PLATE THICKNESS PRESSING DEVICE AND METHOD

Abstract: A material 1 to be shaped is reduced and formed by bringing dies with convex forming surfaces, when viewed from the side of the transfer line of the material 1, close to the transfer line from above and below the material 1, in synchronism with each other, while giving the dies a swinging motion in such a manner that the portions of the forming surfaces of the dies, in contact with the material 1, are transferred from the upstream to the downstream side in the direction of the transfer line.

Description: The present invention relates to a plate reduction press apparatus according to the preamble of claim 2 and to a method concerned with its use, according to the preamble of claim 1. Prior art 1. Fig. 1 shows an example of a roughing mill used for hot rolling, and the roughing mill is provided with work rolls 2a, 2b arranged vertically opposite each other on opposite sides of a transfer line S that transfers a slab-like material 1 to be shaped, substantially horizontally, and backup rolls 3a, 3b contacting the work rolls 2a, 2b on the side opposite to the transfer line. In the above-mentioned roughing mill, the work roll 2a above the transfer line S is rotated counterclockwise, and the work roll 2b underneath the transfer line S is rotated clockwise, so that the material 1 to be shaped is caught between both work rolls 2a, 2b, and by pressing the upper backup roll 3a downwards, the material 1 to be shaped is moved from the upstream A side of the transfer line to the downstream B side of the line, and the material 1 to be shaped is pressed and formed in the direction of the thickness of the slab. However, unless the nip angle  of the material 1 to be shaped as it enters into the work rolls 2a, 2b is less than about 17°, slipping will occur between the upper and lower surfaces of the material 1 to be shaped and the outer surfaces of both work rolls 2a, 2b, and the work rolls 2a, 2b will no longer be able to grip and reduce the material 1 to be shaped.More explicitly, when the diameter D of the work rolls 2a, 2b is 1,200 mm, the reduction Δt of a single rolling pass is about 50 mm according to the above-mentioned nip angle  condition for the work rolls 2a, 2b, so when a material 1 to be shaped with a thickness T0 of 250 mm is rolled, the thickness T1 of the slab after being reduced and formed by a roughing mill becomes about 200 mm.According to the prior art, therefore, the material 1 to be shaped is rolled in a reversing mill, in which the material is moved backwards and forwards while gradually reducing the thickness of the plate, and when the thickness of the material 1 to be shaped is reduced to about 90 mm, the material 1 is sent to a finishing mill.Another system for reducing and forming the material 1 to be shaped according to the prior art is shown in Fig. 2; dies 14a, 14b with profiles like the plane shape of dies for a stentering press machine are positioned opposite each other above and below a transfer line S, and both dies 14a, 14b are made to approach each other and separate from each other in the direction orthogonal to the direction of movement of the material 1 using reciprocating means such as hydraulic cylinders, in synchronism with the transfer of the material 1, while reducing and forming the material 1 to be shaped in the direction of the thickness of the plate.The dies 14a, 14b are constructed with flat forming surfaces 19a, 19b gradually sloping from the upstream A side of the transfer line towards the downstream B side of the line, and flat forming surfaces 19c, 19d that continue from the aforementioned forming surfaces 19a, 19b in a direction parallel to and on opposite sides of the transfer line S.The width of the dies 14a, 14b is set according to the plate width (about 2,000 mm or more) of the material 1 to be shaped.However, when the material 1 to be shaped is rolled with the reversing method using the roughing mill shown in Fig. 1, space is required at each of the upstream A and downstream B ends of the transfer line S of the roughing mill, for pulling out the material 1 to be shaped as it comes out of the roughing mill, so the equipment must be long and large.When the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b shown in Fig. 2, the areas of the forming surfaces 19a, 19b, 19c and 19d in contact with the material 1 to be shaped are much longer than those of the dies of a stentering press machine, and the contact areas increase as the dies 14a, 14b approach the transfer line S, so that a large load must be applied to each of the dies 14a, 14b, during reduction.Furthermore, the power transmission members such as the eccentric shafts and rods for moving the dies 14a, 14b, the housing, etc. must be strong enough to withstand the above reducing loads, so each of these members and the housing must be made large in size.Moreover, when the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b, some of the material 1 is forced backwards towards the upstream A side on the transfer line depending on the shape and the stroke of the dies 14a, 14b, therefore, it becomes difficult to transfer the material 1 to be shaped to the downstream B side of the transfer line.When the material 1 to be shaped is reduced and formed in the direction of its plate thickness using the dies 14a, 14b shown in Fig. 2, the height of the lower surface of the material 1 after being reduced by the dies 14a, 14b is higher than the height of the lower surface of the material 1 immediately before being reduced by the dies, by an amount corresponding to the reduction in thickness.Consequently, the leading end of the material 1 to be shaped tends to droop downwards, therefore the table rollers (not illustrated) installed on the downstream B side of the transfer line, to support the material 1 being shaped, may catch the leading end of the material 1, possibly resulting in damage to both the table rollers and the material 1 being shaped.Recently, the flying-sizing press machine shown in Fig. 3 has been proposed.This flying-sizing press machine is provided with a housing 4 erected on a transfer line S so as to allow movement of a material 1 to be shaped, an upper shaft box 6a and a lower shaft box 6b housed in window portions 5 of the housing 4 opposite each other on opposite sides of the transfer line S, upper and lower rotating shafts 7a, 7b extending substantially horizontally in the direction orthogonal to the transfer line S and supported by the upper shaft box 6a or the lower shaft box 6b by bearings (not illustrated) on the non-eccentric portions, rods 9a, 9b located above and below the transfer line S, respectively, connected to eccentric portions of the rotating shafts 7a, 7b through bearings 8a, 8b at the end portions thereof, rod support boxes 11a, 11b connected to intermediate portions of the upper and lower rods 9a, 9b by bearings 10a, 10b with spherical surfaces and housed in the window portions 5 of the housing 4 and free to slide vertically, die holders 13a, 13b connected to the top portions of the rods 9a, 9b through bearings 12a, 12b with spherical surfaces, dies 14a, 14b mounted on the die holders 13a, 13b, and hydraulic cylinders 15a, 15b whose cylinder units are connected to intermediate locations along the length of the rods 9a, 9b by means of bearings and the tips of the piston rods are connected to the die holders 13a, 13b through bearings.The rotating shafts 7a, 7b are connected to the output shaft (not illustrated) of a motor through a universal coupling and a speed reduction gear, and when the motor is operated, the upper and lower dies 14a, 14b approach towards and move away from the transfer line S in synchronism with the transfer operation.The dies 14a, 14b are provided with flat forming surfaces 16a, 16b gradually sloping from the upstream A side of the transfer line towards the downstream B side of the transfer line so as to approach the transfer line S, and other flat forming surfaces 17a, 17b continuing from the aforementioned forming surfaces 16a, 16b in a direction parallel to the transfer line S.The width of the dies 14a, 14b is determined by the plate width (about 2,000 mm or more) of the material 1 to be shaped.A position adjusting screw 18 is provided at the top of the housing 4, to enable the upper shaft box 6a to be moved towards or away from the transfer line S, and by rotating the position adjusting screw 18 about its axis, the die 14a can be raised and lowered through the rotating shaft 7a, rod 9a, and the die holder 13a.When the material 1 to be shaped is reduced and formed in the direction of the plate thickness using the flying-sizing press machine shown in Fig. 3, the position adjusting screw 18 is rotated appropriately to adjust the position of the upper shaft box 6a, so that the spacing between the upper and lower dies 14a, 16b is determined according to the plate thickness of the material 1 to be shaped by reducing and forming in the direction of plate thickness.Next, the motor is operated to rotate the upper and lower rotating shafts 7a, 7b, and the material 1 to be shaped is inserted between the upper and lower dies 14a, 14b, and the material 1 is reduced and formed by means of the upper and lower dies 14a, 14b that move towards and away from each other and with respect to the transfer line S while moving in the direction of the transfer line S as determined by the displacement of the eccentric portions of the rotating shafts 7a, 7b.At this time, appropriate hydraulic pressure is applied to the hydraulic chambers of the hydraulic cylinders 15a, 15b, and the angles of the die holders 13a, 13b are changed so that the forming surfaces 17a, 17b of the upper and lower dies 14a, 14b, on the downstream B side of the transfer line, are always parallel to the transfer line S.However, the flying-sizing press machine shown in Fig. 3 has much larger contact areas between the forming surfaces 16a, 16b, 17a and 17b of the dies 14a, 14b and the material 1 to be formed, compared to the dies of a plate reduction press machine, and because the above-mentioned contact areas increase as the dies 14a, 14b approach the transfer line S, a large load must be applied to the dies 14a, 14b during reduction.In addition, the die holders 13a, 13b, rods 9a, 9b, rotating shafts 7a, 7b, shaft boxes 6a, 6b, housing 4, etc. must be strong enough to withstand the reducing load applied to the dies 14a, 14b, so that these members are made larger in size.Also, the flying-sizing press machine shown in Fig. 3 may suffer from the problem that the leading and trailing ends of the material 1 being reduced and formed are locally bent to the left or right, or with a camber so that when a long material 1 is being formed it generally warps, unless the centers of the reducing forces from the dies 14a, 14b on the material 1 to be shaped are in close alignment when the material 1 is reduced and formed by the upper and lower dies 14a, 14b. 2. With a conventional rolling mill known in the prior art, in which a material is rolled between two work rolls, there is a reduction ratio limit of normally about 25% due to the nip angle limitation. Therefore, it is not possible to reduce the thickness of a material by a large ratio (for example, reducing a material from about 250 mm thickness to 30 to 60 mm) in a single pass, therefore three or four rolling mills are arranged in tandem in a tandem rolling system, or the material to be rolled is rolled backwards and forwards in a reverse rolling system. However, these systems are accompanied with practical problems such as the need for a long rolling line. On the other hand the planetary mill, Sendzimir mill, cluster mill, etc. have been proposed as means of pressing that allow a large reduction in one pass. However, with these rolling mills, small rolls press the material to be rolled at a high rotational speed, resulting in a great impact, therefore the life of the bearings etc. is so short that these mills are not suitable for mass production facilities.On the other hand, various kinds of press apparatus modified from the conventional stentering press machines have been proposed (for example, Japanese patent No. 014139, 1990, unexamined Japanese patent publication Nos. 222651, 1986, 175011, 1990, etc.).An example of the "Flying-sizing press apparatus" according to the unexamined Japanese patent publication No. 175011, 1990 is shown in Fig. 4; rotating shafts 22 are arranged in the upper and lower sides or the left and right sides of the transfer line Z of a material to be shaped, and the bosses of rods 23 with a required shape are connected to eccentric portions of the rotating shafts 22, and in addition, dies 24 arranged on opposite sides of the transfer line of the material to be shaped are connected to the tips of the rods 23; when the rotating shafts 22 are rotated, the rods 23 coupled to the eccentric portions of the rotating shafts cause the dies 24 to press both the upper and lower surfaces of the material 1 to be shaped, thereby the thickness of the material to be shaped is reduced.However, the above-mentioned high-reduction means are associated with problems such as (1) a material to be reduced cannot be easily pressed by the flying-sizing apparatus in which the material is reduced as it is being transferred, (2) the means are complicated with many component parts, (3) many parts must slide under heavy loads, (4) the means are not suitable for heavily loaded frequent cycles of operation, etc.With conventional high-reduction pressing means known in the prior art, the position of the dies is controlled to adjust the thickness of the material to be pressed by means of a screw, wedge, hydraulic cylinder, etc., and as a result, there are the practical problems that the equipment is large, costly, complicated, and vibrates considerably. 3. Conventionally, a roughing-down mill is used to roll a slab. The slab to be rolled is as short as 5m to 12m, and the slab is rolled by a plurality of roughing-down mills or by reversing mills in which the slab is fed forwards and backwards as it is rolled. In addition, a reduction press machine is also used. Recently, because a long slab manufactured by a continuous casting system has been introduced, there is a demand for the continuous transfer of the slab to a subsequent pressing system. When a material is rough rolled using a roughing-down mill, the minimum nip angle (about 17°) must be satisfied, so the reduction limit Δ t per pass is about 50 mm. Because the slab is continuous, reverse rolling is not applicable, so that to obtain the desired thickness, a plurality of roughing-down mills must be installed in series, or if a single rolling mill is to be employed, the diameter of the work rolls should be very large. Consequently, a reduction press machine is used. Fig. 5 shows an example of such a machine in which the dies are pressed by sliders, to provide a flying-press machine that can press a moving slab. Dies 32 provided above and below the slab 1 are mounted on sliders 33, and the sliders 33 are moved up and down by the crank mechanisms 34. The dies 32, sliders 33 and crank mechanisms 34 are reciprocated in the direction of transferring the slab, by the feeding crank mechanisms 35. The slab 1 is conveyed by pinch rolls 36 and transfer tables 37. When the slab is being reduced, the dies 32, sliders 33 and crank mechanisms 34 are moved in the direction of transferring the slab by means of the feeding crank mechanisms 35, and the pinch rolls 36 transfer the slab 1 in synchronism with this transfer speed. A start-stop system can also be used; the slab 1 is stopped when the system is working as a reduction press machine and the slab is reduced, and after completing reduction, the slab is transferred by a length equal to a pressing length, and then pressing is repeated.There are problems in the design and manufacturing cost of the aforementioned roughing-down mill with large diameter rolls, and the use of rolls with a large diameter results in a shorter life for the rolls because of the low rolling speed and difficulty in cooling the rolls. With the reduction press machine using sliders and feeding crank mechanisms shown in Fig. 5, the cost of the equipment is high because the mechanisms for reciprocating the sliders etc. in the direction of movement of a slab are complicated and large in scale. In addition, the sliders vibrate significantly in the vertical direction. With a reduction press machine using a start-stop system, the slab must be accelerated and decelerated repeatedly from standstill to transfer speed, and vice versa. The slab is transferred using pinch rolls and transfer tables, and these apparatus become large due to the high acceleration and deceleration. 4. When a material is reduced by a large amount, according to the prior art, long dies were used to reduce the material while it was fed through the dies by the length thereof during one or several pressings. Defining the longitudinal and lateral directions as the direction in which the pressed material is moved and the direction perpendicular to the longitudinal direction, respectively, the material to be pressed by a large amount in the longitudinal direction is pressed by dies that are long in the longitudinal direction using single pressing or by means of a plurality of pressing operations while feeding the material to be pressed in the longitudinal direction. Fig. 6 shows an example of the above-mentioned reduction press machine, and Fig. 7 illustrates its operation. The reduction press is equipped with dies 42 above and below a material 1 to be pressed, hydraulic cylinders 43 for pressing down the dies 42, and a frame 44 that supports the hydraulic cylinders 43. A pressing operation is described using the symbols L for the length of the dies 42, T for the original thickness of the material 1 to be pressed, and t for the thickness of the material after pressing. Fig. 7 (A) shows the state of the dies 42 set to a location with thickness T on a portion of material to be pressed next, adjacent to a portion with thickness t which has been pressed. (B) shows the state in which the dies have pressed down from the state (A). (C) is the state in which the dies 42 have been separated from the material 1 being pressed, that has then been moved longitudinally by the pressing length L, and completely prepared for the next pressing, which is the same state as (A). Operations (A) to (C) are repeated until all the material is reduced to the required thickness. The longer the dies, the greater the force that is required for reduction, so the reduction press machine must be large. With a press machine, pressing is usually repeated at high speed. When an apparatus with a large mass is reciprocated at a high speed, a large power is required to accelerate and decelerate the apparatus, therefore the ratio of the power required for acceleration and deceleration to the power needed for reducing the material to be pressed is so large that much power is spent on driving the apparatus. When the material is reduced, the volume corresponding to the thinned portion must be displaced longitudinally or laterally because the volumes of the material before and after reduction are substantially the same. If the dies are long, the material is constrained so that it is displaced longitudinally (this phenomenon is called material flow), so that pressing becomes difficult especially when the reduction is large.When a material to be rolled is reduced conventionally in a horizontal mill, the gap between the rolls of the horizontal mill is set so that the rolls are capable of gripping the material to be rolled considering the thickness of the material after forming, therefore the reduction in thickness allowed for a single pass is limited so that when a large reduction in the thickness is required, a plurality of horizontal mills have to be installed in series, or the material must be moved backwards and forwards through a horizontal mill while the thickness is gradually reduced, according to the prior art. Another system was also proposed in the unexamined Japanese patent publication No. 175011, 1990; eccentric portions are provided in rotating shafts, the motion of the eccentric portions is changed to an up/down movement using rods, and a material to be pressed is reduced continuously by these up/down movements.The system with a plurality of horizontal mills arranged in tandem (series) has the problems that the equipment is large and the cost is high. The system of passing a material to be pressed backwards and forwards through a horizontal mill has the problems that the operations are complicated and a long rolling time is required. The system disclosed in the unexamined Japanese patent application No. 175011, 1990 has the difficulty that large equipment must be used, because a fairly large rotating torque must be applied to the rotating shafts to produce the required reducing force as the movement of the eccentric portions of the rotating shafts has to be changed to an up/down motion to produce the necessary reducing force. 5. Conventionally, a roughing-down mill is used to press a slab. The slab to be pressed is as short as 5 to 12 m, and to obtain the specified thickness, a plurality of roughing-down mills are provided, or the slab is moved backwards and forwards as it is pressed in the reversing rolling method. Other systems also used practically include a flying press machine that transfers a slab while it is being pressed, and a start-stop reduction press machine which stops conveying the material as it is being pressed and transfers the material during a time when it is not being pressed. Since long slabs are produced by continuous casting equipment, there is a practical demand for a slab to be conveyed continuously to a subsequent press apparatus. When a slab is rough rolled in a roughing-down mill, there is a nip angle limitation (about 17°), so the reduction per rolling cannot be made so large. Because the slab is continuous, it cannot be rolled by reverse rolling, therefore to obtain the preferred thickness, a plurality of roughing-down mills must be installed in series, or if a single mill is involved, the diameter of the work rolls must be made very large. There are difficulties, in terms of design and cost, in manufacturing such a roughing-down mill with large-diameter rolls, and large diameter rolls must be operated at a low speed when rolling a slab, so the rolls cannot be easily cooled, and the life of the rolls becomes shorter. Because a flying press can provide a large reduction in thickness and is capable of reducing a material while it is being conveyed, the press can continuously transfer the material being pressed to a downstream rolling mill. However, it has been difficult to adjust the speed of the material to be pressed so that the flying press and the downstream rolling mill can operate simultaneously to reduce and roll the material. In addition, it has not been possible to arrange a start-stop reduction press machine and a rolling mill in tandem to reduce a slab continuously; with the start-stop reduction press, the material being pressed is stopped during pressing, and is transferred when it is not being pressed. Another system in practical use is the flying system in which the sliders that press down on a slab are moved up and down in synchronism with the transfer speed of the slab. In the start-stop system, the heavy slab is accelerated and decelerated every cycle from standstill to the maximum speed Vmax, and accordingly the capacity of the transfer facilities such as the pinch rolls and transfer tables must be large. Because of the discontinuous operation, it is difficult to carry out further operations on a downstream press machine. The flying system requires a large capacity apparatus to produce the swinging motion, and to accelerate and decelerate the heavy sliders according to the speed of the slab. Another problem with this system is that this large capacity apparatus for producing the swinging motion causes considerable vibrations in the press machine. Still another problem with this system is that if the speed of the slab deviates from that of the sliders, flaws may be produced in the slab or the equipment may be damaged. Recently, a high-reduction press machine that can reduce a thick slab (material to be pressed) to nearly 1/3 of its original thickness in a single reduction operation, has been developed. Fig. 8 shows an example of a reduction press machine used for hot pressing. With this reduction press machine, dies 52a, 52b are disposed opposite each other vertically on opposite sides of the transfer line S, and are simultaneously moved towards and away from a material 1 to be pressed that travels on the transfer line S by the reciprocating apparatus 53a, 53b incorporating eccentric axes, rods, and hydraulic cylinders, so that material of a thickness of, for example, 250 mm can be reduced to 90 mm by a single reducing operation. However, the reduction of the aforementioned high-reduction press machine can be as large as 160 mm, that is, the reduction on one side is as large as 80 mm. According to the prior art, there is a small difference of thickness before and after pressing, so the transfer levels of the transfer devices of a press machine on the inlet and outlet sides are substantially the same. With the above-mentioned high-reduction press machine, however, there is the problem that the material 1 to be pressed is bent if the transfer levels are identical. Another problem of the machine is that the transfer device is overloaded. Further, a method and an apparatus according to the preamble of claims 1 and 2, respectively, are known from US-A-3 583 192. The apparatus known from US-A-3 583 192 is operated such that an eccentric at the entry side of the die is operated approximately 150° ahead of the eccentric at the exit side of said die. Thus, the entry end of the die comes into contact with the workpiece approximately 150° ahead of the exit end of said die, resulting in that the eccentric starts to deform the workpiece before said eccentric at the exit side of said die leaves the indicated top dead center position. By operating the apparatus known from US-A-3 583 192 according to the known method, a disadvantageously large load is imposed on the dies during reduction. Further, by operating the known apparatus by the method as disclosed in US-A-3 583 192, the processed material is not efficiently reduced. SUMMARY OF THE INVENTION 1. The present invention has been accomplished under the circumstances mentioned above, and it is an object of the present invention to provide a plate reduction press apparatus and method that can efficiently reduce a material to be shaped in the direction of the thickness of the plate, can securely transfer the material to be shaped, can decrease the load imposed on the dies during reduction, and can prevent bending of the material to be shaped to the left or right as a result of the reducing and forming operations. To achieve the aforementioned object of the present invention, a plate reduction pressing method as defined in Claim 1 and a plate thickness reduction press apparatus as defined in Claim 2 are provided. According to a preferred embodiment of the plate reduction press apparatus specified in Claim 3 of the present invention, the mechanisms for moving the dies backwards and forwards in the plate press apparatus specified in Claim 2 are provided with arms one end of each of which is fixed to the die holder, and guide members which are installed near the die holders and guide the other end of each of the arms. According to a further preferred embodiment of the inventive plate reduction press apparatus specified in Claim 4, the mechanisms for moving the dies backwards and forwards are provided with actuators one end of each of which is connected to one of the die holders through a first bearing and the other end of each thereof is connected to a predetermined fixing member through a second bearing. A preferred embodiment of the inventive plate reduction press apparatus as specified in Claim 5 is composed of the mechanisms for moving the dies backwards and forwards in the inventive plate reduction press apparatus specified in Claim 2, comprised of eccentric shafts for backwards and forwards movements, provided near the die holders and rods for backwards and forwards movements, one end of each of the aforementioned rods being connected to one of the die holders through a first bearing and the other end thereof being connected to one of the eccentric portions of the eccentric shafts for backwards and forwards movements. In the preferred embodiment of the inventive plate reduction press apparatus as specified in Claim 6, the mechanisms for moving the dies backwards and forwards in the plate reduction press apparatus specified in Claim 2 of the present invention are composed of levers one end of each of which is connected to one of the die holders through a first bearing and the other end thereof is connected to a predetermined fixing member through a second bearing. According to the inventive plate reduction pressing method specified in Claim 1 of the present invention, dies with convex forming surfaces protruding towards the transfer line are moved towards the transfer line from above and below the material to be shaped in synchronism with the movement of the material to be shaped, and given a swinging motion such that the portions of the forming surfaces in contact with the material to be shaped move from the downstream side of the transfer line to the upstream side thereof, thereby the areas of the material being shaped, in contact with the forming surfaces, are made small to reduce the pressing load on the dies. According to the inventive plate reduction press apparatus and the preferred embodiments thereof, the die holders on which the dies are mounted are given a swinging motion by the upstream eccentric shafts, downstream eccentric shafts, upstream rods and downstream rods in such a manner that the portions of the forming surfaces of the dies, in contact with the material to be shaped, are shifted from the downstream side to the upstream side of the transfer line, while moving the dies towards the transfer line, thereby the areas of the forming surfaces in contact with the material to be shaped are made small to reduce the load applied to the dies during pressing. Also, when the forming surfaces of the dies are in contact with the material to be shaped, the mechanisms for moving the dies backwards and forwards move the die holders towards the downstream side of the transfer line, and convey the material being reduced and formed without any material being displaced backwards, towards the downstream side of the transfer line. The other objects and advantages of the present invention will be revealed as follows by referring to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of an example of a rolling mill used for hot rolling. Fig. 2 is a schematic view showing an example of reduction forming in the direction of plate thickness of a material to be shaped using dies. Fig. 3 is a conceptual view showing an example of a flying sizing press apparatus. Fig. 4 is a structural view of a conventional high-reduction press machine. Fig. 5 is a view showing a conventional flying reduction press machine. Fig. 6 is a view showing an example of the configuration of a reduction press machine using conventional long dies. Fig. 7 is a view showing the operation of the apparatus shown in Fig. 6. Fig. 8 shows the method of reducing thickness used during hot pressing. Fig. 9 is a general view seen from the side of the transfer line, of the first embodiment of the plate reduction press apparatus according to the present invention. Fig. 10 is a conceptual view showing the displacement of the dies shown in Fig. 9 with respect to the transfer line, and the swinging motion of the dies. Fig. 11 is a conceptual view showing the displacement of the dies shown in Fig. 9 with respect to the transfer line, and the swinging motion of the dies. Fig. 12 is a conceptual view showing the displacement of the dies shown in Fig. 9 with respect to the transfer line, and swinging motion of the dies. Fig. 13 is a conceptual view showing the displacement of the dies shown in Fig. 9 with respect to the transfer line, and the swinging motion of the dies. Fig. 14 is a general view seen from the side of the transfer line, of the second embodiment of the plate reduction press apparatus according to the present invention. Fig. 15 is a general view seen from the side of the transfer line, of the third embodiment of the plate reduction press apparatus according to the present invention. Fig. 16 is a general view seen from the side of the transfer line, of the fourth embodiment of the plate reduction press apparatus according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention are described as follows referring to the drawings. (First embodiment) Figs. 9 to 13 show the first embodiment of the plate reduction press apparatus according to the present invention; this apparatus is provided with a housing 101 erected in a predetermined place on a transfer line S so that a plate-like material 1 to be shaped can pass through the center portion, upstream eccentric shafts 103a, 103b extending in the lateral direction of the material 1 to be shaped and provided with eccentric portions 102a, 102b, downstream eccentric shafts 105a, 105b extending in the same direction as the aforementioned upstream eccentric shafts 103a, 103b and provided with eccentric portions 104a, 104b, upstream rods 106a, 106b and downstream rods 107a, 107b extending up and down, die holders 109a, 109b for mounting dies 108a, 108b, and mechanisms 121a, 121b for moving the dies backwards and forwards. The upstream eccentric shafts 103a, 103b are arranged inside the housing 101 such that the shafts are opposite each other above and below the transfer line S, and the non-eccentric portions 110a, 110b at both ends of the shafts are supported by upstream shaft boxes (not illustrated) mounted in the housing 101 through bearings. The downstream eccentric shafts 105a, 105b are arranged inside the housing 101 in such a manner that the shafts are opposite each other above and below the transfer line S on the downstream B side of the transfer line downstream of the upstream eccentric shafts 103a, 103b, and the non-eccentric portions 111a, 111b at both ends of the shafts are supported by downstream shaft boxes (not illustrated) mounted in the housing 101 through bearings. The drive shaft (not illustrated) of a motor is connected to one end of each of the upstream eccentric shafts 103a, 103b and the downstream eccentric shafts 105a, 105b, through a universal coupling and a gear box, so that each of the eccentric shafts 103a, 103b, 105a and 105b can rotate in synchronism together. The gear box mentioned above is configured in such a manner that when the motor is operated, both upper eccentric shafts 103a, 105a rotate counterclockwise so that the eccentric portion 104a of the downstream eccentric shaft 105a rotates with a phase angle 90' ahead of the phase angle of the eccentric portion 102a of the upstream eccentric shaft 103a, and at the same time, both lower eccentric shafts 103b, 105b beneath the transfer line S rotate clockwise so that the eccentric portion 104b of the downstream eccentric shaft 105b rotates with a phase angle 90° ahead of the phase of the eccentric portion 102b of the upstream eccentric shaft 103b, as shown in Figs. 11 through 15; in addition, the eccentric portions 102a, 104a and the eccentric portions 102b, 104b are positioned symmetrically to each other on opposite sides of the transfer line S. The big ends of the upstream rods 106a, 106b are connected to the eccentric portions 102a, 102b of the upstream eccentric shafts 103a, 103b through bearings 112a, 112b. The big ends of the downstream rods 107a, 107b are connected to the eccentric portions 104a, 104b of the downstream eccentric shafts 105a, 105b through bearings 113a, 113b. The die holders 109a, 109b are installed inside the housing, such that the holders are opposite each other on opposite sides of the transfer line S. Brackets 114a, 114b provided near the upstream A side of the transfer line on the die holders 109a, 109b are connected to the tips of the aforementioned upstream rods 106a, 106b by the pins 115a, 115b and bearings 116a, 116b extending substantially horizontally in the lateral direction of the material 1 to be shaped. The tips of the above-mentioned downstream rods 107a, 107b are connected to brackets 117a, 117b provided near the downstream B side of the transfer line on the die holders 109a, 109b, by the pins 118a, 118b and bearings 119a, 119b, that are parallel to the pins 115a, 115b. By means of these upstream rods 106a, 106b and downstream rods 107a, 107b, and the displacements of the eccentric portions 102a, 102b associated with the rotation of the above-mentioned upstream eccentric shafts 103a, 103b and the displacement of the eccentric portions 104a, 104b associated with the downstream eccentric shafts 105a, 105b, motion is transmitted to the die holders 109a, 109b, so that the die holders 109a, 109b move towards and away from the transfer line S with a swinging action. The dies 109a, 109b mounted on each of the die holders 108a, 108b face the material 1 to be shaped, as it is being passed through the transfer line S, and when viewed from the side of the transfer line S, the dies are provided with forming surfaces 120a, 120b that are convex circular arcs projecting towards the transfer line S. Mechanisms 121a, 121b for moving the dies backwards and forwards are composed of arms 122a, 122b one end of each of which is fixed to the end of one of the die holders 109a, 109b, near the downstream B side of the transfer line, and projecting in the downstream B direction of the transfer line, guide members 124a, 124b fixed at locations near to the downstream B side of the transfer line of the housing 101 and comprised of grooves 123a, 123b inclined at an angle to the transfer line so that the distance from the transfer line increase in the downstream B direction, and guide rings 126a, 126b connected to the tips of the arms 122a, 122b through pins 125a, 125b in a rotatable manner, which engage with the grooves 123a, 123b of the guide members 124a, 124b in a movable manner. The mechanisms 121a, 121b for moving the dies backwards and forwards give the die holders 109a, 109b a reciprocating motion relative to the transfer line S, so that the die holders 109a, 109b move towards and away from the transfer line S with a swinging motion, associated with the rotation of the upstream eccentric shafts 103a, 103b and the downstream eccentric shafts 105a, 105b, as described previously. The operation of the plate reduction press apparatus shown in Figs. 10 through 13 is described as follows, with particular emphasis on the upstream eccentric shaft 103a, downstream eccentric shaft 105a, upstream rods 106a, downstream rods 107a, dies 108a, and die holders 109a, on the upstream side of the transfer line S. When the angles of the eccentric portion 102a of the upstream eccentric shaft 103a and the eccentric portion 104a of the downstream eccentric shaft 105a are defined such that top dead center is 0° (360°), and both eccentric portions 102a, 104a are rotated with the angle of rotation increasing in the counterclockwise direction, and as shown in Fig. 10, the angle of rotation of the eccentric portion 104a of about 45° is assumed to correspond to the angle of rotation of the eccentric portion 102a of about 315°; the die 108a is then in the farthest position from the transfer line S, and the guide ring 126a is located at the end of the guide member 124a, nearest to the downstream side of the transfer line. When both eccentric shafts 103a, 105a rotate counterclockwise from the aforementioned state, the die 108a moves towards the transfer line S. At this time, because the phase angle of the eccentric portion 104a is 90° ahead of the phase angle of the eccentric portion 102a, the end of the die 108a, near to the downstream B side of the transfer line, moves towards the transfer line S before the end near the upstream A side of the transfer line, and at the same time, the guide ring 126a moves towards the upstream A side of the transfer line, in the guide member 124a. As shown in Fig. 11, when the angle of rotation of the eccentric portion 102a becomes about 90° and the angle of rotation of the eccentric portion 104a is about 180°, the guide ring 126a reaches the end of the guide member 124a, near the upstream A side of the transfer line, and the portion of the forming surface 120a of the die 108a, near to the downstream B side of the transfer line, presses the material 1 to be shaped, as it passes along the transfer line S. When both eccentric shafts 103a, 105a rotate and the angle of rotation of the eccentric portion 102a increases and the angle of rotation of the eccentric portion 104a becomes greater than 180°, the guide ring 126a begins to move towards the downstream B side of the transfer line, in the guide member 124a, and the die 108a swings in such a manner that the portion of the forming surface 120a of the die 108a, in contact with the material 1 to be shaped, moves towards the upstream A side of the transfer line from the downstream B side thereof, thus the material 1 to be shaped is subjected to a reducing and forming process. After this, the die 108a moves towards the downstream B side of the transfer line, and feeds the material 1 being reduced and formed towards the downstream B side of the transfer line without any material being forced backwards. As shown in Fig. 12, after the angle of rotation of the eccentric portion 102a becomes about 135° and the angle of rotation of the eccentric portion 104a is about 225°, the portion of the forming surface 120a of the aforementioned die 108a, near the upstream A side of the transfer line, reduces and forms the material 1 to be shaped as the die 108a swings in the downstream direction. Furthermore, as shown in Fig. 13, when the angles of rotation of the eccentric portions 102a, 104a become about 180° and 270°, respectively, the die 108a moves away from the transfer line S. During these operations, the upstream eccentric shaft, 103b, downstream eccentric shaft 105b, upstream rod 106b, downstream rod 107b, die 108b, and die holder 109b, below the transfer line S, also operate in the same way as the ones above the transfer line S as described above, thereby the material 1 to be shaped is reduced and formed from above and below the material. In the plate reduction press apparatus shown in Figs. 9 through 13 as described above, the die holders 109a, 109b on which the dies 108a, 108b are mounted are given a swinging motion by the upstream eccentric shafts 103a, 103b, downstream eccentric shafts 105a, 105b, upstream rods 106a, 106b, and downstream rods 107a, 107b, in such a manner that the portions of the forming surfaces 120a, 120b, in contact with the material 1 to be shaped, of the dies 108a, 108b are transferred from the downstream B side of the transfer line towards the upstream A side thereof as the die holders are brought close to the transfer line S, so that the areas of the forming surfaces 120a, 120b in contact with the material 1 to be shaped are made smaller, so the pressing loads on the dies 108a, 108b can be reduced. Consequently, the forces imposed on the power transmission members such as the eccentric shafts 103a, 103b, 105a, and 105b and the rods 106a, 106b, 107a, and 107b, are reduced, so that these components can be made more compact than those known in the prior art. Moreover, because the die holders 109a, 109b are moved towards the downstream B side of the transfer line by the mechanisms 121a, 121b for moving the dies backwards and forwards when the forming surfaces 120a, 120b of the dies 108a, 108b are in contact with the material 1 to be shaped, the material is never forced backwards, but the material 1 that is reduced and formed can be fed forwards to the downstream B side of the transfer line. (Second embodiment) Fig. 14 shows the second embodiment of the plate reduction press apparatus according to the present invention; in the following figures, the item numbers indicate the same components as those shown in Figs. 9 through 13. This plate reduction press apparatus incorporates mechanisms 127a, 127b for moving the dies backwards and forwards in place of the mechanisms 121a, 121b shown in Figs. 9 through 13 for moving the dies backwards and forwards. The mechanisms 127a, 127b for moving the dies backwards and forwards are composed of brackets 128a, 128b fixed to the end portions of the die holders 109a, 109b, near to the downstream B side of the transfer line, brackets 129a, 129b fixed to portions of the housing 101, near to the downstream B side of the transfer line, and hydraulic cylinders 134a, 134b, the tips of the piston rods 130a, 130b of which are connected to the brackets 128a, 128b through bearings by the pins 131a, 131b and the cylinders 132a, 132b of which are connected to the brackets 129a, 129b through bearings by the pins 133a, 133b. Also with this plate reduction press apparatus, hydraulic pressure is applied to the hydraulic chambers on the head side of the hydraulic cylinders 134a, 134b when the forming surfaces 120a, 120b of the dies 108a, 108b are not in contact with the material 1 to be shaped, thereby the die holders 109a, 109b together with the dies 108a, 108b are moved towards the upstream A side of the transfer line, and when the forming surfaces 120a, 120b of the dies 108a, 108b, are brought into contact with the material 1 to be shaped, hydraulic pressure is applied to the hydraulic chambers on the rod side of the hydraulic cylinders 134a, 134b, thus the die holders 109a, 109b together with the dies 108a, 108b are moved towards the downstream B side of the transfer line; in this way, as for plate reduction press apparatus described previously by referring to Figs. 9 through 13, the material 1 being shaped can be fed towards the downstream B side of the transfer line, without forcing any material in the backward direction. Also, other types of actuators such as screw jacks can be applied instead of the hydraulic cylinders 134a, 134b. (Third embodiment) Fig. 15 shows the third embodiment of the plate reduction press apparatus according to the present invention, and in the figure, item numbers refer to the same components as those shown in Figs. 9 through 13. In this plate reduction press apparatus, mechanisms 135a, 135b for moving the dies backwards and forwards are used in place of the mechanisms 121a, 121b for moving the dies backwards and forwards, shown in Figs. 9 through 13. The mechanisms 135a, 135b for moving the dies backwards and forwards are composed of brackets 128a, 128b fixed to the end portions of the die holders 109a, 109b, on the downstream B side of the transfer line, eccentric shafts 136a, 136b for the backwards and forwards movements, provided at locations on the housing 101, near the downstream B side of the transfer line, which can rotate, and extending substantially horizontally in the lateral direction of the material 1 to be shaped, and rods 139a, 139b for backwards and forwards motion one end of each of which is connected to the bracket 128a or 128b by the pin 137a or 137b, and the other ends of which are connected to the eccentric portions 138a, 138b, of the eccentric shafts 136a, 136b for backward and forward movements through bearings. Also with this plate reduction press apparatus, the eccentric shafts 136a, 136b for backward and forward movements are rotated, and the dies 108a, 108b are moved to the upstream A side of the transfer line together with the die holders 109a, 109b, while the forming surfaces 120a, 120b of the dies 108a, 108b are not in contact with the material 1 to be shaped, and when the forming surfaces 120a, 120b of the dies 108a, 108b come in contact with the material 1 to be shaped, the eccentric shafts 136a, 136b for backward and forward movements are rotated to move the dies 108a, 108b together with the die holders 109a, 109b in the downstream B direction of the transfer line, thereby the material 1 after being reduced and formed can be fed out to the downstream B side of the transfer line without any of the material being forced backwards, in the same manner as with the plate reduction press apparatus described previously by referring to Figs. 9 through 13. (Fourth embodiment) Fig. 16 shows the fourth embodiment of the plate reduction press apparatus according to the present invention, and in the figure, item numbers refer to the same components as those in Figs. 9 through 13. This plate reduction press apparatus incorporates mechanisms 140a, 140b for moving the dies backwards and forwards in place of the mechanisms 121a, 121b for moving the dies backwards and forwards shown in Figs. 9 to 13. The mechanisms 140a, 140b for moving the dies backwards and forwards are composed of brackets 128a, 128b fixed to the end portions of the die holders 109a, 109b, closest to the downstream B side of the transfer line, brackets 141a, 141b whose bases are fixed to predetermined locations on the housing 101 in such a manner that the tips of the brackets are positioned on the side of the die holders 109a, 109b on the opposite side to the transfer line, and levers 144a, 144b one end of each of which is connected to the bracket 128a or 128b by the pin 142a or 142b, and the other ends of which are connected to the brackets 141a, 141b through the bearings of pins 143a, 143b. The mounting locations of brackets 128a, 128b, 141a, and 141b, the distances between connecting points of levers 144a, 144b, and the locations of the bearings of levers 144a, 144b with respect to the brackets 128a, 128b, 141a, and 141b are predetermined in such a manner that as the eccentric shafts 103a, 103b, 105a, and 105b rotate, the die holders 109a, 109b with the dies 108a, 108b mounted on them, move in substantially the same way as those of the plate reduction press apparatus shown in Figs. 9 to 13. This plate reduction press apparatus shown in Fig. 16 according to the present invention can feed out the material 1 after being reduced and formed in the downstream B direction of the transfer line without causing any of the material to be forced backwards, in the same manner as the plate reduction press apparatus described previously according to Figs. 9 to 13. As described above, the plate reduction press apparatus and method according to the present invention offer the following advantages. (1) The plate reduction pressing method specified in Claim 1 of the present invention can reduce the areas of the forming surfaces of the dies that are in contact with a material to be shaped and the loads applied to the dies during pressing, because the forming surfaces of the dies are convex towards the transfer line, and the dies are given a swinging motion in such a manner that the areas of the forming surfaces, that are in contact with the material to be shaped move from the ends in the downstream direction of the transfer line to the ends in the upstream direction while the dies are being moved towards the transfer line from above and below the material to be shaped in synchronism with each other. According to the inventive plate reduction press apparatus defined in Claim 2 and the preferred embodiments thereof, defined in claims 3 to 6, the displacements of the eccentric portions of the upstream and downstream eccentric shafts, with different phase angles, are transmitted to the die holders through the upstream and downstream rods and the dies are given a swinging motion in such a manner that the portions of the convex forming surfaces, that are in contact with the material to be shaped, move from the ends in the downstream direction of the transfer line to the upstream ends, so that the areas of the forming surfaces of the dies that are in contact with the material to be shaped, are made smaller, therefore the loads applied to the dies during pressing can be reduced. (3) According to the inventive plate reduction press apparatus and the preferred embodiments thereof, the loads applied to the dies during pressing are reduced, so the required strengths of the upstream and downstream eccentric shafts, upstream and downstream rods, etc. become moderate, so that these components can be made compact. (4) With the inventive plate reduction press apparatus and the preferred embodiments thereof, the loads applied to the dies during pressing are reduced, the die holders are moved in the downstream direction of the transfer line by the mechanisms for moving the dies backwards and forwards when the forming surfaces of the dies are in contact with the material to be shaped, so the material after being reduced and formed is fed out in the downstream direction of the transfer line without forcing any of the material in the backward direction. Although the present invention has been explained by referring to a number of preferred embodiments, it should be understood that the scope of claims included in the specification of the present invention should not be limited only to the embodiments described above. To the contrary, the scope of rights according to the present invention shall include all modifications, corrections or the like as long as they are included in the scope of the claims attached.

Claims: A plate reduction pressing method in which dies (108a, 108b) with convex forming surfaces (120a, 120b) protruding towards a transfer line (S) are brought close to the transfer line (S) from above and below the material (1) to be shaped, when viewed from the side of the transfer line (S), in synchronism with the movement of the material (1) to be shaped, in such a manner that a portion of the forming surfaces of the material (1) is transferred from the upstream side (A) to the downstream side (B) of the transfer line (S) and the material (1) to be shaped is reduced in the direction of the plate thickness thereof, characterized in that the areas of said convex forming surfaces (120a, 120b), that are in contact with the material (1) to be shaped, move from the end in the downstream (B) direction of said transfer line (S) to the end in the upstream (A) direction of said transfer line (S). A plate reduction press apparatus comprising: die holders (109a, 109b) opposite each other above and below said transfer line (S) in which a material (1) to be shaped is transferred horizontally, dies (108a, 108b) mounted on said die holders (109a, 109b) and comprised of convex forming surfaces (120a. 120b) protruding towards said transfer line (S) when viewed from the side of the transfer line (S), upstream eccentric shafts (103a, 103b) arranged on the side of each die holder (109a, 109b) on the opposite side from the transfer line (S) and extending in the lateral direction of the transfer line (S), downstream eccentric shafts (105a, 105b) arranged on the side of each die holder (109a, 109b) on the opposite side from the transfer line (S) in alignment with said upstream eccentric shafts (103a, 103b), on the downstream side (B) of the transfer line (S), and comprised of eccentric portions (104a, 104b) with a different phase angle from the phase angle of the eccentric portions (102a, 102b) of the upstream eccentric shafts (103a, 103b), upstream rods (106a, 106b) whose tips are connected to portions of the die holders (109a, 109b) near the end of the die holders (109a, 109b) in the upstream direction (A) of the transfer line (S) through bearings (116a, 116b) and whose big ends are connected to the eccentric portions (102a, 102b) of the upstream eccentric shafts (103a, 103b) through bearings (112a, 112b), downstream rods (107a, 107b) whose tips are connected to portions of the die holders (109a, 109b), near the end of the die holders (109a, 109b) in the downstream direction (B) of the transfer line (S) through bearings (119a, 119b) and whose big ends are connected to the eccentric portions (104a, 104b) of the downstream eccentric shafts (105a, 105b) through bearings (113a, 113b), and mechanisms (121a, 121b) for moving the dies (108a, 108b) backwards and forwards that reciprocate said die holders (109a, 109b) relative to the transfer line (S), characterized in that said phase angle of the eccentric portions (104a, 104b) of said downstream eccentric shafts (105a, 105b) is rotating 90° ahead of said phase angle of said eccentric portions (102a, 102b) of said upstream eccentric shafts (103a, 103b). The plate reduction press apparatus specified in claim 2, in which the mechanisms (121a, 121 b) for moving the dies (108a, 108b) backwards and forwards are comprised of arms (122a, 122b) one end of each which is fixed to the die holder (109a, 109b), and guide members (124a, 124b) which are provided near the die holders (109a, 109b) and guide the other end of each of said arms (122a, 122b). The plate reduction press apparatus specified in claim 2, in which the mechanisms (127a, 127b) for moving the dies (108a, 108b) backwards and forwards are comprised of actuators (134a, 134b) one end of each of which is connected to one of the die holders (109a, 109b) through a first bearing (131 a, 131 b) and the other end of each thereof is connected to a predetermined fixing member (129a, 129b) through a second bearing (133a, 133b). The plate reduction press apparatus specified in claim 2, in which the mechanisms (135a, 135b) for moving the dies backwards and forwards are comprised of eccentric shafts (136a, 136b) for backwards and forwards movements, provided near the die holders (109a, 109b), and rods (139a, 139b) for backward and forward movements, one end of each of said rods (139a, 139b) being connected to one of the die holders (109a, 109b) through a first bearing (137a, 137b) and the other end thereof being connected to one end of the eccentric portions (138a, 138b) of the eccentric shafts (136a, 136b) for backward and forward movements. The plate reduction press apparatus specified in claim 2, in which the mechanisms (140a, 140b) for moving the dies (108a, 108b) backwards and forwards are comprised of levers (144a, 144b), one end of each of which is connected to one of the die holders (109a, 109b) through a first bearing (142a, 142b) and the other end thereof is connected to a predetermined fixing member (141a, 141b) through a second bearing (143a, 143b).

Inventors: DODO YASUSHI, FUJII YASUHIRO, IDE KENICHI, IKEMUNE SHOZO, IMAI ISAO, MASUDA SADAKAZU, MOTOYASHIKI YOICHI, MURATA SATOSHI, NARUSHIMA SHIGEKI, OBATA TOSHIHIKO, SATO HISASHI, SATO KAZUYUKI, SEKINE HIROSHI, TAZOE NOBUHIRO, YAMASHINA SHUICHI, YOKOYAMA TAKASHI, DODO, YASUSHI, FUJII, YASUHIRO, IDE, KENICHI, IKEMUNE, SHOZO, IMAI, ISAO, MASUDA, SADAKAZU, MOTOYASHIKI, YOICHI, MURATA, SATOSHI, NARUSHIMA, SHIGEKI, OBATA, TOSHIHIKO, SATO, HISASHI, SATO, KAZUYUKI, SEKINE, HIROSHI, TAZOE, NOBUHIRO, YAMASHINA, SHUICHI, YOKOYAMA, TAKASHI
Applicants: ISHIKAWAJIMA HARIMA HEAVY IND, JFE STEEL CORP, ISHIKAWAJIMA-HARIMA HEAVY INDUSTRIES CO., LTD., JFE STEEL CORPORATION
Application year: 1998
Main classification: B21B13
IPC codes: B21J1, B21B39, B21B1, B21B41, B21J7, B21B15, B21B13