CN1219663C - Large gold coin with high figure relief and its mold making process - Google Patents

Abstract

The present invention relates to a making process for a large gold coin with high figure relief and a mold thereof, which comprises the procedures of rolling and polishing raw material blanks and then carrying out the primary impression treatment. The present invention is characterized in that after the primary impression processed blanks are turned annealed and polished, the secondary impression treatment and turning treatment are carried out in order to remove burs and polish the blanks to manufacture finished products. The molding technology is characterized in that the hot rolling forging procedure, the spheroidizing annealing procedure, the external shape rough machining procedure and the turning procedure are carried out on the blanks; an engraving machine is utilized to directly engrave out a die plate of intaglio characters; then the procedures of quenching, chromium plating and finish machining polishing treatment are carried out. Large gold coin which weighs 10kg and manufactured by the process is the largest gold coin in the current world.

Description

The manufacture craft of large gold coin with high figure relief

One, technical field: the present invention relates to the preparation section of mould in the coinage technology, particularly the manufacture craft of all extraordinary large gold coin of single piece of quality and specification.

Two, background technology: the 10KG large gold coin is the big coin of present the first in the world.Owing to the diameter of single piece of quality and finished product is all very big, and require two-sided high embossed pattern, this makes processing technology in the past to be suitable for.For example, generally speaking, the radius-thickness ratio of base cake is D/H=14-16, and the ratio of figure line height and base cake thickness is 11%, but be defined as the ultra-large type coin of 2mm for figure line height, must determine base cake specification as fundamental relation this moment to scheme line and thickness relationship, ratio like this, base cake thickness can be more than 21mm, if the radius-thickness ratio of pressing 14mm-16mm, base cake diameter in back will reach 294mm-336mm as calculated, and this not only makes outward appearance seem very stupid, force of impression is reached more than 3000 tons, and production will become impossible thereupon.

Three, summary of the invention:

1, goal of the invention: the purpose of this invention is to provide a kind of manufacture craft of large gold coin with high figure relief, the finished diameter of making is 180mm.

2, technical scheme: the present invention is achieved through the following technical solutions:

The manufacture craft of this large gold coin with high figure relief comprises former material base cake rollingly, polishing, handles through impression for the first time, it is characterized in that former material base cake adds processing through machine; After turning, annealing, polishing operation, through impression processing for the second time, finished product is made in turning deburring, polishing to base cake after the first time, impression was handled again.

The machine that relates in the technology adds processing:

(1) machine of former material base cake adds to handle and comprises that the raw material ingot rolling with cuboid becomes sheet material, with the planer fracture, go out blank with spade bed spade, goes out to have the base cake on limit clearly with machined into again, and with the polishing of base cake, preparation impresses;

(2) to the method for turning of base cake between twice impression operation be: base cake internal orifice slope angle is equated with the clear slope angle of die.

3, advantage and effect: manufacture craft of the present invention is improved one by one at the following point of making 10KG ultra-large type souvenir gold coin:

1, determining of trimmed size: single piece of quality according to the rules, take into account the artistic technique of impression basic theories and aesthetic habit, figure line characteristics and main performance etc., preferred diameter and the thickness of determining large gold coin of design.

2, the relevant design of blank and making: determine the blank specification according to trimmed size,, design and produce mold and determine rolling mill practice according to mill capacity and blank specification.

3, die parameter designing and optimization: the design of impressing mould technical parameter will meet the characteristics of large gold coin figure line high relief, and particularly the mould making process of 180mm super large-scale impressing mould will be reformulated.

4, base cake technological design: the super large-scale gold coin must carry out accurate base cake design, consider that limit shape design is sufficient with seal inside and outside guaranteeing clear limit, also have subsequent techniques such as the pre-allowance in car limit, because of once impression is not enough, must after turning, carry out the impression second time, to satisfy single piece of quality requirement of finished product.

5, the unsteady die sleeve mechanism of design super large-scale gold coin is to guarantee that positive back side superelevation relief pattern is easy to be full of and with advancing to be full of; Optimize and select and design silk tooth technological parameter.

6, determining of impression number of times, the middle turning amount of secondary impression and intermediate annealing temperature etc. reduced to possible defective in the impression minimum.

Four, description of drawings: the large gold coin front view that accompanying drawing 1 is made for technology of the present invention;

The large gold coin rearview that accompanying drawing 2 is made for technology of the present invention.

Five, the specific embodiment:

The manufacture craft of large gold coin with high figure relief of the present invention, comprise former material base cake rollingly, polishing, handle, it is characterized in that base cake after impression is handled for the first time is again after turning, annealing, polishing operation through impression for the first time, through impression processing for the second time, finished product is made in turning deburring, polishing.

Adopt the parameter of the made finished product of above-mentioned manufacture craft to be respectively:

The major diameter gold coin comprises that diameter is 100-180mm;

Finished product radius-thickness ratio: D/H=8.5-14

Finished figure line height is about: H=1/10

Finished product side portion silk tooth density is: 0.67

Adopt above-mentioned technology to make the gold coin of diameter 180mm, the making of its blank: with the ingot casting of wide 150mm, thickness 50mm, long 200mm, rolling out thickness is 26mm, width is the sheet material of 200mm, use the planer fracture, spade bed spade goes out blank, makes the base cake on limit clearly with engine lathe, impression is prepared in the polishing of base cake.Under the condition of existing equipment, carry out impression twice with the 1600T forcing press.

To the method for turning of base cake between twice impression operation be: base cake internal orifice slope angle is equated with the clear slope angle of die.With base cake Che Bianzhi diameter 177mm, clear limit thickness 24mm, outer chamfering 1.5-2mm * 45 °, the clear hem width degree in polishing back is 6.0mm, and a lining mouthful state is to be seamlessly transitted to the bottom surface by clear limit internal diameter, and transition width is 5mm, knuckle R=10mm.

Make the mould making process of large gold coin with high figure relief mould therefor: because the die specification is excessive, and the bearing steel blank that mould adopts is the hot rolling forge piece, make the strain cracking tendency in the Quenching Treatment process increase greatly, also be unfavorable for cutting and Carving Machining, therefore the present invention carries out spheroidizing to blank earlier, it is tiny and uniform spherical that carbide is changed into by sheet, makes performance obtain bigger improving; Spheroidizing is in the nitrogen atmosphere furnace annealing, and annealing temperature is 550 ° ± 5 °, temperature retention time 80-90 minute; External form roughing, size car is by drawing made type; Directly undercut characters cut in intaglio die, engraving during die with engraving machine, the speed conditioning signal of engraving machine arrangements for speed regulation is reduced half, 1400mm/min; In order to make stamp surfaces and lining core hardness moderate, avoid being out of shape and the generation of heat treating fault such as cracking, Technology for Heating Processing has been done following improvement: want the classification cooling during quenching, when being cooled to 300-400 ℃, use 860 ℃ of bucks oil cooling instead, be incubated 5.5 hours, in tempering process, 200 ℃ are incubated 5-6 hour, adopt a plurality of impressed current anodes with die chromium plating; The die sleeve structure of floating is particularly adopted in fine finishining in frock.

The technical parameter of designing mould:

(1) Zheng Mian the highest figure line requires the front embossment that stronger third dimension should be arranged, thus projecting motif.

Utilize empirical equation to calculate H=product diameter (180mm) * T _hProportionality coefficient selects T _hBe 0.008-0.015, the highest figure line H is 0.005-0.01, and the highest figure line H is 2mm; The figure line at the back side constitutes T by a plurality of two-dimensional patterns less and that disperse _hBe 0.005-0.01, the highest figure line H is 1.1mm.

(2) clear slope angle: 25 °-45 ° of the clear slope angle scopes that general mould making process requires are defined as 45 ° in this example.(3) clear hem width degree B=product diameter * Qb coefficient 0.025-0.04 gets 0.031 in this example, determines that clear hem width degree is 5.5mm; Utilize empirical equation to calculate clear limit volume again: clear limit volume=figure line volume * gross area/figure line occupied area * QV, gross area in this example/figure line occupied area is 7/8, estimates that the line volume of publishing picture is 24700mm ³, coefficient QV is 1/3, drawing clearly in the above-mentioned formula of substitution, the limit volume is 9409mm ³, known is width and volume clearly, calculating clearly, the limit height is 2.5mm.

The back side: in order to improve artistic effect, clear limit, the back side is designed to double-decker, and nexine is processed into the throwing wet look, and also helps the impression on limit clearly; The clear limit at the back side is 30 °, and visual effect is more satisfactory.According to the aforementioned calculation method, determine the clear hem width degree in the back side and highly be 5.5mm and 2mm.

Claims (3)

1, a kind of manufacture craft of large gold coin with high figure relief comprises former material base cake rollingly, polishing, handles through impression for the first time, it is characterized in that former material base cake adds processing through machine; After turning, annealing, polishing operation, through impression processing for the second time, finished product is made in turning deburring, polishing to base cake after the first time, impression was handled again.

2, the manufacture craft of large gold coin with high figure relief according to claim 1 is characterized in that the parameter of made finished product is respectively:

The major diameter gold coin comprises that diameter is 100-180mm;

Finished product radius-thickness ratio: D/H=8.5-14

Finished figure line height is about: H=1/10

Finished product side portion silk tooth density is: 0.67

3, the manufacture craft of large gold coin with high figure relief according to claim 1 is characterized in that the machine that relates in the technology adds processing:

(1) machine of former material base cake adds to handle and comprises that the raw material ingot rolling with cuboid becomes sheet material, with the planer fracture, go out blank with spade bed spade, goes out to have the base cake on limit clearly with machined into again, and with the polishing of base cake, preparation impresses;

(2) to the method for turning of base cake between twice impression operation be: base cake internal orifice slope angle is equated with the clear slope angle of die.

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