Patent Publication Number: US-3877331-A

Title: Method of control of machine for pulse cutting continuous bar into measured lengths and device for realization thereof

Description:
United States Patent [191 Saveliev et al.  
 [ Apr. 15, 1975 METHOD OF CONTROL OF MACHINE FOR PULSE CUTTING CONTINUOUS BAR INTO MEASURED LENGTHS AND DEVICE FOR REALIZATION THEREOF [76] Inventors: Anatoly Semenovich Saveliev, ulitsa Chkalova, 7, kv. 22; Vadim Grigorievich Kononenko, ulitsa Chkalova, l5, kv. 12; David Alexandrovich Raizman, ulitsa Chernyshevskogo, 84, kv. 29; Vitaly Alexandrovich Boguslavsky, ulitsa Kharkovskaya, 82, kv. 43; Sergei Vasilievich Yatsenko, Moskovsky prospekt, 204/1, kv.36; Vitaly Evgenievich Strizhenko, Osnovyanskaya ulitsa, 56, kv. 1, all of Kharkov, U.S.S.R.  
 [22] Filed: Jan. 31, 1974 [21] Appl. No.: 438,457  
 [52] US. Cl. 83/13; 83/37; 83/72;  
 [5l] Int. Cl B26d 5/12; B26d 3/00; B26d 5/20 [58] Field of Search ..83/72, 361, 362, 364, 370,  
 [56] References Cited UNITED STATES PATENTS 2,655,994 10/1953 Vandenberg 83/72 3,406,601 Clifford 83/72 Primary ExaminerWillie G. Abercrombie [57] ABSTRACT The proposed device has a system of control of an actuating mechanism of filling a combustion chamber with a fuel mixture, said control system being made up of a timer designed to control the time required for the front end of a bar to travel a distance equal to its path travelled at a maximum speed and within the maximum time of filling the combustion chamber with a fuel mixture, a setter of the time required for filling the combustion chamber with a fuel mixture and a comparator of said time intervals.  
 During the bar travel, measurements are taken of the time necessary for the front end of the bar to cover the abovementioned distance and comparison is made thereafter of this time with the time preset for filling the above combustion chamber with the fuel mixture. Depending on the result of the comparison, control is made of the moment when the filling of the chamber starts so that the completion of said chamber filling should coincide with the moment of the front end of the bar reaching a point indicating a measured length of the billet.  
 3 Claims, 5 Drawing Figures METHOD OF CONTROL OF MACHINE FOR PULSE CUTTING CONTINUOUS BAR INTO MEASURED LENGTI-IS AND DEVICE FOR REALIZATION THEREOF The present invention relates to pressure working of metals and more particularly to methods of controlling the machines for the pulse cutting of a continuously casting bar into measured lengths and devices for the realization thereof.  
  The present invention can prove most effective when used for controlling a pulse-action machine utilizing, as an energy source, an air-and-gas mixture and intended for cutting bar pieces on continuous steel casting installations.  
  Known in the art is a method of control of a machine for cutting a continuously casting bar into preset lengths, wherein the machine operating cycle starts with a time lead relative to the moment or place of bar cutting.  
  Known are devices for the realization of this method. They comprise facilities providing for a lead as to the moment or place of bar cutting, fashioned as pickups signalling the position of the bar or time setters which set the time for filling the combustion chamber with a combustible mixture, whose operation depends on the arrangement of a pickup along the axis of the bar travel. In such facilities, the bar position pickup should be spaced at a certain distance from a cutting zone so that the time of the operation of the actuating mechanism designed to help fill the combustion chamber with a combustible mixture and engaged by the pickup would be enough for the front end of a bar to reach a point on the axis of its travel, corresponding to a measured length of a billet being cut. Taken into account are the average speed of the bar travel and the constant, e.g., maximum, time required for filling the combustion chamber with a combustible mixture.  
  The speed of travel of the bar produced in the course of continuous metal casting is variable, as a result of which, the time of the combustion chamber filling being constant, billets produced with the aid of the above devices vary in length.  
  As the shearing force in the course of cutting said continuous bar into billets is required to vary, the time of filling the combustion chamber with a combustible mixture must also vary.  
  This results in the fact that billets thus produced on the above devices have a length differing from the preset one. The rate of casting varying substantially, variations from the preset length ofa billet tend to grow considerably.  
  An object of the present invention is to provide a method of controlling a machine for the pulse cutting of a continuously casting bar and a device for the realization thereof, as would help produce measured lengths with a higher accuracy.  
  This and other objects of the invention are accomplished in a method of control of a machine for the pulse cutting of a continuously casting bar into measured lengths in the course of the continuous casting of metal, consisting in that they start filling the combustion chamber with a combustible mixture with such a time lead, relative to the moment of cutting, that a billet is being cut when its front end reaches a point the distance from which, along the bar travel axis, to a point of said billet cutting is equal to a measured length of the billet, wherein, according to the invention, in the course of the bar travel, measurements are taken of the time of passing, by the front end of said bar, of points spaced one from the other along the axis of its travel to a distance equal to the path of its travel at a maximum speed and at a maximum time required for filling the combustion chamber with a combustible mixture, the latter of the above points, along the direction of said bar travel, being equally spaced from a point indicating the specified length of the billet, comparison is made thereafter of said measured time and the time preset for filling the above combustion chamber with said mixture and, depending on the results of comparison, control is exercised of the moment when the filling of said chamber begins, so that the time of the completion of its filling should coincide with the moment when the front end of the bar reaches the point indicating the measured length of the billet.  
  In a device for the realization of the proposed method, comprising an actuating mechanism of filling the combustion chamber of the machine and a system of control of said mechanism, which sets the moment of its operation relative to the moment of cutting, the system of control of said actuating mechanism, according to the invention, is equipped with a device for measuring the time during which the front end of the bar being cut covers a distance equal to its travel path at a maximum speed and with maximum time required for filling said combustion chamber and signalled by two pickups of bar positioning, placed, along the axis of said bar travel, one from the other at a distance mentioned above, the second of said pickups being arranged at the same said distance from the point indicating the specified length of the billet being cut, a setter of the time of filling the chamber with a combustible mixture and a comparator capable of comparing the time required for the front end of the bar to cover said distance with the time necessary to fill the combustion chamber with the combustible mixture, the results of the comparison being indispenable to control the moment when the filling of said chamber with said mixture begins.  
  The system of control of the actuating mechanism of filling the combustion chamber can be made as a reversible motor controlled from the bar position pickups, said motor being provided for a moving contact group coupled with said actuating mechanism, whose one contact is connected to the electric motor shaft and the second is coupled with said shaft via a sleeve controllable from the combustion chamber filling time setter.  
  The proposed invention permits to separate a continuously casting bar into billets of a measured length with a high accuracy, regardless of variations in the speed of the bar travel during casting and in the time preset for filling the combustion chamber with the combustible mixture. As a result, the economy of the production of measured billets tends to rise and conditions for their further working tend to improve.  
  Following hereinbelow is the description of an exemplary embodiment of the invention with reference to appended drawings, wherein:  
  FIG. 1 shows a block-diagram of the device of the invention;  
  FIG. 2 shows a block-diagram of the system of control of an actuating mechanism of the combustion chamber filling with a combustible mixture; and  
  FIGS. 3, 4 and show the graphs explaining the operating principle of the proposed device.  
  A device for the control of a machine 1 (FIG. 1) for the pulse cutting of a continuously casting bar 2 into measured lengths during the continuous casting of metal comprises an actuating mechanism 3 of filling a combustion chamber 4 with a combustible mixture, said mechanism fitted with a control system 5. Said systern 5 of the control of the actuating mechanism 3 comprises two pickups 6 and 7 signalling the position of the bar 2 and coupled electrically with a time controller 8 designed to control the time of the travel ofa front end 9 of the bar 2 between the pickups 6 and 7. Said pickups 6 and 7 are arranged along the axis of travel of the bar 2 so that they record the moments of passing points 10 and 11 by the front end 9 of the bar 2. Said points 10 and 11 are spaced apart to a distance equal to the path of travel of the bar 2 at a maximum speed and with maximum time required for filling the combustion chamber 4 with a combustible mixture. The point 11 is equally spaced from a point 12 situated on the axis of travel of the bar 2.  
  The distance between the point 12 and a point 13 indicating the place of cutting on the axis of travel of the bar 2 is equal to a measured length ofa billet being cut. The pickup 6 signalling the position of the bar 2 is coupled electrically with a setter 14 designed to set the time for filling the combustion chamber 4 with a combustible mixture. Said time setter l4 and timer 8 which controls the time of travel of the front end 9 of the bar 2 between the points 10 and 11 are coupled electrically with a comparator 15 designed to compare these time intervals and linked with the actuating mechanism 3 of filling the combustion chamber 4 with a combustible mixture.  
  FIG. 2 shows a block-diagram of the system of control of the actuating mechanism 3 of filling said chamber 4, wherein the timer 8 and the comparator 15 are fashioned as a reversible electric motor 16 with a movable contact group 17. Said contact group 17 is made as two movable contacts 18 and 19. The contact 18 is connected to the shaft of the reversible electric motor 16, while the contact 19 is linked with the shaft of said electric motor 16 via a sleeve 20 coupled with the time setter 14 which sets the time for filling the chamber 4 with a combustible mixture. The electric motor 16 is connected to the pickups 6 and 7 signalling the position of the bar 2 via a system 21 of control of the electric motor 15, which effects the starting and reversing of the electric motor 16.  
  The proposed method consists in that they measure the time necessary for the front end 9 of the billet 2 between the points 10 and 11 on the axis of its travel, compare this time with the time preset for filling the combustion chamber 4 with a combustible mixture and obtain a time interval as a result of the comparison. This time interval is counted from the moment when the front end 9 of the bar 2 has passed the point 11 on the axis of its travel. The ending of this time interval marks the moment when the filling starts of the combustion chamber 4 with a combustible mixture. As the time of the travel of the forward edge 9 of the bar 2 between the points 10 and 11 is equal to the time necessary for the front end 9 to move between the points 11 and 12, the filling thereof will be over when said front end 9 reaches the point 12 and this is the moment when a billet is cut. The length of the cut billet is equal to a measured length, as the distance between the points 12 and 13 is equal to the specified length of the cut billet.  
  The operation of the device for the realization of the proposed method consists in the following.  
  The passing of the point 10 by the front end 9 (FIG. 1) of the continuous bar 2 on its travel path operates the pickup 6 of the position of the bar 2, said pickup triggering the timer 8 and the time setter 14. The comparator 15 provided across the output of said time controller 8 and time setter 14 subtracts the preset time interval for filling the combustion chamber 4 from the time interval of the travel of the front end 9 of the bar 2 between the points 10 and 11. The final result of comparison is obtained at the moment when the front end 9 of the bar 2 is reaching the point 1 1 and when the pickup 7 of the bar 2 position operates to cut out the timer 8. The time interval obtained as a result of the comparison is counted from that moment on by the comparator 15 and, once this time interval expired, the actuating mechanism 3 of filling the combustion chamber 4 with a combustible mixture operates. The filling of said combustion chamber 4 will be over when the front end 9 of the bar 2 has reached the point 12 on the way of said bar travel, and at that moment the machine 1 will cut out a billet of a specified length.  
  FIGS. 2-5 serve to clarify the operating principle of the proposed invention at a varying time t t required for filling the combustion chamber 4 and a varying distance between the pickups 6 and 7 of the bar 2 position. In these figures, 8,, indicates a path travelled by the front end 9 of the bar 2, while S and S indicate the paths covered by the contacts 18 and 19.  
  Measurements of the time t,; and of the travel of the front end 9 of the bar 2 by the pickups 6 and 7 between the points 10 and 11, comparison of this time interval with the one preset by the setter 14 of the time t, t of filling the combustion chamber 4 with a combustible mixture and control of the moment t,, of the filling startare effected in the following manner.  
  The triggering of the pickup 6 of the bar 2 positio (time moment t,,) operates both the control system 21 of the electric motor 16 and the setter 14 of the time of filling the combustion chamber 4 with a combustible mixture. The setter 14 engages the sleeve 20 thus connecting the shaft of the electric motor 16 to the movable contact 19 of the contact group 17. As the movable contact 18 is coupled with the shaft of the electric motor 16 directly, said electric motor 16 cut in by the control system 21 moves the contact group 17 until the moment I when the preset time interval t r of the combustion chamber filling elapses. At this moment t the setter 14 of the filling time 1 disconnects the sleeve 20 and the movable contact 19 stops. The electric motor 16 continues to move the movable contact 18 until the moment t of the operation of the pickup 7 with the resultant count of the difference r 2 between the time of the travel of the front end 9 from the point 10 to the point 11 and the preset time t t of filling the combustion chamber 4 with a fuel mixture. At the moment of the operation of the pickup 7, the control system 21 effects the reversing of the electric motor 16 which moves the movable Contact 18 in an opposite direction at a previous-speed, the counting of the result of the comparison t t, taking place at a time. The closing of the contacts 18 and 19 will take place upon the elapse of the time interval t t,, equal to the time interval r n, and this will cause the cutting-in of the actuating mechanism 3 of the combustion chamber filling. Said combustion chamber filling will discontinue at the moment when the front end 9 of the bar 2 reaches the point 12 indicating the measured length of a billet being cut. Within this time I t the movable contact group 17 returns to its initial position, and the cycle repeats itself from the moment t of the arrival of the front end 9 of the bar 2 in the point of the axis of its travel.  
 What we claim is:  
  1. A method of control of a machine for the pulse cutting of a continuously casting bar into measured lengths during the continuous casting of metal, consisting in that, in the course of said bar travel, measurements are taken of the time of passing, by said bar front end, of points spaced one from the other along an axis of said bar travel to a distance equal to the path travelled by said bar at a maximum speed and within maximum time required for filling a combustion chamber with a fuel mixture, the latter of the above points, along the direction of said bar travel, being equally spaced from a point indicating a measured length of a billet comparison is made thereafter of said measured time and the time preset for filling said combustion chamber with said mixture and, depending on the result of the comparison, control is exercised of the moment when the filling of said chamber begins so that the time of the completion of its filling should coincide with the moment when the front end of the bar reaches the pointindicating the measured length of the billet, and this is the moment when the billet is being cut.  
  2. A device for the control of a machine for the pulse cutting of a continuous by casting bar into measured lengths in the course of continuous metal casting, with an actuating device of filling the combustion chamber with the fuel mixture thereof and a system of control of said actuating mechanism, which sets the moment of its operation relative to the moment of cutting and comprising: a timer designed to control the time required for the front end of the bar travel a distance equal to its path travelled at a maximum speed and within the maximum time of filling said combustion chamber, said time controller formed by two pickups signalling the position of said bar and arranged along the axis of its travel to said distance one from the other, the second of said pickups being accomodated at an equal distance from a point indicating the measured length of a billet being cut; a setter of the time for filling said combustion chamber with the fuel mixture; a comparator designed to compare said time interval necessary for said front end to cover said distance and said time interval preset for filling said combustion chamber with the fuel mixture, so that, depending on the results of the comparison, control is exercised of the moment when the filling of said combustion chamber with the fuel mixture starts.  
  3. A device as set forth in claim 2, wherein said system of control of said actuating mechanism of filling said combustion chamber is made as a reversible elec tric motor controlled from said bar positioning pickups and fitted with a movable contact group coupled with said actuating mechanism, one contact of said contact group being connected to the shaft of said electric motor and the second one connected to said shaft via a sleeve controllable from said setter of the time of filling said combustion chamber.