JP3673691B2 - Magnesium alloy screw parts manufacturing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for producing magnesium alloy threaded fastener is excellent in light weight and specific strength.
[0002]
[Prior art]
Screw parts such as bolts and nuts are generally manufactured by cold forging using a metal material such as carbon steel or stainless steel.
[0003]
On the other hand, a magnesium alloy has attracted attention as a light weight material because it has the smallest specific gravity among metal materials currently in practical use and is excellent in specific strength following titanium. However, since magnesium alloys are chemically active, there is a problem that cutting chips are likely to burn, and because the crystal structure of magnesium is a close-packed cubic structure (hcp structure), Because of its poor plastic workability, most magnesium alloys are used as castings .
[0004]
[Problems to be solved by the invention]
Therefore, the present inventors have studied a method for machining threaded parts using a magnesium alloy. And after paying attention to the elongation of the magnesium alloy in the warm forging region of 250 ° C to 400 ° C, that is, plastic workability, various investigations have been made. As a result, warm forging enables efficient forging and thread rolling of threaded parts. I found out.
[0005]
The present invention has been made on the basis of the above knowledge, and the purpose thereof is a magnesium alloy capable of efficiently producing a magnesium alloy screw part which is lightweight by warm forging , excellent in specific strength and stable in quality. An object of the present invention is to provide an apparatus for manufacturing a threaded part.
[0006]
[Means for Solving the Problems]
That is, the magnesium alloy screw part manufacturing apparatus according to the present invention continuously feeds a material obtained by cutting a magnesium alloy wire having an elongation of 50% or more into a predetermined length in a temperature rising state of 250 ° C. to 400 ° C. A punch and a die forging the blank into a threaded part by warm forging, transfer means for transferring the material supplied from the chute to the punch and die, and forging with the punch and die. An apparatus for manufacturing a threaded part including an alignment rail for aligning and supplying the formed blank to a thread rolling die, a chute heating means for heating the chute, and a punch for heating the punch die A die heating means and an alignment rail heating means for heating the alignment rail are provided.
[0007]
Specifically, the chute heating means includes a plurality of electric heating cartridge heaters disposed at the bottom and top of the chute and a heat insulating material surrounding the outer surface of the chute. The punch / die heating means is composed of a plurality of electric heating cartridge heaters disposed around the die forming hole and a heat insulating material surrounding the outer surface of the die. Further, the alignment rail heating means is constituted by a plurality of electric heating cartridge heaters disposed on the alignment rail and a heat insulating material surrounding the outer surface of the alignment rail.
[0008]
The forging speed of the material by the punch dies is 100 mm / sec to 500 mm / sec. When the forging speed is set to 500 mm / sec or more, there is a problem that the uniformity of the heating state of the material cannot be obtained and the quality is not stable. Moreover, since productivity will fall if a forge rate is 100 mm / sec or less, it shall be 100 mm / sec or more.
[0009]
As the magnesium alloy, for example, wrought materials such as ASTM standard AZ31, AZ61A, AZ80A, and ZK60A alloys are suitable.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0011]
The material of the threaded component according to the present invention is a magnesium alloy wire having an elongation of 50% or more at 250 ° C. to 400 ° C., for example, an ATSM standard AZ31 alloy (Al 2.5 to 3.5%, Zn 0.5 to 1.5). %, Mn 0.15% or less, remaining Mg), AZ61A alloy (Al 5.5-7.2%, Zn 0.5-1.5%, Mn 0.15-0.40%, remaining Mg), AZ80A alloy (Al7 0.5 to 9.2%, Zn 0.2 to 1.0%, Mn 0.10 to 0.40%, remaining Mg), ZK60A alloy (Zn 4.8 to 6.2%, Zr 0.4 to 0.8 ° C) %, Remaining Mg) is cut to a predetermined length.
[0012]
FIG. 1 is a schematic front view of a forging portion in a screw part manufacturing apparatus according to the present invention, and FIG. 2 is a schematic plan view of the thread rolling portion. FIG. 3 is a cross-sectional view of the main part of the forging process, and FIG.
[0013]
The forging portion 1 continuously feeds a raw material W obtained by cutting a magnesium alloy wire having an elongation of 50% or more into a predetermined length in a temperature rising state of 250 ° C. to 400 ° C. like the AZ31 alloy described above. The chute 2, punch dies 3, 13, 14 for forging the material W (only the die 3 is shown in FIG. 1), and the material W supplied from the chute 2 are transferred to the punch die 3. And transfer means 4. A plurality of electrothermal cartridge heaters 5 are inserted and fixed at the bottom and top of the chute 2, and the heating temperature of the heater 5 can be adjusted by the temperature sensor 6. The chute 2 is surrounded by a heat insulating material 7 in consideration of thermal efficiency and thermal influence on the forging machine body. The material W that is continuously fed while being aligned in the chute 2 is heated and adjusted to 250 ° C. to 400 ° C. The punch dies 3, 13, and 14 are one-die and two-blow mechanisms, and a plurality of electrothermal cartridge heaters 5 are inserted and fixed in a rectangular die 3 so as to surround the center hole 8. Thus, the heating temperature of the heater 5 can be adjusted. The outer surface of the die 3 is surrounded by a heat insulating material 7. The transfer means 4 includes a swing lever 10 that swings up and down with a support shaft 9 as a fulcrum, a pinch claw 11 attached to the tip of the swing lever 10, and a material W positioned at the forefront of the chute 2. 1 and a transfer arm 12 that sends it to a predetermined position. When the transfer arm 12 has been described above to a predetermined position indicated by an imaginary line in FIG. 1, the swing lever 10 at the standby position M moves downward, When the material W is clamped by the clamping claws 11, the swing lever 10 once returns to the standby position M. Meanwhile, the transfer arm 12 moves backward to receive the next material W. Subsequently, the swing lever 10 moves downward to the operation position N, and the material W sandwiched by the sandwiching claws 11 is transferred to a position facing the center hole 8 of the die 3. The material W transferred to the position facing the center hole 8 of the die 3 is inserted into the center hole 8 of the die 3 by the first punch 13 as shown in FIG. The primary blank B1 (see FIG. 4) is processed. On the other hand, the swing lever 10 returns to the standby position M shown in FIG. Subsequently, a second stage of forging is performed by the second punch 14, and the secondary blank B2 (see FIG. 4) in which the screw head is completed is processed. The processed secondary blank B2 is extruded from the die 3 by the knockout punch 15. The above forging is continuously performed at a forging speed in the range of 100 mm / sec to 500 mm / sec.
[0014]
The above-described two-stage forging with the first punch 13 and the second punch 14 has a high speed due to the one-die / two-blow mechanism, so that the material W is not cooled even if the punch side is not heated. It was sufficient to heat 3. Moreover, since the elongation of the material W during the warm forging was large, the secondary blank B2 in which the screw head was completed by two-stage molding could be processed.
[0015]
As shown in FIG. 2, the thread rolling unit 20 includes an alignment rail 21 that aligns and continuously feeds the secondary blank B <b> 2 having a screw head formed by the forging unit 1, and the alignment rail 21. And a push plate 22 for supplying the most advanced blank B2 to the thread rolling dies 23, 24. A plurality of electrothermal cartridge heaters 5 are inserted and fixed on both sides of the alignment rail 21, and the heating temperature of the heater 5 can be adjusted by the temperature sensor 6. Further, both sides of the alignment rail 21 are surrounded by the heat insulating material 7. Then, the secondary blank B <b> 2 that is continuously fed while being aligned in the alignment rail 21 is heated and adjusted to 250 ° C. to 400 ° C. by the heater 5. The secondary blank B2 thus heated and adjusted to 250 ° C. to 400 ° C. is inserted between the screw rolling dies 23 and 24 by the pressing plate 22, and the thread is rolled to process a magnesium alloy bolt (or small screw). ) S is completed (see FIG. 4). At this time, the screw rolling dies 23 and 24 were able to roll the thread well without heating. In addition, you may make it heat the thread rolling dies 23 and 24 as needed. The manufacturing process of FIG. 4 shows an example in which the material W is 8 mm in diameter and 40 mm in length, and the completed bolt (or small screw) S is M8.
[0016]
【The invention's effect】
As described above , according to the present invention, it is possible to efficiently produce a magnesium alloy screw part that is lightweight, excellent in specific strength, and stable in quality. In particular, since the elongation of the material during forging is large, the number of steps in the manufacturing process can be reduced to reduce the manufacturing cost, and the life of the punching die for forming and the thread rolling die can be greatly extended. is there.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing a forging portion in a screw part manufacturing apparatus according to the present invention.
FIG. 2 is a schematic plan view of the thread rolling portion.
FIGS. 3A and 3B are cross-sectional views of the main part of the forging forming step, where FIG. 3A shows a first step forming step and FIG. 3B shows a second step forming step.
FIG. 4 is an explanatory diagram showing a manufacturing process performed by the manufacturing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Forging molding part 2 Chute | shoot 3,13,14 Punch * die | dye 4 Transfer means 5 Electric heating cartridge heater 6 Temperature sensor 7 Thermal insulation material 10 Oscillating lever 11 Claw claw 12 Transfer arm 20 Thread rolling part 21 Alignment rail 22 Push plate 23, 24 Thread rolling dies W Material B1 Primary blank B2 Secondary blank S Bolt (machine screw)

Claims (5)

A chute for continuously feeding a material obtained by cutting a magnesium alloy wire rod having an elongation of 50% or more to a predetermined length in a temperature rising state of 250 ° C. to 400 ° C., and a blank for a screw part by warm forging the material. A punch die for forging molding, transfer means for transferring the material supplied from the chute to the punch die, and the blank forged by the punch die aligned with a screw rolling die An apparatus for manufacturing a screw component including an alignment rail that performs a chute heating means for heating the chute,
Punch and die heating means for heating the punch and die;
An apparatus for manufacturing a magnesium alloy screw part, comprising: an alignment rail heating means for heating the alignment rail. The chute heating means comprises a plurality of electric cartridge heaters disposed on the bottom and top of the chute, a heat insulating material and a magnesium alloy threaded fastener according to claim 1, characterized in that is constituted by surrounding the outer surface of the chute Manufacturing equipment. The punch-die heating means comprises a plurality of electric cartridge heaters arranged around the molded hole of the die, the magnesium alloy of the heat insulating material and Configured claim 1, wherein the surrounding outer surface of the die Manufacturing equipment for screw making parts. The alignment rail heating means comprises a plurality of electric cartridge heaters disposed in the alignment rail, a magnesium alloy threaded fastener according to claim 1, wherein the outer surface is composed of a heat insulating material surrounding the alignment rail manufacturing device. The apparatus for manufacturing a magnesium alloy screw part according to any one of claims 1 to 4 , wherein a forging speed of the material by the punch and die is 100 mm / sec to 500 mm / sec.

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