JP2017029990A - Method for processing end part of reinforcing-bar and processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for processing an end part of a reinforcing-bar capable of further shortening time for producing the reinforcing-bar with an anchorage part to improve production efficiency.SOLUTION: Provided is a method for processing an end part of a reinforcing-bar, in which the end part of the reinforcing-bar is heated at a plastically deformable temperature in a step for heating the end part of the reinforcing-bar, and an anchorage part is disposed on the end part heated at the plastically deformable temperature by expanding the diameter of the end part by hot-upsetting in a pressurizing step. The heating step comprises: a first heating step for firstly heating the end part of the reinforcing-bar; and a second heating step for mainly heating the firstly heated end part at the plastically deformable temperature. A first heating time period and a main heating time period for the reinforcing-bar are adjusted so that a standby time in which no main heating is performed does not occur. The transfer of the reinforcing-bar from the first heating step to the second heating step and the transfer of the reinforcing-bar from the second heating step to the pressurizing step are synchronized.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rebar end portion processing method and a processing apparatus for hot-setting an end portion of a rebar and providing a rebar fixing portion at the end portion.

  Reinforcing bars, such as deformed reinforcing bars, are used in reinforced concrete structures, precast concrete, and the like. For example, when the deformed reinforcing bar is used for a reinforced concrete structure, a fixing portion for fixing to the reinforcing bar or concrete is provided at an end portion. The fixing part was formed by bending the end of the reinforcing bar into a U-shape or L-shape. However, in order to improve the fixing function and reduce the cost of forming the fixing part, A fixing portion having an enlarged diameter at the end has come to be performed.

  There are two types of devices that can be used as a fixing unit with an enlarged diameter of the end of the reinforcing bar: the reinforcing bar loading position where the reinforcing bar is sequentially loaded, and the reinforcing bar end heating position where the end of the reinforcing bar is heated to a temperature at which plastic deformation is easy by heating. And the rebar to the processing position for making the end of the heated rebar the diameter of the fixing part expanded by hot upsetting, and the rebar unloading position for carrying out the rebar where the fixing part is molded to the outside A processing apparatus for a reinforcing bar end part is known which produces a reinforcing bar having a fixing part at the end part (see Patent Document 1).

JP 2005-288460 A

  By the way, in the above-described rebar end processing apparatus, the rebar is sequentially transferred to the rebar loading position, the rebar end heating position, the processing position, and the rebar unloading position, and each rebar is processed at each of these positions. When the processing of the reinforcing bars is completed at all positions, the reinforcing bars are simultaneously transferred to the next position to improve the production efficiency of reinforcing bars with anchorage. That is, when one reinforcing bar is heated and processed at the same position, one reinforcing bar with a fixing unit cannot be produced unless all the reinforcing bars are processed. For this reason, the time for producing one reinforcing bar with a fixing portion is shortened by heating and processing the reinforcing bar at different positions. However, among the reinforcing bar loading position, reinforcing bar end heating position, processing position and reinforcing bar unloading position, it is the reinforcing bar end heating position that takes the longest time to process the reinforcing bar. The processing time of the reinforcing bars, that is, the heating time, is particularly longer than the processing time of the reinforcing bars at other positions. As a result, as the diameter of the reinforcing bar increases, the heating time of the reinforcing bar becomes longer. Therefore, the time for producing one reinforcing bar with a fixing unit is longer, and the production efficiency may not be improved so much.

  The problem to be solved by the present invention is to provide a method and an apparatus for processing the end of a reinforcing bar that can further shorten the time for producing a reinforcing bar with a fixing portion and improve the production efficiency. .

  In order to solve the above-mentioned problem, the method of processing the end of a reinforcing bar according to the present invention heats the end of the reinforcing bar to a temperature at which plastic deformation is possible in the heating step, and pressurizes the end heated to the plastically deformable temperature. In the method for processing the end of the reinforcing bar, the diameter of the reinforcing bar is increased by hot upsetting, and the fixing part is provided.The heating step includes a primary heating step of primarily heating the end of the reinforcing bar, and a primary heated end. A secondary heating step of main heating to a temperature at which plastic deformation is possible, and adjusting the primary heating time and the main heating time of the reinforcing bar so as not to cause a standby time in which the main heating is not performed in the secondary heating step, The rebar transfer from the primary heating step to the secondary heating step and the rebar transfer from the secondary heating step to the pressurizing step are performed in synchronization.

  In this way, by primarily heating the end of the reinforcing bar, the main heated end of the reinforcing bar is heated to a temperature that can be plastically deformed, and then expanded by hot upsetting to form a fixing part. It is possible to shorten the time for the main heating of the reinforcing bar end to a temperature at which plastic deformation can be performed as compared with the case of heating the reinforcing bar end to a temperature at which plastic deformation can be performed without primary heating. Therefore, the time for producing one fixing portion-attached reinforcing bar is further shortened, and the production efficiency can be further improved.

  In this case, the main heating can be performed at a temperature that gradually decreases from the end of the reinforcing bar toward the other end. Further, the reinforcing bar is a deformed reinforcing bar having ribs protruding along the length direction on the surface, and in the primary heating step, the rib is positioned and then subjected to primary heating, and the deformed reinforcing bar remains in the posture at the time of primary heating. Can be sequentially transferred to the secondary heating step and the pressurizing step. Furthermore, the primary heating can be performed under heating conditions with a steeper temperature gradient than the main heating, and in the primary heating process, when the primary heating of the reinforcing bar is finished, the reinforcing bar is immediately put into the next secondary heating process without causing a waiting time. Can be transferred to. Moreover, the end part of a reinforcing bar can be heated by a high frequency induction heating in a primary heating process and a secondary heating process, and it is preferable that the diameter of a reinforcing bar is 30 mm or more.

  Moreover, in order to solve the said subject, the processing apparatus of the reinforcing bar end part which concerns on this invention hot-sets the end part of the deformed reinforcing bar which has the rib which protruded along the length direction on the surface, and this end part is carried out. An apparatus for providing a fixing unit, wherein after the rib is positioned, a primary heating unit that primarily heats the end of the deformed reinforcing bar, and the end that is primarily heated by the primary heating unit can be plastically deformed. Secondary heating means for main heating to a proper temperature, pressurizing means for expanding the diameter of the end portion heated by the secondary heating means by hot upsetting to form a fixing portion, and the length of the deformed reinforcing bar The primary heating means, the secondary heating means, and the pressurizing means, which are arranged in parallel in a direction orthogonal to the vertical direction, sequentially transferring the deformed reinforcing bar in a positioned posture, and comprising the primary heating. Transfer of the deformed reinforcing bars to the secondary heating means and secondary And transfer to the pressurizing means of heated the deformed bars, characterized in that to perform in synchronization.

  In this case, at least the secondary heating means of the primary heating means and the secondary heating means is arranged so as to cover the outer periphery of the end portion of the reinforcing bar, and heats the end portion by generating an induction current by feeding a high-frequency current. An induction coil is provided, and the induction coil can be formed such that the diameter gradually increases from the end of the reinforcing bar toward the other end.

  According to the present invention, it is possible to further improve the production efficiency by further shortening the time for producing one fixing portion-attached reinforcing bar.

It is a schematic block diagram which shows an example of the processing apparatus of the reinforcing bar end part which concerns on this invention.

  Hereinafter, the processing device of the end of a reinforcing bar concerning the present invention is explained based on an accompanying drawing. As shown in FIG. 1, a rebar end processing apparatus (hereinafter simply referred to as “processing apparatus 1”) according to the present invention hot-sets an end of a rebar 10 and fixes a fixing portion to this end. 11 is provided. Examples of the reinforcing bars 10 include deformed reinforcing bars having protruding portions of semicircular ridges (nodes) 10a and lengthwise ridges (ribs) 10b used for reinforced concrete. Two ribs 10b are provided on the outer surface of the reinforcing bar 10 at intervals of 180 degrees. In this embodiment, a deformed reinforcing bar is used as the reinforcing bar 10, but the present invention is not limited to this. A reinforcing bar that is not a deformed reinforcing bar may be used, and the type of deformed reinforcing bar is not particularly limited. A fixing portion 11 is formed at one or both ends of the reinforcing bar 10. The shape of the fixing unit 11 is not particularly limited as long as the diameter is larger than that of the reinforcing bar 10. For example, a fixing unit by hot upsetting described in Patent Document 1 may be used.

  The processing apparatus 1 includes a primary heating means 2 that primarily heats the end after positioning the rib 10b, and a secondary heating means 3 that heats the end of the primary heated deformed reinforcing bar 10 to a temperature at which plastic deformation is possible. Then, the pressurizing means 4 that expands the diameter of the end portion of the deformed reinforcing bar 10 by hot upsetting to form the fixing portion 11, the deformed reinforcing bar 10 is converted into the primary heating means 2, the secondary heating means 3, and the heating part. And a transfer means 5 for transferring the pressure means 4 in the sequentially positioned posture. The primary heating means 2, the secondary heating means 3 and the pressurizing means 4 are arranged in parallel at the same interval in the direction orthogonal to the length direction of the deformed reinforcing bar 10, and the deformed reinforcing bar 10 is orthogonal to the length direction. In this direction, the primary heating unit 2, the secondary heating unit 3 and the pressurizing unit 4 are sequentially transferred in parallel.

  The primary heating means 2 grips the deformed reinforcing bar 10, a reinforcing bar rotating device 24 that rotates the deformed reinforcing bar 10 around the axis, a rib detection device that detects the orientation of the rib 10 b by rotating the deformed reinforcing bar 10, and the deformed reinforcing bar 10. A clamp device 23 and a primary heating device 21 that primarily heats the end of the deformed reinforcing bar 10 held and fixed by the clamp device 23 are provided.

  In the present embodiment, the rib detection device detects the orientations of the two ribs 10b, and when the orientations of these ribs 10b are such that the reinforcing bar 10 can be guided by the reinforcing bar position regulating device of the pressurizing means 4. This is for stopping the driving of the reinforcing bar rotating device 24 when the vertical direction is reached. That is, when the deformed reinforcing bar 10 is rotated by the reinforcing bar rotating device 24 and the rib 10b is detected, the rotation of the deformed reinforcing bar 10 is stopped in a posture in which the two ribs 10b are oriented in the vertical direction. . The clamp device 23 grips a part of a portion of the deformed reinforcing bar 10 in a posture in which the orientations of the two ribs 10b are in the vertical direction, excluding the end portion where hot upsetting is performed.

  The primary heating device 21 primarily heats the end of the deformed rebar 10 held and fixed by the clamp device 23. For example, the primary heating device 21 is guided to the end of the deformed rebar 10 by a high-frequency current supplied to the induction coil 22. It is an induction heating method that generates an electric current. The induction coil 22 is provided so as to be movable back and forth (movable) with respect to the deformed rebar 10 gripped by the clamp device 23, and the end of the deformed rebar 10 moves into the coil 22 when it moves forward toward the deformed rebar 10. In this state, the end of the deformed rebar 10 is primarily heated by high-frequency induction heating by the induction coil 22. The diameter of the induction coil 22 is not particularly limited and may be the same or different. For example, when the end of the reinforcing bar 10 is inserted into the coil 22, the diameter of the induction coil 22 gradually increases from the end to the other end. The diameter is large.

  The primary heating is not particularly limited as long as the end portion of the reinforcing bar 10 can be heated, and may be performed under the same conditions as the heating conditions of the main heating. However, the primary heating is performed under heating conditions in which the temperature rise of the reinforcing bar 10 is larger than the main heating. Is preferred. That is, since the main heating is performed at a temperature that gradually decreases from the end of the reinforcing bar 10 toward the other end from the viewpoint of the moldability of the fixing unit 11, the heating is performed so that a temperature difference occurs in the heated reinforcing bar 10. However, in primary heating, since such a temperature difference may or may not occur, it is preferable to perform the heating under heating conditions in which the temperature increase of the reinforcing bar 10 is larger than that in the main heating. Thus, it becomes possible to shorten heating time by performing primary heating on the heating conditions in which the temperature rise of the reinforcing bar 10 is larger than the main heating.

  Moreover, it is preferable that the primary heating immediately transfers the reinforcing bar to the next secondary heating step without causing a waiting time after the primary heating of the reinforcing bar 10 is finished. The primary heating device 21 is not limited to the induction heating method using a high-frequency current, and may be a heating method other than the induction heating method, for example, a heating method using a gas flame, or a heating method using a laser beam. The deformed reinforcing bar 10 is transported to the next secondary heating means 3 with the end portions thereof being primarily heated and being sandwiched by the chuck member 52 of the transfer means 5 with the orientation of the two ribs 10b in the vertical direction.

  The secondary heating means 3 is a secondary device that performs main heating (secondary heating) to the plastically deformable temperature at the clamping device 33 that holds the deformed reinforcing bar 10 and the end of the deformed reinforcing bar 10 that is held and fixed by the clamping device 33. And a heating device 31. The clamp device 33 is a part of a portion excluding an end portion where the deformed reinforcing bar 10 is hot upset while the posture of the two ribs 10b transferred from the primary heating means 2 is in the vertical direction. Is to hold.

  The secondary heating device 31 heats the end of the deformed rebar 10 gripped and fixed by the clamp device 33 to a plastically deformable temperature. For example, the deformed rebar 10 is generated by a high-frequency current supplied to the induction coil 32. This is an induction heating method in which an induction current is generated at the end of the. The induction coil 32 is provided so as to be movable back and forth (movable) with respect to the deformed rebar 10 gripped by the clamp device 33, and the end of the deformed rebar 10 moves into the coil 32 when it moves forward toward the deformed rebar 10. In this state, the end of the deformed reinforcing bar 10 is heated to a plastically deformable temperature, for example, 1250 ° C. by high-frequency induction heating by the induction coil 32.

  The main heating is preferably performed at a temperature at which the end of the reinforcing bar 10 can be plastically deformed and gradually decreases from the end toward the other end. The secondary heating device 31 is not particularly limited as long as the end of the rebar 10 can be plastically deformed at a temperature that gradually decreases from the end toward the other end. For example, the end of the rebar 10 When the coil is inserted into the coil 32, the diameter of the induction coil 32 may be gradually increased from the end of the reinforcing bar 10 toward the other end. The secondary heating device is not limited to the induction heating method using a high-frequency current, and may be a heating method other than the induction heating method, for example, a heating method using a gas flame, or a heating method using a laser beam. The deformed reinforcing bar 10 is sandwiched in a posture in which the two ribs 10b are vertically oriented by the chuck member 52 of the transfer means 5 while the end portion is heated to a plastically deformable temperature, and the next pressurizing means 4 is pressed. It is transferred to.

  The pressurizing unit 4 expands the diameter of the end of the deformed reinforcing bar 10 which is clamped to the deformed reinforcing bar 10 and the main heating (heated to a plastically deformable temperature) by hot upsetting, and the fixing unit 11. And a reinforcing bar position restricting device that prevents the deformed reinforcing bar 10 from being distorted or bent when the deformed reinforcing bar 10 is hot upset by the pressing device 41. The clamp device 43 is a part of a portion excluding the end portion where the deformed reinforcing bar 10 is hot upset while maintaining the posture in which the two ribs 10b transferred from the secondary heating means 3 are in the vertical direction. Grip the part. The clamp device 43 is disposed in the pressure device 41.

  The pressure device 41 includes a mold body for forming the end portion of the deformed reinforcing bar 10 into the fixing portion 11 having a predetermined shape, and presses the mold body against the end portion (end surface) of the deformed reinforcing bar 10 to add the end portion in the length direction. And a pressurizing member 42 having an upset cylinder or the like for pressing. The pressurizing device 41 is provided so as to be movable back and forth (movable) with respect to the deformed rebar 10 transferred from the secondary heating means 3, and when it moves forward toward the deformed rebar 10, the end of the deformed rebar 10 and its end The deformed reinforcing bar 10 is inserted in the pressurizing device 41 and the deformed rebar 10 is gripped and fixed by the clamp device 43, and the deformed rebar is heated to a plastically deformable temperature by the pressing member 42 in this fixed state. 10 is pressed against an end portion (end surface) of the plate 10, and the end portion is plastically deformed by hot upsetting to form a fixing portion 11. That is, the end portion of the deformed reinforcing bar 10 heated to the plastically deformable temperature is expanded in diameter by hot upsetting and formed as the fixing portion 11. Further, when the hot upsetting of the end of the deformed reinforcing bar 10 is completed, the pressurizing device 41 is separated from the deformed reinforcing bar 10 after the mold body is separated from the end of the deformed reinforcing bar 10.

  The reinforcing bar position regulating device prevents the deformed reinforcing bar 10 from being distorted or bent when the deformed reinforcing bar 10 is hot upset by the pressurizing device 41, and is disposed in the pressing device 41. Yes. That is, in the rebar position regulating device, during hot upsetting, a compressive force is generated between the mold in the deformed rebar 10 and the clamp device 43 due to the pressure applied from the mold, and the rebar 10 is in this portion. Since it is distorted or bent, the outer surface of this part is guided, that is, the outer surface of the reinforcing bar 10 is restrained to prevent it from being bent or bent. For example, the reinforcing bar 10 in which the rib 10b is positioned vertically is provided. It is configured to guide. The deformed reinforcing bar 10 having the fixing part 11 formed at the end is carried out of the processing apparatus 1 by a carry-out device.

  The transfer means 5 is for transferring the deformed reinforcing bars 10 in the posture in which the ribs 10b are positioned in the primary heating means 2, the secondary heating means 3 and the pressurizing means 4 sequentially in parallel in the direction orthogonal to the length thereof. . The transfer means 5 includes a carry-in device 51 that conveys the deformed rebar 10 to the primary heating means 2, and transfers the deformed rebar 10 from the primary heating means 2 to the secondary heating means 3 and from the secondary heating means 3 to the pressurizing means 4. And a chuck member 52 that transfers the deformed reinforcing bar 10 from the pressurizing means 4 to the outside. The transfer means 5 is configured to transfer the rebar 10 by synchronizing the carry-in device 51, the chuck member 52, and the carry-out device, for example. That is, the transfer means 5 carries the deformed rebar 10 into the primary heating means 2, transfers the deformed rebar 10 from the primary heating means 2 to the secondary heating means 3, and deforms from the secondary heating means 3 to the pressurizing means 4. The transfer of the reinforcing bar 10 and the unloading of the deformed reinforcing bar 10 from the pressurizing means 4 are performed in synchronization. Note that the carry-in device 51 and the carry-out device may transfer the rebar 10 without synchronizing with the chuck member 52.

  Specifically, when the deforming rebar 10 is sequentially transferred to the primary heating means 2, the secondary heating means 3 and the pressurizing means 4, the transfer means 5 finishes the processing of the deformed rebar 10 in each means. The carry-in device 51, the chuck member 52, and the carry-out device are controlled so that the deformed reinforcing bars 10 are transferred to the next means. That is, when one deformed reinforcing bar (first reinforcing bar) 10 is primarily heated by the primary heating means 2 and transferred to the next secondary heating means 3, the next deformed reinforcing bar (second reinforcing bar) 10 is primarily heated. When the first reinforcing bar 10 is controlled to be transferred (conveyed) to the means 2 and heated by the secondary heating means 3 and transferred to the next pressurizing means 4, the second reinforcing bar that is primarily heated is used. 10 is transferred from the primary heating means 2 to the secondary heating means 3 and the next deformed reinforcing bar (third reinforcing bar) 10 is controlled to be transferred (conveyed) to the primary heating means 2. When 10 is processed by the pressurizing means 4 and carried out by the carry-out device, the second rebar 10 is transferred from the secondary heating means 3 to the pressurizing means 4, and the third rebar 10 is moved to the primary heating means 2. To the secondary heating means 3, and the next deformed reinforcing bar (fourth reinforcing bar) 10 is And it is controlled so as to be transported (conveyed) to the next heating unit 2. In this way, when the processing of each deformed reinforcing bar 10 is completed by all three means, the deformed reinforcing bar 10 is synchronously transferred to the next means, and the processing of the deformed reinforcing bar 10 is performed by each of the three means. ing. In addition, although the transfer time to the next means of the deformed reinforcement 10 by the transfer means 5 changes with structures, apparatuses, conditions, etc., it is about 5 second, for example.

Thus, the residence time of the reinforcing bars 10 in the primary heating means 2, the secondary heating means 3 and the pressurizing means 4 is obtained by transferring the reinforcing bars 10 in synchronization with the carry-in device 51, the chuck member 52 and the carry-out device. Be the same.
Since the deformed reinforcing bar 10 is positioned after being carried into the processing apparatus 1 and is heated to a plastically deformable temperature, the deformed reinforcing bar 10 is upset and is carried out from the processing apparatus 1 as a deformed reinforcing bar with a fixing portion. In addition, the heating is distributed by the two means of the primary heating means 2 and the secondary heating means 3, and the upsetting process is performed by the pressurizing means 4. Since the heating time is longer than the positioning of the primary heating means 2 and the secondary heating means 3 in the positioning and heating, the heating is longer than the positioning. Therefore, the substantial heating is distributed to the primary heating means 2 and the secondary heating means 3. become.
The distribution of the heating of the reinforcing bars 10 is performed so that the secondary heating means 3 performs the main heating of the reinforcing bars 10 without waiting time. That is, the reinforcing bar 10 transferred to the secondary heating means 3 is heated immediately after the clamping device 33 is gripped and the induction coil 32 is moved to the reinforcing bar heating position. The heating time is adjusted so that the movement of the coil 32 and the release of the clamping device 33 are performed without being performed and the coil 32 is transferred to the next pressurizing means 4. In the primary heating means 2, a standby time other than positioning (rib detection), gripping by the clamp device 23, movement of the induction coil 22 to the reinforcing bar heating position, primary heating, movement of the coil 22, and release of the clamp device 23 is set. It is preferable to eliminate it (or make it 0 seconds) as much as possible. When positioning is not performed by the primary heating means 2, the time other than the gripping by the clamp device, the movement of the induction coil to the reinforcing bar heating position, and the primary heating is the waiting time.

  Next, the operation of the processing apparatus 1 configured as described above and the processing method according to the present invention will be described. The deformed reinforcing bar 10 is transported to the primary heating means 2 by the carry-in device 51, where it is rotated around the axis by the reinforcing bar rotating device 24, and when the direction of the rib 10b becomes the vertical direction, the rotation is stopped and clamped. It is gripped by the device 23. That is, the deformed reinforcing bar 10 on which the rib 10 b is positioned is gripped by the clamping device 23.

  The induction coil 22 is moved (advanced) so as to cover the outer periphery of the end of the deformed rebar (the deformed rebar with the rib 10b positioned) 10 held by the clamp device 23, and the deformed rebar is subjected to high-frequency induction heating by the induction coil 22. The 10 ends are primarily heated (primary heating step). In the primary heating, the deformed reinforcing bar 10 is cooled when it is transferred from the primary heating means 2 to the secondary heating means 3, so that the deformed reinforcing bar 10 immediately before being heated by the secondary heating means 3 is not completely cooled. To be done at the temperature that is being. After the primary heating, the induction coil 22 is moved (retracted) and held by the chuck device 52 of the transfer means 5 after the gripping by the clamping device 23 is released, and the two ribs 10b are held in the vertical direction. Then, it is transferred to the next secondary heating means 3 in parallel in a direction perpendicular to the axis of the reinforcing bar 10.

  The deformed rebar 10 transferred to the secondary heating means 3 is gripped by the clamp device 33 with the two ribs 10b oriented in the vertical direction, and the induction coil 32 is moved so as to cover the outer periphery of the end portion. Then, the end of the deformed reinforcing bar 10 is fully heated to a plastically deformable temperature, for example, 1250 ° C. (secondary heating step) by high-frequency induction heating by the induction coil 32. Since the deformed reinforcing bar 10 that has been subjected to the main heating is a reinforcing bar that is heated by the primary heating means 2, the time for the main heating is shorter than that of the reinforcing bar that is not heated. After the main heating, the induction coil 32 is moved (retracted) and immediately after the gripping by the clamping device 33 is released, the chuck member 52 of the transfer means 5 immediately keeps the two ribs 10b in the vertical direction. It is clamped and transferred to the next pressurizing means 4 in a direction perpendicular to the axis of the reinforcing bar 10.

  The deformed rebar 10 transferred to the pressurizing means 4 is moved so that the pressurizing device 41 covers the end portion and the like on the end portion and the outer periphery in the vicinity with the posture in which the two ribs 10b are oriented in the vertical direction. (Advance), the deformed rebar 10 is gripped and fixed by the clamp device 43, and the end portion heated to the plastically deformable temperature is plastically deformed by hot upsetting by the pressurizing device 41 to be fixed. 11 (pressure process). The fixing portion 11 is formed at the end, and the deformed reinforcing bar 10 is carried out of the processing apparatus 1 by the carry-out device.

  When the deformed reinforcing bars 10 are sequentially transferred to the primary heating means 2, the secondary heating means 3 and the pressurizing means 4 by the transfer means 5, when the processing of the deformed reinforcing bars 10 is completed by all three means, the next means is taken. The deformed rebar 10 is transferred in synchronization.

  As described above, in the processing apparatus 1 and the processing method according to the present invention, the end of the deformed reinforcing bar 10 is primarily heated by the primary heating means 2 and then heated to the plastically deformable temperature by the secondary heating means 3. In addition, the time for main heating the end of the reinforcing bar to a temperature at which plastic deformation can be performed, that is, the time at the secondary heating means 3 is compared with the case of heating the end of the reinforcing bar to a temperature at which plastic deformation can be performed without primary heating. Can be shortened. Therefore, the time for producing one fixing portion-attached reinforcing bar is further shortened, and the production efficiency can be further improved.

  Specifically, for example, the shape and type of the deformed rebar 10 and the heating conditions of the primary heating means 2 are not generally determined. However, in the case of the D35 deformed rebar, the heating is performed at a frequency of 5.5 kHz and a volume of 70%. When primary heating by high frequency induction heating was performed for about 5 seconds under the conditions, the total time in the primary heating means 2 was about 18.3 seconds. The total time in the primary heating means 2 is as follows: positioning (rib detection) time: about 3 seconds, clamping device gripping time: about 1.5 seconds, induction coil moving time: about 2 seconds, primary heating time: about 5 seconds Coil movement and clamping device release time: about 2 seconds. It took about 19.6 seconds for the primary heating of the deformed reinforcing bar to the plastically deformable temperature by the secondary heating means 3, and the total time in the secondary heating means 3 was 25.1 seconds. The total time in the secondary heating means 3 is as follows: clamping device gripping time: about 1.5 seconds, induction coil moving time: about 2 seconds, main heating time: about 19.6 seconds, coil moving and clamping device release time : About 2 seconds. On the other hand, it took about 33 seconds to fully heat the end of the deformed reinforcing bar to a plastically deformable temperature without primary heating, and the total time was 41.5 seconds. This total time includes positioning (rib detection) time: about 3 seconds, clamping device gripping time: about 1.5 seconds, induction coil moving time: about 2 seconds, main heating time: about 33 seconds, coil moving and clamping device Release time: about 2 seconds. The heating conditions were the same as those for the secondary heating means 3 described above.

  In the case of the deformed reinforcing bar of D51, if the primary heating is performed for 35 seconds, the total time in the primary heating means 2 is 51.8 seconds. The main heating took 49.7 seconds, and the total time in the secondary heating means 3 was 57.6 seconds. On the other hand, in the case of only the main heating without primary heating, it took about 110 seconds and the total time was 122.5 seconds for the main heating of the end of the deformed reinforcing bar to the plastically deformable temperature. The heating conditions for primary heating and main heating were the same as described above.

  As described above, the larger the diameter of the deformed reinforcing bar 10 is, the longer the time for the main heating is. However, the heating time for the main heating can be effectively shortened by the primary heating, and thus the processing apparatus 1 according to the present invention. The processing method is particularly useful for the reinforcing bar 10 having a diameter of 30 mm or more.

By performing the main heating at a temperature that gradually decreases from the end portion of the reinforcing bar 10 toward the other end portion, the fixing portion 11 can be formed with good moldability. In addition, the primary heating time can be shortened by performing the primary heating under heating conditions where the temperature gradient is steeper than that of the main heating.
In the primary heating step, when the primary heating of the reinforcing bar is finished, the main heating of the reinforcing bar that has been subjected to the primary heating can be performed with minimal loss by transferring it to the secondary heating means 3 immediately. That is, when the reinforcing bar is heated, the temperature rises and the temperature decreases immediately after the heating. Therefore, the primary heated reinforcing bar is immediately transferred to the secondary heating means to minimize the temperature drop of the primary heated reinforcing bar. it can. As a result, the main heating time in the secondary heating means 3 can be shortened.

  When the end portion of the deformed reinforcing bar 10 is plastically deformed by hot upsetting by the pressurizing device 41 to form the fixing portion 11, the primary heating is performed at a temperature at which plastic deformation can be performed after the primary heating. The pressing force (propulsive force) for pressing the mold body in the pressurizing device 41 against the end (end surface) of the deformed reinforcing bar 10 can be reduced as compared with the case where heating is performed at a temperature at which plastic deformation is possible. For example, in the case of the deformed reinforcing bar of D35, if the primary heating is present, the time when the load is applied to the upset cylinder (loading time) is 5.8 seconds when the mold is pressed against the end (end face) of the deformed reinforcing bar 10. (Estimated value), and when there is no primary heating, the load time is 7.8 seconds. In the case of the deformed reinforcing bar of D51, the load time is 8.9 seconds when there is primary heating, and the load time is 12.0 seconds when there is no primary heating. As a result, the load on the pressurizing device 41 can be reduced and the cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Primary heating means 3 Secondary heating means 4 Pressurizing means 5 Transfer means 10 Rebar 11 Fixing part

Claims (9)

The end of the reinforcing bar is heated to a temperature that can be plastically deformed in the heating process, and the end heated to this plastically deformable temperature is expanded by hot upsetting in the pressurizing process to provide the fixing part. The processing method of
The heating step is formed by a primary heating step of primarily heating the end of the reinforcing bar, and a secondary heating step of main heating the end of the primary heating to a temperature capable of plastic deformation,
Adjust the primary heating time and the main heating time of the rebar so that the standby time for not performing the main heating in the secondary heating step does not occur,
A method for machining a reinforcing bar end, wherein the transfer of the reinforcing bar from the primary heating step to the secondary heating step and the transfer of the reinforcing bar from the secondary heating step to the pressurizing step are performed in synchronization.   The processing method according to claim 1, wherein the main heating is performed at a temperature that gradually decreases from an end portion of the reinforcing bar toward the other end portion. The reinforcing bar is a deformed reinforcing bar having ribs protruding along the length direction on the surface,
In the primary heating step, primary heating is performed after positioning the ribs,
The processing method according to claim 1 or 2, wherein the deformed reinforcing bar is sequentially transferred to a secondary heating step and a pressurizing step while maintaining a posture during primary heating.   The said primary heating is a processing method of any one of Claims 1-3 performed on the heating conditions whose temperature gradient is steeper than the said main heating.   The processing method according to any one of claims 1 to 4, wherein when the primary heating of the reinforcing bar is finished in the primary heating step, the reinforcing bar is immediately transferred to the next secondary heating step without causing a waiting time.   The said primary heating process and a secondary heating process are the processing methods of any one of Claims 1-5 which heat the edge part of the said reinforcing bar by high frequency induction heating.   The processing method according to claim 1, wherein the reinforcing bar has a diameter of 30 mm or more. A device for hot-setting the end of a deformed reinforcing bar having ribs protruding along the length direction on the surface and providing a fixing portion at the end,
Primary heating means for primarily heating the ends of the deformed reinforcing bars after positioning the ribs;
Secondary heating means for main heating the end portion primarily heated by the primary heating means to a temperature at which plastic deformation is possible;
A pressurizing unit that expands the diameter of the end heated by the secondary heating unit by hot upsetting to form a fixing unit;
Transfer means for sequentially transferring the deformed reinforcing bar in a posture positioned to the primary heating means, the secondary heating means and the pressurizing means arranged in parallel in a direction orthogonal to the length direction of the deformed reinforcing bar; prepare for,
The processing of the end of the reinforcing bar is characterized in that the transfer of the primary heated deformed reinforcing bar to the secondary heating means and the transfer of the secondary heated deformed reinforcing bar to the pressurizing means are performed in synchronization. apparatus. At least the secondary heating means of the primary heating means and the secondary heating means is arranged so as to cover the outer periphery of the end of the reinforcing bar, and an induction coil that heats the end by generating an induction current by feeding a high-frequency current Have
The processing apparatus according to claim 8, wherein the induction coil has a diameter that gradually increases from an end portion of the reinforcing bar toward the other end portion.

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