Patent Publication Number: US-6334350-B1

Title: Automatic machine for the formation of ship&#39;s curved hull-pieces

Description:
This application is a 35 USC 371 of PCT/KR99/00092, filed Mar. 2, 1999. 
     TECHNICAL FIELD 
     This invention relates to an automatic machine to form curved plates of ship&#39;s hull-pieces in shipbuilding process, more particularly, to an automatic machine can form curved plates by heating any one side of the plates locally with heating apparatuses. 
     BACKGROUND ART 
     In the ship production process, a ship&#39;s hull is fabricated by forming the pieces out of the plates with any thickness in accordance with design data and welding these pieces. 
     In general, there are two ways to form the curved hull-pieces: hot forming method and cold forming method. Hot forming method of those methods has been used for the completing work of curved plates, the second, or longitudinal forming process of doubly curved plates, and the remove of undesired deformation by welding as it can easily cause residual thermal plastic deformation by heating. 
     Since plates are heated on along the straight line in the hot forming method, the method is called “line heating process.” This work has been manually performed only by some experts. One worker heats the plate toward the given direction with a heating torch and a cooler or one heats the plate with a torch and another cools down the plate along the heated line with a cooler. 
     Also, in such former work the workers has used templates, the measuring gauges which are previously made of wood in order to make sure how much the plates are formed. If the templates perfectly contact the formed plate at specific locations, they admit that the plate is formed as desired. 
     So far, as previously mentioned all formation process of the curved plates has been manually performed only by some workers. It means that the formation process has been performed only with experiences of the line-heating experts, not with the information which is derived from the accurate and theoretical backgrounds. That has decreased the productivity in the formation of the curved plates and the fabrication has been made inaccurately. But the formation of the curved plates requires the high accuracy in the shipbuilding process. 
     In conclusion, such former process for the formation of the ship&#39;s hull-pieces, in which heating, cooling, and measuring is manually performed by some experts has difficulties in precise fabrication and decreases the efficiency of ship production. And there has not been any automatic machine to complete hot forming process of ship&#39;s hull-pieces. 
     DISCLOSURE OF THE INVENTION 
     In order to improve such problems, our aim in this invention is to provide an automatic machine for the formation of ship&#39;s curved hull-pieces to enable that process by heating, cooling and measuring plates to be systemized, to be standardized, and to be automated according to the prefabricated information instead of experiences of skillful workers. 
     Through the automation of such hot forming works, the productivity in the formation of the curved plates and its accuracy can be improved, this invention is about such automatic machine. 
     To accomplish the previous subjects, this invention has feature that an automatic machine is designed to implement systematic and accurate forming process by equipping the following devices. 
     Jig table to be equipped with many jigs to support any shaped steel plates and load-constraining apparatus to prevent the undesired deformation by uniformly sharing the load among the edges of the plates 
     Heating device including a torch to locally heat one side of steel plates up to the required temperature (about 800° C.), setting up over a jig table and moving before and behind, and left and right 
     Cooling device to immediately cool down the heated plates by spraying out coolant from several nozzles, which is set up around a torch and moves along the same path as the torch 
     Measuring device to measure the formed plates and other information with a gauge to be set up beside the cooling device, and to transmit the data to the control system through A/D converter to convert analogue signals sent by the gauge to digital signals 
     Driving device to include a transverse guide rail, a longitudinal guide rail, motors, chains, belts, etc., all of which enable the torch, the cooler, and the measuring gauge to move in accordance with commands of a control system 
     Control device to consist of main controllers and a display device, where main controllers systematically handle the operations of this machine during forming and the operating state and results are monitored through the display device. 
     According to one aspect of this invention, there is provided an automatic machine for ship&#39;s curved hull-pieces includes jig table to support steel plates; heating device including a torch to heat one side of steel plates up to the required temperature (about 800° C.), setting up over a jig table and moving before and behind, and left and right; cooling device to cool down the heated plates by spraying out coolant from several nozzles, which is set up around a torch and moves along the same path as the torch; measuring device to measure the formed plates and other information with a gauge to be set up beside the cooling device, and to transmit the data to the control system through A/D converter to convert analogue signals sent by the gauge to digital signals; driving device to include a transverse guide rail, a longitudinal guide rail, motors, chains, belts, all of which enable the torch, the cooler, and the measuring gauge to move in accordance with commands of a control system; and control device to consist of main controllers and a display device, where main controllers handle the operations of this machine during forming and the operating state and results are monitored through the display device. 
     According to another aspect of this invention, the heating device can be one of gas-oxygen flaming, laser, electric induction heating, and electronic beam heating. 
     According to another aspect of this invention, there is provided the automatic machine for ship&#39;s curved hull-pieces having the cooling device whose cooling method is one of water cooling and air cooling. 
     According to another aspect of this invention, the heating device by the gas flaming consists of gas-supplying tanks, oxygen-supplying tanks, pressure controllers which control the quantity of gas and oxygen, a heating apparatus, or a torch, and an igniter. 
     According to another aspect of this invention, the jig table consists of the load-constraining device and several jigs to have the function of load-constraining device to uniformly distribute the load at edges of the plate in order to prevent the undesired deformation and the function of jigs to support the bottom of the plates by stretching and shrinking and to be equipped with the contact sensor on its end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is an iso-view which shows total system composition of an automatic line-heating machine for the formation of ship&#39;s curved hull-pieces in this invention; 
     FIG. 2 is a magnified iso-view which in detail shows chief parts in this invention; 
     FIG. 3 is a front view which shows the internal of chief parts in this invention; and 
     FIG. 4 isa sectional view which shows working state of our invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     According to the appended figures below, we intend to definitely explain an automatic machine in our invention. 
     FIG. 1 is an iso-view which shows total system composition of an automatic line-heating machine for the formation of ship&#39;s curved hull-pieces in this invention. This automatic line-heating machine consists of the followings: the heating device to heat the target plates, the cooling device to cool down the heated plates, the measuring device to acquire the data of formed plates and forming information, the driving device to move the previous devices, the control system to handle the previous devices with the main controllers and to display the operating state and the shapes of plates in process with the monitoring device, and the jig table to support the plates. 
     In this invention, the gas-oxygen flaming can be applied as a heating source, which consists of gas-supplying tanks ( 22 ), oxygen-supplying tanks ( 23 ), pressure controllers ( 24 ), the heating apparatus, a torch ( 21 ), and an igniter ( 25 ). Where, the pressure controllers ( 24 ) adjust the quantity of the gas and the oxygen. 
     The heating device should have ability to heat the steel plates up to the required temperature. For example, the heating device needs ability to heat up to 800° C. in the case of forming the thick plates which are widely used in shipbuilding. 
     As a heating source, laser, induction heater, the electronic beam, etc. can be substituted for the gas-oxygen flaming. 
     FIG. 2 in detail shows the arrangement of the heating apparatus ( 21 ), the igniter ( 25 ), the coolant pipe ( 31 ) of the cooling device and the measuring gauge ( 41 ) in this invention. FIG. 3 shows its front view. They are arranged as a single unit. 
     The cooling device above mentioned is installed around the heating apparatus, or torch ( 21 ) and moves along the same path with the heating apparatus ( 21 ) in order to increase the cooling and heating effect on steel plates ( 100 ). To come into effect only after heating, the cooling device has several injection nozzles ( 32 ), and it cools down the heated plate by spraying out coolant on the plates ( 100 ). 
     Cooling methods can be grouped into two types by the kinds of coolant: one is a water-cooling method, and the other is a air-cooling method. In a water-cooling method, a water pipe ( 31 ) is set up to surround the heating apparatus ( 21 ), and we made several injection nozzles on this rounded water pipe ( 31 ), so that the coolant, water is sprinkled around heating position. 
     If the air-cooling is needed, we can stop the water flow by locking the control valve that is attached on the water pipe ( 31 ). The water pipe is made to be in one body with the heat apparatus ( 21 ), so that they can move together. 
     The measuring device above mentioned acquires the forming state of the plates ( 100 ) and transmits the information to the control system, so that we can check the forming state through the display device of the control system. 
     Two types of gauges are available in the measuring devices. One is a contact type, which uses contact probes to measure, and the other is a non-contact type, which uses laser, infrared-rays, etc., instead of probes. In the previous figures, FIG.  2  and FIG. 3, the contact-type gauge ( 41 ) is illustrated. The measuring device consists of a gauge and an A/D convert. The gauge ( 41 ) measures the shape and the forming information of the plates in process and they are transmitted to the control system through A/D converter ( 42 ), which converts analog signals acquired with the gauge to digital signals. We can measure plates whenever we need new forming information, not to speak of the final state of plates. 
     For the driving device previously mentioned, we adopt a general driving device. It lets forming equipment that includes the heating apparatus ( 21 ) and the cooler ( 31 ) move in the transverse, longitudinal, and perpendicular direction. That is, it drives the heating apparatus ( 21 ), the cooler ( 31 ), and measuring gauge ( 41 ) of the measuring device move in accordance with commands of main controllers of the control system. It consists of transverse guide rails ( 51 ), a longitudinal guide rail ( 52 ), and some parts such as motor, chain, belt, and so on which are not illustrated in FIG.  1 . 
     The control system above mentioned is divided into two parts—main controllers ( 61 ) and the monitoring device ( 62 ). The main controllers ( 61 ) indicate the driving device according to the forming information such as location, direction, and velocity. The monitoring device ( 62 ) shows initial information on the work plates, objective curved plates, forming information, and the processing state of formation in process through the display. By showing the processing state on the screen, based upon data measured by the measuring device, this monitoring device ( 62 ) enables workers to check the state of work process at any time. On the jig table ( 10 ) above mentioned the load-constraining apparatus ( 11 ) is installed, which prevents arbitrary deformation of the plates by uniformly distributing loads at edges of the forming plate. Several jigs ( 12 ) are located on the table in order to support the bottom of the target plates. 
     The jigs ( 12 ) above mentioned are the columns that are arranged on the jig table ( 10 ) and that can stretch and shrink perpendicularly. On the top of each jig the contact sensor ( 13 ) is installed. It makes possible firmly supporting an arbitrary shaped plate by adjusting the height of the jig after the control system perceiving the contact. Also it enables the control system to check the formed shape. 
     The work process using this invention composed of the above devices can be described as follows. First, a plate ( 100 ) is located on the jig table ( 10 ) according to the designed data of ship&#39;s hull-pieces and is fixed with the load-constraining devices ( 11 ). In accordance with the indication of the main controller ( 61 ) which the forming information is inputted into, the driving device is operated for heating, cooling, and measuring over the plate ( 100 ), when apparatuses to heat, cool, and measure come to move together automatically. In the fabrication process, the heating device makes the plate ( 100 ) deformed plastically, or permanently by locally heating the plate up to the required temperature, and the load-constraining devices ( 11 ) that supports the edges of the plates accelerates the deformation of the plate ( 100 ) by their pressing. 
     The jigs ( 12 ) support the bottom of plate ( 100 ), and help that the heated plates ( 100 ) are deformed. The deformation is related to the extent of jig supporting. Therefore, it is important that the jigs support the plates firmly in spite of arbitrary shapes of the plates. The contact sensor ( 13 ) that is installed on each jig ( 12 ) enables workers to immediately check whether the forming process is successfully being performed or not, by perceiving the contact between the plate ( 100 ) and jigs. The heating device is set up to heat up the plate up to about 800° C. In this device, the heat source is the mixture of propane gas and oxygen. And the temperature can be regulated through adjusting the control valves. 
     To maximize the heating effect and to be controlled easily, the cooling apparatus—a rounded water pipe ( 31 ) with several injection nozzles ( 32 )—is installed around the heating apparatus, the torch. The coolant that is sprayed out from the water pipe cools the heated part of the plate. 
     In the measuring device, the contact type or the non-contact type can be adopted as a gauge to measure the curved plate. It enables that workers can check the shape of the plate that is either in process or in the finished. The A/D converter converts analog signals acquired with the above gauge to digital signals and these converted signals are transmitted to the control system through this converter. 
     Such devices as heating, cooling, and measuring are connected to the driving device and their movement is controlled automatically according to the indication of the control system. 
     As previously explained in detail, this invention is about a instrument that can automate formation process of ship&#39;s curved hull-pieces. This invention makes the formation process of ship&#39;s hull-pieces be systematic by using concurrently operated devices (heating, cooling, measuring devices), the driving device that drives these devices, and the control device that controls each device. In this invention, since the load is given to the plates by heating, mechanical pressing of the constraints, and jig supporting the plastic deformation can efficiently be caused to make the objective curved plates. By working on jigs, the information can be acquired faster. Since this machine uses automatic measuring device, templates do not have to be made. 
     This invention is a very useful technology that can make remarkable improvement of shipbuilding process by automatically forming curved plates very fast, effectively, and exactly. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as recited in the accompanying claims.