KR102220126B1 - Method of making the preform of a flange - Google Patents

Abstract

An objective of the present invention is to provide a manufacturing method of a preform of a flange which can easily withdraw a preform from a forming mold. According to the present invention, the method manufactures a preform of a flange by using a preform manufacturing apparatus of a flange including a forming mold having an inner cavity for forming a preform of a flange and consisting of a fixed mold unit and a moving mold unit, a base having an embedded pressing device for moving the moving mold unit upwards and supporting and fixing the forming mold, and an annular wall positioned on an upper portion of the base and separated from the outside of the forming mold to be positioned to have a coolant storage space between the forming mold, the base, and the wall. The method comprises: a step of positioning base metal heated to 1,200-1,250°C and then pressing the base metal by a press to make a flat shape; a first forming work step of positioning the flat base metal on the forming mold of the preform manufacturing apparatus and then pressing the flat base metal by a press; a second forming work step of positioning a pusher in the middle of the base metal firstly formed in the forming mold to manufacture a preform with a hollow space having a closed hole by pressing the base metal by a press; a finishing work step of pressing the preform positioned on the forming mold again by a press such that the preform obtained by the second forming work matches the inner cavity of the mold; a step of gripping the finished preform by a preform pickup device to move the preform from the forming mold to a press die to position the preform in a fallen state; and a punching work step of positioning a punch on the closed hole of the preform in a fallen state and then pressing the preform by a press.

Description

Method of making the preform of a flange {Method of making the preform of a flange}

The present invention relates to a method of manufacturing a preform of a flange, and more particularly, to a method of manufacturing a preform of a flange capable of easily withdrawing the preform formed by the preform forming mold of the flange from the forming mold.

The rapid and continuous transport of fluid is carried out through pipes. For this transport, a pipe of a certain diameter and length is connected to create a fluid flow path, and a flange is generally used for the connection between the pipe and the pipe. Currently commonly used flanges are slip on welding flanges that are connected by welding by completely inserting the pipe inside the flange, and partial insertion welding to connect by welding after inserting only a part of the pipe inside the flange. A socket welding flange, a threaded flange that is threaded to connect the inside of the flange and the outside of the tube, and a weld neck flange that can connect the flange to the tube by butt welding. or high hub flange).

Butt-welded flanges are used in harsh environments where high temperatures, pressures or stresses are required. As shown in Fig. 1, the butt-welded flange (1) is a neck (5) and a flange (blade) (3) having a bore (7) of the same inner diameter as the pipe to be connected in the center. It is configured, and the flange portion (3) is formed with a bolt hole (9) for bolt-type fastening with the other flange (1). The butt-welded flange requires a separate process of forming the neck, so the manufacturing cost is relatively high.

In general, a butt-welded flange with a large neck (hereinafter referred to as a flange) is manufactured by hot forming a flange preform having dimensions smaller than the final dimensions (bore diameter, neck height, flange dimension, etc.). , It is through a hot rolling process in a ring rolling mill equipped with a flange part forming roll (main roll), and a machining process to manufacture a flange having a final dimension.

Registration Patent Nos. 1061574, 894034, and 1335651 disclose a method for manufacturing a flange preform, but the preform press-formed in a molding mold having an inner cavity for forming the preform is pressed into the cavity of the mold. There is a problem that it is very difficult to withdraw from. In addition, a cylindrical base material made of a flange material (low alloy carbon steel, stainless steel, non-ferrous metal, etc.) is heated to a predetermined temperature (for example, in the case of steel material, usually 1200 to 1250°C) to form a plate shape. Since this is reheated and press-molded in a molding mold as described above, the molding mold is also heated and deteriorated, so that its life is short.

It is an object of the present invention to provide a method for manufacturing a preform of a flange capable of easily withdrawing a preform formed by a preform forming mold of the flange from the forming mold.

Another object of the present invention is to provide a method for manufacturing a preform of a flange capable of improving the life of the mold by cooling the molding mold to prevent deterioration.

In order to achieve the above object, the present invention is a molding mold having an inner cavity for forming a preform of a flange, a base for supporting and fixing the molding mold, and an annular wall located on the upper side of the base and spaced apart from the molding mold. It uses a preform manufacturing apparatus of a flange having a cooling water storage space between the molding mold, the base and the wall.

In the case of the preform manufacturing apparatus used in the present invention,

(a) The mold is composed of a fixed mold part supported and fixed to the base, and a movable mold part separated from the fixed mold part and movable,

The movable mold part is composed of a head part forming a part of the lower end of the mold cavity and a cylindrical extension part extending from the head part to the lower end of the fixed mold part, and the fixed mold part has a cylindrical central hole into which the movable mold part is inserted. It is formed, but in this central hole, a support jaw for supporting the head of the movable mold part is formed, and the diameter of the extension part of the movable mold part is smaller than the direct hit of the central hole of the fixed mold part, so a second flow path of coolant is formed in this central hole,

(b) The base supports and fixes the fixed mold part, and includes a movable mold part pressing device for moving the movable mold part upward by a certain length, so that the pressing device presses the movable mold part upward and moves it by a certain length. The preform molded in the mold cavity can be moved upward so that it is easy to withdraw from the mold cavity,

The base is composed of an upper base part supporting and fixing the fixed mold part, and a lower base part attached to the lower part of the upper base part and having an internal space in which the pressing device is located, and the upper base part is a first pin hole vertically penetrating the upper base part And a first flow path of cooling water extending from the cooling water storage space to the second flow path is formed between the upper base part and the fixed mold part.

The pressing device is a hollow spring case fixed to the inner space of the lower base part and one side is open, a spring located in the hollow part of the spring case, a cover having a vertical through-type second pin hole and sealing the opening part of the spring case, and One side extends through the first pin hole of the upper base part and the second pin hole of the cover to contact the movable mold part, and the other side is composed of a pin that is elastically supported by a spring, so that the pin is elastically pressed to the upper side of the movable mold part. When the fixed mold part and the moving mold part are in a mated state, the pin is in a position to press the spring.

The method of manufacturing the preform of the flange using the preform manufacturing device of the flange as described above is the step of placing the base material heated at 1200~1250℃ on the press die and then pressing it with a press to form a plate shape. The cooling water injected into the cooling water storage space A first forming operation step of placing the plate-shaped base material in the forming mold of the preform manufacturing apparatus capable of cooling the forming mold by flowing to the second flow passage through the first flow passage and then pressing with a press, forming mold The second molding operation step of manufacturing a preform in which a hollow part having a closed hole is formed by placing a pusher in the center of the first molded base material and pressing it with a press. The preform obtained by the second molding operation is molded to match the inner cavity of the mold. The finishing step of pressing the preform placed on the mold once again with a press, the step of gripping the finished preform with a preform pickup device and moving it from the molding mold to the press die to position it in an inverted state, and closing the preform in the inverted state It consists of a punching step in which a punch is placed in the study and pressurized with a press.

It is preferable to further include a step of cooling the molding mold by supplying cooling water into the cavity of the molding mold from which the preform finished by the preform pickup device has been removed.

According to the present invention, the method for manufacturing a flange preform can easily take out the press-formed preform from the mold, and thus the time required for such a take-out operation is significantly reduced, thereby increasing overall productivity. In addition, since the molding mold can be cooled with cooling water during the preform manufacturing process, deterioration of the mold is prevented and the life of the mold is increased.

1 is a perspective view of a butt-welded flange.
2 is a perspective view of a flange preform manufacturing apparatus according to the present invention.
3 is an exploded perspective view of the device shown in FIG. 2.
4 is a perspective view of a matching state of a molding mold used in the present invention.
5 is an exploded perspective view of the base shown in FIG. 3.
6 is a cross-sectional view taken along AA direction of the device shown in FIG. 2.
7 is an exploded perspective view of the pin shown in FIG. 5.
8(a) to (d) are process charts for manufacturing a preform using the manufacturing apparatus according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a perspective view of a flange preform manufacturing apparatus used in the present invention, FIG. 3 is an exploded perspective view of the apparatus shown in FIG. 2, and FIG. 6 is a cross-sectional view of the manufacturing apparatus shown in FIG.

As shown, the flange preform manufacturing apparatus 10 is composed of a molding mold 12, a base 18 for supporting and fixing the molding mold, and a wall 90 positioned above the base, respectively. It will be described in detail.

The forming mold 12 is for hot forming the flange preform, and is made of carbon steel such as S45C or SCM440. Referring to FIG. 3, the mold 12 used in the present invention includes a fixed mold part 20 supported and fixed to the top of the base 18, and a moving mold part 30 that can be separated from and movable from the fixed mold part. Is composed. Referring to FIG. 4 showing a cross-sectional view when the fixed mold part 20 and the moving mold part 30 are in a matched state, a cavity corresponding to the outer shape of the flange preform is formed inside the mold 12, and the inside of the mold The convex central protrusion 14 is formed on the lower surface 13 of the. Referring back to FIG. 3, the fixed mold part 20 has a cylindrical central hole 15 into which the movable mold part 30 is inserted in the central part, and the central hole 15 has a bottom surface 13 It has a support jaw 22 at a position extending downward by a predetermined length. On the other hand, a fixing groove 24 is formed outside the fixing mold part 20. The movable mold part 30 is supported by the support jaws 22 of the fixed mold part, but forms a part of the lower surface 13 inside the mold and has a head part 32 having a central protrusion 14, and is fixed from the head part. It is composed of a cylindrical extension portion 34 extending to the lower end portion 26 of the mold portion. The diameter of the extension part 34 is smaller than the diameter of the central hole 15 of the fixed mold part, so that a space is formed in the central hole 15 of the fixed mold part 20, and this space is a second flow passage for cooling water ( 99) (see Fig. 6) serves.

The wall 90 located on the upper part of the base 18 is an annular member (for example, SS400 carbon steel) positioned outside the mold 12 so as to maintain a certain distance from the mold 12 and separated from the above-described mold 12 It is desirable to combine possible. In the illustrated embodiment, a groove 93 of the fixing piece 92 into which the wall 90 is inserted into the fixing groove 24 of the fixing mold part 20, and a screw 96 inserted into the groove 94 of the wall ) Is detachably coupled with the mold 12. A lower portion of the wall 90 has a coupling jaw 96 that is in close contact with the coupling jaw 49 of the base 18 to be described later (see FIG. 6 ). It is preferable to prevent water leakage through these parts by performing precision processing to minimize tolerances on the abutting parts of the base 18 and the wall 90, and further, if necessary, apply a suitable waterproofing agent or perform silicone waterproofing treatment. The mold 12, more specifically, the outer surface of the fixed mold part 20, the upper part of the base 18, and the inner surface of the wall 90 are opened upward by the separation of the mold 12 and the wall 90 A space 97 is formed, and this space serves to store cooling water.

Referring to FIG. 6 and FIG. 5 showing an exploded perspective view of the base used in the present invention, the base 18 is composed of an upper base part 40 and a lower base part 50 attached to the lower part of the upper base part. And each of these will be described below.

The upper base portion 40 has an inner space in which the mold 12 as described above is seated and supported, that is, the mold seating portion 41, and the upper portion is in close contact with the coupling jaw 96 of the wall 90 The engaging jaw 49 is formed to engage. Between the lower end 26 of the fixed mold part 20 and the bottom surface of the mold seating part 41 of the upper base part 40, one side is connected to the cooling water storage space 97, and the other side is a second flow passage for cooling water. A first flow path 42 (see Fig. 6) connected to 99 is formed. In the case of the illustrated embodiment, the first flow passage 42 is precisely the bottom surface of the mold seating portion 41 of the upper base portion 40, and the lower end portion 26 of the fixed mold portion 20 in contact with it. By excluding processing and roughening, water naturally flows through the gap formed between the bottom surface of the mold seating part 41 and the lower end 26 of the fixed mold part 20 in contact with it. In another embodiment, a plurality of elongated flow passages toward the second flow passage 99 on the bottom surface of the mold seating portion 41 of the upper base portion and/or the lower portion 26 of the fixed mold portion 20 in contact therewith. May be formed to converge radially. In addition, the upper base portion 40 includes a plurality of drain holes 43 on the inner surface of the mold seating portion 41, and a stopper 44 that is made of a suitable material such as silicon and serves to open and close the drain hole 43. Located. The drain port 43 serves to discharge the cooling water accommodated in the mold seating part 41 as necessary. Meanwhile, a first pin hole 45 into which one side of the pin 70 of the moving mold part pressing device 60 to be described later is inserted is formed in the upper base part 40. An O-ring-groove 46 (see FIG. 6) is formed in the first pin hole 45. The upper base portion 40 and the lower base portion 50 to be described later pass through the bolt hole 48 formed through the upper base portion 40 and are inserted into the bolt insertion hole 58 of the lower base portion 50 It is detachably coupled with a bolt (47). In the illustrated embodiment, for convenience, only one bolt 47 is used, but it is preferable that a plurality of bolts 47 are used.

The lower base part 50 has an inner space 52 that is opened upward. In the inner space 52, a movable mold part pressing device 60 that presses the movable mold part 30 of the molding mold 12 upward and moves it by a predetermined length is positioned, and this pressing device will be described later. A through hole 54 communicating with the inner space 52 is formed under the lower base part 50. Meanwhile, in the bolt insertion hole 58, a thread corresponding to the thread of the bolt 46 is formed.

5 and 6, the moving mold part pressing device 60 includes a spring case 61 having a hollow part 62, a spring 65 located in the hollow part 62 of the spring case, and covering the spring case. It is composed of a cover 66 and a pin 70 reciprocating by a spring 65, and each of them will be described below.

The spring case 61 has a fixing bolt hole 63 formed to be aligned with the through hole 54 of the above-described lower base part 50 at its lower end, and the lower base part by fixing bolts 64 penetrating them. It is fixed in the inner space 52. The spring 65 used in the present invention is a disc spring. The disc spring has a large load capacity with a short stroke in a small space because the accumulated energy per unit volume is much higher than that of the coil spring. As shown, a number of plate springs 65 suitable for the desired load capacity are used to face each other, and although not shown in the illustrated embodiment, a related engineer supports the lower end of the plate spring 65 as needed. It will be appreciated that supports can be used. The cover 66 is formed in a disc shape to seal the spring case 61, and a bolt hole 67 ′ formed on the cover and a bolt hole 67 ″ formed on the upper end of the spring case 61 It is attached to the upper end of the spring case 61 by a fixing bolt 67 (only one is shown for convenience) inserted into. A second pin hole 68 into which a pin 70 to be described later is inserted is formed in the central portion of the cover 65. The pin 70 has a first pin hole 45 of the upper base portion and a second pin hole 68 of the cover on one side based on the stopper 72 that serves to prevent the pin from deviating from the spring case 61 It extends through and contacts the movable mold part 30 and the other side is elastically supported by the spring 65 while being positioned inside the spring case 61. At the lower end of the side elastically supported by the spring 65, a receiving space 73 for accommodating the head of the fixing bolt 64 for fixing the spring case 61 to the inner space 52 of the lower base portion as described above. Is formed. Referring to FIG. 7 showing an exploded perspective view of the pin, the pin 70 includes a main body 71 including a stopper 72 and a tip portion 75. A bolt hole 76 is formed in the tip portion 75 of the pin, and a bolt coupling portion 74 corresponding thereto is formed in the body 71 of the pin, so that the tip portion 75 and the body 71 are formed by the bolt 77. Combines detachably. Therefore, if the tip portion 75 is worn due to contact with the moving mold portion 30 of the mold 12 for hot forming the preform, it is very economical because only the tip portion can be replaced. On the other hand, referring to Figures 3 and 6, the O-ring 79 is located in the main body 71 of the pin, but this O-ring is located in the O-ring groove 46 formed in the upper base 40, Even during the reciprocating movement of the fin 70, the coolant is prevented from flowing into the pressurizing device through the first fin hole 45 of the upper base. The pin 70 used in the present invention is elastically supported by the spring 65 and serves to elastically press the movable mold part 30 upward while reciprocating, and when the spring 65 is in a compressed state, As shown in FIG. 4, when the fixed mold part 20 and the moving mold part 30 are in a matched state, and when the spring 65 is in an uncompressed normal state, as shown in FIGS. 2 and 6 Likewise, the moving mold part 30 is moved upward by a certain length (about 2 cm in the case of the illustrated embodiment).

Hereinafter, a method for manufacturing a preform according to the present invention will be described with reference to FIGS. 8A to 8D showing a process diagram for manufacturing a preform in the above-described manufacturing apparatus.

As shown in FIG. 8(a), the base material 110 is placed on the press die 100 as in the prior art while being heated to 1200 to 1250° C. and pressed in a plate shape with the press 102. The pressed base material is placed in the molding mold 12 of the flange preform manufacturing apparatus 10 used in the present invention and pressed with a press 102, as shown in FIG. 8(b). The press die 100 and the manufacturing apparatus 10 are located on a turntable (not shown) installed under the press 102, so that a single press 102 can be used. As shown in the partially enlarged view, the coolant injected into the space 97 open to the top (refer to the partially enlarged view on the right) is a first flow passage connecting the space 97 and the second flow passage 99 ( It flows to the second flow path 99 through 42 and is maintained at an appropriate height, preferably at a height equal to or less than the support jaw 22 of the fixed mold part 20 (see the left partial enlarged view). The mold 12 maintains optimum strength without deteriorating when maintained at 400 to 500°C, so the cooling water makes the fixed mold part 20 and the moving mold part 30 constituting the mold 12 possible during hot forming. By playing a role of cooling so as to be maintained at this temperature, it plays a role of improving their durability. When pressed by the press 102, as shown in FIG. 4, the moving mold part 30 is brought into a state in conformity with the fixed mold part 20, and the spring 65 is compressed by the pin 70. When the pressing of the press 102 is released after the first molding operation in the mold 12, the compressed spring 65 returns to the non-compressed state and moves the mold part 30 and the molded base material through the pin 70. Push up to the top. When the primary molding operation in the mold 12 is finished, as shown in FIG. 8(c), a closed hole portion 121 is provided in the center of the primary material formed by using a pusher 104. The preform 120 is made by performing a secondary molding operation to form a hollow part. The pusher 104 is also pressed with the press 102, but for convenience, the press 102 is not shown. When the secondary molding operation is finished, the pusher 104 is removed and the press 102 is pressed again to perform a finishing operation so that the preform 120 matches the inner cavity of the mold 12. When the preform 120 is pressed with the press 102 even during the secondary molding and finishing operation, as described above, the moving mold part 30 and the fixed mold part 20 are in a matched state, and the spring 65 It is compressed by the pin 70, and when the pressing of the press 102 is released, the compressed spring 65 returns to the non-compressed state while moving the mold part 30 and the preform 120 through the pin 70. Push it up. When the finishing work is finished and the press 102 is released, the preform 120 is pushed upward and the upper corner is exposed from the fixed mold part 20, so that the preform is a preform well known in the art (not shown). It is easy to move to the next process by easily gripping 120. Since the conventional apparatus uses one single mold, the finished preform remains compressed inside the mold 12. Therefore, it was not easy to hold the preform with the preform pickup device, so the operation to move to the next process was very inconvenient and time consuming, and as a result, productivity was low. After finishing the preform 120, as shown in Fig. 8 (d), is positioned in a state of being inverted to the press die 100 again using a preform pickup device, and punched into the closed hole 121 The final preform 120 is obtained by positioning 106 and performing a punching operation to penetrate the closed hole 121 by pressing with a press 102. The preform 120 thus obtained is made into a flange having a final dimension through a hot rolling process and a machining process in an annular rolling machine equipped with a flange-forming roll as in the prior art. On the other hand, the device 10 from which the preform is removed by the preform pickup device, as shown at the end of FIG. 8(c), first injects coolant into the mold 12 to cool the inside of the mold 12, and then After removing the stopper 44 (refer to FIG. 6) of the base part 40, the cooling water is discharged through the drain hole 43 connected to the mold seating part 41, and finally, the inside of the mold 12 with the air gun 108 Dry it to prepare for the next operation.

In the above, embodiments of the present invention have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains will recognize that various modifications are possible within the scope of the claims to be described later.

Claims (3)

It is composed of a molding mold having an inner cavity for forming the preform of the flange, a base for supporting and fixing the molding mold, and an annular wall located on the top of the base and spaced apart from the molding mold outside the molding mold, and between the molding mold, the base and the wall. Has a storage space for cooling water,
(a) The mold is composed of a fixed mold part supported and fixed to the base, and a moving mold part that can be moved separately from the fixed mold part,
The movable mold part is composed of a head part forming a part of the lower end of the mold cavity and a cylindrical extension part extending from the head part to the lower end of the fixed mold part, and the fixed mold part has a cylindrical central hole into which the movable mold part is inserted. It is formed, but in this central hole, a support jaw for supporting the head of the movable mold part is formed, and the diameter of the extension part of the movable mold part is smaller than the direct hit of the central hole of the fixed mold part, so a second flow path of coolant is formed in this central hole
(b) The base supports and fixes the fixed mold part, and includes a movable mold part pressing device for moving the movable mold part upward by a certain length, so that the pressing device presses the movable mold part upward and moves it by a certain length. The preform molded in the mold cavity can be moved upward so that it is easy to withdraw from the mold cavity,
The base is composed of an upper base part supporting and fixing the fixed mold part, and a lower base part attached to the lower part of the upper base part and having an internal space in which the pressing device is located, and the upper base part is a first pin hole vertically penetrating the upper base part And a first flow path of cooling water extending from the cooling water storage space to the second flow path is formed between the upper base part and the fixed mold part,
A hollow spring case in which the pressing device is fixed to the inner space of the lower base part and one side is open, a spring located in the hollow part of the spring case, a cover having a vertical penetrating second pin hole and sealing the opening of the spring case, And one side extends through the first pin hole of the upper base part and the second pin hole of the cover to contact the movable mold part, and the other side is composed of a pin that is elastically supported by a spring, so that the pin is elastically pressed upward of the movable mold part, A method of manufacturing a preform using a flange preform manufacturing apparatus in a position where the pin presses the spring when the fixed mold part and the moving mold part are in a matched state,
In the above method, the base material heated at 1200 to 1250°C is placed in a press die and then pressurized to form a plate shape, and the cooling water injected into the cooling water storage space flows through the first flow passage to the second flow passage, thereby forming The first forming operation step of placing the plate-shaped base material in the forming mold of the preform manufacturing apparatus capable of cooling the mold and then pressing it with a press. By placing a pusher in the center of the base material first formed in the forming mold A secondary molding step of manufacturing a preform with a hollow part having a closed hole by pressing, a finishing step of pressing the preform located in the molding mold once again with a press so that the preform obtained from the second molding work matches the inner cavity of the mold , The finished preform is gripped by a preform pickup device, moved from the molding mold to the press die, and positioned in an inverted state, and a punch is placed in the closed cavity of the inverted preform and pressed with a press. Flange preform manufacturing method, characterized in that configured. The method of claim 1, further comprising cooling the molding mold by supplying cooling water into the cavity of the molding mold from which the preform finished by the preform pickup device has been removed. The method of claim 2, wherein the cooling of the molding mold comprises cooling the molding mold by supplying cooling water into the cavity of the molding mold from which the finished preform has been removed, discharging the cooling water in the mold cavity, and the mold cavity with an air gun. Preform manufacturing method of a flange, characterized in that consisting of the step of drying the.

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