JP5967395B2 - Mold changing method and die cart in bending press machine - Google Patents

Description

  The present invention relates to a method for exchanging a die at a punch tip in a bending press machine for producing a large-diameter and thick welded steel pipe used for a line pipe or the like by three-time bending press molding, and exchanging the die. It relates to a mold carriage used in

  Conventionally, as a large-diameter and thick-walled steel pipe used for a line pipe, a steel structure or the like, generally, a raw steel plate having a predetermined width, length and thickness is press-formed into a U shape, and then O The so-called “UOE steel pipe”, which is press-formed into a letter shape and then welded to the butt portion to form a raw steel pipe and further expanded in the circumferential direction (so-called pipe expansion) to increase the roundness, is widely used. Yes. In recent years, steel pipes used for line pipes have been increased not only in diameter, length, and thickness, but also in the strength of steel sheets, in order to improve safety and increase size. ing.

  However, in the above-described UOE steel pipe manufacturing method, a large press load is required to press-mold a thick, long and high-strength material steel sheet into a U shape or an O shape. In the conventional UOE steel pipe manufacturing equipment, there are problems that the manufacturing range is limited or the productivity is greatly reduced.

  Therefore, after reducing the press load when manufacturing large diameter, long, thick and high strength steel pipes, bending (so-called end bending) is applied to both width ends of the steel plate, Formed into a substantially cylindrical shape (open tube) having an opening by performing a three-point bending press molding a plurality of times while feeding a predetermined amount in the width direction, and then welding the opening of the open tube by butt welding. Then, a press bend method for manufacturing a steel pipe by correcting the shape has been developed and put into practical use.

  FIG. 1 is a diagram schematically illustrating a method of manufacturing a steel pipe by the press bend method. In this manufacturing method, first, a plurality of punches 2 and a pair of dies 3 are combined from one plate width end portion of the material steel plate 1 having both width end portions bent (crimping press) toward the plate width center. Three-point bending press forming was performed, and one half of the steel sheet except the center of the sheet width was formed into an arc shape (first half press), and then similarly, multiple times from the other sheet width end toward the sheet width center. The other half of the steel sheet except the center of the sheet width is formed into an arc shape to form a substantially C shape (second half press), and finally, the remaining center part of the sheet width is press formed. In general, it is manufactured by making (substantially pressing) an approximately cylindrical shape (open tube) having an opening, and then welding the opening by butting. Note that end bending may not be applied to the material steel plate.

  The bending press machine used for the above three-point bending press forming has a pair of dies arranged at a predetermined interval in the feed direction of the raw steel plate, and a punch capable of moving up and down between the pair of dies. The material steel plate placed on the die is pressed by the punch to bend. The punch is connected to a die (hereinafter simply referred to as “die”) attached to the tip of the punch 2 that is in direct contact with a steel plate as a workpiece, and the die is connected to the press machine body. Usually, it is comprised from the punch support body (henceforth "beam") hold | maintained at the front-end | tip, and both are fastened with the fixing bolt so that attachment or detachment is possible. In addition, although the beam is a unitary object, the mold is usually composed of a plurality of segments so that attachment and detachment work and handling are easy.

  As a method for exchanging dies, several proposals have been made for exchanging tools in small bending machines and punch presses (see, for example, Patent Documents 1 to 4). However, these methods are techniques that can be used only for small bending machines and punch press machines, and are not suitable for changing molds in bending press machines that produce large diameters.

JP 11-005131 A JP 2001-276936 A JP 2002-096120 A JP 2001-150032 A

By the way, it is necessary to exchange the metal mold | die attached to the said punch front-end | tip part according to the change of the steel pipe size (inner diameter, outer diameter) and raw material steel plate (thickness, intensity | strength) to manufacture.
However, in the prior art, as shown in FIG. 2 (a), since the radius of curvature R (tip R) of the mold surface that is in direct contact with the steel plate is relatively small, the steel pipe size and the material steel plate are used. While the range that can respond to the change is wide, the bent part is localized, so the roundness of the steel pipe after forming is inferior, and since it is necessary to press-mold in small increments, the number of presses increases, There was a problem of inferior productivity.

  Therefore, as shown in FIG. 2B, the roundness is increased or the productivity is increased by increasing the tip R in accordance with the diameter of the steel pipe and widening the punch as shown in FIG. Things have been done. However, if the punch width is widened or the tip R is increased as described above, the roundness and productivity are improved, but the die can be frequently changed according to changes in the steel pipe size and material strength. Necessary. In particular, when the width of the mold is widened, not only the load required for pressing is increased, but also the feed amount of the steel sheet is small with respect to the distance between the dies, and the shape of the raw steel sheet on the die is relative to the punch axis. In such a case, a large bending moment is applied to the base of the beam to which the mold is attached, so that the durability of the punch is easily exceeded. Therefore, it is necessary to frequently change the die at the tip of the punch in accordance with changes in the steel pipe size, the raw steel plate, and the press conditions.

  Conventionally, as a method for exchanging the mold, for example, after placing a new mold on a large dummy plate, the dummy plate is horizontally placed using a transport facility for supplying a raw steel plate to a breather. Then, move the new die to the position immediately below the punch (beam), and then lower the punch to bring it into contact with the dummy plate near the new die, and release the bolts. Remove the mold from the beam tip, then move the dummy plate with the transfer equipment described above to move the new mold directly under the beam, fit the new mold to the beam tip, and fasten with the bolt It was done by a series of steps of attaching.

For this reason, in the conventional mold exchanging method, the dummy plate cannot be accurately moved in the horizontal direction, and the position of the die cannot be finely adjusted when placed on the dummy plate. The mold could not be supplied, and it took a long time to attach the mold to the beam tip. In addition, since the mold is divided into a plurality of segments, it is necessary to repeat the above-described replacement operation. Therefore, a great amount of time is required for one mold replacement, and the work efficiency is significantly reduced. Furthermore, since it is necessary to raise and lower the punch in order to change the die, the power of the press machine cannot be turned off. Therefore, it is necessary to take a number of safety measures for ensuring safety, resulting in a reduction in productivity.
In addition, the methods described in Patent Documents 1 to 4 are techniques that can be used only for small bending machines and punch press machines, and are techniques that can be applied as they are to the die exchange of bending press machines that produce large diameters. Absent.

  The present invention has been made in view of the above-described problems of the prior art, and the object thereof is a metal mold that can efficiently and safely perform a die change at the punch tip in a bending press machine in a short time. In addition to proposing a mold exchanging method, an object is to provide a mold carriage used in the method.

  The inventors have intensively studied to solve the above problems. As a result, a mold carriage capable of collectively placing a plurality of divided mold segments is prepared, and the carriage is moved between a pair of dies below the press machine along the length direction of the punch. Therefore, it is possible to accurately position and supply the mold directly under the punch, and further, the carriage is moved using a steel pipe unloading device for unloading the steel pipe after the press forming in which the press machine is installed. Therefore, the present invention has been developed.

That is, the present invention is a method for exchanging a die at a punch tip in a bending press machine that bends a steel plate on a die with a pair of dies and a punch that moves up and down between the dies. Loading and unloading of the mold from directly under the punch is carried on a mold carriage movable between the pair of dies in the length direction of the punch, and the mold carriage is directly under the punch. A die changing method in a bending press machine, wherein carrying-in and carrying-out from directly under a punch are performed using a steel pipe carry-out device arranged in the press machine.

  Further, in the mold exchanging method of the present invention, the mold accommodating portion of the mold carriage is lifted, and the mold is removed from the punch tip and the mold to the punch tip is in contact with the punch tip. It is characterized by attaching the mold.

  Further, in the mold exchanging method of the present invention, the position adjustment in the direction perpendicular to the punch length direction of the mold placed on the mold base in the mold storage unit is performed while the mold is placed. This is performed by moving the mold base.

  The mold exchanging method of the present invention is characterized in that when the mold is divided into a plurality of segments, the molds are exchanged collectively.

  The mold exchanging method of the present invention is characterized in that a plurality of segments are divided into a plurality of sets connected by shims, and the mold cart is loaded and unloaded in units of the set.

  The present invention is also a mold carriage used for exchanging a die at a punch tip in a bending press machine for bending a steel plate on a die with a pair of dies and a punch moving up and down between the dies. A die carriage for exchanging dies in a bending press machine, characterized in that it is a device for unloading a steel pipe after press working installed in the machine, and is movable between the pair of dies in the length direction of the punch. It is.

  The mold carriage according to the present invention is characterized by having a mold storage unit for storing a mold and an elevating mechanism for moving up and down the mold storage unit.

  The mold carriage of the present invention includes a position adjustment mechanism that performs position adjustment in a direction perpendicular to the punch length direction of the mold stored in the mold storage unit for each mold base on which the mold is placed. It is characterized by having.

  According to the present invention, since the die exchange in the bending press machine can be performed efficiently in a short time, it is possible to produce a thick, long and high strength large-diameter welded steel pipe with high productivity. It becomes.

It is a figure which illustrates typically the manufacturing method of the steel pipe by a press bend method. It is a figure explaining the influence which the metal mold | die width | variety of a punch tip has on steel pipe manufacture. It is an example figure explaining the structure of the punch of a bending press machine. It is a figure explaining the cross-sectional structure of a metal trolley | bogie. It is a figure explaining the procedure of metallic mold exchange (detachment method). It is a figure explaining the metallic mold removal work in a metallic trolley. It is a figure explaining the handling method of the metal mold | die divided | segmented into plurality.

The present invention relates to a method of exchanging a die attached to the tip of a punch support in a bending press machine that bends a steel plate on a die with a pair of dies and a punch that moves up and down between the dies.
FIG. 3 is a diagram illustrating a punch structure of a bending press machine used in the present invention. The punch is composed of a punch support 4 (beam) attached to the press body 7 and a die 5 attached to the tip (lower end) of the beam by a fixing bolt 6. A groove 8 into which the lower end of the beam is fitted is formed on the side of the die that contacts the beam tip, and a spacer 9 is inserted between the groove and the beam tip.

  The mold may be a single piece, but usually, it is usually divided into a plurality of segments in consideration of the production and handling of the mold. As described above, conventionally, in the replacement of the above-described mold, the mold is transferred to the lower position of the press machine and unloaded from the lower position of the press machine by moving the mold on the dummy plate. Had gone by. However, in the above method, the mold cannot be accurately positioned at the beam tip, and it takes a lot of time for mounting, which is a cause of hindering productivity. In addition, because it is necessary to move the punch while the press machine is turned on, it is necessary to take multiple safety measures to ensure safety, and this has an unavoidable adverse effect on productivity. It was.

Accordingly, the present invention provides a mold that moves in the length direction of the punch between a pair of dies installed at the lower part of the press machine for carrying in and unloading the mold directly under the punch. It was decided to place it on a trolley.
The mold carriage is placed at a position different from that of the press machine during the pressing operation, and when exchanging the mold, a crane is provided on the carry-out line for carrying out the steel pipe (open pipe) after the press molding. Etc. The mold carriage has a length that allows the molds divided into a plurality of segments to be placed in a lump, and a connecting mechanism, for example, an upward-facing portion is provided at the end of the carriage in the length direction of the press machine. (Or downward) hooks are provided. On the other hand, the steel pipe carrying-out device for carrying out the press-formed steel pipe provided in the press machine is provided with another connecting mechanism for connecting with the connecting mechanism of the mold carriage, for example, a downward (or upward) hook. ing.

And, the carry-in of the mold carriage from outside the press machine directly under the punch of the press machine is to connect the coupling mechanism on the mold carriage side and the coupling mechanism on the steel pipe carry-out device side, and when the steel pipe carry-out device is carried out of the steel pipe. Can be performed by moving in the opposite direction.
On the other hand, when the die carriage is carried out from directly under the punch of the press machine to the outside of the press machine, the extrusion jig provided in the steel pipe carry-out device for carrying out the steel pipe after press molding is brought into contact with the die carriage, or This can be done by connecting the connecting mechanism on the mold carriage side and the connecting mechanism on the steel pipe carry-out device side and moving the steel pipe carry-out device in the steel pipe carry-out direction.
Here, there is no restriction | limiting in particular about the moving means (drive source) of the said steel pipe carrying-out apparatus, For example, you may make it drive with the chain connected to motive power sources, such as a motor, or a belt.

  In addition, the mold trolley may run on a conveyance line composed of V rolls as shown by a broken line in the lower part of FIG. 4, for example, and wheels may be attached to the lower part of the mold trolley. You may make it run on a rail and may use them together, and there is no restriction in particular. In the case of adopting the above V roll, the V roll at the lower part of the press machine is lowered and retracted so as not to hinder the work during the press work, and is raised only at the time of changing the mold. It is preferable to do this.

  4 shows a cross section in a direction perpendicular to the length direction of the punch (hereinafter also referred to as “width direction”). The mold carriage 10 includes a carriage base portion 11 and an upper mold storage portion 12. The mold storage section 12 has an H-shaped cross section in the width direction, and a mold base 13 on which a mold is placed is provided in the upper recess. Further, position adjustment bolts 14 as position adjustment mechanisms for the mold base 13 are provided on both sides of the mold accommodating portion, and the molds in the recesses of the mold accommodating portion are rotated by rotating the bolts. The position in the width direction of the base 13 can be finely adjusted while the mold is placed. By using the position adjusting bolt 14, a new mold can be easily and quickly fitted to the tip of the punch support (beam) with high accuracy.

  Moreover, the said trolley base 11 and the metal mold | die storage part 12 are isolate | separated, and the metal mold | die storage part 12 can be raised / lowered with the hydraulic jack 15 as a raising / lowering function arrange | positioned at the trolley base side. Thereby, when attaching a new die to the punch lower end, the die can be raised while being placed on the die base in the die storage portion and brought into contact with the punch tip (beam tip), Further, when removing the die from the tip of the punch, it is possible to remove the die after raising the die housing portion and bringing the die into contact with the die base. Therefore, in the mold exchanging work, for example, when the operator performs the work of fastening the punch tip and the mold with the fixing bolt or releasing the fastening at the lower part of the press machine, Since there is no need to operate the mold, the mold can be exchanged more safely.

The mold exchanging method of the present invention using the mold carriage is performed according to the following procedure.
<Removal of mold>
A method for removing the mold will be described with reference to FIGS. 5 and 6.
Step 1: An empty mold carriage 10 is mounted on the steel pipe carry-out line 16 from the carriage yard (FIG. 5 (a)).
Step 2: The steel pipe carry-out device 17 is moved to the position of the mold carriage 10 and connected (FIG. 5B).
Step 3: The mold carriage 10 is moved to the position immediately below the punch 2 of the press machine 7 by the steel pipe carry-out device 17 (FIG. 5 (c), FIG. 6 (a)).
Step 4: The mold storage part 12 at the upper part of the mold carriage is raised by the hydraulic jack 15, and the mold base 13 in the storage part and the mold 5 at the tip of the punch are brought into contact with each other (FIG. 5 (d), FIG. 6). (B)).
Step 5: Release the fastening of the fixing bolt 6 and remove the die 5 from the punch tip (beam tip) (FIGS. 5 (d) and 6 (c)).
Step 6: The mold storage unit 12 is lowered together with the mold 5 and received on the mold carriage base 11 (FIGS. 5 (e) and 6 (d)).
Step 7: With the steel pipe carry-out device 17, the mold carriage 10 is pushed out of the press machine and placed on the steel pipe carry-out line 16 (FIG. 5 (f)).
Step 8: The mold carriage 10 is removed from the steel pipe carry-out line 16.

<Installation of mold>
Next, a method for attaching the mold will be described. Note that this method may be performed in substantially the reverse order to the above-described method for removing the mold, and therefore, the illustration is omitted.
Step 1: A mold carriage 10 on which a new mold 5 is placed is mounted on a steel pipe carry-out line 16.
Step 2: The steel pipe carry-out device 17 is moved to the position of the mold carriage 10 and connected.
Step 3: The mold carriage 10 is moved to the position immediately below the punch 2 of the press machine 7 by the steel pipe carry-out device 17.
Step 4: The mold accommodating part 12 at the upper part of the mold carriage is raised by the hydraulic jack 15, and the groove part 8 of the new mold 5 in the accommodating part and the punch support 4 (beam) tip are fitted. At this time, the position of the mold in the width direction is finely adjusted using the position adjusting bolt 14 of the mold base 13.
Step 5: Fasten the fixing bolt 6 and attach the mold 5 to the tip of the beam 4.
Step 6: The mold storage unit 12 is lowered and received by the mold carriage base 11.
Step 7: With the steel pipe carry-out device 17, the mold carriage 10 is pushed out and placed on the steel pipe carry-out line 16.
Step 8: The mold carriage 10 is removed from the steel pipe carry-out line 16.

  Note that the punch exchanging method in the bending press machine of the present invention is not to replace a plurality of segments individually, but as a whole in a batch when the mold is divided into a plurality of segments. It is preferable to carry out. However, when the mold is long, it may be difficult to place the mold on the mold carriage at once. In such a case, it is preferable to divide the mold composed of a plurality of segments into a plurality of sets obtained by connecting a plurality of small segments and place the molds on the mold carriage in units of the above sets.

  In this case, the set has a structure in which a parallel pin is embedded in the joint portion of each segment and the length of the spacer inserted into the groove portion 8 formed in the upper portion of the mold is fastened with a bolt as the set length. preferable. Furthermore, the connecting part between each set is such that the spacer of one set protrudes from the end of the set, and the spacer missing part into which the protruding spacer fits is provided at the end of the other set. It is preferable that they are connected via each other.

  By doing so, the mold composed of a plurality of segments can be placed on the mold carriage without positional deviation in the width direction, and as a result, the mold is attached to the punch support (beam) with high accuracy. It becomes possible. FIG. 7 shows an example in which one mold divided into nine segments is divided into three sets composed of three segments. In addition, it is preferable to perform the order which mounts a some set on a metal trolley | bogie first from the set which provided the spacer missing part.

A prior art method using a dummy plate described in [0011] for exchanging a die of a bending press machine capable of producing a welded steel pipe having an outer diameter of 20 to 56 inches and a pipe thickness of 12.7 to 50.8 mm (Comparative example) and two methods of the mold exchange method (invention example) of the present invention were used, and the required time was compared. The metal mold has a total length of 13.5 m and is divided into nine segments as shown in FIG. 7, and handling was performed with three segments as one set.
As a result, the die replacement time of the example of the present invention could be shortened to about 1/3 compared with the comparative example of the prior art.

1: Material steel plate 2: Punch 3: Die 4: Punch support (beam)
5: Mold 6: Fixing bolt 7: Press machine body 8: Fitting groove 9: Spacer 10: Mold carriage 11: Mold carriage base 12: Mold storage part 13: Mold base 14: Position adjustment mechanism (position Adjustment bolt)
15: Elevating mechanism (hydraulic jack)
16: Steel pipe carry-out line 17: Steel pipe carry-out device 18: Parallel pin

Claims (8)

A die exchanging method of a punch tip in a bending press machine for bending a steel plate on a die with a pair of dies and a punch moving up and down between the dies,
The unloading of the molds from the mold loading and the punch just below to just below the punch, performs by placing between the pair of dies in a die carriage movable in the longitudinal direction of the punch, the gold A die changing method in a bending press machine, wherein a mold carriage is carried into and out of a punch directly using a steel pipe carry-out device arranged in the press machine. The mold storage portion of the mold carriage is lifted, and the mold is removed from the punch tip and attached to the punch tip in a state of being in contact with the punch tip. 2. A mold changing method in the bending press machine according to 1 . The position adjustment in the direction perpendicular to the punch length direction of the mold placed on the mold stage in the mold storage unit is performed by moving the mold stage while the mold is placed. A mold exchanging method in a bending press machine according to claim 1 or 2 . When the mold is divided into a plurality of segments, the mold changing method in bending press according to any one of claims 1 to 3, characterized in that collectively performed exchange of the mold . 5. The mold changing method in a bending press machine according to claim 4 , wherein the plurality of segments are divided into a plurality of sets connected by shims, and loading / unloading to the mold carriage is performed in units of the sets. A die carriage used for exchanging a die at the tip of a punch in a bending press machine for bending a steel plate on a die with a pair of dies and a punch moving up and down between the dies,
An apparatus for unloading a steel pipe after press working installed in the bending press machine, wherein the die can be exchanged between the pair of dies in the length direction of the punch. Mold trolley. The mold carriage for mold replacement in a bending press machine according to claim 6 , further comprising a mold storage section for storing a mold and a lifting mechanism for lifting and lowering the mold storage section. Claim 6 or 7, characterized in that it has a position adjusting mechanism for the direction perpendicular alignment to the punch length direction of the die housed in the mold housing part performs each mold table mounted with the mold Mold trolley for exchanging dies in the bending press machine described in 1.

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