Title of Invention

AUTO TWIN ANGLE AND TAIL END BREAKING MECHANISM IN THE BAR REROLLING MILL FOR BAR RECEIVING ON THE COOLING BED

Abstract

The present invention discloses a braking system used in a section re-rolling mill comprising motion restricting means, which restrict the motion of the sections enroute the cooling bed, braking means which act as brakes for the tail end of the sections, which are enroute the cooling bed, said braking means having a raised and lowered position, driving means, which provide force to said braking means allowing them to engage and disengage from the braking action and control means, which provide control signals to initiate and terminate various mechanical actions.

Full Text

BACKGROUND FIELD OF THE INVENTION This invention relates to an auto-twin angle and tail-end braking mechanism in the bar or section re-rolling mill used for receiving the bar or section on the cooling bed. DISCUSSION OF PRIOR ART Reinforced concrete is perhaps the most common material of construction today. Its demands as well as new applications are ever increasing. Use of mild steel Fe 250 as reinforcement heralded the beginning of RCC construction. The high cost of steel lead to the introduction of high strength steel i.e. CTD / TOR Steel Bars, which were manufacturers in low speed mill and in which each bar had to be individually cold twisted manually. In recent years technology has so advanced that as the hot rolled ribbed bar emerges from the finishing stand of the bar mill, it is rapidly cooled. This quenching process converts the surface layer of the bar to a hardened structure giving excellent yield strength to the bar, which is manufactured in high speed mills totally automatically. Since the bars were cold twisted manually, lower diameter bars were manufactured in coil forms. With the surface of the bar being tempered/hardened it was difficult to manufacture the bar in coil form, and there were no bar receiving systems for high speed mills in the cooling bed. The present invention ameliorates this difficulty by proposing a system for bar receiving on the cooling bed of a re-rolling mill. US 4901942 describes a clamping brake with two brake discs, the second of which is pneumatic for use in a warp mill. US 4625532 describes a high speed rolling mill with traction control operated by increasing the drive force of the rod and/or reducing the braking forces in the cooling device by introducing air into the cooling water. RU 2221659 depicts an apparatus for braking rolled pieces comprising a two position pneumatic cylinder with a motion drive unit to provide the necessary force. JP 63252611 describes braking steel bars using contact friction with a circuit to calculate the amount of distance correction on braking. US 5191818 describes a magnetic braking/distributing apparatus to brake and distribute sheared bars. DE 2153342 depicts a braking system for steel rods comprising of a braking channel closed on three sides. JP 55042770 describes a braking device to stop steel wire at a predetermined position in a rolling mill. Anshin Mills, Malaysia utilizes a system of conveyor belts for their Hot Rolling Combination Merchant Bar and Rod Mill. The drives and controls system were installed by Control Techniques Asia Pacific. The roughing mills have a conveyor system equipped by DC motors and controlled by Control Techniques Mentor Controllers. The bars pass through the Pinch Roll device and Disc shear, which cuts the bars to presettable lengths, that can fit into the cooling bed. The speed of the bar leaving the stand and its instantaneous position is calculated by the PLC. The Run In conveyor to the cooling bed is driven by 32 DC motors connected in parallel across the Mentor controller and has a Kick Off shaft driven by five-35hp DC motors and controlled by five 4-quadrant Mentor Controllers. Slow down and stopping is by regenerative braking with the brake serving as a holding brake only. Slow down and stop position is from the cam box driven from the shaft. The PLC controls all conveyor drives and continuously carries out calculations concerning the motor speed reference of each drive. If the speed of any section is adjusted, the PLC calculates the new speed of all upstream drives and simultaneously updates them. Additionally information concerning the cross sectional area of the billet and the mean roll diameter of each stand is downloaded to the PLC which also deals with sequence control. Communication between the control desk and the control panel is via a remote PLC I/O rack and a data highway. The New Bar Mill for the TMT line of Tata Steel utilizes a Rotary entry system for the process of collecting bars and dropping them on the cooling bed. Beotechnic GmbH of Germany provides operational details of mini steel works wherein the rolled steel bars are cut to length and discharged to the cooling bed from a roller table 200 mm wide and 110 m long consisting in 163 motorized rolls driven by inverter and from a system of aprons actuated through a shaft with eccentrics. All systems are controlled by the PLC, which allows automatic loading/unloading of the steel billets. SUMMARY OF THE INVENTION It is an object of this invention to enable receiving low diameter bar in high speed on the cooling bed of the re-rolling mill, which avoids the need for further processes like straightening of bars. The system further provides brakes which stops the tail end of the bars. The present invention discloses a twin angle bar receiving mechanism, which is used to collect the TMT/CTD bars / profiles like rounds / squares in diameters up to 100 mm leaving the quenching boxes after being sheared / unsheared by the flying / rotator shear in one and two strands. The twin angle is made out of cast iron / steel, for rigidity and durability. The angles used are of the open type rendering it easy to maintain. Further, during the process any cobbles it is easy to remove at a lesser run down time, the bars are collected one by one alternatively in the angle and dropped onto the cooling bed, which can be manual or automatic. The system is most suited for lower diameter bars that are manufactured in high-speed mills. Lower diameter bars are presently manufactured in coil forms, due to the non-availability of technology where the bars can be collected and shifted on the cooling bed. Due to the high-speed rolling brake mechanism is provided which stops the tail and there by the length of the twin angle will be equal to the length of the bar cut on the cooling bed. If there is no break at the tail end it will lead too a very long twin angle & cooling bed than the required length of the bar. The dropping & breaking of bars is done by means of a mechanism / hydraulic / pneumatic system depending upon the speed, size of material. This invention may be summarized as follows: 1. A braking system used in a section re-rolling mill comprising: a. Motion restricting means which restrict the motion of the sections enroute the cooling bed; b. Braking means which act as brakes for the tail end of the sections, which are enroute the cooling bed, said braking means having a raised and lowered position; c. Driving means which provide force to said braking means allowing them to engage and disengage from the braking action; and d. Control means, which provide control signals to initiate and terminate various mechanical actions. 2. A braking system as described above wherein the motion restricting means is comprised of an angled receptacle with at least two arms which are sized to be equal to the length of the sections being rolled, said arms extending from a base portion, said arms defining adjustable angles between themselves and the base. 3. A braking system as described above wherein the braking means is comprised of a lever placed between the arms of the angled receptacle, said lever being capable of moving between a lowered position and a raised position; 4. A braking system as described above wherein the lever is comprised of two arms, a shorter arm acting to counterbalance the motion of a longer arm, with an external and internal length, a central circular portion which fits into a support mechanism, said lever acting as a brake for the sections being rolled out. 5. A braking system as described above wherein the lever is pivoted about the central portion of the angled receptacle by means of a support mechanism found in a plumber block. 6. A braking system as described above wherein the plumber block has a straight base portion and a circular protruding portion, said circular portion fitting the central portion of the lever into it. 7. A braking system as described above wherein the driving means is comprised of a pneumatic cylinder, which assists the lever to move between a lowered position, when the sections are stopped and a raised position, when the sections are allowed to move toward the cooling bed. 8. A braking system as described above wherein the pneumatic cylinder could be replaced with a hydraulic cylinder. 9. A braking system as described above wherein the control means includes a programmable logic controller comprised of a time display unit, a power supply, a set of input/output channels to control several operations such as the length of the rods and the cutting motion initiated by the flying/oblique shears and a set of controls to manipulate the functioning of the driving means and the braking means. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 describes the overall layout of the system. Fig. 2 shows the pneumatic cylinder, which is used to drop and break the bars. Fig. 3 shows the twin angle component that is used to receive the bars. Fig. 4 shows the plumber block. Fig. 5 shows the knife, which is used to cut the bars. Fig. 6 shows the PLC panel. Fig. 7 shows the power supply distribution. Fig. 8a-b show the I/O wiring schematic. Fig. 9a-e shows the control schematic. Fig. 10 shows the terminal details. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In Fig.l. 101 represents the TMT system for thermo mechanical treatment of steel from which the bars go to 102 the pinch roll device. Pinch roll is a rolling device for the bars, which enter the twin angle after passing through the flying shear. The flying shear 103 helps in shearing the bars after which the steel bars are directed towards the twin angle system 104, which transfers bars to the cooling bed 105. In the auto twin angle and tail end braking mechanism, a pneumatic braking system is used for collecting and shifting low diameter bars at high speed onto a cooling bed. The structure of the whole is fabricated with mild steel and the entire system is run on ball bearings of heavy duty type with rigid coupling. Fig.2 depicts the pneumatic cylinder, which consists of a driving part i.e. body 201 and the moveable driven part 202, the piston. The force required to move the lever is transmitted through the piston rod 203 by the displacement of the piston. The pneumatic cylinder and its quantity may be designed as per the required parameters. The hardware is fabricated of mild steel/high tensile/galvanized iron. A mechanical or a hydraulic system can also be used in place of this depending on the customer's requirements. Fig.3. depicts the twin angle fabricated of cast iron/steel, consisting of a base 301 with two arms 302 and 303 having an inner length 304 and outer lengths 305 and 306 respectively. There are two adjacent angles 307 and 309 with a central angle 308 between the two arms. The angle used is of V type, which can be fed by one/two lines. The bar/section size for the twin angle is 6 to 32 mm, 36 to 100 mm. The length of the bar can be set as per the customer's requirements. The drive for the angle system may be mechanical/hydraulic/pneumatic with a minimum speed of 2.5 meter/second and an adjustable maximum speed. It can be controlled both manually as well as by the PLC. Fig.4 depicts the plumber block fabricated of cast/forged steel having a base 401 with a protruding member 402, which supports a lever, whose primary purpose is to stop the bars temporarily, providing a brake. The lever as shown in fig 5 is placed between two angles, which may be adjusted as required. The said lever is connected to the angle, through a controlling shaft that is supported on the plumber block. This shaft is fabricated of bright steel/mild steel/carbon steel. Fig.5.shows the lever, which consists of two arms 501 and 502 attached to a central portion 503. 501 has an outer arm length 504 and an inner arm length 505. 502 has an arm length 506. The lever is connected through a controlling shaft, which is supported on the plumber block (401, 402) that is mounted on a fabricated structure. The pneumatic cylinder provides the force for the lever to move up and down. As the lever moves up, the material is thrown onto the cooling bed. The pneumatic system is given in an angle wherein after cutting, the brake profile stops the angle. Fig.6. describes the PLC panel. 601 is a general representation of the PLC panel with PLC 609, time display unit 608 and control supply on lamp 610. 602 is the mounting plate with earth studs 607 providing the earthing connects. 605 displays the legend for 601 and 604 depicts the cutout dimensions and the bezel which gives the diameter of the whole for 603 the cutout. The PLC carries out all measurements based on signals received and sends additional signals to the cutter and brakes. Fig.7. depicts the power supply distribution. The input lines 701 lead to 702 the preconditioned power supply, which delivers the capped 220V supply to 703 the 750VA transformer. This transmits to 704 the main control supply with control supply voltage on/off. 704 sends the signal the 24V AC/DC converter which sends 706 and 707, 6A and 5A respectively to 711 the 24 hour supply to SH2. Similarly supply voltage 708 MCB3 supplies to 712 SH4 to SH8,709 MCB4 supplies 713 PLC power supply SH2 and 710 MCB5 supplies 714 the HMD (hot metal detector) amplifier. Fig. 8. depicts the PLC I/O wiring schematic wherein the 24 hours DC supply 802 is supplied through 801 SHI to 803 switch X2-15. 803 connects to 804,805 and 806 i.e. the hot metal detector (HMD), switch LSI for cutter towards mechanisml and switch LS2 for cutter towards mechanismll respectively. The bar from the finishing stand passes through HMD (hot metal detector), which detects the signal and passes it to the PLC 609. After receiving the signal, it measures the required length of the bar depending on the program fed by the user. After measuring the bar length needed, it sends a signal to the flying shear/oblique rotary shear to cut the bar. Another signal is received once the bar is cut. The PLC measures the length from the shear to the twin angle as per user design and then applies the brakes to stop the bar in the twin angle. The PLC then signals to the lever to throw the bar out of the twin angle. 807 i.e. input to PLC thus comes from 804, 805 and 806 i.e. the HMD and the two cutter mechanism switches - LSI for mechanisml (movement to the left) and LS2 for mechanismll (movement to the right). 808 is the 14 channel digital input integral to the PLC CPU and 809 is the 10 channel digital output i.e. the signals to be sent of which 810 is QO.O for kick offl, 811 is Q0.1 for kick off2, 812 is Q0.2 for brakes 1&2 and 813 is Q0.3 for brakes 3&4. 814 is Q0.4 for the shifter cum cutter and 815 to 819 are spare channels. The PLC output thus consists of 2 signals sent for kick off, 2 signals for braking and 1 signal for measuring the length of the bar and cutting. 821 to 830 are the spare switches. 820 is the operator interface panel and 831 is HMD amplifier with 220V AC. Fig.9. represents the control schematic for the system wherein 901 the 220V AC from 911 SH4 goes through the main relays 902 to 910 which transmits to the junction boxes 912 to 920 which sends the current signal to 921-929 i.e. the pneumatic solenoids which convert the current signal into an air signal and sends the air signal to the pneumatic cylinder for the operations of kick off, braking and cutting. Fig. 10. shows the Terminal Details which describes the various cables and connections in the system. In PNL X2, converters 1 to 15 with frequencies 21 to 35 and 5 are shown of which converters 4 to 13 with frequencies 26 to 35 are spares. Converter 1 is connected to the HMD amplifier. Converters 2 and 15 are connected to LSI (the cutter towards mechanisml) and 3 and 14 are connected to LS2 (the cutter towards mechanismD). In PNL X3, the spares 4 to 13 with frequencies 44 to 53 are shown. In PNL X4, converters 1 to 15 with frequencies 72 to 83 and 2 are shown of which converters 13 and 14 are spares. Converters 1 to 12 send signals to the field junction box JB1 X4 that transmits to individual solenoids SOV1 to SOV12, which are responsible for sending signal for Kick offl to the pneumatic cylinder and are hence known as kick offl solenoids. The signals from the solenoids are sent to a common junction box JB1 that is shared by the solenoids of PNL X5. In PNL X5, converters 1 to 15 with frequencies 84 to 102 and 2 are depicted of which connectors 13 and 14 with frequencies 101 and 102 are connected directly to the hot metal detector (HMD) sensor. Connectors 1 to 12 send signals to the field junction box JB1 X5 that sends signals to individual solenoids SOV1 to SOV12. These solenoids relay the signals for kick off2 to the common junction box JB1 and are known as kick off2 solenoids. JB1 sends the signal for kick of£2 to the pneumatic cylinder. Converter 15 bypasses the solenoids and relays directly to the common junction box JB1. In PNL X6, converters 1 to 10 are shown in 5 pairs i.e. 1 with 10, 2 with 9, 3 with 8, 4 with 7, and 5 with 6, each pair having the frequencies 96, 97, 98, 99 and 100 respectively. Converter pair 5 with 6 connects to solenoid SOVI, pair 4 with 7 connects to solenoid SOV2 and pair 3 with 8 connects to SOVI. These three pairs send signals to their individual solenoids to relay signals to the pneumatic cylinder for shifter cum cutter operations. Converter pair 1 with 10 sends the signal to SOV1 solenoid, which sends the signal to the pneumatic cylinder to operate brakes 1&2. Converter pair 2 with 9 sends the signal to SOV2, which signals the pneumatic cylinder for the operation of brakes 3&4. CLAIMS 1. A braking system used in a section re-rolling mill comprising: a. Motion restricting means which restrict the motion of the sections enroute the cooling bed; b. Braking means which act as brakes for the tail end of the sections, which are enroute the cooling bed, said braking means having a raised and lowered position; c. Driving means which provide force to said braking means allowing them to engage and disengage from the braking action; and d. Control means, which provide control signals to initiate and terminate various mechanical actions. 2. A braking system of claim 1 wherein the motion restricting means is comprised of an angled receptacle with at least two arms which are sized to be equal to the length of the sections being rolled, said arms extending from a base portion, said arms defining adjustable angles between themselves and the base. 3. A braking system of claim 1 wherein the braking means is comprised of a lever placed between the arms of the angled receptacle, said lever being capable of moving between a lowered position and a raised position; 4. A braking system of claim 3 wherein the lever is comprised of two arms, a shorter arm acting to counterbalance the motion of a longer arm, with an external and internal length, a central circular portion which fits into a support mechanism, said lever acting as a brake for the sections being rolled out. 5. A braking system of claim 4 wherein the lever is pivoted about the central portion of the angled receptacle by means of a support mechanism found in a plumber block. 6. A braking system of claim 5 wherein the plumber block has a straight base portion and a circular protruding portion, said circular portion fitting the central portion of the lever into it. 7. A braking system of claim 3 wherein the driving means is comprised of a pneumatic cylinder, which assists the lever to move between a lowered position, when the sections are stopped and a raised position, when the sections are allowed to move toward the cooling bed. 8. A braking system of claim 7 wherein the pneumatic cylinder could be replaced with a hydraulic cylinder. 9. A braking system of claim 1 wherein the control means includes a programmable logic controller comprised of a time display unit, a power supply, a set of input/output channels to control several operations such as the length of the rods and the cutting motion initiated by the flying/oblique shears and a set of controls to manipulate the functioning of the driving means and the braking means.

Documents:

0141-che-2006-abstract.pdf

0141-che-2006-claims.pdf

0141-che-2006-correspondnece-others.pdf

0141-che-2006-description(complete).pdf

0141-che-2006-description(provisional).pdf

0141-che-2006-drawings.pdf

0141-che-2006-form 1.pdf

0141-che-2006-form 26.pdf

0141-che-2006-form 3.pdf

0141-che-2006-form 5.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 01-08-2011.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 30-04-2012.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 19-01-2012.pdf

141-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 24-03-2014.pdf

141-CHE-2006 AMENDED PAGES OF SPECIFICATION 24-03-2014.pdf

141-CHE-2006 AMENDED CLAIMS 24-03-2014.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 05-12-2011.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 21-01-2011.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 19-03-2012.pdf

141-CHE-2006 CORRESPONDENCE OTHERS 23-05-2012.pdf

141-CHE-2006 FORM-18.pdf

141-CHE-2006 FORM-3 24-03-2014.pdf

141-CHE-2006 POWER OF ATTORNEY 24-03-2014.pdf

141-che-2006 correspondence others 28-07-2009.pdf

141-CHE-2006 EXAMINATION REPORT REPLY RECIEVED 22-10-2012.pdf