JP5287422B2 - Apparatus and method for plastic working of cup-shaped member - Google Patents

Description

  The present invention relates to a plastic working apparatus and method for performing plastic working of a cup-shaped member, in particular, drawing, burring, or overhanging. Here, the cup-shaped member is a cylindrical or dish-shaped member and includes all members formed by drawing, burring, or overhanging processing regardless of the presence or absence of a hole in the bottom.

  Conventional techniques include drawing, burring, and overhanging. However, when the prior art is applied to a shape with a small squeezing rate or a shape with a high inner wall height, there is a problem that a shape failure such as material breakage is caused. Therefore, in order to prevent a shape defect, the material must be processed while maintaining a drawing ratio for preventing the material from being broken, resulting in an increase in the number of steps.

  On the other hand, in the case of Patent Document 1, the bottom of the cup-shaped member is pressed by a double-acting shaft (pin) of a deep drawing press, or in the case of Patent Document 2, the blank outer edge is moved in the centripetal direction by a hydraulic cylinder. In the case of pressing or in Patent Documents 3 and 4, the processing limit has been raised by assisting the material flow of the blank by pressing the blank using an inclined surface. All of these technologies suppress the phenomenon of “wrinkles (generated by stress in the circumferential direction: concerns about conventional drawing)” caused by holding the plate during processing and reducing the diameter when the material flows into the drawing. Therefore, an appropriate surface pressure is applied to suppress “wrinkles”. For this reason, if this plate pressing force becomes too large, the material may not flow in due to the frictional force, causing a problem that the material breaks. In addition, buckling due to assist may occur.

JP-A-9-150223 JP-A-57-152323 JP 2000-288642 A JP 2004-25279 A

  In view of the above problems, the present invention provides a plastic processing apparatus and method for assisting material flow by applying an external force to perform plastic processing of a cup-shaped member, in particular, drawing, burring, or overhang processing. It is.

FIG. 1 is an explanatory diagram for explaining the stress state of burring (a process of making a pilot hole in a burring blank and stretch flanging the edge of the hole) and drawing. FIG. 2 is an explanatory diagram for explaining a stress state when assisting material flow by applying an external force to the blank outer edge. In the case of burring, when the pilot hole is expanded and the tensile force σ _θ exceeds the critical stress σ _b at the pilot hole edge, the processing limit is reached. In the case of drawing, a processing limit occurs on the vertical wall.
As shown in FIG. 2, when an external force is applied to the outer edge of the blank, the material at the outer edge of the blank flows in. Therefore, both have a mechanism in which the tensile force is relaxed and the working limit is increased.

  The present invention takes such a mechanism and adopts a structure that assists material flow by moving the plate presser and the die in the material flow direction while clamping the blank.

  In order to solve the above problems, the invention of claim 1 is directed to a die fixed to one die (20), wherein the inner peripheral surface (10 ') is formed at a predetermined taper angle. A holder (10), a punch (12) fixed to one die (20) at the center of the die holder (10), and a predetermined number of parts, each outer peripheral surface (13 ') being the predetermined taper A movable blank presser (13) formed at a corner and an annular support (14) for supporting the movable blank presser (13) are provided, and the other mold part is divided into the predetermined number of movable dies ( 11), wherein the moving die (11) includes a moving die (11) supported by the other die (30) so as to be slidable in the radial direction. And the movable blank presser (13) Further, the outer peripheral edge portion of the blank (1) is clamped, and the outer peripheral surface (13 ′) of the movable blank presser (13) is moved in accordance with the lowering of the movable die (11) of the other mold part. The die holder (10) slides on the inner peripheral surface (10 ') and moves in the radial direction of the blank (1) to assist the material flow of the blank and plasticize the cup-shaped member. It is characterized by processing.

  As a result, the limit of cracking is increased by assisting the material flow, and the material is gradually drawn by applying compression from the outer diameter side, the bending start point moves, and the bending does not occur suddenly and is good. Can be processed. In addition, even in a shape with a small squeezing ratio and a shape with a high inner wall, the material does not break, and the frictional resistance received from the blank presser and die can be reduced, and defects such as wrinkles and buckling are suppressed. can do.

  A second aspect of the present invention is the apparatus according to the first aspect, wherein the plastic working is drawing, burring, or overhanging.

The invention of claim 3 includes a step of clamping the outer peripheral edge of the blank (1) between the movable die (11) and the movable blank presser (13), each of which is divided into a predetermined number, and the blank (1 ) Is clamped, and the blank is plastically deformed by the punch (12) and the taper is formed at a predetermined taper angle as the movable die (11) is lowered. The movable blank presser (13) having an outer peripheral surface (13 ') slides on the inner peripheral surface (10') formed at the predetermined taper angle of the die holder (10), and the blank (1 ) In the radial direction, and assisting the material flow of the blank comprising plastic processing into a cup-shaped member. Thus, the same effect as that attained by the 1st aspect can be attained.

A fourth aspect of the present invention is the method according to the third aspect of the present invention, characterized in that it is drawing, burring, or overhanging.

  In addition, the code | symbol attached | subjected above is an example which shows a corresponding relationship with the specific embodiment as described in embodiment mentioned later.

It is explanatory drawing explaining the stress state of burring and drawing. It is explanatory drawing explaining the stress state in the case of assisting material flow by applying external force. 1 is a schematic diagram of an embodiment of the present invention. It is a top view of the whole movement die. It is explanatory drawing explaining a process condition, (a) to (d) is a figure explaining the condition where a process progresses with time . It is explanatory drawing of the processing method which assists the material flow of one Embodiment of this invention. It is explanatory drawing explaining other one Embodiment of this invention. It is explanatory drawing explaining an auxiliary punch .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. About each embodiment, the same code | symbol is attached | subjected to the part of the same structure, and the description is abbreviate | omitted.
FIG. 3 is a schematic diagram showing an embodiment of the present invention, where the left side shows a state before processing, and the right side shows a state after processing. One embodiment of the present invention is a form applied to burring. Embodiments applied to drawing, deep drawing, and overhang will be described later.
The burring blank 1 is supplied into the movable blank press 13 by a robot hand or other blank supply device. The lower mold part (the lower mold refers to one mold) will be described. The movable blank presser 13 has a tapered outer periphery 13 ′ and is inserted into the die holder 10 so as to be movable up and down. The die holder 10 is fixed to the lower mold 20, and the taper inclination of the inner peripheral surface 10 ′ of the die holder 10 is the same as the taper inclination of the outer periphery 13 ′ of the moving blank presser 13. The bottom surface of the movable blank presser 13 is supported by an annular support base 14. The annular support 14 is connected to a shaft 15 and is guided by the shaft 15 to move up and down with a receiving pressure necessary for processing.

  A punch 12 is fixed to the lower mold 20 at the center of the inside of the die holder 10. An inner peripheral surface 10 ′ of the die holder 10 is connected to a cylindrical inner surface 10 ″. The annular support 14 slides between the cylindrical inner surface 10 ″ and the outer peripheral surface of the punch 12. The punch 12 has an inclined portion 12 ″ formed at a fixed position from the tip end portion 12 ′. The punch 12 may be a single cylinder without the inclined portion 12 '', and an embodiment in this case will be described later.

  Next, the upper mold portion (the upper mold refers to the other mold) will be described. As shown in the state diagram before the left side processing in FIG. 3, the moving die 11 connected to the upper die 30 is lowered, and the moving die 11 grips the blank outer edge portion against the moving blank presser 13 supplied with the blank 1. . The moving die 11 and the moving blank presser 13 are positioned and aligned by the die holder 10. The lower mold part and the upper mold part refer to one mold and the other mold, respectively, in the case of upside down or horizontal press.

  FIG. 4 is a plan view of the entire moving die 11. In the present embodiment, the moving die 11 and the moving blank presser 13 are divided into eight equal parts. Since it is in a free state before pressurization, it is held by applying a force to spread by inserting a spring between adjacent moving dies, and when it reaches the final processing position, it adheres to each other and stretches the edge of the pilot hole ( See after processing in FIG. For this reason, springs inserted between adjacent moving dies are provided with spring insertion holes between adjacent moving dies so that the springs do not impede contact even if they are in close contact with each other at the final processing position. . This spring allows realignment after processing. Although the movable die 11 and the movable blank presser 13 have been described as being equally divided, they need not be equally divided.

A plate 16 is installed in the upper mold 30, and a key groove 18 is cut in the plate 16, so that the upper mold 30 can slide in alignment with a key provided on the upper part of the moving die 11. . The upper part of the movable die 11 protrudes in the radial direction (inverted L-shaped cross section as seen in FIG. 3), and the upper part of the movable die 11 is supported by the flange part 17 of the upper mold 30 so that the upper part 30 is held. Is retained. The number of the moving dies 11 is not necessarily eight, but may be an arbitrary number. In addition, when a rectangular cylindrical body is formed as the final formed shape, the punch 12 may be a prism and the shape of the moving die 11 corresponding to the corner may correspond to the prism.
Regarding the taper angle of the outer periphery 13 ′ of the moving blank presser 13 and the taper angle of the inner peripheral surface 10 ′ of the die holder 10, the material inflow timing and the inflow speed can be changed by appropriately changing the taper angle.

  Regarding the movement of the movable die 11 divided into eight in the radial direction, in the present embodiment, the key groove 18 is cut in the plate 16 and is fitted and slid with the key provided on the upper portion of the movable die 11. Furthermore, in the lower mold, a key groove may be provided between the annular support 14 and the moving blank presser 13 to move the moving die 11 in the radial direction. As described above, if the key groove 18 is provided on the plate 16 and the moving die 11 and further the key groove is provided between the annular support base 14 and the moving blank presser 13, the operation is further ensured.

Next, the operation of this embodiment will be described.
FIG. 5 is an explanatory diagram for explaining a machining situation, and (a) to (d) are diagrams for explaining a situation in which machining progresses with time. FIG. 6 is an explanatory diagram of a processing method for assisting material flow according to an embodiment of the present invention.
First, when the blank 1 is supplied into the moving blank press 13 by the supply device, the moving die 11 descends and grips and presses the blank 1 with the moving blank press 13. Thereafter, when the movable blank presser 13 is lowered along the taper of the inner peripheral surface 10 ′ of the die holder 10, the inner peripheral edge of the blank 1 passes through the inclined portion 12 ′ of the punch 12, and the state shown in FIG. Become. The annular support 14 is adjusted by fluid pressure or the like via the shaft 15 so that an appropriate surface pressure is applied to the outer edge of the blank 1 by the moving die 11 as the moving blank presser 13 is lowered. Thereafter, the inner peripheral edge of the blank 1 is stretch-flanged as shown in FIGS. In this embodiment, since the movable blank presser 13 moves together with the material, wrinkles are not generated and the fear of breakage is also eliminated.

Since the blank inner edge is not constrained, the aperture angle is increased and the processing is easy. As for the cracks on the inner edge side, since the material flow is assisted, the limit of the cracks is raised and the occurrence is prevented. Further, by applying compression from the outer diameter side, the material is gradually drawn and the bending start point moves, so that the bending can be performed without suddenly occurring. Of course, the processing can be further increased by taking a large die R (see FIG. 5D), tapering the punch (inclined portion 12 ″), and appropriately selecting the taper angle of the movable blank presser 13. Since it becomes easy, these are employ | adopted as needed.
The dimension t in FIG. 5 (a) corresponds to the final flange plate thickness.

  As shown in FIG. 6, the moving plate presser 13 receives the downward force of the moving die 11, pinches the blank 1 (the plate pressing effect of the drawing process similar to the conventional one), and further, the force is tapered in the die holder 10. Can be converted into an external compression force that reduces the diameter of the material toward the center.

As another embodiment of the present invention, the following modifications can be considered.
Although burring has been described so far, as shown in FIG. 7, even with drawing, deep drawing, and overhanging processing, the same apparatus or method as in the above-described embodiment can be used. In the case of a diaphragm, the shape of the punch 12 is determined so that the shape of the cylindrical portion becomes a predetermined shape. In the case of FIG. 7, the inclined portion 12 '' is not provided. Even when burring is performed, a punch without the inclined portion 12 '' may be used.

  If the material flows into the dividing surface of the moving die 11 and R is not formed well, the auxiliary punch 19 may be held in the plate 16 and provided near the dividing surface of each moving die 11. In this case, a space for the auxiliary punch 19 is provided in the moving die so as not to prevent the moving dies 11 from sticking to each other. The auxiliary punch 19 may be fixedly installed on the upper mold 30, but may be moved in the axial direction through the plate 16 of the upper mold 30 to assist the formation of R on the dividing surface. .

DESCRIPTION OF SYMBOLS 1 Blank 10 Die holder 10 'Inner peripheral surface 11 Moving die 12 Punch 13 Moving blank presser 13' Outer peripheral surface 14 Ring support stand 20 Lower mold | type (one type)
30 Upper mold (the other mold)

Claims (4)

One mold part includes a die holder (10) fixed to one mold (20) having an inner peripheral surface (10 ') formed at a predetermined taper angle, and one die part (10) at the center of the die holder (10). A punch (12) fixed to the mold (20), a movable blank presser (13) divided into a predetermined number and each outer peripheral surface (13 ′) formed at the predetermined taper angle, and the movable blank Comprising an annular support (14) for supporting the presser (13);
The other mold part is the movable die (11) divided into the predetermined number, and the movable die (11) is supported by the other mold (30) so as to be slidable in the radial direction ( 11) In the plastic working apparatus provided with
Between the moving die (11) and the moving blank presser (13), the outer peripheral edge of the blank (1) is clamped,
As the movable die (11) of the other mold part descends, the outer blank surface (13 ') of the movable blank presser (13) is the inner peripheral surface (10') of the die holder (10). The plastic processing apparatus which assists the material flow of the blank and plastically processes it into a cup-shaped member, characterized by sliding in the radial direction of the blank (1).   The plastic working apparatus according to claim 1, wherein the plastic working is drawing, burring, or overhanging. Clamping the outer peripheral edge of the blank (1) between the moving die (11) and the moving blank presser (13), each divided into a predetermined number;
The movable die (11) descends with the blank (1) clamped, and the blank is plastically deformed by the punch (12);
As the moving die (11) descends, the moving blank presser (13) having an outer peripheral surface (13 ′) formed at a predetermined taper angle is adjusted to the predetermined taper angle of the die holder (10). Sliding the formed inner peripheral surface (10 ′) and moving in the radial direction of the blank (1);
A method of plastic processing into a cup-shaped member by assisting the material flow of a blank. The method according to claim 3 , wherein the plastic working is drawing, burring, or overhanging.

Images