JP2001205330A - Method and device for cooling inside surface of hollow extruded shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the state of solid solution where the precipitation of alloy component is suppressed to room temperature and to secure precipitation quantity which is effective to impart strength by aging treatment by cooling a hollow extruded shape M just after extrusion from the inside surface. SOLUTION: A chill supply pipe (chill supply hose 11) is inserted into the hollow extruded shape M which is extruded from a die 1 from an opening on the outlet side of the hollow extruded shape M and a distance d from a chill jetting nozzle 12 attached at the tip of the chill supply pipe to the end face on the outlet side of the die 1 is maintained constant. By jetting the chill from the chill jetting nozzle 12 toward the opening on the outlet side from the radial direction of the hollow extruded shape M, the inside surface of the hollow extruded shape M is cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a cooling device for blowing cold air into a hollow extruded member immediately after extrusion to cool the hollow extruded member.

[0002]

2. Description of the Related Art In extrusion molding of a precipitation hardening type aluminum alloy, a solution treatment is performed by cooling an extruded material at a die end immediately after extrusion, and Mg ₂ S is subjected to aging treatment in a later step.
In some cases, a method of precipitating i, CuAl ₂ or the like to impart necessary strength is adopted. Cooling immediately after extrusion prevents the alloy components dissolved in the matrix from being precipitated and coarsened in the cooling stage and preventing the required strength from being obtained after aging treatment. It is necessary to increase the speed. It is easy to increase the cooling rate on the outer surface of the profile. However, extruded shapes include hollow materials having a cross-sectional structure having one or more hollow portions, semi-open materials in which a part of the hollow portion is opened, and the like (hereinafter, these are collectively referred to as hollow extruded shapes). Do). If the cooling rate is increased when cooling such a hollow extruded profile from the outer surface, the thermal stress inside the profile increases, causing shape deformation. For this reason, hollow extruded profiles capable of providing the required strength by aging treatment in the subsequent step without causing deformation only by cooling from the outer surface are limited to those having a certain thickness or less (Japanese Patent Application No. 11-285292). ).

[0003] However, thick hollow sections are also widely used as hollow extruded sections. Since such a thick hollow extruded section is cooled immediately after extrusion and subjected to a solution treatment, cooling from the inside of the section is also required. Even for a hollow extruded profile having a part of the cross section thickened, it is desired to use cooling from the inside together in order to prevent cooling delay of the thick part. As a method of cooling the hollow extruded shape from the inside immediately after the extrusion, a method of injecting cold air into the inside of the hollow extruded shape immediately after the extrusion from a cool air discharge port formed in a mandrel of a die (Japanese Patent Laid-Open No. Hei 8-2067)
No. 29), a method of irradiating a laser beam on the side wall of a hollow extruded profile to form a cool air introduction hole, and blowing cold air into the hollow extruded profile from the cool air introduction hole (Japanese Patent Laid-Open No. 5-200431), etc. It has been known.

[0004]

Forming a cold air discharge port in a mandrel makes it difficult to manufacture a die, and causes an increase in processing load and cost. In addition, since the die is easily damaged due to a decrease in strength due to the perforation of the cool air discharge port, the location of the perforation of the cool air discharge port is restricted, and the internal cooling of a necessary portion cannot be sufficiently performed. On the other hand, if a cold air introduction hole is formed in the side wall of the hollow extruded profile, the commercial value of the product may be greatly impaired. Also, it takes time from immediately after the extrusion to the perforation of the cool air introduction hole, and during the cooling process during this period, the alloy component may precipitate, and the amount of solid solution required for imparting strength by aging treatment may not be secured.

[0005]

SUMMARY OF THE INVENTION The present invention has been devised in order to solve such a problem. A cold air jet nozzle attached to the tip of a cold air supply pipe inserted from the outlet side of the extruder is used in the extruder. An object of the present invention is to reliably cool the hollow extruded shape immediately after extrusion from the inside by being positioned inside the hollow extruded shape immediately after. The cooling method of the present invention, in order to achieve the object, to a hollow extruded shape extruded from a die,
Insert a cold air supply pipe from the outlet opening of the hollow extruded profile,
The distance from the cool air injection nozzle attached to the tip of the cool air supply pipe to the outlet end face of the die is kept constant, and the cool air is supplied from the cool air injection nozzle toward the outlet opening from the radial direction of the hollow extruded profile. It is characterized by spouting.

In a cooling apparatus using a cold air supply hose as a cold air supply pipe, a hose reel wound around a cold air supply hose having a cold air injection nozzle attached to the tip is mounted on a puller, and the cold air supply hose is being extruded by a hose guide. To the inside of the hollow extruded profile. At this time, the cool air injection nozzle is maintained at a position separated by a certain distance from the exit side end surface of the die by sending out the cool air supply hose at the same speed as the moving speed of the puller along the extrusion direction and in the direction opposite to the extrusion direction. . As the delivery mechanism, for example, a hose feed roller that rotatably contacts a rail on which a puller travels is used.

In a cooling device using a telescopic tube, a housing is movably arranged on a rail along an initial table arranged on the exit side of an extruder, extends in a cantilever state on a die side, and has a cold air injection nozzle at a tip. Attach the base end of the telescopic tube with the attached to the housing. When running the housing in the extrusion direction in synchronization with the puller during extrusion molding, the extrusion direction is such that the cold air injection nozzle is maintained inside the hollow extruded shape at a position away from the exit end face of the die by a certain distance. The telescopic tube is extended in the opposite direction and at the same speed as the traveling speed of the housing.

In any of the cooling devices, it is preferable to provide an umbrella-shaped plate at the die side end of the cool air injection nozzle for preventing the blown cool air from being directly blown to the die. The cold air supply hose or the telescopic tube can be sent out to the die side while the support member for maintaining the cold air supply hose or the telescopic tube at the center of the hollow extruded section is attached to the cold air supply hose or the telescopic tube at predetermined intervals.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to cool a hollow extruded profile immediately after extrusion from the inside, it is necessary to discharge hot gas existing inside the hollow extruded profile at a position near a die exit side and replace it with cool air. is there. By blowing cool air into the hollow extruded profile at the position, the hot gas is discharged, and the hollow extruded profile is cooled from the inside. However, since the cold air discharge port is formed in the mandrel and the cold air introduction hole is formed in the hollow extruded section, there is a problem as described above. A method was adopted in which a cold air jet nozzle attached to the end of a cold air supply pipe was inserted into the profile and positioned inside the hollow extruded profile immediately after the extruder.

The extruder pulls the tip of a hollow extruded material M extruded from a die 1 through a platen 2 in an extrusion direction D with a puller 3 as shown in FIG.
While traveling along the rails 4, the hollow extruded section M is sent out onto the initial table 5. At this time, a cool air supply hose 11 is fed into the inside of the hollow extruded section M through the outlet opening as a cool air supply pipe, and a cool air injection nozzle 12 attached to the tip of the cool air supply hose 11 is positioned near the outlet side of the die 1. A cooling mechanism 10 is additionally provided. The cold air supply hose 11 is fed out from a hose reel 13 and is sent out to an outlet side opening of the hollow extruded shape M by a hose guide 14. A nozzle hole 15 (FIG. 2a) whose injection direction is inclined in the extrusion direction D is formed in the cool air injection nozzle 12 attached to the tip of the cool air supply hose 11. An umbrella plate 16 is provided on the die 1 side of the cool air jet nozzle 12 so that the cool air ejected from the nozzle hole 15 does not directly contact the die 1 to cool the die 1.

Since the cold air supply hose 11 is inserted into the high-temperature hollow extruded profile M, it is made of a material having excellent heat resistance and heat insulation properties. A hose that is difficult to bend is preferable. Or,
The support 17 for supporting the cold air supply hose 11 in the hollow extruded section M at an appropriate interval may be sent out from the puller 3 side at an appropriate interval. As the support 17, an arm 17 b extends at least in three directions from a ring 17 a through which the cold air supply hose 11 is inserted, and a roller 17 c that rotates in contact with the inner surface of the hollow extruded shape M is attached to the tip of each arm 17 b. Used (FIG. 2b). The use of the ring 17a which sandwiches the cold air supply hose 11 with a material having a high coefficient of friction, elastic force, spring elasticity or the like prevents slippage between the cold air supply hose 11 and the ring 17a, and is accompanied by the delivery of the cold air supply hose 11. The ring 17a is also fed into the hollow extruded profile M.

For sending out the cold air supply hose 11, for example, a hose feed roller 18 that can be brought into contact with and separated from the rail 4 is used. At the start of extrusion, the hose feed roller 18 is separated from the rail 4 and the cold air supply hose 1 is removed from the hose reel 13.
1 is previously extended by a predetermined length, and the distance from the exit side end surface of the die 1 to the cool air injection nozzle 12 is set to a constant value d. Next, the hose feed roller 18 is brought into contact with the rail 4 to rotate the hose feed roller 18 counterclockwise in FIG. 1 at a peripheral speed equal to the running speed v of the puller 3 in the extrusion direction D. The cold air supply hose 11 in contact with the hose feed roller 18 is sent from the hose reel 13 at a speed equal to the peripheral speed of the hose feed roller 18. for that reason,
The cold air supply hose 11 is sent out to the left in FIG.
Is maintained at a constant position at a distance d from the exit side of the die 1.

The traveling speed v of the puller 3 and the cold air supply hose 1
In order to make the delivery speeds of 1 coincide, it is necessary to prevent slippage between the rail 4 and the hose feed roller 18 and between the cold air supply hose 11 and the hose feed roller 18. For slip prevention, it is effective to increase the frictional resistance of each material or to engage each member with a gear or the like.

Since the nozzle hole 15 is inclined at the tip end of the cold air supply hose 11 in the extrusion direction D, the propulsive force directed leftward in FIG. You. Further, a reaction force is generated when the cool air blown out from the nozzle hole 15 collides with the inner wall of the hollow extruded shape member M. As a result, the cold air supply hose 11 is moved toward the center of the die 1 at a substantially central position inside the hollow extruded profile M.
Is self-supported. Although it is possible to send the cold air supply hose 11 to the die 1 side by the propulsion force of the cold air injection, an extremely large gas pressure is required for that, and the temperature around the die 1 may become unstable. In this regard, if the propulsion is such that the distal end of the cold air supply hose 11 is self-supporting, the gas pressure can be suppressed to such an extent that the extrusion conditions are not adversely affected.

When the cool air injection nozzle 12 is maintained at a position separated by a fixed distance d from the outlet end face of the die 1 and cool air is injected from the cold air injection nozzle 12 from the radial direction of the hollow extruded shape M toward the outlet opening. The hot gas inside the hollow extruded profile M rides on the flow of cool air and is exhausted from the inside of the hollow extruded profile M, and the inside of the hollow extruded profile M is replaced with cold air. As a result, the hollow extruded section M is cooled from the inner side. As the cold air, low-temperature air, liquid nitrogen, mist, or the like is used. As described above, when the hollow extruded shape M is cooled from the inner surface, even if the hollow extruded shape M is thick, it is cooled without causing deformation due to precipitation of alloy components and thermal stress during the cooling process. Becomes possible. Cooling from the inner surface is particularly effective when extruding a hollow extruded shape M having a thick portion exceeding 15 mm. In addition, since the cooling is performed under a certain condition, the quality of the cooled hollow extruded shape material M is also stabilized.

Instead of the cold air supply hose 11, an internal cooling mechanism 20 using the telescopic tube 22 as a cold air supply tube can also be used. Alternatively, it is also possible to arrange an internal cooling mechanism at a fixed position along the initial table 5 and use a cold air supply pipe of a fixed length extending from the internal cooling mechanism to the inside of the hollow extruded section M. However, in this case, a long space along the extrusion direction D is required to remove the cold air supply pipe from the hollow extruded shape material M after the completion of the extrusion molding. The internal cooling mechanism 20 having the telescopic tube 22 is arranged so as to be able to travel along the rail 21 provided on the side of the initial table 5 as shown in FIG. Have been. The telescopic tube 22 is provided on the die 1 side of the internal cooling mechanism 20 in a cantilever state.

The telescopic tube 22 has a plurality of inner tubes 2 attached to the outer tube 22a.
This is a multi-tube in which 2b is inserted. The outer tube 22 a is bent in a crank shape and is rotatably mounted on the housing 23 of the internal cooling mechanism 20. A cold air injection nozzle 24 similar to that shown in FIG. 1 is attached to the tip of the innermost tube 22c. Telescopic tube 2
2, the length can be changed by sequentially sending out the inner tube 22b and the innermost tube 22c from the outer tube 22a. If the rigidity of the telescopic tube 22 is sufficient, the telescopic tube 22 can be supported in a cantilevered state over the entire length of the hollow extruded profile M extruded from the die 1, but the support members 17 similar to FIG. By sending it out and fitting it into the telescopic tube 22, it becomes easy to maintain the cool air injection nozzle 24 substantially in the center of the hollow extruded profile M. The support 17 includes an outer tube 22a,
It is preferable to attach the inner tube 22b and the innermost tube 22c to the tip of the die 1 side. When a pipe having a certain degree of rigidity is used as the outer pipe 22a, the inner pipe 22b, and the innermost pipe 22c constituting the telescopic pipe 22, the arms 17b projecting in three directions.
Instead of the support member 17 (FIG. 2) having the roller 17c mounted thereon,
A support in which a roller is rotatably mounted on an arm projecting downward in one direction can also be used. The rotation of the outer tube 22a in the a-a direction and the rotation of the outer tube 22a to the inner tube 22b,
The delivery of 2c is performed by a drive mechanism (not shown) built in the housing 23. Inner tube 22b and innermost tube 22c
Is equal to the traveling speed v of the hollow extruded profile M traveling in the extrusion direction D, and is sequentially fed from the outer tube 22a at a feeding speed opposite to the extrusion direction D.

The feeding speed of the inner tube 22b and the outer tube 22a is as follows.
The running speed of the hollow extruded section M can be made to match the running speed of the hollow extruded member M by using an appropriate control mechanism that is synchronized with the running speed of the puller 3 or the internal cooling mechanism 20. As the control mechanism, for example, the distance from the exit side surface of the die 1 to the cool air injection nozzle 24 is measured by an optical sensor, an acoustic sensor, a wind pressure sensor, or the like, and the control signal is expanded or contracted based on the measurement result so that the distance becomes constant. A control circuit that outputs to the drive mechanism of tube 22 is used. Since the telescopic tube 22 is sent out in the direction opposite to the extrusion direction D at a delivery speed equal to the traveling speed of the hollow extruded profile M along the extrusion direction D, the cold air injection nozzle 24 attached to the tip of the innermost tube 22c is The distance from the exit end face of the die 1 is maintained at a constant absolute position. Therefore, the hollow extruded shape member M immediately after the extrusion is cooled from the inside by the cool air jetted from the cool air jet nozzle 24 under certain conditions.

[0019]

EXAMPLE A die 1 heated to a temperature of 460.degree. C. was set in an extruder and heated to a temperature of 480.degree.
An extruder container is filled with an IS A6063 aluminum alloy billet and extruded into a 10 m-long extruded pipe (outside diameter 30 mm).
0 mm, thickness 25 mm). At this time, the hollow extruded material M immediately after extrusion was cooled from the outer surface, and also cooled from the inner surface using the internal cooling mechanism 20 shown in FIG. As the internal cooling mechanism 20, an internal cooling mechanism provided with a telescopic pipe 22 having an outer diameter of 100 mm of the innermost pipe 22c was used. At the start of extrusion, the telescopic tube 22 (FIG. 4 a) in the upright state is rotated to position the cool air injection nozzle 24 on the center line of the die 1, and then the cool air injection nozzle 2 is moved from the exit end face of the die 1.
The internal cooling mechanism 20 was moved in the direction opposite to the extrusion direction D until the distance to 4 became 3 m.

Next, the tip of the hollow extruded section M is pulled out with a puller 3.
And puller 3 and internal cooling mechanism 20 are pushed out in the extrusion direction D.
, The hollow extruded section M was extruded at a section speed of 5 m / min (FIG. 4b). During extrusion molding, cooling air at a temperature of 20 ° C. was blown from the cold air injection nozzle 24 at a flow rate of 50 m ³ / min, and the hollow extruded shape M was cooled from the inside. at the same time,
Temperature of 20 ° C from a nozzle arranged around the hollow extruded profile M
Was blown out at a flow rate of 10 m / sec, and the hollow extruded shape M was also cooled from the outside.

Hollow extruded profile M extruded from die 1
As the extrusion length of the die becomes longer, the inner pipe 22b and the innermost pipe 22c are sequentially fed out from the outer pipe 22a so that the distance from the outlet end face of the die 1 to the cool air jet nozzle 24 is maintained at a constant value of 3 m. (FIG. 4c). The cooling conditions were constant throughout the entire process of extruding one billet. Hollow extruded profile M
When the extrusion length reached 15 m, it was regarded that the entire process of extruding one billet was completed, and with the completion of the extrusion, the blowing of cold air was also stopped. Next, the innermost tube 22c and the inner tube 22
b was drawn into the outer tube 22a to shrink the telescopic tube 22, and the hollow extruded section M was separated from the platen 2 by the platen saw 6 (FIG. 4d).

As a result of observing the metal structure of the manufactured hollow extruded shape member M, it was found that there was a precipitate-free matrix over the entire length. 190 ° C. × 180
When aging treatment was performed for minutes, a strength of 190 N / mm ² or more could be imparted. For comparison, a hollow extruded section M was produced under the same conditions except that cooling from the inner surface was omitted. In the obtained hollow extruded shape M, a large number of precipitates are precipitated in the matrix, and the strength after aging treatment is 110 N / mm ^2.
And a low value.

[0023]

As described above, according to the present invention, a cool air supply pipe having a cool air injection nozzle attached at the tip is inserted from the outlet opening of the hollow extruded profile and is fixed at a predetermined distance from the outlet end face of the die. By blowing cool air from a cool air spray nozzle maintained inside the hollow extruded profile at a remote position,
The hollow extruded profile is cooled from the inside. According to this method, a sufficient cooling rate can be obtained even with a thick hollow extruded profile, so that precipitation of alloy components that do not contribute to imparting strength is prevented. Therefore, a sufficient amount of precipitation effective for imparting strength during the aging treatment is sufficiently ensured, and a hollow extruded section having high strength is provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an internal cooling mechanism that uses a cold air supply hose as a cold air supply pipe and has a mechanism for sending a cold air injection nozzle in a reverse direction at a constant speed in accordance with the travel of a puller in an extrusion direction.

FIG. 2 is a cross-sectional view showing a cold air supply hose and a cold air injection nozzle inserted inside a hollow extruded profile.

FIG. 3 is a perspective view of an internal cooling mechanism provided with a telescopic tube as a cold air supply tube.

FIG. 4 is an explanatory diagram of an extrusion molding process using the internal cooling mechanism.

[Explanation of symbols]

1: Die 2: Platen 3: Puller 4: Rail 5: Initial table 6: Platen saw 10: Internal cooling mechanism 11: Cold air supply hose 1
2: Cold air injection nozzle 13: Hose reel 14:
Hose guide 15: Nozzle hole 16: Umbrella plate 17: Support 17a: Ring 17b: Arm 17c: Roller 18: Hose feed roller 20: Internal cooling mechanism 21: Rail 22: Telescopic tube 22a: Outer tube 22b: Inner tube 22c ： Innermost tube 23 ： Housing 24 ： Cool air jet nozzle M ： Hollow extruded shape material D ： Extrusion direction d ： Distance from exit end face of die to cold air jet nozzle

Claims (6)

[Claims] 1. A cold air supply pipe is inserted into a hollow extruded shape extruded from a die through an outlet opening of the hollow extruded shape, and a cold air injection nozzle attached to a tip of the cold air supply pipe exits the die. A method of cooling an inner surface of a hollow extruded profile, wherein a constant distance to an end face is maintained, and cool air is blown from a radial direction of the hollow extruded profile toward an outlet opening from the cool air injection nozzle. 2. A cold air supply hose having a cold air injection nozzle mounted at a tip thereof, a hose reel wound around the cold air supply hose and mounted on a puller, and a hollow extruded material being formed by extruding the cold air supply hose. Equipped with a hose guide that guides inside and a delivery mechanism that sends out the puller at the same speed as the moving direction in the extrusion direction and in the opposite direction to the extrusion direction, and maintains a position at a fixed distance from the exit side end surface of the die A cooling device for cooling the inner surface of the hollow extruded profile, wherein the inner surface of the hollow extruded profile is cooled by the cool air blown out from the cold air injection nozzle. 3. The delivery mechanism according to claim 2, further comprising a hose feed roller rotatably contacting a rail on which the puller runs, and rotating at a circumferential speed opposite to the extrusion direction and at a constant speed equal to the extrusion speed. A cooling device in which a cold air supply hose is fed into a hollow extruded profile by the hose feed roller. 4. A rail along an initial table arranged on the exit side of the extruder, a housing movably arranged on the rail, one end attached to the housing, and extending in a cantilevered state on the die side. Equipped with a telescopic tube and a cool air injection nozzle attached to the end of the telescopic tube.When the housing is run in the extrusion direction in synchronization with the puller during extrusion molding, at a position away from the exit end surface of the die by a certain distance In order to maintain the cold air injection nozzle inside the hollow extruded profile, the telescopic tube is stretched in the direction opposite to the extrusion direction and at the same speed as the traveling speed of the housing. Cooling system. 5. An umbrella-shaped plate provided at an end of the cool air injection nozzle on the die side to prevent cold air blown out from the cool air injection nozzle from being directly blown onto the die. The cooling device according to any one of the above. 6. The cooling device according to claim 2, wherein a support for maintaining the cold air supply hose or the telescopic tube at the center of the hollow extruded section is attached to the cold air supply hose or the telescopic tube at predetermined intervals.