JP2002192243A - Coining method and its machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coining method which lessens process strain occurring at the circumference of a coining section 15 and can make the thickness of the coining section 15 constant. SOLUTION: The coining section 15 of a workpiece 16 is preliminarily coined to a thickness for preliminary coining. The preliminarily coined part of the workpiece 16 is re-crystallized to the initial state and the process strain due to the preliminary coining is eliminated. Then the coining section 15 of the workpiece 16 which has been preliminarily coined and from which the process strain has been eliminated is finally coined to a thickness for the final coining. This lessens the process strain occurring at the circumference of the coining section 15 and can make the thickness of the coining section 15 constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coining method for coining a workpiece and an apparatus therefor.

[0002]

2. Description of the Related Art For example, FIG. 2 shows a prismatic battery 11 such as a lithium battery. The prismatic battery 11 has a rectangular container 12 for accommodating a battery body through one end opening and a battery closing one end opening of the container 12 The battery lid 13 includes a leak valve 14, which is a so-called positive electrode valve, formed by a thin-walled coining portion 15.

[0003] As shown in FIG.
Is a substantially U-shaped groove so as to surround three sides of the leak valve 14,
The coining process is performed to a predetermined thickness t smaller than the thickness T of the plate material 16 of the battery lid 13, and the leak valve 14 can be opened by breaking the coining portion 15.

Conventionally, as shown in FIG. 4, in coining, a coining punch 22 having a punch portion 21 projecting in a substantially U-shape corresponding to the shape of the coining portion 15 and a die 23 are used as compression tools. The plate material 16 is sandwiched between the coining punch 22 and the die 23, and is pressed and compressed by a press machine to perform coining.

The width of the punch portion 21 of the coining punch 22 is substantially the same from the base end side to the tip end side.
Fifteen groove widths are formed to be substantially the same width from the groove opening side to the groove inner side.

[0006]

However, in the conventional coining process, one set of the coining punch 22 and the die
23, the thickness T of the plate 16 is compressed at a time to the thickness t of the coining part 15, so that a processing distortion is generated around the coining part 15 of the plate 16 and the influence of the processing distortion causes the coining part 15 to be deformed. There is a problem that the thickness of the sheet varies.

A pair of coining punch 22 and die 23
In order to compress the sheet thickness T of the sheet material 16 to the sheet thickness t of the coining portion 15 at a time, a large pressing force is required, the load on the coining punch 22 is large, the durability is poor, and the Requires a large press.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is intended to reduce machining distortion occurring around a coining portion, to make the plate thickness of the coining portion constant, and to improve coining accuracy. It is an object to provide a method and an apparatus thereof.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided a crystal in which a coining portion of a workpiece is pre-coined to a thickness of a pre-coining, and a crystal of a processed portion of the pre-coined workpiece is restored. The coining portion of the workpiece which has been subjected to the restoration process and the crystal restoration process is subjected to the main coining process to a thickness of the main coining thinner than the thickness of the preliminary coining.

The pre-coining process is performed by pre-coining the coining portion of the workpiece to the thickness of the pre-coining, and restoring the crystal of the pre-coined processed portion of the workpiece to the original. Since the processing distortion due to is removed, even from this stage, even if the coining part of the workpiece is subjected to this coining to the thickness of this coining, there is little processing distortion generated around the coining part,
The thickness of the coined portion becomes constant.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As the workpiece, a plate 16 of the battery lid 13 of the prismatic battery 11 shown in FIG. 2 is shown, and a coining portion 15 is coined on the plate 16.

Referring to FIG. 1, the coining apparatus includes a coining section 15 of a sheet material 16 and a sheet thickness t1 of a preliminary coining.
Pre-coining means 3 for pre-coining up to
1, a bright hydrogen processing means 32 for performing a bright hydrogen treatment as a crystal restoring processing means for performing a crystal restoring processing for restoring a crystal of a processed portion of the plate material 16 subjected to the preliminary coining processing, and The coining unit 15 includes a main coining unit 33 for performing a main coining process to a main coining plate thickness t smaller than the preliminary coining plate thickness.

The preliminary coining means 31 includes a base 35
And a coining punch 37 having a punch portion 36 protruding from the base portion 35 in a substantially U-shape corresponding to the shape of the coining portion 15, and a sheet material between the coining punch 37 and the coining punch 37.
A die 38 for sandwiching the plate 16 is used as a compression tool. The plate 16 is sandwiched between the coining punch 37 and the die 38, and is pressed and compressed by a press machine to perform preliminary coining.

The punch portion 36 of the coining punch 37 is formed in a tapered or trapezoidal shape having a tapered tip, and the width a of the tip is wider than the width b during the main coining process.

The bright hydrogen treatment means 32 uses, for example, a hydrogen furnace 40 and performs a heat treatment for annealing the plate material 16 pre-coined in the hydrogen furnace 40 at, for example, 1030 ° C. for 6 minutes, that is, a bright hydrogen treatment. The arrangement of the crystals of the plate material 16 is returned to the original crystal, and the processing strain is removed.

The coining means 33 includes a coining punch 44 having a base portion 42 and a punch portion 43 projecting from the base portion 42 in a substantially U-shape corresponding to the shape of the coining portion 15, and a coining punch 44. A die 45 for sandwiching the plate 16 between them is used as a compression tool. The plate 16 is sandwiched between the coining punch 44 and the die 45, and is pressed and compressed by a press machine to perform preliminary coining.

The punch portion 43 of the coining punch 44 is formed in a tapered or trapezoidal shape having a tapered tip, and the width b at the tip is smaller than the width a at the time of preliminary coining.

Next, a coining method will be described.

First, preliminary coining processing is performed. The plate 16 is positioned between the coining punch 37 and the die 38, and the punch portion 36 and the die 38 of the coining punch 37 are positioned.
The sheet material 16 is sandwiched between the two and is pressed and compressed by a press machine, and the coining portion 15 of the sheet material 16 is pre-coined to the pre-coining thickness t1.

The thickness t1 of the preliminary coining is appropriately set in the range of 1/2 to 1/4 according to the thickness T of the material of the plate material 16. For example, when the thickness T is 0.5 mm, The thickness t1 of coining is about 0.2 mm.

The pre-coined coining portion 15, that is, the pre-coining portion 15 a, has a tapered shape in which the groove inner side is tapered and the groove opening side is expanded in accordance with the shape of the punch portion 36 of the coining punch 37. A trapezoidal groove-shaped preliminary coining groove 17a is formed, and the width of the preliminary coining groove 17a on the inner side of the groove is formed to be the same as the width a of the punch portion 36.

Subsequently, a bright hydrogen treatment is performed on the plate material 16 which has been subjected to the preliminary coining process. The pre-coined plate 16 is placed in a hydrogen furnace 40, and subjected to a bright hydrogen treatment at, for example, 1030 ° C. for 6 minutes to return the arrangement of the crystals of the plate 16 to the original crystal, and the processing distortion generated around the coining portion 15 Get rid of.

Subsequently, the main coining of the plate material 16 which has been subjected to the bright hydrogen treatment is performed. The coining section 15 of the plate 16 is positioned and arranged between the coining punch 44 and the die 45, and the punching section 43 and the die 45 of the coining punch 44 are arranged.
The pre-coining portion 15a of the plate 16 is sandwiched between them, and is pressed and compressed by a press machine to perform the main coining of the coining portion 15 of the plate 16 to a thickness t of the main coining. The thickness t of the coining is about 0.03 mm.

The main coining section 15b which has been subjected to the main coining process is added to the preliminary coining section 15a of the coining section 15.
A preliminary coining groove 17b in the form of a taper, that is, a trapezoidal groove is formed in which the inner side of the groove is tapered in accordance with the shape of the punch portion 43 of the coining punch 44 and the groove opening side is expanded. The width at the back of the groove is the punch 4
3 and the same as the width b.

As described above, the coining portion 15 of the plate 16
Is subjected to preliminary coining to a thickness t1 of the preliminary coining, and a crystal restoration process for restoring the crystal of the processed portion of the preliminary coined plate 16 to remove the processing distortion due to the preliminary coining. Even if the coining section 15 of the present invention is subjected to the main coining to the sheet thickness t of the main coining, the processing distortion generated around the coining section 15 can be reduced, the sheet thickness t of the coining section 15 can be made constant, and the coining accuracy can be improved. Can be improved.

In addition, since the coining punch 44 having a width b smaller than the width a at the tip of the coining punch 37 used for the preliminary coining is used in the main coining, the processing distortion generated around the coining portion 15 in the main coining is reduced. Can be reduced.

The punching portions of the coining punches 37 and 44
Since the tips of the plates 36 and 43 are formed in a tapered shape with a tapered tip, the material of the plate 16 moves smoothly during the coining process, and the coining process can be easily performed with a small pressing force, and is applied to the coining punches 37 and 44. The load is small, and the life of the coining punches 37 and 44 can be maintained for a long time.

By dividing the pre-coining process and the main coining process, and by forming the punch portions 36 and 43 of the coining punches 37 and 44 into a tapered shape having a tapered tip, the required coining process is required. The pressure is small.

Further, the preliminary coining process is not limited to one time, and may be performed in a plurality of times. However, since the manufacturing process becomes complicated by increasing the number of times, it is necessary to simplify the manufacturing process. It may be times.

It should be noted that such coining is not limited to the lid 13 of the prismatic battery 11, but can be similarly applied to other coined products, and the same operation and effect can be obtained.

[0032]

According to the present invention, a crystal restoration process for pre-coining a coined portion of a workpiece to a pre-coining plate thickness and returning a crystal of a processed portion of the pre-coined workpiece to an original state. In order to remove the processing distortion due to the preliminary coining processing, even if the coining processing part of the workpiece is subjected to this coining processing to the thickness of this coining from this stage, the processing distortion occurring around the coining processing part can be reduced, The thickness of the coining portion can be made constant, and the coining accuracy can be improved.

[Brief description of the drawings]

1A and 1B show an embodiment of a coining method and an apparatus for coining according to the present invention, wherein FIG. 1A is an explanatory diagram for explaining preliminary coining by a preliminary coining device, and FIG. (C) is an explanatory view for explaining the main coining processing by the main coining processing means.

FIG. 2 is a perspective view of a prismatic battery subjected to coining.

FIGS. 3A and 3B show a conventional coining portion, wherein FIG. 3B is a plan view and FIG. 3C is a cross-sectional view.

FIG. 4 is an explanatory diagram illustrating coining processing by a conventional coining device.

[Explanation of symbols]

 15 Coining part 16 Plate material as workpiece 31 Preliminary coining means 32 Bright hydrogen processing means as crystal restoration processing means 33 Coining means 37,44 Coining punch

Continued on the front page (72) Inventor Kengo Yagi 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 4E087 CA17 5H011 AA09 CC06 DD00 DD03 DD26 KK01

Claims (8)

[Claims] 1. A pre-coining process is performed on a coined portion of a workpiece to a thickness of a pre-coined portion, a crystal restoration process is performed to restore a crystal of a processed portion of the pre-coined processed portion, and a crystal restoration process is performed. A coining method comprising: performing a main coining process on a coined portion of a workpiece to a thickness of a main coining thinner than a thickness of a preliminary coining. 2. The coining processing method according to claim 1, wherein the crystal restoration processing for restoring the crystal of the processed portion of the workpiece subjected to the preliminary coining processing is a bright hydrogen processing. 3. The coining method according to claim 1, wherein a coining punch having a width smaller than a width of a tip of the coining punch used for the preliminary coining is used for the main coining. 4. The coining method according to claim 1, wherein the coining process uses a tapered coining punch having a tapered tip. 5. A pre-coining means for pre-coining a coining portion of a workpiece to a thickness of the pre-coining, and a crystal restoring process for restoring a crystal of a pre-coined processed portion of the workpiece. Crystal restoration processing means, and the main coining processing means for performing the main coining processing on the coining processed portion of the workpiece subjected to the crystal restoration processing to a main coining sheet thickness smaller than the preliminary coining sheet thickness. Coining equipment. 6. The coining apparatus according to claim 5, wherein the crystal restoration processing means performs bright hydrogen processing. 7. The pre-coining processing means and the main coining processing means include a coining punch for performing coining, and the width of the tip of the coining punch of the main coining means is smaller than the width of the tip of the coining punch of the pre-coining processing means. The coining apparatus according to claim 4 or 5, wherein 8. The pre-coining means and the main coining means comprise a tapered coining punch whose tip is tapered.
The coining apparatus according to any of the above.