JP2001047175A - Pressing method for increasing wall thickness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the wall thickness of an arbitrary part not limited to an end face by simplifying components of a die without generating turn-over or cracks, without removing a tapered surface and forming a flat surface in a post-machining manner, and without providing any process to form a tapered surface on an end part of a flat work. SOLUTION: The pressing method for increasing the wall thickness comprises a pre-process in which a flat work(w) constant in wall thickness and formed in a plate is deep-drawn to form an end part w2 projecting in the wall thickness direction with a specified length, and a main process in which an upper surface We of a work end part is pressed by a swaging punch having a flat pressing surface while holding the work-(w) by a die and a punch of the shape agreed with an upper outer side part Wa of the machined work end part w2, an intermediate and lower part Wb of the work end part, an outer and intermediate part Wc of a work bottom part, and an inner part Wd of the work bottom part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for increasing the thickness of an arbitrary portion of a work made of a plastic material such as metal.

[0002]

2. Description of the Related Art A conventional thickening press working method is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-140327. In this method, first, a plate portion formed into a plate shape with a constant thickness as shown in FIG. 6 (A) is curved in the thickness direction as shown in FIG. A work w having an end protruding is formed, and the work w is pressed in the thickness direction with a die and a holding punch (not shown) to increase the thickness of the end.
At this time, the work w is sandwiched between a punch support surface capable of contacting the upper surface of the work w and a die support surface capable of contacting the lower surface of the work w during pressurization as a die and a holding punch,
A gap is secured between the inner peripheral surface of the die and the outer surface of the end of the work w before pressing, and the end of the work w is pressurized by an upsetting punch having an inclined surface protruding outward. The outer surface is increased in thickness.

[0003] Japanese Patent Application Laid-Open No. 6-218442 also discloses a conventional thickening press working method. In this method, a first step of forming a tapered surface at an end of a plate-shaped work having a constant thickness in a plate shape is performed, and a deep drawing is performed with the tapered surface inward, and a constant length is formed in a thickness direction. A second step of forming an end protruding at the end, a die having a larger diameter than the outer diameter of the end, and a radius of curvature at the corner having the same diameter as the inner diameter of the end than the radius of curvature at the corner of the end. While pinching the work with a small holding punch,
A third step of pressing the upper surface of the end portion with an upsetting punch having a flat pressing surface.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method described in the publication, the target product is limited to a cylindrical container, and only the end face of the target product is thickened. Further, in this method, since the top surface of the end portion becomes a tapered surface descending outward, this tapered surface must be removed and flattened by post-processing, which is troublesome and increases costs. In the method described in JP-A-6-218442, the target product is limited to a cylindrical container, and only the end face of the target product is increased in thickness. In this method, a step of forming a tapered surface at the end of the flat work is required, and the number of components of the mold is large, and the equipment cost is also high. The object of the present invention was made in view of the above-mentioned conventional situation, and it is not necessary to remove a tapered surface to form a flat surface by post-processing without forming a roll-up or a crack, and it is not necessary to form a flat work end. In order to provide a thickening press working method capable of simplifying the components of a mold without requiring a step of forming a tapered surface in a part, and increasing the thickness of an arbitrary part without being limited to an end face. is there. Another object of the present invention is to provide a method for increasing the thickness of an arbitrary plate-shaped member without increasing the thickness of an object to be processed by increasing the thickness of a cylindrical container.

[0005]

According to the present invention, there is provided a step of deep drawing a plate-like work formed in a plate shape with a constant thickness to form an end projecting at a constant length in the thickness direction. A die having an upper inner portion having substantially the same shape as an upper outer portion of the end portion of the workpiece after processing, and having an inner inner bottom surface capable of contacting a deeply drawn work bottom outer inner portion. A die having an intermediate portion inner shape that matches the shape of the intermediate portion between the upper outer portion and the workpiece bottom inner outer portion, and an upper outer shape substantially the same as the upper inner portion of the workpiece end after processing And a punch having an inner outer bottom surface capable of abutting on a deep drawn inner part of the work bottom, the punch being provided between the upper inner part of the work end and the inner part of the work bottom. The work with a die having an intermediate portion outer shape that matches the intermediate portion shape after molding Pressure while solved the above problems by providing a thickening press-forming method, wherein the present step of pressing in seated write punch having a flat pressing surface of the upper surface of the workpiece edge, in that it consists of.

[0006]

According to the method of the present invention, a work in which an end protruding at a constant length in the thickness direction is formed by deep drawing in the previous step and the upper part of the work is initially sandwiched by a holding punch and a die while holding the work. Pressure is applied in the thickness direction, and is further applied in the thickness direction while holding the inside of the work bottom at the holding punch and die. At this time, the work has a gap between the holding punch and the die at an arbitrary position between the upper end of the work end and the inner side of the work bottom. Then, while pressurizing with the upsetting punch, the work is restrained by forming the work to the outside while setting it up, so that the shape of the intermediate part between the upper part of the work end and the inner part of the work bottom is increased. The middle of the work, that is, the middle / lower part of the work end, which is the middle part of the work, and the middle / outer part of the work bottom are connected to the middle part. At this time, by forming the pressing punch and the die into an angled or curved shape, the thickness can be increased smoothly from a constant thickness portion having no entanglement or crack. Also, in this method, the number of components of the mold is small, and the equipment cost is low. Therefore, according to this method, it is possible to increase the thickness of an arbitrary portion without causing entanglement or cracks, simplifying the mold structure, and irrespective of the end face.

[0007] Preferably, the inner shape of the middle portion of the die and / or the outer shape of the middle portion of the holding punch has a slope or a curved surface, so that the thickness can be smoothly increased from a constant thickness portion with less entanglement and cracks. Can be. Furthermore, an inner end surface regulating surface is provided inside the inner inner bottom surface of the die or the inner outer bottom surface of the holding punch, and the thickness of an arbitrary plate-shaped member is not limited to a target container, but is limited to the thickening of a cylindrical container. Can be.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the thickness increase press working method of the “pre-process” embodiment, first,
As shown in FIG. 6A, a work w formed into a plate with a constant thickness t is used, and as shown in FIGS.
A preforming mold having 11A, a punch 12, and a lower die 11B is used. The upper die 11A and the lower die 11B may be integrated. In this preforming mold, the upper die
A cavity C1 is formed in the lower die 11A and the lower die 11B, and the work w is formed in a plate shape with a constant thickness t as shown in FIG. 6B by pressing the punch 12 into the cavity C1. It is formed so as to have a plate portion W1 and an end portion W2 which is curved from the plate portion W1 in the thickness direction at a constant thickness t and protrudes by a constant length 1 in the thickness direction.

[This Step] As shown in FIGS. 3, 4 and 5, a mold for increasing the wall thickness is prepared having an upper die 1A, a lower die 1B, a holding punch 2 and an upsetting punch 3. The upper die 1A and the lower die 1B may be integrated. The upper die 1A has a die upper inner portion 1Aa and an inner middle / lower inner portion 1Ab that are shaped to match the outer side of the upper end Wa of the workpiece w end W2, the middle and lower ends of the lower end of the work Wb after molding. The lower die 1B has upper surfaces 1Bc and 1Bd that match the outer / intermediate portion Wc of the work bottom and the inner side of the work bottom Wd after molding.
Similarly, the holding punch 2 has an intermediate / lower outer portion 2b conforming to the shape of the workpiece after molding, a bottom outer / intermediate portion 2c, a bottom inner portion 2d, and an inner end surface regulating surface 2f connected thereto. The upsetting punch 3 has a bottom surface 3e that can contact the top surface We of the workpiece.
Having. The inner end surface regulating surface may be provided on the lower die 1B side.

Then, the workpiece w formed in the preceding step and having an end W2 which is curved from the plate portion W1 in the thickness direction at a constant thickness t and protrudes with a constant length l in the thickness direction is attached to the upper die 1A and the upper die 1A. Stored in lower die 1B, holding punch, upper die 1A and lower die
Initially, the upper end Wa of the work end W2 is sandwiched by 1B, and the work end W2 is pressurized in the thickness direction while regulating the thickness direction of the end W2. Pressing is further performed in the thickness direction with the thickness direction of the lateral portion Wd regulated. At this time, the work w is at the upper end of the work end.
In any part between Wa and the work bottom inner part Wd,
A gap is secured between the holding punch, the upper die 1A and the lower die 1B. Then, during pressurization by the upsetting punch 3, the work w is formed while being outwardly formed, and the work is upset to increase the binding force of the work. After the work between the work upper end portion Wa and the work bottom inner portion Wd is formed. The middle and lower portions Wb of the end of the work and the outer and middle portions Wc of the bottom of the work are made thicker so as to conform to the shape of the middle portion of FIG. At this time, by making the pressing punch and the die have an angle or a curved surface 1Ab, 2b, the wall thickness can be increased smoothly from a constant thickness portion without entanglement or crack. Therefore, according to this method, it is possible to increase the thickness of an arbitrary portion without causing a entanglement or a crack, simplifying a mold structure, and limiting the target product to a cylindrical container and not to an end surface. Can be.

[0011]

According to the present invention, there is no need to remove the tapered surface and flatten the surface by post-processing without forming a roll-up or crack, and it is necessary to form a tapered surface at the end of the flat work. Instead, the present invention provides a method for increasing the thickness of a metal mold by simplifying the components of the mold and increasing the thickness of an arbitrary portion without limiting to an end face. Furthermore, by providing the inner end surface regulating surface inside the inner inner bottom surface of the die or the inner outer bottom surface of the holding punch, the target product is not limited to the thickening process of the cylindrical container, but the thickening process of any plate-shaped member is not limited. To provide a method for increasing the thickness of the press.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a preforming mold and the like before a preprocess in an embodiment, and shows a workpiece before processing.

FIG. 2 shows a state in which the workpiece is deep drawn by the preforming mold of FIG.

FIG. 3 is a partial cross-sectional view of a mold for increasing the thickness of the embodiment before this step.

FIG. 4 is a partial cross-sectional view of a mold for increasing thickness during a main step of the embodiment.

FIG. 5 is a partial cross-sectional view of a mold for increasing thickness after a main step in the embodiment.

6A to 6C are cross-sectional views of the work of the embodiment, wherein FIG. 6A is a cross-sectional view of the work before the pre-process, FIG. 6B is a cross-sectional view of the work after the pre-process and before the main process, and FIG. It is sectional drawing of the workpiece | work after.

[Explanation of symbols]

1A ··· Upper die (die) 1B · · · Lower die (die) 1Aa · · · · Upper inside of the die 1Ab · · · Middle and lower inside of the die 2 · · · Holding punch 2a · · · Inside the bottom of the holding punch 2b · · · Holding punch middle / lower outer part 2b ・ ・ Holding punch middle / lower outer part 2d ・ ・ Holding punch bottom inner part 2f ・ ・ Holding punch inner end face regulating surface 3・ Work W2 ・ ・ Work end Wa ・ ・ Work upper part upper part Wb ・ ・ Work end middle / lower part Wc ・ ・ Work bottom outer / middle part Wd ・ ・ Work bottom inner part We ・ ・ Work end Upper surface

Claims (3)

[Claims] 1. A pre-process in which a plate-like work formed in a plate shape with a constant thickness is deep drawn to form an end projecting at a constant length in a thickness direction, and a work end of the work after processing. A die having an upper inner portion having substantially the same shape as the upper outer portion and having an inner inner bottom surface capable of abutting on a deeply drawn work bottom outer inner portion, wherein the work upper outer portion and the work bottom inner portion are provided. A die having an intermediate inner shape matching the shape of the intermediate portion between the outer portion and the molded portion, and an upper outer portion having substantially the same shape as the upper inner portion of the workpiece end after processing and being deep drawn. A punch having an inner outer bottom surface capable of contacting the inner bottom portion of the work and conforming to the shape of the intermediate portion between the upper inner portion of the end of the work and the inner bottom portion of the work. While pressing the work with a die having an outer shape in the middle, the upper surface of the end of the work A pressurizing process using an upsetting punch having a flat pressurizing surface. 2. The thickening press working method according to claim 1, wherein an inner shape of the intermediate portion of the die and / or an outer shape of the intermediate portion of the pressing punch have a slope or a curved surface. 3. The method for increasing the thickness of a press according to claim 1, wherein an inner end surface regulating surface is provided inside an inner bottom surface of the die or an inner bottom surface of the holding punch.