to variations in accuracy of the target metal tube, such as roundness, straightness, outer diameter, and wall thickness of each layer, and the cutting blade cannot remove the base. Even the plating layer and the resin layer that should remain as the inner layer may be scraped off or damaged. In addition, there is a problem in that it takes time and labor since it is necessary to remove the resin layer without damaging the underlying plating layer or the inner layer, and to remove the resin layer uniformly.

  Therefore, the present inventor is able to peel off the resin layer reliably and without damage to the ground, and even when the outer layer is made of a softer resin than the inner layer even when a polymerized resin layer is provided. Previously proposed a method for stripping the resin layer of the resin-coated metal tube that can strip only the outer layer (Patent Document 1).

In this method, a peeling roll that presses inward in the radial direction from the outside when the resin layer is peeled off from the resin-coated metal tube formed by applying a resin layer to the outer peripheral surface of the metal tube. One of the main features is to press the resin layer and move the metal tube and the pressing means relatively in the circumferential direction. FIG. 7 is a schematic view showing an example of the method. For example, a resin layer (epoxy resin, PVF, polypropylene, polyethylene, polyamide resin, or the like) is formed on the outer peripheral surface of a metal tube 1-1 made of a steel tube having a tube diameter of about 20 mm or less. The resin layer 1-2 is pressed by rotating a plurality of peeling rolls 3 arranged concentrically with the metal tube 1-1 against the resin layer 1-2 of the resin-coated metal tube to which 1-2 is applied. 1-2 is peeled off.
According to this method, the resin layer can be peeled off very easily without damaging the base, and even when the polymer coating resin layer is provided, when the outer layer is made of a softer resin than the inner layer, only the outer layer is removed. There is an effect that it can be peeled off.
In addition, when the resin layer 1-2 of the resin-coated metal tube is pressed inward in the radial direction by the peeling roll 3 from the outside, the reason why the resin layer is peeled off from the outer peripheral surface of the metal tube 1-1 is not clear. The resin layer 1-2 is extended by the peeling roll 3 that rotates while pressing, and the inner peripheral surface of the resin layer is expanded, and the resin layer 1-2 is expanded by the rotation of the peeling roll 3. It seems that peeling occurs at the interface between the peripheral surface and only the resin layer 1-2 is peeled off.

  However, among the resin-coated metal tubes, particularly in the case of a resin-coated metal tube coated with nylon having a high rust-preventing ability, when this nylon coat is removed by the method shown in FIG. 7, as shown in FIG. There arises a problem that nylon burr 1-2 'called "beard" or "dama" occurs in the removed boundary portion. Such burring is not preferable because it may cause problems such as contamination and deterioration of sealing performance, and therefore needs to be removed by a cutter or the like, which increases the number of processes.

As a countermeasure, the present inventor has developed a resin layer called “beard” or “dama” at the boundary portion by the above-described method using a peeling roll even for a nylon-coated resin-coated metal tube having a high rust prevention ability. A method for removing a resin layer that can remove the resin layer satisfactorily without causing burr has been proposed (Patent Document 2).
As shown in FIGS. 9 and 10, this method presses the resin layer 11-2 with the peeling roll 12 that presses inward in the radial direction from the outside, and relatively connects the metal tube 11-1 and the peeling roll 12. In the method in which the resin layer 11-2 is peeled and removed in the circumferential direction, the pressing means provided with the pressing roll 12-2 is returned to the resin layer 11-2 at the location corresponding to the boundary portion of the pressing portion of the peeling roll 12. A rolling processing portion 15 (FIG. 10) having a step and / or an indentation smaller than the thickness of the resin layer is provided.
According to this method, the resin layer can be reliably peeled off without damaging the base, and without causing burr called “beard” or “dama” at the end. The resin layer can be removed satisfactorily.

However, the above resin layer removal method (Patent Document 2) is excellent in that the resin layer can be removed without causing burr called “beard” or “dama” at the end of the resin layer. As shown in FIG. 10, since the rolling process part 15 is provided, the unremoved part 11-2a of the resin layer is inevitably generated. Further, even if stripping is performed by the above-described method using the peeling roll without providing the rolling processing portion 15 (FIG. 10) and preventing burr called “beard” or “dama”, FIG. As shown in FIG. 4, a burr 11-2b may occur at the boundary portion.
Such leftover portions 11-2a and burrs 11-2b have a significant effect on the quality of the product, and are therefore removed manually by a cutting blade after processing. For this reason, it is not preferable because removal of the resin layer remaining part and burrs is time-consuming and processing cost is high, and the underlying plating layer may be damaged by the cutting blade.

In order to solve such problems, the present inventor further proposed a method for removing the resin layer of the resin-coated metal tube, which can mechanically remove the resin layer without leaving it manually (patent) Reference 3).
This method is characterized in that the resin layer is peeled and removed by causing a friction between the resin layer and the peeling roll by making a speed difference between the metal tube and the peeling roll during the peeling process of the resin layer, Not only can the resin layer be completely removed without generating leftovers, burrs, etc., but it also does not damage the base of the resin-coated metal tube, so that the corrosion resistance is not deteriorated.
JP-A-11-82820 Japanese Patent Application No. 2002-143398 Japanese Patent Application No. 2002-342725

However, the resin layer removing methods described in Patent Documents 1 to 3 have the problems described below.
As described above, the resin-coated metal pipe is a relatively thin film composed of an electric-welded pipe, a seamless pipe, a semi-seamless pipe, and a brazed pipe or a welded pipe that is previously wound with a copper alloy plating layer and wound in a single layer or multiple layers. A metal pipe made of a steel pipe having a diameter, for example, a pipe diameter of about 20 mm or less, a polymer resin layer of epoxy resin and PVF coated on the outer peripheral surface of the metal pipe, a film made of polypropylene, polyethylene, polyamide resin, or nylon In the case of a resin-coated metal tube having a high adhesion strength of the resin layer (resin coating), it takes only a considerable amount of time to remove and remove the resin layer using the peeling rolls 3 and 12. In addition, since it is necessary to increase the surface pressure of the peeling roll against the metal pipes 1-1 and 11-1, for example, a thin-walled resin coating having a thickness of 1 mm or less. In the case of a metal tube, as shown in FIG. 12, before the resin layers 1-2 and 11-2 are peeled and removed, the metal tubes 1-1 and 11-1 are reduced in diameter, and the resin layer is peeled off. After removal, the deformation had to be corrected.

  The present invention has been made to solve such a problem, and even in the case of a thin-walled resin-coated metal tube or a resin-coated soft metal tube having a high adhesion strength of a resin layer (resin coating), the metal tube The present invention is intended to propose a method for stripping a resin layer of a resin-coated metal tube that allows a resin layer to be peeled and removed easily and quickly by a peeling roll without reducing the diameter of the resin.

Peeling method of a resin layer of the resin-coated metal tube according to the present invention, when separating and removing the resin layer from the resin-coated metal tube the resin layer formed by depositing on the outer peripheral surface of the metal tube, remove the peeling of the resin layer The resin layer is pressed by a peeling roll that presses inward in the radial direction from the outside in a state where the core metal is inserted into the resin-coated metal tube on the side to be operated, and the metal tube and the peeling roll are relatively circumferentially a method of separating and removing the resin layer moved in, as the core metal, the tip of its telescopic spring plate is plural detachably fixedly fitted in the radial direction, the outer surface of the spring plate is a resin A structure that is elastically fitted to the inner surface of the coated metal tube, or that is hollow for a certain length from its tip, and that a plurality of slits are formed in the axial direction from the open end to the peripheral wall of the hollow portion. In the cored bar at the open end where Those characterized by more slightly by fitted in an elastic material such as rubber of large diameter (solid or hollow), the use of which the core metal is no structured to elastically fitted into the resin-coated metal tube surface It is.
Furthermore, the resin layer peeled off by the peeling roll is cut off with a cutting tip near the tip of the peeling roll.

  According to the method of the present invention, since the surface pressure of the peeling roll against the metal tube can be increased by the action of the metal core, even if it is a thin-walled type resin-coated metal tube with a high adhesion strength of the resin film, the metal tube The resin layer can be peeled and removed easily and quickly by the peeling roll without reducing the diameter of the resin. Further, by using a core metal whose outer peripheral surface is structured to be elastically fitted to the inner surface of the resin-coated metal tube, the resin-coated metal tube can be easily taken in and out of the core metal, and the metal tube of the peeling roll Therefore, the tool life can be extended.

  1 is a schematic longitudinal side view showing an embodiment of a resin coating layer peeling apparatus (tool) for carrying out the method of the present invention, FIG. 2 is a schematic front view of the apparatus shown in FIG. 1, and FIG. 4 is a longitudinal side view showing another embodiment of the cored bar of the apparatus shown in FIG. 2, FIG. 4 is a longitudinal side view showing another embodiment of the cored bar, and FIG. 5 is another side view of the apparatus for carrying out the method of the present invention. FIG. 6 is a schematic front view of the apparatus shown in FIG. 5, 21 is a resin-coated metal tube, 22 is a peeling roll, 23 is a head, 24 is a roll holder, 25, 35, 45. Is a cored bar, and 26 is a cutting tip.

  Resin-coated metal tube 21 is an electric-welded tube, seamless tube, semi-seamless tube, and a brazed tube that is pre-coated with a copper alloy plating layer and wound in a single layer or multiple layers, like the resin-coated metal tube shown in FIG. Alternatively, a metal pipe 21-1 made of a steel pipe having a relatively small diameter made of a welded pipe, for example, a pipe diameter of about 20 mm or less, and a polymer resin layer of epoxy resin and PVF coated on the outer peripheral surface of the metal pipe 21-1. And a single-layered resin layer 21-2 made of polypropylene, polyethylene, polyamide resin, or nylon.

  The peeling roll 22 is constituted by a roll with a slope whose outer peripheral surface is slightly tapered in the axial direction, and each peeling roll is rotatably fitted in a roll holding hole provided in the peripheral surface of a cylindrical roll holder 24. Incorporated so that the outer surface of each peeling roll 22 is in contact with the head 23 supported and provided with an inclination angle twice that of the peeling roll on the inner surface, the roll holder 24 is inward or the head 23 is outward. Alternatively, by moving the roll holder 24 and the head 23 at the same time, the release rolls 22 are rotated while pressing the resin layer 21-2 of the resin-coated metal tube 21 in the radial direction by the taper action of the roll and the head. This is a mechanism for stripping 21-2.

  Moreover, the metal core 25 shown in FIG. 1 is composed of a straight rod (rod) having an outer diameter that can be inserted into and removed from the resin-coated metal tube 21 and is incorporated in the resin coating layer peeling apparatus.

  The removal method of the resin layer 21-2 of the resin-coated metal tube 21 by the apparatus shown in FIGS. 1 and 2 will be described. With the resin-coated metal tube 21 fixed, the core metal 25 of the resin-coated layer peeling apparatus is attached to the resin. Inserted into the coated metal tube 21, and in this state, the roll holder 24 is moved inward, the head 23 is moved outward, or the roll holder 24 and the head 23 are moved simultaneously to remove the plurality of peeling rolls 22 from the metal. The head 23 is rotated while being moved toward the center of the tube 21. When each peeling roll 22 comes into contact with the outer peripheral surface of the resin-coated metal tube 21 almost simultaneously, each peeling roll 22 rotates while pushing the resin layer 21-2 of the resin-coated metal tube 21, and the resin layer 21-2 gradually peels off. Taken. At this time, surface pressure is applied to the resin-coated metal tube 21 by each peeling roll 22, but since the core metal 25 is inserted into the resin-coated metal tube 21, the resin-coated metal tube 21 is a thin-walled pipe. Even so, due to the action of the metal core 25, the resin-coated metal tube 21 does not shrink (deform) due to the large surface pressure applied by each peeling roll 22. Therefore, even a resin-coated metal tube having a thin-walled type and a high adhesion strength of the resin film, the resin layer can be peeled and removed easily and quickly by the peeling roll without reducing the diameter of the metal tube.

Further, as the core bar used in the present invention, the core bars 35 and 45 shown in FIGS. 3 and 4 may be used instead of the straight rod shown in FIG.
That is, the metal cores 35 and 45 shown in FIGS. 3 and 4 are provided with an appropriate elastic deformation portion at the tip of the metal core, and the metal core 35 shown in FIG. A plurality of recesses 35-1 having a length corresponding to the axial length of the plurality of recesses 35-1 are formed at equal intervals in the circumferential direction, and spring plates 35-2 that are elastic in the radial direction are provided in the respective recesses 35-1. Is a structure that is fitted and fixed so as to be slightly larger in diameter than the outer diameter of the core metal main body. Therefore, in the case of this core metal 35, it is elastically fitted in the resin-coated metal tube 21 by the action of a plurality of spring plates 35-2 that are fitted and fixed to the tip portion.
Moreover, the cored bar 45 shown in FIG. 4 uses a pipe-shaped object that is hollow from the tip for a certain length as a main body, and has a plurality of slits 45-1 in the axial direction from the open end to the peripheral wall of the hollow part. A rubber or the like that is formed at equal intervals on the circumference, has a length substantially corresponding to the axial length of the peeling roll 22 and has a diameter slightly larger than the inner diameter of the core metal. In the case of this cored bar 45, the outer peripheral surface of the cored bar is elastically fitted to the inner surface of the resin-coated metal tube by the action of the elastic body 45-2. Is done.

  When a cored bar having a structure in which an appropriate elastic deformation part is provided at the tip of the cored bar and is elastically fitted to the inner surface of the resin-coated metal tube, as shown in FIGS. 3 and 4 above, In addition to facilitating the insertion and removal of the resin-coated metal tube with respect to the core, it is also possible to absorb unnecessary surface pressure with respect to the metal tube of the peeling roll by the elastic deformation portion.

On the other hand, the resin coating layer peeling apparatus shown in FIGS. 5 and 6 has a configuration in which a cutting tip 26 for cutting off the resin layer peeled off by the peeling roll 22 is assembled at the tip of the head 23 of the apparatus. The cutting tip 26 is attached to the bottom surface of the recess 23-1 provided in the opening of the head 23 with a screw 26-1 so that the tip is located near the surface of the resin-coated metal tube 21. ing. Here, an example in which two cutting tips 26 are arranged at equal intervals on the circumference of the concave portion 23-1 of the head 23 is shown, but two cutting tips 26 are not necessarily provided, and one may be provided. Needless to say.
In the case of the resin coating layer peeling device with the cutting tip 26, after the resin layer peeling operation, the resin coating metal tube 21 is peeled off from the resin coating layer peeling device while being rotated, thereby being peeled off by the peeling roll 22. The resin layer is further cut by the cutting tip 26.

It is a schematic longitudinal cross-sectional side view which shows one Example of the resin coating layer peeling apparatus (tool) for implementing this invention method. It is a schematic front view of the apparatus shown in FIG. It is a vertical side view which shows the other Example of the metal core of the apparatus shown in FIG. 1, FIG. It is a vertical side view which similarly shows another Example of a metal core. It is a schematic vertical side view which shows the other Example of the apparatus for enforcing the method of this invention. It is a schematic front view of the apparatus shown in FIG. It is a schematic side view which shows an example of the conventional resin layer peeling apparatus made into the object of this invention. It is a cross-sectional view showing a part of the resin-coated metal tube after the resin layer is removed by the apparatus shown in FIG. It is a schematic side view which shows the other example of the conventional resin layer peeling apparatus made into the object of this invention. FIG. 10 is a cross-sectional half view showing a part of the resin-coated metal tube after the resin layer is removed by the apparatus shown in FIG. 9. It is an enlarged side view which shows a part of resin-coated metal tube after the resin layer removal by the conventional resin layer peeling apparatus. It is a partial expanded vertical side view which shows an example of the diameter-reduced state of the resin-coated metal pipe in the middle of resin layer peeling by the conventional resin layer peeling apparatus.

Explanation of symbols

21 Resin-coated metal tube 22 Peeling roll 23 Head 24 Roll holder 25, 35, 45 Core metal 26 Cutting tip

Claims (3)

When the resin layer is peeled and removed from the resin-coated metal tube formed by attaching the resin layer to the outer peripheral surface of the metal tube, the outer surface is inserted in the resin-coated metal tube on the side where the resin layer is peeled and removed. while pressing the resin layer by peeling roll to further pressed radially inwardly, in a method of separating and removing the resin layer moved the peeling roll and the metal tube relatively circumferential direction, wherein the core metal is In addition, a plurality of radially expandable and contractible spring plates are detachably fitted and fixed to the distal end portion, and the outer surface of the spring plate is elastically fitted to the inner surface of the resin-coated metal tube. Stripping method of resin layer of resin-coated metal tube. When the resin layer is peeled and removed from the resin-coated metal tube formed by attaching the resin layer to the outer peripheral surface of the metal tube, the outer surface is inserted in the resin-coated metal tube on the side where the resin layer is peeled and removed. In the method of pressing the resin layer with a peeling roll that presses inward in the radial direction and moving the metal tube and the peeling roll relatively in the circumferential direction to peel and remove the resin layer, The hollow portion is hollow for a certain length, and a plurality of slits are formed in the axial direction from the opening end to the peripheral wall of the hollow portion, and the opening end portion where the slit is formed is slightly smaller than the inner diameter of the cored bar. Stripping the resin layer of a resin-coated metal tube, wherein an elastic body such as a large-diameter rubber is internally fitted so that the outer peripheral surface of the core metal is elastically fitted to the inner surface of the resin-coated metal tube Method. 3. The method for peeling a resin layer of a resin-coated metal tube according to claim 1, wherein the resin layer peeled by the peeling roll is cut with a cutting tip near the tip of the peeling roll.

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