JP4458603B2 - Mold and mold manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold such as a press mold for bending a blank material into a desired shape or a trimming mold for drawing a blank material and cutting the periphery thereof, and a method for manufacturing such a mold.
[0002]
[Prior art]
The body of an automobile can be obtained by press molding, drawing or trimming a blank material. A mold for performing such molding is generally made of cast iron or cast steel and has high rigidity and can withstand hundreds of thousands of shots. However, the cost for manufacturing the mold increases.
[0003]
Therefore, as a mold suitable for high-mix low-volume production, a mold using a zinc alloy as a base material is disclosed in Japanese Patent Laid-Open Nos. 5-84591, 5-195121, and 5-208296. Yes.
[0004]
That is, Japanese Patent Laid-Open No. 5-84591 discloses that a zinc alloy containing magnesium and aluminum and having a Vickers hardness of 150 or more is build-up welded to a zinc alloy containing aluminum and copper.
Japanese Laid-Open Patent Publication No. 5-195121 proposes a zinc alloy for press dies in which aluminum is 9.5 to 30 wt%, copper is 6.0 to 20 wt%, magnesium is 0.01 to 0.2 wt%, and the balance is zinc. Has been.
Japanese Patent Laid-Open No. 5-208296 proposes the use of a zinc alloy as a base material for a plastic mold, and an aluminum alloy containing Si or the like as a filler material for repairing the mold.
[0005]
The zinc alloy is excellent in workability and the like, but is soft, so that a dissimilar metal must be provided in a specific part in order to provide a cutting blade or the like. Although plating, vapor deposition, sputtering, etc. can be considered as this means, the thickness of the formed dissimilar metal film is thin and inferior in durability, which is disadvantageous in terms of cost.
[0006]
In addition, as disclosed in Japanese Patent No. 2838657, a groove is formed at the edge of the mold, and build-up welding is performed on the groove using a high-hardness filler metal, and thereafter a grinder is used. Means for grinding are also conceivable. However, only Cu-based or Zn-based materials can be directly welded to the zinc alloy. On the other hand, there is no Cu-based or Zn-based material that has sufficient hardness to be used as a cutting blade or the like. Therefore, in parallel with the present application, the present applicant divides overlay welding into a lower overlay and an upper overlay, and uses a copper-based material that can be welded to a zinc alloy as a filler material for the overlay, A proposal has been made to use a nickel-based material that has sufficient hardness as a filler material and can be welded to a copper-based material (underlay).
[0007]
[Problems to be solved by the invention]
FIG. 5 (a) shows the shape of a groove shown in Japanese Patent No. 2838657, and FIG. 5 (b) shows the shape of a conventional groove.
In the case of these conventional groove shapes, as shown in FIG. 6 (a), when forming a bottom 101 on a base material groove 100 and forming a top 102 thereon, the width of the bottom 101 is formed. Is not sufficient, the top 102 is likely to contact the base material. And if it contacts, a sputter | spatter will fly to the site | part and will become poor welding.
[0008]
Further, a large amount of gas is generated when the upper scale 102 is formed. However, if the width of the lower scale 101 is not sufficient, there is no escape space for the gas, and this gas is entrained to form a blow hole.
[0009]
Note that if the groove 100 itself is made large, gas can be discharged through the bottom, but as shown in FIG. 6 (b), the top 102 is the base material at the center of the groove 100. Sputtering occurs on contact with. In order to prevent this, it is necessary to perform a number of underlay weldings on the groove 100, which increases the cost of welding and makes post-processing by a grinder after welding difficult.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the mold according to the present invention comprises an upper mold and a lower mold using an aluminum / copper-based zinc alloy as a base material, and a metal is formed in the groove formed at the edge portion of the upper mold and the lower mold. A hardened portion such as a cutting blade is formed by prime welding, and the shape of the groove further includes a chamfered portion and an extension portion, and the buildup welding is underlay welding made of a copper-based material covering the entire groove. And overlay welding made of a nickel-based material formed on the bottom body welding without contact with the mold body.
[0011]
Copper-based materials can be welded to both zinc alloys and nickel-based materials, and copper-based materials are used as a base, and nickel-based materials are used on top of this base to provide high-hardness meat. It becomes possible to perform serving. And especially a thing without a welding defect, such as a blow hole, is obtained by making it the shape provided with the chamfering part and the extension part as a shape of a groove | channel.
[0012]
Examples of the copper-based material that can be welded to the zinc alloy include pure copper, aluminum bronze, silicon bronze, etc., but silicon bronze is most preferable in terms of weldability. The specific component ratio of silicon bronze is 1.0 to 8.0 wt% for Si (silicon), 0.3 to 4.0 wt% for Mn (manganese), 0.03 to 4.5 wt% for Pb (lead), and Al (aluminum). Is 0.03 to 11.0 wt%, Ni (nickel) is 0.03 to 7.0 wt%, Fe (iron) is 0.03 to 6.0 wt%, and Cu (copper) is the balance.
[0013]
Si (silicon) is an element necessary for deoxidation, and at the same time is an element for increasing hardness. If Si is less than 1.0 wt%, blowholes are likely to occur due to insufficient deoxidation, and if it exceeds 8.0 wt%, many phases are precipitated and embrittled instead of a single phase structure.
Mn (manganese) is an element necessary for deoxidation and desulfurization. If Mn is less than 0.3 wt%, the effect of addition does not appear, and even if it exceeds 4.0 wt%, no further effect is obtained.
Pb (lead) is a cutting improving element. If Pb is less than 0.03 wt%, there is almost no effect of addition, and if it exceeds 4.5 wt%, it becomes excessive and weld cracks are likely to occur.
Al (aluminum) is a colorant, and when Al increases, it changes from copper red to golden, and is also a hardness increasing element. When Al is less than 0.03 wt%, there is almost no effect of addition, and when it exceeds 11.0 wt%, both the hardness elongation decreases.
Ni (nickel) is an element effective for increasing the hardness. If Ni is less than 0.03 wt%, there is almost no effect of addition, and if it exceeds 7.0 wt%, it becomes excessive and the hardness decreases.
Fe (iron) is an element that refines crystal grains and increases hardness. When Fe is less than 0.03 wt%, there is almost no effect of addition, and even if it exceeds 6.0 wt%, it becomes excessive and has no effect of addition.
[0014]
In addition, specific component ratios of the nickel-based material as the overlay are 1.0 to 6.0 wt% for B (boron), 5.0 to 20.0 wt% for Cr (chromium), and 1.0 to 7.0 wt% for Si (silicon). Fe (iron) is preferably 0.03 to 4.0 wt%, Cu (copper) is 0.5 to 6.0 wt%, and Ni (nickel) is the balance.
[0015]
B (boron) is an element that refines crystal grains and increases hardness. If B is less than 1.0 wt%, the effect of addition is extremely small, and if it exceeds 6.0 wt%, it becomes excessive and weld cracking tends to occur.
Cr (chromium) is an element that increases hardness and improves oxidation resistance at high temperatures. If Cr is less than 5.0 wt%, the effect of addition is small, and if it exceeds 20.0 wt%, it becomes excessive and the workability decreases.
Si (silicon) is a deacidifying element and is an element that improves the flow of hot water. If Si is less than 1.0 wt%, the effect of addition to the molten metal flow is small, and if it exceeds 7.0 wt%, it becomes excessive and weld cracking tends to occur.
Fe (iron) is an element that refines crystal grains and increases hardness. When Fe is less than 0.03 wt%, there is almost no effect of addition, and even if it exceeds 4.0 wt%, it becomes excessive and there is no effect of addition.
Cu (copper) is an element effective for improving toughness. If Cu is less than 0.5 wt%, there is almost no effect of addition, and if it exceeds 6.0 wt%, it becomes excessive and the toughness is lowered and weld cracking is likely to occur.
[0016]
On the other hand, in the mold manufacturing method according to the present invention, a groove composed of a chamfered portion and an extended portion is formed on the edge portion of a mold using an aluminum / copper-based zinc alloy as a base material, and then the extended portion is formed on the upper surface. In this way, the entire groove is welded using a copper-based filler metal, and then the upper part is welded using a nickel-based filler material on the lower weld so as not to contact the mold body. In addition to performing welding, this overlay welding is performed while discharging gas through the overlay welding formed on the extension of the groove.
In this manner, by performing the overlay welding while discharging the gas through the overlay welding, it is possible to suppress the occurrence of blowholes.
[0017]
Moreover, as said copper-type filler material, what consists of silicon bronze is preferable, As a component ratio of this silicon bronze, Si (silicon) is 1.0-8.0 wt%, Mn (manganese) is 0.3-4.0 wt%, Pb (lead) is 0.03 to 4.5 wt%, Al (aluminum) is 0.03 to 11.0 wt%, Ni (nickel) is 0.03 to 7.0 wt%, Fe (iron) is 0.03 to 6.0 wt%, and Cu (copper) is the balance The above is preferable as described above.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1A and 1B are diagrams illustrating before and after cutting of a trimming mold apparatus to which the present invention is applied, and FIGS. 2A to 2D illustrate a process of forming a cutting blade of the trimming mold. FIG.
[0019]
The trimming mold apparatus includes an upper mold 1 and a lower mold 2, and the upper mold 1 has an upper end attached to a lift plate 3, and the lower mold 2 is fixed on a base plate 4. A presser pad 5 is supported in the upper mold 1 so as to be movable up and down, and a spring 6 is disposed between the presser pad 5 and the lift plate 3.
[0020]
The presser pad 5 is formed with a concave portion 5a for molding, and the lower mold 2 is formed with a convex portion 2a on which the workpiece W is placed. A cutting blade 7 is provided on the inner peripheral portion of the lower end of the upper die 1, and a cutting blade 8 is provided on the outer peripheral portion of the upper die 2.
[0021]
Thus, as shown in FIG. 1A, after placing the workpiece W on the convex portion 2 a of the lower mold 2, the upper mold 1 and the press pad 5 are lowered together with the lifting plate 3. Then, the lower end of the presser pad 5 protrudes slightly below the lower end of the upper mold 1, and the work pad W presses the periphery of the work W against the upper end outer peripheral portion of the lower mold 2. By further lowering the upper die 1 from this state, the peripheral edge of the workpiece W is cut by the cutting blades 7 and 8 as shown in FIG.
[0022]
Next, a method for forming a cutting blade will be described with reference to FIG. In addition, since both the cutting blades 7 and 8 are formed in the same manner, only the cutting blade 8 of the lower mold 2 will be described.
First, as shown in FIG. 2 (a), a groove 10 is formed on the outer periphery of the upper end of the lower mold 2 by a grinder, an NC machine tool or the like. The groove 10 includes a chamfered portion 10a and an extended portion 10b. The chamfered portion 10a has a length of, for example, 5 mm, the extended portion 10b has a length of 8 mm, and a depth of about 0.5 mm. The chamfered portion 10a may be either C chamfered or R chamfered.
[0023]
Next, the lower die 2 is preheated to prepare for underlay welding described later. The preheating temperature is a maximum of 200 ° C. In addition, the preheating method may heat the entire lower die 2, but only a portion along the groove 10 may be locally heated with a burner or the like.
[0024]
Thereafter, the oxide film is scraped off along the groove 10 by a grinder or an NC machine tool, and then a scale 11 is formed on the groove 10 by TIG welding as shown in FIG. . The conditions of underlay welding are helium or argon as the shielding gas, AC TIG welding of 120 to 150 AMP, and a copper alloy as a filler material for underlay welding. In this example, a copper alloy having Mn (manganese) 0.84 wt%, Si (silicon) 3.7 wt%, and the balance being Cu (copper) was used.
[0025]
Here, by using AC TIG welding, a cleaning action for removing the oxide film works, and as shown in FIGS. 3A and 3B, it is possible to shallowly melt the base metal. And by making the penetration into the base material shallow, it is possible to prevent the zinc alloy component constituting the base material from being rolled up to the surface of the underlay or near the surface. Incidentally, when the zinc alloy component is rolled up during the overlay, spatter is generated during the overlay welding described later.
[0026]
The copper-based material is not limited to the above-mentioned composition, but the above-described ranges, that is, Si (silicon) is 1.0 to 8.0 wt%, Mn (manganese) is 0.3 to 4.0 wt%, and Pb (lead) is 0.03 to 4.5. Preferably, wt%, Al (aluminum) is 0.03 to 11.0 wt%, Ni (nickel) is 0.03 to 7.0 wt%, Fe (iron) is 0.03 to 6.0 wt%, and Cu (copper) is the balance.
[0027]
If the scale 11 is formed so as to cover the chamfered portion 10a and the extended portion 10b of the groove 10 by the above procedure, the thickness of the scale 11 is adjusted to about 2 mm with a grinder or an NC machine tool.
[0028]
Next, at least the bottom 11 and its peripheral edge are heated to a maximum of 250 ° C. in the same manner as described above, and after removing the oxide film again using a grinder, TIG welding is performed on the bottom 11 as shown in FIG. A top 12 is formed at The upper scale 12 is formed so as not to contact the base material.
[0029]
Further, since the bottom 11 is formed up to the extension 10b and the top 12 is not formed up to the extension 10b, only the bottom 11 is formed on the extension 10b. It is close to the molten state due to the heat of overlay welding. On the other hand, gas is generated during overlay welding. Conventionally, there is no escape place for this gas. However, in the present invention, since the extension portion 10b is provided, the gas generated during the overlay welding is discharged from the extension portion 10b to the outside through the bottom overlay 11. .
[0030]
The conditions for the overlay welding are helium or argon as the shield gas, 130 AMP DC TIG welding, and nickel alloy as the filler material for overlay welding. In this embodiment, a nickel alloy having B (boron) 2.3 wt%, Si 3.2 wt%, and the balance Ni (nickel) was used.
[0031]
The nickel alloy is not limited to the above composition, but the above-described ranges, that is, B (boron) is 1.0 to 6.0 wt%, Cr (chromium) is 5.0 to 20.0 wt%, and Si (silicon) is 1.0 to 7.0 wt%. %, Fe (iron) is 0.03 to 4.0 wt%, Cu (copper) is 0.5 to 6.0 wt%, and Ni (nickel) is the balance.
[0032]
Here, since the overlay welding is DC TIG welding, as shown in FIGS. 3A and 3C, the penetration into the bottom 11 of the overlay 12 can be deepened, and the peel strength of the blade edge can be increased. Can be increased.
[0033]
After forming the upper scale 12, the cutting blade 8 is obtained as shown in FIG. 2D by processing with a grinder, NC machine tool, or the like. The cutting blade 8 was able to perform trimming molding of tens of thousands of shots.
[0034]
FIG. 4 is a cross-sectional view showing another embodiment of the groove shape. In this embodiment, not only the extended portion 10b along the upper surface portion but also the extended portion 10c along the standing wall is provided. Thus, the peeling strength of a cutting blade further improves by providing an extension part on both sides on both sides of the chamfered part 10a.
[0035]
In the illustrated example, the trimming mold apparatus has been described. However, the present invention can also be applied to a press mold, and the present invention can be applied to a portion requiring hardness other than the cutting blade.
[0036]
【The invention's effect】
As described above, according to the present invention, the shape of the groove for build-up welding a cutting blade or the like is a shape having a chamfered portion and an extended portion, so that the mold base material is a zinc alloy, and Even if the build-up is made of a copper-based material and a nickel-based material, the gas generated during the build-up welding can be discharged through the build-up, so that welding such as blow holes is possible. It is possible to form a cutting blade or the like that hardly causes defects and has excellent peel strength by overlay welding.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams illustrating before and after cutting of a trimming mold apparatus to which the present invention is applied.
FIGS. 2A to 2D are enlarged views of main parts illustrating a process of forming a cutting blade of the trimming mold.
FIGS. 3A and 3B are photographs (1 ×) showing the metal structure of the cutting blade, FIG. 3B is an enlarged (100 ×) portion B of FIG. 3A, and FIG. The photograph which expanded C part (100 times).
FIG. 4 is a cross-sectional view showing another embodiment of a groove shape.
FIGS. 5A and 5B are views showing the shape of a conventional groove. FIG.
FIGS. 6A and 6B are diagrams pointing out conventional problems.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Upper mold | type, 2 ... Lower mold | type, 2a ... Convex part, 3 ... Elevating plate, 4 ... Base plate, 5 ... Pressing pad, 5a ... Recessed part, 6 ... Spring, 7, 8 ... Cutting blade, 10 ... Groove, 10a ... chamfered portion, 10b, 10c ... extended portion, 11 ... bottom pile, 12 ... top pile

Claims (2)

It consists of an upper die and a lower die made of an aluminum / copper zinc alloy as a base material, and a hardened portion such as a cutting blade is formed by build-up welding on the groove formed in the edge portion of the upper die and the lower die. In the mold, the shape of the groove includes a chamfered portion and a flat extension portion connected to the chamfered portion, the chamfered portion and the extension portion of the groove are covered with a lower welded portion, and the overlay welding is opened. Si (silicon) covering the entire tip is 1.0 to 8.0 wt%, Mn (manganese) is 0.3 to 4.0 wt%, Pb (lead) is 0.03 to 4.5 wt%, Al (aluminum) 0.03 to 11.0 wt%, Ni (nickel) 0.03 to 7.0 wt%, Fe (iron) 0.03 to 6.0 wt%, and Cu (copper) as the balance shape on the lower layer welding portion except a lower prime weld the formed on the extended portion the lower prime welds above comprising B (boron) is 1.0 wt%, Cr (chromium) is 5.0-20.0 wt%, Si (silicon) is 1.0-7.0 wt%, Fe (iron) is 0.03-4 .0wt%, Cu (copper) 0.5~6.0wt%, mold, characterized in that it is composed of the upper overlay clad part made of a nickel-based material with the remainder of Ni (nickel). A groove consisting of a chamfered part and a flat extension connected to the chamfered part is formed at the edge part of a mold made of aluminum / copper zinc alloy as a base material, and then opened so that the extension part becomes the upper surface. Si (silicon) 1.0-8.0 wt%, Mn (manganese) 0.3-4.0 wt%, Pb (lead) 0.03-4.5 wt%, Al (aluminum) Copper filler metal with 0.03 to 11.0 wt%, Ni (nickel) 0.03 to 7.0 wt%, Fe (iron) 0.03 to 6.0 wt%, and Cu (copper) as the balance Then, on the lower welded portion excluding the upper welded portion formed on the extension portion, B (boron) is 1.0 wt% and Cr (chromium) is 5%. 0.0-20.0 wt%, Si (silicon) 1.0-7.0 wt%, Fe (iron) 0.03-4.0 w %, Cu (copper) 0.5~6.0wt%, the production method of the mold, characterized in that applying on layer welding using a nickel-based filler metal to balance the Ni (nickel).

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