JP2008036656A - Apparatus and method of forming flange - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method of forming a flange by which the flange free from edge cracking is formed in one step on a sheet-metal product such as a flat plate, a cylinder or an elliptic tube which are used for automotive parts or the like. <P>SOLUTION: This apparatus for forming the flange is composed of a pair of a piercing punch and a burring punch which are opposed, a burring-side pad energized with a spring so as to be movable by a prescribed stroke in the axial direction on the outer periphery of the burring punch and a piercing-side pad energized with a spring so as to be movable in the axial direction on the outer periphery of the piercing punch opposing to the burring-side pad, a shaft hole into which the piercing punch is inserted and pulled out is provided on the burring punch and also a die cavity into which the burring punch is inserted and pulled out is provided on the piercing-side pad. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flange forming apparatus and a flange forming method for forming a flange by piercing and burring of a sheet metal part, and more particularly, to a flange forming apparatus and a flange forming method for forming a flange without a tip crack in one process.

  When a flange is provided on a sheet metal product such as a flat plate, cylinder or elliptic cylinder, piercing and burring are often used instead of welding. In such a flange forming method, burring is performed after first performing piercing. In this case, if the direction of piercing is the same as the direction of burring, there is an advantage that flange forming can be performed in one step. However, due to burrs generated on the flange end face during piercing, the next burring is in progress. There is a problem of causing cracks.

  With respect to such a problem, in Patent Document 1, according to the burring type die provided with a knockout pin that slides in the shaft hole of the burring die and a coining die that slides in the shaft hole, before burring processing, It is disclosed that by performing coining on the periphery of the pierced hole, a crack-free flange can be formed in one step even if the direction of piercing and the direction of burring are the same.

  Patent Document 2 discloses a press die having a direction in which piercing and burring are performed in different directions, but has a process of continuously piercing and burring a metal plate, and the piercing punch is inserted and removed from the burring punch. A press die having a shaft hole through which pierce scrap is discharged and performing a die function during piercing is disclosed. And according to this press metal mold | die, it is disclosed that the flange without a crack can be shape | molded in one process.

  Further, in Patent Document 3, in a method of performing piercing to form a pilot hole in a plate-like member, and thereafter burring the pilot hole portion to form a flange, the plate-like member of the plate-like member is prior to the piercing. A flange forming method is disclosed in which an uneven portion is formed around the prepared hole forming portion, and the peripheral length of the prepared hole is expanded to allow for the amount of elongation after burring. And according to this flange formation method, it is disclosed that a flange without a tip crack can be easily formed by burring.

Japanese Unexamined Patent Publication No. 09-1251 JP 09-314246 A JP 2005-349427 A

  However, in the case of the burring type disclosed in Patent Document 1, there is a problem that a complicatedly configured mold and operating device must be used. The press die disclosed in Patent Document 2 is used for forming a flange having a small outer diameter on a sheet metal having a small thickness, and is generally used for a sheet metal having a large thickness as used for automobile parts and the like. It is not necessarily suitable as a press die for forming a large flange. In addition, there is a problem that it is not clear what configuration the press mold is used for flange forming. In the case of the flange forming method disclosed in Patent Document 3, there is a problem that a preliminary uneven portion processing is required before piercing.

  The present invention is a flange forming apparatus and a flange forming method with a simple configuration in view of such conventional problems, and there is no crack at the end of a sheet metal product such as a flat plate, a cylinder, or an elliptic cylinder used for automobile parts. An object of the present invention is to provide a flange forming apparatus and a flange forming method capable of forming a flange in one step.

  A flange forming apparatus according to the present invention includes a pair of opposed piercing punches and a burring punch, a burring side pad that is spring-biased so that the outer periphery of the burring punch can move a predetermined stroke in its axial direction, and the burring side pad. The piercing side pad is provided with a piercing side pad that is opposed and spring-biased so that the outer periphery of the piercing punch can move a predetermined stroke in the axial direction. The pad is provided with a die cavity into which the burring punch is inserted and removed.

  In the above invention, it is preferable to provide a driving means that operates to insert the piercing punch into the shaft hole of the burring punch while the workpiece is sandwiched between the burring pad and the piercing pad that are elastically supported. The burring side pad and the piercing side pad and the piercing side pad so that the burring punch is inserted into the die cavity of the pierce side pad in a state where the workpiece is sandwiched between the burring side pad that is elastically supported and the pierce side pad that is fixedly supported. It is preferable to provide driving means for operating the pierce-side pad.

  In the above invention, the height of the flange is preferably about half of the dimensional difference between the outer diameter of the burring punch and the outer diameter of the piercing punch.

  A flange forming method according to the present invention is a flange forming method in which a flange is formed in one step by a pair of opposed piercing punches and a burring punch, and the workpiece placed on the upper surface of the burring punch is processed by the flange. The outer edge portion to be formed is pierced by inserting the piercing punch into the shaft hole provided in the burring punch while sandwiching it between the burring side pad and the piercing side pad facing each other. The piercing side pad and the burring side pad are operated so as to be inserted into a die cavity provided in the side pad, and burring processing is performed.

  In the invention of the flange forming method, the burring side pad and the pierced side pad are both elastically supported during piercing, and the burring side pad is elastically supported and the pierced side pad is fixedly supported during burring. It is better to perform flange molding.

  The flange forming apparatus according to the present invention has a simpler structure than the conventional flange forming apparatus, and forms a flange without a tip crack in a sheet metal product such as a flat plate, a cylinder or an elliptic cylinder used for automobile parts in one step. be able to. The flange forming method according to the present invention can form a flange with no crack at one end in one step, and can produce a stable and high-quality flanged automobile part or the like.

  Hereinafter, embodiments of a flange forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a drawing schematically showing a cross section of a piercing punch and a burring punch portion of a flange forming apparatus according to the present invention. This flange forming apparatus has a pair of opposed piercing punches 10 and a burring punch 20, and has a burring side pad 25 spring-biased so that the outer periphery of the burring punch 20 can move a predetermined stroke in the axial direction thereof. Yes. The burring punch 20 is provided with a shaft hole 22. The piercing punch 10 is inserted into and removed from the shaft hole 22 by a driving means (not shown) as shown by an arrow A in FIG. It is like that. In this example, the piercing punch 10 and the movable die 33 are fixed integrally, and the piercing punch 10 is operated by operating the movable die 33. However, the piercing punch 10 may be operated independently. it can.

  The flange forming apparatus has a pierce-side pad 15 provided on the outer periphery of the pierce punch 10 so as to be opposed to the burring-side pad 25 and spring-biased so as to be movable by a predetermined stroke in the axial direction of the pierce punch 10. is doing. The pierce-side pad 15 is provided with a die cavity 16 so that a burring punch 20 enters and a workpiece is subjected to burring. Thereby, since it is not necessary to provide a dedicated burring die, the flange forming apparatus can have a simpler and more compact structure than the conventional one.

  The burring side pad 25 is spring-biased upward in the drawing by an elastic body 35 fixed to the fixed die 37, and the piercing side pad 15 is spring-down in the drawing by an elastic body 30 fixed to the movable die 33. It is energized. Further, the burring side pad 25 can be moved up and down via the elastic body 30 and the piercing side pad 15 by the operation of the movable die 33. The burring punch 20 is fixed to a fixed die 37.

  The elastic bodies 30 and 35 can use various springs. However, there is an advantage that the structure can be made compact by using a gas spring comprising a cylinder and a piston filled with gas. Further, the required spring force of the elastic bodies 30 and 35 is selected depending on the material of the workpiece, the plate thickness, the outer diameter and height of the flange to be molded, and the like.

  The driving means includes a hydraulic actuator, a solenoid valve, a position sensor, and a timer, and can operate the movable die 33 according to a predetermined time chart. By this driving means and the elastic bodies 30 and 35, the piercing punch 10, the piercing side pad 15, the burring side pad 25 and the burring punch 20 can be operated as required.

  Flange forming of the workpiece is performed by piercing and burring as shown in FIG. 2 by the flange forming apparatus. 2 (a) shows the state before piercing, FIG. 2 (b) shows the state after completion of piercing, FIG. 2 (c) shows the state during burring, and FIG. 2 (d) shows the state after burring. Show.

  That is, in the flange forming of the workpiece 50, first, the workpiece 50 placed on the upper surface of the burring punch 20 is operated by moving the movable die 33 downward by a predetermined stroke in the drawing as shown in FIG. The workpiece 50 is sandwiched between the pierce side pad 15 and the burring side pad 25 which are elastically supported. Next, piercing is performed by operating the piercing punch 10 downward. As shown in FIG. 2 (b), the piercing punch 10 after the piercing process is inserted into the shaft hole 22 of the burring punch 20. During the piercing process, the piercing side pad 15 and the burring side pad 25 are elastically supported by the elastic bodies 30 and 35, respectively. When the piercing process is completed, the bottom of the pierce-side pad 15 comes into contact with the movable die 33, and the pierce-side pad 15 and the movable die 33 are integrated. In this way, in the piercing of not only flat sheet metal products but also sheet metal products having a cylindrical or elliptical cross section, the work piece can be subjected to the required punching pressure without causing deformation, cracks, etc. Piercing can be performed.

  Next, the movable die 33 is operated downward in the drawing, and the burring side pad 25 is operated downward via the pierce side pad 15. At this time, as shown in FIG. 2 (c), the burring punch 20 is inserted into the die cavity 16 provided in the pierce-side pad 15, and burring is performed between the burring punch 20 and the die cavity 16. Done.

  As shown in FIG. 2D, the movable die 33 operates downward until burring is completed. During this burring process (FIGS. 2 (c) and 2 (d)), as described above, the pierce-side pad 15 and the movable die 33 are integrated, and the pierce-side pad 15 is fixedly supported by the movable die 33. However, the elastic body 35 is still in a compressible state, and the burring side pad 25 is in an elastically supported state. As a result, burring can be performed at a required processing pressure without damaging the workpiece.

  As shown in FIG. 3, the burring process is performed by piercing a pad 15 that presses the workpiece 50 from above on an outer edge portion where the flange 53 of the workpiece 50 is formed, and a piercing pad 15 facing the piercing pad 15. With the workpiece 50 held between the burring side pad 25 that presses the workpiece 50 from below, the piercing side pad 15 and the burring side pad 25 are operated downward as indicated by the arrows, and the burring punch 20 and the die cavity 16 are operated. A flange 53 is formed between the two. Then, half of the difference between the outer diameter dB of the burring punch 20 and the outer diameter dP of the piercing punch 10 is substantially equal to the flange height h. To be precise, it is necessary to consider the gap between the die cavity 16 and the burring punch 20 determined by the plate thickness t of the workpiece 50 and the flange height h.

  The configuration of the flange forming apparatus according to the present invention and the case of performing flange forming using the apparatus have been described above. As described above, in the present invention, in the molding of the flange, particularly in the burring process, the workpiece 50 is in a state where the upper and lower surfaces of the outer edge portion where the flange 53 is molded are sandwiched between the pierce side pad 15 and the burring side pad 25. Thus, the flange portion is raised and deformed (burring) using the outer edge portion where the flange 53 is molded as a fulcrum. Further, the burring process of the present invention is performed by the burring punch 20 and the piercing side pad 15 that are aligned with the piercing punch 10 after the piercing process. As a result, in the present invention, stable and high-quality flange molding can be performed with high dimensional accuracy with a matching axial center.

  That is, piercing is performed by inserting the piercing punch into the shaft hole provided in the burring punch while sandwiching the outer edge portion where the flange of the workpiece is formed between the burring side pad and the piercing side pad facing each other. A pair of opposing piercing punches by performing burring by operating the piercing side pad and the burring side pad so that the burring punch is inserted into a die cavity provided in the piercing side pad. With the burring punch, piercing can be performed first, and then burring can be performed immediately, and stable and high-quality flange molding can be performed in one step.

  In this flange forming method, as described above, during piercing, both the burring side pad and the piercing side pad are elastically supported, and during burring, the burring side pad is elastically supported, and the piercing side pad is It is preferable to perform flange molding in a fixed and supported state.

  Using the flange forming device shown in Fig. 1, a flange with an outer diameter of 63 mm and a height of 7 mm is formed on an oval cylindrical automobile part with a cross section of 280 x 200 made of SUS 436 with a thickness of 0.5 mm. A test was conducted. Piercing was done at 8 tons and burring was done at 16 tons. The elastic bodies 30 and 35 used gas springs. The elastic body 30 used for the pierce-side pad 15 uses two gas springs with a maximum load of 700 kg, and the elastic body 35 used for the burring-side pad 25 uses two gas springs with a maximum load of 2900 kg.

  The flange formed by the above test was subjected to visual inspection and dimensional inspection. There were no problems with visual inspection or dimensional inspection. In addition, although a small burr | flash was seen in the process part by the piercing process, by this, the malfunction was not seen in burring process. In this test, the measured values for the dimensions L1, L2, L3, L4, l1, l2, l3, and l4 of each part shown in FIG.

It is a schematic diagram which shows the structure of the flange molding apparatus which concerns on this invention. It is explanatory drawing which shows the procedure of flange shaping | molding. It is explanatory drawing explaining the processing state of a burring process.

Explanation of symbols

10 Piercing punch
15 Earrings putt
16 die cavity
20 Burling punch
22 Shaft hole
25 burring side pad
30 Elastic body
33 Movable die
35 Elastic body
37 Fixed die
50 Workpiece
53 Flange

Claims (6)

A pair of opposed piercing punches and a burring punch, a burring side pad that is spring-biased so that the outer periphery of the burring punch can move a predetermined stroke in its axial direction, and an outer periphery of the piercing punch that faces the burring side pad It consists of a pierced side pad that is spring-biased so that it can move a predetermined stroke in the axial direction,
While providing a shaft hole through which the piercing punch is inserted and removed from the burring punch,
A flange forming apparatus provided with a die cavity into which the burring punch is inserted and removed from the pierce side pad.   A driving means is provided that operates to insert the piercing punch into the shaft hole of the burring punch in a state where the workpiece is sandwiched between the burring pad and the piercing pad that are elastically supported. Item 2. The flange forming apparatus according to Item 1.   The burring side pad and the pierced ear are inserted so that a burring punch is inserted into the die cavity of the pierced side pad while the work piece is sandwiched between the elastically supported burring side pad and the fixedly supported pierce side pad. The flange forming apparatus according to claim 1, further comprising a driving unit that operates the side pad.   The flange forming apparatus according to any one of claims 1 to 3, wherein the flange height is substantially half of a dimensional difference between the outer diameter of the burring punch and the outer diameter of the piercing punch. A flange forming method in which a flange is formed in one step by a pair of facing piercing punches and burring punches,
While sandwiching the work piece placed on the upper surface of the burring punch with the burring side pad and the piercing side pad facing the outer edge where the flange is formed,
Piercing by inserting the piercing punch into the shaft hole provided in the burring punch,
Next, a flange forming method of performing burring by operating the piercing side pad and the burring side pad so that the burring punch is inserted into a die cavity provided in the piercing side pad. At the time of piercing, both the burring side pad and the piercing side pad are elastically supported,
6. The flange forming method according to claim 5, wherein the flange forming is performed while the burring pad is elastically supported and the pierced pad is fixedly supported during burring.

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