JP2012240367A - Extrusion molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion molding device with low maintenance frequency and high productivity, that can mold an extrusion molded product having a hollow part and a rib in the inside with excellent dimension accuracy.SOLUTION: The extrusion molding device includes: an extrusion molding die having an outer die for regulating the outer shape of a resin member and a core for regulating the inner shape of the resin member; an extruder for injecting a melted resin to the extrusion molding die; a magnetic sizing core where a through-hole is opened; a sizing outer die surrounding the sizing core; a support rod whose one end side is inserted to the through-hole of the sizing core, and the other end side is fixed to the core of the extrusion molding die; and a stopper for regulating movement in the axial direction of the support rod of the sizing core. To the sizing outer die, a plurality of magnets and a plurality of electromagnets are fixed, the magnetic force of the electromagnets is adjusted, and the position of the sizing core to the sizing outer die is adjusted.

Description

  The present invention relates to an extrusion molding apparatus using a sizing mold.

Sizing is a semi-finished product formed by pressing or forging, using a die, and squeezing the whole surface or part of the semi-finished product to flow the meat of the semi-finished product, dimensional accuracy in the vertical direction (thickness) It is a processing method that improves the process. Since a profile extrusion molded product such as an IC magazine requires hollow portions and ribs, it tends to be uneven, sink, or deformed during cooling and solidification. There may be slight deviations from the required dimensions. Patent Document 1 is an invention related to a sizing device for the purpose of molding an extrusion-molded product having hollow portions and ribs therein with good dimensional accuracy and surface condition while avoiding deformation and sink marks. .

The sizing device according to Patent Document 1 includes an extrusion mold and a support bar. A sizing die (mold) is provided on the outer side of the exit of the extrusion mold to cool the extrusion-molded product by suction. A support rod projects from the tip of the core of the extrusion mold. A plurality of plate-like sizing cores are supported on the support bar at intervals from the vicinity of the entrance of the sizing die in the extrusion direction. The outer peripheral surface of the sizing core is in sliding contact with the inner wall surface of the extruded product. A refrigerant is continuously supplied to a hollow portion (space) defined by adjacent sizing cores.

JP-A-9-117955

  In the above method, since the sizing core is fixed to the core of the extrusion mold through the support rod, if a dimensional deviation due to the sizing core is detected after the start of molding, without disassembling the periphery of the sizing core It is difficult to correct the position. The dimension correction method includes the first method of moving the sizing core together with the core of the extrusion mold, the second method of moving the sizing core together with the extrusion molding apparatus, and the position at the connecting portion between the core of the extrusion mold and the sizing core. A third method for adjusting the value is conceivable.

In the first method, the dimension of the resin member extruded from the extrusion mold in a shape close to the molded product also changes. Since it is necessary to consider the dimensional change of the resin member in addition to the simply measured dimensional deviation of the molded product, it is difficult to accurately adjust the position so as to satisfy the size of the molded product.

The second method is large and unrealistic because it moves the entire device. In the third method, the position adjustment is performed after removing all the resin extruded from the extrusion mold. After that, since it is necessary to draw the resin again to the extrusion molding line, it takes time and labor.

Thus, it is difficult to correct the position of the sizing core without disassembling the periphery of the sizing core. If the extrusion molding machine is stopped for a long time during disassembly, it is necessary to remove all the resin in the extrusion molding machine, resulting in wasted time and resin.

  Therefore, an object of the present invention is to provide an extrusion molding apparatus that can mold an extrusion molded product having a hollow portion and a rib inside with good dimensional accuracy, has a low maintenance frequency, and high productivity. .

An extrusion molding apparatus according to the present application includes an outer mold that regulates the outer shape of the resin member, an extrusion mold having a core that regulates the inner shape of the resin member, an extruder that injects molten resin into the extrusion mold, A sizing core that has a through hole and has magnetism, a sizing outer mold that surrounds the sizing core, a support bar that is inserted into the through hole of the sizing core at one end and is fixed to the core of the extrusion mold, A stopper that restricts the axial movement of the support rod of the sizing core, and a plurality of magnets and a plurality of electromagnets are fixed to the sizing outer mold, and the sizing outer mold is adjusted by adjusting the magnetic force of the electromagnet It adjusts the position of the sizing core with respect to.

According to the extrusion molding apparatus according to the present application, the sizing core is not fixed to the support rod, and the movement in the extrusion direction of the molded product is limited by the stopper, and the position of the sizing core can be adjusted during the extrusion molding. As a result, it is not necessary to dismantle around the sizing core or redraw the resin member to the line, and it is possible to adjust the position of the sizing core with little loss of the resin member in a short time.

It is a figure which shows the line of an extrusion molding apparatus. It is a perspective view which shows the form of a molded article. FIG. 3 is a cross-sectional view of an extrusion mold and a sizing mold in the first embodiment. It is sectional drawing of the 1st sizing metal mold | die in an extrusion molding apparatus. It is sectional drawing of the 2nd sizing metal mold | die in an extrusion molding apparatus. 6 is a cross-sectional view of an extrusion mold and a sizing mold in Embodiment 2. FIG.

Embodiment 1 FIG.
The line of the extrusion molding apparatus will be described with reference to FIG. The extrusion molding apparatus 100 includes a hopper 1, an extruder 2, a water tank 5, a take-up machine 6, and a cutter 7. The hopper 1 includes a valve and can adjust the supply amount of the resin member. The extruder 2 is connected to the hopper 1 and pushes the molten resin member into the extrusion mold 3. The molten resin member is temporarily molded into a shape close to a molded product by the extrusion mold 3. The resin member 15 a that has been temporarily molded and extruded from the extrusion mold 3 is guided to the sizing mold 4. In the sizing mold 4, the temporarily molded resin member 15a is molded to the same dimensions as the molded product. Sizing refers to a light cold press for the purpose of improving the surface condition and correcting the dimensions.

The sizing mold 4 is immersed in a water tank 5 or configured so that cooling water can be circulated therein. The resin member 15a molded according to the dimensions is cooled below the glass transition point or the softening point so as not to be deformed again. The take-up machine 6 draws out the cooled resin member 15b in accordance with the amount of resin extruded from the extruder 2. The resin member 15b is sent to the cutter 7 and cut into a predetermined length. The completed molded product 30 has a hollow portion (see FIG. 2).

FIG. 3 shows a cross section of the extrusion mold and the sizing mold. The extruder 2 includes a screw 8 and measures, compresses, and extrudes the molten resin 21. The extrusion mold 3 includes an outer mold 3a that regulates the outer shape of the resin member, a core 3b that regulates the inner shape, and a plurality of columns 9 that connect the outer mold 3a and the core 3b. The outer diameter of the core 3b is smaller than the inner diameter of the outer mold 3a. The outer mold 3 a and the core 3 b are integrated by a column 9. A gap is formed between the outer mold 3a and the core 3b, and the molten resin 21 is extruded toward the sizing mold 4 from this gap. Since the temporarily molded resin member 15a has a high viscosity, the resin member 15a enters the sizing mold 4 while maintaining a hollow shape.

The sizing mold 4 includes a sizing outer mold 4a that regulates the outer shape of the temporary molded product and a sizing core 4b that regulates the inner shape. The sizing outer mold 4a is made of metal having a high thermal conductivity and has a structure in which the cooling water 35 flows inside. The sizing outer mold 4a is provided with an inlet and an outlet for cooling water 35, and the resin member 15a molded to a prescribed size is cooled to a temperature at which it does not re-deform.

In order to improve the moldability, when a temporary molded product is vacuum-adsorbed inside the sizing outer mold 4a, a large number of suction holes are opened in the sizing outer mold 4a, and each is connected to a vacuum source. In general, the surface of the sizing die 4 in contact with the resin member is often hard chrome plated from the viewpoint of improving lubricity and wear resistance.

A screw hole is formed in the tip of the core 3b. The support bar 10 is fixed to the core 3b with bolts in such a manner that a flange 11 provided at one end of the support bar 10 is sandwiched. Alternatively, the support rod 10 may be screwed directly and screwed into the screw hole of the core 3b. A cylindrical through hole 31 larger than the outer diameter of the support bar 10 is opened at the center of the sizing core 4b. The other end of the support bar 10 passes through the through hole 31.

The stoppers 12a and 12b are fixed to the support rod 10 and are arranged before and after the sizing core 4b. The stoppers 12a and 12b regulate the movement of the sizing core 4b in the front-rear direction along the support bar 10. A magnetic body 14 and a magnet 20 are disposed on the sizing outer mold 4a and the sizing core 4b.

FIG. 4 is a sectional view showing the form of a sizing mold. The resin member 15a fills the gap between the sizing outer mold 4a and the sizing core 4b. The shape of the sizing core 4b is substantially the same as the shape of the hollow portion provided in the molded product, and is determined in consideration of resin shrinkage due to curing. Since there is a gap 13 between the sizing core 4b and the support bar 10, the sizing core 4b can move in the direction from the center of the support bar 10 toward the outer periphery. Since the gap 13 corresponds to a distance in which the position of the sizing core 4b can be adjusted, it is sufficient that there is a gap equivalent to the thickness of the molded product at the maximum.

The thickness of the sizing core 4b in the extrusion direction of the molded product is not particularly limited. However, if the end of the sizing core 4b is at a softening point where the temperature of the molded product is the limit temperature for shape deformation, the dimensional accuracy of the molded product is high. At this time, it is conceivable that the molded product tightens the sizing core 4b and the extrusion molding line stops due to the shrinkage of the resin due to curing. Therefore, the end of the sizing core 4b satisfies the dimensional accuracy of the molded product required, and the extrusion molding line What is necessary is just to determine from a viewpoint which flows smoothly.

A magnetic body 14 is disposed on the sizing core 4b, and the magnetic body 14 is desirably disposed on the entire circumference of the sizing core 4b as viewed from the extrusion mold 3. However, in the case of a profile extrusion molded product, since the cross-sectional shape of the molded product is complicated, it is difficult to arrange the magnetic body 14 on the entire circumference. Therefore, it is preferable to use a simple approximate shape such as a circle circumscribing the sizing core 4b or a square, and to arrange the entire periphery of the approximate shape at a position overlapping the entire periphery of the sizing core. Further, the sizing core 4b may be formed of a magnetic material.

In the outer sizing die 4a, magnets 20 are arranged by being divided into four parts, upper, lower, left and right so as to surround the sizing core 4b. Furthermore, at least one of the upper and lower sides and the left and right sides of the four magnets 20 are electromagnets 20a, which are connected to a power source capable of changing the current so that the magnetic force can be adjusted. The position of the sizing core 4b is adjusted by adjusting the magnetic force and changing the attractive force generated in the sizing core 4b. In FIG. 4, the right and lower magnets are electromagnets 20a.

In addition, as shown in FIG. 5, the magnets 20 arranged on the sizing outer mold 4a are not four on the top, bottom, left and right, but at least two magnets on any one of the top, bottom, left, and right are arranged, and a total of five magnets 20 are arranged. May be. Each of the two magnets is an electromagnet 20a, and at least one of the magnets arranged at positions not facing these electromagnets is an electromagnet. It is possible to adjust the position and inclination of the sizing core 4b by adjusting the magnetic force of the three electromagnets 20a. In FIG. 5, the right and upper magnets are electromagnets 20a.

Embodiment 2. FIG.
In the embodiment described in the second embodiment, the apparatus structure described in the first embodiment is different from the method for adjusting the position of the sizing core 4b. Since the other points are the same, only the method for adjusting the position of the sizing core 4b will be described below.

In the second embodiment, an air pipe 22 is passed from the outer mold 3 a of the extrusion mold 3 through the column 9 to the core 3 a of the extrusion mold 3. Air is supplied to the periphery of the sizing core 4b through the air pipe 22 passing through the inside of the support rod 10. The number of air pipes 22 is the same as the number of air bags 23 so that each of the air bags 23 can be controlled independently. Air may be supplied not to the inside of the support bar 10 but to the periphery of the sizing core 4b through a joint disposed on the core 3a of the extrusion mold 3 through a pipe arranged along the support bar 10.

A resin or rubber air bag 23 is sandwiched between the sizing core 4 b and the support rod 10. The air bag 23 is connected to an air pipe 22 routed around the sizing core 4b. The gas supply side of the air pipe 22 is connected to an air supply device through a three-way valve 24 and a regulator 25. The direction of the three-way valve 24 that is not connected to the air supply device and the air bag 23 is left open and used for exhausting air in the air bag.

In order to increase the internal pressure of the airbag 23, the regulator 25 is adjusted to adjust the pressure of the air supplied to the airbag 23. When the pressure is reduced, the three-way valve 24 is changed to the exhaust side and the pressure is reduced again. The pressure is adjusted by the regulator 25. Further, by preparing a pressure gauge for measuring the pressure of the air bag 23, it is possible to reduce the pressure only by the exhaust by the three-way valve 24. By setting it as such an apparatus structure, the pressure of each airbag 24 is adjusted and the position of the sizing core 4b is adjusted.

1 hopper, 2 extruder, 5 water tank, 6 take-up machine, 7 cutter, 100 extrusion molding equipment

Claims (2)

An outer mold that regulates the outer shape of the resin member, an extrusion mold having a core that regulates the inner shape of the resin member, an extruder that injects molten resin into the extrusion mold, and a through-hole is opened and magnetic A sizing core having the sizing core, a sizing outer mold surrounding the sizing core, one end side inserted into a through hole of the sizing core, and the other end side fixed to the core of the extrusion mold, and the sizing core A stopper for restricting the movement of the support rod in the axial direction,
An extrusion molding apparatus characterized in that a plurality of magnets and a plurality of electromagnets are fixed to the sizing outer mold, and the position of the sizing core with respect to the sizing outer mold is adjusted by adjusting the magnetic force of the electromagnet. An outer mold that regulates the outer shape of the resin member, an extrusion mold having a core that regulates the inner shape of the resin member, an extruder that injects molten resin into the extrusion mold, and a through hole is opened A sizing core, a sizing outer mold surrounding the sizing core, one end side inserted into a through hole of the sizing core and the other end side fixed to the core of the extrusion mold, and the sizing core A stopper for restricting the movement of the support rod in the axial direction,
A plurality of airbags are loaded in the gap between the sizing core and the support rod, and the size of the airbag is adjusted to adjust the position of the sizing core with respect to the outer sizing mold. Molding device.

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