JP2005282737A - Rubber cylinder body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber cylinder body having improved durability without impairing pressure resistance. <P>SOLUTION: A pair of reinforcing rings 4a, 4b are arranged in parallel. A reinforcing cord 5 is wound to be bridged between the pair of reinforcing rings 4a, 4b and arranged in two lines on the outer and inner face sides. The reinforcing cord 5 is covered with an inner face rubber and an outer face rubber to form a rubber coating. The reinforcing cord 5 is continuously embedded in two reinforcing cord layers 6a, 6b on the outer and inner face sides. The reinforcing rings 4a, 4b lock a continuous portion of the reinforcing cord 5 to improve the pressure resistance. The rubber coating 3 has constant rigidity in a range from the ends to the shell to improve durability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber cylinder used for a diaphragm of an air spring mounted on an air suspension of a railway vehicle or an automobile, a pipe joint as a vibration-proof joint, and the like.

  In general, an air spring equipped in an air suspension of a railway vehicle or an automobile has a structure in which metal fittings connected to a vibration generating side or a vibration receiving side are fastened to both ends of a diaphragm constituting a wall portion of a gas chamber. . The diaphragm is a rubber cylinder in which a pair of reinforcing rings such as a bead ring and a solid ring are embedded in both ends of a cylindrical rubber film to enhance the fastening property with a metal fitting.

  The rubber film in a rubber cylinder such as a diaphragm is a part that repeatedly bends greatly with the vibration of the vehicle, etc., and a reinforcing cord layer is provided by embedding a reinforcing cord to increase its pressure resistance and durability. It is done. As a method for providing the reinforcing cord layer, a ply having a plurality of reinforcing cords is often interposed between the outer rubber and the inner rubber constituting the rubber film.

  A ply is a structure in which a plurality of reinforcing cords are arranged in parallel and wrapped with a thin sheet-like rubber, and the ends of the ply are folded back and locked with reinforcing rings at both ends of the rubber cylinder. The pressure resistance of the rubber cylinder is increased.

Patent document 1 pays attention to the fact that the breakage of the weft yarn of Sudarecord used as a reinforcing cord reduces the durability of the rubber film in order to increase the durability of such a rubber cylinder (air spring). A technique for preventing the breakage by setting the elongation to 80% or more is disclosed.
Japanese Utility Model Publication No. 2001-20148 (paragraph numbers 0008 and 0011)

  By the way, by folding back the end of the ply, the rigidity at the end of the rubber film becomes about twice as large as the rigidity at the body of the rubber film, so that the rigidity suddenly changes in the vicinity of the end of the rubber film. Sudden changes are likely to become the starting point of cracks in the rubber film.

  In other words, even if a reinforcement cord made of a suitable material is used to improve durability as in Patent Document 1, sufficient durability is exhibited by folding the ply to increase pressure resistance. There is a risk that it will be impossible. On the other hand, the one in which the end of the ply end portion is simply omitted and the durability is improved cannot sufficiently lock the end portion of the reinforcing cord, and the pressure resistance is lowered.

  An object of this invention is to provide the rubber cylinder which can improve the durability, without impairing pressure | voltage resistance.

  In view of the above problems, the present invention provides a two-layer reinforcing cord layer in which a pair of reinforcing rings are embedded at both ends of a cylindrical rubber membrane, and a reinforcing cord inclined in the bias direction is embedded in the rubber membrane. Assuming a structure in which the respective bias directions of the two layers of reinforcing cord layers are set so as to cross each other, the two layers of reinforcing cords are wound by winding the reinforcing cords across a pair of reinforcing rings. A rubber cylinder continuously embedded in a layer is provided.

  According to this configuration, the reinforcing cords embedded in the two reinforcing cord layers on the outer surface side and the inner surface side can be made continuous, and the continuous portion can be locked by the reinforcing ring. As a result, the rigidity of the rubber film can be made constant from the end to the trunk while the reinforcing cord is locked by the reinforcing ring, so that the durability of the rubber cylinder can be improved without impairing the pressure resistance. Can be increased. The reinforcing ring may be any type such as a bead ring, a solid ring, or a bead wire.

  The pair of reinforcing rings may have the same diameter, but if they are set to different diameters, a preferred embodiment of the present invention can be provided.

  That is, when the diameters of the reinforcing rings are different from each other, the one constituting the reinforcing cord layer from the plies having a plurality of parallel reinforcing cords constitutes a cylindrical body having a constant diameter formed by embedding the ply in the main rubber, It is necessary to obtain a predetermined shape by expanding or reducing the diameter. Therefore, when the cylinder is expanded or contracted, ply edge pulling and reinforcement cord spacing are likely to be uneven, and the durability of the rubber film is likely to decrease. On the other hand, if a ply having a reinforcing cord interval changed in the length direction is prepared in advance, it becomes difficult to manufacture the ply.

  On the other hand, by adopting the present invention and adopting a configuration in which the reinforcing cord is directly wound around the reinforcing ring, the reinforcing cord is simply arranged in the circumferential direction of the rubber film, and the process of expanding or reducing the diameter is performed. It can be made unnecessary. Thereby, the space | interval of the reinforcement cord in the circumferential direction of a rubber film can be made uniform, and durability of a rubber film can be improved.

  Examples of particularly suitable parts for using the rubber cylinder of the present invention include air spring diaphragms and piping joints as vibration-proof joints.

  In the present invention, a pair of reinforcing rings are embedded at both ends of a cylindrical rubber film, and a two-layer reinforcing cord layer formed by embedding a reinforcing cord inclined in the bias direction is provided on the rubber film. Provided is a method of manufacturing a rubber cylinder in which the bias directions of two reinforcing cord layers are set so as to intersect each other.

  More specifically, first, a pair of reinforcing rings are arranged substantially in parallel with a space therebetween, and then the reinforcing cord is inclined so as to be bridged between the pair of reinforcing rings while being inclined in the bias direction. As a result, the reinforcing cords are arranged in two rows on the outer surface side and the inner surface side, and the bias directions thereof are crossed with each other to form a cylindrical body composed of the reinforcing ring and the reinforcing cord. After covering the inner surface and the outer surface of the cylindrical body with unvulcanized rubber, the unvulcanized rubber is vulcanized to form a rubber film to obtain a rubber cylinder.

  Here, the winding of the reinforcing cord will be described in more detail. One reinforcement cord of the outer surface side and the inner surface side inclined in the bias direction is inverted so as to be hooked on the reinforcement ring, and is continued to the other reinforcement cord. At this time, the bias direction of the reinforcing cord is switched to a symmetric direction with respect to the circumferential direction.

  While repeating this, a plurality of reinforcing cords are made to circulate in the circumferential direction of the rubber film, thereby forming two layers of reinforcing cord layers whose bias directions intersect each other on the entire circumference of the rubber film. The number of turns of the reinforcing cords in the circumferential direction of the rubber film increases as the interval between the reinforcing cords becomes narrower and the inclination angle of the bias direction with respect to the axial direction of the rubber film increases.

  According to this configuration, the reinforcing cords embedded in the two reinforcing cord layers are arranged in a single process, and the conventional ply folding is not required. Can be planned.

  In other words, in order to arrange the reinforcing cords in the bias direction crossing each other using the ply, it is necessary to attach the two plies in separate steps, but by winding the reinforcing cord directly around the reinforcing ring, one step is required. The reinforcement cord can be arranged with. Further, the ply folding step is not required, and the material of the folded portion can be reduced. Since there is no folding of the ply, it is possible to prevent defects such as defective dimensions, poor adhesion, and air entrainment when folding the ply.

  One reinforcing cord may be wound around the pair of reinforcing rings, but the time required for winding the reinforcing cord can be shortened by winding a plurality of reinforcing cords parallel to each other. If the reinforcing cord is wound around the reinforcing ring in a state of being covered with rubber, it is possible to make it difficult to cause a displacement of the reinforcing cord during vulcanization molding.

  Since the unvulcanized rubber is arranged after the reinforcing cords are arranged, the unvulcanized rubber on the outer surface side and the inner surface side can be formed continuously in one process, and the man-hour can be reduced correspondingly. That is, the present invention provides a method for continuously forming unvulcanized rubber from the inner surface side to the outer surface side or from the inner surface side to the outer surface side of the cylindrical body composed of the reinforcing ring and the reinforcing cord.

  As described above, according to the present invention, by wrapping the reinforcement cord so as to span the pair of reinforcement rings, the structure in which the continuous portion of the reinforcement cord on the outer surface side and the reinforcement cord on the inner surface side is locked by the reinforcement ring. Yes. Thereby, the durability of the rubber cylinder can be increased without deteriorating the pressure resistance by making the rigidity of the rubber film constant from the end portion to the trunk portion.

  Further, by arranging the reinforcing cords in one process and making the folded portions at both ends unnecessary, it is possible to reduce man-hours, reduce materials, and improve quality. Furthermore, by making the thickness of the rubber film constant by eliminating the folded portions at both ends, the metal fitting structure can be simplified and the equipment cost can be reduced.

  Hereinafter, the best mode for carrying out a rubber cylinder according to the present invention will be described with reference to the drawings. FIG. 1 is a view showing a main part of an air spring provided with a diaphragm as a rubber cylinder according to the present invention, wherein the upper half is a side view and the lower half is a sectional view.

  This air spring is mounted on an air suspension of a railway vehicle or automobile, and is connected to the vibration generating side or the vibration receiving side at both ends of a diaphragm (rubber cylinder) constituting the wall portion of the gas chamber. It is set as the structure which fastened the metal fitting 2 made.

  The diaphragm 1 is formed by embedding a pair of solid rings (reinforcing rings) 4 a and 4 b for improving the fastening property with the metal fitting 2 at both ends of a cylindrical rubber film 3. The pair of solid rings 4a and 4b have different diameters so that they can be suitably used for piston type air springs.

  The rubber film 3 is provided with a reinforcing cord layer 6 in which a reinforcing cord 5 that is inclined in the bias direction is embedded, and the bias direction is set to a direction that forms an inclination angle of 45 ° with respect to the axial direction of the diaphragm 1, for example. Has been. As the reinforcing cord layer 6, an outer surface side reinforcing cord layer 6a and an inner surface side reinforcing cord layer 6b are provided, and the bias directions of the two layers of reinforcing cord layers 6a and 6b are set to intersect each other. .

  The reinforcement cord 5 is made of nylon, for example, and is wound around the pair of solid rings 4a and 4b. Thereby, the reinforcement cord 5 is continuously embedded in the reinforcement cord layer 6a on the outer surface side and the reinforcement cord layer 6b on the inner surface side, and the continuous portions are locked to the solid rings 4a and 4b.

  Next, a procedure for manufacturing a diaphragm as the rubber cylinder of the present invention will be described. 2 is a conceptual diagram showing a method of winding a reinforcing cord around a pair of solid rings, FIG. 3 is a perspective view of a cylindrical body composed of a pair of solid rings and a reinforcing cord, and FIG. 4 is a front view of the reinforcing cord winding device. FIG. 5 is a side view of the reinforcing cord winding device.

  As shown in FIG. 2, first, a pair of solid rings 4 a and 4 b are arranged substantially in parallel with a space therebetween, and are held by a plurality of rollers 7. Further, a chain (or endless belt) 8 is disposed so as to pass through the inside and outside of the solid rings 4a and 4b, and a single cord bobbin 9 for supplying the reinforcing cord 5 is attached thereto.

  Next, the roller 7 is rotated to rotate the solid rings 4a and 4b in the circumferential direction at a constant rotational speed, while the chain 8 is turned at a constant speed, and the reinforcing cord 5 previously covered with rubber from the single cord bobbin 9 is rotated. Supply. The reinforcing cord 5 is wound around the pair of solid rings 4a and 4b while being repeatedly inverted so as to be caught by the solid rings 4a and 4b while being inclined in the bias direction.

  As shown in FIG. 3, the reinforcing cords 5 wound around the solid rings 4a and 4b are arranged in two rows on the outer surface side and the inner surface side. Thereby, the cylindrical body 10 which consists of solid ring 4a, 4b and the reinforcement cord 5 is comprised. When the reinforcement cord 5 is reversed, the bias direction of the reinforcement cord 5 is switched to a direction symmetric with respect to the circumferential direction of the diaphragm (rubber cylinder) 1, whereby the reinforcement cord 5 on the outer surface side and the reinforcement cord 5 on the inner surface side. And their bias directions cross each other.

  At the stage where the solid rings 4a and 4b are rotated once, the reinforcing cord 5 only exhibits a zigzag that reciprocates in the bias direction, and the reinforcing cords 5 on the outer surface side and the inner surface side have a wide interval. State. Thereafter, the solid rings 4a and 4b are rotated a plurality of times, whereby the reinforcing cords 5 are wound so as to fill the initial interval and arranged at a predetermined interval. Further, since the diameters of the solid rings 4a and 4b are different from each other, the distance between the reinforcing cords 5 is different between the vicinity of the solid ring 4a and the vicinity of the solid ring 4b.

  After constituting the cylindrical body 10, unvulcanized rubber is formed along the circumferential direction of the cylindrical body 10, and the inner surface and the outer surface of the cylindrical body 10 are covered with unvulcanized rubber. At this time, unvulcanized rubber is formed continuously from the inner surface side to the outer surface side of the cylindrical body 10 or from the inner surface side to the outer surface side. Specifically, the nozzle that pushes the unvulcanized rubber is moved from the inner surface side to the outer surface side or from the inner surface side to the outer surface side while rotating the cylindrical body 10 in the circumferential direction.

  A rubber bag is inserted into the inner surface side of the cylindrical body 10 whose inner and outer surfaces are covered with unvulcanized rubber, an internal pressure is applied, the outer surface side is pressed against a mold, and the unvulcanized rubber is vulcanized and molded to form a rubber film. By forming 3, the diaphragm 1 is configured. Since the reinforcing cord 5 is covered with rubber in advance, the reinforcing cord 5 is not easily displaced when vulcanized.

  4 and 5 show an example of the reinforcing cord winding device. This reinforcing cord winding device is attached to the roller 7 that sandwiches the solid rings 4a and 4b with the auxiliary roller 7a, the chain 8 disposed so as to pass inside and outside the solid rings 4a and 4b, and the chain 8. And a single cord bobbin 9 for supplying the reinforcing cord 5 while moving in and out of the solid rings 4a and 4b.

  The roller 7 has a rubber truncated cone shape, and rotates by the driving force transmitted from the motor 11 to rotate the solid rings 4a and 4b in the circumferential direction at a constant rotational speed. A groove 7b for preventing the displacement of the solid rings 4a and 4b is formed in a portion of the roller 7 facing the auxiliary roller 7a, and the solid rings 4a and 4b are firmly sandwiched between the roller 7 and the auxiliary roller 7a. To prevent the fall.

  The diameter of the roller 7 in the two grooves 7b is set to a ratio for rotating the solid rings 4a and 4b having different sizes at the same rotational speed. By making the roller 7 made of rubber, the winding thickness of the solid rings 4a and 4b due to the winding of the reinforcing cord 5 is absorbed.

  The chain 8 is provided with a part 8a that can be opened and closed at a part thereof, so that the inside and outside of the solid rings 4a and 4b can be passed therethrough. The chain 8 is turned at a constant speed by the rotation of the sprocket 12, and the inclination angle in the bias direction is set to a desired angle by adjusting the turning speed and the rotation speed of the solid rings 4a and 4b. ing.

  Next, the result of comparing an air spring provided with a diaphragm as a rubber cylinder of the present invention and a conventional air spring will be described. In the diaphragm 1 of the present invention and the conventional product to be compared here, bead rings are used as the reinforcing rings 4a and 4b in place of the solid rings.

  First, the product of the present invention will be described. The product of the present invention is the diaphragm 1 manufactured by the above-described procedure. The inner diameter on the large diameter side of the rubber film 3 is 318 mm, and the inner diameter on the small diameter side of the rubber film 3 is 285 mm.

  A rubber-coated nylon cord was used as the reinforcing cord 5, the winding angle was 45 ° with respect to the shaft of the diaphragm 1, and the number of windings was 26 / 2.5 cm on the small diameter side. The diameter of the nylon cord is φ0.7 mm (diameter in a rubber-coated state is φ1 mm), the breaking strength is 20 kgf / piece, and the breaking elongation is 20%. The thickness of the unvulcanized rubber that is vulcanized and molded into the main rubber of the rubber film 3 is 2 mm.

  Next, conventional products will be described. In the conventional product, the unvulcanized rubber on the inner surface is wrapped around a molding drum, and two plies and the unvulcanized rubber on the outer surface are affixed to this to form an unvulcanized rubber film, which is then vulcanized. Diaphragm 1 is manufactured by sulfur molding. The inner diameter on the large diameter side of the rubber film 3 is 314 mm, and the inner diameter on the small diameter side of the rubber film 3 is 285 mm.

  The outer diameter of the molding drum is a constant φ285, and after the two plies are attached, the large diameter side is expanded to 314 mm using a special shaper. After expanding the large-diameter side, place bead rings on the large-diameter side and small-diameter side ends, lift the end of the special shaper, fold back the two plies, and apply the unvulcanized rubber on the outer surface side I did it.

  As the reinforcing cord 5, a nylon nylon cord is adopted, which is wrapped with a sheet-like rubber having a thickness of 1 mm to form a ply. The bonding angle of the ply was 45 ° with respect to the axis of the molding drum, and the number of nylon cords was 26 / 2.5 cm. The diameter, breaking strength, and breaking elongation of the nylon cord are the same as those of the present invention. The thickness of the unvulcanized rubber is 2 mm on both the inner surface side and the outer surface side.

  Table 1 shows the result of comparing the man-hours for manufacturing the diaphragm of the present invention and the conventional product. Here, Table 1 shows only the steps different between the product of the present invention and the conventional product, and the steps common to both are omitted.

  The manufacturing process of the present invention alone is 5 processes, and the total time required for each process is 42.6 minutes. The manufacturing process of only the conventional product is 9 processes, and the total time required for each process is 46 minutes. That is, the manufacturing time of the product of the present invention is shorter by 3.4 minutes than the manufacturing time of the conventional product. Note that the time required for vulcanization molding differs between the product of the present invention and the conventional product because the end of the rubber film becomes thicker due to the folding of the ply.

  Of each process, the vulcanization molding process and the winding process of the reinforcing cord in the product of the present invention do not require manpower, so the man-hours that are omitted are 2.6 minutes for the product of the present invention and the conventional product. 6 minutes, and the product of the present invention is 3.4 minutes less than the conventional product.

  Comparing the occurrence rate of defective products, the conventional products have a complicated structure especially in the vicinity of the bead ring and fluctuations in the spacing of the reinforcing cords during the diameter expansion process, resulting in dimensional defects, poor adhesion, and air Defective products that caused entry or the like showed 2% of the total, but in the products of the present invention, no defective products were generated.

  The durability was compared repeatedly by setting the internal pressure (air pressure) to 0.6 MPa and the swing width (compression) to 60 mm, and the durability test was repeated. In the conventional product, peeling occurred at the folded portion of the reinforcing cord at an average number of repetitions of 400,000, and abrasion of the reinforcing cord and topping rubber occurred at the same location at an average number of repetitions of 460,000, resulting in bursts. The product of the present invention had no abnormality until the average number of repetitions reached 1 million. Separation was observed at the large-diameter end at an average number of repetitions of 1.6 million, but no burst occurred until the average number of repetitions reached 2 million.

  According to the above configuration, the reinforcing cords 5 on the outer surface side and the inner surface side are continuously engaged and locked by the reinforcing rings 4a and 4b, so that it is not necessary to turn the end portion of the reinforcing cord 5 (ply). Thereby, the fatigue fracture | rupture which makes the origin the folding | returning part of the reinforcement cord 5 like a conventional product can be prevented. In addition, since the structure is simple, it is possible to eliminate problems such as defective dimensions and air entry.

  Since the end portion of the reinforcing cord 5 is not folded back, the end portion of the rubber film 3 has a constant thickness, the metal fittings 2 at both ends of the air spring are simplified in shape, and the cost is reduced. Fastening and sealing properties can be improved. Moreover, since there is no thick part in an edge part, vulcanization | cure time can be shortened.

  Even when the diameters of the reinforcing rings 4a and 4b at both ends are different, the rubber film 3 can be formed without providing a diameter increasing step as in the prior art. As a result, the manufacturing cost can be reduced, and the quality of the air spring can be improved by keeping the intervals between the reinforcing cords 5 uniform.

  After the cylindrical body 10 composed of the reinforcing rings 4a and 4b and the reinforcing cord 5 is configured, the inner surface and the outer surface of the cylindrical body 10 are covered with unvulcanized rubber, so the unvulcanized rubber on the outer surface side and the inner surface side Unvulcanized rubber can be formed continuously. That is, unlike the prior art, it is not necessary to separate the process of placing the unvulcanized rubber on the inner and outer surfaces with the process of attaching and turning back two plies.

  Further, since the reinforcing cord 5 is arranged while being wound around the reinforcing rings 4a and 4b, the weft for forming a suda record in which the reinforcing cords 5 are arranged can be eliminated. Thereby, the breakage of the weft yarn can be eliminated, and the damage starting from the breakage portion of the weft yarn can be eliminated.

  In addition, this invention is not limited to said embodiment, A change can be suitably added within the scope of the present invention. For example, the rubber cylindrical body according to the present invention may be used for any one in which a reinforcing ring is embedded at both ends of a cylindrical rubber film reinforced with a reinforcing cord, and a diaphragm of an air spring. Instead of this, it may be used for a pipe joint as a vibration-proof joint.

  Further, instead of winding a single reinforcing cord 5, a plurality of reinforcing cords 5 parallel to each other may be wound around the pair of reinforcing rings 4a and 4b. Thereby, the time which winds the reinforcement cord 5 can be shortened.

  The reinforcing rings 4a and 4b may be made of a low rigidity such as a bead wire instead of a solid ring or a bead ring having a high rigidity. In this case, it is possible to stabilize the winding of the reinforcing cord 5 by holding the plurality of rollers 7 so that the bead wires are stretched and flattening the portion around which the reinforcing cord 5 is wound. Further, the pair of reinforcing rings 4a and 4b are not limited to those having different diameters, and may have the same diameter.

The figure which shows the principal part of the air spring provided with the diaphragm as a rubber cylinder which concerns on this invention Conceptual diagram showing the method of winding the reinforcement cord around a pair of solid rings A perspective view of a cylindrical body composed of a pair of solid rings and a reinforcing cord Front view of reinforcement cord winding device Side view of reinforcement cord winding device

Explanation of symbols

1 Diaphragm (Rubber cylinder)
3 Rubber film 4a, 4b Solid ring (reinforcing ring)
5 Reinforcement cord 6 Reinforcement cord layer 10 Tubular body

Claims (7)

A pair of reinforcing rings are embedded in both ends of the cylindrical rubber film, and two layers of reinforcing cord layers are provided in the rubber film, in which reinforcing cords inclined in the bias direction are embedded. In the rubber cylinder set so that the respective bias directions of the reinforcing cord layer intersect each other,
The rubber cord, wherein the reinforcing cord is wound so as to span between the pair of reinforcing rings, and is continuously embedded in the two reinforcing cord layers.   The rubber cylinder according to claim 1, wherein the pair of reinforcing rings are set to have different diameters.   The rubber cylinder according to claim 1 or 2, wherein the rubber cylinder is used as a diaphragm of an air spring. A pair of reinforcing rings are embedded in both ends of the cylindrical rubber film, and two layers of reinforcing cord layers are provided in the rubber film, in which reinforcing cords inclined in the bias direction are embedded. In the method of manufacturing a rubber cylinder that manufactures a rubber cylinder that is set so that the respective bias directions of the reinforcing cord layers intersect each other,
The pair of reinforcing rings are arranged substantially in parallel with a space therebetween, and then the reinforcing cords are wound in such a manner as to be inclined between the pair of reinforcing rings while being inclined in the bias direction. A cylindrical body composed of a reinforcing ring and a reinforcing cord is formed by crossing the bias directions thereof while being arranged in two rows on the side, and thereafter, the inner surface and the outer surface of the cylindrical body are covered with unvulcanized rubber. A method for producing a rubber cylinder, comprising vulcanizing and molding the unvulcanized rubber to form the rubber film.   The method for manufacturing a rubber cylinder according to claim 4, wherein a plurality of reinforcing cords parallel to each other are wound around the pair of reinforcing rings.   The method for producing a rubber cylinder according to claim 4 or 5, wherein the reinforcing cord is wound around a reinforcing ring in a state of being covered with rubber.   The unvulcanized rubber is formed continuously from the inner surface side to the outer surface side or from the inner surface side to the outer surface side of the cylindrical body made of a reinforcing ring and a reinforcing cord. The manufacturing method of the rubber cylinder as described.

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