JP2007015286A - Rust-proofing method for profile steel bar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rust-proofing method for a profile steel bar permitting the application of a rust-proof coating to a profile steel bar without impairing the adhesion strength. <P>SOLUTION: The rust-proofing method of coating the outer peripheral surface of a profile steel bar 1 comprises causing the bar 1 to pass into a coating resin molding machine, coating the outer peripheral surface of the bar with a thermoplastic resin and reshaping the appearance of the coated bar with a reshaping member 12 arranged on the outer periphery of the coated bar 1, while sending the coated bar 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rust-proofing method for deformed steel bars used mainly for PC tendons, anchor materials, and the like.

  Conventionally, the rust prevention processing of a steel rod is generally performed by coating the outer periphery of the steel rod with an epoxy resin, or applying galvanization processing or the like.

  However, in the conventional technology as described above, when the rust-proofing of a deformed steel bar having a concavo-convex portion on the surface, if the synthetic resin material for the rust-preventing coating has a thickness, the undulations of the concavo-convex portion are buried, and the concrete and There is a problem that the adhesion strength with the deformed steel rod is impaired, and on the other hand, in the case of rust prevention by coating with epoxy resin or galvanization, a certain amount of thickness (epoxy resin) In this case, a minimum of 600 microns) is required.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a rust-proofing method for a deformed steel bar that can apply a rust-proof coating to the deformed steel bar without impairing the adhesion strength.

  In order to solve the conventional problems as described above and achieve the intended purpose, the invention according to claim 1 is the rust preventive processing method for a deformed steel bar for coating the outer peripheral surface of the deformed steel bar. The steel rod is passed through a synthetic resin molding machine for coating, and after coating the outer peripheral surface of the deformed steel rod with a thermoplastic resin, the outer periphery of the coated deformed steel rod is fed out while feeding the coated deformed steel rod. It is a rust-proofing method for a deformed steel bar in which the outer shape of the coated deformed steel bar is shaped by a shaping member arranged on the side.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the shaping member has one or a plurality of convex portions that are rotatably arranged with respect to the coated deformed steel rod and project from the inner peripheral surface. Using the shaping die, passing the coated deformed steel rod through the shaping die so that the position of the convex portion is aligned with the position of the spiral groove formed on the outer periphery of the deformed steel rod, The outer shape of the deformed steel bar is shaped by

  In addition to the structure of claim 1, the invention according to claim 3 uses a nut-shaped die that is rotatably arranged with respect to the coated deformed steel bar and has a threaded portion on the inner peripheral surface, as the shaping member. And passing the coated deformed steel rod having a male thread part on the outer periphery of the die, feeding out the coated deformed steel rod, and rotating the die in synchronization with the movement of the deformed steel rod. It is characterized by shaping the external shape of

  According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the shaping member includes a plurality of rollers oriented in a direction intersecting with the circumferential direction of the roller circumferential groove contacting the outer circumference of the coated deformed steel rod. A pair of shaping rollers in which knot grooves are formed at a predetermined interval in the circumferential direction of the roller are used, and a deformed steel rod having a number of knots at intervals in the longitudinal direction is covered with the above-mentioned two shaping rollers. It is characterized in that the outer shape of the coated deformed steel rod is shaped by the shaping roller while feeding the coated deformed steel rod while passing the position of a node between the rollers in accordance with the position of the groove.

  According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the deformed steel bar includes a rib continuous in the longitudinal direction on the outer periphery, and the anticorrosive coating of the rib portion is provided to the two shaping rollers with respect to each other And the rib portion is shaped between the surfaces of both the shaping rollers.

  The invention according to claim 6 is characterized in that, in addition to the configuration of claims 1-4 or 5, the shaping member is shaped immediately after the coated deformed steel rod is heated.

  In addition to the structure of Claim 1-5 or 6, the invention of Claim 7 is characterized in that the thermoplastic resin is a polyethylene resin containing an adhesion promoter.

  The method for rust prevention of a deformed steel rod according to the present invention is a method for rust prevention of a deformed steel rod for coating the outer peripheral surface of the deformed steel rod, wherein the deformed steel rod is passed through a synthetic resin molding machine for coating, After coating the outer peripheral surface of the steel rod with a thermoplastic resin, the coated deformed steel rod is fed by the shaping member arranged on the outer peripheral side of the coated deformed steel rod while feeding the deformed steel rod. By shaping the outer shape, even when a rust-proof coating is applied to the outer periphery of the deformed steel rod, the shape of the concavo-convex portion can be suitably adjusted, and adhesion strength and the like are not impaired.

  The shaping member uses a shaping die which is arranged so as to be rotatable with respect to the coated deformed steel rod and has one or a plurality of convex portions protruding from the inner peripheral surface, and the position of the convex portion on the shaping die. Is passed through the coated deformed steel rod in accordance with the position of the spiral groove formed on the outer periphery of the deformed steel rod, and the outer shape of the deformed steel rod is shaped by the shaping die. The concave groove formed continuously in a spiral shape on the outer periphery can be suitably shaped.

  The shaping member is arranged so as to be rotatable with respect to the coated deformed steel rod, and a nut-shaped die having a thread portion on the inner peripheral surface is used, and the coated deformed steel rod having a male screw portion on the outer periphery is used on the die. Through which the coated deformed steel bar is fed out and the outer shape of the coated deformed steel rod is shaped by rotating the die in synchronism with the movement of the deformed steel rod, thereby forming a coated deformed shape having a screw formed on the outer periphery. The outer shape of the steel rod can be suitably shaped.

  In the shaping member, a plurality of node grooves are formed at predetermined intervals in the circumferential direction of the roller in a direction intersecting with the circumferential direction of the circumferential groove of the roller contacting the outer periphery of the deformed steel rod. Using a pair of shaping rollers, a coated deformed steel bar having a number of nodes spaced in the longitudinal direction is passed between the shaping rollers with the position of the nodes aligned with the position of the groove. The outer shape of the coated deformed steel rod in which a number of nodes are formed at intervals in the longitudinal direction is formed by shaping the outer shape of the coated deformed steel rod by the shaping roller while feeding the coated deformed steel rod. Can be shaped.

  The deformed steel bar has a rib continuously extending in the longitudinal direction on the outer periphery, the antirust coating on the rib portion is arranged with the two shaping rollers arranged at a predetermined distance from each other, and the rib portion is disposed on the surface of the two shaping rollers. By shaping in between, the rust-proof coating of the rib part formed continuously in the longitudinal direction on the outer periphery of the deformed steel rod can be suitably shaped.

  Immediately after the coated deformed steel bar is heated, the outer shape of the deformed steel bar can be suitably shaped by shaping with the shaping member.

  Since the thermoplastic resin is a polyethylene resin containing an adhesion promoter, the coating thickness can be reduced (about 400 microns).

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an outline of a rust preventive coating apparatus for a rust-proof coated deformed steel bar, and reference numeral 1 in the figure denotes a deformed steel bar.

  For example, as shown in FIG. 2, the deformed steel bar 1 has concave grooves (recesses) 2, 2,... Spirally continuous on the outer periphery of a round bar-shaped steel bar.

  The anti-corrosion processing apparatus includes a preheating heater 3, a covering synthetic resin molding machine 4, a reheating heater 5, an external shaper 6, and a cooling device 7 arranged side by side on the line. Is provided with a rust-proof coating and the recesses 2, 2... Can be shaped. In the figure, reference numeral 8 denotes a winding drum.

  For the heaters 3 and 5, an induction heating system is used, and heating is performed in a relatively low frequency range of about 10 kHz to 15 kHz.

  The covering synthetic resin molding machine 4 uses a crosshead type synthetic resin extrusion molding machine shown in FIG. 3, and a molding die 10 is rotatably mounted at the tip of the crosshead portion 9 of the molding machine 4.

  The forming die 10 is formed in a round shape whose inner diameter is larger than the outer diameter of the steel rod by a coating amount.

  The external shaper 6 includes a shaping member arranged on the outer peripheral side of the deformed steel bar that passes therethrough, so that the shaping member contacts the outer circumference of the deformed steel rod to be fed, thereby shaping the outer shape of the coated deformed steel rod. It has become.

  In the shaping member, for example, when shaping the deformed steel bar 1 in which the spiral grooves 2, 2,... Are formed on the outer periphery shown in FIG. A shaping die 12 which is formed and has convex portions 11, 11... On the inner peripheral surface is used.

  The shaping die 12 is rotatably installed with respect to the coated deformed steel rod 1 to be sent out, and the convex portion 11 is passed by passing the coated deformed steel rod 1 with the position of the convex portion 11 aligned with the position of the concave groove 2. The convex portion 11 presses the thermoplastic resin for anticorrosion coating in the spiral groove 2 to adjust the shape of the groove 2 while being guided by the spiral groove 2 and rotating.

  In order to rust-proof the deformed steel bar 1 using such a rust-proofing device, first, the deformed steel bar 1 is passed through the heater 3 and preheated.

  Next, the deformed steel rod 1 in a heated state is passed through the covering synthetic resin molding machine 4 and continuously fed through the deformed steel rod 1 to the center of the crosshead portion 9, during which the thermoplastic synthetic resin material 13 is fed. It is melted and extruded into the crosshead portion 9, and the outer peripheral surface of the deformed steel bar 1 is covered with the synthetic resin material 13.

  The synthetic resin material 13 used for coating is a polyethylene thermoplastic synthetic resin material containing an adhesion promoter.

  The deformed steel rod 1 having a rust-proof coating on the outer periphery passes through a molding die 10 installed at the outlet of the coating synthetic resin molding machine 4, and excess thermoplastic resin on the outer periphery is scraped off.

  Then, after the coated deformed steel bar 1 is reheated through the heater 5, it is fed to the external shaper 6 to shape the outer shape of the coated deformed steel bar 1.

  In the external shaper 6, the coated deformed steel bar is passed through the shaping die 12 with the positions of the concave grooves 2, 2... Aligned with the position of the convex part 11, and the coated deformed steel bar 1 is sent out in this state. Thus, while the shaping die 12 rotates, the convex portion 11 is guided to the concave groove 2 to press the concave groove 2 and shape the concave groove 2.

  And finally after cooling with the cooler 5, it winds up on the drum 8 for winding, and complete | finishes an operation | work.

  In the above-described embodiment, the example in which the shaping die 12 is used as the shaping member has been described. However, other shaping members are used depending on the shape of the deformed steel bar.

  For example, the deformed steel bar 22 is provided with ribs 20, 20 projecting in the longitudinal direction on both sides of the round bar shown in FIG. 5 and a number of nodes 21, 21. In this case, as shown in FIG. 6, a pair of shaping rollers 23, 23 arranged close to each other is used as the shaping member, and the coated deformed steel rod 22 is placed between both shaping rollers 23, 23. The outer shape of the coated deformed steel bar 22 is shaped by passing through.

  This shaping roller 23 is provided with a circumferential groove 24 for shaping the outer periphery of the deformed steel bar, and a number of node grooves 25, 25... Formed at intervals in the circumferential groove direction.

  The circumferential groove 24 is formed in a semicircular cross section whose inner diameter is the outer diameter of the deformed steel rod plus the thickness of the anticorrosion coating, and the depth is approximately 1/2 of the rib thickness from the groove radius. It has become a size.

  The node groove 25 is formed in an arc shape that matches the shape of the node 21, and the pitch between the node grooves 25, 25 is determined according to the pitch between the nodes 21, 21 of the deformed steel rod.

  The shaping rollers 23 and 23 are adjacent to each other with a gap having a size obtained by adding the thickness of the rib 20 to the thickness of the anticorrosion coating between the outer peripheral surfaces thereof.

  Further, the shaping rollers 23 and 23 are installed such that the positions of the node grooves 25 and 25 are shifted from each other by a predetermined angle.

  The deformed steel rod 22 covered between the shaping rollers 23 and 23 is pressed against the inner surface of the circumferential groove 24 by passing the positions of the nodes 21, 21... To the positions of the node grooves 25, 25. Thus, the outer peripheral portion of the deformed steel rod 22 is shaped and pressed against the inner surface of the node groove 25 to shape the portion of the node 21.

  Further, the outer shapes of the ribs 20 and 20 are also shaped by being sandwiched between gaps between the outer circumferences of the shaping rollers 23 and 23.

  In other words, when the coated deformed steel rod moves a distance from one node 21 to the next node 21, the shaping roller 23 rotates by the adjacent node grooves 25 and 25 in synchronization with the same and moves to the next node groove 25. The node 21 is fitted.

  The outer peripheral surface of the deformed steel rod coated thereby is shaped by the inner surface of the circumferential groove 24, and the nodes 21, 21,... Are pressed by the inner surfaces of the respective groove grooves 25, 25 ... It has come to arrange.

  As shown in FIG. 7, the deformed steel rod may have flat portions 30, 30 on both sides and may have screw-like nodes 31, 31,... The shaping roller 23 is formed in a shape in which a knot-like knot is fitted so that the knot groove of the shaping roller 23 is inclined with respect to the circumferential groove.

  In this case, the two shaping rollers are arranged so that their outer peripheral surfaces are in contact with each other so that no projections are formed on the flat surface portion.

  Furthermore, the deformed steel bar may be one in which a screw is formed over the entire circumference. In this case, a nut-shaped die having a female screw formed on the inner peripheral surface is used as the shaping member. The coated deformed steel bar is fed out, and the die is rotated by a power source such as a motor in synchronism with it, so that the outer shape of the coated deformed steel bar can be shaped without rotating the coated deformed steel bar. ing.

  In the above-described embodiment, an example in which a polyethylene resin is used as the thermoplastic resin material has been described. However, other epoxy resins may be used.

It is a block diagram which shows the rust prevention processing apparatus used for this invention method. It is a top view which shows an example of a deformed steel bar. It is sectional drawing which shows the crosshead type synthetic resin molding machine in FIG. (A) is a front view which shows the outline of the external shaper in FIG. 1, (b) is the same sectional drawing. (A) is a side view which shows another example of a deformed steel rod, (b) is the sectional view on the AA line. It is a front view which shows the outline of another example of the external shaper in FIG. (A) is a side view which shows another example of a deformed steel bar, (b) is the BB sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Profile steel bar 2 Groove 3 Heating machine 4 Covering synthetic resin shaping machine 5 Heating machine 6 External shaper 7 Cooling device 8 Winding drum 9 Crosshead part 10 Molding die 11 Convex part 12 Shaping die 13 Thermoplastic synthesis Resin material 20 Rib 21 Node 22 Deformed steel rod 23 Shaping roller 24 Circumferential groove 25 Node groove 30 Planar portion 31 Node (screw shape)

Claims (7)

In the rust-proofing method for deformed steel bars that coats the outer surface of the deformed steel bars,
The deformed steel rod is passed through a synthetic resin molding machine for coating, and after coating the outer peripheral surface of the deformed steel rod with a thermoplastic resin, the coated deformed steel rod is fed out while feeding the coated deformed steel rod. A rust-proofing method for a deformed steel bar, characterized in that an outer shape of the coated deformed steel bar is shaped by a shaping member arranged on the outer peripheral side of the steel sheet.   The shaping member uses a shaping die which is arranged so as to be rotatable with respect to the coated deformed steel rod and has one or a plurality of convex portions protruding from the inner peripheral surface, and the position of the convex portion on the shaping die. The outer shape of the deformed steel rod is adjusted by the shaping die while the coated deformed steel rod is fed through the outer surface of the deformed steel rod in accordance with the position of the spiral groove formed on the outer periphery of the deformed steel rod. The rust preventive processing method of the deformed steel bar according to claim 1 to be shaped.   The shaping member is arranged so as to be rotatable with respect to the coated deformed steel rod, and a nut-shaped die having a thread portion on the inner peripheral surface is used, and the coated deformed steel rod having a male screw portion on the outer periphery is used on the die. 2. The deformed steel rod rust prevention according to claim 1, wherein the coated deformed steel rod is fed out and the outer shape of the coated deformed steel rod is shaped by rotating the die in synchronization with the movement of the deformed steel rod. Processing method.   In the shaping member, a plurality of node grooves are formed at predetermined intervals in the circumferential direction of the roller in a direction intersecting with the circumferential direction of the circumferential groove of the roller contacting the outer periphery of the deformed steel rod. Using a pair of shaping rollers, a coated deformed steel bar having a number of nodes spaced in the longitudinal direction is passed between the shaping rollers with the position of the nodes aligned with the position of the groove. The rust-proofing method for a deformed steel bar according to claim 1, wherein the outer shape of the coated deformed steel bar is shaped by the shaping roller while the coated deformed steel bar is fed out.   The deformed steel bar has a rib continuously extending in the longitudinal direction on the outer periphery, the antirust coating on the rib portion is arranged with the two shaping rollers arranged at a predetermined distance from each other, and the rib portion is disposed on the surface of the two shaping rollers. The rust-proofing method for a rust-proof coated deformed steel bar according to claim 4, wherein the rust-proof clothing deformed steel bar is shaped by passing it in between.   The rust-proofing method for a rust-proof garment-shaped deformed steel bar according to claim 1, wherein shaping is performed by the shaping member immediately after the coated deformed steel bar is heated.   The method for rust-proofing a deformed steel bar according to claim 1, wherein the thermoplastic resin is a polyethylene resin containing an adhesion promoter.