JP2001170715A - Method for forming burring and die device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming burring and a die device by which a final collar is formed high and into uniform thickness by obtaining the uniform thickness without loading concentrated tensile load in the preforming of a metal plate. SOLUTION: When a part of the metal plate 27 where the burring is performed is preformed, by using a knock-out collar provided with a recessed part for relief on its bottom end surface, the metal plate 27 is pressed with a forming punch 20 in the state where the metal plate 27 is not held with the knock-out collar 7 and the forming punch 20, and a stretch forming part 32 is preformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for burring a work material such as a metal plate for manufacturing fins and the like used for a heat exchanger, and a mold apparatus therefor.

[0002]

2. Description of the Related Art In a heat exchanger disposed in an outdoor unit or an indoor unit of an air conditioner, a large number of fins are arranged in parallel with an appropriate gap between their plate surfaces, and are penetrated through these fins. The heat medium flow pipe is integrally fixed.

[0003] The clearance between the plate surfaces of the fins is determined by the height of the collar protruding from the plate-like fin material, and the accuracy and performance of the heat exchanger greatly depends on the accuracy of the height of the collar and the finished state of the collar tip. Affected. However, if the height of the collar is made higher to increase the gap between the plate surfaces, it is difficult to maintain the accuracy of the height of the collar and the finished state of the end of the collar in a good condition. It was difficult to ensure the accuracy and performance of the device.

In order to manufacture a fin that solves the above problem, a conventional burring mold apparatus is disclosed in Japanese Patent Application Laid-Open No. 1-254327, which is a partial sectional view of FIG. An upper die set 2, a punch plate 3, and a forming die 4 that are positioned and fixed on the ram side of the press that constitutes 1 are provided in an overlapping manner. A knockout collar 7 urged to be pushed downward by a spring 6 provided in the through hole 5 is provided at a portion of the forming die 4 below the provided through hole 5, and a lower end surface 8 of the knockout collar 7. A punching punch 11 slidably inserted in a state substantially flush with the lower surface 9 of the through hole 4 and urged upward by a spring 10 provided in the through hole 5 so as not to drop. It provided slidably to 5 and the center hole 12 of the knock-out collar 7 penetrates. Note that 13
Is a bolt for fixing the punch plate 3 to the upper die set 2, and 14 is a bolt for fixing the forming die 4 to the punch plate 3.

[0005] The lower die 15 is formed by a pressing plate 16 for retaining a forming punch, a punch plate 17 for detachably positioning and holding a forming punch, and a lower die set 18 for positioning and fixing the bolster side of the press. The base of the forming punch 20 is positioned and held in a through hole 19 provided through the holding plate 16 for retaining the forming punch and the punch plate 17 so as to be prevented from falling off. The forming punch 20 has a punching hole 21 in the axis thereof, a round portion 22 at a corner of the tip protruding from the lower mold 15, and an outer diameter gradually decreasing toward the tip of the tip outer periphery. A portion 23 is formed, and the maximum outer diameter portion of the introduction portion 23 can pass through the through hole 5 of the forming die 4. Reference numeral 24 denotes a bolt for fixing the retaining plate 16 for retaining the forming punch to the punch plate 17;
Reference numeral 5 denotes a bolt for fixing the punch plate 17 to the lower die set 18.

[0006] Between the upper die 1 and the lower die 15, a forming punch 2 is provided.
A through hole 26 through which a maximum outer diameter of 0 is allowed to pass is provided, and a stripper plate 28 on which a metal plate 27 such as an aluminum plate to be subjected to burring is mounted is provided with a suspension bolt provided on the lower die set 18. It is locked and positioned at 29,
The lower mold 15 is urged by the spring 30 in the direction of the upper mold 1.
And at a predetermined distance from each other.

Reference numeral 31 denotes a cylindrical collar of the metal plate 27 when burring is performed by the above-configured die apparatus.

[0008] The burring mold apparatus having the above-described structure,
In order to form the cylindrical collar 31 by performing burring on the metal plate 27 placed on the stripper plate 28, first, in the burring process diagram of FIG.
As shown in (A), when the upper die 1 is lowered, the lower end surface 8 of the knockout collar 7 and the lower surface 9 of the forming die 4 approach the metal plate 27 which is placed on the stripper plate 28 and is subjected to burring. I do.

Next, as shown in (B), when the lowering of the upper die 1 further proceeds, the lower end surface 8 of the knockout collar 7 and the lower surface 9 of the forming die 4 come into contact with the metal plate 27, and the forming die 4 The lower surface 9 of the spring 3 holds the metal plate 27
0 pushes the stripper plate 28 urged in the direction of the upper mold 1 downward, while the tip of the introduction portion 23 of the forming punch 20 whose base is fixed to the lower mold 15 is urged downward by the spring 6. Knockout color 7
The metal plate 27 relatively projects from the through hole 26 of the stripper plate 28 to the upper surface while sandwiching the metal plate 27 with the lower end surface 8 of the metal die 27, and enters the through hole 5 of the forming die 4. At this time, the portion of the metal plate 27 sandwiched between the lower surface 9 of the forming die 4 and the stripper plate 28, the lower end surface 8 of the knockout collar 7, and the portion sandwiched by the tip of the introduction portion 23 of the forming punch 20. Is formed in the intermediate portion of the preform.

Next, as shown in FIG. 2C, when the upper die 1 further descends, the tip of the introduction portion 23 of the forming punch 20 penetrates deeper into the through hole 5 of the forming die 4. hand,
The lower end surface 8 of the knockout collar 7 is pushed up through the metal plate 27 to further advance the overhanging portion 32 of the metal plate 27, and at the same time, is slidably provided through the center hole 12 of the knockout collar 7. The punching punch 11 has a shape protruding relatively from the knockout collar 7, and the leading end of the punching punch 11 and the forming punch 2.
0, the metal plate 27 is formed by the corner of the entrance of the punched hole 21.
Is punched out to form a hole.

[0011] Next, as shown in (D) and (E), when the lowering of the upper die 1 further proceeds, the introduction portion 2 of the forming punch 20 is moved.
The burring and the ironing of the overhanging portion 32 of the metal plate 27 progress between the hole 3 and the through hole 5 of the forming die 4 through which the maximum outer diameter portion of the introduction portion 23 penetrates.

When the lowering of the upper die 1 proceeds to the final position as shown in FIG. 2F, the overhanging portion 32 of the metal plate 27 is formed between the forming punch 20 and the through hole 5 of the forming die 4.
Is molded into the final cylindrical collar.

However, when burring is performed by the above-described conventional mold apparatus, as shown in FIG. 6B, when the overhanging portion 32 is preformed on the metal plate 27, 4 while the metal plate 27 is sandwiched between the lower surface 9 and the stripper plate 28, the metal plate 27 is simultaneously sandwiched between the lower end surface 8 of the knockout collar 7 and the tip of the introduction portion 23 of the forming punch 20, In order to preform the formed portion 32 on the metal plate 27 with the forming die 4 by projecting the portion, the metal plate 27
The intermediate portion between the portion sandwiched between the lower surface 9 of the forming die 4 and the stripper plate 28 and the portion sandwiched between the lower end surface 8 of the knockout collar 7 and the leading end of the introduction portion 23 of the forming punch 20, that is, After the burring process is completed, since there is no flow due to the slip of the material in the target cylindrical collar, an extreme tensile load is applied to the portion, and the material is stretched. When the tensile load is concentrated near the above-mentioned two holding points of the metal plate 27, the thickness of the metal plate 27 becomes extremely thin, and when the collar 31 is ironed and burred from the metal plate 27, the color cross-sectional view of FIG. As shown in (A) of FIG.
Or, as shown in (B), the height of the collar 31 becomes uneven on its circumference, or as shown in (C),
There was a defect that a crack 34 entered the top of the collar 31.

[0014]

As described above, when burring is performed using a conventional mold apparatus, during preforming, the metal plate is stretched and formed on the metal plate while being sandwiched between the knockout collar and the forming punch. Therefore, a concentrated tensile load is applied to the overhanging portion, and the preforming does not have a uniform thickness.
It also affected the height, etc., resulting in an uneven color.

The present invention solves the above-mentioned problems. In the preforming of a metal plate, a uniform thickness is obtained without applying an intensive tensile load, and a final color is increased and a uniform thickness is obtained. It is an object of the present invention to provide a burring forming method and a mold apparatus that can be formed into a burring.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a slidable knock-out collar in a forming die fixed to an upper die, and a molding punch fixed to a lower die. The tip contacts the metal plate placed on the stripper plate through the through hole of the stripper plate between the upper mold and the lower mold, preforms the overhanging part, and then can slide into the knockout collar The top of the overhanging portion is punched by a punch and a forming punch provided in the punching device. Thereafter, the tip of the forming punch contacts the lower end of the knockout collar and enters the forming die. In the burring forming method of forming the bulging portion by color, the metal plate is slid before the tip of the forming punch comes into contact with the lower end of the knockout collar. This is a burring molding method in which a piercing part is preformed by pressing a forming punch in a state where the lower end of a knockout collar is not in contact with a portion of a metal plate to be subjected to burring while being sandwiched between a ripper plate and a forming die. An intensive tensile load is not applied to the overhang-formed portion, a uniform wall thickness can be obtained, and the final collar can be formed with a high and uniform wall thickness.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that a knockout collar is slidably provided in a forming die fixed to an upper die, and a tip of a forming punch fixed to a lower die is the same as above. It comes into contact with the metal plate placed on the stripper plate through the through hole of the stripper plate between the upper die and the lower die, preforms the overhanging part, and then is slidably provided in the knockout collar The top of the overhang forming part is punched out with a punching punch and a forming punch, and then the leading end of the forming punch contacts the lower end of the knockout collar and enters the forming die, and between the forming die and the forming punch. In the burring forming method for forming the bulging portion by color, the metal plate is stripper pressed before the tip of the forming punch comes into contact with the lower end of the knockout collar. This is a burring forming method in which a forming punch is pressed in a state where the lower end of the knockout collar does not contact the portion of the metal plate to be subjected to the burring process, and the overhanging portion is preformed. Since the forming part is preformed by pressing the forming punch in the state where the lower end of the knockout collar does not contact the part to be processed, a flow due to the slipping of the material occurs in the forming part, and the sufficient thickness It has the effect of being obtained.

According to a second aspect of the present invention, there is provided a stripper in which a knockout collar is slidably provided in a forming die fixed to an upper die, and a tip of the lower die is provided between the upper die and the lower die. A forming punch that contacts the metal plate placed on the stripper plate through the through hole of the plate is provided, and the punching punch that punches out the top of the overformed portion of the preformed metal plate at the tip of the forming punch is knocked out In a burring mold apparatus for slidably provided in a collar and punching the top part after punching out the top part, the tip of the forming punch is pressed against a metal plate in a burring die apparatus for performing color forming between the forming die and the forming punch. When preforming the overhanging part, a recess is provided in the lower end face of the knockout collar behind the metal plate to allow a gap between the tip of the forming punch and the lower end face of the knockout collar. This is a burring mold device that prevents the metal plate from being pinched.When the tip of the forming punch is pressed against the metal plate to preform the formed part, a recess is formed in the lower end surface of the knockout collar behind the metal plate. To prevent the metal plate from being pinched between the tip of the forming punch and the lower end surface of the knockout collar. Having.

According to a third aspect of the present invention, there is provided a stripper in which a knockout collar is slidably provided in a molding die fixed to an upper die, and a tip of the lower die is provided between the upper die and the lower die. A forming punch that contacts the metal plate placed on the stripper plate through the through hole of the plate is provided, and the punching punch that punches the top of the overmolded part of the preformed metal plate at the tip of the forming punch is knocked out In a burring mold apparatus for slidably provided in a collar and punching the top part after punching out the top part, the tip of the forming punch is pressed against a metal plate in a burring die apparatus for performing color forming between the forming die and the forming punch. When preforming the overhanging part, the lower end surface of the knockout collar behind the metal plate does not protrude from the forming die, is inside the forming die, and This is a burring mold device that prevents the metal plate from being pinched between the lower end surface of the checkout collar and the back of the metal plate when the tip of the forming punch is pressed against the metal plate to preform the formed part. The lower end surface of a certain knockout collar does not protrude from the forming die, is inside the forming die, and prevents the metal plate from being pinched between the tip of the forming punch and the lower end surface of the knockout collar. Has an effect that a flow due to slippage of the material occurs and a sufficient thickness is obtained.

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

(Embodiment 1) FIG. 1 is a partial cross-sectional view of a burring die apparatus according to Embodiment 1 of the present invention. The difference from FIG. The lower end surface 8 of the knockout collar 7 slidably inserted into the through-hole 5 of the molding die 4 is substantially flush with the lower surface 9 of the molding die 4, whereas in FIG. Since the concave portion 35 is formed in the lower end surface 8 of the collar 7, when the tip of the forming punch 20 is pressed against the metal plate 27 to preform the formed portion 32, the knockout collar 7 behind the metal plate 27 is formed. The metal plate 27 is not pinched between the lower end surface 8 of the metal mold and the tip of the forming punch 20. Other points are the same as those in FIG. .

In order to form a cylindrical collar by performing burring on the metal plate 27 placed on the stripper plate 28 by the burring mold apparatus in the first embodiment, the burring process shown in FIG. In the process diagram,
First, as shown in (A), when the upper mold 1 is lowered, the lower end face 8 of the knockout collar 7 and the lower face 9 of the forming die 4 are moved.
Approaches the metal plate 27 placed on the stripper plate 28 and subjected to burring.

Next, as shown in (B), when the upper die 1 further descends, the lower surface 9 of the forming die 4 contacts the metal plate 27, and while pressing the metal plate 27, the upper die is pressed by the spring. The pusher 23 pushes the stripper plate 28 urged in the direction 1 downward, while the leading end of the introduction portion 23 of the forming punch 20 having the base fixed to the lower die 15 is relatively abutted against the metal plate 27. By projecting from the through hole 26 of the stripper plate 28 to the upper surface and entering the through hole 5 of the forming die 4, the overhanging portion 32 is preformed on the metal plate 27.

At this time, the concave portion 35 is formed in the lower end surface 8 of the knockout collar 7 behind the portion of the metal plate 27 where the leading end of the introduction portion 23 of the forming punch 20 contacts.
The metal plate 27 is not sandwiched between the tip of the introduction portion 23 of the forming punch 20 and the lower end surface 8 of the knockout collar 7.

The steps after the preforming are the same as those of the conventional example shown in FIGS.
The description is omitted because it is the same as (E) and (F).

As described above, in the preforming in the first embodiment, the overhanging portion 32 is formed without pressing the metal plate 27 by merely pressing the tip of the forming punch 20 against the metal plate 27. The flow due to the slip of the material is generated in the molded portion 32, and a sufficient thickness is obtained.

(Embodiment 2) FIG. 3 is a process chart of a burring process when a metal plate is burred to form a cylindrical collar based on a burring die apparatus according to a second embodiment of the present invention. The burring mold device according to the second embodiment is different from the burring mold device according to the first embodiment in that the burring mold device according to the first embodiment is formed on the metal plate 27 by overhanging the forming part 32.
In order to prevent the metal plate 27 from being pinched between the distal end portion of the introduction portion 23 of the forming punch 20 and the lower end surface 8 of the knockout collar 7 at the time of preliminary molding, a concave portion is formed in the lower end surface 8 of the knockout collar 7. While 35 was formed,
In the burring mold apparatus according to the second embodiment, the lower end surface 8 of the knockout collar 7 does not project from the forming die 4 and is inside the through hole 5 when the overhang forming portion 32 is preformed on the metal plate 27. The other points are the same as those of the burring mold apparatus according to the first embodiment.

First, as shown in (A), when the upper die 1 is lowered, the lower surface 9 of the forming die 4 is moved to the stripper plate 2.
8 is a metal plate 2 to be subjected to burring processing placed on
Approach 7.

Next, as shown in (B), as the upper die 1 further descends, the lower surface 9 of the forming die 4 contacts the metal plate 27 and while pressing the metal plate 27, the upper die is pressed by a spring. The pusher 23 pushes the stripper plate 28 urged in the direction 1 downward, while the leading end of the introduction portion 23 of the forming punch 20 having the base fixed to the lower die 15 is relatively abutted against the metal plate 27. By projecting from the through hole 26 of the stripper plate 28 to the upper surface and entering the through hole 5 of the forming die 4, the overhanging portion 32 is preformed on the metal plate 27.

At this time, the portion of the metal plate 27 with which the leading end of the introduction portion 23 of the forming punch 20 abuts is inside the through hole 5 without the lower end surface 8 of the knockout collar 7 behind projecting from the forming die 4. Therefore, a concave portion 36 is formed therein, and the metal plate 27 is not sandwiched between the distal end portion of the introduction portion 23 of the forming punch 20 and the lower end surface 8 of the knockout collar 7.

The steps after the preforming are the same as those of the conventional burring process shown in FIG.
The description is omitted because it is the same as (F).

As described above, in the preforming according to the second embodiment, the overhanging portion 32 is formed without pressing the metal plate 27 by merely pressing the tip of the forming punch 20 against the metal plate 27. The flow due to the slip of the material is generated in the molded portion 32, and a sufficient thickness is obtained.

As shown in the cross-sectional view of the collar of FIG. 4, the collar shape of the metal plate 27 obtained in the first and second embodiments has a large thickness at the time of preforming before forming the final collar. Since the overhanging molded portion 32 is obtained, the height of the collar 31 can be increased, and a uniform color can be obtained.

[0034]

As described above, according to the burring forming method and the die apparatus of the present invention, when the overhanging portion is preformed on the metal plate, a concentrated tensile load is applied to the overhanging portion. In addition, since a uniform thickness can be obtained, a metal plate having a high and uniform thickness can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a burring die apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a process diagram in a case where burring is performed on a metal plate by the burring die apparatus according to the first embodiment shown in FIG. 1;

FIG. 3 is a process diagram in a case where burring is performed on a metal plate by a burring mold apparatus according to Embodiment 2 of the present invention.

FIG. 4 is a cross-sectional view of a collar obtained by performing a burring process on a metal plate using the burring mold apparatus according to the first and second embodiments.

FIG. 5 is a partial sectional view of a conventional burring mold apparatus.

FIG. 6 is a process diagram when burring is performed on a metal plate by the conventional burring mold apparatus shown in FIG. 5;

FIG. 7 is a cross-sectional view of a collar obtained by performing burring processing on a metal plate using a conventional burring mold apparatus.

[Explanation of symbols]

 Reference Signs List 1 upper die 2 upper die set 3,17 punch plate 4 forming die 5,19,26 through hole 6,10,30 spring 7 knockout collar 8 lower end surface 9 lower surface 11 punching punch 12 center hole 13,14,24,25, 29 Bolt 15 Lower die 16 Pressing plate for retaining forming punch 18 Lower die set 20 Molding punch 21 Punching hole 22 Round part 23 Introducing part 27 Metal plate 28 Stripper plate 31 Collar 32 Overhang forming part 33 Break 34 Crack 35, 36 Recess

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akihito Kikuchi 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Term (reference) 4E048 EA02 4E050 DA07 DA08

Claims (3)

[Claims] A knockout collar is slidably provided in a forming die fixed to an upper die, and a tip of a forming punch fixed to a lower die is provided with a through hole of a stripper plate between the upper die and the lower die. The metal sheet placed on the stripper plate abuts on the stripper plate to preform the overhanging portion, and then the punching and forming punches slidably provided in the knockout collar are used to hold the overhanging portion at the top. Punching the part, after that, the tip of the forming punch abuts the lower end of the knockout collar, enters the forming die, and forms a burring between the forming die and the forming punch in a color forming method of burring. Before the tip of the forming punch abuts the lower end of the knockout collar, hold the metal plate between the stripper plate and the forming die, and A method of forming a burring in which a forming punch is pressed in a state where the lower end of a knockout collar does not come into contact with a portion to be processed, and a bulging portion is preformed. 2. A knockout collar is slidably provided in a molding die fixed to an upper die, and a tip of the lower die is passed through a through hole of the stripper plate between the upper die and the lower die. A punch is provided slidably in the knockout collar to punch a top portion of a bulging portion of the preformed metal plate at the tip of the forming punch. In the burring die apparatus for performing color molding between the forming die and the forming punch, the overhang forming section after punching the portion is used to press the tip of the forming punch and preform the overhang forming section on the metal plate. A recess is provided in the lower end surface of the knockout collar behind the metal plate to prevent the metal plate from being pinched between the tip of the forming punch and the lower end surface of the knockout collar. Ring mold equipment. 3. A knockout collar is slidably provided in a molding die fixed to an upper mold, and a tip of the lower mold passes through a through hole of the stripper plate between the upper mold and the lower mold. A punch is provided slidably in the knockout collar to punch a top portion of a bulging portion of the preformed metal plate at the tip of the forming punch. In the burring die apparatus for performing color molding between the forming die and the forming punch, the overhang forming section after punching the portion is used to press the tip of the forming punch and preform the overhang forming section on the metal plate. The lower end surface of the knockout collar behind the metal plate does not protrude from the forming die, and is inside the forming die, between the tip of the forming punch and the lower end surface of the knockout collar. A burring mold device that does not pinch a metal plate.